Subpial Technique Research Articles

The anterior sylvian point as a reliable landmark for the anterior temporal lobectomy in mesial temporal lobe epilepsy: technical note, case series, and cadaveric dissection.

Mesial temporal lobe epilepsy (MTLE) is one of the most prevalent forms of focal epilepsy in surgical series, particularly among adults. Over the decades, different surgical strategies have been developed to address drug-resistant epilepsy while safeguarding neurological and cognitive functions. Among these strategies, anterior temporal lobectomy (ATL), involving the removal of the temporal pole and mesial temporal structures, has emerged as a widely employed technique. Numerous modifications have been proposed to mitigate the risks associated with aphasia, cognitive issues, and visual field defects. Our approach is elucidated through intraoperative and cadaveric dissections, complemented by neuroradiological and cadaveric measurements of key anatomical landmarks. A retrospective analysis of patients with drug-resistant MTLE who were treated using our ATL technique at IRCCS Neuromed (Pozzilli) is presented. A total of 385 patients were treated with our ATL subpial technique anatomically focused on the anterior Sylvian point (ASyP). The mean FU was 9.9 ± 5.4 years (range 1-24). In total, 84%of patients were free of seizures during the last follow-up, with no permanent neurological deficits. Transient defects were as follows: aphasia in 3% of patients, visual field defects in 2% of patients, hemiparesis in 2% of patients, and cognitive/memory impairments in 0.8% of patients. In cadaveric dissections, the ASyP was found at a mean distance from the temporal pole of 3.4 ± 0.2 cm (range 3-3.8) at the right side and 3.5 ± 0.2 cm (3.2-3.9) at the left side. In neuroimaging, the ASyP resulted anterior to the temporal horn tip in all cases at a mean distance of 3.2 ± 0.3 mm (range 2.7-3.6) at the right side and 3.5 ± 0.4 mm (range 2.8-3.8) at the left side. To the best of our knowledge, this study first introduces the ASyP as a reliable and reproducible cortical landmark to perform the ATL to overcome the patients' variabilities, the risk of Meyer's loop injury, and the bias of intraoperative measurements. Our findings demonstrate that ASyP can be a safe cortical landmark that is useful in MTLE surgery because it is constantly present and is anterior to risky temporal regions such as temporal horn and language networks.

The Outcome of Surgical Excision of Giant Supratentorial Brain Tumors in Pediatrics: A Study of Consecutive 70 Cases at our Institute

Abstract Background: Surgery of giant supratentorial pediatric brain tumors (GSPBT) is challenging. Diagnosis may be misled by the inconspicuous symptoms and signs. Surgery is difficult due to the propensity for severe hemorrhage which is risky in this age group. Aim of Study: We discuss the surgical management of GSPBT with emphasis on how to reach maximal safe resection and different surgical strategies to improve the outcome. Patients and Methods: All Patients with GSPBT under-going elective surgery were included of age 3 months to 12 years. Giant tumors were defined by being larger than 5cm. General anesthesia was performed by neuroanesthesiologists. Various tools and instruments were used such as Cavitating ultrasonic aspirator, microscope and endoscope. Blood trans-fusion was performed as early as possible to replace losses. Extent of removal was assessed from CT or MRI scans. Results: This study included 70 children operated for GSPBT. There were 47 males (67.1%) and 23 females (32.9%). The age ranged from 3 to 144 months with a mean age of 56.3 months. The commonest presenting symptoms were those of raised intracranial pressure (ICP) in 61 cases (87.1%). Gross total resection was achieved in 57 patients (81.4%), debulking up to 80% in 3 patients (4.3%), debulking up to 50% in 1 patient (1.3%) and partial resection less than 50% in 9 patients (12.9%). The amount of blood transfusion ranged from 5 to 300ml/kg with a mean amount of 39.4ml/kg. PNET was the most common pathological diagnosis. Two cases required interruption of the procedure due to massive bleeding causing hypotension (2.9%). There were no complications due to massive blood transfusion. There were no cases of mortality. Conclusion: GSPBT can be totally resected with a good outcome. This needs a team approach including a good an-esthesia team and proper postoperative care. Surgical tech-niques including sub-pial technique, endo scope- assisted microsurgery, and the CUSA may help accomplish this target.

Subpial technique in supratentorial glioma resection: state of the art and analysis of costs and effectiveness in a single institute experience.

