Intracranial Aneurysm Parameters for Predicting a Future Subarachnoid Hemorrhage

Neurosurgery 81:432–440, 2017

Retrospective studies have suggested that aneurysm morphology is a risk factor for subarachnoid hemorrhage (SAH).

OBJECTIVE: To investigate whether various morphological indices of unruptured intracranial aneurysms (UIAs) predict a future rupture.

METHODS: A total of 142 patients with UIAs diagnosed between 1956 and 1978 were followed prospectively until SAH, death, or the last contact. Morphological UIA indices from standard angiographic projections weremeasured at baseline and adjusted inmultivariable Cox proportional hazards regression analyses for established risk factors for SAH.

RESULTS: During a follow-up of 3064 person-years, 34 patients suffered froman aneurysm rupture. In multivariable analyses, aneurysm volume, volume-to-ostium area ratio, and the bottleneck factor separately as continuous variables predicted aneurysm rupture. All the morphological indices were higher (P < .01) after the rupture than before. In final multivariable analyses, current smoking (adjusted hazard ratio 2.50, 95% CI 1.03-6.10, P = .044), location in the anterior communicating artery (4.28, 1.38-13.28, P=.012), age (inversely; 0.95 per year, 0.91-1.00, P = .043), and UIA diameter ≥7 mm at baseline (2.68, 1.16-6.21, P = .021) were independent risk factors for a future rupture. Aneurysm growth during the followup was associated with smoking (P < .05) and SAH (P < .001), but not with the aneurysm indices.

CONCLUSION: Of the morphological indices, UIA volume seems to predict a future rupture. However, as volume correlates with the maximum diameter of the aneurysm, it seems to add little to the predictive value of the maximum diameter. Retrospective studies using indices that are measured after rupture are of little value in risk prediction.


Awake craniotomy to maximize glioma resection: methods and technical nuances over a 27-year period

awake craniotomy

J Neurosurg 123:325–339, 2015

Awake craniotomy is currently a useful surgical approach to help identify and preserve functional areas during cortical and subcortical tumor resections. Methodologies have evolved over time to maximize patient safety and minimize morbidity using this technique. The goal of this study is to analyze a single surgeon’s experience and the evolving methodology of awake language and sensorimotor mapping for glioma surgery.

Methods The authors retrospectively studied patients undergoing awake brain tumor surgery between 1986 and 2014. Operations for the initial 248 patients (1986–1997) were completed at the University of Washington, and the subsequent surgeries in 611 patients (1997–2014) were completed at the University of California, San Francisco. Perioperative risk factors and complications were assessed using the latter 611 cases.

Results The median patient age was 42 years (range 13–84 years). Sixty percent of patients had Karnofsky Performance Status (KPS) scores of 90–100, and 40% had KPS scores less than 80. Fifty-five percent of patients underwent surgery for high-grade gliomas, 42% for low-grade gliomas, 1% for metastatic lesions, and 2% for other lesions (cortical dysplasia, encephalitis, necrosis, abscess, and hemangioma). The majority of patients were in American Society of Anesthesiologists (ASA) Class 1 or 2 (mild systemic disease); however, patients with severe systemic disease were not excluded from awake brain tumor surgery and represented 15% of study participants. Laryngeal mask airway was used in 8 patients (1%) and was most commonly used for large vascular tumors with more than 2 cm of mass effect. The most common sedation regimen was propofol plus remifentanil (54%); however, 42% of patients required an adjustment to the initial sedation regimen before skin incision due to patient intolerance. Mannitol was used in 54% of cases. Twelve percent of patients were active smokers at the time of surgery, which did not impact completion of the intraoperative mapping procedure. Stimulation-induced seizures occurred in 3% of patients and were rapidly terminated with ice-cold Ringer’s solution. Preoperative seizure history and tumor location were associated with an increased incidence of stimulation- induced seizures. Mapping was aborted in 3 cases (0.5%) due to intraoperative seizures (2 cases) and patient emotional intolerance (1 case). The overall perioperative complication rate was 10%.

Conclusions Based on the current best practice described here and developed from multiple regimens used over a 27-year period, it is concluded that awake brain tumor surgery can be safely performed with extremely low complication and failure rates regardless of ASA classification; body mass index; smoking status; psychiatric or emotional history; seizure frequency and duration; and tumor site, size, and pathology.

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