Learning curve and clinical outcome of gastric endoscopic submucosal dissection performed by trainee operators

Endoscopic resection of gastrointestinal tumors: Training levels and professional roles explored

In this editorial, we provide commentary on a recently published study by Zhao et al in the World Journal of Gastrointestinal Oncology. The study discusses the clinical characteristics of patients undergoing endoscopic resection for gastric cancers. We feel it is important to engage our endoscopy community in a discussion on the current evidence in the literature on the necessary number of cases for training in endoluminal surgery techniques, particularly endoscopic submucosal dissection. This includes the latest recommendations from the European Society of Gastrointestinal Endoscopy, as well as a summary of key studies on the learning curve for these techniques. Additionally, we explore the impact of an endoscopist's specialty on endoscopy outcomes, drawing from current evidence in the literature to shape our perspective in this evolving field.

Non-Curative Endoscopic Submucosal Dissection: Current Concepts, Pitfalls and Future Perspectives

Endoscopic submucosal dissection (ESD) is very effective for the treatment of digestive tract neoplasia. However, it is very demanding, with a long learning curve, and, therefore, a significant rate of non-curative resections is expected, considering lesion characteristics, location, and endoscopist experience. The management of patients after a non-curative ESD is not definitely established. It must consider patients' comorbidities and expected survival, as well as the morbidity and mortality of complementary treatments such as surgery, chemotherapy, or radiotherapy. On the other hand, there is a window of opportunity to offer those additional treatments to complete neoplastic treatment and give patients an oncological cure. This decision is sometimes difficult, since the diverse histological criteria that define a non-curative ESD do not have the same weight regarding residual risk and oncological progression. The prediction of residual lesion would be paramount to decide whether to refer patients to surgery; nowadays, this prediction is far from perfect, since most of the patients that undergo surgery due to a non-curative ESD do not have residual neoplasia in the surgical specimen. In this review, ESD curativeness and the management of non-curative ESDs performed for esophageal, gastric, and colorectal lesions will be addressed.

Effects of a training system that tracks the operator's gaze pattern during endoscopic submucosal dissection on hemostasis

BACKGROUND

The early acquisition of skills required to perform hemostasis during endoscopy may be hindered by the lack of tools that allow assessments of the operator's viewpoint. Understanding the operator's viewpoint may facilitate the skills.

AIM

To evaluate the effects of a training system using operator gaze patterns during gastric endoscopic submucosal dissection (ESD) on hemostasis.

METHODS

An eye-tracking system was developed to record the operator's viewpoints during gastric ESD, displaying the viewpoint as a circle. In phase 1, videos of three trainees' viewpoints were recorded. After reviewing these, trainees were recorded again in phase 2. The videos from both phases were retrospectively reviewed, and short clips were created to evaluate the hemostasis skills. Outcome measures included the time to recognize the bleeding point, the time to complete hemostasis, and the number of coagulation attempts.

RESULTS

Eight cases treated with ESD were reviewed, and 10 video clips of hemostasis were created. The time required to recognize the bleeding point during phase 2 was significantly shorter than that during phase 1 (8.3 ± 4.1 seconds vs 23.1 ± 19.2 seconds; P = 0.049). The time required to complete hemostasis during phase 1 and that during phase 2 were not significantly different (15.4 ± 6.8 seconds vs 31.9 ± 21.7 seconds; P = 0.056). Significantly fewer coagulation attempts were performed during phase 2 (1.8 ± 0.7 vs 3.2 ± 1.0; P = 0.004).

CONCLUSION

Short-term training did not reduce hemostasis completion time but significantly improved bleeding point recognition and reduced coagulation attempts. Learning from the operator's viewpoint can facilitate acquiring hemostasis skills during ESD.

Learning curve for endoscopic submucosal dissection in early gastric neoplasm using a multibending endoscope

Background

Endoscopic submucosal dissection (ESD) is a representative treatment modality for early gastric neoplasms. However, the learning curve for beginners performing ESD using a multibending endoscope has not been introduced.

Objective

This study aimed to evaluate the learning curves of operators undergoing intensive training using a multibending endoscope.

Design

This was a retrospective single center study.

Methods

We retrospectively analyzed data of over 1500 consecutive gastric ESDs performed by two operators using a multibending endoscope. A change-point analysis with 50 cases of moving average speeds was used to determine the new target resection speed. Cumulative sum (CUSUM) analysis was used to identify the cases required for proficiency in ESD. Risk-adjusted CUSUM (RA-CUSUM) analysis was performed for each operator after adjusting for confounding factors influencing the resection speed.

Results

In total, 1491 cases were enrolled, with early gastric cancer accounting for 43.2% (n = 644). Overall, the en bloc resection, R0 resection, and curability rates were 97.7%, 96.0%, and 92.3%, respectively. The mean resection speed was 19.8 cm2/h. Because both operators surpassed the commonly used benchmark resection speed of 9 cm2/h in the first 50-case block, we established a new target benchmark of 17.9 cm2/h in the change-point analysis. CUSUM analysis indicated that performing 166 cases overall was required to achieve the benchmark, with the 2 operators needing 153 and 69 cases to meet this target speed after RA-CUSUM analysis.

Conclusion

Using a multibending endoscope for gastric ESD can help beginners achieve safe and excellent outcomes. These findings will serve as a useful guide for beginners attempting to use a multibending endoscope.

Effectiveness of a novel ex vivo training model for gastric endoscopic submucosal dissection training: a prospective observational study conducted at a single center in Japan

BACKGROUND/AIMS

The efficacy of endoscopic submucosal dissection (ESD) for early-stage gastric cancer is well established. However, its acquisition is challenging owing to its complexity. In Japan, G-Master is a novel ex vivo gastric ESD training model. The effectiveness of training using G-Master is unknown. This study evaluated the efficacy of gastric ESD training using the G-Master to evaluate trainees' learning curves and performance.

METHODS

Four trainees completed 30 ESD training sessions using the G-Master, and procedure time, resection area, resection completion, en-bloc resection requirement, and perforation occurrence were measured. Resection speed was the primary endpoint, and learning curves were evaluated using the Cumulative Sum (CUSUM) method.

RESULTS

All trainees completed the resection and en-bloc resection of the lesion without any intraoperative perforations. The learning curves covered three phases: initial growth, plateau, and late growth. The transition from phase 1 to phase 2 required a median of 10 sessions. Each trainee completed 30 training sessions in approximately 4 months.

CONCLUSIONS

Gastric ESD training using the G-Master is a simple, fast, and effective method for pre-ESD training in clinical practice. It is recommended that at least 10 training sessions be conducted.

Orthodontic Rubber Band Traction Improves Trainees' Learning Curve of Colorectal Endoscopic Submucosal Dissection: A Prospective Randomized Study

INTRODUCTION

Colorectal endoscopic submucosal dissection (ESD) is a technically demanding operation with a long learning curve. The aim of this study was to determine whether orthodontic rubber band (ORB)-assisted colorectal ESD could improve the trainees' learning curve as it was shown to shorten colorectal ESD procedure time in trainees and experts.

