Supratentorial Intraparenchymal Haemorrhages during Spine Surgery.

Intracranial haemorrhages are rare but potentially life-threatening complications of spine surgery. Most reported cases involved subdural or cerebellar haemorrhages; supratentorial parenchymal bleeding is very uncommon. We report a 28-year-old woman who underwent resection of a thoracic Ewing's sarcoma, and developed fatal haemorrhages around her cerebral metastases during surgery. The clinical presentations, possible pathogenesis and potential preventive measures are discussed. Patients with disseminated metastases within the neural axis are at risks of intracranial complications during spine surgery. The presence of intracranial mass lesions should be considered as a relative contraindication to intradural spine surgery.

INTRODUCTION

Intracranial haemorrhages are rare but potentially life-threatening complications of spine surgery1,3,6,8). The underlying mechanism is likely due to cerebrospinal fluid (CSF) loss, causing intracranial hypotension and traction on the cerebral veins4). The majority of reported cases involved subdural7) or cerebellar haemorrhages5) that presented in the post-operative period. Supratentorial parenchymal bleeding, on the other hand, is very uncommon. We report a case of multiple intracerebral haemorrhages (ICH) that occurred during intradural spine surgery.

CASE REPORT

A 28-year-old woman presented with an acute onset of bilateral lower weakness. She had a history of Ewing's sarcoma involving the thoracic spine with metastases to the right lung, right kidney and brain (Fig. 1). Palliative systemic chemotherapy, radiotherapy to the right thorax, and whole brain irradiation were given seven months prior. She had no bleeding diathesis. On examination, she did not have any sign of raised intracranial pressure (ICP). Her lower limb motor power was grade 1/5 bilaterally. The sensory level was at T10 dermatome. There was acute urinary retention but intact anal tone. Computerized tomography (CT) of the brain showed multiple cerebral and cerebellar metastases with perifocal oedema (Fig. 2). There was no hydrocephalus. Magnetic resonance studies showed an intradural extramedullary lesion at T4/5 that was causing significant cord compression (Fig. 3).

Fig. 1

T2-weighted magnetic resonance study shows multiple tumours in both cerebral hemispheres seven months prior.

Fig. 2

Pre-operative computerized tomography shows peri-tumoural oedema.

Fig. 3

Contrasted T1-weighted magnetic resonance study shows the spinal metastasis.

Because of previous radiotherapy, surgery was the only treatment option for her. Laminectomy for tumour excision was therefore performed. Intra-operatively, spinal CSF was drained under normal pressure. Her haemodynamics were stable during surgery. The spinal cord was well decompressed after tumour removal. The procedure lasted three hours and 15 minutes. Immediately after surgery, the patient was found to have dilated and non-reactive pupils. CT brain scan showed significant brain swelling and multiple ICHs (Fig. 4). Her family declined further surgery in view of the poor prognosis. She died two days later despite medical therapy. Histological examination of the spinal lesion showed metastatic Ewing's sarcoma. No autopsy was performed.

Fig. 4

Post-operative computerized tomography shows multiple haemorrhages around the cerebral metastases.

DISCUSSION

The pathogenesis of intracranial haemorrhage following spine surgery is incompletely understood. It has been suggested that volume depletion of CSF due to intra-operative loss, occult fistulae or lumbar drainage may result in brain sagging and stretching of the bridging veins1,6). The latter may then bleed and cause subdural haemorrhages2), or undergo thrombosis and cause cerebral infarction. The cerebellum is the commonest site of parenchymal bleeding after spine surgery due to involvement of the superior cerebellar veins5). On the other hand, ICHs due to lumbar CSF loss is uncommon9). Thomas et al.8) reported a patient with supratentorial and infratentorial ICHs after spine surgery from which the patient made an uneventful recovery.

The majority of reported cases presented during the post-operative period3,6). Our patient developed haemorrhages during surgery. Given the rapid course of events, venous thrombosis was unlikely to be responsible. It was possible that a sudden release of spinal CSF could have caused a surge in cerebral perfusion which then led to tumour bleeding. However, simultaneous haemorrhages from several tumours are unusual. Alternatively, in the presence of supratentorial mass lesions, spinal CSF loss may have resulted in brain herniation and haemorrhagic infarction, similar to what could happen after lumbar puncture. Without autopsy findings, we were unable to ascertain the exact mechanism.

External irradiation should be the most appropriate treatment for spinal metastasis, especially in patients with disseminated malignancy. The indication for laminectomy for our patient was weak. But, because of previous radiotherapy, surgery was the only treatment option for our patient, who was young and very keen on surgery for the relief of her acute neurological symptoms. The issue of whether the presence of intracerebral tumours should have contraindicated intradural spine surgery was debatable. Lesions with no mass effect were probably safe; those in our patient, in retrospect, were not. In retrospect, a ventriculostomy would have facilitated ICP control and prevented the creation of a significant craniospinal pressure gradient. Excessive CSF drainage through the spine should be avoided although a head-down prone position may potentially aggravate intracranial hypertension also in the event of haemorrhages. Fluctuations in systemic blood pressure and arterial carbon dioxide level during anaesthesia should be avoided with careful anaesthetic management. The use of peri-operative steroids, tranexamic acid or mannitol may help to reduce tumour swelling and the risks of bleeding. Surgery for the brain lesions prior to spinal operation was a possible option although it was probably not appropriate for our patient with very terminal malignancy. The present case illustrates that spine surgery is potentially hazardous when performed in the presence of intracerebral mass lesions. It should not be considered as first-line treatment when other modalities such as radiotherapy is feasible. Should surgery be needed in extreme cases, patient counseling with regards to this rare but significant complication is essential.

CONCLUSION

Intradural spine surgery may be complicated by supratentorial ICH. In patients with disseminated metastatic diseases, pre-operative imaging studies should be performed to exclude the presence of intracranial mass lesion. Brain lesions that are causing significant mass effect may be at risk of developing haemorrhages. These should be treated first if possible or considered as a relative contraindication to intradural spine surgery. Radiotherapy remains to be the most appropriate treatment for spinal metastasis, especially in patients with terminal malignancy.