BACKGROUND AND OBJECTIVES: Posterior cerebral artery involvement in moyamoya disease (MMD) is associated with occipital hypoperfusion, visual disturbance, recurrent ischemic events, and worse neurological status. In selected patients, posterior circulation–targeted revascularization may represent an important component of surgical management. We evaluated outcomes after a standardized occipital artery–posterior cerebral artery (OA–PCA) bypass strategy using a cortical P4 recipient combined with encephalo-duro-pericranial synangiosis (EDPS) in patients with posterior circulation–involved MMD. METHODS: We retrospectively reviewed consecutive posterior circulation revascularization procedures performed from August 2012 through December 2024. All procedures used a standardized OA–PCA bypass to a cortical P4 recipient combined with EDPS. The primary outcome was bypass patency on follow-up imaging. Secondary outcomes included collateral formation, perfusion improvement, early visual improvement, modified Rankin Scale improvement, and procedure-related perioperative adverse events. RESULTS: A total of 113 procedures in 109 patients were included. Early postoperative computed tomography angiography confirmed bypass patency in all evaluable procedures (112/112, 100%). At 12 months or later, bypass patency was observed in 59 of 102 procedures (57.8%), collateral formation in 63 of 102 procedures (61.8%, grades A-B), and perfusion improvement in 63 of 102 procedures (61.8%). Among 72 procedures with documented preoperative visual disturbance, early visual improvement occurred in 31 (43.1%). Modified Rankin Scale improvement of at least 1 point at last follow-up occurred in 69 of 113 procedures (61.1%). Procedure-related perioperative adverse events were infrequent, and no bypass-related reoperation occurred within 30 days. CONCLUSION: In this single-center retrospective series, standardized OA–PCA bypass using a cortical P4 recipient combined with EDPS was associated with reliable early graft patency and favorable angiographic, perfusion, and clinical outcomes in selected patients with posterior circulation–involved MMD. Late graft status should be interpreted together with collateral development, perfusion findings, and clinical course rather than in isolation.
BACKGROUND AND OBJECTIVES: Treatment of spinal tumors is complex and resource-intensive. The LACE+ index is a validated tool for predicting postoperative readmission and mortality. It incorporates length of stay, acuity of admission, comorbidity (Charlson index), and emergency visits and age, sex, and previous admissions (LACE+). This study assessed whether the LACE+ index has predictive value in patients undergoing spinal tumor surgery. METHODS: Data on patients undergoing spinal oncology surgery (n = 757) with preoperative LACE+ index were collected. Most patients underwent posterior instrumented aiming for gross total resection. Coarsened exact matching was used to account for confounding variables and assess the predictive value of LACE+. Patients with a LACE+ score in the top 50% of the study cohort (score >58, n = 169) were compared with matched patients in the bottom 50% (score <= 58, n = 169). Outcomes assessed included 30- and 90-day emergency department visits, readmissions, reoperations, nonhome discharges, and mortality. RESULTS: The cohort included primary (42.8%), metastatic (56.0%), and unknown spinal tumors (1.2%), with a mean age of 58 years (range 18-88). There were 386 patients with LACE+ <= 58 (51%) and 371 patients with LACE+ >58 (49%). Patients with high LACE+ scores were significantly more likely to be readmitted 30 (Odds ratios [OR] 1.91 [1.13, 3.19], P = .0169) and 90 days (OR 1.86 [1.17, 2.94], P = .0097) after surgery when compared with otherwise matched patients with a low LACE+ score. High LACE+ score patients were also more likely to require postacute care after discharge (OR 2.33 [1.48, 3.66], P = .0001) and have higher mortality rates at 90 days (OR 3.4 [1.25, 9.215], P = .0169). There were no differences in postoperative emergency department visits or reoperations. CONCLUSION: The LACE+ index can prospectively predict readmission, nonhome discharge, and mortality for spinal oncology patients after surgery. Application of the LACE+ index may help risk stratify and guide management of spinal tumor patients in the perioperative setting.
