Burr hole microsurgical subtemporal selective amygdalohippocampectomy.

INTRODUCTION: At present, selective amygdalohippocampectomy (SAH) has become popular in the treatment of drug-resistant mesial temporal lobe epilepsy (TLE). However, there is still an ongoing discussion about the advantages and disadvantages of this approach. METHODS: The study included a consecutive series of 43 adult patients with drug-resistant TLE, involving 24 women and 19 men (1.8/1). Surgeries were performed at the Burdenko Neurosurgery Center from 2016 to 2019. To perform subtemporal SAH through the burr hole with the diameter of 14 mm, we used two types of approaches: preauricular, 25 cases, and supra-auricular, 18 cases. The follow-up ranged from 36 to 78 months (median 59 months). One patient died 16 months after surgery (accident). RESULTS: By the third year after surgery, Engel I outcome was achieved in 80.9% (34 cases) of cases and Engel II in 4 (9.5%) and Engel III and Engel IV in 4 (9.6%) cases. Among the patients with Engel I outcomes, anticonvulsant therapy was completed in 15 (44.1%), and doses were reduced in 17 (50%) cases. Verbal and delayed verbal memory decreased after surgery in 38.5% and 46.1%, respectively. Verbal memory was mainly affected by preauricular approach in comparison with supra-auricular (p = 0.041). In 15 (51.7%) cases, minimal visual field defects were detected in the upper quadrant. At the same time, visual field defects did not extend into the lower quadrant and inside the 20° of the upper affected quadrant in any case. CONCLUSIONS: Burr hole microsurgical subtemporal SAH is an effective surgical procedure for drug-resistant TLE. It involves minimal risks of loss of visual field within the 20° of the upper quadrant. Supra-auricular approach, compared to preauricular, results in a reduction in the incidence of upper quadrant hemianopia and is associated with a lower risk of verbal memory impairment.

Multiple hippocampal transections for mesial temporal lobe epilepsy.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of multiple hippocampal transections (MHT) in the treatment of drug-resistant mesial temporal lobe epilepsy. METHODS: Six patients underwent MHT at Burdenko Neurosurgery Center in 2018. The age of the patients varied from 18 to 43 years. All patients suffered from refractory epilepsy caused by focal lesions of the mesial temporal complex or temporal pole in dominant side. Postoperative pathology revealed neuronal-glial tumors in two patients, focal cortical dysplasia (FCD) of the temporal pole - in two patients, cavernous angioma - in one patient, and encephalocele of the preuncal area - in one patient. RESULTS: All patients underwent surgery satisfactorily. There were no postoperative complications except for homonymous superior quadrantanopia. This kind of visual field loss was noted in four cases out of six. During the follow-up period five patients out of six had Engel Class I outcome (83.3%). In one case, seizures developed after 1 month in a patient with FCD in the uncus (Engel IVA). After surgery, three out of six patients developed significant nominative aphasia. Two patients relative to the preoperative level demonstrated improvement in delayed verbal memory after MHT. Two patients showed a decrease level in delayed verbal memory. In preoperative period, visual memory was below the normal in one patient. Delayed visual memory in two cases impaired compared to the preoperative level. CONCLUSION: MHT can be considered as an effective method of drug-resistant mesial temporal lobe epilepsy caused by tumors of the medial temporal complex. At the same time, MHT makes it possible to preserve memory in patients with structurally preserved hippocampus. However, MHT do not guarantee the preservation of memory after surgery.

Burr Hole Microsurgery for Intracranial Tumors and Mesial Temporal Lobe Epilepsy: Results of 200 Consecutive Operations.

OBJECTIVE: Recently, in modern neurosurgery, a tendency toward low-traumatic surgical approaches has become clear. To provide a minimal degree of injury to the brain tissue, we have offered microsurgical approaches through a burr hole. METHODS: From February 2016 to November 2017, 200 microsurgical interventions through a single burr hole with a diameter of 14 mm were performed. The age of the patients varied from 16 to 79 years. The female/male ratio was 1.6:1. In 176 cases, the procedure was performed on an intracranial mass lesion in various locations. In the remaining 24 cases, selective amygdalohippocampectomy was performed in patients with hippocampal sclerosis. RESULTS: Various surgical approaches were used, including transcortical in 81 (40.5%), retrosigmoid in 38 (19%), subtemporal in 32 (16%), infratentorial supracerebellar in 25 (12.5%), interhemispheric in 17 (8.5%), telovelar in 5 (2.5%), and eyebrow in 2. The extent of lesion removal was evaluated in 167 patients for whom maximal tumor resection had been planned before surgery. Gross total and near total removal was achieved in 145 patients (87%), subtotal in 15 patients (9%), and partial in 7 patients (4%). The operative time ranged from 35 to 300 minutes (median, 80). The interval to extubation postoperatively varied from 5 minutes to 5 days (median, 70 minutes). Of the 200 patients, 195 (97.5%) were mobilized during the first 3 postoperative days. CONCLUSIONS: Burr hole microsurgery provides the ability to perform successful surgery on patients with the most diverse intracranial pathological features through a smaller opening than that used for keyhole surgery.

Cisterna magna arachnoid membrane suturing decreases incidence of pseudomeningocele formation and incisional CSF leakage.

OBJECTIVE: A pseudomeningocele and an incisional cerebrospinal fluid leak are considered frequent complications following neurosurgical operations. The rate of these complications especially increases following neurosurgical procedures on the posterior cranial fossae. According to some publications, the rate of pseudomeningoceles has been reported as high as 40%, whereas that of incisional cerebrospinal fluid leaks is up to 17%. For the purposes of reducing the risk of these complications after a midline suboccipital craniotomy, we propose suturing the arachnoid membrane of the cisterna magna. In this paper, we present a retrospective analysis of arachnoid membrane suturing. METHODS: Seventy patients underwent midline suboccipital craniotomy by the first author between 2012 and 2016 at Burdenko Neurosurgery Institute. In this group was included a consecutive group of patients with posterior fossae tumors where the approach was performed through the cisterna magna arachnoid membrane following midline suboccipital craniotomy and dural opening. The patients were divided into two groups. Group 1 included 38 patients to whom cisterna magna arachnoid membrane suturing was performed with monofilament nonabsorbable suture 7.0., and additionally, the suture was sealed with fibrin adhesive sealant TachoComb®. Group 2 included 32 patients without arachnoid membrane suturing. There was no other significant difference in terms of clinical signs and surgical procedures between these groups. In the postoperative period, the frequency of developing a pseudomeningocele and an incisional cerebrospinal fluid leak was assessed in these two groups. The results were evaluated on the basis of clinical, CT, and MRI data performed in the postoperative period. RESULTS: In the patients who underwent arachnoid membrane suturing (group I), pseudomeningocele formation was observed in one (2.6%) and CSF leak in one (2.6%) of the 38 patients. In group II, in which patients had no arachnoid membrane suturing, we observed pseudomeningocele formation in 11 (34.4%) patients and a CSF leak in 7 (25.0%) out of 28 patients with known follow-up. Statistical analysis of the data indicates a significantly higher risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in a group of patients who did not undergo arachnoid membrane suturing (p < 0.05). CONCLUSIONS: Suturing of the arachnoid membrane of the cisterna magna and its further sealing with fibrin adhesive sealant TachoComb® create an additional barrier for preventing cerebrospinal fluid collection in the extradural space. This technique significantly reduces the risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in patients with midline suboccipital craniotomy.