Introduction
Red dichromatic imaging (RDI) is a next-generation image enhancement technique which works by employing green, amber and red wavelengths. The blood vessels in the deeper tissues absorb the amber light because of strong affinity with hemoglobin. Even though red light can penetrate deep into the tissue, it is weakly absorbed by hemoglobin. RDI enhances the visibility of deep blood vessels and bleeding sources. Hence it leads to early identification of bleeding sources and quicker hemostasis. RDI enhances the contrast between diluted blood and highly concentrated blood, thereby clearly visualizing the bleeding source. Bleeding during POEM is not very uncommon(0.5-0.7%). Early recognition of bleeding points and quicker hemostasis help in decreasing complications. The utility of RDI in the peroral endoscopic myotomy is not studied so far to our knowledge.
Aims & Methods
To assess the reduction in total procedural time using Red dichromatic imaging (RDI) compared to white light imaging in achieving haemostasis during POEM. To identifying avascular mucosal site by identifying and avoiding deep blood vessels using RDI, use of RDI in comparison with white light imaging (WLI) in achieving haemostasis, ease of mucosal entry by using RDI when compared to WLI and psychological stress experienced by endoscopists during haemostasis treatment.
A single centre prospective, randomized study conducted at tertiary referral centre. Patient with achalasia cardia who are undergoing POEM procedure are randomized into two groups- Group 1- Patient undergoing POEM using novel GF 1500 UGI Scope (RDI) and Group 2- patient undergoing procedure using regular white light endoscope. In group 1, RDI mode 2 was used for mucosal injection and incision and RDI mode 1 was used for identifying and controlling bleeding during the procedure.
Results
Achalasia cardia patients(n=103) undergoing POEM procedure where enrolled in this study, with 52 subjects in RDI Group and 51 subjects in WLI group. The mean age in the RDI group was 49.01± 14.78 years and in WLI group was 46.68± 15.58 years (p=0.32). The Eckardt score improved significantly in the both groups and adverse events where similar in both the groups. The total hemostasis time was significantly better (p=0.02) in the RDI group (7.9±12.02 sec) compared to WLI group (18.92±25.89 sec). Therefore the total procedural time was significantly quicker (p=0.02) in the RDI group when compared to the WLI group. However there was no significant advantage (p=0.18) of RDI over WLI in preventing mucosal entry point bleed. The RDI group had significant advantage in parameters like ease of entry (p=0.0001) and stress encountered by the operator (p=0.028).
| RDI (n=52) | WLI (n=51) | p value |
| Age (years) | 49.01±14.78 | 46.68± 15.58
| 0.32 |
| Male: Female | 25:27 | 33:18 | 0.088 |
| Total Procedural time | 54.7±23.93 | 63.33±23.13 | 0.02 |
| Total Hemostasis time | 7.9±12.02 | 18.92±25.89 | 0.02 |
| Easy of entry (Easy vs Difficult) | 41/11 | 16/35
| 0.0001 |
| Psychological stress (Nil or minimal vs moderate or high stress) | 41/11 | 30/21 | 0.028 |
| Procedure approach (Posterior vs anterior) | 41/11 | 42/9 | 0.65 |
| Type of Achalasia (I/II/IIIorNS) | 5/43/4 | 1/42/8 | 0.135 |
| Treatment Naive vs previous procedures for Achalasia | 42/10 | 41/10 | 0.96 |
Conclusion
Bleeding during POEM procedure can be daunting for even an experienced endoscopist and RDI can be helpful in this regard. The total hemostasis time, total procedural time, ease of submucosal entry and stress of the operator is seen to be significantly better using novel RDI. Hence RDI helps in early identification of bleeding sources and quicker hemostasis during POEM.
References
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2. Hirai Y, Fujimoto A, Matsutani N, Murakami S, Nakajima Y, Miyanaga R, Nakazato Y, Watanabe K, Kikuchi M, Yahagi N. Evaluation of the visibility of bleeding points using red dichromatic imaging in endoscopic hemostasis for acute GI bleeding (with video). Gastrointestinal Endoscopy. 2022 Apr 1;95(4):692-700.
3. Anudeep KV, Ramchandani M, Inavolu P, Nabi Z, Reddy DN. Red dichromatic imaging in peroral endoscopic myotomy: a novel image-enhancing technique. VideoGIE. 2021 May 1;6(5):203-6.