Ann Dial Rhinal Laryngol101:1992
CRICOPHARYNGEAL MYOTOMY: INDICATIONS AND TECHNIQUE JEFFREY
A.
McKENNA, MD
HERBERT H. DEDO, MD SAN FRANCISCO, CALIFORNIA
.Available diagnostic tests ev~luating cricopharyngeal dysmotility are expensive, uncomfortable, and unreliable for predicting the results of ~ncopharyngeal myotomy. Cncopharyngeal myotomy should be performed as a diagnostic test when a patient has "block" dysphagia (in which th~ food ~olus stops.rather .than the swallow's being painful) localized to the cricoid level, and when no cancer is seen on esophagram. An ~ffectIve surgIcal.techmque relies on the muscular distention provided by the inflated balloon cuff of a large endotracheal tube, and requires cuttm~ t~e mus.cle fibers of the upper esophagus.. the cricopharyngeus, and the hypopharynx in the posterior midline from a point 1 cm below the c~lcOld cartilage to the level of the thyrohyoid membrane. The cricopharyngeallimits are indistinct until the muscle fibers have been cut. BO~gIes: esophagoscopes, and cuffless en?otracheal tubes insufficiently distend these muscle fibers. A "peanut" sponge in a Kelly clamp is used to Id,:ntIfy an? separate the last muscle fibers from the mucosa so they can be divided. These techniques minimize the risks of esophageal perforation and incomplete muscular transection. Our experience performing 54 cricopharyngeal myotomies is reported. KEY WORDS -
achalasia, cervical dysphagia, cricopharyngeal myotomy, cricopharyngeus muscle, Zenker's diverticulum.
of the inferior pharyngeal constrictor blend into the CP muscle from above, as does the circular esophageal musculature from below." The literature generally states that the CP muscle is in a state of tonic contraction and relaxes during deglutition. This finding was primarily based on observations made during esophagoscopy or manometry, 6 both of which stimulate mucosal stretch receptors and alter normal CP resting physiology. When the function of the CP muscle in the dog was studied electrom yographically (which does not activate esophageal stretch receptors), the CP muscle was found to be relaxed in the resting state between swallows, and during each swallow it had a brief contractionrelaxation-contraction cycle." Manometry in humans is uncomfortable, expensive, inconsistent, and unreliable" with single sensors, and can take longer than a CP myotomy; however, it occasionally has been able to demonstrate a a.I-second delay in CP muscle relaxation in patients with block dysphagia. 9 Cineradiography, in severe cases of solid and liquid block dysphagia and in Zenker's diverticulum, has sometimes been able to demonstrate failure of proper CP relaxation during swallow. 10 In this event, the CP muscle (the "CP bar") indents the bolus of dye as it passes from the hypopharynx into the esophagus. We cannot assume, however, that if the CP muscle relaxes and opens well enough so that no bar indents the passing bolus - especially if it is only the usual liquid barium - that swallowing is normal. 8 Although the exact neurophysiologic mechanism remains controversial, it is accepted that cervical block dysphagia results from a delay or failure of relaxation of the CP muscle during deglutition.
INTRODUCTION
Cervical "block" dysphagia is an uncommon complaint of patients seen by otolaryngologists. Anatomic causes of dysphagia such as cancer, scarring, and foreign bodies need to be excluded by physical examination, esophagram, and, in the rare case in which there is still a question, esophagoscopy. Cricopharyngeal (CP) muscle dysfunction is the most common physiologic cause of cervical block dysphagia, but it has been hard to diagnose in the past. Medical therapy for CP achalasia has been ineffective, and while CP myotomy has been shown to be effective in published clinical reports, 1-3 we now feel its indications have been unduly limited. The literature, in general, advises CP myotomy only when there is cineradiographic or manometric evidence of CP muscle dysfunction, I Surgeons are reluctant to operate solely on the basis of the patient's description of block dysphagia with solid foods (more so than liquids) at the cricoid level. Also, the technique usually described in the literature depends only on esophageal dilation with a bougie or esophagoscope to try to distend the muscle fibers from the lower pharynx into the upper esophagus." This is ineffective and unsafe in our experience. We have found a group of patients who, when selected on a carefully taken history alone, benefit from CP myotomy even though they have "normal" cineradiographic or manometric studies. Therefore, we now advocate CP myotomy as both a diagnostic and therapeutic modality in patients with solid food block dysphagia at the level of the cricoid. ANATOMY AND PHYSIOLOGY
The CP muscle is a sling around the junction of the hypopharynx and esophagus and is attached to the sides of the cricoid cartilage. The oblique fibers
HISTORY AND LITERATURE REVIEW
Valsalva l l is credited with the first modern de-
From the Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California. Presented at the meeting of the American Broncho-Esophagological Association, San Francisco, California, April 1-2, 1989. REPRINTS - Herbert H. Declo, MD, Dept of Otolaryngology, University of California, San Francisco 400 Parnassus Ave Rm 735 A San Francisco CA 94143. ' " ,
216
McKenna & Dedo, Cricopharyngeal Myotomy
scription of the CP region. Killian'! in 1907 more accurately described its muscular anatomy, including the weak triangular area between the inferior constrictor and CP muscles (the site of pharyngoesophageal or Zenker's diverticulum). In 1926 Jackson and Shallow" suggested that CP muscle relaxation failure during deglutition causes these diverticula. Lahey':' in 1946 recommended dilation of the CP muscle as part of the treatment of diverticulum. In 1950 Ashersori" created the term CP achalasia, describing it as a prediverticular state. On the basis of the theory that a dysmotile CP muscle results from bulbar or supranuclear central nervous system disorders, it was hypothesized that the surgical relaxation of the CP muscle would relieve cervical block dysphagia in patients with certain neurologic diseases. In 1951 Kaplan" reported the first successful myotomy in the treatment of cervical dysphagia in a patient with poliomyelitis. The efficacy of CP myotomy has since been documerited," in small series, for amyotrophic lateral sclerosis," Parkinson's disease, cerebrovascular accidents, skull base lesions and surgery, I and oculopharyngeal muscular dystrophy. 18 The usefulness of CP myotomy in head and neck cancer surgery has been recognized for over 30 years. Ogura et al'" noted that during supraglottic laryngectomy the CP muscle was tightly constricted when the surgeon's finger was inside it, and that CP myotomy relaxed the muscle, improved deglutition, and reduced aspiration postoperatively. Mladick et apo and subsequent authors discussed other oncologic procedures in which CP myotomy might be included. Cricopharyngeal achalasia may be a result of gastroesophageal reflux in some patients. In 1977 Henderson and Marryatf" reported on 19 patients who underwent CP myotomy, 17 of whom showed improvement. They performed a CP myotomy on patients who failed medical management of acid reflux with minimal heartburn, who were too ill for a major thoracoabdominal reflux procedure, and who had persistent dysphagia after hiatal hernia repair for reflux. In 1980 Orringer" reported a similar experience. Pulsion (Zenker's) diverticulum may result when normal CP function is disrupted. Konowitz and Biller" have recently reviewed the management of pulsion diverticulum, with emphasis on CP myotomy combined with diverticulopexy. Fundamental to their discussion is the concept that the underlying disorder is failure of the CP muscle to relax during deglutition, not a weak pharyngeal wall. PATIENTS
