Persistent Descending Mesocolon as a Key Risk Factor in Laparoscopic Colorectal Cancer Surgery

Abstract

Background: Persistent descending mesocolon (PDM) is a rare colonic anatomical variant. However, PDM's impact on the technical aspects and outcomes of laparoscopic colorectal cancer resection are unclear. Patients and Methods: This retrospective clinical cohort study was conducted at a high-volume cancer center in Japan to evaluate intra-and postoperative outcomes of laparoscopic colorectal cancer surgery in patients with (PDM+) or without (PDM-) PDM over the past 7 years. Results: Between January 2012 and September 2019, 2,775 patients underwent laparoscopic colorectal cancer resection at our center, including 60 (2.1%) cases of PDM. Preoperative detection was achieved in only 5 patients (8.3%), 39 patients were men, and 21 patients were women. The average age was 67 years. Twenty patients had a history of prior abdominal surgery (33.3%), with little or no subsequent adhesions. The average duration of sigmoidectomy in PDM+ patients (n=17; 217.7±14.2 min) was significantly longer than that in 176.2±2.4 min; p=0.003), as was average blood loss (32.3±10.6 ml vs. 16.7±2.8 ml; p=0.03). Likewise, average operative time for high anterior resection in PDM+ patients (n=11; 227.1±20.2 min) was significantly longer than that in 195.6±3.0 min; p=0.048). Rates of postoperative anastomotic leakage and postoperative recurrence did not differ in both groups. In PDM+ patients, retention of left colic artery had no impact on proximal specimen margins or occurrences of anastomotic leakage. Conclusion: PDM prolongs operative times and increases bleeding in laparoscopic colorectal cancer surgery and should be considered a risk factor when encountered.

Four cases of laparoscopic colectomy for sigmoid colon and rectal cancer with persistent descending mesocolon

“…Enhanced CT was routinely performed in other cases for supportive clinical information. Wang et al [ 8 ] reported that preoperative detection was achieved in 5 (8.9%) out of 60 colorectal cancer patients with PDM. Therefore, even when PDM is not diagnosed by preoperative examinations in colorectal cancer patients, it is necessary to have sufficient knowledge about PDM so that it can be appropriately treated during surgery.…”

“…It has been reported that the frequency of PDM was 2.4% in patients who underwent laparoscopic colectomy for left-sided colorectal cancer [ 2 ]. Moreover, that was 2.1% in patients who underwent laparoscopic colectomy for primary colorectal cancer [ 8 ]. In our institution, the frequency of PDM was 1.9% in 209 patients who had laparoscopic colectomy for left-sided colorectal cancer from January 2014 to December 2019, while that was 1.3% in 307 all the colorectal cancer patients receiving laparoscopic surgery during same period.…”

“…The most important considerations for the surgical treatment of colorectal cancer with PDM are the positional awareness of vessels including the IMA, LCA, and marginal artery in the shortened mesocolon. In PDM cases, the configuration of IMA branching were reported that LCA, S1 or second sigmoid artery (S2), and superior rectal artery (SRA) branched radially from IMA, referred to as “bear-claw IMA” [ 8 ]. Wang et al [ 8 ] reported that LCA was usually much shorter and may configure directly as a part of the marginal artery under those branching patterns.…”

“…In the era of laparoscopic colectomy for colorectal cancer, it has been noticed that there are extensive adhesions and a distinctive anatomy of colonic vessels in cases with PDM. Recently, several reports [ 2 – 8 ] have suggested tips and tricks for laparoscopic colectomy in colorectal cancer with PDM. We herein reported four colorectal cancer patients with PDM who underwent laparoscopic surgery along with the technical aspects, in terms of tips and tricks, including the characteristics of the preoperative images and the anatomical alterations of colorectal arteries and veins during the operation.…”

Laparoscopic Surgery and Robot-Assisted Surgery for Colorectal Cancer With Persistent Descending Mesocolon

“…The LCA forms part of the limbic artery, and the LCA and other limbic arteries may be near each other. 5,6 Laparotomy had a wide eld of view, and the operation was performed while grasping the entire image, so there was no problem. However, laparoscopic surgery has a limited eld of view, so anatomical grasping and recognition may be di cult; therefore, caution is required.…”