Junjun Ma, Jiaoyang Lu, Hiju Hong, Lu Zang, Feng Dong, Bo Feng, Aiguo Lu, Jing Sun, Minhua Zheng. Shanghai Ruijin Hospital, Shanghai Jiaotong University, School of Medicine
We developed a laparoscopic Cephalo-Medial-to-Lateral (CML) approach to perform total mesorectal excision (TME) to address the current technical hurdles in conventional medial approach.
The CML approach involves entrance to the left retrocolic space (LRS) cranially to the origin of the inferior mesenteric artery (IMA). To achieve this, the loose attachments on the jejunum are divided so the small bowel loops could be retracted upper right to reveal the ligament of Treitz, the left mesocolon, the aorta and the inferior mesenteric vessels. The LRS is entered from above the aorta and expanded downward to reach and dissect the central (station 253) lymph nodes. The rectosigmoid space caudally to the IMA is entered conventionally and expanded upward to join the LRS. Lymph nodes inferior to the IMA are dissected in the process. At this stage, the “T-shaped” structure formed by the origin of IMA, the distal IMA and the left colic artery (LCA) are clearly identified and managed; the LCA can be divided individually without compromising lymph nodes dissection. The following pelvic dissection is similar to the conventional approach.
The CML approach was easy to acquire in experienced hands and has been successfully implemented in 32 procedures in our center, data were compared with those obtained from 50 patients underwent the conventional medial approach in the same time period. The additional step to open the LRS in a downward fashion cost 8.1±5.9min but the total operative time was not sacrificed (around 100min in both groups) as the central lymph nodes dissection was facilitated. The CML approach did not cause any additional bleeding or intra/post operative adverse events compared to the conventional approach. The station 253 nodes were examined in more patients (22 cases, 73.3% vs 33 cases, 63.5%) with increased number in each patient (3.45±2.2 vs 1.64±0.7, p=0.001) after CML-TME than the conventional approach. One patient was found to have positive 253 nodes, which represent 8.3% of advanced cases and 25% of T3N2 patients. In this respect, the CML approach could serve as a more standardized procedure to evaluate the potential oncological benefits to remove the station 253 lymph nodes in large cohorts. We conclude that the CML-TME approach is safe, feasible, technical advantageous with potential oncological benefits that need to be further examined in future trials.