Introduction

The squamous cell carcinoma (SCC) of tongue is one of the most common oral cancers. It is an aggressive tumour, and it accounts for 22—39% of oral cavity cancers [6]. The incidence of oral SCC in developed countries is more prevalence in older male population especially in prolonged history of tabaco use and alcohol consumption [1]. Though, recent analysis revealed that there is a rising incidence of young females were diagnosed with oral SCC in the developed nation in Asian-Pacific region [2]. Low social economic status is also known to be significantly associated with the increased risk of oral cancer [5].

Most of the cases occurred over the lateral border of the tongue with very rare cases occurring over the dorsum of tongue, especially at the midline region [3, 4]. Radical surgical is crucial as an early surgical treatment which renders a higher survival rate [4]. Radical resection often causes an intraoral with or without an extraoral defect that warrants reconstruction. We report the experience of managing a patient with tongue cancer by radical resection and soft tissue reconstruction with free radial forearm flap.

Case report

35-year-old previously healthy gentleman presented with 6-months history of a painful non-healing ulcer over the right lateral border of his tongue. The ulcer has gradually increased in size with worsening pain and caused difficulties in speech and mastication. He denied any familial malignancy history, radiation exposure and constitutional symptoms. He was neither a smoker nor an alcohol consumer. On examination, there was a 3×3 cm ulceration with irregular border at the right lateral border of his tongue extending to the floor of mouth. The right submandibular lymph nodes were palpable.

A biopsy of the tongue ulcer revealed a poorly differentiated SCC. The magnetic resonance imaging (MRI) showed a lesion over the right antero-lateral aspect of the tongue involving the hyoglossus, genioglossus and mylohyoid muscles (Fig. 1, 2). The mass appeared not crossing the midline. The nasopharynx, oropharynx, laryngopharynx appeared normal which concluded the diagnosis of oral tongue SCC stage T3N1M0 [10].

Fig. 1. MRI coronal view revealed involvement of tongue muscles.

Fig. 2. MRI sagittal view revealed the mylohyoid, hyoglossus and genioglossus muscles involvement.

Subsequently, he underwent subtotal glossectomy with bilateral selective neck lymph nodes dissection resulted in an intraoral defect involving the tongue and floor of mouth. The right tongue body was excised with posterior margin up to circumvallate papillae and inferiorly including the mylohyoid muscle.

Technique

We reconstructed his tongue and floor of mouth using free radial forearm (RF) fasciocutaneous flap (Fig. 3). Allen test showed normal result prior to flap planning to ensure the ulnar artery supply to the hand was sufficient. We designed a rectangular template (6×13) cm for the skin paddle for harvesting the RF flap. The distal part of the flap is around 2 cm proximal to the wrist crease. A lazy-S line was drawn on the middle of the proximal part of the flap. This incision served for tracing a longer flap’s pedicle proximally (see Fig. 3).

Fig. 3. Flap planning design for Radial forearm flap.

We raised the flap distally. Dissection was based on suprafascial plane preserving the superficial radial nerve and all tendons. The radial artery with vena comitantes and cephalic vein were ligated. Incision was performed up to deep fascia on the ulnar and radial border of the flap. Dissection was continued based on subfascial plane until identification of lateral intermuscular septum. All the muscular and periosteal branches of radial artery were ligated. The radial border of flap was incised and raised based on subfascial plane. The pedicle was traced. Lazy-S incision was performed over the proximal border of the flap. The proximal part of the radial artery was traced and ligated distal to the brachial bifurcation after wound bed preparation just before inset of flap. Pedicle length of 11cm harvested comprised of radial artery with vena comitantes and cephalic vein. Throughout the flap raising procedure, distal circulation was examined to ensure good perfusion to the hand.

On the recipient site, the facial artery, retromandibular vein, and eternal jugular vein were traced and prepared. The proximally based fasciocutaneous radial forearm flap was placed on the floor of the mouth with distal part of the flap facing mandible. The proximal part of the flap was placed in the posterior part of oral cavity. The pedicle was tunneled through subcutaneously to reach the recipients’ vessels in the neck. End to end micro anastomosis performed. The radial artery was anastomosed to the facial artery. A vena comitant was anastomosed to the retromandibular vein and the cephalic vein anastomosed to external jugular vein.

The distal part of the flap was sutured to the edge of the alveolar mucosa. Part of the flap was de-epithelized before in-setting over the alveolar mucosa. The tip of the flap was folded over before suturing to the remaining tongue edge (Fig. 4—6). The de-epithelized part was folded over before inset providing extra soft tissue volume to the floor of the mouth.

Fig. 4. Part of skin paddle was deepithelized prior to inset of flap.

Fig. 5. Flap inset to the floor of mouth with distal part covering the anterior defect and proximal part covering the posterior defect. The pedicle tunnelled subcutaneously to reach the neck recipient vessels.

