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Dive into the research topics where Sergio Carlos Nahas is active.

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Featured researches published by Sergio Carlos Nahas.


Journal of Gastrointestinal Surgery | 2005

Long-term results of preoperative chemoradiation for distal rectal cancer correlation between final stage and survival

Angelita Habr-Gama; RodrigoOliva Perez; Wladimir Nadalin; Sergio Carlos Nahas; Ulysses Ribeiro-Jr; Afonso Henrique Silva e SousaJr.; Fábio Guilherme Campos; Desidério Roberto Kiss; Joaquim Gama-Rodrigues

Neoadjuvant chemoradiation treatment (CRT) has resulted in significant tumor downstaging and improved local disease control for distal rectal cancer. The purpose of the present study was to determine the correlation between final stage and survival in these patients regardless of initial disease stage. Two hundred sixty patients with distal (0-7 cm from anal verge) rectal adenocarcinoma considered resectable were treated by neoadjuvant CRT with 5-FU and leucovorin plus 5040 cGy. Patients with incomplete clinical response 8 weeks after CRT completion were treated by radical surgical resection. Patients with complete clinical response were managed by observation alone. Overall survival and diseasefree survival were compared according to Kaplan-Meier curves and log-rank tests according to final stage. Seventy-one patients (28%) showed complete clinical response (clinical stage 0). One hundred sixtynine patients showed incomplete clinical response and were treated with surgery. In 22 of these patients (9%), pathologic examination revealed pT0 N0 M0 (stage p0), 59 patients (22%) had stage I, 68 patients (26%) had stage II, and 40 patients (15%) had stage III disease. Overall survival rates were significantly higher in stage c0 (P = 0.01) compared with stage p0. Disease-free survival rate showed better results in stage c0, but the results were not significant. Five-year overall and disease-free survival rates were 97.7% and 84% (stage 0); 94% and 74% (stage I); 83% and 50% (stage II); and 56% and 28% (stage III), respectively. Cancer-related overall and disease-free survival may be correlated to final pathologic staging following neoadjuvant CRT for distal rectal cancer. Also, stage 0 is significantly associated with improved outcome.


Revista do Hospital das Clínicas | 2003

Conventional approach x laparoscopic abdominoperineal resection for rectal cancer treatment after neoadjuvant chemoradiation: results of a prospective randomized trial

Sergio Eduardo Alonso Araujo; Afonso Henrique da Silva e Sousa; Fábio Guilherme Caserta Marysael de Campos; Angelita Habr-Gama; Rodrigo Blanco Dumarco; Pedro Paulo de Paris Caravatto; Sergio Carlos Nahas; José Hyppólito da Silva; Desidério Roberto Kiss; Joaquim Gama-Rodrigues

OBJECTIVE The aims of this study were to evaluate the safety and efficacy of laparoscopic abdominoperineal resection compared to conventional approach for surgical treatment of patients with distal rectal cancer presenting with incomplete response after chemoradiation. METHOD Twenty eight patients with distal rectal adenocarcinoma were randomized to undergo surgical treatment by laparoscopic abdominoperineal resection or conventional approach and evaluated prospectively. Thirteen underwent laparoscopic abdominoperineal resection and 15 conventional approach. RESULTS There was no significant difference (p<0,05) between the two studied groups regarding: gender, age, body mass index, patients with previous abdominal surgeries, intra and post operative complications, need for blood transfusion, hospital stay after surgery, length of resected segment and pathological staging. Mean operation time was 228 minutes for the laparoscopic abdominoperineal resection versus 284 minutes for the conventional approach (p=0.04). Mean anesthesia duration was shorter (p=0.03) for laparoscopic abdominoperineal resection when compared to conventional approach : 304 and 362 minutes, respectively. There was no need for conversion to open approach in this series. After a mean follow-up of 47.2 months and with the exclusion of two patients in the conventional abdominoperineal resection who presented with unsuspected synchronic metastasis during surgery, local recurrence was observed in two patients in the conventional group and in none in the laparoscopic group. CONCLUSIONS We conclude that laparoscopic abdominoperineal resection is feasible, similar to conventional approach concerning surgery duration, intra operative morbidity, blood requirements and post operative morbidity. Larger number of cases and an extended follow-up are required to adequate evaluation of oncological results for patients undergoing laparoscopic abdominoperineal resection after chemoradiation for radical treatment of distal rectal cancer.


