Tension Pneumocephalus Secondary to Positive Pressure Ventilation Following Endoscopic Endonasal Skull Base Surgery: Three-Year Follow-Up After Implementation of an Institutional Protocol.

BACKGROUND: Tension pneumocephalus (PMC) is a rare and feared complication following the endonasal endoscopic approach (EEA) to skull base procedures. This is a neurosurgical emergency that requires urgent decompression to avoid catastrophic neurological damage or death. An avoidable cause is the application of positive pressure ventilation (PPV) in EEA patients for postoperative hypoxia. Our institution implemented a hospital-wide protocol in response to this to identify and manage at-risk patients; the present paper aims to identify if this protocol was effective in lowering the rates of tension PMC secondary to PPV. RESULTS: In the 3 years following the implementation of the protocol, 110 patients underwent EEAs, from which 1 case of tension PMC (found to be not secondary to PPV) was identified. This is compared to 2 cases of tension PMC secondary to PPV over the preceding 5 years, out of 406 EEA patients. This constitutes a quantifiable reduction in PPV-related tension PMC in both standard and extended approach EEAs, signifying the effective uptake of the protocol. CONCLUSION: We found no cases of tension PMC after PPV following EEA skull base surgery in our institution since the implementation of an institution-wide guideline. This underscores the utility of our simple and cost-effective preventative protocol in reducing the overall rates of tension PMC following the inadvertent postoperative application of PPV. Further research is needed to study the comparative risks and benefits of PPV in the post-EEA patient and thus inform future iterations of the protocol.

Quality of life in Prolactinoma: A systematic review.

BACKGROUND: Prolactinomas are common tumours that significantly reduce quality-of-life (QOL) due to sellar mass effect, secondary hypogonadism, and the peripheral effects of prolactin. Understanding the factors that influence QOL would provide insights into therapeutic targets to optimise patient outcomes and improve wellbeing in prolactinoma. METHODS: A systematic review was performed in accordance with the PRISMA statement. Studies that reported patient QoL using validated metrics were included. Bias and methodological rigour were assessed using the MINORS criteria. RESULTS: A total of 18 studies were identified studies were available for review, comprising 877 patients. Most were small cross-sectional studies at high risk of bias. Prolactinoma exhibit worse QOL than healthy controls, particularly mental and psychosocial wellbeing. QOL is also worse than patients with non-functional adenomas, but better than those with Cushing's disease and acromegaly. QOL correlates with prolactin levels, and approaches population baseline with prolonged biochemical control. Dopamine agonists and surgery both improve overall QOL, however improvements are more rapid with surgery. CONCLUSION: Poor quality of life in prolactinoma is multifactorial, related to biochemical control, side effects of therapy, and sellar mass effect. Targeting persistent symptoms, reducing healthcare costs, and reducing side-effects of therapy are avenues to improving QOL in patients with prolactinoma.

Vertebral Artery Mobilization During Transcondylar Extreme Far Lateral Approach for Excision of Large Foramen Magnum Meningioma: 2-Dimensional Operative Video.

Foramen magnum meningiomas are challenging lesions owing to their proximity to the lower brainstem, vertebrobasilar system, and lower cranial nerves.1,2 Tumor size, origin, morphology, relationship to neurovascular structures, and bony anatomy determine the optimal surgical approach.2,3 Classically, far lateral approaches have been the workhorse approach to the foramen magnum. Variations of the far lateral including transcondylar and extended transcondylar (paracondylar), with or without transposition of the vertebral artery, are sometimes used for a more lateral approach to the brainstem and clivus. Here, we present a 60-year-old male patient presenting with a large foramen magnum meningioma. Preoperative workup includes computed tomography and MRI with angiography to assess for posterior circulation dominance, anatomic variants including posterior inferior cerebellar artery origin, venous, and bony anatomy.1,4 An extreme far lateral provides access anterior to the vertebral artery to extend exposure beyond the standard far lateral approach. This comprised transcondylar drilling, bony mobilization of the V3 Vertebral artery from C1 foramen transversarium, and dural mobilization of vertebral artery with a dural cuff at its site of dural entry. The patient tolerated the procedure, gross total resection was achieved, and the patient was discharged home. This video demonstrates in detail the steps of exposure, condylar drilling, vertebral artery transposition, and dural opening. These maneuvers can be difficult to conceptualize yet are key to successful extended transcondylar exposure. The patient gave informed consent for surgery and video recording. Institutional Review Board approval was deemed unnecessary.

Preoperative coil localization for spinal surgery is accurate, safe and effective: a single-centre initial experience.

OBJECTIVE AND STUDY DESIGN: This is a retrospective, descriptive study of consecutive patients undergoing novel preoperative pushable coil localization for spinal surgery, in order to evaluate its feasibility, safety and accuracy. METHODS: Consecutive patients who underwent pre-operative coil marking for spinal surgery at our institution from May 2018 to July 2021 were included. Data were collected for coil placement, accuracy, complications and fluoroscopy usage. Patient demographic and relevant perioperative and procedural data were also collected. RESULTS: A total of 34 patients were identified of which 32 (94%) had complete data and imaging at last clinical follow up, with a mean duration of 13.9 months. There were no incorrect level surgeries performed. There were no coil-related complications found in our cohort. CONCLUSIONS: Preoperative coil placement is an accurate, safe and well-tolerated method for level localization in spinal surgeries.

Recurrent haemorrhagic pontine cavernoma resection via a retrosigmoid microsurgical approach.

BACKGROUND: Brainstem cavernomas occasionally require surgical treatment. Appropriate patient selection and thorough understanding of the anatomy and technical nuances involved in microsurgical resection is a pre-requisite in undertaking these challenging cases. CASE DESCRIPTION: We present a video case of a patient with a recurrent haemorrhagic pontine cavernoma. A step-by-step commentary of surgical footage is provided along with clinical, anatomical and technical learning points pertinent to the safe surgical management of these lesions.

Microsurgical clipping of ruptured supraclinoid internal carotid artery aneurysm with extradural clinoidectomy.

BACKGROUND: Supraclinoid Internal Carotid Artery (ICA) aneurysms require additional access to standard pterional craniotomy via extradural clinoidectomy. Existing texts and surgical videos lack clarity, explanation and a clear step by step process. CASE DESCRIPTION: We present a case of a ruptured supraclinoid ICA aneurysm and extradural clinoidectomy along with 3D reconstructed imaging of the case anatomy to guide its resection. Real-time unedited on table rerupture provides an example of management. CONCLUSION: Extradural Anterior Clinoidectomy is a key maneuver in cerebrovascular surgical armamentarium for clipping of supraclinoid aneurysms. Stereotypical Pathological or Surgical Anatomy, its application, and availability with 3D imaging should be facilitates the framing and learning of normal physiological anatomy.

Microsurgical disconnection of a T12/L1 ventral intradural perimedullary arteriovenous fistula (type IV) via instrumented trans-pedicular approach.

CASE DESCRIPTION: We present a case of microsurgical disconnection of a PMAVF supplied by the artery of Adamkiewicz with fistulation at the ventral spinal cord.

Intraoperative Ultrasound and Findings of Lumbar Intradural Disk Herniation Causing Cauda Equina Syndrome.

Intradural lumbar disk herniation (ILDH) is a rare variant and accounts for 0.33%-1.5% of lumbar disk herniations. Although clues exist on preoperative imaging, they remain subtle and most cases of ILDH are diagnosed intraoperatively. Intraoperative ultrasound is a useful adjunct in diagnosing and managing ILDH. We present a case to demonstrate the features of an intradural herniated disk on ultrasound imaging and highlight the utility of intraoperative ultrasonography in establishing diagnosis, guiding dural opening, and confirming adequate nerve root decompression following diskectomy.

The utility of arterial spin labelled perfusion-weighted magnetic resonance imaging in measuring the vascularity of high grade gliomas - A prospective study.