METHODS

This prospective, randomized, controlled clinical study involved 178 patients who underwent colorectal ESD, randomly divided into trainee ORB-assisted ESD (Trainee ORB-ESD; n = 60), trainee conventional ESD (Trainee C-ESD; n = 57), and expert conventional ESD (Expert C-ESD; n = 61) groups. The main outcome was procedure time.

RESULTS

Per Protocol analysis showed a similar operative time in the trainee ORB-ESD and expert C-ESD groups, which was shorter than in the trainee C-ESD group [28.0 (21.0-35.0) and 25.0 (15.0-35.0) vs 41.0 (31.0-52.5) min; ( P < 0.001)]. The trainee ORB-ESD, trainee C-ESD, and expert C-ESD groups differed significantly in resection speed (11.35, 9.07, and 12.56 mm 2 /min, respectively), good visual field exposure rate (96.7%, 80.7%, and 93.4%), and muscle injury rate (5.0%, 17.5%, and 6.6%). However, the trainee ORB-ESD and expert C-ESD groups were similar in these measures, and all 3 groups were similar in adverse events, en bloc resection, R0 resection, and pathology rates. The cumulative sum suggested that the learning inflection point of the trainee ORB-ESD group was earlier than that of the trainee C-ESD group.

DISCUSSION

ORB-ESD shortened colorectal ESD procedure time and improved efficiency in trainees to an expert level. ORB-ESD could shorten the learning curve, justifying its widespread application.

Intraoperative bleeding model for swine gastric endoscopic submucosal dissection via heparinization

Background and study aims: Live swine have a high degree of coagulation and aggregation and using them for training about how to manage intraoperative bleeding during endoscopic submucosal dissection (ESD) is unsatisfactory. This study aimed to identify the appropriate heparin dose in an intraoperative bleeding model and validate its applicability. Methods: First, we explored the dose of heparin required for a swine bleeding model in which the activated clotting time reached and maintained the upper limit of measurement (1500 s) after 10 minutes. Second, we compared intraoperative bleeding and hematoma frequency during ESD for 2-cm lesions between the heparinized bleeding model and control groups. Intraoperative bleeding was classified according to the Forrest classification. Results: The combination of a bolus (300 U/kg), continuous infusion (300 U/kg/h), and a bolus dose (150 U/kg) of heparin 10 minutes after the first infusion was identified as the dose for the bleeding model. Five ESDs were performed in each heparinized bleeding model and the control group. The median number of intraoperative bleeds was significantly higher in the heparinized model than in the control group (5 interquartile range [IQR] 4-7 vs. 3 [IQR 0-4, P = 0.028). All of the intraoperative bleeding events oozing (Forrest Ib) rather than spurting (Forrest Ia). The median number of hematomas was significantly higher in the heparinized model group than in the control group (3 [IQR 1-4] vs. 0 [IQR 0-1], P = 0.023). Conclusions: High doses of heparin significantly increased intraoperative bleeding and hematoma during swine ESD.

Spray coagulation reduces the use of hemostatic forceps for intraoperative bleeding in gastric endoscopic submucosal dissection

Aims

During intraoperative bleeding in endoscopic submucosal dissection (ESD), switching to spray coagulation may be beneficial compared with the continuous use of swift coagulation and can reduce the need for hemostatic forceps. We retrospectively assessed the effectiveness of spray modes on intraoperative bleeding during gastric ESD.

Methods and Results

A total of 316 bleeding events (156 in the Swift group and 160 in the Spray group) were consecutively recorded. In the Swift group, hemostasis was performed using the swift mode with a retracted tip of the needle-type knife, followed by the hemostatic forceps. In the Spray group, bleeding was treated in a stepwise manner: the swift mode, the spray mode, and the hemostatic forceps. All bleeding events were assigned to one of two groups by an endoscopist who retrospectively reviewed the videos. We compared the use of hemostatic forceps, the total hemostatic time, and the cumulative hemostasis rate between the two groups.The use of hemostatic forceps was significantly lower in the Spray group than in the Swift group (32.7% vs. 13.8%, P < 0.001). There was no significant difference in the total hemostatic time (Swift group, 20 s.; Spray group, 16 s.; P = 0.42), whereas the cumulative hemostasis rate with the knife was significantly higher in the Spray group (P = 0.007).

Conclusion

The results suggested that spray coagulation from the tip of the needle-type knife could reduce the use of hemostatic forceps. In gastric ESD, spray coagulation may facilitate the hemostasis of intraoperative bleeding.

Novel gastric endoscopic submucosal dissection training model enhances the endoscopic submucosal dissection skills of trainees: a multicenter comparative study

BACKGROUND

Endoscopic submucosal dissection (ESD) requires high endoscopic technical skills, and trainees should develop effective training methods. In collaboration with KOTOBUKI Medical, we developed the G-Master, which is a non-animal training model that can simulate various parts of gastric ESD. We aimed to clarify the usefulness of the G-Master for inexperienced ESD trainees.

METHODS

We collected data from the first 5 gastric ESD cases conducted by 15 inexperienced ESD trainees at 5 participating centers between 2018 and 2022. The participants were divided into two groups: the G-Master training and non-G-Master training groups. Outcome measurements, such as procedural speed, perforation rate, self-completion rate, and en bloc resection rate, were compared between the two groups retrospectively.

RESULTS

A total of 75 gastric ESD cases were included in this study. The G-Master training group included 25 cases performed by 5 trainees, whereas the non-G-Master training group included 50 cases performed by 10 trainees. The median procedural speed for all cases was significantly faster in the G-Master training group than in the non-G-Master training group. Moreover, the procedural speed was linearly improved from the initial to the last cases in the lower location in the G-Master training group compared with the non-G-Master training group. In addition, although there was no significant difference, the G-Master training group showed lower rates of perforation and a lesser need to transition to expert operators than the non-G-Master training group.

CONCLUSION

The G-Master could improve the ESD skills of inexperienced ESD trainees.

