Access to Meckel's cave for biopsies of indeterminate lesions: a systematic review.

Accessing Meckel's cave (MC) is surgically challenging. Open approaches are complex and often correlated with high morbidity. Endoscopic approaches emerged in the last decade as feasible alternatives to open approaches, especially for sampling indeterminate lesions. This article first analyses available routes to approach Meckel's cave and presents furthermore an illustrative case. We conducted a systematic review and reported according to the guidelines for preferred reporting items for systematic reviews and meta-analyses (PRISMA). Various surgical approaches identified through the search are evaluated and discussed in detail. Additionally, we report on a case of woman with a lesion in MC, which was accessed through an endoscopic transpterygoid approach subsequently diagnosed as a diffuse large B cell lymphoma. Our search delivered 75 articles that included case reports (n = 21), cadaveric studies (n = 32), clinical articles (n = 16), review of the literatures (n = 3), as well as technical notes (n = 2) and a radiological manuscript (n = 1). Open routes included lateral approaches with many variations, mainly intra- and extradural pterional approaches and anterior petrosal, as well as a retrosigmoid intradural suprameatal and a lateral transorbital approach. Endoscopically, MC was reached via approaches that included transpterygoid, transorbital or infraorbital fissure routes. Percutaneous approaches, e.g. through the foramen ovale, were also described. Multiple surgical approaches to MC are currently available. Their different characteristics as well as individual patient factors, such as clinical history and the localization of the disease, have to be considered when choosing a surgical corridor. Studies included in this review highlight the endonasal endoscopic transpterygoidal technique as an excellent corridor for biopsies in the ventral MC.

The extradural extended eyebrow approach: A cadaveric feasibility study.

INTRODUCTION: Extradural anterior clinoidectomy (eAC) is key to expose the paraclinoid region. Several authors have pointed limitations of performing an eAC through a supraorbital craniotomy. In this article, we aim to provide educational material and discuss the technical nuances to successfully perform an eAC throughout a modification of the supraorbital approach, the extradural extended eyebrow approach (xEBA+eAC). METHODS: Four embalmed heads were used for anatomic dissection and perform the xEBA+eAC. Additionally, one head was used for a video demonstration of the surgical approach. RESULTS: The anterior clinoid process was successfully removed, and the ophthalmic artery and paraclinoid region were exposed in all specimens. Drilling the sphenoid wing until exposing the meningo-orbital band and further interdural dissection are vital steps to expose the anterior clinoid process. Removal of the anterior clinoid process can be simplified in 3 osteotomies, including the optic canal unroofing, detachment from the lateral pillar, and drilling of the optic strut. Sectioning of the distal dural ring facilitates the mobilization of the internal carotid artery and the surgical exposure of the ophthalmic artery. CONCLUSIONS: xEBA+eAC is a technically feasible approach that provides exposure to the paraclinoid region, along with anterior and middle cranial fossa.

A prospective randomized clinical trial to evaluate the impact of intraoperative ventilation with high oxygen content on the extent of postoperative pneumocephalus in patients undergoing craniotomies.

Purpose of the article: To determine whether intraoperative ventilation with pure oxygen during the last stage of surgery reduces the occurrence and volume of postoperative pneumocephalus when compared to conventional air/oxygen mixture in patients undergoing craniotomy. MATERIAL AND METHODS: prospective randomized single-blinded study to compare the rate of occurrence and volume of postoperative pneumocephalus in patients undergoing craniotomy receiving intraoperative ventilation with pure oxygen (Group B) versus a conventional air/oxygen 1:1 mixture (Group A) during the last stage of surgery. This trial was registered in ClinicalTrials.gov #NCT02722928, protocol number 2015H0032. RESULTS: One hundred patients were randomized into group 'A' and group 'B'. Seventy patients were included in the final analysis with 39 patients allocated in group 'A' and 31 patients in group 'B'. Median and IQR were used for postoperative penumocephalus volume. Group A: 9.65 [3.61-23.20]; Group B: 7.06 [2.70-20.1]. Our study showed no prophylactic effect on postoperative pneumocephalus volume when using mechanical ventilation with higher oxygen concentrations than the standard FiO2 during the last stage of surgery in patients undergoing craniotomy (p = .47). No statistical difference was found in SICU LOS between groups (median 1,380 min [group A] versus 1,524 min [group B]; p = .18). CONCLUSION: The use of intraoperative mechanical ventilation with pure oxygen was not associated with a prophylactic effect on the occurrence and extent of postoperative pneumocephalus in our patient setting. Published literature describing the extent of postoperative pneumocephalus is limited or highly variable among institutions.