Fig. 6. Radial forearm flap in-setting intraorally suturing to the native tongue edge and floor of mouth.

Outcome

One year later, the reconstructed tongue appeared slightly bulky. However, he was able to swallow and eat a normal diet. The taste over the native tongue was normal. He has slight slurring of speech due to reduced neotongue mobility secondary to contracture. The tip of his tongue was not able to reach the lower lip. The epithelial surface of the flap was well mucosalized (Fig. 7). He completed 35 fractions of radiotherapy which had partly contributed to the contracture. There was no recurrence. The donor site over the left forearm was grafted and healed within 3 weeks (Fig. 8). There was mild hypertrophic scar over the radial side which is managed by scar massaging and pressure garment application.

Fig. 7. The epithelial surface of the flap was well mucosalised.

Fig. 8. The donor site over the left forearm was grafted and fully healed. There was a small amount of hypertrophic scarring over the radial side.

Discussion

The tongue is a very important organ of the body. It consists of oral and pharyngeal parts. The oral part is responsible for speech, mastication, oral hygiene, and oral phase of swallowing while the latter is responsible for smooth pharyngeal phase of swallowing and aspiration prevention.

The radical surgical treatment of tongue SCC requires a partial to total glossectomy which always results in a significant tongue defect and floor of mouth defect due to an optimal three- dimensional safe surgical margin of 1cm [11]. This often has negative impacts on the aesthetic appearance of the oral cavity and swallowing function after surgery [7]. Thus, a tongue reconstruction is always warranted.

The reconstruction aims to maximize the recovery of the tongue’s function which in turn would improve the patient’s recovery and quality of life after surgery. This can be achieved by eliminating the dead space, maintaining the patient’s ability to chew, swallow, speak and restoring the acceptable aesthesis.

The ideal tongue reconstruction achieves watertight closure that separates the neck from the oral cavity. This prevents oro-cutaneous fistula and risk of carotid blowout secondary to salivary exposure. It is important to fold the flap properly to avoid tethering tongue scars which can compromise the tongue mobility. In addition, it is crucial to replenish the dead space by providing sufficient tissue volume that helps in restoring innate function of speech and swallowing. It is pivotal to overcorrect the volume defect as radiotherapy is often indicated after surgery to improve survival and recurrence rate [12]. Radiotherapy is known to cause significant volume loss over time.

Despite the advancement of technology and surgical evolution, it remains a challenge to reconstruct tongue and floor of mouth defects after radical surgery. The reconstruction can range from skin grafting to more complex free flaps. Major determination for choices of reconstruction depends on the defect size, availability of donor vessels at the neck, floor of mouth, any mandibular bone and hypopharynx involvement.

Meanwhile, the types of surgical resections will determine the surgical defect size. Small surgical resection without involving the floor of mouth results in small tongue defect. Partial glossectomy not involving the floor of mouth results in less than a quarter to one third of tongue resected. These defects can be closed primarily, using skin grafting or other skin substitutes and local advancement flap. Partial glossectomy involving the floor of mouth results in loss of one third of the tongue and floor of mouth. In hemi-glossectomy, subtotal glossectomy and total glossectomy, the resulting defect could range from half of the tongue defect to total loss of tongue and extending to the floor of mouth, mandibular and hypopharynx. In these cases, more tissue volume is needed for the reconstruction. Local flaps that could be used for soft tissue coverage are pedicled submental flap, pectoralis major flap, and latissimus dorsi flap. The commonest free flaps that are used for tongue reconstruction are thin ALT and RF flap.

The RF flap is the most suitable flap for the case we described. The defect was moderate in size and half of the native tongue was preserved. Thus, we needed a moderate amount of volume reconstruction. We preferred the RF flap due to its thin and high pliability. It can be easily folded into the shape that mimics the native intraoral contour. When the thin flap is sutured to the remaining native tongue, it helps in mastication, deglutition, and articulation process. Other than that, the RF flap also enables the harvest of long pedicles. A vein graft is not needed. A major advantage of using RF that is not implicated in our case is the possibility of reinnervation using the lateral antebrachial cutaneous nerve. There is a successful reported case of reinnervation of the nerve to the lingual or inferior alveolar nerve to provide sensation to the flap [9]. A disadvantage of using the RF flap is that the donor site is conspicuous. Its scarring can cause contracture which affects hand function. However, our patient’s donor site was well healed. The scar is supple. We are managing it with regular scar massage and pressure garment application. He is satisfied with the outcome of the reconstruction.

Conclusion

The radial forearm flap is a good option for tongue reconstruction when a thin and pliable tissue is needed. It provides acceptable cosmesis, satisfactory functional outcomes and quality of life for patients with oral squamous cell carcinoma. Its benefits outweigh the minor morbidity to the donor site.