The usefulness of gastric submucosal dissection depth to evaluate the learning curve in ESD: an experimental study

INTRODUÇÃO: A técnica de ESD (Endoscopic Submucosal Dissection) é um procedimento endoscópico de grande complexidade, com alto índice de complicações e dificuldades técnicas. Para superar este problema, muitos centros de treinamento em endoscopia vêm publicando a aplicabilidade dos modelos animais para a aquisição de competência em ESD. Em todas as publicações sobre o assunto, a habilidade do aluno é acompanhada pela evolução de variáveis como o tempo de ressecção, ressecção em bloco e complicações tais como sangramento e perfuração; entretanto a profundidade de ressecção nunca foi utilizada como parâmetro de aprendizagem, o que pode ser um fator relevante a ser ensinado, dado que atingir o plano de dissecção ideal é de suma importância para uma ressecção curativa e na prevenção de complicações intraoperatórias. O objetivo do estudo foi analisar o aprendizado em ESD em treinamentos de curta duração através da avaliação da profundidade de submucosa ressecada; e sua associação com complicações. MÉTODOS: estudo experimental; incluídos 25 endoscopistas com experiência em procedimentos terapêuticos ( > 5anos) e 75 peças ressecadas por ESD sendo uma média de 3 resseções por endoscopista. Os parâmetros de aprendizagem (tempo de ressecção, tamanho, taxa de ressecção em bloco, sangramento, perfuração e análise histológica da camada submucosa) foram prospectivamente avaliados. Antes, durante e ao final do treinamento os participantes foram submetidos a um questionário sobre a dificuldade e insegurança em realizar o procedimento. RESULTADOS: Todas as ressecções foram realizadas no corpo gástrico (n=75). O tamanho médio das peças ressecadas foi de 23,97 ± 7,2 mm. O número de complicações como sangramento, perfuração e morte foram respectivamente, 17 (22,67%), 3 (4%) e 0 casos. Na terceira dissecção, tempo médio do procedimento diminuiu de 28,44 ± 9,73 para 18,72 ± 8,81 minutos (p 5years) undergone seventy-five en bloc ESDs in live porcine models. Each participant did at least 3 endoscopic resections. The learning curve parameters (procedure time, specimen size, en-bloc resection rate, perforation, bleeding and histological analysis of the submucosal layer) were prospectively evaluated. During and after each procedure the participants were submitted into a questionnaire about difficulties and insecurities in doing this procedure. RESULTS: ESDs were all completed at the gastric body (n=75). Medium sizes of the specimens resected were 23.97 ± 7.2 mm. Complication as bleeding, perforation and death were seen respectively in 17 (22.67%), 3 (4%) and 0 cases. After the third ESD, procedure mean time has progressively reduced from 28.44 ± 9.73 to 18.72±8.81 minutes (p < 0.001). Bleeding rate were significantly lower when comparing the first to the third resection (p=0.047) and the depth of submucosal resection, in contrast, has increased when comparing the first (53.5±23.76%), second (61.8±26.47%) and third (69.82±27.86) dissection (p=0.073). Results of the questionnaire showed that participants felt increasingly less insecure from the first (95%CI: 100(83.88-100)) until the third (95%CI: 32(17.18-51.78)) ESD procedure (p < 0.001). The group that had bleeding during the procedure resected 37.97±21.13% of the submucosal layer and the non-bleeding group resected 68.66±23.99%, showing a significant association between the depth of submucosal dissection and the incidence of bleeding (p < 0.001). According to the ROC curve analysis, the resulting cutoff value of the submucosal dissection depth for bleeding is 61 %( 64% sensitivity, 94% specificity). When ESD is done deeper than 61% of the submucosal layer the risk of bleeding decreases during the procedure (PPV=0.97, 95%CI: 0.85-0.99). CONCLUSION: The short term ESD training course in live porcine models made a significant improvement on ESD skills regarding on resection time, bleeding rate, insecurity and increased depth of submucosal resection. Association between the depths of submucosal resection with the incidence of bleeding might be significant, which means that deeper in the submucosal layer undergoes the procedure; lower will be the risk of bleedin

