The experimental study and clinical application of temporary intravascular shunt on small blood vessels

Abstract

Objective To investigate the feasibility of temporary intravascular shunt (TIVS) using on small blood vessels and the relation between the length of TIVS and the time of the patency,then observe clinical results of TIVS.Methods The right femoral artery transection model were established in 20 New Zealand white rabbits,which were divided into group A and B (n =10) randomly.The vascular stumps were bridged by the shunts with 2 mm in inner diameter,with the shunts in length in group A and B being 10 cm and 20 cm respectively.Regular observation was carried out after operation for the patency in shunts.The observation endpoint with the shunts completely blocked were as follows:the color of shunts turn into a dark red,no blood flow on Doppler ultrasound testing,no pulse in distal artery.The differences between two groups to reach the end of the time observed.The results on repairing radial artery with TIVS with 3 mm in inner diameter for patients of Gustilo Ⅲ C-type fractures in forearm and broken wrist reimplantation were observed.Results The diameter of the femoral artery of rabbits was 1.5-2.0 mm.After vascular bypass were established,there were pulse in the distal femoral artery and flow signal in shunts could be detected by Doppler ultrasound.With the passage of time,the shunts were gradually from bright red to dark red,distal pulse gradually weakened until it disappears,and the blood flow signal disappears eventually.The time reach observation endpoint in groups A,B were (240.00 ± 122.78) (117.00-363.00) min and(230.00 ± 109.20) (121.00-339.00) min respectively.The difference between the two was not statistically significant.There were 2 clinical cases using TIVS for radial artery,and the bypass time were 180 min and 148 min.After establishing vascular bypass,peripheral blood supply were restored,the vessels remained patency after remove the shunts,distal limbs postoperative were survived.Conclusion Temporary vascular bypass could use for small blood vessels with caliber 1.5-2.0 mm,and the time to maintain through the blood was up to 4 hours.The difference in maintaining patency time using the shunts in length of 10 cm and 20 cm was no significant.Using TIVS in small vessel for replantation of broken wrist could early reconstructed distal blood supply,and reduced limb ischemia time. Key words: Temporary intravascular shunt; Extremity vascular injury ; Open fracture ; Rabbit ; Vascular bypass