Many neurosurgeons advocate subpial technique as the best technique to remove supratentorial gliomas. However, few authors clearly defined advantages and features of this technique. The aim of our study is to describe microsurgical subpial technique related to glioma surgery, with regard to its safety and cost effectiveness. We analyzed retrospectively all consecutive patients surgically treated for supratentorial glioma from January 2017 to April 2018 at Neurosurgery Department of Neuromed Institute. All patients underwent to surgical glioma resection performing microsurgical subpial technique. Extent of resection and neurological complications were evaluated as primary outcomes; Karnofsky Performance Status and postoperative edema extent were secondary outcomes. Statistical analysis was obtained. The study included 70 patients. Gross Total Removal was obtained in 91.3% of patients with low grade glioma (LGG) and in 81% of patients with high grade glioma. Neurological complications amounted to 34% at early assessment in LGG patients, which were permanent at 3 months in 17% of patients. In high grade glioma patients, neurological complications amounted to 51% at early assessment, which were permanent at 3 months in 25% of them. We obtained good postoperative results with regard to the extent of tumor resection using this technique. Subpial resection is an effective surgical technique to get a safer and more complete tumor resection. It should be combined with other modern neurosurgical tools such as neuronavigation, ultrasound and cortical mapping to obtain the best tumor resection and functional neurological preservation.

Multiple Subpial Transections in Eloquent Cortex for Refractory Epilepsy: 2-Dimensional Operative Video.

Although the epilepsy refractory to medical therapy can potentially be cured by the resection of epileptogenic tissue, many patients do not qualify for surgery, because epileptogenic tissue can arise from eloquent areas of the brain, where surgical resection would result in severe neurological deficits. Palliative surgical treatments currently used in these situations include deep brain stimulation, responsive neurostimulation, and vagal nerve stimulation.1 A previously developed technique, multiple subpial transections (MSTs), although used infrequently, is another effective tool.2 Our patient, a 34-yr-old man, had epilepsy that was refractory to medical management. His preoperative work-up demonstrated a potential seizure focus in the left pars opercularis and left superior temporal gyrus, which was verified using invasive stereoelectroencephalography. Functional magnetic resonance imaging demonstrated a significant verbal and motor function in this region. After informed consent was obtained, the patient underwent a left-sided craniotomy. The central portion of the seizure focus was resected using the subpial technique. The surrounding presumed epileptogenic cortex, which was considered functionally eloquent, was then horizontally disconnected with MSTs. For each transection, a small puncture incision was made in the pia, and a vertical cut was completed using Morrell dissectors.2 MSTs were performed circumferentially around the entire resection cavity in 5-mm increments. All hemostasis was achieved with irrigation instead of electrocautery, although noncauterizing hemostatic agents are also acceptable. The patient was neurologically intact after the operation and was discharged home on postoperative day 2. He was free of seizures at 11-month follow-up. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Spinal subpial delivery of AAV9 enables widespread gene silencing and blocks motoneuron degeneration in ALS.

Gene silencing with virally delivered shRNA represents a promising approach for treatment of inherited neurodegenerative disorders. In the present study we develop a subpial technique, which we show in adult animals successfully delivers adeno-associated virus (AAV) throughout the cervical, thoracic and lumbar spinal cord, as well as brain motor centers. One-time injection at cervical and lumbar levels just before disease onset in mice expressing a familial amyotrophic lateral sclerosis (ALS)-causing mutant SOD1 produces long-term suppression of motoneuron disease, including near-complete preservation of spinal α-motoneurons and muscle innervation. Treatment after disease onset potently blocks progression of disease and further α-motoneuron degeneration. A single subpial AAV9 injection in adult pigs or non-human primates using a newly designed device produces homogeneous delivery throughout the cervical spinal cord white and gray matter and brain motor centers. Thus, spinal subpial delivery in adult animals is highly effective for AAV-mediated gene delivery throughout the spinal cord and supraspinal motor centers.

The Survival Advantage of "Supratotal" Resection of Glioblastoma Using Selective Cortical Mapping and the Subpial Technique.

