Pharmacological treatment of gastro-oesophageal reflux in children.

BACKGROUND: Gastro-oesophageal reflux (GOR) is characterised by the regurgitation of gastric contents into the oesophagus. GOR is a common presentation in infancy, both in primary and secondary care, affecting approximately 50% of infants under three months old. The natural history of GOR in infancy is generally of a self-limiting condition that improves with age, but older children and children with co-existing medical conditions can have more protracted symptoms. The distinction between gastro-oesophageal reflux disease (GORD) and GOR is debated. Current National Institute of Health and Care Excellence (NICE) guidelines define GORD as GOR causing symptoms severe enough to merit treatment. This is an update of a review first published in 2014. OBJECTIVES: To assess the effects of pharmacological treatments for GOR in infants and children. SEARCH METHODS: For this update, we searched CENTRAL, MEDLINE, Embase, and Web of Science up to 17 September 2022. We also searched for ongoing trials in clinical trials registries, contacted experts in the field, and searched the reference lists of trials and reviews for any additional trials. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any currently-available pharmacological treatment for GOR in children with placebo or another medication. We excluded studies assessing dietary management of GORD and studies of thickened feeds. We included studies in infants and children up to 16 years old. DATA COLLECTION AND ANALYSIS: We used standard methodology expected by Cochrane. MAIN RESULTS: We included 36 RCTs involving 2251 children and infants. We were able to extract summary data from 14 RCTs; the remaining trials had insufficient data for extraction. We were unable to pool results in a meta-analysis due to methodological differences in the included studies (including heterogeneous outcomes, study populations, and study design). We present the results in two groups by age: infants up to 12 months old, and children aged 12 months to 16 years old. Infants Omeprazole versus placebo: there is no clear effect on symptoms from omeprazole. One study (30 infants; very low-certainty evidence) showed cry/fuss time in infants aged three to 12 months had altered from 246 ± 105 minutes/day at baseline (mean +/- standard deviation (SD)) to 191 ± 120 minutes/day in the omeprazole group and from 287 ± 132 minutes/day to 201 ± 100 minutes/day in the placebo group (mean difference (MD) 10 minutes/day lower (95% confidence interval (CI) -89.1 to 69.1)). The reflux index changed in the omeprazole group from 9.9 ± 5.8% in 24 hours to 1.0 ± 1.3% and in the placebo group from 7.2 ± 6.0% to 5.3 ± 4.9% in 24 hours (MD 7% lower, 95% CI -4.7 to -9.3). Omeprazole versus ranitidine: one study (76 infants; very low-certainty evidence) showed omeprazole may or may not provide symptomatic benefit equivalent to ranitidine. Symptom scores in the omeprazole group changed from 51.9 ± 5.4 to 2.4 ± 1.2, and in the ranitidine group from 47 ± 5.6 to 2.5 ± 0.6 after two weeks: MD -4.97 (95% CI -7.33 to -2.61). Esomeprazole versus placebo: esomeprazole appeared to show no additional reduction in the number of GORD symptoms compared to placebo (1 study, 52 neonates; very low-certainty evidence): both the esomeprazole group (184.7 ± 78.5 to 156.7 ± 75.1) and placebo group (183.1 ± 77.5 to 158.3 ± 75.9) improved: MD -3.2 (95% CI -4.6 to -1.8). Children Proton pump inhibitors (PPIs) at different doses may provide little to no symptomatic and endoscopic benefit. Rabeprazole given at different doses (0.5 mg/kg and 1 mg/kg) may provide similar symptom improvement (127 children in total; very low-certainty evidence). In the lower-dose group (0.5 mg/kg), symptom scores improved in both a low-weight group of children (< 15 kg) (mean -10.6 ± SD 11.13) and a high-weight group of children (> 15 kg) (mean -13.6 ± 13.1). In the higher-dose groups (1 mg/kg), scores improved in the low-weight (-9 ± 11.2) and higher-weight groups (-8.3 ± 9.2). For the higher-weight group, symptom score mean difference between the two different dosing regimens was 2.3 (95% CI -2 to 6.6), and for the lower-weight group, symptom score MD was 4.6 (95% CI -2.9 to 12). Pantoprazole: pantoprazole may or may not improve symptom scores at 0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg pantoprazole in children aged one to five years by week eight, with no difference between 0.3 mg/kg and 1.2 mg/kg dosing (0.3 mg/kg mean -2.4 ± 1.7; 1.2 mg/kg -1.7 ± 1.2: MD 0.7 (95% CI -0.4 to 1.8)) (one study, 60 children; very low-certainty evidence). There were insufficient summary data to assess other medications. AUTHORS' CONCLUSIONS: There is very low-certainty evidence about symptom improvements and changes in pH indices for infants. There are no summary data for endoscopic changes. Medications may or may not provide a benefit (based on very low-certainty evidence) for infants whose symptoms remain bothersome, despite nonmedical interventions or parental reassurance. If a medication is required, there is no clear evidence based on summary data for omeprazole, esomeprazole (in neonates), H2antagonists, and alginates for symptom improvements (very low-certainty evidence). Further studies with longer follow-up are needed. In older children with GORD, in studies with summary data extracted, there is very low-certainty evidence that PPIs (rabeprazole and pantoprazole) may or may not improve GORD outcomes. No robust data exist for other medications. Further RCT evidence is required in all areas, including subgroups (preterm babies and children with neurodisabilities).

