Reconstructing Small-Medium Sized Oral Cavity Defects- Our Experience with the Versatile Famm Flap

Abstract

Background

Restoration of form and function of the oral cavity post resection for oral cavity malignancies is an enormous challenge in head and neck reconstructive surgery. The facial artery musculo-mucosal (FAMM) flap is an unexplored, underutilized yet an extremely versatile option for such defects. In this analysis we review the performance of the FAMM flap used to reconstruct tongue/floor of mouth (FOM) defects following tumor resection.

Materials and Methods

In this retrospective analysis, demographic and disease profiles of 15 patients with Tongue and Floor of Mouth carcinomas reconstructed with a FAMM flap between January 2019 to January 2021 were studied. Complications and functional outcomes were analyzed.

Results

Fifteen patients (10 men, 5 women) were reconstructed using a FAMM flap. Mean age of the study sample was 46.46 years (28–60 years). One flap was lost due to complete flap necrosis following venous congestion, two other flaps suffered distal tip necrosis. Three patients developed an Oro-cutaneous fistula, with one going on to develop a surgical site infection of the neck wound. Patients reconstructed for FOM defects had an excellent functional outcome. For patients reconstructed for a tongue defect, 33.33% of patients complained of restricted tongue mobility and 44.44% were dissatisfied with the quality of speech post operatively.

Conclusion

The versatile FAMM flap is a reliable, easy to harvest and scarless flap. It provides excellent cosmetic and functional results FAMM flap allowing early resumption of normal daily activities making it an ideal option to reconstruct small to medium sized oral cavity defects.

Introduction

Reconstruction of defects created after excision of Oral cavity Squamous Cell Carcinomas (OSCC) can be an extremely challenging task. Complexities arising from perplexing anatomy of the head and neck and the alterations in structure and function caused by surgery only compounds the problem. The surgeon aims to not only reconstruct the defect but also provide cosmesis and restore functionality to the oral cavity post reconstruction.

Plethora of options have been available to reconstruct the defects ranging from healing by secondary intention, skin grafts, local and regional flaps and free flaps based on micro vascular reconstruction. Patient factors, tumor factors and most importantly, characteristics of the defect created along with the status of the surrounding structures determines the ideal option to be used.

First described by Pribaz et al. in 1992, the Facial artery Musculo mucosal (FAMM) flap is a versatile option available to reconstruct small and medium sized oral cavity defects. The flap can be pedicled superiorly with retrograde flow from the angular artery or inferiorly with antegrade flow from the facial artery [1]. It consists of mucosa, submucosa, buccinator muscle and part of the orbicularis oris anteriorly. The FAMM flap is a reliable flap which can provide adequate cosmesis, good function for suitably sized and located defects. It performs well even in a previously irradiated patient [2]. We believe that despite such favorable attributes this is a relatively less explored and less utilized flap in our region.

In this retrospective analysis we review our experience with the FAMM flap for reconstruction of small and medium sized defects of the floor of mouth (FOM) and tongue following resection for oral cavity squamous cell carcinomas (OSCC) at these locations. Analysis of the performance of the flap in terms of viability, functional results and complications was done.

Materials and Methods

After obtaining an approval from the institutional ethics committee, a retrospective review was done of the cases for which a FAMM flap was utilized to reconstruct intra-oral defects created post excision of the tumors of the tongue and FOM. The review was conducted in the Department of Surgical Oncology between January 2019 and January 2021.

Inclusion Criteria

Patients included in the study had T1/T2 stage OSCC of the FOM or less than 1/3rd tongue, with maximum width of the tumor less than 3 cm, had a mouth opening of 4 cm or more and were followed up for a minimum period of two years.

Exclusion Criteria

Patients with mandibular invasion meriting a segmental mandibulectomy, those having a disease at sub sites of the oral cavity other than tongue/FOM, stage T3/T4 disease, patients who have received previous radiotherapy in the concerned field or had undergone previous surgery including ipsilateral neck dissection, patients with pre operative oral submucous fibrosis and patients with metastatic disease were excluded from the study.

Hospital data, patient discharge cards and follow up records were used to analyze patient profiles and disease characteristics. All patients were staged according to AJCC/TNM 2018 classification for head and neck tumors using clinical and radiological means including CECT and CE-MRI and underwent a wide local excision along with neck dissection (levels 1–4) preserving the facial vein and facial artery along with its venae comitantes followed by an immediate reconstruction using an inferiorly pedicled FAMM flap. In three patients’ facial vein was not preserved and venous drainage was based on the venae comitantes and a wide base was kept to allow for drainage through the submucosal venous plexus. No patient received osseo-integrated dental implants. Patients were followed up for a minimum of two years from the date of surgery according to institutional protocols. Assessment was made of the status of the flap, complications of the procedure and functional results like speech, swallowing, mouth opening and tongue mobility.

