Jacob Fairhall

Minimally invasive percutaneous fixation techniques for metastatic spinal disease.

Surgical treatment of spinal metastasis is generally a palliative procedure. Although minimally invasive surgical (MIS) techniques are supposedly less morbid than open techniques, there is a lack of stratification of MIS techniques based on anticipated longevity. A simple stratification into three percutaneous surgical techniques based on modified Tokuhashi score is here proposed.

Intracranial haemorrhage in pregnancy

Intracranial haemorrhage (ICH) is a rare, yet potentially devastating event in pregnancy. There is a risk of maternal mortality or morbidity and a significant risk to the unborn child. The risk of haemorrhage increases during the third trimester and is greatest during parturition and the puerperium. ICH can be extradural, subdural, subarachnoid or intraparenchymal. Causes of bleeding include trauma, arteriovenous malformations, aneurysms, preeclampsia/eclampsia and venous thrombosis. Urgent neurosurgical conditions generally outweigh obstetric considerations in management decisions, although anaesthetic and surgical modifications can be made to minimize adverse effects to the fetus.

Molecular responses of brain endothelial cells to radiation in a mouse model

Although most small arteriovenous malformations (AVM) are curable, over 90% of large lesions are untreatable with current surgery or radiosurgery. Endothelial cells (EC) are believed to be pivotal in the resulting vascular changes after AVM are irradiated, although their role is not fully understood. Elucidating the molecular effects of radiation on EC may allow development of new therapies that modulate the response of AVM to radiation. Cultured murine cerebral EC (bEnd.3) were exposed to a single 25 Gy dose of ionising radiation from a linear accelerator. Expression of the membrane proinflammatory and thrombotic molecules E-selectin, tissue factor (TF) and thrombomodulin (TM) were examined by immunofluorescent staining at times up to three weeks post irradiation. We found that E-selectin is significantly down regulated in the first 24 hours after irradiation. Later there is no significant difference in expression of this molecule between irradiated and non-irradiated groups. TM expression was significantly increased at all times, and the staining intensity of TF remained unchanged three weeks post irradiation. These results contribute to a greater understanding of the proinflammatory and thrombotic changes caused by irradiating normal brain EC.

Durable thrombosis in a rat model of arteriovenous malformation treated with radiosurgery and vascular targeting

OBJECT Radiosurgical treatment of brain arteriovenous malformations (AVMs) has the significant shortcomings of being limited to lesions smaller than 3 cm in diameter and of a latency-to-cure time of up to 3 years. A possible method of overcoming these limitations is stimulation of thrombosis by using vascular targeting. Using an animal model of AVM, the authors examined the durability of the thrombosis induced by the vascular-targeting agents lipopolysaccharide and soluble tissue factor conjugate (LPS/sTF). METHODS Stereotactic radiosurgery or sham radiation was administered to 32 male Sprague-Dawley rats serving as an animal model of AVM; 24 hours after this intervention, the rats received an intravenous injection of LPS/sTF or normal saline. The animals were killed at 1, 7, 30, or 90 days after treatment. Immediately beforehand, angiography was performed, and model AVM tissue was harvested for histological analysis to assess rates of vessel thrombosis. RESULTS Among rats that received radiosurgery and LPS/sTF, induced thrombosis occurred in 58% of small AVM vessels; among those that received radiosurgery and saline, thrombosis occurred in 12% of small AVM vessels (diameter < 200 μm); and among those that received LPS/sTF but no radiosurgery, thrombosis occurred at an intermediate rate of 43%. No systemic toxicity or intravascular thrombosis remote from the target region was detected in any of the animals. CONCLUSIONS Vascular targeting can increase intravascular thrombosis after radiosurgery, and the vessel occlusion is durable. Further work is needed to refine this approach to AVM treatment, which shows promise as a way to overcome the limitations of radiosurgery.

Successful endovascular and surgical treatment of spinal extradural metameric arteriovenous malformation. Case report.

A report of successful combined endovascular and surgical management of an unusual case of metameric (juvenile) spinal arteriovenous malformation (AVM) is presented. The malformation had extradural and paraspinal components, but no intradural elements. It had caused rapid neurological deterioration to near-complete paraplegia prior to treatment (American Spinal Injury Association [ASIA] Grade C). A combination of endovascular occlusion of major feeding vessels and excision of the malformation resulted in a complete neurological recovery (ASIA Grade E). The authors conclude that selected metameric AVMs can be successfully treated with multimodal therapy. This case further illustrates the fact that not all spinal vascular malformations are easily categorized.