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Suzie, Robz, Gemmy
I.5 – Colon, Rectum, and Anus (Lecture)Dr. Mata
June 9, 2013EMBROYOLOGY
The embryonic gastrointestinal tract begins developing during the 4th week of gestation
The primitive gut is derived from the endoderm and divided into three segments Foregut Midgut* Hindgut*
*contribute to the colon, rectum, and anus
MIDGUTDevelops into the
small intestine, ascending colon, and proximal transverse colon
Receives blood supply from the superior mesenteric artery
During the 6th week of gestation, the midgut herniates out of the abdominal cavity, and then rotates 27ocounterclockwise around the superior mesenteric artery to return to its final position inside the abdominal cavity during the 10th week of gestation
MIDGUTDevelops into the
distal transverse colon descending colon rectum and proximal anus
all of which receive their blood supply from the inferior mesenteric artery
during the 6th week of gestation, the distal-most end of the hindgut, the cloaca, is divided by the urorectal septum into urogenital sinus rectum
DISTAL ANAL CANALderived from ectoderm and receives its blood supply
from the internal pudendal artery the dentate line divides the endodermal hindgut from
the ectodermal distal anal canal
ANATOMY the large intestine extends from the ileocecal valve to
the anus it is divided anatomically and functionally into
colon rectum anal canal
the 1st 6 cm of the large intestine just below the ileocecal valve, the ascending colon, and the hepatic flexure form a surgical unit, the right colon
Figure 1. Colon anatomy and measurements
HEPATIC FLEXURE
located under the 9th and 10th costal cartilages in the vicinity of midaxillary line
gallbladder is located anteriorlyduodenum is located posteriorly
ASCENDING COLONThe ascending limb of the right colon is fused to the
posterior body wall and covered by the peritoneumFused variations
Deep lateral paracolic groove to the persistence of an entire ascending mesocolon
TRANSVERSE COLONThe transverse colon hangs in a U or V-shaped curveThe transverse mesocolon is formed by a double
peritoneal foldThe 2 are fused at “X” to form the transverse mesocolon
containing the middle colic artery and vein
DESCENDING COLONCovered anteriorly and on its medial and lateral sides by
peritoneum Has no mesenteryMobilization of the ascending colon is accomplished by
incising the peritoneal reflection at the left gutter along the “white line of Told”
SIGMOID – S shaped2 portions
Iliac portion – fixed and located at the left iliac fossa
Pelvic portion – mobileBegins at the iliac crests and ends at the 3rd sacral
vertebra
RECTUMThe junction between the sigmoid colon and the rectum
has been variously described: A point opposite the left sacroiliac joint Level of the 3rd sacral vertebra Level at which sacculations and epiploic appendages
disappear and taeniae broaden to form a complete muscle layer (long transition)
Level at which the superior rectal artery divides into the right and left branches
Construction with anterior angulation (proctoscopy) Transition between rugose mucosa of the colon and
smooth mucosa of the rectumPosteriorly, the presacral fascia separates the rectum
from the presacral venous plexus and pelvic nervesAt S4, the retrosacral fascia (Waldeyer’s fascia)
extends forward and downward and attaches to the fascia propria at the anorectal junction
Anteriorly, Denonvilliers’ fascia separates the rectum from the prostate and seminal vesicles in men and from the vagina in women. The lateral ligaments support the lower rectum
