Pharmaceutical equivalent 5-aminolevulinic acid fluorescence guided resection of central nervous system tumors: feasibility, safeness and cost-benefit considerations.

PURPOSE: 5-aminolevulinic acid (5-ALA) fluorescence-guided resection (FGR) has been an essential tool in the 'standard of care' of malignant gliomas. Over the last two decades, its indications have been extended to other neoplasms, such as metastases and meningiomas. However, its availability and cost-benefit still pose a challenge for widespread use. The present article reports a retrospective series of 707 cases of central nervous system (CNS) tumors submitted to FGR with pharmacological equivalent 5-ALA and discusses financial implications, feasibility and safeness. METHODS: From December 2015 to February 2024, a retrospective single institution series of 707 cases of 5-ALA FGR were analyzed. Age, gender, 5-ALA dosage, intraoperative fluorescence finding, diagnosis and adverse effects were recorded. Financial impact in the surgical treatment cost were also reported. RESULTS: there was an additional cost estimated in $300 dollars for each case, increasing from 2,37 to 3,28% of the total hospitalization cost. There were 19 (2,69%) cases of asymptomatic photosensitive reaction and 2 (0,28%) cases of photosensitive reaction requiring symptomatic treatment. 1 (0,14%) patient had a cutaneous rash sustained for up to 10 days. No other complications related to the method were evident. In 3 (0,42%) cases of patients with intracranial hypertension, there was vomiting after administration. CONCLUSION: FGR with pharmacological equivalent 5-ALA can be considered safe and efficient and incorporates a small increase in hospital expenses. It constitutes a reliable solution in avoiding prohibitive costs worldwide, especially in countries where commercial 5-ALA is unavailable.

Toward an optimal cadaveric brain model for neurosurgical education: assessment of preservation, parenchyma, vascular injection, and imaging.

OBJECTIVE: We assessed types of cadaveric head and brain tissue specimen preparations that are used in a high throughput neurosurgical research laboratory to determine optimal preparation methods for neurosurgical anatomical research, education, and training. METHODS: Cadaveric specimens (N = 112) prepared using different preservation and vascular injection methods were imaged, dissected, and graded by 11 neurosurgeons using a 21-point scale. We assessed the quality of tissue and preservation in both the anterior and posterior circulations. Tissue quality was evaluated using a 9-point magnetic resonance imaging (MRI) scale. RESULTS: Formalin-fixed specimens yielded the highest scores for assessment (mean ± SD [17.0 ± 2.8]) vs. formalin-flushed (17.0 ± 3.6) and MRI (6.9 ± 2.0). Cadaver assessment and MRI scores were positively correlated (P < 0.001, R2 0.60). Analysis showed significant associations between cadaver assessment scores and specific variables: nonformalin fixation (ß = -3.3), preservation within ≤72 h of death (ß = 1.8), and MRI quality score (ß = 0.7). Formalin-fixed specimens exhibited greater hardness than formalin-flushed and nonformalin-fixed specimens (P ≤ 0.006). Neurosurgeons preferred formalin-flushed specimens injected with colored latex. CONCLUSION: For better-quality specimens for neurosurgical education and training, formalin preservation within ≤72 h of death was preferable, as was injection with colored latex. Formalin-flushed specimens more closely resembled live brain parenchyma. Assessment scores were lower for preparation techniques performed > 72 h postmortem and for nonformalin preservation solutions. The positive correlation between cadaver assessment scores and our novel MRI score indicates that donation organizations and institutional buyers should incorporate MRI as a screening tool for the selection of high-quality specimens.

PEG hydrogel sealant versus fibrin glue in posterior fossa surgery: an economic comparison across five European countries.

