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.

Microsurgical third ventriculostomy with stenting in intrinsic brain tumors involving anterior third ventricle.

OBJECTIVE: Microsurgical fenestration of the third ventricular floor performed in one session with resection of deep seated tumors has been recently demonstrated as an approach to specifically address the concomitant obstructive hydrocephalus. As with endoscopic third ventriculostomy, occlusion of the stoma may result in progression of the obstructive hydrocephalus. In order to provide reliable communication between the basal cisterns and ventricles, we propose stenting of the stoma in cases of direct surgical approach to deep seated tumors. METHODS: After performing tumor resection through the anterior transcallosal approach, premamillar and Liliequist's membranes were identified and fenestrated. A silicon stent was inserted into the prepontine cistern through the fenestrated floor of the third ventricle; the stent connected the third and lateral ventricles with the basal cisterns. RESULTS: Microsurgical ventriculostomy of the third ventricle and stenting of the stoma was performed in 9 patients simultaneously with tumor resection (5 cases), open biopsy (3 cases), or microsurgical dissection of severe adhesions at the level of Monro foramina (1 case). In 7 cases, the third ventricular floor was infiltrated with the tumor and obstruction of the aqueduct persisted after tumor surgery; in 2 patients, high risk of reocclusion at the level of Monro foramen was expected. Stenting of the ventricular system provided patency of the stoma and Monro foramen. None of the patients required a shunt postoperatively. The follow-up time ranged from 3 to 22 months. CONCLUSION: Microsurgical fenestration of the third ventricle floor combined with stoma stenting can be a viable option for hydrocephalus control.