Surgical Site Infections in Pediatric Spine Surgery: Comparative Microbiology of Patients with Idiopathic and Nonidiopathic Etiologies of Spine Deformity

Surgical site infection in pediatric spinal fusion surgery revisited: outcome and risk factors after preventive bundle implementation

Background

Surgical site infections (SSI) contribute to significant morbidity, mortality, length of stay, and financial burden. We sought to evaluate the incidence and risk factors of surgical site infection following pediatric spinal fusion surgery in patients for whom standard perioperative antibiotic prophylaxis and preventive strategies have been implemented.

Methods

We conducted a retrospective study of children aged <18 years who underwent spinal fusion surgery from January 2017 to November 2021 at a quaternary academic pediatric medical center. Univariable analysis was used to evaluate associations between potential risk factors and SSI.

Results

Of 1111 patients, 752 (67.6%) were female; median age was 14.2 years. SSI occurred in 14 patients (1.3%). Infections were superficial incisional (n=2; 14.3%), deep incisional (n=9; 64.3%), and organ/space (n=3; 21.4%). Median time to SSI was 14 days (range, 8 to 45 days). Staphylococcus aureus and Escherichia coli were the most frequently-isolated bacteria. Potential risk factors for SSIs included low body weight (Odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-0.99, p=0.026), ASA classification of ≥3 (OR 24.53, 95%CI 3.20-188.22, p=0.002), neuromuscular scoliosis (OR 3.83, 95%CI 3.82-78.32, p<0.001), prolonged operative time (OR 1.56, 95%CI 1.28-1.92, p<0.001), prolonged anesthetic time (OR 1.65, 95%CI 1.35-2.00, p<0.001), administration of prophylactic antibiotic ≥60 minutes before skin incision (OR 11.52, 95%CI 2.34-56.60, p=0.003), and use of povidone-iodine alone for skin preparation (OR 5.97, 95%CI 1.27-28.06, p=0.024).

Conclusion

In the context of a robust bundle for SSI prevention; low body weight, ASA classification of ≥3, neuromuscular scoliosis, prolonged operative and anesthetic times, administration of prophylactic antibiotic ≥60 minutes before skin incision, and use of povidone-iodine alone for skin preparation increased the risk of SSI. Administration of prophylactic antibiotic within 60 minutes of skin incision, strict adherence to high-risk preventive protocol, and use of CHG-alcohol could potentially reduce the rate of SSI.

Does the Microflora of Surgery Site Infection Change After Prophylactic Use of Vancomycin Powder in the Spine Surgery

Study Design

Retrospective cohort study.

Objective

This study aimed to investigate the characteristics of microflora in patients with deep spinal surgical site infection (SSI) after prophylactic use of vancomycin powder (VP).

Methods

A retrospective analysis was performed on patients after spinal surgery. Patients were grouped according to whether VP use and only patients with deep SSI were included in this study. General information of the patients, the dose of vancomycin, bacterial culture results, drug sensitivity test results, and SSI treatment methods were recorded. The differences of microflora between the two groups were analyzed, and the sensitivity of bacteria in the +VP group to antibiotics was analyzed.

Results

The infection rate in the +VP group was 4.9% (56/1124) vs 6.3% (93/1476) in the No-VP group (P < 0.05). The proportion of Gram-positive bacteria (GPB) in the +VP SSIs was 55.4% vs.74.1% in the No-VP group (P < 0.05). The percentage of Gram-negative bacteria (GNB) in the +VP SSIs was 46.4% vs.30.1% in the No-VP group (P < 0.05). More dose of VP cannot decrease the SSI, but the proportion of GNB in VP >1g SSIs was higher (59.0% vs 32.4%, P < 0.05). In the +VP SSIs, all of the GNB cultured were sensitive to meropenem, and linezolid covered most of the GPB cultured.

Conclusion

Local use of vancomycin powder can reduce the incidence of SSI, but this may lead to changes in the bacterial flora. Once the SSI occurs, the case of GNB infection may be increased. The more dose of VP cannot decrease SSI but may increase the rate of GNB in the +VP SSIs. Once infections still occur after VP use, antibiotics covering GNB may be added. These findings may help guide choice of empiric antibiotics while awaiting culture data.

