9. Cooperberg P, Hazell S, Ashmore PG: Parachute accessoryanterior mitral valve leaflet causing left ventricular outflowtract obstruction. Circulation 1976;53:908–11.

Pneumoperitoneum Secondary toEndoscopic Harvest of SaphenousVein GraftAndreas Lehmann, MD, Johannes Lang, Udo Weisse,and Joachim Boldt, MD

Departments of Anesthesiology and Intensive Care Medicine,and Cardiac Surgery, Klinikum der Stadt Ludwigshafen,Ludwigshafen, Germany

Endoscopic harvest of saphenous vein graft for coronaryartery bypass grafting decreases leg wound complica-tions compared with traditional longitudinal incision. Acase of pneumoperitoneum secondary to endoscopic har-vest of saphenous vein using insufflation of carbondioxide is reported. Hypercarbia, increased peak airwaypressure, but no significant changes of hemodynamics, ormyocardial ischemia were noted. The management ofthis rare complication is described.

(Ann Thorac Surg 2000;69:1937–8)© 2000 by The Society of Thoracic Surgeons

Endoscopic harvest of saphenous vein graft is a clini-cally feasible surgical technique with a significant

reduction in morbidity and a perfect cosmetic result incoronary artery bypass grafting (CABG) patients [1–3]. Tothe authors knowledge no severe complications havebeen reported for endoscopic saphenous vein harvesting.This is a report of a pneumoperitoneum caused by theinsufflation of carbon dioxide (CO2) during the endo-scopic procedure.

A 62-year-old, 73-kg, 172-cm woman was scheduled forcoronary artery revascularization. The patient com-plained for angina pectoris at rest (C.C.S II) during theprevious four months. Coronary angiography showedthree vessel coronary artery disease (CAD) with wellpreserved left ventricular function. Risk factors for CADwere arterial hypertension and hyperlipidemia.

Endoscopic harvest of saphenous vein graft started atthe right upper leg. The endoscopic system was Vaso-view (Origin, Menlo Park, CA) using an insufflation ofCO2 (Electronic Endoflator 264305 20, Karl Storz, Tuttlin-gen, Germany). The flow of CO2 can be adjusted to a

maximum of 12 L/min and a peak pressure ranging from15 to 30 mm Hg. Peak pressure at our institution isadjusted to 18 mm Hg, requiring a flow of CO2 from 0 toabout 2 L/min. After 60 minutes 30 cm of vena saphenamagna were harvested and to get more vein graftsendoscopic procedure was started at the left upper leg.Thirty minutes later the abdomen enlarged significantlyand endexspiratory pCO2 increased from 30 to37 mm Hg, peak airway pressure increased from17 mm Hg to 23 mm Hg. Arterial pCO2 increased to amaximum of 52.3 mm Hg but could be quickly normal-ized by increasing tidal volume. Only mild respiratoryacidosis (pH: 7.31) occurred. There were no significantchanges of hemodynamics except moderate increases inpulmonary vascular resistance from 99 to 159 dyn seccm-5. Mean pulmonary arterial pressure and pulmonarycapillary wedge pressure remained unchanged. No signsof myocardial ischemia were noted. In close cooperationwith the surgeon we decided to continue endoscopicharvesting of saphenous vein. The therapy of this com-plication was a close monitoring of pulse oxymetry,capnometry, blood gas analyses, and hemodynamics.Except increasing tidal volume for an increased ventila-tion no specific therapy was necessary.

After complete revascularization the patient wasweaned uneventfully from cardiopulmonary bypass. Thepatient was transferred to the intensive care unit withstable hemodynamics. The abdomen was normal and nosubcutaneous emphysema was noted. Postoperativechest roentgenogram showed a complete resorption ofCO2, no subcutaneous emphysema or gas below thediaphragm was seen. A resternotomy was necessaryduring the first postoperative night due to excessivebleeding. The patient was extubated within 8 hours afterresternotomy and no further complication was noted.

Comment

Endoscopic harvest of saphenous vein is advantageous toconventional open harvest in CABG patients because ofexcellent cosmetic results, less wound pain and lowerrate of complications [1– 3]. Minor complications for opensaphenectomy-like hematoma, wound dehiscence, infec-tion, and pain are reported in up to 24% [3]. Majorcomplications requiring surgical intervention-like bleed-ing and abscess are less than 1% [3]. Harvest rate forendoscopic technique is slower than for conventionalsaphenectomy [1, 2].

In all endoscopic techniques a subcutaneous dissectiontunnel around saphenous veins is created. The insuffla-tion of CO2 into this tunnel facilitates the preparation ofthe vein and stops small bleedings. Other authors [1, 3]visualize and dissect the vein directly, without using aninsufflation of CO2. Whether our technique using theinsufflation of CO2 is superior to endoscopic proceduresdirect dissecting the vein, must be evaluated in furtherstudies.

Accepted for publication Nov 1, 1999.

Address reprint requests to Dr Boldt, Department of Anesthesiology andIntensive Care Medicine, Klinikum der Stadt Ludwigshafen, Bremserstr79, D-67063 Ludwigshafen, Germany.

