Efficacy of extended thrombo-prophylaxis in major abdominal surgery: what does the evidence show? A meta-analysis.
Venous thromboembolism (VTE) is a frequent complication following major abdominal surgery. The use of low-molecular-weight heparins (LMWH) to prevent thrombotic events in these patients is a common and well documented practice. However, there is some controversy surrounding the duration of the prophylaxis, as it has been suggested that the risk persists for several weeks after surgery. The objective of this meta-analysis is to systematically review the clinical studies that compared safety and efficacy of extended use of LMWH (for three to four weeks after surgery) versus conventional in-hospital prophylaxis. An electronic data base search was performed. Only randomized, controlled studies were eligible. Data on the incidence of deep vein thrombosis (DVT), VTE and bleeding were extracted. Only three studies fulfilled the inclusion criteria. The indication for surgery was neoplastic disease in 70.6% (780/1104) of patients. The administration of extended LMWH prophylaxis significantly reduced the incidence of VTE, 5.93% (23/388) versus 13.6% (55/405), RR 0.44 (CI 95% 0.28 - 0.7); DVT 5.93% (23/388) versus 12.9% (52/402), RR 0.46 (CI 95% 0.29 - 0.74); proximal DVT 1% (4/388) versus 4.72% (19/402), RR 0.24 (CI 95% 0.09 - 0.67). We found no significant difference in major or minor bleeding between the two groups: 3.85% (21/545) in the extended thrombo-prophylaxis (ETP) group versus 3.48% (19/559) in the conventional prophylaxis group; RR 1.12 (CI 95% 0.61 - 2.06). There was no heterogeneity between the studies. We conclude that ETP with LMWH should be considered as a safe and useful strategy to prevent VTE in high-risk major abdominal surgery.
Department of Internal Medicine, Hospital Britanico de Buenos Aires, Buenos Aires, Argentina. febottaro@hotmail.com
Federico Jorge
FJ
Bottaro
Maria Cristina
MC
Elizondo
Carlos
C
Doti
Julio Enrique
JE
Bruetman
Pablo Diego
PD
Perez Moreno
Eduardo Oscar
EO
Bullorsky
Jose Manuel
JM
Ceresetto
D000005:Abdomen / Q000601:surgery*; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D004334:Drug Administration Schedule; D019317:Evidence-Based Medicine; D006470:Hemorrhage / Q000139:chemically induced; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007813:Laparotomy / Q000009:adverse effects* / Q000401:mortality; D017594:Publication Bias; D011655:Pulmonary Embolism / Q000209:etiology / Q000517:prevention & control; D018570:Risk Assessment; D013997:Time Factors; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000209:etiology / Q000517:prevention & control*
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight