Transanal minimally invasive surgery (TAMIS) approach for large juxta-anal gastrointestinal stromal tumour

Gastrointestinal stromal tumours (GISTs) are rarely found in the rectum. Large rectal GISTs in the narrow pelvis sometimes require extended abdominal surgery to obtain free resection margins, and it is a challenge to preserve sufficient anal sphincter and urogenital function. Here we present a 56-year-old male with a locally advanced juxta-anal non-metastatic GIST of approximately 10 cm in diameter. Therapy with imatinib reduced the tumour size and allowed partial intersphincteric resection (pISR). The patient underwent an electrophysiology-controlled nerve-sparing hybrid of laparoscopic and transanal minimally invasive surgery (TAMIS) in a multimodal setting. The down-to-up approach provided sufficient dissection plane visualisation and allowed the confirmed nerve-sparing. Lateroterminal coloanal anastomosis was performed. Follow-up showed preserved urogenital function and good anorectal function, and the patient remains disease-free under adjuvant chemotherapy as of 12 months after surgery. This report suggests that the TAMIS approach enables extraluminal high-quality oncological and function-preserving excision of high-risk GISTs.