Management of entrapped temporal horn: Literature review and operative technique for endoscopic fenestration.

CONTEXT: Entrapment of the temporal horn (TH) is rare condition that can lead to increased intracranial pressure, but there is no consensus on a standard treatment. The aim of this study was to conduct a systematic literature review of the reported cases of TH entrapment and describe our operative technique for endoscopic fenestrations of the lateral ventricle into the basal cisterns. METHODS: We searched the databases Pubmed and Google scholar to find all studies reporting cases of entrapped TH and the subsequent treatment. Additionally, we report two illustrative cases of endoscopic fenestration with a step-by-step description of our surgical technique. RESULTS: Twenty-nine studies with a total of 67 patients were included in the analysis. The mean age was 36.5 years (SD± 21.9), and the female-to-male ratio was 1.5. The most frequent cause of TH entrapment was post-surgical scarring after tumor surgery (n= 30), and the most commonly reported treatment modality was endoscopic fenestration of the TH (n = 14). We observed an increasing use of endoscopic fenestration over time. CONCLUSION: Entrapped TH is a rare condition often requiring surgical treatment. Neuronavigation-guided endoscopic fenestration of the ventricle into the basal cisterns appears to be a safe, efficient, and device-free technique that has gained importance over the past years.

Clinical and therapeutic implications of cavernous sinus invasion in pituitary adenomas.

Invasion of the cavernous sinus by pituitary adenomas impedes complete surgical resection, compromises biochemical remission, and increases the risk of further tumor recurrence. Accurate preoperative MRI-based diagnosis or intraoperative direct inspection of cavernous sinus invasion are essential for optimal surgical planning and for tailoring postoperative therapeutic strategies, depending on whether a total resection has been achieved, or tumoral tissue has been left in surgically inaccessible locations. The molecular mechanisms underlying the invasive behavior of pituitary adenomas remain poorly understood, hindering the development of targeted therapies. Some studies have identified genes overexpressed in pituitary adenomas invading the cavernous sinus, offering insights into the acquisition of invasive behavior. Their main limitation however lies in comparing purely intrasellar specimens obtained from invasive and non-invasive adenomas. Further, precise anatomical knowledge of the medial wall of the cavernous sinus is crucial for grasping the mechanisms of invasion. Recently, alongside the standard intrasellar surgery, extended endoscopic intracavernous surgical procedures with systematic selective resection of the medial wall of the cavernous sinus have shown promising results for invasive secreting pituitary adenomas. The first- and second-generation somatostatin agonist ligands and cabergoline are used with variable efficacy to control secretory activity and/or growth of intracavernous remnants. Tumor regrowth usually requires surgical reintervention, sometimes combined with radiotherapy or radiosurgery which is applied despite their benign nature. Unraveling the molecular pathways driving invasive behavior of pituitary adenomas and their tropism to the cavernous sinuses is the key for developing efficient innovative treatment modalities that could reduce the need for repeated surgery or radiotherapy.

Anatomy of the medial wall of the cavernous sinus: A systematic review of the literature.

The existence, composition, and continuity of the medial wall of the cavernous sinus (MWCS) have been extensively studied and debated. However, the precise nature of this membrane remains unknown. Understanding the anatomical characteristics of the MWCS is crucial, notably in relation to pituitary adenomas, which often invade the cavernous sinus. Indeed, surgical treatment of those tumors is frequently incomplete because of such invasion. The anatomical and molecular basis of the peculiar and often lateralized tropism of adenomatous cells to the cavernous sinus is not yet understood and it has been suggested repeatedly that the MWCS is physiologically frail. During the past three decades, there have been several conflicting accounts of the existence, composition, and continuity of this medial wall, but methodological differences and varying definitions could have contributed to the current lack of consensus regarding it. The aim of this systematic review was to summarize previously published data concerning the existence, anatomy, composition, and continuity of the MWCS.

Monitoring Cochlear Nerve Action Potential for Hearing Preservation in Medium/Large Vestibular Schwannoma Surgery: Tips and Pitfalls.

