Stanford University School of Medicine, Department of Surgery, Stanford, California

Transcription

1 THE RESTRICTIVE PHARYNGEAL FLAP By JAROY WEBER, Jr., M.D., ROBERT A. CHASE, M.D. and RICHARD P. JOBE, M.D. Stanford University School of Medicine, Department of Surgery, Stanford, California THE historical background of pharyngeal flap has been reviewed by many authors (Broadbent and Swinyard, 1959 ; Stark and DeHaan, 196o ; Blackfield et al., 1963 ; Skoog, 1965). Passavant first sutured the velum to the posterior pharynx in Schoenborn fashioned the first inferiorly based pharyngeal flap and later used a superiorly based one. Controversy over the efficacy of the superior versus the inferiorly based flap must have begun at this point. Since then, surgeons such as Rosenthal, Blanchart, Astoul, Moore and Conway have advocated the use of inferiorly based pharyngeal flaps ; while Burian, Skoog, Edgerton, Owsley, the authors, and others have favoured a superiorly based flap (Conway and Goulain, 196o ; Edgerton, 1965 ; Skoog, 1965). Pharyngeal flaps have been used as primary procedures in conjunction with palatal pushbacks and closures and have also been used as secondary procedures with and without pushbacks (Conway, 1951 ; Stark and DeHaan, 196o ; Cox and Silverstein, 1961). Many variations in the surgical technique of pharyngeal flap attachment and design exist. The purpose of this report is to describe patients who have functionally restricting flaps and to discuss the patho-physiology involved. Methods.--Approximately 200 patients have been evaluated in the Stanford Cleft Palate Clinic in the past five years because of evidence of velopharyngeal incompetence. Evaluation has consisted of physical examination, respiratory studies (Chase, 196o), speech ratings by speech pathologists and cin6 voice radiography. Results.--Five cleft palate patients have been seen whose pharyngeal flaps were low on the posterior wall and who had hypernasal speech and nasal emission on respiratory studies. Visual and X-ray examination have shown these soft palates to be held down away from the usual area of velopharyngeal closures. In these cases phonation caused a minimum change in the palate. Cind examination demonstrated a lack of velopharyngeal closure in the lateral projection. On phonation the palate had a bowing configuration lacking the abrupt elevation at the level of the levator insertion (Fig. I-). Of the five patients, three had had inferiorly based pharyngeal flaps, and two had had superiorly based pharyngeal flaps. These procedures were performed at other centres. Two of the patients with low pharyngeal flaps were reoperated with division of the low flap and construction of the new high-based flap attached into the nasal defect of a concurrently done V-Y pushback procedure (Fig. 2). A comparison of pre- and post-operative anatomy, as viewed on the cin6 in one patient, is seen in Figure 3. The patient is a 37-year-old male with a unilateral cleft who had a superiorly based pharyngeal flap six years previously. The intra-oral view of this flap prior to revision is noted in Figure 4. DISCUSSION In normal patients velopharyngeal closure is accomplished when the palate is pulled up against the posterior pharyngeal wall by the levators. This occurs near the plane of

2 348 BRITISH JOURNAL OF PLASTIC SURGERY b FIG. I Palate configuration in a restrictive pharyngeal flap (a) at rest and (b) phonating " ah ". CI FIG. 2 Surgical technique (a) dividing the restrictive flap and (b) constructing a superiorly based flap in conjunction with a V-Y pushback. the hard palate at an area above the tubercle of the atlas (Calnan, 1961 ; Warren and Hofmann, 1961) (Fig. 5). Pharyngeal flaps have several functions in patients with velopharyngeal incompetence. Flaps provide some obturation of themselves (Stark and DeHaan, 196o). Most flaps however are small and more obturation is probably provided by the retro-displacement of the palate caused by the posterior traction resulting from scar contracture in the pharyngeal flap. If a pharyngeal flap is used with a palatal pushback procedure, it provides coverage of the raw nasal surfaces of the palate. In this manner anterior scar contracture is limited in the pushback, making it more effective and lasting.

3 THE RESTRICTIVE PHARYNGEAL FLAP 349 Fig. 3.--Cin6 frames with superimposed tracing at the palate in a patient with a restrictive pharyngeal flap. (a) Pre-operative position at rest ; (b) preoperative position (bowed) phonating " quack " ; (c) post-revision of the flap at rest; (d) post-revision of the flap phonating " quack " FIG. 3 Fla. 4 FIG. 5 Fig. 4.--Intra-oral view of patient with a restrictive pharyngeal flap. Fig. 5.--Norrnal palate configuration when phonating " ah ".

