RODRIGO OLIVA PEREZ

Índice h a partir de 2011
25
Projetos de Pesquisa
Unidades Organizacionais

Resultados de Busca

Agora exibindo 1 - 10 de 65
  • article 3 Citação(ões) na Scopus
    Role of Simulation-Based Training in Minimally Invasive and Robotic Colorectal Surgery
    (2021) ARAUJO, Sergio Eduardo Alonso; PEREZ, Rodrigo Oliva; KLAJNER, Sidney
    Properly performing minimally invasive colorectal procedures requires specific skills. With a focus on patient safety, the training of surgeons on patients is only accepted under exceptionally controlled, expensive, and challenging conditions. Moreover, many new techniques in colorectal surgery have been developed. Therefore, undertaking minimally invasive colorectal surgery in modern times requires specific psychomotor skills that trainee surgeons must gather in less time. In addition, there are not enough proctors with sufficient expertise for such an expressive number of new different techniques likes transanal and robotic procedures. Studies that have demonstrated an improvement in minimally invasive surgery skills to the actual operating room in general surgery and a stepwise approach to surgical simulation with a combination of various training methods appears to be useful in colorectal surgery training programs. However, the scientific evidence on the transfer of skills specifically for colorectal surgery is extremely scarce and very variable. Thus, the evaluation of the results remains quite difficult. In this review, we present the best available evidence on the types of training based on simulation, their characteristics, advantages and disadvantages, and finally the results available on their adoption. Nevertheless, scientific evidence about the benefit of simulation training in minimally invasive colorectal surgery is limited and there is a need to build more robust evidence.
  • article 41 Citação(ões) na Scopus
    Consolidation chemotherapy during neoadjuvant chemoradiation (CRT) for distal rectal cancer leads to sustained decrease in tumor metabolism when compared to standard CRT regimen
    (2016) HABR-GAMA, Angelita; PEREZ, Rodrigo O.; JULIAO, Guilherme P. Sao; PROSCURSHIM, Igor; FERNANDEZ, Laura M.; FIGUEIREDO, Marleny N.; GAMA-RODRIGUES, Joaquim; BUCHPIGUEL, Carlos A.
    Background: Neoadjuvant CRT may lead to significant tumor regression in patients with rectal cancer. Different CRT regimens with consolidation chemotherapy may lead to increased rates of complete tumor regression. The purpose of this study was to understand tumor metabolic activity following two different neoadjuvant CRT regimens using sequential PET/CT imaging in two different intervals following RT. Methods: Patients with cT2-4 N0-2 M0 rectal cancer treated by standard CRT (54Gy and 2 cycles of 5FU-based chemotherapy) or extended CRT (54Gy and 6 cycles of 5FU-based chemotherapy) underwent sequential PET/CT imaging at baseline, 6 weeks and 12 weeks from radiation completion. Results: 99 patients undergoing standard CRT were compared to 12 patients undergoing CRT with consolidation chemotherapy. Patients treated with consolidation CRT had increased rates of complete clinical or pathological response (66 % vs. 23 %; p < 0.001). SUVmax variation between baseline and 6 weeks (88 % vs. 63 %; p < 0.001) and between baseline and 12 weeks (90 % vs. 57 %; p < 0.001) were significantly more pronounced among patients undergoing extended CRT with consolidation chemotherapy. An increase in SUVmax between 6 and 12 weeks was observed in 51 % of patients undergoing standard and 18 % of patients undergoing consolidation CRT (p = 0.04). Conclusions: Most of the reduction in tumor metabolism after neoadjuvant CRT occurs within the first 6 weeks from RT completion. In patients undergoing CRT with consolidation chemotherapy, tumors are less likely to regain metabolic activity between 6 and 12 weeks. Therefore, assessment of tumor response may be safely postponed to 12 weeks in patients undergoing extended CRT with consolidation chemotherapy.
  • article 7 Citação(ões) na Scopus
  • article 26 Citação(ões) na Scopus
    Extralevator Abdominal Perineal Excision Versus Standard Abdominal Perineal Excision: Impact on Quality of the Resected Specimen and Postoperative Morbidity
    (2017) HABR-GAMA, Angelita; JULIO, Guilherme P. Sao; MATTACHEO, Adrian; CAMPOS-LOBATO, Luiz Felipe de; ALEMAN, Edgar; VAILATI, Bruna B.; GAMA-RODRIGUES, Joaquim; PEREZ, Rodrigo Oliva
    Background Abdominal perineal excision (APE) has been associated with a high risk of positive circumferential resection margin (CRM+) and local recurrence rates in the treatment of rectal cancer. An alternative extralevator approach (ELAPE) has been suggested to improve the quality of resection by avoiding coning of the specimen decreasing the risk of tumor perforation and CRM+. The aim of this study is to compare the quality of the resected specimen and postoperative complication rates between ELAPE and ""standard"" APE. Methods All patients between 1998 and 2014 undergoing abdominal perineal excision for primary or recurrent rectal cancer at a single Institution were reviewed. Between 1998 and 2008, all patients underwent standard APE. In 2009 ELAPE was introduced at our Institution and all patients requiring APE underwent this alternative procedure (ELAPE). The groups were compared according to pathological characteristics, specimen quality (CRM status, perforation and failure to provide the rectum and anus in a single specimen-fragmentation) and postoperative morbidity. Results Fifty patients underwent standard APEs, while 22 underwent ELAPE. There were no differences in CRM+ (10.6 vs. 13.6%; p = 0.70) or tumor perforation rates (8 vs. 0%; p = 0.30) between APE and ELAPE. However, ELAPE were less likely to result in a fragmented specimen (42 vs. 4%; p = 0.002). Advanced pT-stage was also a risk factor for specimen fragmentation (p = 0.03). There were no differences in severe (Grade 3/4) postoperative morbidity (13 vs. 10%; p = 0.5). Perineal wound dehiscences were less frequent among ELAPE (52 vs 13%; p < 0.01). Despite short follow-up (median 21 mo.), 2-year local recurrence-free survival was better for patients undergoing ELAPE when compared to APE (87 vs. 49%; p = 0.04). Conclusions ELAPE may be safely implemented into routine clinical practice with no increase in postoperative morbidity and considerable improvements in the quality of the resected specimen of patients with low rectal cancers.
