Risk factors for surgical site infection following spinal instrumentation surgery

Analysis of risk factors for surgical site infection in spinal surgery patients and study of direct economic losses

BACKGROUND

Surgical site infection (SSI) is a serious complication of spine surgery, leading to prolonged hospital stays, re-operations, and economic losses. The aim of the study was to explore the types and quantities of pathogenic bacteria involved, the incidence of SSI, and to identify the independent risk factors and direct economic impact on patients with postoperative SSI in spine surgery.

METHODS

The medical records of spine surgery patients from January 2023 to April 2024 at two hospitals in Xinjiang were retrospectively reviewed. Patients with SSIs were included in the case group, and patients without SSIs were matched 1:1 based on hospital, department, age ± 5 years, primary diagnosis, and the specific surgery type. They were then subjected to univariate and multivariate paired logistic regression analyses. The Wilcoxon signed-rank test was used to compare differences in hospitalization costs and duration of stay between the two groups.

RESULTS

A total of 38 individuals, or 0.63% of the 6018 adults who had spinal procedures, experienced SSI. Findings from the univariate analysis demonstrated a statistically significant correlation between SSI (p < 0.05), intraoperative bleeding of 300 ml or more, and the duration of indwelling drain use. Many separate risk variables for SSI were found by multivariate regression analysis: combined underlying diseases (OR 2.634, 95% CI 1.02-6.78), days with an indwelling urinary catheter (OR 1.38, 95% CI 1.01-1.88), and days with an indwelling drain (OR 1.449, 95% CI 1.01-2.07). The most prevalent bacteria identified as causing skin infections were Staphylococcus aureus and Staphylococcus epidermidis. About $1,688.50 in direct economic loss was attributable to SSI in patients undergoing spine surgery.

CONCLUSIONS

The presence of combined underlying diseases, extended use of indwelling urinary catheters, and prolonged use of indwelling drains significantly increase the risk of SSI in spine surgery patients.

Effect of drain placement in short-level spinal surgery on postoperative wound infection: A meta-analysis

In the meta-analysis, we evaluated the efficacy of placing drainage channels following single- or double-level spine surgery in order to decrease the incidence of postoperative injury. We conducted the analysis with the help of four databases: PubMed, Embase, Cochrane Library and Web of Science. A review of related studies was carried out after evaluating the quality of the literature against the classification and exclusion criteria set for the trial. Calculation of 95% CI, OR and MD was performed with fixed-effect models. A meta-analysis of the data was carried out with RevMan 5.3. Meta-analyses of randomized controlled trial (RCT) did not indicate that there were a statistically significantly different incidence of postoperative wound infections among those who received drainage compared to those who did not receive drainage (OR, 2.29; 95% CI, 0.50, 10.41 p = 0.28). Moreover, there were no statistically significant differences in post-operation hematoma (OR, 1.20; 95% CI, 0.27, 5.28 p = 0.81) and visual analogue scale score (MD, -0.01; 95% CI, -1.34, 1.33 p = 0.99). Thus, placing drainage in short-levels of spine operation did not significantly influence the outcome of postoperative wound complications. Nevertheless, because of the limited sample size chosen for this meta-analysis, caution should be exercised when treating these data. More high-quality RCT trials with a large number of samples are required to confirm the findings.

Investigating the efficacy of vacuum sealing drainage versus traditional negative pressure drainage in treating deep incision infections following posterior cervical internal fixation-a retrospective cohort study

BACKGROUND

Assessing the efficacy and safety of Vacuum Sealing Drainage (VSD) in treating deep incision infections (DII) following posterior cervical internal fixation.

