Alejandro Moreira Grecco, MD, Fernando Dip, MD, Luis Sarotto. Hospital de Clinicas Jose de San Martin
Transanal minimally invasive surgery (TAMIS) has being widely adopted for large rectal polyps. Advantages of TAMIS are due to pneumorectum, good exposure and a wide operative field. Positive margin resections have improved when compared with Parks classic technique, but it has been described a failure in R0 resection up to 10% of the cases. Margin clearance is capital to prevent recurrence of rectal polyps.
The aim of this study is to evaluate the usefulness of Methylene blue Polyp staining to guide the TAMIS approach and increase the margins visibility enhancing the mucosa of rectal adenomas.
Material and method
Five Patients treated for rectal adenomas via TAMIS were included in the study. After the positioning of the TAMIS port (gel point path, applied medical) and the generation of the pneumorectum, we proceed to rinse the lesion and its vicinity with methylene blue 1% . After 5 minutes, the rectum was washed out with saline. The surgery continues as a standard TAMIS resection.
4 patients were women and 1 male of mean age of 63 (±15) years underwent TAMIS at Hospital de Clinicas Jose de San Martin for adenomas located at a mean of 6.8 ±1.5 centimeters from the anal verge. 29% of the rectal circumference was compromised by the lesions . Mean operative time was 61 minutes (40-80) Initial inspection of rectal mucosa with white light did not allow a clear identification of the abnormal mucosa. After MB staining the mucosa of the adenomas was enhanced from the normal rectal tissue. Macroscopically visualization of the polyps margins was possible in all cases after the administration of MB. No complications were reported.Negative margins were confirmed with pathologic reports.
Methyl Blue TAMIS guided procedure is a feasible technique and allow the surgeon a clear visualization of polyp margins.