Comparing the Effect of Spinal Versus General Anesthesia on Postoperative Opioid Use in Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Patient Matched Study
Background/Objectives: Postoperative opioid exposure after lumbar fusion remains a key clinical concern. Understanding which perioperative factors are associated with lower postoperative opioid use may help optimize recovery after minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF). This study aimed to determine if patients undergoing MIS-TLIF under spinal anesthesia (SA) showed lower postoperative opioid use compared to those undergoing MIS-TLIF under general anesthesia (GA). Methods: We retrospectively studied all adult patients (>18 years) undergoing 1- and contiguous 2-level MIS-TLIFs performed by a single surgeon. Patients undergoing the procedure under GA were compared to those undergoing the procedure under SA. Postoperative oral opioid use, up to 3 months post discharge, was collected. A 1:1 propensity score matching (PSM) protocol was implemented. Each outcome variable was initially assessed using univariate regression. Predictor variables with a p-value < 0.2 were included in the multivariate regression model. This was a retrospective, non-randomized study, and residual confounding cannot be excluded despite PSM. Results: The matched groups (n = 50 in each group) did not differ significantly depending on demographics or levels fused. Before regression, mean number of postoperative opioid prescriptions (p = 0.03), mean total operating room (OR) time in minutes (p < 0.01), and median length of stay (LOS) in days (p = 0.03) were significantly different. Multivariate regression showed that the GA group received 216.5 more total morphine milligram equivalents than the SA group (95% CI = 0.7–432.2, p = 0.049). The days of opioid use were higher in the GA group by 3.8 days (95% CI = 0.5 to 7.1, p = 0.025). On multivariate regression, LOS in hours was greater in the GA group by 14.1 h (p = 0.042). Conclusions: SA is an effective anesthetic modality for spinal surgery with the advantages of reduced postoperative opioid use, reduced OR time, and shorter LOS compared to GA.
Abstract 339: Acute Hemodynamic Effects of Strenuous Exercise and Valsalva Maneuvers in Individuals With and Without Intracranial Aneurysms: A Systematic Review
Introduction Although Valsalva maneuvers and strenuous exercise are commonly discouraged in patients with intracranial aneurysms (IAs), the cerebrovascular stress they induce remains poorly characterized. To our knowledge, no prior review has systematically quantified their effects on hemodynamic surrogates of rupture risk. Objective To characterize the acute intracranial hemodynamic effects of strenuous physical activity and Valsalva maneuvers in individuals with and without IAs. Methods We searched PubMed, Embase, Scopus, Web of Science, and Cochrane (February 2025; PROSPERO ID: CRD42025637608) following PRISMA. Eligible studies reported acute changes in SBP, ICP, central venous pressure (CVP), cerebrovascular transmural pressure (CVTMP), middle cerebral artery (MCA) velocity, or CFD‐derived parameters (wall shear stress [WSS], oscillatory shear index [OSI], relative residence time [RRT]) in response to physical exertion or Valsalva. Populations included individuals with or without IAs. Acute neurological symptoms were also reviewed. Results From 2,859 records, 14 studies met inclusion criteria. Eight studies assessed real‐time hemodynamic responses during exercise (91 participants without IAs). Three studies (n=39) showed that resistance exercise increased SBP (mean Δ+21.8 mmHg). Two studies (n=22) showed significant MAP elevation (mean Δ+24.7 mmHg). When combined with a Valsalva maneuver, SBP increased further (mean Δ+26 mmHg; range 20–30). Three studies (n=38) evaluating isolated Valsalva identified significant ICP elevation (mean Δ+15 mmHg; range 5.7–24.3), primarily driven by CVP increases (mean Δ+52.0 mmHg; range 39–56). Breath‐holding during exertion reduced MCA velocity (mean Δ–11.6 cm/s), while continuous ventilation preserved more stable flow. In seven patients, resistance exercise without Valsalva increased CVTMP by 24.5%. In contrast, Valsalva alone raised ICP and CVP without increasing SBP, yielding a CVTMP 11% lower than during exercise alone. These paired observations suggest that Valsalva may transiently offset exercise‐induced transmural stress by raising ICP alongside SBP. However, this effect may be time‐limited and reverse during early recovery—when SBP remains elevated as ICP quickly normalizes—potentially producing a CVTMP rebound above exercise‐only levels. Six CFD studies (11 aneurysms; diameter 6.3–23 mm; 2 ruptured) reported exercise‐related increases in time‐averaged WSS (mean +21.7%, range –4.4% to +50%) and peak WSS (mean +382.3%, range +100% to +628%). Exercise‐induced changes in heart rate and flow pulsatility led to complex redistributions of intra‐aneurysmal WSS, potentially exposing the aneurysmal wall to focal mechanical stress. Conclusion Resistance exercise, especially with breath‐holding, provokes dynamic, time‐sensitive cerebrovascular stress. Valsalva maneuver may transiently lower CVTMP during effort, yet its release with lingering SBP elevation can precipitate delayed transmural pressure surges. The proposed biphasic effect of Valsalva offers a novel conceptual framework for prospective. Our findings underscore the need to define safe, individualized activity thresholds for patients with IAs with patient‐specific validation integrating concurrent physiology and CFD to reduce the risk of IA growth and rupture.