1937Ann Thorac Surg CASE REPORT LEHMANN ET AL2000;69:1937–8 COMPLICATION OF ENDOSCOPIC VEIN HARVESTING

© 2000 by The Society of Thoracic Surgeons 0003-4975/00/$20.00Published by Elsevier Science Inc PII S0003-4975(00)01208-X

No major intraoperative complications during endo-scopic harvesting of saphenous vein have been reported[1–3]. In 5.6% a conversion from endoscopic to conven-tional harvest was necessary [1]. In a series of more than100 patients at our institution, using insufflation of CO2,only one patient developed a pneumoperitoneum sec-ondary to endoscopic harvest of saphenous vein. CO2

expanded in the subcutaneous tissue of the leg, passedalong the groin vessels into the retroperitoneum anddiffused into the abdominal cavity. In abdominal andthoracic endoscopic procedures the insufflation of CO2 isa common technique and its side effects are well known[4, 5]. The increased intraabdominal pressure can disturbalveolar ventilation by alveolar collapse leading to com-promised oxygenation [4]. The insufflated CO2 is ab-sorbed by the blood to an unpredictable extent and mustbe eliminated by the lungs by an increased ventilation[4]. The increased intraabdominal pressure reduces ve-nous return and can compromise circulation, adequatevolume substitution is essential [5]. These effects aremore pronounced in infants [5].

The effects of increased intraabdominal pressure arecorrelated with its height. For patients with a decreasedcardiopulmonary reserve an intraabdominal pressure ofless than 10 to 12 mm Hg is recommended to minimizethe side effects of CO2 insufflation [6–8].

Surgeons must be aware of the problems caused by theinsufflation of CO2 for the endoscopic harvest of saphe-nous veins in CABG patients. The limited experiencewith endoscopic harvesting of saphenous veins does notallow to state generally accepted rules to flow and peakpressure of the insufflation of CO2. The risk of complica-tions seems to rise the longer the procedure lasts, themore CO2 is insufflated, and the higher the peak pressureof insufflation of CO2 is adjusted. If any severe compli-cations are noted the endoscopic procedure should beimmediately converted into an open saphenectomy.

References

1. Allen KB, Griffith GL, Heimansohn DA, et al. Endoscopicversus traditional saphenous vein harvesting: a prospective,randomized trial. Ann Thorac Surg 1998;66:26–32.

2. Kyo S, Kaneko K, Nishikiori Y, Konou R, Hojo H, Omoto R.Endoscopic harvest of saphenous vein graft for coronaryartery bypass grafting: Saitama - Olympus technique. EurJ Cardiothorac Surg 1998;14(Suppl 1):S93–9.

3. Lutz CW, Schlensak C, Lutter G, Schollhorn J, Beyersdorf F.Minimal-invasive, video-assisted vein harvesting for cardiacand vascular surgical procedures. Eur J Cardiothorac Surg1997;12:519–21.

4. Crozier TA. Anesthesiologic aspects of minimally invasivesurgery. Zentralbl Chir 1993;118:573–81.

5. Pighin G, Crozier TA, Weyland W, Ludtke FE, Kettler D.Specifics of anesthesiology in laparoscopic surgery in infancy.Zentralbl Chir 1993;118:628–30.

6. Junghans T, Bohm B, Grundel K, Schwenk W. Effects ofpneumoperitoneum with carbon dioxide, argon, or helium onhemodynamic and respiratory function. Arch Surg 1997;132:272–8.

7. Taura P, Lopez A, Lacy AM, et al. Prolonged pneumoperito-

neum at 15 mmHg causes lactic acidosis. Surg Endosc 1998;12:198–201.

8. Rishimani AS, Gautam SC. Hemodynamic and respiratorychanges during laparoscopic cholecystectomy with high andreduced intraabdominal pressure. Surg Laparosc Endosc1996;6:201–4.

INVITED COMMENTARY

Endoscopic harvest of the greater saphenous vein is atrue minimal invasive procedure with many advantagesfor patients and is associated with a very low risk rate.After conventional open removal on the greater saphe-nous vein, postoperative minor complications are com-mon and patients often experience painful sensations.Minimally invasive endoscopic harvesting of the entiregreater saphenous vein is possible through one singleskin incision, thus avoiding potential infections, espe-cially in the groin. Many different systems exist forminimal invasive endoscopic vein harvesting (includingsystems for single and multiple use, with and withoutCO2-insufflation, etc). The conversion rate into the openconventional technique is necessary in up to 10% and canbe performed without any additional risk for the patient.Therefore the potential advantages of this technique (lessacute and chronic pain, less wound morbidity, fastermobility of the patient) clearly outweigh minor compli-cations associated with this procedure.

The report of Lehmann and coworkers describes one ofthese rare complications of endoscopic vein harvestingusing CO2-insufflation. This complication was managedvery successfully by the authors and has not been re-ported in the literature before. This report, however, isable to focus on this potential complication for thisspecific harvesting procedure and is therefore very help-ful for the scientific community.

However, even though a number of reports have dem-onstrated the clear advantages of the endoscopic mini-mal invasive saphenous vein harvest procedure as com-pared to the conventional open technique, more data arenecessary to address the potential damage of the veinendothelium during endoscopic approach. In all pub-lished reports so far no acute vein graft closures havebeen reported, but more detailed histomorphologic stud-ies are necessary to demonstrate the complete intactnessof the vein endothelium after this new approach forharvesting.

In addition, the percentage of patients revascularizedby complete arterial grafting is increasing and futuredevelopments will show if endoscopic arterial harvestingfor the radial and gastroepiploic artery will be feasible.

Friedhelm Beyersdorf, MD

Department of Cardiovascular SurgeryAlbert-Ludwigs University FreiburgHugstetterstrasse 55D-79106 Freiburg, Germanye-mail: beyers@ch11.ukl.uni-freiburg.de.

1938 CASE REPORT LEHMANN ET AL Ann Thorac SurgCOMPLICATION OF ENDOSCOPIC VEIN HARVESTING 2000;69:1937–8