The causes of recurrence were identified through lower extremity venography and duplex Doppler ultrasound, and the corresponding surgeries were performed for deep, superficial and traffic venous insufficiency and the results were followed up in 60 cases with 66 affected limbs. Among the causes of recurrence after surgery, 95-45% (63/66) of the patients had venous insufficiency of the communication veins, 72-72% (48/66) of the patients had residual saphenous vein trunk and some of its branches, and 43-94% (29/66) of the patients had venous insufficiency of the deep vein valves. The diagnostic accuracy of lower extremity venography in venous patency was 100%; the diagnostic compliance rates of lower extremity venography and duplex ultrasound in the detection of deep venous valve function and residual saphenous vein trunks and branches were 87, 5%, 79, 16%, respectively; the leakage rate of duplex ultrasound in the traffic veins (5, 11%) was significantly lower than that of venography (28, 31%). The postoperative VCSS score after reoperation (1, 9±1, 3) was significantly lower than the preoperative one (7, 00±4, 20) with P6s, counting 8 lateral lower limbs. The comparison of the two tests is shown in Table 3. only the presence or absence of reflux was judged, and the results of both were consistent in 21 limbs, with a compliance rate of 87,5%. In the 13 lower limbs with class II to V reflux found by lower limb venous cascade angiography, all of them showed grade 1-4 reflux by duplex ultrasound, but among the 10 lower limbs where the former showed normal valve function, 3 cases were classified as grade 1 (2 sides) and grade 4 (1 side) reflux by duplex ultrasound. Residual saphenous vein trunk and geniculate branches: 7 cases of lower limb veins were visualized in the root of saphenous vein in 8 lateral limbs by parallelepipedography, among which 1 case was twisted into a mass, and the root of saphenous vein in the remaining 15 cases and 16 lateral limbs were not visualized. The ultrasound showed that the saphenous vein at the saphenofemoral junction was resected in 11 limbs in 10 cases, and there was no residue at the root; in 4 cases, 1 or 2 branches of the saphenous vein were seen at the root of 4 limbs, and 3 of them had clinical manifestations of inguinal varicose vein with soreness and discomfort, and the other 1 case had no clinical symptoms and was not recorded in the statistics of recurrence causes. The saphenous vein was twisted and dilated at the root in one case. The compliance rate between the lower extremity venous cascade angiography and ultrasound was 79,16%. Traffic vein: In the lower extremity venous processional angiogram, one or several dilated and distorted traffic veins can be seen emanating from the deep veins or muscular venous plexus connected to the superficial veins, mostly in the middle and lower part of the medial calf. When the calf is squeezed and quickly relaxed during the duplex ultrasound, there is a reversal of color from blue to red in the refluxing traffic veins. In this paper, a total of 78 traffic veins with reflux were found in 22 cases on 24 limbs, confirmed by surgery. Among them, 54 traffic veins were detected by both lower extremity venography and ultrasound, accounting for 69,10%; 4 traffic veins were missed by ultrasound, accounting for 5,11%; 22 traffic veins were missed by lower extremity venography, accounting for 28,31%. Follow-up results All cases in this group were discharged within 1w to 3w after reoperation, without surgical complications and without perioperative death. In cases with original ulcers, the ulcers had healed by the time of discharge. The follow-up rate was 78,33% (47/60), and the follow-up time ranged from 3 months to 12 years, with a mean of 3,15±2,73 years, with no recurrence of ulcer. The postoperative VCSS score ranged from 0 to 5 points, with a mean of 1,9±1,3, which was significantly lower than that before surgery (7,00±4,20), with significant differences.