Aim: Posterior cranial fossa (PCF) surgery is associated with complications, including cerebrospinal fluid (CSF) leakage. Dural sealants such as polyethylene glycol (PEG)-based hydrogels and fibrin glue can prevent CSF leaks, with evidence suggesting PEG hydrogels may outperform fibrin glue. However, the budget impact of using PEG hydrogels in PCF surgeries in Europe is unclear. Materials & methods: A decision tree was developed based on a previous US model, to assess the budget impact of switching from fibrin glue to PEG hydrogel in PCF surgery across five European countries. Input costs were derived from published sources for the financial year 2022/2023. Health outcomes, including CSF leaks, were considered. Results: The model predicted that using PEG hydrogel instead of fibrin glue in PCF surgery can lead to cost savings in five European countries. Cost savings per patient ranged from EUR 419 to EUR 1279, depending on the country. Sensitivity analysis showed that the incidence of CSF leaks and pseudomeningoceles had a substantial impact on the model's results. Conclusion: PEG hydrogels may be a cost-effective alternative to fibrin glue in PCF surgery. The model predicted that cost savings would be mainly driven by a reduction in the incidence of postoperative CSF leaks, resulting in reduced reliance on lumbar drains, reparative surgery and shortened hospital stays.

Prototype of Low-Cost Microvascular Clips for Laboratory Use.

BACKGROUND: Vascular neurosurgical procedures require temporary or permanent surgical clips to treat cerebral aneurysms, arteriovenous malformations, or bypass surgery. In this scenario, surgical clips should have specific characteristics such as high-quality material, proper design, closing force, and biocompatibility. Due to these characteristics, the price of these clips does not allow their availability at the experimental surgery laboratory worldwide. METHODS: We describe here the technique for manufacturing handcrafted clips of low cost, using dental stainless steel or titanium wire of 0.18 mm, 0.20 mm, or 0.22 mm in diameter. We must complete six steps to obtain the clip using our hands and small electrician needle nose pliers for wire molding. RESULTS: These clips have a closing force of 30-60 gr/cm2 (depending on the wire diameter). They can be used in the experimental surgery laboratory to clip arteries or veins during vascular microsurgery procedures. Also, they can be used as temporary clips with confidence in low-flow bypass (v.gr. superficial temporal artery to middle cerebral artery or occipital artery to posterior inferior cerebellar artery anastomoses). CONCLUSIONS: Making practical low-cost clips for use in laboratory procedures or during low-flow anastomosis as temporary clips is possible. The main advantages are the low cost and the worldwide availability of the basic materials. The main disadvantage is the learning curve to get the ability to master the manufacturing of these clips.

Pediatric neurosurgery through the lens of time-driven activity-based costing: a pilot study.

OBJECTIVE: Time-driven activity-based costing (TDABC) is a method used in cost accounting that has gained traction in health economics to identify value optimization initiatives. It measures time, assigns value to time increments spent on a patient, and integrates the cost of material and human resources utilized in each episode of care. In this study, the authors report the first use of TDABC to evaluate costs in a pediatric neurosurgical practice. METHODS: A clinical pathway was developed with a multifunction team. A time survey among each care team member, including surgeons, medical assistants (MAs), and patient service representatives (PSRs), was carried out prospectively over a 10-week period at a pediatric neurosurgery clinic. Consecutive patient encounters for Chiari malformation (CM), hydrocephalus, or tethered cord syndrome (TCS) were included. Encounters were categorized as new or established. Relative annual personnel costs, using the salary of a PSR as a reference (i.e., 1.0-unit cost), were calculated for all members using departmental financial data after adjustments. The relative capacity cost rates (minute-1) for each personnel, a representation of per capita cost per minute, were then derived, and the relative costs per visit were calculated. RESULTS: A total of 110 visits (24 new, 86 established) were captured, including 40% CM, 41% hydrocephalus, and 19% TCS encounters. Surgeons had the highest relative capacity cost rate (118.4 × 10-6), more than 10-fold higher than that of an MA or PSR (10.65 × 10-6 and 9.259 × 10-6, respectively). Surgeons also logged more time with patients compared with the rest of the care team in nearly all visits (p ≤ 0.002); consequently, the total visit costs were primarily driven by the surgeon cost (p < 0.0001). Overall, surgeon cost constituted the vast majority of the total visit cost (92%-93%), regardless of whether the visits were new or established. Visit costs did not differ by diagnosis. On average, new visits took longer than established visits (p < 0.001). This difference was largely driven by new CM visits (44.3 ± 13.7 minutes), which were significantly longer than established CM visits (29.8 ± 9.2 minutes; p = 0.001). CONCLUSIONS: TDABC may reveal opportunities to maximize value by highlighting instances of variability and high cost in each module of care delivery. Physician leaders in pediatric neurosurgery may be able to use this information to allocate costs and streamline value care pathways.

