Venous thromboembolism prophylaxis by variable doses of parnaparin in super-obese patients: Preliminary report

Background: Severe obesity is a risk factor for venous thromboembolism. The aim of the study is to establish the right dosology of parnaparin, a LMWH, which gives the highest prophylaxis efficacy compared with the lowest hemorrhagic risk and to confirm the LMWH efficacy. Methods: These preliminary data concern 10 patients with BMI >50 kg/m2. We made a clinical evaluation, researching thrombophilic markers, and an instrumental evaluation, with venous echocolordoppler and scintigram of lower limbs and of ilio-caval axis before surgery and after 7 days, and perfusional lung scintigram before surgery and after 9 days. We gave a parnaparin dose of 3,200 I.U. (0.3 ml) in the first day, a dose of 4,250 I.U. (0.4 ml) for 2 days, and a dose of 6,400 I.U. (0.6 ml) for the other two preoperative days and during hospitalization. Parnaparin was given at 8.00 a.m. every day, assaying the level of Xa and IIa factors in the blood, Xa/IIa ratio, in order to verify and to confirm the possibility of an equal efficacy with lower doses. After discharge, we used a dose of 6,400 I.U. (0.6 ml), prolonged for 30 days at home. Results: We found no hemorrhagic events. Only one patient, who interrupted the parnaparin treatment because of allergy at 5th day, had a pulmonary embolism on the 30th day. In the remaining 9 patients there were neither clinical nor instrumental thromboembolic events. Conclusions: According to these preliminary data, parnaparin proved to be a very safe and efficacious drug for thromboembolic venous prophylaxis in super-obese patients undergoing bariatric surgery.