Prevention of Anastomotic Intimal Hyperplasia in Infrainguinal PTFE Bypass Grafts with Distal Arterial Segment Interposition

Abstract

Anastomotic intimal hyperplasia (AIH) is a common cause of graft failure after femoropopliteal polytetrafluoroethylene (PTFE) bypass. Compliance mismatch between the PTFE graft and the native artery may be a significant factor causing AIH. This study examines whether reduction of compliance mismatch by interposition at the distal anastomosis of a segment of superficial femoral artery after eversion endarterectomy could reduce or eliminate AIH and improve graft patency. Between July 1989 and June 1996, PTFE grafts with a distal arterial segment (AS) were used to revascularize 51 limbs in 45 patients (12 men and 33 women). Twenty-five grafts were above-knee (AK) and 26 below-knee (BK). Disabling claudication was the indication in 32 limbs (AK 20, BK 12) and limb-threatening ischemia in 19 (AK 5, BK 14). Physical examination, measurement of ankle-brachial index, and duplex scanning were used to follow up patients at regular intervals. For those patients who had recurrent symptoms and/or reduction of ankle/brachial index (ABI), arteriography was performed. Follow-up ranged from 1-54 months (mean 20 months) for AK grafts and 1-76 months (mean 19 months) for BK grafts. The overall primary patency rate at 4.5 years was 57.2%. There appears to be no significant difference between AK and BK primary patency survival distributions (64.8% vs 48.5%). The primary patency failure distributions for the two ischemic conditions are statistically significant (69.8% vs 31.9%). The limb salvage rate at 4.5 years was 80%. Of the 51 grafts, the causes of the 19 failures included progression of disease in eight, thromboembolus in three, stenosis of the AS in three, poor runoff in one, AIH at the proximal anastomosis in one, and unknown in three. This pilot study suggests that the femoropopliteal PTFE bypass with distal AS interposition provides improved graft patency and limb salvage rates when compared with those published in the literature for PTFE bypass without the AS. Further evaluation is warranted.

Review of Polymeric Biomimetic Small-Diameter Vascular Grafts to Tackle Intimal Hyperplasia

“…Occlusive disease of the popliteal artery or more distal vessels requires bypassing with an autogenous vein to the distal popliteal artery or tibial vessels. The greater saphenous vein, an autologous blood vessel, remains the clinical gold standard. , Repairing diseased blood vessels using autologous vessels has many advantages, such as good tissue compatibility, no risk of immune reaction, matching mechanical properties, and good long-term patency. However, a good-quality autologous vessel is unavailable for many patients requiring surgery due to a previous harvest, anatomical variability (varying internal diameter, wall thickness, or compliance), or disease progression.…”

“…Long-term patency has been achieved in grafts with diameters greater than 6 mm. Nonetheless, for smaller-diameter blood vessels, such as the femoropopliteal and tibial arteries found in the lower limbs, these materials have significant drawbacks, including infection due to technical mismanagement, thrombosis due to the lack of remodeling and growing capabilities of living tissues, and the development of intimal hyperplasia leading to restenosis of the graft. ,− Apart from autologous vessels and synthetic conduits, other prosthetic grafts include homologous grafts obtained from cadavers or donors such as human umbilical vein grafts (CryoVein) and xenografts across species like the bovine jugular graft (Contegra). , When a small-diameter artificial vascular graft (SDAVG) is used in limb procedures, the patency levels are less ideal than other bypass procedures because of the additional continued stress imposed on the graft by limb flexion. The properties, advantages, and current limitations of the materials in the market are discussed in detail in the following sections.…”

Factors Affecting Long-Term Results of Above-Knee Femoropopliteal Bypass

“…16 The development of anastomosis intimal hyperplasia at distal anastomosis level has been shown to play a major role in above-knee femoropopliteal bypasses' long-term patency. [15][16][17][18] We propose that the detrimental effect (with different statistical significance) of the above-reported variables on long-term grafts patency may be related to an increase in the hemodynamic stress at the distal anastomosis 17 and associated development of early intimal hyperplasia. One can therefore hypothesize that both the presence of apparently minor anastomosis technical imperfections and a major diameter mismatch between ePTFE graft and popliteal artery size as well as an inappropriate anastomotic angle might promote significant detrimental hemodynamic effects at distal anastomotic level, leading to the onset of early anastomotic intimal hyperplasia followed by graft occlusion.…”