THE INCIDENCE OF CLINICAL POSTOPERATIVE THROMBOSIS AFTER GASTRIC-SURGERY FOR OBESITY DURING 16 YEARS

Background: Suggested risk factors for postoperative thrombosis such a s high fatty acid levels, hypercholesterolemia and diabetes are common in obese patients. Methods: In a retrospective study, the case record s of 328 patients operated for obesity by gastric procedure from Septe mber 1977 until December 1993 were analyzed: 253 women and 75 men with a mean age of 38 years and a mean body mass index (BMI) of 44 kg/m(2) . The operation time, use of epidural anesthesia, and the occurrence o f risk factors; fatty acid levels, hypercholesterolemia and diabetes w ere recorded. Symptomatic thromboses were verified by phlebography or phlethysmography and pulmonary embolism with ventilation/perfusion sci ntigraphy or autopsy. Results: The mean operating time was 128 minutes , 77% had epidural anesthesia and the mean hospital stay was 12.3 days . The long hospital stay was due to the fact that most patients took p art in different scientific studies perioperatively. The incidence of thromboembolism was 2.4%. Four patients had pulmonary embolism, in one of them this was fatal. Three patients had deep leg vein thrombosis a nd one patient had arm thrombosis secondary to a central venous cathet er. None of these patients had high fatty acids, diabetes or high chol esterol. Of the patients, 298 were given dextran-70 (Macrodex(R), Phar macia) as prophylaxis, seven were given heparin and 23 were given no p rophylaxis. In the patient group without diagnosed thrombosis, 31% had high fatty acid levels, 2% had high cholesterol levels and 9% had dia betes. Conclusions: Obese patients seem to have a moderate risk of dev eloping postoperative thrombosis when an effective prophylaxis is used . High free fatty acids, hypercholesterolemia and diabetes are not obv ious extra risk factors in obese patients. Thromboprophylaxis should b e given to all operated obesity patients regardless of age. The surgeo ns must be aware and investigate promptly any symptoms suggestive of t hromboembolism.