Review Article

Laparoscopy in theMorbidly Obese: Physiologic Considerations andSurgical Techniques to Optimize Success

Stacey A. Scheib, MD, Edward Tanner III, MD, Isabel C. Green, MD, and Amanda N. Fader, MD*From theDivision of Gynecologic Specialties, Department of Gynecology andObstetrics (Drs. Scheib andGreen), and Kelly Gynecologic Oncology Service,

Department of Gynecology and Obstetrics (Drs. Tanner and Fader), Johns Hopkins Hospital, Baltimore, Maryland.

ABSTRACT The objectives of this review were to analyze the literature describing the benefits of minimally invasive gynecologic surgery

The authors decla

Corresponding a

Oncology Servic

kins Hospital, 60

E-mail: afader1@

Submitted Augus

Available at www

1553-4650/$ - see

http://dx.doi.org/1

in obese women, to examine the physiologic considerations associated with obesity, and to describe surgical techniques thatwill enable surgeons to perform laparoscopy and robotic surgery successfully in obese patients. The Medline database wasreviewed for all articles published in the English language between 1993 and 2013 containing the search terms ‘‘gynecologiclaparoscopy’’ ‘‘laparoscopy,’’ ‘‘minimally invasive surgery and obesity,’’ ‘‘obesity,’’ and ‘‘robotic surgery.’’ The incidence ofobesity is increasing in the United States, and in particular morbid obesity in women. Obesity is associated with a wide rangeof comorbid conditions that may affect perioperative outcomes including hypertension, atherosclerosis, angina, obstructivesleep apnea, and diabetes mellitus. In obese patients, laparoscopy or robotic surgery, compared with laparotomy, is associatedwith a shorter hospital stay, less postoperative pain, and fewer wound complications. Specific intra-abdominal access andtrocar positioning techniques, as well as anesthetic maneuvers, improve the likelihood of success of laparoscopy in womenwith central adiposity. Performing gynecologic laparoscopy in the morbidly obese is no longer rare. Increases in the heaviestweight categories involve changes in clinical practice patterns. With comprehensive and thoughtful preoperative and surgicalplanning, minimally invasive gynecologic surgery may be performed safely and is of particular benefit in obese patients. Jour-nal of Minimally Invasive Gynecology (2014) 21, 182–195 � 2014 AAGL. All rights reserved.

Keywords: Laparoscopy; Minimally invasive surgery; Obesity; Physiology; Robotic surgery

DISCUSS

You can discuss this article with its authors and with other AAGL members athttp://www.AAGL.org/jmig-21-3-JMIG-D-13-00473

re no conflicts of interest.

uthor: Amanda N. Fader, MD, Kelly Gynecologic

e, Department of Gynecology and Obstetrics, Johns Hop-

0 N Wolfe St, Ste 249, Baltimore, MD 21287.

jhmi.edu

t 25, 2013. Accepted for publication September 26, 2013.

.sciencedirect.com and www.jmig.org

front matter � 2014 AAGL. All rights reserved.

0.1016/j.jmig.2013.09.009

Utoadth

se your Smartphonescan this QR code

nd connect to theiscussion forum foris article now*

* Download a free QR Code scanner by searching for ‘‘QRscanner’’ in your smartphone’s app store or app marketplace.

The prevalence of obesity in North America has steadilyincreased over time and is now considered an epidemic withsignificant health implications [1,2]. Body mass index(BMI) is a widely used method for estimating body fatmass. The World Health Organization defines class Iobesity as BMI R30, class II obesity as BMI 35 to 40, andclass III obesity as .40 [2] (Table 1). Modifications to theWHO definitions have been made by various organizations,and the surgical literature stratifies classes II and III obesityinto further categories. These exact values are disputed;

however, in general, BMI 35 to 40 has been classified assevere obesity, BMI 40 to 44.9 as morbid obesity, BMIR45 as super obesity, and BMIR60 as super-super obesity(Table 2).

As recently as a decade ago, morbid obesity was consid-ered a rare phenomenon. Lately, the prevalence of morbidand super obesity has risen exponentially faster than theprevalence of obesity alone [1,2]. In 2004, the prevalenceof BMI R40 was 6.9% in female persons in the UnitedStates [3]. In 2011, the US Centers for Disease Controland Prevention [4] reported that more than two-thirds ofadults in the United States were obese or overweight andthat obesity had become the leading public health problemin industrialized nations. Obesity is the leading cause of pre-ventable death in the United States [5]. Increasing BMI is arisk factor for all-cause and cancer-related mortality and inwomen is a major risk factor for development of several fe-male cancers including endometrial and breast cancers [6,7].

Table 1

World Health Organization classification of obesity

Body mass index Classification

,18.5 Underweight

18.5–24.9 Normal weight

25.0–29.9 Overweight

30.0–34.9 Class I obesity

35.0–39.9 Class II obesity

R40.0 Class III obesity

Scheib et al. Laparoscopy in the Morbidly Obese 183

In 2003, it was reported that not only is obesity in theUnited States increasing but that the waist circumference ra-tio is rapidly expanding, demonstrating an increase inabdominal obesity [8]. In 2008, annual medical spendingattributed to obese patients was estimated at more than$147 billion [4,9]. As this epidemiologic trend continues,obesity will become an increasing challenge for healthcareproviders and in particular for gynecologists who performlaparoscopic surgery. The merits of minimally invasivegynecologic surgery for treatment of both benign andmalignant gynecologic conditions are well understood[10,11]. There is great interest in performing minimallyinvasive gynecologic surgery, rather than traditional opensurgery, in obese women, with the hope of reducingcomplications and accelerating recovery. This is ofparticular importance in patients who are morbidly obeseor super obese [12]. However, this population often presentsa unique set of challenges to the surgeon because they havemore severe comorbidities and a greater risk of perioperativecomplications than do their thinner counterparts. From a sur-gical perspective, many female patients are too large forstandard operating room tables, and facilities frequentlylack specialized equipment for patient transport and for per-formance of minimally invasive surgery in obese patients. Inaddition, it is particularly difficult to perform laparoscopicpelvic surgery in female patients with central adipositybecause of the technical challenges of operating through athick abdominal wall, the physiologic stress on the patientimposed by pneumoperitoneum, and anatomic positioningtechniques required to perform pelvic surgery. As a result,surgical teams are not necessarily set up for successful per-formance of laparoscopy, and healthcare workers are athigher risk of injury when transporting or transferring obesepatients from a hospital bed to an operating room table [1].

The objectives of this review were to analyze the litera-ture describing the benefits of minimally invasive gyneco-logic surgery in obese women, to review the physiologicconsiderations associated with obesity, and to describe surgi-cal techniques that will enable surgeons to perform laparos-copy and robotic surgery successfully in obese patients. Ofnote, key points and recommendations are given in boldfacetype throughout the article.

Benefits of Laparoscopy

In the past, laparoscopic surgery was considered a rela-tive contraindication in obese patients. Because overweightand obese women may have a thick abdominal wall, a highconcentration of intraperitoneal and visceral fat, and/or fattyinfiltration of the liver, there is potential for decreased visu-alization of the pelvis and impaired ability to maneuverfreely and safely within the abdominal cavity. Other issuesinclude difficulty with abdominal access, availability oflonger laparoscopic instruments, and limited prospectivedata on the risks associated with laparoscopy in obese gyne-cologic patients.

The feasibility of performing laparoscopy in the obesepatient was first published in the gynecologic literature in1976 [12–14]. Since then, there has been increasingevidence that obese patients benefit from laparoscopicsurgery compared with surgery via laparotomy [13–27].Most of the gynecologic literature in this regard is focusedon gynecologic oncology because obesity is stronglyassociated with endometrial and other cancers in women[14–20,24–27]. In this population, patients who underwenthysterectomy and surgical staging procedures via laparo-scopy or robotics routinely experienced shorter hospitalstay, less pain, earlier return to normal activity, improvedquality of life, and fewer episodes of postoperative ileus,postoperative fever, and wound infections [13–15,18–20,22].However, in some studies, there was an increased probabilityof conversion to laparotomy with increasing BMI and longeroperating times [13–15,20,22]. In multiple clinical trials,including a randomized control trial from the GynecologicOncology Group [20], women with endometrial cancertreated via minimally invasive surgery demonstrated im-proved quality of life and better perioperative outcomeswhen comparedwith thosewho underwent laparotomy. How-ever, data in patients with BMI .40 are limited.