4 350 BRITISH JOURNAL OF PLASTIC SURGERY Dynamic muscular contracture is also said to occur in pharyngeal flaps. This is based on electromyographic recordings showing action potentials in the flap synchronous with palate motion and speech (Broadbent and Swinyard, I959). Since the muscle fibres in the flap are aligned transversely, it seems unlikely that contraction of the muscle would shorten the flap. Increased palatal motion has been seen in this laboratory in patients who have recently undergone palatal pushbacks and pharyngeal flaps. A probable explanation for this increased motion is that the scarred levator musculature of the soft palate is released from the hard palate during the pushback, allowing greater mobility of the palate. In designing the pharyngeal flap, the pattern of normal closure as well as the intended function of the flap should be kept in mind. It would seem reasonable to align the flap for traction in the direction most compatible with normal closure. Superiorly based flaps, as previously described, placed high in the posterior pharyngeal wall have augmented velopharyngeal function and have not appeared significantly to restrict palatal motion, either inferiorly or superiorly (Buchholz et al., I967). Cinds of our patients after pharyngeal flaps have been indistinguishable from those of patients who have had pharyngeal flaps performed at the University of California by the method described by Blackfield (Blackfield et al., I963). Surgical techniques are similar, in that the flaps are raised high on the posterior pharyngeal wall and inserted near the midportion of the soft palate, away from its trailing edge. The traction of the flaps is then in the vicinity of the insertion of the levators (in the area of normal closure of the velum against the posterior pharyngeal wall). Flaps placed low on the posterior pharyngeal wall, as presented here, have been felt to tether the palate in an inferior direction. This action restricts palatal excursion and prohibits palatal closure at the normal area of the posterior pharyngeal wall. Revision of the pharyngeal flap accompanied by a palatal pushback corrected the abnormality in two cases. Since revision of these cases involved a palatal pushback in conjunction with the new pharyngeal flap, this could be interpreted, as presumptive evidence only, that the restrictive flap was the main pathology. It is certain the anatomy prior to revision was inadequate for proper velopharyngeal function. Migration in the post-operative period is another factor which affects the location and pull of the flap (Blackfield et al., I963). Pharyngeal flaps have been reported to migrate post-operatively as a result of scar contracture between the flap and its bed on the pharyngeal wall (Skoog, I965). Methods which counteract this tendency have been described. The Owsley technique folds a portion of the superior palatal mucosa back to cover the raw area of the unattached portion of the flap (Owsley et al., I966). Other authors advocate closure of the bed on the pharyngeal wall (Stark and DeHaan, I96o ; Cox and Silverstein, r96i). Skoog (I965) has devised lateral rotation flaps which are placed beneath the base of the flap covering the raw ~urface. An alternative method which we have used to compensate in part for this effect is to raise the flap as high as possible, thus allowing for some contracture at the inferior migration of the flap. After healing, these flaps cannot be seen on looking directly into the mouth. Scar contracture with inferiorly based flaps, on the other hand, might be beneficial, because the base of the flap would migrate to a higher location. The importance of the site of attachment of the pharyngeal flap to the palate has not been sufficiently emphasised. It is felt that the flap should be sutured at, or anterior to, the central insertion of the levators. This provides a surface for the raw nasal side of the palate over the levator insertion and thereby inhibits scar formation between the levators and the hard palate. A greater excursion of the palate with contraction of the levators is thus obtained. The increased superior motion of the palate due to the levators may also inhibit inferior migration of the flap origin on the post-pharyngeal wall.

5 THE RESTRICTIVE PHARYNGEAL FLAP 351 SUMMARY Five patients with hypernasal speech resulting from low lying restrictive pharyngeal flaps have been observed in this clinic. Two of these were improved by dividing the flaps and constructing a superiorly based flap in conjunction with the palatal pushback. Normal palatal closure has been discussed and a mechanical explanation of the restrictive flap suggested. An argument is presented to stress the importance of two points of surgical technique to achieve maximum velopharyngeal competence : (I) raising the flap high on the posterior pharyngeal wall and (2) attaching it to the superior aspect of the soft palate near the insertion of the levators. REFERENCES BLACKFIELD, H. M., OWSLEY, J. Q., MILLER, E. R. and LAWSON, LUCIE I. (1963). Cinefluorographic analysis of the surgical treatment of cleft palate speech. Plastic reconstr. Surg. 3 I, BROADBENT, T. R. and SWINYARD, C. A. (1959). The dynamic pharyngeal flap. Plastic reconstr. Surg. 23, 3Ol-312. BOCHHOLZ, R. B., CHASE, R. A., JOBE, R. P. and SMITH, H. (1967). The use of the combined palatal pushback and pharyngeal flap operation. Plasticreconstr. Surg. 39,554-56I. CALNAN, J. (1961). The mobility of the soft palate : A radiological and statistical study. Br. J. plast. Surg, 14, CHASE, R. A. (196o). An objective evaluation of palatopharyngeal competence. Plastic reconstr. Surg. 26, CONWAY, H. (1951). Combined use of push-back and pharyngeal flap procedures in management of complicated cases of cleft palate. Plastic reconstr. Surg. 7, CONWAY, H. and GOULIAN, D. (I96o). Experiences with the pharyngeal flap in cleft palate surgery. Plastic reconstr. Surg. 26, Cox, J. B., and SILVERSTEIN, B. (I96I). Experiences with the posterior pharyngeal flap for correction of velopharyngeal insufficiency. Plastic reconstr. Surg. 27, EDGERTON, M. T. (1965). The island flap push-back and the suspensory pharyngeal flap in surgical treatment of the cleft palate patient. Plastic reconstr. Surg. 36, 591-6o3. OWSLEY, J. Q., LAWSON, LUCIE I., MILLER, E. R. and BLACKFIELD, H. M. (1966). Experience with the high attached pharyngeal flap. Plastic reconstr. Surg. 38, SKOOG, T. (1965). The pharyngeal flap operation in cleft palate. Br. J. plast. Surg. 18, STARK, R. B. and DEHAAN, C. R. (196o). The addition of pharyngeal flap to primary palatoplasty. Plastic reconstr. Surg. 26, WARDILL, W. E. M. and WHILLIS, J. (1963). Movements of the soft palate. Surgery Gynec. Obstet. 62, WARREN, D. W. and HOFMANN, F. A. (1961). A cineradiographic study of velopharyngeal closure. Plastic reconstr. Surg. 28,