Surgery II: Colon, Rectum, & Anus PDF

**OUTLINE** I. **Anatomy** II. **Colon Pathology** III. **General Surgical Consideration** IV. **Clinical Evaluation** V. **Inflammatory Bowel Disease** VI. **Diverticular Disease** VII. **Adenocarcinoma and Polyps** VIII. **Other Neoplasm** IX. **Colon Conditions of Infectious Origin**...

**OUTLINE** I. **Anatomy** II. **Colon Pathology** III. **General Surgical Consideration** IV. **Clinical Evaluation** V. **Inflammatory Bowel Disease** VI. **Diverticular Disease** VII. **Adenocarcinoma and Polyps** VIII. **Other Neoplasm** IX. **Colon Conditions of Infectious Origin** X. **Anorectal Disease** XI. **Review Questions** XII. **References** XIII. **Appendix** +-----------------------+-----------------------+-----------------------+ | **LEGEND** | | | +=======================+=======================+=======================+ | ⭐ | 🖊️ | 📖 | | | | | | Must | Lecture | Book | | | | | | Know | *\[lec\]* | *\[bk\]* | +-----------------------+-----------------------+-----------------------+ I. ANATOMY {#i.-anatomy.TransOutline} ========== A. COLON AND VASCULAR SUPPLY {#a.-colon-and-vascular-supply.TransSubtopic1} ---------------------------- - The arterial supply of the colon is highly variable. A diagram of the human body Description automatically generated **Figure 1. Vascular Supply** *(Source: © Lecture)* {#section.TransSub-subtopic2} SUPERIOR MESENTRIC ARTERY {#superior-mesentric-artery.TransSub-subtopic2} ------------------------- Branches into ileocolic artery - **Ileocolic Artery** a. Supplies the terminal ileum and proximal ascending colon - **Right Colic Artery** b. Supplies the ascending colon - **Middle Colic Artery** c. Supplies the transverse colon INFERIOR MESENTRIC ARTERY {#inferior-mesentric-artery.TransSub-subtopic2} ------------------------- Branches into left colic artery - **Left Colic Artery** - Supplies the descending colon - **Sigmoidal Branches** - Supplies the sigmoid colon - **Superior Rectal Artery** - Supplies the proximal rectum MARGINAL ARTERY OF DRUMMOND {#marginal-artery-of-drummond.TransSub-subtopic2} --------------------------- - Terminal branches of each artery form anastomose with the terminal branches of the adjacent artery and communicate via the Marginal Artery of Drummond. INFERIOR MESENTERIC VEIN {#inferior-mesenteric-vein.TransSub-subtopic2} ------------------------ - Ascends in the retroperitoneal plane over the psoas muscle - Continues posterior to the pancreas to join the splenic vein. - During a colectomy: - This vein is often mobilized independently and ligated at the inferior edge of the pancreas.  **Figure 2. Venous Drainage of the Colon** *(Source: © Lecture)* B. LYMPHATIC DRAINAGE {#b.-lymphatic-drainage.TransSubtopic1} --------------------- - Lymphatic drainage of the colon originates in a network of lymphatics in the **MUSCULARIS MUCOSA.** - Lymphatic vessels and lymph nodes follow the regional arteries. - Lymph nodes are found on the: - Epicolic - Bowel Wall - Paracolic - Adjacent to the arterial arcades - Intermediate - Around the mesenteric vessels - Main - At the origin of the superior and inferior mesenteric arteries C. ANAL CANAL {#c.-anal-canal.TransSubtopic1} ------------- - Anatomic anal canal extends from the dentate or pectinate line to the anal verge. - The dentate or pectinate line marks the transition point between columnar rectal mucosa and squamous anoderm. - Lymphatic drainage ABOVE the Dentate Line lead toward the portal circulation. - BELOW the dentate line, blood drains toward the inferior mesenteric vein. - The margin BELOW the Dentate Line (ANODERM) is rich in sensory nerve endings - Causes extreme pain in cases of external hemorrhoids A diagram of the human body Description automatically generated **Figure 3. Anal Canal** *(Source: © Lecture)* D. RECTUM {#d.-rectum.TransSubtopic1} --------- - The rectum is **12-15 cm in length** - Valves of Houston are 3 distinct submucosal folds which extend into the rectal lumen. - - Found posteriorly - Which separates rectum from the presacral venous plexus and the pelvic nerves - **Denonvillier's Fascia** - Found anteriorly - Which separates the rectum from the prostate and seminal vesicles in men and from the vagina in women. - **Waldeyer's Fascia (Retrosacral Fascia)** - Found at S4 - Extends forward and downward and attaches to the fascia propria at the anorectal junction E. ANORECTAL BLOOD SUPPLY {#e.-anorectal-blood-supply.TransSubtopic1} ------------------------- +-----------------------------------+-----------------------------------+ | **Table 1. Anorectal Blood | | | Supply** | | +===================================+===================================+ | **SUPERIOR RECTAL ARTERY** | - - | +-----------------------------------+-----------------------------------+ | **MIDDLE RECTAL ARTERY** | - | +-----------------------------------+-----------------------------------+ | **INFERIOR RECTAL ARTERY** | - - | +-----------------------------------+-----------------------------------+ - A rich network of collaterals connects the terminal arterioles of each of these arteries making the rectum relatively resistant to ischemia.  **Figure 4. Anorectal Blood Supply** *(Source: © Lecture)* II. COLON PATHOLOGIES {#ii.-colon-pathologies.TransOutline} ===================== - Perturbation of the embryologic development of the midgut and hindgut may result in anatomic abnormalities of the colon, rectum, and anus. - **Failure of the midgut to rotate** and return to the abdominal cavity during the tenth week of gestation results to **INTESTINAL MALROTATION** and **COLONIC NON-FIXATION**. - COLONIC DUPLICATION - Failure of canalization of the primitive gut - **Incomplete descent of the urogenital septum** may result in **IMPERFORATE ANUS** and associated **FISTULAS TO THE GENITOURINARY TRACT.** A. LOWER GI BLEEDING {#a.-lower-gi-bleeding.TransSubtopic1} -------------------- - A physician must be objective in evaluating the quantity of blood that has been expelled in cases of lower GI bleeding. - Usually in GI malignancies, bleeding is not massive. It is usually more of an occult type of bleeding. - Massive bleeding occurs if the tumor perforates into a feeding vessel. - Typically, patients with **GI malignancies** presents clinically in the form of chronic bleeding -- **anemia** A diagram of a flowchart Description automatically generated **Figure 5. Approach to Lower GI bleeding** (**see Appendix A**) *(Source: © Lecture)* III. GENERAL SURGICAL CONSIDERATIONS {#iii.-general-surgical-considerations.TransOutline} ==================================== - Colorectal resections are performed for a wide variety of conditions, including neoplasms (benign and malignant), inflammatory bowel diseases, and other benign conditions. A. EXTENT OF RESECTION {#a.