Abnormal in vivo response to sodium nitroprusside after porcine single lung transplantation.

The chronic increase of pulmonary vascular resistance after lung transplantation is only partly due to an active increase in baseline vasomotor tone, but the nature of the acute pulmonary hypertension after ischemia and reperfusion is not known. We studied the effects of sodium nitroprusside on pulmonary hemodynamics during reperfusion in porcine left lung allotransplants. In twelve pigs (weight: 18 to 24 kg) pulmonary arteries of the native and the transplanted lung were cannulated for right-heart bypass. The total blood flow was 2 L/min. Flow distribution between the lungs was measured at equal mean pulmonary artery pressure, and pulmonary vascular resistance at equal and constant flow-i.e., 1 L/min to each lung. After baseline measurements sodium nitroprusside (1, 3, and 9 microg/kg/min) was administered to six animals (SNP group). The control group (n=6) received an equal amount of the vehicle. After 30 min of discontinuation of the drug infusion, the schedule was repeated. In the transplanted lung, pulmonary vascular resistance decreased in all animals during the first hour of reperfusion. During the second drug infusion pulmonary vascular resistance was significantly lower in the SNP group compared with the control group only at the highest infusion rate of the drug (9 microg/kg/min), which also induced a 44% decrease in systemic vascular resistance. Arterial oxygen tension remained comparable in the two groups throughout the study. Our data suggest that other factors besides active vasoconstriction may contribute to the acute increase of pulmonary vascular resistance after lung transplantation.

Pulmonary vasodilatory properties of prostaglandin E1 are blunted after experimental single lung transplantation.

BACKGROUND: Pulmonary dysfunction and right heart failure are still a common clinical problem after single lung transplantation. METHODS: In this study we investigated the pulmonary vasodilatory properties of prostaglandin E1 in pigs during the first 4 hours after left lung allotransplantation. With the use of extracorporeal circulation and total right heart bypass, the right and left pulmonary arteries could be individually perfused and the drug effect in each lung separately analyzed either at equal blood pressures or at equal blood flows in the pulmonary arteries. Twelve animals received in a randomized double-blind fashion either saline solution or an increasing prostaglandin E1 infusion (10, 25, 50, and 100 ng/kg/min; 15 minutes each). After a drug-free period of 75 minutes, the infusion schedule with 25, 50, and 100 ng/kg/min was repeated. RESULTS: During the first part of the study the highest dose of prostaglandin E1 decreased the mean systemic arterial pressure by 25%, but an almost similar decrease occurred in the control animals. During the second infusion period a 28% decrease was observed only in the animals treated with prostaglandin E1. None of the infusions was able to decrease pulmonary vascular resistance. Instead prostaglandin E1 diverted two thirds of the pulmonary blood flow toward the native lung, and this diversion manifested itself as an earlier improvement of the arterial oxygen tension in the drug-treated animals. The end-tidal carbon dioxide values measured from each lung corresponded to those from the common expiratory limb of the system, but there was a distinct gradient in the range of 14 to 20 mm Hg between the arterial and end-tidal carbon dioxide values. CONCLUSIONS: We conclude that prostaglandin E1, in doses tolerated by the systemic circulation, is ineffective in the treatment of the increased pulmonary vascular resistance after single lung transplantation.

Thromboxane receptor blockade does not attenuate pulmonary pressor response in porcine single lung transplantation.

BACKGROUND: The ischemia-reperfusion lung injury is characterized by increased pulmonary vascular resistance, edema, and subsequent deterioration of oxygenation. Other models of acute lung injury suggest that thromboxane A2 may contribute to the pulmonary hypertension after transplantation. METHODS: We studied the effects of the selective thromboxane A2 receptor antagonist SQ 30741 on pulmonary hemodynamics and gas exchange in porcine single lung transplantation using extracorporeal circulation (right heart bypass) with separate cannulations of the right and left pulmonary arteries. Pulmonary vascular resistance was measured at equal and constant flow to each lung. Flow distribution between the lungs was registered at equal pulmonary artery pressures. Twelve pigs (weight 17 to 23 kg) were studied. At the onset of reperfusion a bolus dose of the drug (5 mg/kg) was injected into both pulmonary arteries followed by an infusion (5 mg/kg/hr) for 1 hour (SQ group, n = 6). The control group (n = 6) received an equal amount of vehicle. The systemic and pulmonary hemodynamics and blood gas values were registered during 2 hours of reperfusion. RESULTS: The pulmonary vascular resistance of the transplanted lung was significantly higher compared with the native lung (p < 0.001). Administration of SQ 30741 failed to ameliorate the pulmonary pressor response of the graft in comparison with the control group. No difference was found in the systemic arterial oxygen tension between the two groups. CONCLUSIONS: Thromboxane does not seem to be among the principal mediators in the pulmonary hypertension after transplantation.

