Pectoralis Flap Sternal Reconstruction: Steps & Recovery

Sternal reconstruction using a pectoralis flap restores chest stability and promotes healing in patients with significant sternal defects or complications. This procedure utilizes the pectoralis major muscle to provide coverage, structural support, and improved vascularization, reducing infection risk and enhancing recovery.

Proper sternum reconstruction is crucial for protecting vital structures and maintaining thoracic integrity. This article outlines the key steps involved in performing a pectoralis flap sternal reconstruction and what patients can expect during recovery.

Indications For This Procedure

Pectoralis flap sternal reconstruction is primarily performed for patients with significant sternal defects, often due to complications following median sternotomy, trauma, or oncologic resections. One of the most common indications is deep sternal wound infection (DSWI), which occurs in approximately 1-5% of post-sternotomy patients. Risk factors include diabetes, obesity, prolonged mechanical ventilation, and immunosuppression (El Oakley & Wright, 1996). Left untreated, DSWI can lead to mediastinitis, a life-threatening condition requiring immediate intervention to prevent systemic sepsis and multi-organ failure. The pectoralis flap provides well-vascularized tissue to fill the defect, reducing bacterial colonization and promoting healing.

Beyond infection-related complications, this procedure is necessary in cases of nonunion or sternal dehiscence, where the sternum fails to heal properly after surgical division. Patients with osteoporosis, chronic steroid use, or poor nutrition are particularly susceptible, as these factors impair bone regeneration and increase mechanical instability. Without intervention, persistent sternal instability can lead to chronic pain, respiratory dysfunction, and paradoxical chest wall movement. The pectoralis flap reinforces the sternum while maintaining chest wall flexibility, essential for respiratory function.

Patients undergoing oncologic resections involving the sternum may also require this technique, particularly when large portions of bone and soft tissue are removed due to malignancies such as chondrosarcoma or metastatic disease. The pectoralis flap restores structural integrity while providing a well-vascularized bed for potential adjuvant therapies like radiation. Given that radiation-induced fibrosis can impair healing, the robust blood supply of the pectoralis muscle helps mitigate complications and improve long-term outcomes.

Anatomy Of The Pectoralis Major

The pectoralis major is a broad, fan-shaped muscle essential for upper body movement and serves as the primary muscular component in pectoralis flap sternal reconstruction. Originating from the clavicle, sternum, and upper six costal cartilages, it converges laterally to insert into the intertubercular groove of the humerus. Its extensive attachment points and strong vascular supply make it ideal for reconstructive procedures.

The muscle consists of two heads: the clavicular head, which facilitates shoulder flexion, and the sternocostal head, which contributes to adduction and medial rotation of the humerus. This dual-head structure allows surgeons to tailor the flap to the specific dimensions and location of the sternal defect.

A key feature in reconstruction is its vascular anatomy. The muscle receives its primary blood supply from the thoracoacromial artery, a branch of the axillary artery, with additional contributions from perforating branches of the internal thoracic artery. This dual-source perfusion ensures viability even when portions are mobilized. Studies highlight the role of internal thoracic artery perforators in maintaining perfusion, reducing ischemic complications (Saint-Cyr et al., 2009). Venous drainage follows a similar pattern, with outflow directed through the cephalic and axillary veins, ensuring efficient circulation and reducing postoperative congestion.

Classified as a Type V muscle flap according to the Mathes and Nahai classification, the pectoralis major possesses a dominant vascular pedicle with secondary segmental contributions, enhancing its reliability for large-scale reconstructions. It can be transferred as either a muscle-only or myocutaneous flap, depending on the extent of coverage required. The overlying fascial layer provides additional reinforcement while maintaining a pliable contour. Bilateral mobilization offers further reconstructive options for extensive defects, particularly in dehisced sternotomies or oncologic resections.

Incision And Flap Elevation Steps

The surgical approach begins with precise incision planning to maximize muscle viability while ensuring adequate coverage. Surgeons typically design the incision along the natural contours of the pectoralis major, following the inframammary fold or extending from the lateral border of the sternum toward the axilla. This minimizes cosmetic distortion and preserves neurovascular structures. Careful dissection is essential to prevent unnecessary trauma, as excessive devascularization can compromise perfusion. Electrocautery is often used to achieve hemostasis while minimizing thermal injury.

Once the muscle is exposed, elevation proceeds while preserving the dominant vascular supply. The thoracoacromial artery and internal thoracic artery perforators must be identified and safeguarded. Elevation typically begins at the lateral border, progressing medially while maintaining a subfascial plane. In cases requiring additional coverage, a bilateral pectoralis advancement may be necessary. Surgeons must balance flap mobility with structural integrity, ensuring enough muscle remains anchored for functional recovery.

Tension-free mobilization is critical, as excessive strain can impede vascular flow and increase necrosis risk. Selective division of the humeral insertion may be performed to enhance reach without compromising perfusion. This step is particularly relevant for large post-sternotomy defects. If a myocutaneous flap is needed, careful preservation of the overlying skin paddle ensures adequate soft tissue coverage while maintaining sensation and aesthetics. Sutures or tissue sealants reinforce the flap and minimize seroma formation.

Sternal Reapproximation And Flap Placement

Once the pectoralis flap is elevated, proper sternal reapproximation restores thoracic stability. The extent of sternal separation dictates the approach, with some cases requiring rigid fixation using titanium plates or sternal wires, while others rely on approximation with non-absorbable sutures. If severe sternal dehiscence is present, direct bony apposition may not be feasible, necessitating a bridging technique where the flap provides both vascularized coverage and mechanical support.

Precise positioning ensures adequate coverage while preserving muscle function. The flap is advanced medially, maintaining tension-free placement to prevent ischemic complications. In unilateral flap use, the muscle is rotated to cover the defect, ensuring the vascular pedicle remains undisturbed. When bilateral flaps are necessary, symmetrical advancement minimizes postoperative asymmetry. Quilting sutures secure the flap, reducing dead space and minimizing seroma risk.

Postoperative Considerations

Careful postoperative management ensures successful healing and minimizes complications. Patients are typically monitored in an intensive care setting, particularly if they have comorbidities such as diabetes, chronic obstructive pulmonary disease, or cardiovascular disease. Hemodynamic stability, respiratory function, and fluid balance require close observation, as fluctuations can affect flap perfusion. Pain control is managed through intravenous analgesics, regional nerve blocks, and multimodal strategies to reduce opioid dependence while maintaining comfort.

Early mobility protocols help prevent complications like deep vein thrombosis and pulmonary atelectasis, though excessive upper extremity movement is restricted to protect the flap. Patients should avoid strenuous activities that place tension on the reconstructed sternum, with gradual reintroduction of arm movement over several weeks.

Wound care involves routine inspection for infection, seroma, or hematoma formation, as these can compromise reconstruction success. Long-term follow-up includes imaging assessments, such as CT scans or ultrasound, to evaluate bone healing and flap viability. Rehabilitation programs incorporate physical therapy to restore upper body strength, ensuring patients regain functional capacity without jeopardizing reconstruction stability.