Fifty-four patients underwent CP myotomy by the senior author (H.H.D.) between 1973 and 1991. Records could be obtained on 47. Follow-up was based on chart review and personal communica-
217
tion. Twenty-five (53 %) of the patients were men and 22 (47 %) were women. Patients ranged in age from 26 to 87, with a median age of 64 and an average age of 60.7. The underlying cause of the patients' CP dysfunction was not identified in 17 (36 %) patients. It was identified as postlaryngectomy block dysphagia and/or failure of Blom-Singer speech in 7 (15 %); cerebrovascular accident in 7 (15 %); hiatal hernia with gastroesophageal reflux in 5 (11 %); cranial nerve deficits from neurosurgicalor skull base lesions in 8 (17 %); post -hemiglossectomy status in 1 (2 %); Parkinson's disease in 1 (2 %); and dystonia musculorum deformans in 1 (2 %). Preoperative diagnostic evaluations after indirect laryngoscopy initially included cine-esophagram, esophagoscopy (either rigid or flexible), and single sensor manometry. Seven patients had no preoperative diagnostic tests; these were in the group with multiple cranial nerve deficits (and low risk of cancer, esophageal stenosis, or Zenker's diverticulum). Of the remaining patients, 26 had an esophagram alone, and 7 had both an esophagram and esophagoscopy. Three patients had an esophagram and manometry, and 4 had esophagoscopy alone. The CP manometric studies and the esophagoscopies were unable to demonstrate CP abnormalities, so they are no longer used as diagnostic modalities for CP achalasia. Of the 36 patients who had esophagrams, only 11 patients had identifiable CP abnormalities. Three of these 11 patients had Zenker's diverticulum as a result of their CP dysfunction. The 5 patients with gastroesophageal reflux had minimal abdominal symptoms, had failed medical therapy, and had marked solid food block dysphagia at the cricoid level. INDICATIONS FOR MYOTOMY
In the English literature on CP myotomy, the accepted indication for the procedure is the presence of a CP bar on cine-esophagram. Surgeons naturally prefer that an unequivocal diagnosis be established by a manometrist or radiologist rather than to rely on their own clinical acumen; however, manometry and cine-esophagram do not identify a group of patients whom we have found to benefit from CP myotomy. Cineradiography and manometry are not abnormal in these patients; however, the former is ordinarily performed with liquid radiopaque media when these patients have no problems with liquids. Manometry, as currently performed, uses a probe that has only a single sensor at the level of the CP muscle, which may be against the cricoid cartilage, against the upper esophageal wall during the laryngeal elevation component of deglutition, or causing reflex CP spasm. When a cine-esophagram is performed with barium-coated, chewed solid food, especially the foods that have been "catching" at the CP level, it is sometimes possible to record delay or complete obstruction at the CP muscle. Thus, when the esophagram is done
218
McKenna & Dedo, Cricopharyngeal Myotomy
properly, it may confirm that the complaint is real. Clinically useful manometry of the CP muscle awaits improved sensor technology.
In our opinion, a sufficient basis for diagnosis and surgical treatment is a careful history, and a pharyngoesophagram that shows no evidence of a cancer. This is especially true in the patient with less gross dysphagia than that causing nasal regurgitation, a Zenker's diverticulum, or a CP bar on the cine-esophagram. Patients with CP achalasia who will benefit from CP myotomy typically present with block dysphagia (bolus obstruction) at the level of the cricoid cartilage. They do not have the typical pain that accompanies those cancers large enough to cause dysphagia. They consistently have difficulty swallowing solid foods but not liquids, and require multiple attempts (often with repeated sips of water) to swallow a single bolus of chewed solid food. Nasopharyngeal reflux, laryngeal aspiration, and weight loss are seen only in severe cases. The sensation of a block is present only until the bolus of solid food passes into the esophagus, and is not present when the patient is swallowing liquids, nor between swallows (much less meals), as occurs in globus syndrome. Physical examination of the pharynx, hypopharynx, larynx, and neck is unremarkable, and a routine (liquid barium) esophagram is normal. These selection criteria identify patients with enough CP dysmotility that it should be alleviated or eliminated by CP myotomy, even though it is too subtle to be detected by cineradiography and/or manometry.
tients with a history of cerebrovascular accident are suitable candidates for CP myotomy. If they have marked dysarthria, aphasia, or apraxia, however, they may have less chance of improvement. Patients with these dysfunctions may have such brain disorganization that they cannot or will not initiate a swallow. TECHNIQUE
Cricopharyngeal myotomy has a relatively low risk of morbidity and mortality. Pharyngocutaneous fistula, recurrent laryngeal nerve injury, and incomplete transection of CP muscle fibers are possible risks, but are very unlikely to occur with the following technique. We use a standard left-sided approach to visualize the posterior surface of the CP muscle, as shown in detail in our surgical atlas. 22 The larynx is rotated away from the surgeon with a double hook on the posterior edge of the thyroid cartilage ala so that the posterior pharyngeal wall is visualized. It is important not to let the lower tine of the double hook be applied below the midpoint of the ala; it must stay well away from the recurrent laryngeal nerve, since the nerve passes behind the inferior cornu of the thyroid cartilage. For extra recurrent nerve protection, we cover the inferior cornu with the surgeon's left thumb while installing the double hook.
