The current study enrolled a total of 112 patients (n=112), who comprised 90 men and 22 women. The mean age of the patients was 61.0 years (range, 34 to 86 years). Of the 90 men who underwent pectoralis major flap surgery, 8 patients underwent the operation twice, corresponding to a total of 98 cases. All of the 22 women only underwent the procedure once.
In , pectoralis major flaps are classified according to the cause of use. There were 37 cases for which a pectoralis major flap was used following the resection of malignant tumors; these include 12 cases of oral cancer, 11 cases of oropharyngeal cancer, and 14 cases of hypopharyngeal cancer based on the sites of primary occurrence.
Of the patients with hypopharyngeal cancer, there was one who underwent an incomplete resection of the tumor. This case was classified as an incomplete tumor resection.
There were 21 patients who had skin metastases. Reconstruction should therefore be performed for these patients, who comprised 4 cases of parotid gland cancer, 1 case of submandibular gland cancer, 4 cases of thyroid gland cancer, and 12 cases of metastasis to the cervical lymph node. All of the 50 cases of oral cancer, oropharyngeal cancer, hypopharyngeal cancer, and metastasis to the cervical lymph node proved to be squamous cell carcinomas. There were a total of 4 cases of parotid gland cancer and these included 1 case of mucoepidermoid carcinoma, 1 case of malignant pleomorphic adenoma, 1 case of acinic cell carcinoma, and 1 case of sarcoma. One case of submandibular gland cancer proved to be mucoepidermoid carcinoma. There were 4 cases of thyroid cancer, all of which proved to be papillary carcinomas.
There were a total of 44 cases of postoperative complications for which a pectoralis major flap needed to be performed due to complications of a previous operation. These included 25 cases of fistula, seven cases of skin necrosis on the neck, five cases of necrosis of the pre-existing flap, 2 cases of carotid artery rupture, 3 cases of pharyngostoma closure and 2 cases of wound dehiscence in the oral cavity. Additionally, there were 15 cases of carotid artery protection and 3 cases of an incomplete resection of the tumor due to extensive metastases to multiple tissues.
By the types of pectoralis major flap, there were 107 cases of myocutaneous flap, 12 cases of muscle flap, and 1 case of pectoralis major osteomyocutaneous flap involving the fifth rib. There were also cases of muscle flap; these included 7 cases of carotid artery protection, 2 cases of tumor resection due to an extensive presence of skin metastasis on the neck draining into the cervical lymph node, 2 cases of an extensive skin involvement due to metastasis of the cervical lymph nodes, and 1 case of an incomplete resection of cancer on the neck. A pectoralis major osteomyocutaneous flap was used to reconstruct the mandible and mouth floor where squamous cell carcinomas had invaded.
There were 8 patients for whom a pectoralis major flap surgery was performed twice. There were 4 patients in whom a contralateral pectoralis major musculocutaneous flap was inevitable due to the formation of fistula following the resection of a tumor using an ipsilateral pectoralis major musculocutaneous flap. There were 2 patients for whom a contralateral pectoralis major musculocutaneous flap was performed again due to the partial necrosis of a free flap following the resection of a tumor using an ipsilateral pectoralis major musculocutaneous flap and free flap. There was one patient for whom a pectoralis major musculocutaneous flap was used twice to protect the carotid artery because both carotid arteries were sequentially ruptured postoperatively. In another patient, following a resection of the tumor and ipsilateral pectoralis major musculocutaneous flap, a contralateral pectoralis major musculocutaneous flap was also used due to tumor metastasis to the cervical lymph node because of recurrence.
The size of the skin paddle of the pectoralis major musculocutaneous flap ranged from 2×3 cm to 10×15 cm. The size of the skin paddle was the largest in cases in which the circumferential defect of the hypopharynx was reconstructed. It was 8×12 cm in cases in which a direct closure of the recipient site was performed.
In a total of 76 cases, a pectoralis major flap was used for primary reconstruction. These included 58 cases of primary malignant tumor, 15 cases of carotid artery protection, and 3 cases of an incomplete resection of the tumor. In addition, a pectoralis major flap was also used for secondary reconstruction in a total of 44 cases. These included 39 cases of postoperative complications, 3 cases of pharyngostoma closure, and 2 cases of carotid artery protection that had been performed due to postoperative rupture of the carotid artery.
There were 40 cases of primary tumor with no past history of treatment, and there were 19 salvage cases in which the tumor recurred although they received treatment.
In 37 cases (30.8%), a pectoralis major flap was used for reconstruction to shorten the operation time because of poor general conditions due to systemic diseases. In addition, it was also used for the following reasons: external skin defect (28 cases, 23.3%), postoperative complication (35 cases, 29.2%), carotid artery protection (17 cases, 14.2%), and an incomplete resection of the tumor (3 cases, 2.5%) (). With regard to poor general conditions, there were 12 patients who had both severe diabetes mellitus and hypertension, 8 with cachexia, 8 with ischemic heart disease, 5 with renal failure, and 4 patients with liver cirrhosis.
Reasons for choosing the pectoralis major flap
There were 37 cases (30.8%) of flap-related complications; these included 8 cases of partial necrosis, 12 cases of fistula, 10 cases of wound dehiscence, 6 cases of infection, and 1 case of bleeding. Furthermore, there were 24 cases of major complications, and these included 4 cases of partial necrosis, 12 cases of fistula, 4 cases of wound dehiscence, 3 cases of infection, and 1 case of bleeding. There were 13 cases of minor complications and these included 4 cases of partial necrosis, 6 cases of wound dehiscence, and 3 cases of infection. The complications occurred in 35 men and 2 women. All of the 24 cases of major complications occurred in men. In addition, minor complications occurred in 11 men and 2 women.
For the treatment of partial necrosis, one of the flap-related complications, the following measures were taken: a trapezius musculocutaneous flap (1 case), a split-thickness skin graft (1 case), and a direct closure (1 case). For the treatment of fistula, the following measures were taken: a palatal mucoperiosteal flap (1 case), a contralateral pectoralis major musculocutaneous flap (4 cases), a radial forearm free flap (1 case), a latissimus dorsi musculocutaneous flap (1 case), pharyngostoma formation (3 cases), and a direct closure (2 cases). Direct closure was performed in all of the 4 patients with wound dehiscence and a partial-thickness skin graft was performed in all of the 3 patients with infection. There was 1 case of bleeding in the pectoralis major muscle, which was controlled by suture ligation ().
Treatment for pectoralis major flap-related major complications
At the donor sites, the complications included 1 case of skin necrosis, 1 case of infection, and 3 cases of bleeding. In our series, there were 13 patients who died of sepsis or cardiovascular failure.
Statistical analysis was performed to identify the correlations between the flap-related complications and their risk factors. This showed that the complications were not correlated with such risk factors as age, obesity, a past history of radiotherapy, salvage operation, systemic diseases, primary reconstruction, or the reconstruction of the oral cavity.
The incidence of overall complications (P=0.020) and major complications (P=0.007) was significantly higher in men than in women. Low preoperative albumin levels (<3.8 g/dL) were significantly correlated with the incidence of fistula formation (P=0.030). The frequency of hypopharyngeal reconstruction was significantly correlated with the incidence of major complications (P=0.019) and fistula formation (P=0.012). Finally, the frequency of secondary reconstruction was significantly correlated with the incidence of overall complications (P=0.013) and fistula formation (P=0.030) ().
Correlation between potential risk factors and subcategories of complications