European Journal of Cardiovascular Medicine

Deep sternal wound infection (DSWI) following median sternotomy is a life-threatening complication after this approach for coronary artery bypass grafting (CABG). 1 2 Most of the patients who undergo CABG have associated morbidities such as diabetes mellitus resulting in delayed wound healing. The incidence of sternal wound infections and dehiscence is reported between 0.2 and 10% among patients who undergo sternotomy and mortality of 5 to 20% following sternal dehiscence. 3 The use of bilateral internal mammary arteries (BIMA) for revascularization has been shown to improve graft patency rates and help in reduction of repeated episodes of angina in comparison to the usage of a single internal mammary artery (IMA). 4 5 6 The extensive use of BIMAs precludes a higher incidence of DSWI associated with sternal devascularization. 7 8 This is of concern in patients with predisposing factors such as diabetes, obesity, chronic pulmonary obstructive disease, or diffuse arteriopathy. 9 10 11 12 When DSWI develops, the cardiac surgeons use conventional methods such as wound debridement, rewiring or plating, and closure with or without negative pressure wound therapy (NPWT). In contrast, when these patients are referred to plastic surgeons they are treated with debridement and closure with various flaps. 13 A recent review article by Schiraldi et al advocated flap cover in cases of chronic DSWI should not be delayed for more than 2 weeks after NPWT. 14 In this study, we aim to review our cases of DSWI with respect to their time of referral to a plastic surgical unit and study the correlation between the time of referral to the outcomes.

An observational (retrospective) study was conducted in the Department of plastic surgery in a superspeciality hospital in Central India. The data of the patients from the from January 2023 to December 2024, were retrieved and assessed.

The data was obtained from the electronic medical records of the patients from the hospital database that included demographic data, dates of CABG, dates of presentation of DSWI, and referral to the plastic surgical unit. We defined less than or equal to 15 days from the presentation as an early referral and more than 15 days as a late referral. This was an arbitrary value as there is no mention of cutoff value for time of referral in the literature. Both the groups were compared with respect to the age, gender distribution, classification as per Jones’ criteria, 15 delay in wound healing, presence of microorganisms in wound swab culture, number of NPWT changes, duration between presentation to definitive management, duration between definitive surgery and discharge, choice of a flap, number of flaps, duration from plastic surgery referral to discharge, early and late postoperative course, and postoperative complications and mortality. Institutional Ethics Committee permission was obtained before commencing the study.

A total of 12 cases were analyzed after taking informed consent telephonically from the patient, wherever available. Wounds were classified as per the Jones’ classification:

Table 1 showing Jones and Jurkiewicz et al classification of sternal wound infections.

Inclusion criteria : All patients who underwent CABG through a median sternotomy approach, who had DSWI (types 2A, 2B, 3A, 3B), and who underwent a plastic surgery procedure.

Exclusion criteria: Patients having superficial sternal wound infections (types 1A and 1B), or who underwent any other cardiac procedure other than CABG, and patients lost to follow-up were not included in the study.

All patients with DSWI were assessed with a three-dimensional computed tomography of the thorax, the microbiological culture of the wounds, and routine hematological evaluation and C-reactive protein levels. All patients underwent radical debridement under general anesthesia and specimen of bone and tissue were sent for aerobic, anaerobic, and fungal cultures. Any hardware used for sternal stabilization was removed. Nonadherent dressing with paraffin gauze was applied if the heart was exposed 16 17 followed by NPWT. The set pressure of –75 mm Hg was used when the cardia was not exposed, and –50 mm Hg in exposed cardia. 2 The patients underwent repeat debridement under general anesthesia if deemed necessary during the change of NPWT foam.

Definitive closure was done after all visible necrotic tissue or slough was cleared. In certain cases, the sternum was stable with approximable edges, in which case rewiring was done. As per the wound size, it was decided to do a unilateral pectoralis major muscle advancement flap, bilateral pectoralis major muscle advancement flaps, omental flap, or a combination of both flaps. The pectoralis major muscle advancement flap was done by the technique described previously by the authors. 18 If the defect was large, the omental flap was used as well. After the patient was referred to the plastic surgery unit, our approach was aggressive in terms of radical debridement and early flap cover preferably after one to two sessions of NPWT. The average time between referral to flap was 8 days (range: 5–14).

Statistical Analysis

Data was analyzed using the R statistical software. Both the groups were compared with respect to the demographics. Quantitative data was expressed in median and interquartile range (minimum–maximum). Fisher's exact test was applied to find the association. The p -value < 0.05 was considered as statistically significant.

