Submental Artery Island Flaps (SAIF) for Oral Cavity Cancer: Surgical Technique and Tertiary Care Experience

Abstract

In oral cancer surgeries, oncological outcomes take precious driverseat. But the copassengers like reconstruction, cosmesis, swallowing and speech outcomes deserve equivalent importance. Submental Artery Island Flaps (SAIF) provide an underutilized and extremely versatile option for reconstruction of defects following early stage oral cavity tumour resections. In this prospective observational analysis, we describe the technique, challenges and outcomes of SAIF at our tertiary care institute. Sixteen patients with Stage I and II oral cavity cancers were enrolled between June 2020 to May 2021. Verrucous carcinomas were five and well differentiated carcinomas were 11 patients. After tumour excision and neck dissections, defects were reconstructed with Pedicled submental flaps. Complications and functional outcomes were analyzed over two years. Nineteen percent were ladies and 81% were gentlemen. Median age was 52 years. Tongue tumours formed majority with 56% cases. Largest skin paddle taken was 36 cm². Flap survival was 88%. There were variations in venous drainage of flaps which have been depicted in case figures. There was no report of orocutaneous fistula. Grade 3–4 speech satisfaction was achieved by 81.2% patients at 6 months. Swallowing was excellent, grade 4–5 for 100% of patients at 6 months. One patient had distant metastasis at 7 months and died. SRLR (Submental flap Recurrences) and trismus were zero percent at two years. The unexplored field of submental flaps can be used for oral cancer reconstructions in a versatile way. Donor site easy closures, no scars on face, early resumption of daily activities and short hospital stay makes it one of the ideal options in early stage oral cavity defects.

Introduction

We all have seen the baffling advertisements by our moviestars promoting “exquisite” tobacco products shamelessly. The same products responsible for the life changing oral carcinomas. Battling the war of oral carcinomas has never been easy. In a low resource setting, surgeons aim to provide the best possible reconstruction after tumor excision. With limited budget and facilities, various pedicled flaps are on the table. Trismus, physiological functions, morbidity and cosmesis are kept in mind. The Submental Artery Island flap (SAIF) fits like a box in correctly chosen early stage oral carcinomas [1].

The flap gives good tissue bulk for tongue defects. It forms the floor of mouth quite nicely without disturbing the external surface of mandible. Donor site is closed primarily and merges with the neck incision scar. The color and texture matches aesthetically with the cheek tissue of face [2]. This flap is easy to learn and maneuver. Majority oral carcinoma patients are elderly cohort. They often exhibit lax submental skin. Patients with submental soft tissue excess form excellent candidates.

The SAIF was first mentioned by Martin et al. [3] in 1993. Based on Submental vessels, the pedicle has a good length of 8 cm. If distal end of facial artery is ligated after giving submental vessels, additional length of 2 cm may be obtained. We can obtain flap cover upto 75 cm² [4].

In this study, we share our tertiary care experience of submental flap (SAIF) reconstructions in oral carcinomas and their two year follow up. The techniques we used and complications we faced. Tumour location, staging, reconstructive details, post operative course and outcomes were analyzed. Subjective evaluation of aesthetics, patient satisfaction, problems and their management have been sequentially obtained.

Methods

A Prospective Observational study was conducted in Surgical Oncology Department of Sawai Man Singh (SMS) Hospital, Jaipur between June 2020 and May 2021. Approval was obtained from Ethics Committee SMS Hospital (420/EC/MC 2020). Patients operated for oral cavity cancers and reconstructed with Submental Artery Island Flap (SAIF) were followed for two years.

Inclusion Criteria

Patients included in the study had cT1/T2 cN0 Verrucous/Well differentiated Squamous cell carcinoma of Tongue, Floor of mouth or Buccal Mucosa. All cases had Clinically and radiographically node negative neck which was confirmed with pre operative Ultrasound. Maximum size of tumour which was taken was 4 cm.

