In order to study the biomechanical effect of cyclic loads on revascularization in bone healing, 20 rabbits were chosen for following experiments. Two 2 mm in diameter holes were made at the middle segment of both right and left tibia. A 2 mm in diameter nail was put in 15 mm proximal to the upper hole, and another was put in 15 mm distal to the lower hole. The wound was covered by direct suture with the ends of the nails kept 15 mm out of skin. The medial ends of the two nails were fixed by an iron plate, while the lateral ends were left for cyclic loads. Three Hz cyclic loads, which was near to the cyclic forces when a rabbit runs, was added to the left tibia for experiment, and no loads was add to the right tibia for control. A group of five rabbits were sacrificed respectively in 5, 10, 20 and 30 days postoperatively. The solution of 2% India ink and gelatin was irrigated from aorta to the bone defects. Then the tibia was removed for histologic study. The changes of cells and microvessel were observed. It was shown that the revascularization in experiment group was about 7 days earlier than that of control. The effect was at its peak from 10 to 30 days. It was concluded that cyclic loads could promote revascularization in the healing process of bone defect.
Objective To review various kinds of therapeutic methods for restenosis after reconstructive vascular operation. Methods The literatures about prevention and treatment for restenosis after reconstructive vascular operation were reviewed. Results Therapeutic methods for vascular restenosis include gene therapy, drug treatment, placing external stent around the vein graft and physical therapy. The methods of gene therapy include transferring genes that inhibit the proliferation of vascular smooth muscle cell (VSMC) and inactivating genes that promote the proliferation of VSMC through technology of antisensenucleic acids or RNA interference. Conclusion Current treatment for restenosis after reconstructive varscular operation have both advantages and disadvantages, some of which are still being disputed. With the development of the technology of molecular biology, gene therapy would be the most effective therapy method for vascular restenosis.
【Abstract】 Objective To report cl inical experience in the use of temporary intravascular shunts (TIVS) for quickrestoration of perfusion to the extremity with major vascular injury. Methods Between August 2009 and March 2011, TIVSwas applied temporarily to restore blood perfusion to the extremity in 6 patients with major extremity vascular structure injury secondary to trauma (4 patients) or tumor resection (2 patients), who would received vascular transplantation and underwent long ischemia. The patterns of vascular shunts included external carotid artery-subclavian artery, axillary artery-axillary artery, axillary vein-subclavian vein, brachial artery-brachial artery, brachial vein-brachial vein, brachial artery-radial artery, femoral artery-popliteal artery, and popliteal artery-posterior tibial artery. After TIVS, extensive debridement, fracture fixation, or tumor excision was performed. Then the shunted tubes were removed, and the vessels were repaired definitly. Six vessels were repaired by transplanting the great saphenous veins; one vessel was anastomosed directly without tension; and one vessel was repaired by artificial vascular graft. Results All shunted tubes were successfully established within 5 to 10 minutes (mean, 8.2 minutes). The duration of bypass ranged from 67 to 210 minutes. After establishment of TIVS, blood perfusion to the affected limb was improved. When shunted tubes were removed, thrombosis and partial obstruction occurred in one who accepted amputation, and the others kept patency. No loosening of tubes and haemorrhage occurred. At 2-15 months of follow-up, affected limbs had good blood supply. Conclusion TIVS is rapid and simple, which can quickly restore blood perfusion to the extremity with major vascular injury and shorten the ischemic time of the affected extremity.
ObjectiveTo evaluate the effect of surgical treatment of vertebral artery stenosis and to summarize the experience.MethodThe clinical data of 6 patients undergoing surgical treatment from September 2018 to September 2019 were retrospectively analyzed.ResultsAll the procedures were successfully performed without intraoperative cerebral infarction, injury of thoracic duct or nerve disconnection by mistake. The operative time was 120 to 270 minutes, the median was 180 minutes. The blood loss was 50 to 150 milliliters, and the median was 65 milliliters. One patient suffered from Horner’s syndrome after the operation. One patient suffered from cerebral infarction on 4 days after the operation. During the follow-up of 3–10 months, three patients felt dizziness relieved and there were no anastomotic stricture or new cerebral infarction happened.ConclusionsSurgical treatment is safeand effective for vertebral artery stenosis. Revascularization of the carotid and vertebral arteries at the same time shouldbe avoided.
In 14 dogs, the defect of the abdominal aorta was replaced by 5 to 8.5cm autogen ous peritoneal tube wich was composed of the peritoneum with the posterior sheath of the rectus muscle. The biophysical properties of the peritoneal tube was studied before and after replacement, and it showed that: (1) there was no significant difference between the arterial pressure of grafts and mormal abdominal aorts; (2) the tension strenghth was more than abdominal aorta; (3) the rate of patercy was 100 per cent. Therfore, the autogenous peritoneal tube might serve as a new type of material for replacement of vessels.
Objective To compare the therapeutic effect of one-stage direct revascularization and medicine therapy for the treatment of ischemic moyamoya disease. Methods From March 2002 to March 2008, 18 patients with ischemic moyamoyadisease (12 males and 6 females) were treated, aged 9 to 33 years old. Eighteen patients presented with ischemic stroke, including 11 cases of cerebral infarction and 7 cases of transient ischemic attack. According to Chinese ischemic cardiovascular diseases evaluation tools, 17 patients were classified as low risk ischemic stroke and 1 as modernte risk ischemic stroke. Different levels of occlusion branch of the intracranial carotid arteries and pathosis collaterals were identified by DSA. Fourteen patients and 4 patients were showed unilateral and bilateral hypoperfusion of cerebral blood flow by single photon emission computed tomography, respectively. Eleven patients received superficial temporal artery-middle cerebral artery anastomosis and 7 patients received medicine (anti-PLT agglutinin and calcium channel blocker). Results All incisions healed at stage I. There was no stroke events during perioperation. Anastomosis vessel vasospasm occurred in 2 patients 5 days after operation; and hyperperfusion syndrome in 1 patient 2 weeks afteroperation. All patients were followed up 13-32 months (mean 18 months). In 11 anastomosis patients, 6 underwent 6 stroke events within 12 months; in 7 medicine patients, 6 underwent 11 stroke events within 12 months; and showing a significant difference (P lt; 0.05). The stroke recurrence rate was 85.7% in medicine patients and 54.5% in anastomosis patients 12 months after therapy. DSA showed pathosis collaterals in 7 anastomosis patients and 6 medicine patients 6 months after therapy. After 12 months according to modified Rankin scale, the scores of anastomosis patients were 3 points in 1 case, 2 points in 6 cases and 0-1 point in 4 cases, and the scores of medicine patients were 2 points in 2 cases and 0-1 point in 5 cases; showing no significant difference (P gt; 0.05). Conclusion As long as onset of stroke occurred and ischemic moyamoya disease is diagnosed, one-stage direct revascularization should be performed, which can reduce the rate of stroke recurrence risk and slow down the progression of disease.