Circumferential sulcus-guided resection technique for improved outcomes of low-grade gliomas

J Neurosurg 137:1015–1025, 2022

Many neurosurgeons resect nonenhancing low-grade gliomas (LGGs) by using an inside-out piecemeal resection (PMR) technique. At the authors’ institution they have increasingly used a circumferential, perilesional, sulcusguided resection (SGR) technique. This technique has not been well described and there are limited data on its effectiveness. The authors describe the SGR technique and assess the extent to which SGR correlates with extent of resection and neurological outcome.

METHODS The authors identified all patients with newly diagnosed LGGs who underwent resection at their institution over a 22-year period. Demographics, presenting symptoms, intraoperative data, method of resection (SGR or PMR), volumetric imaging data, and postoperative outcomes were obtained. Univariate analyses used ANOVA and Fisher’s exact test. Multivariate analyses were performed using multivariate logistic regression.

RESULTS Newly diagnosed LGGs were resected in 519 patients, 208 (40%) using an SGR technique and 311 (60%) using a PMR technique. The median extent of resection in the SGR group was 84%, compared with 77% in the PMR group (p = 0.019). In multivariate analysis, SGR was independently associated with a higher rate of complete (100%) resection (27% vs 18%) (OR 1.7, 95% CI 1.1–2.6; p = 0.03). SGR was also associated with a statistical trend toward lower rates of postoperative neurological complications (11% vs 16%, p = 0.09). A subset analysis of tumors located specifically in eloquent brain demonstrated SGR to be as safe as PMR.

CONCLUSIONS The authors describe the SGR technique used to resect LGGs and show that SGR is independently associated with statistically significantly higher rates of complete resection, without an increase in neurological complications, than with PMR. SGR technique should be considered when resecting LGGs.

Safety and Efficacy of Surgical Resection of Unruptured Low-grade Arteriovenous Malformations From the Modern Decade


Neurosurgery 77:948–953, 2015

Recent studies have questioned the utility of surgical resection of unruptured brain arteriovenous malformations (bAVMs).

OBJECTIVE: We performed an assessment of outcomes and complications of surgical resection of low-grade bAVMs (Spetzler-Martin grade I or II) at a single high-volume neurosurgical center.

METHODS: We reviewed all unruptured low-grade bAVMs treated with surgery (with or without preoperative embolization) between January 2004 and January 2014. Stroke rate, mortality, and clinical and radiographic outcomes were examined.

RESULTS: Of 95 patients treated surgically, 85 (25 grade I, 60 grade II) met inclusion criteria, and all achieved radiographic cure postoperatively. Ten patients (11.8%) were lost to follow-up; the mean follow-up of the remaining 85 was 3.3 years. Three patients (3.5%) with grade II bAVMs experienced a stroke; no patients died. Although 20 patients (23.5%) had temporary postoperative neurological deficit, only 3 (3.5%) had new clinical impairment (modified Rankin Scale score $2) at last follow-up. Eight of the 13 patients (61.5%) with preexisting clinical impairment had improved modified Rankin Scale scores of 0 or 1; and 17 of 30 patients (56.7%) with preoperative seizures were seizure-free without antiepileptic medication postoperatively. No significant differences existed in stroke rate or clinical outcome between grades I and II patients at follow-up (Fisher exact test, P = .55 and P . .99, respectively).

CONCLUSION: Surgical resection of low-grade unruptured bAVMs is safe, with a high rate of improvement in functional status and seizure reduction. Although transient postoperative neurological deficit was observed in some patients, permanent treatment- related neurological morbidity was rare.

Brainstem Cavernous Malformations: Surgical Results in 104 Patients and a Proposed Grading System to Predict Neurological Outcomes

Brainstem Cavernous Malformations- Surgical Results in 104 Patients and a Proposed Grading System to Predict Neurological Outcomes

Neurosurgery 76:265–278, 2015

Once considered inoperable lesions in inviolable territory, brainstem cavernous malformations (BSCM) are now surgically curable with acceptable operative morbidity. Recommending surgery is a difficult decision that would be facilitated by a grading system designed specifically for BSCMs that predicted surgical outcomes.

OBJECTIVE: Informed by our efforts to develop a supplementary grading system for arteriovenous malformations, we hypothesized that a similar system might predict long-term outcomes and guide clinical decision-making.

METHODS: A consecutive, single-surgeon series of 104 patients was used to assess preoperative clinical and imaging predictors of microsurgical outcomes. Univariable logistic regression identified predictors and a multivariable logistic regression model tested the association of the combined predictors with final modified Rankin Scale scores. A grading system assigned points for lesion size, location crossing the brainstem’s midpoint, presence of developmental venous anomaly, age, and time from last hemorrhage to surgery.

RESULTS: Average maximal diameter of BSCMs was 19.5 mm; 50% crossed the axial midpoint; 54.8% had developmental venous anomalies; mean age was 42.1 years; and median time from last hemorrhage to surgery was 60 days. One patient died (0.96%), and 15 patients (14.4%) experienced worsened cranial nerve or motor dysfunction, of which 10 increased their modified Rankin Scale scores (9.6%). BSCM grades ranged from 0 to 7 points and predicted outcomes with high accuracy (receiver operating characteristic = 0.86, 95% confidence interval: 0.78-0.94).

CONCLUSION: Rather than developing a grading system for all cerebral cavernous malformations that is weak with BSCMs, we propose a system for the patients who need it most. The BSCM grading system differentiates patients who might expect favorable surgical outcomes and offers guidance to neurosurgeons forced to select these patients.

