Intraoperative Videogrammetry and Photogrammetry for Photorealistic Neurosurgical 3-Dimensional Models Generated Using Operative Microscope: Technical Note.

BACKGROUND AND OBJECTIVES: Intraoperative orientation during microsurgery has a prolonged learning curve among neurosurgical residents. Three-dimensional (3D) understanding of anatomy can be facilitated with realistic 3D anatomic models created from photogrammetry, where a series of 2-dimensional images is converted into a 3D model. This study implements an algorithm that can create photorealistic intraoperative 3D models to exemplify important steps of the operation, operative corridors, and surgical perspectives. METHODS: We implemented photograph-based and video-based scanning algorithms for uptakes using the operating room (OR) microscope, targeted for superficial structures, after surgical exposure, and deep operative corridors, in cranial microsurgery. The algorithm required between 30-45 photographs (superficial scanning), 45-65 photographs (deep scanning), or approximately 1 minute of video recording of the entire operative field to create a 3D model. A multicenter approach in 3 neurosurgical departments was applied to test reproducibility and refine the method. RESULTS: Twenty-five 3D models were created of some of the most common neurosurgical approaches-frontolateral, pterional, retrosigmoid, frontal, and temporal craniotomy. The 3D models present important steps of the surgical approaches and allow rotation, zooming, and panning of the model, enabling visualization from different surgical perspectives. The superficial and medium depth structures were consistently presented through the 3D models, whereas scanning of the deepest structures presented some technical challenges, which were gradually overcome with refinement of the image capturing process. CONCLUSION: Intraoperative photogrammetry is an accessible method to create 3D educational material to show complex anatomy and demonstrate concepts of intraoperative orientation. Detailed interactive 3D models, displaying stepwise surgical case-based anatomy, can be used to help understand details of the operative corridor. Further development includes refining or automatization of image acquisition intraoperatively and evaluation of other applications of the resulting 3D models in training and surgical planning.

Scandinavian Multicenter Acute Subdural Hematoma (SMASH) Study: Study Protocol for a Multinational Population-Based Consecutive Cohort.

BACKGROUND: Traumatic acute subdural hematomas (ASDHs) are associated with high rate of morbidity and mortality, especially in elderly individuals. However, recent reports indicate that the morbidity and mortality rates might have improved. OBJECTIVE: To evaluate postoperative (30-d) mortality in younger vs elderly (≥70 yr) patients with ASDH. Comparing younger and elderly patients, the secondary objectives are morbidity patterns of care and 6 mo outcome according to Glasgow outcome scale (GOS). Finally, in patients with traumatic ASDH, we aim to provide prognostic variables. METHODS: This is a large-scale population-based Scandinavian study including all neurosurgical departments in Denmark and Sweden. All adult (≥18 yr) patients surgically treated between 2010 and 2014 for a traumatic ASDH in Denmark and Sweden will be included. Identification at clinicaltrials.gov is NCT03284190. EXPECTED OUTCOMES: We expect to provide data on potential differences between younger vs elderly patients in terms of mortality and morbidity. We hypothesize that elderly patients selected for surgery have a similar pattern of care as compared with younger patients. We will provide functional outcome in terms of GOS at 6 mo in younger vs elderly patients undergoing ASDH evacuation. Finally, clinical useful prognostic factors for favorable (GOS 4-5) vs unfavorable (GOS 1-3) will be identified. DISCUSSION: An improved understanding of the clinical outcome, treatment and resource allocation, clinical course, and the prognostic factors of traumatic ASDH will allow neurosurgeons to make better treatment decisions.

Outcome after surgical treatment for lumbar spinal stenosis: the lumbar extension test is not a predictive factor.

STUDY DESIGN: A prospective clinical study. OBJECTIVES: To investigate the predictive value of the lumbar extension test for outcome after surgical treatment of lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: Studies have indicated that aggravation of the symptoms from LSS by extension of the lumbar spine has predictive value for the outcome after decompression. The aim of this study was to investigate this theory in a larger group of patients. METHODS: One hundred forty-six consecutive patients surgically treated for LSS were included in the study. The clinical condition was recorded before surgery and at 3, 6, 12, and 24 months after surgery using 3 different scoring systems: Swiss Spinal Stenosis Questionnaire, Neurogenic Claudication Outcome Score, and Oswestry Disability Index. The group of patients with preoperative aggravation of the symptoms by the lumbar extension test, (positive extension test), was compared with the group of patients without aggravation by the test, (negative extension test). RESULTS: Before surgery, patients with a positive extension test scored significantly worse on all disability scoring systems than patients with a negative test. However, the extension test itself had no prognostic value for the overall outcome after lumbar decompression. Using regression models with the 2-year Oswestry Disability Index as dependent variable, only before surgery self-reported health and age were found to have prognostic significance. CONCLUSION: The lumbar extension test has no predictive value for the outcome after surgical treatment of LSS.