Technical nuances of commonly used vascularised flaps for skull base reconstruction.

BACKGROUND AND METHODS: Reconstruction with a vascularised flap provides the most reliable outcome, with post-operative cerebrospinal fluid leak rates of less than 5 per cent. This article aims to review and summarise the critical technical aspects of the vascularised flaps most commonly used for skull base reconstruction. RESULTS: Vascularised flaps are classified as intranasal or extranasal. The intranasal group includes the Hadad-Bassagaisteguy nasoseptal flap, the Caicedo reverse nasoseptal flap, the nasoseptal rescue flap, the posteriorly or anteriorly based lateral wall flaps, and the middle turbinate flap. Extranasal flaps include the transfrontal pericranial and transpterygoid temporoparietal flaps. CONCLUSION: The Hadad-Bassagaisteguy nasoseptal flap is overwhelmingly favoured for reconstructing extensive defects of anterior, middle and posterior cranial base. Its pertinent technical features are described. However, it is essential to master the skills required for the various extranasal or regional vascularised flaps because each can offer a reconstructive alternative for specific patients, especially when open approaches are needed and/or intranasal vascularised flaps are not feasible.

Vidian nerve neurofibroma removed via a transpterygoid approach.

BACKGROUND: Lesions originating in the vidian canal are extremely rare. Most frequently, they are extensions from contiguous carcinomas. We present a rare case of a vidian nerve neurofibroma and discuss its surgical management. CASE REPORT: A 62-year-old woman with a history of a basal cell skin cancer was evaluated for bilateral tinnitus. Imaging revealed a left-sided lesion at the medial aspect of the pterygoid process base, over the vidian canal. Under image-guidance, an endonasal endoscopic transpterygoid approach was performed. The histopathological examination supported the diagnosis of neurofibroma. CONCLUSION: Benign nerve sheath tumors of the vidian nerve should be considered in the differential diagnosis of a vidian canal lesion. Given the propensity of more aggressive tumors, a tissue diagnosis should be warranted in order to coordinate appropriate subsequent treatment. The expanded endonasal transpterygoid approach offers a safe, less invasive, and effective route to perform the excisional biopsy of such a lesion.

Animal model for endoscopic neurosurgical training: technical note.

OBJECTIVE: The learning curve for endonasal endoscopic and neuroendoscopic port surgery is long and often associated with an increase in complication rates as surgeons gain experience. We present an animal model for laboratory training aiming to encourage the young generation of neurosurgeons to pursue proficiency in endoscopic neurosurgical techniques. METHODS: 20 Wistar rats were used as models. The animals were introduced into a physical trainer with multiple ports to carry out fully endoscopic microsurgical procedures. The vertical and horizontal dimensions of the paired ports (simulated nostrils) were: 35×20 mm, 35×15 mm, 25×15 mm, and 25×10 mm. 2 additional single 11.5 mm endoscopic ports were added. Surgical depth varied as desired between 8 and 15 cm. The cervical and abdominal regions were the focus of the endoscopic microsurgical exercises. RESULTS: The different endoscopic neurosurgical techniques were effectively trained at the millimetric dimension. Levels of progressive surgical difficulty depending upon the endoneurosurgical skills set needed for a particular surgical exercise were distinguished. LEVEL 1 is soft-tissue microdissection (exposure of cervical muscular plane and retroperitoneal space); LEVEL 2 is soft-tissue-vascular and vascular-capsule microdissection (aorto-cava exposure, carotid sheath opening, external jugular vein isolation); LEVEL 3 is artery-nerve microdissection (carotid-vagal separation); LEVEL 4 is artery-vein microdissection (aorto-cava separation); LEVEL 5 is vascular repair and microsuturing (aortic rupture), which verified the lack of current proper instrumentation. CONCLUSION: The animal training model presented here has the potential to shorten the length of the learning curve in endonasal endoscopic and neuroendoscopic port surgery and reduce the incidence of training-related surgical complications.

The antero-medial triangle: the risk for cranial nerves ischemia at the cavernous sinus lateral wall. Anatomic cadaveric study.

