Review on the clinical application of autologous fattransplantation in secondary lip malformation after cleft lip surgery

Chao GUO,Lin-hao JIN,Ya LI ,Meng TIAN,Gang ZHANG

The Department of Plastic Surgery,Affiliated Hospital of Guangdong Medical University,Zhanjiang City,Guangdong Province,524001,China

ABSTRACT Congenital cleft lip is a common congenital defect.At present,surgical treatment is the only effective treatment for congenital cleft lip.Currently,there are many surgical methods for cleft lip.Many scholars continue to the improvement of surgical methods,and the immediate effect after surgery is significantly improved.However,despite the continuous improvement of surgical methods,lip and nose deformities are inevitably left after cleft lip.Because the lip occupies an important aesthetic position in the face,the restoration of secondary lip deformity after cleft lip surgery has important clinical significance.There are individual differences in secondary lip deformities in patients with cleft lip,and there are various methods of rehabilitation.There is no uniform treatment standard.This article mainly focuses on the current treatment progress of secondary lip deformities after cleft lip,especially autologous fat transplantation in secondary lip deformity after cleft lip is reviewed as follows.

KEY WORDS secondary lip malformation after cleft lip surgery;autologous fat transplantation

Cleft lip is one of the most common congenital developmental malformations.The incidence of cleft lip andpalatein newborns isabout1.8%,and cleftliprepair is currently the only effective treatment[1].Primary cleft lip repair is usually performed 3 months after birth.There are many surgical methods for cleft lip,and many scholars have made improvements.Currently,the most commonly used surgical methods are the Miliard method (rotational advancement method) and Tennison method (lower triangular valve method)[2].Although the way of primary lip repair is constantly improved and the immediate effect is improved,because the first-stage repair of cleft lip surgery is usually younger,the various anatomical signs are difficult to distinguish,the congenital dysplasia of lip and nose and the technique of the first lip operation are not perfect,so the secondary lip deformity after lip surgery usually needs to be improved and corrected again or more[3].

Lip deformities secondary to cleft lip surgery may have the following phenotypes:upper lip scar,upper lip too long or too tight,discontinuous lip arch,uneven lip red thickness,the distance between lip peak and bilateral oral Angle,and asymmetry of lip peak notch[4].These clinical manifestations can be attributed to scarring of the upper lip,lack of symmetry of the upper lip,abnormal whistles or red lip notch.And the dynamic beauty embodied in the lip’s concave and convex curve,the three-dimensional appearance,the expression,and the movement make the lip play an important aesthetic position in the various organs of the face[5-6].Therefore,the repair of postoperative cleft lip deformity has important clinical significance in plastic surgery.

At present,due to the degree of cleft lip,the choice of one-stage operation,the professional level of the surgeon,postoperative nursing care and growth and development,there are individual differences in patients with cleft lip secondary to the cleft lip,and the methods of rehabilitation are also various,and there is no uniform treatment standard.This article mainly aims at the current treatment progress of lip deformity after cleft lip surgery,especially the research progress of autologous fat transplantation after cleft lip deformity is summarized as follows.

ANATOMY AND AESTHETIC SIGNIFICANCE OF LIPS

Anatomy of lip aesthetics

The lip part refers to the facial tissue around the upper and lower lip and the cleft of the mouth,which is located in the lower 1/3 area of the face,the upper boundary is the nasal bottom line,and the lower boundary reaches the buccal lip sulcus[7].Onizuka,T[8]believed that the contour of the upper lip was very important and complicated.The contour of the upper lip included the free margin of the red lip,the margin of the red lip,the middle part of the human body,the nasal base,and the nasolabial groove,etc.These anatomical positions had a guiding role in the design of surgical incision.The arched curve at the junction of the skin of the upper lip and the mucous membrane of the red lip is called the lip arch,and the central raised part of the white lip is called the human,which is composed of the steep and sunken human concave.There are two symmetrical high points connected to the middle of the lip arch,which together constitutes the lip peak,and the lowest point of the two lip peaks depression,called the lip arch concave,above are the three important marker points in the operation of repairing the cleft lip deformity[4].The mucous membrane of the upper lip is in the middle of the small tuberosity shape protruding for the lip bead,the boundary line between the dry red lip and the wet red lip is called the red line.Other important anatomical marks of the mouth and lips include mouth Angle,cleft mouth,facial groove,nasolabial groove,etc.[9].

