Endovascular-assisted versus conventional in situ saphenous vein bypass grafting: cumulative patency, limb salvage, and cost results in a 39-month multicenter study.

OBJECTIVE: In this retrospective multicenter study, the results of a minimally invasive method of endovascular-assisted in situ bypass grafting (EISB) versus "open" conventional in situ bypass grafting (CISB) were evaluated with a comparison of primary and secondary patency, limb salvage, and cost. METHODS: Enrolled in this study were 273 patients: 117 underwent CISB (42 femoropopliteal, 75 femorocrural) and 156 underwent EISB (41 femoropopliteal, 115 femorocrural). EISB was performed with an angioscopic Side Branch Occlusion system and an angioscopically guided valvulotome. All the patients underwent follow-up examination with serial color-flow ultrasound scanning. RESULTS: Both groups had similar comorbid risk factors for diabetes mellitus, coronary artery heart disease, hypertension, and cigarette smoking. The primary patency rates (CISB, 78.2% +/- 5% [SE]; EISB, 70.5% +/- 5%; P =.156), the secondary patency rates (CISB, 84.1% +/- 4%; EISB, 82.9% +/- 5%; P =.26), and the limb salvage rates (CISB, 85.8%; EISB, 88.4%; P =.127) were statistically similar, with a follow-up period that extended to 39 months (mean, 16.6 months; range, 1 to 40 months). In veins that were less than 2.5 to 3.0 mm in diameter, the EISB grafts fared poorly, with an increased incidence of early (12-month) graft thromboses (CISB, 10 grafts, 8.5%; EISB, 24 grafts, 15.3%). However, wound complications (CISB, 23%; EISB, 4%; P =.003), mean hospital length of stay (CISB, 6.5 days +/- 4.83; EISB, 3.2 days +/- 3.19; P =.001), and mean hospital charges (CISB, $25,349 +/- $19,476; EISB, $18,096 +/- $14,573; P =.001) were all significantly reduced in the EISB group. CONCLUSION: The CISB and EISB midterm primary and secondary patency and limb salvage rates were statistically similar. In smaller veins (< 2.5 to 3.0 mm in diameter), however, EISB is not appropriate because overly aggressive instrumentation may cause intimal trauma, with resultant early graft failure. With the avoidance of a long leg incision in the EISB group, wound complications and hospital length of stay were significantly reduced, which lowered hospital charges and justified the additional cost of the endovascular instruments. When in situ bypass grafting is contemplated, EISB in appropriate patients is a safe, minimally invasive, and cost-effective alternative to CISB.

Limited thrombogenicity of low temperature, laser-welded vascular anastomoses.

BACKGROUND AND OBJECTIVE: Laser welding of vascular anastomoses has been shown to be feasible, but the clinically relevant advantages of this technique remain to be demonstrated. STUDY DESIGN/MATERIALS AND METHODS: To determine whether laser welding decreases initial anastomotic thrombogenicity, argon laser-welded aortic and venacaval anastomoses were constructed in 15 New Zealand white rabbits. Low temperature welding was done in one-half of welded anastomoses using low power ( < 0.7W) and increased irrigation with saline during welding. Anastomotic surface temperature, bursting strength, procedure time, and surface thrombogenicity (111Indium labeled platelet accumulation) were determined at 24 hours and compared to sutured anastomoses. RESULTS: Aortic and vena caval low temperature laser-welded anastomoses were significantly less thrombogenic than sutured or higher temperature laser-welded anastomoses. In addition, bursting strength of welded anastomoses exceeded physiologic requirements and vessel closure time was less with welding than with suture techniques. CONCLUSION: Low temperature laser welding limits anastomotic thrombogenicity, which may improve early patency of venous and small arterial bypass grafts.

Descending thoracic aorta to femoral artery bypass.

Anatomic placement of a synthetic graft from the infrarenal aorta to the iliofemoral vessels has been a long recognized technique used to bypass occlusive disease of the distal aorta and iliofemoral arteries. However, in a few select patients with failure or infection of the abdominal graft, or in patients with a "hostile" abdomen from multiple prior operations, the descending thoracic aorta may be used as an inflow source for the iliofemoral vessels. This paper will discuss the indications, patency data, and technique of descending thoracic aorta to femoral artery bypass with a case presentation.

Does routine stress-thallium cardiac scanning reduce postoperative cardiac complications?

