Junichi Koike, MD, PhD, Kimihiko Funahashi, MD, PhD, Hiroyuki Shiokawa, MD, Mitsunori Ushigome, MD, PhD, Tomoaki Kaneko, MD, Akiharu Kurihara, MD, Hironori Kaneko, MD, PhD. Toho University Medical Center, Omori Hospital, Gastroenterological Surgery
Introduction: TransAnal Minimally Invasive Surgery for total mesorectal excision (TAMIS–TME) of distal rectal cancer facilitates dissection of tumors in the deep pelvic floor. TAMIS provides good visibility and safer transanal TME, while extensive rectal mobilization reduces abdominal procedures and allows RPS using the wound of ileostoma. We report important anatomical landmarks and surgical outcomes of TAMIS-TME followed by RPS.
Subjects: Surgery was performed in 11 patients (9 men and 2 women, mean age: 67.7 years, mean BMI: 20.9) from October 2013.
Transanal procedures: When operating from the anal side under direct vision, after retaining the space for EZ access followed by insufflation, cephalad dissection of the pelvic floor muscles follows loose connective tissue outside the pre-hypogastric nerve fascia as a landmark on the posterior wall. Laterally, dissection proceeds inside the pelvic splanchnic nerves as a landmark. Although dissection through loose connective tissue outside the splanchnic nerves is possible, care is required to avoid nerve damage. In males, dissection between the prostate/seminal vesicles and anterior rectal wall is considered difficult, but magnification facilitates it. Dissection proceeds cephalad from the rectum along the prostate midline to the pouch of Douglas, followed by right and left dissection with awareness of the anterior rectal wall. Using the lateral pelvic fascia enclosing the prostate and rectum as a landmark, transection is done as far from the prostate as possible to prevent neurovascular bundle injury. Dissection near the prostate reaches Denonvillier’s fascia attached to the rectum.
Abdominal procedures: With easy anal side connection through the anterior and posterior walls of the rectum, lateral transection while avoiding neurovascular bundle injury achieves complete extirpation.
Results: procedures: ISR was 6, CAA 3, APR 2 cases. Operation time was 412m (ave.), blood loss was 178.4 ml, postoperative CRP Max was 5.4 mg/dl (ave.)
Summary: When performing TAMIS-TME for distal rectal cancer, magnification achieves not only safer TME, but also decreasing trasabdominal procedures while allowing RPS. However, proficiency in recognizing anatomical landmarks from the anal side is essential.