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.

Based on clinicopathologic analyses of LSTs, 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 cancers (sm1s) and difficult to predict before endoscopic treatment.

Granular type LSTs (LST-Gs) have a lower rate of sm invasion, and most such invasions are found under the largest nodule or depression, which are easier to predict endoscopically. LST-Gs larger than 20 mm can be treated by endoscopic piecemeal mucosal resection (EPMR) rather than by ESD, with the area that has the largest nodule resected before resection of the remaining tumor. LST-Gs larger than 30 mm or 40 mm are possible candidates for ESD because they have higher sm invasion rates and are more difficult to treat even by EPMR; so they have been treated by either EPMR or ESD, based on the individual endoscopist’s judgment.

Estimation of the depth of invasion

A non-invasive pattern 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.

Estimation of the depth of invasion

A non-invasive pattern 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. 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. 1 A) and an insulation-tip (IT) electrosurgical knife (Olympus Optical Co, Tokyo, Japan) (see Fig. 1 B) with carbon dioxide insufflations instead of air insufflation to reduce patient discomfort (see Fig. 1 C). After submucosal injection of 10% glycerin and 5% fructose (Glyceol, Chugai Pharmaceutical Co, Tokyo, Japan) and 0.4% hyaluronic acid (MucoUp, Seikakagu Co, Tokyo, Japan) (see Fig. 1 D) into the sm layer, a circumferential incision was made using the B-knife and an ESD was then performed using the B-knife and IT knife (see Fig. 1 A, B).

The procedures were primarily performed using a B-knife ( A ) and an IT electrosurgical knife ( B ) with carbon dioxide insufflation ( C ) instead of air insufflation to reduce patient discomfort. After injection of Glyceol (Chugai Pharmaceutical Co, Tokyo, Japan) and MucoUp (Seikakagu Co, Tokyo, Japan) ( D ) into the sm layer, a circumferential incision was made using the B-knife and an ESD was performed using the B-knife and IT knife. ( From XEMEX Co, Tokyo, Japan; with permission [ A ]; Olympus Optical Co, Tokyo, Japan; with permission [ B ]; and Seikakagu Co, Tokyo, Japan; with permission [ D ].)

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 Glyceol 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 layer to confirm the appropriate sm layer elevation and then solution 2 was injected into the properly elevated sm layer. Finally, a small amount of solution 1 was injected again to flush out any residual solution 2.

Detailed colorectal ESD procedures

• 1.
  

  The margins of the lesion were delineated before ESD by spraying 0.4% indigo carmine dye ( Fig. 2 A). 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. 2 B). In colorectal cases, it was not necessary to actually mark around lesions because tumor margins can be visualized clearly with indigo carmine.

  
  

  
  

  
  

  
  

  
  

  ESD procedures. ( A ) An LST-NG type lesion 40 mm in size located in transverse colon (reverse view). Lesion margins delineated before ESD using 0.4% indigo carmine dye spraying. ( B ) After injection of Glyceol and sodium hyaluronate acid solution into the sm layer, a half-circumferential incision (anal side) was performed using B-knife (retroflex view). After circumferential incision, sm dissection was performed using the same B-knife. ( C ) Straight view of the lesion after half-circumference marginal resection and sm dissection of the oral side. Additional resection of the margin on the anal side was performed using the B-knife in the straight view. ( D ) Dissection of the sm layer from outside to inside of the lesion is easily performed using the IT knife. ( E ) Ulcer bed after successful en-bloc resection in 1.5 hours. ( F ) Resected specimen was 40 × 30 mm in diameter and histologic findings revealed intramucosal cancer with tumor-free margin.

  
  
  
  
• 2.
  

  The B-knife was inserted into the initial incision, and an electrosurgical current was applied in endocut mode (50 W) using a standard electrosurgical generator (ICC 200, ERBE, Tubingen, Germany) to continue the marginal incision around the oral side of the lesion.

  
  
• 3.
  

  After partial resection of the margin on the oral side of the lesion to ensure adequate submucosal lifting, submucosal dissection was begun using the same B-knife in retroflex view (see Fig. 2 B).

  
  
• 4.
  

  Additional resection of the margin on the anal side was performed using the B-knife in the straight view (see Fig. 2 C).

  
  
• 5.
  

  After the lesion was partially dissected so that the sm layer could be visualized sufficiently, an IT knife (see Fig. 2 D) was used to complete the dissection of the sm layer quickly and safely. The previously indicated solutions were injected repeatedly into the sm layer to maintain the sm fluid cushion so as to minimize the risk of perforation.

  
  
• 6.
  

  Hemostatic forceps were used in soft coagulation mode (70–80 W) to control visible bleeding. The patient’s position was sometimes changed to facilitate visualization of the tissue plane, and dissection continued until the lesion was completely excised.

  
  
• 7.
  

  After the colorectal ESD was completed, routine colonoscopic review to detect any possible perforation or exposed vessels was conducted and minimum coagulation was performed using hemostatic forceps on nonbleeding visible vessels to prevent postoperative bleeding (see Fig. 2 E).

  
  
• 8.
  

  The resected specimen was stretched and fixed to the board using small pins (see Fig. 2 F).