Slow femoral venous flow and venous thromboembolism following inguinal hernioplasty in patients without or with low molecular weight heparin prophylaxis.

Abstract

Prosthetic material (mesh) is commonly used to repair inguinal hernias. Its implantation close to the common femoral vein (CFV) can induce slow flow and favor the appearance of venous thromboembolism (VTE) events. To investigate the speed of flow, diameter and area of the CFV after inguinal hernioplasty. Two hundred and fifty patients receiving open hernioplasty with a non-resorbable mesh for the repair of a unilateral, primary, simple inguinal hernia were prospectively investigated. Patients were stratified, by consensus, into a low or a moderate risk of VTE group. The moderate-risk group (n = 163) received low molecular weight heparin. On day 10 post-operation a blinded Echo-Doppler was carried out, and repeated 7 days later in patients with a venous flow of <15 cm/s. The speed of flow (cm/s), diameter (cm), and area (cm(2)) of the ipsilateral and contralateral CFV of the groin operated upon were measured. No event symptomatic of VTE was documented. One case of asymptomatic deep vein thrombosis (1/163, 0.6%) was found in the moderate-risk group. In 29 patients (2 and 27 in the low- and moderate-risk groups, respectively; p < 0.001) a maximum blood flow velocity of <15 cm/s was found in the ipsilateral CFV; these flows were close to normal in the second measurement. Taking the entire sample into account, the maximum venous blood flow found in the ipsilateral CFV of the operated groin was less than that measured in the contralateral CFV (20.88 vs. 24.01 cm/s; p < 0.001); this difference was significant in both VTE risk groups. The diameter and area of the CFV were both greater in the ipsilateral than the contralateral CFV (p < 0.01); this finding proved to be significant only in hernias of the left groin (p < 0.001). In the immediate postoperative period, inguinal hernioplasty with mesh induces a temporarily slow venous flow in the ipsilateral CFV. However, this does not lead to an increase in the incidence of VTE.