Exclusion Criteria

Patients with stage T3/T4 disease or cN1 either on examination or ultrasound, patients requiring segmental mandibulectomy, having metastasis, multiple primary tumors, recurrent disease, submental flap reconstruction for other head and neck sites, defects secondary to benign disease, history of previous oral or neck surgery, history of previous irradiation were excluded from the study.

Methods

All patients were staged according to American Joint Committee on Cancer (AJCC) 8th classification for head and neck tumours (Table 1). Ultrasound neck was performed along with Contrast Enhanced Computed Tomography (CECT) face and neck with puffed cheek and bone views. After proper smoking cessation counselling and pre op rehabilitation, wide local excision of tumor with ipsilateral/bilateral neck dissection and Submental Artery Island flap (SAIF) reconstruction was done in same setting. Submental vessel perforators originating from Facial artery and vein were preserved with fine dissection of bipolar cautery. Ipsilateral Anterior belly of digastric and mylohyoid were taken with the flap. Meticulous selective debulking of level 1A nodal tissue if visible intraoperatively was done in all cases after rising the submental flap. Dental reconstructions were not received by any patient. Patients were followed up for two years from the date of surgery. Post op complications, their management, functional aspects of swallowing, speech, tongue mobility, patient satisfaction, problems with intraoral hair growth in flap, recurrences and metastasis were noted.

Table 1.

Demographic profile, complications and follow up profile of our patients

	Age	Site of disease	Stage	Complication	CT/RT	Recurrence or metatstais	Status (2YR)
Patient 1	54y/M	Tongue	pT2pN0M0	None	No	None	Alive
Patient 2	50Y/M	Tongue	pT2pN1M0	Partial necrosis- managed conservatively	Yes	None	Alive
Patient 3	45Y/M	Floor of mouth	pT1pN0M0	None	No	none	alive
Patient 4	34Y/M	Buccal mucosa	pT2pN0M0	Congestion-managed conservatively	No	None	Alive
Patient 5	36Y/F	Tongue	pT2pN1M0	None	Yes	None	Alive
Patient 6	40Y/F	Tongue	pT1pN0M0	None	No	None	Alive
Patient 7	62Y/M	Floor of mouth	pT2pN0M0	None	No	None	Alive
Patient 8	55Y/M	Buccal mucosa	pT2pN0M0	Flap necrosis-revision with Pectoralis major myocutaneous flap	No	None	Alive
Patient 9	40Y/M	Tongue	pT2pN0M0	Flap necrosis-revision with Radial forearm flap	No	None	Alive
Patient 10	42Y/F	Tongue	pT2pN0M0	None	No	None	Alive
Patient 11	54Y/M	Floor of mouth	pT2pN0M0	Infection-managed conservatively	No	None	Alive
Patient 12	65Y/M	Floor of mouth	pT2pN0M0	Hematoma-managed conservatively	No	None	Alive
Patient 13	61Y/M	Buccal mucosa	pT2pN1M0	Partial necrosis-managed conservatively	Yes	None	Alive
Patient 14	72Y/M	Tongue	pT1pN0M0	Infection-managed conservatively	No	None	Alive
Patient 15	75Y/M	Tongue	pT1pN0M0	None	No	None	Alive
Patient 16	36Y/M	Tongue	pT2pN0M0	None	No	Metastasis at 7 months	Dead

Surgical Technique [5]

