Risk Factors and Reoperation Rate in Revision Lumbar Disc Herniation Surgery: A Systematic Review and Meta-Analysis of 1,031,348 Patients

Global Spine Journal 2026, Vol. 16(3) 1633-1647

This systematic review and meta-analysis examines reoperation rates and associated risk factors following primary lumbar disc herniation surgery across 25 studies totaling 1,031,348 patients. Pooled reoperation rate was 8.5% overall (adjusted to 10.3% for publication bias), with rates varying by follow-up: 4% at ≤1 year, 11.1% at 1–5 years, and 8.8% beyond 5 years.

Key risk factors identified include smoking, older age, diabetes, and large annular defects, while sex was not significant. The review highlights heterogeneity across study designs and follow-up durations, recommends careful patient selection, extended conservative management or closer surveillance for high-risk patients, and calls for trials comparing revision techniques.

Objective Estimate the reoperation rate after lumbar disc herniation surgery and identify associated risk factors.

Evidence base 25 studies (including observational studies and 3 RCTs) totaling 1,031,348 patients were included.

Overall reoperation rate Pooled reoperation rate was 8.5% (95% CI 6.2%–11.6%); after trim-and-fill adjustment for publication bias it was 10.3% (95% CI 7.6%–14.0%).

Follow-up pattern Reoperation rates differed by follow-up duration: 4% at ≤1 year, 11.1% at 1–5 years, and 8.8% at >5 years (significant subgroup differences).

Smoking risk Smoking was associated with higher odds of reoperation (OR 1.39, 95% CI 1.09–1.78).

Age risk Older age was associated with higher odds of reoperation (OR 1.52, 95% CI 1.25–1.85).

Annular defect risk Larger annular defect size was associated with higher odds of reoperation (OR 2.19, 95% CI 1.07–4.48).

Other factors Diabetes and certain surgical techniques were linked to higher reoperation risk in individual studies; sex was not a significant predictor (OR 1.22, 95% CI 0.96–1.55).

Risk Factors Associated With Revision Microdiscectomy or Subsequent Spinal Fusion Within Two Years of Index Lumbar Microdiscectomy

Spine 2025;50:1392–1399

This large retrospective study found that within two years of lumbar microdiscectomy, 5.5% required revision surgery and 6.6% required spinal fusion. Age 40–59, female sex, and at least one Charlson Comorbidity Index (CCI) comorbidity significantly increased the risk of subsequent fusion, but not revision microdiscectomy.

Revision microdiscectomy rates after index lumbar microdiscectomy were 3.5% at one year and 5.5% at two years.

Lumbar fusion rates were 2.9% at one year and 6.6% at two years after index surgery.

Age 40–59, female sex, and presence of at least one Charlson Comorbidity Index (CCI) comorbidity significantly increased risk of lumbar fusion, but not revision microdiscectomy.

Having ≥1 CCI comorbidity increased the likelihood of needing fusion by about 80%.

Specific comorbidities (e.g., congestive heart failure, peripheral/cerebrovascular disease, diabetes) were strong predictors for time-to-fusion.

Age, sex, and CCI score were not predictive of time-to-revision microdiscectomy.

Results suggest CCI may help identify patients at higher risk for spinal fusion after microdiscectomy.

Findings may guide surgeons in perioperative decision-making and patient counseling.

Early Voice and Swallowing Disturbance Incidence and Risk Factors After Revision Anterior Cervical Discectomy and Fusion Using a Multidisciplinary Surgical Approach

Neurosurgery 94:444–453, 2024

Dysphagia and vocal cord palsy (VCP) are common otolaryngological complications after revision anterior cervical discectomy and fusion (rACDF) procedures. Our objective was to determine the early incidence and risk factors of VCP and dysphagia after rACDF using a 2-team approach.

METHODS: Single-institution, retrospective analysis of a prospectively collected database of patients undergoing rACDF was enrolled from September 2010 to July 2021. Of 222 patients enrolled, 109 patients were included in the final analysis. All patients had prior ACDF surgery with planned revision using a single otolaryngologist and single neurosurgeon. MD Anderson Dysphagia Inventory and fiberoptic endoscopic evaluation of swallowing (FEES) were used to assess dysphagia. VCP was assessed using videolaryngostroboscopy.

RESULTS: Seven patients (6.7%) developed new postoperative VCP after rACDF. Most cases of VCP resolved by 3 months postoperatively (mean time-to-resolution 79 ± 17.6 days). One patient maintained a permanent deficit. Forty-one patients (37.6%) reached minimum clinically important difference (MCID) in their MD Anderson Dysphagia Inventory composite scores at the 2-week follow-up (MCID decline of ≥6), indicating new clinically relevant swallowing disturbance. Forty-nine patients (45.0%) had functional FEES Performance Score decline. On univariate analysis, there was an association between new VCPs and the number of cervical levels treated at revision (P = .020) with long-segment rACDF (≥4 levels) being an independent risk factor (P = .010). On linear regression, there was an association between the number of levels treated previously and at revision for FEES Performance Score decline (P = .045 and P = .002, respectively). However, on univariate analysis, sex, age, body mass index, operative time, alcohol use, smoking, and individual levels revised were not risk factors for reaching FEES Performance Score decline nor MCID at 2 weeks postoperatively.

