CT - computed tomography; PPV - positive predictive value; NPV - negative predictivevalue. *Tumor-SMV-PV interface scale - 0: no interface, 1: abutment ( ≤ 180°), 2: encasement(. 180°), 3: occlusion. **SMV-PV appearance based on the Ishikawa system - 1: normal,2: smooth shift, 3: unilateral narrowing, 4: bilateral narrowing without collaterals, 5: bilateralnarrowing or occlusion with collaterals.

862

Depth of Submucosal Tumor Infiltration and Its Relevance in LymphaticMetastasis Formation for T1b Squamous-Cell and Adenocarcinomas of theEsophagusMichael F. Nentwich, Katharina von Loga, Matthias Reeh, Guido Sauter, Thomas Rösch,Jakob R. Izbicki, Dean Bogoevski

Background: Surgical resection for early esophageal carcinoma has been challenged by lessinvasive endoscopic approaches. As lymph node involvement, one of the major factorsinfluencing patients' overall survival cannot be assessed by endoscopic resection, selectingpatients in need for surgical intervention according to their risk of lymphatic spread ismandatory. Objective: The aim of this study was to evaluate submucosal layer thickness,depth of submucosal tumor infiltration and tumor length as well as lymphatic invasion in T1besophageal carcinomas for its predictiveness on lymphatic metastasis formation. Methods:Histopathological specimens following surgical resection for T1b esophageal carcinomaswere re-evaluated for overall submucosal layer thickness, depth of submucosal tumor infiltra-tion, tumor length as well as lymphatic and vascular infiltration. A ratio of overall submucosallayer thickness and depth of submucosal tumor infiltration was calculated and this proportionof submucosal invasion was used to form sub-categories either in thirds or in halfs of totalsubmucosal gauge. Influence of submucosal invasion as well as tumor length on lymphaticmetastasis formation and overall survival was assessed. Results: A total of 67 Patients withpT1b tumors were analyzed, including 36 adenocarcinomas (53.7%) and 31 squamous-cellcarcinomas (46.3%). Lymph node involvement was seen in 20.9% (14/67) patients. Overallmean thickness of submucosal layer was 5.07mm (SD 1.53mm). Overall proportion ofsubmucosal infiltration was calculated as 64.79% (SD 29.2%). Comparison of overall propor-tion of submucosal infiltration between patients with (62.81%, range 17-97%) and without(65.31%, range 2-99%) lymph node involvement did not show significant differences (p=0.698 Mann-Whitney-U). On log-regression models, only the presence of lymphangioinva-sion and tumor length was significantly associated with positive lymph node involvement.Conclusion: As depth of submucosal tumor infiltration did not correlate with the formationof lymph node metastases and in regard of the risk of lymphatic spread in these cases,surgical resection is warranted whenever the tumor invades the submucosal layer.

863

High Resolution Manometry Classifications for Idiopathic Achalasia inPatients With Chagas Disease EsophagopathyFernando P. Vicentine, Fernando A. Herbella, Luciana C. Silva, Marco E. Allaix, Marco G.Patti

Background: Idiopatic achalasia (IA) and Chagas disease esophagopathy (CDE) share severalsimilarities; however, some differences between the 2 diseases have been noticed. Thecomparison between IA and CDE is important to evaluate if treatment options and theirresults can be accepted universally. High-resolution manometry (HRM) has proved a betterdiagnostic tool compared to conventional manometry. The study of IA patients with the aidof HRM allowed the creation of new classifications of the disease with apparent correlationwith treatment outcomes, as proposed by the Chicago and Rochester groups. The clinicalapplication of HRM parameters in patients with CDE is still elusive. This study aims toevaluate HRM classifications for idiopathic achalasia in patients with CDE. Methods: Westudied 86 patients with achalasia: 45 patients with CDE (54% females, mean age 55.8 ±14.7 years) and 41 patients with IA (58% females, mean age 49.0 ± 19 5 years). All patientsunderwent a HRM when Chicago and Rochester classifications for achalasia were appliedand a barium esophagram to measure esophageal dilatation. Results: The Chicago classifica-tion was present in IA: Chicago I: 32%, Chicago II: 66% and Chicago III: 2%; In CDE:Chicago I: 49%, Chicago II: 51% and Chicago III: 0% (p= 0.178). The Rochester classificationwas present in IA: Rochester I: 2%, Rochester II: 66% and Rochester III: 32%; In CDE:Rochester I: 0%, Rochester II: 51% and Rochester III: 49% (p= 0.178). CDE patients hadmore pronounced degrees of esophageal dilatation (p,0.0001). The degree of esophagealdilatation did not correlate with neither classification (p=0.2); however, an indirect correlationbetween esophageal body pressure amplitude and the degree of esophageal dilatation wasnoticed (p=0.001). In 9 (10%) patients the HRM pattern changed during the test fromChicago I to II. Conclusion: Our results show that: (a) HRM classifications for IA can be

S-1065 SSAT Abstracts

applied in patients with CDE and (b) HRM classifications did not correlate with the degreeof esophageal dilatation. The secondary findings of our study suggest that HRM classificationsmay reflect esophageal repletion and pressurization instead of muscular contraction. Thecorrelation between manometric findings and treatment outcomes for CDE needs to beanswered in a near future.