Arachnoid webs causing rostral syrinx due to ball-valve effect: an illustrative report of two cases.

An arachnoid web is a pathological formation of the arachnoid membrane. It is a rare phenomenon but is known to lead to syrinx formation in the spinal cord along with pain and neurological deficits. On imaging, the 'scalpel sign' is pathognomonic for an arachnoid web. The etiology of syrinx formation from an arachnoid web is currently unknown. This report documents the only two cases of arachnoid webs with an extensive syrinx in which a likely pathophysiologic mechanism is identified. Both cases presented with motor deficits. The patients had no history of trauma or infection. After extensive workup in both patients and observation of the scalpel sign an arachnoid web was suspected. In both cases, the patients were treated surgically after an arachnoid web was suspected. Intra-operative ultrasound visualized in both cases demonstrates a fenestration in the web that allowed passage of cerebrospinal fluid in a rostral-caudal direction due to a ball-valve effect.

Bibliometric analysis of the top 100 cited articles on stereotactic radiosurgery of intracranial meningiomas.

BACKGROUND: Sterotactic radiosurgery is becoming an integral modality in the management of intracranial meningiomas, both as the primary treatment or as adjuvant therapy. This study analyzes the scholarly impact of the top 100 cited articles on the stereotactic radiosurgical management of intracranial meningiomas. METHODS: A ranked list of the 100 most-cited articles was generated using the Scopus database by searching the keywords 'intracranial meningioma' and 'stereotactic radiosurgery'. All articles were then evaluated on multiple criteria regarding both the publication of the articles (year of publication, journal, country of origin, and authors) as well as their methods and foci (type of study, location of studied meningiomas, and type of radiosurgical modality). Quantitaitve and qualitative analyses were then performed from the collected data. RESULTS: The most frequently cited articles on stereotactic radiosurgical management of intracranial meningiomas were published between 1990 and 2016. The average citation-per-year across all papers in the list was 6.1. The most studied anatomic area of intracranial meningiomas was the skull base, with the cavernous sinus being the most well-studied specific site. The most utilized stereotactic radiosurgical modality was Gamma Knife radiosurgery. The country with the highest number of publications was the United States. Twenty-six percent of the articles were published in the journal Neurosurgery; Lunsford, Kondziolka, Flickinger, Sheehan, and Pollock were respectively the most frequent listed authors among this list. The most active academic institute publishing on this topic was the University of Pittsburgh Medical Center. CONCLUSION: Stereotactic radiosurgery is an integral modality in the management of intracranial meningiomas. This bibliometric analysis sheds the light on the ways in which intracranial meningiomas have been studied in the past two decades in order to identify trends among neurosurgeons and radiation oncologists and to reveal areas of rising and declining focus.