The entire upper 1/3rd of the rectum is covered by peritoneum
The mesorectum, which suspends the rectum from the posterior body wall, comes off more laterally, leaving bare progressively more of the posterior rectal wall
The peritoneum finally leaves the rectum and passes anteriorly and superiorly over the posterior vaginal fornix and the uterus in females or over he superior ends of the seminal vesicles and the bladder in males
This creates a depression, the rectouterine or rectovesical pouch With infection, this may become filled with pus
SPACES OF THE ANUS AND RECTUMPelvirectal space
Page 1 of 8
I.4a – Colon, Rectum, and Anus (Lecture)
Ischioanal (ischiorectal) space Intersphincteric spacesSubcutaneous spaceCentral spaceSubmucousspace
PERITONEAL LOCATIONS
Figure 2. Peritoneal Locations
ARTERIAL SUPPLY OF THE COLON
Figure 3. Arterial Supply of the colon
SMA BRANCHES TO THE COLONMiddle colic arteryRight colic artery Ileocolic arteryMeandering Artery of Riolan – communicating between
Middle colic and IMA
MEANDERING ARTERY OF RIOLAN
*blue arrowsSMA
*blue arrows
IMA If the inferior mesenteric artery is divided at “a” above,
the last full anastomosis, collateral circulation toward the rectum is still possible
Division at “b” would interrupt the collateral circulation
SUDECK’S CRITICAL POINTSudeck described a point on the superior rectal artery at
which ligation of the artery would not devascularize a long rectosigmoid stump
This point is just above the origin of the last sigmoid artery
“Ligation below the Sudeck’s point would devascularize the rectum” Not critical as it was thought to be
The concept of Sudeck’s critical point fails to recognize 2 other sources of blood to the rectum
ALTERNATIVE BLOOD SUPPLYOne is the intramural network of arteries in the
submucosal layer of the wall and the other is from collaterals
Branches of the inferior vesical arteryArteries supplying the levator ani muscleThe middle sacral arteryThe posterior retroperitoneal arterial plexus uniting the
parietal and visceral circulationThe inferior rectal artery is responsible for the arterial
blood supply of the distal 2 cm of the anal canal
MARGINAL ARTERY OF DRUMMONDComposed of a series of anastomosing arcades between
branches of the ileocoloc, right colic, middle colic, left colic, and sigmoidal arteries
These form a single looping vesselRuns parallel, 1-8 cm from the intestinal wall
MEANDERING ARTERY OF RIOLANThe long vasa recta branches bifurcate and
anastomose at the antimesenteric border of the bowel after encircling it
The short ones, branches of the marginal artery, are responsible for the mesocolic 2/3rd of the colonic circumference
The vasa recta brevia run subserosally in the wall and penetrate the circular muscle and run in the submucosa
Effect of too much traction on an epiploic appendage resulting injury to one of the long branches of vasa recta followed by antimesenteric ischemia
ORIGIN AND ARTERIAL SUPPLY TO RECTUMUnpaired superior rectal artery
Right and left branchesMiddle rectal artery
Dosro-caudal area Inferior rectal artery
Ventral and medialMedial sacral artery
Posterior wall
VENOUS DRAINAGE OF THE COLON
VENOUS DRAINAGE OF THE RECTUMPortal systemSuperior rectal veinSystemic systemMiddle rectal vein Inferior rectal vein
Page 2 of 8
I.4a – Colon, Rectum, and Anus (Lecture)
Mainly responsible for the venous return of the distal 2 cm of the anal canal
Anastomoses occur between superior rectal vein (portal) and the middle and inferior rectal veins (systemic). These constitute a potential portosystemic shunt.