The diagnosis of large vestibular schwannomas (VS) with retained useful hearing has become increasingly common. Preservation of facial nerve (FN) function has improved using intraoperative EMG monitoring, hearing preservation remains challenging, with the recent use of cochlear nerve action potential (CNAP) monitoring. This prospective longitudinal series of VS with useful hearing operated on using a retrosigmoid approach included 37 patients with a mean largest extrameatal VS. diameter of 25 ± 8.7 mm (81% of Koos stage 4). CNAP was detected in 51% of patients, while auditory brainstem responses (ABR) were present in 22%. Patients were divided into two groups based on the initial intraoperative CNAP status, whether it was present or absent. FN function was preserved (grade I-II) in 95% of cases at 6 months. Serviceable hearing (class A + B) was preserved in 16% of the cases, while 27% retained hearing with intelligibility (class A-C). Hearing with intelligibility (class A-C) was preserved in 42% of cases when CNAP could be monitored in the early stages of VS resection versus 11% when it was initially absent. Changes in both the approach to the cochlear nerve and VS resection are mandatory in preserving CNAP and improve the rate of hearing preservation.

Hypersomnia and narcolepsy in 42 adult patients with craniopharyngioma.

STUDY OBJECTIVES: To evaluate sleep, sleepiness, and excessive need for sleep in patients with craniopharyngioma (a suprasellar tumor which can affect sleep-wake systems). METHODS: A retrospective study of all adult patients living with craniopharyngioma referred to the sleep clinic, who received a sleep interview, nocturnal polysomnography, multiple sleep latency tests (MSLT), and 18-h bed rest polysomnography. Their sleep measurements were compared with those of age- and sex-matched healthy controls. RESULTS: Of 54 patients screened with craniopharyngioma, 42 were analyzed, 80% of whom complained of excessive daytime sleepiness. Sleep testing revealed that 6 (14.3%) of them had secondary narcolepsy (including one with cataplexy), and 11 (26.2%) had central hypersomnia associated with a medical disorder. Compared with controls, patients were more frequently obese, had a shorter mean sleep latency on MSLT, and slept longer on the first night. There was a nonsignificant trend for patients with (vs. without) narcolepsy and hypersomnia to be younger, to have a higher body mass index, to be more likely to have received radiation therapy, and to have more severe damage to the hypothalamus after surgery. Treatment with stimulants (modafinil, pitolisant, and methylphenidate) was beneficial in 9/10 patients. CONCLUSIONS: Nearly half of the patients with craniopharyngioma and sleep disorders have a central disorder of hypersomnolence (narcolepsy and hypersomnia), which should be investigated and lead to considerations beyond sleep apnea syndrome in these obese patients.

Reliability of fast-spin echo T2-weighted three-dimensional sequences to predict endoscopic third ventriculocisternostomy patency in children.

PURPOSE: Clinical and radiological assessment of endoscopic third ventriculocisternostomy (ETV) patency can be challenging in children. The objective of our study was thus to test the accuracy and interrater reliability of 3D fast-spin echo (FSE) T2-weighted sequences to assess the patency of ETV. METHODS: We included all the consecutive children who underwent surgery for ETV over a two-year period and selected the children who presented ETV dysfunction and matched them with children without dysfunction. We evaluated the Kappa interrater reliability of three experienced physicians for prediction of ETV patency using solely the flow void sign in 3D FSE T2-weighted sequences. RESULTS: Nineteen children underwent surgery for ETV dysfunction and 12 children without dysfunction were matched. Sensitivity was 0.79, 0.89 and 0.84 and specificity was 1 for all raters. None of the patent ETV was wrongly considered to be dysfunctional. Fleiss' kappa was 0.871 (p < 0.001). The interrater reliability was excellent with respect to the patency or not of the ETV. CONCLUSION: FSE T2-weighted sequence is a simple and reproducible tool that can be widely used in daily practice to assess the patency of ETV. Interrater reliability of this sequence is high and accessibility in outpatient setting is acceptable.

Learning curve and influencing factors of performing microsurgical anastomosis: a laboratory prospective study.

