Flow reduction in high-flow arteriovenous access using intraoperative flow monitoring

J Vasc Surg. 2006 Dec;44(6):1273-8. doi: 10.1016/j.jvs.2006.08.010.

Abstract

Purpose: This study used intraoperative monitoring of the access flow to evaluate the results of flow reduction in the management of high-flow arteriovenous access-related symptoms of distal ischemia and cardiac insufficiency.

Methods: A retrospective study was conducted of 95 patients (78 with ischemia, 17 with cardiac failure) who underwent flow reduction between 1999 and 2005. A preoperatively measured access flow-volume rate > 800 mL/min for autogenous accesses (n = 77) and > 1200 mL/min for prosthetic accesses (n = 18) was the selection criterion for the use of a flow reduction procedure. Flow reduction was achieved using a spindle-like narrowing suture near the anastomosis and final placement of a polytetrafluoroethylene strip while a flow meter was used for intraoperatively measuring the access flow. The desired postoperative flow was 400 mL/min for autogenous and 600 mL/min for prosthetic accesses.

Results: The mean preoperative access flow was 1469 +/- 633 mL/min in patients with ischemia and 2084 +/- 463 mL/min in patients with cardiac failure, without significant differences between access types. The flow was reduced to 499 +/- 175 mL/min for autogenous accesses and to 676 +/- 47 mL/min for prosthetic accesses. The mean follow-up was 25 months (range, 1 to 73 months). Complete long-term relief of symptoms was observed in 86% of patients with ischemia and in 96% of patients with cardiac failure. Reconstruction significantly increased the digital-brachial index (0.41 +/- 0.12 vs 0.74 +/- 0.11; P < .05) and mean distal arterial pressure (47 +/- 17 mm Hg vs 79 +/- 21 mm Hg; P < .05) in patients with ischemia. Primary patency rates were significantly better for reconstructed autogenous accesses compared with rates of prosthetic accesses (91% +/- 4% vs 58% +/- 12% at 12 months; 81% +/- 6% vs 41% +/- 14% at 36 months; P < .001). The low patency of reconstructed prosthetic accesses is due to the high thrombosis risk of accesses that have a flow < 700 mL/min.

Conclusions: Flow reduction using intraoperative access flow monitoring is an effective and durable technique allowing for the correction of distal ischemia and cardiac insufficiency in patients with a high-flow autogenous access. The desired postoperative access flow of 400 mL/min is not associated with an increased risk of thrombosis. Flow reduction of prosthetic access is as effective; however, a higher access flow than the desired 600 mL/min seems to be necessary to achieve an acceptable patency in prosthetic accesses.

MeSH terms

  • Arteries / physiopathology
  • Arteriovenous Shunt, Surgical / adverse effects*
  • Blood Flow Velocity
  • Blood Pressure
  • Blood Vessel Prosthesis Implantation
  • Cardiac Output, Low / diagnostic imaging
  • Cardiac Output, Low / etiology
  • Cardiac Output, Low / mortality
  • Cardiac Output, Low / physiopathology*
  • Cardiac Output, Low / surgery
  • Extremities / blood supply*
  • Female
  • Follow-Up Studies
  • Graft Occlusion, Vascular
  • Humans
  • Ischemia / diagnostic imaging
  • Ischemia / etiology
  • Ischemia / mortality
  • Ischemia / physiopathology*
  • Ischemia / surgery
  • Male
  • Middle Aged
  • Monitoring, Intraoperative* / methods
  • Regional Blood Flow
  • Retrospective Studies
  • Survival Analysis
  • Time Factors
  • Treatment Outcome
  • Ultrasonography, Doppler, Color
  • Vascular Patency
  • Vascular Surgical Procedures*