Image-guided real-time navigation for transanal total mesorectal excision: a pilot study

Frameless stereotaxy for real-time, image-guided surgery has been most utilized for neurological and orthopedic surgery. Recently, our center has reported the application of real-time navigation for transanal total mesorectal excision. During a 5-month period (June 2013-October 2013), three male patients underwent transanal minimally invasive surgery for total mesorectal excision with image-guided real-time navigation during the transanal portion of the operation. This was completed using a frameless stereotactic navigational system as shown in a demonstration video. Male patients with anterior, locally advanced rectal cancer were selected for enrollment into the pilot study. Three male patients (mean age 69) underwent transanal total mesorectal excision with stereotactic navigation during a 5-month study period. Mean operative time was 402 min, and there were no intra-operative complications recorded. The mean distance from anal verge of the tumor was 6.3 cm (range 4-8 cm). The navigational accuracy was computed to be +/- 3.69 mm (range +/- 3.20 to +/- 4.02 mm). The average navigation setup time was 47 min, not including scan time. The surgical specimens were found to have completely intact mesorectal envelopes (Quirke 3) in all cases. All margins, including radial and distal margins, were negative. Mean postoperative length of stay was 5 days. At a median of 18-month follow-up, there was no evidence of locoregional recurrence or distant metastatic disease. This is the first pilot series to report the use of frameless stereotactic navigation for TAMIS-TME. Stereotactic navigation for transanal total mesorectal excision is shown to be feasible, and may aid in providing colorectal surgeons with the ability to better perform safe, high-quality surgery in select cases.