BACKGROUND AND OBJECTIVES: This anatomical study evaluates the feasibility of deep extracranial-to-intracranial microvascular bypass using the maxillary artery (MA) as a donor vessel accessed through an endoscopic transorbital approach. The aim was to assess potential donor–recipient configurations for revascularization of deep intracranial targets. METHODS: Four adult human cadaveric heads (8 sides) were dissected using a combined endoscopic–microscopic technique. The endoscopic transorbital approach was used to access the infratemporal fossa and expose the MA, while microsurgical techniques were employed for bypass anastomoses to intracranial recipient vessels. Bypass configurations included direct end-to-end MA-to-anterior temporal artery (ATA) and deep posterior temporal artery-to-ATA anastomoses, as well as interpositional bypasses using the superficial temporal artery (STA) to connect the MA to the supraclinoid internal carotid artery (SC-ICA) and second segment of the middle cerebral artery (M2). Feasibility, bypass quality, vessel diameters, graft length, and anatomical depth were assessed descriptively. RESULTS: Direct MA-to-ATA bypass was feasible in 3 of 8 sides and deep posterior temporal artery-to-ATA in 6 of 8. Interpositional MA-to-SC-ICA and MA-to-M2 bypasses using an STA graft were feasible in all 8 sides, as was end-to-end MA-to-STA anastomosis. The mean graft lengths were 30 mm for SC-ICA and 21 mm for M2 bypasses. Depth to target vessels ranged from 46 to 80 mm. Favorable donor–recipient diameter compatibility and short grafts supported anatomically efficient bypass geometry. Most bypasses were rated as good or intermediate quality. CONCLUSION: Deep extracranial-to-intracranial bypass using the MA through an endoscopic transorbital corridor is anatomically feasible and allows multiple donor–recipient configurations through a single minimally invasive route. Direct access to deep targets, accurate donor localization, and short graft constructs are facilitated. These findings establish an anatomical foundation for future clinical application of transorbital MA-based revascularization, particularly in patients requiring flow augmentation to deep-seated targets or with suboptimal cervical donor access.
BACKGROUND AND OBJECTIVES: Augmented reality–based neuronavigation systems (AR-NS) have been proposed as a potential addition to regular neuronavigation systems, such as optical or electromagnetic systems. Accurate image-to-patient registration is a prerequisite for clinical acceptance and implementation of AR-NS in neurosurgical workflows. In this study, the registration performance of a novel AR-NS using a head-mounted display with an integrated red-green-blue camera was compared with that of a state-of-the-art infrared optical neuronavigation system. The performance was evaluated in controlled phantom experiments and in a clinical setting, focusing on registration error, localization precision, and registration time. METHODS: Phantom experiments were performed using a human head model equipped with 8 fiducial markers under controlled conditions. Subsequently, adult patients who were undergoing cranial neurosurgery with preoperative T1-weighted contrast-enhanced MRI were included in the clinical study. In both phantom and clinical settings, the target registration error (TRE) and fiducial registration error were assessed using 7 registration fiducials and one independent target fiducial. The registration time was also recorded. Paired t -tests were used for the statistical analysis. RESULTS: Data from 37 patients were included for analysis. In phantom experiments, sub-3-mm TRE and sub-1-mm point localization were achieved with both systems ( P = .63). In the clinical setting, mean TRE values for AR-NS and infrared optical neuronavigation system were 5.5 ± 3.0 mm [95% CI: 4.8, 6.2] and 4.0 ± 2.0 mm [95% CI: 3.4, 4.7], respectively. The mean TRE difference was 1.2 ± 3.6 mm [95% CI: 0.1, 2.4], P = .047. CONCLUSION: Comparable registration performance was observed in the phantom measurements. A statistically significant difference in the registration performance of the 2 systems was observed in the patient measurements. The difference between the phantom and clinical findings highlights that similar registration performance can be achieved by the 2 systems under controlled circumstances, but the effect of clinical variables on the registration performance requires further investigation.