LYMPHATIC DRAINAGEEpicolic
Under the serosa of the wall of the intestineParacolic
On the marginal artery Intermediate
Along the large arteries (SMA and IMA)Principal
At the root of SMA and IMA
Above the pectinate line, drainage is to inferior mesenteric nodes
Below the line, drainage is to the inguinal nodes
INNERVATION Intramural plexus or intestinal enteric nervous systemMyenteric plexus
AuerbachSubmucosa plexus
Meissner Controls secretions
Table 1. Right vs Left ColonRIGHT COLON LEFT COLON
Sympathetic: lower 6 thoracic segments of the spinal cord
Sympathetic: L1, 2, 3 lumbar splanchnic nerves to the aortic plexus and the inferior mesenteric plexus
Parasympathetic: vagal fibers from the posterior trunk
Parasympathetic – pelvic splanchnic nerves S2, 3, 4
PHYSIOLOGYThe colon is a major site for water absorption and
electrolyte exchangeApproximately 90% of water contained in ileal fluid is
absorbed in the colon (1000 to 2000 ml/d), and up to 5000 ml of fluid can be absorbed daily
Sodium is absorbed actively via a Na-K ATPase channelChloride is absorbed actively via a chloride-bicarbonate
exchange
SHORT-CHAIN FATTY ACIDSShort-chain fatty acids are important sources of
energy for the colonic mucosa, and metabolism by colonocytes provides energy for processes such as active transport of sodium
Short-chain fatty acids (acetate, butyrate, and proprionate) are produced by bacterial fermentation of dietary carbohydrates
Lack of a dietary source for production of short-chain fatty acids, or diversion of the fecal stream by an ileostomy or colostomy, may result in mucosal atrophy and “diversion colitis”
MOTILITY – Cholinergic Response
Unlike the small intestine, the large intestine does NOT demonstrate migratory motor complex
Intermittent contractions of either low or high amplitudeLow-amplitude, short-duration contractions
occur in bursts and appear to move the colonic contents both antegrade and retrograde – absorption of water/electrolytes
High amplitude contractions create“mass movements”
DEFECATIONa complex, coordinated mechanism involving
colonic mass movement, increased intra-abdominal and rectal pressure, and relaxation of the pelvic floor
distention of rectum causes a reflex relaxation of the internal anal sphincter (the rectoanal inhibitory reflex)
this “sampling reflex” allows the sensory epithelium to distinguish solid stool from liquid stool and gas
if defecation does not occur, the rectum relaxes and the urge to defecated passes (the accommodation response)
defecation proceeds by coordination of increasing intra-abdominal pressure via the Valsalva Maneuver increased rectal contraction relaxation of the puborectalis muscle opening of the anal canal
CLINICAL EVALUATIONa complete history and PE is the starting point for
evaluating any patient with suspected disease of the colon and rectum
special attention should be paid to the patient’s past medical and surgical history to detect underlying conditions that might contribute to a gastrointestinal problem
if patients have had prior intestinal surgery, it is essential that one understands resultant gastrointestinal anatomy
in addition, family history of colorectal disease especially inflammatory bowel disease, polyps, and colorectal cancer, is crucial
medication use must be detailed as many drugs cause GI symptoms
before recommending operative intervention, the adequacy of medical treatment must be ascertained
in addition to examining the abdomen, visual inspection of the anus and perineum and careful digital rectal exam are essential
ENDOSCOPYAnoscopy
Useful instrument for examination of the anal canal Anoscopes are made in variety of sizes and measure
approximately 8cm in length A larger anoscope provides better exposure for anal
procedures such as rubber band ligation or sclerotherapy of haemorrhoids
Proctoscopy
IMAGING STUDIESPlain X-rays and Contrast StudiesComputed TomographyVirtual ColonoscopyMagnetic Resonance ImagingPositron Emission TomographyAngiographyEdorectal and Edoanal Ultrasound
PHYSIOLOGIC AND PELVIC FLOOR INVESTIGATIONSAnorectal physiologic testing uses a variety of
techniques to investigate the function of the pelvic floorThese techniques are useful in the evaluation of patients
with incontinence, constipation, rectal prolapse, obstructed defecation, and other disorders of the pelvic floor
ManometryNeurophysiologyRectal Evacuation Studies
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I.4a – Colon, Rectum, and Anus (Lecture)
MANOMETRYPerformed by placing a pressure-sensitive catheter in
the lower rectumCatheter is then withdrawn through the anal canal and
pressures recordedA balloon attached to the tip of the catheter also can be
used to test anorectal sensationThe resting pressure in the anal canal reflects the
