[Inter-fascial dissection in laparoscopic colorectal cancer surgery: principles of retraction and exposure and techniques in fascial separation].

Colorectal surgery for malignancies has evolved into an era of careful and precise dissection along mesorectal or mesocolic fascia to achieve the so-called total mesorectal excision or complete mesocolic excision. The wide use of laparoscopic technique prompted more anatomical, histological, and embryological studies. This leads to a deeper and more precise understanding of fascial anatomy concerning colorectal surgery, though controversies exist. The complicated anatomy of multilayer parietal fasciae and dense adhesion between fasciae at specific sites still represent a major hindrance to perform a precise inter-fascial dissection. Colorectal surgeons should be familiar with the onion-like arrangement of the visceral and parietal fasciae. The dedicated assistants should provide three-directional traction and adjust the direction of forces timely in a manner that the resultant forces are always in a direction perpendicular to the fasciae that are to be dissected. The fixation of the mesorectum and the mesocolon to the pelvic and abdominal wall can also be exploited as a natural counter-retraction. To separate loosely attached visceral and parietal fasciae, the application of splitting forces on opposite fasciae or sliding the forceps along the interface will provide quick separation and maintenance of the integrity of the fasciae. In summary, careful attention to the direction and strength of three directional retractions on parietal and visceral fasciae will help stretch and open up the areolar surgical tissue plane, skillful maneuver in separation and dividing of the attachment of two fasciae will ensure a precise inter-fascial dissection and help achieve total mesorectal excision or complete mesocolic excision, reducing the risk of the residual of the mesentery and inadvertent injuries to adjacent tissues and autonomic nerves.