Surgical Technique

Procedure starts with performing the neck dissection (levels 1–4) with preservation of the facial vein, facial artery along with its venae comitantes. facial vein was sacrificed in three cases in which venous drainage was dependent on the submucous plexus and the venae comitantes of the facial artery. Wide local excision of the oral cavity malignancy is then performed ensuring adequate margins.

Dimensions of the required flap are marked on the buccal mucosa between the retro molar trigone posteriorly and oral commissure anteriorly and from just in front of the Stenson’s papilla till the labial sulcus inferiorly. Flap was designed based on the expected trajectory of the facial artery. Doppler was not used to identify the vessel in any case. Dissection starts posteriorly with the incision on mucosa and submucosa deepened to identify the superior limit of facial artery in relation to the flap where it is ligated and divided. Flap is elevated anteriorly till just behind the oral commissure below the facial artery with the dissection being done in the plane between deep fascial fascia and buccopharyngeal fascia and consists of the mucosa, submucosa, buccinator muscle and a part of orbicularis oris muscle anteriorly. Flap is then brought into the neck deep to the skin and subcutaneous tissue of the face and transposed back into the oral cavity either through the FOM defect or by creating a small passage through the FOM into the oral cavity. The flap is then sutures to the FOM/tongue defect ensuring that sutures do not hamper the tongue mobility and a bite block is placed during the procedure if needed to prevent the molars from crushing into the flap and pedicle. Donor site defect was covered with the buccal pad of fat in all cased and was not closed primarily in any case. All patients were allowed feeds through a naso-gastric tube from POD-1. Clear liquids per orally were allowed from POD-2. Secondary sectioning of the pedicle was not done in any case. Figure 1 describes basic steps of FAMM flap harvest.

Fig. 1.

a Marking the flap on the buccal mucosa along the trajectory of the facial artery, b The facial artery and vein are secured during neck dissection, c Flap is harvested with the facial artery and vein securely identified and preserved, d Insetting of the flap to cover a tongue defect after a wide local excision for a malignancy

Results

Fifteen patients diagnosed with OSCC of the tongue and the floor of mouth underwent a wide local excision of the defect along with elective/therapeutic neck dissection (level1-4) followed by reconstruction with a FAMM flap.

The study sample consisted of 10 men (66.6%) and 5 women (33.3%), with a mean age of 46.46 years (28–60 years) Patients were staged according to the AJCC/TNM 2018 classification for head and neck malignancies with 10 patients having T2 disease (66.6%) and 5 having T1 disease (33.3%). FAMM flap was used to reconstruct tongue defects in 9 patients (60%) and FOM defects in 6 patients (40%). All patients underwent a wide local excision of the defect along with neck dissection performed either electively or for a clinically positive node. On histopathological analysis 4 were diagnosed as having N1 disease (26.6%), 2 had N2a disease (13.33%) and 9 patients (60%) did not have a positive node on HPE. Six patients (40%) with a positive node received adjuvant radiotherapy, of which four were operated for carcinoma of the tongue and two were operated for carcinoma of FOM. None of the patients reported any disease recurrence and were disease free at the time of the last contact. A second stage procedure for flap pedicle detachment and insetting was not used in any patient. No patient had received pre-operative radiotherapy.

Three patients (20%) were observed to have developed flap congestion on POD 1–2 with one patient going on to develop a complete flap necrosis (6.6%). Facial vein was sacrificed in all of these three patients and venous drainage was dependent on the venae comitantes of the facial artery and submucosal venous plexus. One patient was relieved of congestion with the drainage of a hematoma that had formed in the neck (Fig. 2).

Fig. 2.

Venous congestion of the flap which got relieved after drainage of a neck hematoma

The patient who developed complete flap necrosis underwent debridement and take down of the necrosed flap followed by reconstruction with the help of a nasolabial flap on POD-7.

Two other patients with one operated for a tongue defect and other operated for a FOM defect developed a partial flap necrosis (13.33%) of the distal end of the flap of size about 0.5–1 cm by POD 1–2. No debridement or revision surgery was needed and patients were managed conservatively.