Embedding electronic growth charts into clinical practice at a children's hospital.

Embedding electronic growth charts (EGCs) into clinical practice in a children's hospital. We employed initial implementation in the outpatient setting and subsequently extended this across inpatients with the growth chart following the child's records through both settings and significantly increasing growth data documentation.

Glioblastoma exosomes and IGF-1R/AS-ODN are immunogenic stimuli in a translational research immunotherapy paradigm.

Glioblastomas are primary intracranial tumors for which there is no cure. Patients receiving standard of care, chemotherapy and irradiation, survive approximately 15 months prompting studies of alternative therapies including vaccination. In a pilot study, a vaccine consisting of Lucite diffusion chambers containing irradiated autologous tumor cells pre-treated with an antisense oligodeoxynucleotide (AS-ODN) directed against the insulin-like growth factor type 1 receptor was found to elicit positive clinical responses in 8/12 patients when implanted in the rectus sheath for 24 h. Our preliminary observations supported an immune response, and we have since reopened a second Phase 1 trial to assess this possibility among other exploratory objectives. The current study makes use of a murine glioma model and samples from glioblastoma patients in this second Phase 1 trial to investigate this novel therapeutic intervention more thoroughly. Implantation of the chamber-based vaccine protected mice from tumor challenge, and we posit this occurred through the release of immunostimulatory AS-ODN and antigen-bearing exosomes. Exosomes secreted by glioblastoma cultures are immunogenic, eliciting and binding antibodies present in the sera of immunized mice. Similarly, exosomes released by human glioblastoma cells bear antigens recognized by the sera of 6/12 patients with recurrent glioblastomas. These results suggest that the release of AS-ODN together with selective release of exosomes from glioblastoma cells implanted in chambers may drive the therapeutic effect seen in the pilot vaccine trial.

Multidisciplinary Surgical Approach Using Augmented Reality Preplanning for Resection of Giant Thoracic Schwannoma With Robotic-Assisted Thoracoscopic Mobilization.

BACKGROUND AND IMPORTANCE: In adults, primary spinal cord tumors account for 5% of all primary tumors of the central nervous system, with schwannomas making up about 74% of all nerve sheath tumors. Thoracic schwannomas can pose a threat to neurovasculature, presenting a significant challenge to safe and complete surgical resection. For patients presenting with complex pathologies including tumors, a dual surgeon approach may be used to optimize patient care and improve outcomes. CLINICAL PRESENTATION: A 73-year-old female previously diagnosed with a nerve sheath tumor of the fourth thoracic vertebra presented with significant thoracic pain and a history of falls. Imaging showed that the tumor had doubled in size ranging from T3 to T5. Augmented reality volumetric rendering was used to clarify anatomic relationships of the mass for perioperative evaluation and decision-making. A dual surgeon approach was used for complete resection. First, a ventrolateral left video-assisted thoracoscopic surgery was performed with robotic assistance followed by a posterior tumor resection and thoracic restabilization. The patient did well postoperatively. CONCLUSION: Although surgical treatment of large thoracic dumbbell tumors presents a myriad of risks, perioperative evaluation with augmented reality, new robotic surgical techniques, and a dual surgeon approach can be implemented to mitigate these risks.

Mixed Reality in the Operating Room: An Initial Use in Frontal Sinus Setback in Gender-affirming Facial Surgery.

Demand for gender-affirming facial surgery is growing rapidly. Frontal sinus setback, one of the key procedures used in gender-affirming facial surgery, has a particularly high impact on gender perception. Mixed reality (MR) allows a user to view and virtually overlay three-dimensional imaging on the patient and interact with it in real time. We used the Medivis's SurgicalAR system in conjunction with the Microsoft HoloLens Lucille2 (Microsoft). Computed tomography imaging was uploaded to SurgicalAR, and a three-dimensional (3D) hologram was projected onto the display of the HoloLens. The hologram was registered and matched to the patient, allowing the surgeon to view bony anatomy and underlying structures in real time on the patient. The surgeon was able to outline the patient's frontal sinuses using the hologram as guidance. A 3D printed cutting guide was used for comparison. Negligible difference between the mixed reality-based outline and 3D-printed outline was seen. The process of loading the hologram and marking the frontal sinus outline lasted less than 10 minutes. The workflow and usage described here demonstrate significant promise for the use of mixed reality as imaging and surgical guidance technology in gender-affirming facial surgery.

