Occipital Interhemispheric Transtentorial Approach for Tumors of Posterior Third Ventricular Region: Review of Surgical Results.

Background: Controversies exist regarding the ideal surgical approach for tumors in posterior third ventricular region (PTV). Objective: To evaluate the results of occipital interhemispheric transtentorial (OITT) approach for tumors in PTV. Materials And Methods: Thirty-three patients underwent surgery via OITT approach for PTV tumors at Sri Sathya Sai Institute of Higher Medical Sciences during the study period of 5 years (June 2011-May 2016). Ideal trajectory for OITT approach was determined by neuronavigation. Endoscope was used for removing any residual lesion at the blind spots. Results: Postoperative magnetic resonance imaging (MRI) performed in all the patients revealed gross total or near-total (>95%) excision of tumor in 31 patients (93.9%). Preoperative neurological deficits improved either completely or significantly following excision of the tumor in 73.3% (11/15) of the patients. Outcome was good (modified Rankin scale ≤2) at discharge in 93.9% (31/33) and at a final follow-up of 3 months or more in 96.8% (30/31) of the patients. None of the patients died during the postoperative period. Complications included upgaze palsy (transient- 6.1% [2/33], persisting- 3% [1/33]), visual field defects (transient- 3% [1/33], persisting- 3% [1/33]), transient third nerve paresis (1/33-3%), transient hemiparesis (1/33-3%), operative site hematoma (1/33-3%), small posterior cerebral artery (PCA) territory infarct (1/33-3%), and small venous infarct (1/33-3%). At least one follow-up MRI could be performed in 23 patients. Final follow-up MRI revealed no recurrence or increase in the size of the residual lesion compared to postoperative images in 20 patients (20/23-87%) and large recurrence in 3 patients (3/23-13%) with high-grade lesions. Conclusion: Gross total/near-total excision can be performed in majority of the PTV tumors through OITT approach with minimal morbidity and mortality.

Adenosine-Induced transient asystole during surgical treatment of basilar artery aneurysms.

AIM: To evaluate the safety and efficacy of adenosine-induced transient asystole (AITA) during surgery for basilar artery aneurysms. MATERIALS AND METHODS: All the patients with basilar artery aneurysms operated using AITA at our institute during two years period (August 2013-July 2015) were included in this study. RESULTS: Adenosine was used in 11 patients with 13 basilar artery aneurysms. Seven of these aneurysms were basilar bifurcation aneurysms, four were basilar-superior cerebellar artery junction aneurysms, and two were distal basilar trunk aneurysms. The indications for AITA were narrow corridor for placement of temporary clip in 11 aneurysms, intraop rupture in 1 aneurysm, and circumferential dissection of a large aneurysm in 1. The mean dose of adenosine used for inducing asystole was 19.4 mg (range: 15-30 mg) and the mean total dose of adenosine used was 40.6 mg (range: 18-90 mg). A mean of 2 (range: 1-5) AITAs were required during surgical treatment of these aneurysms. The mean duration of a systole was 27 s (range: 9-76 s). There were no complications related to AITA in these patients except for transient rebound hypertension in one patient. Check angiogram revealed complete obliteration of 11 aneurysms and small residual neck in 2 aneurysms. Modified Rankin Scale at three months of follow-up was 0 in seven patients, 1 in two patients, 4 in one patient, and 6 in one patient. CONCLUSION: AITA during surgical management of basilar artery aneurysms is a safe and effective technique and has an important role during surgery for these aneurysms.