1/18/2010 Regarding the use of Heller’s myotomy for treatment of megaesophagus in dogs (see references from human medical literature regarding Heller’s myotomy in treating PEOPLE with megaesophagus, following discussion by Dr. Kathy):
Heller’s myotomy is meant to “loosen” the sphincter between the esophagus and stomach, which is sometimes tight in dogs w/ ME (we THINK, but, don’t really know, in every case of ME). It would not be something I’d suggest unless fluroscopy was performed to get a better idea IF that was a problem. It isn’t a surgery that is commonly done, and there has been some controversy about the long term effectiveness. It MAY be effective in improving the results of vertical feeding. That may help with, but not prevent aspiration pneumonia. In another file there is a case report from 2003 that describes successful resolution of megae after Heller’s myotomy, however. Part of the problem in megaesophagus dogs is a lack of synchrony between the peristaltic wave in the esophagus, and relaxation of the lower esophageal sphincter (LES). In normal swallowing there is relaxation of the musculature immediately in front of the propulsive wave of contraction allowing the food bolus to slide on down and right into the stomach. With some cases of megaesophagus the LES does not relax and the bolus ends up trapped waiting for the door to open. Relaxation of the LES does occur sporadically, but the peristalsis of the esophagus fatigues and stops so there is nothing left to propel the bolus into the stomach when the LES does open. Some work was done on this at Cornell many years ago (probably at least before 1998) that showed that a modified Heller’s myotomy of the distal esophagus was successful in lowering the LES pressure allowing easier movement of food into the stomach when fed in an vertical position. I would guess that success was not present, as there haven’t been a lot of positive (or, negative, for that matter) reports of this surgery being performed in dogs. According to veterinary gastroenterologist, Dr. Washabau, in a presentation to the 2001 WSAVA (http://www.vin.com/VINDBPub/SearchPB/Proceedings/PR05000 /PR00133.htm): “Historically, cardiomyotomy (Heller’s myotomy) was recommended as a therapeutic measure in the belief that mega-esophagus was an achalasic disorder. Since the lower esophageal sphincter is normotensive and relaxes appropriately with swallowing in affected dogs (Washabau, 1992), cardiomyotomy cannot be recommended for the treatment of the disorder. Indeed, many animals treated with myotomy have had poorer outcomes than untreated animals.” So, the bottom line is, we really don’t know if this would be a successful procedure on every dog w/ ME; or, WHICH dogs would benefit.
From the human literature: Patient With Megaesophagus And Advanced Idiopathic Achalasia. Internet Journal of Surgery, 2007 by J. Carvajal Balaguera, M. Mart√≠n Garc√≠a- Almenta, J. Camu√ as Segovia, L. Pe√ a Gamarra, S. Oliart Delgado de Torres, L. Albeniz Aguiriano, C.Ma. Cerquella Hern√ ndez Summary: Laparoscopic Heller myotomy and Dor fundoplication is the surgical procedure of choice for esophageal achalasia. However, treatment of megaesophagus for advanced idiopathic achalasia has been controversial. Some authors recommend a myotomy as initial treatment and reserve esophageal resection for cases with persistent symptoms, whereas others recommend esophagectomy. We report the case of a patient with an esophageal advanced dilatation due to idiopathic achalasia. We have performed laparoscopic Heller myotomy and Dor fundoplication. The postoperative course was uneventful. There is no evidence of recurrence of the dysphagia and the patient is asymptomatic after the first year follow-up. Based on our experience with this case and based on a review of the literature, we discuss the different treatment modalities of this pathology.ABSTRACT FROM AUTHORCopyright of Internet Journal of Surgery is the property of Internet Scientific Publications LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder’s express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. Excerpt from Article: Laparoscopic Heller myotomy and Dor fundoplication is the surgical procedure of choice for esophageal achalasia. However, treatment of megaesophagus for advanced idiopathic achalasia has been controversial. Some authors recommend a myotomy as initial treatment and reserve esophageal resection for cases with persistent symptoms, whereas others recommend esophagectomy. We report the case of a patient with an esophageal advanced dilatation due to idiopathic achalasia. We have performed laparoscopic Heller myotomy and Dor fundoplication. The postoperative course was uneventful. There is no evidence of recurrence of the dysphagia and the patient is asymptomatic after the first year follow-up. Based on our experience with this case and based on a review of the literature, we discuss the different treatment modalities of this pathology. Idiopathic achalasia is a degenerative disease characterized by a defective peristaltic activity of the esophageal body and impaired relaxation of the lower esophageal sphincter, which leads to difficult progression of a bolus into the stomach. It affects 1 in 100.000 individuals. The age of maximum presentation oscillates between 20 and 40 years, although it can appear in all ages. It affects men and women equally. It is not a hereditary disease, although family cases have been described. Surgical treatment of achalasia has evolved dramatically over the past 15 years; since the first report of laparoscopic Heller myotomy by Cushieri et al, and thoracoscopic Heller myotomy by Pellegrini et al. Currently, laparoscopic myotomy is the gold standard for treatment of achalasia. The satisfactory results of this procedure are well documented in several large series. In some cases with a great esophageal dilation or advanced mega-esophagus, myotomy can alleviate also the symptoms of these patients.
Results of Laparoscopic Heller Myotomy for Extreme Megaesophagus: An Alternative to Esophagectomy Scott, Paul D. MD; Harold, Kristi L. MD; Heniford, B. Todd MD, FACS; Jaroszewski, Dawn E. MD Abstract Heller myotomy is recognized as the optimal treatment for achalasia. However, treatment of the markedly dilated esophagus has been debated in the literature. Although esophagectomy has been the standard treatment historically, several studies have examined successful treatment of achalasia with laparoscopic Heller myotomy in the setting of a markedly dilated esophagus (>6 cm). Patients with extreme megaesophagus (>10 cm) are often treated with esophagectomy. We report the successful treatment of 4 patients with extreme megaesophagus with laparoscopic Heller myotomy. Three of the 4 patients also had Toupet fundoplication. The average esophageal diameter was 11.2 cm (10 to 12 cm). In addition to severe dysphagia, all patients had preoperative signs, symptoms, and radiographic evidence of esophageal compression of their heart and lungs. All patients reported relief of their preoperative symptoms. Esophagectomy has not been required to maintain adequate clinical results in any of our patients. We conclude that laparoscopic Heller myotomy is an appropriate alternative to esophagectomy and can be offered to patients with extreme megaesophagus. Dr. Kathy