Value of high-resolution computed tomography in routine evaluation of lung transplantation recipients during development of bronchiolitis obliterans syndrome.

BACKGROUND: Chronic rejection is a major long-term complication after lung transplantation. The purpose of our study was to evaluate the role of repeated high-resolution computed tomographic examinations in monitoring the development of bronchiolitis obliterans syndrome after lung transplantation. METHODS: A total of 126 high-resolution computed tomographic examination in 13 lung transplant recipients was analyzed. During a mean follow-up period of 23 months, bronchiolitis obliterans syndrome developed in eight of the patients. A scoring system from 0 to 10 based on the number of chronic changes on high-resolution computed tomography was developed, and the score of each patient was compared with decline in the forced expiratory volume in 1 second and maximal forced expiratory flow rate of 50% of the forced vital capacity. RESULTS: The score of chronic changes, measured at 1 year after transplantation, correlated inversely with the values of forced expiratory volume in 1 second and maximal forced expiratory flow rate at 50% of the forced vital capacity (p < 0.05). Stage I bronchiolitis obliterans syndrome was associated with scores of 4 to 6 (mean 5.0), stage 2 with scores of 6 to 9 (mean 7.0), and stage 3 with scores of 6 to 9 (mean 7.7). The sensitivity of high-resolution computed tomography was 93% and its specificity was 92% when five chronic changes were used as a cutoff level. CONCLUSIONS: The progress of chronic changes on high-resolution computed tomography occurs concurrently with the development of bronchiolitis obliterans syndrome. High-resolution computed tomography may provide additional morphologic information for noninvasive evaluation of chronic lung rejection.

Angiographic 5-year follow-up study of right gastroepiploic artery grafts.

BACKGROUND: The right gastroepiploic artery (RGEA) has been used from 1987 in coronary artery bypass grafting in several clinical studies. However, the published 1- to 5-year patency rates have been dependent on the selection of patients for angiography. METHODS: In our study, the RGEA was used from March 1987 to May 1990 for coronary artery bypass grafting in 31 consecutive patients, 25 male and 6 female. All but 1 patient had triple-vessel disease, and the mean number of distal anastomoses was 3.9 (range, 2 to 5). Internal thoracic artery grafts were used concomitantly in all patients. RESULTS: One early and two late deaths occurred. All but 1 of the 28 surviving patients underwent clinical and angiographic follow-up examinations 3 months and 5 years after the operation. The 5-year patency of RGEA grafts was 82.1%, with a 95% confidence interval of 63.1% to 93.9%. In 4 of the 5 nonvisualized cases, the recipient coronary artery showed proximal stenosis of up to 70%, allowing substantial competitive flow. The 5-year patency of the RGEA graft was near that of the left internal thoracic artery, at 90.3%, and the right internal thoracic artery, at 94.4%; and superior to the 66.7% patency of venous grafts. CONCLUSIONS: At 5-year follow-up, angiography of RGEA grafts showed good function and a smooth lumen, especially if the proximal stenosis was more than 70%.

Air contamination in open heart surgery with disposable coveralls, gowns, and drapes.

The effect of a polypropylene coverall, replacing shirt and trousers, combined with sterile laminated gowns and drapes compared with an all-cotton system was studied in regard to the dispersion of bacteria and particles in a conventionally ventilated operating theater. The operations carried out were open heart procedures in 30 adult patients. Blood agar sedimentation plates were placed in the operative, anesthesia, and perfusion areas. The mean sedimentation values during 1 hour after the start of operation were as follows in the laminate group: 63 colony-forming units (cfu)/m2 in the operative area; 77 cfu/m2 in the anesthesia area; and 143 cfu/m2 in the perfusion area. The corresponding figures in the cotton group were 350 cfu/m2, 364 cfu/m2, and 437 cfu/m2, respectively (p less than 0.0002). At the beginning of the operation, the mean values noted for colony-forming units in the air at the operative site were 8.0 cfu/m3 in the laminate group and 31 cfu/m3 in the cotton group. One hour later, the values were 10 cfu/m3 and 22 cfu/m3, respectively (p less than 0.0002). At the end of the operation, the number of particles 5 microns or larger in the air at the operative site was 278/m3 in the laminate group and 592/m3 in the cotton group. It is concluded that the use of a polypropylene coverall and laminated gowns and drapes significantly reduces the particle and bacterial contamination of the air and the bacterial sedimentation during cardiac operations.

