1. Do outcomes of surgical treatment for Achalasia depend on the manometric subtype? Keliang Xiao 1, Oscar Crespin 2 Roger Tatum 2, Ana V. Martin 2,Saurabh Khandelwal 2, Brant Oelschlager 2, Carlos Pellegrini 2 UMKC School of Medicine 1, University of Washington School of Medicine 2 Introduction High Resolution Manometry (HRM) yields better understanding of esophageal motility than does conventional manometry, and a new classification system which describes three distinct HRM subtypes of achalasia based on esophageal body contraction patterns appears to be a promising tool in predicting results of treatment with standard Heller Myotomy. The aim of this study is to analyze the outcomes of surgical treatment with extended Heller myotomy for each subtype and to identify additional parameters that may predict success of therapy. Methods From 2008 to 2013 at the University of Washington Medical Center 72 patients underwent laparoscopic extended Heller myotomy for first time. In addition to manometric parameters, clinical records were reviewed for symptom duration, patient age at the time of referral, and preoperative esophageal dilation (stage I-III) as assessed by radiography. We defined treatment failure as no improvement in symptoms and/or need for a second therapy within one year after the operation. Long term follow up data (15 to 46 months) was available for a subset of 25 patients in the form of a survey evaluating overall satisfaction with the operation. Results The 72 myotomy patients included 13 with type I (no contractions), 54 with type II (pan-esophageal pressurizations), and 5 with type III (high-amplitude distal spasm). Failure was found in 1 patient with manometric type I and radiologic stage III esophageal dilation, 1 patient with manometric type II and radiologic stage II esophageal dilation, and none with manometric type III. All of the type I patients had at least some degree of esophageal dilation on radiography, whereas no dilation was found in the type III group. Treatment failure was not observed in any of the patients under 50 years old (n=35) nor in any patients with stage I esophageal dilation. Only one of the 25 patients with long term follow up reported dissatisfaction with the treatment result; this patient had type II achalasia on HRM and esophageal dilation was stage I. Conclusion Overall, laparoscopic extended Heller myotomy is a highly successful treatment for patients with achalasia, and outcomes do not appear to vary significantly according to HRM subtype. Stage I esophageal dilation and age below 50 may be better indicators of consistent symptom relief after surgical therapy for this disease. References 1.Rohof, WO. Et al, “Outcomes of Treatment for Achalasia Depend on Manometric Subtype." Gastroenterology 144.4 (2013): 718- 25. 2. Pandolfino, JE, et al "Achalasia: A New Clinically Relevant Classification by High- Resolution Manometry." Gastroenterology 135.5 (2008): 1526-33. Figure 1. Outcome by Manometric Subtype Figure 2. Outcome by Esophageal Dilation Figure 3. Outcome by Age