Cricopharyngeal myotomy is, of course, contraindicated in globus syndrome. This syndrome is characterized by a nearly constant sensation of a lump, mucus, postnasal drip, or "something stuck" at the level of the cricoid, and commonly increases or enlarges with stressful events. The syndrome has been present for months or years with fluctuation in severity (from severely annoying to absent), and does not disappear between swallows. Globus syndrome patients are easily distinguished from patients with solid food block dysphagia because the former never have difficulty swallowing liquids or solid food.
Distention of the pharyngoesophageal muscle fibers while they are cut is essential. Many devices have been used to try to accomplish distention, including esophagoscopes," esophageal bougies or dilators,"" and esophageal balloons." We found that these devices do not distend the pharynx properly as the surgeon's finger does, so as to display the uncut muscle fibers, during a supraglottic laryngectomy. 19 Since there is no opening in the pharyngeal mucosa during CP myotomy, we have found that a large (36F or 38F) endotracheal tube, with a barrelshaped, low-pressure, high-compliance cuff, is an excellent substitute for the finger because it also provides active but soft distention. We especially like this type of cuff because it distends a long segment and it does not tend to migrate into and distend only the area in which the first fibers are cut, as the older, round cuffs do. The endotracheal tube is best installed in the esophagus by the anesthesiologist after the patient is anesthetized and prior to preparing and draping the skin. If a Zenker's diverticulum is present, it will usually go into the diverticulum. Therefore, in these patients insertion is stopped as soon as the tube has been gently passed behind the cricoid cartilage and resistance is met. Otherwise, there is a potential danger of perforation. Later, when the sac has been exposed surgically and tipped upward, the anesthesiologist eases the distal end of the endotracheal tube into the upper esophagus so the balloon will be within the CP muscle.
In our experience, cricoid block dysphagia pa-
Once the larynx is rotated and the posterior mid-
Gastroesophageal reflux is not a contraindication to performing CP myotomy in patients with solid food block dysphagia. Henderson and Marryatt'" have reported on patients with CP achalasia who were not improved after apparent medical or surgical control of gastric acid reflux until a CP myotomy was performed. We have observed that gastroesophageal reflux symptoms have not been exacerbated by surgical relaxation of the CP muscle. Vocal cord irritation and/or granulomas have not occurred in any of these CP myotomy patients, even when followed up for years.
219
McKenna & Dedo, Cricopharyngeal Myotomy
Area of inferior cornu and RLN under thyroid Hland
Reprinted with perrnission.P A) Demonstration of laryngeal rotation, recurrent laryngeal nerve (RLN) position, and early distention of cricopharyngeal region musculature. B) Residual muscle fibers are identified by adequate distention and also blunt "peanut" dissection. C) Location of cricopharyngeus muscle can be reliably identified only after all fibers have been transeeted.
Endotracheal balloon distending hypopharynx
A
Hypopharynx mucosa Single muscle fibers indenting balloon
Cut esophaHeal constrictor m.
Cut inferior pharyngeal constrictor m.
/ Cut cricopharyngeal m.
line is identified, the anesthesiologist inflates the endotracheal tube cuff (see Figure,22 A). As the muscle fibers are cut, a distended cuff makes the uncut muscle fibers and thin submucosal fascia between the muscle and mucosal layers visually prominent because they indent the balloon (see Figure, B). A "peanut" in a Kelly clamp is used to roll uncut muscle fibers and fascia and loosen them from the underlying hypopharyngeal and esophageal mucosa prior to cutting them with a No. 15 Bard-Parker scalpel blade. During this fiber cutting, one potential pitfall is to mistake the cuff-endotracheal tube junction for an indenting muscle fiber. If the anesthesiologist deflates, moves, and reinflates the endotracheal tube cuff 1 to 2 em caudad and cephalad after some fibers have been cut, the risk of mucosal perforation from this cause is minimized. Also, the electrocautery is used only on muscle, and not on the mucosa, to minimize risk of perforation. Unless Zenker's diverticulum is present, we use a myotomy length of 4 to 5 cm, extending in the pos-
B
A
Thin fascia between muscle layer and mucosa
Cricopht:t
\
ryl1!lft:t1 111·
c
terior midline from the level of the thyrohyoid membrane to 1 ern below the inferior edge of the cricoid cartilage. This cut length assures that all of the CP muscle fibers have been divided, and it has caused no postoperative problems. If there is a Zenker's diverticulum, the upper edge of the CP muscle is obvious since the inferior edge of the neck of the sac is draped over it. In this case, we tip the sac upward, position and inflate the balloon within the CP muscle, and incise its fibers in the posterior midline for 2 em below the neck of the sac. We no longer incise over or resect the sac in order to minimize the risk of mucosal leak. It will contract down and become asymptomatic after the CP muscle obstruction is relieved," especially if the thinned inferior constrictor muscle fibers are left intact on its dorsal surface. If it is larger than 3 or 4 ern, it can be rotated upward and supported with a gut suture through the inferior constrictor left on its posterior surface. Unlike the anatomy atlas illustrations, in a patient the location of the CP musculature can be reliably identified only after all the fibers have been
220
McKenna & Dedo, Cricopharyngeal Myotomy
transected, when its thickness is seen to be greater than that of the very thin esophageal muscle or the intermediate thickness of the inferior pharyngeal constrictor (see Figure, C). RESULTS
Duration of follow-up ranged between 1 month (for 6 patients who did so well they chose not to return) and 163/ 4 years. The average length of followup was 6 1/ 4 years. The surgical outcome was evaluated clinically, since cine-esophagrams cannot demonstrate all symptomatic CP muscle dysfunction. A patient's postoperative deglutition was classified as normal, markedly improved, not improved, or worse in comparison to the preoperative state. No patient reported worsening of the symptoms by CP myotomy. Twenty-one (45 %) patients reported normal swallow postoperatively. Fourteen (30%) patients reported markedly improved swallowing, but fell short of normal. (Therefore 35, or 75 % , were at least markedly improved by the myotomy.) Dramatic objective evidence of improvement was that 2 patients who had required a feeding gastrostomy preoperatively were able to have the tube removed. Six (12.5 %) patients had minimal improvement in symptoms, and 6 (12.5 %) patients had no improvement. Of patients without a known cause for their CP dysfunction, 15 of 17 had a markedly improved or normal swallow. Five of 7 patients who had postlaryngectomy block dysphagia had good or excellent results. In patients with cerebrovascular accidents, 6 of 7 had markedly improved deglutition. (The senior author knows of a patient, whose records were not available, who had suffered a cerebrovascular accident with resultant apraxia and dysarthria and neither improved nor worsened with CP myotomy.) Three of 5 patients with gastroesophageal reflux improved markedly. Of patients with skull base region trauma or neoplasia, only 3 of 8 had significant improvement. This finding would suggest that the presence of multiple lower cranial nerve palsies in patients who undergo CP myotomy makes improvement less likely, although the 3 patients who did improve would argue that the benefit outweighs the minimal risks of the procedure. The patients with Parkinson's disease, dystonia, and hemiglossectomy were markedly improved. The patients were also stratified according to the duration of their follow-up. Thirty-four of the 47 patients had follow-up of 6 months or longer. Of these 34, 25 (74 %) had an excellent or good surgical outcome. Only 1 had a partial recurrence of dysphagia after 6 or 7 years of marked improvement. This rate is not different from the total group improvement rate as outlined above. The patients with less than 6 months of follow-up had an improvement rate of approximately 77 % . This difference is not statistically significant because of the small sample size.
