Analysis of balloon dilatation of human vein graft stenoses

Femoropopliteal Venous Bypass Studied with Intravascular Ultrasound: A Case Report

Purpose:

To describe the ability of intravascular ultrasound (IVUS) to document the status of the greater saphenous vein during bypass surgery, the long-term changes in the bypass, and the effects of balloon angioplasty on vein graft stenoses.

Methods:

An 80-year-old female underwent in situ femoropopliteal venous bypass grafting. Vein graft stenosis developed 6 months later, necessitating balloon angioplasty. The angioplasty failed, and a polytetrafluoroethylene (e-PTFE) interposition graft was placed. Ten months after bypass surgery, balloon angioplasty was performed for new stenoses. This procedure also failed, and the venous bypass and interposition graft were removed and replaced by an e-PTFE graft. IVUS images obtained during the first surgery were compared with those obtained 10 months later. Histologic sections were used to confirm the IVUS findings.

Results:

IVUS detected a distinct narrowed venous segment, pre-existent intimal thickening, and disrupted valves. Over the follow-up period, both the pre-existent intimal thickening and the narrowed segment evolved into stenoses, necessitating treatment. Luminal gain after balloon angioplasty of graft stenosis was associated with vascular damage.

Conclusions:

This report shows that IVUS has the ability to document long-term venous bypass alterations and to demonstrate the effect of balloon angioplasty on venous bypass stenoses.

Histopathological features of in situ vein bypass stenoses

OBJECTIVES

To analyse the histopathological features of in situ vein bypass stenoses.

MATERIALS AND METHODS

Nineteen specimens of primary (n = 16) or recurrent (n = 3) vein graft stenoses obtained from 17 patients during surgical revision were prepared for light microscopy and immunohistochemical investigation. The median time interval from bypass surgery to stenosis excision was 5 months (range 2-52 months). Twenty-seven saphenous vein segments obtained from patients undergoing primary bypass surgery served as controls.

RESULTS

Graft stenoses were characterised by moderate to severe intimal hyperplasia composed of actin positive but desmin negative cells, interspersed with areas of fibrosis. A single layer of factor VIII positive endothelial cells were identified on the luminal surface. The media, separated from the intima by a poorly defined elastic lamina, usually appeared normal or mildly hyperplastic and consisted of smooth muscle cells, which stained positive for actin as well as for desmin. The adventitia was composed of loose connective tissue in which lymphocytes, plasma cells and giant cells were occasionally seen. Atheromatous material was absent from intragraft lesions, but was observed in one specimen, which was harvested from a proximal anastomotic lesion. The majority of pre-bypass vein segments showed evidence of intimal thickening whereas medial hyperplasia was less common.

CONCLUSIONS

In situ vein bypass stenoses mainly consisted of intimal hyperplasia and varying degrees of fibrosis. Similar but less pronounced morphological changes were found in pre-bypass vein segments. The nature of the actin positive but desmin and factor VIII negative intima cells is uncertain, and further studies are needed to characterise this cell type.

Antibodies to cardiolipin may increase the risk of failure of peripheral vein bypasses

OBJECTIVES

To assess the association between antibodies to cardiolipin and infrainguinal vein graft patency.

MATERIALS AND METHODS

Plasma levels of antibodies to cardiolipin, haemostatic factors, lipids and the smoking marker carboxyhaemoglobin were determined preoperatively and 6 weeks postoperatively in 80 patients undergoing infrainguinal vein bypass surgery. Bypass patency was assessed by ankle blood pressure measurements and ultrasound duplex scanning at 1 week, 6 weeks, 3, 6, 9 and 12 months. A localised increase in the graft peak systolic velocity by a factor of 2.5 or more was considered to indicate a significant stenosis.

RESULTS

Antibodies to cardiolipin were identified in seven (9%) patients preoperatively. In four of these seven patients the bypasses thrombosed within 3 months after surgery and another two developed stenoses. At 6 months the primary bypass patency, i.e. patency without stenosis, was 14% (95% confidence interval (CI) 0-33%) in patients with antibodies to cardiolipin, as opposed to 57% (95% CI 45-69%) in patients without these antibodies (log rank test: p = 0.03). Diabetes mellitus was also associated with a reduced 6 months primary bypass patency (38% (95% CI 16-60%) vs. 58% (95% CI 45-71%), p = 0.006). A Cox regression analysis showed that both the presence of antibodies to cardiolipin and diabetes independently contributed towards predicting the overall risk of bypass failure.

CONCLUSION

Antibodies to cardiolipin were identified in 9% of patients undergoing infrainguinal vein bypass surgery and appeared to be associated with increased risk of bypass failure.