Evolution of the meta-neurosurgeon: A systematic review of the current technical capabilities, limitations, and applications of augmented reality in neurosurgery.

Background: Augmented reality (AR) applications in neurosurgery have expanded over the past decade with the introduction of headset-based platforms. Many studies have focused on either preoperative planning to tailor the approach to the patient's anatomy and pathology or intraoperative surgical navigation, primarily realized as AR navigation through microscope oculars. Additional efforts have been made to validate AR in trainee and patient education and to investigate novel surgical approaches. Our objective was to provide a systematic overview of AR in neurosurgery, provide current limitations of this technology, as well as highlight several applications of AR in neurosurgery. Methods: We performed a literature search in PubMed/Medline to identify papers that addressed the use of AR in neurosurgery. The authors screened three hundred and seventy-five papers, and 57 papers were selected, analyzed, and included in this systematic review. Results: AR has made significant inroads in neurosurgery, particularly in neuronavigation. In spinal neurosurgery, this primarily has been used for pedicle screw placement. AR-based neuronavigation also has significant applications in cranial neurosurgery, including neurovascular, neurosurgical oncology, and skull base neurosurgery. Other potential applications include operating room streamlining, trainee and patient education, and telecommunications. Conclusion: AR has already made a significant impact in neurosurgery in the above domains and has the potential to be a paradigm-altering technology. Future development in AR should focus on both validating these applications and extending the role of AR.

Machine Learning in Spine Surgery: A Narrative Review.

Artificial intelligence and machine learning (ML) can offer revolutionary advances in their application to the field of spine surgery. Within the past 5 years, novel applications of ML have assisted in surgical decision-making, intraoperative imaging and navigation, and optimization of clinical outcomes. ML has the capacity to address many different clinical needs and improve diagnostic and surgical techniques. This review will discuss current applications of ML in the context of spine surgery by breaking down its implementation preoperatively, intraoperatively, and postoperatively. Ethical considerations to ML and challenges in ML implementation must be addressed to maximally benefit patients, spine surgeons, and the healthcare system. Areas for future research in augmented reality and mixed reality, along with limitations in generalizability and bias, will also be highlighted.

Single institution series describing external ventricular drain (EVD) placement and short- and long-term complications related to placement accuracy.

Background: The placement of an external ventricular drain (EVD) for the treatment of acute hydrocephalus is one of the most common life-saving procedures that neurosurgeons perform worldwide. There are many well-known complications associated with EVD placement, including tract hemorrhages, intra-parenchymal and subdural hemorrhages, infection, and catheter misplacement. Given the variety of complications associated with EVD placement and the inconsistent findings on the relationship of accuracy to complications, the present study reviewed short- and long-term complications related to EVD placement at our institution. Methods: A retrospective review was conducted for all consecutive patients who underwent bedside EVD placement for any indication between December 2020 and December 2021. Collected variables included demographic information, etiology of disease state, pre-and post-operative head computed tomography measurements, and post-procedural metrics (immediate and delayed complications). Results: A total of 124 patients qualified for inclusion in our study. EVDs that were non-functioning/exchanged were not significantly related to age, accuracy, ventriculomegaly, sex, disposition, laterality, type of EVD used, intraventricular hemorrhage (IVH), etiology, or Kakarla Grade (KG) (all P > 0.17). The need for a second EVD was similarly not related to age, accuracy, ventriculomegaly, sex, disposition, location, laterality, type of EVD used, IVH, etiology, or KG (all P > 0.130). Patients who died, however, were significantly more likely to have a second contralateral EVD placed (18.2% vs. 4.9% P = 0.029). We also found that left-sided EVDs were significantly more likely to fail within seven days of placement (29.4% vs 13.3%, P = 0.037; relative risk (RR) 1.93, 95% confidence interval: 1.09-3.43), unrelated to age, sex, etiology, type of EVD, IVH, location of the procedure, or accuracy (all P > 0.07). This remained significant when using a binary logistic regression to control for ventriculomegaly, accuracy, mortality, age, sex, and etiology (P = 0.021, B = 3.43). Conclusion: In our cohort, although a clear relationship between inaccuracy and complication rates was not found, our data did demonstrate that left-sided EVDs were more likely to fail within the immediate postoperative time point, and patients who died were more likely to have a second, contralateral EVD placed.

