Risk Factors for Postoperative Deep Infection after Instrumented Spinal Fusion Surgeries for Degenerative Spinal Disease: A Nationwide Cohort Study of 194,036 Patients

The impact of negative pressure wound therapy on surgical wound infection, hospital stay and postoperative complications after spinal surgery: A meta-analysis

To systematically assess the effect of negative pressure wound therapy (NPWT) on postoperative surgical wound infection, length of hospital stay and postoperative complications after spinal surgery. Relevant studies on the application of NPWT in spinal surgery were conducted via a computerised database search, including PubMed, EMBASE, Web of Science, MEDLINE, Cochrane Library, China National Knowledge Infrastructure (CNKI) and Wanfang, from inception to June 2023. The identified literature was rigorously screened and data extraction was performed by two investigators independently. The quality of the relevant studies was evaluated using the Newcastle-Ottawa scale (NOS). The effect size for count data was determined by the odds ratio (OR), while the impact size for measurement data was expressed as the standardised mean difference (SMD). The 95% confidence interval (CI) was calculated for each effect magnitude. Stata 17.0 software was used for the meta-analysis. Ten papers, totalling 1448 patients, were finally included. This study demonstrated that NPWT led to a statistically significant reduction in the occurrence of postoperative surgical wound infections (OR: 0.377, 95% CI: 0.238-0.598, p < 0.001), fewer postoperative complications (OR: 0.526, 95% CI: 0.360-0.770, p = 0.001) and a shortened hospital stay (SMD: -0.678, 95%CI: -1.324 to -0.031, p = 0.040) after spinal surgery compared with the control group. When compared with other treatment approaches, NPWT also demonstrated a substantial reduction in surgical wound infections and postoperative complications, as well as a shorter duration of hospitalisation after spinal surgery.

Diagnostic trends of preoperative venous thromboembolism and its clinical implications in patients who underwent surgery for degenerative spinal diseases

BACKGROUND CONTEXT

Although the risk of postoperative venous thromboembolism (VTE) in patients who undergo surgery for degenerative spinal disease has received attention, patients experiencing prolonged pain and disability while awaiting or considering surgery have not received adequate attention regarding the risk of VTE.

PURPOSE

To investigate the epidemiology of preoperative VTE in patients undergoing surgery for degenerative spinal disease.

DESIGN

Retrospective cohort study using a nationwide database.

PATIENT SAMPLE

Patients who underwent surgery for degenerative spinal disease.

OUTCOME MEASURES

Preoperative occurrence of VTE.

METHODS

Data from 2014 to 2018 were obtained from the Korean National Health Insurance claims database. The occurrence of preoperative VTE within a 1-year period divided into 12 time intervals of 30 days each was investigated. The patients were categorized into two groups based on the presence of preoperative VTE. Multivariable logistic regression analysis was conducted to identify the factors associated with preoperative VTE. To validate the relationship between degenerative spinal disease and preoperative VTE, the diagnostic trends of preoperative VTE were analyzed in accordance with the identified risk factors.

RESULTS

The overall incidence of preoperative VTE was 50 per 10,000 individuals. Multivariable analysis revealed that VTE occurred more frequently in older patients with specific medical comorbidities, particularly in those with a lumbar spinal lesion accompanied by arthritis of the hip, knee, or shoulder. We also found that the incidence rates of preoperative VTE, as well as the gradient of their increase, began to rise approximately 2 to 3 months prior to the index surgery, peaking just before the index surgery. This diagnostic trend was consistently observed in all patients irrespective of the presence of other risk factors.

CONCLUSIONS

The incidence of preoperative VTE in patients with degenerative spinal disease exhibited a sharp increase immediately before surgery, with similar rates to those of postoperative VTE. Clinicians managing patients with degenerative spinal disease should be vigilant for preoperative as well as postoperative VTE.

Effectiveness of prophylactic intranasal photodynamic disinfection therapy and chlorhexidine gluconate body wipes for surgical site infection prophylaxis in adult spine surgery

BACKGROUND

Current measures to prevent spinal surgical site infection (SSI) lack compliance and lead to antimicrobial resistance. We aimed to examine the effectiveness of bundled preoperative intranasal photodynamic disinfection therapy (nPDT) and chlorhexidine gluconate (CHG) body wipes in the prophylaxis of spine SSIs in adults, as well as determine our institutional savings attributable to the use of this strategy and identify adverse events reported with nPDT-CHG.

METHODS

We performed a 14-year prospective observational interrupted time-series study in adult (age > 18 yr) patients undergoing emergent or elective spine surgery with 3 time-specific cohorts: before rollout of our institution's nPDT-CHG program (2006-2010), during rollout (2011-2014) and after rollout (2015-2019). We used unadjusted bivariate analysis to test for temporal changes across patient and surgical variables, and segmented regression to estimate the effect of nPDT-CHG on the annual SSI incidence rates per period. We used 2 models to estimate the cost of nPDT-CHG to prevent 1 additional SSI per year and the annual cumulative cost savings through SSI prevention.