Studies comparing robotics vs conventional laparoscopyin the management of obese gynecologic surgical patientsare conflicting. Some studies have found no difference inability to perform the surgery via minimally invasive tech-niques or in general outcomes [28–30]. In 2 retrospectivestudies of patients who underwent gastric bypass theresults were equivalent in intraoperative and postoperativecomplication rates and hospital stay; however, operativetimes in the robotic group were shorter as BMI increased[31,32]. Other studies have reveal longer operating roomtime for robotic surgery [33,34]. One reason postulated infavor of robotic surgery in morbidly obese patients is re-duced surgeon fatigue. In addition, compared with straightstick laparoscopic instruments, the articulated wristedrobotic instruments enable fluid movements so that thesurgeon can navigate around a thick abdominal wall orvisceral fat with relative ease. Also, the wristed roboticinstruments essentially move the torque of the surgicalinstruments away from the abdominal wall, unlike inconventional laparoscopy. There are few studies in the

184 Journal of Minimally Invasive Gynecology, Vol 21, No 2, March/April 2014

gynecologic literature that compare laparoscopy withrobotic surgery in obese gynecologic patients. In a retro-spective study of women with endometrial cancer, roboticsurgery was associated with less blood loss, shorteroperative time, and increased lymph node retrieval thanwith laparoscopy. However, the study was limited by asmall number of patients, and it was not clear that allsurgeons were equally skilled in conventional laparoscopyand robotic surgery [19]. Further prospective studies arerequired to define the best and most cost-effective minimallyinvasive surgical method in obese women. It is clear in othersurgical disciplines that super obese women also benefitfrom laparoscopic surgery [35,36]. In the bariatric surgerypopulation, the laparoscopic approach to gastric bypassresults in less postoperative pain, decreased impairment ofpostoperative pulmonary function, shorter hospital stay,quicker return to work and other activities of daily living,and decreased rates and severity of wound infections whencompared with open gastric bypass surgery [37]. Long-term follow-up also has demonstrated that the laparoscopicapproach, compared with open surgery, is associated witha substantial decrease in the rate of incisional hernias (about7:1) and decreased infection rates (10.5% vs 1.3%) [35].

Health Risks Associated With Obesity

According to the National Institutes of Health, an in-crease of R20% above ideal body weight is associatedwith health risks. With BMI .40, healthcare costs aredouble those in a patient of normal weight patient [38].Compared with adults of normal weight, adults with BMI.40 are at increased risk of diabetes mellitus (odds ratio[OR], 7.37; 95% confidence interval [CI], 6.39–8.50), hyper-tension (OR, 6.38; 95% CI, 5.67–7.17), and hypercholester-olemia (OR, 1.88; 95% CI, 1.67–2.13) [39]. They are alsomore likely to have asthma (OR, 2.72; 95% CI, 2.38–3.12)and arthritis (OR, 4.41; 95% CI, 3.91–4.97) [39]. There isan association between angina, sudden death, and obesity[40]. Given these associations, life expectancy in obesewomen may be reduced by up to 8 years [41].

Gynecologic Conditions and Obesity

There is clearly a correlation between obesity andmultiplegynecologic conditions. Obesity increases the risk of men-strual dysfunction, myomas, polycystic ovarian syndrome,anovulatory bleeding, subfertility, endometrial hyperplasiaand cancer, urinary and fecal incontinence, and pelvic organprolapse [42–62].

Obesity results in adipose tissue aromatization of an-drogen to estradiol. This excess estradiol is converted totestosterone via 17b-hydroxysteroid dehydrogenase. Thisnet excess testosterone contributes to the metabolic affectsof polycystic ovary syndrome and virilization of obesewomen, who have longermenstrual cycles andmore frequentanovulatory cycles.

Endometrial cancers in obese women are generallybelieved to have an endocrine cause related to adipose tissuearomatization of androstendione. This results in excessestradiol, which is further enhanced by low levels of sexhormone–binding globulin, which increases the levels ofbioavailable estrogen [45–54]. The net result is an increasein unopposed estrogen in obese women, which canpromote cancer in hormonally responsive tissues. Much ofthe data are limited for the patient population with BMIR40.

Obesity is an independent risk factor for urinary and fecalincontinence and pelvic organ prolapse [55,56]. The OR forurinary incontinence is as high as 1.6 per 5-unit increasein BMI [57–59]. The extent of obesity is associatedwith severity of incontinence [55,59]. For BMI .40, theprevalence of urinary incontinence was 66.9%, and analincontinence was 32.0% in women considering bariatricsurgery [60]. Obesity is thought to increase intra-abdominal pressure, resulting in increased intravesical pres-sure and increased pressure at maximal cystometric capacity[56,61,62]. In addition, obesity may result in inducedneurogenic bladder disease [61].

Obesity-Associated Changes in Anatomy and Physiology

Understanding the differences in the anatomy and physi-ology of the morbidly obese female patient is critical to thesafe and successful performance of minimally invasive sur-gery in this population.

Cardiovascular System

Increased body mass in obese patients leads to a host ofhemodynamic and cardiovascular changes, with resultantphysiologic abnormalities. There is an increased energyrequirement associated with physically moving the ex-panded body and perfusing excess tissue to meet metabolicdemands [42]. In this situation, heart disease develops fromcardiovascular adaptation to increased body mass andincreased metabolic demand. Increased oxygen demand inturn leads to increased cardiac output, larger stroke volume,decreased vascular resistance, and increased cardiac work.Elevated cardiac stroke volume and cardiac output causehypertension and cardiomegaly. The increase in cardiacsize elevates systemic arterial pressure, ultimately leadingto congestive heart failure [42]. Increased pulmonary arterypressure caused by ventricular dysfunction can contribute tofailure that manifests as peripheral edema. In addition, unex-plained cardiac arrhythmias are also more common in obesepatients. The cardiopathology of obesity includes eccentricand concentric ventricular hypertrophy, which leads totachyarrhythmia or to a prolonged Q-T interval on the elec-trocardiogram (ECG). Both of these are risk factors for sud-den death. Autopsy studies have shown that, compared withindividuals of normal weight, obese patients can have 20%to 55% larger cardiac diameters, hypertrophied ventricles,

Scheib et al. Laparoscopy in the Morbidly Obese 185

and increased cardiac weight. Further, obesity is an indepen-dent risk factor for a venous thromboembolic event (VTE)[42,63,64].

Pulmonary System

Oxygen consumption and carbon dioxide production aremore pronounced in obese patients. Excess body weightaround the ribs, chest, under the diaphragm, and intra-abdominally causes reduced chest wall compliance.Impeded chest wall expansion combined with increased ox-ygen demand result in decreased lung compliance. In themorbidly obese, the respiratory function is characterizedby alterations in the pulmonary volumes, both static and dy-namic. There is a reduction in functional vital capacity, func-tional residual capacity (FRC), total lung volume, total lungcapacity, and expiratory reserve volume, which is character-istic of a restrictive pattern. In the morbidly obese patientwith BMI .40, vital capacity (or maximum volume of airthat can be exhaled or inspired) is reduced by 20% to50%, and maximum voluntary ventilation is reduced byapproximately 30%. This results in a substantial alterationin the FRC and total lung capacity. The expiratory reservevolume is also compromised, by 35% to 60%, because theobese abdomen displaces the diaphragm into the chest.These values are even worse in patients who have the addedcompromise of obstructive sleep apnea (OSA), or obesityhyperventilation syndrome.

There are additional risk factors that impair respiratoryfunction. An increase in the amount of soft tissue of the up-per airway and increased tongue size lead to an increase inupper airway resistance. Large breasts increase the difficultyof direct laryngoscopy because additional adipose tissuecompromises the already small space between the breastsand the mouth, into which the handle of a conventionallaryngoscope fits. Mask ventilation and oxygenation canbe impaired owing to a sharp decrease in lung volumewith the induction of anesthesia. Reduced lung compliance,increased airway resistance, and the possible presence of alarge volume of gastric contents, even after an overnightfast, may favor pulmonary aspiration. Waist–hip ratio seemsto influence gas exchange in the obese patient [65]. Largerwaist–hip ratio correlates with poor gas exchange and seemsto be related to arterial blood gas values [65]. In addition,general anesthesia further reduces FRC by an additional20%, and this, coupled with the steep Trendelenburg posi-tion often required to safely perform gynecologic laparos-copy, further compromises FRC.

Gastrointestinal System

Esophageal dysfunction is prevalent in obese patients.There is an increased incidence of hiatal hernias and gastro-esophageal reflux disease, even in the absence of symptoms[42]. The esophageal pathology of obesity is clearly relatedto increased intra-abdominal pressure [66]. Intra-abdominal

pressure is 2 to 3 times greater in the morbidly obese vs non-obese patients [67]. Furthermore, gastric function may alsobe abnormal in obese patients. Several studies have sug-gested that obese patients are more likely to have largegastric volumes, lower gastric pH, and delayed emptying,which places them at increased risk of gastric acid aspirationduring and after surgery. Expanded volumes of cervical, sub-cutaneous, intrathoracic, and intra-abdominal adipose tissuemay also contribute to this phenomenon [66].

Preoperative Considerations

History and Physical

A comprehensive medical history and physical examina-tion should include questions about the patient’s exercisetolerance and OSA screening questions [68]. Obese individ-uals have a higher incidence of comorbidities owing to theirweight, which confers a greater overall operative risk [43].An obesity surgery mortality risk score has been validatedin patients undergoing bariatric surgery [69,70]. Cigarettesmoking compounds the respiratory function and oxygen-ation compromise in this population. Ideally, patients shouldstop smoking 8 weeks before elective surgery [71]. If thereis any evidence of fungal or bacterial infection in skin foldsor under the pannus, these infections should be treated beforesurgery to optimize wound healing postoperatively.

Preoperative Testing

In general, the recommendations of respective societiesfor preoperative evaluation and testing of surgical patientsat moderate to high risk also apply to obese patients [72].Laboratory tests and imaging studies should be tailored onthe basis of the patient’s risk factors and not the degree ofobesity [73]. Basic laboratory tests may include a completeblood cell count, blood glucose concentration, electrolytepanel, renal function tests, urine or serum b-human chori-onic gonadotropin concentration, and blood typing andscreening [66,67]. A baseline ECG should be obtained inobese individuals of any age who are undergoing majorabdominal surgery.[74].