Of the 36 patients who had preoperative (liquid media) esophagrams, 25 were reported as having normal anatomy and motility through the pharyngoesophageal segment, in spite of the patients' vivid description of solid food block dysphagia. Of these 25 patients, 7 (28 %) had normal swallowing postoperatively, 13 (52 %) had marked improvement, 2 (8 %) had minimal improvement, and 3 (12 %) showed no improvement. Thus, 80 % of these symptomatic patients, with "normal" esophagrams preoperatively, benefited from CP myotomy, because we rejected the conventional diagnostic criteria of an abnormal liquid cine-esophagram. Also, all of the patients who had "normal" manometry preoperatively - in spite of severe clinical block dysphagia - had normal or markedly improved deglutition postoperatively. Two patients had previously received diagnoses of CP dysfunction and had undergone myotomy by other surgeons, without improvement. After we repeated the CP myotomy using the technique described above, both patients reported that their swallowing had returned to normal. During the operation we found that they had not had a complete CPmyotomy. No patient developed vocal cord paralysis or a hematoma. One patient developed a slight wound infection, which quickly responded to antibiotics. One patient developed a small pharyngocutaneous leak on the second postoperative day, which healed spontaneously in 3 days. SUMMARY
Deglutition is a complex neurophysiologic act. Disruption of the normal relaxation of the CP muscle during swallow results in block cervical dysphagia of solid foods, or CP achalasia. Medical treatment has not been effective. These patients' symptoms have been cured or alleviated by CP myotomy. Manometry and cineradiography are not effective in correctly identifying all of the patients who will benefit from CP myotomy. Eighty percent of these patients were markedly improved or given normal swallow by CP myotomy performed on the basis of specific symptoms described earlier, even though their cine-esophagrams and/or manometries revealed no disease. We therefore advocate CP myotomy as a diagnostic test on patients with solid food block dysphagia after excluding cancer, other anatomic lesions such as esophageal scar, and globus syndrome. Cricopharyngeal myotomy also relieves the dysphagia and lets the sac shrink when a Zenker's diverticulum is present. Gastroesophageal reflux is not a contraindication. The described technique minimizes the risks of mucosal perforation and incomplete fiber transection. The technique relies on the use of a cuffed endotracheal tube, which acts as an active muscular distention device, and creation of a myotomy of adequate length and depth to ensure complete division of the CP muscle.
McKenna & Dedo, Cricopharyngeal Myotomy
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REFERENCES 1. Ross ER, Green R, Auslander MO, Biller HF. Cricopharyngeal myotomy: management of cervical dysphagia. Otolaryngol Head Neck Surg 1982;90:434-41.
13. Jackson C, Shallow TA. Diverticulum of esophagus pulsion, traction, malignant and congenital. Ann Surg 1926;83: 112-20.
2. Bonavina L, Khan N, DeMeester T. Pharyngoesophageal dysfunctions: the role of cricopharyngeal myotomy. Arch Surg 1985;120:541-9. 3. Mitchell R, Armanini G. Cricopharyngeal myotomy: treatment of dysphagia. Ann Surg 1975;181:262-6.
14. Lahey FH. Pharyngoesophageal diverticulum: its management and complications. Ann Surg 1946;124:617-36. 15. Asherson N. Achalasia of the cricopharyngeal sphincter: record of cases with profile pharyngograms. J Laryngol Otol 1950;64:747-58.
4. Konowitz PM, Biller HF. Diverticulopexy and cricopharyngeal myotomy: treatment for the high-risk patient with a pharyngoesophageal (Zenker's) diverticulum. Otolaryngol Head Neck Surg 1989;100:146-53.
16. Kaplan S. Paralysis of deglutition, a post-poliomyelitis complication treated by section of the cricopharyngeus muscle. Ann Surg 1951;133:572-3.
5. Inglefinger F. Esophageal motility. Physiol Rev 1958;35: 533-84. 6. Hurwitz AL, Nelson JA, Haddad JK. Oropharyngeal dysphagia: manometric and cineesography findings. Dig Dis Sci 1975;20:313-24. 7. Levitt MN, Dedo HH, Ogura JH. The cricopharyngeus muscle, an electromyographic study in the dog. Laryngoscope 1965;75:122-36. 8. Orringer MB. Extended cervical esophagomyotomy for cricopharyngeal dysfunction. J Thorac Cardiovasc Surg 1980;80: 669-79. 9. Fyke F, Code C. Resting and deglutition pressures in the pharyngoesophageal region. Gastroenterology 1955;29:24-35. 10. Crichlow T. The cricopharyngeus in radiography and cine-radiography. Br J Radiol 1956;29:546-56.