Safe and effective hybrid endoscopic submucosal dissection with ALL IN ONE snare in porcine gastric model (with video)

This study aimed to evaluate the safety and efficiency of hybrid endoscopic submucosal dissection (H-ESD) using a newly developed ALL IN ONE (AIO) snare. This was a matched control study in a porcine model. Five paired simulated stomach lesions 2-2.5 cm in size were removed by H-ESD using an AIO snare or conventional ESD (C-ESD) using an endoscopic knife. The outcomes of the two procedures were compared, including en-bloc resection rates, procedure times, intraprocedural bleeding volumes, muscular injuries, perforations, thicknesses of the submucosal layer in resected specimens, and stomach defects. All simulated lesions were resected en-bloc. Specimens resected by H-ESD and C-ESD were similar in size (7.68 ± 2.92 vs. 8.42 ± 2.42 cm2; P = 0.676). H-ESD required a significantly shorter procedure time (13.39 ± 3.78 vs. 25.99 ± 4.52 min; P = 0.031) and submucosal dissection time (3.99 ± 1.73 vs. 13.1 ± 4.58 min; P = 0.003) versus C-ESD; H-ESD also yielded a faster dissection speed (241.37 ± 156.84 vs. 68.56 ± 28.53 mm2/min; P = 0.042) and caused fewer intraprocedural bleeding events (0.40 ± 0.55 vs. 3.40 ± 1.95 times/per lesion; P = 0.016) than C-ESD. The thicknesses of the submucosal layer of the resected specimen (1190.98 ± 134.07 vs. 1055.90 ± 151.76 μm; P = 0.174) and the residual submucosal layer of the stomach defect (1607.94 ± 1026.74 vs. 985.98 ± 445.58 μm; P = 0.249) were similar with both procedures. The AIO snare is a safe and effective device for H-ESD and improves the treatment outcomes of gastric lesions by shortening the procedure time.

Novel quantitative assessment indicators for efficiency and precision of endoscopic submucosal dissection in animal training models by analyzing an electrical surgical unit

OBJECTIVES

Although endoscopic submucosal dissection (ESD) training is important, quantitative assessments have not been established. This study aimed to explore a novel quantitative assessment system by analyzing an electrical surgical unit (ESU).

METHODS

This was an ex vivo study. Step one: to identify the novel efficiency indicators, 20 endoscopists performed one ESD each, and we analyzed correlations between their resection speed and electrical status. Step two: to identify the novel precision indicators, three experts and three novices performed one ESD each, and we compared the stability of the electrical status. Step three: three novices in step two performed 19 additional ESDs, and we analyzed the learning curve using novel indicators.

RESULTS

Step one: the percentage of total activation time (AT) of ESU in the procedure time (β coefficient, 0.80; P < 0.01) and AT required for submucosal dissection (β coefficient, -0.57; P < 0.01) were significantly correlated with the resection speed. Step two: coefficient of variation of the AT per one pulse (0.16 [range, 0.13-0.17] vs. 0.26 [range, 0.20-0.41], P = 0.049) and coefficient of variation of the peak electric power per pulse during mucosal incision (0.14 [range, 0.080-0.15] vs. 0.25 [range, 0.24-0.28], P = 0.049) were significantly lower in the experts than in the novices. Regarding the learning curve, the percentage of total AT of ESU in the procedure time and AT required for submucosal dissection had a trend of improvement.

CONCLUSION

Novel indicators identified by analyzing ESU enable quantitative assessment for endoscopist's skill.

Learning curve for endoscopic resection of gastric gastrointestinal stromal tumors: a single-center experience

BACKGROUND

endoscopic resection (ER) is widely used in the treatment of gastric gastrointestinal stromal tumors (gGISTs). However, no studies have previously described the learning curve (LC) for ER of gGISTs. This study aimed to evaluate the LC based on multifarious operative outcomes.

METHODS

one hundred consecutive patients who underwent ER of gGISTs by a single endoscopist from January 2017 to December 2022 were included. Patients were analyzed in groups of ten to minimize demographic differences, and operative time (OT), conversion rate, intraoperative and postoperative complication were assessed to evaluate the LC. Meanwhile, for the OT, the LC was further analyzed using the cumulative sum (CUSUM) method and patients were organized chronologically in three phases.

RESULT

there was a statistically significant decrease in OT, conversion to laparoscopic surgery, and postoperative complication after 30 cases (median 80.0 min vs 56.0 min, p < 0.001; 10.0 % vs 0 %, p = 0.025; 33.3 % vs 10.0 %, p = 0.004), rate of intraoperative complications after 20 cases (15.0 % vs 1.3 %, p = 0.025). CUSUM chart demonstrated that OT increased dramatically before around 30 cases (phase 1) and decreased after 60 cases (phase 3), with a plateau phase in the middle 30 cases (phase 2). Among the three phases, the R0 resection and conversion rate were not significantly different. However, OT, intraoperative and postoperative complications were gradually decreased (p < 0.05).

CONCLUSIONS

the LC of ER of gGISTs is approximately 60 cases. However, about 30 cases were sufficient to acquire skills to reduce complications and conversion rate during the ER procedure.

Assessment of a Real-world Learning Curve for the Endoscopic Resection of Gastric Gastrointestinal Stromal Tumors

BACKGROUND

Endoscopic resection (ER) is a proven treatment for gastric gastrointestinal stromal tumors (gGISTs). We aimed to assess the learning curve (LC) associated with ER for gGISTs and identify determinants.

METHODS

We conducted an analysis of 289 patients who underwent the ER of gGISTs by an experienced endoscopist. To characterize the LC, we employed cumulative sum analysis of the duration of surgery. The participants were divided into an early phase (cases 1-50) and a later phase (case 51-289), which were compared. Furthermore, we identified risk factors for the conversion from endoscopic to laparoscopic resection (LR).

RESULTS

The durations of surgery and hospitalization were shorter, and there were fewer complications and fasting days in the later phase. The conversion rates to LR were 6.0% and 2.5% in the early and later phases, respectively. The tumor diameter (≥3.0 cm) and invasion beyond the muscularis propria were significant risk factors for conversion to LR (odds ratio 17.92, 95% confidence interval 2.66-120.87; and 58.03, 6.40-525.84; respectively).

CONCLUSIONS

The LC for ER of gGISTs lasts for approximately 50 cases. In addition, tumors ≥3.0 cm in diameter and those that invade beyond the muscularis propria are more likely to require conversion to LR.

Safe and Efficient Procedures and Training System for Endoscopic Submucosal Dissection

Recent improvements in endoscopists' skills and technological advances have allowed endoscopic submucosal dissection (ESD) to become a standard treatment in general hospitals. As this treatment entails a high risk of accidental perforation or hemorrhage, therapeutic procedures and training methods that enable ESD to be conducted more safely and efficiently are constantly being developed. This article reviews the therapeutic procedures and training methods used to improve the safety and efficiency of ESD and describes the ESD training system used in a Japanese university hospital at which the number of ESD procedures has gradually increased in a newly established Department of Digestive Endoscopy. During the establishment of this department, the ESD perforation rate was zero among all procedures, including those conducted by trainees.

Development and validation of a preoperative difficulty scoring system for endoscopic resection of gastric gastrointestinal stromal tumor: a multi-center study

BACKGROUND

Endoscopic resection (ER) is a promising technique for resecting gastric gastrointestinal stromal tumors (gGISTs); however, ER is technically challenging. This study aimed to develop and validate a difficulty scoring system (DSS) to determine the difficulty for ER of a gGIST.

METHODS

This retrospective study enrolled 555 patients with gGISTs in multi-centers from December 2010 to December 2022. Data on patients, lesions, and outcomes of ER were collected and analyzed. A difficult case was defined as an operative time ≥ 90 min, or the occurrence of severe intraoperative bleeding, or conversion to laparoscopic resection. The DSS was developed in the training cohort (TC) and validated in the internal validation cohort (IVC) and external validation cohort (EVC).

