Management and clinical outcome of posterior fossa arteriovenous malformations: report on a single-centre 15-year experience

OBJECTIVES

Posterior fossa brain arteriovenous malformations (PFbAVMs) are rare lesions. Management is complicated by eloquence of adjacent neurological structures, multimodality treatment is often necessary, and obliteration is not always possible. We describe a 15-year experience in the management of posterior fossa brain AVMs with a focus on clinical outcome.

METHODS

From 1989 to 2004, prospectively collected information on 106 patients with diagnosis of a PFbAVMs was obtained. Clinical and angioarchitectural characteristics, management options and complications are described and reviewed to evaluate their impact on final outcome as measured by the Modified Rankin Score (mRS).

RESULTS

Ninety-eight patients were followed for an average of 3.3 years (1-14.6). The male-to-female ratio was 1:1. Ninety-five out of 98 patients (96.9%) were symptomatic at presentation, with 61 (62.2%) intracranial haemorrhages. Sixty-two patients were treated (46 cerebellar, 16 brainstem). Ten haemorrhages occurred in follow-up (4.1%/year). The mRS was obtained in 62 patients and was classified as low (good, mRS<or=2) or high (poor, mRS>or=3). Haemorrhage was the only predictor of poor mRS at presentation (p = 0.0229). A poor clinical outcome was correlated with the presence of AA (p = 0.0276), a poor initial mRS (p<0.0001) and the number of treatments needed (p = 0.0434). Patients were significantly more likely to improve than to deteriorate over time (p = 0.0201).

CONCLUSION

The final clinical outcome in PFbAVMs relates directly with the presence of associated aneurysms, number of treatments needed to obliterate the AVM and mRS at presentation. Despite the fact that patients tend to improve after brain AVM haemorrhage, the relationship of MRS at presentation and final outcome suggests that an expedited, more definitive treatment is probably a better choice, especially in patients with good grades after the initial bleeding.

Outcomes and quality of life assessment in patients undergoing endoscopic surgery for pituitary adenomas

The endoscopic technique is increasingly being used for the resection of pituitary adenomas. Its efficacy and safety have been generally accepted, but its impact on the quality of life of the patients treated has not been previously addressed. Most of the studies assessing the quality of life after long-term cure of pituitary adenomas suggest a significantly impaired quality of life (QoL) in all subgroups of pituitary tumours. In our study we analyse QoL data following endoscopic surgery, and attempt comparisons with normative and data from standard approaches. The validated health questionnaire SF-36 was sent to 80 patients who had undergone pure endoscopic resection of a pituitary adenoma. Fifty-four patients returned the completed questionnaire. Outcomes were compared with normative data for the Short Form-36 (SF-36) Heath survey for the general Canadian population. We also compared the results amongst different types of adenomas. We attempted a comparison to previous studies on quality of life for patients who underwent conventional trans-sphenoidal surgery. Our study suggests only minimal impairment of quality of life in patients after successful treatment of pituitary adenomas using the endoscopic approach. There were only very few differences in the perceived quality of life within the different subgroups of adenomas. There was a trend to improved scores in the endoscopic group compared with previous studies in patients treated by conventional approaches. Whilst our data suggest minimal impact on the quality of life for patients after endoscopic removal of pituitary adenomas, further studies with larger number of patients and longer follow-up are required to encourage this finding.

The perianeurysmal environment: influence on saccular aneurysm shape and rupture

PURPOSE

The purpose of this study was to evaluate whether interactions between intracranial cerebral saccular aneurysms and the perianeurysmal environment (PAE), in the form of contact constraints, influence aneurysm shape and risk of rupture.

METHODS

A total of 190 consecutive aneurysms during a 34-month period were retrospectively analyzed. Of these, 124 were ruptured (group 1) and 66 were unruptured (group 2). Pretreatment high-resolution CT angiography was available for each aneurysm and was the determinant inclusion criterion. Aneurysm size and location, type of hemorrhage, initial Glasgow Coma Scale rating, World Federation of Neurological Societies grade, Fisher grade, and presence of concomitant aneurysms were recorded. Contact constraints between aneurysms and anatomical structures of the PAE were identified for each aneurysm and further subdivided into balanced or unbalanced depending on whether contact constraints occurred symmetrically on the aneurysm wall. Regular or irregular shape was recorded and correlated to contact constraints.