After aseptic painting and draping, Pinch test was done for laxity of donor area. Primary closure of donor site was the aim. Ellipse shaped flap marked. Upper incision sketched 1.5 cm below the inferior border of mandible [6]. This will hide the scar and prevent eversion of lower lip. It is marked from angle to angle. Transverse ellipse completed with lower incision 3.5–4 cm below the upper incision. The transverse neck incision marked on ipsilateral or bilaterally in continuity with flap marking. Flaps always raised subplatysmally. Lower neck flap raised upto clavicle. It facilitates closure later on. Thereafter upper cervical flap raised while carefully preserving marginal mandibular nerve. Lips are always kept in view. Facial artery and vein identified beneath marginal mandibular nerve. Facial vein has quite a variable course draining in Internal or External Jugular vein by communicating with anterior division of retromandibular vein. Neck dissection started with level Ib [1]. Lateral to border of anterior belly of digastric, subamandibular gland along with level Ib nodes dissected taking care not to damage the submental vessels. These vessels separated from superiomedial aspect of gland carefully. Level 1b dissection completed with facial vessels. Submental vessels completely skeletonized and in view. At this point hypoglossal nerve and lingual nerve clearly seen. Lingual artery ligated in carcinoma tongue cases. Level 2–4 dissection completed preserving mother vessels. Care is taken of external and internal jugular vein with its origin to facial vein. Wide local excision ± marginal mandibulectomy completed taking adequate margins for primary tumor. Frozen section was not attempted in any of the cases. Beginning with flap harvesting, Subplatysmal dissection started while deepening superior and inferior border of flap. Anterior jugular veins that enter the flap inferiorly are ligated. Anterior belly of digastric and mylohyoid sutured and taken with the flap by incising attachment to mandible [5, 7]. The submental perforators usually travels either deep (70%) or superficial (30%) to the anterior belly of the digastric muscle, and finishes behind the mandibular symphysis. Hence preserved with this maneuver [5]. Geniohyoid muscle visible underneath which should not be taken. Contralateral flap side raised uptil midline. In our institutional practice, deeper continuation of submental vessels is ligated securely to allow rotation of proximally based flap. The distal end of facial vessels is not ligated. Mylohyoid insertion to hyoid is incised to make the flap fully free medially. After the harvesting, flap is delicately hanging on submental pedicle. For Tongue and floor of mouth defects, tunnel is made medial to inferior border of mandible in floor of mouth preserving lingual mucosa of mandible for maintenance of groove and proper flap suturing. For buccal mucosa defect, flap tunnelled between lateral border of mandible and skin. Flap sutured ensuring sutures don’t hamper tongue mobility. Cotton gauze placed for 6 h in bulky flap to prevent molars from crushing into flap and pedicle. Donor site primarily closed with interrupted vicryl round body 3–0 and skin staplers. All patients given feeds through nasogastric tube from Post op day(POD) 1. Clear liquids and swallowing exercises started from POD 2. Figures 1 and 2 describes various steps in cases of SAIF harvest.

Fig. 1.

submental flap reconstruction after excision of floor of mouth tumour and bilateral neck dissection (vein variation 1)

Fig. 2.

Submental flap reconstruction after excision of tongue tumour and unilateral neck dissection (vein variation 2)

Results

Sixteen patients formed the study sample. It consisted of (n = 3, 19%) Ladies and (n = 13, 81%) Gentlemen. Age varied between 34 and 75 years. (Median age-52 years). Majority were tongue tumours-9/16 (56%) while floor of mouth and buccal mucosa tumors formed 4/16 (25%) and 3/16(19%) respectively. According to AJCC 8th classification, Stage I (n = 4, 25%) and Stage II (n = 12, 75%) formed the study group. Eleven patients had Well differentiated squamous cell carcinoma while 5 patients had verrucous carcinoma. During primary resection, four patients of floor of mouth tumor and both patients of buccal mucosa tumor (n = 7/16) underwent composite resection with marginal mandibulectomy. All had unilateral neck dissection, 4 underwent bilateral neck dissections. Submental flaps used were pedicled musculocutaneous. Ten patients had submental vein draining into Internal jugular vein while 6 patients had it draining into external jugular vein. Flap skin paddle ranged from 3 × 3 cm (9 cm²) to 6 × 6 cm (36 cm²). Primary closure was obtained at all donor sites.

Two patients had complete flap necrosis. First of buccal mucosa defect was revised with pectoralis major myocutaneous flap POD 3 and other patient of tongue defect with radial artery fasciocutaneous free flap POD 4. In both patients submental vein was draining into external jugular vein. Two patients had partial necrosis, one patient had venous congestion, two patients had surgical site infections. All of them were managed conservatively. One patient developed neck hematoma requiring local intervention. Overall, flap survival was 88%.

