Duodenal endoscopic submucosal dissection (ESD) is technically difficult due to the unique anatomic features. The risks include intraprocedural complications, delayed bleeding, and perforation. A small-caliber-tip transparent hood is useful. Mechanical stretching of the submucosal tissue allows safe dissection and effective prevention of bleeding with minimum muscle injury under direct visualization of the submucosal tissue and blood vessels. A short double-balloon endoscope is useful to stabilize control of the endoscope tip in distal duodenal ESD. Selection of ESD in the duodenum should be made cautiously considering both benefits and risks of the procedure.
Key points
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Duodenal endoscopic submucosal dissection (ESD) is technically difficult due to insufficient mucosal elevation and poor mucosal contraction.
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In duodenal ESD, abundant blood vessels in the submucosal layer and thin muscle layer pose a serious risk of bleeding and perforation.
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Selection of ESD in the duodenum should be made cautiously with full consideration of difficulties and risks.
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Minimize thermal injury to the muscle layer to avoid delayed perforation.
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Tunneling method with an ST hood is recommended in duodenal ESD.
Video of endoscopic submucosal dissection for early duodenal cancer accompanies this article
Introduction
Endoscopic submucosal dissection (ESD) has been recognized as an advanced endoscopic resection technique effective at achieving en bloc resection of superficial neoplastic lesions. En bloc resection of a large superficial gastric neoplasm without resorting to snaring was first reported by Yamamoto and colleagues in 2001. Initial indication of ESD was mainly focused on gastric lesions. Since then, its use has gradually spread to other parts of the gastrointestinal (GI) tract, including the esophagus and colorectum. However, duodenal ESD is still considered a difficult procedure with a high risk. Even in Japan, where ESD was developed, duodenal ESD is performed only in a small number of institutions by endoscopists who possess advanced skill and experience in ESD.
Superficial duodenal neoplasms without lymph node metastasis can be cured by endoscopic resection. Although endoscopic mucosal resection of duodenal neoplasms was first described in 1992, it remains a difficult procedure. Technically, duodenal ESD is considered even more difficult. Although several reports of successful ESD for duodenal lesions have been published, application of ESD to duodenal lesions should be prudently selected, knowing that the duodenum is the most difficult and risky place for performing ESD in the GI tract.
This article describes ESD techniques applicable to duodenal lesions.
Introduction
Endoscopic submucosal dissection (ESD) has been recognized as an advanced endoscopic resection technique effective at achieving en bloc resection of superficial neoplastic lesions. En bloc resection of a large superficial gastric neoplasm without resorting to snaring was first reported by Yamamoto and colleagues in 2001. Initial indication of ESD was mainly focused on gastric lesions. Since then, its use has gradually spread to other parts of the gastrointestinal (GI) tract, including the esophagus and colorectum. However, duodenal ESD is still considered a difficult procedure with a high risk. Even in Japan, where ESD was developed, duodenal ESD is performed only in a small number of institutions by endoscopists who possess advanced skill and experience in ESD.
Superficial duodenal neoplasms without lymph node metastasis can be cured by endoscopic resection. Although endoscopic mucosal resection of duodenal neoplasms was first described in 1992, it remains a difficult procedure. Technically, duodenal ESD is considered even more difficult. Although several reports of successful ESD for duodenal lesions have been published, application of ESD to duodenal lesions should be prudently selected, knowing that the duodenum is the most difficult and risky place for performing ESD in the GI tract.
This article describes ESD techniques applicable to duodenal lesions.
Factors of difficulty in duodenal ESD
Anatomic Features
The duodenal wall consists of the mucosal, submucosal, proper muscle, and serosal layers, similar to other areas of the GI tract. However, the posterior wall lacks the serosal layer.
The proper muscle layer of the duodenum is very thin and soft. It is even thinner than in the esophagus and colorectum. Therefore, the duodenal wall is prone to perforation by submucosal dissection technique. Just by exposing the muscle layer on the posterior wall, without obvious perforation, insufflation can cause air leak to the retroperitoneal space through the thin muscle layer.
Risk of delayed perforation is also high in the duodenum, probably due to the thin muscle layer and the hazardous effect of duodenal contents (mainly bile and pancreatic juice). Therefore, submucosal dissection should be performed with minimal thermal injury to the muscle layer and by leaving a thin layer of submucosal tissue on the surface of the muscle layer.
The submucosal tissue of the duodenum is coarse compared with that of the esophagus and colorectum. In the duodenal bulb, adequate mucosal elevation by submucosal injection is often difficult to obtain. This is most likely due to the presence of dense Brunner glands, which make dissection difficult.
In the second and third portion of the duodenum, good mucosal protrusion is usually created by submucosal injection with relative ease. However, it quickly disperses after mucosal incision. Therefore, it is difficult to maintain sufficient submucosal thickening during the ESD procedure in the duodenum.
In addition, blood vessels are abundant in the duodenal submucosal layer. Therefore, it is often difficult to control bleeding during submucosal dissection.
The duodenal mucosal layer also has a unique feature different from other parts of the GI tract. In the esophagus, stomach, and colorectum, mucosa shrinks after incision, resulting in the opening of the wound exposing the submucosal layer. However, duodenal mucosa does not shrink after incision. Therefore, it is difficult to expose the submucosal layer after mucosal incision.
In the second portion of the duodenum, there exist the major and minor papillae. Imprudent or accidental injuries to the papilla can cause pancreatitis. Therefore, the major and minor papillae should be identified to clarify their involvement or proximity to the lesion before starting ESD in the second portion of the duodenum.
All the above-mentioned anatomic features of the duodenum make duodenal ESD technically challenging.
Endoscopic Maneuverability
The duodenum is anatomically fixed in the retroperitoneum. However, endoscopic control in the duodenum is often poor, unstable, and sometimes paradoxic, due to free flexure of endoscope shaft in the wide lumen of the stomach. It is difficult for endoscopists to maintain the proper distance between the tip of the endoscope and the duodenal lesion because of poor control of the flexible endoscope. Rotation of the endoscope shaft to the left can easily cause unintentional withdrawal of the endoscope tip.
Selection of ESD in the Duodenum
Selection of ESD in the duodenum should be made cautiously, with full consideration of the above-mentioned difficulties and risks. However, en bloc R0 resection (complete resection with no microscopic residual tumor) achievable with ESD is also appealing in the duodenum. Using ESD, en bloc R0 resection is achievable even for large flat lesions ( Fig. 1 ) or lesions with some fibrosis due to minute submucosal invasion or biopsy scars ( Fig. 2 ). Recurrent lesions after piecemeal endoscopic mucosal resection could make endoscopic resection even more difficult. Surgical resection procedures for duodenal lesions are complicated and invasive. As long as the procedure is performed reliably and safely, ESD is beneficial for patients, even in the duodenum.
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