Esophagomyotomy versus Forceful Dilation for Achalasia of the Esophagus: Results in 899 Patients

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1 Esophagomyotomy versus Forceful Dilation for Achalasia of the Esophagus: Results in 899 Patients Nsidinanya Okike, M.D., W. Spencer Payne, M.D., David M. Neufeld, M.D., Philip E. Bernatz, M.D., Peter C. Pairolero, M.D., and David R. Sanderson, M.D. ABSTRACT Between 1949 and 1976, 899 patients underwent treatment for achalasia of the esophagus at the Mayo Clinic, 431 by forceful hydrostatic or pneumatic dilation and 468 by a standardized transthoracic esophagomyotomy. Esophageal leak and mediastinal sepsis was an uncommon but major complication of both types of therapy, occumng four times more often with dilation (4%) than with myotomy (l0/o), although no deaths resulted from this in either group. The 30-day mortality was 0.2% after myotomy and 0.5% after forceful dilation. Although there was minimal morbidity and mortality with either modality, the late results were significantly superior after myotomy. Excellent to good results were obtained by 85% of the group treated with myotomy but only by 65% of those treated with hydrostatic dilation. Late poor results were encountered three times more frequently after dilation (19%) than after myotomy (6%). Analysis of poor results after myotomy indicates that late serious complications of gastroesophageal reflux developed in only 3% of patients operated on. At the Mayo Clinic, both esophagomyotomy and forceful hydrostatic or pneumatic dilation of the cardia have been long employed in the palliation of the esophageal obstructive symptoms of achalasia [8]. Because of conflicting reports regarding the relative value of these procedures, the present review was undertaken. In it, we compare the results in 200 patients treated by esophagomyotomy from 1967 through 1975 with the results in 268 patients treated by esophagomyotomy before 1967 [31. Further, the combined surgical series of these 468 patients undergoing esophagomyotomy were compared with a series of 431 patients From the Mayo Clinic and Mayo Foundation, Rochester, MN. Presented at the Fifteenth Annual Meeting of The Society of Thoracic Surgeons, Jan 15-17, 1979, Phoenix, AZ. Address reprint requests to Dr. Payne, Mayo Clinic, Rochester, MN with achalasia treated by forceful dilation (Figure). Current Series of Esophagomyotomy ( ) Clinical Aspects To be included, each patient must have undergone the initial esophagomyotomy for achalasia at the Mayo Clinic during the period 1967 through The 200 patients (98 male and 102 female patients) fulfilling these criteria ranged from 5 to 81 years old at the time of operation (median age, 51 years). All patients were symptomatic, with complaints of esophageal obstruction and dysphagia; 70% had symptoms of regurgitation of retained esophageal contents, and 30% had painful esophageal distress described as either spasm or heartburn. Sixtyone percent of the patients had lost 4.5 to 41 kg before treatment, with 18% having lost more than 14 kg. Ten percent had radiographic evidence of aspiration pneumonitis at diagnosis. Although none of the patients in this series had had previous operations for achalasia, 96 of the 200 had previously undergone some form of esophageal dilation therapy, without improvement in the symptoms. All 200 patients underwent radiographic examination of the esophagus, with the demonstration of distal esophageal obstruction and the characteristic tapered narrowing of the esophagogastric junction and varying degrees of amotile dilatation of the esophagus. Dilatation of the esophagus was mild in 20%, moderate in &%, and severe in 35%. Before operation, 16 (8%) patients had radiographic evidence of a sliding esophageal hiatal hernia as well as achalasia. All but 17 of the 200 patients underwent esophageal manometric study before operation. In 86% (157 patients) of these studies, the findings were those of classic achalasia, whereas in 14% (26 patients), the motility was that of "vigorous" achalasia [lo] by Mayo Foundation

2 120 The Annals of Thoracic Surgery Vol 28 No 2 August 1979 a - C performed, as well as the esophagomyotomy. Postoperatively, patients resume a liquid diet the day after operation and rapidly progress to a general diet in the ensuing 3 to 4 days. Most patients leave the hospital within a week of operation. Results EARLY RESULTS. Of the 200 patients operated on during the 1967 through 1975 era, only 6 experienced significant postoperative complica-,,,,,,,,,,,,, tions: 5 had pneumonitis or atelectasis and 1, a YEAR transient cardiac arrhythmia. In these 200 Observed trends in the management of 899 patients operations, there were no clinically evident with achalasia of the esophagus at the Mayo Clinic esophageal leaks and no postoperative deaths. from 1948 through Depicted is the percentage LATE FOLLOW-UP AND RESULTS. Complete distribution of the two forms of treatment by year. Note the shift in emphasis toward esophagomyotorny (solid follow-up information was available on all 200 curve) in lieu offorceful hydrostatic or pneumatic dila- patients during Follow-up ranged from 3 tion (dotted curve) since to 11 years (average, 6.5 years). Twelve patients died during the follow-up period, but no death Endoscopic examination performed in all patients before operation demonstrated esophageal hypomotility, varied sizes, differing degrees of tortuosity, and various amounts of food retention and stasis esophagitis. Generally, the stomach could be entered with the endoscope without marked resistance. was related to the esophageal problem. The criteria for evaluating the effectiveness of the operations were similar to those applied to the 1949 through 1966 series of 268 patients with achalasia treated by esophagomyotomy [31 and the 408 treated by hydrostatic dilation [9]. To be considered to have an excellent result, the patient must be completely asymptomatic, have Operative Technique and Care The surgical technique of esophagomyotomy in the current era was identical to that previously described and employed at the Mayo Clinic since 1949 [3, 81. Essentially, the procedure consists of a left transthoracic longitudinal esophagomyotomy, which extends from the esophagogastric junction distally, to a point 7 to 10 cm proximally, to the level of the left inferior pulmonary vein. Care is taken to avoid undue traction on the esophagus or dissection around the esophageal hiatus which might lead to the development of a hiatal hernia. Approximately 50% of the circumference of the esophageal mucosal tube is freed of overlying muscularis to allow the mucosa to pout through the myotomy. Care is taken to avoid injury to vagal fibers and not to extend the myotomy onto the stomach. If an anatomical sliding esophageal hiatal hernia is present, it is repaired. In the present series, either an Allison repair (4 patients) or a Belsey-type repair (12 patients) was gained weight, and have returned to full-time work. The patient classified as having good results must fulfill the same requirements but can. continue to have occasional dysphagia when eating certain foods, when hurried, or when under nervous stress. A patient having a fair result, although fulfilling most of these criteria and although experiencing definite improvement, would continue to have occasional to frequent episodes of dysphagia and occasional regurgitation. Poor results indicate no improvement or worsening of the condition. Of the 200 patients, 94% had definite improvement; 90% had either excellent or good results, and 4% had fair results in that they were improved by the operation but had some distress. Six percent had poor results; their condition was unchanged or had worsened from the preoperative status. An attempt was made to correlate certain preoperative features with results. Results were unaffected by age, sex, duration of symptoms, previous dilation

3 121 Okike et al: Esophagomyotomy vs Dilation for Achalasia Table 1. Results of Esophagornyotomy and Diaphragmatic Hernia Repair in 16 Patients with Achalasia Belsey Allison Result Technique Repair Total Excellent Good Fair Poor 1" lh 2 Total "Reflux, stricture. "Persistent achalasia. therapy, degree of esophageal dilatation on roentgenographic examination, the finding of "vigorous" or "classic" achalasia on preoperative motility study, or the presence of a hiatal hernia or type of repair employed (Table 1). Comparison of Current Series with Previous Series of Esophagomyotomy ( ) The experience at the Mayo Clinic with transthoracic esophagomyotomy for achalasia has been the subject of continued analysis since its introduction into our practice in 1949 [2, 4,7]. A detailed analysis of the entire Mayo Clinic experience before 1967 was reported by Ellis and Olsen [3]. The late results of esophagomyotomy in 256 of the 268 patients treated in that experience were compared with the results in the 200 patients in the current series and the results in the combined experience of 456 patients (Table 2). Although the clinical material and duration of follow-up showed minor variations, results in Table 2. Comparison of Results of Esophagomyotomy for Achalasiaa Total (256 (200 (456 Result Patients) Patients) Patients) Excellent Good Fair Poor aresults presented as percentage of patients in each category. the two surgical series were not statistically different. The records of the 29 patients (6%) with poor results in the combined series of 456 patients were analyzed to identify possible underlying causes for failure. In 14 patients, the cardia was rendered incompetent by the operation, with subsequent development of reflux esophagitis and its complications: 10 in the early study and 4 in the later series. All 14 patients were first seen with intractable heartburn or subsequent stricture formation or both. In the other 15 patients, recurrent or persistent distal esophageal obstruction appeared to be related to the unrelieved esophageal motility problem: 6 in the early series and 9 in the later series. These 15 patients experienced symptoms of dysphagia and regurgitation identical to their preoperative distress, without significant heartburn and little or no resistance to passage of a 50F dilator through the cardia. Radiographic examination demonstrated esophageal food retention, progression in