Efficacy of superiorly based nasolabial flap in post-mucor infrastructure maxillectomy defects

ABSTRACT

Purpose of the Study:

Reconstruction of post-mucor oral cavity defects (ranging from simple alveolectomy defects to complete maxillectomy defects) will improve the function, esthetics, and general health of an individual. Various surgical and prosthetic options are available for the successful reconstruction of the defects. The nasolabial flap has versatile role in the reconstruction of oral cavity defects because of its proximity to the defect area, optimal esthetic results, and less surgical morbidity unlike distant flaps. In this study, we assessed the efficiency of the nasolabial flap in reconstruction of post-mucor infrastructure maxillectomy defects in 42 individuals by comparing the pre-surgical and post-surgical abilities to speak and swallow.

Patients and Methods:

Patients with post-mucor infrastructure maxillectomy defects were involved in this prospective study. Fifty-one patients who met the inclusion criteria were selected. All the study parameters (swallowing ability, hypernasality, speech intelligibility, and subjective satisfaction of an individual) were assessed preoperatively. Reconstruction of the defect was done with a superiorly based nasolabial flap. Nine patients were lost to follow up, and 42 patients were followed up for six months to evaluate the study parameters.

Results:

Pre-surgical and post-surgical statistical data analysis shows that there is a significant improvement in the functional outcomes of an individual. 76% of the patients showed no signs of nasal regurgitation, dribbling of saliva, or coughing upon swallowing after reconstruction of the defect with nasolabial flap. Significant improvement in speech after the closure of maxillary defect was observed as 93% of patients had socially acceptable speech and 64.5% had normal intelligible speech postoperatively. Upon subjective satisfaction assessment, 64% of the patients were satisfied with the treatment procedure.

Conclusion:

Closure of oro-antral communication and creation of a seal between oral and nasal cavities using the nasolabial flap leads to improvement in the function of an individual in terms of speech intelligibility and swallowing ability. The nasolabial flap can be considered as an optimal option for managing post-mucor infrastructure maxillectomy defects by restoring functional and psychosocial well-being of a person.

INTRODUCTION

COVID-19 pandemic caused the world “locked down” for months. Post-COVID phase was not uneventful for all the individuals as an appreciable percentage of the population went through a post-COVID burden like post-COVID depression, immunosuppression, and superinfections. One of the post-COVID complications which is of concern to a craniofacial surgeon is rhino-orbital-cerebral mucormycosis (ROCM). The post-COVID prevalence of mucormycosis is 50 times that of pre-COVID period, which highlights the global burden of mucormycosis.[1]

Management of rhino maxillary mucormycosis is the scheduled dosage of anti-fungal therapy with complete debridement of the diseased bone and multimodality therapy from various specialities like craniofacial surgery, oto-rhinology, ophthalmology, neurology, and maxillofacial prosthodontics.[2]

Surgical reconstruction options for intraoral defects range from local flaps to free flaps. The nasolabial flap being the local flap can be easily tunneled into the oral cavity for the reconstruction of defects over maxillary and mandibular alveolus, buccal mucosa, the floor of the mouth, and closure of oro-antral communication.[3] Superiorly based nasolabial flap is a viable option to reconstruct the intraoral defects involving the maxillary alveolus, adjacent palate, or floor of the maxillary sinus (closure of oro-antral communication). Through this article, we would like to assess the efficacy of nasolabial flap in case of infrastructure maxillectomy defects created post-surgical debridement of mucormycosis. According to author’s knowledge, this is the first study to evaluate the efficacy of nasolabial flap in surgical reconstruction of intraoral defects in post-mucor individuals.

PATIENTS AND METHODS

It is a prospective study on patients with oro-antral communication and/or oro-nasal communication created post-surgical debridement in the case of rhinomaxillary mucormycosis. The study was conducted in the department of oral and maxillofacial surgery in a tertiary care institution in Northern India from May 2022 to November 2022, after obtaining informed consent from the patients and institutional ethical approval (Ref. code: XII-PGTSC-IIA/P1) abiding by ethical principles stated in the declaration of Helsinki.

Inclusion criteria

• 1) Patients with alveolar defects, oro-antral/nasal communication, created due to post-ROCM infrastructure maxillectomy, in which primary closure is not feasible.

• 2) Disease-free period of at least five months as seen clinically and in radiographs.

• 3) The patient who is not willing to wear an obturator.

Exclusion criteria

• 1) Remanent/recurrence disease detected clinically/radiographically.

• 2) Patient not consenting to the procedure.