-extent-of-resection.TransSubtopic1} ---------------------- - Curative resection of a colorectal cancer is usually best accomplished by performing a proximal mesenteric vessel ligation and radical mesenteric clearance of the lymphatic drainage basin of the tumor site. - Resection of a benign process does not require wide mesenteric clearance. - **Emergency resection** - - **Minimally Invasive Techniques of Resection** - - **Ileocolic Resection** - - RIGHT HEMICOLECTOMY {#right-hemicolectomy.TransSub-subtopic2} ------------------- - A right colectomy is used to remove lesions or disease in the right colon - Oncologically the most appropriate operation for curative intent resection of proximal colon carcinoma. - **Ileocolic vessels**, **right colic vessels**, and **right branches** of the **middle colic vessels** are **ligated and divided**. - Approximately **10 cm of terminal ileum** are usually included in the resection. - A primary ileal-transverse colon anastomosis is almost always possible. +-----------------------------------+-----------------------------------+ | What we cut in right | - - - - - | | hemicolectomy: | | | | Extent of resection for carcinoma | |  | of the colon: **CECAL CANCER** | +-----------------------------------+-----------------------------------+ EXTENDED RIGHT HEMICOLECTOMY {#extended-right-hemicolectomy.TransSub-subtopic2} ---------------------------- +-----------------------------------+-----------------------------------+ | | - - - - | | | | | | Extent of resection for carcinoma | | | of colon: **HEPATIC FLEXURE** | +-----------------------------------+-----------------------------------+ TRANSVERSE COLECTOMY {#transverse-colectomy.TransSub-subtopic2} -------------------- +-----------------------------------+-----------------------------------+ |  | Lesions in the mid and distal | | | transverse colon may be resected | | | by: | | | | | | - Ligating the middle colic | | | vessels a resecting the | | | transverse colon | | | | | | - Followed by colonic | | | anastomosis. | | | | | | Extent of resection for carcinoma | | | of colon: **TRANSVERSE COLON | | | CANCER** | +-----------------------------------+-----------------------------------+ SEGMENTAL RESECTION SPLENIC FLEXURE {#segmental-resection-splenic-flexure.TransSub-subtopic2} ----------------------------------- +-----------------------------------+-----------------------------------+ | | - For lesions or disease states | | | confined to the distal | | | transverse colon, splenic | | | flexure, or descending colon, | | | a left colectomy is | | | performed. | | | | | | - The left branches of the | | | middle colic vessels, the | | | left colic vessels, and the | | | first branches of the sigmoid | | | vessels are ligated. | | | | | | - A colocolonic anastomosis can | | | usually be performed. | | | | | | Extent of resection for carcinoma | | | of colon: **SPLENIC FLEXURE | | | CANCER** | +-----------------------------------+-----------------------------------+ LEFT HEMICOLECTOMY {#left-hemicolectomy.TransSub-subtopic2} ------------------ +-----------------------------------+-----------------------------------+ |  | An extended left hemicolectomy | | | | | | - An option for distal | | | transverse colon. | | | | | | - The left colectomy is | | | extended proximally to | | | include the right branches of | | | the middle colic vessels. | | | | | | Extent of resection for carcinoma | | | of colon: **DESCENDING COLON | | | CANCER** | +-----------------------------------+-----------------------------------+ SEGMENTAL SIGMOID RESECTION {#segmental-sigmoid-resection.TransSub-subtopic2} --------------------------- +-----------------------------------+-----------------------------------+ | | - Lesions in the sigmoid colon | | | require ligation and division | | | of the sigmoid branches of | | | the inferior mesenteric | | | artery. | | | | | | - The entire sigmoid colon | | | should be resected to the | | | level of the peritoneal | | | reflection and an anastomosis | | | created between the | | | descending colon and upper | | | rectum. | | | | | | - Full mobilization of the | | | splenic flexure is often | | | required to create a | | | tension-free anastomosis. | | | | | | - reserved for individuals who | | | are not fit Low anterior | | | resection | | | | | | - Normally for the distal | | | sigmoid and proximal rectal | | | tumors. | +-----------------------------------+-----------------------------------+ B. TYPES OF COLORECTAL RESECTION {#b.-types-of-colorectal-resection.TransSubtopic1} -------------------------------- - Ileocectomy - Ascending Colectomy - Right Hemicolectomy - Extended Right Hemicolectomy - Transverse Colectomy - Left Hemicolectomy - Extended Left Hemicolectomy - Sigmoid Colectomy SUBTOTAL COLECTOMY AND TOTAL COLECTOMY {#subtotal-colectomy-and-total-colectomy.TransSub-subtopic2} -------------------------------------- - Total or subtotal colectomy is occasionally required for patients w/: - Fulminant colitis - Attenuated FAP - Synchronous colon carcinomas - In this procedure, the ileocolic vessels, right colic vessels, middle colic vessels, and left colic vessels are ligated and divided. - The superior rectal vessels are preserved. TOTAL PROCTOCOLECTOMY {#total-proctocolectomy.TransSub-subtopic2} --------------------- - The entire colon, rectum, and anus are removed, and the ileum is brought to the skin as a **BROOKE ILEOSTOMY**. ANTERIOR RESECTION {#anterior-resection.TransSub-subtopic2} ------------------ - General term used to describe resection of the rectum from an abdominal approach to the pelvis with no need for a perineal, sacral, or other **Table 2. Types of Anterior Resection** ------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Type** **Description** **HIGH ANTERIOR RESECTION** Resection of the distal sigmoid colon and upper rectum is the appropriate operation for benign lesions and disease at the rectosigmoid junction such as diverticulitis. **LOW ANTERIOR RESECTION** Used to remove lesions in the upper and mid rectum. **EXTENDED LOW RESECTION** Used to remove lesions located in the distal rectum, but several centimeters above the sphincter.  **Figure 6. Low anterior resection (Upper left: Posterior mesorectum; Upper right: Anterior mesorectum; Bottom: Sigmoid, rectum and T2 mass)** *(Source: © Lecture)* HARTMAN'S PROCEDURE {#hartmans-procedure.TransSub-subtopic2} ------------------- - Colon or rectal resection without an anastomosis in which a colostomy or ileostomy is created. - The distal colon or rectum is left as a blind pouch. ABDOMINAL PERINEAL RESECTION {#abdominal-perineal-resection.TransSub-subtopic2} ---------------------------- - Involves removal of the entire rectum, anal canal, and anus with construction of a permanent colostomy from the descending or sigmoid colon. COLECTOMY {#colectomy.TransSub-subtopic2} --------- **Table 3. Terminology Of Types Of Colorectal Resections** ------------------------------------------------------------ ------------------------------ A → C Ileocecectomy A + B → D Ascending colectomy A + B → F Right hemicolectomy A + B → G Extended right hemicolectomy E + F → G + H Transverse colectomy G → I Left hemicolectomy F → I Extended left hemicolectomy J + K Sigmoid colectomy A + B → J Subtotal colectomy A + B → K Total colectomy A + B → L Total proctocolectomy C. TYPES OF ANASTOMOSES {#c.-types-of-anastomoses.TransSubtopic1} ----------------------- - Anastomoses may be created between two segments of bowel in a multitude of ways. - The geometry of the anastomosis may be: - End-to-end - End-to-side - Side-to- end - Side-to-side - The anastomotic technique may be hand-sewn or stapled. - The submucosal layer of the intestine provides the strength of the bowel wall and must be incorporated in the anastomosis to assure healing. - The choice of anastomosis depends on the operative anatomy and surgeon preference. +-----------------------------------+-----------------------------------+ | **Table 4. Types of Anastomoses** | | +===================================+===================================+ | **End-to-end** | - An end-to-end anastomosis can | | | be performed when two | |  | segments of bowel are roughly | | | the same caliber. | | | | | | - This technique is most often | | | employed in rectal resections | | | but may be used for | | | colocolostomy or small bowel | | | anastomoses. | +-----------------------------------+-----------------------------------+ | **End-to-side** | - Useful when one limb of bowel | | | is larger than the other. | | | | | | - This most commonly occurs in | | | the setting of chronic | | | obstruction. | +-----------------------------------+-----------------------------------+ | **Side-to-Side** | - Allows a large, | | | well-vascularized connection | |  | to be created on the | | | antimesenteric side of two | | | segments of intestine. | | | | | | - This technique is commonly | | | used in ileocolic and small | | | bowel anastomoses. | +-----------------------------------+-----------------------------------+ D. TECHNIQUES OF ANASTOMOSES {#d.