Background: Dynamic susceptibility contrast (DSC) perfusion weighted imaging (PWI) currently remains the gold standard technique for measuring cerebral perfusion in glioma diagnosis and surveillance. Arterial spin labelling (ASL) PWI is a non-invasive alternative that does not require gadolinium contrast administration, although it is yet to be applied in widespread clinical practice. This study aims to assess the utility of measuring signal intensity in ASL PWI in predicting glioma vascularity by measuring maximal tumour signal intensity in patients based on pre-operative imaging and comparing this to maximal vessel density on histopathology. Methods: Pseudocontinuous ASL (pCASL) and DSC images were acquired pre-operatively in 21 patients with high grade gliomas. The maximal signal intensity within the gliomas over a region of interest of 100 mm2 was measured and also normalised to the contralateral cerebral cortex (nTBF-C), and cerebellum (nTBF-Cb). Maximal vessel density per 1 mm2 was determined on histopathology using CD31 and CD34 immunostaining on all participants. Results: Using ASL, statistically significant correlation was observed between maximal signal intensity (p < 0.05) and nTBF-C (p < 0.05) to maximal vessel density based on histopathology. Although a positive trend was also observed nTBF-Cb, this did not reach statistical significance. Using DSC, no statistically significant correlation was found between signal intensity, nTBF-C and nTBF-Cb. There was no correlation between maximal signal intensity between ASL and DSC. Average vessel density did not correlate with age, sex, previous treatment, or IDH status. Conclusions: ASL PWI imaging is a reliable marker of evaluating the vascularity of high grade gliomas and may be used as an adjunct to DSC PWI.

Headache Improvement Following Endoscopic Resection of Pituitary Adenomas.

BACKGROUND: Headache is a common symptom in patients with pituitary adenomas. Research on whether resection of pituitary adenomas via the endoscopic endonasal approach (EEA) affects headaches is limited, and the pathophysiology of headaches associated with pituitary adenomas remains unclear. This study aimed to determine if resection of pituitary adenomas via the EEA improves headaches and investigate factors that may be associated with headaches in patients with pituitary adenoma. METHODS: A prospectively collected database of 122 patients undergoing resection of pituitary adenoma via the EEA was analyzed. Patient-reported headache severity was collected prospectively using the Headache Impact Test (HIT-6) at preoperative baseline and 4 postoperative time points (3 weeks, 6 weeks, 3 months, and 6 months). RESULTS: Adenoma size and subtype, cavernous sinus invasion, and hormonal status were not associated with preoperative headache burden. In patients with preoperative headaches (HIT-6 score >36), significant decreases in HIT-6 score were observed postoperatively at 6 weeks (5.5-point improvement, 95% CI 1.27-9.78, P < 0.01), 3 months (3.6-point improvement, 95% CI 0.01-7.18, P < 0.05), and 6 months (7.5-point improvement, 95% CI 3.43-11.46, P < 0.01). The only factor associated with headache improvement was cavernous sinus invasion (P = 0.003). Adenoma size and subtype and hormonal status were not associated with postoperative headache burden. CONCLUSIONS: Resection via the EEA is associated with significant improvement in headache-related impact on patient functioning from ≥6 weeks after surgery. Patients with cavernous sinus invasion are more likely to experience improvement in headaches. The mechanism of headaches associated with pituitary adenoma still requires clarification.

Glucocorticoids and Water Balance: Implications for Hyponatremia Management and Pituitary Surgery.

Water balance is fundamental to all homeostasis. The hypothalamic-pituitary-adrenal axis influences water balance through the effects of corticotropin-releasing hormone and cortisol on arginine vasopressin secretion and the peripheral effects of cortisol on hemodynamics and renal water handling. In this review, we explored the complex interplay of glucocorticoids with water balance, with particular attention to hyponatremia and pituitary surgery.

The utility of internal spinal marking for intraoperative localisation: A systematic review.

BACKGROUND: Incorrect level spinal surgery is an avoidable complication, with significant ramifications. Several pre-operative spinal marking techniques have been described to aid intraoperative localisation. METHODS: A systematic search of Ovid MEDLINE, and EMBASE was performed from inception to July 2022. All publications describing cases of internal spinal marking were included for further analysis. 22 articles describing 503 patients satisfied our eligibility criteria. RESULTS: A number of localisation techniques, including endovascular coiling (n = 16), fiducials (n = 177), dye (n = 109), needle/fixed wire (n = 199), cement (n = 4), and gadolinium tubes (n = 1) were described. The highest rates of technical success were observed with endovascular coiling, fiducials, cement and dye (100 %), and complication rates were lowest with endovascular coiling, fiducials and cement (0 %). CONCLUSIONS: Overall, internal spinal marking was effective and safe. When considering practicality and efficacy, fiducial marking appears the optimal technique, as it can be performed in the outpatient setting under local anaesthesia. This review demonstrates the need for more targeted investigation into localisation methods in spinal surgery.