  • article 62 Citação(ões) na Scopus
    Baseline T Classification Predicts Early Tumor Regrowth After Nonoperative Management in Distal Rectal Cancer After Extended Neoadjuvant Chemoradiation and Initial Complete Clinical Response
    (2017) HABR-GAMA, Angelita; JULIAO, Guilherme Pagin Sao; GAMA-RODRIGUES, Joaquim; VAILATI, Bruna Borba; ORTEGA, Cinthia; FERNANDEZ, Laura Melina; ARAUJO, Sergio Eduardo Alonso; PEREZ, Rodrigo Oliva
    BACKGROUND: Selected patients with rectal cancer and complete clinical response after neoadjuvant chemoradiation have been managed nonoperatively with acceptable outcomes. However, approximate to 20% of these patients will develop early tumor regrowth. Identification of these patients could select candidates for more intensive follow-up. OBJECTIVE: The purpose of this study was to investigate the influence of baseline radiological T classification on recurrences after a complete clinical response managed nonoperatively after chemoradiation. DESIGN: This was a retrospective review of a prospective collected database. SETTINGS: The study was conducted at a single center. PATIENTS: Patients with distal rectal cancer (cT2-4N0-2M0) undergoing extended chemoradiation (54 Gy + 5-fluorouracil-based chemotherapy) were eligible. Patients were reassessed for tumor response at 10 weeks after radiation completion. Patients with complete clinical response (clinical, radiological, and endoscopic) were managed nonoperatively and strictly followed. MAIN OUTCOMES MEASURES: Complete clinical response rates, early tumor regrowth rates (<12 mo), local recurrence-free survival, and distant metastases-free survival were measured. RESULTS: A total of 91 consecutive patients with rectal cancer underwent extended chemoradiation. Sixty-one patients developed initial complete clinical response (67%). cT2 patients developed similar initial complete clinical response rates compared with cT3/T4 (72% vs 63%; p = 0.403). Early tumor regrowths were more frequent among baseline cT3/4 when compared with cT2 patients (30% vs 3%; p = 0.007). There were no differences in late local recurrences (p = 0.593) or systemic recurrences (p = 0.387). Local recurrence-free survival was significantly better for cT2 patients at 1 year (96% vs 69%; p = 0.009). After Cox regression analysis, baseline T stage was an independent predictor of improved local recurrence-free survival at 1 year (p = 0.03; OR = 0.09 (95% CI, 0.01-0.81)). LIMITATIONS: This study was limited by its small sample size, retrospective nature, and short follow-up. CONCLUSIONS: cT2 patients who develop complete clinical response after extended chemoradiation managed nonoperatively are less likely to develop early tumor regrowths when compared with cT3/4 patients. cT3/4 patients should undergo more intensive follow-up after a complete clinical response to allow for early detection of early regrowths.
  • article 93 Citação(ões) na Scopus
    Achieving a Complete Clinical Response After Neoadjuvant Chemoradiation That Does Not Require Surgical Resection: It May Take Longer Than You Think!
    (2019) HABR-GAMA, Angelita; JULIAO, Guilherme P. Sao; FERNANDEZ, Laura M.; VAILATI, Bruna B.; ANDRADE, Andres; ARAUJO, Sergio E. A.; GAMA-RODRIGUES, Joaquim; PEREZ, Rodrigo O.
