THROMBECTOMY IN PATIENTS WITH THROMBOSIS OF ARTERIO-VENOUS FISTULA: CASE SERIES

Abstract

Introduction. Thanks to the use of renal replacement therapy at the current stage of medical development, complete medical and social rehabilitation of patients with end-stage chronic renal failure is possible. The key to effective programmed hemodialysis is the formation of adequate permanent vascular access. Ensuring the optimal use and functioning of permanent vascular access is a multidisciplinary challenge. Currently, none of the known options for permanent vascular access is ideal, but a native arteriovenous fistula meets the requirements to a greater extent. Complications from vascular access for hemodialysis remain relevant for their solution today. The most common complication of vascular access is thrombosis of an arteriovenous fistula. For patients with chronic renal failure who are on programmed hemodialysis, thrombosis of vascular access is a great danger, which ultimately can lead to the impossibility of further hemodialysis and is the main reason for hospitalization and high mortality of this contingent of patients and needs an urgent solution.
 Clinical cases. 17 patients underwent thrombectomy from the subcutaneous "fistula". vein of the upper extremity. The age of the patients was 49.0 (44.0-61.0) years. By gender, the studied patients were distributed as follows: women - 9 (53%), men - 8 (47%). Among 17 (100%) operated patients, 12 (71%) had late thrombosis, 5 (29%) had early thrombosis of arteriovenous fistula,. Of 5 (100%) patients with early thrombosis of arteriovenous fistula, thrombectomy was effective in 2 (40%) patients (p=0.038). On the other hand, in 12 (100%) patients with late thrombosis of arteriovenous fistula, thrombectomy was successful in only 4 (33%) cases.
 Discussion. The cause of thrombosis of any vascular anastomosis is primarily hyperplasia of the neointima due to the proliferation of smooth muscle cells of the vascular wall. This circumstance leads to the formation of stenosis of the anastomosis, and as soon as the stenosis values become hemodynamically significant (> 50% of the lumen of the vessel), the risk of developing thrombosis increases by more than 50%. Thrombectomy alone is insufficient to restore patency of the permanent vascular access in the long term, as flow-limiting stenosis is present in more than 85% of cases.
 Conclusions. Neointimal hyperplasia is the main cause of progressive stenosis of arteriovenous fistula and subsequent thrombosis. Thrombectomy is indicated for thrombosis of arteriovenous fistula in the early postoperative period (up to 30 days after arteriovenous fistula formation). Thrombectomy alone is not enough to restore the patency of the permanent vascular access in the long term, and the final treatment requires its reconstruction at an early stage or the creation of a new arteriovenous fistula.