Endoscopy 2016; 48(08): 697-698
DOI: 10.1055/s-0042-110399
Editorial
© Georg Thieme Verlag KG Stuttgart · New York

How can we make the learning curve of endoscopic submucosal dissection for (Western) endoscopists less steep?

Alanna Ebigbo
Department of Gastroenterology, Klinikum Augsburg, Germany
,
Helmut Messmann
Department of Gastroenterology, Klinikum Augsburg, Germany
› Author Affiliations
Further Information

Publication History

Publication Date:
26 July 2016 (online)

Endoscopic submucosal dissection (ESD) is a difficult-to-learn method for the treatment and resection of early gastrointestinal cancers and precancerous lesions. In the hands of an expert, ESD is a highly efficient means of achieving complete en bloc resection, producing impressive rates of curative R0 resection coupled with low recurrence and complication rates, especially when compared with standard methods such as endoscopic mucosal resection [1].

However, the very high level of skill, dedication, and know-how required renders ESD not only difficult to learn, but also makes it difficult to achieve a high level of proficiency and expertise. The technical requirements and personal abilities involved in performing ESD at an expert level refer not only to the endoscopy expert performing the procedure but also to the assisting staff and the institution as a whole.

The ESD technique and technical specification were developed in Japan, and Asian endoscopists, particularly those from Japan, Korea, and China, remain the pacesetters in this field [2] [3]. Nevertheless, Western endoscopists have since recognized the significance of ESD, and with the aid and assistance of Asian colleagues, high levels of expertise have now been achieved in various centers in the Western world [4] [5].

At our center in Augsburg, Germany, ESD expertise was initially achieved in an untutored learning-by-doing manner, although intermittent on-site supervision by Japanese experts was possible. However, although all relevant parameters of competence (en bloc resection rate, procedure time, and complication rate) improved significantly between 2004 and 2012, the improvement was gradual and the learning curve was tedious [6] [7].

Today, the training of second-generation ESD interventionists at our center includes a step-up approach based on recommendations of Japanese experts [4] [8]. However, owing to the low rate of ESD cases in the lower stomach compared with rates in Japan, most of our teaching interventions are performed in the rectum. At our center, a total of about 850 ESD interventions have been performed in the past 10 years, of which about 45 % were performed in the rectum.

The first step includes observation of expert ESD procedures and image training. After observation of about 30 human cases, the trainee begins technical training in the porcine stomach. Various centers in Europe offer ESD hands-on courses in the porcine stomach. Worthy of mention is the Salzburg ESD Workshop, where a small group of trainees perform live piglet ESD under the direct supervision of both Japanese and Western experts [9]. Hereafter, ESD under expert supervision, starting in the gastric antrum and rectum, is allowed, after which independent ESD interventions can be performed. By adopting this step-by-step approach involving constant expert supervision, faster proficiency can be achieved. After passing through these steps, our trainee was able to perform the first 30 ESDs in the rectum and lower stomach, with an excellent en bloc resection rate and low complication rate.

In this issue of Endoscopy, Bhatt et al. [10] report on the use of video-based supervision for learning and training of basic ESD. In their paper, ESD technique was successfully learned from scratch by two endoscopists after only a basic theoretical introduction by an expert. ESD procedures were video recorded and then assessed by a Japanese expert, who made technical suggestions and correctional comments. The authors then nicely demonstrated improvement in both efficiency as well as complication rate in the ESD procedures performed on the ex vivo porcine stomach. The authors attribute the recorded improvement to the video-based corrections and suggestions made by the Japanese expert after each ESD procedure. Trainees then implemented these suggestions and corrections during the next ESD.

In our opinion, certain important principles for achievement of basic technical ESD ability were taken into consideration.

  1. Trainees first received basic theoretical ESD know-how (basic steps, equipment, technique, pitfalls) by an expert before hands-on training.

  2. Hands-on training was first performed on a porcine model. A point of interest could be the difference between training on live piglets as opposed to the ex-vivo training demonstrated by Bhatt et al. On the one hand, live piglet stomachs better simulate the real situation and give the trainee more opportunity to face bleeding complications and perform hemostasis. Blood clotting inhibitors can be injected, thereby increasing the likelihood and strength of bleeding, making it necessary to apply instruments such as the Coagrasper or hemoclips. On the other hand, basic ESD technique on its own is very complex, involves endoscopic techniques not usually used in other procedures, and as such, basic steps of cutting and dissection need to be understood in a practical sense before complication management is approached.

  3. Feedback and suggestions for improvements were given frequently by an expert in between procedures, hereby giving trainees ample time to first understand the errors or omissions made and then to implement corrections during the next procedure.

The novel aspect behind this approach to learning basic ESD techniques is the video-based supervision by a Japanese expert. Bhatt et al. have shown that this approach may be a reasonable alternative, especially in a setting where direct and immediate expert supervision is not possible. However, it is worth noting that trainees in the Bhatt et al. study were able to perform porcine ESD with a satisfactory frequency of at least every 2 weeks, enabling a steady learning curve; in addition, expert advice was timely and systematic. This may not always be feasible in a normal setting. Secondly, as the authors rightly point out, the transition from porcine to human ESD is a long and difficult stage, and should be accompanied by an expert. Due to various reasons mentioned in the article, ESD procedures carried out efficiently on the porcine stomach convey only initial abilities toward proficiency in real-life human cases.

The theoretical principles of ESD are easily understood, the basic ability of cutting and dissection may follow more or less quickly depending on the trainee’s talent. However, certain subtle points are often only grasped in a real-life setting. Faced with the task of reaching the submucosal space, Western endoscopists performing ESD often overlook details such as the pull of gravity or the principle of tissue traction. The correct position of the patient and, if necessary, the simple repositioning of the patient during the course of a procedure, often makes the difference. In addition, the complete circumferential mucosal incision without proper penetration into the submucosal space may lead to premature loss of tissue traction. Japanese experts are often observed performing a pocket first or a proper one-sided submucosal dissection before completing circumferential cutting. These simple principles are best explained to a trainee during a procedure.

The idea of creating a strategy and following a logical plan is often propagated by Japanese experts. It may be possible to train such strategic points in human cases using a video-based approached. The video-assisted training principles demonstrated by Bhatt et al. could very well be extended to real-life cases. Video recordings of lesions could be discussed with an expert before ESD is performed. Suggestions for strategy and a dissection plan can be made together with the expert before the procedure is performed. Then, video recording of the procedure can be discussed with the expert with the aim of implementing corrections and strategic suggestions during the next ESD.

Before the basic techniques of ESD are learned, trainees must be aware that further expertise in human cases can only be achieved by frequent and continuous practice. In our opinion, ESD should be performed at least once a week in order to have a continuous learning curve without unnecessary drops in competency due to low practice frequency. Therefore, ESD techniques are probably best learned by endoscopists in high-volume centers, with a sufficient number of cases being encountered to further their expertise in the real-life human setting.

In summary, Bhatt et al. were able to demonstrate efficient training of the basic ESD technique using video-based supervision. In the correct setting and with the necessary infrastructure, this method of ESD training could serve as an alternative to a hands-on workshop with experts. After acquisition of basic ESD skill, video-based supervision of real-life cases could further increase expertise, especially in a setting where immediate and on-site supervision is not possible.

 
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