Surgery For Stenosis Research Articles

Does Paraspinal Muscle Mass Predict Lumbar Lordosis before and after Decompression for Degenerative Spinal Stenosis?

Retrospective Cohort Study. The purpose of this study was to determine if muscle mass and quality of the lumbar paraspinal muscles was associated with improvements in lumbar lordosis and other sagittal parameters after isolated posterior lumbar decompression surgery for lumbar spinal stenosis. Over time, either due to degenerative changes or other spinal conditions, individuals may develop sagittal imbalance. In patients with lumbar spinal stenosis, sagittal imbalance can further exacerbate symptoms of pain and radiculopathy. Sarcopenia of paraspinal muscles has been implicated in previous spine research as a variable with influence on surgical outcomes. Sagittal parameters were measured on preoperative and postoperative lateral lumbar radiographs and included lumbar lordosis (LL), sacral slope (SS), and pelvic tilt (PT). Preoperative MRI images were evaluated at the base of the L4 vertebral body to assess muscles mass of the psoas muscle and paravertebral muscles (PVM) and Goutallier grade of the PVM. Patients were divided into 3 muscle size groups based on PVM normalized for body size (PVM/BMI): Group A (smallest), Group B, and Group C (largest). Patients in Group C had greater LL preoperatively (51.5° vs. 47.9° vs. 43.2, P=0.005) and postoperatively (52.2° vs. 48.9° vs. 45.7°, P=0.043). There was no significant difference in the ∆LL values between groups (P>0.05). Patients in Group C had larger SS preoperatively (35.2° vs. 32.1° vs. 30.0°, P=0.010) and postoperatively (36.1° vs. 33.0° vs. 31.7°, P=0.030). Regression analysis showed that PVM/BMI was a significant predictor of LL preoperatively (P=0.039) and postoperatively (P=0.031), as well as SS preoperatively (P=0.001) and postoperatively (P<0.001). Muscle mass of the paravertebral muscles significantly impacts lumbar lordosis and sacral slope in patients with lumbar spinal stenosis before and after posterior lumbar decompression. These findings highlight a need to address risk factors for poor muscle quality in patients with sagittal imbalance.

Development and Validation of Machine Learning-Based Predictive Model for Prolonged Hospital Stay after Decompression Surgery for Lumbar Spinal Canal Stenosis.

Precise prediction of hospital stay duration is essential for maximizing resource utilization during surgery. Existing lumbar spinal stenosis (LSS) surgery prediction models lack accuracy and generalizability. Machine learning can improve accuracy by considering preoperative factors. This study aimed to develop and validate a machine learning-based model for estimating hospital stay duration following decompression surgery for LSS. Data from 848 patients who underwent decompression surgery for LSS at three hospitals were examined. Twelve prediction models, using 79 preoperative variables, were developed for postoperative hospital stay estimation. The top five models were chosen. Fourteen models predicted prolonged hospital stay (≥14 days), and the most accurate model was chosen. Models were validated using a randomly divided training sample (70%) and testing cohort (30%). The top five models showed moderate linear correlations (0.576-0.624) between predicted and measured values in the testing sample. The ensemble of these models had moderate prediction accuracy for final length of stay (linear correlation 0.626, absolute mean error 2.26 days, standard deviation 3.45 days). The c5.0 decision tree model was the top predictor for prolonged hospital stay, with accuracies of 89.63% (training) and 87.2% (testing). Key predictors for longer stay included JOABPEQ social life domain, facility, history of vertebral fracture, diagnosis, and Visual Analogue Scale (VAS) of low back pain. A machine learning-based model was developed to predict postoperative hospital stay after LSS decompression surgery, using data from multiple hospital settings. Numerical prediction of length of stay was not very accurate, although favorable prediction of prolonged stay was accomplished using preoperative factors. The JOABPEQ social life domain score was the most important predictor.

Predictors of Patient Dissatisfaction after Lumbar Spinal Canal Stenosis Surgery: A Multicenter Retrospective Study.

Recently, patient satisfaction has gained prominence as a crucial measure for ensuring patient-centered care. Furthermore, patient satisfaction after lumbar spinal canal stenosis (LCS) surgery is an important metric for physician's decision of surgical indication and informed consent to patient. This study aimed to elucidate how patient satisfaction changed after LCS surgery to identify factors that predict patient dissatisfaction. We retrospectively reviewed time-course data of patients aged ≥40 years who underwent LCS surgery at multiple hospitals. The participants completed the Zurich Claudication Questionnaire (ZCQ) and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) before surgery and then 6 months and 1 year postsurgery. Patient satisfaction was categorized according to the postoperative score of the satisfaction domain of the ZCQ: satisfied, score ≤2.0; moderately satisfied, 2.0< score ≤2.5; and dissatisfied, score >2.5. The study enrolled 241 patients. Our data indicated a satisfaction rate of around 70% at 6 months and then again 1 year after LCS surgery. Among those who were dissatisfied 6 months after LCS surgery, 47.6% were more satisfied 1 year postsurgery. Furthermore, 86.2% of those who were satisfied 6 months after LCS surgery remained satisfied at 1 year. Multivariable analysis revealed that age (relative risk, 0.5; 95% confidence interval, 0.2-0.8) and preoperative score of psychological disorders on the JOABPEQ (relative risk, 0.2; 95% confidence interval, 0.03-0.08) were significantly associated with LCS surgery dissatisfaction. In addition, the receiver operating characteristic curve analysis revealed that the cutoff value for the preoperative score of psychological disorder of the JOABPEQ was estimated at 40 for LCS surgery dissatisfaction. Age and psychological disorders were identified as significant predictors of dissatisfaction, with a JOABPEQ cutoff value providing potential clinical applicability.