On evaluation for complications of the procedure, 3 patients (20%) presented with an oro-cutaneous fistula developing on POD 4–6 because of development of a gap between the defect and the flap. Two of these patients were managed conservatively, while one patient developed a Surgical Site Infection (SSI) of the neck wound due to infection of the constantly dripping saliva into the neck. This patient had to undergo debridement and re-suturing.

Table 1 summarizes the demographic, disease and complication profiles of the patients included in the present review.

Table 1.

Demographic, disease and complication profiles of our patients

S.no	Age/Sex	Site	TNM	Complications	Management
1	45/M	TONGUE	T2N0M0	None	–
2	38/M	TONGUE	T1N0M0	None	–
3	41/F	FOM	T2N1M0	Oro-cutaneous fistula	Conservative
4	54/M	TONGUE	T2N0M0	Congestion/complete flap necrosis	Debridement, Nasolabial Flap
5	43/F	TONGUE	T1N0M0	None	–
6	55/F	FOM	T2N0M0	Congestion	Conservative
7	60/M	TONGUE	T1N1M0	None	–
8	58/M	TONGUE	T2N0M0	Partial distal flap necrosis	Conservative
9	46/M	FOM	T2N2AM0	Oro-cutaneous fistula/SSI	Debridement/Re-suturing
10	48/M	FOM	T2N0M0	Partial distal flap necrosis	Conservative
11	40/F	TONGUE	T2N1M0	None	–
12	34/M	TONGUE	T1N0M0	Congestion- Neck hematoma	Drainage of neck hematoma
13	28/M	FOM	T1N0M0	None	–
14	57/F	TONGUE	T2N1M0	None	–
15	50/M	FOM	T2N2AM0	Oro-cutaneous fistula	Conservative

Functional outcomes were subjectively assessed on follow up by the patient as well as the surgical team. Five patients (33.3%) complained of slight difficulty in opening their mouth post operatively and were assessed to have slight trismus which did not prevent adequate oral intake of food in any patient. None of the 15 patients complained of difficulty in swallowing and were consuming normal diet on prolonged follow up. For the patients who underwent reconstruction of FOM defects, no patient complained of difficulty in tongue protrusion or speech and articulation. All of these patients were assessed to have tongue protrusion beyond the vermilion border and normal speech by the surgical team. Three of the nine patients (33.3%) operated for tongue carcinomas were bothered by restricted tongue mobility post operatively with two of these patients assessed as being not able to protrude their tongue beyond the incisors. Four of these nine patients (44.4%) were stressed by the quality of their post operative speech with the surgical team assessment being partially intelligible speech for two patients and unintelligible speech for one patient and an almost normal speech for one patient.

All patients reconstructed for either FOM or tongue defects were satisfied with the post operative aesthetics like facial symmetry, commissure and smile.

Patients undergoing radiotherapy post operatively were not seen to have any difference in functional or cosmetic outcomes in comparison with those who did not receive radiotherapy.

Discussion

Any restorative and reconstructive procedure for intra oral defects, especially the tongue and floor of mouth needs to ensure adequate cosmesis, facial symmetry and post operative functionality including tongue mobility, swallowing and speech and nutrition.

This thin musculo-mucosal flap provides similar hair free tissue to the mucosa that was excised and can be harvested along with neck dissection by carefully preserving the facial artery. Insetting is done during the same procedure as that of the primary tumor resection and because of its great arc of rotation and high Length: Width ratio of 5:1 the FAMM flap offers great mobility [3]. The shortcomings of this flap are that it can’t be utilized in patients with pre -existing trismus as almost 20% of patients complain of decreased mouth opening following the procedure [4]. To ensure primary closure of the donor site, the width of the flap has to be kept at a maximum of 3 cm [5]. Lastly a second stage procedure is sometimes required to detach the pedicle after three weeks of insetting. O’Leary et al. suggested a method to increase the width of the flap by relocating the opening of the Stenson’s duct into the adjacent mucosa after initially lifting the duct along with the flap and is relocated later on which can increase the size and range of the flap [6].

Despite these few drawbacks the FAMM flap can provide good functional and structural restoration.