Despite being a critical component of any cerebrovascular procedure, acquiring skills in microsurgical anastomosis is challenging for trainees. In this context, simulation models, especially laboratory training, enable trainees to master microsurgical techniques before performing real surgeries. The objective of this study was to identify the factors influencing the learning curve of microsurgical training. A prospective observational study was conducted during a 7-month diploma in microsurgical techniques carried out in the anatomy laboratory of the school of surgery. Training focused on end-to-end (ETE) and end-to-side (ETS) anastomoses performed on the abdominal aorta, vena cava, internal carotid and jugular vein, femoral artery and vein, caudal artery, etc. of Wistar strain rats under supervision of 2 expert anatomical trainers. Objective and subjective data were collected after each training session. The 44 microsurgical trainees enrolled in the course performed 1792 anastomoses (1577 ETE, 88%, vs. 215 ETS, 12%). The patency rate of 41% was independent from the trainees' surgical background and previous experience. The dissection and the temporary clamping time both significantly decreased over the months (p < 0.001). Technical mistakes were independently associated with thrombosis of the anastomoses, as assessed by the technical mistakes score (p < 0.01). The training duration (in weeks) at time of each anastomosis was the only significant predictor of permeability (p < 0.001). Training duration and technical mistakes constituted the two major factors driving the learning curve. Future studies should try and investigate other factors (such as access to wet laboratory, dedicated fellowships, mentoring during early years as junior consultant/attending) influencing the retention of surgical skills for our difficult and challenging discipline.

Safety and Effectiveness of First-line Endovascular Management of Low-Grade Brain Arteriovenous Malformations : Single Center Experience in 145 Patients.

PURPOSE: Spetzler-Martin grade (SMG) I-II (low-grade) brain arteriovenous malformations (BAVMs) are often considered safe for microsurgical resection; however, the role of endovascular treatment (EVT) remains to be clarified in this indication, especially for unruptured BAVMs. The purpose of our study was to assess the safety and effectiveness of endovascular treatment as the first-line treatment for low-grade BAVMs. METHODS: From our local database, we retrospectively retrieved patients with low-grade BAVMs, either ruptured or unruptured, treated by embolization as first-line treatment in our department between January 2005 and January 2020. The primary endpoint was the total obliteration rate of BAVMs, and secondary endpoints were hemorrhagic complications and final clinical outcome, assessed through shift of the modified Rankin scale, and mortality rate secondary to BAVM embolization. RESULTS: A total of 145 patients meeting inclusion criteria and treated by EVT as first-line therapy were included in the study (82 ruptured and 63 unruptured BAVMs). Overall, complete exclusion of BAVMs was achieved in 110 patients (75.9%); 58 patients (70.7%) with ruptured and 52 (82.5%) unruptured BAVMs, including 37.9% BAVMs excluded by EVT alone (35.5% among ruptured and 44.4% among unruptured BAVMs) and 38% by combined treatment (EVT and surgery or EVT and SRS). There was no BAVM volume cut-off predictive for total obliteration by embolization alone. Early minor hemorrhagic complications were reported in 14 patients (9.6%) and early major hemorrhagic complications were reported in 5 patients (3.4%). No late hemorrhagic complications (0%) occurred; mortality rate was 0.7% (1/145 patients). Improved/unchanged mRS was reported in 137 patients (94.5%). CONCLUSION: Endovascular treatment alone or associated with others exclusion techniques, might be safe and effective for complete exclusion of low-grade brain arteriovenous malformations regardless of the volume.

Anterior interhemispheric approach for anterior fossa dural arteriovenous fistulas.

Anterior fossa dural arteriovenous fistulas (AF-DAVF) usually display a cortical venous drainage and are therefore at risk for rupture. Microsurgery is traditionally considered in many centers as the first-line treatment since endovascular treatment (EVT) entails a lower cure rate and significant ophthalmic risks. The anterior interhemispheric approach (AIA), originally described by Mayfrank in 1996, seems to offer the effectiveness of microsurgery while limiting the risks related to subfrontal craniotomy. The objective of this study was to analyze the surgical outcomes of patients who underwent this surgical approach for the treatment of AF-DAVF. We hereby describe our 10 years' experience of patients treated for an AF-DAVF with this technique in our institution and retrospectively analyzed our results. In addition, we describe our operative technique and its specificities. Eleven patients with AF-DAVF were included in our study. The definitive cure of the fistula was confirmed in all cases with postoperative cerebral angiography. All patients had a good neurological outcome and no major complication occurred. Brain retractors were never used during surgery, the frontal sinus was never opened neither, and anosmia was never observed after surgery. Anterior interhemispheric approach seems to be safe and effective to treat AF-DAVF with lower risks than other surgical approaches. This technique could be more widely considered when facing such midline vascular lesion.