The tissue structure of the lips is the outer skin with the lining mucosa,and the orbicularis oris muscle is closely connected with the skin and mucosa of the lips,which can be divided into five layers:skin,superficial fascia,the muscle layer,submucosa and mucosa[10].The perioral muscles are divided into the upper and lower muscle layers,the upper quadratus labialis,the laughter muscle and the zygomatic muscle,and the lower quadratus labialis,the orbicularis,the buccal muscle,the deltoid muscle and the buccal muscle[11].Branches of the facial artery are the main blood supply to the mouth and lips,including the upper and lower lip arteries,the lower orbital artery and the ophthalmic artery.Branches of the upper and lower mandibular nerves are the main sensory nerves of the mouth and lips,while the motor nerves come from the facial nerve[12].

Aesthetic standards for lips

The aesthetic standard of the lip is:the front lip is symmetrical,the upper lip is thinner than the lower lip,slightly protruding from the front of the lower lip,the Angle of the mouth slightly upturned,located on the vertical line of the pupil line.Lip red line is smooth,color is ruddy,lip peak is located in the person kurtosis,lip bead slightly protruding,the upper lip of the person concave and people in the sharp concave and convex,so that the lip has a three-dimensional sense.The lip arch corresponds to the red line,forming a beautiful red lip profile.The side lip is on the line between the tip of the nose and the chin point.The upper lip covers part of the lower lip,and the slightly warped lip bead makes the lip more flexible[5,7,13].The aesthetic standard of lips is relative,but it can be evaluated from the height,thickness and shape of lips:(1) lip height:the height of the upper lip is 2.00cm-2.45cm for adult males and 1.70cm-2.06mm for females,in which the ratio of oral lips is:upper lip height:lower lip height:mental height:1:1:1[14].(2) lip shape:the red edge of the upper lip has an arc shape,bow shape,and bridge shape,among which the bow shape conforms to aesthetic standards.(3) lip thickness:refers to the upper and lower lip light closed,the thickness of the upper and lower lip,the ratio is 2:3,red lips from the Angle of the mouth to the middle of the gradual thickening.According to the thickness is divided into (1) thin lip,thickness less than 4mm;(2) thick lips,thickness of 5-8 mm;(3) thick lips,thickness in 9～12 mm;(4) thick convex lips,with a thickness greater than 12 mm[15].

SECONDARY LIP DEFORMITY AFTER CLEFT LIP SURGERY

Concept of secondary lip deformity after cleft lip surgery

The concept of postoperative malformation of cleft lip refers to the secondary malformation after primary repair or reoperation of congenital cleft lip.Deng[16]believed that “postoperative deformity of cleft lip” can be divided into the following two conditions:one part is that patients are limited by congenital conditions and must have defects left after the first operation,but they can be corrected by the second operation;The other part refers to the secondary malformation caused by the improper design and operation of the surgeon.Therefore,the secondary lip malformations after cleft lip surgery not only include malformations and developmental malformations caused by congenital limitations of their conditions but also include malformations caused by lack of technology.

Clinical classification of secondary lip deformities after cleft lip surgery

The secondary lip deformities after cleft lip surgery can be mainly manifested as upper lip scar,too long or too tight upper lip,discontinuous lip arch,uneven lip red thickness,bilateral oral Angle distance between lip peak and asymmetric lip peak notch,etc.[4].These clinical phenotypes can be summarized as upper lip scarring,lack of upper lip symmetry,whistle deformity,or red lip notch.

Classification of secondary lip deformities after cleft lip surgery

At present,there is no unified standard for the severity of lip deformity secondary to cleft lip.Now there are several grades in the literature review.

According to the defect area:Small:the defect area accounts for less than 1/3 of the total lip;Medium:the defect area occupies 1/3-1/2 of the whole lip;Large:the defect area accounts for more than 1/2 of the total lip.Jian[17]proposed that the extent of the maxillary incisor teeth and gums before exposure,whistling deformities can be divided into Ⅳ level,is the present domestic is more scholars used the whistle deformity severity classification method.