The data of 12 patients who had DSWI out of 36 patients who underwent median sternotomy for CABG was collected. Out of them, 8 patients underwent definitive plastic surgery management with flap cover. 3 patients required multistage debridement and delayed closure, while only 1 patients could undergo single-stage debridement and immediate closure. The age distribution was comparable in both the early and late groups with a slight male preponderance in the late group. As per the Jones’ classification type 2B was the commonest and the distribution of severity of cases was found to be similar in both the groups. No association was found between the presence or absence of diabetes as a preexisting comorbidity ( p -value = 0.19). No association was found between the usage of BIMA during CABG ( p -value = 0.79).

The delay in wound healing was defined as the inability of the wound to heal completely by the end of 2 weeks from the time of definitive closure. The patients who could not undergo definitive closure or who died soon after closure were excluded only from the analysis of delayed wound healing. There was no difference in outcome of early versus late referral ( Table 2 ). Both the early and late referral groups were compared as per the following variables such as presence of microorganisms, duration from definitive surgery to discharge, postoperative complications, number of NPWT changes before definitive closure, mortality, presentation to definitive surgery, duration from plastic referral to discharge, number of flaps, presence of microorganisms in bone culture, postoperative shoulder movement, postoperative scar, and the number of cardiothoracic procedures before plastic surgery referral ( Table 3 ). But time of referral has affected the total duration of wound healing as average duration of treatment of DSWI in early and late groups were 16.58 and 89.36 days, respectively (excluding the earlier outlier 5,088 days). The number of procedures done by the cardiothoracic team (resuturing, rewiring, and local debridement with NPWT in both the groups before referral to the plastic surgery unit) is significant ( p = 0.001) and has delayed overall duration of wound healing. The rest of the variables that were compared in both the groups did not show significant differences ( Table 3 ). In our series, 91% patients reported unrestricted shoulder movement. Statistically significant difference was not found in the two groups with respect to postoperative complications. However, the odds ratio of 1.39 shows that late referral leads to 30% increased chances of prolonged hospital stay (> 7 days), though statistically not significant ( Table 4 ).

Table 2. Correlation of time of referral to the delay in wound healing.

Table 3. Effect of early versus late referral on various variables.

Table 4. Effect of early versus late referral on key outcomes.

The approach of cardiac surgeons and plastic surgeons to DSWI differs drastically. 19 The traditional approach of cardiac surgeons has been sternal debridement, rewiring, and closed drainage as opposed to the plastic surgeons’ approach that is more radical with aggressive debridement and definitive closure with flaps. According to Brandt and Alvarez, 19 the first-line treatment of DSWI showed better outcomes through a plastic surgical strategy than those achieved by the traditional approach of cardiac surgeons. In our study, both the early and late referral groups had similar outcomes with respect to the total treatment duration after their referral to the plastic surgery unit. This is due to the fact that in both groups, the treatment offered by plastic surgeons was radical debridement and early flap cover.

A similar study comparing immediate versus delayed one-stage sternal debridement and pectoralis major muscle flaps was done by Cabbabe and Cabbabe. 20 Delayed group consisted of 14.8% patients who underwent multiple procedures by the cardiothoracic team for sternal infection and were referred to plastic surgery for sternal dehiscence and persistent infection after 22 to 63 days of an established DSWI diagnosis. The immediate group had 85.2% patients who were seen by a plastic surgeon within 4 days of the diagnosis. The plastic surgical management was a one-step debridement and bilateral pectoral muscle flap reconstruction. In our series, it was not possible to close the wound immediately.

In the series by Ringelman et al, 21 the pectoralis major was used as either a transposition flap or a reverse turnover flap that needed extensive dissection and caused denervation, leading to cosmetically unacceptable bulges, impairing the normal shoulder functioning and required other modality for complete wound coverage. Fifty-one percent of patients complained of persistent pain, 33% had shoulder weakness, and 25% had unacceptable cosmetic result. Ascherman et al 22 and Scully et al 23 have reported great results after usage of pectoralis major flaps and omental flap at 2 and 3 years, respectively. In our series, 83% patients reported unrestricted shoulder movement and 85% reported cosmetically acceptable scars. The striking difference in the study by Ringelman et al and all the other studies including ours was that they have used a transposition or a turnover flap, whereas we have used advancement and double breasting flaps, 18 based on the thoracoacromial pedicle. Since the plane of the muscle is same in the advancement flap, there are no bulges associated, resulting in better functionally and cosmesis in our series.

In our study, time of referral has affected the total duration of wound healing as average duration of treatment of DSWI in early and late groups were 16.58 and 89.36 days, respectively (excluding the earlier outlier 5,088 days). The number of procedures done by the cardiothoracic team (resuturing, rewiring, and local debridement with NPWT in both the groups before referral to the plastic surgery unit) is significant ( p = 0.001) and has delayed overall duration of wound healing. The rest of the variables that were compared in both the groups did not show significant differences ( Table 3 ). In our series, 91% patients reported unrestricted shoulder movement. Statistically significant difference was not found in the two groups with respect to postoperative complications. However, the odds ratio of 1.39 shows that late referral leads to 30% increased chances of prolonged hospital stay (> 7 days), though statistically not significant.

