عمليات اصلاح العيوب الخلقية- الشفة الارنبية


 

Cleft lip operation

 

The cleft affects the obvious facial form as an anatomic deformity and has functional consequences, affecting the child’s ability to eat, speak, hear, and breathe. Consequently, rehabilitation of a child born with a facial cleft must involve a multidisciplinary approach and be staged appropriately with the child’s development.

 

The need for intervention must be balanced against its subsequent effect on normal growth. In the child born with a bilateral cleft, the surgeon initially is faced with a protrusive pre-maxilla and the difficulty of achieving adequate columellar length and vertical height to the lip during reconstruction.

 

 

 

 

 

 

 

 

 

 

Bilateral cleft lip repair. (A) The prolabial width is typically set at 4-5 mm. (B) The prolabial flap is elevated to the base of the columella. The adjacent flaps are turned over to create a labial sulcus. (C) The orbicularis oris muscle, dissected from the overlying skin, is approximated across the midline. (D) The skin is approximated, and the Cupid’s bow is created from the lateral vermilion flaps.

 

The overall occurrence of cleft lip with or without cleft palate is approximately 1 in 750 to 1 in 1000 live births, establishing it as one of the most common congenital anomalies.

 

Incidence varies by race, with clefts occurring more commonly in Asians (1 in 500 births), less frequently in whites (1 in 750 births), and even less frequently in African Americans (1 in 2000 births).

These racial variations in incidence are not observed with the isolated cleft palate. In terms of gender, the incidence of cleft lip/palate is more common in males, while the incidence of cleft palate alone is more common in females.

 

The most common presentation is cleft lip and palate (approximately 45%), followed by cleft palate alone (35%) and cleft lip alone (approximately 20%). Unilateral cleft lips are more common than bilateral cleft lips and occur more commonly on the left side (left cleft lip:right cleft lip:bilateral cleft lip – 6:3:1).

 

In a large series reported in the literature, bilateral clefts are observed in approximately 15% of patients with clefts. This translates to an overall incidence of approximately 1 in 5000 to 1 in 6500 births.

 

Clefting is a multifactorial issue, with both genetic and environmental causes cited. The observation of clustered cases of facial clefts in a particular family indicates a genetic basis.

 

Clefting of the lip and/or palate is associated with more than 500 syndromes. The overall incidence of associated anomalies or syndromes is approximately 30% for cleft lip with or without cleft palate and 50% for isolated cleft palate.

 

Pathophysiology

 

In short, the branchial arches are responsible for the formation of several areas, including the mouth and lip. Mesenchymal migration and fusion occurs during weeks 4-7 of gestation. The first branchial arch is responsible for the formation of the maxillary and mandibular processes. The maxillary and mandibular prominences form the lateral borders of the primitive mouth or stomodeum.

 

Mesenchymal migration and fusion of the primitive somite-derived facial elements (central fronto-nasal, 2 lateral maxillary, mandibular processes), at 4-7 weeks gestation, are necessary for the normal development of embryonic facial structures.

 

When migration and fusion are interrupted for any reason, a facial cleft develops along embryonic fusion lines. The embryonic development of the primary palate (lip and palate anterior to the incisive foramen) differs from the secondary palate (palate posterior to the incisive foramen).

 

The developing processes of the medial nasal prominence, lateral nasal prominence, and maxillary prominences form the primary palate. Fusion occurs, followed by “streaming” of mesodermal elements derived from the neural crest.

 

In contrast, the secondary palate is formed by the fusion of palatal processes of the maxillary prominence alone. The difference in embryonic development suggests the possibility of differing degrees of susceptibility to genetic and environmental influences and accounts for the observed variation in incidences.

 

In summary, a bilateral cleft lip results from the failure of fusion of the medial nasal prominences with the maxillary prominences bilaterally.

 

Kernahan developed a classification scheme in which the defect can be classified onto a Y-shaped symbol. In this diagram, the incisive foramen is represented as the focal point. This system has been applied to both cleft lip and palate.

Millard modification of Kernahan striped-Y classification for cleft lip and palate. The small circle indicates the incisive foramen; the triangles indicate the nasal tip and nasal floor.

