Surgical debridement with retention of spinal instrumentation and long-term antimicrobial therapy for multidrug-resistant surgical site infections after spinal surgery: a case series

Surgical Site Infection After Posterior Stabilization of the Spine - When do we Have to Remove the Implants?

STUDY DESIGN

Retrospective data analysis.

OBJECTION

The primary objective of this investigation was to analyze if treatment of Postoperative surgical site infections (PSSI) after posterior stabilization of the spine (PS) without radiological signs of screw loosening (RSL) shows a sufficient success rate without implant removal and if there was any difference between early and late PSSI.

SUMMARY OF BACKGROUND DATA

PSSI after PS are usually treated by implant removal and reinstrumentation if loosening of one of more screws is detected. There is presently no conclusive data that shows the success rate of the treatment of PSSI after PS without implant removal if no RSL are perceived.

MATERIALS AND METHODS

All patients who were treated for a PSSI after PS without RSL in a single spine center from 12/2009 to 03/2020 were enrolled in a retrospective analysis. Patients were treated by revision surgery with debridement and irrigation and subsequent antibiotic therapy. Implant removal was performed if the initial treatment did not lead to an improvement in wound healing and normalization of laboratory values. Statistical analysis was performed by Statistical Package for the Social Sciences 25. Descriptive data are given as mean and standard error of mean, a χ 2 test was performed.

RESULTS

Of the 32 enrolled patients, 17 had an early PSSI, 15 a late PSSI. In 71.9% (23/32), the PSSI was treated without implant removal: 12/17 in early PSSI, 11/15 in late PSSI. The difference was not significant ( P >0.05). One patient died, all other patients were discharged from the hospital with no remaining laboratory signs of the infection and with closed soft tissues.

CONCLUSIONS

In our group of patients, the success rate of irrigation and debridement without implant removal was 71.9%. In the light of this data, performing at least two irrigations and debridement before implant removal seems to be a valid treatment option in PSSI after PS if there are no RSL in early and late PSSI.

Does Postoperative Spine Infection Bacterial Gram Type Affect Surgical Debridement or Antibiotic Duration?

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim was to evaluate differences in readmission rates, number of debridements, and length of antibiotic therapy when comparing bacterial gram type following lumbar spinal fusion infections.

SUMMARY OF BACKGROUND DATA

Surgical site infections (SSIs) after spinal fusion serve as a significant source of patient morbidity. It remains to be elucidated how bacterial classification of the infecting organism affects the management of postoperative spinal SSI.

METHODS

Patients who underwent spinal fusion with a subsequent diagnosis of SSI between 2013 and 2019 were retrospectively identified. Patients were grouped based on bacterial infection type (gram-positive, gram-negative, or mixed infections). Poisson regressions analyzed the relationship between the type of bacterial infection and the number of irrigation and debridement (I&D) reoperations, and the duration of intravenous (IV) antibiotic therapy. Significance was set at P <0.05.

RESULTS

Of 190 patients, 92 had gram-positive (G+) infections, 57 had gram-negative (G-) infections, and 33 had mixed (M) infections. There was no difference in 30 or 90-day readmissions for infection between groups (both P =0.051). Patients in the M group had longer durations of IV antibiotic treatment (G+: 46.4 vs. G-: 41.0 vs. M: 55.9 d, P =0.002). Regression analysis demonstrated mixed infections were 46% more likely to require a greater number of debridements ( P =0.001) and 18% more likely to require an increased duration of IV antibiotic therapy ( P <0.001), while gram-negative infections were 10% less likely to require an increased duration of IV antibiotic therapy ( P <0.001) when compared with G- infections.

CONCLUSION

Spinal SSI due to a mixed bacterial gram type results in an increased number of debridements and a longer duration of IV antibiotics required to resolve the infection compared with gram-negative or gram-positive infections.

LEVEL OF EVIDENCE

Level III.

Clinical Outcome of Postoperative Surgical Site Infection in Patients with Posterior Thoracolumbar and Lumbar Instrumentation

OBJECTIVE

Postoperative surgical site infection (SSI) is associated with greater rates of disability, especially in instrumented spinal surgeries. The management of implant-associated surgical site infections (SSI) is challenging. We analyzed the data from our hospital databases to assess the incidence and characteristics related to postoperative surgical site infection (SSI) after posterior thoracolumbar and lumbar instrumentation.

METHODS

Patient demographics, infection characteristics, details of treatment, and perioperative factors were reviewed (Jan 2010 to Dec 2020). The Oswestry disability index (ODI), Patient Health Questionnaire-9 (PHQ-9), and Visual Analog Scale (VAS) scores for back and leg pain were analyzed preoperatively and postoperatively until last follow-up.