RESULTS

Compared with unruptured aneurysms, ruptured aneurysms were found to be larger and more irregular, to develop more contact constraints with the PAE, and to show higher rates of unbalanced contact constraints. Ruptured aneurysms had a tendency to be found in locations of a constraining PAE. Irregular shape was positively correlated with the presence of an unbalanced contact constraint, even in the absence of obvious contour deformations from an imprint of an adjacent structure.

CONCLUSION

The existence of contact constraints between intracranial saccular aneurysms and the PAE were shown to influence shape and risk of aneurysm rupture. Modifications of wall shear stress by contact constraints are discussed. Analysis of contact constraints between aneurysm and the PAE could be considered additional parameters in the assessment of risk of aneurysm rupture.

Multilobar Electrocorticography Monitoring During Intracranial Aneurysm Surgery

INTRODUCTION

To detect a neuronal threshold of tolerance to ischemia, the usefulness of multilobar electrocorticography (mEcoG) during intracranial aneurysm surgery was compared to the scalp EEG and correlated with the postoperative neurological status and the radiological findings.

METHODS

Twenty-one patients harboring intracranial aneurysms were monitored by simultaneous scalp EEG and lobe-dependent mEcoG during surgical clipping. The patients were divided into group A (6 patients with no temporary clipping) and group B (15 patients with temporary clipping).

RESULTS

New focal modifications of the mEcoG signal with high frequency (HF)-beta3 and delta waves were observed in none of the patients in group A and all of the patients in group B. These anomalies were followed by focal burst suppression pattern in eight cases (53%) in group B. These changes were detected in only two cases (9%) on the scalp EEG. New corticographic changes resolved in eight patients (53%) in group B. Among the seven patients in group B who had persistent focal burst pattern after clip removal, six (85%) presented with new neurological deficit or new hypodensity on CT. The Glasgow Outcome Scale was good (IV or V) in 85% of cases.

CONCLUSION

mEcoG is more sensitive than scalp EEG. The appearance and persistence of the focal burst suppression pattern shown on mEcoG, was associated with a new neurological deficit or new hypodensity, whereas HF-beta3 or delta waves per se were not associated with new changes. A better comprehension of these EEG anomalies could determine the duration of temporary clipping and consequently influence the surgical strategy.

Orthostatic intolerance and syncope associated with Chiari type I malformation

The Chiari type I malformation (CM1) is characterized by herniation of cerebellar tonsils to at least 3-5 mm below the plane of foramen magnum and can present with a wide variety of clinical symptoms, frequently including occipital headaches, secondary to bulbar and/or medullary distress. Rarely, syncopal episodes have also been described and attributed to either compression of the midbrain ascending reticular system, or vascular compromise (vertebrobasilar artery compression, hypotension). We report the first case of a CM1 patient with frequently recurring syncope due to postural orthostatic tachycardia syndrome (POTS), a form of orthostatic intolerance, whose symptoms resolved completely after surgical intervention. It is important to stress that it is not clear whether the described association of POTS and CM1 in our patient is a fortuitous finding in an isolated case or a reflection of a more systematic association between the two pathologies.

Occipital condyle fractures in children. Case report and review of the literature

Occipital condyle fractures (OCF) are seldom described in children, with only 14 cases reported in the literature. We report the observation of a 13-year-old child in whom such a fracture was diagnosed. A review of the paediatric cases allowed us to identify the clinical features of OCF in children. The average age was found to be 10 years, and the causative traumatism was most often related to road traffic or sporting accidents with associated head injury. The level of consciousness was depressed in 67% of the cases, and in 53%, an injury to the cranial nerves, brain stem or high spinal cord was present. Neck pain with reduction of head mobility was reported in 27% of the cases. Treatment was generally conservative, i.e. a hard collar or halo vest for an average of 8 weeks. The course was favourable with respect to osseous consolidation, mobility and pain. On the other hand, the neurological deficits improved, but sequelae remained. Early diagnosis and treatment is mandatory since the secondary displacement of fractured fragments can injure the cranial nerves in a delayed fashion or even be fatal due to compression of the brain stem.

Is the rupture of cerebral berry aneurysms influenced by the perianeurysmal environment?

PURPOSE

To evaluate contact between cerebral berry aneurysms and the perianeurysmal environment and to study the influence this contact has on aneurysm rupture.