USEFULNESS OF GASTRIC SUBMUCOSAL DISSECTION DEPTH TO EVALUATE SKILL ACQUIREMENT IN SHORT TERM TRAINING COURSES IN ESD: AN EXPERIMENTAL STUDY

ABSTRACT BACKGROUND: Endoscopic submucosal dissection (ESD) is a complex endoscopic procedure, with high rates of adverse events and technical difficulties. To overcome that problem, many training centers published the importance of animal models for skill acquirement in ESD. However, no study has used the submucosal dissection depth (DSUB) as a parameter to evaluate the learning curve in ESD, which might be a relevant factor since an optimal resection plane is important to achieve a curative resection and avoid intraoperative complications. OBJECTIVE: This study aimed to assess ESD skill acquirement after short-term training sessions by evaluating the submucosal dissection depth (DSUB) and the association with adverse events. METHODS: This experimental study included 25 experienced endoscopists in therapeuthic procedures (>5years) and 75 specimens resected by ESD (three resections / endoscopist). Learning parameters (resection time, size, en bloc resection rate, bleeding, perforation and submucosal dissection depth) were prospectively evaluated. The percentages of DSUB of all specimens resected were calculated. RESULTS: All specimens were resected from the gastric body (n=75). The mean size of the resected specimens was 23.97±7.2 mm. The number of adverse events, including bleeding, perforation, and death, were 17 (22.67%), 3 (4%), and 0 cases, respectively. The average mean time by the third dissection decreased from 28.44±9.73 to 18.72±8.81 min (P61% of the submucosal layer, the risk for bleeding during the procedure decreased (PPV, 0.97; 95% CI, 0.85-0.99). CONCLUSION: Improvement in the learning curve in ESD and a better cognitive ability were seen by the third dissection in these short term training courses. And a significant association between DSUB and the risk of bleeding

INITIAL EXPERIENCE OF ENDOSCOPIC SUBMUCOSAL DISSECTION IN BRAZIL TO TREAT EARLY GASTRIC AND ESOPHAGHEAL CANCER: a multi-institutional analysis

Objective This study aimed to evaluate the feasibility and clinicopathological characteristics of early gastric and esophageal cancers treated with endoscopic submucosal dissection (ESD) at five centers in Brazil. Methods Five centers in Brazil reported their initial experience with ESD. The cases reported had already been collected by each center before pooled analysis. Results Were resected 62 gastric lesions; 52(83,8%) of the gastric lesions were well-differentiated adenocarcinoma, 31(50%) from the antrum, 24 (38.7%) type IIa. 51 (82.2%) lesions had en-block resection with three showing lateral margin compromise. Concerning invasion, 25 (40.3%) tumors were M1. Mean tumor diameter was 18.9 mm (range, 0.6-5.0 cm) and mean procedure duration was 119.45 minutes. Gastric perforation occurred in three (4.8%) patients. Mean follow-up duration was 11.3 months, with two local recurrences and one death from pneumonia Seven months after treatment. Of the 16 esophageal lesions resected, 14 (87.4%) were squamous cell carcinoma, 10 (62.5%) were located proximally and 8 (50.0%) type IIa. Mean tumor diameter was 23.8 mm (range, 6-60 mm). Thirteen (81.2%) lesions had en-block resection with five cases of lateral margin compromise. Eight (50.0%) lesions were M1. Mean procedure duration was 78 minutes (range, 20-150 min). Complications included pneumomediastinum in two (12.5%) patients and stenosis in one (6.2%). Mean duration of follow-up was 8.6 months, with no local recurrence despite the presence of lateral margin compromise. Conclusion Different centers in Brazil feasibly perform ESD with a high success rate