Medium-term restenosis after carotid endarterectomy by patch type: a single-centre retrospective study comparing biological with synthetic patch materials

Abstract

Introduction: Carotid endarterectomy (CEA) with patch angioplasty is associated with lower restenosis rates compared with primary closure alone. However, evidence regarding patch-material superiority in the mitigation against neointimal hyperplasia and restenosis is limited. This retrospective observational study investigated medium-term restenosis rates between commercially available biological and synthetic carotid patches.

Methods: All primary CEA with patch angioplasty performed between 2007 and 2019 at a single university hospital were identified from theatre records. Restenosis was defined using the European Society for Vascular Surgery duplex criteria, either moderate (50-69%, PSV >213cm/s) or critical (70-99%, PSV >274cm/s). Chi-square tests and Kaplan-Meier curves were used to compare restenosis rates between biological (bovine pericardium) and synthetic patches (Dacron, PFTE and polyester-urethane).

Results: Overall, 127 CEAs were included in the restenosis analysis. Bovine pericardium was the patch material used most frequently (60%, n=75). Median follow-up with duplex was 40.0 months (range 0-144). Moderate restenosis was detected in 14 CEAs (11%) and critical restenosis in 10 (7.8%). Compared with synthetic material, bovine was significantly associated with >50% restenosis but not >70% (p=0.042 and p=0.197, respectively). However, Kaplan-Meier curves demonstrated similar rates of >50% and >70% restenosis between patch types at five years (p=0.081 and p=0.080, respectively). There was no significant difference in peri-operative complication rates between patch types.

Conclusions: These results indicate medium-term restenosis rates after CEA are similar between biological and synthetic patches. However, well-designed randomised control trials are required to definitively answer the question of which patch material is superior for carotid reconstruction.

Keywords: Carotid endarterectomy; Neointimal hyperplasia; Patch angioplasty; Restenosis; Vascular graft materials.

Figure 1

Graph illustrating changing trends in choice of patch material for CEA over the study period. The number of CEAs performed with each patch type during two-year intervals demonstrates bovine surpassing synthetic patches. CAE = carotid endarterectomy.

Figure 2

Kaplan-Meier curve illustrating rates of >70% restenosis over time. At five years, 89.3% (n=67/75) of bovine pericardial patches were patent compared with 98.1% (n=51/52) of synthetic patches (p=0.080). CAE = carotid endarterectomy.

Figure 3

Kaplan-Meier curve illustrating rates of >50% restenosis over time. At five years, 85.3% (n=64/75) of bovine pericardial patches were patent compared with 96.2% (n=50/52) of synthetic patches (p=0.081). CAE = carotid endarterectomy.

Figure 4

Kaplan-Meier curve illustrating all-cause mortality over time. At five years, 81.8% (n=63/77) of bovine pericardial patches were alive compared with 70.9% (n=39/55) of synthetic patches (p=0.297). CAE = carotid endarterectomy.