Introduction
Endoscopic submucosal dissection (ESD) is widely performed in Asia. Its adoption in Western countries has been slow, primarily due to concerns about longer learning curves and higher complication rates. A new ESD service based on a single operator without an on-site tutor was introduced in a UK tertiary hospital using exclusively speedboat-RS2 device (advanced bipolar radiofrequency for cutting and microwave coagulation).
Aims & Methods
This study aims to evaluate the learning curve and outcomes of the first 100 SSDs. Data were collected prospectively from September 2019 to April 2023. The learning curve was analyzed based on 4 quartiles (n=25 per quartile) and the outcomes evaluated were resection speed, en-bloc and R0 resection rate. The adverse events rate in the first 30 days post-SSD was used as safety outcomes.
Results
100 patients underwent SSDs and the median age was 67 years. The median Charlson Comorbidity Index (CCI) score was 3. 61% were male and 53% of the lesions were in the rectum. Majority (75%) of the lesions were removed en-bloc and 69% had R0 resections.
| Row Labels | Count | Count of en-bloc procedures | Resection speed (cm2/hr) | En-bloc (%) | R0 resection (%) | Mean duration of procedure (mins) | Mean size of lesions (cm) |
| 1 | 25 | 16 | 4.0 | 64 | 63 | 233 | 4.9 |
| 2 | 25 | 17 | 6.6 | 68 | 71 | 194 | 4.8 |
| 3 | 25 | 21 | 6.7 | 84 | 67 | 152 | 4.7 |
| 4 | 25 | 21 | 7.9 | 84 | 76 | 142 | 5.2 |
| Total | 100 | 75 | 6.0 | 75 | 69 | 180 | 4.9 |
The en-bloc resection rate for quartiles 1, 2, 3 and 4 were 64%, 68%, 84%, and 84%. The R0 resection rate was 63%, 71%, 67% and 76%, respectively. The 4th quartile met the European Society of Gastrointestinal Endoscopy (ESGE) recommendation for the R0 resection rate ≥75% but not for the en-bloc resection rate ≥90%.
1The mean duration of SSDs for respective quartiles were 233, 194, 152 and 142 minutes which indicated shorter resection times (142mins) despite larger lesions in the 4th quartile (5.2cm). The resection speed was 4.0, 6.6, 6.7 and 7.9cm
2/hr, respectively. The 4th quartile resection speed of 7.9cm
2/hr after 100 SSDs demonstrated a shorter learning curve than the 7.0cm
2/hr achieved after 200 ESDs in a similar study performed in the US which evaluated a new ESD service from a single operator without on-site tutoring.
2The adverse event rate was 7%(n=7). 5% were due to delayed bleeding, requiring further endoscopic interventions. The risk factors were use of anticoagulants and liver cirrhosis. 2% had localized perforation with Sydney classification of mucosal injury type III which were managed with endoscopic clips. This study achieved the safety standards of ESGE which recommends an adverse event rate of <10% and perforation rate of <3%.
1The surgical conversion rate post-SSDs in early stages of training was 4%(n=4). These were adenocarcinomas with hybrid(n=2) and R1 en-bloc resections(n=2).
The results have an understandably longer learning curve than
Japan but we demonstrated remarkable progress in resection speed, en-bloc and R0 resection rate over the 4 quartiles as well as a shorter learning curve than previously reported in the West for a new service based on a single operator without on-site tutoring.
2,3Conclusion
This study demonstrated that a new ESD service based on a single-operator without an on-site tutor achieved safety outcomes and R0 resection rate recommended by ESGE. Whilst further experience is required to achieve en-bloc resection rate ≥90% and resection speed ≥9cm2/hr, the results from the first 100 cases suggest that the learning curve for SSD without on-site tutoring may be shorter than previously reported in the West.2,3
References
1. Pimentel-Nunes P, Pioche M, Albéniz E, Berr F, Deprez P, Ebigbo A, Dewint P, Haji A, Panarese A, Weusten BLAM, Dekker E, East JE, Sanders DS, Johnson G, Arvanitakis M, Ponchon T, Dinis-Ribeiro M, Bisschops R. Curriculum for endoscopic submucosal dissection training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement. Endoscopy. 2019 Oct;51(10):980-992. doi: 10.1055/a-0996-0912. Epub 2019 Aug 30. PMID: 31470448.
2. Zhang X, Ly EK, Nithyanand S, Modayil RJ, Khodorskiy DO, Neppala S, Bhumi S, DeMaria M, Widmer JL, Friedel DM, Grendell JH, Stavropoulos SN. Learning Curve for Endoscopic Submucosal Dissection With an Untutored, Prevalence-Based Approach in the United States. Clin Gastroenterol Hepatol. 2020 Mar;18(3):580-588.e1. doi: 10.1016/j.cgh.2019.06.008. Epub 2019 Jun 18. PMID: 31220645.
3. Sauer M, Hildenbrand R, Oyama T, Sido B, Yahagi N, Dumoulin FL. Endoscopic submucosal dissection for flat or sessile colorectal neoplasia >20mm: A European single-center series of 182 cases. Endosc Int Open. 2016Aug;4(8):E895-E900. Doi:10.1055/s-0042-111204. Epub 2016 Aug 11. PMID: 27540580
Disclosure
None