Use of Vancomycin Powder in Spinal Deformity Surgery in Cerebral Palsy Patients is Associated With Proteus Surgical Site Infections

PURPOSE

Surgical site infection (SSI) rates in pediatric spinal deformity surgery for cerebral palsy (CP) patients are higher than that in idiopathic scoliosis. The use of vancomycin powder is associated with decreased risk of SSI in neuromuscular patients. Prior studies in adult and pediatric early-onset scoliosis patients have shown that vancomycin powder alters microbacterial profile in patients that develop SSI. However, the effects of topical vancomycin powder on microbiology in spinal deformity surgery for CP patients has not been studied.

METHODS

An international multicenter database of CP neuromuscular scoliosis patients was used in this retrospective cohort study. All patients that underwent posterior spinal instrumented fusion for CP neuromuscular scoliosis from 2008 to 2019 were queried, and 50 cases complicated by postoperative SSI were identified. Intraoperative antibiotic details were documented in 49 cases (98.0%). Microbiology details were documented in 45 cases (91.8%). Microbiology for patients that received topical vancomycin powder were compared with patients that did not. A multivariate regression model was used to control for potential confounders.

RESULTS

There were 45 patients included in this study. There were 27 males (60.0%) and 18 females (40.0%). Mean age at surgery was 14.8±2.4 years. There were 24 patients that received topical vancomycin powder (53.3%). The mean time from index surgery to SSI was 4.3±11.3 months.On univariate analysis of microbiology cultures by vancomycin powder cohort, there were no significant differences in culture types. Proteus spp. trended on significance with association with vancomycin powder use (P=0.078). When controlling for potential confounders on multivariate analysis, intraoperative topical vancomycin powder was associated with increased risk for proteus infection (adjusted odds ratio: 262.900, 95% confidence interval: 1.806-38,267.121, P=0.028).

DISCUSSION

In CP patients undergoing pediatric spinal deformity surgery, the use of vancomycin powder was independently associated with increased risk for proteus infections. Further study into antibiotic regimens for spinal deformity surgery in the CP population should be performed.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Gram-Negative Surgical Site Infections After 989 Spinal Fusion Procedures: Associated Factors and the Role of Gram-Negative Prophylactic Antibiotic Coverage

BACKGROUND

To identify, analyze, and report the patient- and procedure-related factors associated with surgical site infection (SSI) after spinal fusion (SF) surgery.

METHODS

We included any SSI-SF from January 2013 to September 2015. A total of 989 spine surgeries that required instrumentation were performed.

RESULTS

Twenty-four out of 989 (2.43%) patients presented with SSI. More than half of the SSI cases (54%) got infected with either exclusively gram-negative bacteria or a combination of gram-negative and gram-positive bacteria; 9.1% of the surgeries involved the sacral spine (90 out of 989 patients). SSI in long constructs (more than 3 levels) was performed in 66.7% compared with 33.3% with short constructs; 87.5 % of the reported SSI (21 patients) were done through a posterior approach. Of patients who had SSI, 87.5% received prophylactic antibiotics, 92% were operated on during the daytime shift, 50% required blood transfusion, and 79% required surgical debridement. Four patients out of 24 patients died (17%) due to unrelated SSI complications.

CONCLUSIONS

The overall incidence of gram-negative infections after long SFs remains low in our study population. Despite this low overall incidence, our results demonstrate a relative higher incidence of gram-negative SSIs in surgeries involving more than 3 spinal levels and for all those involving the sacral spine. We propose that there may be a potential benefit of gram-negative prophylactic antibiotic coverage in patients falling in either 1 of these categories. Further multivariate analysis and/or randomized studies may be necessary to confirm our results.

LEVEL OF EVIDENCE

3.

Enhanced recovery after surgical correction of adolescent idiopathic scoliosis

BACKGROUND

Few publications in the literature examine enhanced recovery after scoliosis surgery (ERAS) in children, despite significant scientific interest in adults. The objective of the current study was to describe an ERAS protocol for surgical correction of adolescent idiopathic scoliosis (AIS) and its results.

METHODS

ERAS outcomes were measured in two patient cohorts. Historical controls and ERAS groups were selected from patients managed for scoliosis surgery in 2015 and 2018, respectively. The ERAS protocol included fasting minimization, carbohydrate loading, the avoidance of background morphine infusions, perioperative opioid-sparing protocols, the use of a cooling brace, early physiotherapy, feeding and oral medications, and the early removal of urinary catheters and surgical drains. The main outcome of the study was hospital length of stay.

