Abstract
This study represents the surgical experience of 4481 microvascular free flap cases performed at the authors’ institution in China, between 1979 and 2013. Four thousand four hundred and eighty-one patients underwent reconstruction with 4640 flaps: 56% radial forearm flaps, 8% iliac crest flaps, 13% fibula flaps, 10% anterolateral thigh flaps, and other flaps. In the overwhelming majority of cases, the flap transfer was required following tumour resection (97.5%). Three hundred and twenty minor complications (6.9%) occurred. One hundred and eighteen major complications (2.5%) were encountered: 114 cases of failure (2.4%) and four deaths. Among the 118 cases with major complications, 26 – 22.0% – had received radiotherapy; this proportion was higher than the 6.9% in the minor complications group and 8.1% in the non-intervention group. Venous thrombosis was the most common complication at the recipient site and was the main cause of flap failure. When a compromised flap is identified, surgical re-exploration should not be delayed. This study confirms that free flaps are reliable in achieving successful reconstruction in the head and neck region; however this technique requires extensive clinical experience. Owing to the large number of flap options, microsurgeons should always pay attention to the details of the different surgical defects and choose the most appropriate flap.
In the oral and maxillofacial region, microsurgical free flap transfer is often necessary to cover extensive defects after tumour resection or severe trauma, to maintain good oral function and facial symmetry. Microsurgery requires extensive anatomical knowledge and an experienced surgical team, coupled with a vigilant and dedicated postoperative care team. However, for most centres this type of surgery still represents an extraordinary challenge.
In 1959, Seidenberg et al. described the first free flap transfer, which was a jejunum flap used to cover an oesophageal defect. Taylor et al. described fibula free flap transfer as the first microsurgical bone graft and since then it has gained tremendous popularity for reconstruction of the mandible and maxilla. Another important milestone was the first description of the vascularized radial forearm free flap (RFFF) by Yang et al. at the PLA Shenyang General Hospital in 1979 ; this has undoubtedly played a significant role in soft tissue reconstruction in the head and neck region.
The RFFF was used extensively in China before the year 2007. The advantage of the RFFF is that it is thin, pliable, and offers a reliable and long pedicle with a suitable diameter, thereby allowing it to be used for the majority of both intraoral and extraoral defects. However, disadvantages include its thin nature, which limits its use when applied to large defects of the tongue and composite defects, and donor site scarring. As a result, the use of the anterolateral thigh flap (ALTF) has become more and more widespread.
The main options for mandible and maxilla reconstruction are the fibula free flap, iliac free flap (deep circumflex iliac artery (DCIA) flap), and scapula free flap. These flaps have their respective advantages and disadvantages. The choice for mandible and maxilla reconstruction is dependent on the defect type.
The Shanghai Ninth People’s Hospital is the largest oral and maxillofacial and head and neck cancer centre in China, treating approximately 1500 oral cancer cases each year, with the majority of these cases requiring reconstruction. About 30% of these cases need a free flap reconstruction for large defects. In 2008, our department reported an advanced staged oral cancer case requiring reconstruction of an extensive oral and maxillofacial defect. This patient underwent reconstruction with three flaps – a fibula flap, latissimus dorsi flap, and pectoralis major myocutaneous flap – to reconstruct the floor of the mouth, neck skin, and mandible ( Figs. 1–5 ).
The purpose of this research was to report and analyze the incidence of the use of free flaps and the success and failure rates of free flap tissue transfer in the oral and maxillofacial region over the last 34 years at the Shanghai Ninth People’s Hospital.
Materials and methods
In this retrospective analysis, we investigated 4481 patients undergoing a total of 4640 microsurgical reconstructions, which were conducted in the Surgical Oncology Ward of the Department of Oral and Maxillofacial Surgery (from 1979 to 2012) and Department of Oral and Maxillofacial – Head and Neck Oncology (2012–2013) of the Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine. Cases with complete records, including demographic, clinical, and surgical data, were included. In addition to the systematic record research, documents from the in-hospital patient administration system were used for data acquisition for the period 2007–2013. However, as patient records were handwritten between 1979 and 2006, some clinical data were lost due to faded handwriting.