METHODS

We retrospectively studied the clinical effects of VSD and Traditional Negative Pressure Drainage (TND) on 12 patients with deep incision infection after posterior cervical fixation surgery who were treated in our department from 2012 to 2020. A comparison of patient-related factors (age, gender, BMI, comorbidities, initial internal fixation surgery segment, preoperative laboratory inflammation indicators) and surgical-related factors (postoperative duration of fever, positive rate of drainage fluid bacterial culture, Visual Analogue Scale (VAS) score at 3 days after surgery, laboratory indicators at 3 days after surgery, debridement frequency and drainage time, hospital stay, internal fixation retention rate, and infection recurrence rate) between the VSD group and the TND group was conducted using independent sample t tests to draw experimental conclusions.

RESULTS

This study included 12 patients, with six cases of VSD (5 males and 1 female) and six cases of TND (4 males and 2 females). The VSD group had significantly lower postoperative fever time (1.50 ± 0.46 days vs. 4.28 ± 0.97 days, P < 0.05), a higher positive rate of bacterial cultures in drainage fluid (5/6 vs. 2/6, P < 0.05), lower 3 day VAS scores (3.13 ± 0.83 vs. 3.44 ± 0.88, P < 0.05), lower 3 day CRP levels (66.89 ± 23.65 mg/L vs. 57.11 ± 18.18 mg/L, P < 0.05), a shorter total drainage time (14.50 ± 2.98 days vs. 22.56 ± 3.01 days, P < 0.05), and a higher total drainage flow rate (395.63 ± 60.97 ml vs. 155.56 ± 32.54 ml, P < 0.05) than the TND group (the total drainage volume throughout the entire treatment process). In addition, the frequency of debridement (2.67 ± 0.52 times vs. 3.17 ± 0.41 times, P < 0.05) and average hospital stay (23.13 ± 3.27 days vs. 34.33 ± 6.86 days, P < 0.05) were significantly lower in the VSD group, although both groups retained internal fixation.

CONCLUSIONS

VSD is a secure and effective treatment for deep incision infections that results from cervical posterior internal fixation surgery.

Association between malnutrition and surgical site wound infection among spinal surgery patients: A meta-analysis

A surgical site infection (SSI) is one of the most common complications of spinal surgery. Malnutrition has also been linked to SSI after other surgical procedures. However, whether malnutrition is a risk factor for SSI after spinal surgery remains controversial. Therefore, we performed a meta-analysis to comprehensively evaluate the relationship between malnutrition and SSI. Relevant studies of the correlation between malnutrition and SSI were retrieved from the Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure and Wanfang Data from database inception to 21 May 2023. Two reviewers independently assessed the included studies, and a meta-analysis was performed using STATA 17.0 software. A total of 24 articles with 179 388 patients were included: 3919 and 175 469 cases comprised the SSI and control groups, respectively. The meta-analysis results showed that malnutrition significantly increased the SSI incidence (odds ratio, 1.811; 95% confidence interval, 1.512-2.111; p < 0.001). These results suggest that patients with malnutrition are at higher risk for SSI after surgery. However, because of significant differences in sample sizes among studies, and because some studies had limitations to their methodological quality, further validation of these results by additional high-quality studies with larger sample sizes is necessary.

Preoperative Epidural Steroid Injection Does Not Increase Infection Risk Following Posterior Cervical Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of this study was to characterize the infection risk of preoperative epidural steroid injection (ESI) in patients undergoing posterior cervical surgery.

SUMMARY OF BACKGROUND DATA

ESI is a helpful tool for alleviating pain and is often used as a diagnostic tool before cervical surgery. However, a recent small-scale study found that ESI before cervical fusion was associated with an increased risk of postoperative infection.

MATERIALS AND METHODS

Patients from 2010 to 2020 with cervical myelopathy, spondylosis, and radiculopathy who underwent posterior cervical procedure including laminectomy, laminoforaminotomy, fusion, or laminoplasty were queried from the PearlDiver database. Patients who underwent revision or fusion above C2 or who had a diagnosis of neoplasm, trauma, or preexisting infection were excluded. Patients were divided on whether they received an ESI within 30 days before the procedure and subsequently matched by age, sex, and preoperative comorbidities. The χ 2 analysis was used to calculate the risk of postoperative infection within 90 days. Logistic regression controlling for age, sex, Elixhauser Comorbidity Index, and operated levels was conducted within the unmatched population to assess infection risk for injected patients across procedure subgroups.

