Preoperative risk factors and radiographic findings predictive of laparoscopic conversion to open procedures in Crohn's disease.

INTRODUCTION: Laparoscopy is accepted as a standard surgical approach for Crohn's disease. However, the rate of conversion is high, ranging from 15 to 70 % depending on the population. There are also concerns that conversion results in worsened outcomes versus an initial open procedure.
METHODS: This study evaluated preoperative radiographic findings to determine who is at increased risk of conversion and may therefore benefit from an initial open approach. A case-matched study included patients from 2004 to 2013 with preoperative CTE/MRE who underwent laparoscopic surgery converted to an open approach, and compared them to laparoscopically completed controls with similar age, same surgeon, and number of previous abdominal operations. Studies were reviewed by two blinded radiologists. Variables included abdominal AP diameter, amount of subcutaneous fat, peritoneal versus pelvic location of disease (greater or lesser hemipelvis or abdomen), intestinal location of disease (colon, TI, ileum, jejunum), and presence, length, and location of strictures, simple or complex fistula, phlegmon, or abscess. Conditional logistic regression evaluated relationships between radiographic variables and conversion. Twenty-seven patients meeting study criteria were compared with 81 controls.
RESULTS: A negative association between conversion and disease in the left lesser pelvis was found (p = 0.019) and neared significance for left abdomen (p = 0.08). Positive correlations were found with pelvic fistulas (p = 0.003), complex fistulas (p = 0.017), and pelvic abscesses (p = 0.009) and neared significance for Society of Abdominal Radiology classification (p = 0.058).
CONCLUSION: Preoperative imaging in patients with Crohn's disease can help in selecting the most suitable cases to approach laparoscopically and reduce conversion rates and should be evaluated in conjunction with other preoperative factors.