Four-dimensional digital subtraction angiography for exploration of spinal cord vascular malformations: preliminary experience.

BACKGROUND: The precise understanding of the angioarchitecture of spinal vascular malformations (SVMs) is often difficult to reach with conventional digital subtraction angiography (DSA). The purpose of our study was to evaluate the potential of four-dimensional DSA (4D-DSA) (Siemens Healthcare) in the exploration of SVMs. METHODS: We retrospectively studied all patients who underwent spinal DSA, including 4D-DSA acquisition, from July 2018 to June 2019 at a single institution. All spinal DSA acquisitions were performed under general anesthesia. 4D-DSA acquisitions were acquired with the protocol '12 s DSA Dyna4D Neuro'. 12 mL of iodixanol 320 mg iodine/mL were injected via a 5 F catheter (1 mL/s during the 12 s 4D-DSA acquisition). Inter-rater (three independent reviewers) and intermodality agreements were assessed. RESULTS: Nine consecutive patients (six men, three women, mean age 55.3±19.8 years) with 10 SVMs (spinal dural arteriovenous fistulas n=3, spinal epidural arteriovenous fistulas n=2, spinal pial arteriovenous fistulas n=2, and spinal arteriovenous malformations n=2; one patient had two synchronous pial fistulas) had spinal DSA, including 4D-DSA acquisition. Inter-rater agreement was good and moderate for the venous drainage pattern and the SVM subtype, respectively. In 9 of 10 cases, the quality of the acquisition was graded as good. Satisfactory concordance between 4D-DSA and the selective microcatheterization was observed in 90% of cases for the location of the shunt point. CONCLUSION: 4D-DSA acquisition may be helpful for a better understanding of the angioarchitecture of SVMs. Larger series are warranted to confirm these preliminary results.

Microsurgical Transcranial Approach of 112 Paraoptic Meningiomas: A Single-Center Case Series.

BACKGROUND: Predictors of visual outcomes after optic nerve decompression are controversial. OBJECTIVE: To identify the predictors of poor visual outcomes after surgery of meningiomas responsible of a compressive optic neuropathy. METHODS: We focused on paraoptic meningiomas (POMs), which gathered tuberculum sellae meningiomas (TSMs) and anterior clinoid meningiomas (ACMs) responsible for visual impairment or threatening visual function, that underwent surgery at our institution between January 2009 and December 2015 and analyzed the clinical and radiological findings of our patients. RESULTS: Among 112 patients who underwent surgery for a POM, a preoperative visual deficit was present in 108 patients (96.4%). Six months after surgery, 79 patients (70.5%) had a visual improvement, 15 patients (13.4%) had an unchanged vision, and 18 patients (16.1%) had deteriorated vision. A preoperative visual deficit of 6 mo or more was a strong predictor of poor visual outcome after surgery (P = .034). Poor visual outcome after surgery was not significantly related to the size of the tumor (P = .057), the age of the patient (P = .94), or the tumor extension into the optic canal (P = .47). CONCLUSION: The duration of preoperative visual deficit was found to be a strong predictor of poor visual outcomes after surgery in POMs Other predictors of poor visual outcomes are still needed and are currently under evaluation in a prospective study at our institution.

Isolated Bilateral Hypoglossal Palsy Complicating a Fourth Ventricle Ependymoma Surgery.

