Surgery and recurrence in Crohn’s disease

Abstract

Previous studies on risk factors for resection and postoperative recurrence in Crohn's disease (CD) have given inconclusive results. The aim of this study is to assess the probability of resection and recurrence in the treatment of CD and to define factors affecting the course of the disease.

Paper I: 1936 patients in Stockholm County diagnosed with CD between 1955 and 1989 were evaluated in an epidemiological study. Possible cases were searched for in diagnosis registers covering hospital admissions during 1955-92 and out-patient visits to the internal medicine units during 1993- 94. In addition, gastroenterologists in private practice were asked about possible cases. The diagnosis was established according to the criteria proposed by Lennard-Jones, considering the history, radiological and endoscopic, examination, and macroscopic findings at surgery.

An increase was found in the mean annual incidence for Crohn´s disease in Stockholm county. In 1955 the incidence was around 1.5 new cases per 100.000 inhabitants and year. During the two later decades of the study period the increased incident rate levelled off and stabilised at approximately 4.6 per 100.000 inhabitants and year. An increase was seen in colorectal Crohn´s disease. The highest age-specific incidence was found in patients aged 15 - 29 years at diagnosis. The median age at diagnosis increased from 25 years in 1960-1964 to 32 years in 1985-1989.

Paper II: The aim of this study is to assess the risk for resection and postoperative recurrence, as well as the presence of independent risk factors for resection and recurrence in the large cohort of 1936 patients with CD. 142411936 (73%) of the patients were treated with at least one intestinal resection. 650 of these subsequently developed recurrent disease and in 355 patients a re-resection was undertaken after a medium time of 6 years.

A high frequency of surgery was found, with more than 50% of the patients treated with resection during the first two years after diagnosis. Factors such as small bowel, ileocaecal, continuous ileocolonic involvement, the female sex, perianal fistulas and a diagnosis in the early part of the study period (1955-89) gave a high probability of resection, whereas childhood at diagnosis gave a low probability of resection.

Recurrence rates were 33% and 44% at 5 and 10 years after resection. In the assessment of risk factors, perianal fistulas, small bowel or ileocolonic extent of disease at diagnosis increased recurrence. Gender, age groups at diagnosis, disease duration before surgery, time trends, indication for surgery and the presence of granulomas did not show any impact on relapse rates.

Paper III: A subgroup of 907 patients with primary ileocaecal CD was reviewed. Resection rates were respectively 61, 77 and 83 per cent, one, five and ten years after diagnosis. Relapse rates were 28 and 36 per cent, five and ten years after the first resection.

Assessing the independent factors it was found that a younger age at diagnosis resulted in low resection rates, on the other hand perianal disease and long resection segments increased recurrence, contrary to being diagnosed during the later part of the study period (1975-89), or undergoing primary surgery for a palpable mass or abscess, which decreased recurrence.

Paper IV: The cumulative probability of recurrent disease over time, after the four major types of colectomy for Crohn´s colitis was evaluated in a survival curve. Included were subtotal colectomy with ileostomy, subtotal colectomy with ileorectal anastomosis (IRA), proctocolectomy with ileostomy and segmental colonic resection. Probable risk factors for recurrent disease were evaluated in a multivariate analysis. After colectomy with IRA and segmental colonic resection an increased relative risk for recurrent disease of 2.9 and 3.0 respectively was found. A history of perianal disease implies a high probability of recurrent disease. A decreased risk of recurrence was found in the age group 30-44 years at diagnosis.