Neurosurgery Blog

Acta Neurochir (2011) 153:1611–1619. DOI 10.1007/s00701-011-1021-6

Internal carotid artery (ICA) is predominant localization of giant intracranial aneurysms (GIAs). The rupture of GIA is supposed to be related to higher risk of poor clinical outcome. Although endovascular techniques are still being developed, they seem to be unsatisfactory in the mean of GIAs.

Methods Included in the retrospective analysis were 78 giant and 250 smaller surgically treated ICA aneurysms. Exclusion criteria were multiple and blood blister-like aneurysms. Neurological deficit on admission, clinical and radiological presentation, gender, age, segment of ICA, surgical methods, accessory techniques and complications were analyzed. Death rate and short- and long-term outcome of giant aneurysms were compared with smaller aneurysms and risk factors formortality, unfavorable short- and long-term outcome were determined.

Results There was no difference in general and surgical complications between ICA aneurysm size groups, as well as in occurrence of newly diagnosed neurological deficit after the operation. There were similar mortality rates, proportion of unfavorable outcome, and low health related quality of life for giant and smaller aneurysms. A 12.2% death rate for all ICA aneurysms was achieved. Trapping method as well as Fisher grades 3 and 4 increased mortality risk in the smaller aneurysm group. No significant factors were related to an unfavorable outcome in the ruptured giant aneurysm group. Patients older than 65, Hunt-Hess grades 4 and 5, Fisher grade 4, and newly diagnosed deficit after operation were connected with unfavorable outcome in the ruptured smaller aneurysm group. Newly diagnosed neurological deficit was also an unfavorable outcome risk factor in both giant and smaller ICA unruptured aneurysms. No difference was noted in long-term health-related quality of life between the giant and smaller ICA groups. Higher age and presence of concomitant disease were independent factors affecting quality of life, although obtained data were incomplete.

Conclusions The study breaks the stereotype of unfavorable giant ICA aneurysms treatment results. Mortality rate, shortand long-term outcome after the operation of giant and smaller ICA aneurysms are similar. Higher age, patients’ condition at admission, and the amount of extravasated blood and trapping method are poor prognostic factors in patients with smaller ICA aneurysm

Acta Neurochir (2010) 152:1099–1116.DOI 10.1007/s00701-010-0633-6

Within the realm of neurosurgery, petroclival meningiomas are regarded as probably the most difficult tumour to be treated by microsurgery. This is due to the not infrequently large size of the tumours which, although predominantly located in the posterior fossa, may occupy more than one cranial compartment, with often significant space-occupying effect and brain stem compression. Frequent tight brain stem adherence as well as encasement of the basilar artery, its perforators and cranial nerves adds to the sometimes extreme difficulties of surgical tumour removal. Counselling patients as well as pre- and intraoperative decision making in petroclival meningiomas is even more difficult because upon clinical and radiological tumour detection, despite sometimes surprisingly large tumours, clinical symptoms are often only mild. Summarising the complicated development of petroclival meningioma surgery over the last 60 years, this paper represents the conceptual thinking of the author in regard to the treatment of petroclival meningiomas which has evolved over more than two decades, based on a special interest in these treacherous tumours, and accumulated experiences in the treatment of over 150 patients. Surgical concepts and the operative decision-making process are demonstrated in four illustrative cases.

Methods Over a period of slightly over 20 years, between January 1988 and December 2008, 161 patients with petroclival meningiomas were managed clinically by the author or under his direct surveillance in four academic neurosurgical institutions. The observation period ranged from 4 to 242 months. Thirteen patients were lost to followup so, all together, complete data were available for 148 patients. In 119 patients (80%), the tumour was large. Giant tumours accounted for 7% and 11 patients, medium-sized tumours were found in 12 patients (8%) and small tumours in only six patients (4%). Sixty-two percent of the patients had invasion of Meckel’s cave or some part of the cavernous sinus, mainly the posterior region to different degrees. All giant tumours and one third of the large tumours extended into more than one cranial fossa.