-techniques-of-anastomoses.TransSubtopic1} ---------------------------- HAND SEWN {#hand-sewn.TransSub-subtopic2} --------- Hand-sutured anastomoses - **SINGLE LAYER** - Running stiches or Interrupted stitches - **DOUBLE LAYER** - Continuous inner layer or Interrupted outer layer - **Suture material** - Permanent or Absorbable. - After distal rectal or anal canal resection, a trans-anal, hand-sewn coloanal anastomosis may be necessary to restore bowel continuity. - This can be done in conjunction with an anal canal mucosectomy to allow the anastomosis to be created at the dentate line STAPLED {#stapled.TransSub-subtopic2} ------- - Linear cutting/stapling devices are used to divide the bowel and to create side-to-side anastomoses. - The anastomosis may be reinforced with interrupted sutures if desired. - Circular cutting/stapling devices can create end-to-end, end-to-side, or side-to-end anastomoses. - These instruments are particularly useful for creating low rectal or anal canal anastomoses where the anatomy of the pelvis makes a hand-sewn anastomosis technically difficult or impossible. #### PROCEDURE {#procedure.TransSub-subtopic3} **A**. The patient is in a modified lithotomy position. **B**. After resection of the rectosigmoid and placement of purse- string sutures proximally and distally, the stapler is inserted into the anal canal and opened. **C**. Rectal purse-string suture is tied to secure the rectal stump to the rod of the stapler, and the colonic purse-string is tied to secure the colon to the anvil of the stapler. **D**. The stapler is closed and fired. **E**. The stapler is removed, leaving a circular stapled end-to-end anastomosis E. OSTOMIES {#e.-ostomies.TransSubtopic1} ----------- - Stoma May be temporary or permanent. It may be end- on or a loop. - *Done usually during emergencies that causes the procedure to be aborted. What we do here is we take out the proximal bowel and we put it back in place after some time* ILEOSTOMY {#ileostomy.TransSub-subtopic2} --------- +-----------------------------------+-----------------------------------+ | **Table 5. Ileostomy** | | +===================================+===================================+ | **Temporary Ileostomy** | **Permanent Ileostomy** | +-----------------------------------+-----------------------------------+ | - A temporary ileostomy is | - A permanent ileostomy is | | often used to "protect" an | sometimes required after | | anastomosis that is at risk | total proctocolectomy or in | | for leakage (low in the | patients with obstruction. | | rectum, in an irradiated | | | field, in an | - The end of the small | | immunocompromised or | intestine is brought through | | malnourished patient, and | the abdominal wall defect and | | during some emergency | matured | | operations). | | | | | | - A segment of distal ileum is | | | brought through the defect in | | | the abdominal wall as a loop. | | +-----------------------------------+-----------------------------------+ | **Complications of Ileostomy** | | +-----------------------------------+-----------------------------------+ | - **Early** complications | | | | | | | | | | | | - - - - | | | | | | | | | | | | - **Late** complications | | | | | | | | | | | | - - - | | +-----------------------------------+-----------------------------------+ BROOKE ILEOSTOMY {#brooke-ileostomy.TransSub-subtopic2} ---------------- +-----------------------------------+-----------------------------------+ | **Table 6. Figure Review** | | +===================================+===================================+ | | *A.* Four sutures incorporating | | | the cut end of the ileum, the | | | seromuscular layer at the level | | | of the anterior rectus fascia, | | | and the subcuticular edge of the | | | skin are placed at 90° to each | | | other. | | | | | | *B.* The sutures are tied to | | | produce stomal eversion | | | | | | *C*. Simple sutures from the cut | | | edge of the bowel to the | | | subcuticular tissue complete the | | | maturation of the ileostomy. | +-----------------------------------+-----------------------------------+ COLOSTOMY {#colostomy.TransSub-subtopic2} --------- +-----------------------------------+-----------------------------------+ | **Table 7. Colostomy** | | +===================================+===================================+ | **Temporary Colostomy** | - **Loop** | | | | | | - - - | | | | | | - **End** | | | | | | - - - | | | | | | - **Mucus Fistula** | | | | | | - | | | | | | - **Double Barrel** | | | | | | - | +-----------------------------------+-----------------------------------+ | **Permanent Colostomy** | When permanent fecal diversion is | | | required, a colostomy is often | | | beneficial due to a decreased | | | risk for dehydration and | | | electrolyte abnormalities | | | associated with permanent | | | ileostomy, which is particularly | | | beneficial in older patients. | +-----------------------------------+-----------------------------------+ | **Complications of Ileostomy** | | +-----------------------------------+-----------------------------------+ | - **Colostomy necrosis** | | | | | | - | | | | | | - **Retraction** | | | | | | - | | | | | | - **Obstruction** | | | | | | - | | | | | | - **Parastomal hernia** | | | | | | - | | | | | | - **Prolapse** | | | | | | - | | | | | | - **Dehydration** | | | | | | - | | | | | | - **Skin irritation** | | | | | | - | | +-----------------------------------+-----------------------------------+ F. PREOPERATIVE PREPARATIONS {#f.-preoperative-preparations.TransSubtopic1} ---------------------------- - Preoperative preparation of a patient who is expected to require a stoma includes Enterostomal Therapy (ET) nurse consultation - Preoperative planning includes **Counseling, Education, & Stoma siting.** CHEMICAL PREPARATION (ANTIBIOTICS) {#chemical-preparation-antibiotics.TransSub-subtopic2} ---------------------------------- - Addition of oral antibiotics to the preoperative mechanical bowel preparation has been thought to decrease postoperative infection by further decreasing the bacterial load of the colon. MECHANICAL PREPARATION (BOWEL PREP) {#mechanical-preparation-bowel-prep.TransSub-subtopic2} ----------------------------------- - Decreasing the bacterial load in the colon and rectum will decrease the incidence of postoperative infection. - Uses cathartics to rid the colon of solid stool the night before surgery. The most used regimens include **Polyethylene Glycol (PEG) solutions or Magnesium Citrate*.*** - *Both are equally efficacious in bowel cleansing.