Cardiology consultation should be considered in patientswith hypertension, abnormal ECG changes, OSA, or suspectfindings on clinical examination [75]. If an exercise stresstest is warranted but is not possible to perform secondaryto technical or patient-related reasons, transesophageal do-butamine stress echocardiography may be useful [76]. Incases of major surgery, pulmonary function tests may beconsidered if there is respiratory insufficiency at rest. Theprevalence of undiagnosed OSA in all surgical patients,both obese and non-obese, is high, at approximately 24%[77]. Other causes of hypercapnia including hypoventilationsyndrome, pickwickian syndrome, chronic obstructive pul-monary disease, left ventricular failure, and hypothyroidismshould also be considered [78]. In this context, arterial bloodgas measurement may provide additional information.

186 Journal of Minimally Invasive Gynecology, Vol 21, No 2, March/April 2014

Diabetes

Preoperative glycemic control should be optimized withthe use of medical therapy, nutrition, and physical activity.Administered agents and insulin should be introduced asneeded. Reasonable targets for preoperative glycemic con-trol should include hemoglobin A1c of 7% or a fasting bloodglucose concentration of %110 mg/dL [78]. Consider with-holding glucose-containing intravenous solutions in the im-mediate postoperative period in patients with type II diabetesbecause the adrenergic response to surgerymay cause hyper-glycemia. However, in patients with type I diabetes aglucose-containing solution and an insulin pump should beused in this setting.

Medications

It is particularly important to discontinue all medicationsthat increase the potential for hypercoagulability and/orbleeding. Transdermal and oral estrogen therapy should bediscontinued. To reduce the risk of postoperative thrombo-embolic phenomenon, it has been recommended that beforescheduled surgery premenopausal women should receive 1cycle of hormonal contraceptive therapy and that in post-menopausal women hormone replacement therapy be dis-continued for 3 weeks [78]. Other agents that increase therisk of VTE include ginseng, coenzyme Q10, green tea,and vitamin K. A number of medications, herbal agents,and vitamins increase the risk of bleeding and includeaspirin, clopidogrel, warfarin sodium, gingko, ginseng,vitamin E, garlic, omega 3 fatty acids, dong quaim, andwillow bark.

Beta blockade may be cardioprotective in the periopera-tive setting in patients with hypertension or coronary arterydisease who are already receiving a prescribed beta blocker.However, recent randomized trials and meta-analyses havesuggested that perioperative beta blockade may be harmfulwhen used in patients not already receiving this class ofmedication [79]. Therefore, it is recommended that in obesewomen undergoing non-cardiac surgery beta blockade notbe initiated in the perioperative period unless recommendedby an internist or cardiologist after a cardiac workup.

Use of all other cardiac, neurologic, vascular, and endo-crine medications is beyond the scope of this article, anddiscontinuation of specific therapies should be determinedon an individual basis according to patient comorbiditiesand national society guidelines.

Venous Thromboembolism

The overall incidence of clinicalVTE related to benign gy-necologic surgery is 0% to 2% [80]. However, most of this ev-idence comes from retrospective studies in non-obesepatients, and the laparoscopic surgical procedures studiedwere relatively simple. Nevertheless, most laparoscopic sur-gical procedures performed to treat benign gynecologic con-

ditions are categorized as associated with moderate or highrisk for VTE by the American College of Chest Physicians(ACCP) and the American College of Obstetricians and Gy-necologists, based on procedures.30 minutes, and at a min-imum require one method of prophylaxis [80,81]. Based onthe literature, mechanical prophylaxis using sequentialcompression devices is standard treatment. It is critical inobese patients, however, that such devices are appropriatelyfitted; otherwise, they will not necessarily be protectedfrom developing a VTE. Alternatively, pharmacologicprophylaxis using the standard dose of subcutaneousenoxaparin (30 or 40 mg every 12 hours) or subcutaneousunfractionated heparin (5000 IU every 8 hours) has beenused most extensively. Increasing laparoscopic surgicalcomplexity correlates with increasing rates of VTE aftersurgery [82]. In the only randomized trial comparing lap-aroscopic versus open hysterectomy, bilateral salpingo-oophorectomy, and pelvic and para-aortic lymphadectomyfor treatment of endometrial cancer, the risk of VTE wasequivalent at about 2% [20]. The ACCP recommends dualprophylaxis using sequential compression devices and hepa-rin 3 times a day (or daily lowmolecular weight heparin) untildischarge in all gynecologic patients with cancer and pro-longed prophylaxis for 2 to 4 weeks after discharge in thosewith additional risk factors such as age.60 years or historyof VTE [80]. Such therapy substantially decreases the risk ofVTE in this setting [83].

Obesity is an independent risk factor for VTE. The ACCPguidelines identify patients undergoing bariatric surgery asat high risk for VTE and recommend routine pharmacologicprophylaxis combined with mechanical prophylaxis [80,84].It has been suggested that these regimens are safe optionsthat result in low risk of VTE and bleeding. The AmericanAssociation of Clinical Endocrinologists, the ObesitySociety, and the American Society for Metabolic andBariatric Surgery guidelines also have recommended useof an inferior vena cava (IVC) filter in patients undergoingbariatric surgery who are at particularly high risk of VTE.Insertion of preoperative IVC filters may be considered inpatients with a history of active or recent VTE, BMI .55,immobility, hypercoagulable disorders, increased right-sided heart pressure (pulmonary artery pressure .40 mmHg), severe OSA, or evidence of venous stasis [85]. How-ever, no such formal recommendations exist in the settingof laparoscopy in obese patients undergoing gynecologicsurgery. While use of an IVC filter may be beneficial inthe setting of laparoscopic surgery in patients with an activeVTE, the decision to use a filter in other situations should beconsidered with caution because the procedure is not withoutrisks [86–90].

We recommend that morbidly obese women undergoinggynecologic laparoscopy receive a combination of pharma-cologic and mechanical prophylaxis during surgery and hos-pitalization. Extended prophylaxis after discharge may beconsidered on the basis of comorbidities and mobility.

Scheib et al. Laparoscopy in the Morbidly Obese 187

Informed Consent

Certain risks are higher in the obese patient populationand must be disclosed to the patient and listed on a writtensurgical consent form. There is increased risk of infectionin obese patients undergoing surgery, although the etiologyis not entirely clear. Theories include evidence of impairedglucose tolerance leading to leukocyte dysfunction [91],hypercortisol-induced immunosuppression, and elevatedlevels of tumor necrosis factor-a [92–96].

The risk of VTE is increased as well. The risk of mortalityis 0.3 at high-volume centers with experienced staff [97], and0.7% in centers with lower volume [69,70]. The incidence ofperipheral nerve injury occurs more commonly in the obesepopulation. Prognosis depends on the amount of compressiveforce applied and the duration of the compression [98,99].The most common peripheral nerves injured in gyne-cologic surgery are the ulnar and sciatic nerves; however,femoral, genitofemoral, and brachial plexus injuries mayalso occur.

In obese patients, the rate of conversion to laparotomy ishigher than in their thinner counterparts. This may be multi-factorial and includes inability to optimize the critical viewof the pelvis, technical challenges related to abdominal andvisceral fat, difficulty with ventilation in both the supine andTrendelenburg positions, intolerance of pneumoperitoneum,or surgeon inexperience. In this population, there is a distinctcorrelation between BMI, duration of surgery, and length ofhospital stay [100]. Because of the time needed for preoper-ative and intraoperative planning, positioning, and perfor-mance of the surgery, laparoscopic surgery may requiremore time under anesthesia in obese women than in individ-uals of normal weight. In addition, obese patients mayrequire a longer hospital stay to optimize comorbiditiesand their perioperative status.

Perioperative Considerations

Prophylactic Measures

Currently, based on the guidelines for colorectal surgeryand absence of evidence for use in gynecologic laparoscopyinvolving the deep posterior compartment, there is limiteduse of mechanical bowel preparations [101–105]. Mechan-ical bowel preparation before gynecologic laparoscopy maybe unnecessary and leads to dehydration and electrolytederangements in patients, especially those who are elderly.However, most of these studies were performed in womenof normal weight who did not undergo complex surgery.Owing to increased visceral adiposity, the baseline view isimpaired in the morbidly obese patients compared withnormal weight counterparts. This can be compounded ifthey cannot tolerate steep Trendelenburg positioning. In themorbidly obese patient, a mechanical bowel preparation thenight before surgery may improve visualization by decom-pressing a large rectosigmoid colon. A recent randomizedstudy demonstrated that the quality of the surgical field in

patients undergoing advanced gynecologic laparoscopicprocedures is similar after mechanical bowel preparationusing either oral sodium phosphate solution or a sodiumphosphate enema [104]. However, this decision must be indi-vidualized in patients with medical issues that are influencedby fluid balance because mechanical bowel preparations maydisrupt electrolyte levels.

Obese patients demonstrate increased intra-abdominalpressure, high volumes of low pH gastric volume, and highrates of gastroesophageal reflux disease [106–108]. It isrecommended that histamine receptor blockade beadministered before intubation and that an orogastric ornasogastric tube be placed after intubation and beforeinitial trocar insertion, in particular when a left upperquadrant incision is considered [106–108]. Ranitidine,50 mg, administered intravenously 60 to 90 minutes beforesurgery is a common regimen.

