Does minimally invasive spine surgery improve outcomes in the obese population? A retrospective review of 1442 degenerative lumbar spine surgeries

90-Day Emergency Department Utilization and Readmission Rate After Full-Endoscopic Spine Surgery: A Multicenter, Retrospective Analysis of 821 Patients

BACKGROUND AND OBJECTIVES

Emergency department (ED) utilization and readmission rates after spine surgery are common quality of care measures. Limited data exist on the evaluation of quality indicators after full-endoscopic spine surgery (FESS). The objective of this study was to detect rates, causes, and risk factors for unplanned postoperative clinic utilization after FESS.

METHODS

This retrospective multicenter analysis assessed ED utilization and clinic readmission rates after FESS performed between 01/2014 and 04/2023 for degenerative spinal pathologies. Outcome measures were ED utilizations, hospital readmissions, and revision surgeries within 90 days postsurgery.

RESULTS

Our cohort includes 821 patients averaging 59 years of age, who underwent FESS. Most procedures targeted the lumbar or sacral spine (85.75%) while a small fraction involved the cervical spine (10.11%). The most common procedures were lumbar unilateral laminotomies for bilateral decompression (40.56%) and lumbar transforaminal discectomies (25.58%). Within 90 days postsurgery, 8.0% of patients revisited the ED for surgical complications. A total of 2.2% of patients were readmitted to a hospital of which 1.9% required revision surgery. Primary reasons for ED visits and clinic readmissions were postoperative pain exacerbation, transient neurogenic bladder dysfunction, and recurrent disk herniations. Our multivariate regression analysis revealed that female patients had a significantly higher likelihood of using the ED (P = .046; odds ratio: 1.77, 95% CI 1.01-3.1 5.69% vs 10.33%). Factors such as age, American Society of Anesthesiologists class, body mass index, comorbidities, and spanned spinal levels did not significantly predict postoperative ED utilization.

CONCLUSION

This analysis demonstrates the safety of FESS, as evidenced by acceptable rates of ED utilization, clinic readmission, and revision surgery. Future studies are needed to further elucidate the safety profile of FESS in comparison with traditional spinal procedures.

Does obesity and varying body mass index affect the clinical outcomes and safety of biportal endoscopic lumbar decompression? A comparative cohort study

BACKGROUND

Endoscopic spine surgery has recently grown in popularity due to the potential benefits of reduced pain and faster recovery time as compared to open surgery. Biportal spinal endoscopy has been successfully applied to lumbar disc herniations and lumbar spinal stenosis. Obesity is associated with increased risk of complications in spine surgery. Few prior studies have investigated the impact of obesity and associated medical comorbidities with biportal spinal endoscopy.

METHODS

This study was a prospectively collected, retrospectively analyzed comparative cohort design. Patients were divided into cohorts of normal body weight (Bone Mass Index (BMI)18.0-24.9), overweight (BMI 25.0-29.9) and obese (BMI > 30.0) as defined by the World Health Organization (WHO). Patients underwent biportal spinal endoscopy by a single surgeon at a single institution for treatment of lumbar disc herniations and lumbar spinal stenosis. Demographic data, surgical complications, and patient-reported outcomes were analyzed. Statistics were calculated amongst treatment groups using analysis of variance and chi square where appropriate. Statistical significance was determined as p < 0.05.

RESULTS

Eighty-four patients were followed. 26 (30.1%) were normal BMI, 35 (41.7%) were overweight and 23 (27.4%) were obese. Patients with increasing BMI had correspondingly greater American Society of Anesthesiologist (ASA) scores. There were no significant differences in VAS Back, VAS Leg, and ODI scores, or postoperative complications among the cohorts. There were no cases of surgical site infections in the cohort. All cohorts demonstrated significant improvement up to 1 year postoperatively.

CONCLUSIONS

This study demonstrates that obesity is not a risk factor for increased perioperative complications with biportal spinal endoscopy and has similar clinical outcomes and safety profile as compared to patients with normal BMI. Biportal spinal endoscopy is a promising alternative to traditional techniques to treat common lumbar pathology.

Characterizing utilization patterns and reoperation risk factors of interspinous process devices: analysis of a national claims database

INTRODUCTION

Interspinous process devices (IPDs) were developed as minimally invasive alternatives to open decompression surgery for spinal stenosis. However, given high treatment failure and reoperation rates, there has been minimal adoption by spine surgeons. This study leveraged a national claims database to characterize national IPD usage patterns and postoperative outcomes after IPD implantation.

METHOD

Using the PearlDiver database, we identified all patients who underwent 1- or 2-level IPD implantation between 2010 and 2018. Univariate and multivariable logistic regression was performed to identify predictors of the number of IPD levels implanted and reoperation up to 3 years after the index surgery. Right-censored Kaplan-Meier curves were plotted for duration of reoperation-free survival and compared with log-rank tests.