* - *Usually, we don't use Castor oil. We use simple laxatives like Dulcolax (Bisacodyl)* STOMA SITE PLANNING {#stoma-site-planning.TransSub-subtopic2} ------------------- - Preoperative stoma sitting is crucial for a patient's postoperative function and quality of life - A poorly placed stoma can result in leakage and skin breakdown. Ideally, a stoma should be placed in a location that the patient can easily see and manipulate, within the rectus muscle, and below the belt line - *We place it within the rectus abdominis so that there will be muscular support -- achieving a small degree of continence.* URETERAL STENTS {#ureteral-stents.TransSub-subtopic2} --------------- - Useful for identifying the ureters intraoperatively and are placed via cystoscopy after induction of general anesthesia and removed at the end of the operation. - *Placed in cases of big tumors so that we may prevent ligation of the ureters* MULTIDISCIPLINARY TEAMS {#multidisciplinary-teams.TransSub-subtopic2} ----------------------- - *Team should include not only the surgeon but also the oncologist, radio-oncologist, depending on the type and stage of cancer you are treating.* IV. CLINICAL EVALUATION {#iv.-clinical-evaluation.TransOutline} ======================= A. ENDOSCOPY {#a.-endoscopy.TransSubtopic1} ------------ +-----------------------------------+-----------------------------------+ | **Table 8. Endoscopy** | | +===================================+===================================+ | **Endoscopy** | **Details** | +-----------------------------------+-----------------------------------+ | **Anoscopy** | - Most useful instrument for | | | examination of the anal canal | | | | | | | | | | | | - | | | | | | | | | | | | - **Larger Anoscope**: better | | | exposure for anal procedures | | | (such as rubber band ligation | | | or sclerotherapy of | | | hemorrhoids) | | | | | | - Procedure: | | | | | | | | | | | | - - | +-----------------------------------+-----------------------------------+ | | - Rigid Proctoscope is useful | | | for examination of the rectum | | | and distal sigmoid colon. | | | | | | - Occasionally used | | | therapeutically | | | | | | - Size | | | | | | | | | | | | - - - | | | | | | | | | | | | - **Suction**: necessary for an | | | adequate proctoscopic | | | examination. | +-----------------------------------+-----------------------------------+ | | - Video or fiber-optic flexible | | | sigmoidoscopy and colonoscopy | | | provide excellent | | | visualization of the colon | | | and rectum | | | | | | - Both can be used | | | diagnostically and | | | therapeutically | | | | | | - **Sigmoidoscopy** | | | | | | - - | | | | | | - **Colonoscopy**: | | | | | | | | | | | | - - - | | | | | | | | | | | | - **Diagnostic Colonoscopies** | | | | | | - | | | | | | - **Therapeutic Colonoscopies** | | | | | | - | | | | | | - **Electrocautery** | | | | | | - | +-----------------------------------+-----------------------------------+ | | - Emerging endoscopy that uses | | | a small ingestible camera: | | | Largely been used to detect | | | small bowel lesions. | | | Suggested use for diagnosing | | | colorectal disease (although | | | utility in the evaluation of | | | colorectal disease remains | | | unproven). | | | | | | - Procedure: | | | | | | - | +-----------------------------------+-----------------------------------+  B. IMAGING {#b.-imaging.TransSubtopic1} ---------- PLAIN X-RAYS AND CONTRAST STUDIES {#plain-x-rays-and-contrast-studies.TransSub-subtopic2} --------------------------------- - Continue to play an important role in the evaluation of patients with suspected colon and rectal disease **Plain X-Rays of the abdomen** (supine, upright, and diaphragmatic views) for detecting free intra- abdominal air, bowel gas patterns suggestive of small or large bowel obstruction, and volvulus. **Contrast Studies** for evaluating obstructive symptoms, delineating fistulous tracts, and diagnosing small perforations or anastomotic leaks **Double-contrast barium enema** has been used as a back- up examination if colonoscopy is incomplete. **Gastrografin** cannot provide the mucosal detail provided barium; **\*\*recommended if perforation or leak is suspected.** Detection of small lesions can be extremely difficult, especially in a patient with extensive diverticulosis. For this reason, a colonoscopy is preferred for evaluating non-obstructing mass lesions in the colon. - Specificity/Sensitivity: Double-contrast barium enema: 70% to 90% sensitive for the detection of mass lesions greater than 1cm in diameter ANGIOGRAPHY {#angiography.TransSub-subtopic2} ----------- Occasionally used for the detection of bleeding within the colon or small bowel. To visualize hemorrhage angiographically -- bleeding must be relatively brisk (approximately 0.5 to 1.0 mL per minute). Extravasation of contrast identified -- infusion of vasopressin or angiographic embolization can be therapeutic - ⭐**Best imaging modality to localize site of GI bleeding** ENDOGRAPHY AND ENDOANAL ULTRASOUND {#endography-and-endoanal-ultrasound.TransSub-subtopic2} ---------------------------------- Normal rectal wall -- appears as five-layer structure Ultrasound -- can reliably differentiate most benign polyps from invasive tumors based on the integrity of the submucosal layer. Can also differentiate superficial T1-T2 from deeper T3-T4 tumors. Also prove useful for early detection of local recurrence after surgery. - Specific Use: - Endorectal ultrasound: used to evaluate the depth of invasion of neoplastic lesions in the rectum. - Endoanal ultrasound: used to evaluate the layers of the anal canal. - ⭐REMEMBER: - **Endorectal: depth** - **Endoanal: layer** Differentiation of internal anal sphincter, external anal sphincter and puborectalis muscle. Particularly useful for detecting sphincter defects and for outlining complex anal fistulas. C. PHYSIOLOGIC AND PELVIC FLOOR INVESTIGATIONS {#c.-physiologic-and-pelvic-floor-investigations.TransSubtopic1} ---------------------------------------------- - 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 {#manometry.TransSub-subtopic2} --------- - ⭐Best diagnostic tool **to evaluate fecal transit problems** - Problems: - 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. - Results: - **Resting pressure in the anal canal:** reflects the function of the internal anal sphincter (normal, 40--80 mmHg) - **Squeeze pressure**: Maximum voluntary contraction pressure minus the resting pressure; reflects function of the external anal sphincter (normal, 40--80 mmHg above resting pressure) - **High-pressure zone**: estimates the length of the anal canal (normal, 2.0-4.0 cm). - **Rectoanal inhibitory reflex:** detected by inflating a balloon in the distal rectum; absence of this reflex is characteristic of Hirschsprung's disease D. LABORATORY STUDIES {#d.-laboratory-studies.TransSubtopic1} --------------------- - Use/Significance: - Screening test for colonic neoplasms in asymptomatic average-risk individuals. - Nonspecific test for peroxidase contained in hemoglobin - The efficacy of this test is based on serial testing because most colorectal malignancies bleed intermittently. - Result: - **POSITIVE** - occult bleeding from any gastrointestinal source. - Further investigation, usually by colonoscopy - **FALSE-POSITIVE** - food (red meat, some fruits and vegetables and vitamin C) - **Immunochemical FOBT** - Increased specificity - Rely on monoclonal or polyclonal antibodies to react with the intact globin portion of human hemoglobin and are more specific for identifying occult bleeding from the colon or rectum V. INFLAMMATORY BOWEL DISEASE {#v.