17. Lebo CP, Kwei SU, Norris FH Jr. Cricopharyngeal myotomy in amyotrophic lateral sclerosis. Laryngoscope 1976;86:862-8. 18. Dayal VS, Freeman J. Cricopharyngeal myotomy for dysphagia in oculopharyngeal muscular dystrophy. Report of a case. Arch Otolaryngol 1976;102:115-6. 19. Ogura JH, Saltzstein SL, Spjut HJ. Experiences with conservation surgery in laryngeal and pharyngeal carcinoma. Laryngoscope 1961;71:258-76. 20. Mladick R, Horton C, Adamson J. Immediate cricopharyngeal myotomy - an adjunctive technique for major oral pharyngeal resection. Plast Reconstr Surg 1971;47:6-11. 21. Henderson R, Marryatt G. Cricopharyngeal myotomy as a method of treating cricopharyngeal dysphagia secondary to gastroesophageal reflux. J Thorac Cardiovasc Surg 1977;74:721-5. 22. Dedo HH. Surgery of the larynx and trachea. Philadelphia, Pa: BC Decker, 1990:61-79.
11. Valsalva A. De humana tratatus. Quibus interposita est muscurorim uvulae at que pharyngs. Utrecht, 1717.
23. Lore JM Jr. Cricopharyngeal myotomy. In: Meier AE, ed. An atlas of head and neck surgery. 3rd ed. Philadelphia, Pa: WB Saunders, 1988:978-9.
12. Killian G. The mouth of the esophagus. Laryngoscope 1907;17:421-8.
24. Thawley SE, Ogura JH. Cricopharyngeal myotomy. Laryngoscope 1978;88:872-4.
THE DEAFNESS RESEARCH FOUNDATION 1993 RESEARCH GRANTS AVAILABLE The Deafness Research Foundation invites applications for 1993 grant support of research projects directed to any aspect of the ear, egoinvestigation offunction, physiology, biochemistry, genetics, anatomy, or pathology. Grant support is given for one year, in an amount that cannot exceed $15.000. but can competitively be renewed for one or two additional years. Applications are reviewed for the scientific merit of the proposed investigations and for their direct or potential clinical value. The deadlines for applications for 1993 grant support are as follows: first year applications should be postmarked by July 15. 1992. and renewal applications should be postmarked by August 15. 1992. For information and applications. please contact Wesley H. Bradley, MD, Medical Director, The Deafness Research Foundation, 9 East 38th Street. New York, NY 10016; telephone (212) 684-6556; fax (212) 779-2125.
CRICOPHARYNGEAL MYOTOMY: INDICATIONS AND TECHNIQUE JEFFREY
A.
McKENNA, MD
HERBERT H. DEDO, MD SAN FRANCISCO, CALIFORNIA
.Available diagnostic tests ev~luating cricopharyngeal dysmotility are expensive, uncomfortable, and unreliable for predicting the results of ~ncopharyngeal myotomy. Cncopharyngeal myotomy should be performed as a diagnostic test when a patient has "block" dysphagia (in which th~ food ~olus stops.rather .than the swallow's being painful) localized to the cricoid level, and when no cancer is seen on esophagram. An ~ffectIve surgIcal.techmque relies on the muscular distention provided by the inflated balloon cuff of a large endotracheal tube, and requires cuttm~ t~e mus.cle fibers of the upper esophagus.. the cricopharyngeus, and the hypopharynx in the posterior midline from a point 1 cm below the c~lcOld cartilage to the level of the thyrohyoid membrane. The cricopharyngeallimits are indistinct until the muscle fibers have been cut. BO~gIes: esophagoscopes, and cuffless en?otracheal tubes insufficiently distend these muscle fibers. A "peanut" sponge in a Kelly clamp is used to Id,:ntIfy an? separate the last muscle fibers from the mucosa so they can be divided. These techniques minimize the risks of esophageal perforation and incomplete muscular transection. Our experience performing 54 cricopharyngeal myotomies is reported. KEY WORDS -
achalasia, cervical dysphagia, cricopharyngeal myotomy, cricopharyngeus muscle, Zenker's diverticulum.
of the inferior pharyngeal constrictor blend into the CP muscle from above, as does the circular esophageal musculature from below." The literature generally states that the CP muscle is in a state of tonic contraction and relaxes during deglutition. This finding was primarily based on observations made during esophagoscopy or manometry, 6 both of which stimulate mucosal stretch receptors and alter normal CP resting physiology. When the function of the CP muscle in the dog was studied electrom yographically (which does not activate esophageal stretch receptors), the CP muscle was found to be relaxed in the resting state between swallows, and during each swallow it had a brief contractionrelaxation-contraction cycle." Manometry in humans is uncomfortable, expensive, inconsistent, and unreliable" with single sensors, and can take longer than a CP myotomy; however, it occasionally has been able to demonstrate a a.I-second delay in CP muscle relaxation in patients with block dysphagia. 9 Cineradiography, in severe cases of solid and liquid block dysphagia and in Zenker's diverticulum, has sometimes been able to demonstrate failure of proper CP relaxation during swallow. 10 In this event, the CP muscle (the "CP bar") indents the bolus of dye as it passes from the hypopharynx into the esophagus. We cannot assume, however, that if the CP muscle relaxes and opens well enough so that no bar indents the passing bolus - especially if it is only the usual liquid barium - that swallowing is normal. 8 Although the exact neurophysiologic mechanism remains controversial, it is accepted that cervical block dysphagia results from a delay or failure of relaxation of the CP muscle during deglutition.
