SURGERY_1.5 Colon, Rectum, and Anus (Lecture).docx

I.5 – Colon, Rectum, and Anus (Lecture) Dr. Mata June 9, 2013 EMBROYOLOGY  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 MIDGUT  Develops 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 MIDGUT  Develops 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 CANAL  derived 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

Suzie, Robz, Gemmy

HEPATIC FLEXURE  located under the 9th and 10th costal cartilages in the vicinity of midaxillary line  gallbladder is located anteriorly  duodenum is located posteriorly ASCENDING COLON  The ascending limb of the right colon is fused to the posterior body wall and covered by the peritoneum  Fused variations  Deep lateral paracolic groove to the persistence of an entire ascending mesocolon TRANSVERSE COLON  The transverse colon hangs in a U or V-shaped curve  The transverse mesocolon is formed by a double peritoneal fold  The 2 are fused at “X” to form the transverse mesocolon containing the middle colic artery and vein DESCENDING COLON  Covered anteriorly and on its medial and lateral sides by peritoneum  Has no mesentery  Mobilization of the ascending colon is accomplished by incising the peritoneal reflection at the left gutter along the “white line of Told” SIGMOID – S shaped  2 portions  Iliac portion – fixed and located at the left iliac fossa  Pelvic portion – mobile  Begins at the iliac crests and ends at the 3rd sacral vertebra RECTUM  The 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 rectum  Posteriorly, the presacral fascia separates the rectum from the presacral venous plexus and pelvic nerves  At 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 Page 1 of 8

 With infection, this may become filled with pus

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SPACES OF THE ANUS AND RECTUM Pelvirectal space Ischioanal (ischiorectal) space Intersphincteric spaces Subcutaneous space Central space Submucousspace PERITONEAL LOCATIONS

Figure 2. Peritoneal Locations ARTERIAL SUPPLY OF THE COLON

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 POINT  Sudeck 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 SUPPLY  One is the intramural network of arteries in the submucosal layer of the wall and the other is from collaterals  Branches of the inferior vesical artery  Arteries supplying the levator ani muscle  The middle sacral artery  The posterior retroperitoneal arterial plexus uniting the parietal and visceral circulation  The inferior rectal artery is responsible for the arterial blood supply of the distal 2 cm of the anal canal MARGINAL ARTERY OF DRUMMOND  Composed 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 vessel  Runs parallel, 1-8 cm from the intestinal wall

Figure 3. Arterial Supply of the colon

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SMA BRANCHES TO THE COLON Middle colic artery Right colic artery Ileocolic artery Meandering Artery of Riolan – communicating between Middle colic and IMA MEANDERING ARTERY OF RIOLAN

*blue arrows SMA

MEANDERING ARTERY OF RIOLAN  The 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 RECTUM  Unpaired superior rectal artery  Right and left branches  Middle rectal artery  Dosro-caudal area  Inferior rectal artery  Ventral and medial  Medial sacral artery  Posterior wall VENOUS DRAINAGE OF THE COLON

*blue arrows I.4a – Colon, Rectum, and Anus (Lecture)

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VENOUS DRAINAGE OF THE RECTUM Portal system Superior rectal vein Systemic system Middle rectal vein Inferior rectal vein  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 DRAINAGE  Epicolic  Under the serosa of the wall of the intestine  Paracolic  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 system  Myenteric plexus  Auerbach  Submucosa plexus  Meissner  Controls secretions Table 1. Right vs Left Colon RIGHT COLON LEFT COLON  Sympathetic: L1, 2, 3  Sympathetic: lower 6 lumbar splanchnic nerves thoracic segments of the to the aortic plexus and spinal cord the inferior mesenteric plexus  Parasympathetic: vagal  Parasympathetic – pelvic fibers from the posterior splanchnic nerves S2, 3, 4 trunk

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PHYSIOLOGY The colon is a major site for water absorption and electrolyte exchange Approximately 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 channel Chloride is absorbed actively via a chloride-bicarbonate exchange

SHORT-CHAIN FATTY ACIDS  Short-chain fatty acids are important sources of energy for the colonic mucosa, and metabolism by I.4a – Colon, Rectum, and Anus (Lecture)

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 amplitude  Low-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” DEFECATION  a 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 intraabdominal pressure via  the Valsalva Maneuver  increased rectal contraction  relaxation of the puborectalis muscle  opening of the anal canal CLINICAL EVALUATION  a 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 ENDOSCOPY  Anoscopy  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 STUDIES  Plain X-rays and Contrast Studies  Computed Tomography  Virtual Colonoscopy Page 3 of 8