Training in Skull Base Endonasal Endoscopic Surgery: Development and Validation of a Novel Low-Cost Simulation with Animal Cadaveric Model.

BACKGROUND: Endoscopic skull base surgery is constantly evolving and its scope has expanded. The acquisition of surgical skills involves a long learning curve with significant risks for the patient. Therefore, training in the laboratory has become essential to achieve appropriate proficiency and reduce the morbidity and mortality associated with these procedures. The objective of our work is to develop and validate a cost-effective and easily replicable simulator for endonasal endoscopy training using a swine cadaveric model. METHODS: We used fresh Pietrain swine heads. Training exercises of increasing complexity were performed. A Specific Technical Skills and Knowledge Scale was created considering the objectives to be assessed in each task. After the simulation, the trainees were required to answer a satisfaction survey. RESULTS: Ten participants were recruited (5 neurosurgery residents and 5 neurosurgeons). The simulator assessment showed statistically significant differences between groups. Performance was better among the group with endoscopic surgery experience. Face validity was assessed through a postsimulation questionnaire showing an overall mean score of 28.7 out of 30, indicating a highly positive overall assessment of the simulator. Furthermore, 100% of the trainees believe that including endoscopy training in their education would be beneficial. CONCLUSIONS: The endonasal endoscopy training simulator using a swine cadaveric model is a useful and accessible tool for enhancing surgical skills in this field. It provides an opportunity for training outside the operating room, reducing the potential risks associated with patient practice, and improving the training of residents.

Arachnoid Welding-A Simple and Economical Method of Arachnoid Closure to Prevent Cerebrospinal Fluid Leak.

BACKGROUND: Collection of cerebrospinal fluid (CSF) in the subdural compartment is a major cause of postoperative morbidity, especially for posterior fossa surgeries. Arachnoid closure techniques, including suturing of the arachnoid and use of synthetic sealants, have been described in the literature. However, they are not always feasible or effective and have not been universally adopted. METHODS: We describe the technique of arachnoid welding for a case of brainstem cavernoma. This is a simple, cost-effective, and easily reproducible technique using readily available bipolar cautery kept at a low-current setting. At the end of surgery, the arachnoid leaflets are closely approximated, and bipolar cautery is used to seal the edges together. An illustrative video shows the technical nuances of this procedure. This technique can also be applied for arachnoid closure at other cranial and spinal sites. RESULTS: Arachnoid closure can act as an effective natural barrier to keep CSF in its physiological subarachnoid compartment. It provides an additional barrier to prevent CSF leak. It also prevents morbidity associated with adhesions and arachnoiditis. Proper closure of arachnoid makes durotomy during repeat surgery much easier and avoids injury to the underlying pia. A brief review of related literature shows the benefits of closing the arachnoid before dural closure and the different techniques that have been described so far. CONCLUSIONS: The arachnoid welding technique has a wide application, is easy to learn, and can be used especially for posterior fossa surgeries in which rates of CSF leak are the highest.

Assessment of jugular bulb variability based on 3D surface models: quantitative measurements and surgical implications.