INTRODUCTION
Cervical "block" dysphagia is an uncommon complaint of patients seen by otolaryngologists. Anatomic causes of dysphagia such as cancer, scarring, and foreign bodies need to be excluded by physical examination, esophagram, and, in the rare case in which there is still a question, esophagoscopy. Cricopharyngeal (CP) muscle dysfunction is the most common physiologic cause of cervical block dysphagia, but it has been hard to diagnose in the past. Medical therapy for CP achalasia has been ineffective, and while CP myotomy has been shown to be effective in published clinical reports, 1-3 we now feel its indications have been unduly limited. The literature, in general, advises CP myotomy only when there is cineradiographic or manometric evidence of CP muscle dysfunction, I Surgeons are reluctant to operate solely on the basis of the patient's description of block dysphagia with solid foods (more so than liquids) at the cricoid level. Also, the technique usually described in the literature depends only on esophageal dilation with a bougie or esophagoscope to try to distend the muscle fibers from the lower pharynx into the upper esophagus." This is ineffective and unsafe in our experience. We have found a group of patients who, when selected on a carefully taken history alone, benefit from CP myotomy even though they have "normal" cineradiographic or manometric studies. Therefore, we now advocate CP myotomy as both a diagnostic and therapeutic modality in patients with solid food block dysphagia at the level of the cricoid. ANATOMY AND PHYSIOLOGY
The CP muscle is a sling around the junction of the hypopharynx and esophagus and is attached to the sides of the cricoid cartilage. The oblique fibers
HISTORY AND LITERATURE REVIEW
Valsalva l l is credited with the first modern de-
From the Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California. Presented at the meeting of the American Broncho-Esophagological Association, San Francisco, California, April 1-2, 1989. REPRINTS - Herbert H. Declo, MD, Dept of Otolaryngology, University of California, San Francisco 400 Parnassus Ave Rm 735 A San Francisco CA 94143. ' " ,
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scription of the CP region. Killian'! in 1907 more accurately described its muscular anatomy, including the weak triangular area between the inferior constrictor and CP muscles (the site of pharyngoesophageal or Zenker's diverticulum). In 1926 Jackson and Shallow" suggested that CP muscle relaxation failure during deglutition causes these diverticula. Lahey':' in 1946 recommended dilation of the CP muscle as part of the treatment of diverticulum. In 1950 Ashersori" created the term CP achalasia, describing it as a prediverticular state. On the basis of the theory that a dysmotile CP muscle results from bulbar or supranuclear central nervous system disorders, it was hypothesized that the surgical relaxation of the CP muscle would relieve cervical block dysphagia in patients with certain neurologic diseases. In 1951 Kaplan" reported the first successful myotomy in the treatment of cervical dysphagia in a patient with poliomyelitis. The efficacy of CP myotomy has since been documerited," in small series, for amyotrophic lateral sclerosis," Parkinson's disease, cerebrovascular accidents, skull base lesions and surgery, I and oculopharyngeal muscular dystrophy. 18 The usefulness of CP myotomy in head and neck cancer surgery has been recognized for over 30 years. Ogura et al'" noted that during supraglottic laryngectomy the CP muscle was tightly constricted when the surgeon's finger was inside it, and that CP myotomy relaxed the muscle, improved deglutition, and reduced aspiration postoperatively. Mladick et apo and subsequent authors discussed other oncologic procedures in which CP myotomy might be included. Cricopharyngeal achalasia may be a result of gastroesophageal reflux in some patients. In 1977 Henderson and Marryatf" reported on 19 patients who underwent CP myotomy, 17 of whom showed improvement. They performed a CP myotomy on patients who failed medical management of acid reflux with minimal heartburn, who were too ill for a major thoracoabdominal reflux procedure, and who had persistent dysphagia after hiatal hernia repair for reflux. In 1980 Orringer" reported a similar experience. Pulsion (Zenker's) diverticulum may result when normal CP function is disrupted. Konowitz and Biller" have recently reviewed the management of pulsion diverticulum, with emphasis on CP myotomy combined with diverticulopexy. Fundamental to their discussion is the concept that the underlying disorder is failure of the CP muscle to relax during deglutition, not a weak pharyngeal wall. PATIENTS
Fifty-four patients underwent CP myotomy by the senior author (H.H.D.) between 1973 and 1991. Records could be obtained on 47. Follow-up was based on chart review and personal communica-
217
tion. Twenty-five (53 %) of the patients were men and 22 (47 %) were women. Patients ranged in age from 26 to 87, with a median age of 64 and an average age of 60.7. The underlying cause of the patients' CP dysfunction was not identified in 17 (36 %) patients. It was identified as postlaryngectomy block dysphagia and/or failure of Blom-Singer speech in 7 (15 %); cerebrovascular accident in 7 (15 %); hiatal hernia with gastroesophageal reflux in 5 (11 %); cranial nerve deficits from neurosurgicalor skull base lesions in 8 (17 %); post -hemiglossectomy status in 1 (2 %); Parkinson's disease in 1 (2 %); and dystonia musculorum deformans in 1 (2 %). Preoperative diagnostic evaluations after indirect laryngoscopy initially included cine-esophagram, esophagoscopy (either rigid or flexible), and single sensor manometry. Seven patients had no preoperative diagnostic tests; these were in the group with multiple cranial nerve deficits (and low risk of cancer, esophageal stenosis, or Zenker's diverticulum). Of the remaining patients, 26 had an esophagram alone, and 7 had both an esophagram and esophagoscopy. Three patients had an esophagram and manometry, and 4 had esophagoscopy alone. The CP manometric studies and the esophagoscopies were unable to demonstrate CP abnormalities, so they are no longer used as diagnostic modalities for CP achalasia. Of the 36 patients who had esophagrams, only 11 patients had identifiable CP abnormalities. Three of these 11 patients had Zenker's diverticulum as a result of their CP dysfunction. The 5 patients with gastroesophageal reflux had minimal abdominal symptoms, had failed medical therapy, and had marked solid food block dysphagia at the cricoid level. INDICATIONS FOR MYOTOMY
In the English literature on CP myotomy, the accepted indication for the procedure is the presence of a CP bar on cine-esophagram. Surgeons naturally prefer that an unequivocal diagnosis be established by a manometrist or radiologist rather than to rely on their own clinical acumen; however, manometry and cine-esophagram do not identify a group of patients whom we have found to benefit from CP myotomy. Cineradiography and manometry are not abnormal in these patients; however, the former is ordinarily performed with liquid radiopaque media when these patients have no problems with liquids. Manometry, as currently performed, uses a probe that has only a single sensor at the level of the CP muscle, which may be against the cricoid cartilage, against the upper esophageal wall during the laryngeal elevation component of deglutition, or causing reflex CP spasm. When a cine-esophagram is performed with barium-coated, chewed solid food, especially the foods that have been "catching" at the CP level, it is sometimes possible to record delay or complete obstruction at the CP muscle. Thus, when the esophagram is done
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properly, it may confirm that the complaint is real. Clinically useful manometry of the CP muscle awaits improved sensor technology.