RESULTS

Over the study period, 13 493 patients (mean 964 per year) underwent elective or emergent spine surgery. From 2006 to 2019, the mean age, mean Charlson Comorbidity Index (CCI) score and mean Spine Surgical Invasiveness Index (SSII) score increased from 48.4 to 58.1 years, from 1.7 to 2.6, and from 15.4 to 20.5, respectively (p < 0.001). Unadjusted analysis confirmed a significant decrease in the annual number (74.6 to 26.8) and incidence (7.98% to 2.67%) of SSIs with nPDT-CHG (p < 0.001). After adjustment for mean age, mean CCI score and mean SSII score, segmented regression showed an absolute reduction in the annual SSI incidence rate of 3.36% per year (p < 0.001). The estimated annual cost to prevent 1 additional SSI per year was about $1350-$1650, and the estimated annual cumulative cost savings were $2 484 856-$2 495 016. No adverse events were reported with nPDT-CHG.

CONCLUSION

Preoperative nPDT-CHG administration is an effective prophylactic strategy for spinal SSIs, with significant cost savings. Given its rapid action, minimal risk of antimicrobial resistance, broad-spectrum activity and high compliance rate, preoperative nPDT-CHG decolonization should be the standard of care for all patients undergoing emergent or elective spine surgery.

A meta-analysis of risk factors for non-superficial surgical site infection following spinal surgery

BACKGROUND

Surgical site infection (SSI) is the most common complications in spinal surgery. In SSI, non-superficial surgical site infections are more likely to result in poor clinical outcomes. It has been reported that there are multiple factors contributing to postoperative non-superficial SSI, but still remains controversial. Therefore, the aim of this meta-analysis is to investigate the potential risk factors for non-superficial SSI following spinal surgery.

METHODS

A systematic database search of PubMed, Embase, Web of Science, Cochrane Library and Clinical Trials was performed for relevant articles published until September 2022. According to the inclusion and exclusion criteria, two evaluators independently conducted literature screening, data extraction and quality evaluation of the obtained literature. The Newcastle-Ottawa Scale (NOS) score was used for quality evaluation, and meta-analysis was performed by STATA 14.0 software.

RESULTS

A total of 3660 relevant articles were initially identified and 11 articles were finally included in this study for data extraction and meta-analysis. The results of meta-analysis showed that the diabetes mellitus, obesity, using steroids, drainage time and operative time were related to the non-superficial SSI. The OR values (95%CI) of these five factors were 1.527 (1.196, 1.949); 1.314 (1.128, 1.532); 1.687(1.317, 2.162); 1.531(1.313, 1.786) and 4.255(2.612, 6.932) respectively.

CONCLUSIONS

Diabetes mellitus, obesity, using steroids, drainage time and operative time are the current risk factors for non-superficial SSI following spinal surgery. In this study, operative time is the most important risk factor resulting in postoperative SSI.

The epidemiology of concurrent infection in patients with pyogenic spine infection and its association with early mortality: A nationwide cohort study based on 10,695 patients

BACKGROUND

Generally, a sufficient duration of relevant antibiotics based on an appropriate culture combined with proper surgical treatment guarantees a favorable clinical outcome in patients with pyogenic spine infections. However, a patient's condition often deteriorates as concurrent infections occur in other organs, leading to mortality. Therefore, this study aimed to investigate the epidemiology of concurrent infections in patients with a pyogenic spine infection and estimate the rates and risks of early mortality.

METHODS

Patients with a pyogenic spine infection were identified using a national claims database that includes the entire population. The epidemiology of the six types of concurrent infections was investigated, and the corresponding early mortality rates and risks were estimated. The results were validated internally by bootstrapping and externally by defining two additional cohorts for sensitivity analysis.

RESULTS

Among 10,695 patients with a pyogenic spine infection, the prevalence of the six types of concurrent infections was 11.3 % for urinary tract infections, 9.4 % for intra-abdominal infections, 8.5 % for pneumonia, 4.6 % for septic arthritis or osteomyelitis of the extremities, 0.7 % for central nervous system infections, and 0.5 % for cardiac infections. Patients with a concurrent infection had approximately 4-fold greater mortality than those without (3.3 % vs. 0.8 %). The early mortality rates were particularly higher in patients with multiple or specific types of concurrent infections, including central nervous system infections, cardiac infections, and pneumonia. In addition, the mortality trends differed significantly according to the number and type of concurrent infections.

CONCLUSIONS

These data on six types of concurrent infection among patients with pyogenic spinal infection can be used as a source of reference by clinicians.

