Inflammatory Bowel Disease


Ulcerative Colitis

  1. Definition
    • diffuse, nonspecific inflammatory disease of the mucosal lining of the colon and rectum
    • most commonly involves the rectum, and may extend in a proximal and continuous fashion to involve other parts of the colon

  2. Etiology
    • unknown
    • no bacterial or viral agent has been implicated
    • family history is the most important risk factor
    • altered immune response to external and host antigens may also play a role
    • smoking is protective

  3. Pathology
    • disease is confined to the mucosal and submucosal layers, sparing the muscularis
    • begins in the rectum and may spread proximally to involve the entire colon
    • terminal ileum is involved 10% of the time: ‘backwash ileitis’
    • superficial ulcers and crypt abscesses are early pathologic signs

  4. Clinical Manifestations
    • bloody diarrhea is the most common early symptom
    • disease severity may range from mild disease with 4 or less bowel movements/day to severe disease with 10 or more stools/day with continuous bleeding
    • other symptoms may include abdominal pain, weight loss, tenesmus, fever
    • extraintestinal manifestations may also be present: arthritis, iritis, erythema nodosum, pyoderma gangrenosum, hepatic dysfunction, sclerosing cholangitis
    • usually presents as a chronic, low-grade illness in most patients; however, in 15% it may have an acute and fulminating course

  5. Diagnosis
    • stool studies are necessary to exclude infectious colitis
    • colonoscopy is of value in determining the extent of disease but endoscopic biopsies will not usually differentiate ulcerative colitis from Crohn’s colitis unless granulomas are seen
    • rectal sparing and skip areas are most consistent with Crohn’s disease
    • barium enema may show loss of haustral markings and ulcerations; in severe disease, the colon has the appearance of a rigid tube (stovepipe colon)

    Ulcerative colitis - Stovepipe Colon
  6. Medical Management
    • acute attacks are usually treated with corticosteroids (40 to 60 mg prednisone QD)
    • steroid enemas are effective in left colon disease or proctitis
    • intravenous steroids are used in severe attacks for a period of 5 to 7 days
    • sulfasalazine inhibits mucosal prostaglandin synthesis and is used to prevent relapses in the chronic phase of disease
    • immunomodulators such as azathioprine, 6-mercaptopurine, cyclosporine are used in steroid-unresponsive disease
    • antitumor necrosis factor antibodies (infliximab) are used for maintenance therapy and as second line therapy in steroid-refractory UC
    • antibiotics have no proven value in the treatment of ulcerative colitis

  7. Indications for Surgery
    • removal of the entire colon and rectum cures ulcerative colitis

    1. Urgent or Emergent Indications
      1. Massive Hemorrhage
        • rare, occurring in < 1% of patients
        • 50% of patients also have toxic megacolon
        • total abdominal colectomy with ileostomy is the usual procedure
        • if bleeding from the rectum persists, emergency proctectomy may be required
        • a completion proctectomy with pouch reconstruction can be done at a later date

      2. Toxic Megacolon
        1. Clinical Manifestations
          • occurs in 6% to 13% of patients with ulcerative colitis
          • symptoms include abdominal pain, severe diarrhea, distention
          • signs include abdominal tenderness, fever, tachycardia, lethargy, and shock
          • KUB usually shows dilatation of the transverse colon (>8cm)
          • chronic steroid use can mask many of the signs and symptoms

          Toxic Megacolon
        2. Management
          • unless peritonitis is present, the initial therapy is medical
          • fluid and electrolyte replacement, broad-spectrum antibiotics, high-dose steroids, NG decompression, and serial abdominal films are the initial therapies
          • if there is no improvement within 24 to 48 hours, then surgery is indicated
          • total abdominal colectomy with an ileostomy and Hartmann’s pouch is associated with a lower mortality rate than emergent total proctocolectomy
          • the rectum should be divided as low as possible and a mushroom catheter left in place to help prevent stump blowout

      3. Fulminating Acute Ulcerative Colitis
        • an acute episode that is not responsive to IV steroids or biologic agents will require an emergent abdominal colectomy, ileostomy, and Hartmann’s pouch

