Portal de Periódicos da CAPES

Interventional chromoendoscopy: specific aspects for the colon

2014; Elsevier BV; Volume: 79; Issue: 3 Linguagem: Inglês

10.1016/j.gie.2013.09.002

1097-6779

Nicholas Tutticci, Michael J. Bourke,

Colorectal Cancer Surgical Treatments

We congratulate Drs. Monkemuller and Wilcox on their creative conceptualization of interventional chromoendoscopy.1Monkemuller K. Wilcox C.M. Interventional chromoendoscopy.Gastrointest Endosc. 2013; 78: 346-350Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar We believe that some additional aspects specific to the colon are important to emphasize. The agents in common use, indigo carmine and methylene blue, clearly show the loose areolar connective tissue of the submucosa (SM). They do not stain adipose tissue. Nonstaining adipose tissue within resection defects in the proximal colon is not uncommon and may be a source of concern and confusion, but it is of no clinical import to the informed endoscopist (Fig. 1).2Holt B.A. Bourke M.J. Wide field endoscopic resection for advanced colonic mucosal neoplasia: current status and future directions.Clin Gastroenterol Hepatol. 2012; 10: 969-979Abstract Full Text Full Text PDF PubMed Scopus (90) Google Scholar A basic tenet underpinning safety in endoscopic resection is inspection of the postresection defect.2Holt B.A. Bourke M.J. Wide field endoscopic resection for advanced colonic mucosal neoplasia: current status and future directions.Clin Gastroenterol Hepatol. 2012; 10: 969-979Abstract Full Text Full Text PDF PubMed Scopus (90) Google Scholar Despite initial adequate injection of dye-containing solution, the entire resection defect may not stain uniformly. Topical submucosal chromoendoscopy (TSC) facilitates the interrogation of unstained areas.3Holt B.A. Jayasekeran V. Sonson R. et al.Topical submucosal chromoendoscopy defines the level of resection in colonic EMR and may improve procedural safety (with video).Gastrointest Endosc. 2013; 77: 949-953Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar This simple technique involves flushing (not injecting) the dye-containing solution over the defect to create the characteristic homogenous blue mat appearance of obliquely intersecting submucosal fibers (Fig. 2). This technique facilitates complete evaluation of the mucosal defect for evidence of muscularis propria (MP) injury. Areas of fibrosis and MP do not take up dye and are thus more easily identified. Red areas in the SM are not muscle fibers; they are areas of SM hemorrhage and can be confirmed as such by TSC.3Holt B.A. Jayasekeran V. Sonson R. et al.Topical submucosal chromoendoscopy defines the level of resection in colonic EMR and may improve procedural safety (with video).Gastrointest Endosc. 2013; 77: 949-953Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar We originally described the evidence of MP injury in the resection defect as the mirror target sign and the corresponding pale, gray-white, nonstaining disc on the underside of the resection specimen as the target sign (Fig. 3).4Swan M.P. Bourke M.J. Moss A. et al.The target sign: an endoscopic marker for the resection of the muscularis propria and potential perforation during colonic endoscopic mucosal resection.Gastrointest Endosc. 2011; 73: 79-85Abstract Full Text Full Text PDF PubMed Scopus (122) Google Scholar We now accept that the term “target” is used for both signs. The “target” within the defect is characterized by a white cautery ring where the MP has been excised or incised (in which case the muscle fibers separate to create the typical appearance). We concur with the authors' caution against sublesional carbon tattoo. Sterile carbon suspension placed separately from a lesion or resection site with the intent of localization may inadvertently track beneath the lesion/resection area. It is not biologically inert and may generate significant submucosal fibrosis, negatively affecting the success and safety of endoscopic therapy (Fig. 4).5Moss A. Bourke M.J. Pathmanathan N. Safety of colonic tattoo with sterile carbon particle suspension: a proposed guideline with illustrative cases.Gastrointest Endosc. 2011; 74: 214-218Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar We have recently proposed a colonic tattoo guideline5Moss A. Bourke M.J. Pathmanathan N. Safety of colonic tattoo with sterile carbon particle suspension: a proposed guideline with illustrative cases.Gastrointest Endosc. 2011; 74: 214-218Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar where injection at least 3 cm distal to the lesion/resection site is recommended to minimize this complication. The authors were given the opportunity to respond to this letter but declined. Interventional chromoendoscopyGastrointestinal EndoscopyVol. 78Issue 2PreviewChromoendoscopy is one of the most common image enhancement methods used in luminal gastroenterology.1 Although the role of chromoendoscopy in finding lesions is still being debated, its role in defining lesions is well-established.2-4 Lesions can be defined by observing the mucosal surface and subsurface. Mucosal surface analysis is centered on finding dissimilarities of the mucosal integrity, detecting growths, determining the shape of lesions, and delineating the lesion’s margins. Submucosal inspection (or submucosal surface analysis) is focused on visualizing the underlying vascular pattern of a given lesion. Full-Text PDF