Bloodless splenic surgery: the safe warm-ischemic time

To assess the feasibility of a technique of bloodless splenic surgery, experiments were performed to determine the safe warm-ischemic time of the spleen. Ten mongrel dogs were divided into two groups. Group I (n = 5) underwent division of all collateral splenic vessels, followed by total splenic artery and vein occlusion for 3 hours. Group II (n = 5) underwent similar collateral devascularization, but with total occlusion of the splenic pedicle for 2 hours. All animals underwent sulfur colloid scintiscanning preoperatively and 2 weeks postoperatively. Blood specimens were analyzed for the presence of Howell-Jolly bodies and immunoglobulin (Ig) G IgG and IgM levels. Pathological examination of the spleens was performed 2 weeks postoperatively. Postoperative scintiscanning showed very poor splenic visualization in two of the five group I dogs. Pathologically these spleens had extensive necrosis. The remaining eight spleens had normal scans, and only mild congestion was noted. Howell-Jolly bodies were found in all group I dogs (mean, 14.6) but in only 2 group II dogs (mean, 0.6). In four group I dogs, a marked decrease in peripheral IgG was noted. Splenic immunoglobulin levels and peripheral IgM were similar in both groups. This study demonstrates that 3 hours of warm splenic ischemia resulted in splenic necrosis and loss of function in 40% of the dogs tested. Two hours of ischemia appears to be safe for dogs; certainly 1 hour should be safe for humans and should allow sufficient time for most splenic surgical procedures.