Post-operative deepvein thrombosis is infrequent in Alaska Natives

The expected rate of deep vein thrombosis (DVT) after laparotomy or major joint surgery has been reported to be 20 to 50% for unprophylaxed non-native patients. DVT prophylaxis for surgical patients at the Alaska native Medical Center has typically not been offered as the perceived rate of DVT and pulmonary embolism in our patient population has been very low. Retrospective analysis of positive venous duplex scans at our institution revealed only four cases of post-operative DVT during a two-year interval. This study was designed to document the actual rate of post-operative DVT in Alaskan natives not provided with routine DVT prophylaxis.

Prospective cohort study of DVT in open abdominal, open knee, open hip and pelvic fracture surgery patients at the Alaska native Medical Center from 1999-2001.

The day prior to expected discharge, we performed venous duplex ultrasonography on 67 patients with open abdominal surgery, major open knee or hip surgery, or pelvic fracture who received no DVT prophylaxis. Some patients included in the study were also asked questions about their consumption of marine mammals and fish, and the native blood quanta was estimated in all patients using existing data bases.

Sixty percent of the study population was determined to be at high risk for DVT using standard risk stratification methods. Dietary habits varied widely, but were largely reported as being "traditionally" native. Nearly all patients had 50% or more "native blood". Only one of 67 patients developed a documented post-operative DVT.

Post-operative deep vein thrombosis in Alaskan natives not provided with routine DVT prophylaxis is rare. The data does not provide a clear indication as to why Alaskan natives may be at decreased risk for post-operative DVT.