RESULTS

Patients (n = 4865) received 1-level (n = 3246) or 2-level (n = 1619) IPDs. Patients who were older (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.01-1.03, P < .001), male (aOR 1.31, 95% CI 116-1.50, P < .001), and obese (aOR 1.19, 95% CI 1.05-1.36, P < .01) were significantly more likely to receive a 2-level IPD than to receive a 1-level IPD. The 3-year reoperation rate was 9.3% of patients when mortality was accounted for during the follow-up period. Older age decreased (aOR 0.97, 95% CI 0.97-0.99, P = .0039) likelihood of reoperation, whereas 1-level IPD (aOR 1.37, 95% CI 1.01-1.89, P = .048), Charlson Comorbidity Index (aOR 1.07, 95% CI 1.01-1.14, P = .018), and performing concomitant open decompression increased the likelihood of reoperation (aOR 1.68, 95% CI 1.35-2.09, P = .0014).

CONCLUSION

Compared with 1-level IPDs, 2-level IPDs were implanted more frequently in older, male, and obese patients. The 3-year reoperation rate was 9.3%. Concomitant open decompression with IPD placement was identified as a significant risk factor for subsequent reoperation and warrants future investigation.

A Tubular-Mounted Digital Camera Versus Optical Surgical Microscope for Minimally Invasive Lumbar Decompression Surgery: The Impact on Operative Times, Ergonomics, and Workflow

OBJECTIVE

Understanding ergonomic impact is foundational to critically evaluating value and safety of enabling technologies in minimally invasive spine surgeries. This study assessed the impact of a tubular-mounted digital camera (TMDC) versus an optical surgical microscope (OSM) in single-level minimally invasive spine surgeries on operative times, durotomy rate, surgeon ergonomics, safety, and operating room workflow.

METHODS

This retrospective study compared consecutive single-level minimally invasive lumbar decompression surgeries in a TMDC cohort (September 2021-June 2022) with an historical OSM cohort (January 2020-July 2021). Data included patient demographics, operative times, durotomy incidence, surgeon ergonomics (Rapid Entire Body Assessment scores), and equipment impact via staff surveys. Operative times were assessed by t test, while Pearson χ2 test compared sex. Age, body mass index, and Charlson Comorbidity Index comparisons were made by Wilcoxon rank sum tests, and survey results were analyzed with Wilcoxon signed rank tests.

RESULTS

TMDC and OSM groups included 74 and 82 patients, respectively. Age, sex, and Charlson Comorbidity Index did not significantly differ between groups. The TMDC group had a higher body mass index (29.6 ± 5.1) than the OSM group (29.0 ± 7.5) (P = 0.04). The TMDC group had significantly shorter operative times (57.3 ± 16.6 minutes) than the OSM group) (66.7 ± 22.5 minutes) (P = 0.004), with no difference in durotomy rates (P = 0.42). TMDC use yielded lower Rapid Entire Body Assessment scores compared with OSM (4.1 ± 0.77) (P < 0.001). Surveys indicated improved safety, setup time, and workflow with TMDC (P < 0.001).

CONCLUSIONS

TMDC in single-level minimally invasive lumbar decompression surgery improved surgeon ergonomics, reduced operative times, and maintained durotomy rates, enhancing operating room efficiency. Evaluating ergonomic impact of technology is vital for safety and value assessment.

Comparison of biportal endoscopic technique and uniportal endoscopic technique in Unilateral Laminectomy for Bilateral Decomprssion (ULBD) for lumbar spinal stenosis

OBJECTIVE

Unilateral laminotomy for bilateral decompression (ULBD) has been adopted widely to treat lumbar spinal stenosis (LSS). The objective of the study is to investigate clinical and radiological outcomes of the biportal endoscopic ULBD (BE-ULBD) and uniportal endoscopic ULBD (UE-ULBD).

METHODS

We collected retrospectively 65 patients' data who met the inclusion criteria (July 2019-June 2021). 33 patients underwent BE-ULBD surgery, and 32 patients underwent the UE-ULBD surgery, and were followed up for at least 1 year. The following preoperative and postoperative outcomes were compared between groups: the visual analog scale (VAS) for pain, the Oswestry disability index (ODI) for nerve function, and modified Macnab criteria for satisfaction, the cross-sectional area of the dural sac (DSCSA), the mean angle of facetectomy.

RESULTS

Age, BMI, gender, levels of involvement and duration of symptoms were not significantly different at baseline in this study. Clinical data showed that postoperative ODI, VAS scores and Modified Macnab Criteria were not statistically different between the two groups. The BE-ULBD group had a shorter operation time than the UE-ULBD group (P < 0.001). Patients in the BE-ULBD group had a larger postoperative expansion of DSCSA expansion postoperatively (85.58 ± 3.16 mm2 VS 71.43 ± 3.35 mm2, P < 0.001) and a larger contralateral facetectomy angle (63.95 ± 3.34° vs 57.80 ± 3.43°, P < 0.001) compared with patients in the UE-ULBD group. There were no statistical differences in the incidence of postoperative complications between the two groups.

CONCLUSION

Both the BE-ULBD and the UE-ULBD yielded clinical improvement in terms of pain and stenosis symptoms. The BE-ULBD technique has the advantages of the shorter operation time, larger DSCSA expansion and larger contralateral facetectomy angle.