In our opinion, a sufficient basis for diagnosis and surgical treatment is a careful history, and a pharyngoesophagram that shows no evidence of a cancer. This is especially true in the patient with less gross dysphagia than that causing nasal regurgitation, a Zenker's diverticulum, or a CP bar on the cine-esophagram. Patients with CP achalasia who will benefit from CP myotomy typically present with block dysphagia (bolus obstruction) at the level of the cricoid cartilage. They do not have the typical pain that accompanies those cancers large enough to cause dysphagia. They consistently have difficulty swallowing solid foods but not liquids, and require multiple attempts (often with repeated sips of water) to swallow a single bolus of chewed solid food. Nasopharyngeal reflux, laryngeal aspiration, and weight loss are seen only in severe cases. The sensation of a block is present only until the bolus of solid food passes into the esophagus, and is not present when the patient is swallowing liquids, nor between swallows (much less meals), as occurs in globus syndrome. Physical examination of the pharynx, hypopharynx, larynx, and neck is unremarkable, and a routine (liquid barium) esophagram is normal. These selection criteria identify patients with enough CP dysmotility that it should be alleviated or eliminated by CP myotomy, even though it is too subtle to be detected by cineradiography and/or manometry.
tients with a history of cerebrovascular accident are suitable candidates for CP myotomy. If they have marked dysarthria, aphasia, or apraxia, however, they may have less chance of improvement. Patients with these dysfunctions may have such brain disorganization that they cannot or will not initiate a swallow. TECHNIQUE
Cricopharyngeal myotomy has a relatively low risk of morbidity and mortality. Pharyngocutaneous fistula, recurrent laryngeal nerve injury, and incomplete transection of CP muscle fibers are possible risks, but are very unlikely to occur with the following technique. We use a standard left-sided approach to visualize the posterior surface of the CP muscle, as shown in detail in our surgical atlas. 22 The larynx is rotated away from the surgeon with a double hook on the posterior edge of the thyroid cartilage ala so that the posterior pharyngeal wall is visualized. It is important not to let the lower tine of the double hook be applied below the midpoint of the ala; it must stay well away from the recurrent laryngeal nerve, since the nerve passes behind the inferior cornu of the thyroid cartilage. For extra recurrent nerve protection, we cover the inferior cornu with the surgeon's left thumb while installing the double hook.
Cricopharyngeal myotomy is, of course, contraindicated in globus syndrome. This syndrome is characterized by a nearly constant sensation of a lump, mucus, postnasal drip, or "something stuck" at the level of the cricoid, and commonly increases or enlarges with stressful events. The syndrome has been present for months or years with fluctuation in severity (from severely annoying to absent), and does not disappear between swallows. Globus syndrome patients are easily distinguished from patients with solid food block dysphagia because the former never have difficulty swallowing liquids or solid food.
Distention of the pharyngoesophageal muscle fibers while they are cut is essential. Many devices have been used to try to accomplish distention, including esophagoscopes," esophageal bougies or dilators,"" and esophageal balloons." We found that these devices do not distend the pharynx properly as the surgeon's finger does, so as to display the uncut muscle fibers, during a supraglottic laryngectomy. 19 Since there is no opening in the pharyngeal mucosa during CP myotomy, we have found that a large (36F or 38F) endotracheal tube, with a barrelshaped, low-pressure, high-compliance cuff, is an excellent substitute for the finger because it also provides active but soft distention. We especially like this type of cuff because it distends a long segment and it does not tend to migrate into and distend only the area in which the first fibers are cut, as the older, round cuffs do. The endotracheal tube is best installed in the esophagus by the anesthesiologist after the patient is anesthetized and prior to preparing and draping the skin. If a Zenker's diverticulum is present, it will usually go into the diverticulum. Therefore, in these patients insertion is stopped as soon as the tube has been gently passed behind the cricoid cartilage and resistance is met. Otherwise, there is a potential danger of perforation. Later, when the sac has been exposed surgically and tipped upward, the anesthesiologist eases the distal end of the endotracheal tube into the upper esophagus so the balloon will be within the CP muscle.
In our experience, cricoid block dysphagia pa-
Once the larynx is rotated and the posterior mid-
Gastroesophageal reflux is not a contraindication to performing CP myotomy in patients with solid food block dysphagia. Henderson and Marryatt'" have reported on patients with CP achalasia who were not improved after apparent medical or surgical control of gastric acid reflux until a CP myotomy was performed. We have observed that gastroesophageal reflux symptoms have not been exacerbated by surgical relaxation of the CP muscle. Vocal cord irritation and/or granulomas have not occurred in any of these CP myotomy patients, even when followed up for years.
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McKenna & Dedo, Cricopharyngeal Myotomy
Area of inferior cornu and RLN under thyroid Hland
Reprinted with perrnission.P A) Demonstration of laryngeal rotation, recurrent laryngeal nerve (RLN) position, and early distention of cricopharyngeal region musculature. B) Residual muscle fibers are identified by adequate distention and also blunt "peanut" dissection. C) Location of cricopharyngeus muscle can be reliably identified only after all fibers have been transeeted.
Endotracheal balloon distending hypopharynx
A
Hypopharynx mucosa Single muscle fibers indenting balloon
Cut esophaHeal constrictor m.
Cut inferior pharyngeal constrictor m.
/ Cut cricopharyngeal m.