BACKGROUND: Isolated bilateral hypoglossal palsy is a rare condition that has never been described after surgery in the lower part of the fourth ventricle. In this article, we discuss various possible etiologies and relevant anatomy considerations of the rhomboid fossa. CASE DESCRIPTION: We describe a case of bilateral hypoglossal palsy with tongue ptosis following surgery of an ependymoma in the lower part of the fourth ventricle. Immediate postoperative imaging showed ischemic lesions in both hypoglossal nuclei, not compatible with any known arterial territory. Two etiologies could be identified: a venous medullary infarct of the medulla oblongata or direct injury of both hypoglossal nuclei due to their midline position. Finally, the patient improved progressively and returned to normal. CONCLUSIONS: Intraoperative neurophysiologic monitoring of hypoglossal nerves, in addition to facial nerves, should be performed for tumors in this location.

Endovascular versus surgical treatment for improvement of oculomotor nerve palsy caused by unruptured posterior communicating artery aneurysms.

BACKGROUND: There is no consensus regarding the best treatment option for unruptured aneurysms of the posterior communicating artery (PCom) presenting with oculomotor nerve palsy (ONP). We aimed to assess predictors of ONP recovery in a multicenter series of consecutive patients. MATERIALS AND METHODS: A retrospective review of prospective databases in three tertiary neurosurgical centers was carried out, selecting patients with ONP caused by unruptured PCom aneurysms, treated by surgical clipping or embolization, between January 2006 and December 2013. Patient files and imaging studies were used to extract ophthalmological assessments, treatment outcomes, and follow-up data. Predictors of ONP recovery during follow-up were explored using univariate and multivariate analyses. RESULTS: We identified 55 patients with a median ONP duration before treatment of 11 days (IQR 4.5-18); the deficit was complete in 27 (49.1%) and incomplete in 28 (50.9%) cases. Median aneurysm size was 7 mm (IQR 5-9). Twenty-four (43.6%) patients underwent surgical clipping and 31 (56.4%) embolization as the primary treatment. Overall, ONP improved in 40 (72.7%) patients and persisted/recurred in 15 (27.3 %). Surgery, interval to complete treatment <4 weeks, aneurysm recurrence during follow-up, and retreatment during follow-up were significantly correlated with ONP outcome in the univariate analysis. In the multivariate analysis, independent predictors of ONP improvement were interval to complete treatment <4 weeks (OR 5.15, 95% CI 1.37 to 23.71, p=0.015) and aneurysm recurrence during follow-up (OR 0.1, 95% CI 0.02 to 0.47, p=0.003). CONCLUSION: There was no significant difference in ONP recovery between surgical clipping and embolization. The best predictor for ONP recovery was timely, complete, and durable aneurysm exclusion.

High Prevalence of Developmental Venous Anomaly in Diffuse Intrinsic Pontine Gliomas: A Pediatric Control Study.

BACKGROUND: No link has been demonstrated between diffuse intrinsic pontine glioma and developmental venous anomaly in pediatric patients. OBJECTIVE: To determine the prevalence of developmental venous anomaly in a pediatric cohort of diffuse intrinsic pontine glioma. METHODS: We performed a retrospective cohort study (1998-2017) of consecutive pediatric patients harboring a diffuse intrinsic pontine glioma (experimental set, n = 162) or a craniopharyngioma (control set, n = 142) in a tertiary pediatric neurosurgical center. The inclusion criteria were the following: age <18 yr at diagnosis; histopathological diagnosis of diffuse intrinsic pontine glioma or craniopharyngioma according to the 2016 World Health Organization classification of tumors of the central nervous system; no previous oncological treatment; and available preoperative magnetic resonance imaging performed with similar acquisition protocol. RESULTS: We found a significantly higher prevalence of developmental venous anomaly in the experimental set of 162 diffuse intrinsic pontine gliomas (24.1%) than in the control set of 142 craniopharyngiomas (10.6%; P = .001). The prevalence of developmental venous anomalies was not significantly impacted by demographic data (sex, age at diagnosis, and underlying pathological condition), biomolecular analysis (H3-K27M-mutant subgroup, H3.1-K27M-mutant subgroup, and H3.3-K27M-mutant subgroup), or imaging findings (anatomic location, anatomic extension, side, and obstructive hydrocephalus) of the studied diffuse intrinsic pontine gliomas. CONCLUSION: We report a higher prevalence of developmental venous anomaly in pediatric diffuse intrinsic pontine glioma patients than in control patients, which suggests a potential underlying common predisposition or a causal relationship that will require deeper investigations.