Clinical and radiologic outcomes of biportal endoscopic lumbar discectomy in obese patients: a retrospective case-control study

BACKGROUND

Obese patients have a higher risk of complications during spinal surgery than non-obese patients. To the best of our knowledge, no studies have examined the differences in clinical and radiological outcomes after biportal endoscopic lumbar discectomy (BELD) between obese and non-obese patients. The study evaluated the association between obesity and outcomes after BELD in patients with lumbar disc herniation.

METHODS

This was a retrospective case-control study conducted from March 2017 to March 2021 at two hospitals with 360 patients who underwent BELD after showing no improvement with conservative treatment. Clinical and radiologic outcomes were retrospectively analyzed after BELD in the non-obese (body mass index [BMI] < 30 kg/m²) and obese (BMI ≥ 30 kg/m²) groups. Demographic data and surgery-related factors were compared between the two groups. Clinical outcomes were followed up for 12 months after surgery and analyzed for differences.

RESULTS

A total of 211 patients were enrolled in this study, and through case-control matching, the data of 115 patients (29, obese group; 86, non-obese group) were analyzed. The two groups showed no significant differences in Oswestry Disability Index, European Quality of Life-5 Dimensions (EQ-5D), and visual analog scale scores measured immediately after BELD and 12 months after surgery. After surgery, back pain, radiating leg pain, and EQ-5D scores improved. However, there was no significant difference in improvement, residual herniated disc, hematoma, or recurrence between the groups.

CONCLUSIONS

Obese patients who underwent BELD for lumbar disc herniation showed no significant difference in clinical and radiologic outcomes compared with non-obese patients.

Minimally Invasive Surgical Decompression without Fusion for the Treatment of Lumbar Synovial Cysts: Feasibility and Long-Term Outcomes

BACKGROUND

Lumbar synovial cysts (LSCs) can cause painful radiculopathy and sensory and/or motor deficits. Historically, first-line surgical treatment has been decompression with fusion. Recently, minimally invasive laminectomy without fusion has shown equal or superior results to traditional decompression and fusion methods.

OBJECTIVE

This study investigates the long-term efficacy of minimally invasive laminectomy without fusion in the treatment of LSC as it relates to the rate of subsequent fusion surgery.

METHODS

A retrospective review was performed over a 10-year period of patients undergoing minimally invasive laminectomy for symptomatic LSCs. The primary end point was the rate of revision surgery requiring fusion.

RESULTS

Eighty-five patients with symptomatic LSCs underwent minimally invasive laminectomy alone January 2010-August 2020 at our institution. The most common location was L4-5 (72%). Preoperative imaging identified spondylolisthesis (grade 1) in 43 patients (57%), none of which was unstable on available dynamic radiographs. Average procedure duration was 93 minutes, with 78% of patients discharged home on the same day of surgery. Over 46 months of mean follow-up, 17 patients (20%) required 19 revision operations. Of those operations, 16 were spinal fusions (17.6%). Median time to fusion surgery was 36 months. There were no identifiable risk factors on multivariate regression analysis that predicted the need for fusion.

CONCLUSIONS

Minimally invasive laminectomy is an effective first-line treatment for symptomatic LSCs and avoids the need for fusion in most treated patients. Of our patients, 18% required a fusion over 46 months, suggesting that further studies are required to guide patient selection.

Minimally invasive posterior lumbar surgery in the morbidly obese, obese and non-obese populations: A single institution retrospective review

BACKGROUND

There is a paucity of information regarding outcomes in minimally invasive surgical (MIS) approaches to posterior lumbar surgery in morbidly obese patients. We seek to determine if there are differences in operative variables and early complication rates in morbidly obese patients undergoing MIS posterior lumbar surgery compared to obese and non-obese patients.

METHODS

A single institution retrospective review of patients undergoing MIS posterior lumbar surgery (decompression and/or fusion) between 2013 and 2016 was performed. Morbidly obese patients (BMI ≥ 40) were compared to obese (BMI 30-39.9) and non-obese (BMI < 30) cohorts. Postoperative complication rates and perioperative variables including estimated blood loss, operative time, and outcome measures including length of stay (LOS), in-hospital complications, readmission, and disposition were assessed.

RESULTS

47 morbidly obese, 135 obese and 224 non-obese patients underwent posterior MIS instrumented fusion. 59 morbidly obese, 182 obese and 314 non-obese patients underwent posterior MIS decompression. The morbidly obese group experienced a greater rate of deep vein thrombosis and had an increased hospital LOS (p < 0.05). Morbidly obese patients who underwent MIS decompression experienced increased postoperative complications (p < 0.01), and increased LOS (p < 0.0001) compared to obese and non-obese patients. There were no differences in revision rates, readmissions, and other complications including surgical site infection. Morbid obesity was an independent predictor of overall complications and increased LOS on multivariate analysis.

CONCLUSION

Morbidly obese patients undergoing posterior MIS fusion had a higher rate of complications and increased LOS. While weight loss should be encouraged, complication rates remains acceptably low in morbidly obese patients and MIS posterior lumbar surgery should still be offered.