Assessing the Impact of Preoperative MRI-Based Vertebral Bone Quality Scores on 5-Year Prognosis in Lumbar Spine Surgery.

Retrospective cohort study. To assess the utility of preoperative vertebral bone quality (VBQ) scores in predicting the 5-year clinical outcomes following lumbar spine surgery. Osteoporosis poses a significant concern in older adults undergoing spinal surgery. The VBQ score, assessed through preoperative magnetic resonance imaging (MRI), is associated with subsequent osteoporotic fractures and postoperative complications. However, previous report on the impact of VBQ score on mid-term clinical outcomes after lumbar spine surgery remains lacking. A total of 189 patients who underwent lumbar surgery (≤3-disc levels) for lumbar spinal stenosis between 2010 and 2016 were enrolled. Patients were classified into high (>3.35), middle (2.75 to 3.35), and low (<2.73) VBQ score groups based on tertiles. Clinical scores, including Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Short Form-36 (SF-36), were recorded preoperatively and 1, 2, and 5 years postoperatively. Comparative analysis showed significant differences among the VBQ groups throughout the study period in low back pain (P=0.013), walking ability (P=0.005), social life function (P=0.010) of JOABPEQ, and physical component summary of the SF-36 (P=0.018) following lumbar spine surgery. A higher VBQ score was significantly correlated with worse 5-year postoperative outcomes for all domains except for lumbar function of the JOABPEQ using multiple linear regression analysis, adjusting for age, sex, BMI, hyperlipidemia, surgical procedures, and each preoperative score. A high preoperative VBQ score is a risk factor for poor 5-year clinical outcomes after lumbar spine surgery. Evaluation of the VBQ score through routine preoperative MRI facilitates osteoporotic screening in lumbar patients without radiation exposure and healthcare costs, while also demonstrating its potential as a prognostic indicator of postoperative clinical outcomes. 3.

Change in Lumbar Lordosis after Decompressive Surgery in Lumbar Spinal Stenosis Patients and Associations with Patient Related Outcomes 2 Years after Surgery. Radiological and Clinical Results from the NORDSTEN Spinal Stenosis Trial.

A prospective cohort study. The aim was to investigate changes in lumbar lordosis (LL) and its association to changes in patient reported outcome measures (PROMs) after decompressive surgery for lumbar spinal stenosis (LSS). Few studies have addressed change in LL after decompression surgery for LSS in relation to outcomes. Pre- and postoperative data from 310 patients having standing x-ray both before and 2 years after surgery were included. The patients were grouped based on the change in LL preoperatively to 2 years after surgery; group 1: <5 degrees (n=196), group 2: ≥5 <10 degrees (n=55) or group 3: ≥10 degrees (n=59) of change in LL. The changes in function, disability and pain were assessed by the Oswestry Disability Index (ODI), Numeric Rating Scale (NRS), and the Zurich claudication questionnaire (ZCQ). The three groups were compared regarding baseline variables using the ANOVA test for continuous variables and the chi-square test for categorical variables. The groups were further compared with a likelihood ratio test in relation to changes in PROMs 2 year after surgery and outcomes were adjusted for respective baseline PROMs, age, sex, smoking, BMI, Schizas and Pfirrmann scores. LL was significantly changed at group level 2 years after surgery with a mean difference of 2.2 (SD 9.4) degrees ( P =0.001). The three LL change groups did not show any significant differences in patient characteristics, function, disability, and pain at baseline. The two groups with a change of more than 5 degrees in LL 2 year after surgery (group 2 and 3) had significantly greater improvements in ODI ( P =0.022) and ZCQ function ( P =0.016) in the adjusted analyses, but was not significant for back and leg pain. Changed LL after decompressive surgery for LSS was associated with improved ODI and physical function.