OBJECTIVE: Vascular damage in the cavernous sinus can cause ischemic injury to the cranial nerves. An appropriate anatomical knowledge of the blood supply to the cranial nerves can help to reduce the morbidity associated with cavernous sinus surgery. MATERIAL AND METHODS: Three formalin-fixed and six adult cadaveric fresh heads, with common carotid arteries injected, were used for anatomical dissection in this study. A fronto-temporal craniotomy was performed and the cavernous sinus was explored according to the Dolenc technique. With microsurgical dissection and photographic documentation, we demonstrate the anatomy of the superior orbital fissure artery in the antero-medial triangle. RESULTS: The 12 explored cavernous sinuses demonstrated the presence of two principal branches directly from the intracavernous internal carotid artery that supply the cranial nerves: the infero-lateral trunk and the meningohypophyseal trunk. The artery of the Superior Orbital Fissure (SOF), originated more often from the infero-lateral trunk, and vascularized the III, IV, VI, and VI, and ophtalmic division of the trigeminal nerve (TGN VI) at their entry in the fissure. CONCLUSION: In this study we demonstrate that the superior orbital fissure artery is a branch from the infero-lateral trunk which runs immediately under the reticularis layer at the level of the anteromedial triangle in the lateral wall of the cavernous sinus. The blood supply to all cranial nerves in the SOF is at risk to injury when the lateral wall of the cavernous sinus is transgressed at the anteromedial triangle since the SOF-artery runs superficially at this level.

Ventral extradural spinal meningeal cyst causing cord compression: neurosurgical treatment

Spinal extradural meningeal cysts are typically formed by a thin fibrotic membranous capsule, macroscopically similar that of an arachnoid membrane, filled by cerebro spinal fluid and related to a nerve root or to the posterior midline. Ventral location is extremely rare and when it occurs they usually cause spinal cord herniation through the ventral dural gap. A 61 year-old man who began with a two years long history of insidious tetraparesis, spasticity and hyperreflexia in lower extremities, and flaccid atrophy of upper limbs, without sensory manifestations, is presented. Investigation through magnetic resonance imaging demonstrated an extensive spinal ventral extradural cystic collection from C6 to T11. The lesion was approached through a laminectomy and a cyst-peritoneal shunt was introduced. The cyst reduced in size significantly and the patient is asymptomatic over a 48 months follow-up. This is the first reported case of a spontaneous ventral extradural spinal meningeal cyst causing cord compression. Cyst-peritoneal shunt was effective in the treatment of the case and it should be considered in cases in which complete resection of the cyst is made more difficult or risky by the need of more aggressive surgical maneuvers.

Cistos meníngeos extradurais espinhais são formados tipicamente por estreita cápsula membranosa fibrótica, macroscopicamente semelhante a uma membrana de aracnóide, repleta de líquor e relacionada com uma raiz nervosa ou com a linha média posterior. Eles são extremamente raros em posição anterior e, quando ocorrem, habitualmente causam herniação da medula espinhal pela falha dural ventral. O caso de um homem de 61 anos de idade que iniciou com tetraparesia, espasticidade e hiperreflexia em membros inferiores, e flacidez com hipotrofia nos membros superiores, sem manifestação sensitiva, é apresentado. A investigação com ressonância magnética demonstrou extensa coleção cística extradural ventral à medula de C6 a T11. A lesão foi abordada diretamente via laminectomia com introdução de derivação cisto-peritoneal, reduzindo o cisto e tornando o paciente assintomático com um seguimento de 48 meses. Este é o primeiro caso relatado de cisto meníngeo extradural ventral espontâneo causando compressão medular. A derivação cisto-peritoneal se mostrou eficaz no tratamento do caso e deve ser considerada em situações em que a ressecção completa do cisto esteja impossibilitada, ou dificultada pela necessidade de manobras cirúrgicas mais agressivas e arriscadas.

Symptomatic muscle involvement in neurosarcoidosis: a clinicopathological study of 5 cases.

We report on the clinical course and histopathologic muscle alterations of five patients diagnosed with neurosarcoidosis, who underwent biopsy due to their muscle manifestations. The five patients were females and only one was less than 40 years of age. Proximal muscle weakness was presented by all and only two patients complained of myalgia. Only normal values of serum muscle enzymes were detected. Electromyography revealed diverse findings such as normal, myopathic and neuropathic patterns. Granuloma was not present in one muscle biopsy. Two patients thoroughly recovered by taking only prednisone and one patient required a methotrexate addition for 3 months before becoming asymptomatic. The other two patients received azathioprine, one due to steroid side effects but without a satisfactory evolution, and the other to strengthen the prednisone régime, with excellent results.

Cerebrospinal fluid fistula as the presenting manifestation of pituitary adenoma: case report with a 4-year follow-up.

