Author: Professor Guy Maddern, Chair, ANZASM

Case summary

A 51-year-old woman was admitted to hospital after experiencing a seizure at home. She had significant comorbidities including several autoimmune diseases, pulmonary fibrosis and previous pulmonary emboli. Examination in the emergency department found she had a Glasgow coma score of 14, with left sixth nerve palsy.

Investigations confirmed a significant posterior fossa subarachnoid haemorrhage. Further imaging confirmed a mid-basilar segment, broad-based dissecting aneurysm. Her condition was stable, so she was transferred to the intensive care unit (ICU).

The complexity of the condition prompted discussion at a senior level between the treating consultant neurosurgeon and the interventional neuroradiologist. Options for management were discussed with the patient’s relatives in view of her medical history. Direct surgical intervention was considered unreasonable; interventional treatment was considered the best option to proceed.

Given that the patient was considered at high risk of developing obstructive hydrocephalus (secondary to the subarachnoid haemorrhage), an external ventricular drain was inserted prior to interventional neuroradiology. It was also recognised that following the interventional neuroradiology treatment of the basilar aneurysm, the patient would require dual antiplatelet therapy and heparin, which would compromise the placement of an external ventricular drain.

Insertion of the external ventricular drain took place without complication. The patient then proceeded to interventional neuroradiology for successful placement of flow-diverting stents to treat the mid-basilar dissecting aneurysm.

During these procedures, the patient was given 6000 units of heparin. Initial activated partial thromboplastin time (APTT) at 17:10 (prior to the intervention) was 28 seconds. On return to ICU, the patient had commenced aspirin and a described ‘high-risk heparin infusion procedure protocol’ comprising 800 units of heparin per hour. The patient was stable in ICU for some hours.

At 04:00 (some six hours or so after the procedure), it was noted that the patient’s APTT was above 200 seconds. The test had been performed about an hour earlier. Heparin infusion ceased. Approximately two hours later, the patient deteriorated with a sudden seizure and increasing intracranial pressure. She was resuscitated.

A repeat computed tomography (CT) scan showed significant re-bleeding. Further intervention was considered futile, and the patient died.

Discussion

The initial assessment, management and decision-making around the treatment of this patient’s complex problem was at a high level and certainly met the current standards of best practice. Documentation of these discussions within the notes is clear. It is also clear that detailed discussions were undertaken with the family regarding complications in the patient’s care.

The external ventricular drain and interventional neuroradiology treatment of the aneurysm seemed quite successful. Following the treatment (five or six hours later), the patient had a sudden re-bleed and she succumbed to this bleeding.

The reasons why this re-haemorrhage occurred remain unclear. Two possibilities are that the aneurysm had not been completely secured, or that inappropriate over-anticoagulation led or contributed to the re-bleeding.

It seems reasonable to conclude that over-heparinisation of the patient was a significant factor leading to the re-bleed.

Clinical lessons

The 2024 healthcare landscape has a proliferation of anticoagulation and antiplatelet therapies, with an ever-widening scope of clinical indications. These can be both therapeutic and prophylactic. The dosing, monitoring and reversal of these therapies is complex. Bleeding remains an archenemy of the surgeon and increasingly the non-surgical interventionalist. We must ensure that our surgical teams are very clear about the management of these therapies. This requires careful risk stratification, tight therapeutic protocols, multidisciplinary consultation, unambiguous communication and robust handover.