ARGININE VASOPRESSIN DEFICIENCY INDUCES DECREASED CARDIAC FIBROSIS RATE AND MEAN ARTERIAL BLOOD PRESSURE IN RATS WITH EXPERIMENTAL ABDOMINAL AORTIC STENOSIS

Cardiac fibrosis (CF) involves the accumulation of extracellular matrix proteins in the interstitial space, often seen in various cardiac pathologies. Each year, cardiovascular diseases claim the lives of 17.9 million people worldwide. Cardiac fibroblasts and myofibroblasts, equipped with vasopressin receptors (AVP), play a crucial role in regulating cell signaling pathways associated with CF development. AVP, an immunomodulatory hormone, influences immune responses, and its deficiency results in a decrease in immune activity. Abdominal aortic stenosis (AS) serves as an experimental model for left cardiac overload hypertension and CF. Neurointermediate pituitary lobectomy (NIL) induces a permanent decrease in circulating AVP levels, showcasing regression of hepatic fibrosis in liver damage models. The quest for effective alternative treatments for cardiac fibrosis poses a substantial challenge for researchers. In this experiment, groups of male Wistar rats weighing approximately 250 g (8/group) were categorized into: 1) Intact Control (IC), 2) Abdominal Aortic Stenosis (AS), 3) Neurointermediate pituitary lobectomy (NIL), and 4) AS+NIL. The AS and AS+NIL groups underwent abdominal aortic stenosis surgery on day one of the experiment. By week 5, the NIL and NIL+AS groups underwent NIL surgery. Prior to sacrifice at week 10, intracarotid mean blood pressure (MBP) was assessed in all groups. Following sacrifice, the hearts were removed, fixed in neutral formalin, and processed in paraffn for histopathological examination using H-E, Masson's trichrome, and Sirius red staining. Results revealed an elevated MBP in the AS group (156 ± 27.1 vs. 114 ± 30 mmHg in the IC), normalized in the AS+NIL group (110 ± 40.9 mmHg), and a mild decrease in the NIL group (87 ± 7.6 mmHg). The evaluation of CF in histological slides concurred with the MBP findings; a significant increase in CF occurred in the AS group compared to the IC, NIL, and AS+NIL groups, with almost complete reversion of CF observed in the AS+NIL group. In summary, this study demonstrates that AVP deficiency induces arterial hypotension, and in the AS+NIL group, AVP deficiency led to: 1) a decrease in blood pressure to normal levels and 2) reversion of cardiac fibrosis. Further experiments are warranted to determine if the decrease in blood pressure and cardiac overload are suffcient to inhibit profibrogenic mechanisms and/or activate antifibrogenic mechanisms. Additionally, investigations are needed to explore whether AVP deficiency, beyond inhibiting the inflammatory process, promotes the activation of antifibrogenic mechanisms. The present results offer new avenues for a deeper understanding of the molecular and cellular mechanisms through which AVP deficiency or the use of AVP receptor antagonists significantly influences fibrosis regulation in organ fibrotic diseases. Funding by Autonomous University of Aguascalientes (PIFF22-1). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Construct validation of the Japanese Core Outcome Measures Index and the impact of diseases on patient-reported outcome measures in preoperative patients with lumbar spinal stenosis and disk herniation: a single-center observational study

PurposeThe primary objective was to validate the construct validity of the Japanese Core Outcome Measures Index (COMI) in preoperative patients aged 60 years or older undergoing lumbar spine surgery for lumbar spinal stenosis (LSS) and lumbar disk herniation (LDH). Additionally, as a secondary aim, we explored the impact of these diseases on quality of life (QOL).MethodsThe analysis included 199 preoperative patients aged 60 and above who were scheduled for lumbar spine surgery. To assess QOL, Japanese versions of the COMI, Oswestry Disability Index (ODI), EuroQol-5 Dimension-3 Level (EQ-5D-3L), and SF-12v2 were employed. The study assessed the validity of the COMI and compared demographic and clinical characteristics between the LSS (147 cases) and LDH (52 cases) groups. It used multivariate covariance analysis (MANCOVA) to examine the impact of diseases (LSS and LDH) on each patient-reported outcome measure while considering covariates.ResultsCompared to the LSS group, the LDH group showed more difficulty with the COMI summary score (LSS/LDH [mean]: 6.9/8.1, p < 0.001), ODI score (46.8/57.4, p < 0.001), and EQ-5D utility (0.53/0.43, p < 0.001). The LDH group also reported more difficulties in the COMI-function, COMI-symptom-specific well-being, COMI-disability, ODI-personal care, ODI-social life, and SF-12v2-bodily pain subscales. MANCOVA demonstrated that these results were not influenced by covariates such as gender and medical history.ConclusionsThis study highlights the distinct impact of LSS and LDH on preoperative QOL in older patients undergoing lumbar spinal surgery. Tailored interventions are essential to address the specific challenges posed by these conditions and improve patient-centered outcomes and postoperative recovery.

Identification of microRNA biomarkers simultaneously expressed in circulating extracellular vesicles and atherosclerotic plaques.