Antibiotic Prophylaxis for Surgery in Morbidly ObesePatients

The current standard of care for routine prophylaxis is 2 gcefazolin intravenously in any woman undergoing hysterec-tomy, with repeat dosing after 3 hours or with an estimatedblood loss of.1500 mL unless there are allergies or contra-indications [109]. There is insufficient evidence as towhether this is adequate for both the serum and adiposelevels. To date, no studies have examined cefazolin levelsand minimal inhibitory concentrations with respect to bacte-ria associated with clean-contaminated gynecologic surgery.In the general surgery literature, 2 g cefazolin providesadequate coverage for gram-negative rods and gram-positive cocci associated with clean-contaminated abdom-inal surgery in morbidly obese patients [110]. If bowel orbladder surgery is anticipated, consider a broader spectrumantibiotic.

General Anesthesia

As mentioned, FRC is decreased in obese patients; there-fore, oxygen desaturation may occur more quickly duringapneic episodes than in patients of normal weight [111].As a consequence, preoxygenation before induction mustbe of sufficient duration (at least 5 minutes) and with aclose-fitting face mask. Despite this effort, hypoxemia maystill occur in morbidly obese patients. BMI is not a predictorof difficult intubations; rather, it is the severity of the pa-tient’s comorbidities. With induction of anesthesia, oxygen-ation and mask ventilation are more difficult owing to asharp decrease in lung volume, a decrease in lung compli-ance, and an increase in airway resistance. To alleviate theintra-abdominal pressure compressing the diaphragm, areverse Trendelenburg position or the beach chair positionhas proved effective for ventilation and to decrease the riskof pulmonary aspiration. Usually, obese patients whotolerate induction of anesthesia and supine positioning

188 Journal of Minimally Invasive Gynecology, Vol 21, No 2, March/April 2014

probably will tolerate pneumoperitoneum and Trendelen-burg positioning.

Anesthesiologists may have a low threshold for usinginvasive monitoring. Because of low voltage, interpretationof the ECG may be hampered. In addition, blood pressurecuffs and pulse oximeters are not always available in theappropriate sizes for use in the morbidly obese patient.

Specific ventilation techniques that may be helpful inthe setting of morbid obesity with central adiposity includethe use of pressure control ventilation. Pressure controlventilation improves the lung ventilation-perfusion ratio,generates higher instantaneous flow peaks, and may enablebetter alveolar recruitment [112]. Higher inspiratorypressure is sometimes necessary when ventilatory compli-ance is reduced by the weight of the abdominal viscerain the steep Trendelenburg position. The fraction of in-spired oxygen should be maintained between 0.4 and0.8 [113].

With extubation, the incidence of atelectasis can bereduced by combining a recruitment maneuver with a subse-quent positive end-expiratory pressure application of 10 cmH2O at the time of extubation [112–115]. The patient shouldagain be placed in the beach chair position or with the upper

Fig. 1

Obese patient positioning for laparoscopy.

body elevated 30 to 45 degrees to account for changes inlung volume and thoracic compliance. The patient shouldbe transferred from the operating room while in a semi-recumbent position. Otherwise, change from a semi-recumbent to the supine position can result in a substantialdecrease in the partial pressure of oxygen in arterial blood.In addition, patients who have been in the Trendelenburgposition for a prolonged time during laparoscopic surgeryare at increased risk of laryngeal edema. If there is any evi-dence of this, maintain intubation and sedation until theswelling and edema have resolved.

Positioning

Extra time should be allotted for patient positioning beforeperformance of laparoscopy or robotic surgery. Several keypoints regarding important considerations related to posi-tioning are shown in Figure 1. Obese patients are at greaterrisk of pressure sores and nerve injuries than are non-obesepatients. This risk depends on the amount of compressive forceused and the duration of the compression [98,99,116]. Com-pression for 6 to 8 hours or longer can result in structuraldamage to nerves [99,116]. The most common observed

Scheib et al. Laparoscopy in the Morbidly Obese 189

nerve injuries associated with obese patients are ulnar andsciatic neuropathies.

Ideally, a bariatric bed should be used if available. A bar-iatric bed is wider, accommodates the weight of most obesepatients, and enables more feasibility, with tucking of thearms. Furthermore, it has a lower profile and can be loweredcloser to the floor for laparoscopic surgery.

The steep Trendelenburg position may result in brachialplexus nerve stretch injuries in obese patients as a result ofdownward shifting [117]. Use of an anti-skid material suchas egg crate foam, gel pad, or surgical bean bag minimizessuch injury in patients with BMI .30 [118]. The anti-skidmaterial is placed directly on the bed, and the patient isplaced directly on the anti-skid material. The weight of thepatient in relationship to the anti-skid material creates a sub-stantial drag coefficient that keeps the patient from slippingon the bed while in the steep Trendelenburg position [119].Caution should be exercised with the use of shoulder blocksor with leaving arms untucked because of the risk of poten-tial brachial plexus injury [117,119]. If the patient’s arms areleft extended and the patient slides or the surgeon leans onthe patient’s arms, the risk of brachial plexus injuryincreases [117,119]. If shoulder braces are used, theyshould be placed over the acromioclavicular joint to avoida location that is too medial or lateral on the shoulder.

Both of the patient’s arms should be tucked in the militaryposition, with legs in the low lithotomy position, and corpo-real padding should be liberally applied around the hips,knees, and arms [120]. Although it may seem challengingto tuck one or both arms in morbidly obese women, it isalmost always possible with the use of bed extenders orsleds. This enables the surgeon to stand farther up the table,which is more ergonomic for the surgeon. Inasmuch as both

Fig. 2

Left upper quadrant approach in a patient with central obesity.

arms are tucked, consider placing 2 intravenous lines beforepositioning. If padding or straps across the chest are used,they should not be too constrictive, to avert compromisingventilation.

Even with perfect positioning, however, a nerve injurymay occur. It is our preference and strong recommendationto tuck both arms at the patient’s sides, with generous corpo-real padding, and to consider use of an egg crate mattress orbean bag or gel pad to prevent patient slippage while in theTrendelenburg position (Fig. 1).

Abdominal Access Techniques

In obese patients, the distance from the skin to the fasciaand from the fascia to the peritoneum is increased. Accord-ing to a Cochrane review, use of the Veress technique can beassociated with a higher rate of false entry and preperitonealinsufflation in this patient population [121]. Potentially saferand more appropriate entry techniques in obese womeninclude use of the open Hasson technique or directly visual-ized insertion with an optical trocar in the left upper quadrant(Fig. 2). Long or bariatric length trocars are often required inthis setting to overcome the increase in abdominal wallthickness.

Ideally, the umbilicus is the thinnest entry point into theabdomen. As BMI increases, the umbilicus migratescaudally in respect to the aortic bifurcation [122,123]. Forthis reason, the umbilicus as the initial point of entryshould be used with caution in obese patients because thismay compromise adequate triangulation with the surgicalpathology. If a patient with central adiposity but nosubstantial panniculus, a 90-degree umbilical entry approachmay be considered. Given that many obese women have a

190 Journal of Minimally Invasive Gynecology, Vol 21, No 2, March/April 2014

prominent panniculus with caudal migration of the umbili-cus, stronger consideration should be given to a supraumbil-ical or left upper quadrant initial entry site to ensure asuccessful, safe entry and so that triangulation with respectto the pelvis and gynecologic organs is achieved (Figs. 2and 3). The initial entry point should be selected to provideoptimal triangulation in respect to the surgical pathology.Trocars, in turn, must be placed more lateral and cephaladin obese women than in women of normal weight (Fig. 3).

In 1974, Palmer [124] first described use of a small trocar3 cm below the left costal margin in the mid-clavicular linefor an abdominal entry point in women with a history ofabdominal surgery (Fig. 2). After induction of general anes-thesia, an orogastric or nasogastric drainage tube is placed.The bed is made level. We usually prefer to be within 2 to3 cm of the subcostal margin in the mid-clavicular linebecause the rib cage helps to elevate the abdominal wall.There tends to be less subcutaneous fat at the left upperquadrant insertion site than at the umbilicus [125]. A5-mm incision in made. The anterior wall is then elevatedwith the surgeon’s non-dominant hand or by an assistant.Alternatively, penetrating clamps can be used to elevatethe abdominal wall; however, it should be elevated onlyminimally or the layers of the wall may be separated,increasing the distance the trocar must traverse before ac-cessing the peritoneal cavity. The optical trocar is insertedperpendicularly, visualizing each layer: subcutaneous fat,anterior rectus sheath, rectus muscle, posterior rectus sheath,preperitoneal fat, and peritoneum. A left upper quadrant en-try is contraindicated in patients with a history of gastricbypass, splenectomy, or splenomegaly.

Fig. 3

Trocar placement in a patient of normal weight vs an obese patient.

Panniculus Management and Prevention of LaparotomyConversion

Conversion to open surgery can be prevented with appro-priate changes in ventilation, limiting the use of the steepTrendelenburg position, decreasing the insufflation pressure,or mechanically retracting the panniculus. Retraction tech-niques to maintain the panniculus in the caudad positioncan improve the ability to ventilate the patient’s lungs[120]. The Foley lap lift is a technique in which a 14 F Foleycatheter is passed through the abdominal wall, the balloon isinflated, and the catheter is pulled up and clamped to aretractor holder attached to the angled foot of the bed[126]. Another technique involves towel clamps to the loweredge of the panniculus with 1 L saline bags attached andallowed to hang between the legs. An Ioban adhesive dres-sing (3M Co., St. Paul, MN) may also be used to securethe panniculus to the thighs.

