Procedure-Related Temporal Infarct After Retractorless Transsylvian Selective Amygdalohippocampectomy and Impact on 2-Year Epilepsy Outcome

BACKGROUND

Selective amygdalohippocampectomy (SAH) is designed to treat patients with mesial temporal lobe epilepsy (MTLE).

OBJECTIVE

To determine the volume and impact of temporal lobe infarction after retractorless transsylvian SAH (en bloc resection of the hippocampus) that have not been reported.

METHODS

A retrospective analysis of patients treated with retractorless transsylvian SAH. Infarctions were detected by magnetic resonance imaging (MRI) within the first week after the operation. Neuropsychological testing was performed preoperatively and 6 mo later. Seizure outcome was evaluated 2 yr after epilepsy surgery.

RESULTS

Between 2010 and 2014, a total of 30 patients were included in this study. Analysis of postoperative MRI showed the following: (1) mean removal volume of the hippocampus-parahippocampus was 5.72 cm3, and (2) mean volumes of temporal and insular infarctions were 1.71 and 0.25 cm3, respectively. Twenty-five patients (83.3%) were free of disabling seizures (Engel class I) at 2 yr of outcome. Neuropsychological testing revealed improvement in Perceptual Organization Index (P = .036) and verbal paired associates II (P = .014) after the operation. Neither infarction volume nor removal volume was related to epilepsy outcome in linear regression model.

CONCLUSION

Transsylvian SAH has comparable seizure outcomes but bears inherent risks of vasospasm/vascular injury. Immediate postoperative small infarction volume around resection cavity or along surgical corridor was noticed after retractorless transsylvian SAH, which did not cause neuropsychological deteriorations, in contrast to previous study with the use of self-sustaining rigid retraction system. Further study should be performed to compare procedure-related infarctions and their impacts on neuropsychological outcomes in different selective approaches.

Retractorless interhemispheric transtentorial approach for large lesions in the posterior incisural space

Background:

Surgical resection of lesions in the posterior incisural space presents a significant surgical challenge, which may result in postoperative visual complications and other neurological deficits. We, therefore, describe a retractorless interhemispheric transtentorial approach that avoids surrounding brain structures with positive outcomes and no complications or visual damage.

Case Description:

We present four cases of lesions in the posterior incisural space that was treated with a retractorless interhemispheric transtentorial approach. Two patients were previously seen at another institution for a falcotentorial meningioma. We resected the meningiomas with a parietal-occipital interhemispheric transtentorial approach with no neurological deficits. A third patient presented with a large superior vermian hemangioblastoma with a steep angle of the tentorium. The fourth patient had a large upper vermian metastatic lesion with progressive enlargement, which was refractory to radiation treatments and chemotherapy, and we achieved partial resection. Postoperative visual function was completely preserved in all patients.

Conclusion:

A carefully executed retractorless interhemispheric approach in select cases is an effective option to reduce morbidity and prevent visual complications when removing lesions in the posterior tentorial incisure.

The Radiographic Effects of Surgical Approach and Use of Retractors on the Brain After Anterior Cranial Fossa Meningioma Resection

OBJECTIVE

There is an increasing trend toward skull base (SB) approaches and retractorless surgery to minimize brain manipulation during surgery. We evaluated the radiographic changes over time after surgical resection of anterior cranial fossa meningiomas with and without both SB approaches and/or fixed retractor systems.

METHODS

All adults undergoing primary resection of an anterior cranial fossa World Health Organization grade I meningioma through a craniotomy at a single academic tertiary-care institution from 2010 to 2015 were retrospectively reviewed. Magnetic resonance imaging scans were reviewed and contrast-enhanced tumor and fluid-attenuated inversion recovery (FLAIR) volumes were measured. Matched-pair analyses between patients who underwent SB and non-SB approaches, as well as retractorless and retractor-assisted (RA) surgery, were made.

RESULTS

Of the 136 total patients, 20 (15%), 12 (9%), 46 (34%), and 58 (43%) underwent SB/retractorless, SB/RA, non-SB/retractorless, and non-SB/RA surgery, respectively. Patients who underwent non-SB and RA surgery each independently had longer times to FLAIR resolution than those who underwent SB (20.9 vs. 5 months; P = 0.04) and retractorless (12 vs. 5.2 months; P = 0.02) surgery, respectively. Patients who underwent both non-SB and RA surgery had the longest median time to FLAIR resolution (30 months vs. 4 months in SB/retractorless, 3.6 months in SB/RA, and 3 months in non-SB/retractorless; P < 0.05).

CONCLUSIONS

The use of SB approaches in combination with retractorless surgery may decrease the duration needed for FLAIR resolution after surgery. The results from this study therefore advocate SB approaches and retractorless surgery along the anterior SB when possible.