CONCLUSION: VCP is more likely to occur in long-segment rACDF but is often temporary. Clinically relevant and functional rates of dysphagia approach 37% and 45%, respectively, at 2 weeks postoperatively after rACDF.

Comparison of Perioperative Complications After Anterior–Posterior Versus Posterior–Anterior–Posterior Cervical Fusion: A Retrospective Review of 153 Consecutive Cases

Neurosurgery 93:373–386, 2023

Although published data support the utilization of circumferential fusion to treat select cervical spine pathologies, it is unclear whether the posterior–anterior–posterior (PAP) fusion has increased risks compared with the anterior–posterior fusion.

OBJECTIVE: To evaluate the differences in perioperative complications between the 2 circumferential cervical fusion approaches.

METHODS: One hundred fifty-three consecutive adult patients who underwent single-staged circumferential cervical fusion for degenerative pathologies from 2010 to 2021 were retrospectively reviewed. Patients were stratified into the anterior–posterior (n = 116) and PAP (n = 37) groups. The primary outcomes assessed were major complications, reoperation, and readmission.

RESULTS: Although the PAP group was older (P = .024), predominantly female (P = .024), with higher baseline neck disability index (P = .026), cervical sagittal vertical axis (P = .001), and previous cervical operation rate (P < .00001), the major complication, reoperation, and readmission rates were not significantly different from the 360°group. Although the PAP group had higher urinary tract infection (P = .043) and transfusion (P = .007) rates, higher estimated blood loss (P = .034), and longer operative times (P < .00001), these differences were insignificant after the multivariable analysis. Overall, operative time was associated with older age (odds ratio [OR] 17.72, P = .042), atrial fibrillation (OR 158.30, P = .045), previous cervical operation (OR 5.05, P = .051), and lower baseline C1-7 lordosis (OR 0.93, P = .007). Higher estimated blood loss was associated with older age (OR 1.13, P = .005), male gender (OR 323.31, P = .047), and higher baseline cervical sagittal vertical axis (OR 9.65, P = .022).

CONCLUSION: Despite some differences in preoperative and intraoperative variables, this study suggests both circumferential approaches have comparable reoperation, readmission, and complication profiles, all of which are high.

Transforaminal Lumbar Interbody Fusion Versus Posterolateral Fusion Alone in the Treatment of Grade 1 Degenerative Spondylolisthesis

Neurosurgery 93:186–197, 2023

Transforaminal lumbar interbody fusion (TLIF) and posterolateral fusion (PLF) alone are two operations performed to treat degenerative lumbar spondylolisthesis. To date, it is unclear which operation leads to better outcomes.

OBJECTIVE: To compare TLIF vs PLF alone regarding long-term reoperation rates, complications, and patient-reported outcome measures (PROMs) in patients with degenerative grade 1 spondylolisthesis.

METHODS: A retrospective cohort study using prospectively collected data between October 2010 and May 2021 was undertaken. Inclusion criteria were patients aged 18 years or older with grade 1 degenerative spondylolisthesis undergoing elective, single-level, open posterior lumbar decompression and instrumented fusion with ≥1-year follow-up. The primary exposure was presence of TLIF vs PLF without interbody fusion. The primary outcome was reoperation. Secondary outcomes included complications, readmission, discharge disposition, return to work, and PROMs at 3 and 12 months postoperatively, including Numeric Rating Scale-Back/Leg and Oswestry Disability Index. Minimum clinically important difference of PROMs was set at 30% improvement from baseline.

RESULTS: Of 546 patients, 373 (68.3%) underwent TLIF and 173 underwent (31.7%) PLF. Median follow-up was 6.1 years (IQR = 3.6-9.0), with 339 (62.1%) >5-year follow-up. Multivariable logistic regression showed that patients undergoing TLIF had a lower odds of reoperation compared with PLF alone (odds ratio = 0.23, 95% CI = 0.54-0.99, P = .048). Among patients with >5-year follow-up, the same trend was seen (odds ratio = 0.15, 95% CI = 0.03-0.95, P = .045). No differences were observed in 90-day complications (P = .487) and readmission rates (P = .230) or minimum clinically important difference PROMs.

CONCLUSION: In a retrospective cohort study from a prospectively maintained registry, patients with grade 1 degenerative spondylolisthesis undergoing TLIF had significantly lower long-term reoperation rates than those undergoing PLF.

Reoperations after primary and revision lumbar discectomy

The Spine Journal 22 (2022) 1983−1989

Published rates for disc reherniation following primary discectomy are around 6%, but the ultimate reoperation outcomes in patients after receiving revision discectomy are not well understood. Additionally, any disparity in the outcomes of subsequent revision discectomy (SRD) versus subsequent lumbar fusion (SLF) following primary/revision discectomy remains poorly studied.