esophageal size, and characteristic tapered distal obstruction. Either incomplete operation or refusion of the cut muscle was considered responsible for their distress. This impression was further confirmed at reoperation in 3 patients. Comparison of Esophagomyotomy with Hydrostatic Dilation ( ) Ongoing reviews of the results of various treatments for achalasia of the esophagus at the Mayo Clinic have resulted in an increasingly important role for surgical treatment (see Figure). Only 23 new patients have been treated by forceful dilation since 1967, making a total of 431 patients so treated. Briefly, the procedure involves preliminary esophageal bougienage with a 41F sound over a previously swallowed thread to identify the level of the cardia and permit passage of the larger unit. This is followed by the placement of a hydrostatic or pneumatic dilator, which is positioned in such a way that the inflatable bag straddles the esophagogastric junction. Inflation is carefully performed using 549 to 670 cm of water pressure, or 150 to 200 mm Hg if a pneumatic dilator is employed. Pressure is sustained for several seconds before the procedure is terminated. Sanderson and colleagues [9] previously

4 122 The Annals of Thoracic Surgery Vol 28 No 2 August 1979 Table 3. Comparison of Results of Hydrostatic Dilation and Esophagomyotomy ( ) Esophago- Dilation myotomy (431 (468 Factors Patients) Patients) Result (YO) Excellent " Good a Fair 16 9 Poor 19 6 Follow-up (yr) 1 to 18 1 to 17 No. of patients Percent Age (Yr) 1 to 85 4 to 81 "Significantly different Cp < 0.001). analyzed the late results of forceful dilation for achalasia in 311 of the 431 patients so managed since These results were compared with the combined esophagomyotomy experience (Table 3). The criteria for evaluating the effectiveness of forceful dilation were similar to those applied for evaluating esophagomyotomy. The late results of esophagomyotomy were significantly better than those for forceful dilation (p < 0.001). While most (82%) of the patients treated by hydrostatic dilation underwent treatment once, 16% were dilated twice and 2% were dilated three or more times. A comparison of the early serious posttreatment morbidity and mortality indicated the more favorable risk of esophagomyotomy: 5 patients undergoing esophagomyotomy had esophageal leak (3 requiring reoperation), whereas 19 patients undergoing dilation had esophageal leak (10 requiring operation). The 2 deaths after dilation could not be directly related to the procedure, although 1 patient died 5 days and the other, two weeks after treatment. The single surgical death occurred during operation as a consequence of an extreme hyperthermia and fatal cardiac dysrhythmia. Comment The current treatment of achalasia is directed at palliation of the symptoms of achalasia. At the present time, there is no known means of "curing" achalasia by restoring peristalsis to the body of the esophagus or restoring the normal response of the lower esophageal sphincter to swallowing. Nevertheless, significant improvement can be accomplished by weakening the lower esophageal sphincter using either myotomy or forceful dilation. That neither method is wholly capable of effecting highly satisfactory results in all patients treated is clearly apparent. However, a properly performed esophagomyotomy can effect consistent, prolonged, and significantly more favorable results than can forceful dilation, and with less risk. Whether subjecting patients to sequential treatment and its cumulative risk is justified has not been answered by this study. Patients who have failed to benefit from forceful dilation seem to respond to esophagomyotomy as well as if they had not had previous treatment. However, occasionally, intramural esophageal hemorrhage and fibrosis from previous forceful dilation may preclude the subsequent performance of an effective myotomy. Our group believes that surgical treatment should be the initial therapy for the reasons just indicated. Our current practice is to elect forceful dilation only when the patient's condition does not permit general anesthesia and a major operation or if the patient declines operation. It should be noted, however, that a significant anatomical esophageal hiatal hernia can preclude the safe and effective performance of forceful dilation, and patients with vigorous achalasia respond less well to dilation than do patients with classic achalasia [lo]. The 16 patients with preexisting diaphragmatic hernia in the current surgical series and the 67 patients with vigorous achalasia treated surgically in the combined surgical series achieved the usual satisfactory result of operation. Although our results with esophagomyotomy have remained consistent and gratifyingly favorable for most patients, 6% of patients continue to have poor results after operation. In our analysis, these poor results were attributable either to failure by incompletely relieving the obstructive achalasia of the lower esophageal sphincter or to failure by rendering the sphincter incompetent. Some surgeons have reported