In other studies where deaths were caused, after the first episode, they started using paraffin impregnated gauze dressing as an interface between the NPWT foam and the exposed heart to reduce the negative pressure. 24 The reasons that could have caused serious bleeding during NPWT are infectious erosion 16 25 26 or a displacement of the heart toward or in between the sternal edges 27 and fibrous adherence of the right ventricle (RV) to the sternum. 28

Even if the patients are referred late to a plastic surgical unit, aggressive and radical debridement, judicious use of NPWT, and early definitive flap cover are the key to managing this life-threatening condition. Hence, we have proposed aggressive treatment protocol for management of DSWI. 29 In patients with positive bone culture, the intravenous antibiotics are continued for 6 weeks. 2

The patients who were referred late to us were treated by cardiac team per the traditional conservative approach (resuturing, rewiring and NPWT). This was a significant factor in both the groups in our series. The plastic surgical approach was more aggressive and radical with removal of all the hardware and nonviable bone. Delay in referral to plastic surgery unit after onset of symptoms of DSWI increased the total duration of wound healing, thereby increasing the overall morbidity. With our aggressive approach of early flap cover, we did not find any significant difference in the other variables such as presence of microorganisms, duration from definitive flap surgery to discharge, postoperative complications, number of NPWT changes before definitive closure, mortality, duration from plastic referral to discharge, number of flaps, presence of microorganisms in bone culture, postoperative shoulder movement, and postoperative scars in both early and late referral groups. Late presentation had equally better outcome contrary to general belief that mortality will be higher in late referral group. Hence, we conclude that despite late referral, with good technique and methodological approach, we were able to achieve similar outcomes as early referral. However, early reference could lead to highly significant reduction in total duration of hospital stay and wound healing.

As seen in the study, procedures done by cardiothoracic team for DSWI ( p = 0.001) only prolonged total recovery time and did not give additional benefits in terms of early wound healing. Although the statistical difference between outcomes of early and late cases managed by plastic surgeons after referral to them is not significant in terms of mortality or post-flap cover functionality, delayed wound healing, and postoperative complications, yet an early reference could lead to highly significant reduction in total duration of hospital stay, wound healing, and costs. Early referral of post-CABG DSWI to plastic surgeons by the cardiothoracic surgeons is highly recommended.

Human subjects: Consent was obtained or waived by all participants in this study. Aryabhatta Knowledge University, issued approval 280/22. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue.