Feasibility and Usability of Augmented Reality Technology in the Orthopaedic Operating Room.

PURPOSE OF REVIEW: Augmented reality (AR) has gained popularity in various sectors, including gaming, entertainment, and healthcare. The desire for improved surgical navigation within orthopaedic surgery has led to the evaluation of the feasibility and usability of AR in the operating room (OR). However, the safe and effective use of AR technology in the OR necessitates a proper understanding of its capabilities and limitations. This review aims to describe the fundamental elements of AR, highlight limitations for use within the field of orthopaedic surgery, and discuss potential areas for development. RECENT FINDINGS: To date, studies have demonstrated evidence that AR technology can be used to enhance navigation and performance in orthopaedic procedures. General hardware and software limitations of the technology include the registration process, ergonomics, and battery life. Other limitations are related to the human response factors such as inattentional blindness, which may lead to the inability to see complications within the surgical field. Furthermore, the prolonged use of AR can cause eye strain and headache due to phenomena such as the vergence-convergence conflict. AR technology may prove to be a better alternative to current orthopaedic surgery navigation systems. However, the current limitations should be mitigated to further improve the feasibility and usability of AR in the OR setting. It is important for both non-clinicians and clinicians to work in conjunction to guide the development of future iterations of AR technology and its implementation into the OR workflow.

Tetra-compartmental spinal infection with conus medullaris syndrome: illustrative case.

BACKGROUND: Recent literature suggests that spinal infections are increasing in prevalence. Any compartment can be infected in the spine; however, multicompartmental infections are rare. OBSERVATIONS: To the authors' knowledge, this report is the only reported case of a tetra-compartmental spinal infection consisting of epidural, subdural, subarachnoid, and intramedullary components with a contiguous lumbar spondylodiscitis resulting in conus medullaris syndrome requiring surgical intervention. LESSONS: This case highlights the importance of surgical intervention in severe cases such as the one illustrated in this report. Second, magnetic resonance imaging with and without contrast is required to check for spreading of the infection as these findings may change the surgical approach. Last, the use of intraoperative ultrasound is paramount to evaluate the subdural and intramedullary compartments in severe cases.

Combined exploratory laparotomy, transpsoas, and thoracic approach to resection of a giant spinal ganglioneuroma: illustrative case.

BACKGROUND: Ganglioneuromas are rare peripheral nervous system tumors of neural crest origin. Most are often asymptomatic and incidentally found, but large tumors can cause mass effect. Herein, the authors report a case of a giant ganglioneuroma that arose from the lumbar foramina into the retroperitoneal and thoracic cavities. OBSERVATIONS: A 62-year-old female presented with low back pain, left lower extremity swelling, and increased sensation of an abdominal mass. Surgical treatment options were reviewed with the patient and coordinated care was planned by surgical oncological specialists. The patient opted for multistage exploratory laparotomy for abdominal mobilization, diaphragm resection, and en bloc resection with neuromonitoring. After surgery, the patient experienced significant improvement in symptoms. LESSONS: A combined surgical exposure involving gastrointestinal, thoracic, and neurological surgeons can be important in the safe resection of ganglioneuromas that span multiple body cavities. Hence, a thorough preoperative assessment could help plan surgery accordingly.

Understanding Effects of Visual Feedback Delay in AR on Fine Motor Surgical Tasks.

