Stepwise super minimally invasive full-thickness resection for locally advanced rectal cancer after achieving near clinical complete response with neoadjuvant therapy

Organ preservation strategies like "watch-and-wait" are increasingly used in LARC patients with cCR/near-cCR postneoadjuvant therapy [1]. Local recurrence remains critical, with 14.9–25% incidence within 2 years, necessitating effective salvage interventions [2]. While endoscopic techniques provide super minimally invasive solutions for superficial tumors [3], the management of deep local recurrences involving or penetrating the muscularis propria presents substantial challenges. We describe an innovative stepwise super minimally invasive full-thickness resection (sft-SMIR) technique. A 75-year-old female presented with LARC in the low rectum (initial staging: cT2–3N0M0). Following short-course radiotherapy and two cycles of chemoradiotherapy, she achieved a near-clinical complete response (ncCR). After multidisciplinary discussion, sft-SMIR surgery was performed ([Fig. 1], [Video 1]). First, the laterally spreading tumor (LST) and scars after neoadjuvant therapy were fully exposed, and the lesion area was marked ([Fig. 1] a, b). Second, ESD was performed in the LST and scar surrounding areas ([Fig. 1] c). Third, a traction device of a rubber band and clips was applied to fully expose the intrinsic muscle layer and deep scar areas at the lesion site. Then, the intrinsic muscle layer was incised by an electric knife, and the extracellular mesorectum was exposed ([Fig. 1] d). Fourth, the intrinsic muscle layer after ESD and the full-thickness defect after EFTR were displayed ([Fig. 1] e). Finally, the closure of the full-thickness defect was achieved by using clips to seal the muscle layer against the muscle layer ([Fig. 1] f). The specimen was fixed and photographed with both sides ([Fig. 1] g, h). Postoperative pathology suggests intramucosal carcinoma with curative resection.