Presentation

 

As with the unilateral cleft, a wide range of clinical presentations of the bilateral cleft lip and palate is possible, from the simple microform cleft to the complete cleft bilaterally involving the lip, alveolus, palate, and nose. Bilateral cleft lip is typically classified as either complete or incomplete.

 

In addition, the cleft may present with varying degrees of asymmetric involvement of the lip and palate. Any degree of combination of involvement of the lip, primary palate, and secondary palate can exist. Recognizing these potentially asymmetric variations is essential in planning operative treatment and evaluating postoperative results.

 

Treatment planning

 

Orthodontic treatment can be initiated a few weeks following birth, prior to surgical intervention. Other adjunct procedures include lip adhesion, pre-surgical orthopedics, primary nasal correction, and naso-alveolar molding. These procedures attempt to reduce the deformity. Nasoalveolar molding is the active molding and repositioning of the nasal cartilage and alveolar processes with an appliance. This orthodontic intervention takes advantage of the plasticity of the cartilage that likely results from residual maternal estrogens.

 

Relevant Anatomy

 

Understanding normal lip and nasal anatomy is essential to recognize the distortion caused by a facial cleft. The elements of the normal lip include the central philtrum, which is demarcated laterally by the philtral columns and inferiorly by the cupid’s bow and tubercle. Just above the junction of the vermilion-cutaneous border is a mucocutaneous ridge referred to as the white roll.

 

Within the red lip are 2 distinct areas: the dry vermilion (the more keratinized portion of the lip that is exposed to air) and the wet mucosa.

 

The primary muscle of the lip is the orbicularis oris. It has 2 well-defined components: the deep (internal) layer and the superficial (external) layer. The deep fibers run circumferentially from commissure (modiolus) to commissure (modiolus) and function as the primary sphincter for oral feeding.

 

The superficial fibers run obliquely, interdigitating with the other muscles of facial expression to terminate in the dermis, and function to provide subtle shades of expression and precise movements of the lip for speech.

The superficial fibers of the orbicularis decussate in the midline and insert into the skin lateral to the opposite philtral groove, forming the philtral columns. The resulting philtral dimple is centrally depressed, as no muscle fibers directly insert into the dermis in the midline. The tubercle of the lip is shaped by the pars marginalis, the portion of the orbicularis along the vermilion forming the tubercle of the lip with eversion of the muscle.

 

In the upper lip, the levator labii superioris contributes to the form of the lip. Its fibers arise from the medial aspect of the infraorbital rim and sweep down to insert near the vermilion cutaneous junction. The most medial fibers of the levator labii superioris sweep down to insert near the corner of the ipsilateral philtral column and vermilion-cutaneous junction, helping to define the lower philtral column and the peak of the Cupid’s bow

 

Contraindication to cleft lip repair:

  • Malnutrition, anemia, or other pediatric conditions that result in the patient’s inability to tolerate general anesthesia are contraindications to this procedure.
  • Cardiac anomalies that may coexist must be addressed prior to the lip repair.

 

Workup: Examination and lab. Investigations:

 

A thorough physical examination is performed, not limited to the head and neck region, to uncover associated anomalies in the infant presenting with a unilateral cleft lip with or without a palatal cleft. Additional workup is determined by physical findings that suggest involvement of other organ systems.

 

The child’s weight, oral intake, and growth and/or development are of primary concern and must be followed closely. Routine laboratory studies typically are not required, other than a hemoglobin study shortly before the planned lip repair.

Operative details:

 

The rotation-advancement method of Millard advances a mucocutaneous flap from the lateral lip element into the gap of the upper portion of the lip resulting from the inferior downward rotation of the medial lip element. The repair attempts to place the lip scars along anatomic lines of the philtral column and nasal sill. Conceptually, Millard’s approach is elegant but it is not always technically easy to accomplish without some modifications to deal with the wide variation in clefts. As with any other repair, consistency in achieving a good result is operator-dependent.

 

General anesthesia is used with a noncuffed oral endotracheal tube positioned midline. Typically the otolaryngologist then examines the ears; if needed, myringotomy and pressure equalizing tubes are placed.

 

Prior to infiltration with a local anesthetic (0.5% lidocaine with 1:200,000 epinephrine), mark the anatomic landmarks and tattoo them with a methylene blue dye.