The patients ranged in age from 2 to 91 years, with a mean age of 58.6 years; 2754 were males and 1727 were females. The medical records and details of the primary tumour site, flap type, management of the jaw, vessels from the donor site, vessels at the recipient site, and complications were analyzed. The free flaps selected for reconstruction are listed in Table 1 . Of the reconstructions performed, 8.3% were carried out in patients after chemotherapy, 8.5% after radiotherapy, and 4.4% after chemoradiotherapy. Primary maxilla–mandible reconstructions were performed in cases with benign tumours and malignant tumours with a low risk of recurrence.
| Flap type | 1979–2006 | 2007–2013 | 1979–2013 | |||
|---|---|---|---|---|---|---|
| Number | Proportion | Number | Proportion | Total | Proportion | |
| Chinese flap | 1721 | 64.12% | 861 | 44.02% | 2582 | 55.65% |
| Latissimus dorsi flap | 250 | 9.31% | 62 | 3.17% | 312 | 6.72% |
| Free pectoralis major myocutaneous flap | 153 | 5.70% | 12 | 0.61% | 165 | 3.56% |
| Free fibula (myocutaneous) flap | 227 | 8.46% | 398 | 20.35% | 625 | 13.47% |
| DCIA | 257 | 9.58% | 112 | 5.73% | 369 | 7.95% |
| Scapula bone flap | 10 | 0.37% | 6 | 0.31% | 16 | 0.34% |
| Anterolateral thigh flap | 8 | 0.30% | 462 | 23.62% | 470 | 10.13% |
| Scapula flap | 16 | 0.60% | 16 | 0.82% | 32 | 0.69% |
| Gracilis muscle flap | 8 | 0.30% | 8 | 0.41% | 16 | 0.34% |
| Other a | 34 | 1.27% | 19 | 0.97% | 53 | 1.14% |
| Total | 2684 | 100% | 1956 | 100% | 4640 | 100% |
a Including the following: lateral arm free flap, gastrocnemius flap, pedicle rectus muscle flap, lateral thoracic flap, etc.
The recipient vessels were divided into two groups, a conventional group and an unconventional group. The recipient vessels included the facial artery, common facial vein, external jugular vein, and superior thyroid artery.
Complications after microsurgery were divided into major and minor complications. Major complications included flap and donor site complications for which additional surgery was required and life-threatening events or death. Minor complications were those that resolved with the use of interventions including minor debridement, minor plastic surgery, and secondary wound healing.
Data were collected in table format in Microsoft Excel 2010 (Microsoft Corporation, Redmond, WA, USA).
Results
From January 1979 to December 1989, 522 cases of microsurgical reconstruction were completed, with a 91.9% (480/522) survival rate. From January 1990 to August 1997, 629 cases were completed, with a 97.3% (612/629) survival rate. From September 1997 to December 2006, 1533 cases were completed, with a survival rate of 98.2% (1506/1533). From January 2007 to December 2013, 1956 cases were completed, with a survival rate of 98.4% (1924/1956).
The radial/ulnar forearm flap was the flap most often harvested in our patients (55.7% of 4640 cases) ( Table 1 ). However, the number decreased after the year 2007. In terms of soft tissue grafts, the ALTF was the second most used after the RFFF (10.1%), followed by the latissimus dorsi flap and free pectoralis major myocutaneous flap. With regard to hard tissue reconstruction, the fibula flap was the flap most often harvested (625 cases, 13.5%), followed by the DCIA and scapula bone flap.
