Laparoscopic right hemicolectomy with CME: standardization using the "critical view" concept

Abstract

Background: Complete mesocolic excision is gradually becoming an established oncologic surgical principle for right hemicolectomy. However, the procedure is technically demanding and carries the risk of serious complications, especially when performed laparoscopically. A standardized procedure that minimizes technical hazards and facilitates teaching is, therefore, highly desirable.

Methods: An expert group of surgeons and one anatomist met three times. The initial aim was to achieve consensus about the surgical anatomy before agreeing on a sequence for dissection in laparoscopic CME. This proposal was evaluated and discussed in an anatomy workshop using post-mortem body donors along with videos of process-informed procedures, leading to a definite consensus.

Results: In order to provide a clear picture of the surgical anatomy, the "open book" model was developed, consisting of symbolic pages representing the corresponding dissection planes (retroperitoneal, ileocolic, transverse mesocolic, and mesogastric), vascular relations, and radicality criteria. The description of the procedure is based on eight preparative milestones, which all serve as critical views of safety. The chosen sequence of the milestones was designed to maximize control during central vascular dissection. Failure to reach any of the critical views should alert the surgeon to a possible incorrect dissection and to consider converting to an open procedure.

Conclusion: Combining the open-book anatomical model with a clearly structured dissection sequence, using critical views as safety checkpoints, may provide a safe and efficient platform for teaching laparoscopic right hemicolectomy with CME.

Keywords: Colon cancer; Complete mesocolic excision; Critical view; Laparoscopy; Right hemicolectomy; Standardization.

Fig. 1

The open book model with the ileocolic-, the transverse mesocolic-, and the mesogastric page is shown (A, B). These pages form a symbolic book whose back is located at the axis of the venous GPCT (SRCV superior right colic vein, RBMCA right branch of middle colic artery, RGEV right gastroepiploic vein, GPCT gastro-pancreatico-colic trunk of Henle). See also Video No. 1

Fig. 2

Step 1: the correct dissection plane between the retroperitoneum and the ileocolic page can be ensured when the duodenum is viewed from ventral and below (red arrow) (A). The mesenteric root (dotted line) must consequently be located ventral to the viewer´s eye. B shows a corresponding intraoperative view (see also Video No. 2) with the duodenum and pancreas dorsal and the mesocolon ventral to the level of dissection. This view from medial under the ileocolic page is established by the medial to lateral dissection approach exposing the retroperitoneum. (Color figure online)

Fig. 3

Step 2: the V-View determines (A) the area of the ileocolic mesentery distal to the ileocolic vessels and on the right side of the SMV. B Shows the corresponding intraoperative view (Video No. 2) with the ileocolic and SMV axis highlighted (arrows)

Fig. 4

Step 3: A after incision of the ileocolic mesentery the SMV is dissected and the ICV divided (curved red arrow). B Shows the corresponding intraoperative view (Video No. 2) with the ICV after dissection. (Color figure online)

Fig. 5

Step 4: A division of the ICA, B shows the corresponding intraoperative view (Video No. 2) with the ICA before division (curved red arrow). The preparation then continues along the dotted line (A) in the axis of the SMV. (Color figure online)

Fig. 6

Step 5: before the dissection line on the right side of the middle colic vessels can be followed toward the transverse colon, the lesser sac needs to be opened by entering the gastrocolic ligament from the left side (red arrow A), which allows for a two-sided approach of the transverse mesocolic mesentery and the venous confluence of the GPCT. B Shows the corresponding intraoperative view (Video No. 3) with the lesser sac opened and the pancreas visible. (Color figure online)

Fig. 7

Step 6: dissection following the transverse mesocolon superiorly leads to the establishment of a sulcus (A). This sulcus runs along the inferior border of the pancreas, reaches the venous GPCT on the right side of the SMV, and crosses the pancreatic head toward the ventral renal fascia. The SRCV requires special attention as it bridges the gap between the transverse mesocolic and the mesogastric page. B Shows the corresponding intraoperative view (Video No. 3) with the lesser sac opened and the pancreas visible

Fig. 8

Step 7: division of the transverse mesocolic mesentery must not compromise left transverse mesocolic perfusion. This can only be ensured when division of arterial vasculature is limited to the right branch of the middle colic artery (A) which has to be unmistakably identified (curved red arrow). B Shows the corresponding intraoperative view (Video No. 4) with the right branch of the middle colic artery encircled with a ligature

Fig. 9

Step 8: the dissection of the venous confluence of the GPCT completes the mobilization of the colonic mesentery prior to bowl resection. Ventrally adjacent lymphatic tissue to the GPCT together with the SRCV remains with the resected specimen to ensure oncologic radicality. The trunk itself remains in situ (A). Furthermore, complete control of this vessel region prevents the risk of bleeding due to avulsion of the vessel when the colon is exteriorized from the abdomen for resection and anastomosis. B Shows the corresponding intraoperative view (Video No. 4) shortly before division of the GPCT veins