1. Pan L, Mo R, Zhou Q, Wang D. Deep sternal wound infection after cardiac surgery in the Chinese population: a single-centre 15-year retrospective study. J Thorac Dis. 2017;9(09):3031–3037.
2. Immer F F, Durrer M, Mühlemann K S, Erni D, Gahl B, Carrel T P. Deep sternal wound infection after cardiac surgery: modality of treatment and outcome. Ann Thorac Surg. 2005;80(03):957–961.
3. Landes G, Harris P G, Sampalis J S et al. Outcomes in the management of sternal dehiscence by plastic surgery: a ten-year review in one university center. Ann Plast Surg. 2007;59(06):659–666.
4. Stevens L M, Carrier M, Perrault L P et al. Single versus bilateral internal thoracic artery grafts with concomitant saphenous vein grafts for multivessel coronary artery bypass grafting: effects on mortality and event-free survival. J Thorac Cardiovasc Surg. 2004;127(05):1408–1415.
5. Berreklouw E, Rademakers P P, Koster J M. van Leur L, van der Wielen BJW, Westers P. Better ischemic event-free survival after two internal thoracic artery grafts: 13 years of follow-up. Ann Thorac Surg. 2001;72(05):1535–1541.
6. Sahasrabudhe P, Jagtap R, Jadhav A, Panse N, Juvekar N, Patwardhan S. Audit of 37 cases of deep sternal wound infections (DSWIs) following 2418 coronary artery bypass graftings (CABGs) Indian J Thorac Cardiovasc Surg. 2016;32(02):103–112.
7. Arnold M. The surgical anatomy of sternal blood supply. J Thorac Cardiovasc Surg. 1972;64(04):596–610.
8. Seyfer A E, Shriver C D, Miller T R, Graeber G M. Sternal blood flow after median sternotomy and mobilization of the internal mammary arteries. Surgery. 1988;104(05):899–904.
9. Ottino G, De Paulis R, Pansini S et al. Major sternal wound infection after open-heart surgery: a multivariate analysis of risk factors in 2,579 consecutive operative procedures. Ann Thorac Surg. 1987;44(02):173–179.
10. Kouchoukos N T, Wareing T H, Murphy S F, Pelate C, Marshall W G., Jr Risks of bilateral internal mammary artery bypass grafting. Ann Thorac Surg. 1990;49(02):210–217.
11. Loop F D, Lytle B W, Cosgrove D M et al. J. Maxwell Chamberlain memorial paper. Sternal wound complications after isolated coronary artery bypass grafting: early and late mortality, morbidity, and cost of care. Ann Thorac Surg. 1990;49(02):179–186.
12. Grossi E A, Esposito R, Harris L J et al. Sternal wound infections and use of internal mammary artery grafts. J Thorac Cardiovasc Surg. 1991;102(03):342–346.
13. Sachithanandan A, Nanjaiah P, Nightingale P et al. Deep sternal wound infection requiring revision surgery: impact on mid-term survival following cardiac surgery. Eur J Cardiothorac Surg. 2008;33(04):673–678.
14. Schiraldi L, Jabbour G, Centofanti P et al. Deep sternal wound infections: Evidence for prevention, treatment, and reconstructive surgery. Arch Plast Surg. 2019;46(04):291–302.
15. Jones G, Jurkiewicz M J, Bostwick J et al. Management of the infected median sternotomy wound with muscle flaps. The Emory 20-year experience. Ann Surg. 1997;225(06):766–776.
16. van Wingerden J J, Segers P, Jekel L. Major bleeding during negative pressure wound/V.A.C.®–therapy for postsurgical deep sternal wound infection–a critical appraisal. J Cardiothorac Surg. 2011;6:121.
17. Gustafsson R I, Sjögren J, Ingemansson R. Deep sternal wound infection: a sternal-sparing technique with vacuum-assisted closure therapy. Ann Thorac Surg. 2003;76(06):2048–2053.
18. Sahasrabudhe P, Jagtap R, Waykole P, Panse N, Bhargava P, Patwardhan S. Our experience with pectoralis major flap for management of sternal dehiscence: a review of 25 cases. Indian J Plast Surg. 2011;44(03):405–413.
19. Brandt C, Alvarez J M. First-line treatment of deep sternal infection by a plastic surgical approach: superior results compared with conventional cardiac surgical orthodoxy. Plast Reconstr Surg. 2002;109(07):2231–2237.
20. Cabbabe E B, Cabbabe S W. Immediate versus delayed one-stage sternal débridement and pectoralis muscle flap reconstruction of deep sternal wound infections. Plast Reconstr Surg. 2009;123(05):1490–1494.
21. Ringelman P R, Vander Kolk C A, Cameron D, Baumgartner W A, Manson P N. Long-term results of flap reconstruction in median sternotomy wound infections. Plast Reconstr Surg. 1994;93(06):1208–1214.
22. Ascherman J A, Hugo N E, Sultan M R, Patsis M C, Smith C R, Rose E A.Single-stage treatment of sternal wound complications in heart transplant recipients in whom pectoralis major myocutaneous advancement flaps were used J Thorac Cardiovasc Surg 1995110(4 Pt 1)1030–1036.
23. Scully H E, Leclerc Y, Martin R D et al. Comparison between antibiotic irrigation and mobilization of pectoral muscle flaps in treatment of deep sternal infections. J Thorac Cardiovasc Surg. 1985;90(04):523–531.
24. Jones S M, Banwell P E, Shakespeare P G. Interface dressings influence the delivery of topical negative-pressure therapy. Plast Reconstr Surg. 2005;116(04):1023–1028.
25. Grauhan O, Navarsadyan A, Hussmann J, Hetzer R. Infectious erosion of aorta ascendens during vacuum-assisted therapy of mediastinitis. Interact Cardiovasc Thorac Surg. 2010;11(04):493–494.
26. Petzina R, Malmsjö M, Stamm C, Hetzer R. Major complications during negative pressure wound therapy in poststernotomy mediastinitis after cardiac surgery. J Thorac Cardiovasc Surg. 2010;140(05):1133–1136.
27. Malmsjö M, Petzina R, Ugander M et al. Preventing heart injury during negative pressure wound therapy in cardiac surgery: assessment using real-time magnetic resonance imaging. J Thorac Cardiovasc Surg. 2009;138(03):712–717.
28. Abu-Omar Y, Naik M J, Catarino P A, Ratnatunga C. Right ventricular rupture during use of high-pressure suction drainage in the management of poststernotomy mediastinitis. Ann Thorac Surg. 2003;76(03):974–975.
29. Sahasrabudhe P, Shankhadhar V K, Langer V. Chest wall reconstruction. In: Agarwal K, ed. Textbook of Plastic, Reconstructive and Aesthetic Surgery, Vol IV. New Delhi: Thieme. 2019:1–36.