function of the internal anal sphincter (Normal: 40-80 mmHg)
SQUEEZE PRESSURE Defined as the maximum voluntary contraction
pressure minus the resting pressure Reflects function of the external anal sphincter
(Normal: 40-80 mmHg ABOVE resting pressure)The high-pressure zone
Estimates the length of the anal canal (Normal: 2.0 – 4.0 cm)
The rectoanal inhibitory reflex Can be detected by inflating a balloon in the distal
rectum Absence of this reflex is characteristic of
HIRSCHSPRUNG’S DISEASE
NEUROPHYSIOLOGIC TESTINGAssesses function of the pudendal nerves and
recruitment of puborectalis muscle fibersPudendal nerve terminal motor latency measures the
speed of transmission of a nerve impulse through the distal pudendal nerve fibers (Normal: 1.8 – 2.2 msec)
Needle EMG has been used to map both the pudendal nerves and the anatomy of the internal and external sphincters
However, this examination is painful and poorly tolerated by most patients
Needle EMG has largely been replaced by pudendal nerve motor latency testing to assess pudendal nerve function and endoanal ultrasound to map the sphincters
RECTAL EVACUATION STUDIES Include the balloon expulsion test and video
defecographyBALLOON EXPULSION
Assess a patient’s ability to expel an intrarectal balloon
VIDEO DEFECOGRAPHY Provides a more detailed assessment of defecation Barium paste is placed in the rectum and defecation
is them recorded fluoroscopically Used to differentiate nonrelaxation of the
puborectalis, obstructed defecation, increased perineal descent, rectal prolapse and intussuception, rectocele, and enterocele
Addition of vaginal contrast and intraperitoneal contrast is useful in delineating complex disorders of the pelvic floor
LABORATORY STUDIESFecal Occult Blood TestingStool StudiesSerum TestsTumor MarkersGenetic Testing
FECAL OCCULT BLOOD TESTINGFOBT is used as a screening test for colonic neoplasms in
asymptomatic, average-risk individualsThe efficacy of this test is based upon serial testing
because the majority of the colorectal malignancies will bleed intermittently
Has been a nonspecific test for peroxidase contained in haemoglobin
STOOL STUDIESAre often helpful in evaluating the etiology of diarrheaWet-mount examination reveals the presence of faecal
leukocytes, which may suggest colonic inflammation or the presence of an invasive organism such as invasive E. coli or Shigella
Stool cultures can detect pathogenic bacteria, ova, and parasites
C. difficile colitis is diagnosed by detecting bacterial toxin in the stool
Steatorrhea may be diagnosed by adding Sudan red stain to a stool sample
SERUM TESTSSpecific laboratory tests that should be performed will be
dictated by the clinical scenarioPreoperative studies generally include CBC and
electrolyte panelThe addition of coagulation studies, liver function tests,
and blood typing/cross-matching depends upon the patient’s medical condition and the proposed surgical procedure
TUMOR MARKERSCarcinoembryonic antigen (CEA) may be elevated in 60-
90% of patients with colorectal cancerDespite this, CEA is NOT an effective screening tool for
this malignancyMany practitioners follow serial CEA levels after curative-
intent surgery in order to detect early recurrence of colorectal cancer
However, this tumor marker is nonspecific and no survival benefit has yet been proven
Other biochemical markers (ornithine decarboxylase, urokinase) have been proposed, but none has yet proven sensitive or specific for detection, staging, or predicting prognosis of colorectal CA
GENETIC TESTINGAlthough familial colorectal CA syndromes such as FAP
and HNPCC are rare, information about the specific genetic abnormalities underlying these disorders has led to significant interest in the role of genetic testing for colorectal CA
Tests for mutations in the APC gene responsible for FAP and in mismatch repair genes responsible for HNPCC, are commercially available and extremely accurate in families with known mutations
Although many of these mutations are also present in sporadic colorectal cancer, the accuracy of genetic testing in average individuals is considerably lower
These tests are not recommended for screening. Because of the potential psychosocial implications of genetic testing, it is strongly recommended that professional genetic counsellors be involved in the care of any patient considering these tests
NOTE: The following topics under Evaluation of Common Symptoms are not emphasized by Doc Mata but are still included in the ppt. Tinamad na ata siya gumawa ng ppt kasi sobrang copy-paste lang from Schwartz.
EVALUATION OF COMMON SYMPTOMSABDOMINAL PAIN
A nonspecific symptom with a myriad of causesPain related to colon and rectum can result from
obstruction (either inflammatory or neoplastic), inflammation, perforation or ischemia.