Other regional flaps which can be used to cover similar defects are the nasolabial flap, platysmal flap, the supraclavicular and the submental flap. The Pectoralis Major Myo-Cutaneous (PMMC) flap suffers from being too bulky which is not aesthetically pleasing and flap insetting can cause tongue fixation [3, 5]. The submental and supra clavicular flap have higher rates of flap failure and a compromised neck dissection as the surgeon might leave some fibro-fatty tissue behind while cautiously isolating and securing the pedicle to provide adequate blood supply to the flap [7, 8]. Infra hyoid flap is also suitable for FOM reconstructions as it provides a supple, non-bulky skin cover. The risk of a compromised neck dissection and an imperative need to save the external and internal jugular vein to prevent necrosis are the relative drawbacks of the infrahyoid flap [9]. The nasolabial flap leaves the patient with a big scar on his/her face which can lead to cheek distortion and ectropion and cosmetic dissatisfaction [10]. Apart from the FAMM flap and the platysmal flap, all other flaps will lead to patient complaining of intra oral hair growth post operatively. The thin and pliable platysmal flap is ideal for reconstructing FOM defects but has unpredictable results in situations where ipsilateral neck dissection has been performed [9, 11]. Previous neck surgery and irradiation are also relative contraindications to usage of this flap [3]. Similar to the FAMM flap is the buccinator artery based buccinator musculo-mucosal flap. But as this flap has a smaller arc of rotation and achieves a smaller length it can be used only for lateral FOM defects [12].

In our review 3 patients suffered from venous congestion of the flap of which one developed a complete flap loss and had to be debrided and reconstructed using a nasolabial flap. Other two were successfully managed conservatively. Although a number of authors have mentioned that preservation of facial vein is not vital for venous drainage of the flap [5, 13], in our series venous congestion was probably caused in all the three cases due to loss facial vein during neck dissection, with venous drainage being dependent on the venae comitantes and submucosal venous plexus. Similar rates of flap loss and venous congestion were reported by Joshi et al., Ashtiani et al. and O’Leary et al. with rates of complete or partial flap necrosis ranging between 5–14% [6, 14, 15]. Ayad et al. reported a 20% rate of partial flap necrosis in patients being reconstructed for primary FOM defects. The higher rate was attributed to an older age and co-morbidities of the study sample [3]. Only two patients in our study group had to undergo revision surgery for complications, one for debridement of the flap lost due to complete necrosis and other for the patient who developed an SSI following an oro-cutaneous fistula. The remaining patients having congestion or partial flap necrosis were managed with conservative treatment.

Although Previous chemotherapy and radiotherapy are not contra-indications for utilizing this flap, O’Leary et recommended that this flap should be avoided in patients receiving pre -operative radiotherapy due to difficulties in finding boundaries of the residual tumor in such patients and complications like integration failure that they faced in previously irradiated patients [6].

Other functional results in terms of post operative cosmesis (Fig. 3), oral competence and articulation were largely satisfactory and similar to previous reports. As reported by Jowett et al., cosmetic and mimetic function is largely dependent on preservation of the facial nerve branches and muscles like zygomaticus major and lip elevators [8]. Extremely careful dissection is needed to safeguard these structures as they are almost adherent to the plane of dissection of the flap. Like previously mentioned studies, our series also reports minimum impact on smile, facial symmetry, lip elevation and depression functions. Jowett et al. further identified complications like upper lip anesthesia due to infra-orbital nerve injury and loss of perioral rhytids which probably resulted from injury to orbicularis oris [8]. The present study did not evaluate these complications.

Fig. 3.

Acceptable cosmesis and facial symmetry post reconstruction with FAMM flap

Limitations

The small sample size and the retrospective nature of the present study prevents it from objectively analyzing the spectrum of conditions for which the flap can be used and post operative functional outcomes.

Another limitation was the failure to study effects of pre-operative radiotherapy on the procedure as none of our patients were irradiated before surgery.

Conclusion

The FAMM flap is a reliable option to reconstruct small and medium sized intra oral mucosal defects of the FOM and tongue with similar tissue harvested and inset in the same sitting. This is a versatile, cheaper option with good functional results and cosmesis which allows early patient ambulation and nutritional intake and is easy to harvest and use. There are minimal donor site morbidities and circumvents issues like compromised neck dissection to ensure adequate vascular supply, intra oral hair growth, excessive bulk and a large facial or donor site skin scar. The versatility of the flap lies in numerous locations and indications for which it can be used. Despite such overwhelming advantages it continues to be an under-utilized flap in operation theatres and under discussed option in literary settings.

Funding

None.

Declarations

Conflict of interest

None.

Institutional Ethics Committee Approval

Taken.

Informed Consent

An informed consent was obtained from every participant before enrolling them in the study.