What are the Rates, Reasons, and Risk Factors of 90-day Hospital Readmission After Lumbar Discectomy?: An Institutional Experience

The Reoperation, Readmission, and Complication Rates at 30 Days Following Lumbar Decompression for Cauda Equina Syndrome

Background and objective Cauda equina syndrome (CES) is considered a surgical emergency, and its primary treatment involves decompression of the nerve roots, typically in the form of discectomy or laminectomy. The primary aim of this study was to determine the complication, reoperation, and readmission rates within 30 days of surgical treatment of CES secondary to disc herniation by using the PearlDiver database (PearlDiver Technologies, Colorado Springs, CO). The secondary aim was to assess preoperative risk factors for a higher likelihood of complication occurrence within 30 days of surgery for CES. Methods A total of 524 patients who had undergone lumbar discectomy or laminectomy for CES were identified. The outcome measures were 30-day reoperation rate for revision decompression or lumbar fusion, and 30-day readmissions related to surgery. The patient data collected included medical history and surgical data including the number of levels of discectomy and laminectomy. Results Based on our findings, intraoperative dural tears, valvular heart disease, and fluid and electrolyte abnormalities were significant risk factors for readmission to the hospital within 30 days following surgery for CES. The most common postoperative complications were as follows: visits to the emergency department (63 patients, 12%), surgical site infection (21 patients, 4%), urinary tract infection (14 patients, 3%), and postoperative anemia (11 patients, 2%). Conclusions In the 30-day period following lumbar decompression for cauda equina syndrome, our findings demonstrated an 8% reoperation rate and 17% readmission rate. Although CES is considered an indication for urgent surgery, gaining awareness about reoperation, readmission, and complication rates in the immediate postoperative period may help calibrate expectations and inform medical decision-making.

Time of Discharge and 30-Day Re-Presentation to an Acute Care Setting After Elective Lumbar Decompression Surgery

BACKGROUND

Evidence regarding the consequence of efforts to increase patient throughput and decrease length of stay in the context of elective spine surgery is limited.

OBJECTIVE

To evaluate whether early time of discharge results in increased rates of hospital readmission or return to emergency department for patients admitted after elective, posterior, lumbar decompression surgery.

METHODS

We conducted a retrospective cohort study of 779 patients admitted to hospital after undergoing elective, posterior, lumbar decompression surgery. Multiple logistic regression evaluated the relationship between time of discharge and the primary outcome of return to acute care within 30 days, while controlling for sociodemographic, procedural, and discharge characteristics.

RESULTS

In multiple logistic regression, time of discharge earlier in the day was not associated with increased odds of return to acute care within 30 days (odds ratio [OR] 1.18, 95% CI 0.92-1.52, P = .19). Weekend discharge (OR 1.99, 95% CI 1.04-3.79, P = .04) increased the likelihood of return to acute care. Surgeon experience (<1 year of attending practice, OR 0.43, 95% CI 0.19-1.00, P = .05 and 2-5 years of attending practice, OR 0.50, 95% CI 0.25-1.01, P = .054), weekend discharge (OR 0.49, 95% CI 0.27-0.89, P = .02), and physical therapy evaluation (OR 0.20, 95% CI 0.12-0.33, P < .001) decreased the likelihood of discharge before noon.

CONCLUSION

Time of discharge is not associated with risk of readmission or presentation to the emergency department after elective lumbar decompression. Weekend discharge is independently associated with increased risk of readmission and decreased likelihood of prenoon discharge.

Early Readmission and Reoperation After Percutaneous Transforaminal Endoscopic Decompression for Degenerative Lumbar Spinal Stenosis: Incidence and Risk Factors

PURPOSE

To identify the incidence rates and risk factors for early readmission and reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS).

PATIENTS AND METHODS

A total of 1011 DLSS patients who underwent PTED were retrospectively evaluated. Of them, 58 were readmitted, and 31 underwent reoperation. The patients were matched with 174 control patients to perform case-control analyses. The clinical and preoperative imaging data of each patient were recorded. Univariate analyses were performed using independent sample t-tests and Fisher's exact tests. Furthermore, the risk factors for early readmission and reoperation were analyzed using multivariate logistic regression analyses.

RESULTS

The incidence rates of readmission and reoperation within 90 days after PTED were 5.7% and 3.1%, respectively. Age (odds ratio [OR]=1.054, p=0.001), BMI (OR=1.104, p=0.041), a history of lumbar surgery (OR=3.260, p=0.014), and the number of levels with radiological lumbar foraminal stenosis (LFS, OR=2.533, p<0.001) were independent risk factors for early readmission. The number of levels with radiological LFS (OR=5.049, p<0.001), the grade of surgical-level facet joint degeneration (OR=2.010, p=0.023), and a history of lumbar surgery (OR=10.091, p<0.001) were independent risk factors for early reoperation.