PURPOSE: To determine the 8-year SRD/SLF rates and time until SRD/SLF after primary/revision discectomy respectively.

STUDY DESIGN: Retrospective cohort study.

PATIENT SAMPLE: Patients undergoing primary or revision discectomy, with records in the PearlDiver Patient Records Database from the years 2010 to 2019.

OUTCOME MEASURES: Subsequent surgery type and time to subsequent surgery.

METHODS: Patients were grouped into primary or revision discectomy cohorts based off of the nature of “index” procedure (primary or revision discectomy) using ICD9/10 and CPT procedure codes from 2010 to 19 insurance data sets in the PearlDiver Patient Records Database. Preoperative demographic data was collected. Outcome measures such as subsequent surgery type (fusion or discectomy) and time to subsequent surgery were collected prospectively in PearlDiver Mariner database. Statistical analysis was performed using BellWeather statistical software. A Kaplan-Meier survival analysis of time to SLF/SRD was performed on each cohort, and log-rank test was used to compare the rates of SLF/SRD between cohorts.

RESULTS: A total of 20,147 patients were identified (17,849 primary discectomy, 2,298 revision discectomy). The 8-year rates of SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01) and SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) were higher after revision versus primary discectomy. Time to SLF was shorter after revision versus primary discectomy (709 vs. 886 days, p<.01). After both primary and revision discectomy, the 8-year rate of SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) is greater than SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01).

CONCLUSIONS: Compared to primary discectomy, revision discectomy has higher rates of SLF (10.4% vs. 6.2%), and faster time to SLF (2.4 vs. 1.9 years) at 8-year follow up.

Do the newly proposed realignment targets for C2 and T1 slope bridge the gap between radiographic and clinical success in corrective surgery for adult cervical deformity?

J Neurosurg Spine 37:368–375, 2022

Surgical correction of cervical deformity (CD) has been associated with superior alignment and functional outcomes. It has not yet been determined whether baseline or postoperative T1 slope (T1S) and C2 slope (C2S) correlate with health-related quality-of-life (HRQoL) metrics and radiographic complications, such as distal junctional kyphosis (DJK) and distal junctional failure (DJF). The objective of this study was to determine the impact of T1S and C2S deformity severity on HRQoL metrics and DJF development in patients with CD who underwent a cervical fusion procedure.

METHODS All operative CD patients with upper instrumented vertebra above C7 and preoperative (baseline) and up to 2-year postoperative radiographic and HRQoL data were included. CD was defined as meeting at least one of the following radiographic parameters: C2–7 lordosis < −15°, TS1–cervical lordosis mismatch > 35°, segmental cervical kyphosis > 15° across any 3 vertebrae between C2 and T1, C2–7 sagittal vertical axis > 4 cm, McGregor’s slope > 20°, or chin-brow vertical angle > 25°. Spearman’s rank-order correlation and linear regression analysis assessed the impact of T1S and C2S on HRQoL metrics (Neck Disability Index [NDI], modified Japanese Orthopaedic Association [mJOA] scale, EuroQOL 5-Dimension Questionnaire [EQ-5D] visual analog scale [VAS] score, and numeric rating scale [NRS]–neck) and complications (DJK, DJF, reoperation). Logistic regression and a conditional inference tree (CIT) were used to determine radiographic thresholds for achieving optimal clinical outcome, defined as meeting good clinical outcome criteria (≥ 2 of the following: NDI < 20 or meeting minimal clinically important difference, mild myelopathy [mJOA score ≥ 14], and NRS-neck ≤ 5 or improved by ≥ 2 points), not undergoing reoperation, or developing DJF or mechanical complication by 2 years.

RESULTS One hundred five patients with CD met inclusion criteria. By surgical approach, 14.7% underwent an anterioronly approach, 46.1% a posterior-only approach, and 39.2% combined anterior and posterior approaches. The mean baseline radiographic parameters were T1S 28.3° ± 14.5° and C2S 25.9° ± 17.5°. Significant associations were found between 3-month C2S and mJOA score (r = −0.248, p = 0.034), NDI (r = 0.399, p = 0.001), EQ-5D VAS (r = −0.532, p < 0.001), NRS-neck (r = 0.239, p = 0.040), and NRS-back (r = 0.264, p = 0.021), while significant correlation was also found between 3-month T1S and mJOA score (r = −0.314, p = 0.026), NDI (r = 0.445, p = 0.001), EQ-5D VAS (r = −0.347, p = 0.018), and NRS-neck (r = 0.269, p = 0.049). A significant correlation was also found between development of DJF and 3-month C2S (odds ratio [OR] 1.1, 95% confidence interval [CI] 1.01–1.1, p = 0.015) as well as for T1S (OR 1.1, 95% CI 1.01–1.1, p = 0.023). Logistic regression with CIT identified thresholds for optimal outcome by 2 years: optimal 3-month T1S < 26° (OR 5.6) and C2S < 10° (OR 10.4), severe 3-month T1S < 45.5° (OR 0.2) and C2S < 38.0° (no patient above this threshold achieved optimal outcome; all p < 0.05). Patients below both optimal thresholds achieved rates of 0% for DJK and DJF, and 100% met optimal outcome.