5 1.23 Okike et al: Esophagomyotomy vs Dilation for Achalasia a considerably higher incidence of reflux esophagitis and its complications than the 3% observed in the present series [6]. The higher incidence could be due to the late development of hiatal hernia or the overzealous extension of the myotomy onto the stomach in an effort to relieve completely the sphincteric obstruction. Still others have suggested that the myotomy should be extended onto the stomach routinely in order to destroy the sphincter and that an antireflux procedure should be routinely incorporated in the initial surgical effort [l, 5, 111. Appealing as this may be, insufficient data have been published to establish the role of the combined myotomy-antireflux procedure as routine practice in the initial surgical treatment of achalasia. In our very limited experience with this combination in patients with preexisting hiatal hernia, the results would not appear to justify its use as a routine in all patients. However, we continue to support the concept of repair of a preexisting hiatal hernia at the time of esophagomyotomy, utilizing a Belseytype antireflux procedure. Contrary to reported experience [ill, we have found that, when achalasia is present, the Nissen antireflux procedure is unpredictably obstructive to the amotile esophagus when used for correction of late postoperative reflux problems. Although it may seem that the surgeon who performs esophagomyotomy must choose between either incomplete relief of achalasia or incompetence of the cardia, the present study indicates that 94% of patients treated by a properly performed esophagomyotomy obtain significant long-term palliation of esophageal distress, with minimal morbidity and mortality and without producing either of these undesirable side-effects. References 1. Black J, Vorbach AN, Collis JL: Results of Heller s operation for achalasia of the oesophagus: the importance of hiatal repair. Br J Surg 63:949, Ellis FH Jr, Kiser JC, Schlegel JF, et al: Esophagomyotomy for esophageal achalasia: experimental, clinical, and manometric aspects. Ann Surg 166:640, Ellis FH Jr, Olsen AM: Achalasia of the esophagus. Major Probl Clin Surg 9:1, Ellis FH Jr, Olsen AM, Holman CB, et al: Surgical treatment of cardiospasm (achalasia of the esophagus): considerations of aspects of esophagomyotomy. JAMA 166:29, Henderson RD: Motor Disorders of the Esophagus. Baltimore, Williams & Wilkins, Nemir P Jr, Fallahnejad M, Bose B, et al: A study of the causes of failure of esophagocardiomyotomy for achalasia. Am J Surg 121:143, Payne WS, Ellis FH Jr, Olsen AM: Achalasia of the esophagus: a follow-up study of patients undergoing esophagomyotomy. Arch Surg 81:411, Payne WS, Olsen AM: The Esophagus. Philadelphia, Lea & Febiger, Sanderson DR, Ellis FH Jr, Olsen AM: Achalasia of the esophagus: results of therapy by dilation, Chest 58:116, Sanderson DR, Ellis FH Jr, Schlegel JF, et al: Syndrome of vigorous achalasia: clinical and physiologic observations. Dis Chest 52:508, Schomacher PH, Biinte H: Die chirurgische Therapie der Achalasie. Chirurg 49:25, 1978 Discussion DR. RONALD c. ELKINS (Oklahoma City, OK): The experience at the Mayo Clinic with esophageal disease represents one of the larger clinical experiences in the world. The completeness of their records and the detailed evaluation of these data are a credit to all of the physicians involved. The present report clearly demonstrates the ability of a properly performed esophagomyotomy to provide subjective and objective relief for the patient with achalasia. Unfortunately, the present operative approach is not completely effective, and in fact, attempts to reproduce the results reported today have in general produced a much higher incidence of failure. In reviewing the literature, it becomes clear that 10 to 25% of patients in whom a modified Heller myotomy was performed have an unsatisfactory long-term result. In most of these patients, failure relates to the development of reflux esophagitis, although in the patients just reviewed this occurred only in 50% of those with poor results and its incidence in those patients with fair results was not reported. During the past seven years we have evaluated more than 800 patients with esophageal disease and have identified 48 patients with achalasia. This group of patients was very heterogeneous in that many of them had undergone multiple attempts at esophageal dilation as well as many previous surgical procedures. In this group of patients, gastroesophageal reflux was demonstrated by the standard acid reflux testing in 15 of the 48 patients, for an incidence of 31%. Six of the patients had not undergone previous dilation or had had a previous opera-

