A review of the AATS guidelines for the prevention and management of sternal wound infections

Pecto-intercostal Fascial Plane Block: A Novel Technique for Analgesia in Patients with Sternal Dehiscence

ABSTRACT

Sternal wound complications following sternotomy need a multidisciplinary approach in high-risk postoperative cardiac surgical patients. Poorly controlled pain during surgical management of such wounds increases cardiovascular stress and respiratory complications. Multimodal analgesia including intravenous opioids, non-opioid analgesics, and regional anesthesia techniques, like central neuraxial blocks and fascial plane blocks, have been described. Pecto-intercostal fascial plane block (PIFB), a novel technique, has been effectively used in patients undergoing cardiac surgery. Under ultrasound (US) guidance PIFB is performed with the aim of depositing local anesthetic between two superficial muscles, namely the pectoralis major muscle and the external intercostal muscle. The authors report a series of five cases where US-guided bilateral PIFB was used in patients undergoing sternal wound debridement. Patients had excellent analgesia intraoperatively as well as postoperatively for 24 hours with minimal requirement of supplemental analgesia. None of the patients experienced complications due to PIFB administration. The authors concluded that bilateral PIFB can be effectively used as an adjunct to multimodal analgesia with general anesthesia and as a sole anesthesia technique in selected cases of sternal wound debridement.

Thorax support vest to prevent sternal wound infections in cardiac surgery patients-a systematic review and meta-analysis

OBJECTIVES

Midline sternotomy is the main surgical access for cardiac surgeries. The most prominent complication of sternotomy is sternal wound infection (SWI). The use of a thorax support vest (TSV) that limits thorax movement and ensures sternal stability has been suggested to prevent postoperative SWI.

METHODS

We performed a meta-analysis to evaluate differences in clinical outcomes with and without the use of TSV after cardiac surgery in randomized trials. The primary outcome was deep SWI (DSWI). Secondary outcomes were superficial SWI, sternal wound dehiscence, and hospital length of stay (LOS). A trial sequential analysis was performed. Fixed (F) and random effects (R) models were calculated.

RESULTS

A total of 4 studies (3820 patients) were included. Patients who wore the TSV had lower incidence of DSWI [odds ratio (OR) = F: 0.24, 95% confidence interval (CI), 0.13-0.43, P < 0.01; R: 0.24, 0.04-1.59, P = 0.08], sternal wound dehiscence (OR = F: 0.08, 95% CI, 0.02-0.27, P < 0.01; R: 0.10, 0.00-2.20, P = 0.08) and shorter hospital LOS (standardized mean difference = F: -0.30, -0.37 to -0.24, P < 0.01; R: -0.63, -1.29 to 0.02, P = 0.15). There was no difference regarding the incidence of superficial SWI (OR = F: 0.71, 95% CI, 0.34-1.47, P = 0.35; R: 0.64, 0.10, 4.26, P = 0.42). The trial sequential analysis, however, showed that the observed decrease in DSWI in the TSV arm cannot be considered conclusive based on the existing evidence.

CONCLUSIONS

This meta-analysis suggests that the use of a TSV after cardiac surgery could potentially be associated with a reduction in sternal wound complications. However, despite the significant treatment effect in the available studies, the evidence is not solid enough to provide strong practice recommendations.

Development of a risk score to predict occurrence of deep sternal dehiscence requiring operative debridement

OBJECTIVE

Severe deep sternal wound (DSW) complications after cardiac surgery are a source of cost, morbidity, and mortality. Our objective was to develop and validate a clinical risk score for predicting risk of DSW requiring operative bone debridement, the most severe form of sternal dehiscence.

METHODS

A retrospective review was conducted of patients who underwent open cardiac surgery at a single institution between October 2007 and March 2019. Primary outcome was DSW requiring sternal bone debridement. Potential risk factors were screened using Least Absolute Shrinkage and Selection Operator (LASSO) and significant covariates were included in a logistic regression prediction model. Interval validation was performed using 10-fold cross-validation. A novel sternal wound dehiscence risk score was derived from the relative parameterization estimates.

RESULTS

One hundred thirty-four of 8403 patients (1.6%) were identified as having a DSW. Female sex (odds ratio [OR], 2.75; 95% CI, 2.58-2.93), body mass index (OR, 1.0946; 95% CI, 1.09-1.09), percent glycated hemoglobin (OR, 1.31; 95% CI, 1.28-1.33), peripheral vascular disease (OR, 2.38; 95% CI, 2.2005-2.5752), smoking (OR, 1.66; 95% CI, 1.53-1.79) and elevated creatinine level (OR, 1.20; 95% CI, 1.18-1.22) were independent predictors of DSW. Patients were categorized as minimal risk (0%-1%), low risk (2%-3%), intermediate risk (4%-7%), and high risk (9%-64.0%) on the basis of risk score.

CONCLUSIONS

This risk stratification model for DSW requiring operative debridement might provide individualized estimates of risk, and guide counseling and potential risk mitigation strategies.

[Postoperative sternomediastinitis: morphology of lesion, treatment strategy]

OBJECTIVE

To analyze bone tissue damage at different stages of disease (El Oakley classification), treatment options for each clinical situation and results after each approach.

MATERIAL AND METHODS

There were 45 patients with wound complications after cardiac surgery between October 2022 and September 2023. Thirty-eight (84.4%) patients underwent CABG, 7 (15.6%) patients - heart valve or aortic surgery. Mean age of patients was 68.1±10.3 years. There were 35 men (77.8%) and 10 women (22.2%). The first type was found in 11 (24.5%) patients, type 2-3 - 19 (42.2%), type 4 - 4 (8.8%), type 5 - 11 (24.5%) patients.