Two key elements are involved in the markings: the placement of the final position of the new Cupid’s bow peak and the vertical length of the philtral column to be created on the cleft side. Referring to the diagram, Point 3 is determined as the mirror image of Point 2 based on the distance from the midpoint to the peak of the Cupid’s bow on the noncleft side.

 

The peak on the cleft side, Point 4, is not determined as easily but typically is placed level with Point 2, where the dry vermilion is widest and the white roll above is well developed. The white roll and dry vermilion taper off medial to this point. It is unreliable to determine the peak on the cleft side using the distance between the peak of the Cupid’s bow from the commissure on the noncleft side because of unequal tension of the underlying orbicularis muscle.

 

Once the anatomic points are marked, draw incision lines that define the 5 flaps involved in the lip reconstruction. These are the inferior rotation flap (R) of the medial lip element, the medial advancement flap (A) of the lateral lip element, the columellar base flap (C) of the medial lip element, and the two pared mucosal flaps of the medial (m) and lateral (l) lip elements. Two additional flaps that refine the repair often are used: a white roll flap and a vermilion triangular flap to allow for a smoother transition at the vermilion cutaneous junction and at the vermilion contour.

 

The essential marking is the line that determines the border between the R and C flaps. This line becomes the new philtral column on the cleft side. For the vertical lengths of the philtrum on the cleft side and noncleft side to be symmetric, the length of the rotation advancement flap (y) should equal the vertical length of the philtral column (x) on the noncleft side (distance between alar base and Cupid’s bow peak).

 

For the two lengths, x and y, to be equal, the path of y must be curved as illustrated. In marking the curve, take care to avoid a high arching curve that comes too high at the columellar base to create a generous philtrum, as this significantly diminishes the size of the C flap.

 

While all flaps are marked, the authors typically refine the design of the A flap after the R and C flaps are repositioned appropriately so that it more accurately is tailored to fill the gap left by the inferior rotation of the R flap and the final placement of the C flap.

 

Pare the margins of the cleft and develop the m and l flaps. The l flap can be used to inset into the nasal vestibule lining, and the m flap can be used as part of the orolabial vestibule lining as needed. Alternatively, both flaps can be used to reconstruct the nasal and oro-vestibular lining of the nasal floor depending on the situation. The pars marginalis of the orbicularis typically is tethered by its abnormal insertion and further is pared, allowing the constricted muscle to expand.

 

In the region of the vermilion-cutaneous junction, incise the muscle for approximately 2-3 mm on either side of the cleft paralleling the vermilion border to allow development of vermilion-cutaneous muscular flaps for final alignment.

 

Develop the R and C flaps by incising the line (x) between the flaps to allow inferior rotation of the R flap so that it lies horizontally tension free with Point 3, level with Point 2. For this to occur, release must be at all levels (skin, subcutaneous tissue, muscle, fibrous attachments to the anterior nasal spine, labial mucosa).

 

Occasionally an additional 1- to 2-mm back cut just medial to the noncleft philtral column is required along with a mucosal back cut to allow for adequate inferior rotation of the R flap. The back cut occasionally can be limited to the subdermal portion to avoid lengthening the cutaneous scar. See the image below.

Millard repair. With maximal rotation of the R flap, any residual lip length discrepancy can be corrected with an inferior Z-plasty or a triangular flap. In a secondary correction, further rotation of the R flap can be considered.

 

Correspondingly free the C flap with the medial crus of the alar cartilage and allow it to be repositioned, creating a large gap to be filled by the A flap.

 

Develop the A flap from the lateral lip element for advancement into the gap between the R and C flaps. In developing the A flap, keep the incision along the alar base at a minimum; it rarely is required to extend much beyond the medial-most aspect of the alar base.

 

The key to allowing adequate mobilization of the A flap is the subcutaneous release of the fibrous attachments of the alar base to the piriform margin of the maxilla and not necessarily a continued cutaneous incision along the alar margin. Other surgeons have chosen to mobilize the ala at the subperiosteal level. See the image below.

Millard repair. Millard repair. The medial lip element [R] is rotated inferiorly and the lateral lip element [A] is advanced into the resulting upper lip defect. The columellar flap [C] is then used to create the nasal sill (see text for details).