A tilt test should be performed after intubation and properpositioning. The patient is placed in a Trendelenburg posi-tion for 2 to 5 minutes, and the patient’s cardiac and respira-tory statuses are observed. This is repeated again afterinsufflation. If normotension and inspiratory pressure of 30to 40 mm Hg are maintained, the patient is likely to toleratelaparoscopic surgery [120]. Adjustments may need to bemade in the insufflation pressure level, the degree of Trende-lenburg positioning, and the pressure support ventilationsettings to maintain stable cardiac and respiratory status.As partial pressure of arterial carbon dioxide levels increase,the patient should periodically be taken out of the Trendelen-burg position or even placed in a reverse Trendelenburgposition, and the peritoneum should be desufflated to rest

Table 2

Summary of key points

General

� Awoman with BMI .40 is at increased risk of diabetes mellitus, hypertension, and hypercholesterolemia.

� Obesity increases the risk of menstrual dysfunction, myomas, polycystic ovary syndrome, anovulatory bleeding, subfertility, endometrial hyperplasia

and cancer, urinary and fecal incontinence, and pelvic organ prolapse.

� Oxygen consumption and carbon dioxide production are more pronounced in obese persons.

� Excess body weight around the ribs, chest, under the diaphragm, and intra-abdominally causes reduced chest wall compliance.

� General anesthesia and steep Trendelenburg positioning reduce functional residual capacity.

� Obesity is a known independent risk factor for venous thromboembolic disease (VTE).

� The overall incidence of VTE related to benign gynecologic surgery is 0% to 2%.

Preoperative considerations

� A comprehensive medical history and physical examination should include questions about a patient’s exercise tolerance and obstructive sleep apnea

screening questions.

� A baseline electrocardiogram should be obtained in obese persons of any age undergoing major abdominal surgery.

� Stop all medications that increase the potential for hypercoagulability and/or bleeding.

� Certain risks are increased in the obese patient population and they must be disclosed to the patient and listed on a written surgical consent.

Positioning

� Extra time should be allotted to accommodate for patient positioning before performance of laparoscopy or robotic surgery. Several key points

regarding important considerations related to positioning are shown in Figure 1.

� Tuck both of the patient’s arms at the sides in military position, with legs in the low lithotomy position and generous corporeal padding.

� Consider use of an egg crate mattress or bean bag or gel pad to prevent patient slippage in the Trendelenburg position (Fig. 1).

Anesthesia considerations

� Histamine receptor blockade should be administered before intubation, and an orogastric or nasogastric tube should be placed after intubation and

before initial trocar insertion.

� Pressure control ventilation improves the lung ventilation–perfusion ratio, generates higher instantaneous flow peaks, and may enable better alveolar

recruitment.

Prophylaxis

� It is critical that obese patients wear appropriately fitted sequential compression devices so that they are protected from a VTE.

� We recommend a combination of pharmacologic and mechanical prophylaxis for surgery and during hospitalization.

Surgical considerations

� Mechanical bowel preparation or enema the night before surgery may improve visualization by decompressing a redundant, adipose rectosigmoid

colon.

� As BMI and central adiposity increase, the umbilicus migrates caudally in respect to the aortic bifurcation.

� The initial entry point should be selected to provide optimal triangulation and visualization of disease.

� Trocars should be positioned more lateral and cephalad in obese women than in women of normal weight (Fig. 3).

� A fatty or redundant rectosigmoid colon may be managed using a puppet stitch placed through the epiploic appendices, with attachment of the stitch to

the anterior abdominal wall or left upper quadrant.

Postoperative considerations

� Volume overload should be prevented.

� Consider withholding glucose-containing intravenous solutions in the immediate postoperative period in patients with type II diabetes because of the

adrenergic response of surgery, which may cause hyperglycemia. However, patients with type I diabetes should be given a glucose-containing solution

and an insulin pump in this setting.

� Respiratory distress or failure to wean from ventilatory support should raise suspicion and prompt an evaluation for acute postoperative complications

such as pulmonary edema or pulmonary embolism.

� Have a low threshold for keeping the patient in the hospital if postoperative milestones are not achieved in the first 24 hours after surgery.

� Extended VTE prophylaxis after discharge may be considered on the basis of comorbid conditions and mobility.

Scheib et al. Laparoscopy in the Morbidly Obese 191

the patient and normalize partial pressure of arterial carbondioxide levels during the surgery.

Intraperitoneally, a fatty or redundant rectosigmoid colonmay be managed using a puppet stitch placed through the ep-iploic appendices and attachment of the stitch to the anteriorabdominal wall or left upper quadrant. Alternatively, anadditional accessory trocar may be used to retract the bowel.Insofar as incisional closure, obese patients are at higher riskof herniation at the trocar sites because of increased intra-

abdominal pressure [127]. Therefore, it is imperative thatthe fascia on all trocar sites R10 mm is closed. Direct visu-alization of the fascia may be difficult; however, a fascialclosure device may help in these cases.

Fluid Management

Administration of intravenous fluids is based on centralvenous pressuremeasurements inmany institutions. However,

192 Journal of Minimally Invasive Gynecology, Vol 21, No 2, March/April 2014

owing to the increased intra-abdominal pressure, centralvenous pressure may be falsely elevated, suggesting fluidrestriction [122]. Volumetric variables of preload such asglobal end-diastolic volume index may be advantageous[122]. Dynamic variables of fluid responsiveness such asstroke volume variation and pulse pressure variation mayalso be reliable in obese patients [122]. Volume overloadshould be prevented, and only enough fluids should be admin-istered to maintain a urinary output of 30 mL/hr [78].

Postoperative Management

After surgery, patients with known or presumed cardio-vascular disease, OSA, and high perioperative risk shouldbe managed in the intensive care unit for the first 24 to 48postoperative hours. Respiratory distress or failure to weanfrom ventilatory support should raise suspicion and promptan evaluation for acute postoperative complications suchas pulmonary edema or pulmonary embolism [78].

Pulmonary System

The patient should recover in the semi-recumbent posi-tion postoperatively to minimize intrapulmonary shunting[128,129]. Early ambulation is beneficial in decreasingimpairment of lung function induced by anesthesia [78].Aggressive pulmonary toilet with incentive spirometry,coughing exercises, and deep breathing are important to re-inflate dependent lung regions. If the patient has OSA, earlyinstitution of continuous positive airway pressure is needed[78]. Short-acting opioids should be preferred because riskof respiratory depression and other adverse respiratoryevents increase in OSA and obesity [78]. Pulse oximetryshould be used to determine adequate saturation.

Hospitalization

If there is presence of OSA, the patient should beadmitted for at least 23-hour observation because of theincreased risk of pulmonary complications. In general, oneshould have a low threshold for keeping the patient admittedif postoperative milestones are not achieved in the first24 hours after surgery.

Conclusion

Obesity is common in the United States, and minimallyinvasive gynecologic surgeons are likely to treat an in-creasing number of obese patients. Increases in these heav-iest weight categories involve changes in clinical practicepatterns, and treating the morbidly and super obese willnot be a rare event moving forward. Contrary to previous re-ports, laparoscopy is not contraindicated in obese patients.Indeed, this population experiences less pain, faster recov-ery, and fewer postoperative complications after minimallyinvasive surgery compared with laparotomy. Laparoscopyand robotic surgery in this patient cohort should involve

careful preoperative evaluation, surgical preparation, andpatient counseling about expectations and risks and benefits.Several techniques are available to facilitate minimally inva-sive surgery in obese patients, and conversion rates to lapa-rotomy are low in the hands of experienced, high-volumesurgeons. To optimize surgical outcomes, surgeons musthave an understanding of the physiologic changes associatedwith general anesthesia and laparoscopy in the obese and thesuccessful surgical techniques required to feasibly andsafely perform minimally invasive surgery in this popula-tion. During the postoperative period, aggressive pulmonarycare, pain control, early feeding and ambulation, and deepvenous thrombosis prophylaxis are recommended.

References

1. Sturm R. Increases in clinically severe obesity in the United States,

1986-2000. Arch Intern Med. 2003;163:2146–2148.

2. Sturm R. Increases in morbid obesity in the USA: 2000-2005. Public

Health. 2007;121:492–496.

3. Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ,

Flegal KM. Prevalence of overweight and obesity in the United States,

1999-2004. JAMA. 2006;295:1549–1555.

4. US Centers for Disease Control and Prevention. Obesity: halting the

epidemic by making health easier. At a Glance 2011. Available at

http://www.cdc.gov/chronicdisease/resources/publications/aag/pdf/

2011/Obesity_AAG_WEB_508.pdf. Accessed August 18, 2013.

5. Danaei G. The preventable causes of death in the United States:

comparative risk assessment of dietary, lifestyle, and metabolic risk

factors [published correction appears in PLos Med. 2011;8]. PLoS

Med. 2009;6:e10000058.

6. NIH, NHLBI Obesity Education Initiative. Clinical Guidelines on the

Identification, Evaluation, and Treatment of Overweight and Obesity

in Adults. Available at http://www.nhlbi.nih.gov/guidelines/obesity/

ob_gdlns.pdf. Accessed August 18, 2013.