Prostaglandin E1 or prostacyclin in Euro-Collins solution fails to improve lung preservation.

BACKGROUND: In search of the ideal composition of the flush solution for pulmonary preservation, we studied the effects of prostaglandin E1 (PGE1) and prostacyclin as an additive to Euro-Collins solution (ECS) on pulmonary hemodynamics and gas exchange in a porcine single lung transplantation model using extracorporeal circulation and right heart bypass. METHODS: Twenty-two pigs served as donors. The animals were randomized to receive either modified ECS alone (control group, n = 8), ECS with 100 micrograms/L of PGE1 (PGE1 group, n = 6), or ECS with 200 micrograms/L of prostacyclin (prostacyclin group, n = 8). Left lung transplantation was performed in 22 recipients after approximately 4 hours of cold ischemia. RESULTS: Carbon dioxide elimination was significantly depressed in the two prostaglandin groups, and the use of PGE1 was associated with a significant decrease in arterial oxygen tension compared with the control group. Both drugs were inefficient in alleviating the increase in pulmonary vascular resistance after transplantation. CONCLUSION: The use of prostaglandins as constituents of the flush solution was not followed by any improvement of early graft function after cold ischemia.

Minimally invasive coronary artery bypass grafting using the right gastroepiploic artery.

BACKGROUND: Anastomosis of the left internal thoracic artery to the left anterior descending artery without sternotomy and without cardiopulmonary bypass is a standard approach in minimally invasive coronary artery bypass grafting. To expand the indications for minimally invasive coronary artery bypass grafting from one-vessel disease to two-vessel disease, we began to perform anastomosis of the right gastroepiploic artery (RGEA) to the right coronary artery (RCA). METHODS: From February to November 1996, an RGEA graft was used in 25 of the 100 patients who underwent minimally invasive coronary artery bypass grafting at our clinic. Eleven of the patients had only RCA disease and 14 had both RCA and left anterior descending artery disease. One of the operations was a redo coronary artery bypass grafting. The RGEA was anastomosed to the RCA through a laparotomy incision and the left internal thoracic artery was anastomosed to the left anterior descending artery through a left anterior thoracotomy. In 5 patients, the RGEA was lengthened by venous grafting. RESULTS: All patients underwent angiography after operation; 82.6% of the RGEA grafts and all the left internal thoracic artery grafts were functioning well. In three of the four nonvisualized RGEA grafts, the percentage of proximal stenosis of the RCA seen on postoperative angiography was not critical (40%, 50%, and 50%, respectively), allowing significant competitive flow through the native bypassed RCA. The patency of all the RGEA grafts without competitive flow was 95%, with a 95% confidence interval of 75.1% to 99.9%. CONCLUSIONS: The indications for minimally invasive coronary artery bypass grafting could be extended to primary operations in patients with left anterior descending artery and RCA lesions by using both the left internal thoracic artery and the RGEA.

Right gastroepiploic artery as a coronary bypass graft.

Between November 1987 and April 1988, the right gastroepiploic artery (GEA) was used as a coronary artery bypass graft in 11 patients, 9 men and 2 women. In 1 of them, the GEA was used because no veins were available; in the others, the GEA was used to avoid the use of vein grafts. The GEA was anastomosed to the right coronary artery in all patients, and internal mammary artery grafts were used to bypass the left anterior descending and circumflex coronary arteries. All patients survived the operation. There were no early and, to date, there have been no late complications of the abdominal component of the operation. Postoperative coronary angiography showed a patent right GEA in 9 patients (82%). In 1 patient the GEA was occluded, probably because of an enlarged liver. If the long-term patency of right GEA grafts is similar to that of internal mammary artery grafts, wider use of this viable graft is indicated.

Nitecapone as an additive to crystalloid cardioplegia in patients who had coronary artery bypass grafting.