The tongue was the most common defect site (1123/4481, 25.1%), followed by the mandible (718/4481, 16.0%), floor of the mouth (600/4481, 13.4%), cheek (568/4481, 12.7%), and oropharynx (394/4481, 8.8%) ( Table 2 ).
| Defect site | Cases | Proportion |
|---|---|---|
| Tongue | 1123 | 25.06% |
| Palate | 133 | 2.97% |
| Cheek | 568 | 12.68% |
| Floor of the mouth | 600 | 13.39% |
| Maxilla | 217 | 4.84% |
| Mandible | 718 | 16.02% |
| Oropharynx | 394 | 8.79% |
| Skull base | 56 | 1.25% |
| Lip | 42 | 0.94% |
| Maxillofacial skin | 63 | 1.41% |
| Skin of the parotid region | 35 | 0.78% |
| Retromolar region | 108 | 2.41% |
| Skin of the neck | 70 | 1.56% |
| Larynx | 20 | 0.45% |
| Perforating defects | 215 | 4.80% |
| Other | 119 | 2.66% |
| Total | 4481 | 100% |
Squamous cell carcinoma was the most frequent pathological diagnosis ( Table 3 ). The majority of patients had not received chemotherapy or radiotherapy; 8.3% of patients had received radiotherapy before surgery, 8.5% had received chemotherapy, and 4.4% had received chemoradiotherapy.
| Pathological diagnosis | Cases | Proportion |
|---|---|---|
| Squamous cell carcinoma | 2415 | 53.89% |
| Ameloblastoma | 237 | 5.29% |
| Mucoepidermoid carcinoma | 197 | 4.40% |
| Osteosarcoma of the jaw | 166 | 3.70% |
| Keratocystic odontogenic tumour | 161 | 3.59% |
| Vascular malformations | 143 | 3.19% |
| Osteoradionecrosis of the jaws | 139 | 3.10% |
| Sarcoma of the soft tissue | 130 | 2.90% |
| Adenoid cystic carcinoma | 112 | 2.50% |
| Skin malignant tumour | 112 | 2.50% |
| Failure of last repair operation | 67 | 1.50% |
| Melanoma | 58 | 1.29% |
| Osteomyelitis | 58 | 1.29% |
| Malignant pleomorphic adenoma | 49 | 1.09% |
| Trauma | 49 | 1.09% |
| Ossifying fibroma | 45 | 1.00% |
| Fibrous dysplasia | 31 | 0.69% |
| Myxoma of the jaws | 27 | 0.60% |
| Central carcinoma of the jaws | 27 | 0.60% |
| Epithelial dysplasia | 18 | 0.40% |
| Pleomorphic adenoma | 9 | 0.20% |
| Myofibroblastoma | 9 | 0.20% |
| Osteoblastoma | 7 | 0.16% |
| Myoepithelial carcinoma | 5 | 0.11% |
| Clear cell carcinoma | 5 | 0.11% |
| Acinic cell carcinoma | 4 | 0.09% |
| Malignant fibrous histiocytoma | 4 | 0.09% |
| Other | 197 | 4.40% |
| Total | 4481 | |
Regarding the vessels at the recipient sites, the facial artery and superior thyroid artery were most often used for anastomosis, while the common facial vein and external jugular vein were the two most commonly used veins. In complex defects, contralateral vessels, transverse cervical vessels, the pedicle from the previous operation, and the cephalic vein were used ( Tables 4 and 5 ).
| Artery at the recipient site | Cases |
|---|---|
| Facial artery | 1898 |
| Superior thyroid artery | 1409 |
| External carotid artery | 75 |
| Lingual artery | 129 |
| Transverse cervical artery | 127 |
| Occipital artery | 6 |
| Superficial temporal artery | 73 |
| Pedicle of the last graft flap | 6 |
| Pedicle of a combined flap | 35 |
| Unknown | 882 |
| Total | 4640 |
| Vein at the recipient site | Cases |
|---|---|
| Common facial vein | 1098 |
| External jugular vein | 1162 |
| Branch of the jugular vein | 720 |
| Cervical anterior vein | 9 |
| Lingual vein | 7 |
| Superficial temporal vein | 76 |
| Superior thyroid vein | 178 |
| Facial vein | 376 |
| Transverse cervical vein | 13 |
| Thoracoacromial vein | 7 |
| Cephalic vein | 4 |
| Pedicle of a combined flap | 4 |
| Pedicle of the last graft flap | 7 |
| Unknown | 979 |
| Total | 4640 |
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