CONCLUSION

This study confirmed that aging, a higher BMI, a history of lumbar surgery, and more levels with radiological LFS were associated with a higher risk of early readmission. More levels with radiological LFS, a higher grade of surgical-level facet joint degeneration, and a history of lumbar surgery were predictors of early reoperation. These results are helpful in patient counseling and perioperative evaluation of PTED.

Charlson Comorbidity Index score predicts adverse post-operative outcomes after far lateral lumbar discectomy

INTRODUCTION

The Charlson Comorbidity Index (CCI) score has been shown to predict 10-year all-cause mortality and post-neurosurgical complications but has never been examined in a far lateral disc herniation (FLDH) population. This study aims to correlate CCI score with adverse outcomes following FLDH repair.

PATIENTS AND METHODS

All patients (n = 144) undergoing discectomy for FLDH at a single, multihospital academic medical system (2013-2020) were retrospectively analyzed. CCI scores were determined for all patients. Univariate logistic regression was used to determine the ability of CCI score to predict adverse outcomes.

RESULTS

Mean age of the population was 61.72 ± 11.55 years, 69 (47.9%) were female, and 126 (87.5%) were non-Hispanic white. Patients underwent either open (n = 92) or endoscopic (n = 52) FLDH repair. Average CCI score among the patient population was 2.87 ± 2.42. Each additional point in CCI score was significantly associated with higher rates of readmission (p = 0.022, p = 0.014) in the 30-day and 30-90-day post-surgery window, respectively, and emergency department visits (p = 0.011) within 30-days. CCI score also predicted risk of reoperation of any kind (p = 0.013) within 30 days of the index operation. In addition, CCI score was predictive of risk of reoperation of any kind (p = 0.008, p < 0.001; respectively) and repeat neurosurgical intervention (p = 0.027, p = 0.027) within 30-days and 90-days of the index admission (either during the same admission or after discharge).

CONCLUSIONS

This study suggests that CCI score is a useful metric to predict of numerous adverse postoperative outcomes following discectomy for FLDH.

Predicting patient outcomes after far lateral lumbar discectomy

INTRODUCTION

The LACE+ (Length of Stay, Acuity of Admission, Charlson Comorbidity Index (CCI) Score, Emergency Department (ED) visits within the previous 6 months) index has never been tested in a purely spine surgery population. This study assesses the ability of LACE + to predict adverse patient outcomes following discectomy for far lateral disc herniation (FLDH).

PATIENTS AND METHODS

Data were obtained for patients (n = 144) who underwent far lateral lumbar discectomy at a single, multi-hospital academic medical center (2013-2020). LACE + scores were calculated for all patients with complete information (n = 100). The influence of confounding variables was assessed and controlled with stepwise regression. Logistic regression was used to test the ability of LACE + to predict risk of unplanned hospital readmission, ED visits, outpatient office visits, and reoperation after surgery.

RESULTS

Mean age of the population was 61.72 ± 11.55 years, 69 (47.9 %) were female, and 126 (87.5 %) were non-Hispanic white. Patients underwent either open (n = 92) or endoscopic (n = 52) surgery. Each point increase in LACE + score significantly predicted, in the 30-day (30D) and 30-90-day (30-90D) post-discharge window, higher risk of readmission (p = 0.005, p = 0.009; respectively) and ED visits (p = 0.045). Increasing LACE + also predicted, in the 30D and 90-day (90D) post-discharge window, risk of reoperation (p = 0.022, p = 0.016; respectively), and repeat neurosurgical intervention (p = 0.026, p = 0.026; respectively). Increasing LACE + score also predicted risk of reoperation (p = 0.011) within 30 days of initial surgery.

CONCLUSIONS

LACE + may be suitable for characterizing risk of adverse perioperative events for patients undergoing far lateral discectomy.

Predictors of postoperative complications after selective dorsal rhizotomy

BACKGROUND

Selective dorsal rhizotomy (SDR) reduces spasticity in children with cerebral palsy (CP). We analyzed potential preoperative predictors of complications after SDR via single-level laminectomy at the conus medullaris.

METHODS

One hundred and forty SDRs performed in children (2-17 years) with CP were included in this retrospective study (March 2016 to July 2019). Of these children, 69% were ambulatory (Gross Motor Functional Classification System (GMFCS) II and III). Variables associated with wound dehiscence and infections, cerebrospinal fluid (CSF) leaks, and prolonged epidural pain management were analyzed statistically.