Atherosclerosis is a widespread disorder of the cardiovascular system. The early detection of plaques by circulating biomarkers is highly clinically relevant to prevent the occurrence of major complications such as stroke or heart attacks. It is known that extracellular vesicles (EVs) are important in intercellular communication in atherosclerotic disorders and carry many components of their cells of origin, including microRNAs (miRNAs). In this study, we test the assumption that miRNAs present in material acquired from plaques in patients undergoing surgery for atherosclerotic carotid artery stenosis are also expressed in circulating EVs obtained from the identical patients. This would allow the adoption of a liquid biopsy approach for the detection of plaques. We studied 22 surgical patients with atherosclerotic carotid arterial stenosis and 28 healthy controls. EVs were isolated from serum by precipitation. miRNA expression profiles of serum-derived EVs were obtained by small RNA sequencing and in plaque material simultaneously acquired from patients. A comparative analysis was performed to identify circulating atherosclerosis-associated miRNAs that are also detectable in plaques. Seven miRNAs were found to be differentially regulated in patient serum compared with the serum of healthy controls. Of these, miR-193b-5p, miR-193a-5p, and miR-125a-3p were significantly upregulated in patients compared with that in healthy controls and present in both, circulating EVs and plaque material. An overrepresentation analysis of experimentally validated mRNA targets revealed an increased regulation of inflammation and vascular growth factors, key players in atherosclerosis and plaque formation. Our findings suggest that circulating EVs reflect plaque development in patients with symptomatic carotid artery stenosis, which can serve as biomarker candidates for detecting the presence of atherosclerotic plaques.

Postoperative complications after surgery for lumbar spinal stenosis, assessment using two different data sources

PurposeLumbar spinal stenosis (LSS) is a prevalent disorder, and surgery for LSS is a common procedure. Postoperative complications occur after any surgery and impose costs for society and costs and additional morbidity for patients. Since complications are relatively rare, medical registries of large populations may provide valuable knowledge. However, recording of complications in registries can be incomplete.To better estimate the true prevalence of complications after LSS surgery, we reviewed two different sources of data and recorded complications for a sample of Norwegian LSS patients.Methods474 patients treated surgically for LSS during 2015 and 2016 at four hospitals reported to a national spine registry (NORspine).Postoperative complications were recorded by patients in NORspine, and we cross-referenced complications documented in NORspine with the patients´ electronic patient records (EPR) to re-test the complication rates. We performed descriptive statistics of complication rates using the two different data sources above, and analyzed the association between postoperative complications and clinical outcome with logistic regression.ResultsThe mean (95%CI) patient age was 66.3 (65.3–67.2) years, and 254 (53.6%) were females. All patients were treated with decompression, and 51 (10.7%) received an additional fusion during the index surgery. Combining the two data sources, we found a total rate for postoperative complications of 22.4%, the NORspine registry reported a complication rate of 15.6%, and the EPR review resulted in a complication rate of 16.0%. However, the types of complications were inconsistent across the two data sources. According to NORspine, the frequency of reoperation within 90 days was 0.9% and according to EPR 3.4%. The rates of wound infection were for NORspine 3.1% and EPR review 2.1%.There was no association between postoperative complication and patient reported outcome.ConclusionPostoperative complications occurred in 22% of LSS patients. The frequency of different postoperative complications differed between the two data sources.

Time Course of Asymptomatic Stenosis in Multiple Lumbar Spinal Stenosis-Five-Year Results of Selective Decompression of Symptomatic Levels.

Background: In the diagnosis of lumbar spinal stenosis (LSS), finding stenosis with magnetic resonance imaging (MRI) does not always correlate with symptoms such as sciatica or intermittent claudication. We perform decompression surgery only for cases where the levels diagnosed from neurological findings are symptomatic, even if multiple stenoses are observed on MRI. The objective of this study was to examine the time course of asymptomatic stenosis in patients with LSS after they underwent decompression surgery for symptomatic stenosis. Materials and Methods: The participants in this study comprised 137 LSS patients who underwent single-level L4-5 decompression surgery from 2003 to 2013. The dural sac cross-sectional area at the L3-4 disc level was calculated based on preoperative MRI. A cross-sectional area less than 50 mm2 was defined as stenosis. The patients were grouped, according to additional spinal stenosis at the L3-4 level, into a double group (16 cases) with L3-4 stenosis, and a single group (121 cases) without L3-4 stenosis. Incidences of new-onset symptoms originating from L3-4 and additional L3-4-level surgery were examined. Results: Five years after surgery, 98 cases (72%) completed follow-up. During follow-up, 2 of 12 patients in the double group (16.7%) and 9 of 86 patients in the single group (10.5%) presented with new-onset symptoms originating from L3-4, showing no significant difference between groups. Additional L3-4 surgery was performed for one patient (8.3%) in the double group and three patients (3.5%) in the single group; again, no significant difference was shown. Conclusion: Patients with asymptomatic L3-4 stenosis on preoperative MRI were not prone to develop new symptoms or need additional L3-4-level surgery within 5 years after surgery when compared to patients without preoperative L3-4 stenosis. These results indicate that prophylactic decompression for asymptomatic levels is unnecessary.

