Safety and Efficacy of Percutaneous Transforaminal Endoscopic Decompression Under Local Anesthesia in Frail Elderly Patients with Severe Lumbar Spinal Stenosis

Safety and Efficacy of Percutaneous Transforaminal Endoscopic Decompression Under Local Anesthesia in Frail Elderly Patients with Severe Lumbar Spinal Stenosis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Safety and Efficacy of Percutaneous Transforaminal Endoscopic Decompression Under Local Anesthesia in Frail Elderly Patients with Severe Lumbar Spinal Stenosis Miao Wang, Hui Yi Liu, Fan Dong Wang, Guang Zhou Li, Yu Chen, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6678941/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract Objective: To evaluate the safety and efficacy of percutaneous transforaminal endoscopic decompression (PTED) under local anesthesia in frail elderly patients (≥ 75 years) with severe lumbar spinal stenosis (LSS). Methods: Forty-one patients (mean age: 82.4 ± 4.2 years) with severe central LSS (MRI grade ≥ 3), lateral recess stenosis (grade II in 38 cases), advanced disc degeneration (Pfirrmann IV–V), and frailty (score ≥ 3) underwent unilateral PTED. Outcomes included operative time, hospitalization duration, clinical metrics (VAS, ODI, Barthel Index), radiological improvements (dural sac cross-sectional area [DSCA], stenosis grading), and complications. Results: Mean operative time was 100.6 ± 19.2 minutes, with a postoperative hospital stay of 3.85 ± 1.21 days. At final follow-up (20.1 ± 4.2 months), significant improvements were observed: VAS back pain decreased from 3.65 ± 0.48 to 2.43 ± 0.50 ( p < 0.01), VAS leg pain from 6.51 ± 0.50 to 2.07 ± 0.41 ( p < 0.001), ODI from 67.2 ± 8.1 to 26.7 ± 6.9 ( p < 0.001), and Barthel Index from 54.2 ± 8.2 (moderate disability) to 77.8 ± 6.12 (near independence) ( p < 0.001). Radiologically, the dural sac cross-sectional area (DSCA) increased from 53.5 ± 21.2 mm² preoperatively to 70.8 ± 25.1 mm² postoperatively ( p < 0.001). Lateral recess stenosis resolved in 90.2% of cases (IQR: 0 [0–1]), and foraminal stenosis improved in 68.3% (IQR: 1 [1–1]). Complications included residual leg pain (9.8%), deep vein thrombosis (4.9%), and no reoperations. Conclusions: PTED under local anesthesia is a safe and effective minimally invasive strategy for frail elderly patients with severe LSS, providing durable symptom relief and functional restoration. Lateral recess decompression is critical for optimal outcomes. Larger prospective studies are warranted to validate these findings. Lumbar spinal stenosis Percutaneous transforaminal endoscopic decompression Frailty Elderly Minimally invasive surgery Figures Figure 1 Figure 2 Figure 3 Introduction The accelerating global demographic shift towards aging populations has resulted in a marked increase in degenerative lumbar pathologies, particularly lumbar spinal stenosis (LSS), among elderly individuals 1 . Severe cases of LSS, often complicated by concurrent degenerative conditions such as disc herniation, spondylolisthesis, or scoliosis, frequently require surgical intervention 2 . Open fusion surgery remains the established gold standard for these complex cases, providing stability and significant relief from low back and radicular pain, thereby improving quality of life 3 . However, elderly patients undergoing fusion surgery face disproportionately elevated rates of surgery-related adverse events 4 , 5 , including postoperative cognitive dysfunction associated with general anesthesia 6 , instrumentation failure due to osteoporosis, accelerated adjacent segment disease, and prolonged recovery attributable to diminished physiological reserves 7 . These risks pose substantial challenges in surgical decision-making for both patients and clinicians. Percutaneous transforaminal endoscopic decompression (PTED) under local anesthesia has emerged as a minimally invasive alternative, offering effective neural decompression with reduced tissue trauma and faster recovery compared to open fusion 8 . While prior studies have reported favorable short-term safety and efficacy of PTED in elderly populations 9 – 11 , critical limitations compromise their conclusions. First, chronological age does not inherently correlate with the severity of degeneration; however, heterogeneous spinal degeneration, which has been largely overlooked in existing studies, directly influences surgical complexity, operative duration, and clinical outcomes. The absence of standardized assessments for stenosis severity (e.g., grading systems) and anatomical subtypes (central vs. lateral recess stenosis) introduces selection bias, as mixed cohorts may obscure true treatment effects. Second, elderly patients with lumbar spinal stenosis (LSS) often present with multiple comorbidities (e.g., cardiovascular disease, diabetes), contributing to unquantified variability in surgical risk. The lack of preoperative physiological resilience metrics (e.g., frailty scores) further compromises cohort homogeneity, potentially inflating safety estimates. To address these gaps, we conducted a retrospective cohort study of high-risk elderly patients (age ≥ 75 years) with severe LSS (stenosis grade ≥ 3) and frailty scores > 3, selected from a single-center percutaneous transforaminal endoscopic decompression (PTED) database. By integrating comprehensive evaluations of degenerative severity (including stenosis grading, disc morphology, pedicle rotation), comorbidity profiles, and serial clinical-radiographic outcomes, this study aims to (1) assess the perioperative safety of PTED in frail elderly patients and (2) determine the durability of functional and symptomatic improvements. Our findings aim to refine risk stratification and support evidence-based surgical planning for this vulnerable population. Methods Patients A retrospective analysis was conducted on patients aged 75 years and older with lumbar spinal stenosis (LSS) who underwent single-level percutaneous transforaminal endoscopic decompression(PTED)between February 2022 and December 2023. The inclusion criteria for this study were as follows: (1) Clinical diagnosis of symptomatic lumbar spinal stenosis with ineffective conservative treatment for at least three months; (2) Underwent single-level PTED treatment. The exclusion criteria included the following: absence of severe lumbar spinal stenosis 12 , prior history of spinal surgery, imaging evidence of segmental instability, FRAIL scale score below 3 points 13 , concurrent lumbar infection or tumor, incomplete data, or loss to follow-up. All patients were followed up for a minimum of 12 months postoperatively. This study was approved by the institutional ethics committee, and all participants provided written informed consent. Surgical technique PTED procedures were all performed by a senior spine surgeon (MW) with sufficient experience, at a single level, under local anesthesia, with the patient placed in a prone position. The patient can communicate with the surgeon throughout the entire operation to prevent intraoperative nerve root injury, and the surgeon was allowed to assess the patient's tolerance. For patients with multilevel stenosis, to determine the level most responsible for the symptoms and best suited for the procedure, a transforaminal selective nerve root block was performed. In all patients with bilateral stenosis, decompression was performed exclusively on the symptomatic side of the lower extremity to address the clinical manifestations effectively. The detailed surgical procedures have been comprehensively described in other previous publications 10 . Clinical evaluation Demographic data for all study participants were collected, including gender, age, BMI, the American Society of Anesthesiologists (ASA) Score 14 , FRAIL scale 13 , comorbidities, responsibility segment, side of lower limb pain, degree of degeneration (kyphosis, scoliosis, pedicle rotation, Pfirrmann grading of disc), and MRI grade of stenosis 12 (central, lateral recess, foramen). Postoperative hospital stay, operation time, and follow-up time were also recorded. The visual analog scale (VAS) was used to assess leg pain and low back pain. The Oswestry Disability Index (ODI) was used to evaluate clinical functional status. The Barthel Index for Activities of Daily Living (ADL) 15 was employed to assess changes in independent living activities both before and after surgery. Surgical satisfaction was evaluated using the modified Macnab criteria. Additionally, postoperative complications were assessed in this study. Radiological evaluation The investigators conducted the measurements utilizing integrated software tools for area quantification embedded within the Picture Archiving and Communication System (PACS). The dural sac cross-sectional area (DSCA) was measured in square millimeters by at least three independent readers, including two orthopedic surgeons and one musculoskeletal radiologist (Figure. 3K-L). Preoperatively and one month postoperatively, the DSCA was assessed at the narrowest level of the responsible segment. Additionally, the MRI stenosis grades of the central spinal canal, lateral recess, and intervertebral foramen were evaluated and documented both pre- and post-operatively. Both the changes in cross-sectional area and stenosis grade were included in the subsequent statistical analysis. Statistical analysis Statistical analyses were performed using SPSS version 24.0. Data normality was assessed using the Shapiro-Wilk test. Continuous variables are presented as mean ± standard deviation for normal distributions or as median (IQR) for non-normal distributions. Parametric data were compared with a paired t-test, while nonparametric data were analyzed using the Wilcoxon signed-rank test. Repeated-measures data were analyzed using Repeated Measures ANOVA with Bonferroni correction. Categorical variable frequencies were compared using the Chi-square or Fisher's exact test. A p-value < 0.05 indicated statistical significance. Results A total of 41 elderly patients with frailty and severe lumbar spinal stenosis were included in this study. The detailed screening flowchart is shown in Figure. 