Endoscopic Submucosal Dissection of Non-Polypoid Colorectal Neoplasms
Section snippets
Indications for colorectal ESD
The indication for colorectal ESD at the National Cancer Center Hospital (NCCH) in Tokyo, Japan, is a nongranular type LST (LST-NG) larger than 20 mm.12
Based on clinicopathologic analyses of LSTs,4, 16 LST-NGs, which are large (>1 cm) superficial elevated NP-CRNs with a smooth surface, have a higher rate of submucosal (sm) invasion, which can be difficult to predict endoscopically. About 30% of LST-NGs with sm invasions are multifocal, and such invasions are primarily superficial submucosal
Estimation of the depth of invasion
A non-invasive pattern17, 18 should be verified in each lesion, indicating suitability for EMR or ESD: the estimated invasion depth should be less than that of superficial submucosal cancers (sm1s). No biopsy is performed before ESD because it can cause fibrosis and may interfere with submucosal lifting.
Cessation period of anticoagulant and antiplatelet before ESD
ESD is considered to be a high-risk procedure.19 Most patients receiving aspirin or ticlopidine alone underwent ESD after a cessation period of 5 to 7 days and restarted the drugs after 7 days if possible. Patients receiving warfarin used intravenous heparin or subcutaneous low-molecular-weight heparin in the perioperative period and resumed warfarin after the ESD procedure.
ESD procedure at NCCH
The procedures were primarily performed using a ball-tip bipolar needle knife (B-knife) (XEMEX Co, Tokyo Japan) (Fig. 1A)20 and an insulation-tip (IT) electrosurgical knife (Olympus Optical Co, Tokyo, Japan) (see Fig. 1B) with carbon dioxide insufflations instead of air insufflation to reduce patient discomfort (see Fig. 1C).11 After submucosal injection of 10% glycerin and 5% fructose (Glyceol, Chugai Pharmaceutical Co, Tokyo, Japan)21 and 0.4% hyaluronic acid14 (MucoUp, Seikakagu Co, Tokyo,
Submucosal injection solution
A mixture of 2 solutions was prepared before the procedure to create a longer-lasting sm fluid cushion.
Solution 1: Indigo carmine dye (2 mL of 1% solution) and epinephrine (1 mL of 0.1% solution) were mixed with 200 mL Glyceol21 in a container, which was then drawn into a 5-mL disposable syringe.
Solution 2: MucoUp was drawn into another 5-mL syringe with a smaller amount of indigo carmine dye and epinephrine. During the actual ESD procedure, a small amount of solution 1 was injected into the sm
Detailed colorectal ESD procedures
- 1.
The margins of the lesion were delineated before ESD by spraying 0.4% indigo carmine dye (Fig. 2A). After creation of the submucosal fluid cushion, an initial incision was made with the B-knife at the oral side of the lesion (see Fig. 2B).20 In colorectal cases, it was not necessary to actually mark around lesions because tumor margins can be visualized clearly with indigo carmine.
- 2.
The B-knife was inserted into the initial incision, and an electrosurgical current was applied in endocut mode (50
Clinical outcome of ESD at NCCH
The en-bloc resection rate was 88% and the curative resection rate was 86% among 500 ESDs (Table 1). Of these, 127 were tubular adenomas, 315 were intramucosal cancers or minute sm cancers (sm1s), 55 were submucosal deep cancers (sm2s), 2 were carcinoid tumors, and 1 was mucosa-associated lymphoma tissue. The median operation time was 90 minutes, and the mean size of resected specimens was 40 mm (range, 20–150 mm).
Complications of ESD at NCCH
The postoperative bleeding rate for ESD was 1.0% (5 of 500), which is almost the same as that for conventional EMR (see Table 1). In contrast, the perforation rate for ESD was 2.6% (13 of 500), which is considerably higher than that for conventional EMR (1.3%); only 1 perforation case needed emergency surgery because of ineffective endoscopic clipping. There have been no delayed perforations observed.
Technical progress of colorectal ESD
Until recently, colorectal ESDs have been performed mainly in Japan10, 11, 12, 13, 14, 15, 22, 23 because of the technical difficulty involved in the procedure. Also, the most frequent indication for ESD, early gastric cancer, is more common in Japan than in Western countries.24 Some trained endoscopists, however, have started to do colorectal ESDs in Europe25 and the United States.26
Given the thinness of the colonic wall, the use of specialized knives,7, 20 distal attachments,14 and hypertonic
Comparison between ESD and EMR
The primary advantage of ESD compared with EPMR is a higher en-bloc resection rate for large colonic tumors that had been treated by surgery previously. Consequently, ESD has a lower recurrence rate compared with EPMR (2% vs 14%) and also results in a better quality of life for patients compared with surgery. Future studies should be designed to compare the clinical outcomes of ESD and surgery but not of ESD and EMR because the indications for ESD and EMR are different as are the tumor
Instructions on post-ESD care
From data analysis between ESD and EMR, follow-up endoscopy is recommended after 1 year for curative en-bloc ESD cases and after 6 months for piecemeal ESD cases considering local recurrence rates.28 Even for pathologic curative resection cases, computed tomographic examination or endoscopic ultrasound imaging is recommended to examine lymph node metastasis or distant metastasis for sm1 cases and piecemeal resection cases.
Surgery is recommended for sm2s or cancers of deeper invasion or when
Summary
ESD is a safe and effective procedure for treating colorectal LST-NGs larger than 20 mm and LST-Gs larger than 30 mm because it has a higher en-bloc resection rate and is less invasive than surgery. Establishment of a training system for technically more difficult colorectal ESD and further refinement of ESD instruments are encouraged for the increased use of colorectal ESD not only in Japan but also throughout the world.
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