PURPOSE: High-riding jugular bulbs (JBs) among other anatomical variations can limit surgical access during lateral skull base surgery or middle ear surgery and must be carefully assessed preoperatively. We reconstruct 3D surface models to evaluate recent JB classification systems and assess the variability in the JB and surrounding structures. METHODS: 3D surface models were reconstructed from 46 temporal bones from computed tomography scans. Two independent raters visually assessed the height of the JB in the 3D models. Distances between the round window and the JB dome were measured to evaluate the spacing of this area. Additional distances between landmarks on surrounding structures were measured and statistically analyzed to describe the anatomical variability between and within subjects. RESULTS: The visual classification revealed that 30% of the specimens had no JB, 63% a low JB, and 7% a high-riding JB. The measured mean distance from the round window to the jugular bulb ranges between 3.22 ± 0.97 mm and 10.34 ± 1.41 mm. The distance measurement (error rate 5%) was more accurate than the visual classification (error rate 15%). The variability of the JB was higher than for the surrounding structures. No systematic laterality was found for any structure. CONCLUSION: Qualitative analysis in 3D models can contribute to a better spatial orientation in the lateral skull base and, thereby, have important implications during planning of middle ear and lateral skull base surgery.

Micromirrors in Neurosurgery: Technical Overview and Benefits Assessment.

AIM: To weight the benefits and limitations of intraoperative use of micromirrors in neurosurgery. MATERIAL AND METHODS: Surgical cases where micromirrors were employed were retrospectively selected from the surgical database of five different surgeons in different hospitals. Complications directly attributable to the micromirrors were assessed intraoperatively and confirmed with postoperative neuroimaging studies. RESULTS: Fourteen patients were selected. The site of the lesion was as follows: posterior fossa (43%), frontal lobe (22%), temporal lobe (14%), parietal lobe (7%), insula (7%), and basal ganglia (7%). Five tumors (35%) were gliomas, 3 (21%) epidermoid, and 3 (21 %) supratentorial metastases. Two patients underwent microvascular decompression for neurovascular conflict, and 1 harbored a brain arteriovenous malformation. A gross total resection was achieved in all the tumors and the AVM, while an effective decompression was successfully performed in both patients with conflict. No complications directly attributable to the use of the micromirror occurred. A relatively easy learning curve was noted. CONCLUSION: Micromirrors proved to be useful in enhancing the visualization of neurovascular structures and pathology residuals within deep-seated surgical fields without the need for fixed brain retraction. Their cost-effectiveness and easy learning curve constitute solid reasons for advocating a revitalization of this ?old but gold? tool in neurosurgery.

Retrosigmoid versus Retrolabyrinthine Posterior Petrosal Route to the Petroclival Area: Quantitative Assessment of Endoscope-Assisted Approaches and Correlations with Morphometric Features.

OBJECTIVE: Using a cadaveric model, we compared endoscope-assisted retrosigmoid (EAR) and endoscope-assisted retrolabyrinthine posterior petrosal (EARPP) approaches towards the petroclival area, regarding surgical exposure and instrument maneuverability, also verifying how some petroclival morphometric parameters correlate with these variables. METHODS: In five cadaver heads, EAR approach was performed on one side and EARPP on the other (10 approaches). Under endoscopic view, neuronavigation coordinates were acquired to compute areas of exposure (petroclival and pontomedullary) and maneuverability at Dorello's canal entrance to run the comparison. Correlations of these variables with petroclival angle and clival depth were also analyzed. RESULTS: EAR and EARPP showed equivalence regarding surgical exposure (petroclival: 365.85 ± 133.12 mm2 and 320.62 ± 103.44 mm2, respectively, P = 0.69; pontomedullary: 255.83 ± 88.26 mm2 and 229.80 ± 74.39 mm2, respectively, P = 0.83), but EAR afforded greater maneuverability at Dorello's canal (1155.88 ± 134.35 mm2, P = 0.03). The petroclival angle and clival depth showed different strong correlations with maneuverability depending upon the route, but not with surgical exposure in both approaches. CONCLUSIONS: Endoscopic techniques can spare the need for additional steps of greater morbidity when approaching the petroclival area in both routes. A simpler and faster approach as EAR was favored over EARPP in this standardized quantitative assessment. The petroclival angle and clival depth may interfere with maneuverability, but not with surgical exposure in both endoscope-assisted approaches.