-inflammatory-bowel-disease.TransOutline} ============================= **Table 9. Ulcerative Colitis vs. Crohn's Disease** ----------------------------------------------------- ------------------------ --------------------------------- **Characteristic** **Ulcerative Colitis** **Crohn's Disease** **Usual Location** Rectum, Left Colon Anywhere **Rectal Involvement** Common Uncommon **Fistulas** Rare Common **Ulcers** Irregular, continuous Linear with transverse fissures **Bowel Stricture** Rare Common **Depth** Shallow, Mucosal Transmural **Carcinoma** Increased Increased - *It's important to distinguish Ulcerative Colitis from Chron's Disease because in cases of the latter, surgery is usually avoided, and conservation of GI segments is the goal. There is a high chance of recurrence in Crohn's disease that's why surgery is usually avoided.* - **Ulcerative Colitis**: bloody diarrhea common, but not sudden severe bleeding - **Crohn's;** 1/3 with gross blood in stools; only 0.7-1.9% with acute severe bleeding A. ULCERATIVE COLITIS {#a.-ulcerative-colitis.TransSubtopic1} --------------------- **Figure 7. "collar-button ulcers" in Ulcerative Colitis** *(Source: ©Batch 2025 Trans)* - Involves the colonic mucosa and submucosa A mucosal disease. Usual presentation would be abdominal pain, intractable diarrhea, and bleeding. - Male \> Female - Limited to the colon and rectum - Mucosa may be atrophic and crypt abscesses common - Chronic inflammation of GI tract - ⭐**Key feature: CONTINUOUS involvement of rectum and colon (skip lesions suggest Crohn's disease)** CLINICAL PICTURE {#clinical-picture.TransSub-subtopic2} ---------------- - Characterized by remissions and exacerbations Onset: - Insidious - with minimal bloody stools - Abrupt - with severe diarrhea and bleeding, tenesmus, abdominal pain, and fever CHRONIC ULCERATIVE COLITIS {#chronic-ulcerative-colitis.TransSub-subtopic2} -------------------------- - Mild & Moderate acute findings: Mucosal edema crypt abscess on rectal involvement - Severe acute disease: **PSEUDOPOLYPS** w/ marked mucosal inflammation & edema - Late changes: Discrete ulcers, pus SURGICAL TREATMENT FOR ULCERATIVE COLITIS {#surgical-treatment-for-ulcerative-colitis.TransSub-subtopic2} ----------------------------------------- #### INDICATIONS FOR SURGERY {#indications-for-surgery.TransSub-subtopic3} - Active disease **unresponsive to medical therapy** - Risks of cancer -- based on workup - Severe bleeding +-----------------------------------+-----------------------------------+ | **Table 10. Surgical Procedure | | | Options for Ulcerative Colitis** | | +===================================+===================================+ | **Procedure** | **Details** | +-----------------------------------+-----------------------------------+ | **Proctocolectomy with Brooke | - Brings ileum to the skin | | Ileostomy** | | | | - Curative w/ one operation | +-----------------------------------+-----------------------------------+ | **Colectomy with Ileorectal | - Not curative; cancer risk | | Anastomosis** | persists (5-50%) | | | | | | - Contraindicated among | | | patients with Severe rectal | | | disease, Rectal dysplasia, & | | | Rectal CA | +-----------------------------------+-----------------------------------+ | **Total Proctocolectomy with | - ⭐**Best therapy** | | Ileoanal Anastomosis with Pouch** | | | | - Curative w/ continence | | | | | | - Contraindicated among | | | patients with Crohn's | | | disease, Diarrhea, & Rectal | | | CA | +-----------------------------------+-----------------------------------+ B. CROHN'S DISEASE {#b.-crohns-disease.TransSubtopic1} ------------------  **Figure 8. "String" sign in Crohn's Disease** *(Source: ©Batch 2025 Trans)* - TRANSMURAL INFLAMMATION: may occur anywhere in the GIT - Affects **entire wall of the GIT** - Extraintestinal symptoms proceeds those of intestinal symptoms - **Female** \> Male - Chronic inflammation of GI tract CLINICAL PRESENTATION {#clinical-presentation.TransSub-subtopic2} --------------------- - Early findings: - Rectal sparing - Perianal disease - Aphthous ulceration - Moderate changes: - Linear ulcers - ⭐Cobblestoning - ⭐Skip lesions - Late changes: - Contact bleeding - Confluent ulcers - Structures & mucosal bridging INDICATIONS FOR SURGICAL TREATMENT IN CROHN'S DISEASE {#indications-for-surgical-treatment-in-crohns-disease.TransSub-subtopic2} ----------------------------------------------------- - **Ileocolic Crohn's Disease:** Internal fistula and abscess- 38% Intestinal obstruction- 37% Perianal fistula- 15% Poor response to medical therapy- 6% - **Colonic Crohn's Disease (when surgery participates):** Internal fistula and abscesses -25% Perianal disease- 23% Severe disease w/ poor response to medical therapy-21% Toxic megacolon- 19% Intestinal obstruction -12% C. MEDICAL THERAPY FOR ULCERATIVE COLITIS AND CROHN'S DISEASE {#c.-medical-therapy-for-ulcerative-colitis-and-crohns-disease.TransSubtopic1} ------------------------------------------------------------- - **Sulfasalazine**: lowers the inflammation - **Metronidazole** (as well as 2^nd^ Generation Cephalosporins) - Crohn's ileocolitis & colitis - Perineal colitis - Not effective in active ulcerative colitis - **Corticosteroid** - Lowers antibody - Oral for mild to moderate active ulcerative colitis and Crohn's disease - Parenteral for severe or toxic ulcerative colitis or Crohn's disease - **Immunosuppressive Agents** - Steroid sparing - Refractory disease VI. DIVERTICULAR DISEASE {#vi.-diverticular-disease.TransOutline} ======================== - Clinical term used to describe the presence of symptomatic diverticula. - Macroscopic form - 3-5% bleed noticeably per rectum - **Right-sided bleed more common** - **"Arterial"** - Frequently severe - Stops spontaneously: 80-90% - Recurrence: 25% - Mortality: 5-10% - Lack of dietary fiber - The most accepted theory - Results in smaller stool volume, requiring high intraluminal pressure and high colonic wall tension for propulsion A. DIVERTICULA {#a.-diverticula.TransSubtopic1} -------------- - Small mucosal pockets in the wall of the colon that conceivably fill with stagnant fecal material or undigested food particles. - Obstruction of the neck of the diverticulum may result in distention of the diverticulum secondary to mucus secretion and overgrowth of normal colonic bacteria. B. DIVERTICULOSIS {#b.-diverticulosis.TransSubtopic1} ----------------- - Refers to the presence of **diverticula without inflammation.** - **Sigmoid colon**: most common site of diverticulosis C. DIVERTICULITIS {#c.-diverticulitis.TransSubtopic1} ----------------- - Refers to **inflammation and infection associated with diverticula** - Inflammation of one or more diverticula - Microperforation of a diverticula - estimated to occur in 10% to 25% of people with diverticulosis - **COMPLICATIONS** - Abscess - Intestinal obstruction - Intestinal perforation - Intestinal fistula - Sepsis/Septic shock - **OPERATIVE MANAGEMENT:** "STAGED Procedure" - One Stage - Two Stage - Three Stage A diagram of the inside of a large intestine Description automatically generated **Figure 9.