RESULTS

The difficulty occurred in 97 cases (17.5%). The DSS comprised the following: tumor size ≥ 3.0 cm (3 points) or 2.0-3.0 cm (1 point); location in the upper third of the stomach (2 points); invasion depth beyond the muscularis propria (2 points); lack of experience (1 point). The area under the curve (AUC) of DSS in IVC and EVC was 0.838 and 0.864, respectively, and the negative predictive value (NPV) was 0.923 and 0.972, respectively. The proportions of difficult operation in easy (score 0-3), intermediate (score 4-5), and difficult (score 6-8) categories were 6.5%, 29.4%, and 88.2% in the TC, 7.7%, 45.8%, and 85.7% in the IVC, and 7.0%, 29.4%, and 85.7% in the EVC, respectively.

CONCLUSIONS

We developed and validated a preoperative DSS for ER of gGISTs based on tumor size, location, invasion depth, and endoscopists' experience. This DSS can be used to grade the technical difficulty before surgery.

Automated machine learning to predict the difficulty for endoscopic resection of gastric gastrointestinal stromal tumor

Background

Accurate preoperative assessment of surgical difficulty is crucial to the success of the surgery and patient safety. This study aimed to evaluate the difficulty for endoscopic resection (ER) of gastric gastrointestinal stromal tumors (gGISTs) using multiple machine learning (ML) algorithms.

Methods

From December 2010 to December 2022, 555 patients with gGISTs in multi-centers were retrospectively studied and assigned to a training, validation, and test cohort. A difficult case was defined as meeting one of the following criteria: an operative time ≥ 90 min, severe intraoperative bleeding, or conversion to laparoscopic resection. Five types of algorithms were employed in building models, including traditional logistic regression (LR) and automated machine learning (AutoML) analysis (gradient boost machine (GBM), deep neural net (DL), generalized linear model (GLM), and default random forest (DRF)). We assessed the performance of the models using the areas under the receiver operating characteristic curves (AUC), the calibration curve, and the decision curve analysis (DCA) based on LR, as well as feature importance, SHapley Additive exPlanation (SHAP) Plots and Local Interpretable Model Agnostic Explanation (LIME) based on AutoML.

Results

The GBM model outperformed other models with an AUC of 0.894 in the validation and 0.791 in the test cohorts. Furthermore, the GBM model achieved the highest accuracy among these AutoML models, with 0.935 and 0.911 in the validation and test cohorts, respectively. In addition, it was found that tumor size and endoscopists' experience were the most prominent features that significantly impacted the AutoML model's performance in predicting the difficulty for ER of gGISTs.

Conclusion

The AutoML model based on the GBM algorithm can accurately predict the difficulty for ER of gGISTs before surgery.

Comparison of treatment outcomes between endoscopic submucosal dissection with the needle-type knife and insulated-tip knife for superficial esophageal neoplasms

Our study aimed to compare the treatment outcomes between endoscopic submucosal dissection (ESD) with an insulated-tip knife (ESD-IT) and a needle-type knife (ESD-N) for large superficial esophageal neoplasms, as no study of this kind has been previously reported. We used the dataset of a multicenter, randomized controlled trial that compared conventional ESD (C-ESD) and traction-assisted ESD (TA-ESD) for superficial esophageal neoplasms. We compared the procedural outcomes between ESD-IT and ESD-N in a post hoc analysis and conducted sub-analyses based on traction assistance and electrical knife type. We included 223 (EST-IT, n = 169; ESD-N, n = 54) patients with no significant differences in baseline characteristics. The operator handover rate due to ESD difficulties was significantly higher in ESD-N (ESD-IT = 0.6% vs. ESD-N = 13.0%, P = 0.001), while the injection volume was significantly higher in ESD-IT than in ESD-N (40.0 vs. 20.5 mL, P < 0.001). Other outcomes were comparable between both groups (procedural time: 51.0 vs. 49.5 minute, P = 0.89; complete resection: 90.5% vs. 90.7%, P > 0.99; and complication rate: 1.8% vs. 3.7%, P = 0.60 for ESD-IT and ESD-N, respectively). In the sub-analyses, the handover rate was significantly lower with TA-ESD than with C-ESD for ESD-N (3.2% vs. 26.1%, P = 0.034), and a significantly smaller injection volume was used in TA-ESD than in C-ESD for ESD-IT (31.5 vs. 47.0 mL, P < 0.01). ESD with either endoscopic device achieved favorable treatment outcomes with low complication rates. The handover rate in ESD-N and the injection volume in ESD-IT improved with the traction method.

Robot-assisted endoscopic submucosal dissection contributes to efficient and safe learning for novices: Prospective pilot cross-over ex vivo study (with video)

OBJECTIVES

The lack of effective countertraction to expose the submucosal layer contributes to the technical complication and adverse events in endoscopic submucosal dissection (ESD). We aimed to evaluate the efficacy and safety of a novel endoscopic robot (flexible auxiliary single-arm transluminal endoscopic robot [FASTER]) for ESD learning for novices.

METHODS

This was a prospective, cross-over designed pilot study in ex vivo porcine stomach. Four ESD novices were randomized to either FASTER-assisted ESD first (FC) group or a conventional ESD first (CF) group, performed 40 gastric ESDs using each technique, then crossed over to another technique. The performance and learning curve were compared between the two groups.

RESULTS

In the first phase, novices in the FC group demonstrated significantly better performance with shorter procedure time (25.6 ± 7.8 vs. 38.9 ± 13.4 min; P < 0.001) and submucosal dissection time (13.9 ± 5.5 vs. 23.1 ± 11.0 min; P < 0.001), higher direct-vision dissection ratio (84.0 ± 7.9% vs. 43.5 ± 20.7%; P < 0.001), and lower muscular injury (2.5 vs. 40.0%; P < 0.001) and task load (4 vs. 5; P < 0.001). Fewer ESDs were required to gain early proficiency in the FC group. When crossed to the second phase, procedure time in the FC group was prolonged but the muscular injury rate did not increase significantly. In total, endoscopists in the FC group tended to have a lower task load (4 vs. 5; P = 0.008) and less muscular injury (10.0 vs. 21.3%; P = 0.05).

CONCLUSION

Flexible auxiliary single-arm transluminal endoscopic robot-assisted learning reduces the technical difficulty of ESD for novices and the safety profile can sustain in following conventional ESD. These results indicated that FASTER has potential implications for ESD training in clinical practice.

Resection speed of endoscopic submucosal dissection according to the location of gastric neoplasia: a learning curve using cumulative sum analysis

BACKGROUND

There is few study evaluating the relationship between endoscopic submucosal dissection (ESD) resection speed and the lesion characteristics of gastric neoplasia. We investigated the learning curve of consecutive ESDs using cumulative sum (CUSUM) analysis.