• 3) Patients with underlying medical comorbidities contraindicating the surgical procedure.

Two hundred and seven mucormycosis patients were reported to our institution, out of which 174 patients underwent infrastructure maxillectomy. Fifty-one patients met the study criteria. They underwent surgical reconstruction of intraoral defects by the nasolabial flap. Nine patients were lost to follow up, and 42 patients were followed up for six months to assess the study parameters

Surgical technique

All patients were treated under local anesthesia. A night before the surgery, Tab. Alprazolam (0.5 mg) was given. Analgesics were administered intravenously during the procedure. Local infiltration was given using 2% lignocaine hydrochloride with a vasoconstrictor. Bleeding induced over the surgical margins of the recipient site [Figure 1] to promote healing. A fusiform shaped superiorly based nasolabial flap was marked on the cheek as per the size of the defect. The superior limit of the flap was caudal to medial canthus along the nasofacial junction, and inferior limit was at the level of the corner of the mouth with the medial border along the nasofacial groove. A random patterned flap is elevated in an “inferior to superior fashion” in a plane superficial to the facial musculature, including the subdermal plexus in subcutaneous tissue [Figure 2]. The superiorly based nasolabial flap was then transferred intraorally through a transbuccal tunnel to cover the defect area [Figure 3]. A tunnel should have adequate width to prevent compression of the pedicle unless it will lead to flap congestion. Two-staged technique was opted, and the flap was sutured in a vertical mattress manner to the recipient site. Revision of the pedicle was done after three weeks. We did a weekly follow-up for four weeks and then monthly follow-up for three months to assess the study parameters [Figure 4]. Figures 5 and 6 show the radiological and clinical images of a patient, respectively.

Figure 1.

Clinical picture showing the intraoral defect

Figure 2.

Superiorly based nasolabial flap harvesting

Figure 3.

Nasolabial flap tunneled into the oral cavity

Figure 4.

Clinical picture after reconstruction of the defect with nasolabial flap at 1 month follow-up

Figure 5.

Image showing radiographs (a) 3D reconstructed view of computed tomography (CT) (b) MRI showing the maxillary alveolar defect (c) Coronal section showing the oro-antral communication in relation to left maxilla

Figure 6.

Clinical images of a patient (a) Intra-oral defect area (b) Nasolabial flap sutured in position (c) Postoperative image showing healing of the donor site (d) Nasolabial flap during third month follow-up

Study parameters

1) Swallowing ability

Because of the lack of adequate lip support and nasal regurgitation due to oro-antral communication, swallowing capacity will get compromised. Nasal regurgitation, dribbling, or coughing while swallowing suggests compromised swallowing capacity.

2) Hypernasal speech:

Oro-nasal communication leads to abnormal resonance in voice due to increased airflow through the nose during speech. Hypernasality leads to unintelligible speech.

Hypernasality for each patient was assessed pre-surgically and post-surgically by three people

1. Speech therapist

2. Oral surgeon

3. A family member of the patient.

Grading of hypernasality is as follows:[4]

0-WNL

• 1- Mild (socially acceptable speech, nasality on high vowels and patient satisfaction)

• 2- Moderate (socially unacceptable speech, nasality on high and low vowels)

• 3- Severe (Very unacceptable speech)

3) Speech intelligibility.

Hypernasality, lack of palate-tongue contact, and lip seal make the speech unintelligible. Speech grading was done before and after the reconstruction of the intraoral defect using a seven-point speech intelligibility rating scale [Table 1].[5]

Table 1.

Speech intelligibility grading scale

Description of speech	Point scale
Normal	0
Can understand without difficulty; however, felt speech is not normal	1
Can understand with little effort occasionally need to ask for repetition	2
Can understand with concentration and effort specially by sympathetic listener	3
Can understand with difficulty and concentration by family but not others	4
Can understand with effort if content is known	5
Cannot understand at all even content is known	6

4) Subjective satisfaction

Reconstruction of palatal defects not only improves the swallowing, speaking, and general health of the patient, but also leads to an increase in the mental well-being of an individual. Subjective satisfaction of the patient post-surgically was measured using a five-point Likert scale.