Abstract 337: Exercise and Straining as Potential Triggers of Aneurysmal Rupture: A Systematic Review
Introduction The risk of aneurysmal subarachnoid hemorrhage (aSAH) during exercise is not well quantified. We assessed temporal clustering of aSAH around physical exertion and around Valsalva‐like activities (defecation or urination). Objectives To estimate the proportion of aSAH cases temporally linked to strenuous activities using reported exposure‐to‐onset window uwing within‐person odds of rupture from case‐crossover studies. Methods We searched PubMed/MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library from inception through January 2025, and hand‐searched reference lists (PRISMA‐aligned; PROSPERO CRD42025637608). Eligible studies reported the activity at aSAH onset or within a defined pre‐onset window. Exposures were analyzed separately (exertion; defecation/urination). Primary proportional estimates used each study's own exposure‐to‐onset window as reported. To improve comparability, subgroup analysis was performed with only a prespecified subset pooled consecutive case series that explicitly used a ≤2‐hour window between the index activity and aSAH. Within‐person odds ratios (ORs) were abstracted from case‐crossover studies. Risk of bias for observational exposure studies was assessed with ROBINS‐E by two independent reviewers. Results Sixteen studies (published 1980–2022) from 10 countries were included with 5,815 cases of aSAH (mean age 55 years; 60.6% female). Designs comprised 10 case series, 3 case reports, 2 case‐crossover studies, and 1 case‐control study. Activity‐at‐onset was recorded for 4,219/5,815 (72.6%); among these 4,219 patients, mean age was 52.7 years. Using each study's reported window, 308/4,219 (7.3%) aSAH occurred during or within the study‐defined window after physical exertion, and 387/4,219 (9.2%) during/within the window after defecation or urination 695/4,219 (16.5%) were temporally linked to either exposure. In the subset of 10 consecutive case series restricted to ≤2 hours, 275 (5.4%) were linked to exertion and 385 (7.6%) to defecation/urination (combined 660; 13.0%). Study‐specific proportions ranged from 0.8–21.3% for exertion and 2.0–15.4% for defecation/urination. Two case‐crossover studies reported higher within‐person odds of rupture after moderate‐to‐vigorous exertion (OR 2.4–2.7). Temporal clustering of aSAH around exertion or straining was observed in 13–17% of cases, depending on dataset and inclusion criteria. Conclusions Although this relatively high rate of temporal association between aSAH and exercise might suggest an increased risk of aneurysm rupture during strenuous activity, variable definitions and unstated exposure‐to‐onset windows do not permit causal inference. Prospective or registry‐embedded case‐crossover studies using standardized exposure definitions (intensity, duration) and objective exposure capture are needed to refine immediate‐risk estimates and identify patient‐level susceptibility modifiers.