6 124 The Annals of Thoracic Surgery Vol 28 No 2 August 1979 tive procedure at the time of reflux. This leads me to ask whether Dr. Okike and his associates evaluated any of their patients before operative intervention or dilation for gastroesophageal reflux. The presence of gastroesophageal reflux in a patient with achalasia is a particularly devastating event because of the total loss of the normal protective mechanism of esophageal peristalsis. Operative intervention that can exacerbate this serious problem should be avoided. We have advocated the use of an antireflux procedure of the Belsey type on all patients undergoing a modified Heller procedure. Twenty patients were operated on during the past six years and to date they have all had an excellent postoperative result. Because of our dissatisfaction with the Belsey procedure in the treatment of patients with reflux esophagitis, and in the absence of motility disturbance, 2 patients were treated with a combination of a modified Heller procedure and a Nissen fundoplication. Both patients had persistent dysphagia requiring reoperation and conversion of the Nissen fundoplication to a Belsey Mark IV procedure. A cursory review of the literature reveals there are now several centers that have reported the use of an antireflux procedure in a combination with the modified Heller procedure. All have developed this operative approach because of dissatisfaction with their results in patients treated with a modified Heller procedure. Although this series from the Mayo Clinic has a very low incidence of reflux, our early results encourage us to continue the use of an antireflux procedure with a modified Heller procedure. DR. VICTOR H. KAUNITZ (Teton Village, WY): I would like to raise two points in discussion of this excellent paper from the Mayo Clinic. The first point concerns operative exposure and ease of performing the myotomy. Several years ago I found that the crural muscle can be divided with complete impunity. There are almost no discernible postoperative ill effects from division and resuture of hiatal muscle. By cleanly dividing the crus at thoracotomy and carefully laying back the anterior and posterior flaps of the diaphragm without dividing or stretching the phrenoesophageal membrane attachments, excellent exposure of the entire gastroesophageal junction and lower esophageal sphincter area is obtained. This allows for adequate myotomy without disruption of the phrenoesophageal attachments, thereby preventing the production of a small sliding hiatus hernia. The second point concerns persistent achalasia and reflux esophagitis. Although the authors state that persistent achalasia, not reflux esophagitis, is the major cause of poor results of myotomy, I believe that reffux esophagitis and spasm most certainly are causes of postoperative problems. Small hiatus hernias are notoriously more troublesome than large ones. If the lower esophageal sphincter migrates upward, into or through the hiatus, into the posterior mediastinum, it tends to become incompetent. Reflux then occurs, with all the resulting problems. The surgeon can either fail to recognize a small sliding hernia or produce one, as quite often happens, by overzealous dissection under an intact crus in the desire to perform an adequate myotomy. I would like to suggest the following: (1) Exposure for myotomy can be improved greatly and quite simply by clean division, with later resuture of crural muscle. It is not necessary to produce a hernia in dissecting the area for a myotomy. (2) If a hernia is present, it should be corrected by whatever appropriate maneuver the surgeon considers advisable. DR. HENRY J. HEIMLICH (Cincinnati, OH): It is a pleasure to discuss this fine presentation from the Mayo Clinic. In 1978, my colleagues and I reported the results of pneumatic dilation for achalasia, with similar findings (Ann Otol Rhino1 Laryngol 87:519, 1978). However, our conclusions are quite different from those in this paper. The words forceful or rapid dilation should be abandoned. The balloon of the dilator is gradually distended, under fluoroscopic control, and full distention is maintained for a period of five minutes. The pneumatic dilator cannot distend beyond a fixed diameter since it is encased in a nylon bag. Pneumatic dilation is safer in most instances, therefore, than the hydrostatic balloon, which continually expands as the pressure is increased. Interestingly, our roentgenographic findings on barium swallow done after dilation show greater patency of the cardia than is usually seen after cardiomyotomy. The clinical results are excellent in 75% of patients. I would like to ask the authors the following question: Since approximately 80 of each 100 of their patients obtain as good a result with dilation as with cardiomyotomy, is it not advisable to use dilation first on the 100 patients and reserve cardiomyotomy for the 20 patients with inadequate results? Dilation is a fifteen-minute procedure requiring no general anesthesia and only one-day hospitalization. We prefer that method to performing approximately 80 unnecessary thoracotomies with surgical disruption of the hiatus, one and a half to two weeks of convalescence, and frequent, long-term pain after thoracotomy. It is noted that, in this paper, the 1 death from cardiomyotomy was a result of anesthesia, which would not occur with dilation. The difference in the actual number of complications resulting from the two methods is statistically not significant. The 2 deaths following dilation were stated to be unrelated to the procedure and perhaps are a result of selecting patients for dilation, rather than operation, because they were high operative risks.

