Vascular injury during anterior exposure of the spine

Abstract

Fusion of the spine is often performed from an anterior approach requiring mobilization of aorta, iliac artery, and vein. This study describes the preferred techniques and incidence of vascular complications at a spine center. Information and operative notes on all consecutive patients undergoing anterior exposure were entered into a database that was retrospectively reviewed. Four hundred eighty-two procedures performed on 480 patients at one spine center between January of 1997 and December of 2002 were analyzed. Demographics, technique, levels of exposure, and history of prior spine surgery were recorded. Primary outcomes measured included intraoperative vascular complications, estimated operative blood loss, and operative mortality. Vascular injury was defined as any case in which a suture was required to control bleeding. Major vascular injuries were defined as those requiring transfusion, vascular reconstruction, or blood loss greater than 300 cc. An intraoperative vascular injury occurred in 11% (54/480) of patients. The majority of these (45/54) were minor injuries treated with simple suture repair. Nine (1.9%) major vascular injuries did occur; the majority identified and treated during the exposure and not the spinal fusion. One patient required a return to the operating room 24 hours after the initial procedure for removal of packs placed to control severe bleeding from an avulsed branch of the internal iliac vein. Median estimated blood loss (EBL) was 150 cc and there were no mortalities. Eighty-three percent of overall injuries involved exposure of L4-5, and this was statistically significant odds ratio (OR) 2.73, P = .005. The lowest incidence of injury occurred when L5-S1 alone was exposed (5.1% of injuries) OR .34, P = .01. Prior spine procedures did not significantly increase the risk of injury, P = .67. Other factors that did not significantly increase risk included gender, multiple levels vs single levels and technique of exposure. Exposure to the lumbar spine can be readily accomplished via a retroperitoneal approach. Minor vascular injuries during exposure, mostly venous, are not uncommon and are easily repaired. They are increased when L4-5 is part of the exposure and are lowest when L5-S1 alone is exposed. Major injuries occur in less than 2% of patients.