Management of pituicytomas: a multicenter series of eight cases.

PURPOSE: Pituicytomas and spindle cell oncocytomas (SCOs) are two rare neoplasms of the sellar and suprasellar region, known to be challenging as they are extremely vascular and almost always misdiagnosed, altering our surgical planning and the patients' outcomes. Also we argue that recent update concerning the pathology findings of these tumors should be more widely generalized to our practice. METHODS: This is a retrospective multicenter study, reporting the clinical manifestations, radiological characteristics, histopathological features, treatment strategies and long-term outcomes of patients who have been treated for a Pituicytoma at various institutions in Paris, France over the past 10 years. In addition, we compared our results to the world literature in order to identify similarities concerning the radiographic diagnosis and the treatment strategies of these tumors. RESULTS: Eight patients were operated on in four different hospitals. Misdiagnosis was constant before surgery, pituitary adenoma or craniopharyngioma being suspected. During surgery (transsphenoidal approach: six cases, transcranial approach: two cases) unusual tumors were noted, with important bleeding in most cases. Complete resection could be obtained in five patients. Pathological diagnosis was confirmed in all cases. During the follow up two recurrences occurred. One was subsequently treated with radiotherapy, the other underwent a second surgery. CONCLUSION: Recent updates concerning the histological diagnosis of pituicytomas should be generalized to our practice in order to provide a better understanding of this rare pathology and its natural course.

Spontaneously Resolving Symptomatic Subdural Hygromas After Cerebellopontine Angle Tumor Surgery.

BACKGROUND: Subdural hygroma is a rare disease most commonly encountered in posttraumatic patients. Even more rarely, it has been described as a complication of cerebellopontine angle tumor requiring surgical evacuation. CASE DESCRIPTION: This report discusses 2 patients who underwent surgery for cerebellopontine angle tumor and who both developed symptomatic subdural hygromas a few days later. Both became highly symptomatic but symptoms resolved spontaneously and promptly before planned surgery. CONCLUSIONS: These 2 cases highlight the 2 principal pathogenesis theories for the development of subdural hygromas (arachnoid tear and effusion) and suggest a theory for their sudden and spontaneous resolution: the pressure equilibrium opening the valve created by the arachnoid tear. Eventhough surgical treatment remains the recommended attitude, these cases show that conservative treatment can be an option in some cases.

Predictors of desaturation during patient transport to the postoperative anesthesia care unit: an observational study.

BACKGROUND: The transport of postoperative patients to the postoperative anesthesia care unit (PACU) is a high-risk period for hypoxemia. The aim of this study was to determine risk factors for hypoxemia during transfers to the PACU. METHODS: An observational, prospective, monocentric, and noninterventional study was conducted in the University Hospital of Toulouse in 2015 during a 5-week period. All patients who were transferred to PACU were included. Twenty-eight variables related to patient, surgery, and anesthesia were recorded. Hypoxemia during transfer was defined as Spo2 <90%. RESULTS: Five hundred five patients were included. The incidence of hypoxemia during transfer was 13%. After logistic regression analysis, 3 risk factors for desaturation were identified: sedation score >2, Spo2 <96% before exiting the operating room (OR), and body mass index >30 kg/m2. The 72% of patients were transferred without oxygen. Most of the hypoxemia appears in these patients. CONCLUSION: The development of hypoxemia during transfer from the OR to the PACU was greater in patients who were obese, were more sedated, or had lower oxygen saturations upon leaving the OR. The rates of hypoxemia were greater among patients in whom supplemental oxygen was not administered. Supplemental oxygen should be considered in higher risk patients.

Management Scheme for Cerebral Wegener Granulomatosis: An Unusual Pseudotumoral Skull Base Pathology.

Granulomatosis with polyangiitis (Wegener disease) is a rare antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis that seldom involves brain and meninges. We present a case of a 35-year-old woman with granulomatosis with polyangiitis involving the brain and the meninges. The histologic diagnosis required a complete resection of the lesion. Despite the possibility of postoperative wound infection, surgery was mandatory to ascertain the diagnostic and to treat locally.