Submucosal injection and min-probe endoscopic ultrasound to determine the eligibility of endoscopic submucosal dissection for colitis-associated neoplasia

Aims Long-standing ulcerative colitis (UC) increases the risk of colorectal cancer (CRC). Endoscopic submucosal dissection (ESD) can be one of the therapeutic options for ulcerative colitis-associated neoplasia (UCAN). A non-lifting sign has been suggested as an indicator of neoplastic submucosal invasion or the infeasibility of endoscopic treatment. However, not only malignant submucosal invasion but also benign submucosal fibrosis related to chronic inflammation can cause non-lifting signs. Moreover, endoscopic assessment of the lifting status is not objectively measurable. Therefore, determining endoscopic resectability is challenging in practice. We investigated the potential role of submucosal cushion thickness after submucosal injection measured by mini-probe endoscopic ultrasound (EUS) to determine ESD eligibility of UCAN.

Methods Between 2022 and November 5th, 2024, 22 UC patients having 23 UCANs were referred for therapeutic decision-making. Colonoscopy and EUS were performed by a single expert. After scanning UCANs, hyaluronic acid solution or saline was injected submucosally, and then submucosal cushion thickness was measured by EUS. ESD was performed when the submucosal cushion thickness was>1.5 mm. UCANs showing submucosal cushion≤1.5 mm or unmeasurable due to poor EUS quality were considered surgical candidates. Continuous variables were presented as median and range.

Results The median age was 58 (37-75) years and seventeen of 22 male patients. The duration of UC was 16 (3-40) years. The estimated lesion size was 21 (10-180) mm. The endosonographically measured submucosal cushion thickness at the thinnest site was 2.7 (0.8-9.9) mm. After submucosal injection, five were lifted well and 11 were lifted incompletely. Seven lesions were non-lifted or not submucosally injectable. EUS showed sufficient submucosal cushion in 16 lesions (ESD-eligible), and insufficient submucosal cushion in 6. Adequate EUS images were not demonstrated in one lesion. ESD was performed for 16 ESD-eligible lesions and surgery was recommended for the remaining seven lesions. The procedure time for ESD was 58.5 (29-210) min. En bloc and R0 resection rate was 100% (16/16) and 81.3% (13/16), respectively. The vertical resection margin was clear in all cases, but the lateral margin was indeterminate or involved in 3 cases. The histologic diagnosis of UCAN treated by ESD was as follows: 9 low-grade dysplasias (LGDs), 3 high-grade dysplasias (HGDs), and 2 sessile serrated lesions. Six patients who underwent proctocolectomy were diagnosed with invasive CRC (n=4), multiple HGD (n=1), and LGD (n=1).

Conclusions EUS after submucosal injection for UCAN can quantify the submucosal cushion thickness, which is a potential and objective criterion for determining ESD eligibility in UCAN.

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Artikel online veröffentlicht:
27. März 2025