OBJECTIVE: Prophylactic cardiac revascularization in patients with ischemic myocardium could reduce postoperative cardiac complications after aortic reconstruction. However, the effectiveness of this approach has not been documented. SUMMARY BACKGROUND DATA: Stress-thallium scanning can identify patients with ischemic myocardium. Morbidity and mortality after aortic reconstruction appears to be largely caused by co-existent coronary artery disease, and patients who have had recent cardiac revascularization have few postoperative cardiac complications. METHODS: Preoperative stress-thallium scanning was evaluated prospectively in 146 patients undergoing aortic reconstruction. Patients with positive studies underwent coronary arteriography and cardiac revascularization, when appropriate. Postoperative cardiac complications and long-term survival in these patients were compared with results from 172 similar patients undergoing aortic reconstruction without stress-thallium scanning. Results also were analyzed to determine predictors of postoperative cardiac events. RESULTS: Forty-one per cent of patients undergoing stress-thallium testing underwent coronary arteriography, and 11.6% had cardiac revascularization. In contrast, 14.7% of patients treated without stress-thallium testing had coronary arteriography, and 4.1% had revascularization (p < 0.01). Despite this, cardiac mortality, serious cardiac complications, and long-term cardiac mortality were similar in both groups. Only advanced age and intraoperative complications (but not a positive stress-thallium test) predicted postoperative cardiac events. CONCLUSIONS: Preoperative stress-thallium testing confirmed a high incidence of significant coronary artery disease in patients undergoing aortic reconstruction, but prophylactic cardiac intervention does not reduce operative or long-term mortality. Thus, the risk and expense of routine stress-thallium testing and subsequent cardiac revascularization cannot be justified.

Rotational atherectomy for treatment of occluded prosthetic grafts.

Potentially, percutaneous rotational atherectomy (RA) can be used to open occluded prosthetic arterial bypass grafts with less morbidity than surgical catheter thrombectomy. However, RA could damage prosthetic grafts or produce significant distal emboli. To investigate this, acutely thrombosed and chronically occluded prosthetic grafts, harvested from dogs, were placed in an ex vivo perfusion system and recanalization was attempted using the TRAC-Wright rotational atherectomy system. Urokinase (UK) was delivered through the RA catheter in one-half of the procedures. Graft surface thrombogenicity and graft mechanical integrity after successful recanalization were determined and debris released during recanalization was collected. Results were compared to those from grafts opened by catheter thrombectomy. One hundred percent (22/22) of acute prosthetic graft occlusions and 39% (16/41) of chronic prosthetic graft occlusions were opened using RA, similar to results achieved using catheter thrombectomy. In addition, surface thrombogenicity after recanalization of acute graft occlusion with RA was lower than that after catheter thrombectomy (P < 0.05) and infusion of UK improved RA success in chronically occluded grafts (52% vs 25%). Debris generated during RA averaged 15-18 micrograms, equivalent to debris generated during catheter thrombectomy, and graft mechanical integrity was unaffected by recanalization using RA. Thus, rotational atherectomy is a minimally invasive means of safe and effective prosthetic graft recanalization that produces a less thrombogenic graft than thrombectomy.

Laser angioplasty.

Laser energy has the potential for selective ablation of atherosclerotic plaque through minimally invasive means. As currently practiced, laser angioplasty requires the adjunct of balloon angioplasty in most cases and has limited application compared with more conventional methods of revascularization. However, new advances in guidance systems, delivery devices, and laser sources may allow realization of the full benefit of this technology at some point in the future.

Utility of femorofemoral bypass. Comparison of results with indications for operation.

Sixty-eight patients underwent femorofemoral bypass (FFB) at the University of Louisville Affiliated Hospitals over a 9-year period from 1980 to 1989. There were patients with acute ischemia requiring emergency operation, those with chronic ischemia following failed aortic reconstruction, good-risk patients with chronic ischemia who had FFB as the procedure of choice, and poor-risk patients who were unsuitable for other procedures. Patients operated on for acute ischemia had a significant number of infectious complications, with five of eight graft failures in this group due to infection. Primary patency rates were similar in all groups, with a 5-year primary patency of 42 per cent. Overall operative mortality was 4.4 per cent. Satisfactory limb salvage rates (75%) suggest that FFB is an acceptable option for providing inflow in patients with acute ischemia or for patients with a failed previous vascular prosthesis. FFB provides adequate inflow in poor-risk patients not suitable for aortic reconstruction, but patency rates do not warrant its use as a procedure of choice in good-risk patients.

Effects of electrolyte or colloid infusion on the injured lung.

Diffuse lung injury (acid aspiration) and a modest intravascular volume deficit (15% total blood volume) were produced in mongrel dogs. Replacement of lost volume was with shed blood plus an equal volume hydroxy ethyl starch (Group I) or shed blood plus balanced salt solution (3 ml/ml shed blood). Extravascular lung value (EVLW) measurements were used to quantitate edema formation and alveolar arterial oxygen gradient (A-a and O2) was monitored on a reflection of hypoxia. No significant differences were observed in A-a and O2 between groups despite a significantly larger amount of pulmonary edema in Group I (hydroxy ethyl starch).