RESULTS

Overall, 299,417 patients were identified with 3897 having received a preoperative ESI and 295,520 who did not. Matching resulted in 975 in the injected group and 1929 in the control group. There was no significant difference in postoperative infection rate in those who received an ESI within 30 days preoperatively and those who did not (3.28% vs. 3.78%, odds ratio=0.86, 95% CI: 0.57-1.32, P =0.494). Logistic regression accounting for age, sex, Elixhauser Comorbidity Index, and levels operated demonstrated that injection did not significantly increase infection risk in any of the procedure subgroups.

CONCLUSIONS

The present study found no association between preoperative ESI within 30 days before surgery and postoperative infection in patients undergoing posterior cervical surgery.

Ultrasound-guided percutaneous micro-drainage tube irrigation combined with high negative pressure tube drainage versus debridement with closed suction irrigation for treating deep surgical site infection after spinal surgery

It is difficult to avoid deep surgical site infection after spinal surgery. Debridement combined with closed suction irrigation (CSI) and other treatment methods lead to greater trauma and lower satisfaction. We developed a new method for the treatment of SSI, which has the advantages of less invasiveness and lower cost. The cohort of this retrospective study comprised 26 patients with SSI after undergoing spinal surgery in our hospital from August 2017 to March 2022. The patients were divided into CSI and microtube drainage group according to treatment methods. The durations of antibiotic use and hospital stay, hospitalization costs, and functional scores during follow-up were compared between the two groups. The only baseline characteristic that differed between the two groups was sex. Infection was controlled in both groups and there were no recurrences during follow-up. However, the length of hospital stay after the first operation and the total length of stay were significantly greater in the CSI group. Hospitalization costs and antibiotic costs were significantly higher in the CSI group. Additionally, the duration of intravenous antibiotic use was significantly longer in the CSI group. Both the CSI and microtube drainage groups had significantly improved of Short Form Health Survey (SF-36) scores 6 months postoperatively. However, 3 months postoperatively, SF-36 scores were significantly lower in the CSI group. Compared with debridement followed by CSI, percutaneous micro-drainage tube irrigation combined with high negative pressure tube drainage is a more efficient and economical means of treating SSI after spinal surgery.

Association of preoperative hypoprotein malnutrition with spinal postoperative complications and other conditions: A systematic review and meta-analysis

BACKGROUND

Postoperative complications of spinal surgery are a common clinical problem, which impose significant economic and clinical burdens on patients and medical staff. Previous studies have suggested a close relationship between low-protein malnutrition and postoperative complications of surgery. However, the relationship between preoperative malnutrition and various orthopedic postoperative complications remains unclear.

PURPOSE

To investigate the association between protein malnutrition and postoperative complications and outcomes.

METHODS

We conducted a systematic search of the PubMed, Embase, Cochrane Library, and Web of Science databases for published research articles between the database inception and February 28th, 2023, that evaluated the association between malnutrition and the risk of postoperative complications and death in spinal surgery patients. Malnutrition was defined as low pre-albumin and albumin levels before surgery. Two evaluators independently extracted study data and assessed the risk of bias in each study. Fixed- or random-effect models were used to calculate the pooled effect estimates. Funnel plots and Egger's tests were used to detect publication bias, and the Trim-and -Fill method was conducted to evaluate the impact of publication bias on the results.