Safety and effectiveness of spinal dural defect repair in the management of superficial siderosis: A systematic review and patient-level analysis.

OBJECTIVE: Superficial siderosis (SS) is a disabling neurodegenerative condition that may be caused by spinal dural defects. Surgical repair is increasingly performed, however clinical outcomes remain unclear. METHODS: A systematic search of PubMed, MEDLINE, and EMBASE was conducted (inception to February 2020). Studies reporting cases of (i) superficial siderosis, (ii) spinal dural defect, (iii) and surgical closure of the defect were included. Demographic characteristics, clinical presentation, operative technique and clinical outcome were extracted for patient-level analysis. RESULTS: A total of 26 publications were included, which reported 38 patients with a median age of 58 years, and a male predominance (78.9 %). Ataxia (85.7 %) and hearing loss (80.0 %) were the most common presenting symptoms. The causative dural defect was most commonly ventral in location (91.7 %) and most commonly identified by CT myelography (48.6 %). Operative technique was highly variable and included primary suture, fibrin glue, dural substitute, or tissue (fat or muscle) graft. Clinical improvement was reported in 21 %, with stabilisation of symptoms in the majority (66 %) and clinical deterioration in 13.2 %. Surgical complications were observed in 7.9 %. CONCLUSION: In patients with superficial siderosis and spinal dural defect, operative closure leads to improvement or stabilisation of symptoms in the vast majority (87%) of patients.

Quality of life and surgical outcomes in incidental pituitary adenomas undergoing endoscopic endonasal resection.

OBJECTIVE: Incidental, asymptomatic pituitary adenomas require nuanced, shared decision-making, which is limited by a poor understanding of their natural history and effects on quality of life (QOL). A greater understanding of the effects of surgery would inform evidence-based care. METHODS: A multicenter review of consecutive pituitary adenomas resected via an endoscopic endonasal approach (EEA) between late 2016 and mid-2021 was performed, with prospective, longitudinal QOL assessment (at 3 and 6 weeks and at 3, 6, and 12 months) postoperatively using the 35-item Anterior Skull Base Questionnaire. RESULTS: Of 366 adenomas resected during the study period, 52 (14.2%) were incidentally discovered, of which 51 (98.1%) were macroadenomas. Preoperative QOL in patients with these incidentalomas was better than in those with adenomas presenting with endocrinopathy (p < 0.01), visual failure (p = 0.02), or headache (p = 0.03). Surgery was performed due to visual field deficits (13.5%, n = 7); ophthalmoplegia (1.9%, n = 1); radiological compression or contact of the optic apparatus (63.5%, n = 33); functional status (growth hormone-secreting tumor) (5.8%, n = 3); and clinically significant growth (15.4%, n = 8). Surgical outcomes were excellent, with vision improved in 100% (7/7) and complete resection in 84.6% (44/52). There were 2 (3.8%) cases of new cortisol deficiency, 3 (5.8%) cases of transient postoperative diabetes insipidus, and 4 (7.7%) cases of postoperative hyponatremia. There were no perioperative complications and no cases of postoperative CSF leakage. QOL transiently decreased during the first 3 weeks after surgery, then improved to above baseline levels by 3 months (p = 0.03) and continued to improve throughout the first postoperative year (p = 0.03). All surgical indications demonstrated an overall mean improvement in QOL at 3 months. QOL benefits were not affected by age or tumor size. CONCLUSIONS: Resection of pituitary adenomas via the EEA provided a tangible benefit for patients within 3 months. Surgery via the EEA is safe, effective, and beneficial for patients with pituitary incidentalomas meeting accepted criteria for intervention.

The HACKD Score-Predicting Extent of Resection of Pituitary Macroadenomas Through an Endoscopic Endonasal Transsphenoidal Approach.