1. The baseline characteristics of these patients are summarized in Table 1 . The mean age was 82.4 ± 4.2 years (range: 76–98), with 21 males and 20 females. The mean BMI was 21.95 ± 2.83. The ASA classification was grade II in 15 cases and grade III in 26 cases. All patients met the frailty criteria (score ≥ 3). The primary responsible segment was located at L4/5 (33 cases), with the remaining cases involving L5/S1. Regarding lumbar degenerative changes, 16 patients had segmental kyphosis, 18 had scoliosis, and 25 exhibited rotational displacement of the superior vertebra relative to the inferior vertebra at the responsible segment. All cases showed disc degeneration of Pfirrmann grading ≥ 4. For lumbar stenosis: All 41 patients had severe central canal stenosis (MRI grade ≥ 3). Thirty-eight patients had concurrent severe lateral recess stenosis on the symptomatic side. Foraminal stenosis was predominantly mild-to-moderate, with severe foraminal stenosis observed in only 11 cases. All patients had ≥ 5 comorbidities, with osteoporosis, hypertension, pulmonary disease, and cardiovascular disease being the top four. Notably, all patients had a negative Lasegue’s sign preoperatively. The mean operative time for PTED was 100.6 ± 19.2 minutes (range: 65–135), and the average postoperative hospital stay was 3.85 ± 1.21 days. The mean follow-up duration was 20.1 ± 4.2 months (range: 15–27). Subgroup analysis based on central canal stenosis severity (Grade III vs. IV) revealed no significant differences in the above parameters except for frailty scores (details in Table 1 ). Table 1 Demographic Characteristics and Clinical Data of 41 Patients with Severe Lumbar Spinal Stenosis Central stenosis Grade III (n = 21) Central stenosis Grade IV (n = 20) P Value Total(n = 41) Characteristics Age (years) 82.9 ± 3.7 (79–93) 81.9 ± 4.6 (76–98) 0.45 82.4 ± 4.2 (76–98) Gender Male: 13, Female: 8 Male: 8, Female: 12 0.8 Male/Female = 21/20 BMI (kg/m²) 22.4 ± 2.4 (17.1–25.7) 21.4 ± 3.1 (15.2–27) 0.25 21.95 ± 2.83(15.2–27) ASA Score II: III = 6༚15 II: III = 9༚11 0.27 II: III = 15༚26 FRAIL scale (≥ 3: frail) Scale 5/Scale4 /Scale 3 = 1/13/7 Scale 5/Scale4 /Scale 3 = 11/7/2 0.009 Frail: 41 (100%) Comorbidities Hypertension:20 Pulmonary disease: 13 Cardiovascular disease: 14 Cerebrovascular disease: 14 Diabetes : 9 Osteoporosis:21 Use anticoagulants:6 Digestive tract disease:6 Renal insufficiency: 3 Rheumatoid arthritis: 1 Hypertension:18 Pulmonary disease: 20 Cardiovascular disease: 10 Cerebrovascular disease: 14 Diabetes : 5 Osteoporosis:20 Use anticoagulants:3 Digestive tract disease:10 Renal insufficiency: 5 Hematological disorders: 1 NA Hypertension:38 Pulmonary disease: 33 Cardiovascular disease: 24 Cerebrovascular disease:28 Diabetes : 14 Osteoporosis:41 Use anticoagulants :9 Digestive tract disease:16 Renal insufficiency: 8 Hematological disorders: 1 Rheumatoid arthritis: 1 Responsibility segment L4/5: (16) L5/S1:(5) L4/5: (17) L5/S1:(3) 0.75 L4/5:L5/S1 = 33:8 Lasegue sign Negative Negative NA Negative: 41(100%) Lower limb pain Left/Right = 9/12 Left/Right = 12/8 0.27 Left/Right = 21/20 Kyphosis Present: 6 Present: 10 0.16 Present/Absent = 16/25 Scoliosis Present: 7 Present: 11 0.16 Present/Absent = 18/23 Pedicle rotation Present: 11 - Present: 14 0.24 Present/Absent = 25/16 Pfirrmann grading Grade4:Grade5 = 19:2 Grade4:Grade5 = 12:8 0.06 Grade4:Grade5 = 31:10 MRI grade of lateral stenosis Severe(2):Moderate(1) = 18:2 Severe(2):Moderate(1) = 19:1 1.00 Severe(2):Moderate(1)= 38:3 MRI grade of foramen stenosis None(0):Mild(1):Moderate(2): Severe(3) = 1: 6༚8༚5 None(0):Mild(1):Moderate(2):Severe(3) = 4: 5༚6༚6 0.64 None(0):Mild(1):Moderate(2): Severe(3) = 5༚11༚14༚11 Postoperative hospital stay (days) 3.57 ± 1.03(2–7) 4.15 ± 1.34(3–8) 0.12 3.85 ± 1.21(2–8) Operation time (minutes) 96.42 ± 19.88 105 ± 17.39 0.15 100.6 ± 19.2(65–135) Follow-up time (months) 20.1 ± 3.9 19.9 ± 4.3 0.87 20.1 ± 4.2(15–27) Notes: Statistical methods:Continuous variables (e.g., age, BMI, postoperative stay): Independent t-test (normality verified by Shapiro-Wilk test, p > 0.05). Categorical variables (e.g., gender, kyphosis): Chi-square test or Fisher’s exact test (applied if expected frequency < 5). Ordinal variables (e.g., FRAIL scale, MRI grade of foramen stenosis): Mann-Whitney U test. Significance level: = 0.05 (two-tailed). ASA: American Society of Anesthesiologists. Significant improvements were observed in clinical outcomes compared to preoperative values. The VAS Back score decreased from 3.65 ± 0.48 preoperatively to 2.43 ± 0.50 at last follow-up (p < 0.01), while the VAS Leg score declined from 6.51 ± 0.50 to 2.07 ± 0.41 (p < 0.001). The ODI index decreased markedly from 67.2 ± 8.1 to 26.7 ± 6.9 (p < 0.001). Concomitant with alleviation of leg pain, particularly in walking capacity, the Barthel ADL index increased significantly from 54.2 ± 8.2 to 77.8 ± 6.12 (p < 0.001), reflecting enhanced functional independence (details in Table 2 ). Postoperative temporal analysis revealed distinct recovery trajectories: VAS back score showed no significant differences from preoperative values at 1 week or 3 months (p > 0.05) but declined progressively thereafter, reaching significance by final follow-up (p < 0.001). In contrast, VAS leg score decreased significantly from 1 week postoperatively (p 0.05). Similarly, the Barthel ADL index increased incrementally through 6 and 12 months but stabilized subsequently (p > 0.05 vs. 12-month values) (Figure. 2A-D). Radiological outcomes confirmed anatomical efficacy, with the dural sac cross-sectional area (DSCA) expanding from 53.5 ± 21.2 mm² preoperatively to 70.83 ± 25.1 mm² postoperatively (p < 0.001) (Figure. 2E). MRI grading improvements included a 29.2% reduction in central stenosis severity (postoperative IQR: 3 [3–4]), 90.2% resolution of lateral recess stenosis (IQR: 0 [0–1]), and 68.3% alleviation of foraminal stenosis (IQR: 1 [1–1]) (Table 3 ). According to Macnab criteria, 90.2% of patients (37/41) achieved excellent/good outcomes (Figure. 2F). Complications included residual leg pain (9.8%, 4/41), persistent back pain (7.3%, 3/41), and deep vein thrombosis (4.9%, 2/41), with no instances of surgical site infection, neurological injury, spinal hematoma, or recurrent ipsilateral stenosis. Notably, no patients developed contralateral stenosis symptoms during follow-up. Table 2 Comparison of preoperative and postoperative clinical outcomes across follow-up time points Preoperative Postoperative 1 week 3months 6 months 12months Postoperative last follow-up P Value (The last follow -up compared with preoperative ) Outcome VAS Back 3.65 ± 0.48 3.78 ± 0.47 3.51 ± 0.5 3.02 ± 0.35 2.56 ± 0.63 2.43 ± 0.5 < 0.001 VAS Leg 6.51 ± 0.5 4.68 ± 0.93 3.19 ± 0.4 2.43 ± 0.67 2.21 ± 0.47 2.07 ± 0.41 < 0.001 ODI% 67.2 ± 8.1 51.7 ± 5.0 44.2 ± 5.8 39.1 ± 5.7 28.1 ± 6.9 26.7 ± 6.9 < 0.001 The Barthel ADL Index 54.2 ± 8.2 — — 72.3 ± 8.06 77.4 ± 6.33 77.8 ± 6.12 < 0.001 Notes:Data presented as Mean ± Standard Deviation (SD). P values indicate statistical significance between preoperative and the last follow -up time (paired tests with Bonferroni correction)."—": Data not available for specific time points. Abbreviations: VAS = Visual Analog Scale; ODI = Oswestry Disability Index; ADL = Activities of Daily Living. Table 3 Spinal Stenosis Grading Changes Using Wilcoxon Signed-Rank Test Preoperative Median (IQR) Postoperative Median (IQR) Z Value P Value Improvement Rate (%) Stenosis Type Central 4 (3–4) 3 (3–4) -3.46 < 0.001 29.2% Lateral 2 (2–2) 0 (0–1) -5.5 < 0.001 90.2% Foraminal 2 (1–3) 1 (1–1) -4.8 < 0.001 68.3% Notes:Improvement rate: Percentage of patients with reduced postoperative grades. Effect sizes (r): Central = 0.54, Lateral = 0.86, Foraminal = 0.75. IQR = Interquartile Range A representative case is shown in Figure.3 Discussion While debates persist regarding the optimal surgical approach for lumbar spinal stenosis (LSS), decompressive surgery—whether alone or combined with fusion—has proven effective for patients unresponsive to conservative treatment 16 . However, the aging population presents unique challenges in surgical decision-making for elderly LSS patients. Frail individuals often suffer from reduced mobility due to debilitating back and leg pain, compounded by cardiopulmonary comorbidities that exacerbate physiological vulnerability. Existing evidence highlights a strong correlation between frailty and severe perioperative complications in fusion surgery 7,17 , necessitating less invasive alternatives. Although minimally invasive techniques, such as micro-endoscopic decompressive laminotomy under general anesthesia (as reported 18 in octogenarians with LSS and spondylolisthesis), demonstrate efficacy, their invasiveness remains suboptimal compared to percutaneous transforaminal endoscopic decompression (PTED). Despite promising reports on PTED for elderly LSS patients 9-11,19,20 , critical gaps persist in safety and efficacy evaluations due to insufficient frailty assessments, heterogeneous degenerative severity, and inconsistent patient selection criteria. In this study, all 41 enrolled patients met predefined frailty criteria (frailty score ≥3) and exhibited severe central canal stenosis (grade III–IV), with 38 cases presenting concomitant severe lateral recess stenosis(grade II). Grading of disc degeneration at the symptomatic level was classified as Pfirrmann grades IV–V. All procedures were performed under local anesthesia in the prone position via percutaneous transforaminal endoscopic decompression, with a mean operative duration of 100.6 ± 19.2 minutes (range: 65–135). This operative time was shorter than the 147.8 ± 48.05 minutes reported by Wang et al. 11 but exceeded the 75 minutes (range: 50–110) documented by Chen et al 9 . The observed variation may be attributed to our exclusion of obese patients (BMI <27) and a surgical strategy prioritizing nerve root canal decompression over extensive central canal enlargement, thereby reducing procedural complexity compared to Wang et al.’s approach. Conversely, the shorter operative time in Chen et al.’s cohort may reflect the inclusion of patients with milder degenerative changes, as their study lacked detailed stratification of lumbar degeneration severity—a critical factor influencing foraminoplasty and intraspinal decompression time. Notably, all patients—including those with hypertension, cardiovascular disease, or pulmonary comorbidities—successfully completed the procedure without intraoperative complications. The brief postoperative hospitalization (3.85 ± 1.21 days) further underscores PTED’s minimally invasive profile and its minimal physiological impact on frail elderly patients. During follow-up, no major complications or mortality occurred, aligning with prior studies reporting low complication rates 20,21 . Two cases of deep vein thrombosis (DVT) were attributed to postoperative immobility due to pain-related anxiety; both resolved with anticoagulation, emphasizing the necessity of early postoperative mobilization. A common concern with limited decompression is the risk of symptom recurrence. However, no cases required reoperation during follow-up, contrasting with the low but nonzero reoperation rates in previous studies. We hypothesize that this may reflect the inclusion of patients with “end-stage” degenerative pathology, as evidenced by advanced disc degeneration (Pfirrmann IV–V) and the absence of contralateral symptoms despite radiographic stenosis in all cases. This hypothesis, supported by the stability of degenerative changes during follow-up, warrants validation through long-term comparative imaging studies in future investigations. Regarding surgical efficacy, patients exhibited significant improvements in VAS Back, VAS Leg, and ODI scores at final follow-up. A notable observation was the markedly lower preoperative back pain scores in our cohort (3.65 ± 0.48) compared to those reported by Wang et al.