CONCLUSIONS The severity of CD, defined by T1S and C2S at baseline and especially at 3 months, can be predictive of postoperative functional improvement and occurrence of worrisome complications in patients with CD, necessitating the use of thresholds in surgical planning to achieve optimal outcomes.

Recurrent Low-Grade Gliomas: Does Reoperation Affect Neurocognitive Functioning?

Neurosurgery 90:221–232, 2022

Reoperations in patients with recurrent low-grade gliomas (RLGG) were proposed to control tumor residual and delay the risk of malignant transformation over time.

OBJECTIVE: To investigate neurocognitive outcomes in patients with RLGG who underwent a second surgery with awake monitoring.

METHODS: In this retrospective study, patients who underwent a second awake surgery for RLGG were included. Patients had presurgical and 3-mo postsurgical neuropsychological assessments. Data were converted into Z-scores and combined by the cognitive domain. Number of patients with cognitive deficits (Z-score <À1.65), variations of Z-scores, and extent of resection (EOR) were analyzed.

RESULTS: Sixty-two patients were included (mean age: 41.2 ± 10.0 yr). None had permanent neurological deficits postoperatively. Eight patients (12.9%) had a cognitive deficit preoperatively. Four additional patients (6.5%) had a cognitive deficit 3 mo after reoperation. Among other patients, 13 (21.0%) had a mild decline without cognitive deficits while 29 (46.8%) had no change of their performances and 8 (12.9%) improved. Overall, 94.2% of the patients returned to work. There were no correlations between EOR and Z-scores. Total/ subtotal resections were achieved in 91.9% of the patients (mean residual: 3.1 cm3 ). Fiftyeight patients (93.5%) were still alive after an overall follow-up of 8.3 yr.

CONCLUSION: Reoperation with awake monitoring in patients with RLGG was compatible with an early recovery of neuropsychological abilities. Four patients (6.5%) presented a new cognitive deficit at 3 mo postoperatively. Total/subtotal resections were achieved in most patients. Based on these favorable outcomes, reoperation should be considered in a more systematic way.

Middle Meningeal Artery Embolization Versus Conventional Treatment of Chronic Subdural Hematomas

Neurosurgery 89:486–495, 2021

Middle meningeal artery (MMA) embolization is an emerging minimally invasive endovascular technique for chronic subdural hematoma (cSDH). Currently, limited literature exists on its safety and efficacy compared with conventional treatment (open- surgical-evacuation-only).

OBJECTIVE: To compare MMA embolization to conventional treatment.

METHODS: Retrospective analysis of patients with cSDHs treated with MMA embolization in a single center from 2018 to 2019 was performed. Comparisons were made with a historical conventional treatment cohort from 2006 to 2016. Propensity score matching analysis was used to assemble a balanced group of subjects.
RESULTS: A total of 357 conventionally treated cSDH and 45 with MMA embolization were included. After balancing with propensity score matching, a total of 25 pairs of cSDH were analyzed. Comparing the embolization with the conventional treatment group yielded no significant differences in complications (4% vs 4%; P > .99), clinical improvement (82.6% vs 83.3%; P = .95), cSDH recurrence (4.3% vs 21.7%; P = .08), overall re-intervention rates (12% vs 24%; P = .26), modified Rankin scale >2 on last follow-up (17.4% vs 32%; P = .24), as well as mortality (0% vs 12%; P = .09). Radiographic improvement at last follow-up was significantly higher in the open surgery cohort (73.9% vs 95.6%; P = .04). However, there was a trend for lengthier last follow-up for the historical cohort (72 vs 104 d; P = .07).

CONCLUSION: There was a trend for lower recurrence and mortality rates in the embolization era cohort. There were significantly higher radiological improvement rates on last follow-up in the surgical only cohort era. There were no significant differences in complications and clinical improvement.

Risk factors for reoperation after lumbar total disc replacement at short-, mid-, and long-term follow-up

DOI:https://doi.org/10.1016/j.spinee.2021.02.020

The reoperation rate following TDR (Total Disc replacement) has been established at short- and mid-term time points through the Food and Drug Administration Investigational Device Exemption (FDA IDE) trials. However, these trials include highly selected centers and surgeons with strict governance of indications. The utilization of TDR throughout the community needs further analysis.

PURPOSE

To identify the risk factors for lumbar spine reoperation in patients undergoing lumbar total disc replacement (TDR) at short-, mid-, and long-term follow-up.