Plain X-rays and judicious use of contrast studies and/or a CT scan can often confirm the diagnosis
Gentle retrograde contrast studies (barium or Gastrografin enema) may be useful in delineating the degree of colonic obstruction
PELVIC PAINCan originate from the distal colon and rectum or from
adjacent urogenital structuresTenesmus may result from proctitis or from a rectal or
rectrorectal massCyclical pain associated with menses, esp when
accompanied by rectal bleeding suggests a diagnosis of endometriosis
PID also can produce significant abdominal and pelvic pain
The extension of a peridiverticular abscess or periappendiceal abscess into the pelvis may also cause pain
CT scan and/or MRI may be useful in differentiating these diseases
Page 4 of 8
I.4a – Colon, Rectum, and Anus (Lecture)
Proctoscopy (if tolerated) also can be helpfulOccasionally, laparoscopy will yield diagnosis
ANORECTAL PAINMost often secondary to an anal fissure or perirectal
abscess and/or fistulaPE can usually differentiate these conditionsOther less common causes:
Anal canal neoplasms Perianal skin infection Dermatologic conditions Proctalgiafugax–results from levator spasm and
may present without any other anorectal findingsPE is critical in evaluating patients with anorectal pain If a patient is too tender to examine in the office, an
examination under anesthesia is necessaryMRI may be helpful in select cases where the etiology of
pain is elusive
LOWER GI BLEEDINGThe first goal in evaluating and treating a patient with
GI haemorrhage is adequate resuscitationThe principles of ensuring a patient airway, supporting
ventilation, and optimizing hemodynamic parameters apply and coagulopathy and/or thrombocytopenia should be corrected
The second goal is to identify the source of haemorrhage
Because the most common source of GI haemorrhage is esophageal, gastric or duodenal, nasogastric aspiration should always be performed
Return of bile suggests that the source of bleeding is distal to the ligament of Treitz
If aspiration reveals blood or nonbile secretions, or if symptoms suggest an upper intestinal source, esophagogastroduodenoscopy is performed
Anoscopy and/or limited proctoscopy can identify hemorrhoidal bleeding
A technetium-99-tagged RBC scan is extremely sensitive and is able to detect as little as 0.1 ml/h of bleeding; however, localization is imprecise
If the technetium-99-tagged RBC scan is positive, angiography can then be employed to localised bleeding
Infusion of vasopressin or angioembolization may be therapeutic
Alternatively, a catheter can be left in the bleeding vessel to allow localization at the time of laparotomy
If the patient is hemodynamically stable, a rapid bowel perforation (over 4-6 hours) can be performed to allow colonoscopy
Colonoscopy may identify the cause of the bleeding, and cautery or injection of epinephrine into the bleeding site may be used to control haemorrhage
Colectomy may be required of bleeding persists despite these interventions
Intraoperative colonoscopy and/or enteroscopy may assist in localizing bleeding. If colectomy is required, a segmental resection is preferred if the bleeding source can be localized. "Blind" subtotal colectomy may very rarely be required in a patient who is hemodynamically unstable with ongoing colonic hemorrhage of an unknown source. In this setting, it is crucial to irrigate the rectum and examine the mucosa by proctoscopy to ensure that the source of bleeding is not distal to the resection margin
Occult blood loss from the GI tract may manifest as iron-deficiency anemia or may be detected with FOBT. Because colon neoplasms bleed intermittently and rarely present with rapid hemorrhage, the presence of occult fecal blood should always prompt a colonoscopy. Unexplained iron-deficiency anemia is also an indication for colonoscopy.
Hematochezia commonly is caused by hemorrhoids or fissure. Sharp, knife-like pain and bright-red rectal bleeding with bowel movements suggest the diagnosis of fissure.