Occult lymph nodal metastasis involving level I in pathology were (n = 2/16, 12.5%). Both underwent post operative radiotherapy. None of these two patients developed recurrence. No patient had indication for pre op or post op chemotherapy. Fifteen patients (93%) were disease free at two years follow up. One patient had lung metastasis 7 months post surgery and died. Recurrences were zero percent.

Functional and aesthetic outcomes were subjectively assessed till two years. None of the patients complained of decreased mouth opening or had trismus on examination. All of them resumed full solid diet, swallowing was Grade 4–5 (Table 2) for 100% patients at 6 months. Patients who underwent tongue reconstruction, all 9 of them undertook speech counselling. Tongue protrusion was beyond incisors for most. (7/9). For floor of mouth reconstructions with SAIF, at 6 months follow up all had good tongue protrusion beyond vermillion, satisfactory articulation & swallowing. One patient of Floor of mouth reconstruction complained of flap bulkiness for which flap debulking was offered but patient preferred counselling and conservative management. Overall 81.2% (13/16) were satisfied with their quality of speech, Grade 3–4 (Table 2).

Table 2.

Postoperative Speech and swallowing evaluation [17].

Source: Sittitrai P, Ruenmarkkaew D, Klibngern H. Pedicled Flaps versus Free Flaps for Oral Cavity Cancer Reconstruction: A Comparison of Complications, Hospital Costs, and Functional Outcomes. Int Arch Otorhinolaryngol. 2022 Jul 11;27(1):e32–e42. doi: 10.1055/s-0042-1751001. PMID: 36714904; PMCID: PMC9879635

Score	Speech	Swallowing
5	All speech is understood (excellent)	Full diet
4	Speech is sometimes not understood (good)	Soft diet
3	Speech can be understood when conversational content is already known (fair)	Liquid diet
2	Speech can sometimes be understood (poor)	Combined oral and feeding tube
1	Nothing is understood (bad)	Exclusively by feeding tube

In follow up of 2 years, most patients did not need radiotherapy (81%). They complained of hair growth in the skin paddle of flap. Five patients managed with hair depilation creams and trimming. Three patients undertook Laser treatment.

All patients reconstructed with SAIF were satisfied with facial aesthetics like neck scar, face symmetry, commissure closure and smile. Figure 3 portrays outcomes in various cases.

Fig. 3.

Follow up of various cases

Discussion

We are not going to argue that gold standard of reconstruction is free flap. Radial forearm free flap (RFFF) provides speech and swallowing grade 4 to 5. (Table 2) But for elderly patients (increased ASA or CCI score) with multiple comorbidities who cannot afford longer operative times and redo surgeries, pedicled flap provide a better option [8]. For early stage oral carcinomas, choices amongst pedicled flaps are pectoralis major myocutaneous(PMMC) flap, submental flap, facial artery myocutaneous(FAMM) flap and infrahyoid flap.

Patel et al. in his comparative study found submental flap (SAIF) to be advantageous over RFFF with shorter operative time, shorter hospital stay and rare wound dehiscence in donor area. More RFFF patients were identified with partial skin graft loss, restriction of grip strength, wrist movements and arm function. Functional outcomes for swallowing and speech, local recurrence rate as well as overall recurrence rates were similar. SAIF should be the first choice in oral cavity reconstructions with reduced patient morbidity and lower care costs [9–11].

PMMC flaps leads to bulky volume, requirement of secondary revisional surgeries and often shoulder dysfunction. In females with heavy breasts, flap harvesting is quite morbid [12]. SAIF has no difference in survival rate when compared to PMMC and deltopectoral flaps [13]. FAMM flap harvesting causes more than 20% trismus postoperatively and needs donor site grafting or buccal fat pad graft. Maximum size of flap which can be taken is 3 cm. Reduced mouth opening is a relative contraindication. SAIF does not cause trismus. Most Patient have grade 4 to 5 diet (Table 2) at 6 months. Size can be taken upto 75 cm² [4, 11]. Due to the removal of excess cervical skin, SAIF causes tightening in the anterior cervical region and this creates a positive aesthetic result [14].