Results The treatment modalities in the 148 patients were as follows: microsurgery alone was performed in 71 patients (48%), microsurgery and adjuvant radiosurgery in 22 patients (15%) so in 93 patients (63%), altogether, microsurgery was the primary treatment. Twenty-nine patients (20%) underwent radiosurgery as their only treatment, and two patients (1%), during the very early phase of the study period, received radiotherapy. Twentyfour patients (16%) were only observed without any additional therapy. Gross total resection was achieved in 34 patients (37%), and subtotal resection, defined as removal of more than 90% of the tumour volume, was performed in another 36 patients (39%). Radical tumour removal was possible in 76% of the patients. There was no procedure-related death within 3 months post-surgery; the early post-op surgical complication rate was 31% with new neurological deficits or worsening of pre-existing deficits. During the observation period, almost all patients recovered significantly bringing the percentage of permanent neurological deficits, again mainly cranial nerve deficits, down to 22%.

Conclusions Based on the experiences of the author, the following treatment principles in petroclival meningiomas are proposed: small tumours in asymptomatic patients should be observed. If tumour growth is detected on serial magnetic resonance imaging or treatment is desired by the patient, surgery should be the first choice. Radiosurgery in growing small tumours should be reserved to patients with advanced age or significant co-morbidities. In medium-sized tumours and symptomatic patients, radical surgery should be attempted, if possible by judicious intraoperative judgement. In large and giant petroclival meningiomas, tumour resection as radical as possible judged intraoperatively with decompression of neural structures should be performed, followed by observation and, in the case of growing tumour remnants, radiosurgery. Thus, by a combined application of advanced microsurgical techniques, thoughtful, intraoperative decision making with limited surgical aggressively and, in selected patients, with small tumours or small tumour remnants simple observation or alternative or adjunct radiosurgery, excellent results as measured by tumour control and preservation of quality of life can be achieved.

Childs Nerv Syst (2010) 26:75–79.DOI 10.1007/s00381-009-0983-7

In the current literature, there are essentially no comparisons of quality of life (QOL) outcome after endoscopic third ventriculostomy (ETV) and shunt in childhood hydrocephalus. Our objective was to compare QOL in children with obstructive hydrocephalus, treated with either ETVor shunt. Methods A cross-sectional survey was conducted at SickKids, Toronto of children between ages five and 18 years, with obstructive hydrocephalus due to aqueductal obstruction and no other brain abnormalities. Measures of QOL were the Hydrocephalus Outcome Questionnaire and the Health Utilities Index Mark 3. A subset of patients was given the Wechsler Intelligence Scales for Children (WISC-IV). Results A total of 47 of 59 (80%) eligible patients participated (24 had ETV as primary treatment, 23 had shunt as primary treatment), with a mean age of 12.1 years (standard deviation 3.9) at assessment. The ETV group was older at initial surgery (p<0.001) and had larger ventricle size at last follow-up (p= 0.047). In all QOL measures, there were no significant differences between the ETV group and shunt group (all p≥ 0.09). Treatment failure, hydrocephalus complications, and the presence of a functioning ETV at assessment were not associated with QOL differences. Among the 11 children (six ETV, five shunt) who were given the WISC-IV, there were no significant differences between the scores of the ETV group and shunt group (all p≥0.11). Conclusions This is the first study to provide a meaningful comparison of QOL after ETV and shunt in children. These preliminary results suggest that there is no obvious difference in QOL after ETVand shunt.

Not uncommonly, spine surgeons and physiatrists note a mismatch between patient-reported outcome measures, where one measure might indicate a good outcome and another indicates an inferior outcome after spine treatment. This may be the result of patient characteristics that lead to changes in internal standards, values, and conceptualization of their own health-related quality of life. This can result in a ‘‘moving goal post’’ when a self-report outcome measure is used for prepost comparisons. These ‘‘response shifts’’ may obfuscate relevant changes of interest to clinicians and are meaningful and worthy of study in and of themselves.

