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Jeong et al. Mini-invasive Surg 2019;3:38 I http://dx.doi.org/10.20517/2574-1225.2019.42 Page 5 of 11

Patient position is also important in TAMIS surgery. In general, it is true that positioning the lesion at the
bottom is convenient and advantageous for surgery. However, it is not necessary to vary the position of the
patient to place the lesion at 6 o’clock as in TEM conditions, or to adjust the system to center the field of
vision during surgery.

Wherever the lesion is located under the lithotomy position, it is relatively easy to access, but some authors
[17]
still mention that the prone position is helpful for anterior proximal lesions .
[18]
Albert et al. first suggested that the lesions be placed below when introducing the TAMIS, but a recent
publication stated that lithotomy position could resolve all lesions.

Even in malignant lesions, local recurrence rate is low in lesions within T1, but local recurrence rate is
significantly increased in T2 lesions.

NCCN guidelines for rectal cancer: local excision
Current guidelines for local excision of rectal cancer, e.g., the criteria for including the use of TAMIS, are
based on long-term survival and outcome data. National guidelines recommend transanal local excision
of only those T1N0 rectal cancers that meet the following criteria: < 30% circumference of bowel, < 3 cm
in size, > 3-mm margins, mobile, nonfixed, within 8 cm of anal verge, endoscopically removed polyp
with cancer or indeterminate pathology, no negative pathologic features such as lymphovascular or
perineural invasion, no evidence of lymphadenopathy on pretreatment imaging, and tumors that are well
to moderately differentiated. Furthermore, they recommend that local excision of more proximal lesions
[19]
would be technically feasible using transanal microscopic surgery or TAMIS .
FUTURE AND THE FINAL GOAL OF TRANSANAL MINIMALLY INVASIVE SURGERY
NOTES for rectal cancer
When the pelvic delamination is complete through TaTME, this space can serve as a common path for
access into the abdominal cavity. Under these conditions, various organs and intestines can be accessed
from the abdominal cavity and surgical procedures can be performed. This is NOTES if the resulting
[20]
extract is removed through the anus .
This procedure consists of three steps: anal, intraperitoneal, and second anal stage. In the first stage,
TaTME takes place. In the second stage, vascular and mesenteric dissection is performed simultaneously
with colonic mobilization. If necessary, splenic flexure mobilization is also performed. Finally, in the third
stage, specimen pull through, transection, and anastomosis occur [Figure 3].

However, to approach the intraperitoneal through the transanal approach, there are some challenges that
must be considered as well as some difficulties to overcome in the technical aspect. First, the condition of
the anal sphincter should be compared with the characteristics of the lesion. The anus should be sufficiently
intact and allow for safe passage of the extract, including the lesion. The second is the prominence of pelvic
promontory. Usually, the transanal approach to inferior mesenteric artery (IMA) and inferior mesenteric
vein (IMV) is possible without major difficulties. However, in some older patients, there are severe bends
and protrusions of the pelvic promontory. This acts as a major obstruction to accessing the abdominal
cavity and, in severe cases (in cases where it is impossible to attempt a straightening of the spine by
changing the patient’s position), a transabdominal approach should be added. Third, long shafted devices
should be prepared for possible splenic flexure mobilization, as well as smooth manipulation of IMA and
IMV. Commercially available laparoscopic instruments can reach up to 46 cm. If further distances are
predicted from the patient’s radiology data, surgery by NOTES should be considered difficult [Figure 4].