To 110th anniversary of cardiac surgeon and researcher Igor N. Meshalkin

Igor N. Meshalkin (1913–1996) was Soviet cardiac surgeon, Dr. Sci. (Medicine). He was a graduate of the 2nd Moscow State Medical Institute (2nd MSMI, now the N.I. Pirogov Russian National Research Medical University). He was a participant in the Great Patriotic War. Igor N. Meshalkin began his professional career as a medical resident and an assistant of the clinic of faculty surgery in the 2nd MSMI since 1947; then as a medical resident of the Main Military Hospital of the Armed Forces of the USSR since 1951 and an assistant of the general surgery department of the pediatric faculty in the 2nd MSMI since 1954. In 1958–1963, he headed the Department of Acquired Heart Diseases in the Institute of Experimental Biology and Medicine (now the E.N. Meshalkin National Medical Research Center). In 1963–1977, Igor N. Meshalkin was the head of the department in the Central Clinical Hospital of the 4th Main Directorate of the USSR Ministry of Health. His research interests were focused on urgent abdominal surgery, thoracic surgery, mitral stenosis surgery. Igor N. Meshalkin was the author of 55 scientific works including two monographs. Received 8 November 2023. Accepted 14 November 2023. Funding: The study did not have sponsorship. Conflict of interest: The authors declare no conflict of interest. Contribution of the authors: The authors contributed equally to this article. Acknowledgment: The authors would like to thank Marina, daughter of Igor N. Meshalkin, for providing personal documents and photographs.

Surgery for Spinal Stenosis in Achondroplasia: Causes of Reoperation and Reduction of Risks.

Individuals with achondroplasia are prone to symptomatic spinal stenosis requiring surgery. Revision rates are thought to be high; however, the precise causes and rates of reoperation are unknown. The primary aim of this study is to investigate the causes of reoperation after initial surgical intervention in individuals with achondroplasia and spinal stenosis. In addition, we report on surgical techniques aimed at reducing the risks of these reoperations. A retrospective review was conducted over an 8-year period of all patients with achondroplasia at a single institution that serves as a large referral center for patients with skeletal dysplasias. Patients with achondroplasia who underwent spinal surgery for stenosis were identified and the need for revision surgery was studied. Data collected included demographic, surgical, and revision details. Fisher exact test was used to determine if an association existed between construct type and the need for revisions. Thirty-three of the 130 (22%) patients with achondroplasia required spinal stenosis surgery. Twenty-four individuals who met the criteria were selected for analysis. The initial spine surgery was at an average age of 18.7 years (SD: 10.1y). Nine patients (38%) required revision surgeries, and 3 required multiple revisions. Five of 9 (56%) of the revisions had primary surgery at an outside institution. Revision surgeries were due to caudal pseudarthrosis (the distal instrumented segment) (8), proximal junctional kyphosis (PJK) (7), and new neurological symptoms (7). There was a significant association found between construct type and the need for revision ( P =0.0111). The pairwise comparison found that short fusions were significantly associated with the need for revision compared with the interbody group ( P =0.0180). PJK was associated with short fusions when compared with the long fusion group ( P =0.0294) and the interbody group ( P =0.0300). Caudal pseudarthrosis was associated with short fusions when compared with the interbody group ( P =0.0015). Multivariate logistic regression found long fusion with an interbody was predictive of and protective against the need for revision surgery ( P =0.0246). To date, none of the initial cases that had long fusions with caudal interbody required a revision for distal pseudarthrosis. In patients with achondroplasia, the rate of surgery for spinal stenosis is 22% and the risk of revision is 38% and is primarily due to pseudarthrosis, PJK, and recurrent neurological symptoms. Surgeons should consider discussing spinal surgery as part of the patient's life plan and should consider wide decompression of the stenotic levels and long fusion with the use of an interbody cage at the caudal level in all patients to reduce risks of revision. Level IV-Retrospective case series.

Dural Sac Cross-sectional area change from preoperatively and up to 2 years after decompressive surgery for central lumbar spinal stenosis: investigation of operated levels, data from the NORDSTEN study.

The aim of the present study was to investigate how canal area size changed from before surgery and up to 2 years after decompressive lumbar surgery lumbar spinal stenosis. Further, to investigate if an area change postoperatively (between 3 months to 2 years) was associated with any preoperative demographic, clinical or MRI variables or surgical method used. The present study is analysis of data from the NORDSTEN- SST trial where 437 patients were randomized to one of three mini-invasive surgical methods for lumbar spinal stenosis. The patients underwent MRI examination of the lumbar spine before surgery, and 3 and 24 months after surgery. For all operated segments the dural sac cross-sectional area (DSCA) was measured in mm2. Baseline factors collected included age, gender, BMI and smoking habits. Furthermore, surgical method, index level, number of levels operated, all levels operated on and baseline Schizas grade were also included in the analysis. 437 patients were enrolled in the NORDSTEN-SST trial, whereof 310 (71%) had MRI at 3 months and 2 years. Mean DSCA at index level was 52.0mm2 (SD 21.2) at baseline, at 3 months it increased to 117.2mm2 (SD 43.0) and after 2 years the area was 127.7mm2 (SD 52.5). Surgical method, level operated on or Schizas did not influence change in DSCA from 3 to 24 months follow-up. The spinal canal area after lumbar decompressive surgery for lumbar spinal stenosis increased from baseline to 3 months after surgery and remained thereafter unchanged 2 years postoperatively.

