SERGIO CARLOS NAHAS
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Gastroenterologia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina - Médico
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conferenceObject POSTOPERATIVE TEM COMPLICATIONS FOR THE TREATMENT OF RECTAL NEOPLASIA ARE FREQUENT BUT MILD. RISK FACTORS AND TIME BEHAVIOR STUDY(2014) MARQUES, C.; NAHAS, C.; RIBEIRO, U.; BUSTAMANTE, L.; PINTO, R.; MORY, E.; CECCONELLO, I.; NAHAS, S.bookPart Lesões neoplásicas precoces em cólon e reto(2014) MIYAJIMA, Nelson Tomio; NOVAES, André Luiz de Oliveira; KAWAGUTI, Fabio Shiguehissa; NAHAS, Caio R.; NAHAS, Sergio CarlosbookPart Ileocolonoscopia(2014) REINA-FORSTER, Carolina Eliane; NAHAS, Sergio Carlos; ATUí, Fabio; KAWAGUTI, Fabio Shiguehissa; MOURA, Eduardo Guimarães Hourneaux de- Single-Session Baseline Virtual Reality Simulator Scores Predict Technical Performance for Laparoscopic Colectomy: A Study in the Swine Model(2014) ARAUJO, Sergio Eduardo Alonso; SEID, Victor E.; BERTONCINI, Alexandre B.; HORCEL, Lucas A.; NAHAS, Sergio C.; CECCONELLO, IvanOBJECTIVE: Virtual reality (VR) simulation helps reducing the learning curve of laparoscopic colectomy. Moreover, it may be used to ascertain surgeons' pretraining skills. It was aimed to establish predictive validity of specific parameters gathered during VR simulation training on sigmoid colectomy- and whether simulator parameters correlate with technical performance during the same operation in a swine model. DESIGN: Surgeons novice to laparoscopic colectomy underwent a single VR simulation session on sigmoid colectomy. Next, all participants performed a laparoscopic sigmoidectomy in the swine. Operations were recorded. Performance evaluation was conducted by 2 board-certified colorectal surgeons blinded to surgeons' simulator scores using an instrument specific to laparoscopic colectomy. For each participant, a mean score of specific skills was calculated. Linear regression analysis was used to identify simulator parameters that were best related to the score. The stepwise method was used to select parameters. The magnitude of the regression model was measured by the coefficient of determination (R-2) value. SETTING: The University of Sao Paulo Medical Center is a high-volume, public practice, university-affiliated hospital. PARTICIPANTS: A total of 14 first-year residents in digestive tract surgery were included. RESULTS: Analysis of variance demonstrated that the regression model was significant (p = 0.0001), and an association between simulation scores and specific skills was confirmed. The R2 value was 99%. The VR simulator parameters that strongly correlated with specific skills during laparoscopic colectomy in the swine were safe use of electrosurgery/energy device and safety of medial-to-lateral dissection. CONCLUSIONS: A single VR simulation session for novice surgeons in the sigmoid colectomy module generates baseline scores that highly correlated with performance of specific skills during a laparoscopic colectomy in the swine. This information may be useful in an attempt to tailor VR simulator practice according to a surgeon's needs.
- Predicting complete response to neoadjuvant CRT for distal rectal cancer using sequential PET/CT imaging(2014) PEREZ, R. O.; HABR-GAMA, A.; JULIAO, G. P. Sao; LYNN, P. B.; SABBAGH, C.; PROSCURSHIM, I.; CAMPOS, F. G.; GAMA-RODRIGUES, J.; NAHAS, S. C.; BUCHPIGUEL, C. A.Molecular imaging using positron emission tomography/computerized tomography (PET/CT) may add relevant incremental diagnostic information to standard structural cross-sectional imaging. Such information may allow identification of patients with rectal cancer that are more likely to develop complete tumor regression after neoadjuvant chemoradiation therapy (CRT). The objective of this report was to identify PET/CT features that are associated with a complete response after CRT. 99 cT2-4N0-2M0 distal rectal cancer patients (a parts per thousand currency sign7 cm from anal verge) were included in this prospective single center trial (NCT 00254683). Patients underwent baseline PET/CT followed by 54 Gy and 5-fluorouracil-based neoadjuvant CRT. After completion of therapy, patients underwent 6- and 12-week PET/CT. Clinical assessment of tumor response was performed at 12 weeks and was blinded to radiological information. Patients were treated according to clinical assessment. There were seven patients with a complete pathological response (pCR) and 16 with a complete clinical response (cCR) (23 complete responders). Comparison of pCR exclusively and non-pCR revealed that only baseline primary tumor standard uptake value (SUV) was a significant predictor of response. Comparison of complete responders (pCR or cCR) and non-complete responders showed that depth of rectal wall uptake at baseline PET/CT (p = 0.002) and variation between baseline and 12-week maximum standard uptake value (SUVmax) of primary tumor (p = 0.001) were independent predictors for complete response at multivariate analysis. A decrease > 67 % between baseline and 6-week or 76 % between baseline and 12-week SUVmax were associated with complete response (pCR or cCR; p = 0.02 and p < 0.001, respectively). Positron emission tomography/computerized tomography at baseline, 6 and 12 weeks, may provide information regarding patients with a higher likelihood of developing complete tumor regression following neoadjuvant CRT.