Scale:

1. Very satisfied

2. Satisfied

3. Neither satisfied nor satisfied

4. Somewhat dissatisfied

5. Dissatisfied.

OBSERVATIONS AND RESULTS

This study consisted of 85% of males and 15% of females belonging to the mean age group of 49 ± 12 years. 74.5% of the patients had unilateral defects, 12% had anterior maxilla involvement, and 13.5% had bilateral defects. None of the patients in our study had any cutaneous defect. Range of disease-free period in the sample population was 5–11 months. Pre-surgical and post-surgical statistical data analysis showed that there is a significant improvement in the functional outcomes of an individual. According to chi square test and Wilcoxon signed rank test, a significant improvement was found in all study parameters. 76% of the patients showed no signs of nasal regurgitation, dribbling of saliva, or coughing upon swallowing after reconstruction of the defect with nasolabial flap [Table 2]. 5% of the patients showed compromised swallowing pattern postoperatively. Significant improvement in speech after the closure of maxillary defects was observed as 93% of patients (Grade 0 and Grade 1 of hypernasality score) had normal socially acceptable speech postoperatively [Table 3]. Reduced hypernasality increased the speech intelligibility with 64.5% patients having normal intelligible speech postoperatively. [Table 4] Majority of the patients (64%) are satisfied with the treatment procedure because of the improved functional outcomes and psychological well-being of an individual [Figure 7].

Table 2.

Statistical analysis comparing pre- and post-surgical swallowing ability

Criteria	No complication	N	N + D/N + C	N + D + C	chi sq	P
Preop	-	18 (42.5%)	15 (36%)	9 (21.5%)	53.11	<0.001
Postop	32 (76%)	2 (5%)	6 (14.5%)	2 (5%)

N=nasal regurgitation; D=dribbling, C=coughing

Table 3.

Statistical analysis comparing pre- and post-surgical hypernasality of speech

Grading	Grade 0	Grade 1	Garde 2	Grade 3	chi sq	P
Preop	-	12 (28.5%)	12 (28.5%)	18 (43%)	53.94	<0.001
Postop	36 (86%)	3 (7%)	2 (5%)	1 (2%)

Table 4.

Table showing pre and post-surgical values according to speech intelligibility scale

Score	0	1	2	3	4	6	7
Preop	8 (19%)	4 (9.5%)	17 (41%)	11 (26%)	2 (4.5%)	-	-
Postop	27 (64.5%)	7 (16.5%)	5 (12%)	3 (7%)	-	-	-

Figure 7.

Distribution of cases according to subjective satisfaction

DISCUSSION

Mucormycosis is an angio-invasive disease caused by fungi of the order mucorales. Through inhalation, it reaches the paranasal sinuses, from where it will spread to adjacent structures causing rhino-orbito-cerebral mucormycosis.[6] Currently, the incidence of mucormycosis is increased 50-fold from pre-COVID rates because of the immunosuppression caused by the COVID-19 infection and the steroids used in treating the COVID-19 infection.[7] Management of mucormycosis includes anti-fungal therapy and debridement of necrotic tissue to reduce the fungal load.

Mucormycosis can involve the entire palate, maxilla, nasal cavity, and orbit. The surgical defect can range from simple oro-antral communication to a defect necessitating the reconstruction of the whole maxilla.

These defects in post-mucor individuals can be managed by prosthetic rehabilitation using obturator placement or by using surgical reconstruction (options including but not limited to local flaps like a temporalis flap, buccal fat pad flap, nasolabial flap, tongue flap; regional flaps like pectoralis major myocutaneous flap and free flaps like anterolateral thigh flap, radial forearm flap, free fibular flap, and iliac crest graft) and patient-specific implants.[8]

Few authors suggested that immediate reconstruction can be performed in case of mucormycosis defects, ensuring that the margins are free of fungal hyphae. The average time of delayed reconstruction was 16.7 weeks.[9]

The main reconstructive goal in the case of oro-antral communication in case of post-mucor individuals is to maintain a proper seal between the oral cavity, nasal cavity, and antrum to facilitate normal deglutition and speech. Many patients are not compliant toward wearing an obturator because of a lack of proper retention and added weight of the prosthesis.

Patients affected with mucormycosis are immunocompromised so are not good candidates for extensive surgeries and free flap reconstruction techniques because of the effect of fungi on vasculature as well.[10] So, among the local flaps nasolabial flap can be a reliable and less morbid alternative to reconstruct the infrastructure maxillectomy defects, as it can be harvested as a random flap with a thickness sufficient to restore oral cavity defects.

The history of the nasolabial flap dates to 600 BC when Sushruta addressed “cheek flap” in his recordings. In 1868, Karl Thiersch used a superiorly based nasolabial flap to close a palatal fistula resulting from a gunshot wound. Half a decade later, Johannes Esser used the inferiorly based nasolabial flap and named it as “Esser’s skin flap” to close a palatal fistula.[11] In 1980, Elliott H Rose used a nasolabial flap pedicled over the facial artery and vein to reconstruct the floor of the mouth.[12] Since then, the nasolabial flap is having a wide range of applications in the reconstruction of orofacial defects like the closure of oro-antral communication, reconstruction of facial defects over the nose, ala and tip of the nose, upper and lower lip, buccal mucosa, the floor of the mouth, and in case of oral submucous fibrosis.

