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
9 resultados
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- A novel approach for the treatment of pelvic abscess: transrectal endoscopic drainage facilitated by transanal endoscopic microsurgery access(2012) MARTINS, B. C.; MARQUES, Carlos Frederico Sparapan; NAHAS, Caio Sergio Rizkallah; HONDO, Fabio Yuji; POLLARA, Wilson; NAHAS, Sergio Carlos; RIBEIRO JUNIOR, U.; CECCONELLO, Ivan; MALUF-FILHO, FauzePostoperative pelvic abscesses in patients submitted to colorectal surgery are challenging. The surgical approach may be too risky, and image-guided drainage often is difficult due to the complex anatomy of the pelvis. This article describes novel access for drainage of a pelvic collection using a minimally invasive natural orifice approach. A 37 year-old man presented with sepsis due to a pelvic abscess during the second postoperative week after a Hartmann procedure due to perforated rectal cancer. Percutaneous drainage was determined by computed tomography to be unsuccessful, and another operation was considered to be hazardous. Because the pelvic fluid was very close to the rectal stump, transrectal drainage was planned. The rectal stump was opened using transanal endoscopic microsurgery (TEM) instruments. The endoscope was advanced through the TEM working channel and the rectal stump opening, accessing the abdominal cavity and pelvic collection. The pelvic collection was endoscopically drained and the local cavity washed with saline through the scope channel. A Foley catheter was placed in the rectal stump. The patient's recovery after the procedure was successful, without the need for further intervention. Transrectal endoscopic drainage may be an option for selected cases of pelvic fluid collection in patients submitted to Hartmann's procedure. The technique allows not only fluid drainage but also visualization of the local cavity, cleavage of multiloculated abscesses, and saline irrigation if necessary. The use of TEM instrumentation allows safe access to the peritoneal cavity.
- Accuracy of positron emission tomography/computed tomography and clinical assessment in the detection of complete rectal tumor regression after neoadjuvant chemoradiation Long-Term Results of a Prospective Trial (National Clinical Trial 00254683)(2012) PEREZ, Rodrigo Oliva; HABR-GAMA, Angelita; GAMA-RODRIGUES, Joaquim; PROSCURSHIM, Igor; JULIAO, Guilherme Pagin Sao; LYNN, Patricio; ONO, Carla Rachel; CAMPOS, Fabio Guilherme; SOUSA JR., Afonso Henrique Silva e; IMPERIALE, Antonio Rocco; NAHAS, Sergio Carlos; BUCHPIGUEL, Carlos AlbertoBACKGROUND: Neoadjuvant chemoradiation (CRT) therapy may result in significant tumor regression in patients with rectal cancer. Patients who develop complete tumor regression have been managed by treatment strategies that are alternatives to standard total mesorectal excision. Therefore, assessment of tumor response with positron emission tomography/computed tomography (PET/CT) after neoadjuvant treatment may offer relevant information for the selection of patients to receive alternative treatment strategies. METHODS: Patients with clinical T2 (cT2) through cT4NxM0 rectal adenocarcinoma were included prospectively. Neoadjuvant therapy consisted of 54 grays of radiation and 5-fluorouracil-based chemotherapy. Baseline PET/CT studies were obtained before CRT followed by PET/CT studies at 6 weeks and 12 weeks after the completion of CRT. Clinical assessment was performed at 12 weeks after CRT completion. PET/CT results were compared with clinical and pathologic data. RESULTS: In total, 99 patients were included in the study. Twenty-three patients were complete responders (16 had a complete clinical response, and 7 had a complete pathologic response). The PET/CT response evaluation at 12 weeks indicated that 18 patients had a complete response, and 81 patients had an incomplete response. There were 5 false-negative and 10 false-positive PET/CT results. PET/CT for the detection of residual cancer had 93% sensitivity, 53% specificity, a 73% negative predictive value, an 87% positive predictive value, and 85% accuracy. Clinical assessment alone resulted in an accuracy of 91%. PET/CT information may have detected misdiagnoses made by clinical assessment alone, improving overall accuracy to 96%. CONCLUSIONS: Assessment of tumor response at 12 weeks after CRT completion with PET/CT imaging may provide a useful additional tool with good overall accuracy for the selection of patients who may avoid unnecessary radical resection after achieving a complete clinical response. Cancer 2012;35013511. (C) 2011 American Cancer Society.