RESULTS

Systemic inflammatory response syndrome was observed in 7 (36.8%) persons of the 1st group, 14 (73.7%) ones of the 2nd group, 4 (100%) patients of the 3rd group and 2 (18.2%) patients of the 4th group. C-reactive protein and procalcitonin increased in all patients with the highest values in groups 2 and 3. Redo soft tissue inflammation occurred in all groups after treatment. Mean incidence was 25%. Two (10.5%) patients died in the 2nd group and 1 (25%) patient in the 3rd group.

CONCLUSION

The modern classification of sternomediastinitis does not fully characterize severity of disease in a particular patient. Simultaneous debridement with wound closure demonstrates acceptable mortality (within 10%). The highest mortality rate was observed in patients with diffuse lesions of the sternum. Less aggressive treatment approaches are possible for stable anterior chest wall.

Co-Management Reduces Mortality in Post-Sternotomy Mediastinitis

Background: Post-sternotomy mediastinitis (PSM) is one of the most feared complications of cardiac surgery. The impact of a multidisciplinary management approach on this pathology is yet unknown. Patients and Methods: A multidisciplinary approach based on a co-management model (CMM) of care was initiated in January 2018 because of the incorporation of a hospitalist unit on a cardiac surgery department. An observational retrospective cohort study was designed to evaluate the impact of the CMM of care compared to the standard model (SM) of care in patients diagnosed with PSM. Our primary and secondary outcomes were survival time and treatment failure rate (two or more surgical procedures needed to solve PSM or PSM-related death), respectively. Data related to patient death date were collected from the Spanish National Death Index. A multivariable Cox regression model was created using those variables believed to be clinically relevant. Results: Ninety-one patients developed PSM from January 2010 to June 2020. Regarding the pre-operative clinical status, surgical procedure, and PSM severity, both groups had similar baseline characteristics. Patients were followed for a mean of 27.54 ± 30.5 months. A total of 60.3% of the SM group and 11.1% of the CMM group (p < 0.001) died. Treatment failure occurred in 53 patients (72.6%) in the SM group versus 7 (38.6%) in the CMM group (p = 0.007). The CMM independently reduced overall mortality (hazard ratio [HR], 0.11; 95% confidence interval [CI]. 0.01-0.83) and treatment failure rate (HR, 0.01; 95% CI, 0.001-0.183). Gram-positive bacterial infection (HR, 3.73; 95% CI, .6-8.3), and complete osteosynthesis material removal (HR, 0.47; 95% CI, 0.24-0.91) also influenced mortality in our model. Conclusions: A co-management care model reduced overall mortality in patients diagnosed with post-sternotomy mediastinitis.

Surgical Site Infection in Cardiac Surgery

Surgical site infections (SSIs) are one of the most significant complications in surgical patients and are strongly associated with poorer prognosis. Due to their aggressive character, cardiac surgical procedures carry a particular high risk of postoperative infection, with infection incidence rates ranging from a reported 3.5% and 26.8% in cardiac surgery patients. Given the specific nature of cardiac surgical procedures, sternal wound and graft harvesting site infections are the most common SSIs. Undoubtedly, DSWIs, including mediastinitis, in cardiac surgery patients remain a significant clinical problem as they are associated with increased hospital stay, substantial medical costs and high mortality, ranging from 3% to 20%. In SSI prevention, it is important to implement procedures reducing preoperative risk factors, such as: obesity, hypoalbuminemia, abnormal glucose levels, smoking and S. aureus carriage. For decolonisation of S. aureus carriers prior to cardiac surgery, it is recommended to administer nasal mupirocin, together with baths using chlorhexidine-based agents. Perioperative management also involves antibiotic prophylaxis, surgical site preparation, topical antibiotic administration and the maintenance of normal glucose levels. SSI treatment involves surgical intervention, NPWT application and antibiotic therapy.

Gram-negative bacteria as a cause of mediastinitis after cardiac surgery

PURPOSE OF REVIEW

Poststernotomy mediastinitis (PSM) remains a serious infection and is significantly associated with high morbidity, short-term and long-term mortality. Gram-negative bacteria (GNB) are an underestimated cause of PSM, and there is little information on the risk factors, prevention, diagnosis and management of GNB PSM.

RECENT FINDINGS

The pathogenesis of PSM is the result of a complex and multifactorial interplay between intraoperative wound contamination, host-related and surgical host factors but GNB are probably mostly translocated from other host site infections. GNB are frequent cause of PSM (18-38% of cases) and GNB PSM have shown to more frequently polymicrobial (20-44%). GNG PSM has shown to occur earlier than Gram-positive PSM. Early diagnosis is crucial to successful treatment. The management of PSM needs a combination of culture-directed antimicrobial therapy and an early extensive surgical debridement with either immediate or delayed closure of the sternal space. Antibiotic treatment choice and duration should be based on clinical evaluation, evolution of inflammatory markers, microbiological tests and imaging studies. Mortality has shown to be significantly higher with GNB PSM compared with other causes and the inappropriateness of initial antibiotic therapy may explain the worse outcome of GNB PSM.

SUMMARY

GNB PSM is usually undervalued in the setting of PSM and have shown to be a frequent cause of inappropriate treatment with adverse prognostic potential. There is a need for efforts to improve knowledge to prevent and adequately treat GNB PSM.