The soft palate is involved in activities such as speech, swallowing and mastication, and the deformities and dysfunctions caused by defects are significant. The causes of soft palate defects are mainly caused by tumor removal, congenital defects or trauma. The soft palate defect leaves a partial or complete cavernous defect, which leads to the communication of the oral and nasal cavities, loss of palatopharyngeal closure, the patient has symptoms such as slurred speech, nasal reflux during eating and drinking, and serious voice and swallowing dysfunction, which seriously affects the patient’s work, life and study, and greatly reduces the patient’s quality of life and physical and mental health. Therefore, the repair and reconstruction of soft palate defects is very important.
The purpose of soft palate reconstruction surgery is to separate the oral and nasal cavities, reconstruct the normal oral and nasal cavity channels, improve the symptoms of food reflux and slurred speech when eating, restore the function of palatopharyngeal closure, and maintain the normal oral function of patients’ speech and diet. It reduces patients’ fear of post-surgical dysfunction and deformity, improves the cure rate, survival rate and quality of life of survivors, and enables patients to participate in normal social life as early as possible after surgery.
It is still a very difficult problem to solve the function of the reconstructed soft palate (especially the large or total defect of soft palate).
The advantages and disadvantages of each procedure are briefly described below.
Palatal flap
An island-shaped palatal mucoperiosteal flap with a large palatal vascular bundle as the tip is rotated 180 degrees to repair an ipsilateral or near midline defect, or a composite tissue flap with a frontal flap or subchin flap to repair the nasal surface of the soft palate through the defect.
Advantages: The palatal flap is an island flap with well-known vascular blood supply, which is rich in blood supply, easily viable, and of appropriate thickness. The tissue of the palatal flap originates from within the oral cavity and has the same secretory function as the normal oral mucosa, which cannot be replaced by other tissue flaps.
Disadvantages: poor elasticity and limited flap supply. Only suitable for smaller defects. Loss of the palatal vault and malocclusion may occur after palatal mucoperiosteal flap repair in developing patients, indicating the possibility of affecting the development of the maxilla, and therefore should be used with caution in developing children.
Lingual flap
Advantages: The lingual flap is similar to the soft palate in that it is a mucosal-covered muscular organ with similar function, and both are in the same oral environment. As long as the thickness of the flap is above 0.7 cm, the submucosal vascular network can be preserved and the blood supply of the flap can be guaranteed as long as a thin layer of muscle fibers is retained on the flap. The tongue flap is used for soft palate defect shaping, has strong adaptability and resistance to infection, and has good results. The tongue is quite close to the soft palate, and it is very easy to repair a soft palate defect by taking a tongue flap with the tip at the root of the tongue and rotating the suture. The thickness of the flap is moderate and not bulky, and the donor area does not require skin grafting and is less prone to contracture.
Disadvantages: the amount of material taken is limited and it is only suitable for repairing small defects of the soft palate.
Frontal flap
Advantages: there is a superficial temporal artery in the frontal flap with tip, with thick vascular caliber, superficial stroke, constant position, rich flap blood flow, long vascular tip, convenient and flexible transfer, and easy survival. The thickness of the flap is 0.5-1.0 cm, the tip length can reach 12-16 cm, it can be rotated 13O degrees, and it is easy to reach the soft palate without the need of microvascular anastomosis technique. The thickness of the flap is close to the normal tissue of the soft palate, and it can be folded or formed into a composite flap with the posterior pharyngeal wall tissue flap to repair the soft palate through defect. The surgical method is simple and easy to master, the flap is less time consuming, and the flap does not sag significantly and has little effect on the degree of airway patency.
Disadvantages: The frontal donor area needs to be deformed by skin grafting, which seriously affects the aesthetics and is not easily accepted by young and female patients. When the flap is transferred to form a tunnel, part of the rostral process of the mandible needs to be chiseled out and the 2nd and 3rd upper molars on the affected side need to be extracted, which is more traumatic. It takes 3 weeks to break the tip in phase II. Before dissection, the hair and sebaceous glands of the skin at the tip are prone to recurrent infections in the tunnel.