Weekend Admission Increases Risk of Readmissions Following Elective Cervical Spinal Fusion

Objective: The “weekend effect” occurs when patients cared for during weekends versus weekdays experience worse outcomes. But reasons for this effect are unclear, especially amongst patients undergoing elective cervical spinal fusion (ECSF). Our aim was to analyze whether index weekend admission affects 30- and 90-day readmission rates post-ECSF.Methods: All ECSF patients > 18 years were retrospectively identified from the 2016–2018 Healthcare Cost and Utilization Project Nationwide Readmissions Database (NRD), using unique patient linkage codes and International Classification of Diseases, Tenth Revision codes. Patient demographics, comorbidities, and outcomes were analyzed. Univariate logistic regression analyzed primary outcomes of 30- and 90-day readmission rates in weekday or weekend groups. Multivariate regression determined the impact of complications on readmission rates.Results: Compared to the weekday group (n = 125,590), the weekend group (n = 1,026) held a higher percentage of Medicare/Medicaid insurance, incurred higher costs, had longer length of stay, and fewer routine home discharge (all p < 0.001). There was no difference in comorbidity burden between weekend versus weekday admissions, as measured by the Elixhauser Comorbidity Index (p = 0.527). Weekend admissions had higher 30-day (4.30% vs. 7.60%, p < 0.001) and 90-day (7.80% vs. 16.10%, p < 0.001) readmission rates, even after adjusting for sex, age, insurance status, and comorbidities. All-cause complication rates were higher for weekend admissions (8.62% vs. 12.7%, p < 0.001), specifically deep vein thrombosis, infection, neurological conditions, and pulmonary embolism.Conclusion: Index weekend admission increases 30- and 90-day readmission rates after ECSF. In patients undergoing ECSF on weekends, postoperative care for patients at risk for specific complications will allow for improved outcomes and health care utilization.

Changes in Sleep Problems in Patients Who Underwent Surgical Treatment for Degenerative Spinal Disease with a Concurrent Sleep Disorder: A Nationwide Cohort Study in 3183 Patients during a Two-Year Perioperative Period

Sleep disturbance is prevalent in patients with degenerative spinal disease, and recent studies have reported that surgical treatment is more effective for improving sleep quality than conservative treatment. We aimed to investigate the perioperative changes of sleep problems in patients who underwent surgical treatment for degenerative spinal disease with a concurrent sleep disorder, and presented them according to various clinical profiles possibly associated with sleep disturbance. In addition, we identified factors associated with poor sleep improvement after surgery. This study used data from the Korea Health Insurance Review and Assessment Service database from 2016 to 2018. We included 3183 patients aged ≥19 years who underwent surgery for degenerative spinal disease and had a concurrent sleep disorder. Perioperative changes in the two target outcomes, including the use of sleep medication and hospital visits owing to sleep disorders, were precisely investigated according to factors known to be associated with sleep disturbance, including demographics, comorbidities, and spinal regions. Logistic regression analysis was performed to identify factors associated with poor improvement in terms of sleep medication after surgery. All estimates were validated using bootstrap sampling. During the 1-year preoperative period, the use of sleep medications and hospital visits owing to sleep disorder increased continuously. However, they abruptly decreased shortly after surgical treatment, and throughout the 1-year postoperative period, they remained lower than those in the late preoperative period. At the 1-year follow-up, 75.6% (2407 of 3183) of our cohort showed improvement in sleep medication after surgery. Multivariable analysis identified only two variables as significant factors associated with non-improvement in sleep medication after surgery: depressive disorder (odds ratio (OR) = 1.25 [1.06-1.48]; p = 0.008), and migraine (OR = 1.42 [1.04-1.94]; p = 0.028). We could not investigate the actual sleep quality and resultant quality of life; however, our results justify the necessity for further high-quality studies that include such information and would arouse clinicians' attention to the importance of sleep disturbance in patients with degenerative spinal disease.

Prevalence of Sleep Disturbance and Its Risk Factors in Patients who Undergo Surgical Treatment for Degenerative Spinal Disease: A Nationwide Study of 106,837 Patients

