Prevalence and distribution of incompetent perforating veins in chronic venous insufficiency

Purpose: The purpose of this study was the investigation of the prevalence and distribution of incompetent perforating veins (IPVs) in patients with different classes of chronic venous insufficiency (CVI) as defined by the updated clinical, etiologic, anatomic, and pathologic classification (CEAP) in relation to the pattern and the extent of venous reflux. Material and methods: The study included 468 limbs of 330 subjects who ranged in age from 18 to 101 years (median, 49 years). The investigation entailed a medical history, a clinical examination, and color flow duplex imaging of the lower limb veins, which were performed by the same vascular surgeon operator. The patients were classified into 7 clinical classes according to CEAP. The superficial and deep venous systems were scanned, with an emphasis on the detection of IPVs. Venous reflux was considered abnormal when its duration exceeded 0.5 seconds. IPVs were classified as medial, posterior, and anterolateral in the upper, middle, or lower third of the thigh or calf (9 thigh and 9 calf fields). Results: The IPVs were found mainly in the medial aspect, more frequently in the middle third of calf, followed by the lower calf and the middle thigh. IPVs were rare in the lateral aspect of the thigh, the medial upper and posterior lower thigh and the posterior upper and lower calf. The prevalence of the IPVs and of deep vein incompetence increased significantly with the clinical severity of CVI (r = .95, P < .01, and r = .9, P < .01, respectively). In the limbs with a documented perforating vein (PV) incompetence, the ratios of calf-to-thigh IPVs and of superficial-and-deep (S + D) over superficial-alone (S; IS + D]/S] venous incompetence increase significantly (r = .87, P < .01 and r = .9, P < .01, respectively) with CEAP grade. The prevalence of reflux involving all systems (S + D + PV) increases significantly (r = .9, P < .01) with clinical severity. In legs with CVI of CEAP 2 to 6, reflux was invariably proximal (thigh) and distal (below knee). Conclusion: In CVI, IPVs are located predominately in the media] aspect of the lower extremity, more often in the middle third of the calf, followed by the lower calf and middle thigh. The prevalence of IPVs and their calf-to-thigh ratio increase linearly with the clinical severity of CVI. Both the prevalence of deep vein incompetence and the ratio of superficial and deep to superficial ([S + D]/s) increase linearly with CEAP classification. These findings support the significant relationship between deep venous reflux and PV incompetence, although the latter may exist in the absence of the former. In CEAP classes 2 to 6, reflux is invariably proximal and distal. Incompetence involving all systems (S + D + PV) increases in prevalence with the severity of CVI.