Endovascular treatment and neurosurgical clipping in subarachnoid hemorrhage: a systematic review of economic evaluations.

INTRODUCTION: There are two treatment modalities for aneurysmal subarachnoid hemorrhage: endovascular treatment (EVT) and neurosurgical clipping. Results of economic evaluations are needed to gain insight into the relationship between clinical effectiveness and costs of these treatment modalities. This important information can inform both clinical decision-making processes and policymakers in facilitating Value-Based Healthcare. EVIDENCE ACQUISITION: Databases (PubMed, Embase, Cochrane Library, the Centre for Reviews and Dissemination, EBSCO, and Web of Science) were searched for studies published until October 2020 that had performed economic evaluations in aneurysmal subarachnoid hemorrhage patients by comparing EVT with neurosurgical clipping. The quality of reporting and methodology of these evaluations was assessed using the associated instruments (i.e. CHEERS statement and CHEC-list, respectively). EVIDENCE SYNTHESIS: A total of 6 studies met the inclusion criteria. All included studies reported both effects and costs, however five did not relate effects to costs. Only one study related effects directly to costs, thus conducted a full economic evaluation. The reporting quality scored 81% and the methodological quality scored 30%. CONCLUSIONS: The quality of published cost-effectiveness studies on the treatment of aneurysmal subarachnoid hemorrhage is poor. Six studies reported both outcomes and costs, however only one study performed a full economic evaluation comparing EVT to neurosurgical clipping. Although the reporting quality was sufficient, the methodological quality was poor. Further research that relates health-related quality of life measures to costs of EVT and neurosurgical clipping is required - specifically focusing on both reporting and methodological quality. Different subgroup analyses and modeling could also enhance the findings.

A Low-Cost Mobile Training Model for Biportal Endoscopic Spinal Surgery.

AIM: To design a practical, low-cost, and freely mobile training model for biportal endoscopic spine surgery to improve the surgeons? abilities in basic endoscopic skills, including triangulation, two-dimensional visualization, and one-handed control of the instruments. MATERIAL AND METHODS: The training model involved three stages: triangulation, drilling, and punching. It was composed of sawbones covered by solid and impenetrable materials (a cardboard box was used), monitor (laptop or mobile phone), and hand tools, including an ear endoscope cameras for mobile phone and laptop, Dremel® style + rotary tool at 22000 rpm, Dremel® 2.0-mm diamond wheel point burr, Kerrison punch, No.11 blade, 18 G spinal needle, and mobile phone holder. RESULTS: The model was set up with easily accessible materials and could be performed everywhere. It can also be used to perform laminotomy on sawbones using a high-speed diamond burr and Kerrison punch under a two-dimensional endoscopic view. CONCLUSION: The training model can be useful in improving the endoscopic skills of all spine surgeons, particularly neurosurgeons and those who have little to no experience in endoscopic procedures. Additionally, it can provide familiarity on two-dimensional endoscopic views and triangulation.

Seven bypasses simulation set: description and validity assessment of novel models for microneurosurgical training.