(6.15 ± 0.86) 11 and Xie et al. (6.7 ± 1.15) 20 . This discrepancy may stem from our strict exclusion of lumbar instability and dynamic spondylolisthesis, as well as the inclusion of frail patients with reduced physical activity, which likely contributed to milder baseline back pain. Postoperatively, transient exacerbation of ipsilateral back pain occurred in some patients at one week, suggesting that localized tissue trauma from minimally invasive maneuvers may temporarily aggravate symptoms. However, three months after PTED, with significant relief of leg pain and improvement of walking distance, and strict anti-osteoporosis treatment (all patients were diagnosed with osteoporosis before surgery), the low back pain symptoms were significantly relieved, until the last follow-up. Leg pain "rebound" observed in some cases at one week—attributed to postoperative edema or inflammatory responses following neural decompression—resolved completely by three months. This transient pattern underscores the importance of preoperative patient counseling to manage expectations and enhance satisfaction 22 . Residual leg pain requiring analgesics persisted in four patients, with MRI revealing inadequate lateral recess decompression. This highlights the necessity of prioritizing thorough lateral recess decompression during PTED for frail elderly patients with severe LSS. Quantitative analysis demonstrated a significant increase in dural sac cross-sectional area (DSCA) postoperatively, attributable to resection of hypertrophic ligamentum flavum, osteophytes, and herniated disc material. However, only 29.2% of cases showed definitive central canal improvement on MRI, consistent with prior evidence that symptom relief correlates poorly with central canal metrics 23,24 . Conversely, foraminal stenosis improvement (68.3%) strongly aligned with ODI enhancements, as reported by Jørn Aaen et al., emphasizing the critical role of foraminal and lateral recess decompression in functional recovery. Moreover, as the establishment of the working channel during PTED inevitably requires foraminal enlargement, the improvement rate of foraminal stenosis in our cohort reached 68.3%. This high rate of foraminal and lateral recess stenosis improvement contributed to significant enhancements in Oswestry Disability Index (ODI) scores, consistent with prior findings 25 . Frailty and severe lumbar spinal stenosis (LSS) impose profound burdens on quality of life in elderly patients due to chronic pain and ambulatory limitations, exacerbating caregiver dependency. In our cohort, the preoperative Barthel Index for Activities of Daily Living (ADL) was 54.2 ± 8.2, reflecting moderate disability requiring assistance. Following percutaneous transforaminal endoscopic decompression (PTED), functional independence improved significantly, with the Barthel Index rising to 72.3 ± 8.06 at 6 months and stabilizing at 77.8 ± 6.12 by final follow-up. These results demonstrate that PTED provides sustained functional benefits in frail elderly patients with severe LSS, effectively restoring autonomy and reducing caregiving demands. This study has several limitations. First, despite stringent inclusion criteria ensuring internal consistency, the small sample size necessitates validation through larger multicenter cohorts with long-term follow-up. Second, the retrospective design lacks non-surgical controls, limiting causal inferences regarding PTED’s necessity; prospective studies are required to address this. Third, PTED’s steep learning curve may influence outcomes, as technical proficiency varies with surgeon experience. Conclusions To the best of our knowledge, this is the first retrospective study to confirm the safety and efficacy of unilateral PTED under local anesthesia for frail elderly patients (≥75 years) with severe LSS, integrating frailty assessments (frailty score ≥3) and stringent degenerative criteria (central stenosis grade ≥3). Our results underscore PTED’s potential as a viable minimally invasive strategy for this high-risk population, balancing procedural safety with durable clinical improvements. Declarations Clinical trial number: not applicable Ethics approval and consent to participate This study was approved by the Ethics Committee of Suining Central Hospital (Approval No.: KYLLKS20250090), and all procedures complied with the ethical principles of the Declaration of Helsinki. Written informed consent was obtained from all participants or their legal guardians prior to participation. Consent for publication All patients or their legal guardians consented to the publication of anonymized data. This manuscript contains no personally identifiable information. Availability of data and materials The datasets and materials generated during this study are available from the corresponding author upon reasonable request. Raw imaging data are subject to ethical committee approval prior to access due to patient privacy concerns. Competing interests The authors declare no competing interests, including financial, academic, or other conflicts of interest. Funding This study received no specific funding. Authors' contributions Miao Wang: Study design, surgery performance, data analysis, and manuscript writing. Hui Yi Liu: Data collection and analysis. Fan Dong Wang: Surgical assistance and telephone follow-up. Guang Zhou Li (Corresponding Author): Study design supervision and imaging analysis. Yu Chen: Imaging analysis. Jia Zhuang Zheng: Case screening and quality control. Acknowledgements The author expresses deepest gratitude to Ms. Xue wen Yin, his cherished partner, for her multifaceted support during this research. Her meticulous coordination of domestic logistics facilitated sustained academic focus, particularly during experimental iterations and statistical validation phases. Authors' information (optional) Not applicable. References Fehlings MG, Tetreault L, Nater A, et al. The Aging of the Global Population: The Changing Epidemiology of Disease and Spinal Disorders. Neurosurgery. 2015;77(Suppl 4):S1–5. Jensen RK, Skovsgaard CV, Ziegler DS, et al. Surgical trends and regional variation in Danish patients diagnosed with lumbar spinal stenosis between 2002 and 2018: a retrospective registry-based study of 83,783 patients. BMC Health Serv Res. 2023;23(1):665. Martin BI, Mirza SK, Spina N, Spiker WR, Lawrence B, Brodke DS. 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Frailty is a Risk Factor for Postoperative Complications in Older Adults with Lumbar Degenerative Disease: A Prospective Cohort Study. Clin Interv Aging. 2024;19:1117–26. Rosen DS, O'Toole JE, Eichholz KM, et al. Minimally invasive lumbar spinal decompression in the elderly: outcomes of 50 patients aged 75 years and older. Neurosurgery. 2007;60(3):503–9. discussion 509–510. Ahn Y, Keum HJ, Son S. Percutaneous Endoscopic Lumbar Foraminotomy for Foraminal Stenosis with Postlaminectomy Syndrome in Geriatric Patients. World Neurosurg. 2019;130:e1070–6. Xie P, Feng F, Chen Z, et al. Percutaneous transforaminal full endoscopic decompression for the treatment of lumbar spinal stenosis. BMC Musculoskelet Disord. 2020;21(1):546. Bao BX, Zhou JW, Yu PF, Chi C, Qiang H, Yan H. Transforaminal Endoscopic Discectomy and Foraminoplasty for Treating Central Lumbar Stenosis. Orthop Surg. 2019;11(6):1093–100. Rault F, Briant AR, Kamga H, Gaberel T, Emery E. Surgical management of lumbar spinal stenosis in patients over 80: is there an increased risk? Neurosurg Rev. 2022;45(3):2385–99. Hermansen E, Myklebust TA, Weber C, et al. Postoperative Dural Sac Cross-Sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial. Spine (Phila Pa 1976). 2023;48(10):688–94. Minetama M, Kawakami M, Teraguchi M, et al. MRI grading of spinal stenosis is not associated with the severity of low back pain in patients with lumbar spinal stenosis. BMC Musculoskelet Disord. 2022;23(1):857. Aaen J, Banitalebi H, Austevoll IM, et al. Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression. Acta Neurochir (Wien). 2023;165(8):2121–9. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 07 Sep, 2025 Reviews received at journal 26 Jul, 2025 Reviews received at journal 24 Jul, 2025 Reviewers agreed at journal 22 Jul, 2025 Reviews received at journal 22 Jul, 2025 Reviewers agreed at journal 11 Jul, 2025 Reviewers agreed at journal 11 Jul, 2025 Reviewers invited by journal 11 Jul, 2025 Editor invited by journal 20 Jun, 2025 Editor assigned by journal 19 May, 2025 Submission checks completed at journal 19 May, 2025 First submitted to journal 16 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6678941","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":484278323,"identity":"b5537f68-10d1-41f2-b4ff-fbe7c9937ef5","order_by":0,"name":"Miao Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5ElEQVRIiWNgGAWjYBACNv7mAwYfftjY2TczNj5IqKghrIVP4lhC4cyetGQD9uZmgwdnjhHWIseQo/CZh+0w4wae422SD1uYiXAYwxnGjTN4mJnNJRLbKhIb2Bj427sT8Gth7j1s8MGCjc9yRmLbjcQdMgwSZ85uIGDLuTTDGTw8zAw3QFrOsDEYSOQS0pJj/puHTYKxAailILGNmSgtBsY8bAaMG84cbGMgTgswkA1n9iQkS7Y3NksknDnGQ9Av8v3gqPxvx8/M/vDjj4oaOf72XvxaMAAPacpHwSgYBaNgFGAFAKYqTO+70y5LAAAAAElFTkSuQmCC","orcid":"","institution":"Suining Central Hospital","correspondingAuthor":true,"prefix":"","firstName":"Miao","middleName":"","lastName":"Wang","suffix":""},{"id":484278324,"identity":"b9649fb6-25fb-4225-b9f6-7dc53c71e9f6","order_by":1,"name":"Hui Yi Liu","email":"","orcid":"","institution":"Suining Central Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"Yi","lastName":"Liu","suffix":""},{"id":484278325,"identity":"a403de5e-83b3-4792-bf88-7115262b562a","order_by":2,"name":"Fan Dong Wang","email":"","orcid":"","institution":"Suining Central Hospital","correspondingAuthor":false,"prefix":"","firstName":"Fan","middleName":"Dong","lastName":"Wang","suffix":""},{"id":484278326,"identity":"2d8e9626-68a1-4f76-9a59-373bb826da48","order_by":3,"name":"Guang Zhou Li","email":"","orcid":"","institution":"Suining Central Hospital","correspondingAuthor":false,"prefix":"","firstName":"Guang","middleName":"Zhou","lastName":"Li","suffix":""},{"id":484278327,"identity":"2a0f926c-6d19-4b91-91fa-6ca80081bc0c","order_by":4,"name":"Yu Chen","email":"","orcid":"","institution":"Suining Central Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yu","middleName":"","lastName":"Chen","suffix":""},{"id":484278328,"identity":"81d7b620-1cf4-4984-9cd5-1e78a78a535e","order_by":5,"name":"Jia Zhuang Zheng","email":"","orcid":"","institution":"Suining Central Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jia","middleName":"Zhuang","lastName":"Zheng","suffix":""}],"badges":[],"createdAt":"2025-05-16 08:38:37","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6678941/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6678941/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87030650,"identity":"fae195f1-df70-4104-9d85-64b37756ee35","added_by":"auto","created_at":"2025-07-18 12:46:00","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":215746,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart describing of the inclusion of individuals\u003c/p\u003e","description":"","filename":"Figure.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6678941/v1/e85a556ec819ac4e1dde6c57.jpg"},{"id":87030652,"identity":"7ab4a987-6a73-4825-844b-4a9c01553722","added_by":"auto","created_at":"2025-07-18 12:46:00","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":764663,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative and postoperative outcomes: A. Visual analogue scale for back pain(VAS Back Score), B. Visual analogue scale for leg pain(VAS Leg Score), C. Oswestry\u0026nbsp;Disability Index(ODI%), D. The Barthel Index for Activities of Daily Living(The Barthel ADL Index), E. The dural sac cross-sectional area, F.Surgical satisfaction evaluated according to Macnab criteria.\u003csub\u003e*** \u003c/sub\u003eindicate statistical significance, ns indicate no statistical significance.\u003c/p\u003e","description":"","filename":"OnlineFigure.2.png","url":"https://assets-eu.researchsquare.com/files/rs-6678941/v1/41614c281a6bfe764344b088.png"},{"id":87030653,"identity":"62f83452-83fc-4b9e-adcf-3174aa49af34","added_by":"auto","created_at":"2025-07-18 12:46:01","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":6821318,"visible":true,"origin":"","legend":"\u003cp\u003ePercutaneous transforaminal endoscopic decompression performed on\u003c/p\u003e\n\u003cp\u003ea 83-year-old female patient diagnosed with L4/5 severe lumbar spinal stenosis.\u003c/p\u003e\n\u003cp\u003eA. Lumbar anteroposterior X-ray showed mild scoliosis and pedicle rotation at L4/5,B. Lateral X-rays showed no L4/5 lumbar spondylolisthesis,C. The intraoperative anteroposterior X-ray confirmed the successful establishment of the working channel,D. The intraoperative lateral X-ray confirmed the successful establishment of the working channel, E. The narrow foramen and spinal canal were visualized under endoscopic guidance , F. Following partial resection of the ligamentum flavum and intervertebral disc, the arrow indicates the location of the compressed nerve root, G. Further decompression of the lateral recess area was performed, H. Complete decompression of the nerve root transit area was successfully achieved, I. Preoperative MRI showed L4/5 severe central spinal canal stenosis (Grade=4) and severe lateral recess stenosis (Grade=2), J.Postoperative MRI demonstrated a reduction in central spinal canal stenosis (Grade = 2) and left lateral recess stenosis (Grade = 1),K. Preoperative L4/5 dural sac area=42.40mm\u003csup\u003e2\u003c/sup\u003e,L. Postoperative L4/5 dural sac area=71.36mm\u003csup\u003e2 \u003c/sup\u003eat one month. Abbreviations:SAP= Superior articular process, LF= Ligamentum flavum, TNR= Traversing nerve root.\u003c/p\u003e","description":"","filename":"Figure.3.png","url":"https://assets-eu.researchsquare.com/files/rs-6678941/v1/02557f9c6cc4f62b023d4435.png"},{"id":87032907,"identity":"321b3e66-c0cb-47d1-9769-30affa2baa4e","added_by":"auto","created_at":"2025-07-18 13:02:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":10761760,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6678941/v1/53c9ac1e-fad4-4888-9f94-0040c1051ec6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Safety and Efficacy of Percutaneous Transforaminal Endoscopic Decompression Under Local Anesthesia in Frail Elderly Patients with Severe Lumbar Spinal Stenosis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe accelerating global demographic shift towards aging populations has resulted in a marked increase in degenerative lumbar pathologies, particularly lumbar spinal stenosis (LSS), among elderly individuals\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Severe cases of LSS, often complicated by concurrent degenerative conditions such as disc herniation, spondylolisthesis, or scoliosis, frequently require surgical intervention\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Open fusion surgery remains the established gold standard for these complex cases, providing stability and significant relief from low back and radicular pain, thereby improving quality of life\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. However, elderly patients undergoing fusion surgery face disproportionately elevated rates of surgery-related adverse events\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e, including postoperative cognitive dysfunction associated with general anesthesia\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e, instrumentation failure due to osteoporosis, accelerated adjacent segment disease, and prolonged recovery attributable to diminished physiological reserves\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. These risks pose substantial challenges in surgical decision-making for both patients and clinicians.\u003c/p\u003e\u003cp\u003ePercutaneous transforaminal endoscopic decompression (PTED) under local anesthesia has emerged as a minimally invasive alternative, offering effective neural decompression with reduced tissue trauma and faster recovery compared to open fusion\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. While prior studies have reported favorable short-term safety and efficacy of PTED in elderly populations\u003csup\u003e\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e, critical limitations compromise their conclusions. First, chronological age does not inherently correlate with the severity of degeneration; however, heterogeneous spinal degeneration, which has been largely overlooked in existing studies, directly influences surgical complexity, operative duration, and clinical outcomes. The absence of standardized assessments for stenosis severity (e.g., grading systems) and anatomical subtypes (central vs. lateral recess stenosis) introduces selection bias, as mixed cohorts may obscure true treatment effects. Second, elderly patients with lumbar spinal stenosis (LSS) often present with multiple comorbidities (e.g., cardiovascular disease, diabetes), contributing to unquantified variability in surgical risk. The lack of preoperative physiological resilience metrics (e.g., frailty scores) further compromises cohort homogeneity, potentially inflating safety estimates. To address these gaps, we conducted a retrospective cohort study of high-risk elderly patients (age\u0026thinsp;\u0026ge;\u0026thinsp;75 years) with severe LSS (stenosis grade\u0026thinsp;\u0026ge;\u0026thinsp;3) and frailty scores\u0026thinsp;\u0026gt;\u0026thinsp;3, selected from a single-center percutaneous transforaminal endoscopic decompression (PTED) database. By integrating comprehensive evaluations of degenerative severity (including stenosis grading, disc morphology, pedicle rotation), comorbidity profiles, and serial clinical-radiographic outcomes, this study aims to (1) assess the perioperative safety of PTED in frail elderly patients and (2) determine the durability of functional and symptomatic improvements. Our findings aim to refine risk stratification and support evidence-based surgical planning for this vulnerable population.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003ePatients\u003c/p\u003e\u003cp\u003eA retrospective analysis was conducted on patients aged 75 years and older with lumbar spinal stenosis (LSS) who underwent single-level percutaneous transforaminal endoscopic decompression(PTED)between February 2022 and December 2023. The inclusion criteria for this study were as follows: (1) Clinical diagnosis of symptomatic lumbar spinal stenosis with ineffective conservative treatment for at least three months; (2) Underwent single-level PTED treatment. The exclusion criteria included the following: absence of severe lumbar spinal stenosis\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e, prior history of spinal surgery, imaging evidence of segmental instability, FRAIL scale score below 3 points\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, concurrent lumbar infection or tumor, incomplete data, or loss to follow-up. All patients were followed up for a minimum of 12 months postoperatively. This study was approved by the institutional ethics committee, and all participants provided written informed consent.