CONSTIPATION AND OBSTRUCTED DEFECATIONConstipation has a myriad of causes:
Underlying metabolic
Pharmacologic Endocrine Psychologic Neurologic causes often contribute to the problem
A stricture or mass lesion should be excluded by colonoscopy or barium enema. After these causes have been excluded, evaluation focuses on differentiating slow-transit constipation from outlet obstruction. Transit studies, in which radiopaque markers are swallowed and then followed radiographically, are useful for diagnosing slow-transit constipation.
Anorectal manometry and EMG can detect nonrelaxation of the puborectalis, which contributes to outlet obstruction. The absence of an anorectal inhibitory reflex suggests Hirschsprung's disease and may prompt a rectal mucosal biopsy.
Defecography can identify rectal prolapse, intussusception, rectocele, or enterocele.
Medical management is the mainstay of therapy for constipation and includes fiber, increased fluid intake, and laxatives. Outlet obstruction from nonrelaxation of the puborectalis often responds to biofeedback.Surgery to correct rectocele and rectal prolapse has a variable effect on symptoms of constipation, but can be successful in selected patients.
Subtotal colectomy is considered only for patients with severe slow-transit constipation (colonic inertia) refractory to maximal medical interventions. Although this operation almost always increases bowel movement frequency, complaints of diarrhea, incontinence, and abdominal pain are not infrequent, and patients should be carefully selected
DIARRHEA AND IRRITABLE BOWEL SYNDROMEDiarrhea is also a common complaint and is usually a
self-limited symptom of infectious gastroenteritis. If diarrhea is chronic or is accompanied by bleeding or abdominal pain, further investigation is warranted
Irritable bowel syndrome is a particularly troubling constellation of symptoms consisting OF Crampy abdominal pain Bloating Constipation Urgent diarrhea
GENERAL SURGICAL CONSIDERATIONS Anterior ResectionHigh Anterior resection
Low Anterior ResectionExtended Low Anterior Resection
Hartmann’s Procedure and Mucus FistulaAbdominoperineal Resection
Extent of resection for carcinoma of the colon. A.Cecal cancer. B. Hepatic flexure cancer. C. Transverse colon cancer. D. Splenic flexure
cancer. E. Descending colon cancer. F. Sigmoid colon cancer
INFLAMMATORY BOWEL DISEASEULCERATIVE COLITIS
Rare in FilipinosCommon in Caucasians esp in Jews
Page 5 of 8
I.4a – Colon, Rectum, and Anus (Lecture)
Non-specific, idiopathic mucosal inflammation of the colon and rectum
Usually begins at the rectum moving proximally by direct extension (mucosa and submucosa)
Inflammation stops at the ileocolic junctionBloody mucoid diarrhea, abdominal pain, tenesmus,
fever
TREATMENTSulfasalazine – 4g/day relapse rate 9%/yrRowasa – topical enema of 5-ASASteroids, azathioprine, cyclosporine, mercaptopurine,
tacrolimusTotal abdominal colectomy with end ileostomy
CROHN’S DISEASENonspecific, transmural inflammationExacerbation/remissionMouth to anus, bloody diarrheaExtraintestinal manifestationSkip lesion, rectal sparing (40%)Terminal ileum and cecum (41%), SI (35%)Fistula, abscess, obstruction, stricture
NEOPLASMS OF THE LARGE INTESTINEPOLYP
A grape-like protrusion of tissue into the bowel lumen Sessile Pedunculated: flat on the mucosal surface Epithelial or submucosal: has a stalk Non-neoplastic Neoplastic
NON-NEOPLASTIC POLYPHyperplastic JuvenilePeutz-Jegher Syndrome
NEOPLASTIC POLYPTubular adenomaVillous adenomaTubulovillous adenoma
FAMILIAL ADENOMATOUS POLYPOSISa general neoplastic disorder of the intestineaffected area: mainly large bowelother: stomach, duodenum, small intestinemost important thing: colorectal CA develops before age
40 in nearly all untreated patients inherited as a Mendelian dominant. The gene
