An Objective Evaluation of an Injured Vessel Wall Using Fluorescein Sodium before Microvascular Anastomosis in an Experimental Rat Model

Abstract

The aim of this study was to establish an objective evaluation method for intraoperative detection of damaged vascular endothelium in avulsion injuries. Twenty male Fischer rats were randomly assigned to control or experimental groups ( N = 10, each). Crush-avulsion injury was performed on right femoral arteries. Resection of damaged segments was performed according to operative microscopic findings in the control group; fluorescein sodium was applied to the artery lumen before resection in the experimental group to help visualize the damaged endothelium. Microvascular repair was performed in five rats in each group. In the other animals, the whole length of the femoral arteries was resected to assess the actual extent of injury histologically. At the end of the follow-up period, patency of microvascular anastomoses was examined and the lengths of the resected segments were compared with the actual length of the injured segment measured histologically. The difference between these two measurements was statistically significant in the control group ( P < 0.05) but not in the experimental group ( P > 0.05). Anastomosis patency was significantly higher in the experimental group ( P < 0.0001). In conclusion, fluorescein sodium may help to accurately determine the length of the injured vascular segment in avulsion injuries.

Evaluation of the Extent of Vessel Avulsion Injury: An Experimental Study Using a Rabbit Model

“…However, it also has disadvantages, such as dye entering the surgical field and special equipment being required. Studies aimed at determining levels have been performed, 4,8,[14][15][16] but the standard method is an experimental avulsion model. Level determination was performed histopathologically, and studies have produced no recommendations concerning the practical extent of damage determination capable of use in clinical practice.…”

“…In practical terms, the extent of injury is determined on the basis of these findings, and previous studies have regarded endothelial findings as more significant. [2][3][4][5][6][7][8][9][10][11][12][13] Experimental methods have been reported concerning the pathophysiology of avulsion injury, 4,8,[14][15][16] but there is no practical method for determining the extent of vascular injury. Although some authors have suggested that endothelial findings are more significant, there is no firm scientific evidence showing which of the clinically used adventitial and lumen findings are more effective.…”

Blunt Trauma Induced Closed Femoral Bone Fracture in a Rat Model: Are Vessels Safe to Use for Microsurgery? Further Insight into the Zone of Injury Concept

“…issues if free flap reconstruction is needed [3,4]. In cases of closed fractures, reconstruction of post-traumatic defects is often delayed until skin necrosis has already set in, even if the skin appears intact.…”

“…In addition, the damaged segment of the vessels, the "zone of injury," and the increased thrombogenic effect in this segment may result in late skin necrosis or anastomosis issues if free flap reconstruction is needed. 3,4 In cases of closed fractures, reconstruction of posttraumatic defects is often delayed until skin necrosis has already set in, even if the skin appears intact. It is still uncertain what exactly is happening to the vessels within the injury zone when there is no apparent vascular damage.…”

Training in micro-vascular anastomosis using rat femoral vessels: comparison of immediate and delayed patency rates.

“…This could have resulted in lower delayed patency rates, and can be considered as a drawback of the study. Newer modalities like intraoperative near-infrared indocyanine-green (ICG) angiography and mini Doppler systems have been used to evaluate anastomosis patency in the rat femoral vessels (16,20). Though expensive, these techniques could avoid a reexploration surgery to check for delayed patency.…”