Risk factors for post sternotomy wound complications across the patient journey: A systematised review of the literature

BACKGROUND

Around 36,000 cardiac operations are undertaken in the United Kingdom annually, with most procedures undertaken via median sternotomy. Wound complications occur in up to 8% of operations, with an associated mortality rate of around 47% in late or undetected cases.

OBJECTIVE

To undertake a systematised literature review to identify pre-operative, peri-operative and post-operative risk factors associated with sternal wound complications.

METHODS

Healthcare databases were searched for articles written in the English language and published between 2013 and 2021. Inclusion criteria were quantitative studies involving patients undergoing median sternotomy for cardiac surgery; sternal complications and risk factors.

RESULTS

1360 papers were identified, with 25 included in this review. Patient-related factors included: high BMI; diabetes; comorbidities; gender; age; presenting for surgery in a critical state; predictive risk scores; vascular disease; severe anaemia; medication such as steroids or α-blockers; and previous sternotomy. Peri-operative risk increased with specific types and combinations of surgical procedures. Sternal reopening was also associated with increased risk of sternal wound infection. Post-operative risk factors included a complicated recovery; the need for blood transfusions; respiratory complications; renal failure; non-diabetic hyperglycaemia; sternal asymmetry and sepsis.

CONCLUSION

Pre, peri and post-operative risk factors increase the risk of sternal wound complications in cardiac surgery. Generic risk assessment tools are primarily designed to provide mortality risk scores, with their ability to predict risk of wound infection questionable. Tools that incorporate factors throughout the operative journey are required to identify patients at risk of surgical wound infection.

Comparative Evaluation on Impacts of Fibronectin, Heparin-Chitosan, and Albumin Coating of Bacterial Nanocellulose Small-Diameter Vascular Grafts on Endothelialization In Vitro

In this study, we contrast the impacts of surface coating bacterial nanocellulose small-diameter vascular grafts (BNC-SDVGs) with human albumin, fibronectin, or heparin–chitosan upon endothelialization with human saphenous vein endothelial cells (VEC) or endothelial progenitor cells (EPC) in vitro. In one scenario, coated grafts were cut into 2D circular patches for static colonization of a defined inner surface area; in another scenario, they were mounted on a customized bioreactor and subsequently perfused for cell seeding. We evaluated the colonization by emerging metabolic activity and the preservation of endothelial functionality by water soluble tetrazolium salts (WST-1), acetylated low-density lipoprotein (AcLDL) uptake assays, and immune fluorescence staining. Uncoated BNC scaffolds served as controls. The fibronectin coating significantly promoted adhesion and growth of VECs and EPCs, while albumin only promoted adhesion of VECs, but here, the cells were functionally impaired as indicated by missing AcLDL uptake. The heparin–chitosan coating led to significantly improved adhesion of EPCs, but not VECs. In summary, both fibronectin and heparin–chitosan coatings could beneficially impact the endothelialization of BNC-SDVGs and might therefore represent promising approaches to help improve the longevity and reduce the thrombogenicity of BNC-SDVGs in the future.

How to build a multi-arterial coronary artery bypass programme: a stepwise approach

Observational evidence shows that the use of multiple arterial grafts (MAG) is associated with longer postoperative survival and improved clinical outcomes. The current European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines on myocardial revascularization recommend the use of MAG in appropriate patients. However, a significant volume-to-outcome relationship exists for MAG, and lack of sufficient experience is associated with increased operative risk. A stepwise approach to building experience with MAG allows successful implementation of this technique into routine coronary surgery practice.

Bilateral internal thoracic artery use in coronary artery bypass grafting in the post-ART era - Perspective

There is still lack of convincing evidence about the superiority of bilateral internal thoracic artery (BITA) use in coronary artery bypass grafting (CABG) and BITA grafts continue to be underutilized. Arterial Revascularization Trial (ART) did not demonstrate the superiority of BITA versus single ITA grafting after 10 years. We have reviewed the most recent literature, assessed the current status as well as indications of BITA grafting in the post-ART era. We believe that BITA grafting is not appropriate for all patients especially in light of the findings of ART. However, the use of BITA is justified in patients of younger age and those without comorbidities (poorly controlled diabetes, obesity, chronic obstructive pulmonary disease, previous mediastinal irradiation, long-term steroid use, elderly women). Further prospective randomized studies with long-term follow-up are needed to validate the benefits of BITA grafting.

Sternal wound closure in the current era: the need of a tailored approach

OBJECTIVE

Median sternotomy remains the most common access to perform cardiac surgery procedures. However, the experience of the operating surgeon remains a crucial factor during sternal closure to avoid potential complications related to poor sternal healing, such as mediastinitis. Considering the lack of major randomized controlled trials and the heterogeneity of the current literature, this narrative review aims to summarize the different techniques and approaches to sternal closure with the aim to investigate their reflections into clinical outcomes and to inform the choice on the most effective closure method after median sternotomy.

METHODS

A literature search through PubMed, Embase, EBSCO, Cochrane database of systematic reviews, and Web of Science from its inception up to April 2019 using the following search keywords in various combinations: sternal, sternotomy, mediastinitis, deep sternal wound infection, cardiac surgery, closure.

RESULTS

Single wire fixation methods, at present, seems the most useful method to perform sternal closure in routine patients, although patients with a fragile sternum might benefit more from a figure-of-eight technique. In high-risk patients (e.g. chronic pulmonary disease, obesity, bilateral internal mammary artery harvesting, diabetes, off-midline sternotomy), rigid plate fixation is currently the most effective method, if available; alternatively, weave techniques could be used.

CONCLUSION

The choice among the sternal closure techniques should be mainly inspired and tailored on the patient's characteristics, and correct judgement and experience play a pivotal role. A decisional algorithm has been proposed as an attempt to overcome the absence of specific guidelines and to guide the operative approach. This operative approach might be used also in non-cardiac procedure in which median sternotomy is required, such as in case of thoracic surgery.