Cancer | 2012

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)

Rodrigo Oliva Perez; Angelita Habr-Gama; Joaquim Gama-Rodrigues; Igor Proscurshim; Guilherme Pagin São Julião; Patricio B. Lynn; Carla Rachel Ono; Fábio Guilherme Campos; Afonso Henrique da Silva e Sousa; Antonio Rocco Imperiale; Sergio Carlos Nahas; Carlos Alberto Buchpiguel

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.


CardioVascular and Interventional Radiology | 2013

Transient Ischemic Rectitis as a Potential Complication after Prostatic Artery Embolization: Case Report and Review of the Literature

Airton Mota Moreira; Carlos Frederico Sparapan Marques; Alberto A. Antunes; Caio Sergio Rizkallah Nahas; Sergio Carlos Nahas; Miguel Angel de Gregorio Ariza; Francisco Cesar Carnevale

Prostatic artery embolization (PAE) is an alternative treatment for benign prostatic hyperplasia. Complications are primarily related to non-target embolization. We report a case of ischemic rectitis in a 76-year-old man with significant lower urinary tract symptoms due to benign prostatic hyperplasia, probably related to nontarget embolization. Magnetic resonance imaging revealed an 85.5-g prostate and urodynamic studies confirmed Inferior vesical obstruction. PAE was performed bilaterally. During the first 3 days of follow-up, a small amount of blood mixed in the stool was observed. Colonoscopy identified rectal ulcers at day 4, which had then disappeared by day 16 post PAE without treatment. PAE is a safe, effective procedure with a low complication rate, but interventionalists should be aware of the risk of rectal nontarget embolization.


Techniques in Coloproctology | 2009

Transanal endoscopic microsurgery: indications, results and controversies

André Roncon Dias; Caio Sergio Rizkallah Nahas; Carlos Frederico Sparapan Marques; Sergio Carlos Nahas; Ivan Cecconello

Transanal endoscopic microsurgery (TEM) was introduced in 1983 as a minimally invasive technique allowing the resection of adenomas and early rectal carcinomas unsuitable for local or colonoscopic excision which would otherwise require major surgery. After 25 years, there is still much debate about the procedure. This article presents the TEM technique, indications, results and complications, focusing on its role in rectal cancer. The controversial points addressed include long-term results, TEM in high-risk T1 lesions, TEM associated with combined modality therapy (CMT) for invasive rectal cancer and salvage therapy after TEM. The future perspectives for TEM are promising and its association with CMT will probably expand the select group of patients who will benefit from the procedure.


Revista do Hospital das Clínicas | 1999

Bowel preparation for colonoscopy: comparison of mannitol and sodium phosphate. Results of a prospective randomized study

Angelita Habr-Gama; Robert William de Azevedo Bringel; Sergio Carlos Nahas; Sergio Eduardo Alonso Araujo; Afonso Henrique de Souza Junior; João Elias Calache; Paulo Roberto Arruda Alves