\u003c/p\u003e\u003cp\u003eSurgical technique\u003c/p\u003e\u003cp\u003ePTED procedures were all performed by a senior spine surgeon (MW) with sufficient experience, at a single level, under local anesthesia, with the patient placed in a prone position. The patient can communicate with the surgeon throughout the entire operation to prevent intraoperative nerve root injury, and the surgeon was allowed to assess the patient's tolerance. For patients with multilevel stenosis, to determine the level most responsible for the symptoms and best suited for the procedure, a transforaminal selective nerve root block was performed. In all patients with bilateral stenosis, decompression was performed exclusively on the symptomatic side of the lower extremity to address the clinical manifestations effectively. The detailed surgical procedures have been comprehensively described in other previous publications\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eClinical evaluation\u003c/p\u003e\u003cp\u003eDemographic data for all study participants were collected, including gender, age, BMI, the American Society of Anesthesiologists (ASA) Score\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e, FRAIL scale\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, comorbidities, responsibility segment, side of lower limb pain, degree of degeneration (kyphosis, scoliosis, pedicle rotation, Pfirrmann grading of disc), and MRI grade of stenosis\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e (central, lateral recess, foramen). Postoperative hospital stay, operation time, and follow-up time were also recorded.\u003c/p\u003e\u003cp\u003eThe visual analog scale (VAS) was used to assess leg pain and low back pain. The Oswestry Disability Index (ODI) was used to evaluate clinical functional status. The Barthel Index for Activities of Daily Living (ADL)\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e was employed to assess changes in independent living activities both before and after surgery. Surgical satisfaction was evaluated using the modified Macnab criteria. Additionally, postoperative complications were assessed in this study.\u003c/p\u003e\u003cp\u003eRadiological evaluation\u003c/p\u003e\u003cp\u003eThe investigators conducted the measurements utilizing integrated software tools for area quantification embedded within the Picture Archiving and Communication System (PACS). The dural sac cross-sectional area (DSCA) was measured in square millimeters by at least three independent readers, including two orthopedic surgeons and one musculoskeletal radiologist (Figure. 3K-L). Preoperatively and one month postoperatively, the DSCA was assessed at the narrowest level of the responsible segment. Additionally, the MRI stenosis grades of the central spinal canal, lateral recess, and intervertebral foramen were evaluated and documented both pre- and post-operatively. Both the changes in cross-sectional area and stenosis grade were included in the subsequent statistical analysis.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eStatistical analyses were performed using SPSS version 24.0. Data normality was assessed using the Shapiro-Wilk test. Continuous variables are presented as mean ± standard deviation for normal distributions or as median (IQR) for non-normal distributions. Parametric data were compared with a paired t-test, while nonparametric data were analyzed using the Wilcoxon signed-rank test. Repeated-measures data were analyzed using Repeated Measures ANOVA with Bonferroni correction. Categorical variable frequencies were compared using the Chi-square or Fisher's exact test. A p-value \u0026lt; 0.05 indicated statistical significance.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 41 elderly patients with frailty and severe lumbar spinal stenosis were included in this study. The detailed screening flowchart is shown in Figure. 1. The baseline characteristics of these patients are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The mean age was 82.4 ± 4.2 years (range: 76–98), with 21 males and 20 females. The mean BMI was 21.95 ± 2.83. The ASA classification was grade II in 15 cases and grade III in 26 cases. All patients met the frailty criteria (score ≥ 3). The primary responsible segment was located at L4/5 (33 cases), with the remaining cases involving L5/S1. Regarding lumbar degenerative changes, 16 patients had segmental kyphosis, 18 had scoliosis, and 25 exhibited rotational displacement of the superior vertebra relative to the inferior vertebra at the responsible segment. All cases showed disc degeneration of Pfirrmann grading ≥ 4. For lumbar stenosis: All 41 patients had severe central canal stenosis (MRI grade ≥ 3). Thirty-eight patients had concurrent severe lateral recess stenosis on the symptomatic side. Foraminal stenosis was predominantly mild-to-moderate, with severe foraminal stenosis observed in only 11 cases. All patients had ≥ 5 comorbidities, with osteoporosis, hypertension, pulmonary disease, and cardiovascular disease being the top four. Notably, all patients had a negative Lasegue’s sign preoperatively. The mean operative time for PTED was 100.6 ± 19.2 minutes (range: 65–135), and the average postoperative hospital stay was 3.85 ± 1.21 days. The mean follow-up duration was 20.1 ± 4.2 months (range: 15–27). Subgroup analysis based on central canal stenosis severity (Grade III vs. IV) revealed no significant differences in the above parameters except for frailty scores (details in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDemographic Characteristics and Clinical Data of 41 Patients with Severe Lumbar Spinal Stenosis\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCentral stenosis Grade III (n = 21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eCentral stenosis Grade\u003c/p\u003e\u003cp\u003eIV (n = 20)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP Value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTotal(n = 41)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristics\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e82.9 ± 3.7 (79–93)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e81.9 ± 4.6 (76–98)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e82.4 ± 4.2 (76–98)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMale: 13, Female: 8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMale: 8, Female: 12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMale/Female = 21/20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m²)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22.4 ± 2.4 (17.1–25.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e21.4 ± 3.1 (15.2–27)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e21.95 ± 2.83(15.2–27)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eASA Score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eII: III = 6༚15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eII: III = 9༚11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eII: III = 15༚26\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFRAIL scale (≥ 3: frail)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eScale 5/Scale4 /Scale 3 = 1/13/7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eScale 5/Scale4 /Scale 3 = 11/7/2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.009\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eFrail: 41 (100%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComorbidities\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHypertension:20\u003c/p\u003e\u003cp\u003ePulmonary disease: 13 Cardiovascular disease: 14\u003c/p\u003e\u003cp\u003eCerebrovascular disease: 14\u003c/p\u003e\u003cp\u003eDiabetes : 9\u003c/p\u003e\u003cp\u003eOsteoporosis:21\u003c/p\u003e\u003cp\u003eUse anticoagulants:6\u003c/p\u003e\u003cp\u003eDigestive tract disease:6\u003c/p\u003e\u003cp\u003eRenal insufficiency: 3\u003c/p\u003e\u003cp\u003eRheumatoid arthritis: 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHypertension:18\u003c/p\u003e\u003cp\u003ePulmonary disease: 20 Cardiovascular disease: 10\u003c/p\u003e\u003cp\u003eCerebrovascular disease: 14\u003c/p\u003e\u003cp\u003eDiabetes : 5\u003c/p\u003e\u003cp\u003eOsteoporosis:20\u003c/p\u003e\u003cp\u003eUse anticoagulants:3\u003c/p\u003e\u003cp\u003eDigestive tract disease:10\u003c/p\u003e\u003cp\u003eRenal insufficiency: 5 Hematological disorders: 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHypertension:38\u003c/p\u003e\u003cp\u003ePulmonary disease: 33 Cardiovascular disease: 24\u003c/p\u003e\u003cp\u003eCerebrovascular disease:28\u003c/p\u003e\u003cp\u003eDiabetes : 14\u003c/p\u003e\u003cp\u003eOsteoporosis:41\u003c/p\u003e\u003cp\u003eUse anticoagulants :9\u003c/p\u003e\u003cp\u003eDigestive tract disease:16\u003c/p\u003e\u003cp\u003eRenal insufficiency: 8 Hematological disorders: 1\u003c/p\u003e\u003cp\u003eRheumatoid arthritis: 1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eResponsibility segment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eL4/5: (16)\u003c/p\u003e\u003cp\u003eL5/S1:(5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eL4/5: (17)\u003c/p\u003e\u003cp\u003eL5/S1:(3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eL4/5:L5/S1 = 33:8\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLasegue sign\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNegative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNegative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNegative: 41(100%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLower limb pain\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLeft/Right = 9/12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLeft/Right = 12/8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eLeft/Right = 21/20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eKyphosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePresent: 6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePresent: 10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePresent/Absent = 16/25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eScoliosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePresent: 7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePresent: 11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePresent/Absent = 18/23\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePedicle rotation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePresent: 11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e- Present: 14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePresent/Absent = 25/16\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePfirrmann grading\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGrade4:Grade5 = 19:2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGrade4:Grade5 = 12:8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eGrade4:Grade5 = 31:10\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMRI grade of\u003c/p\u003e\u003cp\u003elateral stenosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSevere(2):Moderate(1) =\u003c/p\u003e\u003cp\u003e18:2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSevere(2):Moderate(1) =\u003c/p\u003e\u003cp\u003e19:1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eSevere(2):Moderate(1)=\u003c/p\u003e\u003cp\u003e38:3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMRI grade of foramen stenosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNone(0):Mild(1):Moderate(2):\u003c/p\u003e\u003cp\u003eSevere(3) = 1: 6༚8༚5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNone(0):Mild(1):Moderate(2):Severe(3) = 4: 5༚6༚6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNone(0):Mild(1):Moderate(2): Severe(3) = 5༚11༚14༚11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative hospital stay (days)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.57 ± 1.03(2–7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.15 ± 1.34(3–8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.85 ± 1.21(2–8)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOperation time (minutes)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e96.42 ± 19.