MATERIALS AND METHODS

In a series of 76 consecutive patients, pre- and post-contrast CT images of 87 aneurysms were evaluated. Aneurysm locations were identified and aneurysms were divided into two different groups depending on whether they had ruptured or not. Contact between aneurysms and the perianeurysmal environment was studied when present, and considered to be balanced or unbalanced according to symmetry of contact and type of contact interface, i.e. with bone, dura, etc.

RESULTS

Rupture occurred in 47 aneurysms at an average maximum dome size of 7.4 mm. There was contact with elements of the perianeurysmal environment in 38 (81%) of ruptured cases and no evidence of contact in 7 (15%). The nature of contact was unclear in 2 (4%) ruptured aneurysms. In the aneurysms with contact, the nature of contact was unbalanced in 34 (72%) and balanced in 4 (9%). Unbalanced aneurysms ruptured at significantly smaller sizes (average: 7.7 mm) than balanced aneurysms (average: 11.4 mm). Seven aneurysms of small size (3.3-6.9 mm, average: 4.8 mm) were found to have ruptured, despite the fact that they were too small to exhibit contact with the perianeurysmal environment. In 40 unruptured aneurysms (average size: 6.3 mm), contact with the perianeurysmal environment was found in 15 aneurysms, for which balanced contact was found in 11 (27.5%) and unbalanced contact in 4 (10%), and no contact in 25 (62.5%). The average size of the aneurysms without contact (3.7 mm) was significantly smaller than that with balanced contact (10.3 mm) or with unbalanced contact (11.3 mm).

CONCLUSION

Aneurysms exhibit contact with their perianeurysmal environment as soon as they reach a size that exceeds their allowance given by the local subarachnoid space. The contact with the environment was found to be an additional determinant parameter in the evolution of cerebral berry aneurysms and their risk to rupture.

Endovascular coiling compared with surgical clipping for the treatment of unruptured middle cerebral artery aneurysms: an update

OBJECT

In 1999 we reported that 94% of unruptured middle cerebral artery (MCA) aneurysms managed prospectively between 1993 and 1997, according to a protocol favoring endovascular coiling, were best treated by surgical clipping. The goal of the current study was to delineate the most appropriate treatment option for unruptured MCA aneurysms today, considering the technical advances in imaging and in endovascular treatment.

METHODS

35 consecutive patients harboring 40 unruptured MCA aneurysms were treated between 1997 and December 2000. Patients with unruptured cerebral aneurysms are managed prospectively according to the same protocol as reported previously [1]: the primary treatment recommendation is endovascular packing with Guglielmi detachable coils (GDCs). Surgical clipping is recommended after failed attempt at coil placement or in the presence of angioanatomical features that contraindicate that type of endovascular therapy.

RESULTS

One unruptured MCA aneurysm was treated by endovascular embolization, 37 unruptured MCA aneurysms were clipped, whereas 2 unruptured MCA aneurysms were trapped with simultaneous extracranial-intracranial revascularization. Postoperative angiography revealed complete exclusion of all aneurysms. Preservation of vascular permeability was demonstrated in all clip-reconstructed aneurysms, despite arterial branches frequently originating from the aneurysmal base. Cerebral revascularization of the distal MCA was successful in the 2 patients with giant aneurysms. None of the patients presented permanent disabling complications from the treatment of the unruptured MCA aneurysm.

CONCLUSION

Despite major technical advances in imaging and in endovascular treatment of cerebral aneurysms, surgical clipping still is the most efficient treatment for unruptured MCA aneurysms at the beginning of the new millennium.

Therapeutic decision and management of aneurysmal subarachnoid haemorrhage based on computed tomographic angiography

The purpose of this study was to evaluate the potential of high quality computed tomographic angiography (CTA) to replace digital subtraction angiography (DSA) in cases of ruptured saccular aneurysms and perform early surgical clipping or coiling on the basis of CTA alone. In a prospective study, 100 patients with aneurysmal subarachnoid haemorrhage (SAH) diagnosed by computed tomography underwent CTA. CTA revealed a total of 118 aneurysms including all ruptured aneurysms. A decision of direct surgical clipping, endovascular coiling or therapeutic abstention was made in 89 cases (89%) on the basis of CTA alone. Sixty-one direct surgical procedures were performed after CTA. Twenty-six cases underwent DSA for immediate endovascular treatment of the ruptured aneurysm. In 11 cases (11%), a DSA was performed prior to the therapeutic decision because of unclear aneurysm. Four cases were not treated because of initial poor clinical grade. The surgical findings were compared with CTA data and were considered accurate in all but one case. All patients underwent postoperative DSA within 10 days after SAH. The sensitivity and the specificity of CTA for the detection of all aneurysms, as compared with postoperative DSA, were 95.1 and 100%, respectively. A total of six unruptured aneurysms were missed initially, but were visible retrospectively on CTA in all but one case and were found in patients with multiple aneurysms in whom the ruptured aneurysm was detected by CTA. Current quality CTA allows reliable pretreatment planning for the majority of cases of aneurysmal subarachnoid haemorrhage and diminishes the pretreatment evaluation time critically. Complementary pretreatment DSA is required in situations where CTA characteristics of the ruptured aneurysm is unsatisfactory.