      4. Perforation
        • may be associated with toxic megacolon
        • abdominal colectomy with ileostomy

    2. Elective Indications
      1. Intractability
        • most common indication for surgery
        • chronic ulcerative colitis may become a physical and social burden to the patient
        • persistent need for long-term medical therapy has many complications (and costs)
        • continence-preserving surgical procedures are an option for many patients to consider
        • extracolonic manifestations responsive to surgery include erythema nodosum, arthritis, and eye disease
        • primary sclerosing cholangitis and ankylosing spondylitis do not respond to surgery

      2. Carcinoma
        • patients with ulcerative colitis have an increased risk of developing colon cancer, which is frequently multifocal
        • the likelihood of carcinoma developing is related to both the extent of colonic involvement and the duration of the disease
        • after 10 years of pancolonic disease, the risk of colon cancer is approximately 1% a year
        • patients with chronic ulcerative colitis need routine surveillance colonoscopy with random 4 quadrant mucosal biopsies every 10 cm
        • the presence of dysplasia is an indication for proctocolectomy
        • strictures are also frequently malignant, and are an indication for surgery

      3. Growth Retardation
        • failure to mature and grow at an acceptable rate is an accepted indication for surgery in children

  8. Choice of Operation
    1. Subtotal Colectomy and Ileostomy
      • operation of choice in emergency settings since it is the least morbid procedure
      • another indication is in patients who have indeterminant colitis – this allows complete pathologic examination of the colon to rule out Crohn’s disease
      • may consider leaving a long rectal stump as a mucous fistula to avoid the risk of an intraperitoneal stump leak
      • preserves the option for an ileal pouch-anal anastomosis (IPAA) after recovery

    2. Proctocolectomy and Ileostomy
      • curative, since it removes all the diseased mucosa
      • poorly accepted by patients and physicians
      • a permanent ileostomy is difficult to manage
      • significant complications of the procedure include injury to the pelvic parasympathetic nerves, resulting in bladder and sexual dysfunction, and poor healing of the perineal wound
      • to avoid pelvic nerve injury the mesorectum should be divided close to the rectal wall and the dissection should avoid the pelvic side walls
      • perineal wound problems may be reduced by performing an intersphincteric proctectomy which preserves the levator ani and external sphincter muscles
      • these muscles may then be used in the closure of the perineum
      • procedure is limited to patients with significant comorbid disease, poor sphincter function, or concurrent rectal cancer

    3. Subtotal Colectomy with Ileorectal Anastomosis
      • used as a compromise operation in patients who are not candidates for ileoanal anastomosis (indeterminant colitis) and who refuse an ileostomy
      • since pelvic surgery is associated with infertility secondary to adhesions, this approach may be chosen by young women who want to have children – once her family is complete, then a completion proctectomy and ileal pouch reconstruction can be performed
      • advantages of this approach include avoidance of an ileostomy and normal sexual and bladder function
      • however, there are many disadvantages to this procedure:
        • proctitis is not eliminated and 25% of patients will require completion proctectomy
        • risk of developing cancer remains in the rectal segment
        • functional results vary, with some patients having intractable diarrhea

    4. Proctocolectomy and Continent Ileostomy
      • goal is to avoid the need for an external appliance
      • patients must manually evacuate the pouch
      • associated with a high rate of technical complications requiring reoperation
      • rarely performed today - most common indication is in patients who have had a failed ileoanal anastomosis

    5. Ileoanal Anastomosis (IPAA)
      • operation consists of a near total proctocolectomy, endorectal ileal pouch-anal anastomosis, and diverting loop ileostomy
      • the advantages of this operation include elimination of almost all diseased mucosa, preservation of the anorectal sphincter, and avoidance of a permanent ileostomy
      • functional results are generally good: the average number of daily bowel movements is 5 and nocturnal bowel movements is 1; daytime incontinence is rare, however, nocturnal seepage is much more common
      • most frequent late complication is pouchitis, which can be cured in most cases by a short course of metronidazole
      • small bowel obstructions are frequent (20%)
      • sexual dysfunction in males and infertility in females remain significant problems
      • contraindicated in patients with Crohn’s colitis
      • may be done open or laparoscopically