We report the case of a young woman who presented with cerebrospinal fluid (CSF) rhinorrhea due to an undiagnosed and untreated pituitary adenoma. The tumor had extended well beyond sella turcica and caused bony erosion. The patient initially refused surgery and was treated with bromocriptine and a radiation therapy. CSF leakage did not improved and she was submitted to surgery by the transsphenoidal approach with removal of a tumor mass located in sphenoid sinus and sellar region. Origin of the leak was localized and repaired with fascia lata and a lumbar subarachnoid drain was left in place for 5 days. After 4 years she has normal serum PRL levels and no rhinorrhea. The management, complications and mechanisms involved in this rare condition are discussed.

Posterior approach for soft cervical disc herniation: a neglected technique?

BACKGROUND: The ideal approach to the treatment of soft cervical disc herniation remains controversial. Recent reports emphasize several variations of anterior cervical approaches, including the introduction of instrumentation techniques. New issues have been raised and modern neurosurgeons seem to be less familiar with the posterior approach. The objective of this study was to analyze the results obtained by surgical treatment via a posterior approach of soft cervical disc herniation. METHOD: Fifty-one patients who underwent laminectomy/flavectomy and disc removal for the treatment of soft cervical disc herniation in the period of 1990 to 1999 were analyzed retrospectively. Relief of pain and motor and sensory improvement were the criteria used to measure the success of the procedure. RESULTS: Most of the patients presented with acute radiculopathy. Radicular involvement was as follows: 25 cases-C7 root, 19 cases-C6 root, 4 cases-C5 root, and 3 cases-C8 root. Total relief of pain was obtained in 49 of 51 patients (96%). Motor improvement was obtained in 35 of 46 patients (76%) and sensory improvement in 22 of 35 patients (62.8%) in the short term. The mean time of hospitalization was 3 days. There was no mortality and no morbidity. CONCLUSION: The advantage of this method, in selected cases, over the classical anterior approach, is that there is no need for grafting, thus avoiding the additional pain and possible complications at the donor and receptor sites, while obtaining similar results.

Diagnosis of dermatomyositis and polymyositis: a study of 102 cases.

UNLABELLED: Patients with dermatomyositis (DM) or polymyositis (PM) were studied retrospectively. The patients were divided into four groups: definite PM 24, probable PM 19, definite DM 34 and mild-early DM 25 cases. PM patients complained more often proximal muscle weakness [p <0.01]. DM patients complained more arthralgia [p <0.05], dysphagia [p <0.03] and weight loss [p <0.04]. Five patients had a malignant neoplasm and 9 had other connective-tissue disease. DM presented higher ESR than PM [p <0.002]. PM presented more significant increase in creatine kinase (CK) [p <0.02] and in alanine aminotransferase (ALT) [p <0.001] levels. Electromyography showed myopathic pattern in 76%. Muscle biopsy was the definitive test. Perifascicular atrophy was more frequent in definite DM than in mild-early DM group [p <0.03]. CONCLUSION: A small association with connective-tissue diseases and neoplasms was found. DM and PM are clinically different. DM presents systemic involvement affecting the skin, developing more severe arthralgia, dysphagia and weight loss and presenting higher values of ESR. PM presents a restricted and more significant involvement of muscles generating more weakness complaints and higher levels of serum muscle enzymes.

Prognostic factors in mesial temporal lobe epilepsy surgery.

Eighty-four patients submitted to anterior temporal lobectomy were evaluated retrospectively in order to correlate the different type of simple partial seizure (SPS) and their prognostic implications in patients with mesial temporal sclerosis. The patients were divided in two groups following the classification of Engel; Group 1 (53 patients) included patients Class I (without seizures or of good outcome) and Group 2 (31 patients) included Classes II, III and IV (with seizures or of bad outcome). The two groups were compared and results showed no statistical difference in relation to the demographic aspects as sex, side of surgery, age at onset of seizures and time of the patients' postoperative follow-up. Statistical analysis revealed no relationship between type of SPS and outcome. SPS did not show a statistical value in localizing the side of pathology. However, when the two groups were compared statistically in terms of patients' ages at the time of surgery, and the time elapsed from the onset of the seizures to the surgical intervention, it was observed that Group 1 (of good outcome) had seizures for smaller interval (p <0.05) and was operated at an earlier age (p<0.02) than Group 2 (of bad outcome). The presence or the type of SPS can not be used as a prognostic measure; surgical therapy must be considered as soon as clinical resistance is demonstrated.