- Optimal Timing for Assessment of Tumor Response to Neoadjuvant Chemoradiation in Patients With Rectal Cancer: Do All Patients Benefit From Waiting Longer Than 6 Weeks?(2012) PEREZ, Rodrigo O.; HABR-GAMA, Angelita; JULIAO, Guilherme P. Sao; GAMA-RODRIGUES, Joaquim; SOUSA JR., Afonso H. S.; CAMPOS, Fabio Guilherme; IMPERIALE, Antonio R.; LYNN, Patricio B.; PROSCURSHIM, Igor; NAHAS, Sergio Carlos; ONO, Carla Rachel; BUCHPIGUEL, Carlos AlbertoPurpose: To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-D-glucose-labeled positron emission tomography/computed tomography ([18 FDG] PET/CT) imaging and correlate with response to CRT. Methods and Materials: Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials. org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks fromCRT completion). Clinical assessment was at 12 weeks. Maximal standard uptakevalue (SUVmax) of the primary tumor wasmeasured and recorded at eachPET/CTstudy after 1 h (early) and3 h (late) from 18 FDGinjection. Patientswith an increase in early SUVmax between 6 and 12 weeks were considered "" bad"" responders and the others as ""good"" responders. Results: Ninety-one patients were included; 46 patients (51%) were ""bad"" responders, whereas 45 (49%) patients were "" good"" responders. "" Bad"" responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; PZ. 001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; PZ. 008) and exhibited greater final tumor dimension (4.3cmvs. 3.3cm; PZ. 03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CTwas a significant predictor of "" good"" response (accuracy of 67%). Conclusions: Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients. (C) 2012 Elsevier Inc.
conferenceObject Endoscopic Submucosal Dissection (ESD) Versus Transanal Endoscopic Microsurgery (TEM) for the Treatment of Early Rectal Cancer(2012) KAWAGUTI, Fabio S.; NAHAS, Caio Sergio R.; MARQUES, Carlos Frederico S.; MARTINS, Bruno C.; RETES, Felipe A.; LIMA, Marcelo S.; SATO, Cezar F.; MEDEIROS, Raphael S. De; NAHAS, Sergio C.; SAKAI, Paulo; MALUF-FILHO, Fauze- Abdominoperineal Excision: Evolution of a Centenary Operation(2012) CAMPOS, Fabio Guilherme; HABR-GAMA, Angelita; NAHAS, Sergio Carlos; PEREZ, Rodrigo OlivaDuring the last century, great improvements have been made in rectal cancer management regarding preoperative staging, pathologic assessment, surgical technique, and multimodal therapies. Surgically, there was a move from a strategy characterized by simple perineal excision to complex procedures performed by means of a laparoscopic approach, and more recently with the aid of robotic systems. Perhaps the most important advance is that rectal cancer is no longer a fatal disease as it was at the beginning of the 20th century. This achievement is definitely due in part to Ernest Mile's contribution regarding lymphatic spread of tumor cells, which helped clarify the natural history of the disease and the proper treatment alternatives. He advocated a combined approach with the rationale to clear ""the zone of upward spread."" The aim of the present paper is to present a brief review concerning the evolution of rectal cancer surgery, focusing attention on Miles' abdominoperineal excision of the rectum (APR) and its controversies and refinements over time. Although APR has currently been restricted to a small proportion of patients with low rectal cancer, recent propositions to excise the rectum performing a wider perineal and a proper pelvic floor resection have renewed interest on this procedure, confirming that Ernest Miles' original ideas still influence rectal cancer management after more than 100 years.
- Assessing the extent of colon lengthening due to splenic flexure mobilization techniques: a cadaver study(2012) ARAUJO, Sergio Eduardo Alonso; SEID, Victor Edmond; KIM, Nam Jin; BERTONCINI, Alexandre Bruno; NAHAS, Sergio Carlos; CECCONELLO, IvanCONTEXT: Failure of a colorectal anastomosis represents a life-threatening complication of colorectal surgery. Splenic flexure mobilization may contribute to reduce the occurrence of anastomotic complications due to technical flaws. There are no published reports measuring the impact of splenic flexure mobilization on the length of mobilized colon viable to construct a safe colorectal anastomosis. OBJECTIVE: The aim of the present study was to determine the effect of two techniques for splenic flexure mobilization on colon lengthening during open left-sided colon surgery using a cadaver model. DESIGN: Anatomical dissections for left colectomy and colorectal anastomosis at the sacral promontory level were conducted in 20 fresh cadavers by the same team of four surgeons. The effect of partial and full splenic flexure mobilization on the extent of mobilized left colon segment was determined. SETTING: University of Sao Paulo Medical School, Sao Paulo, SP, Brazil. Tertiary medical institution and university hospital. PARTICIPANTS: A team of four surgeons operated on 20 fresh cadavers. RESULTS: The length of resected left colon enabling a tension-free colorectal anastomosis at the level of sacral promontory achieved without mobilizing the splenic flexure was 46.3 (35-81) cm. After partial mobilization of the splenic flexure, an additionally mobilized colon segment measuring 10.7 (2-30) cm was obtained. After full mobilization of the distal transverse colon, a mean 28.3 (10-65) cm segment was achieved. CONCLUSION: Splenic flexure mobilization techniques are associated to effective left colon lengthening for colorectal anastomosis. This result may contribute to decision-making during rectal surgery and low colorectal and coloanal anastomosis.
