Introduction

Placenta Accreta Spectrum (PAS) is a spectrum of pathology clinically characterized by the inability to safely separate the placenta at the time of delivery. PAS can lead to massive hemorrhage and, for high grade pathology, necessitates a scheduled cesarean hysterectomy. Long operating times, general anesthesia, risk of hemorrhage, and need for blood transfusion predispose PAS patients to venous thromboembolism (VTE) on top of an already elevated risk in pregnancy (0.12%). We aim to investigate the efficacy of a novel anticoagulation regimen, or “VTE bundle,” in reducing VTE incidence in patients with PAS.

Methods

A retrospective cohort study was conducted on all scheduled cesarean hysterectomies completed for PAS at Michigan Medicine. Patients with active malignancy were excluded. VTE bundle included 4 components: intra-operative administration of subcutaneous heparin, anticoagulation restarted within 8 hours post-operatively and continued through discharge, and prophylactic anticoagulant prescribed at discharge. Chart review and REDCap database were used to obtain data. Primary outcome was VTE incidence within six weeks of delivery. Secondary outcomes of wound dehiscence, emergency department visits, reoperation, and readmission within six weeks of surgery were analyzed individually and as a composite by logistic regression using SAS software.

Results

90 patients were included, 20 (22.2%) received the complete VTE bundle. Of remaining patients, 28.5% were delayed in restarting post-operative anticoagulation but received all components. 65.7% were missing one or more components. 5.7% received no prophylactic anticoagulation. Two patients (2.2%) had a recorded episode of postpartum VTE, with no significant difference in rate of VTE incidence (p = 0.339) or secondary outcomes between those who did and did not receive the complete bundle (see Table 1).

Conclusion

There was no difference in VTE rate between patients who received the complete bundle and those who did not. Analysis revealed a low clinical adherence to complete VTE bundle administration. The importance of continued work in this area is underscored by the 18-fold higher risk of VTE in this cohort compared to pregnant people generally. Future work will focus on quality improvement interventions to increase compliance with VTE bundle administration and facilitate better evaluation of the bundle in preventing VTE.

Tables and Figures

Table 1: Primary Outcome, Venous Thromboembolism (VTE) Incidence Within 6 Weeks of Delivery