Peroral endoscopic myotomy (POEM) is a novel endoscopic technique for the treatment of achalasia and other esophageal motility disorders. Initially, it was introduced to the world by Inoue et al. in 2008.7 Thereafter; it was rapidly disseminated because of low invasiveness, higher efficacy and technical novelty. The steps of performing POEM include mucosal incision, submucosal tunnel creation, myotomy and closure of the incision. Mucosotomy (2.8%) is the most common adverse event in patients undergoing POEM.8 It can be due to excessive use of cautery because bleeding points could not be seen clearly with white light during active ooze. RDI will help in early recognition of the bleeding points, thus prompt hemostasis. Bleeding during POEM is not very uncommon(0.5-0.7%).9 Early recognition of bleeding points and quicker hemosasis help in decreasing complications. The utility of RDI in the peroral endoscopic myotomy is not studied so far to our knowledge. Hence in this study we would like to look into the utility of red dichromatic imaging in per-oral endoscopic myotomy.

After obtaining departmental and ethics committee clearance, study will be conducted in AIG Hospitals, Hyderabad. Written informed consent will be taken from the patient or relative before enrolling into the study. After enrolment, participants were allocated into Red dichromatic imaging group(Group 1) and White light imaging group(Group 2). All patients will undergo endoscopy prior to the procedure.

All the procedures in this study will be performed by single endoscopic trainee, previously performed less than ten procedures.

Red Dichromatic Imaging (RDI) works by employing green, amber and red wavelength.

• Green light (520-550nm)
• Amber (595-610nm)
• Red Light (620-640nm)

Group 1: Per-oral endoscopic myotomy will be performed using novel Evis X1 endoscopy(Olympus corporation, Tokyo, Japan) system. RDI mode 1 and Mode 2 will be used during the procedure. Submucosal bleb will be created by injecting mixture of indigo carmine and normal saline. RDI mode 2 will be used for submucosal injection and Mucosal incision. RDI Mode 2 helps in detection of deep mucosal or submucosal vessels which are the major cause of bleeding. Submucosal dissection and myotomy will be performed under white light. However when there is bleeding, RDI mode 1 will be used for the detection of bleeding point. Bleeding will be controlled with spray coagulation or using Coagrasper. Hemostasis treatment will be performed by switching to RDI only at the time of bleeding during the procedure.

Group 2: Per-oral endoscopic myotomy will be performed using CV-190 Gastroscope (Olympus corporation, Tokyo, Japan). White light imaging is used during entire procedure. Submucosal bleb will be created by injecting mixture of indigo carmine and normal saline. Initial submucosal injection and Mucosal incision will be performed under white light. RDI Entry point bleed and ease of entry into the tunnel will be marked by trainee at the end of the procedure. Submucosal dissection and myotomy will be performed under white light. When there is bleeding, bleeding point is identified with white light and hemostasis is achieved.

Inclusion Criteria:

• • Consecutive consenting patients of both gender posted for POEM in the department of Medical Gastroenterology, AIG Hospitals.

Exclusion Criteria:

• • Patients aged under 18 years of age

  • Unable to provide informed consent
  • Inherited or acquired coagulopathy likely to affect the risk of bleeding
  • Receiving anticoagulant therapy that could not be stopped or bridged prior to procedure
  • Breast feeding, pregnant and lactating women's

Upto 80 - 100 subjects