Is bypass graft technique effective in arteriovenous graft?

Background: Arteriovenous graft (AVG) requires percutaneous transluminal angioplasty (PTA) to maintain its patency; however, bypass graft technique is often chosen in cases requiring PTA again within 3 months. We retrospectively examined whether bypass graft technique is effective for AVG. Methods: The sample patient population consisted of 50 patients who underwent bypass graft technique on the venous side of the AVG between April 2012 and March 2014. The primary and assisted patencies of the technique were calculated, and compared by the type and length of the bypass graft. Kaplan-Meier method and log-rank test were used for the calculation and comparison of the patency, respectively. p<0.05 was considered statistically significant. Results: The reasons for surgery were thrombotic occlusion (27 cases), frequent PTA (15 cases) and others (8 cases). Frequent PTA was conducted within 3 months in 22 of 27 thrombotic occlusion cases (making 37/50, or 74%). Moreover, thrombectomy was required in 34 cases (68%). The 1-year primary and 1-year assisted patencies of the technique were 6.5% and 72.6%, respectively. When the endpoint was frequent PTA within 3 months after the technique, 1-year primary patency was 45.9%. Conclusions: The 1-year primary patency of the technique was poor, and patency was hard to maintain without the assistance of PTA. Given that frequent PTA was conducted in 74% of patients, it may be a cause for the poor patency. Many cases required thrombectomies, which have the disadvantage of being more invasive than PTA. We concluded that bypass graft technique is not valuable for cases that received frequent PTA.