Class I:1T1crown exposed 1/2,class II:1T1crown fully exposed with2T2crown exposed 1/2 to 2/3 in the proximal longitudinal crown;Ⅲ level:1 t1 crowns all shine the attachment and a gum 1/2,or t2 crowns 2 shows more than two-thirds;Ⅳ level:1 t1 crown and corresponding gum shines and t2 crowns in nearly 2 longitudinal more than two-thirds.Note :(T is the permanent teeth,t is the deciduous teeth ,and 1-8 represents the teeth in different positions[18])

According to the different components of the defect,it can be divided into 4 categories:red lip mucosal defect,white lip defect,white lip,and red lip defect and fullthickness defect.

OBJECTIVES OF SECOND-STAGE REPAIR OF SECONDARY LIP DEFORMITIES AFTER CLEFT LIP SURGERY

The standard of “beautiful normal” proposed by professor Millard,a famous cleft lip expert,has become the goal of plastic surgeons in repairing cleft lip surgery.Yang[19]proposed that the ideal effect of repairing secondary deformities after cleft lip surgery is to achieve the alignment of lip red edges,artificially form a concave and convex lip peak,reduce incisions and scar hyperplasia on the skin of upper lip,plump and red lips without tissue depression,the height of both lips is the same,and the left and right lips are symmetrical,and the upper lip should not be overly tense.It is difficult to repair unilateral lip deformity symmetrically,so it is not necessary to require that the length of bilateral lips be the same,and bilateral lip deformity repair should fully retain the upper lip tissue,to avoid the upper lip too tight.

TREATMENT OF LIP DEFORMITY AFTER CLEFT LIP SURGERY

The treatment of secondary lip malformation after cleft lip surgery is mainly surgical treatment,and the symmetry,lip shape,and lip scar of lip malformation can be corrected by surgery,while tissue filling can be used to correct the red lip depression and lip peak is not obvious.

Surgical treatment

Upper lip scar:cut the scar of the white lip and red lip to the muscle layer,and completely remove the scar if the tissue volume is sufficient.If the tissue volume is insufficient,only the scar epidermis can be removed,and the subcutaneous scar tissue can be retained to form scar flap locally to reconstruct the middle part or lip bead.

The upper lip is not symmetrical:there are various manifestations of the asymmetry of the upper lip,such as unequal lip length on both sides,inconspicuous lip peaks,unequal peak heights on both sides,and discontinuous lip arches.(1) The patients with two sides of the lip length is not equal to the patient,according to the preoperative design can be removed directly redundant tissue;(2) The patients with no lip peak,m-shaped resection is performed in the central part of the lip arch to remove excess tissue.After the incision is sutured in the upper and lower positions,the lip peak and lip depression of the lip arch can be presented.(3) The patients with different height of the two sides of the lip peak,should fully dissociate the adhesion tissue,free orbicularis oris muscle,make it fully rotate or promote,contrapposto suture,and to make the concave upper lip tissue more plump,sometimes can be incision on both sides of orbicularis oris muscle overlap suture;(4) The patients with discontinuous labial arch,the flap should be cut preoperatively and then sutured after crossing or translocation[4]

Whistle malformation or lipstick notch:correction of whistle malformation or lipstick notch should be considered according to the height and width of a tissue defect,the height of upper lip,the thickness of lipstick and the degree of tension of labial tie.Type Z,V,double V or Z,the v-type combined incision was designed in the oral mucosa.The labial mucosa was incised according to the design line,and the labial ligature was detached,then the mucosal flap was stripped and made,and then sutured in layers after crossing or pushing forward[13].

The patients with red lip depression and insignificant lip peak,tissue materials can be used for filling correction.Common filling materials are autologous adipose tissue,autologous adipose true skin flap,and chemical synthetic materials.

Filling with autologous fat particles by injection

Autologous granule fat is an ideal filling material for soft tissue filling,which has the advantages of extensive sources,convenient materials,good biocompatibility,good filling form,and less trauma,etc.,and has been widely applied in correcting the depression caused by insufficient facial tissue volume[20].After autologous granule fat transplantation in the donor area,the early fat is in a state of ischemia,which requires the infiltration of tissue fluid from the recipient area to obtain the required nutrients and establishes new blood circulation in the recipient area.Studies have also confirmed that the less damage the fat cells suffer in the process of fat aspiration,the more survival rate they have[21].

