Extra-axial endoscopic third ventriculostomy: preliminary experience with a technique to circumvent conventional endoscopic third ventriculostomy complications

Abstract

OBJECTIVE Endoscopic third ventriculostomy (ETV) is mostly safe but may have serious complications. Most of the complications are inherent to the procedure’s intra-axial nature. This study aimed to explore an alternative route to overcome inherent issues with conventional ETV. The authors performed supraorbital, subfrontal extra-axial ETV (EAETV) via the lamina terminalis. METHODS This prospective study began in October 2021 and included patients with obstructive triventricular hydrocephalus with a Glasgow Coma Scale score of 8 or more and a minimum follow-up of 3 months. Patients with multiloculated hydrocephalus and those younger than 1 year of age were excluded. The preoperative parameters etiology, symptoms, Evans’ Index, frontal occipital horn ratio (FOHR), and third ventricle index were recorded. The surgical procedure is described. Postoperative evaluation included clinical (modified Rankin Scale [mRS]) and radiological assessment with CT and cine phase-contrast MRI. Preoperative and postoperative parameters were compared statistically. RESULTS Ten patients were included in this study. Six patients had acute hydrocephalus, and 4 had chronic hydrocephalus. After EAETV, all patients showed clinical improvement. An mRS score of 0 or 1 was achieved in 9 patients, but the mRS score remained at 4 in a patient with tectal tuberculoma. There was a significant reduction in Evans’ Index, FOHR, and third ventricle index after EAETV (p < 0.05). The mean percent reduction in Evans’ Index was 20.80% ± 13.89%, the mean percent reduction in FOHR was 20.79% ± 12.98%, and the mean percent reduction in the third ventricle index was 37.45% ± 14.74%. CSF flow voids were seen in all cases. The results of CSF flow quantification parameters were as follows: mean peak velocity 3.82 ± 0.93 cm/sec, mean average velocity 0.10 ± 0.05 cm/sec, mean average flow rate 46.60 ± 28.58 μL/sec, mean forward volume 39.90 ± 23.29 μL, mean reverse volume 34.10 ± 15.98 μL, mean overall flow amplitude 74.00 ± 27.61 μL, and mean stroke volume 37.00 ± 13.80 μL. One patient developed a minor frontal lobe contusion. The frontal air sinus was breached in 5 patients, but none had CSF rhinorrhea. Transient supraorbital hypesthesia was seen in 3 patients. No patient had electrolyte disturbance or change in thirst or fluid intake habits. CONCLUSIONS EAETV is a feasible, safe, and effective surgical alternative to conventional ETV.

Cumulative Exposure to Oxidized Low-Density Lipoprotein is a Potential Predictor for Prognosis in Acute Ischemic Stroke: A Cohort Study

“…Functional prognosis at 90 days was measured by Modi ed Rankin Scale (mRS) scores obtained via telephone interview. The favorable functional prognosis was de ned as the mRS 0-2, with the poor functional prognosis de ned as mRS ≥ 3 [20].…”

Commentary: Extra-Axial Endoscopic Third Ventriculostomy for the Treatment of Slit Ventricle Syndrome: 2-Dimensional Operative Video

“…The authors demonstrate the efficacy of their approach in this small series (14 patients) with limited follow-up. 7 The authors are commended for their creativity in proposing this alternative, given their described resource limitations, but it is not clear how we should reconcile the morbidity of a craniotomy and intracranial approach with alternatives in other settings. The authors' reinvigoration of microsurgical techniques first pioneered in 1922 could be considered, as the authors describe, when other options are not possible.…”

“…The authors' reinvigoration of microsurgical techniques first pioneered in 1922 could be considered, as the authors describe, when other options are not possible. 7 Extra-axial microsurgical third ventriculostomy (MTV) was historically considered quite invasive. However, with the use of a keyhole approach as seen here and by Van Lindert, the MTV may allow for faster patient recovery and decreased tissue trauma.…”

Extra-Axial Endoscopic Third Ventriculostomy for the Treatment of Slit Ventricle Syndrome: 2-Dimensional Operative Video

“…4,5 We have recently introduced a similar endoscopic extra-axial alternative to conventional ETV for managing hydrocephalus. 6 A transventricular or subfrontal lamina terminalis fenestration is successful in 70% to 100% cases of hydrocephalus. 7-10 Extra-axial ETV (EAETV) can mitigate inherent issues with conventional ETV in managing SVS.…”