7. Centers for Disease Control and Prevention. Overweight and obesity.

Available at http://www.cdc.gov/obesity/. Accessed August 18, 2013.

8. Li C, Ford ES, McGuire LC, Mokdad AH. Increasing trends in waist

circumference and abdominal obesity among US adults. Obesity

(Silver Spring). 2007;15:216.

9. Finkelstein EA, Trogdon JG, Cohen JW, Dietz W. Annual medical

spending attributable to obesity: payer- and service-specific estimates.

Health Affairs (Millwood). 2009;28:w822–w831.

10. Eltabbakh GH, Shamonki MI, Moody JM, Garafano LL. Hysterec-

tomy for obese women with endometrial cancer: laparoscopy or lapa-

rotomy? Gynecol Oncol. 2000;78(3 Pt 1):329–335.

11. Scribner DR Jr, Walker JL, Johnson GA, McMeekin DS, Gold MA,

Mannel RS. Laparoscopic pelvic and paraaortic lymph node dissection

in the obese. Gynecol Oncol. 2002;84:426–430.

12. Loffer FD, Pent D. Laparoscopy in the obese patient. Am J Obstet

Gynecol. 1976;125:104–108.

13. Holtz G. Laparoscopy in the massively obese female. Obstet Gynecol.

1987;69(3 Pt 1):423–424.

14. Pasic R, Levine RL, Wolfe WM. Laparoscopy in morbidly obese

patients. J Am Assoc Gynecol Laparosc. 1999;6:307–312.

15. Eltabbakh GH, Piver MS, Hempling RE, Recio FO. Laparoscopic

surgery in obese women. Obstet Gynecol. 1999;94(5 Pt 1):704–708.

16. Yu CKH, Cutner A, Mould T, Olaitan A. Total laparoscopic hysterec-

tomy as a primary surgical treatment for endometrial cancer in

morbidly obese women. BJOG. 2005;112:115–117.

17. O’Hanlan KA, Dibble SL, Fisher DT. Total laparoscopic hysterectomy

for uterine pathology: impact of body mass index on outcomes.Gyne-

col Oncol. 2006;103:938–941.

Scheib et al. Laparoscopy in the Morbidly Obese 193

18. Eisenhauer EL, Wypych KA, Mehrara BJ, et al. Comparing surgical

outcomes in obese women undergoing laparotomy, laparoscopy, or

laparotomy with panniculectomy for the staging of uterine malig-

nancy. Ann Surg Oncol. 2007;14:2384–2391.

19. Gehrig PA, Cantrell LA, Shafer A, Abaid LN,Mendivil A, Boggess JF.

What is the optimal minimally invasive surgical procedure for endo-

metrial cancer staging in the obese and morbidly obese woman?

Gynecol Oncol. 2008;111:41–45.

20. Walker JL, Piedmonte MR, Spirtos NM, et al. Laparoscopy compared

with laparotomy for comprehensive surgical staging of uterine cancer:

Gynecologic Oncology Group Study LAP2. J Clin Oncol. 2009;27:

5331–5336.

21. Camanni M, Bonino L, Delpiano EM, Migliaretti G, Berchialla P,

Deltetto F. Laparoscopy and body mass index: feasibility and outcome

in obese patients treated for gynecologic diseases. J Minim Invasive

Gynecol. 2010;17:576–582.

22. Geppert B, L€onnerfors C, Persson J. Robot-assisted laparoscopic hys-

terectomy in obese and morbidly obese women: surgical technique

and comparison with open surgery. Acta Obstet Gynecol Scand.

2011;90:1210–1217.

23. Nawfal AK, OradyM, Eisenstein D,Wegienka G. Effect of body mass

index on robotic-assisted total laparoscopic hysterectomy. J Minim

Invasive Gynecol. 2011;18:328–332.

24. Lau S, Buzaglo K, Vaknin Z, et al. Relationship between body mass

index and robotic surgery outcomes of women diagnosed with endo-

metrial cancer. Int J Gynecol Cancer. 2011;21:722–729.

25. Burke WM, Gossner G, Goldman NA. Robotic surgery in the obese

gynecologic patient. Clin Obstet Gynecol. 2011;54:420–430.

26. Gallo T, Kashani S, Patel DA, Elsahwi K, Silasi DA, Azodi M.

Robotic-assisted laparoscopic hysterectomy: outcomes in obese and

morbidly obese patients. JSLS. 2012;16:421–427.

27. Tang KY, Gardiner SK, Gould C, Osmundsen B, Collins M,

Winter WE 3rd. Robotic surgical staging for obese patients with endo-

metrial cancer. Am J Obstet Gynecol. 2012;206:513.e1–513.e6.

28. Myers SR, McGuirl J, Wang J. Robot-assisted versus laparoscopic

gastric bypass: comparison of short-term outcomes. Obes Surg.

2013;23:467–473.

29. Sundi D, Reese AC,Mettee LZ, Trock BJ, Pavlovich CP. Laparoscopic

and robotic radical prostatectomy outcomes in obese and extremely

obese men. Urology. 2013;82:600–605.

30. Markar SR, Karthikesalingam AP, Venkat-Ramen V, Kinross J,

Ziprin P. Robotic vs. laparoscopic Roux-en-Y gastric bypass in

morbidly obese patients: systematic review and pooled analysis. Int

J Med Robot. 2011;7:393–400.

31. Sanchez BR, Mohr CJ, Morton JM, Safadi BY, Alami RS, Curet MJ.

Comparison of totally robotic laparoscopic Roux-en-Y gastric bypass

and traditional laparoscopic Roux-en-Y gastric bypass. Surg Obes

Relat Dis. 2005;1:549–554.

32. Edelson PK, Dumon KR, Sonnad SS, Shafi BM, Williams NN.

Robotic vs. conventional laparoscopic gastric banding: a comparison

of 407 cases. Surg Endosc. 2011;25:1402–1408.

33. Vilallonga R, Fort JM, Caubet E, Gonzalez O, Armengol M. Robotic

sleeve gastrectomy versus laparoscopic sleeve gastrectomy: a compar-

ative study with 200 patients. Obes Surg. 2013;23:1501–1507.

34. Scozzari G, Rebecchi F, Millo P, Rocchietto S, Allieta R, Morino M.

Robot-assisted gastrojejunal anastomosis does not improve the results

of the laparoscopic Roux-en-Y gastric bypass. Surg Endosc. 2011;25:

597–603.

35. Puzziferri N, Austrheim-Smith IT,Wolfe BM,Wilson SE, NguyenNT.

Three-year follow-up of a prospective randomized trial comparing

laparoscopic versus open gastric bypass. Ann Surg. 2006;243:

181–188.

36. Schwarzkopf R, Thompson SL, Adwar SJ, Liublinska V, Slover JD.

Postoperative complication rates in the ‘‘super-obese’’ hip and knee ar-

throplasty population. J Arthroplasty. 2012;27:397–401.

37. Gould JC, Garren MJ, Boll V, Starling JR. Laparoscopic gastric

bypass: risks vs. benefits up to two years following surgery in

super-super obese patients. Surgery. 2006;140:524–529. discussion

529–531.

38. Andreyeva T, Sturm R, Ringel JS. Moderate and severe obesity have

large differences in health care costs. Obes Res. 2004;12:1936–1943.

39. Mokdad A, Ford ES, Bowman BA, et al. Prevalence of obesity, dia-

betes, and obesity-related health risk factors, 2001. JAMA. 2003;

289:76–79.

40. Kannel WB, Brand N, Skinner JJ Jr, Dawber TR, McNamara PM. The

relation of adiposity to blood pressure and development of hyperten-

sion: the Framingham Study. Ann Intern Med. 1967;67:48–49.

41. Fontaine KR, Redden DT,Wang C,Westfall AO, Allison DB. Years of

life lost due to obesity. JAMA. 2003;289:187–193.

42. Kral JG. Morbidity of severe obesity. Surg Clin North Am. 2001;81:

1039–1061.

43. Kral JG. Morbid obesity and related health risks. Ann Intern Med.

1985;103(6 Pt 2):1043–1047.

44. Calle EE, Rodriguez C, Walker-Thurmond K, Thun MJ. Overweight,

obesity, and mortality from cancer in a prospectively studied cohort of

U.S. adults. N Engl J Med. 2003;348:1625–1638.

45. Nisker JA, Hammond GL, Davidson BJ, et al. Serum sex hormone-

binding globulin capacity and the percentage of free estradiol in post-

menopausal women with and without endometrial carcinoma: a new

biochemical basis for the association between obesity and endometrial

carcinoma. Am J Obstet Gynecol. 1980;138:637–642.

46. Braunwald E, Fauci A, Kasper DL, Hauser SL, Longo DL,

Jameson JL, editors. Harrison’s Principles of Internal Medicine.

15th ed. New York: McGraw-Hill; 2001.

47. Gangemi M, Meneghetti G, Predebon O, Scappatura R, Rocco A.

Obesity as a risk factor for endometrial cancer. Clin Exp Obstet Gyne-

col. 1987;14:119–122.

48. Akhmedkhanov A, Zeleniuch-Jacquotte A, Toniolo P. Role of exoge-

nous and endogenous hormones in endometrial cancer: review of the

evidence and research perspectives. Ann N Y Acad Sci. 2001;943:

296–315.