Latency is a pervasive issue in various systems that can significantly impact motor performance and user perception. In medical settings, latency can hinder surgeons' ability to quickly correct movements, resulting in an experience that doesn't align with user expectations and standards of care. Despite numerous studies reporting on the negative effects of latency, there is still a gap in understanding how it impacts the use of augmented reality (AR) in medical settings. This study aims to address this gap by examining how latency impacts motor task performance and subjective perceptions, such as cognitive load, on two display types: a monitor display, traditionally used inside an operating room (OR), and a Microsoft HoloLens 2 display. Our findings indicate that both level of latency and display type impact motor performance, and higher latencies on the HoloLens result in relatively poor performance. However, cognitive load was found to be unrelated to display type or latency, but was dependent on the surgeon's training level. Surgeons did not compromise accuracy to gain more speed and were generally well aware of the latency in the system irrespective of their performance on task. Our study provides valuable insights into acceptable thresholds of latency for AR displays and proposes design implications for the successful implementation and use of AR in surgical settings.

Outcomes and Treatment Algorithm in Glioblastoma Patients 80 Years and Older.

OBJECTIVE: The current standard of care for patients with glioblastoma (GBM) is maximal safe resection followed by adjuvant radiation therapy with concurrent temozolomide chemotherapy. Previous studies that identified this treatment regimen focused on younger patients with GBM. The proportion of patients with GBM over the age of 80 years is increasing. We investigate whether elderly patients benefit from the current standard of care with additional maximal safe resection. METHODS: Clinical, operative, radiographic, demographic, genetic, and outcomes data were retrospectively collected for patients treated for histologically confirmed World Health Organization grade 4 GBM at University of Pittsburgh Medical Center from 2009 to 2020. Only patients 80 years and older were included (n = 123). Statistically significant values were set at P < 0.05. RESULTS: A univariate Cox proportional hazards analysis of GBM patients aged >80 years identified the use of temozolomide, radiation, Karnofsky Performance Status (KPS) > 70, and methylguanine DNA methyltransferase methylation with increased overall survival (OS). Further multivariate Cox proportional hazards model analysis showed that the variables identified in the univariate analysis passed multicollinearity testing, and that use of temozolomide, KPS >70, and gross total resection were shown to significantly impact survival. Survival analysis showed that patients with biopsy alone had a shorter median OS compared with patients who received resection, temozolomide, and radiation (P < 0.0001, median OS 1.6 vs. 7.5 months). Additionally, patients who underwent biopsy and then received temozolomide and radiation had a shorter median OS when compared with patients who received resection, temozolomide, and radiation (P = 0.0047, median OS 3.6 vs. 7.5 months). CONCLUSIONS: For elderly patients with KPS >70, GTR followed by radiation and temozolomide is associated with maximum OS.

Intraoperative Imaging and Optical Visualization Techniques for Brain Tumor Resection: A Narrative Review.

Advancements in intraoperative visualization and imaging techniques are increasingly central to the success and safety of brain tumor surgery, leading to transformative improvements in patient outcomes. This comprehensive review intricately describes the evolution of conventional and emerging technologies for intraoperative imaging, encompassing the surgical microscope, exoscope, Raman spectroscopy, confocal microscopy, fluorescence-guided surgery, intraoperative ultrasound, magnetic resonance imaging, and computed tomography. We detail how each of these imaging modalities contributes uniquely to the precision, safety, and efficacy of neurosurgical procedures. Despite their substantial benefits, these technologies share common challenges, including difficulties in image interpretation and steep learning curves. Looking forward, innovations in this field are poised to incorporate artificial intelligence, integrated multimodal imaging approaches, and augmented and virtual reality technologies. This rapidly evolving landscape represents fertile ground for future research and technological development, aiming to further elevate surgical precision, safety, and, most critically, patient outcomes in the management of brain tumors.

A systematic comparison of the accuracy of monocular RGB tracking and LiDAR for neuronavigation.

With the advent of augmented reality (AR), the use of AR-guided systems in the field of medicine has gained traction. However, the wide-scale adaptation of these systems requires highly accurate and reliable tracking. In this work, the tracking accuracy of two technology platforms, LiDAR and Vuforia, are developed and rigorously tested for a catheter placement neurological procedure. Several experiments (900) are performed for each technology across various combinations of catheter lengths and insertion trajectories. This analysis shows that the LiDAR platform outperformed Vuforia; which is the state-of-the-art in monocular RGB tracking solutions. LiDAR had 75% less radial distance error and 26% less angle deviation error. Results provide key insights into the value and utility of LiDAR-based tracking in AR guidance systems.