BACKGROUND: Predicting extent of resection before pituitary surgery is imperative for operative planning and patient counseling. In the era of endoscopic endonasal transsphenoidal surgery (EEA), a specific, reliable tool for predicting resection of macroadenomas would have widespread applications. OBJECTIVE: To identify factors that predict resection of pituitary macroadenomas through the EEA. METHODS: A prospectively maintained, multicenter database of 277 consecutive macroadenomas resected through the EEA was analyzed. Multivariate logistic regression identified predictors of gross total resection (GTR). A simple scoring system, the Hardy, Age, Clival, Knosp, Depth (HACKD) Score, was developed and tested. RESULTS: GTR was achieved in 82.3% (228/277) of cases. Older than 50 years (odds ratio [OR] 2.96, P = .01), clival extension (OR 5.87, P < .01), Hardy grade C or D suprasellar extension (OR 3.91, P = .01), Knosp grade 3 or 4 cavernous sinus invasion (OR 7.62, P < .01), and tumor depth >20 mm (OR 5.14, P < .01) were all associated with subtotal resection. The HACKD score, awarding 1 point each for Hardy grade C or D, and older than 50 years, and 2 points each for clival extension, Knosp grades 3 or 4, and tumor depth >20 mm, demonstrated excellent discriminative ability (AUROC 0.887, 95% CI: 0.839-0.934). The rate of GTR progressively decreased with a higher HACKD score. Rates of GTR were 95.8% (182/190) for low (HACKD ≤2), 59.5% (44/74) for moderate (HACKD 3-5), and 15.4% (2/13) for high (HACKD 6+) HACKD scores. CONCLUSION: The HACKD score is a simple and accurate tool based on the largest study analyzing predictors of GTR in pituitary macroadenomas operated through the EEA.

Validation of the anterior skull base questionnaire 35 in endoscopic pituitary adenoma surgery.

Patient quality of life (QOL) is an important metric of surgical success. To guide therapeutic advances in pituitary adenoma surgery, a validated, comprehensive instrument to quantify QOL is required. We aim to evaluate the validity of the 35 item anterior skull base questionnaire (ASBQ-35) in patients undergoing pituitary adenoma surgery. A total of 168 patients undergoing endoscopic resection of pituitary adenomas underwent longitudinal QOL assessment using the ASBQ-35 and the 22-item Sinonasal Outcomes Test (SNOT-22) over the first postoperative year. Validity of the ASBQ-35 was assessed by internal consistency, test-retest reliability, responsiveness to clinical change, and concurrent validity with the SNOT-22. Internal consistency of the ASBQ-35 was excellent, with a Cronbach's alpha > 0.95 across all timepoints. Test-retest reliability between 3 and 6 months (ICC = 0.82, p < 0.001) and 6 months and 12 months (ICC = 0.78, p < 0.001) was robust. Concurrent validity with SNOT-22 was strong across all timepoints (absolute Pearson r ≥ 0.63, p < 0.001). Mean ASBQ-35 scores were significantly worse at 3 weeks compared to preoperative baseline (mean difference - 0.28, p < 0.01); however, by 12 months, scores had significantly improved (mean difference + 0.24, p < 0.01), indicating that the scale is responsive to clinical change. Each of the 6 domains of the ASBQ, and all 35 component questions, contributed to the discriminative of the ASBQ to measure QOL during the first postoperative year. The ASBQ-35 is a valid, comprehensive tool for assessing QOL after endoscopic pituitary adenoma surgery. Each component of the ASBQ-35 contributed to the overall assessment of QOL during the first postoperative year.

Postoperative fluid restriction to prevent hyponatremia after transsphenoidal pituitary surgery: An updated meta-analysis and critique.

