EUS-guided ethanol ablation for pancreatic cystic lesions

  (Ablação de cisto de pâncreas com álcool guiada por EUS)   For the management of pancreatic cystic lesions (PCLs), the traditional approach is watch and see, or resection based on the risk of malignancy. However, there is unmet need due to the indolent behavior of pancreatic cystic lesions. Currently, EUS-guided ethanol ablation therapy (EUS-EA) has been considered to solve the unmet need for management of pancreatic cystic lesions.   EUS-EA for PCLs was accomplished using the following protocol (Video).

1. The longest diameter was measured
2. 80% of the cystic fluid was aspirated, after which 99% ethanol was injected and stored in the cyst for 1 min
3. Step number 2 was repeated twice, but retention time was prolonged to 3~5min
4. All injected ethanol and remnant cystic fluid was aspirated

        Although many studies about EUS-guided ablation therapy recently reported certain level of complete response (CR) rate 9-85%) and epithelial ablation (0-100%) (1-3), there are some limitations in this therapy as following: existence of Non-responder; existence of severe complications; difficulty in the confirmation of histological CR via imaging study; difficulty in imaging surveillance of malignancy; uneven effect in the ablation of epithelium; difficulty in operation after failure.   In our single-center retrospective study, we compared the clinical outcomes of EUS-guided ethanol ablation with those of the natural course of PCLs. Between 84 matched pairs of both groups, there were no significant differences in overall survival (194.12 ± 5.60 vs 247.54 ± 12.70 months, p = 0.235) (4). The surgical resection rate (4.8% versus 26.2%, p < 0.001) was significantly lower in the EUS-EA group. CR was observed only in the EUS-EA group and the CR rate was 32.1%. Although EUS-EA for PCLs with low risk of malignancy might not obtain a survival benefit, expect the better quality of life through the avoidance of unnecessary surgical resection and the lower surveillance cost by certain level of CR rate.   In conclusion, roles of EUS-EA are avoidance of unnecessary surgery or surgical complications and reduction of imaging follow-up as surveillance. EUS-EA could be considered a useful treatment option, but careful application is needed because of the limited effects in some type of PCLs. Therefore, tentative candidates can be suggested as followings:

• cystic lesion without high risk stigmata,
• uni- or oligolocular cystic lesion,
• cyst larger than 2cm in size,
• slowly growing cyst,
• reluctant or high-risk surgical patients.

   

Reference

1. Bartel MJ, Raimondo M. Endoscopic Management of Pancreatic Cysts. Dig Dis Sci. 2017;62(7):1808-15.
2. Caillol F, Poincloux L, Bories E, Cruzille E, Pesenti C, Darcha C, et al. Ethanol lavage of 14 mucinous cysts of the pancreas: A retrospective study in two tertiary centers. Endosc Ultrasound. 2012;1(1):48-52.
3. Gomez V, Takahashi N, Levy MJ, McGee KP, Jones A, Huang Y, et al. EUS-guided ethanol lavage does not reliably ablate pancreatic cystic neoplasms (with video). Gastrointestinal endoscopy. 2016;83(5):914-20.
4. Choi JH, Lee SH, Choi YH, Kang J, Paik WH, Ahn D-W, et al. Clinical outcomes of endoscopic ultrasound-guided ethanol ablation for pancreatic cystic lesions compared with the natural course: a propensity score matching analysis. Therapeutic Advances in Gastroenterology. 2018;11:1756284818759929.