Prevalence of lower extremity venous disease in inflammatory bowel disease

Inflammatory bowel disease (IBD) has long been considered a risk factor for venous thromboembolism (VTE). Whereas most patients have persistent venous valvular dysfunction following lower extremity deep venous thrombosis (DVT), we hypothesized that patients with IBD would have an increased prevalence of valvular incompetence and changes of chronic DVT (reduced venous caliber with thickened walls) relative to patients with irritable bowel syndrome (IBS) or normal volunteers.

Subjects with confirmed IBD, clinical features of IBS or normal volunteers underwent complete, prospective duplex ultrasound assessment of their lower extremity venous vascular system. The sonographer performing the venous study was blinded to the clinical diagnosis of the patients. Valvular incompetence was graded as mild, moderate or severe based on accepted criteria.

Eighty patients with IBD (ulcerative colitis, UC: 66; Crohn's disease: 14), 80 patients with IBS, and 80 healthy volunteers agreed to participate. One patient with UC was found to have non-occlusive chronic DVT within the left superficial femoral vein. Mild and moderate valvular incompetence was evenly distributed between the 3 groups. No patients met criteria for either acute DVT or severe venous incompetence.

In patients with IBD, neither valvular incompetence nor chronic venous obstruction are over-represented compared to patients with IBS or normal volunteers. In this prospective assessment of venous physiology by duplex ultrasound, we were not able to confirm prior reports that IBD is a major risk factor for VTE.