** Diverticulosis vs Diverticulitis UNCOMPLICATED DIVERTICULITIS {#uncomplicated-diverticulitis.TransSub-subtopic2} ---------------------------- - Characterized by **Left Lower Quadrant pain** and **Tenderness** - CT-scan findings - Pericolic soft tissue stranding, colonic wall thickening and/or phlegmon. - Most patients will respond to outpatient therapy with broad- spectrum oral antibiotics and a low-residue diet COMPLICATED DIVERTICULITIS {#complicated-diverticulitis.TransSub-subtopic2} -------------------------- - Includes diverticulitis with **abscess, obstruction, diffuse peritonitis (free perforation),** or **fistulas** between the colon and adjacent structures - Long term sequelae - Colovesical - Colovaginal - Coloenteric fistulas - Hinchey Classification - Basis of whether you will do conservative or surgical management - Often used to describe the severity of complicated diverticulitis +-----------------------------------+-----------------------------------+ | **TABLE 11. Hinchey | | | classification** | | +===================================+===================================+ | **STAGE** | **DEFINITION** | +-----------------------------------+-----------------------------------+ | **Stage I** | Includes colonic inflammation | | | | | | with an associated pericolic | | | | | | abscess | +-----------------------------------+-----------------------------------+ | **Stage II** | Includes colonic inflammation | | | | | | with a retroperitoneal or pelvic | | | | | | abscess | +-----------------------------------+-----------------------------------+ | **Stage III** | Associated with purulent | | | peritonitis | +-----------------------------------+-----------------------------------+ | **Stage IV** | Associated with fecal peritonitis | +-----------------------------------+-----------------------------------+ - Treatment depends on the patient's overall clinical condition and the degree of peritoneal contamination and infection - **Small Abscesses (\ rectum) - Female (\> colon) - Etiology/Risk factor - Aging - The dominant risk factor for colorectal cancer, with incidence rising steadily after age 50 years - Diet high in saturated or polyunsaturated fats - Diet high in saturated or polyunsaturated fats - Diet high in oleic acid (olive oil, coconut oil, fish oil) - Does not increase risk - Colorectal carcinoma occurs more commonly in populations that consume diets high in animal fat and low in fiber +-----------------------------------+-----------------------------------+ | **TABLE 12. FORMS OF Colorectal | | | CA** | | +===================================+===================================+ | **Type** | **Description** | +-----------------------------------+-----------------------------------+ | **MACROSCOPIC FORM** | - Ulcerating type (most common) | | | | | | - Polypoid or fungating both | | | ulcerating type | | | | | | - Colloid CA | | | | | | - Bulky growth w/ | | | gelatinous appearance | | | | | | - Signet Ring Cell CA | | | | | | - Intracellular Mucinous | | | | | | - Infiltrating CA | | | | | | - Submucosal Spread | +-----------------------------------+-----------------------------------+ | **MICROSCOPIC FORM** | - Adenocarcinoma | +-----------------------------------+-----------------------------------+ +-----------------------------------+-----------------------------------+ | **TABLE 13. GRONNELL GRADING** | | | | | | **Based on invasive tendency, | | | glandular arrangement, nuclear | | | polarity and frequency of | | | mitosis.** | | +===================================+===================================+ | **GRADE** | **Description** | +-----------------------------------+-----------------------------------+ | **Grade I** | Low grade / well differentiated | +-----------------------------------+-----------------------------------+ | **Grade II** | Average grade / moderately | | | Differentiated | +-----------------------------------+-----------------------------------+ | **Grade III** | High grade / poorly | | | differentiated | +-----------------------------------+-----------------------------------+ A. ADENOCARCINOMA {#a.-adenocarcinoma.TransSubtopic1} ----------------- - ADENOMA-CARCINOMA SEQUENCE - It is now well accepted that most colorectal carcinomas evolve from adenomatous polyps - *"They are from the glands of the mucosa and they start as a polyp, you don't usually get symptoms unless malaki na siya.* *This could cause obstruction kapag malaki na siya, and usually mataas na yung staging niya or bleeding. Initially you would have occult bleeding lang, and unless malaking malaki na, gross bleeding can occur and could make the patient anemic."* GENETIC MODEL COLORECTAL TUMORGENESIS {#genetic-model-colorectal-tumorgenesis.TransSub-subtopic2} ------------------------------------- - Mutation may cause: - Activation of K-ras (an oncogene) - Inactivation of tumor- suppressor gene: - APC - DCC (deleted in colorectal carcinoma) - P53  **Figure 11.** Genetic Model Colorectal Tumorigenesis **Figure 12.** Levels of invasive carcinoma in pedunculated and sessile polyps. "The most important layer in terms of cancer invasiveness is the **SUBMUCOSA** because there are numerous lymphatic channels in that layer. " B. POLYPS {#b.-polyps.TransSubtopic1} --------- - A polyp is a nonspecific clinical term that describes any projection from the surface of the intestinal mucosa regardless of its histologic nature. +-----------------------------------+-----------------------------------+ | **Table 14. Type of Polyps** | | +===================================+===================================+ | **Type** | **Description** | +-----------------------------------+-----------------------------------+ | **Neoplastic Polyps** | - These lesions are dysplastic. | | | The risk of malignant | | | degeneration is related to | | | both the size and type of | | | polyp. | | | | | | - Adenomatous \--\> associated | | | with malignancy in only 5% of | | | cases. | | | | | | - Villous adenomas \--\> harbor | | | cancer in up to 40%; highest | | | cancer risk | +-----------------------------------+-----------------------------------+ | **Hyperplastic Polyps** | - Usually small (\ | | | | | | - Flat lesions and frequently | | | difficult to visualize. | | | | | | - Some of these polyps will | | | develop into invasive | | | cancers. | | | | | | - should be treated like | | | adenomatous polyps | +-----------------------------------+-----------------------------------+ | **Hamartomatous/ Juvenile | - Usually are not premalignant | | Polyps** | | | | - Characteristic polyps of | | | childhood but may occur at | | | any age | | | | | | - May cause Bleeding, | | | Intussusception, Obstruction | | | | | | - Grossly, identical to | | | adenomatous polyps treated by | | | polypectomy | +-----------------------------------+-----------------------------------+ | **Inflammatory Polyps** | - Occur most commonly in the | | | context of inflammatory bowel | | | disease | | | | | | - Not premalignant, but they | | | cannot be distinguished from | | | adenomatous polyps based on | | | gross appearance | +-----------------------------------+-----------------------------------+ C. INHERITED COLORECTAL CARCINOMA {#c.-inherited-colorectal-carcinoma.TransSubtopic1} --------------------------------- - Inherited non-sex linked autosomal dominant disease w/ hundreds of adenomatous polyps through the entire colon and rectum - **Non-sex linked**, Mendelian dominant - 1/3 without family history (spontaneous mutation) - **Rectal bleeding** & **diarrhea** very common - Various extracolonic symptoms - Untreated, cancer by age 40 - Treatment: **COLECTOMY** **Figure 13.** Familial Adenomatous Polyposis Coli GARDNER'S SYNDROME {#gardners-syndrome.TransSub-subtopic2} ------------------ - Familial polyposis, osteomatosis, epidermoid cyst, fibromas of the skin (desmoid tumor) -- the most important extracolonic expression. - Treatment: - Total proctolectomy w/ ileostomy - Colectomy w/ ileorectal anastomosis - Examine other members of the family TURCOT SYNDROME {#turcot-syndrome.TransSub-subtopic2} --------------- - Familial polyposis, brain tumors (gliomas or medulloblastomas) - Treatment: - Same w/ colorectal involvement D. HEREDITARY NONPOLYPOSIS COLON CANCER (LYNCH SYNDROME) {#d.-hereditary-nonpolyposis-colon-cancer-lynch-syndrome.TransSubtopic1} -------------------------------------------------------- - Autosomal dominant pattern - Error in mismatch repair (RER pathway) - Extremely rare (1-3% of all colon cancers) - Appear more common in proximal colon - Associated w/ extra-colonic malignancies (endometrial -- most common in women, ovarian, pancreas, stomach, small bowel, biliary & Urinary tract) - Characterized by the development of colorectal carcinoma at an early age - 3 or more relatives with colorectal cancer (one must be first degree relative of other two) - Colorectal cancer involving at least 2 generations - One or more colorectal cancer cases before age 50 - **Lynch I** - Cancer Family Syndrome - **Lynch II** - Site-specific colon cancer syndrome - **Screening Colonoscopy** - Recommended annually for at risk patients beginning at either age 20 to 25 years or 10 years younger than the youngest age at diagnosis in the family. +-----------------------------------------------------------------------+ | **TABLE X15 Clinical characteristics, Pathologic Prognosticators** | | | | **Clinical Presentation, Genetic Changes of Lynch Syndrome (HNPCC)** | +=======================================================================+ | **CLINICAL CHARACTERISTICS** | +-----------------------------------------------------------------------+ A table with text and numbers Description automatically generated -------------------------------- **PATHOLOGIC PROGNOSTICATORS** --------------------------------  --------------------------- **CLINICAL PRESENTATION** --------------------------- A table with a list of information Description automatically generated --------------------- **GENETIC CHANGES** ---------------------  E. STAGING AND PREOPERATIVE EVALUATION OF COLON CANCERS {#e.-staging-and-preoperative-evaluation-of-colon-cancers.TransSubtopic1} ------------------------------------------------------- - **STAGING** - Colorectal cancer staging is based on tumor depth and the presence or absence of nodal or distant metastases. - Older staging systems, such as the Dukes' Classification and its Astler-Coller modification, have been replaced by the tumor-node-metastasis (TNM) staging system described by the American Joint Committee on Cancer (AJCC). +-----------------------------------+-----------------------------------+ | **TABLE 16. (TNM) staging system | | | described by the American Joint | | | Committee on Cancer (AJCC).** | | +===================================+===================================+ | **STAGE** | **DESCRPTION** | +-----------------------------------+-----------------------------------+ | **Stage I** | Confined to the mucosa | +-----------------------------------+-----------------------------------+ | **Stage II** | Traverses the whole bowel wall, | | | but without lymph node | | | involvement | +-----------------------------------+-----------------------------------+ | **Stage III** | Traverses the whole bowel wall, | | | but with lymph node involvement | | | like your epicolic nodes, | | | pericolic nodes | +-----------------------------------+-----------------------------------+ | **Stage IV** | Pag lumabas na ng colon and | | | there's involvement of adjacent | | | organs and metastasis | | | | | | Liver, Brain, Lungs (most | | | commonly affected) | | | | | | Can spread hematogenously or | | | lymphatics | +-----------------------------------+-----------------------------------+ F. STAGE SPECIFIC MANAGEMENT {#f.-stage-specific-management.TransSubtopic1} ---------------------------- **Figure 14.** Diagnostic algorithm for rectal cancer. CT = computed tomography; MRI = magnetic resonance imaging; U/S = ultrasound **Rectal Cancer** - Neoadjuvant Chemo radiation - Surgical Approach - Adjuvant Chemotherapy - Adjuvant radiation VIII. OTHER NEOPLASM {#viii.-other-neoplasm.TransOutline} ==================== A. ANAL CANAL AND PERIANAL TUMORS {#a.-anal-canal-and-perianal-tumors.TransSubtopic1} --------------------------------- +-----------------------+-----------------------+-----------------------+ | **Table 17. Anal | | | | Canal and Perianal | | | | Tumors** | | | +=======================+=======================+=======================+ | **Tumor** | **Description** | **Treatment** | +-----------------------+-----------------------+-----------------------+ | **Bowen's Disease** | - Anal | - Mixed Resection / | | | Intraepithelial | ablation | | | Neoplasm | | | | | - High recurrence: | | | - Squamous Cell CA | 3 to 6 months | | | in situ of the | follow up | | | anus | | | | | | | | - Precursor to an | | | | invasive squamous | | | | cell CA | | | | | | | | - Associated with | | | | infection of | | | | **human papilloma | | | | virus, | | | | HIV-positive | | | | homosexual** | | +-----------------------+-----------------------+-----------------------+ | **Epidermoid | - Includes: | - Recurrence | | Carcinoma** | | usually requires | | | | radical resection | | | | | | | - - - - | - Metastasis to | | | | inguinal lymph | | | | nodes is a poor | | | | prognostic sign. | | | - Slow-growing | | | | tumor and usually | | | | presents as an | | | | intra-anal or | | | | perianal mass. | | | | | | | | - **Pain and | | | | bleeding may be | | | | present** | | | | | | | | - Lesions that | | | | persist greater | | | | than 3 to 6 | | | | months after | | | | therapy may | | | | represent | | | | persistent | | | | disease and | | | | should be | | | | biopsied. | | +-----------------------+-----------------------+-----------------------+ | **Verrucous | - Locally | Wide local excision | | Carcinoma** | **aggressive form | | | (Buschke-Lowenstein | of condyloma | | | | acuminata.** | | | Tumor, Giant | | | | Condyloma Acuminata) | | | | | | | | | - Lesions do not | | | | metastasize. They | | | | can cause | | | | extensive local | | | | tissue | | | | destruction and | | | | may be grossly | | | | indistinguishable | | | | from epidermoid | | | | carcinoma. | | +-----------------------+-----------------------+-----------------------+ | **Basal Cell | - **Rare** and | - Wide local | | Carcinoma** | resembles basal | excision | | | cell carcinoma | | | | elsewhere on the | - Larger lesions: | | | skin | Radical resection | | | | and/or radiation | | | Raised, pearly | therapy | | | edges with | | | | central | | | | ulceration | | | | | | | | - Slow growing | | | | tumor that rarely | | | | metastasizes. | | +-----------------------+-----------------------+-----------------------+ | **Adeno-** | - Extremely rare | Radical resection, | | | | usually after | | **carcinoma** | - Usually | neoadjuvant | | | represents | chemoradiation, is | | | downward spread | usually required. | | | of a low rectal | | | | adenocarcinoma | | | | | | | | - May occasionally | | | | arise from the | | | | anal glands or | | | | may develop in a | | | | chronic fistula. | | +-----------------------+-----------------------+-----------------------+ | **Extramam-** | - Adenocarcinoma | Wide local excision | | | in-situ arising | | | **mary** | from the apocrine | | | | glands of the | | | **Perianal Paget's | perianal area. | | | Disease** | | | | | - The lesion is | | | | typically | | | | plaque-like and | | | | may be | | | | indistinguishable | | | | from high-grade | | | | intraepithelial | | | | lesions. | | +-----------------------+-----------------------+-----------------------+ | **Melanoma** | - Rare | Both radical | | | | resection (APR) and | | | Less than 1% of | wide local excision | | | all anorectal | have been advocated. | | | malignancies | | | | | | | | 1% to 2% of | | | | melanomas. | | | | | | | | - Overall 5-year | | | | survival: less | | | | than 10%, | | | | | | | | many patients | | | | present with | | | | systemic | | | | metastasis and/or | | | | | | | | deeply invasive | | | | tumors at the | | | | time of diagnosis | | | | | | | | - Few patients | | | | present with | | | | isolated local or | | | | locoregional | | | | disease that is | | | | potentially | | | | resectable for | | | | cure | | +-----------------------+-----------------------+-----------------------+ B. BENIGN COLORECTAL CONDITIONS {#b.