METHOD Eighty patients were prospectively randomized for precolonoscopic cleansing either with 750ml of 10% mannitol (Group M) or 180ml of a sodium phosphate preparation (Group NaP). Laboratory examinations before and after preparation on all patients included hemoglobin, hematocrit, sodium, potassium, phosphorous, calcium and serum osmolarity. A questionnaire was used to assess undesirable side effects and patient tolerance to the solution. The quality of preparation was assessed by the endoscopist who was unaware of the solution employed. RESULTS Statistically significant changes were verified in serum sodium, phosphorous, potassium and calcium between the two groups, but no clinical symptoms were observed. There were no significant differences in the frequency of side effects studied. Six of the eight patients in Group NaP who had taken mannitol for a previous colonoscopy claimed better acceptance of the sodium phosphate solution. The endoscopic-blinded trial reported excellent or good bowel preparation in 85% prepared with sodium phosphate versus 82.5% for mannitol (p=0.37). CONCLUSIONS Quality of preparation and frequency of side effects was similar in the two solutions. The smaller volume of sodium phosphate necessary for preparation seems to be related to its favorable acceptance. Nevertheless, the retention of sodium and phosphate ions contraindicates the use of sodium phosphate in patients with renal failure, cirrhosis, ascites, and heart failure.


Diseases of The Colon & Rectum | 2009

Screening anal dysplasia in HIV-infected patients: is there an agreement between anal pap smear and high-resolution anoscopy-guided biopsy?

Caio Sergio Rizkallah Nahas; Edesio Vieira da Silva Filho; Aluisio A.C. Segurado; Raphael F.F. Genevcius; Renê Gerhard; Eliana B. Gutierrez; Carlos Frederico Sparapan Marques; Ivan Cecconello; Sergio Carlos Nahas

PURPOSE: The purpose of this study was to analyze the agreement between anal Pap smear and high-resolution anoscopy-guided biopsy in diagnosing anal dysplasia in HIV-infected patients. METHODS: We conducted cross-sectional analysis of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa statistics, using a three-tiered cytologic and histologic grading system (normal, low-grade dysplasia, and high-grade dysplasia). Estimates of sensitivity, specificity, and predictive values were calculated using a two-tiered cytologic and histologic grading system (“without dysplasia” and “with dysplasia of any grade”). Estimates were also calculated for the detection of high-grade dysplasia. RESULTS: During a one-year period, 222 patients underwent 330 anal Pap smears followed by high-resolution anoscopy-guided biopsies. There were 311 satisfactory Pap smears with concurrent biopsies. Considering histology the standard, the frequency of anal dysplasia was 46%. Kappa agreement between anal Pap smear and biopsy was 0.20. For detection of anal dysplasia of any grade, anal Pap smear showed sensitivity of 61%, specificity of 60%, positive predictive value of 56%, and negative predictive value of 64%. For high-grade dysplasia, anal Pap smear showed sensitivity of 16% and specificity of 97%. CONCLUSION: Anal Pap smears alone were not sensitive enough to rule out anal dysplasia. We recommend that high-resolution anoscopy-guided biopsy be incorporated as a complementary screening test for anal dysplasia in high-risk patients. Following baseline high-resolution anoscopy, these individuals could be followed with serial anal cytology to dictate the need for future high-resolution anoscopy-guided biopsies.


Diseases of The Colon & Rectum | 2000

Radiation-induced total regression of a highly recurrent giant perianal condyloma

Carlos Walter Sobrado; Marcelo Mester; Wladimir Nadalin; Sergio Carlos Nahas; Sylvio Figueiredo Bocchini; Angelita Habr-Gama

We report a case of a highly recurrent giant perianal condyloma, or Buschke-Lowenstein tumor, which was successfully treated by telecobalt therapy. We conclude that radiation therapy is an optional treatment modality for the management of giant perianal condylomata in selected cases.


Techniques in Coloproctology | 2006

Early results of the treatment of internal hemorrhoid disease by infrared coagulation and elastic banding: a prospective randomized cross-over trial

Carlos Frederico Sparapan Marques; Sergio Carlos Nahas; Caio Sergio Rizkallah Nahas; C. W. Sobrado; Angelita Habr-Gama; Desidério Roberto Kiss