49. Enriori CL, Reforzo-Membrives J. Peripheral aromatization as a risk

factor for breast and endometrial cancer in postmenopausal women:

a review. Gynecol Oncol. 1984;17:1–21.

50. Grodin JM, Siiteri PK,Macdonal PC. Source of estrogen production in

postmenopausal women. J Clin Endocrinol Metab. 1973;36:207–214.

51. Pettigrew R, Hamilton-Fairley D. Obesity and female reproductive

function. Br Med Bull. 1997;53:341–358.

52. Siiteri PK. Steroid hormones and endometrial cancer. Cancer Res.

1978;38(11 Pt 2):4360–4366.

53. Lucisano A, Acampora MG, Russo N, Maniccia E, Montemurro A,

Dell’Acqua S. Ovarian and peripheral plasma levels of progestogens,

androgens and oestrogens in post-menopausal women. Maturitas.

1984;6:45–53.

54. Anderson DC. Sex-hormone-binding globulin.Clin Endocrinol. 1974;

3:69–96.

55. Burgio KL, Zyczynski H, Locher JL, Richter HE, Redden DT,

Wright KC. Urinary incontinence in the 12-month postpartum period.

Obstet Gynecol. 2003;102:1291–1298.

56. Dwyer PL, Lee ET, Hay DM. Obesity and urinary incontinence in

women. Br J Obstet Gynaecol. 1988;95:91–96.

57. Brown JS, Seeley DG, Fong J, Black DM, Ensrud KE, Grady D.

Urinary incontinence in older women: who is at risk? study of Osteo-

porotic Fractures Research Group. Obstet Gynecol. 1996;87(5 Pt 1):

715–721.

58. Brown JS, Grady D, Ouslander JG, Herzog AR, Varner RE, Posner SF.

Heart and Estrogen/Progestin Replacement Study (HERS) Research

Group. Prevalence of urinary incontinence and associated risk factors

in postmenopausal women. Obstet Gynecol. 1999;94:66–70.

59. Hannestad YS, Rortveit G, Daltveit AK, Hunskaar S. Are smoking and

other lifestyle factors associated with female urinary incontinence? the

Norwegian EPINCONT Study. BJOG. 2003;110:247–254.

60. Richter HE, Burgio KL, Brubaker L, et al. Urinary Incontinence Treat-

ment Network. Factors associated with incontinence frequency in a

194 Journal of Minimally Invasive Gynecology, Vol 21, No 2, March/April 2014

surgical cohort of stress incontinent women. Am J Obstet Gynecol.

2005;193:2088–2093.

61. Cummings JM, Rodning CB. Urinary stress incontinence among

obese women: review of pathophysiology therapy. Int Urogynecol J

Pelvic Floor Dysfunct. 2000;11:41–44.

62. Noblett KL, Jensen JK, Ostergard DR. The relationship of body mass

index to intra-abdominal pressure as measured by multichannel cyst-

ometry. Int Urogynecol J Pelvic Floor Dysfunct. 1997;8:323–326.

63. Rocha AT, de Vasconcellos AG, da Luz Neto ER, Ara�ujo DM,

Alves ES, Lopes AA. Risk of venous thromboembolism and efficacy

of thromboprophylaxis in hospitalized obese medical patients and in

obese patients undergoing bariatric surgery. Obes Surg. 2006;16:

1645–1655.

64. Hamad GG, Choban PS. Enoxaparin for thromboprophylaxis in

morbidly obese patients undergoing bariatric surgery: findings of the

Prophylaxis against VTE Outcomes in Bariatric Surgery Patients

ReceivingEnoxaparin (PROBE)Study.Obes Surg. 2005;15:1368–1374.

65. Zavorsky GS,Murias JM, Kim do J, Gow J, Sylvestre JL, Christou NV.

Waist-to-hip ratio is associated with pulmonary gas exchange in the

morbidly obese. Chest. 2007;131:362–367.

66. Sugerman HJ. Effects of increased intra-abdominal pressure in severe

obesity. Surg Clin North Am. 2001;81:1063–1075. vi.

67. Nguyen NT, Lee SL, Anderson JT, Palmer LS, Canet F, Wolfe BM.

Evaluation of intra-abdominal pressure after laparoscopic and open

gastric bypass. Obes Surg. 2001;11:40–45.

68. Livingston EH, Langert J. The impact of age and Medicare status on

bariatric surgical outcomes. Arch Surg. 2006;141:1115–1120. discus-

sion 1121.

69. DeMaria EJ, Portenier D, Wolfe L. Obesity surgery mortality risk

score: proposal for a clinically useful score to predict mortality risk

in patients undergoing gastric bypass. Surg Obes Relat Dis. 2007;3:

134–140.

70. DeMaria EJ, Murr M, Byrne TK, et al. Validation of the obesity sur-

gery mortality risk score in a multicenter study proves it stratifies mor-

tality risk in patients undergoing gastric bypass for morbid obesity.

Ann Surg. 2007;246:578–582. discussion 583–584.

71. Bluman LG, Mosca L, Newman N, Simon DG. Preoperative smoking

habits and postoperative pulmonary complications. Chest. 1998;113:

883–889.

72. Fleisher LA, Beckman JA, Brown KA, et al. ACC/AHA 2007 Guide-

lines on Perioperative Cardiovascular Evaluation and Care for Noncar-

diac Surgery: executive summary: a report of the American College of

Cardiology/American Heart Association Task Force on Practice

Guidelines (Writing Committee to Revise the 2002 Guidelines on

Perioperative Cardiovascular Evaluation for Noncardiac Surgery)

developed in collaboration with the American Society of Echocardi-

ography, American Society of Nuclear Cardiology, Heart Rhythm

Society, Society of Cardiovascular Anesthesiologists, Society for Car-

diovascular Angiography and Interventions, Society for Vascular

Medicine and Biology, and Society for Vascular Surgery. J Am Coll

Cardiol. 2007;50:1707–1732.

73. Ramaswamy A, Gonzalez R, Smith CD. Extensive preoperative

testing is not necessary in morbidly obese patients undergoing gastric

bypass. J Gastrointest Surg. 2004;8:159–164. discussion 164–165.

74. Schumann R, Jones SB, Ortiz VE, et al. Best practice recommenda-

tions for anesthetic perioperative care and pain management in weight

loss surgery. Obes Res. 2005;13:254–266.

75. Poirier P, Alpert MA, Fleisher LA, et al. American Heart Association

Obesity Committee of the Council on Nutrition, Physical Activity and

Metabolism, Council on Cardiopulmonary Perioperative and Critical

Care, Council on Cardiovascular Surgery and Anesthesia, Council

on Cardiovascular Disease in the Young, Council on Cardiovascular

Nursing, Council on Clinical Cardiology. Cardiovascular evaluation

and management of severely obese patients undergoing surgery: a sci-

ence advisory from the American Heart Association. Circulation.

2009;120:86–95.

76. Bhat G, Daley K, Dugan M, Larson G. Preoperative evaluation for

bariatric surgery using transesophageal dobutamine stress echocardi-

ography. Obes Surg. 2004;14:948–951.

77. Isono S. Obstructive sleep apnea of obese adults: pathophysiology

and perioperative airway management. Anesthesiology. 2009;110:

908–921.

78. Mechanick JI, Kushner RF, Sugerman HJ, et al. American Association

of Clinical Endocrinologists, Obesity Society, American Society for

Metabolic & Bariatric Surgery. Executive summary of the recommen-

dations of the American Association of Clinical Endocrinologists, the

Obesity Society, and American Society for Metabolic & Bariatric Sur-

gery medical guidelines for clinical practice for the perioperative

nutritional, metabolic, and nonsurgical support of the bariatric surgery

patient [partial retraction appears in Endocr Pract. 2008;14:650; pub-

lished correction appears in Endocr Pract. 2009;15:768]. Endocr

Pract. 2008;14:318–336.

79. Bouri S, Shun-Shin MJ, Cole GD, Mayet J, Francis DP. Meta-analysis

of secure randomized controlled trials of b-blockade to prevent

perioperative death in non-cardiac surgery. Heart. 2013; http://

dx.doi.org/10.1136/heartjnl-2013-304262.

80. Rahn DD, Mamik MM, Sanses TV, et al. Society of Gynecologic Sur-

geons Systematic Review Group. Venous thromboembolism prophy-

laxis in gynecologic surgery: a systematic review. Obstet Gynecol.

2011;118:1111–1125.

81. Geerts WH, Bergqvist D, Pineo GF, et al. American College of Chest

Physicians. Prevention of venous thromboembolism: American Col-

lege of Chest Physicians Evidence-Based Clinical Practice Guidelines

(8th edition). Chest. 2008;133(6 Suppl):381S–453S.

82. Nick AM, Schmeler KM, Frumovitz MM, et al. Risk of thromboem-

bolic disease in patients undergoing laparoscopic gynecologic surgery.

Obstet Gynecol. 2010;116:956–961.

83. Einstein M, Kushner DM, Connor JP, et al. A protocol of dual prophy-

laxis for venous thromboembolism prevention in gynecologic cancer

patients. Obstet Gynecol. 2008;112:1091–1097.