Reassessing the minimum 2-year follow-up standard after lumbar decompression surgery: a 2-month follow-up seems to be an acceptable minimum

BACKGROUND CONTEXTAcademic orthopedic journals and specialty societies emphasize the importance of two-year follow-up for patient-reported outcome measures (PROMS) after spine surgery, but there are limited data evaluating the appropriate length of follow-up. PURPOSETo determine whether PROMs, as measured by the Oswestry Disability Index (ODI), would change significantly after 2-months postoperatively after lumbar decompression surgery for disc herniation or spinal stenosis. STUDY DESIGNRetrospective analysis of prospectively and consecutively enrolled patients undergoing lumbar decompression surgery between 2020 and 2021 from a single surgeon spine registry. PATIENT SAMPLEOne hundred sixty-nine patients. OUTCOME MEASURESODI, achievement of minimum clinically important difference (MCID), revisions. METHODSPatients without a preoperative baseline score were excluded. Completion of the ODI questionnaire was assessed at the follow-up points. The median ODI was compared at time baseline, 2-month, 1-year and 2-year follow-up. Risk of reoperation was assessed with receiver operating characteristic (ROC) analysis to identify at-risk ODI thresholds of requiring reoperation. RESULTSMedian ODI significantly improved at all time points compared to baseline (median baseline ODI: 40; 2-month ODI: 16, p=.001; 1-year ODI: 11.1, p=.001; 2-year ODI: 8, p=.001). Posthoc analysis demonstrated no difference between 2-months, 1-year and 2-year postoperative ODI (p=.9, p=.468, p=.606). The MCID was met in 87.9% of patients at 2 months, 80.7% at 1 year, and 87.3% at 2 years postoperatively. Twelve patients (7.7%) underwent revision surgery between 2 months and 2 years after the index surgery (median time to revision: 5.6 months). ROC curve analysis demonstrated that an ODI score ≥24 points at 2-months yielded a sensitivity of 85.7% and a specificity of 71.8% for predicting revision after lumbar decompression (AUC=0.758; 95% CI: 0.613–0.903). The Youden optimal threshold value of ≥24 points at 2-month postop ODI yielded an odd ratio (OR) for revision of 15.3 (CI: 1.8–131.8; p=.004). The positive predictive value (PPV) and negative predictive value (NPV) were 15.4% and 98.8%, respectively. CONCLUSIONTwo-year clinical follow-up may not be necessary for future peer-reviewed lumbar decompression surgery studies given that ODI plateaus at 8 weeks. Patients with a score ≥24 points at 2-months postoperatively have a higher risk of requiring a second surgery within the first 2 years and warrant continued follow-up.

Polytomous Rasch Analyses of Surgeons' Decision-Making on Choice of Procedure in Endoscopic Lumbar Spinal Stenosis Decompression Surgeries.

With the growing prevalence of lumbar spinal stenosis, endoscopic surgery, which incorporates techniques such as transforaminal, interlaminar, and unilateral biportal (UBE) endoscopy, is increasingly considered. However, the patient selection criteria are debated among spine surgeons. This study used a polytomous Rasch analysis to evaluate the factors influencing surgeon decision-making in selecting patients for endoscopic surgical treatment of lumbar spinal stenosis. A comprehensive survey was distributed to a representative sample of 296 spine surgeons. Questions encompassed various patient-related and clinical factors, and responses were captured on a logit scale graphically displaying person-item maps and category probability curves for each test item. Using a Rasch analysis, the data were subsequently analyzed to determine the latent traits influencing decision-making. The Rasch analysis revealed that surgeons' preferences for transforaminal, interlaminar, and UBE techniques were easily influenced by comfort level and experience with the endoscopic procedure and patient-related factors. Harder-to-agree items included technological aspects, favorable clinical outcomes, and postoperative functional recovery and rehabilitation. Descriptive statistics suggested interlaminar as the best endoscopic spinal stenosis decompression technique. However, logit person-item analysis integral to the Rasch methodology showed highest intensity for transforaminal followed by interlaminar endoscopic lumbar stenosis decompression. The UBE technique was the hardest to agree on with a disordered person-item analysis and thresholds in category probability curve plots. Surgeon decision-making in selecting patients for endoscopic surgery for lumbar spinal stenosis is multifaceted. While the framework of clinical guidelines remains paramount, on-the-ground experience-based factors significantly influence surgeons' selection of patients for endoscopic lumbar spinal stenosis surgeries. The Rasch methodology allows for a more granular psychometric evaluation of surgeon decision-making and accounts better for years-long experience that may be lost in standardized clinical guideline development. This new approach to assessing spine surgeons' thought processes may improve the implementation of evidence-based protocol change dictated by technological advances was endorsed by the Interamerican Society for Minimally Invasive Spine Surgery (SICCMI), the International Society for Minimal Intervention in Spinal Surgery (ISMISS), the Mexican Spine Society (AMCICO), the Brazilian Spine Society (SBC), the Society for Minimally Invasive Spine Surgery (SMISS), the Korean Minimally Invasive Spine Society (KOMISS), and the International Society for the Advancement of Spine Surgery (ISASS).