AbstractBackgroundRubber band ligation (RBL) is probably the most commonly performed nonsurgical therapy for hemorrhoidal disease. Infrared coagulation (IRC) is one of the most recent advances based on the use of “heat”. Recent studies have demonstrated similar efficacy for both modalities. This prospective randomized crossover trial compared IRC and RBL for pain, complications, effectiveness, and patient satisfaction and preference in the treatment of internal hemorrhoids (IH).MethodsPatients were randomized to receive either RBL (Group A) or IRC (Group B) for treatment of the first hemorrhoid; in a second procedure two weeks later, patients underwent the other procedure on the second hemorrhoid, thereby serving as their own control. The procedure preferred by the patient was employed two weeks later for the third hemorrhoid. Post-treatment pain was evaluated on a visual analog scale and on the basis of the percentage of patients requiring analgesics. Bleeding and early outcome of treatment were also recorded, together with the patient’s satisfaction.ResultsA total of 94 patients were included in this study (47 patients in each group). At 30 minutes and 6 hours after treatment, pain scores were significantly higher in patients treated with RBL than in those treated with IRC (p<0.01). There was no significant difference in pain scores between the two procedures immediately and 24 hours after the procedures (p<0.05). After 72 hours and one week, the pain scores for RBL and IRC were similar. The percentage of patients using analgesics was significantly higher in RBL group than in IRC group at 6 hours (29.6% vs. 19.2%, respectively; p<0.05) and 24 hours (22.5% vs. 13.5%, respectively; p<0.05) after treatment. However, significant differences were not noted at 72 hours (12.7% vs. 6.4%; p<0.05) and one week (5.6% vs. 7.1%; p>0.05) after the procedures. There were significantly higher incidences of bleeding immediately, 6 hours, and 24 hours after RBL compared to IRC (immediate: 32.4% vs. 4.3%; 6 hours: 13.4% vs. 3.6%, 24 hours: 26.8% vs. 10.2%, respectively; p<0.01). However, there were no significant differences noted regarding the incidence of bleeding between the two groups at 72 hours. Complications were more likely after RBL than IRC, however this difference was not significant (p>0.05). Overall, 91 patients (96.8%) were successfully treated and 93 patients (99%) were very satisfied with the treatment. In the third treatment session, 50% of patients selected RBL and 50% chose IRC.ConclusionsBoth RBL and IRC were well-accepted and highly efficacious methods for the treatment of IH; in addition, both procedures were associated with relatively minor complications. However, RBL was associated with more pain than IRC in the 24-hour postoperative period.


Journal of Surgical Education | 2008

Early Rectal Cancer: Local Excision or Radical Surgery?

Alexandre Jin Bok Audi Chang; Caio Sergio Rizkallah Nahas; Sergio Eduardo Alonso Araujo; Sergio Carlos Nahas; Carlos Frederico Sparapan Marques; Desidério Roberto Kiss; Ivan Cecconello

BACKGROUND Sphincter preservation, disease control, and long-term survival are the main goals in the treatment of rectal cancer. Although transanal local excision is attractive because it is a sphincter sparing procedure, some contradictory data exist in the literature about its ability to locally control disease and provide overall survival comparable with radical procedures, even for patients with early stage tumor. PURPOSE To compare transanal local excision and radical surgery treatment results based on the appropriate data in literature. METHODS We reviewed the literature to identify the current recurrence and survival rates of both techniques as well as the salvage surgery success. A PubMed search of the last 10 years was performed, and a total of 10 nonrandomized studies were identified; only 1 study was prospective, 5 were comparative, and 5 were case reports. RESULTS Five-year overall survival rate varied from 69% to 83% in the local excision group versus 82% to 90% for the radical excision group. Local recurrence rates ranged from 9% to 20% for local excision and from 2% to 9% for radical surgery. Systemic recurrence rates ranged from 6% to 21% for local excision and from 2% to 9% for radical surgery. CONCLUSION Radical surgery is the more definitive cancer treatment; however, it does not eliminate local excision as a reasonable choice for many patients, who will have lesser procedure-related morbidity and will accept an increased risk of tumor recurrence, a prolonged period of postoperative cancer surveillance, and a decreased success rate by salvage surgery.

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