Low-pressure suction and low-speed centrifugation of fat were used in fat suction to minimize the damage to fat cells during the suction process.The use of multi-layer,multi-tunnel,multi-point injection transplantation allows the transplanted granular fat to have more contact with the recipient area for each minimum volume.This technique,known as “3L3M”,helps increase the retention rate of fat.Besides,some scholars have found that the combination of co-growth factors can increase the survival rate of fat transplantation,and the application of autologous plateletrich plasma combined with autologous fat granules to fill the facial sag in Cervelli[22]showed that the survival rate of fat transplantation and the retention of fat were significantly improved.Yoshimura[23]found that a large number of autologous vascular stromal layer fragment cells (SVF) were found in the lip suctioned fat,the main components of which were ADSCs,which contained multiple types of pluripotent stem cells.The mixture of SVF and granular fat could improve the survival rate of fat and the retention of fat.Klinger et al.[24]proved from the histopathological level that scar structure changes occurred after autologous fat transplantation,and the transplanted fat granules promoted local collagen regeneration,scar angiogenesis,dermal hyperplasia and a series of other changes,which provided the basis for the improvement of scar texture.Koonce[25]through the retrospective analysis of 52 cases of cleft lip postoperative patients with secondary whistle deformity or red lip concave deformity application of autologous fat granules filling can effectively increase the lips organizational capacity,for the light lip deformity,filling material can be a fat lip lack of soft tissue and reshape the lip effect,some patients can better restore symmetry and reconstruction of the lips lip bead.Application of fat transplantation of patients with cleft lip time not sure,some scholars think the first phase of the cleft lip surgery parallel fat transplantation is beneficial,Balkin DM[26]retrospective study,the first phase of the cleft lip surgery and with autologous fat transplantation,followed up for 1 years later found that children with good lip scar is not obvious and lip,and found the infant source ADSCs more abundant than adults source,consider to promote tissuepathologyprincipleofreducingscarhyperplasia.Zellner[27]alsoconfirmedthatpartial tissue removal during cleft lip repair may increase skin tension and lead to more pronounced scarring.While fat transplantation provides a potential source of soft tissue and stem cells,it makes sense to repair the scar appearance and overall lip contour of the cleft lip.

Therefore,autologous fat transplantation can not only play a filling role to improve the appearance of lip deformities but also promote collagen remodeling in the repair process through ADSCs to improve the appearance of scars.

autologous filling with dermal fat flap

The fat flap with dermis is usually excised from concealed parts of the body,which has the advantage of a wide range of sources.The soft texture of the tissue flap with the dermis and the rich capillary network under the dermis can establish blood supply in the early stage after transplantation,and the absorption rate is lower than that of fat transplantation[28].Oksana[29]believed that autologous fat flap with dermis was autologous tissue with strong anti-infection ability,easy survival after transplantation and longer maintenance time.However,there are also some shortcomings such as scar left in the donor area,uneven filling area and hard touch.

The tissue compatibility and safety of fat flap with dermis are unmatched by other biochemical materials,especially suitable for the face with abundant blood supply.

hyaluronic acid filling

Hyaluronic acid constitutes the main component of the extracellular matrix and has good biocompatibility.By filling the lips with hyaluronic acid,the volume can be increased to improve the lip sag,thus achieving the effect of lip augmentation and instant natural shaping[30].The safety of hyaluronic acid is high,and there are fewer complications reported by lip injection.A small number of patients may have local induration,which generally occurs within 72h,and can be dissolved by injecting hyaluronidase without correction[31].The effectiveness of the hyaluronic acid injection depends on the technique of the injector and the quality of the hyaluronic acid selected.

Prosthesis implant

Nurse T believes that the implant of the prosthesis into the lip can effectively increase the fullness of the lip,and the size of the prosthesis can be customized.However,its biocompatibility is poor,and the softness of tissue is quite different from that of lips,so it has some disadvantages such as local hard touch,self-discomfort and influence function[32].

SUMMARY

The secondary lip deformities after cleft lip surgery usually require repeated or multiple operations to perfect and correct the defects.However,new incisions need to be formed again for surgical treatment,and the surgical trauma is large,and new scars are formed.Scar contracture may still lead to secondary deformity.Therefore,at present,minimally invasive treatment of lip deformities secondary to cleft lip is a new research direction.At present,it is better to fill the tissue of lip deformities secondary to cleft lip with lip depression deformities and insignificant lip peaks,while surgical treatment is still needed for lip shape changes.Therefore,it is the focus of future research to seek new individual therapy or explore combined operation for patients with lip deformity secondary to cleft lip,to improve the appearance of the lip,the nature of lip scar and the function of the lip to the greatest extent.