Laparoscopic sphincter-preserving surgery (intersphincteric resection) after neoadjuvant imatinib treatment for gastrointestinal stromal tumor (GIST) of the rectum

Gastrointestinal stromal tumors (GISTs) of the rectum are rarely found, and radical surgery such as abdominoperineal resection would be necessary for large rectal GIST. On the other hand, therapy for GIST has changed significantly with the use of imatinib. Neoadjuvant imatinib therapy may reduce tumor size and may potentially prevent extended surgery. Moreover, when sphincter-preserving surgery is carried out laparoscopically, it can be performed as minimally invasive surgery with preservation of the anus. From 2008 to 2011, five patients with rectal GIST were treated in our hospital. All patients received preoperative imatinib treatment (400 mg/day) and underwent laparoscopic sphincter-preserving surgery after 4-12 months of this treatment. Initial median tumor size was 31 mm (range, 24-88). At the time of operation, the median tumor size was 24 mm (range, 11-52). Sphincter-preserving surgery was performed in all patients. Three patients underwent laparoscopic intersphincteric resection (ISR), and two patients underwent transanal full-thickness local resection and recto-anal anastomosis following laparoscopic ISR. Macroscopically complete resection was achieved, and microscopically, the resection margin was not involved of residual tumors. The median duration of postoperative hospital stay was 16 days (range, 13-30). No recurrence occurred in all patients during 1 to 4 years. The present study suggests that neoadjuvant imatinib therapy might be effective to prevent extended surgery for rectal GIST, and laparoscopic sphincter-preserving surgery is safe and technically feasible. We recommend a combination of neoadjuvant imatinib therapy and laparoscopic ISR for locally advanced rectal GIST.