conferenceObject COMPLETE PATHOLOGIC RESPONSE IS ASSOCIATED WITH LESS THAN 12 LYMPH NODES IN THE SPECIMEN OF PATIENTS WITH RECTAL CANCER UNDERGOING NEOADJUVANT THERAPY FOLLOWED BY TOTAL MESORECTAL EXCISION(2014) NAHAS, C.; NAHAS, S.; BUSTAMANTE, L.; MARQUES, C.; COTTI, G.; RIBEIRO JUNIOR, U.; HOFF, P.; CECCONELLO, I.; SALLES, R.; PINTO, R.; IMPERIALE, A.bookPart Retopatias e colopatias actínicas(2014) LIMA, Marcelo Simas de; CAMPOS, Mariana Iennaco de Siqueira; MARQUES, Carlos Frederico Sparapan; NAHAS, Sergio Carlos- Do colorectal cancer resections improve diabetes in long-term survivors? A case-control study(2014) FAINTUCH, Joel; HAYASHI, Silvia Y.; NAHAS, Sergio C.; YAGI, Osmar K.; FAINTUCH, Salomao; CECCONELLO, IvanA clinical study was designed that aimed to analyze whether resection of the large bowel in cancer patients might benefit diabetes mellitus. This prospective case-control study included retrospective information. Patients (n = 247) included diabetic and euglycemic groups with colorectal cancer operations (n = 60), cancer gastrectomy (n = 72), exclusive chemoradiotherapy for rectal cancer (n = 46), and noncancer clinical controls (n = 69). Follow-up periods were, respectively, 79.2 +/- A 27.4, 86.8 +/- A 25.1, 70.0 +/- A 26.3, and 85.1 +/- A 18.2 months (NS). Diabetes groups included patients with prediabetes. Diabetes remission, defined as conversion from diabetes to prediabetes or from this condition to normal, was documented in, respectively, 32.4 % (11 of 34), 41.2 % (14 of 34), 7.1 % (1 of 14), and 7.7 % (3 of 39) in the four cohorts (P = 0.004). Within the same period, progression of euglycemic participants to diabetes occurred in 30.8 % (8 of 26), 63.2 % (24 of 38), 25.0 (8 of 32), and 20.0 % (6 of 30) (P = 0.028). Diabetes amelioration was associated with weight loss in gastrectomy patients but not in the other groups. Dietary intake, estimated in the two surgical populations, did not predict outcome. Diabetes amelioration after colorectal interventions was demonstrated, but progression of euglycemic patients toward prediabetes was not changed in comparison with nonsurgical controls. It is speculated that reshaping of the bowel microbiome or hormone changes after colorectal interventions underlay the improvement in diabetes. Body weight fluctuations could not be incriminated in this investigation.
bookPart Abordagem endoscópica das lesões subepiteliais do cólon e do reto(2014) RETES, Felipe Alves; MEDRADO, Bruno Frederico O. Azevedo; SOBRADO, Carlos Walter; NAHAS, Sergio Carlos; ARTIFON, Everson Luiz de Almeida- Minimally Invasive Approach to Chagasic Megacolon: Laparoscopic Rectosigmoidectomy With Posterior End-to-Side Low Colorectal Anastomosis(2014) ARAUJO, Sergio E. A.; BERTONCINI, Alexandre B.; NAHAS, Sergio C.; CECCONELLO, IvanThe effectiveness of anterior resection for the surgical treatment of Chagasic megacolon and the advantages of laparoscopy for performing colorectal surgery are well known. However, current experience with laparoscopic surgery for Chagasic megacolon is restricted. Moreover, associated long-term results remain poorly analyzed. The aims of the present study were to ascertain the immediate results of laparoscopic anterior resection for the surgical treatment of Chagasic megacolon, to identify risk factors associated with adverse outcomes, and to settle late results. A retrospective review of a prospective database was conducted. Between November 2000 and September 2012, 44 patients with Chagasic megacolon underwent laparoscopic anterior resection with posterior end-to-side low colorectal anastomosis. Fifteen (34.1%) patients were male. Mean age was 51.6 years (31 to 77 y). The mean body mass index (BMI) was 22.9 kg/m(2) (16.9 to 36.7 kg/m(2)). Thirty-four previous abdominal operations had been performed. Mean operative time was 265 minutes (105 to 500 min). Four surgeons operated on all cases. Surgeon's experience with the operation was not associated with surgical time (P=0.36: linear regression). Mean operative time between patients with and without previous abdominal surgery was similar (237.7 vs. 247.5 min: P=0.78). There was no association between BMI and the duration of the operation (P=0.22). Intraoperative complications occurred in 2 (4.5%) cases. Conversion was necessary in 3 (6.8%) cases. There was no association between conversion and previous abdominal surgery (P=0.56) or between conversion and surgeon's experience (P=0.43). However, a significant association (P=0.01) between BMI and conversion was observed. Postoperative complications occurred in 10 (22.7%) cases. Anastomotic-related complications occurred in 4 cases. Two of them required diversion ileostomy. Restoration of transanal evacuation was achieved in all cases. Mean duration of postoperative hospital stay was 9.8 days (4 to 45 d). Of 19 patients with known clinical late follow-up, only 1 (5.3%) reported use of enemas and 5 (26.3%) reported use of laxatives. Thirteen (68.4%) patients reported daily bowel movements. There was no association between postoperative complications and use of laxatives (P=0.57). It was concluded that laparoscopic anterior resection for Chagasic megacolon is safe. Obesity was a risk factor for conversion. Restoration of transanal evacuation after surgical treatment of infectious complications was achieved. Minimally invasive surgery for Chagasic megacolon is associated with satisfactory late intestinal function with no significant constipation relapse.