RESULTS

Five children (3.6%) showed prolonged wound healing, which was associated with obesity (BMI z-score ≥ 1.64; odds ratio (OR) 24.4; 95% confidence interval (CI) 3-199; p = 0.003). Two cases (1.4%) had superficial surgical site infections (SSIs), which was associated with obesity (p = 0.004) and thrombocytopenia (< 180,000 G/l; p = 0.028). The area under the curve at ≥ 1.55 BMI z-score for SSI was 0.97 (95% CI 0.93-0.99, p = 0.024), with a sensitivity and specificity for SSI of 100 and 94.9%, respectively. CSF leaks occurred in four (2.9%) children, associated with age ≤ 5 years (p = 0.029). Fifteen (10.7%) children required prolonged (4-5 days) epidural pain treatment, which was associated with non-ambulatory GMFCS levels (IV and V) (OR 3.6; 95% CI 1.2-10.8; p = 0.008).

CONCLUSIONS

SDR is safe for all GMFCS levels. Obesity predicts prolonged wound healing and SSI. Prolonged pain management via epidural pain catheter is safe, but care should be taken with non-ambulatory children.

30-Day Recurrence, Readmission Rate, and Clinical Outcome After Emergency Lumbar Discectomy

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To investigate the 30-day recurrence rate after emergency lumbar discectomy. Secondary aims were to investigate the factors affecting the 30-day recurrence and readmission rates and clinical outcome.

SUMMARY OF BACKGROUND DATA

Excluding cauda equine syndrome (CES) due to massive intervertebral disc herniation, emergency surgery for lumbar disc herniation (LDH) is rarely required. The operation may, however, be performed for other reasons such as persistent or progressive motor paresis associated with radiculopathy or uncontrolled pain. Literature on these topics is scarce.

METHODS

All patients admitted for inpatient care after a visit to the emergency department (ED) due to acute low back pain and who had subsequently undergone an emergency lumbar discectomy during the 4-year study period were included in the study. Patients attending the ED who subsequently had a delayed discectomy formed the control group. Recurrence and readmission rates were analyzed and clinical outcome at 30 days post-surgery was assessed with the Oswestry Disability Index (ODI) and the visual analog pain scale (VAS).

RESULTS

One hundred thirty patients were admitted to the hospital after visiting the ED and underwent an emergency discectomy after a median of 1.0 days from admittance. Six patients in the study group [4.6% (95% CI: 2.1-9.7)] had recurrent LDH and nine patients in total [6.9% (95% CI: 3.9-12.6)] were readmitted within 30 days. None of the baseline variables clearly predicted recurrence. Mean ODI difference between the study group and controls was 8.1 (95% CI: -6.7-23.2). BMI and surgery by a non-spine surgeon were associated with higher ODI values.

CONCLUSION

An emergency discectomy is associated with a higher rate than expected of both recurrent LDHs and 30-day readmissions. Surgeon experience and patient-related factors had minor effects on the 30-day clinical outcome.

LEVEL OF EVIDENCE

4.

Machine Learning With Feature Domains Elucidates Candidate Drivers of Hospital Readmission Following Spine Surgery in a Large Single-Center Patient Cohort

BACKGROUND

Unplanned hospital readmissions constitute a significant cost burden in healthcare. Identifying factors contributing to readmission risk presents opportunities for actionable change to reduce readmission rates.

OBJECTIVE

To combine machine learning classification and feature importance analysis to identify drivers of readmission in a large cohort of spine patients.

METHODS

Cases involving surgical procedures for degenerative spine conditions between 2008 and 2016 were retrospectively reviewed. Of 11 150 cases, 396 patients (3.6%) experienced an unplanned hospital readmission within 30 d of discharge. Over 75 pre-discharge variables were collected and categorized into demographic, perioperative, and resource utilization feature domains. Random forest classification was used to construct predictive models for readmission from feature domains. An ensemble tree-specific method was used to quantify and rank features by relative importance.

RESULTS

In the demographics domain, age and comorbidity burden were the most important features for readmission prediction. Surgical duration and intraoperative oral morphine equivalents were the most important perioperative features, whereas total direct cost and length of stay were most important in the resource utilization domain. In supervised learning experiments for predicting readmission, the demographic domain model performed the best alone, suggesting that demographic features may contribute more to readmission risk than perioperative variables following spine surgery. A predictive model, created using only enriched features showing substantial importance, demonstrated improved predictive capacity compared to previous models, and approached the performance of state-of-the-art, deep-learning models for readmission.

CONCLUSION

This strategy provides insight into global patterns of feature importance and better understanding of drivers of readmissions following spine surgery.

Is academic department teaching status associated with adverse outcomes after lumbar laminectomy and discectomy for degenerative spine diseases?