METHODS

A total of 356 ESDs performed by a single endoscopist were grouped chronologically into three learning periods. The ESD procedure was defined to be fast when resection speed was > 9.0 cm²/hour. The CUSUM method was used to assess the number of ESDs required for achieving proficiency and mastery.

RESULTS

Mean resection speed was significantly faster in Phase III (15.1 cm²/hour) compared to those in Phase I (9.3 cm²/hour) and II (11.4 cm²/hour) (p < 0.001). Tumors in the stomach's upper and middle third location were significantly associated with difficulty in attaining the fast resection speed (odds ratios, 0.05 and 0.36) compared to the lower third location. The number of ESDs required to achieve a competency for fast resection was 15 for tumors in the lower third of the stomach and 98 for those in the upper/middle third location, respectively. In the lower third location of the tumor, the CUSUM curve revealed that 75 cases were needed to achieve proficiency and 174 cases to achieve mastery. However, mastery was not achieved in ESD for the upper/middle third tumor during the study period.

CONCLUSION

The time required to achieve relevant competency in gastric ESD depends on the tumor location.

Risk Factors Indicating Difficulty During Gastric Endoscopic Submucosal Dissection for Inexperienced Endoscopists: A Retrospective Study

AIM

Factors that may make endoscopic submucosal dissection (ESD) difficult for operators have been evaluated according to results based on the performance of experienced endoscopists. This study aimed to verify the predictors of difficult gastric ESD for ESD beginners.

METHODS

From January 2015 to December 2021, 466 superficial gastric neoplasms were treated with ESD at Showa University Hospital. Excluding 103 lesions that performed ESD by experts who experienced more than 80 ESDs, a total of 363 lesions were included. The lesions were divided into two groups according to the ESD performance experience of the operator: ESD beginner (EB; ESD experience≤30 cases) and ESD intermediate (EI; ESD experience 31-80 cases) groups. Relationships between difficult ESD (having at least one of the following: procedure time>60 min, incomplete resection, change of operator, and occurrence of severe complications) and clinicopathological findings of the lesion were analyzed.

RESULTS

The complete resection rates and the difficult ESD rates in the EB and EI groups were 99.3%, 94.8%, and 61.2%, 50.7%, respectively. In the EB group, univariate analysis showed that difficult ESD rate was significantly higher in the non-lower third lesions, the lesser curvature lesions, and cancerous lesions. In the EI group, univariate analysis showed that difficult ESD rate was significantly higher in lesion with ≥20 mm size, lesser curvature lesions, lesions with ulcers, and submucosal cancers. Multivariate analysis showed that the lesser curvature location and cancerous histology in the EB group and ≥20 mm lesion size, the lesser curvature location and submucosal invasion in the EI group were independent predictors of difficult ESD.

CONCLUSIONS

The lesser curvature location is recognized as independent ESD difficulty factor for both beginners and intermediates. Cases with lesions located in the lesser curvature should not be selected for gastric ESD training by beginners.

Learning curve analysis for duodenal endoscopic submucosal dissection: A single-operator experience

BACKGROUND AND AIMS

Superficial duodenal epithelial tumors are emerging targets for endoscopic submucosal dissection (ESD). However, it is unknown how competence is achieved in duodenal ESD. This study aimed to elucidate the learning curve for duodenal ESD.

METHODS

This retrospective observational study included 100 consecutive patients who underwent duodenal ESD by a single endoscopist between March 2014 and September 2021. The primary outcome was to define the learning curve for duodenal ESD by an endoscopist with sufficient non-duodenal ESD experience. Cumulative sum (CUSUM) curve analysis was used to assess the learning curve in terms of procedural speed. Comparative analyses of phases identified using the CUSUM method were performed.

RESULTS

In total, 98 patients were included in the analysis. Evaluation of the cumulative sum curve revealed four distinct phases in the graph: phase I, cases 1-25 (learning phase); phase II, cases 26-47 (proficiency phase); phase III, cases 48-72 (mastery phase); and phase IV, cases 73-98 (after introduction of general anesthesia). The median procedural speed was significantly faster in phase II than in phase I (11.1 mm² /min vs 7.0 mm² /min, P = .002). Clinically significant intraoperative perforation tended to decrease through phase II to phase IV (22.7%, 12.0%, and 3.8% in phases II, III, and IV, respectively). Delayed perforation occurred only in phases I and II.

CONCLUSIONS

Duodenal ESD requires 25 cases to gain proficiency and 50 to achieve mastery even for an endoscopist with extensive non-duodenal ESD experience.

Development of new gastric endoscopic submucosal dissection training model: A reproducibility evaluation study

Background and study aims  Gastric endoscopic submucosal dissection (ESD) is a highly technical procedure mainly due to the distinctive shape of the stomach and diverse locations of lesions. We developed a new gastric ESD training model (G-Master) that could accurately recreate the location of the stomach and assessed the reproducibility of located lesions in the model. Methods  The model comprises a simulated mucous membrane sheet made of konjac flour and a setting frame, which can simulate 11 locations of the stomach. We assessed the reproducibility of each location in the model by assessing the procedure speed and using a questionnaire that was distributed among experts. In the questionnaire, each location was scored on a six-point scale for similarity of locations. Results  The mean score for all locations was high with > 4 points. Regarding locations, lower anterior and posterior walls had medium scores with 3 to 4 points. The procedure speed was slower in the greater curvature of the upper and middle gastric portions, where ESD is considered more difficult than the overall procedure speed. Conclusions  The new gastric ESD training model appears to be highly reproducible for each gastric location and its application for training in assuming actual gastric ESD locations.

Endoscopic Treatment of Superficial Gastric Cancer: Present Status and Future

Although the mortality rates of gastric cancer (GC) are gradually declining, gastric cancer is still the fourth leading cause of cancer-related death worldwide. This may be due to the high rate of patients who are diagnosed with GC at advanced stages. However, in countries such as Japan with endoscopic screening systems, more than half of GCs are discovered at an early stage, enabling endoscopic resection (ER). Especially after the introduction of endoscopic submucosal dissection (ESD) in Japan around 2000, a high en bloc resection rate allowing pathological assessment of margin and depth has become possible. While ER is a diagnostic method of treatment and may not always be curative, it is widely accepted as standard treatment because it is less invasive than surgery and can provide an accurate diagnosis for deciding whether additional surgery is necessary. The curability of ER is currently assessed by the completeness of primary tumor removal and the possibility of lymph node metastasis. This review introduces methods, indications, and curability criteria for ER of EGC. Despite recent advances, several problems remain unsolved. This review will also outline the latest evidence concerning future issues.

Diode Laser-Can It Replace the Electrical Current Used in Endoscopic Submucosal Dissection?

BACKGROUND/AIMS

A new medical fiber-guided diode laser system (FDLS) is expected to offer high-precision cutting with simultaneous hemostasis. Thus, this study aimed to evaluate the feasibility of using the 1,940-nm FDLS to perform endoscopic submucosal dissection (ESD) in the gastrointestinal tract of an animal model.