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Magnetic Resonance Imaging Positron Emission Tomography Angiography Edorectal and Edoanal Ultrasound PHYSIOLOGIC AND PELVIC FLOOR INVESTIGATIONS Anorectal physiologic testing uses a variety of techniques to investigate the function of the pelvic floor These techniques are useful in the evaluation of patients with incontinence, constipation, rectal prolapse, obstructed defecation, and other disorders of the pelvic floor Manometry Neurophysiology Rectal Evacuation Studies

MANOMETRY  Performed by placing a pressure-sensitive catheter in the lower rectum  Catheter is then withdrawn through the anal canal and pressures recorded  A balloon attached to the tip of the catheter also can be used to test anorectal sensation  The 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 TESTING  Assesses function of the pudendal nerves and recruitment of puborectalis muscle fibers  Pudendal 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 defecography  BALLOON 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 STUDIES  Fecal Occult Blood Testing  Stool Studies I.4a – Colon, Rectum, and Anus (Lecture)

 Serum Tests  Tumor Markers  Genetic Testing FECAL OCCULT BLOOD TESTING  FOBT is used as a screening test for colonic neoplasms in asymptomatic, average-risk individuals  The 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

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STOOL STUDIES Are often helpful in evaluating the etiology of diarrhea Wet-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 TESTS  Specific laboratory tests that should be performed will be dictated by the clinical scenario  Preoperative studies generally include CBC and electrolyte panel  The 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 MARKERS  Carcinoembryonic antigen (CEA) may be elevated in 60-90% of patients with colorectal cancer  Despite this, CEA is NOT an effective screening tool for this malignancy  Many 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 TESTING  Although 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 SYMPTOMS ABDOMINAL PAIN  A nonspecific symptom with a myriad of causes

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 Pain 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 PAIN  Can originate from the distal colon and rectum or from adjacent urogenital structures  Tenesmus may result from proctitis or from a rectal or rectrorectal mass  Cyclical 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  Proctoscopy (if tolerated) also can be helpful  Occasionally, laparoscopy will yield diagnosis ANORECTAL PAIN  Most often secondary to an anal fissure or perirectal abscess and/or fistula  PE can usually differentiate these conditions  Other less common causes:  Anal canal neoplasms  Perianal skin infection  Dermatologic conditions  Proctalgiafugax–results from levator spasm and may present without any other anorectal findings  PE is critical in evaluating patients with anorectal pain  If a patient is too tender to examine in the office, an examination under anesthesia is necessary  MRI may be helpful in select cases where the etiology of pain is elusive LOWER GI BLEEDING  The first goal in evaluating and treating a patient with GI haemorrhage is adequate resuscitation  The 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 I.4a – Colon, Rectum, and Anus (Lecture)

 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 DEFECATION  Constipation 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 SYNDROME  Diarrhea 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 Resection High Anterior resection Low Anterior Resection Extended Low Anterior Resection Page 5 of 8

Hartmann’s Procedure and Mucus Fistula Abdominoperineal Resection

 most 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 FEATURES SYMPTOMATIC PATIENTS  Loose stool  Lower abdominal pain  Weight loss  Diarrhea  Passage of blood and mucus

ASYMPTOMATIC PATIENTS  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 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

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INFLAMMATORY BOWEL DISEASE ULCERATIVE COLITIS Rare in Filipinos Common in Caucasians esp in Jews 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 junction Bloody mucoid diarrhea, abdominal pain, tenesmus, fever

TREATMENT  Sulfasalazine – 4g/day relapse rate 9%/yr  Rowasa – topical enema of 5-ASA  Steroids, azathioprine, cyclosporine, mercaptopurine, tacrolimus  Total abdominal colectomy with end ileostomy       

CROHN’S DISEASE Nonspecific, transmural inflammation Exacerbation/remission Mouth to anus, bloody diarrhea Extraintestinal manifestation Skip lesion, rectal sparing (40%) Terminal ileum and cecum (41%), SI (35%) Fistula, abscess, obstruction, stricture

NEOPLASMS OF THE LARGE INTESTINE POLYP  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 POLYP  Hyperplastic  Juvenile  Peutz-Jegher Syndrome NEOPLASTIC POLYP  Tubular adenoma  Villous adenoma  Tubulovillous adenoma FAMILIAL ADENOMATOUS POLYPOSIS  a general neoplastic disorder of the intestine  affected area: mainly large bowel  other: stomach, duodenum, small intestine

I.4a – Colon, Rectum, and Anus (Lecture)