STUDY DESIGN/SETTING

This study is a multi-center retrospective cohort study utilizing the New York Statewide Planning and Research Cooperative System database.

PATIENT SAMPLE

We identified 1,368 patients who underwent an elective primary lumbar TDR in New York State between January 1, 2005 and September 30, 2013.

OUTCOME MEASURES

The primary functional outcome of interest was lumbar reoperation, specifically the evaluation of independent risk factors for lumbar reoperation at a minimum of 2 years, with sub-analyses performed at 5 and ten years.

METHODS

International Classification of Diseases, Ninth revision codes were utilized to identify patients undergoing a primary lumbar TDR. We excluded patients with primary/revision lumbar fusion procedures and revision disc replacement procedures. Hospital academic status was determined by the Accreditation Council for Graduate Medical Education. Unique encrypted patient identifiers allowed for longitudinal follow-up for reoperation. Logistic regression models compared reoperation and no-reoperation cohorts, and were performed on sub-analyses for significant univariate predictors of reoperation.

RESULTS

Between January 2005 and September 2013, 1368 patients underwent a primary lumbar TDR. Reoperation occurred in 8.8% by 2 years, 15.8% by 5 years, and 19.5% by ten years. Diabetics were more likely to have reoperations (7.5% vs 3.8%, p=.013). Teaching hospitals experienced a decreased reoperation rate compared to nonteaching hospitals at 2-year (5.0% vs 10.5%, p=.002), 5-year (10.7% vs 17.9%, p=.002) and 10-year (11.7% vs 21.9%, p=.045) follow-up. Lumbar fusion was the most common reoperation (14.2%).

CONCLUSION

We identified an 8.8% reoperation rate after inpatient lumbar TDR at 2-years, 15.8% at 5-years, and 19.5% at 10-years. When stratifying by teaching status, reoperation rates at teaching centers align with those reported in FDA IDE studies. Diabetes was the only patient factor influencing reoperation rate. There is a growing consensus that lumbar TDR is a durable and appropriate surgical option for lumbar degenerative disc disease. Proper indications are crucial to obtaining good outcomes with lumbar TDR.

 

Readmission and reoperation for hydrocephalus: a population-based analysis across the spectrum of age

J Neurosurg 134:1210–1217, 2021

Hydrocephalus is a common, chronic illness that generally requires lifelong, longitudinal, neurosurgical care. Except at select research centers, surgical outcomes in the United States have not been well documented. Comparative outcomes across the spectrum of age have not been studied.

METHODS Data were derived for the year 2015 from the Nationwide Readmissions Database, a product of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality. In this data set patients are assigned state-specific codes that link repeated discharges through the calendar year. Discharges with diagnostic codes for hydrocephalus were extracted, and for each patient the first discharge defined the index admission. The study event was readmission. Observations were censored at the end of the year. In a similar fashion the first definitive surgical procedure for hydrocephalus was defined as the index operation, and the study event was reoperation for hydrocephalus or complications. Survival without readmission and survival without reoperation were analyzed using life tables and Kaplan- Meier plots.

RESULTS Readmission rates at 30 days ranged between 15.6% and 16.8% by age group without significant differences. After the index admission the first readmission alone generated estimated hospital charges of $2.25 billion nationwide. Reoperation rates at 30 days were 34.9% for infants, 39.2% for children, 47.4% for adults, and 32.4% for elders. These differences were highly significant. More than 3 times as many index operations were captured for adults and elders as for infants and children. Estimated 1-year reoperation rates were 74.2% for shunt insertion, 63.9% for shunt revision, but only 34.5% for endoscopic third ventriculostomy. Univariate associations with survival without readmission and survival without reoperation are presented.

CONCLUSIONS In the United States hydrocephalus is predominantly a disease of adults. Surgical outcomes in this population-based study were substantially worse than outcomes reported from research centers. High reoperation rates after CSF shunt surgery accounted for this discrepancy.

Effect of fixed-setting versus programmable valve on incidence of shunt revision after ventricular shunting for idiopathic normal pressure hydrocephalus

J Neurosurg 133:564–572, 2020

Although ventricular shunting is an effective therapy for idiopathic normal pressure hydrocephalus (iNPH), the effect of shunt valve type on the incidence of revision surgery is not well defined. To address this issue, shunt revision rates between patients with iNPH receiving a fixed-setting valve (FSV) versus a programmable valve (PV) were compared.

METHODS Patients with iNPH treated with ventricular shunting between 2001 and 2017 were included for analysis. The incidence of shunt revision was noted and risk factors for revision were identified using a Cox proportional hazards model. Costs associated with admission for ventricular shunt procedures were obtained from the Vizient national database.