RESULTS

Of the 27,881 procedures collected from the databases, 521 were diagnosed with SSI (1.8%), and 191(36.7%) received at least one revision surgery for SSI. Infection rate was significantly higher in patients with lumbar spinal stenosis than those with scoliosis or kyphosis (P<0.01). Methicillin-sensitive Staphylococcus aureus (43.4%) was the most commonly isolated pathogen. The rate of complication secondary to antibiotics treatment was 7.8%, and long-term antibiotic suppression was reported in 15.2% of patients. Instrumentation was retained in 175 patients (91.6%) and all SSIs were controlled without recurrence during the follow-up.

CONCLUSION

Analysis of 27,881 patients showed an average SSI rate of 1.8%. Patients with deep wound SSI can be successfully treated in most cases with retention of instrumentation. Early diagnosis, positive revision surgery with strict irrigation, thorough debridement, and a long-term course of antibiotics are critical for eradicating infection, retaining implants, decreasing morbidity, and achieving wound healing.

The use of novel knotless barbed sutures in posterior long-segment lumbar surgery: a randomized controlled trial

Background

The study carries the aim to compare the clinical efficacy and economic outcomes of using barbed suture closure versus conventional closure for wounds after posterior long-segment lumbar surgery.

Methods

One hundred and eighty-one patients undertaking posterior long-segment lumbar surgery participated in the prospective randomized controlled trial study to receive either barbed suture wound closure (n = 91) or conventional suture closure (n = 90). Outcome measures included operating room time (ORT), wound closure time, length of incision, length of hospital stay (LOS), 90-day readmission rates, wound complications of dehiscence and infection, and costs.

Results

Barbed suture group was related with significantly lower ORT (P = 0.036), wound closure time (P < 0.001) and average wound closure time (P < 0.001), and significantly lower wound complication rates (dehiscence and infection) (P = 0.031). No significant differences were found when compared with conventional suture group in terms of length of incision (P = 0.086), length of hospital stay (P = 0.174), readmission rates up to 90 days after the surgical procedure (P = 0.232) and costs (P = 0.205).

Conclusion

The study suggested the knotless barbed suture technique outperformed the conventional suture in shortening operating room time, wound closure time and average wound closure time, and reducing wound complication rates.

Trends in Reoperation for Surgical Site Infection After Spinal Surgery With Instrumentation in a Multicenter Study

STUDY DESIGN

A multicenter retrospective analysis of a prospectively maintained database.

OBJECTIVE

To examine the characteristics of reoperation for surgical site infection (SSI) after spinal instrumentation surgery, including the efficacy of treatment for SSI and instrumentation retention.

SUMMARY OF BACKGROUND DATA

Aging of the population and advances in surgical techniques have increased the demand for spinal surgery in elderly patients. Treatment of SSI after this surgery has the main goals of eliminating infection and retaining instrumentation.

METHODS

The subjects were 16,707 patients who underwent spine surgery with instrumentation in 11 hospitals affiliated with the Nagoya Spine Group from 2004 to 2015. Details of those requiring reoperations for SSI were obtained from surgical records at each hospital.

RESULTS

There were significant increases in the mean age at the time of surgery (54.6-63.7 years) and the number of instrumentation surgeries (726-1977) from 2004 to 2015. The incidence of reoperation for SSI varied from 0.9% to 1.8%, with a decreasing trend over time. Reoperation for SSI was performed in 206 cases (115 men, 91 women; mean age 63.2 years). The average number of reoperations (1.4 vs. 2.3, P < 0.05), time from SSI to first reoperation (4.3 vs. 9.5 days, P < 0.05), and the methicillin-resistant Staphylococcus identification rate (20% vs. 37%, P < 0.01) were all significantly lower in cases with instrumentation retention (n = 145) compared to those with instrumentation removal (n = 61).

CONCLUSION

There were marked trends of aging of patients and an increase in operations over the study period; however, the incidences of reoperation and instrumentation removal due to SSI significantly decreased over the same period. Rapid debridement after SSI diagnosis may have contributed to instrumentation retention. These results can serve as a guide for developing strategies for SSI treatment and for improved planning of spine surgery in an aging society.

LEVEL OF EVIDENCE

3.

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.

Consensus on the Role of Antibiotic Use in SSI Following Spinal Surgery

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 17 focused on the use of antibiotics in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Negative Pressure Wound Therapy Versus Closed Suction Irrigation System in the Treatment of Deep Surgical Site Infection After Lumbar Surgery

OBJECTIVE

We compared the efficacy of a closed suction irrigation system (CSIS) and negative pressure wound therapy (NPWT) for deep surgical site infection (SSI) after lumbar surgery with instrumentation.

