Minimally invasive medial supraorbital, combined subfrontal-interhemispheric approach to the anterior communicating artery complex-a cadaveric study.

INTRODUCTION: In selected cases, microsurgical clipping remains a valuable treatment alternative to endovascular occlusion of anterior communicating artery (AComA) aneurysms. Their clipping is challenging and carries a risk of postsurgical cognitive impairment. We evaluate the microsurgical anatomy of a new, minimally invasive combined interhemispheric-subfrontal approach to the AComA complex via a medial supraorbital craniotomy. METHODS: In this descriptive anatomic study, four alcohol-embedded, silicon-injected human cadaver heads were used. In each of the two cadavers, the AComA complex was approached from either the right or left side. An operating microscope and standard microsurgical instruments were used. RESULTS: After a medial eyebrow incision, a medial supraorbital minicraniotomy was performed. The frontal sinus was opened and cranialized. Following the dural opening, a subfrontal arachnoid dissection was performed to identify the optico-carotid complex. By following the A1 segment, a low-lying AComA complex could be visualized. Shifting the corridor towards the midline enabled an interhemispheric dissection. This dissection resulted in a wide superior-inferior corridor. Higher-lying AComA complexes could also be visualized. The achieved exposure of the AComA complex would allow safe dissection and clipping of low- and high-lying AComA aneurysms, with minimal retraction and preservation of the surrounding anatomical structures, in particular the perforators. CONCLUSIONS: We demonstrate the anatomy of a novel approach for surgical clipping of AComA aneurysms. Our study suggests that this approach provides good exposure without concomitant structural and vascular injury and thus might reduce the risk of procedure-related morbidity.

Effect of ADAMTS-13 on cerebrovascular microthrombosis and neuronal injury after experimental subarachnoid hemorrhage.

BACKGROUND: Microthrombosis and reactive inflammation contribute to neuronal injury after subarachnoid hemorrhage (SAH). ADAMTS-13 cleaves von Willebrand factor multimers, and inhibits thrombus formation and, seemingly, inflammatory reactions. OBJECTIVE: To investigate the effect of ADAMTS-13 in experimental SAH. METHODS: A total of 100 male C57/BL6 mice were randomly assigned to four groups: sham (n = 15), SAH (n = 27), vehicle (n = 25), and ADAMTS-13 (n = 23; 100 µL per 10 g of body weight of 100 µg of ADAMTS-13 per 1 mL of 0.9% NaCl; 20 min after SAH). Neurologic performance was assessed on days 1 and 2 after SAH. Animals were killed on day 2. The amounts of subarachnoid blood, microthrombi, apoptosis and degenerative neurons were compared. The degree of neuronal inflammation and vasospasm was also compared. In five mice each (SAH and ADAMTS-13 groups), bleeding time was assessed 2 h after SAH. RESULTS: Systemic administration of ADAMTS-13 achieved significant amelioration of microthrombosis and improvement in neurologic performance. ADAMTS-13 reduced the amount of apoptotic and degenerative neurons. A tendency for decreased neuronal inflammation was observed. ADAMTS-13 did not show any significant effect on vasospasm. The degree of systemic inflammation was not changed by ADAMTS-13 administration. ADAMTS-13 neither increased the amount of subarachnoid blood nor prolonged the bleeding time. CONCLUSIONS: ADAMTS-13 may reduce neuronal injury after SAH by reducing microthrombosis formation and neuronal inflammation, thereby providing a new option for mitigating the severity of neuronal injury after SAH.

Monitoring of the inflammatory response after aneurysmal subarachnoid haemorrhage in the clinical setting: review of literature and report of preliminary clinical experience.

BACKGROUND: Clinical and experimental studies showed a marked inflammatory response in aneurysmal subarachnoid haemorrhage (SAH), and it has been proposed to play a key role in the development of cerebral vasospasm (CVS). Inflammatory response and occurrence of CVS may represent a common pathogenic pathway allowing point of care diagnostics of CVS. Therefore, monitoring of the inflammatory response might be useful in the daily clinical setting of an ICU. The aim of the current report is to give a summary about factors contributing to the complex pathophysiology of inflammatory response in SAH and to discuss possible monitoring modalities. METHODS: Review and analysis of the existing literature and definition of own study protocols. RESULTS: In cerebrospinal fluid, interleukin (IL)-6 has been found to be significantly higher in patients with CVS during the peri-vasospasm period. While systemic inflammatory response syndrome, high C-reactive protein levels and leukocyte counts has been linked with the occurrence of CVS, less has been reported about cytokines levels in the jugular bulb of the internal jugular vein and in the peripheral blood. Preliminary evaluation of own data suggests, that IL-6 values in the peripheral blood and the arterio-jugular differences of IL-6 are increased with the inflammatory response after SAH. CONCLUSION: Monitoring of the inflammatory response, in particular IL-6, might be a useful tool for the daily clinical management of patients with SAH and CVS.

Thalamic cavernous angioma: paraculminar supracerebellar infratentorial transtentorial approach for the safe and complete surgical removal.

BACKGROUND: The thalamic cavernous angioma (CA) represents a neurosurgical challenge because of the critical neurologic functions of the thalamus and its surrounding structures and of their deep location inside the brain. Although the natural history of the thalamic CA remains undefined, several studies suggest the poor outcome of those patients especially if the symptomatic thalamic CA is treated conservatively. We describe the advantage of the paraculminar supracerebellar approach to the lesions in the brainstem. OBJECTIVE: We studied the usefulness and the safety of the paraculminar supracerebellar infratentorial transtentorial approach for the patients with thalamic CA. METHODS: One hundred and ninety two consecutive patients with CA were treated at the Department of Neurosurgery in the Zurich University Hospital between 1993 and 2003. Among these patients, we analyzed six patients (four female, mean age 43) with thalamic CA who underwent surgical removal with the paraculminar supracerebellar transtentorial approach. We retrospectively reviewed their medical charts, the neuroradiological images, and the operative notes/video records. RESULTS: Four patients of the six presented with thalamic hemorrhage. CA existed in the left thalamus in four patients and in the right in two. Preoperative symptoms included sensorimotor disturbance (three cases), double vision (three cases), Parinaud syndrome (one case), and thalamic pain (one case). All patients had the thalamic CA completely removed without any postoperative deterioration. CONCLUSIONS: This study suggests that for the removal of thalamic cavernous angioma the paraculminar supracerebellar infratentorial transtentorial approach provides the spacious surgical field with reduced risks of damaging and sacrificing surrounding vascular and neuronal system. This approach could proffer one of the best and safest surgical routes for the radical removal of thalamic cavernous angioma.