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e105 ± 17.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e100.6 ± 19.2(65–135)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFollow-up time (months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e20.1 ± 3.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.9 ± 4.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e20.1 ± 4.2(15–27)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eNotes: Statistical methods:Continuous variables (e.g., age, BMI, postoperative stay): Independent t-test (normality verified by Shapiro-Wilk test, p \u0026gt; 0.05). Categorical variables (e.g., gender, kyphosis): Chi-square test or Fisher’s exact test (applied if expected frequency \u0026lt; 5). Ordinal variables (e.g., FRAIL scale, MRI grade of foramen stenosis): Mann-Whitney U test.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eSignificance level: = 0.05 (two-tailed). ASA: American Society of Anesthesiologists.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eSignificant improvements were observed in clinical outcomes compared to preoperative values. The VAS Back score decreased from 3.65 ± 0.48 preoperatively to 2.43 ± 0.50 at last follow-up (p \u0026lt; 0.01), while the VAS Leg score declined from 6.51 ± 0.50 to 2.07 ± 0.41 (p \u0026lt; 0.001). The ODI index decreased markedly from 67.2 ± 8.1 to 26.7 ± 6.9 (p \u0026lt; 0.001). Concomitant with alleviation of leg pain, particularly in walking capacity, the Barthel ADL index increased significantly from 54.2 ± 8.2 to 77.8 ± 6.12 (p \u0026lt; 0.001), reflecting enhanced functional independence (details in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Postoperative temporal analysis revealed distinct recovery trajectories: VAS back score showed no significant differences from preoperative values at 1 week or 3 months (p \u0026gt; 0.05) but declined progressively thereafter, reaching significance by final follow-up (p \u0026lt; 0.001). In contrast, VAS leg score decreased significantly from 1 week postoperatively (p \u0026lt; 0.001), plateaued at 6 months, and remained stable thereafter. ODI scores improved gradually from 1 week to 12 months, with no further changes at last follow-up (p \u0026gt; 0.05). Similarly, the Barthel ADL index increased incrementally through 6 and 12 months but stabilized subsequently (p \u0026gt; 0.05 vs. 12-month values) (Figure. 2A-D). Radiological outcomes confirmed anatomical efficacy, with the dural sac cross-sectional area (DSCA) expanding from 53.5 ± 21.2 mm² preoperatively to 70.83 ± 25.1 mm² postoperatively (p \u0026lt; 0.001) (Figure. 2E). MRI grading improvements included a 29.2% reduction in central stenosis severity (postoperative IQR: 3 [3–4]), 90.2% resolution of lateral recess stenosis (IQR: 0 [0–1]), and 68.3% alleviation of foraminal stenosis (IQR: 1 [1–1]) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). According to Macnab criteria, 90.2% of patients (37/41) achieved excellent/good outcomes (Figure. 2F). Complications included residual leg pain (9.8%, 4/41), persistent back pain (7.3%, 3/41), and deep vein thrombosis (4.9%, 2/41), with no instances of surgical site infection, neurological injury, spinal hematoma, or recurrent ipsilateral stenosis. Notably, no patients developed contralateral stenosis symptoms during follow-up.\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"±\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"±\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"±\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"±\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of preoperative and postoperative clinical outcomes across follow-up time points\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePreoperative\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePostoperative 1 week\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3months\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e12months\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003ePostoperative last follow-up\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eP Value\u003c/p\u003e\u003cp\u003e(The last follow -up\u003c/p\u003e\u003cp\u003ecompared with preoperative )\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOutcome\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVAS Back\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c2\"\u003e\u003cp\u003e3.65 ± 0.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.78 ± 0.47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.51 ± 0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c5\"\u003e\u003cp\u003e3.02 ± 0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c6\"\u003e\u003cp\u003e2.56 ± 0.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c7\"\u003e\u003cp\u003e2.43 ± 0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVAS Leg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c2\"\u003e\u003cp\u003e6.51 ± 0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.68 ± 0.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.19 ± 0.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c5\"\u003e\u003cp\u003e2.43 ± 0.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c6\"\u003e\u003cp\u003e2.21 ± 0.47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c7\"\u003e\u003cp\u003e2.07 ± 0.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eODI%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c2\"\u003e\u003cp\u003e67.2 ± 8.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e51.7 ± 5.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e44.2 ± 5.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c5\"\u003e\u003cp\u003e39.1 ± 5.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c6\"\u003e\u003cp\u003e28.1 ± 6.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c7\"\u003e\u003cp\u003e26.7 ± 6.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThe Barthel ADL Index\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c2\"\u003e\u003cp\u003e54.2 ± 8.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e—\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e—\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c5\"\u003e\u003cp\u003e72.3 ± 8.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c6\"\u003e\u003cp\u003e77.4 ± 6.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"±\" colname=\"c7\"\u003e\u003cp\u003e77.8 ± 6.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"8\"\u003eNotes:Data presented as Mean ± Standard Deviation (SD). P values indicate statistical significance between preoperative and the last follow -up time (paired tests with Bonferroni correction).\"—\": Data not available for specific time points. Abbreviations: VAS = Visual Analog Scale; ODI = Oswestry Disability Index; ADL = Activities of Daily Living.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSpinal Stenosis Grading Changes Using Wilcoxon Signed-Rank Test\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePreoperative Median (IQR)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePostoperative Median (IQR)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eZ Value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP Value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eImprovement Rate (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStenosis Type\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCentral\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4 (3–4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (3–4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-3.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e29.2%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLateral\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2–2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0–1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-5.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e90.2%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eForaminal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (1–3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1–1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e-4.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt; 0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e68.3%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eNotes:Improvement rate: Percentage of patients with reduced postoperative grades.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eEffect sizes (r): Central = 0.54, Lateral = 0.86, Foraminal = 0.75. IQR = Interquartile Range\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eA representative case is shown in Figure.3\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eWhile debates persist regarding the optimal surgical approach for lumbar spinal stenosis (LSS), decompressive surgery\u0026mdash;whether alone or combined with fusion\u0026mdash;has proven effective for patients unresponsive to conservative treatment\u003csup\u003e16\u003c/sup\u003e. However, the aging population presents unique challenges in surgical decision-making for elderly LSS patients. Frail individuals often suffer from reduced mobility due to debilitating back and leg pain, compounded by cardiopulmonary comorbidities that exacerbate physiological vulnerability. Existing evidence highlights a strong correlation between frailty and severe perioperative complications in fusion surgery\u003csup\u003e7,17\u003c/sup\u003e, necessitating less invasive alternatives. Although minimally invasive techniques, such as micro-endoscopic decompressive laminotomy under general anesthesia (as reported\u003csup\u003e18\u003c/sup\u003e in octogenarians with LSS and spondylolisthesis), demonstrate efficacy, their invasiveness remains suboptimal compared to percutaneous transforaminal endoscopic decompression (PTED). Despite promising reports on PTED for elderly LSS patients\u003csup\u003e9-11,19,20\u003c/sup\u003e, critical gaps persist in safety and efficacy evaluations due to insufficient frailty assessments, heterogeneous degenerative severity, and inconsistent patient selection criteria.