BACKGROUND: Nitecapone has been shown to have a protective effect against ischemia-reperfusion injury in experimental heart transplantation and in Langendorff preparations. This prospective, randomized study assessed the effects of nitecapone in patients who had coronary artery bypass grafting. METHODS: Thirty patients with normal myocardial function were randomly divided into control patients (n = 15), who received crystalloid (Plegisol) cardioplegia, and nitecapone patients, who received nitecapone in a 50 microM solution (n = 15) in Plegisol. Cardioplegia was administered as an initial dose of 15 mL/kg of body mass after cross-clamping and 2 mL/kg every 15 minutes. Simultaneous coronary sinus and aortic blood samples, and myocardial biopsies were taken at 1, 5, and 10 minutes after unclamping. Hemodynamics were measured invasively for 24 hours and with transesophageal echocardiography for 3 hours after cardiopulmonary bypass. RESULTS: There were no adverse effects. The incidence of ventricular arrhythmias was significantly lower in the treatment group during the recovery period (p = 0.02). Cardiac output and stroke volume did not differ significantly between the groups. The conjugated dienes gradient between the aorta and the coronary sinus increased significantly during the first minute of reperfusion in the control group (p = 0.02) compared with the nitecapone group. Myeloperoxidase activity in myocardial biopsies was higher in the control group (2.3 times higher at 5 minutes and 3.2 times higher at 10 minutes) than in the nitecapone group (p = 0.13). CONCLUSIONS: Nitecapone did not exert any significant hemodynamic effects in patients with normal ejection fraction.

The conventionally ventilated operating theatre and air contamination control during cardiac surgery--bacteriological and particulate matter control garment options for low level contamination.

OBJECTIVE: The purpose of the study was to compare the usefulness of a conventional bacteriological technique with that of particle counting under lower air contamination and better aseptic conditions achieved with special staff garments and covering for the patient. Contamination levels were estimated with continuous on line air particle counting measurement, volumetric intermittent short period aerobic bacteriological cultures and wound surface contact cultures. METHODS: In a series of 66 consecutive coronary artery bypass operations performed by the same team and in the same theatre using different types of patient and staff clothing, the impact of a reduced bacteriological and particulate contamination were assessed. The volumetric air contamination of particles > or =5 microm and bacteria-carrying particles were monitored 30 cm above the sternal wound. The bacterial contamination and bacterial wound infections in the sternal and leg wounds were assessed as well. RESULTS: With the alternative garment and textile system, the air counts fell from 25 colony-forming units (CFU)/m3 to 7 CFU/m3 (P < 0.0038). The contamination of the sternal wound was reduced by 46% and that of the leg wound by >90%. In order to give continuous contamination feedback during the whole operation to the theatre staff, particle counts > or =5 microm were monitored and visualized. Air particle counts decreased rapidly from 850 particles/m3 and stabilized to approximately 50 particles/m3 when the alternative clothing system was used (P < 0.001). Low particle counts > or =5 microm should offer the possibility to indirectly estimate air bacteria carrying particle counts during the entire operation. Less than 20% of the total count in this size group carries bacteria. The low air contamination was achieved even in an ordinary ventilated theatre when individual team members used clean air suits in combination with impermeable patient drapes. When air particle level < or =50 particles/m3 is reached, the bacterial air contamination is in the order of that of orthopaedic hip operations. The staff must during the entire operation adjust their activity to air asepsis. CONCLUSIONS: The use of clean air suits and impermeable patient clothing results in a low exogenous contamination of air and wound. Continuous air particle monitoring is a good intraoperative method to monitor the air contamination longitudinally in an operating theatre.

Pseudoaneurysm of the left ventricle following mitral valve replacement. Report of two cases and review of the literature.

Two cases of left ventricular (LV) pseudoaneurysm following mitral valve replacement (MVR) are presented. In one patient the false aneurysm developed after an initially successful correction of intraoperative left ventricular wall rupture while the other case resulted from an apparently uncomplicated MVR performed because of staphylococcal endocarditis. Both cases were detected by combined 2-dimensional and Doppler echocardiography. The operative treatment was similar in both patients. After extirpation of the old prosthesis, the orifice of the pseudoaneurysm was closed from inside the heart, either with a Dacron patch or using interrupted sutures supported by a teflon pledget. One of the patients died one month postoperatively but the other one recovered and is clinically well 6 months after repair. She has, however, a residual communication between the LV and the pseudoaneurysm.

