Long-term histologic results of vein grafting with the telescoping anastomotic technique

Modified Sleeve Anastomosis in Large Muscular Arteries of Sheep

OBJECTIVE

The purpose of this investigation was to test a modified telescopic anastomosis in large muscular arteries.

MATERIAL AND METHODS

The right carotid arteries in 30 sheep (average weight 57+/-5.7 kg) were transected and anastomosed end to end using two guided sutures and compared with a control group (10 sheeps) using two external sutures (Lauritzen method).

RESULTS

The mean time to complete the anastomosis (4.5 min) and hemostasis (4.3 min) in the experimental group was less than the control group (17.3 min for anastomosis and 6.4 min for hemostasis) (P<0.05). In addition, the total amount of blood loss during the modified anastomosis was significantly lower than Lauritzen method (3.8 versus 8 ml). In both experimental and control groups the scanning electron microscopy (SEM) at 90th day post-operation revealed a continuous smooth layer of endothelial cells covering the anastomotic junction.

CONCLUSIONS

Anastomosis with two guided sutures is easy and faster to perform and could be applicable to an acutely transected vessel.

Vascular grafts in the rat model: an anatomic study

Vascular grafts in animal models have been used extensively in the microsurgical laboratory, and the rat offers an excellent source of graft to meet these needs. In this study, we compiled a list of vessels that were previously identified in experimental literature for use as vascular grafts in the rat model. We then dissected and measured both arterial and venous grafts taken from these sites in 12 adult rats. The surgical procedure for approaching each vascular graft was recorded. The diameter and harvestable length, the start and end points, and the number of branches of the graft were tabulated. We believe that these data will provide valuable insight applicable to the use of the rat vascular graft in microsurgical research and training.

Long-term result of arterial grafts interposed for arterial defects using the telescoping anastomotic technique: histological and angiographic study

The arterial grafting model for arterial defects provides an ideal environment for the microvascular telescoping anastomosis because tension of the repaired vessel is maintained low and deformities of the inserted vessel end is minimal due to the thick arterial wall. The left femoral artery was grafted in 46 rats into the defect created in the right femoral artery using the telescoping anastomotic technique at both the proximal and distal anastomoses. The grafts were seen histologically and angiographically 3 to 4 months postoperatively in order to fairly evaluate the telescoping anastomosis in terms of long-term patency, stenosis, and changes in the outer and inner walls at the anastomosis. All arterial grafts were patent 3 to 4 months postoperatively and there were no aneurysms at the anastomoses. Enlargement of the graft diameter was minimal. The rate of stenosis at the anastomosis was smaller than that 1-day postoperatively. Even though the thick arterial wall was initially inserted and the intimal hyperplasia was still present at the anastomosis 3 to 4 months postoperatively, the long-term stenosis was relatively mild due to the atrophy in the overlapped walls.

A comparison by burst testing of three types of vascular anastomosis

A new in vivo test for burst strength of arterial anastomoses was tested in 40 rats. Twelve had a severed right femoral artery reanastomosed by the traditional nine-suture technique. In a second group of 12, a modified telescoping sleeve method of reanastomosis was used. In a third group of 12, a laser-assisted anastomosis using four stay sutures was performed. Four rats had sham procedures. Immediately after reanastomosis three vessels from each group plus all four sham surgical vessels were subjected to burst testing. These tests were performed again on the repaired vessels at 1 week, 1 month, and 2 months. All the vessels were patent at burst testing. All repairs held at all times to greater than 160 mm mean arterial pressure. The four-suture telescopic anastomosis technique was consistently strongest over time, but all techniques showed adequate strength at all time intervals.

Long-term results of vein grafts interposed in arterial defects using the telescoping anastomotic technique and fibrin glue

Fibrin glue has been applied in the anastomosis of vein grafts placed in rat femoral arteries using the telescoping technique at both ends of the graft. 34 out of 35 grafts which were patent 1 to 3 weeks post-operatively were kept for 3 months to assess the long-term patency, and the effect of the glue on the diameters of the graft and femoral artery. All 34 grafts were patent 3 months post-operatively. Excessive enlargement of the graft diameter was alleviated by the fibrin glue without affecting the diameter of the femoral artery. The diameter at the proximal anastomosis was 66% and that at the distal anastomosis was 87% of the diameter of the femoral artery.

Comparison of the telescoping anastomotic technique with the end-to-end technique utilizing vein grafts for venous defects: short- and long-term results

The telescoping anastomotic technique was used for both anastomoses of vein grafts placed in the rat left epigastric vein in an effort to make the anastomosis easier and faster. Vein grafting in the right epigastric vein was completed using the conventional technique. The 20 rats with 20 left and 13 right vein grafts, which were patent at 3 weeks, were seen again 3 months postoperatively to compare the two techniques with regard to long-term stenosis and histological changes. Patency of the grafts 2 hr postoperatively was also compared between the two techniques in another 25 rats to eliminate the influence of recanalization on patency. All the vein grafts, which had been patent 3 weeks postoperatively, remained patent after 3 months and no statistically significant difference was found between the telescoping and conventional technique in the degree of stenosis. The vein grafts 2 hr postoperatively were all patent in both groups.

New burst test method for comparing strengths of blood vessel repairs

An in vivo system was developed which allows researchers to determine the intraluminal pressures necessary to burst anastomosed blood vessels. Rat femoral arteries underwent standard microsurgical anastomoses and sham surgeries. After 6 min of leak-free blood flow, the vessels were ligated and cannulated with PE 50 tubing. The catheter was tied into position with 6-0 suture, constructing a water-tight balloon of tissue inclusive of the repair site around the tubing, then attached via a "Y" adapter to a pressure transducer with a digital readout and to a saline filled syringe in an infusion pump. The digital readout from the transducer accurately expressed the pressure on the anastomosis. The highest pressure recorded when the anastomosis ruptured was taken to be the anastomotic burst pressure. Mean burst pressure for 9 suture anastomoses was 326 mm mercury. All vessel burst pressures exceeded rat mean systolic pressure; 90% exceeded rat maximum systolic pressure. All sham surgeries failed to burst, even at pressures exceeding 1,500 mm Hg. The burst pressure test clearly provides researchers with a valid quantitative measure for in vivo comparison of the efficacies of various anastomotic techniques.