SAIF rarely causes orocutaneous fistula as compared to other flaps. Musculofascial component of flap occludes the dead space resulting from tumor removal and provides watertight closure of defects [10]. The diversity of Submental flap is beautiful. When greater volume is required, the flap can be raised as a musculocutaneous flap with the mylohyoid muscle, or bone tissue can be harvested as an osseomusculocutaneous flap [15].

Tongue reconstructions formed the majority of the cohort (56%). In tongue lesions, the constant discomfort while chewing food makes the patient present early with clinically negative neck nodes. Submental flap makes a good choice for these early lesions as the required length of pedicle is less as compared to other subsites, flap is non bulky and bony reconstruction is usually not needed in early stage tongue lesions.

Time and again, it has been shown no risk of recurrence with SAIF flaps in level I node negative patients [1, 15, 16]. SIF-related locoregional recurrence (SRLR) the term introduced by Miao et al. [17] in 2023 is critical to separate the SRLR from the other local and regional relapses (those away from the flap and non-level I region), as the former seems to be a better measure (rather than the locoregional failure rates) to know if the harvesting of SIF resulted in incomplete clearance of lymph node basins from level-I (that could have potentially harboured occult metastatic disease). Howard et al. did not experience SRLR due to metastatic disease transfer with SAIF technique, which they have applied for 11 years in their studies in cN0. But cN1 is an unfavourable factor for SRLR, overall survival and tumour recurrence [17]. Furthermore, according to the results of elective neck dissection in the clinical No neck, the rate of occult metastasis at level I by Howard was 10%. In this study it was 12.5%.

Talking about SAIF in cN1 nodal disease, numbered studies advocate its use without compromising local recurrence. Patients who have a cervical lymph node diameter less than 1.5 cm, no clinical evidence of extracapsular invasion and whose sentinel lymph nodes are carefully dissected are their eligible candidates [10]. But this is not recommended in most studies.

Evaluating speech and swallowing (Table 2) pedicled versus free flap reconstruction, flap types, and primary site location were not associated with poor results. T staging was the only factor shown to influence poor speech function, while T staging and Large defect size were the factors associated with poor swallowing function [18]. SAIF provided grade 4 to 5 results in more than 80% of our patients. None of the patients developed temporary marginal mandibular palsy. Nerve stimulator may be used in cases of doubt [6, 19, 20].

Length of the pedicle is adequate for oral cavity reconstructions. SAIF can also be used for facial and temporal defects. Techniques to elongate the pedicle are the additional dissection of the pedicle, Y-V procedure, the reverse flow flap, section of the facial vein and microvascular anastomosis. And their choice wants to be mainly conditioned by the site of the defect [21, 22].

Limitations

Small size of study sample, limited follow up of two years, no comparative arm for free flap or other pedicled flaps and no evaluation in node positive patients are some factors which can be improved in further studies. For patient satisfaction instead of subjective tools, objective tools like PROMS (Patient reported outcome measure) or (VAS) Visual analogue score could have been better.

Conclusions

Submental flap is a reliable and cost effective option for oral cavity defect reconstruction. With proper patient selection, oncological safety is not compromised. In female patients where pectoralis major myocutaneus flap is less sustainable and aesthetically displeasing, submental flap forms an excellent choice. Bulky submental area in females and elderly patients helps in providing adequate weight to the flap. All patients in our series were contented with cosmetic appearance. However, Hair bearing nature of flap is a limitation.

Funding

None.

Declarations

Conflict of interest

None.

Ethical Approval

Taken. Obtained from Scientific Committee, SMS Medical College and Attached Group of Hospitals, Jaipur- Ethics number: SMS- 420/EC/MC 2020.

Informed Consent

Obtained from every participant before enrollment in the study.