Diagnosis and treatment of spontaneous aorto-caval fistula.

The diagnostic features and operative results of six patients with spontaneous aorto-caval fistula associated with abdominal aortic aneurysm were analyzed. Abdominal pain, pulsatile abdominal mass and haematuria were constant preoperative findings in all patients. Radiological signs of congestive heart failure of various degrees were present in five, abdominal bruit in four and preoperative renal failure in three patients. As preoperative diagnostic examinations i.v. pyelography was done in two patients and ultrasound scanning and angiography of the abdominal aorta in a further two patients. In one ultrasound scanning a dilated inferior vena cava and hepatic veins were seen as an indirect sign of ACF, while in both angiograms the ACF was seen. In these two cases the diagnosis of ACF was made preoperatively, while in four other cases the diagnosis was made during the operation. Three patients survived the operation and were still alive after eight months, four years and six years respectively. Postoperative complications developed in two patients: postoperative ileus in one and deep venous thrombosis and pneumonia in another. Because of its rarity aorto-caval fistula is difficult to diagnose. The presence of haematuria in a patient suffering from abdominal aortic aneurysm should strongly suggest the diagnosis of an aorto-caval fistula.

Polydioxanone in coronary vascular surgery.

We have used polydioxanone (PDS) in 50 patients who underwent coronary artery bypass grafting. The anastomoses consisted of suturing an autologous vein graft to the coronary artery (122 operations), a vein graft to the aorta (63 operations) and the internal mammary artery to the coronary artery (33 operations). The recipient coronary artery was subjected to endarterectomy in 28 instances. The anastomoses proved to be reliable in the early postsurgical period; no bleeding was attributed to the PDS suture. Clinical follow-up for a maximum of two-and-half years, completed using control coronary angiograms in selected cases, demonstrated good results. The practical properties of PDS were evaluated to be at least as good as those of polypropylene. Experiments have clearly shown that small artery anastomoses heal more favourably after the use of absorbable sutures than after the use of nonabsorbable sutures. Because of this finding and on the basis of our clinical experience, we believe the application of PDS in coronary surgery should be recommended as an alternative treatment.

Surgical treatment of acute myocardial ischaemia related to coronary angioplasty with special reference to use of perfusion balloon catheter and long-term outcome.

Twenty of 569 consecutive patients (3.5%) undergoing percutaneous transluminal coronary angioplasty required emergency coronary artery bypass grafting for acute closure of the dilated vessel. In seven patients an intracoronary autoperfusion balloon catheter was inserted to ensure antegrade blood flow across the injured zone of the coronary artery. The time needed for completion of the bypass grafts ranged from 100 to 399 minutes (mean 180 minutes). An average of 1.9 coronary artery bypasses was inserted. In total, 11 of the 20 patients (55%) developed new Q waves and had elevated CK-MB levels. However, the myocardial infarction rate was only 14% in those with a perfusion balloon catheter as against 77% in those without one. The insertion of a ball-out catheter permitted greater utilization of the internal mammary artery as a bypass graft. Angiographic follow-up was conducted after a mean of 28 months (19 patients). The patency rate of the bypass grafts placed in the emergency setting was relatively good (91%). Thallium tomography revealed a scar of variable size in all 17 patients studied and a reversible exercise perfusion defect requiring coronary reangioplasty in three patients. In conclusion, the insertion of a perfusion balloon catheter after abrupt coronary occlusion during coronary angioplasty solved the problems of acute myocardial ischemia and markedly lowered the definite myocardial infarction rate. This technique ensures favourable haemodynamic conditions for emergency myocardial revascularization.

St. Jude versus CarboMedics: follow-up after prosthetic valve replacement.

