Endoscopic intermuscular dissection of early rectal cancer with deep submucosal invasion
Marcella Safi, Carl-Fredrik Rönnow, Henrik ThorlaciusAbstract
Introduction
Recent data show that the depth of submucosal invasion is not a risk factor of lymph node metastasis in T1 colorectal cancer. Thus, endoscopic resection of early cancers with deep submucosal invasion may be possible. The aim of this study was to evaluate the role of endoscopic intermuscular dissection (EID) in early rectal cancer.
Methods
This study includes the first 40 cases of EID performed in Sweden between 2023–2026. All patients included had macroscopic suspicion of deep submucosal invasion in the rectum. EID is defined by endoscopic resection between the circular and longitudinal part of the muscularis propria. Curative resection was defined as an R0 resection without lymphovascular invasion, high grade budding or poor differentiation. Study outcomes were the percentages of technical success, R0 resection, curative resection, and adverse events.
Results
40 patients underwent EID with suspicious macroscopic early rectal cancer. En bloc resection was achieved in 39 patients. 10 lesions were benign, 27 cases were T1, and three were T2 cancers. All T2 cases resulted in non-curative resection. R0 resection rate was achieved in 85% in patients with T1 cancer. 24 of 27 cases with T1 cancer had deep submucosal invasion (Sm2/3). Curative resection was 63% in all T1 cases and 67% (16/24) in T1 rectal cancer with deep submucosal invasion. Six patients had minor postoperative complications and 2 patients had major postoperative complications.
Discussion
EID appears to be a feasible method to treat patients with early rectal cancer and deep submucosal invasion.