responsible (APC gene) has now been identified on the short arm of chromosome 5
Males and Females equally affected
CLINICAL FEATURESSYMPTOMATIC
PATIENTSASYMPTOMATIC
PATIENTS Loose stool Lower abdominal painWeight lossDiarrheaPassage of blood and
mucus
Usually are diagnose during screening or incidentally
Polyps are usually visible on sigmoidoscopy by the age of 15 years and will almost always be visible by age 30
Carcinoma of the large bowel occurs 10-20 years after the onset of polyposis
SOME EXTRA-INTESTINAL MANIFESTATIONSBENIGN MALIGNANT
Endocrine adenomaOsteomaEpidermoid cystHypertrophic retinal
pigmentationMedulloblastoma
Duodenal carcinomaDesmoid tumorBile duct, pancreatic CACA stomach
TREATMENT
Restorative proctocolectomy with an ileoanal anastomosisNowadays more frequently used Indicated esp in cases:
With serious rectal involvement with polyps Who are likely to be poor at attending for follow up With an established cancer of the rectum or sigmoid
Colectomy with ileorectal anastomosisWas practiced in the past as usual operation because it
avoids ileostomy in a young patient
CARCINOMA COLON
INCIDENCE OF CANCER-PhilippinesMALE FEMALE
1. Lungs2. Liver3. Colon/Rectum4. Stomach5. Prostate
1. Breast2. Cervix/Uterus3. Colon/Rectum4. Lungs5. Thyroid6. Ovary7. Liver
PREDISPOSING FACTORS Low-fibre containing dietSmoked fishHigh content of refined carbohydrate in dietRed meat Less intake of micronutrients esp Selenium
PATHOLOGYMicroscopically
Columnar cell CA originating in the colonic epithelium
Macroscopically Tumor may take one of four forms Type 1 – Annular Type 2 – Tubular Type 3 – Acinar Type 4 – Cauliflower (is the least malignant form)
Spreading Local Lymphatic Hematogenous
CLINICAL FEATURESCA of the LEFT side of the colon:
Pain Alteration of bowel habit Palpable lump Distension
CA of the SIGMOID Pain Tenesmus Bladder symptoms
CA of the CECUM and ASCENDING colon: Anemia Lump in the right iliac fossa Acute appendicitis Intermittent obstruction
May present with features of metastasis Palpable liver Jaundice Ascites
INVESTIGATIONSDiagnostics
Endoscopy Sigmoidoscopy Colonoscopy With tissue biopsy
Radiology Double contrast barium enema - Shows irregular
filling defect Ultra-sonography - Liver metastasis CT Scan - Local invasion esp in Pelvis
TREATMENTPreoperative preparation:
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I.4a – Colon, Rectum, and Anus (Lecture)
General: Correction of anemia by blood Correction of nutritional imbalance Correction of electrolyte imbalance Resuscitation if there is intestinal obstruction,
perforationSpecial preparation:
Dietary restriction to fluids for 2 days before operation
Laxative Enema Prophylactic antibiotics
Operation: Laparotomy is done The tumor is assessed for resectibility by checking
involvement ino Livero Peritoneumo Local lymph nodeso Tumor itself for Mobility
In cases of operable cases: Operations are done to remove the primary tumor
and the draining lymph nodes Removal of the portion of colon surrounding the
tumor depends on the side of the original tumor
CA PROCEDURE1. CA of the cecum/ascending colon
Right hemicolectomy
2. CA of the hepatic flexure
Resection will be extended correspondingly
3. CA of the transverse colon
Excision of the transverse colon and the 2 flexures together with the transverse mesocolon and the 2 flexures together with the transverse mesocolon and the greater omentum followed by end to end anastomosis
Alternative: extended right hemicolectomy
4. CA of the splenic flexure or descending colon
Resection from right colon to descending colon
Sometimes removal of colon up to the ileum with an ileorectal anastomosis
In cases of INoperable cases: Palliative procedure is done
LOCATION OF GROWTH PROCEDURE1. Upper part left colon Transverse colostomy2. Pelvic colonic growth Left iliac fossa colostomy3. Ascending colon growth