Abstract 290: Treatment Strategies for Residual and Recurrent Aneurysms After Woven EndoBridge Therapy: A Multicenter Propensity‐Matched Analysis
Introduction Post‐market and multicenter studies report low complete occlusion rates (41‐49%) and higher retreatment rates (13%) following WEB deployment, compared to 3.8% with microsurgical clipping. While retreatment after WEB has been shown to be technically feasible, data on final angiographic outcomes remain limited. We performed a retrospective analysis of prospective databases from 14 cerebrovascular centers in the US to compare the safety and efficacy of retreatment versus continued observation for residual and recurrent aneurysms after initial WEB deployment. Materials/Methods Multinomial logistic regression was used to identify baseline characteristics of untreated and residual/recurrent aneurysms that may act as confounders, which then underwent propensity scored matching (PSM). Results Among 211 patients (125 observed, 86 retreated), retreatment was more common in initially ruptured aneurysms (p<0.001), which showed higher recurrence (p=0.036) and sac‐dominant residuals (p=0.004). These were primarily due to WEB compression on follow‐up (p=0.001), rather than incomplete occlusion with an appropriately sized device (p<0.001). Retreatment was associated with significantly higher rates of complete angiographic occlusion at last follow‐up compared to observation alone (p<0.001), a finding that remained consistent across subgroups defined by initial unruptured status, residual type, and recurrence patterns (all p<0.05). Clipping demonstrated higher, though statistically insignificant, rates of complete occlusion; flow diversion and stent‐assisted coil embolization yielded comparable complete occlusion rates at follow‐up. After propensity score matching, retreatment remained significantly associated with higher rates of complete angiographic occlusion (all p<0.05), with comparable outcomes observed between clipping and various endovascular approaches as above. Conclusion Retreatment improved complete occlusion rates; however, no aneurysmal hemorrhages occurred in either group. Further intervention may be unnecessary when the WEB device—whether compressed or intact (BOSS 0/1)—adequately protects the dome. In cases where WEB compression significantly exposes the aneurysm wall, stent‐assisted coiling or flow diversion can be performed safely and successfully, depending on vascular anatomy and surgeon preference. image image
Spinal versus general anesthesia in robotic minimally invasive transforaminal lumbar interbody fusion: a comparative study on surgical outcomes
OBJECTIVE The implementation of robotics and spinal anesthesia (SA) in spine surgery is rapidly expanding, offering significant benefits for an increasingly complex and aging patient population with degenerative spinal disease. Here, the authors present the largest cohort to date evaluating the combined use of these two techniques in minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF). METHODS The authors retrospectively analyzed surgical outcomes of a series of patients who underwent robot-assisted (RA)–MIS TLIF under SA and general anesthesia (GA) at their institution from 2018 to 2024. Primary outcomes included operative times and postoperative pain intensity. Secondary outcomes included estimated blood loss, intraoperative complications, postoperative functional status, length of stay (LOS), and discharge status. To address potential confounders, a 1:1 propensity score–matching and regression analysis was implemented. Statistical analyses were conducted using Python. RESULTS A total of 209 patients underwent RA-MIS TLIF, with 31 (14.83%) receiving SA and 178 (85.17%) GA. After propensity score matching, the SA cohort demonstrated significantly shorter median total operating room (OR) time, total procedure time, time from entering the OR to skin incision, and time from closure to leaving the OR (all p < 0.01). Additionally, postoperative pain scores were significantly lower (p < 0.01), and LOS was significantly shorter (p < 0.01) in the SA cohort. Regression analysis, adjusting for potential confounders, further supported these findings. CONCLUSIONS RA-MIS TLIF fusion under SA is a safe and effective approach that significantly reduces operative time, postoperative pain, and hospital LOS in patients undergoing surgery for degenerative lumbar spine disease.
Dual Approach for Basilar Artery Fenestration Aneurysm With Insights From Computational Fluid Dynamics
BACKGROUND AND IMPORTANCE: Basilar artery fenestration aneurysms (BAFAs) present significant clinical challenges because of their high rupture risk and complex anatomy. Comprehensive management strategies are required, including thorough vascular assessment and post-treatment surveillance. Integration of complementary analyses such as computational fluid dynamics (CFD) holds promise in facilitating preoperative planning for these intricate lesions. CLINICAL PRESENTATION: A 60-year-old female was diagnosed with a BAFA during evaluation for headaches. Digital subtraction angiography revealed the aneurysm projecting posteriorly with a neck predominantly based on the right limb of the fenestration. After initial treatment with a pipeline embolization device, the aneurysm remained patent, requiring further treatment. A secondary approach with stent-assisted loose-packing coil embolization was then performed, resulting in complete occlusion of the aneurysm. Analysis of pretreatment 3-dimensional rotational angiogram images with CFD provided critical hemodynamic insights. It identified that 38.89% of the aneurysm area was exposed to low wall shear stress (WSS) and 11.5% was exposed to high WSS, indicating a high rupture risk profile with significant areas of both low and high WSS. In addition, low WSS was observed in regions corresponding to daughter sacs, suggesting a higher rupture risk. Streamline analysis indicated increased inflow through the right vertebral artery and the right limb of the fenestration, supporting the initial angiographic impression and guiding the choice of therapeutic strategy. CONCLUSION: This is the first study to analyze the morphology and pretreatment hemodynamics of a BAFA using CFD, illustrating the potential for future development of individualized therapeutic approach–based CFD in complex aneurysms.
Commentary: Assessment of the Subarcuate Canaliculus as a Landmark in Middle Fossa Surgery