Endoscopic Interhemispheric Disconnection for Intractable Multifocal Epilepsy: Surgical Technique and Functional Neuroanatomy

Abstract

BACKGROUND Callosotomy represents a palliative procedure for intractable multifocal epilepsy. The extent of callosotomy and the benefits of adding anterior and posterior commissurotomy are debated. OBJECTIVE To describe a new technique of a purely endoscopic procedure to disconnect the corpus callosum, the anterior, posterior, and habenular commissures through the use of a single burr hole via a transfrontal transventricular route. METHODS Our surgical series was retrospectively reviewed in terms of seizure control (Engel's class) and complication rate. Five cadaveric specimens were used to demonstrate the surgical anatomy of commissural fibers and third ventricle. RESULTS The procedure may be divided into 3 steps: (1) endoscopic transventricular transforaminal anterior commissure disconnection; (2) disconnection of posterior and habenular commissures; and (3) total callosotomy. Fifty-seven patients were included in the analysis. A favorable outcome in terms of epilepsy control (Engel class 1 to 3) was found in 71.4% of patients undergoing callosotomy coupled with anterior, posterior, and habenular commissure disconnection against 53% of patients with isolated callosotomy (P = .26). Patients with drop attacks had better epilepsy outcome independently from the surgical procedure used. CONCLUSION The full endoscopic callosotomy coupled with disconnection of anterior, posterior and habenular commissures is a safe alternative to treat multifocal refractory epilepsy. A gain in seizure outcome might be present in this cohort of patients treated with total interhemispheric disconnection when compared with isolated callosotomy. Larger studies are required to confirm these findings.

Safety, Feasibility, and Efficacy of Additional Extraventricular Anterior Commissurotomy With Corpus Callosotomy

“…Similar to our study, they failed to show statistically significant results for favorable seizure outcomes in patients who underwent additional commissurotomy. 10 Therefore, the benefit of additional AC for the treatment of epilepsy requires further validation.…”

“…Similar to our study, they failed to show statistically significant results for favorable seizure outcomes in patients who underwent additional commissurotomy. 10 Therefore, the benefit of additional AC for the treatment of epilepsy requires further validation. Combined CC and AC was earlier abandoned in clinical practice because of the morbidities thought to be related to acute disconnection syndrome.…”

“…However, additional AC is not popular. 10,11,27,28 performed a complete callosotomy coupled with disconnection of the anterior commissure, posterior commissure, and habenular commissure using a fully endoscopic technique. Similar to our study, they failed to show statistically significant results for favorable seizure outcomes in patients who underwent additional commissurotomy.…”

“…Commissurotomy has been performed since the 1970s; in recent years, studies have reported that the anterior, posterior, and habenular commissures can be safely disconnected endoscopically. 10,11 Considering this, we believe that there is no evidence against the addition of anterior commissurotomy (AC). This study aimed to evaluate the safety and seizure outcomes of patients who underwent CC with and without AC and to describe the surgical aspects of microscopic AC.…”

Surgical aspects using an exoscope for corpus callosotomy: initial experience for epilepsy surgery

“…Corpus callosotomy (CC) has traditionally been recognized as a microsurgical technique, as with other neurosurgical procedures. In contrast, little experience with endoscopic callosotomy has been reported [9][10][11]. We have started to recognize the utility of an endoscopy that can resolve some of the difficulties encountered in microsurgery to disconnect the rostrum and genu of the corpus callosum.…”