A Novel 5-Aminolevulinic Acid-Enabled Surgical Loupe System-A Consecutive Brain Tumor Series of 11 Cases.

BACKGROUND: The concept of maximally safe resection (MSR) has been shown to improve clinical outcomes in the treatment of high-grade gliomas (HGGs). To achieve MSR, surgical adjuncts such as functional imaging, neuronavigation, intraoperative mapping, ultrasound, and fluorescence-guided surgery are routinely used. 5-Aminolevulinic acid (5-ALA) is an oral agent that has been increasingly adopted in fluorescence-guided resection of HGG. In randomized clinical trials of 5-ALA, it has been shown to increase the extent of resection and progression-free survival in HGG. Current commercially available 5-ALA detection systems are all microscope-based and can sometimes be cumbersome to use. OBJECTIVE: To present our experience using a novel 5-ALA-enabled surgical loupe system. METHODS: 5-ALA-enabled loupes were used in 11 consecutive patients with either suspected HGG on magnetic resonance imaging or recurrence of known lesions. Lesion appearance was examined under white light, 5-ALA loupes, and a 5-ALA microscope. Tumor specimens were checked for fluorescence and sent for pathologic examination. RESULTS: In our experience, a 5-ALA-enabled surgical loupe system offers excellent visualization of 5-ALA in patients with HGG. In 10 of 11 patients, fluorescent tissue was confirmed to be high-grade glioma by pathology. In 1 patient, tissue was not fluorescent, and final pathology was World Health Organization grade I meningioma. CONCLUSION: A 5-ALA-enabled surgical loupe system offers excellent intraoperative visualization of 5-ALA fluorescence in HGG and can be a viable surgical adjunct for achieving MSR of HGG.

The application of augmented reality-based navigation for accurate target acquisition of deep brain sites: advances in neurosurgical guidance.

OBJECTIVE: The objective of this study is to quantify the navigational accuracy of an advanced augmented reality (AR)-based guidance system for neurological surgery, biopsy, and/or other minimally invasive neurological surgical procedures. METHODS: Five burr holes were drilled through a plastic cranium, and 5 optical fiducials (AprilTags) printed with CT-visible ink were placed on the frontal, temporal, and parietal bones of a human skull model. Three 0.5-mm-diameter targets were mounted in the interior of the skull on nylon posts near the level of the tentorium cerebelli and the pituitary fossa. The skull was filled with ballistic gelatin to simulate brain tissue. A CT scan was taken and virtual needle tracts were annotated on the preoperative 3D workstation for the combination of 3 targets and 5 access holes (15 target tracts). The resulting annotated study was uploaded to and launched by VisAR software operating on the HoloLens 2 holographic visor by viewing an encrypted, printed QR code assigned to the study by the preoperative workstation. The DICOM images were converted to 3D holograms and registered to the skull by alignment of the holographic fiducials with the AprilTags attached to the skull. Five volunteers, familiar with the VisAR, used the software/visor combination to navigate an 18-gauge needle/trocar through the series of burr holes to the target, resulting in 70 data points (15 for 4 users and 10 for 1 user). After each attempt the needle was left in the skull, supported by the ballistic gelatin, and a high-resolution CT was taken. Radial error and angle of error were determined using vector coordinates. Summary statistics were calculated individually and collectively. RESULTS: The combined angle of error of was 2.30° ± 1.28°. The mean radial error for users was 3.62 ± 1.71 mm. The mean target depth was 85.41 mm. CONCLUSIONS: The mean radial error and angle of error with the associated variance measures demonstrates that VisAR navigation may have utility for guiding a small needle to neural lesions, or targets within an accuracy of 3.62 mm. These values are sufficiently accurate for the navigation of many neurological procedures such as ventriculostomy.