Femoropopliteal venous bypass studied with intravascular ultrasound: a case report

PURPOSE

To describe the ability of intravascular ultrasound (IVUS) to document the status of the greater saphenous vein during bypass surgery, the long-term changes in the bypass, and the effects of balloon angioplasty on vein graft stenoses.

METHODS

An 80-year-old female underwent in situ femoropopliteal venous bypass grafting. Vein graft stenosis developed 6 months later, necessitating balloon angioplasty. The angioplasty failed, and a polytetrafluoroethylene (e-PTFE) interposition graft was placed. Ten months after bypass surgery, balloon angioplasty was performed for new stenoses. This procedure also failed, and the venous bypass and interposition graft were removed and replaced by an e-PTFE graft. IVUS images obtained during the first surgery were compared with those obtained 10 months later. Histologic sections were used to confirm the IVUS findings.

RESULTS

IVUS detected a distinct narrowed venous segment, pre-existent intimal thickening, and disrupted valves. Over the follow-up period, both the pre-existent intimal thickening and the narrowed segment evolved into stenoses, necessitating treatment. Luminal gain after balloon angioplasty of graft stenosis was associated with vascular damage.

CONCLUSIONS

This report shows that IVUS has the ability to document long-term venous bypass alterations and to demonstrate the effect of balloon angioplasty on venous bypass stenoses.

Percutaneous transluminal angioplasty of infrainguinal vein graft stenosis: long-term outcome

The aim of this prospective study was to examine the long-term outcome of infrainguinal vein graft stenosis managed by percutaneous transluminal angioplasty (PTA) as first-line treatment. Thirty-three infrainguinal vein graft stenoses detected by graft surveillance during a 44-month period were treated initially by PTA. The median (range) follow-up after angioplasty was 39 (18-56) months. Although 19 stenoses were successfully treated by a single PTA, 14 stenoses recurred at a median (range) interval of 8.5 (1-39) months. Restenosis occurred more frequently in the distal third of a graft (P = 0.002) compared with that in the proximal or mid-grafts, and restenosis was more common in in situ than reversed vein grafts (P = 0.03). It is concluded that infrainguinal vein graft stenoses were successfully treated by single PTA. There was, however, a high restenosis rate after angioplasty of stenosis in the distal third of a vein graft and, while approximately one third of such stenoses can be treated by a single PTA, the optimal management of recurrent stenosis requires further investigation.

Directional atherectomy in the treatment of anastomotic neointimal hyperplasia associated with prosthetic arterial grafts: technique and preliminary results

The development of anastomotic neointimal hyperplasia is a common cause of late prosthetic arterial bypass graft failure. The cost and morbidity of graft failure are high, hence the widespread use of graft surveillance programmes in order to detect graft-related stenoses before they progress to occlusion. However, the optimal treatment of stenoses secondary to neointimal hyperplasia is not clear, with a number of authors reporting poor results with both balloon angioplasty and surgical revision. We report our early experience with the Simpson atherectomy catheter in the treatment of anastomotic neointimal hyperplasia associated with prosthetic arterial grafts at eight sites in seven patients. A high technical success rate may be expected and further long-term studies of this mode of treatment are indicated.

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

The purpose of this retrospective study is to review our ongoing experience with the use of angioscopy during reoperation for failed or failing infrainguinal vein bypass grafts and define the role of angioscopy in the management of this clinically demanding patient group. All hospital records, arteriograms, and intraoperative angioscopic video recordings of 79 consecutive failed or failing grafts (76 patients) examined with angioscopy during reoperation between 1987 and 1993 were reviewed. Clinical and intraoperative data, comparison of the preoperative arteriogram and intraoperative angioscopic findings, and surgical decisions or interventions resulting from the additional angioscopic findings were collated and analyzed according to a predetermined protocol. Sixty-six additional angioscopic findings were noted during the 79 reoperations and resulted in 61 additional interventions and surgical decisions with salvage of all or part of the graft in 90.9% in the early (< 30 day) failed (group 1), 84.6% in the late (> 30 day) failed (group 2), and 90.3% in the late (> 30 day) failing grafts (group 3). The amount of residual thrombus within the graft, as assessed by angioscopy after all interventions, was the critical determinant for overall early graft patency (p < 0.001) and long-term patency for all the subgroups after reoperation (group 1, p < 0.001; group 2, p = 0.0016; and group 3, p = 0.0194). Intraoperative angioscopy has an important role in these challenging procedures. It provides additional and useful information that not only influences the conduct and extent of the reoperative surgery but may provide insights into the pathogenesis of graft failure.