PURPOSE: To provide a background on response shift with an emphasis on distinctions relevant to spinal interventions, both surgical and nonsurgical. To describe current methods for detecting and investigating response shift phenomena, and to propose specific hypotheses that can be tested in collaborative research. METHODS AND RESULTS: Two types of methods will be briefly described: methods that require new data collection; and methods that use recent statistical and technical advances to implement secondary analysis of existing data. Two specific testable hypotheses for spinal disorders are suggested along with suggested methods for testing these hypotheses. CONCLUSIONS: A response shift will cause the patient to use the same functional outcome report measure differently pre- and posttreatment. Response shift phenomena are likely to affect the measurement properties of standard spine outcome measures and to obfuscate differences between treatments in clinical trials and cost-effectiveness studies. They point to a need for developing strategies in clinical practice to manage response shifts so that they enhance patient well-being.

Neurosurgery 64:654–663, 2009 DOI: 10.1227/01.NEU.0000340684.60443.55

OBJECTIVE: To conduct a prospective, open, nonrandomized study of treatment- associated morbidity in patients undergoing microsurgery or gamma knife radiosurgery (GKRS) for vestibular schwannomas.

METHODS: Ninety- one patients with vestibular schwannomas with a maximum tumor diameter of 25 mm in the cerebellopontine angle were treated according to a prospective protocol either by GKRS (63 patients) or open microsurgery (28 patients) using the suboccipital approach. Primary end points included hearing function, according to the Gardner- Robertson scale, and facial nerve function, according to the House- Brackmann scale at 2 years. Clinical data included a balance platform test, score for tinnitus and vertigo using a visual analog scale, and working ability. Patients responded to the qualityof- life questionnaires Short- Form 36 and Glasgow Benefit Inventory.

RESULTS: Three elderly GKRS patients withdrew; all remaining patients were followed for 2 years. Both primary end points were highly significant in favor of GKRS (P<0.001). Evidence of reduced facial nerve function (House- Brackmann grade 2 or poorer) at 2 years was found in 13 of 28 open microsurgery patients and 1 of 60 GKRS patients. Thirteen of 28 patients who underwent surgery had serviceable hearing (Gardner- Robertson grade A or B) preoperatively, but none had serviceable hearing postoperatively. Twentyfive of 60 GKRS patients had serviceable hearing before treatment, and 17 (68%) of them had serviceable hearing 2 years after treatment. The tinnitus and vertigo visual analog scale score, as well as balance platform tests, did not change significantly after treatment, and working status did not differ between the groups at 2 years. Quality of life was significantly better in the GKRS group at 2 years, based on the Glasgow Benefit Inventory questionnaire. One GKRS patient required operative treatment within the 2-year study period.

CONCLUSION: This is the second prospective study to demonstrate better facial nerve and hearing outcomes from GKRS than from open surgery for small- and medium- sized vestibular schwannomas.

J Neurooncol (2009) 95:301–305 DOI 10.1007/s11060-009-9946-9

Extended survival of 3 or more years is rare in patients with glioblastoma (GBM) but is becoming more common. Clinical outcome has not been well studied. We reviewed GBM patients at Memorial Sloan-Kettering Cancer Center between 2001 and 2003 who were seen for two or more visits. Patient characteristics and long-term clinical outcomes were reviewed for patients who had survived 3 or more years following diagnosis. Thirty-nine (11%) of 352 GBM patients were identified as long-term survivors. Median survival was 9.15 years (range: 3–18 years). Median age was 47 years (range: 16–69); 13% were 65 years or older. Median KPS was 90 (range: 50–100). One long-term survivor underwent biopsy alone; 19 patients each had either complete or subtotal resection. All received focal radiotherapy (RT) with a median dose of 5940 cGy; 18% received concurrent temozolomide. Adjuvant chemotherapy was administered to 35 (90%). Twelve patients (31%) remained in continuous remission. Twenty-seven had tumor progression a median of 29.2 months after diagnosis (range: 1.2–167 months); 18 had multiple relapses. Median KPS at last follow-up was 70 (range: 40–100); 85% of long-term survivors had at least one significant neurologic deficit. Eleven (28%) had clinically significant RT-induced leukoencephalopathy, 9 (23%) developed RT necrosis and 9 (23%) treatment-related strokes. Treatment-related complications occurred a median of 2.7 years from diagnosis (range: 0.9–11.5 years).

Long-term survivors remain rare, but are found across all age groups despite multiple recurrences; clinically significant delayed complications of treatment are common.