RESULTS There were 348 patients included for analysis, with 98 patients (28.1%) receiving a PV. Shunt revision occurred in 73 patients (21.0%), with 12 patients (3.4%) undergoing multiple revisions. Overall revision rates were lower in patients receiving a PV (13.3% vs 24.0%; p = 0.027), as was the incidence of multiple revisions (0.0% vs 4.8%; p = 0.023). Patients with initial placement of an FSV were also more likely to undergo valve exchange during follow-up (12.4% vs 2.0%; p = 0.003). Patients with a PV were less likely to undergo revision due to persistent symptoms without obstruction (2.0% vs 8.8%; p = 0.031) and distal obstruction (1.0% vs 6.8%; p = 0.030). In a multivariate Cox proportional hazards model, initial placement of a PV was associated with reduced risk of revision due to persistent symptoms without obstruction (OR 0.27, 95% CI 0.04–0.93; p = 0.036). PVs were associated with more frequent shunt series (1.3 vs 0.6; p < 0.001) and head CT scans (3.6 vs 2.7; p = 0.038) during follow-up. There was no significant difference in mean total costs between patients receiving an FSV and a PV ($24,282.50 vs $24,396.90; p = 0.937).

CONCLUSIONS The authors’ results suggest that PVs lead to reduced rates of shunt revision in patients with iNPH, and decreased risk of revision due to persistent symptoms of iNPH, thereby justifying the higher upfront cost of PVs despite similar overall treatment costs between these devices.

 

Thirty-Day Outcomes After Craniotomy for Primary Malignant Brain Tumors

Neurosurgery 83:1249–1259, 2018

Despite improved perioperative management, the rate of postoperative morbidity and mortality after brain tumor resection remains considerably high.

OBJECTIVE: To assess the rates, causes, timing, and predictors of major complication, extended length of stay (>10 d), reoperation, readmission, and death within 30 d after craniotomy for primary malignant brain tumors.

METHODS: Patients were extracted from the National Surgical Quality Improvement Program registry (2005-2015) and analyzed using multivariable logistic regression.

RESULTS: A total of 7376 patientswere identified, ofwhich 948 (12.9%) experienced a major complication. The most common major complications were reoperation (5.1%), venous thromboembolism (3.5%), and death (2.6%). Furthermore, 15.6% stayed longer than 10 d, and 11.5% were readmitted within 30 d after surgery. The most common reasons for reoperation and readmission were intracranial hemorrhage (18.5%) and wound-related complications (11.9%), respectively. Multivariable analysis identified older age, higher body mass index, higher American Society of Anesthesiologists (ASA) classification, dependent functional status, elevated preoperative white blood cell count (white blood cell count [WBC], >12 000 cells/mm3), and longer operative time as predictors of major complication (all P < .001). Higher ASA classification, dependent functional status, elevated WBC, and ventilator dependence were predictors of extended length of stay (all P < .001). Higher ASA classification and elevatedWBCwere predictors of reoperation (both P<.001). Higher ASA classification and dependent functional status were predictors of readmission (both P < .001). Older age, higher ASA classification, and dependent functional status were predictors of death (all P< .001).

CONCLUSION: This study provides a descriptive analysis and identifies predictors for short term complications, including death, after craniotomy for primary malignant brain tumors.

 

Autologous Cranioplasty is Associated with Increased Reoperation Rate: A Systematic Review and Meta-Analysis

Consensus regarding selection of synthetic versus autologous flap reimplantation for cranioplasty after decompressive craniectomy has not been reached and the multiple factors considered for each patient make comparative analysis challenging. This study examines the association between choice of material and related complications.

METHODS: A systematic literature review and meta-analysis were performed using PubMed for articles reporting delayed cranioplasty after decompressive craniectomy using a cohort design comparing autologous bone and synthetic implants. Extracted data included implant material and incidence of infection, reoperations related to implant, wound complications, and resorption. –

RESULTS: One randomized controlled trial and 11 cohort studies were included for a total of 1586 implants (950 bone, 636 synthetic). Autologous implants had significantly more reoperations than did synthetic implants (n [1586 implants; odds ratio [OR], 1.91; 95% confidence interval [CI], 1.40e2.61). Reoperations were most often because of resorption (54%, n [ 159/295) followed by infection (41%, n [ 121/295). The pooled incidence of resorption in autologous implants was 20% (n [ 159/791). Among the other outcomes, there was no significant difference for infections (n [ 1586; OR, 1.24; CI, 0.82e1.88) or wound complications (n [ 678; OR, 0.56; CI, 0.22e1.45). For the trauma subpopulation, there was no significant difference in infection rate with either material (n [ 197; OR, 1.89; CI; 0.59e6.09).

CONCLUSIONS: Autologous implants had significantly more reoperations primarily because of the intrinsic risk of resorption (level of evidence 3b).

Reoperation for Recurrent Glioblastoma and Its Association With Survival Benefit

multifocal glioblastoma

Neurosurgery 79:678–689, 2016

Glioblastoma is the most common and aggressive primary brain tumor. Despite current treatment, recurrence is inevitable. There are no clear guidelines for treatment of recurrent glioblastoma.

OBJECTIVE: To investigate factors at initial surgery predictive of reoperation, and the prognostic variables associated with survival, including reoperation for recurrence.