A substantial body of evidence suggests that cytoreductive surgery is a prerequisite to prolonging survival in patients with glioblastoma (GBM). To evaluate the safety and impact of "supratotal" resections beyond the zone of enhancement seen on magnetic resonance imaging scans, using a subpial technique. We retrospectively evaluated 86 consecutive patients with primary GBM, managed by the senior author, using a subpial resection technique with or without carmustine (BCNU) wafer implantation. Multivariate Cox proportional hazards regression was used to analyze clinical, radiological, and outcome variables. Overall impacts of extent of resection (EOR) and BCNU wafer placement were compared using Kaplan-Meier survival analysis. Mean patient age was 56 years. The median OS for the group was 18.1 months. Median OS for patients undergoing gross total, near-total, and subtotal resection were 54, 16.5, and 13.2 months, respectively. Patients undergoing near-total resection ( P = .05) or gross total resection ( P < .01) experienced statistically significant longer survival time than patients undergoing subtotal resection as well as patients undergoing ≥95% EOR ( P < .01) when compared to <95% EOR. The addition of BCNU wafers had no survival advantage. The subpial technique extends the resection beyond the contrast enhancement and is associated with an overall survival beyond that seen in similar series where resection of the enhancement portion is performed. The effect of supratotal resection on survival exceeded the effects of age, Karnofsky performance score, and tumor volume. A prospective study would help to quantify the impact of the subpial technique on quality of life and survival as compared to a traditional resection limited to the enhancing tumor.

The Survival Advantage of "Supratotal" Resection of Glioblastoma Using Selective Cortical Mapping and the Subpial technique.

The Survival Advantage of "Supratotal" Resection of Glioblastoma Using Selective Cortical Mapping and the Subpial technique.

SURG-12THE SUB-PIAL RESECTION TECHNIQUE FOR SUPRA-MAXIMAL RESECTION OF GLIOBLASTOMAS

BACKGROUND: Despite advances in chemotherapy and surgical approaches, the median overall survival (OS) for patients with GBM remains poor. A “supra-maximal” resection, using the sub-pial technique for low-grade gliomas aims to remove immediately proximate abnormal tissue beyond the zone of enhancement on MRI. The purpose of this study is to evaluate the feasibility and survival benefit of this technique in patients with GBM. METHODS: We retrospectively evaluated 86 consecutive patients operated on for primary GBM using the sub-pial technique with or without BCNU wafer implantation and adjuvant therapy. Presenting clinical, radiological and outcome data were collected. Multivariate Cox proportional hazards regression was used to analyze variables associated with survival. Survival was compared using Kaplan-Meier plots to stratify the impact of extent of resection (EOR) and BCNU. RESULTS: Patient age (mean) was 56 years with a 93.8% median EOR. Median OS for the group was 18.1 months and 54, 16.5 and 13.2 for GTR, NTR and STR respectively. 34.2 and 13.2 months for patients with >95% and <95% EOR. Patients undergoing NTR (p = 0.05) or GTR (p < 0.01) experienced longer survival time than patients undergoing STR as well as ≥ 95% EOR (p < 0.01) when compared to <95% EOR. BCNU had no additional advantage on survival in this cohort. CONCLUSIONS: This is the first study to evaluate the use of the sub-pial technique for resection of GBM. This technique is associated with an OS benefit not previously seen in other similar series in which resection of the enhancement portion is performed. The effect of supra-maximal resection on survival exceeded the effects of age, KPS and tumor volume at presentation. A prospective study is needed to evaluate the impact of the sub-pial technique in both quality of life and survival as compared to a traditional resection of the enhancing portion of the tumor.

The sub-pial resection technique for intrinsic tumor surgery

Background:The technique of sub-pial resection, first described in the early 1900s, was later refined by Penfield and Jasper for removal of supratentorial epileptic cortex. This technique has not been widely adopted for intrinsic tumor resection, for which the most widely used technique involves piecemeal aspiration of the tumor. This technique of “staying within the tumor” results in persistent bleeding, with obscuration of the tumor/brain interface, potentially yielding less than satisfactory results. In our experience, the sub-pial technique is useful for resections of supratentorial intrinsic tumor. We report the use of sub-pial resection technique and present illustrative cases.Methods:The sub-pial resection technique is described along with important clinical decision-making guidelines. Representative cases are presented to discuss application of the sub-pial technique and to demonstrate surgical results.Results:The sub-pial technique preserves the pia during cortical resections and makes it easier to protect and identify normal anatomy, including sulci, gyri, cranial nerves, and major vascular structures. This reduces bleeding, making surgery safer and more efficient. In most cases, an en bloc resection can be accomplished, permitting more accurate histopathology and more extensive tissue acquisition for research purposes.Conclusion:The sub-pial technique can be incorporated into strategies for supratentorial intrinsic tumor resections, including temporal, frontal, occipital, and insular tumors, at para-Sylvian or para-insular-sulcus locations.