Role of angioscopy in reoperation for the failing or failed infrainguinal vein bypass graft

Timing of Pedal Bypass Failure and Its Impact on the Need for Amputation

Although the utility of dorsalis pedis (DP) bypass for limb ischemia has been well established, the fate of limbs with a failed bypass to the DP artery remains unclear. Data of all patients undergoing DP bypass grafting within a 12-year period from two university hospitals' vascular registries were retrospectively reviewed. Outcomes of early (<30 days) and delayed graft failure (>30 days) were examined. The Student's t-test and chi-squared test were used for univariate analysis; patency rates and patient survival were calculated using the Kaplan-Meier product limit method. Of 1434 DP bypass grafts, 277 (19.3%) failed grafts were identified. Sixty five (4.5%) grafts failed early (within 30 days of surgery) and 212 (14.8%) failed late at a mean time of 15.3 months (range, 1.5-105 months) after initial bypass. Of the 65 limbs with early graft failure, 28 (43.1%) proceeded directly to amputation and 20 underwent additional revascularization attempts, but limb salvage was achieved in only 7 patients; in 45 (69.2%) patients no further revascularizations were attempted. Seventy-four (34.9%) patients with late graft failure underwent redo revascularization. Thirty-nine (52.6%) had their limb saved with graft revision, but 35 patients (47.3%) ultimately lost their limb. In 138 patients with late graft failure (65.1%) no further revascularization attempts were performed. Sixty-two (44.9%) required major amputation. Overall, 49.8% of patients with failed pedal grafts ultimately suffered limb loss. Early graft failure resulted in a significantly higher rate of major amputation that did late graft failure (63.1% vs. 45.8%, respectively; p = 0.015). These results indicate that early occlusion of pedal bypass often leads to immediate major amputation and interventions to maintain graft patency in this setting are often futile. Late failure of pedal bypass is associated with a lower likelihood of amputation because of a higher rate of success of bypass revisions and a lower occurrence of critical ischemia with graft failure.

Fresh arterial homograft transplantation: a novel concept for critical limb ischaemia

INTRODUCTION

homografts have been used since the early days of vascular surgery, but have failed to provide long-term success. Arteries supplying organ transplants seldom show signs of biodegradation. We therefore introduced fresh arterial homograft repair with consecutive immunosuppression (ATX).

AIM

to assess feasibility and clinical usefulness of ATX.

SETTING

university teaching hospital.

MATERIAL AND METHOD

conduits were harvested during multi-organ procurement and stored in Custodiol. Implantation followed immediately. Viability of the transplant was documented in all cases. Patients received immunosuppression for the duration of bypass function.

RESULTS

thirteen patients received ATX for critical limb ischaemia (M/F: 11/2, age: 62yr, previous revascularisations: 4.5 (1-8), median run-off index 5, previous organ transplant: n=2. Most bypasses were anastomosed to single tibial or pedal vessels. There was no early failure. Within an average follow up of 12 months there were 6 graft thromboses in 5 patients, successfully revised in 4. Three limbs were lost after 2, 5 and 6 months due to graft failure. Graft rejection was shown in 1 out of 3 explanted grafts.

CONCLUSION

we report a concept, which may circumvent the problem of biologic graft degeneration. Limb salvage was possible in 75% at 12 months in otherwise difficult circumstances.

Angioscopy

Angioscopy provides a magnified, real-time, 360-degree view of the endoluminal surface of blood vessels, yielding unique information that is often complementary to conventional angiography. This unique perspective can significantly enhance one's perception and appreciation of endovascular disease. Although angioscopy is primarily used as a research tool, its ability to characterize accurately the morphology and color of atherosclerotic lesions may lead to improved treatment and better clinical outcomes.

Redo bypass surgery to the infrapopliteal arteries for critical leg ischaemia

OBJECTIVES

to evaluate the results of redo bypass surgery to the infrapopliteal artery and the value of adjuvant arteriovenous fistula (AVF) in this setting.

DESIGN

retrospective study.

MATERIALS

fifty-one redo reconstructions to the infrapopliteal arteries were done for critical leg ischaemia in 45 patients who have had primary infrainguinal reconstructions to the popliteal artery in 20 cases (39%), the crural arteries in 18 (35%), and the pedal arteries in 13 (25%).

METHODS

a PTFE prosthesis was used in 21 cases (41%). A Miller cuff was used in 16 prosthetic grafts. Adjuvant AVF was added to three autogenous vein and 12 prosthetic grafts.