METHODS: A retrospective cohort study was performed, including adult patients diagnosed with glioblastoma between January 2010 and December 2013. Student t test and Fisher exact test compared continuous and categorical variables between reoperation and nonreoperation groups. Univariable and Cox regression multivariable analysis was performed.

RESULTS: In a cohort of 204 patients with de novo glioblastoma, 49 (24%) received reoperation at recurrence. The median overall survival in the reoperation group was 20.1 months compared with 9.0 months in the nonreoperation group (P = .001). Reoperation was associated with longer overall survival in our total population (hazard ratio, 0.646; 95% confidence interval, 0.543-0.922; P = .016) but subject to selection bias. Subgroup analyses excluding patients unlikely to be considered for reoperation suggested a much less significant effect of reoperation on survival, which warrants further study with larger cohorts. Factors at initial surgery predictive for reoperation were younger age, smaller tumor size, initial extent of resection $50%, shorter inpatient stay, and maximal initial adjuvant therapy. When unfavorable patient characteristics are excluded, reoperation is not an independent predictor of survival.

CONCLUSION: Patients undergoing reoperation have favorable prognostic characteristics, which may be responsible for the survival difference observed. We recommend that a large clinical registry be developed to better aid consistent and homogenous data collection.

Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis

Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis

Acta Neurochir (2016) 158:1103–1113

The microsurgical unilateral laminotomy (MUL) technique for bilateral decompression of lumbar spinal stenosis (LSS) is a less destabilizing alternative to laminectomy and leads to good short-term outcomes. However, little is known about the long-term results including predictive factors.

Methods: Medical records of patients who underwent MUL for LSS decompression between 2005 and 2010 were reviewed, and a questionnaire was distributed to complement the long-term outcome data. The study population consisted of 176 patients including 17 patients with stable grade I spondylolisthesis. Complications and reoperations were meticulously analyzed. Clinical outcome was measured using a modified Prolo scale and was further dichotomized in good vs. poor outcome. Predictive factors were obtained from uni- and multivariate analyses.

Results: The median age of the cohort was 70.0 years and the follow-up 71.7 months. Complications occurred in 5.1%of the patients. The overall reoperation rate was 17.0 %, including surgery, which was exclusively performed at other levels in 4.0 %. The reoperation rate for fusion was 4.5 %. Good neurogenic claudication outcome faded from 98.3 % at hospital discharge to 47.2 % at 6 years. Multivariate analysis identified previous lumbar operation as a potential independent predictor of a reoperation; potential independent predictors of poor longterm claudication outcome were older age, female gender, higher body mass index (BMI) and tobacco smoking.

Conclusions: In our experience, the long-term reoperation rate after MUL for LSS is not negligible and higher in previously operated patients. It seems like the good initial clinical results after MUL may fade over time, and several patient-related predictive factors including potentially modifiable obesity and tobacco smoking seem to play an important role.

Incidence of Adjacent Segment Disease Requiring Reoperation After Lumbar Laminectomy Without Fusion

ADJACENT SEGMENT DISEASE AFTER LUMBAR LAMINECTOMY

Neurosurgery 78:192–199, 2016

Adjacent segment disease (ASD) has not been described after laminectomy without fusion.

OBJECTIVE: To determine the incidence of ASD after a 1- or 2-level lumbar laminectomy.

METHODS: We retrospectively reviewed medical records of all patients who underwent 1- or 2-level, bilateral lumbar laminectomy without fusion for degenerative spinal disease (all follow-up $1 year). ASD was defined as clinical and/or radiographic evidence of degenerative spinal disease that required reoperation at the level above or below the index laminectomy.

RESULTS: Of the 398 patients, the incidence of ASD requiring reoperation was 10%. The 39 ASD cases were almost equally distributed at L2-L3 (31%), L3-L4 (26%), and L5-S1 (31%), and to a lesser extent at L4-L5 (15%) (P = .51). The ASD incidences of 10% and 9% were equivalent after a 1- and 2-level laminectomy, respectively (P = .76). Rostral ASD was statistically more common than caudal ASD after both the 1- (P , .001) and 2- (P , .001) level laminectomy. Of the 39 ASD cases, 95% required laminectomy, 26% discectomy, and 49% fusion. Average time to ASD was 4 years. After a Kaplan-Meier analysis, time to reoperation for ASD was equivalent among the 1- and 2-level laminectomy cohorts (log-rank test, P = .13).

CONCLUSION: The cumulative incidence of ASD requiring reoperation was 10% over a mean of 4 years. Both the 1- and 2-level laminectomy cohorts experienced equivalent incidences and rates of ASD. Of the 39 operations for ASD, about half required a fusion.

Complications associated with the Dynesys dynamic stabilization system

dynesys

Neurosurg Focus 40 (1):E2, 2016

The Dynesys dynamic stabilization system is an alternative to rigid instrumentation and fusion for the treatment of lumbar degenerative disease. Although many outcomes studies have shown good results, currently lacking is a comprehensive report on complications associated with this system, especially in terms of how it compares with reported complication rates of fusion.

