Pharmaceutical thrombosis prophylaxis, bleeding complications and thromboembolism in a national cohort of hysterectomy for benign disease.

BACKGROUND: Pharmaceutical thrombosis prophylaxis (PTP) with low-molecular-weight heparin (LMWH) is highly effective in preventing venous thromboembolic events (VTEs) and fatal pulmonary embolism. Important risk factors for VTEs are surgery and immobilization, along with malignancy. Many studies involving gynaecological malignancies show no increased risk for bleeding complications with PTP. Little is known about the PTP-associated risk for bleeding complications with hysterectomy for benign disease, or about current VTE incidence in the less-invasive hysterectomy methods.

METHODS: Our observational prospective national 1-year cohort from 1 January to 31 December 2006 in 53 hospitals represented 79.4% (5297 of 6645) of hysterectomies performed for benign cause in Finland in 2006. We evaluated PTP use and VTE incidence. Operative and post-operative bleeding complications were analysed with logistic regression adjusted for confounders: age, BMI, experience of the gynaecological surgeon, hospital type, indication for hysterectomy, uterine weight, operative haemorrhage, concomitant surgery, adhesiolysis and antibiotic prophylaxis.

RESULTS: Hysterectomies were performed by three main approaches: 2345 vaginal hysterectomies (VHs, 44%), of which 1433 were for uterine prolapse and 912 for other indications, 1679 laparoscopic hysterectomies (LHs, 32%) and 1255 abdominal hysterectomies (AHs, 24%). PTP was given to 64.8% of patients (3420 of 5279) and was identified as LMWH in 3313 patients (97%); 107 left unidentified. By type of hysterectomy, PTP was given in VH for uterine prolapse to 73.2% of patients, VH for other indication to 51.6%, in LH to 59.4% and in AH to 71.9%. For all hysterectomies analysed together, PTP doubled the odds for post-operative haemorrhage or haematoma. By type of hysterectomy, PTP associated with post-operative haemorrhage or haematoma in VH for prolapse [2.7% of PTP given, versus 0.8% of no PTP; odds ratio (OR): 4.82, 95% confidence interval (CI): 1.38-16.83]; and in AH (3.1% versus 1.4%; OR: 2.87, 95% CI: 1.03-7.98), and in AH also with post-operative transfusion (3.1% versus 1.4%; OR: 3.34, 95% CI: 1.41-7.88). For LH and VH for indications other than prolapse, the effect of PTP on post-operative haemorrhage was non-significant. For VH, the risk for post-operative haemorrhage fell with age. Operative mean haemorrhage with all hysterectomy types, and operative bleeding complications in AH and VH also fell with age. Obesity increased haemorrhage and operative bleeding complications for LH and VH, whereas post-operative bleeding complications were less for the obese in AH. VTEs were 6 of 5279 (0.1%): two PEs each occurred after AH and VH, and two deep venous thromboses after LH.

CONCLUSIONS: With a relatively wide PTP coverage (64.8%), VTEs were rare (0.1%). All affected had received PTP. Analysis of efficacy, meaning interpretation of how many VTEs or deaths were prevented, cannot be done from our observational study but related to safety in hysterectomy for benign disease, PTP associated with post-operative bleeding complications with AH and with VH for prolapse.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov protocol (NCT00744172).