RESULTS

at 2 years, the primary patency rate was 42%, the secondary patency was 43%, the limb salvage was 67%, the survival was 77%, and 53% of patients were alive with salvaged leg. The primary patency rate with a vein graft was 44% at 1 year, with prosthesis plus AVF 67%, but with prosthesis without AVF only 19%. Secondary patency rates were similar. Prosthetic graft with AVF and those without AVF achieved a 1-year leg salvage rate of 100% and 51%, respectively (p =0.01). Patients with adjuvant AVF had a worse 2-year survival rate that those without AVF (31% vs 89%) (p =0.007; RR: 8.87, CI 95%: 1.62-48.42).

CONCLUSIONS

redo bypass surgery using autogenous vein graft may achieve satisfactory long-term results. The use of adjuvant AVF may improve patency of redo infrapopliteal prosthetic bypass grafts.

Early vein bypass thrombectomy is associated with an increased risk of graft related stenoses

OBJECTIVES

To assess the risk of graft stenoses following early thrombectomy of peripheral vein bypasses.

DESIGN

Prospective study of 371 vein bypasses performed at the Vascular Service, Rigshospitalet, Copenhagen from January 1991 through December 1992.

MATERIALS AND METHODS

Thirty-six vein bypasses reopened by thrombectomy within 30 days postoperatively (group I) and 335 bypasses not subjected to early thrombectomy (group II) were studied by ultrasound duplex scanning 3, 6, 9, 12, 18, 24, 36 and 48 months postoperatively. A localised increase in the peak systolic velocity of 250% or more was considered an indicator for significant stenosis.

RESULTS

In the perioperative period nine (2%) patients died, 30 (8%) bypasses occluded and 14 (4%) patients were lost to follow-up. Among the 318 patients remaining at risk at 1 month graft stenoses were identified in 39% (9/23) in group I compared to 17% (51/295) in group II, p = 0.03. Late bypass revisions were required in 35% (8/23) in group I as opposed to 9% (28/295) in group II, p = 0.004. Despite this high number of revisional procedures the 12-months secondary bypass patency was lower in recanalised grafts (38% vs. 82%, p < 0.00001).

CONCLUSION

Early vein bypass thrombectomy is associated with a two-fold increased risk of graft related stenoses and a reduced secondary bypass patency.

Infrapopliteal bypasses to severely calcified, unclampable outflow arteries: two-year results

PURPOSE

Although severe, circumferential calcification of distal outflow vessels is frequently encountered, its effect on bypass graft patency rates has not been well established.

METHODS

Using a computerized vascular registry database, we conducted a retrospective review of 1957 bypass grafts with distal anastomoses to infrapopliteal vessels performed at a single institution between 1990 and 1995. Of these cases, 101 procedures involved outflow arteries classified by the operating surgeon as severely calcified and unclampable (requiring intraluminal occluders for vascular control), whereas in 105 cases the outflow arteries had no calcification present at the distal anastomotic site. The remaining cases had varying intermediate degrees of calcification and were not analyzed. Indication for bypass procedure was limb-threatening ischemia in 90% of severe calcification cases and in 84% of cases without calcification. Atherosclerotic risk factors were similar except for the presence of diabetes (92% vs 74%, p < 0.001), creatinine level > 2.0 mg/dl (21% vs 8%, p < 0.01), and dialysis dependency (17% vs 3%, p < 0.001), all of which were more prevalent in the severe calcification group. Infrapopliteal distal anastomotic location and type of conduit ( > 90% autogenous vein) were comparable between groups.

RESULTS

Primary patency, secondary patency, and foot salvage rates at 24 months were 60%, 65%, and 77% for the severe calcification group and 74%, 82%, and 93% for the no calcification group, respectively. With secondary procedures comprising 26% of cases in each group, data from the 150 primary procedures were reanalyzed separately. In this primary procedure group, 24-month primary patency, secondary patency, and foot salvage rates were 66%, 69%, and 77% for the severe calcification group and 84%, 90%, and 96% for the no calcification group, respectively. Although patency and salvage rates were consistently lower for the severe calcification group in all analyses, these differences did not achieve significance by log-rank life-table analysis at 2-year follow-up. Perioperative 30-day mortality (0.99% severe calcification vs 0.95% no calcification) and 24-month survival rates (84% severe calcification vs 83% no calcification) were also similar between groups.

CONCLUSION

These data suggest that effective techniques exist to perform infrapopliteal bypasses to severely calcified, unclampable outflow arteries with results comparable with those obtained with clampable, uncalcified vessels. The finding of severe, circumferential calcification of outflow target arteries should not dissuade vascular surgeons from distal bypass for limb salvage indications.

Angioscopy in vascular surgery: the state of the art

Although angioscopy is considered by many vascular surgeons to be a valuable clinical tool, others view it as expensive and unnecessary. To better define the appropriate role for angioscopy in vascular surgery, a critical review of the recent literature was undertaken. Angioscopy allows more complete valvulotomies with fewer endothelial injuries when preparing autogenous veins to be used as arterial conduits, and results in more complete thromboembolectomy of native arteries and grafts. Angioscopy can replace completion arteriography in infrainguinal arterial reconstructions with an equivalent clinical outcome. Angioscopy may be useful in the assessment of carotid endarterectomy, femoral vein valve repair, and pulmonary embolectomy. It has been useful in various research applications. The rate of complications is less than 1%. Angioscopy is of benefit in preparing veins to be used as arterial conduits and in performing thromboembolectomy. In some circumstances it can replace intraoperative arteriography. Other applications await further validation. The risks of angioscopy are acceptably low.

The role of routine angioscopy in vascular access surgery

PURPOSE

The purpose of this retrospective study is to describe our techniques, review our experience, and determine the feasibility, safety, and role of the routine use of angioscopy during primary and revision vascular access surgery.

METHODS

Between February 1991 and October 1993, intraoperative angioscopy was routinely performed in 84 consecutive operations (51 patients) for vascular access surgery. We reviewed the videotaped recordings of the angioscopic studies together with the clinical data according to a predetermined protocol.

RESULTS

There were 43 primary procedures (36 autogenous arteriovenous fistulas and 7 bridge graft fistulas) and 41 revision procedures for failed vascular access (7 autogenous arteriovenous fistulas and 34 graft bridge fistulas). In 20.9% of the primary vascular access procedures, abnormal endoluminal findings were noted. Based on these findings, only one additional intervention was performed. In revision vascular access surgery, abnormal endoluminal findings were noted in 92.7%, resulting in additional surgical interventions in 65.9% of the procedures. In the revised synthetic bridge graft fistulas, stenosis of the midgraft (n = 9) as a result of needle insertion for dialysis was more common than at venous anastomosis (n = 4). Detection and correction of endoluminal abnormalities resulted in a 30-day patency of 66.6% as opposed to 33.3% when none was detected (p < or = 0.012, Fisher's exact test).

CONCLUSIONS

Routine angioscopy is technically feasible and can be performed safely in anuric patients during vascular access surgery. It provides additional and useful intraoperative information that may significantly alter the surgical procedure. Routine angioscopy may also provide new insights into the pathophysiology of vascular access failure.

The Role of Routine Angioscopy in Vascular Access Surgery

Purpose:

The purpose of this retrospective study is to describe our techniques, review our experience, and determine the feasibility, safety, and role of the routine use of angioscopy during primary and revision vascular access surgery.

Methods:

Between February 1991 and October 1993, intraoperative angioscopy was routinely performed in 84 consecutive operations (51 patients) for vascular access surgery. We reviewed the videotaped recordings of the angioscopic studies together with the clinical data according to a predetermined protocol.

Results:

There were 43 primary procedures (36 autogenous arteriovenous fistulas and 7 bridge graft fistulas) and 41 revision procedures for failed vascular access (7 autogenous arteriovenous fistulas and 34 graft bridge fistulas). In 20.9% of the primary vascular access procedures, abnormal endoluminal findings were noted. Based on these findings, only one additional intervention was performed. In revision vascular access surgery, abnormal endoluminal findings were noted in 92.7%, resulting in additional surgical interventions in 65.9% of the procedures. In the revised synthetic bridge graft fistulas, stenosis of the mid-graft (n = 9) as a result of needle insertion for dialysis was more common than at venous anastomosis (n = 4). Detection and correction of endoluminal abnormalities resulted in a 30-day patency of 66.6% as opposed to 33.3% when none was detected (p ≤ 0.012, Fisher's exact test).

Conclusions:

Routine angioscopy is technically feasible and can be performed safely in anuric patients during vascular access surgery. It provides additional and useful intraoperative information that may significantly alter the surgical procedure. Routine angioscopy may also provide new insights into the pathophysiology of vascular access failure.