“Snare-ectomy” of an early carcinoma in the cardia – a landmark for therapeutic endoscopy

From its early beginnings endoscopy represented a quantum leap in diagnosis because of its ability to visualize a target lesion, and its reliability soon increased once it became possible to obtain tissue samples for histological evaluation. However until, at most, 50 years ago endoscopy was not reliable enough for therapeutic purposes as its limited visibility and maneuverability precluded any attempt at precise therapy.

Thus, “Therapeutic snare-ectomy of an early carcinoma in the cardia” by Henke & Ottenjann [1], published in Endoscopy in 1973, was a landmark case report of endoscopic resection of early gastric cancer. The procedure itself, “endoscopic snare-ectomy,” was quite simple, being what we would now call “piecemeal polypectomy.” However, it must have been very challenging and stressful at that time, without any precedent case or sufficient and appropriate equipment. It is readily understandable that everyone involved was afraid of serious complications such as massive bleeding and perforation. Therefore, a cautious approach was adopted that involved removing the entire lesion in three sessions spread over 3 weeks; this for a semipedunculated lesion that nowadays would be considered to be easily removable in a single session [2]. Nevertheless, as the authors mention, endoscopic resection was considered to be a far better option compared to “operative biopsy” or surgical resection, especially for this elderly person with some co-morbidity.

Looking back at the history of endoscopic resection, mechanical resection of gastric polyps using a steel wire was initially reported by Tsuneoka in 1968. Subsequently, Niwa introduced the use of high frequency current for smooth resection of polypoid lesions in 1969. Later, in 1971, Shinya first reported colon snare polypectomy in the U.S. and Deyhle also reported colon polypectomy in Germany. Furthermore, in 1973, Deyhle described a new endoscopic resection technique consisting of submucosal injection and snaring that was very similar to current EMR techniques [3]. The injection of solution into the submucosal layer would reduce vertical margin positivity rates and the burning effect of diathermy on the muscle layer. However it was too early to introduce this technique more widely since it was regarded as a risky procedure in the colon at that time.

In contrast, endoscopic resection of early gastric cancers and premalignant lesions was eagerly awaited by many endoscopists because of the high incidence of gastric cancer and its poor prognosis in the early 1970 s. Especially in Japan, where the incidence of gastric cancer was extremely high, early detection and early treatment of gastric cancer was considered to be a priority. Therefore, endoscopic diagnosis of early gastric cancers was highly developed in Japan and various endoscopic resection techniques, including strip biopsy and endoscopic mucosal resection with a cap-fitted panendoscope (EMRC), were developed in the 1980 s and 1990 s. Most of these techniques could be used to resect much bigger lesions than polypectomy and were available even for flat and depressed lesions. Essentially, target lesions for EMR were theoretically early gastric cancers with a negligible risk of lymph node metastasis and technically amenable, in terms of size and location, to en bloc resection. Thus, in the past, actual targets were relatively small (< 2 cm) differentiated-type mucosal cancers. Unfortunately, resections frequently became piecemeal and en bloc resection rates for 1 – 2-cm lesions were around 40 % – 60 %.

A new endoscopic resection technique consisting of mucosal incision and submucosal dissection was developed to solve this problem. As this technique did not use a snare wire, there was no limitation in terms of the size of the lesion. Alongside this, the scenarios of early gastric cancers with negligible risk for lymph node metastasis became evident through retrospective analysis of more than 5000 surgically treated cases [4]. As a result, the use of this new technique spread all over Japan more rapidly than expected. Clinical results were excellent even though we treated much larger and more technically difficult lesions with expanded indications [5]. Since the technique itself was completely different and the clinical results were far better than with EMR, in 2003 this technique was termed “endoscopic submucosal dissection” (ESD).

Currently more than 48 000 gastric ESDs are performed per year and the numbers of esophageal and colorectal ESDs are also steadily increasing in Japan. And the long-term outcomes of ESD are very good, even for colonic lesions [6]. Because of the perceived significant advantages of this procedure, ESD is now regarded as the standard treatment option for early gastric cancer in Western countries also; however, it is still controversial with regard to early esophageal and colorectal cancers, because of the technical difficulties and longer procedure times. Although the demand for ESD is rapidly increasing in many countries, an appropriately structured training system is necessary to establish ESD in the West.

Reviewing the history of diagnostic and therapeutic endoscopy, an innovation happens every 15 – 20 years. Therefore, new revolutionizing technology might be emerging that will create a further step change in the near future. For example, artificial intelligence (AI) holds promise for automated detection and evaluation of target lesions. However, in the use of AI for therapeutic endoscopy continues to be challenging and difficult. Therefore, ESD might remain in the mainstream for a while, until the next big wave of innovation in therapeutic endoscopy. Nevertheless, classical polypectomy and EMR continue to serve as standard of care for smaller lesions, especially in the colon and duodenum, because of their cost – effectiveness and favorable risk – benefit ratio.

Fig. 1 Advanced endoscopic resection. There are two main types of endoscopic resection for mucosal and slightly submucosal invasive lesions: endoscopic mucosal resection (EMR) (panel A) and endoscopic submucosal dissection (ESD) (panel B). Both resection techniques allow removing the lesion in one piece (i. e. in toto). Furthermore, a complete or curative resection (i. e. surgical R0) with free lateral and vertical margins is possible when using EMR or ESD. Notice that by using a submucosal cushion removal of the lifted lesion becomes easier and safer. Illustration: Michal Rössler

• References

• 1 Henke M, Ottenjann R. Therapeutic snare-ectomy of an early carcinoma in the cardia. Endoscopy 1973; 5: 225-228
• 2 Kakushima N, Yahagi N, Fujishiro M. et al. Efficacy and safety of endoscopic submucosal dissection for tumors of esophagogastric junction. Endoscopy 2006; 38: 170-174
• 3 Deyhle P, Largiadèr F, Jenny S. et al. A method for endoscopic electroresection of sessile polyps. Endoscopy 1973; 5: 38-40
• 4 Gotoda T, Yanagisawa A, Sasako M. et al. Incidence of lymph node metastasis from early gastric cancer: estimation with a large number of cases at two large centers. Gastric Cancer 2000; 3: 219-225
• 5 Ono H, Kondo H, Gotoda T. et al. Endoscopic mucosal resection for treatment of early gastric cancer. Gut 2001; 48: 225-229
• 6 Yamada M, Saito Y, Takamaru H. et al. Long-term clinical outcomes of endoscopic submucosal dissection for colorectal neoplasms in 423 cases: a retrospective study. Endoscopy 2017; 49: 233-242