OBJECTIVE: Microsurgical training remains indispensable to master cerebrovascular bypass procedures, but simulation models for training that accurately replicate microanastomosis in narrow, deep-operating corridors are lacking. Seven simulation bypass scenarios were developed that included head models in various surgical positions with premade approaches, simulating the restrictions of the surgical corridors and hand positions for microvascular bypass training. This study describes these models and assesses their validity. METHODS: Simulation models were created using 3D printing of the skull with a designed craniotomy. Brain and external soft tissues were cast using a silicone molding technique from the clay-sculptured prototypes. The 7 simulation scenarios included: 1) temporal craniotomy for a superficial temporal artery (STA)-middle cerebral artery (MCA) bypass using the M4 branch of the MCA; 2) pterional craniotomy and transsylvian approach for STA-M2 bypass; 3) bifrontal craniotomy and interhemispheric approach for side-to-side bypass using the A3 branches of the anterior cerebral artery; 4) far lateral craniotomy and transcerebellomedullary approach for a posterior inferior cerebellar artery (PICA)-PICA bypass or 5) PICA reanastomosis; 6) orbitozygomatic craniotomy and transsylvian-subtemporal approach for a posterior cerebral artery bypass; and 7) extended retrosigmoid craniotomy and transcerebellopontine approach for an occipital artery-anterior inferior cerebellar artery bypass. Experienced neurosurgeons evaluated each model by practicing the aforementioned bypasses on the models. Face and content validities were assessed using the bypass participant survey. RESULTS: A workflow for model production was developed, and these models were used during microsurgical courses at 2 neurosurgical institutions. Each model is accompanied by a corresponding prototypical case and surgical video, creating a simulation scenario. Seven experienced cerebrovascular neurosurgeons practiced microvascular anastomoses on each of the models and completed surveys. They reported that actual anastomosis within a specific approach was well replicated by the models, and difficulty was comparable to that for real surgery, which confirms the face validity of the models. All experts stated that practice using these models may improve bypass technique, instrument handling, and surgical technique when applied to patients, confirming the content validity of the models. CONCLUSIONS: The 7 bypasses simulation set includes novel models that effectively simulate surgical scenarios of a bypass within distinct deep anatomical corridors, as well as hand and operator positions. These models use artificial materials, are reusable, and can be implemented for personal training and during microsurgical courses.

Subpial technique in supratentorial glioma resection: state of the art and analysis of costs and effectiveness in a single institute experience.

BACKGROUND: Many neurosurgeons advocate subpial technique as the best technique to remove supratentorial gliomas. However, few authors clearly defined advantages and features of this technique. The aim of our study is to describe microsurgical subpial technique related to glioma surgery, with regard to its safety and cost effectiveness. METHODS: We analyzed retrospectively all consecutive patients surgically treated for supratentorial glioma from January 2017 to April 2018 at Neurosurgery Department of Neuromed Institute. All patients underwent to surgical glioma resection performing microsurgical subpial technique. Extent of resection and neurological complications were evaluated as primary outcomes; Karnofsky Performance Status and postoperative edema extent were secondary outcomes. Statistical analysis was obtained. RESULTS: The study included 70 patients. Gross Total Removal was obtained in 91.3% of patients with low grade glioma (LGG) and in 81% of patients with high grade glioma. Neurological complications amounted to 34% at early assessment in LGG patients, which were permanent at 3 months in 17% of patients. In high grade glioma patients, neurological complications amounted to 51% at early assessment, which were permanent at 3 months in 25% of them. CONCLUSIONS: We obtained good postoperative results with regard to the extent of tumor resection using this technique. Subpial resection is an effective surgical technique to get a safer and more complete tumor resection. It should be combined with other modern neurosurgical tools such as neuronavigation, ultrasound and cortical mapping to obtain the best tumor resection and functional neurological preservation.

A Cost-Effective, Adjustable, Dynamic Subcortical Stimulation Device - Technical Note.

Brain mapping and neuromonitoring remain the gold standard for identifying and preserving functional neuroanatomic regions during safe, maximal brain tumor resection. Subcortical stimulation (SCS) can identify white matter tracts and approximate their distance from the leading edge of an advancing resection cavity. Dynamic (continuous) devices permitting simultaneous suction and stimulation have recently emerged as time-efficient alternatives to traditional static (discontinuous) techniques. However, the high cost, fixed cap size, and fixed tube diameter of commercially available suction devices preclude universal adoption. Our objective is to modify available suction devices into monopolar probes for subcortical stimulation mapping. We describe our technique using a novel, cost-effective, dynamic SCS technique as part of our established neuromonitoring protocol. We electrified and insulated a conventional variable suction device using an alligator clip and red rubber catheter, respectively. We adjusted the catheter's length to expose metal on both sides, effectively converting the suction device into a monopolar stimulation probe capable of cortical and subcortical monopolar stimulation that does not differ from commercially available discontinuous or continuous devices. We fashioned a dynamic SCS suction probe using inexpensive materials compatible with all suction styles and sizes. Qualitative and quantitative analysis in future prospective case series is needed to assess efficacy and utility.