RESULTS

A total of 26 studies were included in this meta-analysis, comprising 17 retrospective cohort studies and 9 case-control studies. The study included more than 86,000 participants. Analysis of postoperative complications revealed that the overall incidence of malnutrition-related complications after surgery was 3.17 times higher (OR = 3.17, 95% CI 2.69-3.75, z = 13.57, P < 0.05). The incidence of surgical site infections was 2.08 times higher (OR = 2.08, 95% CI 1.66-2.62, z = 6.307, P < 0.05), and the incidence of postoperative urinary tract infections was 2.55 times higher (OR = 2.55, 95% CI 1.80-3.60, z = 5.30, P < 0.05). The incidence of postoperative sepsis was 3.31 times higher (OR = 3.31, 95% CI 2.31-4.75, z = 6.51, P < 0.05), and the incidence of postoperative pneumonia was 3.02 times higher (OR = 3.02, 95% CI 1.331-6.857, z = 2.64, P = 0.008 < 0.05). The incidence of postoperative cardiac complications was 4.24 times higher (OR = 4.24, 95% CI 2.45-7.35, z = 5.15, P < 0.05), and the incidence of postoperative renal complications was 4.04 times higher (OR = 4.04, 95% CI 2.06-7.93, z = 4.05, P < 0.05). The incidence of postoperative pulmonary complications was 2.38 times higher (OR = 2.38, 95% CI 1.46-3.87, z = 6.98, P < 0.05), while the incidence of postoperative thrombotic complications was 2.76 times higher (OR = 2.76, 95% CI 1.756-4.345, z = 4.40, P < 0.05). Furthermore, the incidence of transfusion during and after surgery was 1.33 times higher (OR = 1.33, 95% CI 1.13-1.56, z = 3.40, P = 0.001 < 0.05), the incidence of postoperative readmission was 1.67 times higher (OR = 1.67, 95% CI 1.24-2.27, z = 3.33, P = 0.001 < 0.05), and the risk of postoperative death was 6.01 times higher (OR = 6.01, 95% CI 4.51-8.01, z = 12.27, P < 0.05). After conducting a publication bias test and Trim-and -Fill method analysis, we found no evidence of publication bias, and the results remained stable.

CONCLUSION

Preoperative low protein malnutrition is closely related to the incidence of postoperative complications and postoperative status. More prospective multicenter studies should be conducted to validate this conclusion. Furthermore, more effective assessment and intervention of preoperative nutritional status should be carried out to prevent the occurrence of postoperative complications and mortality risk.

Risk factors for surgical site infection in advanced neuromodulation pain procedures: a retrospective study

Aim: To assess the effects of diabetes mellitus (DM) and related variables on surgical site infection (SSI) risk in neuromodulation. Methods: This retrospective study followed patients who underwent neuromodulation procedures for at least 9 months to identify postoperative infections. Demographics, clinical characteristics and surgical outcomes were compared. Results: Of 195 cases included, 5 (2.6%) resulted in SSIs. Median HbA1c was significantly higher for the cases with SSIs (8.2 vs 5.6%; p = 0.0044). The rate of SSI was significantly higher among patients with DM (17.9 vs 0%; p = 0.0005), HbA1c≥7% (37.5 vs 0%; p = 0.0009), and perioperative glucose ≥200 mg/dl (40 vs 2.3%; p = 0.0101). Conclusion: DM, elevated HbA1c and perioperative hyperglycemia may all contribute to increased risk of SSIs with neuromodulation procedures.

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.

Surgical site infection in spinal surgery: a bibliometric analysis

BACKGROUND

Surgical site infection (SSI) is a common complication in spinal surgery that can significantly affect the patient's prognosis. Despite advances in surgical techniques and infection control measures, SSI remains a considerable concern for healthcare providers and patients alike. In recent years, there has been a steady increase in studies related to SSI in spine surgery, leading to the publication of numerous informative articles. However, the current state and trends of research in the field of spinal SSI remain unclear. This study aims to conduct a bibliometric analysis of SSI-related articles in spine surgery to identify research status and trends. Meanwhile, we identify the top 100 most cited articles for further analysis.

