Negative Pressure Wound Therapy in Surgical Site Infections of Sternotomy Wounds – A Case Series Study in Neonates and Infants

The surgical site infections (SSIs) following midline sternotomy incisions for congenital heart disease repair surgeries are associated with higher mortalities and morbidities. Due to advancements in the field of wound care, however, there has been a gradual reduction in these rates.¹ Over the years, SSIs have been managed through the use of several methods, including secondary healing achieved by daily dressing changes and antibiotic irrigations; in some cases, surgical debridement, direct closure, and flap covers have been used. The successful use of negative pressure (NP) therapy following a thorough surgical debridement is also well established for the management SSIs of sternotomy wounds in adults.² This case series study further highlights the importance and benefits of incorporating NP therapy in the management of SSIs of sternotomy wounds in neonatal and infant groups following cardiac surgery.

This case series includes 3 patients with congenital heart disease who were treated in our department from August 2022 to December 2022 and developed SSIs of sternotomy incisions after cardiac surgery (Table 1). All patients were initially treated by the operating pediatric cardiothoracic vascular (CTV) surgeon before the patients were referred to our department for further management. Two patients were neonates at the time of presentation, and 1 patient was approximately 5 weeks old. The referring CTV surgeon initially treated all 3 patients for sternal wound dehiscence; postoperatively, sepsis developed in 1 patient who required ventilator care and underwent multiple sittings of debridement and secondary suturing by the CTV surgical team before the case was referred to our department. 

After arriving at our department, all patients underwent thorough surgical debridement with removal of sternal wires. The surgical sites were then covered with hydrophobic porous polyurethane ether foams, which were fixed in place with sterile adhesive transparent tapes and connected through sensor tracts and tubes to a NP vacuum-assisted closure device (KCI UK Holdings Ltd). The small dimensions of the wound in infants posed a challenge, causing skin maceration of the wound margins. To overcome this, we liberally applied sterile adhesive tapes over the wound margins and surrounding skin and then used smaller foam inside the wound, which was covered with wider foam of the proper width to correctly place the sensor tract over the wound (Figure 4).³ In our study, we used a negative pressure of 50 mm Hg as we found that using pressure higher than 50 mm Hg was associated with issues like bradycardia and respiratory depression that were not observed at lower pressure.³

The NP therapy was placed with the patient in the operating room under general anesthesia and was replaced weekly. All patients were treated with appropriate intravenous antibiotics during the course of treatment, tracing the tissue culture sensitivity studies. The final surgical closure was achieved in all 3 patients either by direct closure (2 cases) or by split-thickness skin grafting (1 case) after obtaining a proper healthy granulating tissue with negative cultures for microbes. The mean time of treatment was 33 days (range: 21-49 days) (Figures 1, 2, and 3). All patients were managed in the neonatal intensive care unit with proper monitoring of clinical conditions. The patient who achieved closure with split-thickness skin grafting had received NP dressings over the graft that were removed after the first dressing change on day 5. 

The incidence of SSIs following a sternotomy incision for cardiac surgery is reported to be near 9%, and the associated mortality rate ranges from 14% to 47%.¹ NP wound therapies have shown good clinical results in management of sternal wound complications in adults when combined with thorough surgical debridement.² 

Although several studies have evaluated the incidence and associated risk factors for sternal wound complications in pediatric cases, there is not any uniformity in the management of these conditions. Traditional conservative management with open wound care has resulted in increased morbidity and mortality. Although reconstructive options with muscle flap cover are the preferred treatments in adults, such procedures are highly demanding in infant groups, both physically and psychologically.³

NP therapy has shown wound healing results superior to those of traditional treatment, which can be attributed to its ability to reduce chronic inflammatory edema through increased local blood supply and lymphatic drainage along with accelerated granulation tissue formation.⁴ In addition, this improved blood supply also helps deliver more antibiotics to the wound site, combating harmful microbes and ultimately reducing bacterial load.² 

Reports in literature of NP wound therapy use in neonates and infants are limited, and our experience underlines the benefits and importance of the strategy in patients in these age groups with SSIs of sternotomy wounds.^5,6 Despite the small sizes of the wounds in our patients, NP wound therapy resulted in prompt granulation tissue formation. All wounds achieved definite closure and good sternal stability at the end of treatment.

Low-pressure NP therapy can be used safely in the management of the sternal wound SSIs and has definite advantages over conventional treatments, resulting in significantly reduced morbidity and treatment duration.⁷  However, it has to be emphasized that proper thorough surgical wound debridement should always precede NP therapy. During the course of our study, we found that the use of suction pressures over 50 mm Hg was associated with cardiorespiratory complications like bradycardia and respiratory distress. We found that suction pressure of 50 mm Hg, however, was well tolerated by our infant patients.