Interpretable Machine Learning–Based Prediction of Intraoperative Cerebrospinal Fluid Leakage in Endoscopic Transsphenoidal Pituitary Surgery: A Pilot Study

Purpose Transsphenoidal surgery (TSS) for pituitary adenomas can be complicated by the occurrence of intraoperative cerebrospinal fluid (CSF) leakage (IOL). IOL significantly affects the course of surgery predisposing to the development of postoperative CSF leakage, a major source of morbidity and mortality in the postoperative period. The authors trained and internally validated the Random Forest (RF) prediction model to preoperatively identify patients at high risk for IOL. A locally interpretable model-agnostic explanations (LIME) algorithm is employed to elucidate the main drivers behind each machine learning (ML) model prediction. Methods The data of 210 patients who underwent TSS were collected; first, risk factors for IOL were identified via conventional statistical methods (multivariable logistic regression). Then, the authors trained, optimized, and audited a RF prediction model. Results IOL reported in 45 patients (21.5%). The recursive feature selection algorithm identified the following variables as the most significant determinants of IOL: Knosp's grade, sellar Hardy's grade, suprasellar Hardy's grade, tumor diameter (on X, Y, and Z axes), intercarotid distance, and secreting status (nonfunctioning and growth hormone [GH] secreting). Leveraging the predictive values of these variables, the RF prediction model achieved an area under the curve (AUC) of 0.83 (95% confidence interval [CI]: 0.78; 0.86), significantly outperforming the multivariable logistic regression model (AUC = 0.63). Conclusion A RF model that reliably identifies patients at risk for IOL was successfully trained and internally validated. ML-based prediction models can predict events that were previously judged nearly unpredictable; their deployment in clinical practice may result in improved patient care and reduced postoperative morbidity and healthcare costs.

Endoscopic Endonasal Intraconal Approach for Orbital Tumor Resection: Case Series and Systematic Review

Intraorbital tumor could be approached by numerous surgical methods. The neuroendoscopic endonasal approach could provide a feasible corridor for indicated tumors. Herein we present a series of 6 consecutive intraorbital tumors from April 2018 to October 2020, which received endonasal endoscopic resection. Cadaveric dissection was performed for the intraconal approach, and the literature was also reviewed. Five tumors were located intraconally, while one extraconally. The pathology revealed 1 angioleiomyoma, 1 cavernous hemangioma, 1 pilocytic astrocytoma, 1 meningioma, and 2 schwannomas. Five of the six achieved gross total resection, including 3 tumors with lateral extension beyond the optic nerve. Preoperative visual deterioration was observed in 4 of the 6 patients, and all got improvement postoperatively. Transient oculomotor nerve palsy was presented in one patient postoperatively. No cerebrospinal fluid leakage, enophthalmos, or strabismus was observed. The median follow-up time is 27 months (11~41 months). At the 6-month follow-up, the visual acuity remained unchanged compared with that at discharge. Proptosis was resolved in 2 of the 3 patients; diplopia was improved in one patient. In conclusion, endoscopic endonasal intraconal approach could be suitable for selected pathological conditions, and for both medial or beyond medial extraconal and intraconal orbital tumors.

Greater occipital nerve blockade using ultrasound guidance for the headache of spontaneous intracranial hypotension - A case report -

BackgroundSpontaneous intracranial hypotension occurs due to cerebrospinal fluid leakage from the spinal column, and orthostatic headache is the most common clinical presentation. Recent studies showed that bilateral greater occipital nerve blockade demonstrated clinical efficacy in relieving post-dural puncture headache after caesarean section. CaseA 40-year-old male who presented severe orthostatic headache was consulted to our pain clinic from neurology department. He initially felt a dull nature pain over the whole occipital area which then spread over the frontal and parietal areas. His headache was combined with nausea and vomiting. An epidural blood patch was delayed until final cisternography, and bilateral greater occipital nerve blockade using ultrasound guidance was performed instead. After the blockade, the previously existing headache around the occipital and parietal areas disappeared completely, but mild headache persisted around the frontal area.ConclusionsGreater occipital nerve blockade could be a good therapeutic alternative to improve headache resulting from spontaneous intracranial hypotension.

Polymethylmethacrylate-augmented Cannulated Pedicle Screw Fixation for High-energy Vertebral Compression Fracture with Osteoporosis

Background: High-energy vertebral compression fractures (HVCFs) with osteoporosis puts forward higher requirement for the stability of pedicle screw internal fixation system. However, few studies have concentrated on the clinical outcomes of cannulated pedicle screw to augment fixation with polymethylmethacrylate (PMMA) under this condition. This study aims to investigate the mid-term efficacy of bone cement-injectable cannulated pedicle screw (CICPS) in HVCFs with osteoporosis.Methods: Eighteen patients with HVCFs (T < -2.5) were underwent spinal fixation by CICPS from 2012 to 2017. The operation time, blood loss, and hospitalization time were recorded. Pain and functional recovery were evaluated by Visual Analog Scale VAS) and Oswestry Disability Index (ODI), respectively. X-ray films were taken to evaluate the loss of vertebral height, kyphosis angle, pedicle screw loosening, and bony fusion. Surgical related complications were also recorded.Results: The average follow-up time was 18.5 ± 8.7 months (range, 6-54 months). VAS and ODI scores indicated significant improvements in postoperative pain and activity function (P < 0.05). Comparing the last follow-up with the postoperative imaging findings, the loss of vertebral height and kyphosis angle was 3.4 ± 1.2 mm and 7.8 ± 3.8°, respectively. The rate of bone graft fusion was 100% while no case was involved in screw loosening or extraction. 1 case of superficial infection, 2 cases of PMMA leakage, and 1 case of cerebrospinal fluid leakage were found.Conclusions: CICPS fixation using PMMA augmentation may be suggested as a feasible surgical technique in osteoporotic patients with HVCFs.