Intraorbital ophthalmic artery aneurysm associated with basilar tip saccular aneurysm

We present a rare case of intraorbital ophthalmic artery aneurysm found incidentally, together with a ruptured aneurysm of the tip of the basilar artery. The intraorbital aneurysm was asymptomatic, and no treatment was offered. Angiographic control was recommended to detect any progression. Treatment may be indicated for documented enlargement or significant mass effect of the aneurysm.

Preoperative silk suture embolization of cerebral and dural arteriovenous malformations

OBJECT

The aim of this study was to evaluate the use of silk sutures as a medical implant when applied for the embolization of cerebral and dural arteriovenous malformations (AVMs). The facility of surgery and the clinical significance of complications related to preoperative silk suture embolization were evaluated immediately after surgery and at long-term follow up.

METHODS

Thirty-four patients harboring 29 cerebral and five dural AVMs underwent embolization in which silk alone or in association with other agents was used. Medical and radiological records obtained in these 34 patients were reviewed retrospectively. The cerebral AVMs were classified according to the Spetzler-Martin grading system and the dural AVMs to the Djindjian grading system. The facility of the resection and the adverse outcomes, including new neurological deficits, hemorrhage, and fever, as well as histopathological evidence of vessel inflammatory changes, were determined in each case. In all 23 surgical cases, the AVM could be easily manipulated and excised. New temporary neurological deficits occurred in three patients. A high Spetzler-Martin grade was not associated with a higher incidence of new neurological deficits. One delayed-onset hemorrhage was detected after embolization. Fever was present in 24% of the patients. No sign of significant vasculitis or perivascular inflammation was found on radiological or histopathological examination.

CONCLUSIONS

Silk sutures are safe embolic agents especially for proximal occlusion of AVM feeding vessels. New permanent neurological deficits were not encountered in this series. Fever was considered to be a minor, temporary side effect of silk suture embolization.

Subarachnoid hemorrhage: a rare presentation of cerebral venous thrombosis

Because of its large spectrum of clinical manifestations, diagnosis of cerebral venous thrombosis may be very difficult. Since appropriate treatment influences prognosis, early recognition of this condition is extremely important. We report a subarachnoid hemorrhage as a rare initial manifestation of cerebral venous thrombosis. A 58-year-old woman was admitted with severe headache of sudden onset, neck stiffness, dysarthria, and ataxia. Computed tomography scan showed a subarachnoid hemorrhage in the right posterior fossa. Magnetic resonance imaging coupled with magnetic resonance angiography revealed right transverse/sigmoid sinus thrombosis with hemorrhagic infarction of the right cerebellar hemisphere leading to a pseudotumoral appearance and displacing the fourth ventricle. Anticoagulant treatment resulted in rapid clinical recovery and in resolution of the radiological signs of infarction and of the subarachnoid and subdural hemorrhages.

PMMA cementoplasty in symptomatic metastatic lesions of the S1 vertebral body

We describe a lateral transiliac direct puncture approach to the S1 vertebral body for polymethylmethacrylate (PMMA) cementoplasty of painful metastatic lesions. This approach was performed using a 15-cm-long trocar needle with 3-mm outer diameter, introduced under general anesthesia and fluoroscopic control. A lateral projection was used to center the needle just in front of the spinal canal and subjacent to the superior plate of the S1 vertebral body. Needle progression was controlled using anteroposterior and lateral fluoroscopic projections alternately with a needle course parallel to an axial plane, avoiding conflict with the S1 foramen. After needle tip placement in the center of the S1 vertebral body, diluted PMMA with a setting time of 8 min was delivered. Ipsilateral lesions of the lateral sacral compartment were filled with the same needle by stepwise withdrawal and continuous PMMA injection.