e8 Scientific Papers: 2014 Clinical Congress RESULTS: One hundred seventy two patients underwent percutaneous drainage of diverticular abscesses. The mean abscess size was 6.1 cm and located either in the pelvis (n¼129) or the abdomen (n¼43), Of the 141 patients had resolution of symptoms with percutaneous drainage, 77 had elective colonic resection and 64 did not. Of the 64 patients managed non-operatively 13 died within one year and the recurrence-free survival rate among the remaining 51 was 77.9%6.6% (mean SEM at 5 years). The colectomy-free survival among these 51 patients was 82.8% 6.0% at 5 years. CONCLUSIONS: A significant number of patients successfully recover from complicated diverticulitis following percutaneous drainage. Subsequent non-operative management carries an acceptable risk for recurrent episodes and may be considered as a reasonable management option. Procalcitonin reveals early dehiscence in colorectal surgery: the PREDICS study Valentina Giaccaglia, MD, Pier F Salvi, MD, PhD, Maria Serena Antonelli, MD, Giuseppe R Nigri, MD, PhD, FACS, FRCS, FASCRS, F Corcione, MD, Felice Pirozzi, MD, Nicolo` de Manzini, MD, FRCS, Biagio Casagranda, MD, Genoveffa Balducci, MD, Vincenzo Ziparo, MD S. Andrea Hospital Sapienza Rome University, Rome, Italy and Monaldi Hospital, Naples, Italy and Ospedali Riuniti, Trieste, Italy INTRODUCTION: Procalcitonin (PCT) is a biomarker used to monitor bacterial infections and guide antibiotic therapy. Anastomotic leak (AL) after colorectal surgery is a severe complication associated with relevant short and long-term sequelae. We designed a multicentric observational study to test if PCT might be a sensitive and reliable marker of AL after colorectal surgery (ClinicalTrials.govIdentifier: NCT01817647). METHODS: We report the preliminary results of 400 patients operated on, between January 2013 and February 2014, for malignant colorectal diseases and in elective setting. White blood count (WBC), C-reactive protein (CRP) and PCT levels were measured in 3rd and 5th POD. AL and all postoperative complications were recorded. RESULTS: We registered 26 (6.5%) anastomotic leaks. In 3rd POD, mean PCT levels where significantly higher in patients with AL than in the other complications group or no complications group (respectively, 4.25, 1.93 and 1.24 ng/ml; p<0.0001). In 5th POD, NPV and PPV for AL with PCT < 2.33 ng/ml are 98.1% and 37.5%, with a specificity of 91.3%. ROC curve for biomarkers shows that, in 3rd POD, PCT has better AUC than CRP (0.791 vs 0.756). In 5th POD, PCT and CRP have similar AUC (0.867 vs 0.871). CONCLUSIONS: PCT demonstrated to have a good NPV for AL both in 3rd and in 5th POD. The best diagnostic performance of J Am Coll Surg PCT is obtained in 5th POD. Low levels of PCT, <1.76 ng/ml in 3rd POD and/or <2.33 ng/ml in 5th POD, together with low CRP values, might be safely added as additional criteria of discharge protocols after colorectal surgery. Pre-operative and pathologic assessment in neoadjuvant setting for rectal cancer: the experience of “RECOM group” Stefano Scabini, MD, Edoardo Rimini, Emanuele Romairone, Luca Mastracci, Federica Grillo, MD, Almalina Bacigalupo, Ciro Marrone, Roberto Murialdo, MD, Gabriele Zoppoli, Alberto Ballestrero IRCCS Azienda Ospedaliera Universitaria San Martino, Genoa, Italy INTRODUCTION: Neoadjuvant radiochemotherapy (NCRT) reduces the risk of local recurrence in patients with locally advanced rectal cancer (LARC). We believe that the addition of endoluminal ultrasonografy (EUS) can improve the diagnostic accuracy for select patients candidate to NCRT and for predict which patients had responded to therapy. METHODS: 115 patients with low or middle rectal cancer was observed (REctal COMmittee) between January 2010 to January 2014 with low or middle rectal cancer; 61 (stage II-III) received NCRT followed by curative tumor specific mesorectal excision (96% laparoscopic). All patients were staged with pelvic MRI; 50 of them performed EUS+MRI before and after NCRT. RESULTS: The mean age of patients was 63.7 years (SD: 11.1, range: 36-84) and 52% of them had tumor in lower third of rectum. Median time for restaging exams was 33 days (11-68) after preoperative treatment. Pathological complete response was observed in 24% of patients, partial response in 50%, no response in 21% and progression disease in 5%. There was concordance between EUS and MRI after NCRT in 94% of cases with regard T stage and 74% for N stage. Pelvic MRI predicted pathological T stage in 74 % versus 64% for EUS and in 52% versus 74% respectively for N stage. CONCLUSIONS: MRI showed good diagnostic performances for restaging rectal cancer after NCRT but nodal staging remains challenging. Our data suggest that EUS improve the capacity to predict N loco-regional involvement. Therefore, the combined use of the two Methods could improve the accuracy of restaging in patients with LARC underwent NCRT. Neoadjuvant chemoradiation for rectal cancer based on preoperative magnetic resonance imaging: interim analysis of the German OCUM trial (NCT01325649) Martin E Kreis, MD, FACS, Reinhard Ruppert, MD, Henry Ptok, MD, Joachim Strassburg, FRCS, MD, Christoph A Maurer, MD, Theodor T Junginger, MD, Susanne Markel, MD, Paul Hermanek, MD