Table 5.

Studies on venous thromboembolism prophylaxis methods for major abdominopelvic cancer surgery

Reference and country	Design	Patient	Method	VTE incidence	Risk
Bergqvist et al. (2002) [10] Denmark, France, Grace, Israel, Italy, Sweden, Switzerland, United Kingdom	Prospective, randomized, double-blind, placebo-controlled	613 patients who underwent open abdominal surgery for gastrointestinal, urological and gynecological cancer	After perioperative thromboprophylaxis with enoxaparin for 6-10 days for all patients, one group received enoxaparin and the other group received placebo for up to 4 weeks.	Incidence of VTE in the first 30 days:	Absolute risk reduction: 7.2%
				Total 8.4% (28 patients) Extended prophylaxis: 4.8% Placebo: 12%	Relative risk reduction: 60%
Kakkar et al. (2010) [9] United Kingdom, Spain, Italy	Prospective, randomized, double-blind, placebo-controlled	625 patients who underwent open abdominal surgery for gastrointestinal, urological and gynecological cancer	All patients received thromboprophylaxis with bemiparin for an average of 8 days perioperatively. The bemiparin group was given prophylaxis for another 20 days, while the other group was given placebo.	Incidence of VTE in the first 30 days:	Relative risk reduction 80% when mortality is excluded (P=0.01)
				Bemiparin group: 10.1% Placebo group: 13.3%
Vedovati et al. (2014) [28] Italy	Prospective, randomized, single-blind	225 patients who underwent elective laparoscopic surgery for colorectal cancer	All patients received prophylaxis for an average of 8 days perioperatively with LMWH. One group continued thromboprophylaxis, while the other group continued with placebo.	Incidence of VTE in the first 30 days:	-
				Total 4.9% Placebo: 9.7% (11 hasta) Extended prophylaxis: 0.0
Lee et al. (2016) [12] Korea	Prospective cohort	548 patients who underwent open or laparoscopic abdominal surgery for colorectal cancer	None of the patients received perioperative thromboprophylaxis for VTE	Including asymptomatic cases, the incidence of VTE is 3% (12 patients), symptomatic VTE is <1% (2 patients)	-
Kim et al. (2013) [13] Korea	Prospective cohort	610 patients who underwent palliative or curative surgery for gastric cancer	None of the patients received perioperative thromboprophylaxis for VTE	Incidence of VTE in the first 30 days:	-
				Total: 2.4%

VTE, venous thromboembolism; -, not reported.