What is Ulcerative colitis ?
Ulcerative colitis is an inflammatory process of the colonic mucosa characterized by alterations in bowel function, most commonly bloody diarrhea with tenesmus. It has a male predominance. The disease always involves the rectum and extends continuously variable distances in the proximal colon. Patients often have abdominal pain, fever, and weight loss. As the duration of the inflammation increases, pathologic changes progress. Initially, mucosal ulcers and crypt abscesses are seen. Later, mucosal edema and pseudopolyps (islands of normal mucosa surrounded by deep ulcers) develop, and the end-stage pathologic changes show a flattened, dysplastic mucosa. The lumen is normal in diameter. Cancer must be considered in any colonic stricture in a patient with ulcerative colitis.
A. Indications for surgery
Failure to respond to medical treatment. Inability to wean from high-dose steroids after two successive tapers prompts evaluation for surgery.
The risk of malignancy is related to the extent and duration of the disease but not the intensity of the disease. Colitis-associated cancer usually infiltrates submucosally and has signet-ring histology. The risk increases by 1%/year after 10 years of disease. Colonoscopy is performed 7 to 10 years after the diagnosis and every 1 to 2 years thereafter, with random biopsies every 10 cm and directed biopsies of mass lesions. Resection is recommended for dysplasia or stricture.
Severe bleeding that does not respond adequately to medical therapy requires resection for control.
Acute severe fulminant colitis [white blood cell count (WBC) >16,000, fever, abdominal pain, distention] initially is treated with bowel rest, antibiotics, steroids, and avoidance of contrast enemas, antidiarrheals, and morphine. If the patient develops worsening sepsis or peritonitis, abdominal colectomy with end-ileostomy is performed.
B. Surgical management
Surgical management aims at removing the colorectal mucosa while maintaining bowel function as much as possible. Because the disease is localized to the rectum and colon, curative resection is possible. Sphincter-sparing procedures are preferred to preserve the functions of continence and defecation. However, they are associated with higher postoperative complication risk. Anal sphincter function is assessed with manometry to ensure normal function before contemplation of a sphincter-sparing procedure in a patient medically able to undergo the operation.
Restorative proctocolectomy (ileal pouch–anal anastomosis, IPAA)
maintains enteral continuity through the anal sphincter mechanism and is the operation of choice in most patients. A total proctocolectomy is carried out to the anal transition zone. The rectum is transected, leaving the sphincters and levators intact. A distal ileal pouch is constructed over a distance of 15 cm in a J configuration, pulled through the sphincters, and stapled or sutured to the rectal cuff. Stapled anastomoses leaving a 2-cm cuff of anal canal mucosa technically are easier but require long-term surveillance of the residual mucosa. A diverting loop ileostomy is constructed, then reversed 3 months later after healing of the distal anastomosis. Complications include increased stool frequency (five to seven times daily), nocturnal soiling (20%), pouch fistula (<10%), and pouchitis (28%), an intermittent inflammatory process that typically responds to metronidazole. Pouch capacity increases over time; eventually, the patient needs to empty the pouch an average of four to five times daily.
Total proctocolectomy with end-ileostomy
is performed in patients who have perioperative sphincter dysfunction or incontinence and in high-risk patients who would not tolerate potential postoperative complications. Most patients do well with a well-placed Brooke ileostomy that has a spigot configuration and empties into a bag appliance in an uncontrolled fashion. A Kock pouch or continent ileostomy does not empty spontaneously, does not require a permanent appliance, and requires cannulation six to eight times daily. These are more difficult to construct and prone to obstruction. This alternative is occasionally offered to patients who desire continence or who have severe skin allergies, which make ileostomy appliances problematic