METHODS

We searched for all articles related to spinal SSI in the Web of Science Core Collection, recording the publication year, country, journal, institution, keywords, and citation frequency for further analysis. In addition, we identified and analyzed the top 100 most cited articles.

RESULTS

A total of 307 articles related to spinal SSI were identified. All of these articles were published between 2008 and 2022, with the number of publications showing an increasing trend over the years. The related articles originated from 37 countries, with the USA contributing the most (n = 138). The institution with the highest number of publications and citations was Johns Hopkins University (14 articles; 835 citations). Among the journals, Spine had the highest number of articles (n = 47). The prevention of spinal SSI has been a research hotspot in recent years. Among the top 100 most cited articles, the most common research theme was the risk factors associated with spinal SSI.

CONCLUSIONS

In recent years, research related to spinal SSI has attracted the attention of numerous clinicians and scholars. As the first bibliometric analysis of spinal SSI, our study aims to provide pragmatic guidance for clinicians to learn the research status and trends in this field and improve their vigilance toward SSI.

Inflammatory biomarkers behavior profile among patients following elective degenerative spine surgery and their differences with those coursing with a postoperative spinal infection: Protocol for a Systematic Review

BACKGROUND

The incidence of postoperative spinal infection (PSI) ranges from 0% to 10%, devastatingly affecting the patient prognosis and increasing costs to the healthcare system because of higher morbidity. Postoperative spinal infections require a high level of suspicion as they are difficult to diagnose, especially in the early postoperative state, because of many confounding factors such as clinical symptoms, serum biomarkers rise or confusing imaging studies. Current research has focused on serum biomarkers at the early stages of disease, nevertheless, most rely on retrospective cohorts with serum biomarkers studied individually and at different time points.

OBJECTIVE

To determine the Inflammatory biomarkers behavior profile among patients following elective degenerative spine surgery and their differences with those coursing with postoperative spinal infection.

METHODS

The proposed systematic review will follow the PRISMA statement. This protocol was registered at PROSPERO on January 19th, 2022, obtaining the following register CRD42022304645 on February 19th, 2022. We will include studies related to biomarkers in adult patients operated on because of degenerative spinal diseases, and those developing a postoperative spinal infection. The following information will be extracted: (1)study title; (2)Study Author (3)year; (4)evidence-level; (5)Research-type; (6)diagnosis group (elective postoperative degenerative disease / PSI); (7a)region (Cervical, Thoracic, Lumbosacral, Coccigeal); (7b)Type of infection by anatomical or radiological site, (8)Surgery-Type (including instrumentation or not); (9)number of cases; (10)mean age or individual age; and (11) individual serum biomarker values from the preoperative state up to 90 days postop for both groups including: (10a)interleukine-6, (10b)Presepsine, (10c)Erythrocyte Sedimentation Rate, (10d)Leukocyte Count, (10e)Neutrophil Count, (10f)C-Reactive Protein, (10g)Serum Amyloid, (10h)White Cell Count, (10i)Albumin, (10j)Prealbumin, (10k)Procalcitonin, (10L)Retinol associated protein, (10M)Dickopf-1, (11)postoperative days at symptoms or diagnosis, (12)Type of organism, (13)day of starting antibiotics, (14)duration of treatment and (15)any biases (including comorbidities, especially those affecting immunological status). All biomarkers' data will be presented graphically over time. Figure 1 contains the flow diagram of the methodology.

RESULTS

No ethical approval will be required, as this review is based on published data and does not involve interaction with human participants. The search for this systematic review commenced in February 2021, and we expect to publish the findings in middle 2023.

CONCLUSIONS

The present study will provide the biomarkers' behavior profile for PSI and patients following elective surgery for degenerative spinal diseases from the preoperative period up to 90 days postoperative providing cut-off values at the day of diagnosis. It will provide clinicians with a better background to diagnose based on highly trustable information based on cut-off values from this systematic review. Finally we expect this review to provide a basis for future research on biomarkers to establish more accurate and timely diagnosis in the early stages of illness ultimately impacting the patient's physical and mental health, reducing the disease burden.