The nasolabial flap can be harvested as both an axial and random pattern flap. Inferiorly based axial patterned flap is based on the facial artery; superiorly based axial patterned flap is based on the infraorbital artery. The randomly patterned flap is based on the subdermal plexus lying within the subcutaneous fat layer.[13] Recent studies have shown that we can choose nasolabial flap even after ligation of the ipsilateral facial artery because it also receives blood supply from the infraorbital artery, the transverse facial branch of the superficial temporal artery. The nasolabial flap shows excellent survival even after radiotherapy.[14]

Defects created post-maxillectomy can be classified by Brown et al. as depicted in Figure 8.[15]

Figure 8.

Brown’s classification of maxillectomy defects

Patients with Class 2 browns defects (either unilateral or bilateral) are ideal candidates for reconstruction using a nasolabial flap.

Advantages of nasolabial flap are as follows:

• 1) less morbid to patient

• 2) can be used as a both axial and random patterned flap

• 3) less bulky than regional flaps and free flaps

• 4) can be performed as a minor oral surgical procedure under sedation, eliminating the risk of general anesthesia.

Disadvantages of nasolabial flap are as follows:

• 1) cannot be used if the disease process involves the skin of the donor area

• 2) intraoral hair growth, especially in males

• 3) scar over the face

• 4) chances of compromised oral competence in case of bilateral nasolabial flap.

Successful reconstructive surgery generally will be discussed in terms of flap vitality. But the restoration of function and improving quality of life plays a very vital role in terms of the patient’s needs.

In the case of individuals with post-mucor maxillectomy defects, oro-antral communication and lack of seal between oral and nasal cavities lead to compromised swallowing and speaking ability. Clinical assessment of a swallowing pattern of a healthy individual shows no signs of dribbling, coughing, or nasal regurgitation. In the case of post-maxillectomy or oro-antral communication, depending on the extent of the defect, the swallowing pattern will get disturbed, leading to nasal regurgitation, coughing, or dribbling. Considering these three as the parameters to assess the swallowing capacity, the sample population divided into four categories ranged from individuals with no difficulty in swallowing to individuals with nasal regurgitation, coughing, or dribbling while swallowing. Statistical analysis showed a significant improvement in the swallowing capacity of an individual after reconstructing the defect with a nasolabial flap. 76% of the patients postoperatively showed no complications during swallowing [Table 2].

Altered speaking ability because of oro-nasal communication and palatal defects as they pose difficulty in articulation of palatal consonants leads to hypernasality and reduced speech intelligibility. Preoperative and postoperative analysis of hypernasality showed a significant improvement in speech after the closure of maxillary defects as 93% of patients have socially acceptable speech postoperatively [Table 3].

Reconstruction of oral cavity defects and reduced hypernasality makes speech more intelligible [Table 4] and improves the psychological strength of an individual. In the survey to assess the subjective satisfaction of an individual, most of the patients (64%) are satisfied with the treatment procedure [Figure 7]. Preoperatively majority of the patients are dependent on Ryles tube for feeding purposes. Reconstruction of oral cavity defects facilitates the oral intake of food and improves general health and psychological well-being of individual.

Complications encountered post-surgically are flap dehiscence (two cases) leading to persistent oro-antral communication (two patients), tip necrosis (six patients), and hematoma formation (one patient). Re-suturing was done to manage flap dehiscence and communication. Conservative management was done for tip necrosis and hematoma.

CONCLUSION

The nasolabial flap can be considered an acceptable reconstruction option for the oral cavity defects and closure of oro-antral communication in patients with post-mucor infrastructure maxillectomy defects because of less surgical time, the robust blood supply of the flap, and reduced donor site morbidity. Reconstruction using a nasolabial flap improves the quality of life by improving speech intelligibility, swallowing, and overall health of an individual.

Ethical Statement/Confirmation of patient’s permission

This procedure is as per The Code of Ethics of the World Medical Association (Declaration of Helsinki).

Consent to participate

Entire procedure was explained, and consent is obtained from the patient.

Declaration of patient consent

The authors declare that they have obtained consent from patients. Patients have given their consent for their images and other clinical information to be reported in the journal. Patients understand that their names will not be published and due efforts will be made to conceal their identity but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.