Coronary artery bypass grafting (CABG) is a critical surgical procedure that aims to improve myocardial perfusion in patients with severe coronary artery disease. By creating a bypass around blocked coronary arteries, CABG significantly enhances myocardial blood flow, reduces angina symptoms, and lowers myocardial infarction risk. Typically, CABG is performed via a median sternotomy, which involves a vertical incision along the sternum. Although this approach is effective, it can lead to various complications, including non-infectious sternal dehiscence (NISD) and post-sternotomy mediastinitis, particularly in patients with pre-existing comorbidities such as obesity and diabetes.

In CABG procedures, grafts are commonly harvested from the saphenous vein, radial artery, or internal mammary artery (IMA). Given its superior long-term patency, bilateral IMA harvest is often considered to improve graft durability in selected patients. While the use of bilateral IMAs provides improved graft outcomes, it also compromises sternal vascularity, predisposing the bone to ischemic changes and delayed healing, which may progress to sternal dehiscence in severe cases. This risk is especially relevant in patients with diminished tissue perfusion or impaired regenerative capacity [1,2]. Typically, traditional methods for managing sternal dehiscence include using muscle flaps or regional flaps, such as the pectoralis major or latissimus dorsi. Although these techniques are well-established, they may be inadequate for addressing complex anterior chest wall defects, particularly when the defect extends beyond the reach of local flaps or occurs in patients with comorbidities such as diabetes or renal failure that impair wound healing. Because of these restrictions, alternative approaches providing effective coverage and promoting healing are required.

The omental flap has thus emerged as a valuable reconstructive option. Its rich vascular supply, derived from the right and left gastroepiploic arteries and short gastric vessels, enhances its ability to support tissue regeneration and healing [3]. Despite the invasive nature of harvesting the omentum, its versatility and effectiveness make it a compelling choice for complex cases. This case report explores the application of an omental flap combined with a split-thickness skin graft (STSG) in managing a severe anterior chest wall defect following CABG with bilateral IMAs. By detailing the patients’ surgical journey and outcomes, this report aims to demonstrate the efficacy of this approach and provide insights into its potential benefits and limitations for future cases. This report was reviewed and approved by the Institutional Review Board of St. Mary’s Hospital (No. OC24ZASI0130). Written informed consent was obtained from the participant prior to her inclusion in the report.

A 45-year-old female with a history of hypertension, diabetes mellitus, and end-stage renal disease requiring dialysis was diagnosed with non-ST-elevation myocardial infarction and triple-vessel coronary artery disease. She underwent off-pump CABG utilizing bilateral IMAs in a Y-configuration at an external facility. In the early postoperative period, sternal wound disruption occurred, accompanied by serous discharge and partial exposure of the underlying sternum. Initial management included negative pressure wound therapy (NPWT) followed by coverage with a pectoralis major muscle flap. Despite these measures, the wound failed to heal completely, with persistent dehiscence and poor granulation.

Two months after the index surgery, the patient was referred to our department with a 6×12 cm anterior chest wall defect extending from the mid to lower sternum. Clinical examination showed a wound bed with relatively healthy granulation tissue interspersed with necrotic debris but no purulent discharge or foul odor (Fig. 1). The underlying sternum and surgical wires were exposed. Laboratory findings including inflammatory markers were within normal ranges, suggesting no active infection. Empirical intravenous antibiotics were administered perioperatively and discontinued after negative wound culture results. Serial debridements were performed until the wound bed became clean and well-granulated, at which point definitive reconstruction was undertaken.

Several reconstructive options were evaluated for managing the complex chest wall defect. Initially, a pectoralis major musculocutaneous flap was considered; however, this approach had previously been attempted unsuccessfully at an external facility. Regional flaps were also evaluated, but were deemed inadequate, particularly for covering the extensive lower portion of the defect. Given the absence of bilateral IMAs due to the prior CABG, a vertical rectus abdominis myocutaneous flap was not feasible either. Similarly, the latissimus dorsi flap was ruled out due to the significant distance from the defect and concerns about increased scarring and delayed healing at the donor site. Free flap options, such as the deep inferior epigastric artery perforator flap, were also considered. However, the lack of adequate recipient vessels, along with the patient’s comorbidities, rendered this approach unsuitable. Consequently, the focus shifted towards a more viable solution that considered the patient’s overall health status and anatomical challenges.

Based on these considerations, an omental flap combined with an STSG was selected. This approach was well suited to both the patient’s health status and the complexity of the defect. Under general anesthesia, the wound was debrided to remove eschar and non-viable tissue, leaving an 8×12 cm defect.

The omental flap was laparoscopically harvested by a general surgeon. The greater omentum was mobilized from the transverse colon and divided along the left gastroepiploic arcade while preserving the right gastroepiploic vascular pedicle. It was transferred to the chest wall through a subxiphoid tunnel and gently advanced into the defect. The omentum was then spread over the exposed sternum to fill the dead space and secured to the surrounding soft tissue with multiple interrupted 4-0 Vicryl sutures (Fig. 2). An STSG was harvested from the left thigh using a pneumatic dermatome, meshed at a 1:1.5 ratio for increased coverage, and applied over acellular dermal matrix (ADM; MatriDerm, MedSkin Solutions Dr. Suwelack AG) to promote dermal regeneration (Fig. 3). The graft was secured with metallic staples, and NPWT was used to maintain negative pressure of 80 mmHg, optimizing graft adherence and fluid removal. The wound healed well with healthy granulation tissue, although a small central area required additional time for secondary healing. Three months after the surgery, the primary wound had healed completely without any major complications (Fig. 4). At the 1-year postoperative follow-up, a soft, asymptomatic protrusion was observed in the epigastric area, suggestive of a reducible hernia (Fig. 5). This was monitored with imaging and regular follow-ups to prevent any further complications.

