Crohns Disease

Crohn's disease is not an uncommon disease that frequently recurs following surgical intervention. Clinical recurrence rates have been estimated by the National Cooperative Crohn's Disease Study to be 78% after 20 years [76] or as high as 60% at 5 years and 94% at 15 years [77]. Recurrence necessitating surgery is estimated at 15 to 40% at 10 years and 50 to 70% at 20 years following the initial resection [78-80]. Several studies have demonstrated that although the radiographic appearance of Crohn's may wax and wane over time in a given bowel segment, there is no significant progression longitudinally over time [81-83].

Many studies have tried to analyze the predictive factors for the extremely high and alarming recurrence rates. The involvement of the terminal ileum and the neoterminal ileum following surgery raises the possibility of reflux of colonic contents through the ileocecal valve as an etiological factor [84]. D'Haens et al. found that the duration of recurrent disease in the neoterminal ileum correlated with the extent of disease on presurgical studies [84]. Other studies showed that patients with ileocolic disease preoperatively had a higher rate of recurrence than those without terminal ileal involvement [79,85]. These patients also came to surgery earlier than those with more limited disease. A study from Norway suggested that younger patients (both at the onset of symptoms as well as the time of surgery) were at higher risk for recurrence than their more senior counterparts [86]. Yet another study contradicted this finding and found no relationship between the age of the patient and the rate of recurrence [87]. Distal colonic [86] and perianal disease [79] were also negative predictors for a disease-free postoperative course.

Another area of study has been the length of resected small bowel and the histological appearance of the margins of resection. The presence of granulomas or other evidence of inflammation at the margins of resection should be expected to lead to an increased rate of postoperative recurrence. This has been verified in at least two studies [86,88] but surprisingly refuted in at least one other [89]. Another study showed that resections of more than 25 cm of ileum and more than 50 cm of combined small and large bowel resulted in decreased rates of rehospitalization and reoperation [87]. Greater lengths of colon along with at least 25 cm of small-bowel resection did not result in an improved clinical outcome.

Some studies have suggested that there are two subgroups of patients with Crohn's disease [80,90,91]. In the more aggressive type, perforation may be part of the initial presentation. Those patients are more prone to early relapse postoperatively [90]. In the second group, patients with symptoms appearing less than 6 months prior to surgery had a 50% higher recurrence rate than those with a 10-year history of symptomatology [80]. The presence of postoperative complications following the initial surgery was also a predictor of early recurrence of the disease.

The postoperative appearance of Crohn's disease is similar to that seen preoperatively [92-96] (Fig. 5.26). Enteroclysis revealed evidence of submucosal disease in more than 60% of patients studied postoper-atively [82]. This submucosal disease was evidence by a progression of changes from thickened to irregular to complete effacement of folds. Mucosal disease was evidence by superficial ulcerations in two-thirds of patients. Transmural disease was evidence by decreased pliability and reduced peristaltic activity in the intestinal segments. True stricture formation, a cobblestone appearance, and deep ulcerations and/or sinus tracts were also evidence of transmural disease. There was good correlation of the clinical activity of the disease and the radiographic appearance. Patients with transmural disease had a high rate of clinical symptoms when compared with those only having mucosal or submucosal disease. Patients with normal postoperative small-bowel enemas had no clinical evidence of recurrence [82].

Transabdominal sonography has already been shown to be of value in selecting patients with suspected Crohn's disease for barium studies.

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