419 Synergistic White Matter Injury Secondary to Chronic Cerebral Hypoperfusion and Air Pollution is Reduced by Microglia-Specific TLR4-Knockdown

INTRODUCTION: Air pollution is recognized as a neurotoxin which damages white matter and increases the risk of cognitive decline. Our previous work in a murine model found that air pollution in the setting of chronic cerebral hypoperfusion (CCH) leads to a synergistic deleterious effect on white matter. Air pollution studies have shown that increased microglial activation was associated with neurotoxicity. We hypothesize that inhibition of a microglial-specific TLR4 pathway will decrease the neurodegenerative effects that normally result from combined CCH and air pollution. METHODS: Our air pollution model used eight weeks of standardized Diesel Exhaust Particles (DEP) from National Institute of Science and Technology (DEP NIST2975). We performed bilateral carotid stenosis (BCAS) surgery to induce CCH using Wild Type (WT) and TLR4 flx/flx (CX3CR1CreER +/-) (TLR4-KD) in 2-month-old male mice. WT and TLR4-KD mice were randomized into eight groups as follows: WT-filtered air (FA), WT-DEP, WT-FA-BCAS, WT-DEP-BCAS, TLR4-KD-FA, TLR4-KD-DEP, TLR4-KD-FA-BCAS, and TLR4-KD-DEP-BCAS. Neurotoxicity was quantified with immunohistochemistry of degraded myelin basic protein (dMBP), ionized calcium-binding adaptor molecule-1 (Iba-1), and complement (C5a). RESULTS: DEP exposure resulted in increased white matter injury in corpus callosum (dMBP), worsened by the presence of CCH (p = 0.004) and significantly attenuated by TLR4-KD (p = 0.005). DEP exposure resulted in increased white matter microglial activation (Iba-1), worsened by the presence of CCH (p &lt; 0.0001) and significantly attenuated by TLR4-KD (p = 0.04).DEP exposure resulted in increased white matter complement activation (C5a), worsened by the presence of CCH (p &lt; 0.0001) and significantly attenuated by TLR4-KD (p &lt; 0.0001). CONCLUSIONS: Microglial-specific TLR4-KD reduces air pollution-induced neurotoxicity measured by white matter injury, microglial activation, and neuroinflammation.

Diagnostic and prognostic significance of miR-486-5p in patients who underwent minimally invasive surgery for lumbar spinal stenosis.

This study aimed to investigate the expression and clinical value of microRNA miR-486-5p in diagnosing lumbar spinal stenosis (LSS) patients and predicting the clinical outcomes after minimally invasive spinal surgery (MISS) in LSS patients, and the correlation of miR-486-5p with inflammatory responses in LSS patients. This study included 52 LSS patients, 46 patients with lumbar intervertebral disk herniation (LDH) and 42 healthy controls. Reverse transcription quantitative PCR was used to detect miR-486-5p expression. The ability of miR-486-5p to discriminate between different groups was evaluated by receiver-operating characteristic analysis. The visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopaedic Association (JOA) scores at 6months postoperatively were used to reflect the clinical outcomes of LSS patients. Enzyme-linked immunosorbent assay was used to measure the levels of inflammatory factor [interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)]. The correlation of miR-486-5p with continuous variables in LSS patients was evaluated by the Pearson correlation coefficient. Expression of serum miR-486-5p was upregulated in LSS patients and had high diagnostic value to screen LSS patients. In addition, serum miR-486-5p could predict the 6-month clinical outcomes after MISS therapy in LSS patients. Moreover, serum miR-486-5p was found to be positively correlated with the levels of IL-1β and TNF-α in patients with LSS. miR-486-5p, increased in LSS patients, can function as an indicator to diagnose LSS and a predictive indicator for the clinical outcomes after MISS therapy in LSS patients. In addition, miR-486-5p may regulate LSS progression by modulating inflammatory responses.