- Histopathological evaluation and risk factors related to the development of pouchitis in patients with ileal pouches for ulcerative colitis(2012) ARASHIRO, Roberta Thiery de Godoy; TEIXEIRA, Magaly Gemio; RAWET, Viviane; QUINTANILHA, Alina Guimaraes; PAULA, Henrique Moura de; SILVA, Adriano Zanon; NAHAS, Sergio Carlos; CECCONELLO, IvanOBJECTIVE: Many changes in mucosal morphology are observed following ileal pouch construction, including colonic metaplasia and dysplasia. Additionally, one rare but potential complication is the development of adenocarcinoma of the reservoir. The aim of this study was to evaluate the most frequently observed histopathological changes in ileal pouches and to correlate these changes with potential risk factors for complications. METHODS: A total of 41 patients were enrolled in the study and divided into the following three groups: a non-pouchitis group (group 1) (n = 20; 8 males; mean age: 47.5 years) demonstrating optimal outcome; a pouchitis without antibiotics group (group 2) (n = 14; 4 males; mean age: 47 years), containing individuals with pouchitis who did not receive treatment with antibiotics; and a pouchitis plus antibiotics group (group 3) (n = 7; 3 males; mean age: 41 years), containing those patients with pouchitis who were administered antibiotics. Ileal pouch endoscopy was performed, and tissue biopsy samples were collected for histopathological analysis. RESULTS: Colonic metaplasia was found in 15 (36.6%) of the 41 patients evaluated; of these, five (25%) were from group 1, eight (57.1%) were from group 2, and two (28.6%) were from group 3. However, no correlation was established between the presence of metaplasia and pouchitis (p = 0.17). and no differences in mucosal atrophy or the degree of chronic or acute inflammation were observed between groups 1, 2, and 3 (p > 0.45). Moreover, no dysplasia or neoplastic changes were detected. However, the degree of mucosal atrophy correlated well with the time of postoperative follow-up (p = 0.05). CONCLUSIONS: The degree of mucosal atrophy, the presence of colonic metaplasia, and the degree of acute or chronic inflammation do not appear to constitute risk factors for the development of pouchitis. Moreover, we observed that longer postoperative follow-up times were associated with greater degrees of mucosal atrophy.
bookPart Videocirurgia colorretal por acesso único(2012) ARAUJO, Sergio Eduardo Alonso; SEID, Victor Edmond; CAMPOS, Fábio Gulherme; BERTONCINI, Alexandre Bruno; ALVES, Aline Marcílio; HORCEL, Lucas de Araujo; NAHAS, Sergio Carlos; CECCONELLO, Ivan- Reduced Population of Interstitial Cells of Cajal in Chagasic Megacolon(2012) ARAUJO, Sergio Eduardo Alonso; DUMARCO, Rodrigo Blanco; RAWET, Viviane; SEID, Victor Edmond; BOCCHINI, Sylvio Figueiredo; NAHAS, Sergio Carlos; CECCONELLO, IvanBackground/Aims: In Chagasic megacolon, there is a reduction in the population of interstitial cells of Cajal. It was aimed to evaluate density of Cajal cells in the resected colon of Chagasic patients compared to control patients and to verify possible association between preoperative and postoperative bowel function of megacolon patients and cell count. Methodology: Sixteen megacolon patients (12 female; mean age 54.4 (31-73)) were operated on. Pre- and postoperative evaluation using Cleveland clinic constipation score was undertaken. Resected colons were examined. Cajal cells were identified by immunohistochemistry (anti-CD117). The mean cell number was compared to resected colons from 16 patients (7 female; mean age 62.8 (23-84)) with non-obstructive sigmoid cancer. Association between pre- and postoperative constipation scores and cell count for megacolon patients was evaluated using the Pearson test (r). Results: A reduced number of Cajal cells (per field: 2.84 (0-6.6) vs. 9.68 (4.3-13); p<0.001) were observed in the bowel of megacolon patients compared to cancer patients. No correlation between constipation score before (r=-0.205; p=0.45) or after surgery (r=0,291; p=0.28) and cell count in megacolon was observed. Conclusions: Patients with megacolon display marked reduction of interstitial cells of Cajal. An association of constipation severity and Cajal cells depopulation was not demonstrated.