\u003c/p\u003e\n\u003cp\u003eIn this study, all 41 enrolled patients met predefined frailty criteria (frailty score \u0026ge;3) and exhibited severe central canal stenosis (grade III\u0026ndash;IV), with 38 cases presenting concomitant severe lateral recess stenosis(grade II). Grading of disc degeneration at the symptomatic level was classified as Pfirrmann grades IV\u0026ndash;V. All procedures were performed under local anesthesia in the prone position via percutaneous transforaminal endoscopic decompression, with a mean operative duration of 100.6 \u0026plusmn; 19.2 minutes (range: 65\u0026ndash;135). This operative time was shorter than the 147.8 \u0026plusmn; 48.05 minutes reported by Wang et al.\u003csup\u003e11\u003c/sup\u003ebut exceeded the 75 minutes (range: 50\u0026ndash;110) documented by Chen et al\u003csup\u003e9\u003c/sup\u003e. The observed variation may be attributed to our exclusion of obese patients (BMI \u0026lt;27) and a surgical strategy prioritizing nerve root canal decompression over extensive central canal enlargement, thereby reducing procedural complexity compared to Wang et al.\u0026rsquo;s approach. Conversely, the shorter operative time in Chen et al.\u0026rsquo;s cohort may reflect the inclusion of patients with milder degenerative changes, as their study lacked detailed stratification of lumbar degeneration severity\u0026mdash;a critical factor influencing foraminoplasty and intraspinal decompression time.\u0026nbsp;Notably, all patients\u0026mdash;including those with hypertension, cardiovascular disease, or pulmonary comorbidities\u0026mdash;successfully completed the procedure without intraoperative complications. The brief postoperative hospitalization (3.85 \u0026plusmn; 1.21 days) further underscores PTED\u0026rsquo;s minimally invasive profile and its minimal physiological impact on frail elderly patients.\u0026nbsp;During follow-up, no major complications or mortality occurred, aligning with prior studies reporting low complication rates\u003csup\u003e20,21\u003c/sup\u003e. Two cases of deep vein thrombosis (DVT) were attributed to postoperative immobility due to pain-related anxiety; both resolved with anticoagulation, emphasizing the necessity of early postoperative mobilization.\u003c/p\u003e\n\u003cp\u003eA common concern with limited decompression is the risk of symptom recurrence. However, no cases required reoperation during follow-up, contrasting with the low but nonzero reoperation rates in previous studies. We hypothesize that this may reflect the inclusion of patients with \u0026ldquo;end-stage\u0026rdquo; degenerative pathology, as evidenced by advanced disc degeneration (Pfirrmann IV\u0026ndash;V) and the absence of contralateral symptoms despite radiographic stenosis in all cases. This hypothesis, supported by the stability of degenerative changes during follow-up, warrants validation through long-term comparative imaging studies in future investigations.\u003c/p\u003e\n\u003cp\u003eRegarding surgical efficacy, patients exhibited significant improvements in VAS Back, VAS Leg, and ODI scores at final follow-up. A notable observation was the markedly lower preoperative back pain scores in our cohort (3.65 \u0026plusmn; 0.48) compared to those reported by Wang et al.(6.15 \u0026plusmn; 0.86)\u003csup\u003e11\u003c/sup\u003e and Xie et al. (6.7 \u0026plusmn; 1.15)\u003csup\u003e20\u003c/sup\u003e. This discrepancy may stem from our strict exclusion of lumbar instability and dynamic spondylolisthesis, as well as the inclusion of frail patients with reduced physical activity, which likely contributed to milder baseline back pain.\u0026nbsp;Postoperatively, transient exacerbation of ipsilateral back pain occurred in some patients at one week, suggesting that localized tissue trauma from minimally invasive maneuvers may temporarily aggravate symptoms. However, three months after PTED, with significant relief of leg pain and improvement of walking distance, and strict anti-osteoporosis treatment (all patients were diagnosed with osteoporosis before surgery), the low back pain symptoms were significantly relieved, until the last follow-up.\u003c/p\u003e\n\u003cp\u003eLeg pain \u0026quot;rebound\u0026quot; observed in some cases at one week\u0026mdash;attributed to postoperative edema or inflammatory responses following neural decompression\u0026mdash;resolved completely by three months. This transient pattern underscores the importance of preoperative patient counseling to manage expectations and enhance satisfaction\u003csup\u003e22\u003c/sup\u003e. Residual leg pain requiring analgesics persisted in four patients, with MRI revealing inadequate lateral recess decompression. This highlights the necessity of prioritizing thorough lateral recess decompression during PTED for frail elderly patients with severe LSS.\u003c/p\u003e\n\u003cp\u003eQuantitative analysis demonstrated a significant increase in dural sac cross-sectional area (DSCA) postoperatively, attributable to resection of hypertrophic ligamentum flavum, osteophytes, and herniated disc material. However, only 29.2% of cases showed definitive central canal improvement on MRI, consistent with prior evidence that symptom relief correlates poorly with central canal metrics\u003csup\u003e23,24\u003c/sup\u003e. Conversely, foraminal stenosis improvement (68.3%) strongly aligned with ODI enhancements, as reported by J\u0026oslash;rn Aaen et al., emphasizing the critical role of foraminal and lateral recess decompression in functional recovery.\u0026nbsp;Moreover, as the establishment of the working channel during PTED inevitably requires foraminal enlargement, the improvement rate of foraminal stenosis in our cohort reached 68.3%. This high rate of foraminal and lateral recess stenosis improvement contributed to significant enhancements in Oswestry Disability Index (ODI) scores, consistent with prior findings\u003csup\u003e25\u003c/sup\u003e. Frailty and severe lumbar spinal stenosis (LSS) impose profound burdens on quality of life in elderly patients due to chronic pain and ambulatory limitations, exacerbating caregiver dependency. In our cohort, the preoperative Barthel Index for Activities of Daily Living (ADL) was 54.2 \u0026plusmn; 8.2, reflecting moderate disability requiring assistance. Following percutaneous transforaminal endoscopic decompression (PTED), functional independence improved significantly, with the Barthel Index rising to 72.3 \u0026plusmn; 8.06 at 6 months and stabilizing at 77.8 \u0026plusmn; 6.12 by final follow-up. These results demonstrate that PTED provides sustained functional benefits in frail elderly patients with severe LSS, effectively restoring autonomy and reducing caregiving demands.\u003c/p\u003e\n\u003cp\u003eThis study has several limitations. First, despite stringent inclusion criteria ensuring internal consistency, the small sample size necessitates validation through larger multicenter cohorts with long-term follow-up. Second, the retrospective design lacks non-surgical controls, limiting causal inferences regarding PTED\u0026rsquo;s necessity; prospective studies are required to address this. Third, PTED\u0026rsquo;s steep learning curve may influence outcomes, as technical proficiency varies with surgeon experience.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eTo the best of our knowledge, this is the first retrospective study to confirm the safety and efficacy of unilateral PTED under local anesthesia for frail elderly patients (\u0026ge;75 years) with severe LSS, integrating frailty assessments (frailty score \u0026ge;3) and stringent degenerative criteria (central stenosis grade \u0026ge;3). Our results underscore PTED\u0026rsquo;s potential as a viable minimally invasive strategy for this high-risk population, balancing procedural safety with durable clinical improvements.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eClinical trial number: not applicable\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee of Suining Central Hospital (Approval No.: KYLLKS20250090), and all procedures complied with the ethical principles of the Declaration of Helsinki. Written informed consent was obtained from all participants or their legal guardians prior to participation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll patients or their legal guardians consented to the publication of anonymized data. This manuscript contains no personally identifiable information.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets and materials generated during this study are available from the corresponding author upon reasonable request. Raw imaging data are subject to ethical committee approval prior to access due to patient privacy concerns.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests, including financial, academic, or other conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study received no specific funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMiao Wang: Study design, surgery performance, data analysis, and manuscript writing.\u003c/p\u003e\n\u003cp\u003eHui Yi Liu: Data collection and analysis.\u003c/p\u003e\n\u003cp\u003eFan Dong Wang: Surgical assistance and telephone follow-up.\u003c/p\u003e\n\u003cp\u003eGuang Zhou Li (Corresponding Author): Study design supervision and imaging analysis.\u003c/p\u003e\n\u003cp\u003eYu Chen: Imaging analysis.\u003c/p\u003e\n\u003cp\u003eJia Zhuang Zheng: Case screening and quality control.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe author expresses deepest gratitude to Ms. Xue\u0026nbsp;wen Yin, his cherished partner, for her multifaceted support during this research. Her meticulous coordination of domestic logistics facilitated sustained academic focus, particularly during experimental iterations and statistical validation phases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information (optional)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFehlings MG, Tetreault L, Nater A, et al. The Aging of the Global Population: The Changing Epidemiology of Disease and Spinal Disorders. Neurosurgery. 