Validity of duplex-ultrasound in identifying the cause of groin recurrence after varicose vein surgery

Introduction: Often groin recurrences after varicose vein surgery are diagnosed and classified with the help of a duplex ultrasound scan. There are, however, no studies indicating if duplex ultrasound scans can reliably distinguish between the different forms of recurrent vessels, ie, neovascularization or a residual stump. To address this issue, we have conducted a prospective study in which ultrasound scan assessment of groin recurrences was compared to the histological classification of the recurrent groin veins. Materials and Methods: All patients undergoing redo-surgery for symptomatic groin recurrences after previous stripping of the greater saphenous vein (GSV) during a 1-year period (May 2006-May 2007) were included in the study. Preoperatively, all patients had a duplex-ultrasound scan examination of the groin vessels. Based on the duplex scan findings, the recurrent veins in the groin were classified as either a residual stump or neovascularization. During the redo-surgery, a specimen of the recurrent groin veins was obtained and underwent histologic evaluation. Based on histologic criteria, the recurrence was also classified as a residual stump or neovascularization. Results: During the 1-year study period, 125 groin recurrences in 95 consecutive patients (74 female, 21 male, mean age 58.7 years, standard deviation [SD] 10.3 years) were included. In the 119 cases where both duplex-ultrasound scan and histological evaluation were available, a residual stump was seen at the histological examination in 80.7% of cases, a neovascularization in 10.9% of cases, and a combination of both entities in 8.4% of cases. Duplex-ultrasound scan classified the recurrent groin veins as a residual stump in 68.1% of cases, as neovascularization in 26.1%, and as a combination of both in 5.8% of cases. With histological classification as the gold-standard, duplex ultrasound scans reached a sensitivity of 77.1% and a positive predictive value of 91.4% in correctly identifying a residual stump as the cause of recurrence. For the correct classification of neovascularization, sensitivity was 61.5% and the positive predictive value 25.8%, while a combination of both was recognized with a sensitivity of 10% and a positive predictive value of 14.3%. Conclusion: While duplex-ultrasound scan is a reliable tool to diagnose groin recurrences after varicose vein surgery, its validity in classifying the different types of recurrent groin vessels is limited. Especially the correct identification of neovascularization which is poor with a sensitivity of 62% and a positive predictive value of 26%. Histological examination should still be regarded as the gold-standard when trying to differentiate between different types of groin recurrences. (J Vasc Surg 2009;49:968-72.)