RESULTS

Overall, 82 controls and 81 ERAS patients were recruited. ERAS protocols were observed in over 80% of patients for almost items. Median length of hospital stay was significantly lower in the ERAS group (- 3 [95% confidence interval: -2; -4] days). Median morphine consumption was reduced by 25% and 35% on days 2 and 3, respectively. The incidence of PONV did not differ between the two groups, and the incidence of constipation decreased slightly but significantly in the ERAS group on day 2. Pain intensity at rest and movement were lower in the ERAS group at day 2 and 3.

CONCLUSIONS

The current study suggests an ERAS protocol after adolescent idiopathic scoliosis surgery is associated with reduced hospital length of stay and improved postoperative care.

Implant Retention or Removal for Management of Surgical Site Infection After Spinal Surgery

STUDY DESIGN

A literature review.

OBJECTIVE

To summarize the implant removal rate, common bacterial organisms found, time of onset, ratio of superficial to deep infection, and regurgitating the prevalence among all the retrospective and prospective studies on management and characterization of surgical site infections (SSIs).

METHODS

PubMed was searched for articles published between 2000 and 2018 on the management or characterization of SSIs after spinal surgery. Only prospective and retrospective studies were included.

RESULTS

A total of 49 articles were found relevant to the objective. These studies highlighted the importance of implant removal to avoid recurrence of SSI. The common organisms detected were methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermis, Staphylococcus epidermis, Staphylococcus aureus, and Propionibacterium acnes, with prevalence of 1% to 15%. A major proportion of all were deep SSI, with minority reporting on late-onset SSI.

CONCLUSION

Long-term antibiotics administration, and continuous irrigation and debridement were common suggestion among the authors; however, the key measure undertaken or implied by most authors to avoid risk of recurrence was removal or replacement of implants for late-onset SSI.

Antibiotic prophylaxis in high-risk pediatric spine surgery: Is cefazolin enough?

STUDY DESIGN

Retrospective study.

OBJECTIVE

To describe pathogens found in SSI during pediatric-instrumented spine surgery, and to assess the relationship between pathogens and the etiology of the spinal deformity. Surgical site infection (SSI) after pediatric spine fusion is a well-known complication with incidence rates between 0.5 and 42%, associated with the patient underlying disorder. Pathogens involved in SSI seem to be related to patient characteristics, such as the etiology of the spinal deformity. GNB (gram-negative bacilli) are more frequent in neuropathic, muscular, and syndromic conditions. High-risk pediatric patients with a spine deformity undergoing instrumented surgery might benefit from receiving perioperative intravenous prophylaxis for GNB.

METHODS

We conducted a retrospective study at our tertiary-care pediatric hospital from January 2010 to January 2017. We reviewed records of all episodes of SSI that occurred in the first 12 months postoperatively. All patients who underwent instrumented spine surgery were included in this study.

RESULTS

We assessed 1410 pediatric-instrumented spine surgeries; we identified 68 patients with deep SSIs, overall rate of 4.8%. Mean age at instrumented spine surgery was 12 years and 9 months. Time elapsed between instrumented surgery and debridement surgery was 28.8 days. Cultures were positive in 48 and negative in 20. Of the 48 positive culture results, 41 (72%) were GNB, 12 (21%) gram-positive cocci (GPC), three (5%) gram-positive anaerobic cocci (GPAC), and one (2%) coagulase-negative staphylococci (CoNS). Of the 68 patients with primary SSIs, 46 were considered to have a high risk of infection, which reported GNB in 81%, GPC in 15%, GPAC in 2%, and CoNS in 2%.

CONCLUSION

Cefazolin prophylaxis covers GPC and CoNS, but GNB with unreliable effectiveness. Gram-negative pathogens are increasingly reported in SSIs in high-risk patients. Adding prophylaxis for GNB in high-risk patients should be taken into account when considering spine surgery.

LEVEL OF EVIDENCE

IV.

Is Cutibacterium acnes early surgical site infection rate related to the duration of antibiotic prophylaxis in adolescent idiopathic scoliosis surgery?

PURPOSE

Cutibacterium acnes (C. acnes) is a gram-positive anaerobic bacillus located in pilosebaceous glands, usually responsible for late postoperative surgical site infections (SSI). A recent study performed in our institution highlighted an unexpected emergence of C. acnes early SSI. One potential explanation was the change of the perioperative antibioprophylaxis (ATB) protocol, which switched from 48 h postoperative cefamandole to intraoperative only cefazoline. The aim of this study was therefore to investigate the influence of the ATB duration on the occurrence of C. acnes early SSI, by comparing the incidence rates during 3 consecutive ATB protocols.

