Posterior Suboccipital Approach Research Articles

Applicability of the Conventional Suboccipital Approach for Resection of Foramen Magnum Meningiomas: Early Experience with a Case Series

Background Data: Foramen magnum (FM) meningiomas are always considered challenging cases for neurosurgeons. The challenge is even heftier with early experience with limited access to up-to-date neurosurgical gadgets. Besides the anatomical complexity of the region, FM meningiomas tend to grow in proximity to eloquent structures making the task even tougher. Multiple approaches have been advocated to manage these lesions; nevertheless, adopting an approach according to your experience and circumstances would be best. Purpose: To present our experience with 16 cases of FM meningiomas operated via posterior suboccipital approach and discuss the validity of this approach. Study Design: A retrospective cohort study. Patients and Methods: We reviewed our hospital records for patients where the posterior suboccipital approach was performed for foramen magnum meningiomas in the period between November 2014 and January 2019 at our institution. Lesions with anterior location or limited posterolateral extension and those with vertebral artery encasement were excluded. We could trace 16 patients with FM meningiomas operated upon using the midline suboccipital approach. Patients’ imaging included IV gadolinium-enhanced MRI brain and CT angiography including brain and neck for diagnostic and planning purposes. Recorded outcome variables were pre- and postoperative Japanese Orthopedic Association (JAO) scale, extent of tumor excision according to Simpson’s grading, operative blood loss, duration of surgery, hospital stay, and perioperative complications. Follow-up data were recorded from our outpatient clinic chart records. Results: Twelve patients were females and 4 were males with a mean age of 40.64±8.69 years (range, 29–56 years). The mean preoperative JOA score improved from 14.875±1.690 to 15.63±0.99 at the last postoperative follow-up. Total resection was achieved in 10 cases (6, grade I; 4, grade II), subtotal resection in 4 patients, and partial resection in 2 patients. Patients with residual lesions (N=6) were managed with Gamma Knife. The mean operative time was 261.25±55.33; the mean blood loss was 682.5±84.19; the mean hospital stay was 7.25±2.05 days. Transient CSF leak was the most common recorded complication (N=9). The mean follow-up period was 13±7.186 months. Conclusion: Our data suggest that the posterior midline suboccipital approach is a safe and effective option in the management of FM meningiomas that are mainly posterior or posterolateral. (2019ESJ203)

Foramen magunum meningioma presented as subarachnoid haemorrhage

A 59-year-old woman was admitted with to our hospital with a sudden severe headache that had lasted for 5 days. Neck stiffness was present, but no other neurological deficits were present. Subarachnoid hemorrhage and intra-tumor hemorrhage were not noted on a head computed tomography (HCT). The patient's cerebrospinal fluid was xanthochromic. Magnetic resonance imaging (MRI) demonstrated a gadolinium-enhanced tumor with hemorrhagic changes around the foramen magnum. After conservative therapy, MRI showed a decrease in tumor size and a dural tail sign. This tumor was diagnosed as a hemorrhagic meningioma, and was resected with a posterior suboccipital approach. Histology confirmed that this tumor was a benign transitional meningioma with hemorrhagic change. This is a rare case involving benign meningioma onset by hemorrhagic change. Postoperative tumor recurrence was not present.

Apnea as an uncommon preoperative manifestation of medulla cavernous malformation: Surgical treatment and literature review

Objective. Apnea is not a common preoperative manifestation of medulla cavernous malformations (CMs). The role of surgical resection in patients suffering from apnea secondary to hemorrhage from medulla CMs requires further definition. Methods. Medical records and radiographs were reviewed retrospectively for four patients treated surgically for medulla CMs in our institution between 2008 and 2011. Recent outcomes for these patients were also evaluated. The modified Rankin Scale (mRS) was used to evaluate neurological function. Results. All four patients (3 male, 1 female; mean age: 41.3 years) suffered two or three hemorrhages with a preoperative mRS of five and, due to the loss of autonomous respiration and consciousness, underwent a preoperative tracheotomy for mechanical ventilation, which lasted an average of 4.5 days. Prior to surgery, all patients had recovered to the point of maintaining spontaneous breath and normal blood gas values with oxygen supplementation. Lesions were totally resected in all patients via the posterior suboccipital approach. Postoperative ventilation was continued in one patient for 1 day. The mean postoperative mRS score at discharge was 3.5, and all patients had improved from their previous scores. The tracheostomy was closed in three patients at 15, 16, and 35 days after surgery. After a mean follow-up of 34.7 months, the most recent mRS scores were 3, 2, 2, and 2; no recurrent hemorrhage was noted, and three patients lived independently. Conclusion. In carefully selected patients with hemorrhage due to medulla CMs, favorable outcomes can be achieved even if apnea was a part of the preoperative clinical presentation. Surgery should be considered in these patients, particularly in those with repeated hemorrhages, and apnea should not be considered an absolute contraindication to surgery.