METHODS

We included 31 patients (NPWT group, n =16; CSIS group, n = 15) with deep SSIs after lumbar surgery with instrumentation from 2007 to 2017. The medical records were reviewed and patient characteristics, laboratory results, infection details, and treatment interventions were recorded. The Japanese Orthopaedic Association score and Oswestry disability index were used to assess pain and functional outcomes preoperatively and 3 and 12 months postoperatively. The cost of SSIs were compared between the NPWT and CSIS groups.

RESULTS

No significant differences were found in the baseline characteristic data between the NPWT and CSIS groups. Implants were retained in all patients in the CSIS group, but required removal from 2 patients with late infections in the NPWT group. The average hospital stay was 36.8 ± 10.5 days and 33.4 ± 18.9 days in the NPWT and CSIS groups, respectively. The cost was greater in the NPWT group than in the CSIS group. Both NPWT and CSIS significantly reduced the Oswestry disability index and improved the Japanese Orthopaedic Association scores, but no significant difference was found between the 2 groups.

CONCLUSIONS

Our results have shown that both NPWT and CSIS are efficient techniques for the management of deep SSI after lumbar surgery with instrumentation. CSIS was more economical and the NPWT system was portable and easier for postoperative nursing care.

The Use of Vacuum Dressings for Dead Space Management in Deep Surgical Site Infections Allows Implant and Bone Graft Retention

STUDY DESIGN

Retrospective, descriptive study.

OBJECTIVES

Managing early surgical site infection following elective lumbar spine surgery remains a challenge with controversy regarding retention of instrumentation and bone graft. Wound closure may also pose considerable challenges. We aim to report on our method of managing deep surgical site infections complicating elective spine surgery with surgeon assembled deep vacuum dressings. Identification of causative organisms with their sensitivities was a secondary objective.

METHODS

Patients were identified from a prospectively maintained, single-surgeon database from 2003-2015. Patients who had an infective or trauma related diagnosis, cervical procedures, and were younger than 18 years were excluded. Records were reviewed to identify bacteriology, laboratory tests performed, antibiotics administered, and type and frequency of surgical management. One thousand two hundred twenty patients qualified for inclusion, with 19 identified as having developed acute wound sepsis.

RESULTS

All patients had surgical debridement on the day of presentation and the majority of wounds were managed with a vacuum dressing. In all but 1 patient was instrumentation retained. Specimens for culture were taken at each debridement and antibiotics changed accordingly. Patients received a minimum 6 weeks of antibiotics.

CONCLUSIONS

The management of deep surgical site infection is labor intensive and frustrating for both surgeon and patient due to the unexpected prolonged admission. Management goals are identification and eradication of the causative organism with subsequent healing of the surgical wound. This process is enhanced with the use of negative-suction dressings made from theatre stock replaced at regular intervals and allows retention of bone graft and instrumentation in the majority of cases.

Molecular Characteristics of Methicillin-Resistant Staphylococcus epidermidis on the Abdominal Skin of Females before Laparotomy

Staphylococcus epidermidis, especially methicillin-resistant strains, may be the source of surgical site infections and may be a reservoir of staphylococcal cassette chromosome mec (SCCmec) for S. aureus. The aim of this study was to investigate the prevalence of methicillin-resistant S. epidermidis (MRSE) on the abdominal skin of females before laparotomy and determine the molecular characteristics and antimicrobial susceptibility patterns of these isolates. MRSE was found in 54 of 157 isolates based on mecA gene detection, and there was no difference in icaA gene carriage rate between MRSE and methicillin-susceptible S. epidermidis (MSSE) isolates. Antimicrobial susceptibility profiles were determined by broth microdilution antimicrobial susceptibility testing according to the latest CLSI manuals. All MRSE isolates had unfavorable antimicrobial susceptibility patterns. Twenty-three MRSE strains (42.6%) were multi-drug resistant. SCCmec typing and pulsed field gel electrophoresis (PFGE) typing was performed. Thirty-nine (72.2%) had a single SCCmec type, whereas 1.9% had two types. Fourteen strains (25.9%) were non-typeable (NT). The most frequent MRSE genotype was SCCmec type IVa. High diversity with PFGE patterns was obtained for MRSE, and there were no isolates exhibiting identical pulsotype. The results confirm that methicillin-resistant strains are frequently present among S. epidermidis on the abdominal skin of females before laparotomy. Moreover, resistance profiles seem to have no association with the SCCmec types or PFGE types for most common antibiotics.