Optimizing technical success of renal revascularization: the impact of intraoperative color-flow duplex ultrasonography

Abstract

Purpose: Technical problems with renal revascularization can be difficult to detect, especially with end points of transaortic renal endarterectomies or anastomosis of bypass grafts to small distal renal arteries. If missed, such technical mishaps may not be recognized until after operation, when the chance for timely renal salvage has often been lost.

Methods: To evaluate the value of newer color-flow duplex imaging, we performed intraoperative ultrasonography on 35 patients undergoing revascularization of 64 renal arteries, 29 patients undergoing transaortic endarterectomy, and 6 undergoing bypass grafting. Most patients (24/35; 69%) underwent concomitant aortic reconstruction. Ninety-four percent had hypertension, whereas 66% had associated chronic renal insufficiency.

Results: Technical abnormalities prompting operative revision were identified during surgery in 10.9% of reconstructed main renal arteries (7/64). These included two occlusions, three intimal defects, and one extrinsic tissue band after endarterectomy plus one graft anastomotic stenosis. Color-flow imaging revealed all of them. Technical defects were also associated with higher peak-systolic flow velocities (mean 2.62 m/sec; range 2.00 to 3.50 m/sec) than normal-appearing arteries (mean 1.34 m/sec; range 0.40 to 2.50 m/sec) (p = 0.004). Eighty-six percent of the defects (6/7) were immediately correctable. One patient required nephrectomy. Postoperative angiograms revealed two asymptomatic small branch-vessel occlusions (3%). Compared with preoperative levels (p < 0.01), both hypertension and renal insufficiency improved initially. The clinical outcome of patients requiring intraoperative revision did not differ from that of patients undergoing normal intraoperative studies.

Conclusion: Intraoperative color-flow duplex detection and surgical correction of technical problems with renal revascularization have enhanced our technical success and been associated with long-term results comparable to those of patients undergoing normal intraoperative studies.