METHODS

In this prospective animal pilot study, gastric and colorectal ESD using the FDLS was performed in ex vivo and in vivo porcine models. The completeness of en bloc resection, the procedure time, intraprocedural bleeding, histological injuries to the muscularis propria (MP) layer, and perforation were assessed.

RESULTS

The en bloc resection and perforation rates in the ex vivo study were 100% (10/10) and 10% (1/10), respectively; those in the in vivo study were 100% (4/4) and 0% for gastric ESD and 100% (4/4) and 25% (1/4) for rectal ESD, respectively. Deep MP layer injuries tended to occur more frequently in the rectal than in the gastric ESD cases, and no intraprocedural bleeding occurred in either group.

CONCLUSION

The 1,940-nm FDLS was capable of yielding high en bloc resection rates without intraprocedural bleeding during gastric and colorectal ESD in animal models.

Assistant skill in gastric endoscopic submucosal dissection using a clutch cutter

BACKGROUND

A clutch cutter is a scissor-type knife used in endoscopic submucosal dissection (ESD) for gastrointestinal tract tumors. The assistant during the ESD using a clutch cutter (ESD-C) needs to rotate the device and grasp the target tissue appropriately; therefore, the assistant's skill may affect the technical outcomes of ESD-C.

AIM

To determine how assistant skill level affected the technical outcomes of gastric ESD-C using an ex vivo porcine training model.

METHODS

In this pilot study, mock lesions of 15-30 mm in diameter were created in the middle or lower third of the porcine stomach. A total of 32 ESD-C procedures were performed by 16 trainees. Each trainee operator performed two ESD-C procedures; one ESD-C was assisted by an expert (ESD-C-E), and the other was assisted by a non-expert (ESD-C-NE). The total procedure time of the ESD was set as the primary outcome, and en bloc resection rate, complete procedure rate, perforation rate, and each procedure time/speed for mucosal incision or submucosal dissection were set as the secondary outcomes. In addition, we investigated factors associated with the difficulty of ESD including incompletion of ESD procedure, a long procedure time (≥ 20 min) or intraoperative perforation.

RESULTS

The median total procedure time of the ESD-C-E was significantly shorter than that of the ESD-C-NE (12.9 min vs 21.9 min, P = 0.001). The en bloc resection rate was 100% in both groups. Complete resection rates of the ESD-C-E and ESD-C-NE groups were 100% and 93.8%, respectively. No intraoperative perforation was observed in both groups. In the multivariate analysis, assistant skill was significantly associated with the difficulty of ESD, with the highest odds ratio of 16.5.

CONCLUSION

Assistance by an expert is an important factor when trainees perform ESD-C procedures.

Usefulness of tumor traction with a snare and endoclips in gastric submucosal tumor resection: a propensity-score-matching analysis

Background

Endoscopic resection, including endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFR), was used to resect small gastric submucosal tumors (SMTs). Our team explored a method of tumor traction using a snare combined with endoclips to assist in the resection of SMTs. This study aims to explore the safety and effectiveness of the method.

Methods

This research performed a propensity-score-matching (PSM) analysis to compare ESD/EFR assisted by a snare combined with endoclips (ESD/EFR with snare traction) with conventional ESD/EFR for the resection of gastric SMTs. Comparisons were made between the two groups, including operative time, en bloc resection rate, perioperative complications, and operation-related costs.

Results

A total of 253 patients with gastric SMTs resected between January 2012 and March 2019 were included in this study. PSM yielded 51 matched pairs. No significant differences were identified between the two groups in perioperative complications or the costs of disposable endoscopic surgical accessories. However, the ESD/EFR-with-snare-traction group had a shorter median operative time (39 vs 60 min, P = 0.005) and lower rate of en bloc resection (88.2% vs 100%, P = 0.027).

Conclusions

ESD/EFR with snare traction demonstrated a higher efficiency and en bloc resection rate for gastric SMTs, with no increases in perioperative complications and the costs of endoscopic surgical accessories. Therefore, the method seems an appropriate choice for the resection of gastric SMTs.

Introduction of gastric endoscopic submucosal dissection and skill acquisition in a regional hospital

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is standard treatment for early gastric cancer. With aging of the population in Japan being more pronounced in rural areas, the availability of ESD at regional hospitals is becoming important. Here, we assessed the learning curve of one physician for skill acquisition in gastric ESD.

METHODS

The subjects were 34 patients (38 lesions) who underwent gastric ESD at a regional hospital between October 2014 and March 2017 and 15 patients (15 lesions) who underwent the procedure at a university hospital between April 2017 and April 2018. The resection periods of the first 19 lesions and subsequent 19 lesions at the regional hospital were defined as the first and seconds periods, and the resection period of 15 lesions at the university hospital was defined as the third period. The learning curve across the three periods was assessed using the cumulative sum analysis method.

RESULTS

The resection speed in the first, second, and third periods were 6.4 ± 4.1, 6.9 ± 3.4, and 9.4 ± 5.4 mm2/min, respectively (not significant). The slope of the learning curve began to increase at the 30th patient. The en bloc resection and curative resection rates did not differ significantly among the three periods. There were no serious procedure-related complications.

CONCLUSION

This study showed that the introduction of gastric ESD at a regional hospital is possible, and that a certain skill level was acquired by the 30th patient. Furthermore, with careful patient selection, favorable results can be obtained and procedural safety ensured.

A machine learning approach to predict surgical learning curves

BACKGROUND

Contemporary surgical training programs rely on the repetition of selected surgical motor tasks. Such methodology is inherently open ended with no control on the time taken to attain a set level of proficiency, given the trainees' intrinsic differences in initial skill levels and learning abilities. Hence, an efficient training program should aim at tailoring the surgical training protocols to each trainee. In this regard, a predictive model using information from the initial learning stage to predict learning curve characteristics should facilitate the whole surgical training process.

METHODS

This paper analyzes learning curve data to train a multivariate supervised machine learning model. One factor is extracted to define the trainees' learning ability. An unsupervised machine learning model is also utilized for trainee classification. When established, the model can predict robustly the learning curve characteristics based on the first few trials.

RESULTS

We show that the information present in the first 10 trials of surgical tasks can be utilized to predict the number of trials required to achieve proficiency (R²=0.72) and the final performance level (R²=0.89). Furthermore, only a single factor, learning index, is required to describe the learning process and to classify learners with unique learning characteristics.

CONCLUSION

Using machine learning models, we show, for the first time, that the first few trials contain sufficient information to predict learning curve characteristics and that a single factor can capture the complex learning behavior. Using such models holds the potential for personalization of training regimens, leading to greater efficiency and lower costs.

Gastric endoscopic submucosal dissection: a systematic review and meta-analysis on risk factors for poor short-term outcomes

OBJECTIVE

Endoscopic submucosal dissection (ESD) is now established as the first option to manage early gastric neoplasms, but its efficacy may vary according to diverse factors. We aimed to systematically identify risk factors for poor short-term outcomes of gastric ESD with the purpose to improve patients' selection and management.