 

A lateral labial mucosal vestibular release also is required to mobilize the A flap medially and to avoid a tight-appearing postoperative upper lip deformity. Do not forget that the maxillary alveolar arches typically are at different heights in the coronal plane, and the ala must be released completely and mobilized superior medially to achieve symmetry, although ultimately its maxillary support is inadequate until arch alignment and bone grafting can be accomplished.

 

As part of the mobilization of the ala, make an incision along the nasal skin-mucosal vestibular junction (infracartilaginous) where the previously developed l flap may be interposed if needed. Currently, the trend is toward more aggressive mobilization and repositioning of the lower lateral cartilages as an integral part of the cleft lip repair.

 

Widely undermine the nasal tip between the cartilage and the overlying skin approaching laterally from the alar base and medially from the columellar base.

 

While the A flap can be inserted as a mucocutaneous flap incorporating the orbicularis, the authors repair the muscle separately to allow for differential re-orientation of its vectors. Dissect the muscle from the overlying skin and the underlying mucosa to accomplish this and divide it into bundles that can be repositioned and interposed appropriately.

 

Once all the flaps are developed and the medial and lateral lip elements are well mobilized, begin reconstruction. Typically, this begins with creating the labial vestibular lining from superior to inferior and then proceeding to the junction of the wet-dry vermilion with completion of the remainder of the vermilion after the cutaneous portion of the lip is completed.

 

At this point, the labial mucosa can be advanced as needed, with additional lengthening and a back cut to allow for adequate eversion of the lip and to avoid a tight-appearing lip postoperatively.

 

Direct attention to approximating the muscle bundles. Appropriately reorient the nasolabial group of muscles toward the nasal spine. Follow this by approximating the orbicularis, interdigitated with its opposing element along the full length of the vertical lip. Inset the C flap to create a symmetric columellar length and flare at its base. Millard originally described the C flap to cross the nasal sill to insert into the lateral lip element as a lateral rotation-advancement flap.

 

Millard later refined the C flap as a medial superior rotation flap to insert into the medial lip element, augmenting the columellar height and creating a more natural flare at the base of the medial footplate. The latter method occasionally results in a nexus of scars at the base of the columellar with unfavorable healing if the flaps are not well planned. However, others continue to use the C flap in either position as needed. Two of the most common variations described with utilization of the C Flap to correct the hemi-columellar deficiency (Millard II] and the nasal sill alar base region [Millard I].

 

Set the ala base in place. As the C and A flaps and the ala are inset, take care to leave an appropriate width to the nasal sill to avoid a constricted-appearing nostril, which is nearly impossible to correct as a secondary deformity.

 

Approximate the vermilion-cutaneous junction and inset the vermilion mucocutaneous triangular flap. If the lip appears to be vertically short at this point, the authors inset a small, 2- to 3-mm triangular flap into the medial lip just above the vermilion.

 

Use dermal sutures to approximate the skin edges. Final approximation is with either rapidly absorbing sutures or nylon sutures, ideally removed at 5 days. If the cutaneous edges are well approximated with dermal sutures alone, the authors occasionally use a cyanoacrylate-type adhesive.

 

Reposition the cleft alar cartilage with suspension/transfixion sutures and a stent. Further shape the ala with through-and-through absorbable sutures as needed.

 

Postoperative Details

 

Oral feedings: The child who is breastfed, is encouraged to resume uninterrupted breastfeeding after surgery. Bottle-fed children can resume feedings immediately following surgery with the same crosscut nipple used before surgery.

 

Activities: The parents are instructed to avoid giving the child pacifiers or toys with sharp edges for 2 weeks after surgery. No other particular restrictions on activity are necessary. Some centers do advocate the use of Velcro elbow immobilizers on the patient for 10 days to minimize the risk of inadvertent injury to the lip repair. These are periodically removed several times a day under supervision.

 

Lip care: The exposed suture line at the base of the nose and red lip can be cleaned using cotton swabs with diluted hydrogen peroxide, and topical antibiotic ointment can be applied several times a day. The permanent sutures are removed on postoperative day 7. If cyanoacrylate adhesive is used, no additional care is required in the immediate postoperative period until the adhesive film comes off.

 

The parents should expect noticeable scar contracture, erythema, and firmness 4-6 weeks post-surgery, and that this gradually begins to improve 6-12 months after the procedure. Typically, the parents are instructed to massage the upper lip during this phase and to avoid placing the child in direct sunlight until the scar matures.

 

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