Cost-Effectiveness Analysis of the Application of a Porcine-Derived Fibrin Sealant for the Treatment of Cerebrospinal Fluid Leak in China.

PURPOSE: This study aimed to evaluate the cost-effectiveness of a porcine-derived fibrin sealant (PFS) for treating cerebrospinal fluid (CSF) leaks in cranial surgery compared with sutures alone from the perspective of public hospital management in China. METHODS: A decision tree model of cranial surgery patients with intraoperative CSF leak was constructed in R 3.6.3. The cost-effectiveness of using PFS with dural sutures was compared versus using sutures alone. Efficacy and safety data were obtained from a randomized controlled, single-blinded clinical trial that enrolled 200 patients (NCT03110783). Effectiveness was measured as the success rate of CSF leak treatment and the rate of postoperative complication. Hospital procurement costs were used to provide cost measurements from the hospital administrator's perspective. FINDINGS: The PFS strategy had a higher success rate of CSF leak treatment (97.81% vs 49.21%) and a lower complication rate (9.49% vs 14.29%), based on results from the clinical trial. Using PFS also resulted in cost savings amounting to $374.97 in additional intraoperative CSF leak repairs ($18.07 vs $393.04) and $66.68 in postoperative complication treatment ($131.90 vs $198.58). Both one-way sensitivity analysis and probabilistic sensitivity analysis confirmed that the model results were stable against input variations. IMPLICATIONS: The decision tree analysis revealed that using PFS in conjunction with sutures was associated with improved clinical performance and lower overall costs. PFS in combination with sutures is the dominant strategy for treating CSF leak from the perspective of hospital decision-makers.

Development of a Novel Low-Cost Exoscope to Expand Access to Microneurosurgical Care in Low- and Middle-Income Countries.

BACKGROUND: Less than a quarter of the world population has access to microneurosurgical care within a range of 2 hours. We introduce a simplified exoscope system to achieve magnification, illumination, and video recording in low-resource settings. METHODS: We combined an industrial microscope tube, a heavy-duty support arm, a wide-field c-mount digital microscope camera, and a light-emitting diode ring light. All parts were sterilized with ethylene oxide. We performed 13 spinal and 3 cranial surgeries with the help of the low-budget exoscope. RESULTS: The average preoperative setup time was 12.8 minutes. The exoscope provided similar magnification and illumination like a conventional binocular microscope. It allowed operating in a comfortable posture. The field of vision ranged from 30 mm-60 mm. The surgical field was captured by a 16-megapixel two-dimensional camera and projected to a 55-inch high-definition television screen in real time. Image quality was similar to that of a conventional microscope although our exoscope lacked stereoscopic view. Adjusting camera position and angle was time-consuming. Thus, the benefit of the exoscope was most notable in spine surgeries where the camera remained static for most of the time. The total cost of the exoscope was approximately U.S. $ 750. CONCLUSIONS: Our low-budget exoscope offers similar image quality, magnification, and illumination like a conventional binocular microscope. It may thus help expand access to neurosurgical care worldwide. Users may face difficulty adapting to the lack of depth perception in the beginning. Prospective studies are needed to assess its usability and effectiveness compared to the microscope.

Performance of the Modified Adult Spinal Deformity Frailty Index in Preoperative Risk Assessment.