BACKGROUND: Hyponatremia is a common and potentially dangerous complication of transsphenoidal surgery. Prophylactic postoperative fluid restriction has been trialled as a method to reduce the incidence of postoperative hyponatremia. METHODS: A systematic review of the literature was performed in accordance with the PRISMA statement. Risk of bias was assessed using the MINORS criteria. Meta-analysis was performed using the random-effects model. RESULTS: A total of 6 retrospective cohort studies were available for analysis. Fluid restriction was commonly between 1000 and 1500 ml/day and limited to the first postoperative week. Overall, the rate postoperative hyponatremia was fourfold less in the fluid restricted cohorts (3.4 % vs 11.2 %, OR 0.24 (95 %CI 0.15-0.38), p < 0.01). There was no difference in readmission rates (1.4 % vs 3.9 %, OR 0.32 (95 %CI 0.09-1.13), p = 0.08) or postoperative diabetes insipidus (14.5 % vs 18.6 %, OR 0.82 (95 %CI 0.50-1.36), p = 0.45) between fluid restricted and control cohorts. CONCLUSION: Prophylactic postoperative fluid restriction is a cheap, easily implemented intervention that appears to reduce the rate of postoperative hyponatremia, but not necessarily re-admission rates. Whether these prevented cases of hyponatremia are clinically significant remains to be demonstrated.

Relationship between herniated intervertebral disc fragment weight and pain in lumbar microdiscectomy patients.

OBJECTIVE: The relationship between lumbar disc herniation (LDH) size and the severity of preoperative pain and its impact on postoperative recovery is incompletely understood. This study was conducted to investigate the association between herniated disc fragment weight and pain before and after microdiscectomy. METHODS: A consecutive series of patients from an ongoing randomised controlled trial (ACTRN12616001360404) were included in this study. Included patients were aged between 18 and 75, had a clinical diagnosis of radiculopathy, and MRI evidence of a concordant single-level lumbar disc herniation. All patients underwent standard microdiscectomy without aggressive discectomy or curettage of the endplates. Disc fragment weight was measured intraoperatively. RESULTS: A total of 122 patients with a mean age of 49.5 ± 12.8 years, were included. The median weight of disc fragment was 0.545 g (95% CI 0.364 - 0.654 g). There was no relationship between disc weight and the duration of symptoms (p = 0.409) severity of preoperative leg pain (p = 0.070) or preoperative back pain (p = 0.884). Disc fragment weight was demonstrated to have no correlation with clinically significant postoperative leg pain improvement (p = 0.535) or back pain (p = 0.991). Additional LDH factors, including radiological percentage of canal compromise (p = 0.714), herniation classification (p = 0.462), and vertebral level (p = 0.788) were also shown to have no effect on leg pain outcomes. CONCLUSIONS: Disc fragment weight had no effect on the severity of pain at presentation or after microdiscectomy. Patients benefit from surgery equally, regardless of the size of LDH.

Quality of Life in Craniopharyngioma: A Systematic Review.

BACKGROUND: Craniopharyngiomas are morbid tumors that significantly reduce patients' quality of life (QoL). The lifelong burden of endocrine, visual, hypothalamic, and limbic dysfunction can have disastrous consequences for the physical and psychosocial health of patients. Elucidating the factors that influence QoL could guide therapeutic interventions to improve patient well-being. METHODS: A systematic review was performed in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement using the PubMed and Medline databases. Studies that had reported patient QoL using validated metrics in both adult and pediatric populations were included. Bias and methodological rigor were assessed using the MINORS (methodological index for nonrandomized studies) criteria. RESULTS: A total of 25 studies, including 2025 patients, were available for review. Most studies were small, retrospective, cohort studies with a high risk of bias. The QoL of the patients with craniopharyngioma was lower than that of the general population. Hypothalamic involvement was consistently the strongest predictor of QoL. Endocrinopathy contributed to morbidity but could be ameliorated by hormone replacement therapy. Social and emotional dysregulation and a poor memory are common complaints after surgery, and iatrogenic damage to the infundibulum, hypothalamus, limbic system, and frontal lobes might underlie these concerns. Sleep-wake cycle dysfunction and hypothalamic obesity are serious consequences of hypothalamic damage. CONCLUSIONS: An experienced multidisciplinary team is necessary to optimally manage the complex cases of these patients. The poor QoL of patients with craniopharyngioma is multifactorial. However, the contribution of iatrogenesis is not insubstantial. Improved surgical techniques, focusing on hypothalamic preservation, and adjuvant treatment options are required to improve the well-being of these patients.