910

Does Preoperative Imaging Accurately Predict Main Duct Involvement inIntraductal Papillary Mucinous NeoplasmMorgan R. Barron, Joshua A. Waters, Janak A. Parikh, John DeWitt, Mohammad A. Al-Haddad, Eugene P. Ceppa, Michael G. House, Nicholas J. Zyromski, Attila Nakeeb, HenryA. Pitt, C. Max Schmidt

Objective: Main pancreatic duct (MPD) involvement is a well-demonstrated risk factor formalignancy in intraductal papillary mucinous neoplasm (IPMN). Preoperative radiographicdetermination of IPMN type (main, mixed, or branch) is relied upon heavily in preoperativeoncologic risk stratification. We hypothesize that preoperative radiographic assessment ofMPD involvement in IPMN is an accurate predictor of pathologic MPD involvement. Methods:Data regarding all patients undergoing resection for IPMN at a single, academic institutionbetween 1992 and 2012 were gathered prospectively. Retrospective analysis of imaging,clinical, and pathologic data was undertaken. Preoperative classification of IPMN type wasbased on cross-sectional imaging (CT or MRI). Results: Three-hundred and sixty four patientsunderwent resection for IPMN. Of these, 335 had adequate data on both radiographic andpathologic parameters for comparison. Of 184 suspected branch duct (BD) IPMN, 35 (19%)demonstrated MPD involvement on final pathology. Of 84 mixed-type (MT) IPMN 16 (19%)demonstrated no MPD involvement. Of 68 suspected main duct (MD) IPMN 13 (19%)demonstrated no MPD involvement. Of 35 of 184 (19%) that had a suspected BD IPMNbut were found to have MPD involvement on pathology, 12 (34%) had invasive carcinoma.Alternatively, in patients with suspected MD or MT IPMN who ultimately were found tohave no main duct involvement on pathology 2 (7%) demonstrated invasive carcinoma.Conclusion: In resected IPMN, MPD involvement has been demonstrated as an independentrisk factor for invasive cancer. Preoperative radiographic IPMN type correlates with finalpathology in 81%of patients. In addition, risk of invasive carcinoma correlates with pathologicpresence (or absence) of main duct involvement. Consequently, preoperative imaging foroncologic risk stratification may over or under weigh risk in up to one in five patients.

911

Spleen Preserving Laparoscopic Distal Pancreatectomy for a SolidPseudopapillary Tumor in a Male Patient. (This Video Demonstrates TechnicalDetails of a Rare Tumor of the Pancreas in a Male Patient. Only Few CasesHave Been Reported in Males)Bestoun H. Ahmed, Reginald L. Griffin, Ziad Awad, Carmine Volpe, Michael S. Nussbaum

A 31-y-old patient had a blunt abdominal trauma. CT scan showed an incidental tumor inthe body of the pancreas. EUS-guided cytology was Solid pseudopapillary tumor. Patientin right semi-lateral position. Division of gastrocolic omentum. Release of splenic flexure ofthe colon. Transection of the body of the pancreas after separating splenic vessels. Separationof the pancreas from the vessels. Extraction of the specimen in a pouch. Operative time:170 minutes. Blood loss: 50 ml. Tolerated food on day 2. Discharged on day 4. Pathology:6x5 cm tumor like FNA result with clear margins .In conclusion: Laparoscopic spleenpreserving approach is feasible in the management of this tumor

912

High Fat Diet Enhances Villus Growth During Adaptation After Massive SmallBowel ResectionPamela M. Choi, Raphael C. Sun, Jun Guo, Christopher R. Erwin, Brad Warner

Background: Adaptation is a compensatory process following small bowel resection (SBR)that results in villus growth and enhanced mucosal surface area. In prior studies, High FatDiet (HFD) had been shown to enhance adaptation responses if fed immediately followingSBR. The purpose of this study was to determine if HFD could further enhance villus growthafter resection-induced adaptation had already taken place. Methods: C57/Bl6 mice, aged6-8 weeks, underwent a 50% proximal SBR or sham operation (bowel transection withreanastomosis alone) and then provided a standard rodent liquid diet (LD) ad lib. After atypical period of adaptation (7 days), SBR and sham-operated mice were randomized toreceive either LD or HFD (42% kcal/fat) for an additional 7 days. Mice were individualcaged, and food intake and feces output were measured daily. Mice were then harvested,and small intestine was collected for analysis. Results: There were no differences in caloricintake or stool output between any of the groups. However, Sham mice had increased weightgain compared to SBR mice independent of diet. As shown in Figure 1, adaptation occurredin both SBR groups, however the SBR/HFD had significantly increased villus height comparedto SBR/LD. When compared to their sham counterparts, there was a 102.3% increase invillus height in the HFD group compared to only 42.6% in the LD group. Real-Time PCRwas performed from mRNA of isolated intestinal villus cells, and CD36 expression wasmarkedly elevated after high fat diet (greater than 50-fold) in the SBR/HFD group comparedwith SBR/LD mice. Conclusion: While a week-long exposure to increased enteral fat alonedid not affect villus morphology in sham-operated mice, HFD significantly increased villusgrowth in the setting of resection-induced adaptation. These data support the clinical utilityof enteral fat in augmenting adaptation responses in patients who have been subjected tomassive SBR. Increased expression of CD36 suggests a possible mechanistic role in dietaryfat metabolism and villus growth in the setting of short gut syndrome.

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