Preoperative fatty infiltration of paraspinal muscles assessed by MRI is associated with less improvement of leg pain 2 years after surgery for lumbar spinal stenosis

PurposeFatty infiltration (FI) of the paraspinal muscles may associate with pain and surgical complications in patients with lumbar spinal stenosis (LSS). We evaluated the prognostic influence of MRI-assessed paraspinal muscles’ FI on pain or disability 2 years after surgery for LSS.MethodsA muscle fat index (MFI) was calculated (by dividing signal intensity of psoas to multifidus and erector spinae) on preoperative axial T2-weighted MRI of patients with LSS. Pain and disability 2 years after surgery were assessed using the Oswestry disability index, the Zurich claudication questionnaire and numeric rating scales for leg and back pain. Multivariate linear and logistic regression analyses (adjusted for preoperative outcome scores, age, body mass index, sex, smoking status, grade of spinal stenosis, disc degeneration and facet joint osteoarthritis) were used to assess the associations between MFI and patient-reported clinical outcomes. In the logistic regression models, odds ratios (OR) and 95% confidence intervals (CI) were calculated for associations between the MFI and ≥ 30% improvement of the outcomes (dichotomised into yes/no).ResultsA total of 243 patients were evaluated (mean age 66.6 ± 8.5 years), 49% females (119). Preoperative MFI and postoperative leg pain were significantly associated, both with leg pain as continuous (coefficient − 3.20, 95% CI − 5.61, − 0.80) and dichotomised (OR 1.51, 95% CI 1.17, 1.95) scores. Associations between the MFI and the other outcome measures were not statistically significant.ConclusionPreoperative FI of the paraspinal muscles on MRI showed statistically significant association with postoperative NRS leg pain but not with ODI or ZCQ.

Abstract P453: Racial Disparities in Early Use of Transcarotid Artery Revascularization Among High-Risk and Symptomatic Black and White Adults With Carotid Artery Stenosis

Introduction: Differential access to new technologies may contribute to racial disparities in health outcomes. We examined the adoption of transcarotid artery revascularization (TCAR) among high-risk Black and white adults undergoing surgery for carotid artery stenosis. Hypothesis: We hypothesized that Black adults would be less likely than white adults to receive TCAR since its introduction to the US market in 2015. Methods: We conducted a retrospective analysis of the prospectively collected Vascular Quality Initiative surgical database from 1/2015 to 12/2021, which includes 100% of the TCAR procedures performed during this period. Non-Hispanic Black and non-Hispanic white adults were included if they met Centers for Medicare &amp; Medicaid Services high-risk criteria due to anatomy, medical comorbidities, and/or recent symptoms (ipsilateral stroke or transient ischemic attack). We used logistic regression to quantify associations of race with receipt of TCAR (versus other surgical procedure for carotid stenosis) overall and by specific high-risk features. Results: There were 119,128 surgical procedures performed for carotid artery stenosis (14.3% TCAR) (mean age 72 years, 5.3% Black, 38.5% female). Black patients were less likely than white patients to receive TCAR after adjustment for patient and disease characteristics (aOR 0.91, 95% CI 0.83, 0.99). Among patients with only one high-risk feature (e.g., only high-risk anatomy), TCAR use did not vary by race. However, Black patients were less likely to receive TCAR in subgroups with multiple high-risk features ( Figure ). Not all hospitals performed TCAR, and Black patients were less likely to be treated at TCAR-capable hospitals (aOR 0.93, 95% CI 0.88, 0.98). TCAR use did not vary by race at TCAR-capable hospitals ( Figure ). Conclusions: Adoption of TCAR was lower among Black compared to white high-risk patients, for whom TCAR offers the most benefit. Differential access to hospitals with newer technology may explain these disparities.

Laryngeal Mask Airway Versus Endotracheal Intubation during Lacrimal Duct Stenosis Surgery in Children-A Retrospective Analysis.

Background: The use of laryngeal masks in the surgical treatment of infantile lacrimal duct stenosis is controversial due to the potential risk of aspiration. Aims: This study investigates airway procedures in children aged <6 years for surgery of lacrimal duct stenosis in a tertiary care university hospital. Methods: After institutional approval, airway procedures, duration of anesthesiological measures, and airway-related complications were retrospectively analyzed. Patients were divided into two groups according to the airway procedures used (endotracheal tube [ET] vs. laryngeal mask [LMA] airway). Associations were calculated using the Chi-square test or Mann-Whitney U-test. Results: Clinical data of 84 patients (ET n = 36 [42.9%] vs. LMA n = 48 [57.1%]) were analyzed. There were no significant differences in surgical treatment, age distribution, and pre-existing conditions between the groups. None of the patients showed evidence of tracheal aspiration or changes in measured oxygen saturation. LMA airway shortened time for anesthesia induction (p = 0.006) and time for recovery/emergence period (p = 0.03). In contrast, the time to discharge from the recovery room was significantly prolonged using LMA (p = 0.001). A total of 7 adverse events were recorded. Five of these were directly or indirectly related to ET (laryngo-/bronchospasm; muscle relaxant residual). Conclusions: LMA airway for infantile lacrimal duct stenosis seems to be a safe procedure and should be used in appropriate pediatric patients due to its lower invasiveness, low complication rate, and time savings.