2015;77(Suppl 4):S1\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJensen RK, Skovsgaard CV, Ziegler DS, et al. Surgical trends and regional variation in Danish patients diagnosed with lumbar spinal stenosis between 2002 and 2018: a retrospective registry-based study of 83,783 patients. 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BMC Musculoskelet Disord. 2023;24(1):573.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKitthanyateerakul P, Tankumpuan T, Davidson PM. Cognitive dysfunction in older patients undergoing non-neurosurgery in the immediate postoperative period: A systematic review. Nurs Open. 2024;11(8):e70023.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang SK, Wang QJ, Wang P, et al. The impact of frailty on clinical outcomes of older patients undergoing enhanced recovery after lumbar fusion surgery: a prospective cohort study. Int J Surg. 2024;110(8):4785\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGadjradj PS, Harhangi BS, Amelink J, et al. Percutaneous Transforaminal Endoscopic Discectomy Versus Open Microdiscectomy for Lumbar Disc Herniation: A Systematic Review and Meta-analysis. Spine (Phila Pa 1976). 2021;46(8):538\u0026ndash;49.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen X, Qin R, Hao J, et al. Percutaneous endoscopic decompression via transforaminal approach for lumbar lateral recess stenosis in geriatric patients. Int Orthop. 2019;43(5):1263\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang J, Wu H, Kong Q, et al. Full Endoscopic Transforaminal Decompression Surgery for Symptomatic Lumbar Spinal Stenosis in Geriatric Patients. World Neurosurg. 2019;127:e449\u0026ndash;59.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang L, Wang T, Fan N, et al. Clinical outcome of percutaneous endoscopic lumbar decompression in treatment of elderly patients with lumbar spinal stenosis: a matched retrospective study. Int Orthop. 2024;48(1):201\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSpinnato P, Petrera MR, Parmeggiani A, et al. A new comprehensive MRI classification and grading system for lumbosacral central and lateral stenosis: clinical application and comparison with previous systems. Radiol Med. 2024;129(1):93\u0026ndash;106.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMorley JE, Malmstrom TK, Miller DK. A simple frailty questionnaire (FRAIL) predicts outcomes in middle aged African Americans. J Nutr Health Aging. 2012;16(7):601\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSankar A, Johnson SR, Beattie WS, Tait G, Wijeysundera DN. Reliability of the American Society of Anesthesiologists physical status scale in clinical practice. Br J Anaesth. 2014;113(3):424\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ede Haan R, Limburg M, Schuling J, Broeshart J, Jonkers L, van Zuylen P. [Clinimetric evaluation of the Barthel Index, a measure of limitations in dailly activities]. Ned Tijdschr Geneeskd. 1993;137(18):917\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWei FL, Zhou CP, Liu R, et al. Management for lumbar spinal stenosis: A network meta-analysis and systematic review. Int J Surg. 2021;85:19\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang Y, Wu Q, Han M, et al. Frailty is a Risk Factor for Postoperative Complications in Older Adults with Lumbar Degenerative Disease: A Prospective Cohort Study. Clin Interv Aging. 2024;19:1117\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRosen DS, O'Toole JE, Eichholz KM, et al. Minimally invasive lumbar spinal decompression in the elderly: outcomes of 50 patients aged 75 years and older. Neurosurgery. 2007;60(3):503\u0026ndash;9. discussion 509\u0026ndash;510.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhn Y, Keum HJ, Son S. Percutaneous Endoscopic Lumbar Foraminotomy for Foraminal Stenosis with Postlaminectomy Syndrome in Geriatric Patients. World Neurosurg. 2019;130:e1070\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXie P, Feng F, Chen Z, et al. Percutaneous transforaminal full endoscopic decompression for the treatment of lumbar spinal stenosis. BMC Musculoskelet Disord. 2020;21(1):546.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBao BX, Zhou JW, Yu PF, Chi C, Qiang H, Yan H. Transforaminal Endoscopic Discectomy and Foraminoplasty for Treating Central Lumbar Stenosis. Orthop Surg. 2019;11(6):1093\u0026ndash;100.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRault F, Briant AR, Kamga H, Gaberel T, Emery E. Surgical management of lumbar spinal stenosis in patients over 80: is there an increased risk? Neurosurg Rev. 2022;45(3):2385\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHermansen E, Myklebust TA, Weber C, et al. Postoperative Dural Sac Cross-Sectional Area as an Association for Outcome After Surgery for Lumbar Spinal Stenosis: Clinical and Radiological Results From the NORDSTEN-Spinal Stenosis Trial. Spine (Phila Pa 1976). 2023;48(10):688\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMinetama M, Kawakami M, Teraguchi M, et al. MRI grading of spinal stenosis is not associated with the severity of low back pain in patients with lumbar spinal stenosis. BMC Musculoskelet Disord. 2022;23(1):857.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAaen J, Banitalebi H, Austevoll IM, et al. Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression. Acta Neurochir (Wien). 2023;165(8):2121\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Lumbar spinal stenosis, Percutaneous transforaminal endoscopic decompression, Frailty, Elderly, Minimally invasive surgery","lastPublishedDoi":"10.21203/rs.3.rs-6678941/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6678941/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eObjective: To evaluate the safety and efficacy of percutaneous transforaminal endoscopic decompression (PTED) under local anesthesia in frail elderly patients (\u0026ge;\u0026thinsp;75 years) with severe lumbar spinal stenosis (LSS).\u003c/p\u003e\u003cp\u003eMethods: Forty-one patients (mean age: 82.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2 years) with severe central LSS (MRI grade\u0026thinsp;\u0026ge;\u0026thinsp;3), lateral recess stenosis (grade II in 38 cases), advanced disc degeneration (Pfirrmann IV\u0026ndash;V), and frailty (score\u0026thinsp;\u0026ge;\u0026thinsp;3) underwent unilateral PTED. Outcomes included operative time, hospitalization duration, clinical metrics (VAS, ODI, Barthel Index), radiological improvements (dural sac cross-sectional area [DSCA], stenosis grading), and complications.\u003c/p\u003e\u003cp\u003eResults: Mean operative time was 100.6\u0026thinsp;\u0026plusmn;\u0026thinsp;19.2 minutes, with a postoperative hospital stay of 3.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21 days. At final follow-up (20.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2 months), significant improvements were observed: VAS back pain decreased from 3.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48 to 2.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01), VAS leg pain from 6.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50 to 2.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), ODI from 67.2\u0026thinsp;\u0026plusmn;\u0026thinsp;8.1 to 26.7\u0026thinsp;\u0026plusmn;\u0026thinsp;6.9 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and Barthel Index from 54.2\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2 (moderate disability) to 77.8\u0026thinsp;\u0026plusmn;\u0026thinsp;6.12 (near independence) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Radiologically, the dural sac cross-sectional area (DSCA) increased from 53.5\u0026thinsp;\u0026plusmn;\u0026thinsp;21.2 mm\u0026sup2; preoperatively to 70.8\u0026thinsp;\u0026plusmn;\u0026thinsp;25.1 mm\u0026sup2; postoperatively (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Lateral recess stenosis resolved in 90.2% of cases (IQR: 0 [0\u0026ndash;1]), and foraminal stenosis improved in 68.3% (IQR: 1 [1\u0026ndash;1]). Complications included residual leg pain (9.8%), deep vein thrombosis (4.9%), and no reoperations.\u003c/p\u003e\u003cp\u003eConclusions: PTED under local anesthesia is a safe and effective minimally invasive strategy for frail elderly patients with severe LSS, providing durable symptom relief and functional restoration. Lateral recess decompression is critical for optimal outcomes. Larger prospective studies are warranted to validate these findings.\u003c/p\u003e","manuscriptTitle":"Safety and Efficacy of Percutaneous Transforaminal Endoscopic Decompression Under Local Anesthesia in Frail Elderly Patients with Severe Lumbar Spinal Stenosis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-18 12:45:56","doi":"10.21203/rs.3.rs-6678941/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-08T03:51:54+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-27T03:12:17+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-24T09:20:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"332505479506575011806747471155338945962","date":"2025-07-22T23:15:05+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-22T06:30:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"204472418554379975168757575017960893291","date":"2025-07-12T01:38:53+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"177553860310346719929445554344886747859","date":"2025-07-11T16:56:56+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-11T16:43:37+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-06-20T19:16:28+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-19T04:55:07+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-05-19T04:50:51+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Musculoskeletal Disorders","date":"2025-05-16T08:33:45+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1ac08951-e3d7-4cb4-b64b-65dbf21e27df","owner":[],"postedDate":"July 18th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-09-23T16:38:12+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-18 12:45:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6678941","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6678941","identity":"rs-6678941","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}