METHODS

Between January 2007 and September 2017, all patients who underwent posterior fusion for AIS were retrospectively reviewed. Early C. acnes SSI were reported and compared between 3 periods, during which the ATB protocols were modified. January 2007-February 2012: Intraoperative Cefamandole continued 48 h (protocol 1) March 2012-August 2016: Single shot of intraoperative Cefazoline (protocol 2) September 2016-September 2017: Intraoperative Cefazoline continued 48 h (protocol 3).

RESULTS

Fifty-three early SSI (7.2%) were reported among the 732 posterior AIS fusions included. Global incidence of C. acnes infection was 2.9%. The incidence of C. acnes in early SSI increased from 0 to 4.9% between protocol 1 and 2, but was reduced to 1.7% with protocol 3.

CONCLUSIONS

Early C acnes SSI can be explained by the difficulty to eradicate this pathogen with current skin preparation procedures and some Beta-lactam antibiotics tolerance. Longer duration antibioprophylaxis is preferable to prevent from early C. acnes SSI.

Clinical Characteristics and Outcomes of Staphylococcus aureus Implant-associated Infections in Children

BACKGROUND

Staphylococcus aureus is a significant cause of implant-associated infections (IAIs). Data detailing the optimal treatment of IAIs are lacking in children. We describe the clinical features and outcomes of pediatric patients with S. aureus IAIs seen at Texas Children's Hospital.

METHODS

Patients and their isolates were identified from a S. aureus surveillance database from 2008 to 2016 in Houston, TX. Demographic and clinical data were collected retrospectively. Fisher's exact was used for statistical analysis.

RESULTS

Forty-five patients with 47 IAIs were identified. Most patients had an infected orthopedic implant: 22 (47%) spinal rods and 19 (40%) with other orthopedic hardware. Thirty (64%) IAIs developed within 90 days of implant placement. Six patients had polymicrobial infections and 3 patients were bacteremic. Of the 47 IAI isolates, 34 (72%) were methicillin-susceptible S. aureus (MSSA) and 13 (28%) were methicillin-resistant S. aureus. All children underwent surgical irrigation, debridement and antibiotic therapy. Of the 47 IAI episodes, 22 of the implants were removed at time of initial presentation, 7 implants had delayed removal, and 18 implants remained in place. Successful treatment was achieved in all patients with immediate implant removal (22/22) and in 83% of patients with implant retention (15/18), including 10 patients with early postoperative infections (<3 months) and 5 patients with late postoperative infections (>3 months). Four patients had recurrence of infection.

CONCLUSIONS

The majority of S. aureus IAIs were methicillin-susceptible S. aureus. All children with immediate implant removal and most children with retained implants were treated successfully with surgery and antibiotic therapy.

Surgical site infection following elective nonspinal paediatric orthopaedic surgery: a prospective review

The aim of this study was to determine the rate of surgical site infection (SSI) and the factors that predispose to it in children undergoing nonspinal orthopaedic surgery. Over a 6-month period, 326 children who underwent 334 nonspinal elective orthopaedic surgical procedures were prospectively reviewed for the development of surgical site infections. A total of 14 sites became infected, with an overall infection rate of 4.19%. All the infections were superficial, and the only causative organism detected was Staphylococcus aureus. Operating times longer than 1 h and surgical wounds greater than 10 cm in length were positively associated with SSIs. Although there were differences between male and females, type of admission, the use of prophylactic antibiotics, degree of wound contamination and the grades of surgeons, these differences were not statistically significant. The results of this prospective study provide valuable information that was not previously available to the practicing paediatric orthopaedic surgeon.

Does Staphylococcus aureus nasal decontamination affect the rate of early surgical site infection in adolescent idiopathic scoliosis surgery?

PURPOSE

Surgical site infection (SSI) is a main complication after adolescent idiopathic scoliosis (AIS) surgery. Nasal colonization with S. aureus is a known risk factor for developing nosocomial infections in cardiac surgery. However, the risk in orthopedic surgery remains unclear, especially in spine surgery. This study aims to report the efficacy of a preoperative nasal decontamination program in S. aureus carriers on the incidence of early SSI after AIS posterior surgery.