Foramen magnum meningiomas – experience with the posterior suboccipital approach

The aim of this study is to analyse short- and long-term results after surgical treatment of foramen magnum meningiomas and to identify the possible advantages of the posterior suboccipital approach over lateral and anterior approaches. Between 1992 and 2006, 16 patients with foramen magnum meningiomas were operated on in our institution, and in all cases a posterior suboccipital approach was utilised with lateral extension of the bone opening according to the position of the tumour. In 14 patients, intraoperative monitoring of the lower cranial nerves was performed. Localisation of the tumours was ventral (3), ventrolateral (10), dorsal (1) and dorsolateral (2). Mean age of the patients was 61 years (ranging from 40 to 85 years). Preoperative and postoperative function was classified according to the McCormick scale. We found in eight patients a postoperative upgrading of at least one grade, in five patients an unchanged status and a deterioration in only two patients. Complete removal of the tumour was possible in 14 cases (Simpson 1–2). The follow-up period varied from 24 to 119 months (mean 43.5 months), during this time there were no recurrences. Removal of foramen magnum meningiomas can be performed safely today with the use of microsurgical techniques and intraoperative monitoring. In our experience, the posterior suboccipital approach is suitable for the majority of these tumours.

Experience of a single institution treating foramen magnum meningiomas

Despite the introduction of skull base approaches, there is still controversy in the optimum surgical management of foramen magnum meningiomas. Between January 1990 and January 2003, 22 patients underwent 23 surgical procedures with a diagnosis of foramen magnum meningioma at Marmara University, Department of Neurosurgery. The suboccipital approach was used for 2 posteriorly located tumors with radiological total removal. The paramedian suboccipital approach was replaced by the far-lateral modification in the treatment of ventral meningiomas. 1 of the 20 ventral tumors was operated twice. The classical suboccipital approach was followed by the far-lateral modification. A gross-total removal was achieved in 21 patients. The overall morbidity was 32%. No specific and clinically significant complications attributable to the far-lateral modification were observed. The far-lateral approach has improved the success of surgery in ventrally located lesions. The posterior suboccipital approach is still indicated in the removal of lesions placed posterior to the dentate ligament.

Surgery on Anterior Foramen Magnum Meningiomas Using a Conventional Posterior Suboccipital Approach: A Report on an Experience with 17 Cases

Surgery on Anterior Foramen Magnum Meningiomas Using a Conventional Posterior Suboccipital Approach: A Report on an Experience with 17 Cases

Stereotactic trigeminal nucleotomy for dysesthetic facial pain.

Trigeminal nucleotomy is a relatively simple, straightforward stereotactic procedure, acting at the deafferentation site, i.e., at the nucleus caudalis. Patients were operated on in a seated position, by a posterior suboccipital approach. Out of a series of 196 patients, 143 underwent trigeminal nucleotomy for deafferentation. Clinical diagnoses were 52 cases of postherpetic pain dysesthesia, 35 of anesthesia dolorosa, 46 of dysesthetic state with superimposed tic-like sequelae of trigeminal surgery performed elsewhere and 9 of posttraumatic neuropathy. Abolition of allodynia or marked reduction in, or disappearance of deep background pain was achieved in 72.0% of the cases overall. Results are analyzed for each clinical category. There were no side effects of any kind. Follow-up ranged from 4 to 17 years. This seems to be the procedure of choice for deafferentation facial pain.

Surgical implantation and biocompatibility of central nervous system auditory prostheses.

As part of a program to determine the feasibility of a CNS auditory prosthesis, the tissue reaction to electrodes chronically implanted in the cochlear nucleus (CN) of the guinea pig was examined. Varied open operative approaches and microelectrode designs were utilized. Silicon substrate thin film and platinum-iridium wire electrodes, tethered and untethered, were placed successfully in different divisions of the CN. Implantation through a posterior suboccipital approach was most successful. Histologic examinations demonstrated a glial cell proliferation confined to the area of the electrode track that never exceeded 15 microns in width. No neuronal loss or significant effect on cell morphology was seen, and reactive cells were absent. Electrode migration was apparent in a minority of animal preparations. Although potential problems were identified, our findings lend support to the feasibility of implanting a neuroprosthesis in the CN and have helped to establish methods for future studies of chronic intranuclear stimulation.