The preoperative use of navigated transcranial magnetic stimulation facilitates early resection of suspected low-grade gliomas in the motor cortex

The preoperative use of navigated transcranial magnetic stimulation facilitates early resection of suspected low-grade gliomas in the motor cortex

Acta Neurochir (2013) 155:1813–1821

Resection is recommended for low-grade gliomas, but often it is not performed if the tumor is suspected of invading the primary motor cortex. The study aim is to assess what influence preoperative navigated transcranial magnetic stimulation (nTMS) has on the treatment strategy and clinical outcome for suspected low-grade gliomas in presumed motor eloquent location.

Methods This paper reports on all our patients with gliomas in the primary motor cortex that were non-enhancing on MRI, since we began using nTMS (n=11). For the comparison group, we identified the 11 most recent such patients just before we started using nTMS.

Results Exact delineation of motor functional versus nonfunctional cortical tissue was provided by nTMS in all cases, also within the area of altered FLAIR signal. In 6 out of 11 cases, the nTMS mapping result changed the treatment plan towards early and more extensive resection. Only one nTMS patient had another seizure within the follow-up period, whereas four patients in the comparison group had further seizures. In the nTMS group, 1 of 4 patients with pre-op neurological deficits improved by one year; whereas the comparison group had increased neurological deficits in 3 of the 8 patients not having surgery. The median (range) change of tumor volume from baseline to 1 year was −83 % (−67 % to −100 %) in the nTMS group, but +12 % (+40 % to −56 %) in the comparison group (p<0.001).

Conclusions nTMS provides accurate motor mapping results also in infiltrative gliomas and enables more frequent and more extensive surgical resection of non-enhancing gliomas in or near the primary motor cortex. The substantial differences observed here in neurological and oncological outcomes suggest that further comparative research is warranted.

Surgical Treatment of Giant Intracranial Arteriovenous Malformations

Neurosurgery 67:1359–1370, 2010 DOI: 10.1227/NEU.0b013e3181eda216

The treatment of giant arteriovenous malformations (AVMs) remains a challenge in the neurosurgical field. Microsurgery is one of the most effective ways for eliminating giant cerebral AVMs.

OBJECTIVE: To review surgical outcomes in treating the disease, and form conclusions regarding the indications for and outcomes of surgical treatment in giant intracranial AVMs.

METHODS: We studied 40 consecutive cases of giant AVMs treated in Beijing Tiantan Hospital between 2000 and 2008. The radiologic and clinical features were analyzed. The Spetzler-Martin grading system was used to classify the patients. All patients were surgically treated, and the final outcomes of the patients were gathered for analysis.

RESULTS: The major presenting symptoms were seizures, headaches, hemorrhage, and neurological deficits. The mean AVM diameter was 6.3 cm. According to the Spetzler- Martin grading system, 5 patients had grade III lesions, 21 had grade IV lesions, and 14 had grade V lesions. Out of the total 40 patients, 31 (77.5%) demonstrated excellent or good outcome. Complications included hemiparalysis, aphasia, hemianopia, cranial nerve dysfunction, and seizures. After follow-up, 27 of 30 (90%) surviving patients presented normal function or minimal symptoms.

CONCLUSION: Presurgical evaluation of every candidate and treatment choice is the determining factor in therapy for giant AVMs. For giant cerebral AVMs located superficially or not involving critical components, a good outcome can be expected through surgical resection. The obliteration and recurrence rates were satisfying, and the complication rate was acceptable.

A comparison between surgical resection in combination with WBRT or hypofractionated stereotactic irradiation in the treatment of solitary brain metastases

Peter Lindvall & Per Bergström & Per-Olov Löfroth &A. Tommy Bergenheim

Acta Neurochir (2009) 151:1053-1059

The standard treatment of solitary brain metastases previously has been tumour resection in combination with whole-brain radiation therapy (WBRT). Stereotactic radiotherapy has emerged as a non-invasive treatment option especially for small brain metastases. We now report our results on resection + WBRT or hypofractionated stereotactic irradiation (HCSRT) in the treatment of solitary brain metastases.

Between 1993 and 2004 patients with metastatic cancer and solitary brain metastases were selected for surgical resection + WBRT or HCSRT alone at the Umeå University Hospital. Fifty-nine patients were treated with surgical resection + WBRT (34 male, 25 female, mean age 63.3 years). Forty-seven patients were treated with HCSRT alone (15 male, 32 female, mean age 64.9 years). Findings In patients followed radiologically, 28% treated with resection + WBRT showed a local recurrence after a median time of 8.0 months, whereas there was a lack of local control in 16% in the HCSRT group after a median time of 3.0 months. There was a significantly longer survival time for patients treated with resection + WBRT (median 7.9, mean 12.9 months) compared to HCSRT (median 5.0, mean 7.6 months). Even in patients with a tumour volume <10 cc, there was a significantly longer survival in favour of resection + WBRT (median 8.4, mean 17.4 months) compared to HCSRT (median 5.0, mean 7.9 months).

Conclusion This retrospective and non-randomised study indicates that surgical resection in combination with WBRT may be an option even for small brain metastases suitable for treatment with HCSRT. Since survival and local control following resection + WBRT was at least as favourable as compared to HCSRT alone, tumour location and expected neurological outcome may be the strongest aspect when selecting treatment modality.

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