Bioresorbable plate fracture after cranioplasty caused by head injury: a pediatric case

Background Recently, bone fixation materials have been developed as surgical materials. Bioabsorbable materials offer several advantages over other materials and are widely used. We report a rare case of the fracture of bioresorbable plates caused by head injury and describe some considerations. Case description A 6-year-old boy suffered from consciousness disturbance. He was admitted to our hospital and diagnosed with left frontal subcortical hemorrhage due to ruptured arteriovenous malformation (AVM). He received the surgery of removal of the AVM with decompressive craniectomy. He was discharged without any neurologic deficit and underwent the cranioplasty 4 months after the initial surgery. Two months after the last treatment, he was fallen and hit his left frontal head. The next day, he noticed an abnormal bulge in the injured area. We diagnosed the bulging as cerebrospinal fluid leakage because of the dural tear. The repairment of dural tear was performed. We found that two bioresorbable plates used by cranioplasty were both cracked, and the dura mater beneath them was torn. We repaired the damaged dura with an artificial dura mater. After surgery, cerebrospinal fluid leakage did not occur. Conclusion It has been reported that the durability of bioresorbable plates is no less than that of titanium plates. We experienced a relatively rare case in which bioabsorbable plate used for bone fixation was damaged due to head trauma. After craniotomy or cranioplasty using bioresorbable plates, special attention should be paid to head trauma that involves bone flap sinking force and side bending stress.

Surgical Treatment and Clinical Outcomes of Petroclival Meningiomas: A Single-Center Experience of 107 Patients

ObjectiveThis study aimed to establish optimal surgical strategies via reviewing the clinical outcomes of various surgical approaches for the pertroclival meningiomas (PCMs).MethodsThis retrospective study enrolled 107 patients with PCMs at the authors’ institution from year 2010 to 2020. Patient demographics, the clinical characteristics, various operative approaches, major morbidity, post-operative cranial nerve deficits and tumor progression or recurrence were analyzed.ResultsThe subtemporal transtentorial approach (STA), the Kawase approach (KA), the retrosigmoid approach (RSA) and the anterior sigmoid approach (ASA), namely the posterior petrosal approach (PPA) were adopted for 17 cases, 22 cases, 31 cases and 34 cases respectively. Total or subtotal resection was achieved in 96 cases (89.7%). The incidence of new-onset and aggravated cranial nerve dysfunction were 13.1% (14/107) and 10.4% (15/144), respectively. Furthermore, 14 cases suffered from intracranial infection, 9 cases had cerebrospinal fluid leakage, and 3 cases sustained intracranial hematoma (1 case underwent second operation). The mean preoperative and postoperative Karnofsky Performance Status (KPS) score was 80 (range 60-100) and 78.6 (range 0-100), but this was not statistically significant (P&gt;0.05). After a mean follow-up of 5.1 years (range 0.3- 10.6 years), tumor progression or recurrence was confirmed in 23 cases. Two cases died from postoperative complications.ConclusionsFor the treatment of PCMs, it is still a challenge to achieve total resection. With elaborate surgical plans and advanced microsurgical skills, most patients with PCMs can be rendered tumor resection with satisfactory extent and functional preservation, despite transient neurological deterioration during early postoperative periods.

Magnetic resonance imaging predicted the therapeutic response of patients with spinal cerebrospinal fluid leakage undergoing targeted epidural blood patch

Objectives: Most patients with spinal cerebrospinal fluid (CSF) leakage require an epidural blood patch (EBP); however, the response to treatment is varied. This study aimed to compare the magnetic resonance imaging (MRI) findings at follow-up between EBP effective and non-effective groups and to identify imaging findings that predict EBP treatment failure. Methods: We retrospectively reviewed 48 patients who received EBP treatment for spinal CSF leakage. These patients were stratified into two groups: EBP effective (n = 27) and EBP non-effective (n = 21) using the results of the 3 month MRI as the endpoint. Results: Compared to the EBP non-effective group, the patients in the EBP effective group had a lower spinal CSF leakage number (2.67 vs 12.48; p = 0.001), lower spinal epidural fluid accumulation levels (3.00 vs 7.48; p = 0.004), brain descend (11.11% vs 38.10%; p = 0.027), pituitary hyperemia (18.52% vs 57.14%; p = 0.007), and decreased likelihood of ≥three numbers of spinal CSF leakage (25.93% vs 90.48%; p = 0.001) in the post-EBP MRI. Clinical non-responsiveness (OR: 57.84; 95% CI: 3.47–972.54; p = 0.005) and ≥three numbers of spinal CSF leakage (OR: 15.13; 95% CI: 1.45–159.06; p = 0.023) were associated with EBP failure. Between these variables,≥three numbers of spinal CSF leakage identified using the post-EBP MRI demonstrated greater sensitivity in predicting EBP failure compared to clinical non-responsiveness (90.48% vs 61.9%). Conclusion: The number of spinal CSF leakage identified using the post-EBP MRI with a cut-off value of three is an effective predictor of EBP failure. Advances in knowledge: Compared to clinical responsiveness, the post-EBP MRI provided a more objective approach to predict the effectiveness of EBP treatment in patients with spinal CSF leakage.