7 125 Okike et al: Esophagomyotomy vs Dilation for Achalasia DR. FRANKLIN HENRY ELLIS, JR (Boston, MA): I want to compliment the authors on this superb series, well analyzed and well presented. It is destined to become a classic in the literature on achalasia. It is particularly gratifying to me to see our original series confirmed by these data. They are identical to the early results we obtained at the Lahey Clinic in that the overall improvement rate is 94% and the overall incidence of postoperative reflux is 3%. It is almost as though the two series were copies of one another. I have a few questions and then I would like to discuss briefly my experience with esophagomyotomy. Did any of the patients in the early series have further follow-up? I am particularly interested to know if cancer of the esophagus developed in any of them. Some of those patients could have been followed up for close to thirty years now. One would think that cancer would not result following relief of the distal obstruction, but there have been a few reports of cancer of the esophagus following esoph agomyotom y. My own smaller experience involves 64 patients operated on between January, 1970, and January, It differs from the Mayo Clinic series in that 10% of these patients had had previous myotomy elsewhere. The overall improvement rate is practically identical, 92.4% and 94%, though the follow-up period is shorter. Four patients had poor results: 1 had previously had a Nissen fundoplication unbeknown to us; reflux esophagitis developed in 1; another had previously had a myotomy and had a megaesophagus; and the fourth patient had an inadequate myotomy, with persistent dysphagia. The question I would like to ask the authors concerns their overall results. Even though they are identical to the early series in terms of overall improvement, they show a marked reduction in fair results and a considerable improvement in excellent results. These results suggest either that the surgical technique was altered or that the method of selecting patients for the second group was different from that used in the first group. DR. PAYNE: I appreciate Dr. Elkins s contribution to this discussion, particularly since his conclusions are contrary to ours. I wish to emphasize that current management of achalasia is not curative since it restores neither peristalsis nor physiological response of the lower esophageal sphincter. We do, however, palliate exceedingly well by properly performing an esophagomyotomy. By adhering to the technical details defined, significant gastroesophageal incompetence is rare. The incidence of complications from gastroesophageal reflux on long-term follow-up in our large series was only 3%, an incidence considerably less than the late failure rate of currently available antireflux operations. Thus, I am forced to conclude that the routine incorporation of an antireflux procedure with myotomy represents a therapeutic overkill and, in our limited experience, a result no better than myotomy alone. With regard to Dr. Kaunitz s comments, I would emphasize that one should avoid dissection around the hiatus or creation of unusual traction on the esophagus that might lead to the production of an anatomical hiatal hernia. In our experience, the presence of a hiatal hernia with esophagomyotomy is an invitation to serious gastroesophageal reflux. The presence of a hiatal hernia is the only circumstance that we consider to be an indication for an antireflux procedure with myotomy for achalasia. In response to Dr. Heimlich, I can only point to our own experience with the high failure rate of pneumatic and hydrostatic dilation on long-term follow-up, with a fourfold increase in morbidity, compared with myotomy. Further, nearly half of the patients we operated on had had one or more previous forceful dilations without improvement, but did obtain notable benefit from subsequent operations. Finally, we are all greatly indebted to Dr. Ellis for his many contributions to the current surgical management of achalasia. In response to his question regarding the late development of cancer in the patient who successfully underwent myotomy for achalasia, I can only state that we are only now beginning to see the occasional patient with this complication developing some twenty years after myotomy. I have no statistical data regarding this incidence. I think we must continue to consider achalasia as precancerous, irrespective of the type of previous palliation of achalasia. With regard to the inquiry about the results in the two surgical series, I would emphasize only that our statisticians do not find any significant differences between those of the recent and previous series. I would add, however, that the recent series does not include patients undergoing repeat myotomy. Such reoperations were included in the earlier series, and this alone may account for minor variations observed.