      1. J-Pouch Creation
        • pouch is created with the last 30 cm of ileum using a GIA stapler
        • imperative that the pouch reach the dentate line without tension
        • posterior attachments of the small bowel mesentery must be mobilized up to the third portion of the duodenum
        • dividing the ileocolic artery near its origin with the SMA can give additional length
        • relaxing incisions can also be made in the anterior and posterior surfaces of the mesentery to gain additional length
        • adequate length is confirmed when the apex of the pouch reaches past the symphysis pubis

      2. Ileal Pouch Anal-Anastomosis
        1. Double-Stapled anastomosis
          • preserves the anal transition zone, which contains nerves for distinguishing between air, liquid, and stool
          • associated with better postoperative continence, especially at night
          • performed with the EEA stapler
          • leaves behind a small amount of rectal mucosa that is at risk for development of dysplasia and cancer, as well as inflammation
          • known rectal dysplasia is a contraindication

        2. Mucosectomy and Hand-Sewn Anastomosis
          • mucosa from the anal canal and distal rectum is excised transanally
          • small islands of mucosa can be left behind, making scheduled pouchoscopy mandatory
          • associated with higher rates of anastomotic stricture, septic complications, incontinence, and pouch failure than a stapled anastomosis

          IPAA anastomoses
      3. Ileostomy
        • most surgeons use a protective ileostomy after IPAA
        • ileostomy decreases the risk of pelvic sepsis from an anastomotic leak
        • before ileostomy closure, the pouch must be assessed for healing – digital rectal exam, pouchoscopy, contrast study
        • some surgeons will skip the ileostomy in good risk patients

Crohn's Colitis

  1. Pathology
    • 15% of patients with Crohn’s have disease limited to the colon
    • characterized by transmural inflammation with aphthoid ulcers
    • noncaseating granulomas are pathognomonic, as are fistulas
    • discontinuous segmental involvement
    • rectum is often spared (40%) and the ileum is often involved
    • perianal disease is common
    • 15% of cases cannot be differentiated from ulcerative colitis (indeterminate colitis)

  2. Clinical Manifestations
    • abdominal pain, non-bloody diarrhea, and weight loss are the most common symptoms
    • may present with complications of the disease: abscesses, fistulas, strictures
    • toxic megacolon occurs less frequently than in ulcerative colitis

  3. Therapy
    • neither medical therapy nor surgery is curative
    • corticosteroids are the time-tested treatment for acute Crohn’s disease
    • anti-TNF antibodies are used for inducing and maintaining remission in moderate to severe or steroid-refractory disease
    • surgery is limited to the treatment of complications and intractability

  4. Choice of Operation
    1. Proctocolectomy and Ileostomy
      • procedure of choice for patients with intractable pancolonic disease or concomitant anorectal and colonic disease
      • also indicated if fecal incontinence is too severe to warrant preserving the rectum
      • to reduce problems with nonhealing perineal wounds, an intersphincteric proctectomy may be performed
      • an ileal pouch-anal anastomosis should not be done in a patient with Crohn’s disease because of the risk of recurrence in the pouch and fistulas at the anastomosis
      • likewise, a continent ileostomy should also not be done

    2. Segmental Resection
      • segmental resection can be performed for patients with localized disease
      • must accept the fact that recurrent disease in the colon is common
      • 60% of patients require a second operation within 10 years
      • good option for patients with limited disease who wish to avoid a stoma
      • resection with diversion is appropriate for obstruction from a stricture

    3. Total Abdominal Colectomy with Ileorectal Anastomosis
      • indicated in patients with rectal and anal sparing who wish to avoid an ileostomy
      • patients must have good continence, because they will have multiple watery bowel movements
      • will need frequent surveillance of the rectum for recurrence of CD, as well as for dysplasia and cancer
      • ~50% of patients will require completion proctectomy and ileostomy within 10 years







References

  1. Sabiston, 20th ed., pgs 1339 - 1353
  2. Schwartz, 10th ed., pgs 1195 - 1201
  3. Cameron, 10th ed., pgs 154 - 160, 160 – 163, 163 – 168
  4. UpToDate. Surgical Management of Ulcerative Colitis. Phillip R. Fleisher, MD, FACS. Feb 24, 2020. Pgs 1 – 25