-benign-colorectal-conditions.TransSubtopic1} ------------------------------- VOLVULUS {#volvulus.TransSub-subtopic2} -------- - Occurs when an air-filled segment of the colon twists about its mesentery. - The **SIGMOID colon** is involved in up to 90% of cases - Can involve the cecum (\ - Chronic Constipation - Produces a large, redundant colon (chronic megacolon) that predisposes to volvulus, especially if the mesenteric base is narrow. +-----------------------------------+-----------------------------------+ | **Table 18. Types of Volvulus** | | +===================================+===================================+ | **Type** | **Description** | +-----------------------------------+-----------------------------------+ | **SIGMOID VOLVULUS** | - Can often be differentiated | | | from cecal or transverse | | | colon volvulus by the | | | appearance of plain X-rays of | | | the abdomen. | | | | | | - Produces a characteristic | | | BENT INNER TUBE or **COFFEE | | | BEAN** appearance, with the | | | convexity of the loop lying | | | in the Right Upper Quadrant | | | (opposite the site of | | | obstruction). | +-----------------------------------+-----------------------------------+ | **CECAL VOLVULUS** | - Results from non-fixation of | | | the right colon. | | | | | | - X-rays of the abdomen: | | | | | | characteristic **KIDNEY- | | | SHAPED**, air-filled | | | structure in the Left Upper | | | Quadrant (opposite the site | | | of obstruction | | | | | | - Gastrografin enema | | | | | | Confirms obstruction at the | | | level of the volvulus | +-----------------------------------+-----------------------------------+ | **TRANSVERSE COLON VOLVULUS** | - Extremely rare | | | | | | - Risk factors: | | | | | | - Non-fixation of the colon | | | | | | - Chronic constipation with | | | megacolon | | | | | | - Radiographic appearance: | | | | | | - Resembles sigmoid | | | volvulus | | | | | | - Gastrografin enema reveal a | | | more proximal obstruction. | +-----------------------------------+-----------------------------------+ ISCHEMIC COLITIS {#ischemic-colitis.TransSub-subtopic2} ---------------- - Appears to result from low flow and/or small vessel occlusion - Spontaneous or postoperative - Clinical manifestations: - Bloody diarrhea or gross blood in stools - Mucosa violaceous - Bleeding severe - Abdominal pain and tenderness ANGIODYSPLASIA (VASCULAR ECTASIA) {#angiodysplasia-vascular-ectasia.TransSub-subtopic2} --------------------------------- - The two common GI pathologies that manifest with massive bleeding are - Diverticulosis - Angiodysplasia - Focal submucosal ectasia - Acquired by aging 25-50% present in people \60 yrs - Very common in the elderly - Most common in CECUM & RIGHT COLON - Multiple in at least 25% - "Venous" - Rarely severe - Intermittent with 85% rebleed IX. COLON CONDITIONS OF INFECTIOUS ORIGIN {#ix.-colon-conditions-of-infectious-origin.TransOutline} ========================================= - Variety of other infections with bacteria, parasites, fungi, or viruses may cause colonic inflammation. +-----------------------------------+-----------------------------------+ | **Table 19. Infectious origins of | | | colon conditions** | | +===================================+===================================+ | **Type** | **Organism** | +-----------------------------------+-----------------------------------+ | **COMMON** BACTERIAL INFECTIONS | - Enterotoxic, E. coli | | | | | | - C. jejuni | | | | | | - Yersinia enterocolitica | | | | | | - S. typhi | | | | | | - Shigella | | | | | | - N. gonorrhoeae | +-----------------------------------+-----------------------------------+ | LESS COMON | - Mycobacterium tuberculosis | | | | | | - M. bovis | | | | | | - Actinomycosis israelii, | | | | | | - Treponema pallidum (syphilis) | +-----------------------------------+-----------------------------------+ | **PARASITIC infections** are also | - Amebiasis | | relatively common | | | | - Cryptosporidiosis | | | | | | - Giardiasis | +-----------------------------------+-----------------------------------+ | **FUNGAL infections** are | - Candida species | | extremely rare in otherwise | | | healthy individuals. | - Histoplasmosis | +-----------------------------------+-----------------------------------+ | **Most common VIRAL infections** | - HIV | | that produce colitic symptoms | | | | - Herpes simplex viruses | | | | | | - CMV | +-----------------------------------+-----------------------------------+ A. PSEUDOMEMBRANOUS COLITIS {#a.-pseudomembranous-colitis.TransSubtopic1} --------------------------- - Rarely severe - Caused by **C. difficile** - A gram-positive anaerobic bacillus. - Clostridium difficile colitis - Extremely common and is the leading cause of nosocomially acquired diarrhea  **Figure 15. Colonic Segment with Pseudomembranous Colitis** *(Source: © Lecture)* X. ANORECTAL DISEASE {#x.-anorectal-disease.TransOutline} ==================== - *Just a run through discussion. Detailed discussion on Anorectal Module* A. HEMORRHOIDS {#a.-hemorrhoids.TransSubtopic1} -------------- - Vascular cushions in anal canal - Help "fine-tune" continence; protects sphincters; closes anus completely - Primary and secondary locations - Pathologic: - Bleeding, thrombosis, strangulation, sepsis → Bleeding "ARTERIAL" +-----------------------------------+-----------------------------------+ | **Table 20. Hemorrhoids** | | +===================================+===================================+ | **Hemorrhoids** | **Details** | +-----------------------------------+-----------------------------------+ | **Classification** | - External | | | | | | - Internal | | | | | | - Mixed | +-----------------------------------+-----------------------------------+ | | - Venous obstruction | | | | | | - Prolapse of vascular cushions | | | | | | - Age/constipation/straining | | | | | | - Heredity | | | | | | - Diet | +-----------------------------------+-----------------------------------+ | | - Bleeding | | | | | | - Prolapse and Lumps | | | | | | - Pain and Discomfort | | | | | | - Discharge, Hygiene Problems, | | | Pruritus | +-----------------------------------+-----------------------------------+ | | - Anoscopy/Proctoscopy | | | | | | - Barium Enema | | | | | | - Colonoscopy | +-----------------------------------+-----------------------------------+ | | - Thrombosis: internal/external | | | | | | - Infection | | | | | | - Anemia | | | | | | - Perianal Dermatitis | +-----------------------------------+-----------------------------------+ | | - Medical | | | | |