CLINICALTRIAL

PROSPERO register ID: CRD42022304645.

Association between hypoalbuminemia and complications after degenerative and deformity-correcting spinal surgeries: A systematic review and meta-analysis

Objective

The current review was designed to explore if hypoalbuminemia is associated with increased complications in patients undergoing spinal degenerative and deformities surgeries.

Methods

The search for eligible studies was conducted on the databases of PubMed, Embase, Web of Science, and CENTRAL up to 20th June 2022. Complication rates were pooled to obtain odds ratio (OR) and 95% confidence intervals.

Results

Thirteen studies were included. We found that hypoalbuminemia was significantly associated with increased risk of all complications (OR: 2.72 95% CI: 2.04, 3.63 I ²= 58% p < 0.00001), mortality (OR: 7.73 95% CI: 3.81, 15.72 I ²= 0% p < 0.00001), revision surgery (OR: 3.15 95% CI: 1.53, 6.48 I ²= 87% p = 0.002), readmissions (OR: 1.96 95% CI: 1.29, 2.98 I ²= 23% p = 0.02), surgical site infections (OR: 2.97 95% CI: 1.90, 4.63 I ²= 38% p < 0.00001), wound complications (OR: 2.31 95% CI: 1.17, 4.56 I ²= 48% p = 0.02), pulmonary complications (OR: 3.74 95% CI: 2.66, 5.26 I ²= 0% p < 0.00001), renal complications (OR: 3.04 95% CI: 1.22, 7.54 I ²= 0% p = 0.02), cardiac complications (OR: 4.33 95% CI: 2.14, 8.77 I ²= 0% p < 0.0001), urinary tract infections (OR: 2.08 95% CI: 1.80, 2.41 I ²= 0% p < 0.00001), and sepsis (OR: 4.95 95% CI: 1.87, 13.08 I ²= 64% p = 0.01) as compared to those with normal albumin.

Conclusion

Hypoalbuminemia is a significant risk factor for complications after spinal degenerative and deformity surgeries. Research is also needed on the role of nutritional support in improving outcomes after spinal degenerative and deformity surgeries.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022340024.

Safety and efficacy of negative pressure wound therapy in treating deep surgical site infection after lumbar surgery

PURPOSE

To evaluate the efficacy and safety of negative pressure wound therapy (NPWT) for post-operative deep surgical site infection (SSI) after posterior instrumented spinal surgery.

METHODS

We retrospectively compared the clinical outcomes of NPWT with standard debridement for deep SSI after posterior instrumented spinal surgery from 2012 to 2020 in our department. The primary outcomes were peri-operative characteristics including positive organism results, duration of fever, and visual analogue scale (VAS) pain scores three days after re-operation. The secondary outcomes were post-operative characteristics including implant infection recurrence, implant retention rate, duration of hospitalization, and VAS at discharge. Pearson's chi-squared analysis (categorical) and Student's t test (continuous) were used to determine the differences.

RESULTS

Thirty-four patients were included, of which 19 underwent NPWT, and 15 underwent standard debridement. Patients in the NPWT group all significantly improved primary outcomes including duration of fever after re-operation (0.95 ± 1.13 vs 4.07 ± 5.35, P = 0.001), positive organism results (14 of 19 vs 2 of 15, P < 0.01), and VAS at 3 days after re-operation (2.58 ± 0.69 vs 3.40 ± 1.06, P < 0.05). Patients in NPWT group exhibited significant decrease in implant infection recurrence (0 of 19 vs 5 of 15, P < 0.01), implant retention rate (19 of 19 vs 10 of 15, P < 0.01), duration of hospitalization (27.74 ± 10.95 vs 37.67 ± 13.67, P < 0.01).

CONCLUSIONS

NPWT is a feasible and safe treatment option for deep SSI after posterior instrumented spinal surgery.

