Intimal growth on the luminal surface of arteriovenous grafts in rats.

BACKGROUND: Endothelial cells are known to grow on the luminal surface of arteriovenous grafts (AVGs) used in hemodialysis. Although endothelial cells are important for preventing infection, a detailed growth of endothelial cells in AVGs is unknown. This study sought to create a simpler animal model of AVGs and to investigate how endothelial cells form on the luminal surface. METHODS: Polyethylene grafts were placed between the cervical artery and vein of Wistar rats. The grafts were removed at 6 h, 24 h, 3 days, or 7 days after placement. The luminal surface was observed under optical and polarizing microscopy and stained with endothelial cell markers (LEL, CD31), the progenitor cell marker CD34, and the macrophage marker ED-1. RESULTS: Microscopy demonstrated many diffuse vascular endothelial cells on the luminal surface of AVGs after placement. While there was no difference in the number of LEL-positive cells between the arterial side (AS) and venous side (VS) at 6 h or 7 days, there were significantly more of these cells on the VS at both 24 h and 3 days (p < 0.05). Analysis at 24 h showed some CD31-positive cells and few CD34-positive cells. CONCLUSIONS: This was the first study to use a simple rat model of AVG placement. Endothelial cell formation was initially more active on the VS than on the AS, but these cells subsequently increased in number across the luminal surface. Future clinical studies might contribute clinically by confirming whether AS versus VS puncture results in different infection rates.

Analysis of factors for post-percutaneous transluminal angioplasty primary patency rate in hemodialysis vascular access.

BACKGROUND: Although percutaneous transluminal angioplasty has been established as a first-line therapy for access failure in dialysis, there are few reports on primary patency after percutaneous transluminal angioplasty. We investigated factors associated with primary patency following the first percutaneous transluminal angioplasty performed after vascular access construction in patients with arteriovenous fistula, including blood flow volume before and after percutaneous transluminal angioplasty and previously reported factors. METHODS: We used medical records at six dialysis centers to retrospectively identify and analyze prognostic factors for primary patency after percutaneous transluminal angioplasty in 159 patients with arteriovenous fistula who underwent initial percutaneous transluminal angioplasty after vascular access construction. RESULTS: Multivariate analysis with the Cox proportional hazard model showed that primary patency after percutaneous transluminal angioplasty in patients with arteriovenous fistula was significantly associated with lesion length (hazard ratio, 1.76; 95% confidence interval, 1.01-3.07; P = 0.045), and blood flow volume after percutaneous transluminal angioplasty (hazard ratio, 0.71; 95% confidence interval, 0.60-0.84; P < 0.001). When blood flow volume after percutaneous transluminal angioplasty was classified into three categories, risks of outcome events defining the end of primary patency after percutaneous transluminal angioplasty were significantly lower for 400-630 mL/min (hazard ratio, 0.38; 95% confidence interval, 0.21-0.68; P = 0.001) and >630 mL/min (hazard ratio, 0.16; 95% confidence interval, 0.06-0.40; P < 0.001) compared with <400 mL/min. CONCLUSION: Our study showed that blood flow volume after percutaneous transluminal angioplasty is an important prognostic factor for primary patency after percutaneous transluminal angioplasty in patients with arteriovenous fistula.

A patient with arteriovenous fistula of simultaneously performed anastoplasty for excessive blood flow and graft bypass to secure an outflow tract.

INTRODUCTION: We report a case in which we performed an anastomotic part septal formation surgery (anastoplasty) and artificial blood vessel replacement surgery. CASE DESCRIPTION: When forearm arteriovenous fistula occlusion of a dialysis patient was observed, there was a thrombus in the vein of the whole forearm from the anastomotic part. We performed a septum formation surgery to suppress the blood flow in the vein near the anastomotic site, and artificial blood vessel replacement was performed on the high stenosis of the cephalic vein of the elbow. Postoperative blood flow was stable and hemodialysis was possible. Although there are various blood flow suppression methods for suppressing excessive blood flow, we report a case in which an anastomotic part septal formation surgery and artificial blood vessel replacement to secure an outflow passage were performed at the same time. CONCLUSION: Anastoplasty for excessive blood flow is considered to be an effective means in this case.