Randomized, controlled trial of low molecular weight heparin vs. no deep vein thrombosis prophylaxis for major colon and rectal surgery in Asian patients

PURPOSE: Routine deep venous thrombosis prophylaxis is controversial in Asi an patients, because deep venous thrombosis incidence was considered neglig ible. Because of recent reports of significantly higher incidences, a rando mized, controlled trial was conducted to assess the effectiveness and compl ications of enoxaparin prophylaxis (low molecular weight heparins) in major colorectal surgery. METHODS: Three hundred twenty consecutive patients wer e randomly assigned to control or low molecular weight heparins groups. Pat ients in the low molecular weight heparins group were given perioperative e noxaparin starting 12 hours before surgery. The surgeon (blinded) assessed for difficulties related to possible enoxaparin. administration. Independen t blinded observers performed daily clinical assessments and Doppler studie s (at the 3rd and 5th postoperative day). Deep venous thrombosis was confir med by duplex ultrasound, and pulmonary embolism was confirmed by lung scan s or postmortem examinations. RESULTS: Deep venous thrombosis developed in 5 of 169 (3 percent) controls and 0 of 134 low molecular weight heparins pa tients (P = 0.045). Three of the deep venous thrombosis patients had pulmon ary embolism, which was fatal in one patient. The surgeons were unable to p erceive any increased surgical difficulties in the low molecular weight hep arins group. The bleeding-related complications were significantly higher i n the low molecular weight heparins patients (controls, n = 3 (1.8 percent) ; low molecular weight heparins, n = 9 (6.7 percent)). However, apart from one subdural hematoma and two abdominal hemorrhages needing re-exploration, which also occurred in one of the controls. these complications were minor bruises at the wounds, drains. or injection sites. CONCLUSION: Deep venous thrombosis prophylaxis is needed in Asian patients undergoing major colore ctal surgery.