Impact of chronic hyperlipidemia on perioperative complications in patients undergoing lumbar fusion: a propensity score matching analysis

PURPOSE

Lumbar fusion is widely used to treat degenerative and traumatic conditions of the spine, with various perioperative complications. This study compared lumbar fusion complications in patients with and without chronic hyperlipidemia.

METHODS

Using the MSpine division of the PearlDiver database, patients with or without chronic hyperlipidemia who underwent lumbar fusions were identified. The appropriate Current Procedural Terminology (CPT) codes identified patients with single- or multi-level lumbar spinal fusion surgeries. International Classification of Diseases (ICD-9 and ICD-10) codes identified patients with chronic hyperlipidemia. The surgical and medical complications were obtained utilizing the appropriate ICD-9, ICD-10, and CPT codes. Propensity score matching analysis was used to control for confounding factors. Chi-square test was applied to compare the incidence of complications among different groups.

RESULTS

In single-level fusion group, patients with hyperlipidemia had a higher incidence of wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), deep venous thrombosis/pulmonary embolism (P = 0.031), myocardial infarction (P < 0.001) cerebrovascular accident (P < 0.001), renal failure (P < 0.001), sepsis (P < 0.001), and urinary tract infection/incontinence (P < 0.001). In multi-level fusion group, patients with hyperlipidemia had a higher incidence of nerve root injury (P = 0.034), wound complications (P < 0.001), surgical site infection (P < 0.001), failed back syndrome (P < 0.001), hardware removal (P < 0.001), revision (P = 0.002), myocardial infarction (P < 0.001), renal failure (P < 0.001), and urinary tract infection/incontinence (P < 0.001).

CONCLUSION

Following lumbar fusion, patients with chronic hyperlipidemia have an increased risk of perioperative complications, including wound complications, surgical site infection, failed back surgery syndrome, hardware removal, myocardial infarction, renal failure, and urinary tract infection/incontinence.

Incidence of Surgical Site Infection After Spine Surgery: A Systematic Review and Meta-analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

The objective of this study was to investigate the incidence of surgical site infection (SSI) in patients following spine surgery and the rate of microorganisms in these cases.

SUMMARY OF BACKGROUND DATA

Many studies have investigated the incidence and risk factors of SSI following spinal surgery, whereas no meta-analysis studies have been conducted regarding the comprehensive epidemiological incidence of SSI after spine surgery.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases for relevant studies that reported the incidence of SSI after spine surgery, and manually screened reference lists for additional studies. Relevant incidence estimates were calculated. Subgroup analysis, sensitivity analysis, and publication bias assessment were also performed.

RESULTS

Our meta-analysis included 27 studies, with 603 SSI cases in 22,475 patients. The pooled SSI incidence was 3.1%. Subgroup analysis revealed that the incidence of superficial SSI was 1.4% and the incidence of deep SSI was 1.7%. Highest incidence (13.0%) was found in patients with neuromuscular scoliosis among the different indications. The incidences of SSI in cervical, thoracic, and lumbar spine were 3.4%, 3.7%, and 2.7%, respectively. Compared with posterior approach surgery (5.0%), anterior approach showed a lower incidence (2.3%) of SSI. Instrumented surgery had a higher incidence of SSI than noninstrumented surgery (4.4% vs. 1.4%). Patients with minimally invasive surgery (1.5%) had a lower SSI incidence than open surgery (3.8%). Lower incidence of SSI was found when vancomycin powder was applied locally during the surgery (1.9%) compared with those not used (4.8%). In addition, the rates of Staphylococcus aureus, Staphylococcus epidermidis, and methicillin-resistant Staphylococci in microbiological culture results were 37.9%, 22.7%, and 23.1%, respectively.

CONCLUSION

The pooled incidence of SSI following spine surgery was 3.1%. These figures may be useful in the estimation of the probability of SSI following spine surgery.

LEVEL OF EVIDENCE

3.