    BACKGROUND: Patients with rectal cancer who achieve complete clinical response after neoadjuvant chemoradiation have been managed by organ-preserving strategies and acceptable long-term outcomes. Controversy still exists regarding optimal timing for the assessment of tumor response after neoadjuvant chemoradiation. OBJECTIVE: The purpose of this study was to estimate the time interval for achieving complete clinical response using strict endoscopic and clinical criteria after a single neoadjuvant chemoradiation regimen. DESIGN: This was a retrospective review of consecutive patients managed by 54-Gy and consolidation 5-fluorouracil-based chemotherapy. Assessment of response was performed at 10 weeks after radiation. Patients with suspected complete clinical response were offered watch-and-wait strategy and reassessment every 6 to 8 weeks until achievement of strict criteria of complete clinical response or overt residual cancer. SETTINGS: This study was conducted at a single tertiary care center. PATIENTS: Patients with complete clinical response who underwent a successful watch-and-wait strategy until last follow-up were eligible. Dates of radiation completion and achievement of strict endoscopic and clinical criteria (mucosal whitening, teleangiectasia, and no ulceration or irregularity) were recorded. Patients with incomplete response or with initial complete clinical response followed by local recurrence or regrowth were excluded. MAIN OUTCOMES MEASURES: The distribution of time intervals between completion of radiation and achievement of strict complete clinical response was measured. Patients who achieved early complete clinical response (<= 16 wk) were compared with late complete clinical response (>16 wk). RESULTS: A total of 49 patients achieved complete clinical response and were successfully managed nonoperatively. A median interval of 18.7 weeks was observed for achieving strict complete clinical response. Only 38% of patients achieved complete clinical response between 10 and 16 weeks from radiation completion. Patients with earlier cT status (cT2/T3a) achieved a complete clinical response significantly earlier when compared with those patients with more advanced disease (T3b-d/4; 19 vs 26 wk; p = 0.03). LIMITATIONS: This was a retrospective study with a small sample size. CONCLUSIONS: Assessment at 10 to 16 weeks may detect a minority of patients who achieve complete clinical response without additional recurrence after neoadjuvant chemoradiation. Patients suspected for a complete clinical response should be considered for reassessment beyond 16 weeks before definitive management when considered for a watch and wait strategy. See Video Abstract at http://links.lww.com/DCR/A901.
  • article 1 Citação(ões) na Scopus
    Putting down the scalpel in rectal cancer management - a historical perspective
    (2018) PEREZ, R. O.; HABR-GAMA, A.
    The surgical management of rectal cancer has evolved from a disease without any possibility of cure in the early 1700s where surgical management consisted of the palliative drainage of disease related abscesses to the present day where surgical cure is not only possible but also possible with sphincter or even organ preservation. Prof Habr-Gama's lecture describes the evolution of the surgical management of rectal cancer and the current focus on organ preservation.
  • conferenceObject
    Implications of Akt inhibition for neoadjuvant radiotherapy: improving the rectal cancer treatment
    (2016) KOYAMA, Fernanda C.; RAMOS, Camila; HABR-GAMA, Angelita; ALVES, Venancio Avancini Ferreira; PEREZ, Rodrigo O.; CAMARGO, Anamaria Aranha
  • article 377 Citação(ões) na Scopus
    Watch and Wait Approach Following Extended Neoadjuvant Chemoradiation for Distal Rectal Cancer: Are We Getting Closer to Anal Cancer Management?
    (2013) HABR-GAMA, Angelita; SABBAGA, Jorge; GAMA-RODRIGUES, Joaquim; JULIAO, Guilherme P. Sao; PROSCURSHIM, Igor; AGUILAR, Patricia Bailao; NADALIN, Wladimir; PEREZ, Rodrigo O.
    BACKGROUND: No immediate surgery (Watch and Wait) has been considered in select patients with complete clinical response after neoadjuvant chemoradiation to avoid postoperative morbidity and functional disorders after radical surgery. OBJECTIVE: The purpose of this study was to demonstrate the long-term results of patients who had a complete clinical response following an alternative chemoradiation regimen and were managed nonoperatively. DESIGN: This is a prospective study. SETTINGS: This study was conducted at a single center. PATIENTS: Seventy consecutive patients with T2-4N0-2M0 distal rectal cancer were studied. Neoadjuvant chemoradiotherapy included 54 Gy and 5-fluorouracil/leucovorin delivered in 6 cycles every 21 days. Patients were assessed for tumor response at 10 weeks from radiation completion. Patients with incomplete clinical response were referred to immediate surgery. Patients with complete clinical response were not immediately operated on and were monitored. MAIN OUTCOME MEASURES: The primary outcomes measured were the initial complete clinical response rates after 10 weeks and the sustained complete clinical response rates after 12 months from chemoradiotherapy. RESULTS: One patient died during chemoradiotherapy because of cardiac complications. Forty-seven (68%) patients had initial complete clinical response. Of these, 8 developed local regrowth within the first 12 months of follow-up (17%). Thirty-nine sustained complete clinical response at a median follow-up of 56 months (57%). An additional 4 patients (10%) developed late local recurrences (>12 months of follow-up). Overall, 35 patients never underwent surgery (50%). LIMITATIONS: This study is limited by the short follow-up and small sample size. CONCLUSION: Extended chemoradiation therapy with additional chemotherapy cycles and 54 Gy of radiation may result in over 50% of sustained (>12 months) complete clinical response rates that may ultimately avoid radical rectal resection. Local failures occur more frequently during the initial 12 months of follow-up in up to 17% of cases, whereas late recurrences are less common but still possible, leading to 50% of patients who never required surgery. Strict follow-up may allow salvage therapy in the majority of these patients (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A113.)