line is identified, the anesthesiologist inflates the endotracheal tube cuff (see Figure,22 A). As the muscle fibers are cut, a distended cuff makes the uncut muscle fibers and thin submucosal fascia between the muscle and mucosal layers visually prominent because they indent the balloon (see Figure, B). A "peanut" in a Kelly clamp is used to roll uncut muscle fibers and fascia and loosen them from the underlying hypopharyngeal and esophageal mucosa prior to cutting them with a No. 15 Bard-Parker scalpel blade. During this fiber cutting, one potential pitfall is to mistake the cuff-endotracheal tube junction for an indenting muscle fiber. If the anesthesiologist deflates, moves, and reinflates the endotracheal tube cuff 1 to 2 em caudad and cephalad after some fibers have been cut, the risk of mucosal perforation from this cause is minimized. Also, the electrocautery is used only on muscle, and not on the mucosa, to minimize risk of perforation. Unless Zenker's diverticulum is present, we use a myotomy length of 4 to 5 cm, extending in the pos-
B
A
Thin fascia between muscle layer and mucosa
Cricopht:t
\
ryl1!lft:t1 111·
c
terior midline from the level of the thyrohyoid membrane to 1 ern below the inferior edge of the cricoid cartilage. This cut length assures that all of the CP muscle fibers have been divided, and it has caused no postoperative problems. If there is a Zenker's diverticulum, the upper edge of the CP muscle is obvious since the inferior edge of the neck of the sac is draped over it. In this case, we tip the sac upward, position and inflate the balloon within the CP muscle, and incise its fibers in the posterior midline for 2 em below the neck of the sac. We no longer incise over or resect the sac in order to minimize the risk of mucosal leak. It will contract down and become asymptomatic after the CP muscle obstruction is relieved," especially if the thinned inferior constrictor muscle fibers are left intact on its dorsal surface. If it is larger than 3 or 4 ern, it can be rotated upward and supported with a gut suture through the inferior constrictor left on its posterior surface. Unlike the anatomy atlas illustrations, in a patient the location of the CP musculature can be reliably identified only after all the fibers have been
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McKenna & Dedo, Cricopharyngeal Myotomy
transected, when its thickness is seen to be greater than that of the very thin esophageal muscle or the intermediate thickness of the inferior pharyngeal constrictor (see Figure, C). RESULTS
Duration of follow-up ranged between 1 month (for 6 patients who did so well they chose not to return) and 163/ 4 years. The average length of followup was 6 1/ 4 years. The surgical outcome was evaluated clinically, since cine-esophagrams cannot demonstrate all symptomatic CP muscle dysfunction. A patient's postoperative deglutition was classified as normal, markedly improved, not improved, or worse in comparison to the preoperative state. No patient reported worsening of the symptoms by CP myotomy. Twenty-one (45 %) patients reported normal swallow postoperatively. Fourteen (30%) patients reported markedly improved swallowing, but fell short of normal. (Therefore 35, or 75 % , were at least markedly improved by the myotomy.) Dramatic objective evidence of improvement was that 2 patients who had required a feeding gastrostomy preoperatively were able to have the tube removed. Six (12.5 %) patients had minimal improvement in symptoms, and 6 (12.5 %) patients had no improvement. Of patients without a known cause for their CP dysfunction, 15 of 17 had a markedly improved or normal swallow. Five of 7 patients who had postlaryngectomy block dysphagia had good or excellent results. In patients with cerebrovascular accidents, 6 of 7 had markedly improved deglutition. (The senior author knows of a patient, whose records were not available, who had suffered a cerebrovascular accident with resultant apraxia and dysarthria and neither improved nor worsened with CP myotomy.) Three of 5 patients with gastroesophageal reflux improved markedly. Of patients with skull base region trauma or neoplasia, only 3 of 8 had significant improvement. This finding would suggest that the presence of multiple lower cranial nerve palsies in patients who undergo CP myotomy makes improvement less likely, although the 3 patients who did improve would argue that the benefit outweighs the minimal risks of the procedure. The patients with Parkinson's disease, dystonia, and hemiglossectomy were markedly improved. The patients were also stratified according to the duration of their follow-up. Thirty-four of the 47 patients had follow-up of 6 months or longer. Of these 34, 25 (74 %) had an excellent or good surgical outcome. Only 1 had a partial recurrence of dysphagia after 6 or 7 years of marked improvement. This rate is not different from the total group improvement rate as outlined above. The patients with less than 6 months of follow-up had an improvement rate of approximately 77 % . This difference is not statistically significant because of the small sample size.
Of the 36 patients who had preoperative (liquid media) esophagrams, 25 were reported as having normal anatomy and motility through the pharyngoesophageal segment, in spite of the patients' vivid description of solid food block dysphagia. Of these 25 patients, 7 (28 %) had normal swallowing postoperatively, 13 (52 %) had marked improvement, 2 (8 %) had minimal improvement, and 3 (12 %) showed no improvement. Thus, 80 % of these symptomatic patients, with "normal" esophagrams preoperatively, benefited from CP myotomy, because we rejected the conventional diagnostic criteria of an abnormal liquid cine-esophagram. Also, all of the patients who had "normal" manometry preoperatively - in spite of severe clinical block dysphagia - had normal or markedly improved deglutition postoperatively. Two patients had previously received diagnoses of CP dysfunction and had undergone myotomy by other surgeons, without improvement. After we repeated the CP myotomy using the technique described above, both patients reported that their swallowing had returned to normal. During the operation we found that they had not had a complete CPmyotomy. No patient developed vocal cord paralysis or a hematoma. One patient developed a slight wound infection, which quickly responded to antibiotics. One patient developed a small pharyngocutaneous leak on the second postoperative day, which healed spontaneously in 3 days. SUMMARY
Deglutition is a complex neurophysiologic act. Disruption of the normal relaxation of the CP muscle during swallow results in block cervical dysphagia of solid foods, or CP achalasia. Medical treatment has not been effective. These patients' symptoms have been cured or alleviated by CP myotomy. Manometry and cineradiography are not effective in correctly identifying all of the patients who will benefit from CP myotomy. Eighty percent of these patients were markedly improved or given normal swallow by CP myotomy performed on the basis of specific symptoms described earlier, even though their cine-esophagrams and/or manometries revealed no disease. We therefore advocate CP myotomy as a diagnostic test on patients with solid food block dysphagia after excluding cancer, other anatomic lesions such as esophageal scar, and globus syndrome. Cricopharyngeal myotomy also relieves the dysphagia and lets the sac shrink when a Zenker's diverticulum is present. Gastroesophageal reflux is not a contraindication. The described technique minimizes the risks of mucosal perforation and incomplete fiber transection. The technique relies on the use of a cuffed endotracheal tube, which acts as an active muscular distention device, and creation of a myotomy of adequate length and depth to ensure complete division of the CP muscle.
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THE DEAFNESS RESEARCH FOUNDATION 1993 RESEARCH GRANTS AVAILABLE The Deafness Research Foundation invites applications for 1993 grant support of research projects directed to any aspect of the ear, egoinvestigation offunction, physiology, biochemistry, genetics, anatomy, or pathology. Grant support is given for one year, in an amount that cannot exceed $15.000. but can competitively be renewed for one or two additional years. Applications are reviewed for the scientific merit of the proposed investigations and for their direct or potential clinical value. The deadlines for applications for 1993 grant support are as follows: first year applications should be postmarked by July 15. 1992. and renewal applications should be postmarked by August 15. 1992. For information and applications. please contact Wesley H. Bradley, MD, Medical Director, The Deafness Research Foundation, 9 East 38th Street. New York, NY 10016; telephone (212) 684-6556; fax (212) 779-2125.
