Posterior Fossa Surgeries: Early Use of Low Molecular Weight Heparin, Postoperatively, Causing Intraparenchymal Hemorrhage

Use of anticoagulants in neurosurgery has been debated for very long. The critical nature of the issue led to numerous clinical trials which showed safety of anticoagulation in cranial surgeries. However, data for posterior fossa surgeries is scarce. Owing to the unique cytoarchitecture of cerebellum, it is more prone to bleed, which renders the use of anticoagulants controversial. Several studies have depicted the safety and efficacy of unfractionated heparin in cranial surgeries. But low-molecular-weight heparin (LMWH) has shown increased risk of bleed as compared with unfractionated. This warrants a study focusing on LMWH evaluating the risk of posterior fossa hemorrhage. We present cases of posterior fossa bleed following the use of LMWH in cranial surgeries. We also propose the recommendations for anticoagulants use in cranial, especially posterior fossa, surgeries.

We report 6 cases of posterior fossa bleeds. Devastating long-term outcomes were observed when LMWH (Lovenox) was initiated within first few days of operation. A 48-year-old male who underwent translabyrinthine craniotomy developed deep venous thrombosis (DVT) on postoperative day (POD) 3, but due to high risk of bleeding, anticoagulation was not started until POD 5. Patient had posterior fossa bleed on POD 6 but recovered completely and did not have any residual weakness. This highlights the importance of timing of initiation of anticoagulants. In the light of these cases, here are our recommendations for using anticoagulants:

1. Patient should be positioned in operating room carefully optimizing venous return.

2. Anticoagulation should not be initiated without discussing with surgeon.

3. Duplex ultrasound should be done every day in case of development of DVT

4. Heparin (5000 SQ BID) can be start on POD 4 if patient is immobilized.

5. It is safe to start heparin and warfarin in case of pulmonary embolism (PE), if it occurs on POD 2 or later.

6. Lovenox should not be initiated until 1 month postoperatively.