BACKGROUND CONTEXT

Lumbar laminectomy and discectomy surgeries are among the most common procedures performed in the United States, and often take place at academic teaching hospitals, involving the care of resident physicians. While academic institutions are critical for the maturation of the next generation of attending surgeons, concerns have been raised regarding the quality of resident-involved care. There is conflicting evidence regarding the effects of resident participation in teaching hospitals on spine surgery patient outcomes. As the volume of lumbar laminectomy and discectomy increases, it is imperative to determine how academic status impacts clinical and economic outcomes.

PURPOSE

The purpose of this study is to determine if lumbar laminectomy and discectomy surgeries for degenerative spine diseases performed at academic teaching centers is associated with more adverse clinical outcomes and increased cost compared to those performed at nonacademic centers.

STUDY DESIGN/SETTING

This study is a multi-center retrospective cohort study using a New York Statewide database.

PATIENT SAMPLE

We identified 36,866 patients who met the criteria through the New York Statewide Planning and Research Cooperative System who underwent an elective lumbar laminectomy and/or discectomy in New York State between January 1, 2009 and September 30, 2014.

OUTCOME MEASURES

The primary functional outcomes of interest included: length of stay, cost of the index admission; 30-day and 90-day readmission; 30-day, 90-day, and 1-year return to the operating room.

METHODS

International Classification of Diseases, Ninth revision codes were utilized to define patients undergoing a laminectomy and/or discectomy who also had a diagnosis code for a lumbar spine degenerative condition. We excluded patients with a procedural code for lumbar fusion, as well as those with a diagnosis of scoliosis, neoplasm, inflammatory disorder, infection or trauma. Hospital academic status was determined by the Accreditation Council for Graduate Medical Education. Unique encrypted patient identifiers allowed for longitudinal follow-up for readmission and re-operation analyses. We extracted charges billed for each admission and calculated costs through cost-to-charge ratios. Logistic regression models compared teaching and nonteaching hospitals after adjusting for patient demographics and comorbidities.

RESULTS

Compared to patients at nonteaching hospitals, patients at teaching hospitals were more likely to be younger, male, non-Caucasian, be privately insured and have fewer comorbidities (p<.001). Patients undergoing surgery at teaching hospitals had 10% shorter lengths of stay (2.7 vs. 3.0 days, p<.001), but 21.5% higher costs of admission ($13,693 vs. $11,601 p<.001). Academic institutions had a decreased risk of return to the operating room for revision procedures or irrigation and debridement at 30 days (OR:0.70, 95% confidence interval [CI]: 0.60-0.82, p<.001), 90 days (OR:0.75, 95%CI: 0.66-0.86, p<.001), and 1 year (OR:0.84, 95%CI: 0.77-0.91, p<.001) post index procedure. There was no difference in 30- and 90-day all-cause readmission, or discharge disposition between the two groups.

CONCLUSIONS

Elective lumbar laminectomy and discectomy for degenerative lumbar conditions at teaching hospitals is associated with higher costs, but decreased length of stay and no difference in readmission rates at 30- and 90-days postoperatively compared to nonteaching hospitals. Teaching hospitals had a decreased risk of return to the operating room at 30 days, 90 days and 1 year postoperatively. Our findings might serve as an impetus for other states or regions to compare outcomes at teaching and nonteaching sites.

Incidental Durotomy Following Transforaminal Lumbar Interbody Fusion Performed with the Modified Wiltse Approach

PURPOSE

 Incidental durotomy is an intraoperative complication that occurs in 3 to 27% of lumbar spine surgeries. It has been reported more commonly following revision spinal procedures.

STUDY OBJECTIVES

 To investigate the frequency of incidental durotomy while performing transforaminal lumbar interbody fusion (TLIF) using the modified Wiltse approach. A secondary goal was to compare the incidence of durotomy in patients undergoing primary spine surgery with those undergoing revision surgery.

METHODS

 A group of consecutive patients who had undergone (TLIF) in the last 10 years ending in 2015 were enrolled in the study. All patients underwent TLIF via the modified Wiltse approach that included a central midline skin incision, followed by a paravertebral blunt dissection of the paraspinal muscles to reach the transverse processes. The deep paravertebral dissection was done conservatively, one side at a time. Demographic and clinical data were collected when relevant to the comparison.

RESULTS

 The study cohort encompassed 257 patients: 200 primary cases and 57 revisions. The frequency of incidental durotomy was equal in both groups: 3.5% each (7/200 and 2/57). All durotomies were repaired primarily. No other immediate or late complications were observed during follow-up.

CONCLUSION

 The present study displays a limited incidence of durotomy in the primary interventions and to a lesser degree in the revisions, all of which had used a TLIF performed with the modified Wiltse approach. This procedure probably circumvented the need for further revisions.