Internal Mammary Vessels - Alternate Recipient Vessels in Microvascular Head and Neck Reconstruction
The application of microvascular free tissue transfer for reconstruction of the head and neck is well established. Improved outcomes, as well as surgical and technological advances have broadened the applications of microvascular free flaps in these defects. Post-operative complications such as pharyngocutaneous fistulas, tracheal or esophageal stenoses, or recurrent pathology occasionally require secondary or even tertiary reconstruction with free tissue transfers. The disrupted anatomy and fibrotic changes resulting from primary reconstruction, neck dissection and irradiation present the surgeon with a high risk of provoking vascular or nervous injury when dissecting in previously operated or irradiated sites. This prompts a search for alternative recipient vessels for microvascular anastomosis. The transverse cervical, inferior thyroid, and arteries of the thyrocervical trunk have all been proposed[1]. The internal mammary vessels (IMVs) have a proven record in breast reconstruction but recently have found application in special circumstances in head and neck reconstruction[2]. This investigation describes the advantages of the internal mammary vessels (IMVs) as suitable recipient vessels for head and neck reconstruction when access to traditional vasculature is unavailable.
Methods
We reviewed a series of 8 consecutive free flaps utilizing the IMVs spanning 2011-2013 at Oregon Health and Science University in Portland, Oregon. Retrospective analysis reviewed patient age, diagnosis, previous interventions, previous radiation status, indication for IMV use, donor site, and complications. Cases were analyzed based on flap survival and complications. Common technique utilized a 3-4cm incision over ribs 2 or 3 and lateral reflection of pectoralis major. Periosteal elevators free the intercostal musculature from rib and a 2-3cm segment is removed. Removal of the posterior perichondrium reveals the vessels, taking great care to maintain integrity of the chest wall and avoid pneumothorax[2].
Results
The mean age of patients was 64 (range 47-83). Indications for surgery included recurrence of malignancy (38%), primary malignancy (25%), pharyngocutaneous fistula (25%) and tracheal necrosis (12%). The IMVs were selected for use in five patients (63%) because no other vessels were accessible, in two patients (25%) they were adjacent the surgical defect, and in one patient (12%) as a rescue vessel due to a thrombosed and unsalvageable inferior thyroid artery. No patients required vein interposition grafts. Radiation of the head and neck was a contributing factor in 63% of subjects. Flap types used in this series included the Anterior Lateral Thigh, Radial Forearm, and Ileocolic. Two cases were complicated by pneumothorax noted intraoperatively and required chest tubes. Only one case (12%) resulted in flap failure and takeback. During the study period, three patients (38%) succumbed due to progression or recurrence of original disease.
Conclusion
The consistent anatomy, bilaterality, and location outside of the neck make the IMVs useful recipients for local tissue transfers, or as alternative recipients in the vessel depleted neck. The major challenge with this procedure is the long pedicle length required to reach the surgical defect, however this is overcome by selecting suitably pedicled flaps such as the radial forearm flap or using vein interposition grafts[1]. The single near-term flap failure in our study did well after takeback and while three patients died during the study period, none were directly related to flap failure. Overall, the IMVs provide reliable and predictable outcomes when considering the typical heavily pre-treated population with advanced disease. Given this, our series demonstrates successful use of these vessels in situations with few other options.
1.Urken, M.L., et al., Internal mammary artery and vein: recipient vessels for free tissue transfer to the head and neck in the vessel-depleted neck. Head Neck, 2006. 28(9): p.797-801.
2.Schneider, D.S., et al., Use of Internal Mammary Vessels in Head and Neck Microvascular Reconstruction. Arch Otolaryngol Head Neck Surg, 2012. 138(2): p.5.