SOME EXTRA-INTESTINAL MANIFESTATIONS BENIGN MALIGNANT  Endocrine adenoma  Duodenal carcinoma  Osteoma  Desmoid tumor  Epidermoid cyst  Bile duct, pancreatic CA  Hypertrophic retinal  CA stomach pigmentation  Medulloblastoma TREATMENT Restorative proctocolectomy with an ileoanal anastomosis  Nowadays 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 anastomosis  Was practiced in the past as usual operation because it avoids ileostomy in a young patient CARCINOMA COLON INCIDENCE OF CANCER-Philippines MALE FEMALE 1. Lungs 1. Breast 2. Liver 2. Cervix/Uterus 3. Colon/Rectum 3. Colon/Rectum 4. Stomach 4. Lungs 5. Prostate 5. Thyroid 6. Ovary 7. Liver

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PREDISPOSING FACTORS Low-fibre containing diet Smoked fish High content of refined carbohydrate in diet Red meat Less intake of micronutrients esp Selenium

PATHOLOGY  Microscopically  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 Page 6 of 8

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CLINICAL FEATURES CA 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 INVESTIGATIONS

 Diagnostics  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 TREATMENT Preoperative preparation:  General:  Correction of anemia by blood  Correction of nutritional imbalance  Correction of electrolyte imbalance  Resuscitation if there is intestinal obstruction, perforation  Special 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 in o Liver o Peritoneum o Local lymph nodes o 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 1. CA of the cecum/ascending colon 2. CA of the hepatic flexure 3. CA of the transverse colon

PROCEDURE  Right hemicolectomy  Resection will be extended correspondingly  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

I.4a – Colon, Rectum, and Anus (Lecture)

 Alternative: extended right hemicolectomy 4. CA of the splenic flexure  Resection from right colon or descending 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 PROCEDURE 1. Upper part left colon  Transverse colostomy 2. Pelvic colonic growth  Left iliac fossa colostomy 3. Ascending colon growth  By-pass ilio-colic anastomosis

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ANORECTAL DISEASES Haemorrhoids Ischiorectal abscess Fistula in ano Fissure in ano Warts Fournier’s gangrene Foreign body

HEMORRHOIDAL DISEASE  Primary Locations  3-7-11 o’clock positions  Left Lateral – Right Anterior – Right Posterior

 Submucosal cushion contains venules, arterioles, smooth muscle fibers  Part of continence mechanism  Excessive straining, increase abdominal pressure, hard stools  Bleeding, thrombosis, prolapse  External haemorrhoids distal to dentate line  Internal haemorrhoids proximal to dentate line  External Skin Tag  Redundant fibrotic skin at the anal verge due to previous thrombosed external haemorrhoid of past operation GRADING GRADE 1. FIRST DEGREE 2. SECOND DEGREE 3. THIRD DEGREE 4. FOURTH DEGREE

DESCRIPTION  Bulge into anal canal, prolapse beyond dentate line  Prolapse through anus, reduce spontaneously  Require manual reduction  Cannot be reduced prone to strangulation MANAGEMENT

MEDICAL  Diet  Sitz bath  Suppositories

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SURGICAL Excision: Milligan Morgan Rubber Band Ligation Harmonic Scalpel

ANAL FISSURE  Etiology:  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 Page 7 of 8

 Rectal examination / proctosigmoidoscopy

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 Posterior – curved tracts  Exception: >3 cm curved

TREATMENT CONSERVATIVE SURGICAL Anal hygience/bulk  Lateral internal forming agents sphincterotomy (chronic Hot sitz bath stage) Local anesthetic jelly Botolinum

ANORECTAL ABSCESS  5 potential spaces  Perianal space  Ischiorectal space  Intersphincteric space  Deep posterior anal space  Etiology:  Infection or anal gland  Organism (fecal and cutaneous flora) 1. E. coli 2. Bacteroides fragilis 3. Staphylococcus 4. Stretptococcus 5. Clostridium sp.  Manifestation  Pain in the anal region  Treatment  Drainage/antibiotic  Hygiene  Hot sitz bath TYPES OF ANORECTAL ABSCESS 1. Perianal abscess 2. Ischiorectal abscess  Diffuse swelling of ischio-rectal fossa 3. 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  Drainage: through the anal canal lining or through internal sphincteric muscle 4. Supralevator abscess  Uncommon  Mimic acute intra-abdominal condition  Etiology: extension of o Intersphincteric abscess o Ischiorectal abscess o Intra-abdominal abscess

 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 fibrosis 2. Open the fibrous tract on the second stage after 6-8 weeks

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NECROTIZING PERI-ANAL & PERINEAL INFECTION  Etiology:  Neglected or delayed treatment of primary anorectal infection  Extension of UTI particularly the periurethral gland  Manifestation  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 canal  Etiology:  Complication of perianal abscess  Classification:  Inter-sphincteric  Trans-sphincteric  Supra-sphincteric  Extra-sphincteric  Salmon Goodsalls Rule  To locate the internal opening  Anterior – straight tracts I.4a – Colon, Rectum, and Anus (Lecture)

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