Derrick L. Green1, Charu Lata2, Jing Wan1, Sabita Roy1, Steven M. Santilli1
1Department of Surgery, University of Minnesota, Minneapolis, MN; 2Veterans Affairs Medical Center, Minneapolis, MN.
OBJECTIVES: Intimal hyperplasia (IH) is the cause of most failed arterio-venous fistulae (AVF), resulting in repeat procedures and leading to increased utilization of scarce health care resources. Our lab has previously demonstrated the role of supplemental oxygen (O2) in preventing IH and smooth muscle cell proliferation (SMCp) at an artery to graft anastomosis and at the deployment site of an intra-arterial stent. This study is to examine the effect of supplemental O2 in preventing IH and SMCp at an AVF in a rabbit model.
METHODS: 96 rabbits were randomized into three groups: Group 1 ̶ control; Group 2 ̶ AVF without supplemental O2; and Group 3 ̶ AVF with supplemental O2. Rabbits receiving supplemental O2 received 30% oxygen for 42 days. Specimens were collected at days 1,3,7,21,42, and 90. IH and SMCp were measured at the fistula site as well as in the artery and vein proximal and distal to the fistula.
RESULTS: IH was first noted at day 3 and significantly increased through day 90 at all locations in the non-oxygen supplemented groups. There was no significant IH noted in the O2 supplemented groups at any location or any time point (See Table). SMCp was noted at Day 3 through Day 21 in the non-oxygen supplemented group while almost no SMCp was noted in the O2 supplemented groups at any location or time point.
CONCLUSIONS: Without O2 supplementation SMCp begins at day 3 and is no longer noted at day 21 after creation of an AVF while IH begins by day 3 and increases at least through day 90 after creation of an AVF. Forty-two days of 30% supplemental O2 inhibits both IH and SCMp after creation of an AVF. This data suggests a role for short-term administration of low-dose O2 to prevent both IH and SMCp after creation of an AVF prolonging fistula patency and function.
AUTHOR DISCLOSURES: D. L. Green, Nothing to disclose; C. Lata, Nothing to disclose; S. Roy, Nothing to disclose; S. M. Santilli, Nothing to disclose; J. Wan, Nothing to disclose.
Table: Measurement of Intimal Hyperplasia at Fistula Site
Posted April 2012