STUDY DESIGN: Retrospective single-center, consecutively enrolled database of adult spinal deformity (ASD) patients. OBJECTIVE: The aim of this study was to assess the performance of the mASD-FI in predicting clinical and patient-reported outcomes after ASD-corrective surgery. SUMMARY OF BACKGROUND DATA: The recently described modified Adult Spinal Deformity frailty index (mASD-FI) quantifies frailty of ASD patients, but the utility of this clinical prediction tool as a means of prognosticating postoperative outcomes has not been investigated. METHODS: ASD patients with available mASD-FI scores and HRQL data at presentation and 2-years postop were included.Patients were stratified by mASD-FI score using published cutoffs: not frail (NF <7), frail (F, 7-12), severely frail (SF, >12). Analysis of vaiance assessed differences in patient factors across frailty groups. Linear regression assessed the relationship of mASD-FI with length of stay (LOS) and HRQLs. Multivariable logistic regression revealed how frailty category predicted odds of complications, infections and reoperation. RESULTS: A total of 509 patients included (59 years, 79%F, 27.7 kg/m 2 ). The cohort presented with moderate baseline deformity: sagittal vertical axis (83.7 mm ± 71), PT (12.7° ± 10.8°), PI-LL (43.1° ± 21.1°). Mean preoperative mASD-FI score was 7.2, frailty category: NF (50.3%), F (34.0%), SF (15.7%).Age, BMI, and Charlson Comorbidity Index increased with frailty categories (all P < 0.001); however, fusion length ( P = 0.247) and osteotomy rate ( P = 0.731) did not. At baseline, increasing frailty was associated with inferior Oswestry Disability Index (ODI), EuroQol 5-Dimension Questionnaire (EQ-5D), SRS-22r, Pain Catastrophizing Scale, and NRS Back and Leg (all P < 0.001). Greater frailty was associated with increased LOS and reduced postoperative HRQL. Controlling for complication incidence, baseline mASD-FI predicted 2 year postop scores for year ODI (b = 0.7, 0.58-0.8, P < 0.001) SRS (b = -0.023, -0.03 to -0.02, P < 0.001), EQ-5D (b = -0.003, -0.004 to -0.002, P < 0.001). F and SF were associated with greater odds of unplanned revision surgery and complications. CONCLUSION: Higher preoperative mASD-FI score was associated with significantly greater complications, higher rate of unplanned reoperations and lower postoperative HRQL in this investigation. The mASD-FI provides similar prognostic utility while reducing burden for surgeons and patients.

Comparative Anatomical Assessment of Full vs Limited Transcavernous Exposure of the Carotid-Oculomotor Window.

BACKGROUND: Although the full transcavernous approach affords extensive mobilization of the oculomotor nerve (OMN) for exposure of the basilar apex and interpeduncular cistern region, this time-consuming procedure requires substantial dural dissection along the anterior middle cranial fossa. OBJECTIVE: To quantify the extent to which limited middle fossa dural elevation affects the carotid-oculomotor window (C-OMW) surgical area during transcavernous exposure after OMN mobilization. METHODS: Four cadaveric specimens were dissected bilaterally to study the C-OMW area afforded by the transcavernous exposure. Each specimen underwent full and limited transcavernous exposure and anterior clinoidectomy (1 procedure per side; 8 procedures). Limited exposure was defined as a dural elevation confined to the cavernous sinus. Full exposure included dural elevation over the gasserian ganglion, extending to the middle meningeal artery and lateral middle cranial fossa. RESULTS: The C-OMW area achieved with the limited transcavernous exposure, compared with full transcavernous exposure, provided significantly less total area with OMN mobilization (22 ± 6 mm2 vs 52 ± 26 mm2, P = .03) and a smaller relative increase in area after OMN mobilization (11 ± 5 mm2 vs 36 ± 13 mm2, P = .03). The increase after OMN mobilization in the C-OMW area after OMN mobilization was 136% ± 119% with a limited exposure vs 334% ± 216% with a full exposure. CONCLUSION: In this anatomical study, the full transcavernous exposure significantly improved OMN mobilization and C-OMW area compared with a limited transcavernous exposure. If a transcavernous exposure is pursued, the difference in the carotid-oculomotor operative corridor area achieved with a limited vs full exposure should be considered.