By-pass ilio-colic anastomosis
ANORECTAL DISEASESHaemorrhoids Ischiorectal abscessFistula in anoFissure in anoWartsFournier’s gangreneForeign body
HEMORRHOIDAL DISEASEPrimary Locations
3-7-11 o’clock positions Left Lateral – Right Anterior – Right Posterior
Submucosal cushion contains venules, arterioles, smooth muscle fibers
Part of continence mechanismExcessive straining, increase abdominal pressure, hard
stoolsBleeding, thrombosis, prolapseExternal haemorrhoids distal to dentate line Internal haemorrhoids proximal to dentate lineExternal Skin Tag
Redundant fibrotic skin at the anal verge due to previous thrombosed external haemorrhoid of past operation
GRADINGGRADE DESCRIPTION
1. FIRST DEGREE Bulge into anal canal, prolapse beyond dentate line
2. SECOND DEGREE Prolapse through anus, reduce spontaneously
3. THIRD DEGREE Require manual reduction4. FOURTH DEGREE Cannot be reduced prone
to strangulation
MANAGEMENTMEDICAL SURGICAL
DietSitz bathSuppositories
Excision:Milligan MorganRubber Band LigationHarmonic Scalpel
ANAL FISSUREEtiology:
Passage of large hard stool Conditions (Crohn’s disease, ulcerative colitis,
syphilis, TB, leukemia)Manifestations
Burning pain during and after bowel movement Bright red blood on toilet paper
Diagnosis Rectal examination / proctosigmoidoscopy
TREATMENTCONSERVATIVE SURGICAL
Anal hygience/bulk forming agents
Hot sitz bath Local anesthetic jellyBotolinum
Lateral internal sphincterotomy (chronic stage)
ANORECTAL ABSCESS5 potential spaces
Perianal space Ischiorectal space Intersphincteric space Deep posterior anal space
Etiology: Infection or anal gland Organism (fecal and cutaneous flora)
1. E. coli2. Bacteroides fragilis3. Staphylococcus4. Stretptococcus5. Clostridium sp.
Manifestation Pain in the anal region
Treatment Drainage/antibiotic Hygiene Hot sitz bath
TYPES OF ANORECTAL ABSCESS1. Perianal abscess2. Ischiorectal abscess
Diffuse swelling of ischio-rectal fossa3. Intersphincteric abscess
No apparent sign of swelling or induration in the perianal area
CLUE: deep seated tenderness when circumanal pressure is applied above the dentate line
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I.4a – Colon, Rectum, and Anus (Lecture)
Drainage: through the anal canal lining or through internal sphincteric muscle
4. Supralevator abscess Uncommon Mimic acute intra-abdominal condition Etiology: extension ofo Intersphincteric abscesso Ischiorectal abscesso Intra-abdominal abscess
NECROTIZING PERI-ANAL & PERINEAL INFECTIONEtiology:
Neglected or delayed treatment of primary anorectal infection
Extension of UTI particularly the periurethral glandManifestation
Pain, tenderness, and swelling with crepitation of perianal and scrotum or labia
Black spot on the site (necrosis)Treatment
Broad spectrum antibiotics Debridement Hyperalimentation/diverting colostomy and/or
cystostomy
FISTULA-IN-ANO Inflammatory tract with secondary opening (external)
and a primary opening (internal) in the anal canalEtiology:
Complication of perianal abscessClassification:
Inter-sphincteric Trans-sphincteric Supra-sphincteric Extra-sphincteric
Salmon Goodsalls Rule To locate the internal opening Anterior – straight tracts Posterior – curved tracts Exception: >3 cm curved
Manifestation: Previous history of perianal abscess Rule out ulcerative colitis and Crohn’s disease
(colonoscopy/barium enema)Treatment:
Identify the primary opening (probing/methylene blue/fistulography)
Fistulotomy/fistulectomy (healing by secondary intention)
If fistula is high in relation to anorectal ring, do a 2 stage procedure:1. Insert a seton wire or suture to the tract for
several weeks to create fibrosis2. Open the fibrous tract on the second stage after
6-8 weeks
-END-
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