Clinical and pathological assessment of different suture techniques for microvascular anastomosis in rat femoral artery

Abstract

This study examined the clinical and pathological features after a microvascular anastomosis of a rat femoral artery using four different suture techniques. Sixty Sprage-Dawely rats were divided randomly into 4 groups. Fifteen bisected arteries (one from each animal) in Group I, II, III and IV were sutured with the simple interrupted suture, continuous suture, sleeve suture and cuff suture, respectively. The anastomosis times in Group I, II, III and IV were 28.67, 14.67, 15.47 and 15.93 min, respectively. Immediate bleeding that stopped without intervention (grade I) was observed in 67%, 73% and 60% of the anastomosed vessels in Groups II, III and IV, respectively, while 60% of the vessels in Group I showed light bleeding that was inhibited by gentile pressure (grade II). All vessels examined appeared to be patent at 5 and 15 min after the anastomosis. On the 7th day postoperatively, the vessels of Group I showed the highest patency rate (93%) compared with Groups II (67%), III (73%) and IV (87%). Moreover, there were more pronounced pathological changes in Group I than in the other groups. These changes included endothelial loss, endothelial proliferation, degeneration and necrosis of the tunica media. Suture materials surrounded by an inflammatory reaction were also observed. In conclusion, the simple interrupted suture is preferable for microvascular anastomosis due to its highest patency rate. The other techniques investigated can be good alternatives because of their short anastomotic time and moderate pathological changes.

Fig. 1

Anastomosis time for the different suture techniques. The continuous, sleeve and cuff techniques resulted in a significant reduction of the anastomotic time compared with the interrupted technique (^*p < 0.01). ^†Group I: simple interrupted suture, Group II: continuous suture, Group III: sleeve suture, Group IV: cuff suture.

Fig. 2

Histopathological findings after an anastomosis of the femoral arteries using the different suture techniques. (A) Simple interrupted suture; Longitudinal section showing a loss of endothelial cells (thin arraow), vacuolated and necrosed tunica media (TM) and the presence of suture materials (thick arrow) surrounded by inflammatory cells (asterisk). (B) Simple interrupted suture; Transverse section showing suture materials in the lumen (arrow) surrounded by endothelial cells. (C) Simple interrupted suture; Transverse section showing an inflammatory cellular reaction surrounding the suture material (arrow). (D) Continuous suture; Transverse section showing slight narrowing of the lumen. (E) Sleeve suture; Transverse section showing narrowing of the lumen and the presence of suture materials in the wall (arrow). (F) Cuff suture; Transverse section showing slight narrowing of the lumen and endothelial proliferation (arrow). H&E stain.

Fig. 3

Scanning electron micrographs after femoral artery anastomosis using the different suture techniques. (A) Normal femoral artery showing spindle-shaped endothelial cells (asterisk). (B) Simple interrupted suture showing suture threads (asterisk), intimal holes (arrow) and signs of regeneration (arrowhead). (C) Simple interrupted suture showing fibrin network (arrow) partially covering the suture thread (asterisk). (D) Continuous suture showing a gap filled with fibrin between the two arterial ends (arrows) and normal endothelium at both sides (arrowheads). (E) Simple interrupted suture showing signs of regeneration consisting of endothelial cells (arrowhead) covering the suture thread (asterisk). (F) Sleeve suture showing the proximal (arrowhead) and distal (double arrowhead) segments with neoendothelization (arrow).