This case underscores the complexities of managing anterior chest wall defects following CABG, particularly with bilateral IMA usage. Sternal dehiscence, while relatively rare, poses significant challenges and can lead to serious complications, particularly in patients with multiple comorbidities.

The use of bilateral IMAs in CABG is associated with superior long-term graft patency and improved survival rates. However, this approach can compromise sternal blood flow, thereby increasing the risk of NISD. Although NISD has an overall incidence of less than 1% in CABG patients, it is more prevalent among those undergoing bilateral IMA procedures [1,2]. The diminished blood supply to the sternum from bilateral IMA usage, while beneficial for graft longevity, creates a greater risk of wound complications [4,5].

Several risk factors contribute to the development of NISD following CABG, particularly when bilateral IMAs are utilized. Obesity, diabetes, and advanced age are critical factors that exacerbate wound healing challenges and increase the likelihood of complications. The reduction in blood supply to the sternum caused by bilateral IMA compromises perfusion to locoregional flaps, which depend on sufficient vascularity for successful coverage. Furthermore, the distance of these flaps from the defect site often limits their ability to provide tension-free coverage, increasing the risk of wound dehiscence. In cases where free flaps might be considered, the absence of reliable recipient vessels due to previous surgeries further complicates reconstruction efforts. Traditional locoregional flaps, like the serratus anterior or latissimus dorsi, may not provide sufficient reach or coverage for complex intrathoracic or lower sternal defects.

Among various reconstructive options, the omental flap provides robust vascularized tissue that can effectively fill irregular, three-dimensional spaces and obliterate dead space. Its blood supply from the right and left gastroepiploic arteries and short gastric vessels promotes rapid revascularization and improved resistance to infection. Moreover, the omentum’s abundance of lymphatic channels may offer additional benefits in managing infected or colonized wounds, further enhancing its role in complex reconstructions [6]. It is particularly effective for managing complex defects, including those in difficult-to-reach areas such as the lower sternum.

However, the omental flap also has several limitations. Hernias, occurring in up to 32% of cases, are often unavoidable when transferring the omentum subcutaneously to the chest, as a tunnel that is too narrow may cause ischemia, whereas one that is too wide increases the risk of incisional hernia. In addition to the risk of hernia and bowel injury, intra-abdominal harvesting increases surgical complexity, and the flap volume may be inadequate for large or full-thickness defects. While the risk of hernia formation can be reduced through laparoscopic harvesting and by splitting the diaphragm to pass the omentum through it, postoperative bleeding remains another concern, occurring in about 15% of cases and requiring careful management [6,7]. However, in cases where herniation is stable and asymptomatic without evidence of strangulation, conservative management with close observation can be considered, as was done in this case.

In the presenting case, the choice of an omental flap combined with a STSG over an ADM proved effective. This approach was appropriate given the patient’s overall health status and the complexity of the defect, achieving complete healing with only minor secondary intervention. The omental flap provided well-vascularized coverage, while the ADM enhanced dermal regeneration and integration of the overlying graft, resulting in stable and durable wound closure despite the challenges associated with bilateral IMAs harvest.

This case also extends the applicability of previously established chest wall reconstruction algorithms, which typically recommend the omental flap for lower sternal or thoracoabdominal defects [8]. Building on this principle, our case in volved an extensive defect extending from the middle to the lower sternum, where the omental flap successfully provided tension-free coverage and favorable healing. Despite the absence of both internal mammary arteries after CABG and the presence of multiple comorbidities, the omental flap served as a reliable salvage option when conventional locoregional flaps were not feasible due to anatomical or vascular limitations.

Despite this success, challenges remain. The development of a small epigastric hernia in this case underscores the need for vigilant monitoring and preventative strategies. While managed conservatively, the hernia highlights the need to consider additional reinforcement methods, such as synthetic mesh, to prevent complications and improve long-term outcomes. Synthetic mesh can enhance wound strength and tissue integration but may introduce risks such as infection or graft failure [9]. Future research should focus on long-term outcomes of omental flaps and STSGs in chest wall reconstruction, including strategies to prevent complications like herniation. Investigating the efficacy of synthetic mesh and other reinforcement methods will be crucial. Additionally, research should assess the applicability of these techniques across various patient populations with different comorbidities and anatomical challenges.

In conclusion, the use of an omental flap combined with STSG is an effective strategy for managing complex anterior chest wall defects following CABG with bilateral IMAs. The omental flap’s rich vascular supply and the STSG’s complementary role offer a robust solution where traditional methods may be inadequate. Ongoing research and refinement of these techniques will be vital for improving surgical outcomes and advancing chest wall reconstruction practices.