Chin flap
Advantages: The donor flap area is close to the soft palate defect and is in the same field as the cervical contouring procedure. The donor flap area is concealed and does not significantly affect the morphology of the donor area after excision. Due to the large amount of tissue available in the cervical flap, the subchin donor area can be sutured directly without skin grafting. The flap can be up to 9 cm × 6 cm in size, and the donor area can still be directly pulled together and sutured. The flap is soft, elastic, moderately thick (1 cm to 1.5 cm), easy to shape, and the postoperative effect is more satisfactory. The flap has constant vascular anatomy, reliable blood supply, long vascular tips, and safer transfer.
Disadvantages: long scar formation in the donor area, which affects the aesthetics. This flap is contraindicated in patients with previous radiotherapy to the neck. The flap is contraindicated in those with positive subchin lymph nodes. This flap should be used with caution for submandibular lymph node metastases; if the lymph node is within a certain distance from the subchin artery and vein and the size is within lcm, this flap can still be considered. This flap should be used with caution for lymph node metastases in the internal jugular vein chain.
Forearm flap
Advantages: The forearm flap is moderately thick and thin, soft in texture, easy to shape, and has a large repair range. The flap does not cause narrowing of the oral and nasal cavities due to bloating, which affects airway patency. The flap has a long vascular tip and a thick diameter that matches most of the vessels in the maxillofacial region, making flap removal and vascular anastomosis relatively easy. Flap removal and tumor excision can be performed simultaneously, which shortens the operation time.
Disadvantages: the need for vascular anastomosis, high technical requirements, relatively long operation time, large damage to the donor area, the need for skin grafting, forearm and skin grafting donor area are left with more obvious scar. Although the use of forearm flap free graft for total soft palate reconstruction is more satisfactory in terms of shape and restoration of eating and swallowing functions, the forearm flap lacks muscle, thus the reconstructed soft palate lacks motor function, and the reconstruction of motor function of the soft palate is limited.
Insular buccal muscle mucosal flap, cephalic longissimus flap
The soft palate is reconstructed by using bilateral insular buccal muscle mucosal flaps, bilateral long cephalic muscle flaps, combined with posterior pharyngeal wall flaps to reconstruct the shape of the soft palate, improve articulation and food reflux, and restore the function of palatopharyngeal closure.
Disadvantages: The operation is difficult and the anatomical structure of the area is complicated; however, as long as the operator is familiar with the anatomy and fine operation, the operation is easy to master. Soft palate cancer involving the buccal mucosa is a contraindication to this procedure.
Advantages of combined posterior pharyngeal wall flap
The combined posterior pharyngeal wall flap is fixed to the free edge of the formed soft palate, which can cover the nasal side of the flap on the one hand, and play a suspending role on the other hand, which can prevent the formed soft palate from feeling foreign body due to sagging and touching the tongue root, and facilitate the palatopharyngeal closure during articulation, which can make the reconstructed soft palate closer to normal in shape and function. The posterior pharyngeal flap can also act as a closure device. When pronouncing, the lateral wall of the pharynx with normal mobility moves toward the midline and contacts the posterior pharyngeal flap, further reducing the pharyngeal cavity and facilitating complete palatopharyngeal closure.
Postoperative treatment
Appropriate postoperative application of anti-vascular spasm drugs and avoid excessive head movement or excessive speech to reduce the activity of the soft palate and avoid pressure on the tip. Fluid diet. Do good perioperative oral hygiene care and apply systemic antibiotics postoperatively to prevent infection.
Discharge instructions
At the time of discharge, the patient’s transplanted flap was already alive, but the tactile pain sensation in the flap graft area was sluggish because the regeneration process of the terminal dermal nerve on the wound surface took a long time; it took 3 months for the speech and swallowing function to recover gradually. Patients should keep their mouth clean, avoid eating spicy, hard and rough diet for 3 months, avoid catching cold, pay attention to rest and nutrition, quit smoking and alcohol, and have regular outpatient review.