Modified periinsular hemispherotomy: operative anatomy and technical nuances

Abstract

<jats:p>Surgical options for pediatric patients with marked dysfunction of a single epileptogenic hemisphere have evolved over time. Complications resulting from highly resective operations such as anatomical hemispherectomy, including superficial siderosis and secondary hydrocephalus, have led to the development of less resective and more disconnective functional hemispherectomy. Functional hemispherectomy has recently given rise to hemispherotomy, the least resective operation primarily aimed at disconnecting the abnormal hemisphere. Hemispherotomy is effective in decreasing seizure frequency and most likely decreases the risk of postoperative complications when compared with its predecessors. Hemispherotomy is a technically challenging operation that requires a thorough understanding of 3D cerebral anatomy to ensure adequate hemispheric disconnection without placing important structures at risk. The details of germane operative anatomy are not currently available because of the difficulty in exposing this operative anatomy adequately in cadavers to prepare detailed instructive illustrations. Using 3D graphic models, the authors have prepared 2D overlay illustrations to discuss the relevant operative nuances for a modified form of this procedure. Through hemispherotomy, experienced surgeons can effectively treat patients with unilateral epileptogenic hemisphere dysfunction while limiting potential complications.</jats:p>

Tailored suprainsular partial hemispherotomy: a new functional disconnection technique for stroke-induced refractory epilepsy

“…31,34 These procedures can lead to seizure freedom in 90%-95% of patients. 23,34 However, this type of surgical management does not improve cognitive prognosis 34 and carries a high risk of hemianopia, verbal memory impairment, and olfactory deficits. 12,34 There are arguments in favor of choosing disconnection surgery instead of resective options, notably to avoid the intracranial dead space created by hemispherectomy, which is associated with a risk of superficial hemosiderosis and consequently the risk of de novo epilepsy and hydrocephalus.…”

Surgical Management of Epilepsy in Adolescent Patients

“…In such cases, following lateralization and localization of the onset of seizures to one cerebral hemisphere, extensive surgical intervention is often needed to sever the path of epileptic discharges and effectively isolate (and sometimes remove) the epileptogenic zone itself, that is, the diseased hemisphere. 47,48 It should be noted that up to the approximate age of 14 years, pediatric and adolescent patients benefit from neuroplasticity, which confers a substantially greater degree of neurological recovery than in adults undergoing more aggressive surgical intervention of this sort.…”

Pediatric functional hemispherectomy: operative techniques and complication avoidance

“…18 Subsequent modifications of the functional hemispherectomy have resulted in smaller craniotomies and the development of hemispherotomies, which have minimized the amount of brain tissue resected and operative time, thereby reducing operative morbidity and mortality while maintaining an equivalent rate of seizure control. 6,11,19,20,23 In this paper, we discuss the multidisciplinary evaluation and preoperative workup that is prerequisite prior to disconnection surgery at Seattle Children's Hospital. We present the surgical technique for a modified functional hemispherectomy/hemispherotomy, which combines elements of the peri-insular hemispherotomy described by Villemure and Daniel and the vertical parasagittal hemispherotomy described by Delalande et al 1,6,21 In addition, we review outcomes following modern disconnection surgery and discuss strategies to prevent common complications such as incomplete disconnection, the use of an osteoplastic flap, and the prevention of delayed hydrocephalus.…”