For the present study, the authors reviewed the literature to find all studies involving the Dynesys dynamic stabilization system that reported complications or adverse events. Twenty-one studies were included for a total of 1166 patients with a mean age of 55.5 years (range 39–71 years) and a mean follow-up period of 33.7 months (range 12.0–81.6 months). Analysis of these studies demonstrated a surgical-site infection rate of 4.3%, pedicle screw loosening rate of 11.7%, pedicle screw fracture rate of 1.6%, and adjacent-segment disease (ASD) rate of 7.0%. Of studies reporting revision surgeries, 11.3% of patients underwent a reoperation. Of patients who developed ASD, 40.6% underwent a reoperation for treatment.

The Dynesys dynamic stabilization system appears to have a fairly similar complication-rate profile compared with published literature on lumbar fusion, and is associated with a slightly lower incidence of ASD.

Complications following cranioplasty: incidence and predictors in 348 cases

cranioplasty

J Neurosurg 123:182–188, 2015

The factors that contribute to periprocedural complications following cranioplasty, including patient-specific and surgery-specific factors, need to be thoroughly assessed. The aim of this study was to evaluate risk factors that predispose patients to an increased risk of cranioplasty complications and death.

Methods The authors conducted a retrospective review of all patients at their institution who underwent cranioplasty following craniectomy for stroke, subarachnoid hemorrhage, epidural hematoma, subdural hematoma, and trauma between January 2000 and December 2011. The following predictors were tested: age, sex, race, diabetic status, hypertensive status, tobacco use, reason for craniectomy, urgency status of the craniectomy, graft material, and location of cranioplasty. The cranioplasty complications included reoperation for hematoma, hydrocephalus postcranioplasty, postcranioplasty seizures, and cranioplasty graft infection. A multivariate logistic regression analysis was performed. Confidence intervals were calculated as the 95% CI.

Results Three hundred forty-eight patients were included in the study. The overall complication rate was 31.32% (109 of 348). The mortality rate was 3.16%. Predictors of overall complications in multivariate analysis were hypertension (OR 1.92, CI 1.22–3.02), increasing age (OR 1.02, CI 1.00–1.04), and hemorrhagic stroke (OR 3.84, CI 1.93–7.63). Predictors of mortality in multivariate analysis were diabetes mellitus (OR 7.56, CI 1.56–36.58), seizures (OR 7.25, CI 1.238–42.79), bifrontal cranioplasty (OR 5.40, CI 1.20–24.27), and repeated surgery for hematoma evacuation (OR 13.00, CI 1.51–112.02). Multivariate analysis was also applied to identify the variables that affect the development of seizures, the need for reoperation for hematoma evacuation, the development of hydrocephalus, and the development of infections.

Conclusions The authors’ goal was to provide the neurosurgeon with predictors of morbidity and mortality that could be incorporated in the clinical decision-making algorithm. Control of a patient’s risk factors and early recognition of complications may help practitioners avoid the exhaustive list of complications.

Unsuccessful Percutaneous Endoscopic Lumbar Discectomy: A Single-Center Experience of 10 228 Cases

Unsuccessful Percutaneous Endoscopic Lumbar Discectomy- A Single-Center Experience of 10 228 Cases

Neurosurgery 76:372–381, 2015

Percutaneous endoscopic lumbar discectomy (PELD) has remarkably evolved with successful results. Although PELD has gained popularity for the treatment of herniated disc (HD), the risk of surgical failure may be a major obstacle to performing PELD. We analyzed unsuccessful cases requiring reoperation.

OBJECTIVE: To find common causes of surgical failure and elucidate the limitations of the conventional PELD technique.

METHODS: A retrospective review was performed on all patients who had undergone PELD between January 2001 and December 2012. Unsuccessful PELD was defined as a case requiring reoperation within 6 weeks after primary surgery. Chart review was done, and preoperative, intraoperative, and postoperative radiographic reviews were performed. All unsuccessful PELD cases were classified according to the type of HD, location of herniation, extruded disc migration, working channel position, and intraoperative and postoperative findings.

RESULTS: In 12 years, 10 228 patients had undergone PELD; 436 (4.3%) cases were unsuccessful. The causes were incomplete removal of HDs in 283 patients (2.8%), recurrence in 78 (0.8%), persistent pain even after complete HD removal in 41 (0.4%), and approach-related pain in 21 (0.2%). Incomplete removal of the HD was caused by inappropriate positioning (95 cases; 33.6%) of the working channel and occurred in central HDs (91 cases; 32.2%), migrated HDs (70 cases; 24.7%), and axillary type HDs (63 cases; 22.3%).

CONCLUSION: Proper surgical indications and good working channel position are important for successful PELD. PELD techniques should be specifically designed to remove the disc fragments in various types of HD.