A Revised Arterial Anastomosis Technique for Improving Mouse Renal Transplant Outcomes.

Abstract

PURPOSE: One of the most challenging research microsurgical techniques is the mouse kidney transplant. Despite being first reported over 40 years ago, very few laboratories have been able to make use of this important model due to its technical difficulty. One of the main obstacles to using this procedure is the high incidence of arterial thrombosis with traditional arterial anastomosis. We hypothesized that thrombosis is caused by a tortuous route and areas of turbulence along the path blood flows from recipient abdominal aorta to donor aorta, and on into the renal artery. We propose that disruption in smooth flow dynamics leads to thrombus formation and graft loss. METHODS: Kidney transplants were performed using traditional and revised methods. Kidney histology and apoptosis were assessed by a nephropathologist in a blinded fashion, and function was measured using serum creatinine (sCr). Acute tubular injury (ATI) was scored as follows: 0 = none, 1 ≤10%, and 5 > 75% of tubules involved. RESULTS: Traditional arterial anastomosis involved square dissection of the donor abdominal aorta which, when sewn to the recipient aorta required blood flow to negotiate a bend of >90°. Here we describe a revised method of donor aorta harvest by creating a heel and toe cuff (Fig. 1a). The traditional method resulted in a tortuous path (Fig. 1b), while the revised method straightened the flow path and reduced the recipient aorta to donor arterial cuff angle to <90° (Fig. 1c). Arterial thrombus incidence decreased from 35% to 0%, without a change in warm ischemia time ( 38 ± 3 vs. 38 ± 5 mins for revised technique vs. traditional technique, P=NS). The revised technique resulted in excellent function (sCr=0.4mg/dL) and histology, with pathological ATI score=1, and apoptosis score=0. CONCLUSION: The revised arterial anastomosis technique using a heel and toe cuff results in a straighter flow path thereby reducing thrombus formation and improving mouse renal transplant outcomes.Figure: No Caption available.