84. Clarke-Pearson DL, Abaid LN. Prevention of venous thromboembolic

events after gynecologic surgery [published correction appears in Ob-

stet Gynecol. 2012;119:872]. Obstet Gynecol. 2012;119:155–167.

85. Agarwal R, Hecht TE, Lazo MC, Umscheid CA. Venous thromboem-

bolism prophylaxis for patients undergoing bariatric surgery: a sys-

tematic review. Surg Obes Relat Dis. 2010;6:213–220.

86. Abou-Nukta F, Alkhoury F, Arroyo K, et al. Clinical pulmonary

embolus after gastric bypass surgery. Surg Obes Relat Dis. 2006;2:

24–28. discussion 29.

87. Hamad GG, Bergqvist D. Venous thromboembolism in bariatric

surgery patients: an update of risk and prevention. Surg Obes Relat

Dis. 2007;3:97–102.

88. Scholten DJ, Hoedema RM, Scholten SE. A comparison of two

different prophylactic dose regimens of low molecular weight heparin

in bariatric surgery. Obes Surg. 2002;12:19–24.

89. Miller MT, Rovito PF. An approach to venous thromboembolism

prophylaxis in laparoscopic Roux-en-Y gastric bypass surgery. Obes

Surg. 2004;14:731–737.

90. Cotter SA, Cantrell W, Fisher B, Shopnick R. Efficacy of venous

thromboembolism prophylaxis in morbidly obese patients undergoing

gastric bypass surgery. Obes Surg. 2005;15:1316–1320.

91. Hotamisligil GS, Olefsky JM, Kurahara C, Taylor K. A defect in

cell-mediated immune function in insulin-resistant diabetic and obese

subjects. J Lab Clin Med. 1980;96:535–543.

92. Krishnan EC, Trost L, Aarons S, Jewell WR. Study of function and

maturation of monocytes in morbidly obese individuals. J Surg Res.

1982;33:89–97.

93. Friedman JM. Obesity in the new millennium. Nature. 2000;404:

632–634.

94. Smith AI, Funder JW. Proopiomelanocortin processing in the pituitary,

central nervous system, and peripheral tissues. Endocr Rev. 1988;9:

159–179.

Scheib et al. Laparoscopy in the Morbidly Obese 195

95. Hotamisligil GS, Arner P, Caro JF, Atkinson RL, Spiegelman BM.

Increased adipose tissue expression of tumor necrosis factor-alpha

in human obesity and insulin resistance. J Clin Invest. 1995;95:

2409–2415.

96. Andronico G, Cottone S, Mangano MT, et al. Insulin, renin-

aldosterone system and blood pressure in obese people. Int J Obes

Relat Metab Disord. 2001;25:239–242.

97. Miller K, Hell E. Laparoscopic surgical concepts of morbid obesity.

Langenbecks Arch Surg. 2003;388:375–384.

98. Lundborg G, Dahlin LB. Anatomy, function, and pathophysiology of

peripheral nerves and nerve compression.HandClin. 1996;12:185–193.

99. Berhane L, Kurman R, Smith S. Lower extremity paralysis after oper-

ative laparoscopy from conversion disorder: a case report. J Reprod

Med. 1998;43:831–835.

100. Artuso D, Wayne M, Kaul A, Baramian M, Teixeira J, Cerabona T.

Extremely high body mass index is not a contraindication to laparo-

scopic gastric bypass. Obes Surg. 2004;14:750–754.

101. G€uenaga KF, Matos D, Wille-Jørgensen P. Mechanical bowel prepara-

tion for elective colorectal surgery [update]. Cochrane Database Syst

Rev. 2011;9:CD001544.

102. Muzii L, Bellati F, Zullo MA, et al. Mechanical bowel preparation

before gynecologic laparoscopy: a randomized, single-blind, controlled

trial. Fertil Steril. 2006;85:689–693.

103. Lijio D, Ferrero S,Mistrangelo E, et al. Bowel preparation before lapa-

roscopic gynaecological surgery in benign conditions using a 1-week

low fibre diet: a surgeon blind, randomized and controlled trial. Arch

Gynecol Obstet. 2009;280:713–718.

104. Yang LC, Arden D, Lee TT, et al. Mechanical bowel preparation for

gynecologic laparoscopy: a prospective randomized trial of oral so-

dium phosphate solution vs single sodium phosphate enema. J Minim

Invasive Gynecol. 2011;18:149–156.

105. Won H, Maley P, Salim S, Rao A, Campbell NT, Abbott JA. Surgical

and patient outcomes usingmechanical bowel preparation before lapa-

roscopic gynecologic surgery: a randomized controlled trial. Obstet

Gynecol. 2013;121:538–546.

106. Shenkman Z, Shir Y, Brodsky JB. Perioperative management of the

obese patient. Br J Anaesth. 1993;70:349–359.

107. Vaughan RW, Bauer S, Wise L. Volume and pH of gastric juice in

obese patients. Anesthesiology. 1975;43:686–689.

108. Lam AM, Grace DM, Penny F, Vezina WC. Prophylactic intravenous

cimetidine reduces the risk of acid aspiration in morbidly obese

patients [abstract]. Anesthesiology. 1983;59:A242.

109. ACOGCommittee on Practice Bulletins: Gynecology. ACOGPractice

Bulletin No. 104. Antibiotic prophylaxis for gynecologic procedures.

Obstet Gynecol. 2009;113:1180–1189.

110. Forse RA, Karam B, MacLean LD, Christou NV. Antibiotic prophy-

laxis for surgery in morbidly obese patients. Surgery. 1989;106:

750–756. discussion 756–757.

111. Juvin P, Lavaut E, Dupont H, et al. Difficult tracheal intubation is

more common in obese than in lean patients. Anesth Analg. 2003;

97:595–600.

112. Cadi P, Guenoun T, Journois D, Chevallier JM, Diehl JL, Safran D.

Pressure-controlled ventilation improves oxygenation during laparo-

scopic obesity surgery compared with volume-controlled ventilation.

Br J Anaesth. 2008;100:709–716.

113. Pelosi P, Ravagnan I, Giurati G, et al. Positive end-expiratory pressure

improves respiratory function in obese but not in normal subjects dur-

ing anesthesia and paralysis. Anesthesiology. 1999;91:1221–1231.

114. Reinius H, Jonsson L, Gustafsson S, et al. Prevention of atelectasis

in morbidly obese patients during general anesthesia and paralysis:

a computerized tomography study. Anesthesiology. 2009;111:

979–987.

115. Talab HF, Zabani IA, Abdelrahman HS, et al. Intraoperative ventila-

tory strategies for prevention of pulmonary atelectasis in obese

patients undergoing laparoscopic bariatric surgery. Anesth Analg.

2009;109:1511–1516.

116. Massey EW, Pleet AB. Compression injury of the sciatic nerve during

prolonged surgical procedure in a diabetic patient. J Am Geriatr Soc.

1980;28:188–189.

117. Coppieters MW. Shoulder restraints as a potential cause for stretch

neuropathies: biomechanical support for the impact of shoulder girdle

depression and arm abduction on nerve strain. Anesthesiology. 2006;

104:1351–1352.

118. Klauschie J, Wechter ME, Jacob K, et al. Use of anti-skid material

and patient-positioning to prevent patient shifting during robotic-

assisted gynecologic procedures. J Minim Invasive Gynecol. 2010;

17:504–507.

119. Bradshaw AD, Advincula AP. Postoperative neuropathy in gyneco-

logic surgery. Obstet Gynecol Clin North Am. 2010;37:451–459.

120. Lamvu G, Zolnoun D, Boggess J, Steege JF. Obesity: physiologic

changes and challenges during laparoscopy. Am J Obstet Gynecol.

2004;191:669–674.

121. Ahmad G, O’Flynn H, Duffy JM, Phillips K, Watson A. Laparoscopic

entry techniques. Cochrane Database Syst Rev. 2012;2:CD006583.

122. HurdWW, Bude RO, DeLancey JO, Pearl ML. The relationship of the

umbilicus to the aortic bifurcation: implications for laparoscopic tech-

nique. Obstet Gynecol. 1992;80:48–51.

123. Hurd WH, Bude RO, DeLancey JO, Gauvin JM, Aisen AM. Abdom-

inal wall characterization with magnetic resonance imaging and

computed tomography: the effect of obesity on the laparoscopic

approach. J Reprod Med. 1991;36:473–476.

124. Palmer R. Safety in laparoscopy. J Reprod Med. 1974;13:1–5.

125. Tulikangas PK, Nicklas A, Falcone T, Price LL. Anatomy of the left

upper quadrant for cannula insertion. J Am Assoc Gynecol Laparosc.

2000;7:211–214.

126. StanyMP,Winter WE 3rd, Dainty L, Lockrow E, Carlson JW. Laparo-

scopic exposure in obese high-risk patients with mechanical displace-

ment of the abdominal wall. Obstet Gynecol. 2004;103:383–386.

127. Tonouchi H, Ohmori Y, KobayashiM, KusunokiM. Trocar site hernia.

Arch Surg. 2004;139:1248–1256.

128. Vaughan RW,Wise L. Postoperative arterial blood gas measurement in

obese patients: effect of position on gas exchange. Ann Surg. 1975;

182:705–709.

129. Vaughan RW, Bauer S, Wise L. Effect of position (semirecumbent

versus supine) on postoperative oxygenation in markedly obese sub-

jects. Anesth Analg. 1976;55:37–41.