Spinal surgeons have not yet considered sleep disturbance an area of concern; thus, a comprehensive study investigating the epidemiology of sleep disturbance in patients with degenerative spinal disease is yet to be conducted. This study aimed to fill this research gap by investigating the epidemiology of sleep disturbance in patients who underwent spinal surgery for degenerative spinal disease and identifying the associated risk factors. This nationwide, population-based, cohort study, used data from January 2016 and December 2018 from the Korea Health Insurance Review and Assessment Service database. This study included 106,837 patients older than 19 years who underwent surgery for degenerative spinal disease. Sleep disorder was initially defined as a diagnosis of a sleep disorder made within one year before the index surgery and identified using the International Classification of Diseases, 10th revision, codes F51 and G47 (main analysis). We also investigated the use of sleep medication within 90 days prior to the index surgery, which was the target outcome of the sensitivity analysis. The prevalence of sleep disturbance was precisely investigated according to various factors, including demographics, comorbidities, and spinal region. Logistic regression analysis was performed to identify the independent factors associated with sleep disturbance. The results of the statistical analysis were validated using sensitivity analysis and bootstrap sampling. The prevalence of sleep disorder was 5.5% (n = 5847) in our cohort. During the 90 days before spinal surgery, sleep medication was used for over four weeks in 5.5% (n = 5864) and over eight weeks in 3.8% (n = 4009) of the cohort. Although the prevalence of sleep disturbance differed according to the spinal region, the spinal region was not a significant risk factor for sleep disorder in multivariable analysis. We also identified four groups of independent risk factors: (1) Age, (2) other demographic factors and general comorbidities, (3) neuropsychiatric disorders, and (4) osteoarthritis of the extremities. Our results, including the prevalence rates of sleep disturbance in the entire patient population and the identified risk factors, provide clinicians with a reasonable reference for evaluating sleep disturbance in patients with degenerative spinal disease and future research.

Construct and Validate a Predictive Model for Surgical Site Infection after Posterior Lumbar Interbody Fusion Based on Machine Learning Algorithm

Purpose. Surgical site infection is one of the serious complications after lumbar fusion. Early prediction and timely intervention can reduce the harm to patients. The aims of this study were to construct and validate a machine learning model for predicting surgical site infection after posterior lumbar interbody fusion, to screen out the most important risk factors for surgical site infection, and to explore whether synthetic minority oversampling technique could improve the model performance. Method. This study reviewed 584 patients who underwent posterior lumbar interbody fusion for degenerative lumbar disease at our center from January 2019 to August 2021. Clinical information and laboratory test data were collected from the electronic medical records. The original dataset was divided into training set and validation set in a 1 : 1 ratio. Seven machine learning algorithms were used to develop predictive models; the training set of each model was resampled using synthetic minority oversampling technique. Finally, the model performance was assessed in the validation set. Results. Of the 584 patients, 33 (5.65%) occurred surgical site infection. Stepwise logistic regression showed that preoperative albumin level (OR 0.659, 95% CI 0.563-0.756), diabetes (OR 9.129, 95% CI 3.816-23.126), intraoperative dural tear (OR 8.436, 95% CI 2.729-25.334), and rheumatic disease (OR 8.471, 95% CI 1.743-39.567) were significant predictors associated with surgical site infection. The performance of the AdaBoost Classification Trees model was the best among the seven machine learning models, and synthetic minority oversampling technique improved the performance of all models. Conclusion. The prediction model we constructed based on machine learning and synthetic minority oversampling technique can accurately predict surgical site infection, which is conducive to clinical decision-making and optimization of perioperative management.

Recurrence Rates and Its Associated Factors after Early Spinal Instrumentation for Pyogenic Spondylodiscitis: A Nationwide Cohort Study of 2148 Patients

Recent studies have consistently reported the safety and effectiveness of early spinal instrumentation for pyogenic spondylodiscitis. However, none of these studies investigated the recurrence rate or associated factors based on this specific group of patients. Recurrence prediction models that are not based on a homogenous cohort of patients undergoing early spinal instrumentation show theoretical limitations for clinical use. A nationwide, population-based, retrospective cohort study using a claims database was planned to investigate the recurrence rate and its associated factors in patients who underwent early instrumented spinal fusion surgery for pyogenic spondylodiscitis. We used data from the Korean National Health Insurance claims database collected between 2014 and 2018. A total of 2148 patients who underwent early (within 6 weeks after the diagnosis) instrumented spinal fusion surgery for pyogenic spondylodiscitis were included, including 1925 patients (90%) without recurrence and 223 patients (10%) with recurrence. Logistic regression models were used to identify factors associated with recurrence, and sensitivity analysis was performed according to two different definitions for recurrence: shorter (2 weeks or more) and longer (6 weeks or more) periods of antibiotic therapy for recurrence. The recurrence rates in our cohort were 14.1%, 10.4%, and 8.0% at 2, 4, and 6 weeks, respectively, in relation to the duration of antibiotic treatment for recurrence. We identified age 60−69 years (OR = 2.42), age > 70 years (OR = 2.29), posterior thoracic approach (OR = 1.85), multiple surgical approaches (OR = 4.17), use of a cage (OR = 1.66), transfusion (OR = 2.55), antibiotics for resistant organisms (OR = 2.55), and systemic steroid treatment over 2 weeks (OR = 2.27) as the factors associated with recurrence. The recurrence rates and associated factors from our first population-based and the largest clinical study can be practically used as a reasonable reference and provide clinicians with an acceptable tool for the comprehensive risk assessment for recurrence after early spinal instrumentation for pyogenic spondylodiscitis.