BACKGROUND: The purpose of the present study was to evaluate the immediate and long-term outcome of patients with two types of mechanical bileaflet heart valves operated on in the same institution by the same group of surgeons. METHODS: A comparative analysis was made in 229 consecutive patients receiving either the St. Jude Medical (SJM) or CarboMedics (CMS) bileaflet mechanical valve in 1990-1991. There were no differences in the preoperative demographics between the two groups. At operations simultaneous coronary bypass operation was performed in 40 patients out of 134 (30%) in the SJM group and 95 (44%) in the CMS group (p=0.026). Sixteen patients in the SJM group underwent replacement of the ascending aorta with a composite graft and none in the CMS group. RESULTS: There was no difference in hospital mortality between the SJM (6.7%) and CMS (6.3%) groups or in other immediate postoperative complications. The patients were followed up to 32 months. There were more patients in the NYHA class I and II in the CMS group (88%) than in the SJM group (69%), p<0.002. Three were 11 thromboembolic events (0.051% per patient year) in the SJM group and one thromboembolic event (0.008% per patient year) in the CMS group. There were no other differences between the groups in long-term survival, rate of bleeding, infective endocarditis or perivalvular leakage. CONCLUSIONS: With the exception of a little more favourable exercise tolerance and fewer thromboembolic events in the CMS group there were no other differences in the outcome of patients with these two types of bileaflet mechanical valves.

Effect of antiplatelet and anticoagulant therapy on patency of femorotibial bypass grafts.

In a retrospective study, 210 autogenous femorotibial saphenous vein grafts inserted during the 15 years from 1967 to 1982 were followed-up for a mean period of 62.3 +/- 5.7 months. Seven patients, who had had eight grafts died in hospital. The remaining 202 grafts fell into three groups: (1) Sixty grafts in patients who received 325 mg of dipyridamole and 1.0 g of acetylsalicylic acid daily, starting on the second postoperative day and continuing for six months. (2) One hundred and two grafts in patients on no antithrombotic therapy. (3) Forty grafts in patients on warfarin therapy to maintain the prothrombin time (prothrombin-proconvertin method) within the therapeutic range (0.10 to 0.20). Medication was continued for six months. This group included more high-risk patients than the other two groups. The mean ages and the incidence of risk factors did not vary significantly between the groups. The patency rates in three groups at five years were 62.5%, 44.0% and 26.0% and at ten years 48.5%, 25.0% and 21.5% for the dipyridamole and acetylsalicylic acid, no therapy and warfarin groups, respectively. The limb salvage rates were 100%, 96% and 85% in the dipyridamole and acetylsalicylic acid, no therapy and warfarin groups respectively. Thus, the best results were seen in the aspirin/dipyridamole group.

Femorotibial bypass grafting for lower limb ischaemia.

The results of 305 femorotibial bypass grafts performed in 246 patients are presented. Of these operations 246 were primary and 58 secondary or tertiary. A total of 66 diabetic patients were in the series. An autogenous saphenous vein graft was employed in 196 primary operations, the other grafts used being PTFE, human umbilical cord vein graft, venous allograft and knitted dacron velour graft. Hospital mortality was 8 patients (2.6%), while late mortality was 73 patients, 39 of them having had patent grafts. There were 89 (29.2%) immediate or early hospital failures. Two-hundred-sixteen grafts were followed for a mean observation time of 62.3 +/- 5.7 months. The cumulative patencies were analyzed using the life-table method. One, five, and ten year overall patencies for saphenous vein grafts as indicated by claudication were 73%, 53% and 35%, respectively. In rest pain, the patency rates were 62%, 46% and 40% at similar intervals. In impending gangrene the patencies were 43%, 35% and 20%, respectively. The patencies for arterial substitutes were generally poor, i.e., 35% and 15% at one and five years. None of the graft substitutes were followed for up to ten years. Diabetic patients had a significantly lower patency rate than nondiabetics (p = 0.002). The impact was remarkable if impending gangrene co-existed. In all these situations the early graft failure ensued. Both the run-off and inflow status affected the patency rates. This was significantly lower (p = 0.001) when only one distal branch was visualized in angiography.

Femoral-tibial bypass for limb salvage.

From 1967 to 1982, 305 femoral tibial bypasses were performed. Of these 180 (59%) were performed on limb salvage indication. A reversed autogenous saphenous vein was used in 134 instances, among 46 vein substitutes there were 15 vein allografts, 13 human umbilical cord vein grafts, 12 PTFE grafts and six dacron grafts. Hospital mortality was six patients. An additional 37 patients died during the follow-up period. The patency rates for saphenous vein bypass grafts were 62.5%, 48%, and 25% at one, five, and ten years, respectively, and 33% and 25% at one and five years, respectively, for the vascular substitutes. The mean +/- SD follow-up time was 62.27 +/- 5.7 months. During the early postoperative period 23 legs (12.7%) had to be amputated. During the follow-up period an additional 14 legs (7.8%) were lost giving a limb salvage rate of 79.5%.