METHODS

Three online databases (MEDLINE, ISI Web of Knowledge and Scopus) were searched (last search on June 2018) for poor outcomes of gastric ESD (deep submucosal invasion, piecemeal/incomplete resection, noncurative resection and local recurrence).

RESULTS

One hundred five studies were included referring to 52.126 ESDs. Undifferentiated histology and upper location (vs lower) were associated with submucosal invasion [odds ratio (OR) = 2.42 [95% confidence interval (CI), 1.62-3.61] and OR = 3.20 (1.04-9.86), respectively] and deep submucosal invasion [OR = 2.98 (2.02-4.39) and OR = 2.35 (1.45-3.81), respectively]. Lesion size greater than 30 mm and ulceration were associated with piecemeal resection [OR = 2.78 (1.17-6.60) and OR = 2.76 (1.23, 6.20), respectively]. Lesion size greater than 30 mm, ulceration, upper location and fibrosis were risk factors for incomplete resection [OR = 3.83 (2.68-5.49), OR = 4.06 (1.62-10.16), OR = 3.71 (2.49-5.54) and OR = 4.46 (1.66-11.96), respectively]. A noncurative resection was more often observed for lesions located in the upper third of the stomach [OR = 1.49 (1.24-1.79)], depressed morphology [OR = 1.49 (1.04-2.12)] and those outside standard criteria [OR = 3.56 (2.31-5.48)]. Older age was significantly linked with local recurrence rates [OR = 3.08 (1.13-5.02)].

CONCLUSION

Several risk factors influence poor efficacy short-term outcomes of gastric ESD that may be used to inform both patients and health providers about the expected efficacy.

Learning Curve for Open Reduction and Internal Fixation of Displaced Intra-articular Calcaneal Fracture by Extensile Lateral Approach Using the Cumulative Summation Control Chart

BACKGROUND

Open reduction and internal fixation (ORIF) of displaced intra-articular calcaneal fracture (DIACF) by extensile lateral approach is widely used but is technically challenging. In this study, the learning curve for ORIF of DIACF by extensile lateral approach was investigated.

METHODS

Between March 2014 and July 2018, 45 cases consisting of 40 patients underwent operative treatment for DIACF by the extensile lateral approach performed in all instances by a single surgeon. A moving average and cumulative summation control chart (CUSUM) were used for learning curve analyses. Operative failure was defined when at least 1 of the following parameters were unsatisfactory: reduction of Gissane angle and Böhler angle, posterior facet congruency, calcaneal width, subfibular impingement, axial alignment, or calcaneocuboid joint congruency.

RESULTS

The mean operating time was 117.4 minutes. Regarding the quality of reduction, the mean preoperative sum of the 7 parameters was 5.1 and improved to 0.6 postoperatively. The CUSUM for operative success peaked in the 20th case. The CUSUM and moving average graphics of operating time peaked at the 9th case and registered nadirs at the 34th case, with slight ascent and decent. The operating time for 20 cases in phase 1 (1-20) and for 25 cases in phase 2 (21-45) of the learning curve did not differ significantly. There was no statistical difference in the severity of fracture pattern. By comparison, in phase 2, patients showed a significantly better postoperative reduction quality.

CONCLUSION

As indicated by multidimensional statistical analyses, primary technical competence in improving the reduction quality of DIACF was achieved after the initial learning period with 20 cases. After the learning curve for ORIF of DIACF, a better reduction quality in the sum of reduction parameters was observed.

LEVEL OF EVIDENCE

Level III, comparative series.

Learning Curve Analysis of Open Kasai Portoenterostomy for Biliary Atresia

BACKGROUND

Open Kasai portoenterostomy (KPE) remains the mainstay of treatment for biliary atresia (BA) even in the era of minimally invasive surgery and is generally considered to be technically challenging. This study describes the learning curve (LC) of open KPE and its effect on outcomes.

MATERIALS AND METHODS

In our center, the caseload of BA was relatively low with average annual caseload below five in the past, and open KPE was started in the early 2000s. This study retrospectively enrolled the first 35 consecutive children undergoing open KPE for BA by the same surgeon in our center between June 2003 and April 2014. The LC was evaluated using the cumulative sum (CUSUM) method for operative time (OT).

RESULTS

The CUSUM LC of OT, which peaked at the 23rd case, was best modeled as a second-order polynomial with equation CUSUM (min) = -0.8851 × case number² + 33.54 × case number -45.978 (R² = 0.7287). The LC consisted of two distinct phases: phase 1 (the initial 23 cases), representing the initial learning phase and phase 2 (the remaining 12 cases), representing acquisition of technical competency. Preoperative parameters were comparable between the two phases (each P > 0.05). Of note, OT and estimated blood loss significantly decreased in phase 2 compared with phase 1 (P < 0.001; P < 0.001, respectively). Furthermore, the rates of early jaundice clearance and 2-y native liver survival significantly increased in phase 2 (P = 0.032; P = 0.034, respectively).

CONCLUSIONS

The two phases identified by CUSUM analysis of OT represents characteristic stages of LC for open KPE of the surgeon in our center. It is possible for surgeons to achieve competency of this demanding technique in centers with relatively low caseload of BA and late start of KPE.

Clutch Cutter knife efficacy in endoscopic submucosal dissection for early gastric neoplasms

AIM

To compare the outcomes of endoscopic submucosal dissection (ESD) for gastric neoplasms using Clutch Cutter (ESD-C) or other knives (ESD-O).

METHODS

This was a single-center retrospective study. Gastric neoplasms treated by ESD between April 2016 and October 2017 at Kitakyushu Municipal Medical Center were reviewed. Multivariate analyses and propensity score matching were used to reduce biases. Covariates included factors that might affect outcomes of ESD, including age, sex, underlying disease, anti-thrombotic drugs use, tumor location, tumor position, tumor size, tumor depth, tumor morphology, tumor histology, ulcer (scar), and operator skill. The treatment outcomes were compared among two groups. The primary outcome was ESD procedure time. Secondary outcomes were en bloc, complete, and curative resection rates, and adverse events rates including perforation and delayed bleeding.

RESULTS

A total of 155 patients were included in this study; 44 pairs were created by propensity score matching. Background characteristics were quite similar among two groups after matching. Procedure time was significantly shorter for ESD-C (median; 49 min) than for ESD-O (median; 88.5 min) (P < 0.01). However, there was no significant difference in treatment outcomes between ESD-C and ESD-O including en bloc resection rate (100% in both groups), complete resection rate (100% in both groups), curative resection rate (86.4% vs 88.6%, P = 0.730), delayed bleeding (2.3% vs 6.8%, P = 0.62) and perforation (0% in both groups).

CONCLUSION

ESD-C achieved shorter procedure time without an increase in complication risk. Therefore, ESD-C could become an effective ESD option for gastric neoplasms.