METHODS

Between January 2014 and July 2017, all AIS patients were screened preoperatively with nasal swabs and decontaminated if positive 5 days before surgery. Early SSI was identified, and microorganisms findings were analyzed within nasal carriage and compared to a previous series published before the decontamination program (2007-2011).

RESULTS

Among the 331 AIS posterior fusion performed during the study period, incidence of positive nasal swab was 23% (n = 75). Those were preoperatively decontaminated. In comparison with the period before the nasal decontamination program, incidence of S. aureus early SSI significantly decreased from 5.1 to 1.3%, p < 0.05. None of those S. aureus decontaminated patients had an early S. aureus SSI. In all cases of S. aureus infections, S. aureus nasal screening was negative with a mean delay of 315 days (± 115) before surgery, which was significantly different from the global cohort (104 days ± 67, p < 0.05).

CONCLUSIONS

Preoperative S. aureus nasal decontamination was associated with a significant decrease in S. aureus SSI. Optimal delay of nasal screening needs to be optimized in order to diagnose intermittent S. aureus carriers. These slides can be retrieved under Electronic Supplementary Material.

Postoperative Spinal Implant Infections in Children: Risk Factors, Characteristics and Outcome

BACKGROUND

Postoperative infection is a major complication of spinal surgery with implants. We aimed to identify risk factors for, and characteristics of, postoperative spinal infections in children.

METHODS

We performed a retrospective observational study of all children who underwent posterior spinal fusion with instrumentation in 2 referral hospitals in 2008-2013. Spinal infections were defined as local and/or general signs of infection that required surgical treatment in the early postoperative phase (ie, within 30 days). Data were collected on a standardized questionnaire from medical charts.

RESULTS

Of the 450 children who underwent spinal surgery, 26 (5.8%) were diagnosed with early postoperative spinal implant infection, with a median age of 14 years (interquartile range, 13-17) and a median delay of 13 days postsurgery (interquartile range, 7-18). Postoperative infection was more common in children with neurologic scoliosis as compared with idiopathic scoliosis (12.2% [15/123] versus 2.4% [5/211]; P < 0.01). Neurologic scoliosis was an independent predictor of spinal implant infections (hazard ratio, 3.87 [1.72-8.69]; P < 0.001). Main pathogens were Staphylococcus aureus (n = 14) and Enterobacteriaceae (n = 8). All children underwent early surgery (wound exploration, debridement and lavage) and antibiotics for a median duration of 19 weeks [interquartile range, 12-26]. Two children (7.7%) required a second surgery. Spinal implants could be retained in all, and no relapse occurred with a follow-up of ≥24 months after antibiotic discontinuation.

CONCLUSIONS

Postoperative spinal implant infection is not rare in pediatric patients, especially with neurologic scoliosis. Most children may be cured with implant retention if managed with early surgery followed by a 3-month course of appropriate antibacterial agents.

Predictive factors of intraoperative cell salvage during pediatric scoliosis surgery. Cell saver during scoliosis surgery in children

INTRODUCTION

Blood-saving strategy during spinal surgery in children often includes recombinant erythropoietin (rEPO) and antifibrinolytic therapapy (AFT). The aim of this study was to investigate the efficacy of intraoperative blood salvage in decreasing homologous blood transfusion.

MATERIAL AND METHODS

Using the prospective data from patients operated during a one year period for scoliosis correction, we calculate the predictable hematocrit at day postoperative 1 without the use of blood salvage and compare it to the target hematocrit transfusion according to patient's status. Predictors analyzed were: age, weight, surgical indication, Cobb's angle, ASA status, preoperative hemoglobin, number of level fused, sacral fusion and thoracoplasty. Statistical analyses were performed using a classification tree analysis.

RESULTS

This study included 147 patients. Blood salvage was estimated avoiding homologous blood transfusion in 17 patients. Predictors of the efficacy of blood salvage were: neuromuscular indications, number of level fused and BMI. Blood salvage was found totally ineffective in: patients with no neuromuscular diseases with either: surgeries interesting<13 levels fused or surgeries interesting>13 levels with a preoperative BMI ≥ 21. In all other cases, blood salvage can decrease homologous transfusion. The model exhibited 97% of accurate for the prediction if the inefficacy of blood salvage. The AUCROC of the model was 0.93 [95% confidence interval 0.9 to 0.99] and the overall validation was 60.1% of explained variability.

CONCLUSION

The present study indicates that blood salvage is ineffective under certain circumstances. More studies are mandatory to confirm these results.