Propensity score-matching analysis to compare clinical outcomes of endoscopic submucosal dissection for early gastric cancer in the postoperative and non-operative stomachs

Background

Endoscopic submucosal dissection (ESD) of the postoperative stomach (ESD-P) for early gastric cancer (EGC) is considered a technically difficult procedure. However, it is difficult to compare the outcomes of ESD-P and ESD of the non-operative stomach (ESD-N) because their baseline characteristics are different. Therefore, we aimed to compare the technical outcomes of ESD-P with those of ESD-N using a propensity score-matching analysis to compensate for the differences.

Methods

The chart records of 1046 patients with EGC who were treated with ESD between January 2004 and July 2016 at Kitakyushu Municipal Medical Center in Japan were reviewed in this retrospective study. Multivariate analyses and propensity score-matching were performed for age, sex, lesion location, lesion size, tumor invasion, tumor size, ulcer (scar), and operator skill. The primary outcome was procedure time. Secondary outcomes were percentages of en bloc, complete, and curative resections, and percentages of adverse events, which were evaluated between the two groups.

Results

Forty-one patients were in the ESD-P group and 1005 patients were in the ESD-N group. Propensity score-matching created 41 matched pairs. According to the adjusted comparisons, ESD-P required a significantly longer procedure time (85 min vs 51 min, p < 0.001). Other treatment outcomes showed an en bloc resection rate of 100% for both groups (p = 1) and complete resection rates of 95.1 and 97.6% (p = 1), curative resection rates of 90.2 and 90.2% (p = 1), perforation during ESD rates of 2.4 and 0% (p = 1), and postprocedure bleeding rates of 2.4 and 2.4% (p = 1) for the ESD-P and ESD-N groups, respectively. For the ESD-P group, lesions on the suture line or anastomotic site were significantly associated with longer procedure times (p = 0.038).

Conclusions

ESD-P was a more time-consuming procedure than ESD-N. However, ESD-P and ESD-N achieved high rates of curative resection with a low rate of adverse events for the treatment of EGC. ESD could be selected as the treatment for EGC even in the postoperative stomach provided that careful attention is given to lesions on the suture line or anastomotic site.

Splash M-knife versus Flush Knife BT in the technical outcomes of endoscopic submucosal dissection for early gastric cancer: a propensity score matching analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer. A new multi-functional ESD device was developed to achieve complete ESD with a single device. A metal plate attached to its distal sheath achieves better hemostasis during the procedure than the other needle-knife device, Flush Knife BT®, that has been conventionally used. The aim of this study was to compare the technical outcomes of ESD for early gastric cancer using the Splash M-Knife® with those using the Flush Knife BT.

METHODS

We conducted a retrospective review of the case records of 149 patients with early gastric cancer treated with ESD using the needle-type ESD knives between January 2012 and August 2016 at Kitakyushu Municipal Medical Center. Lesions treated with ESD using the Splash M-knife (ESD-M) and the Flush Knife BT (ESD-F) were compared. Multivariate analyses and propensity score matching were used to compensate for the differences in age, gender, underlying disease, antithrombotic drug use, lesion location, lesion position, macroscopic type, tumor size, presence of ulceration, operator level and types of electrosurgical unit used. The primary endpoint was the requirement to use hemostatic forceps in the two groups. The secondary endpoints of procedure time, en bloc and complete resection rates, and adverse events rates were evaluated for the two groups.

RESULTS

There were 73 patients in the ESD-M group, and 76 patients in the ESD-F group. Propensity score matching analysis created 45 matched pairs. Adjusted comparisons between the two groups showed a significantly lower usage rate of hemostatic forceps in the ESD-M group than in the ESD-F group (6.7% vs 84.4%, p < 0.001). Treatment outcomes showed an en bloc resection rate of 100% in both groups; complete resection rate of 95.6% vs 100%, p = 0.49; median procedure time of 74.0 min vs 71.0 min, p = 0.90; post-procedure bleeding of 2.2% vs 2.2%, p = 1, in the ESD-M and ESD-F groups, respectively. There were no perforations in either group.

CONCLUSIONS

ESD-M appeared to reduce the usage of hemostatic forceps during ESD for early gastric cancer without increasing the adverse effects. Thus, it may contribute to a reduction in the total ESD cost.

Evaluation of endoscopic submucosal dissection using a new endosurgical knife DN-D2718B: a first clinical feasibility study

BACKGROUND AND STUDY AIMS

Endosurgical devices with injection function have been reported to decrease endoscopic submucosal dissection (ESD) operation times for experts, but the efficacy of these devices for inexperienced endoscopists is unclear. The aim of this study was to evaluate the feasibility of ESD using a novel ESD knife (DN-D2718B).

PATIENTS AND METHODS

This is a single-center prospective pilot clinical feasibility study. Patients diagnosed with superficial gastrointestinal neoplasms were enrolled. A pre-specified group of ESD trainees with ESD experience on a porcine gastric model and fewer than 30 cases of ESD in their selected fields performed ESD under expert supervision, using the DN-D2718B. En bloc resection rates, R0 resection rates, procedure times, and incidence of intra-operational/post-operational adverse events were assessed.

RESULTS

Between June 2015 and January 2016, 13 esophageal, 27 gastric, and 14 colorectal ESD cases were performed per-protocol with mean resection speeds of 10.2, 12.0, and 15.5 mm 2 /min, respectively. There were no intra-operational complications.

CONCLUSION

ESD with this novel knife is feasible even when performed by non-experts.

Concomitant stromal tumor and early cancer of the stomach: What should be done?

Concomitant gastric stromal tumor (GST) and gastric cancer (GC) is uncommon; even more uncommon is a concomitant GST and early stage GC (EGC). Tumor resection by endoscopic submucosal dissection (ESD) for concomitant GST and EGC has not been reported. We sought to define the clinical importance of detection of concomitant GST and EGC during the first esophagogastroduodenoscopy (EGD), and compare the clinical outcomes of ESD versus radical surgery for the treatment of concomitant GST and EGC. Our investigation was a retrospective cohort study. Patients with concomitant GST and EGC who underwent ESD or radical surgery were enrolled at the university-affiliated hospital from January 2005 to January 2015. The detection rate of concomitant GST and EGC during the first EGD was 3/25 (12%). Among 25 patients, 14 underwent ESD and 11 underwent surgery. Mean operation time and hospital stay were significantly shorter in the ESD group than the surgery group. There were no significant differences in terms of rates of en bloc resection, complete resection, and early complications. Late complications were more common in the surgery group than in the ESD group. The median follow-up duration was 58.9 months. Three- or 5-year overall survival rates were 100% for both groups and no patient died of EGC and GST. There was no local recurrence in the 2 groups; however, 3 metachronous EGC lesions were found during the follow-up period in the ESD group as follows: the simultaneous occurrence of GST and EGC was uncommon; the detection rate of concomitant GST and EGC was very low at the first EGD; and ESD appeared to be a safe, efficient, and popular treatment option for concomitant GST and EGC, that met the ESD absolute indication, and the outcomes were comparable to those achieved with surgery.