of Complete Mesocolic Excision for Colon Cancer

Fig. 11.1

Mesocolic lymph node stations according to the Japanese Society for Cancer of the Colon and Rectum. D1–D4 defined by colors: D1 red, D2 blue, D3 green, and D4 black. Right colic artery (dotted). (Used with permission of Wolters Kluwer from Bertelsen et al. [41])

Central Venous Ligation (CVL)

The group from Erlangen, Germany, has proposed nodal dissection even more extended than the D3 standard proposed by the Japanese, noted as central vascular ligation [7]. This description is pertinent to a right colectomy. Dissection in the plane of Toldt’s fascia between the mesocolic fascia and the retroperitoneum is performed with sharp dissection. Surgery involves a Kocher maneuver and takedown of the mesenteric attachments to the duodenum and uncinate process of the pancreas with complete dissection around the superior mesenteric vein and superior mesenteric artery. For tumors of the cecum and proximal ascending colon, the right branches of the middle colic artery and middle colic vein are ligated centrally. For tumors located more distally in the ascending colon, hepatic flexure or proximal transverse colon (proximal to the left branch of middle colic artery) lymph node removal is taken down to origin of the middle colic and ileocolic artery with these arteries divided centrally. For tumor in the distal transverse colon, lymph nodes in the gastrocolic ligament are included in the resection, as are gastroepiploic vessels, and their branches to the stomach are divided for a length of approximately 10 cm either side of the tumor. It is important to understand this definition, in contrast to the definition of D3, and they are often inappropriately discussed interchangeably in the literature.

Role for Minimally Invasive Surgery in CME

Laparoscopic colectomy is widely accepted as a preferred surgical technique for colon cancer [9]. CME was initially described as a massive open operation, albeit with good oncologic outcomes. The challenge for the surgeon is to use minimally invasive techniques to achieve the same oncologic outcomes while maintaining the benefits of MIS approach. Many reports continue to emerge describing the technical considerations for achieving a CME resection for colon cancer using laparoscopic or robotic surgery [10–15]. Most of these studies examine outcomes in resection of either the right colon or the transverse colon, as a proximal lymphadenectomy in a left colectomy is not technically difficult and is often performed [10]. Of these types of resection, transverse colectomy tends to be more technically difficult, with longer operative times due to increased technical complexity [16]. The technical complexity comes from dealing with the intricacies of the middle colic vessels, which are often shorter and have more varied branching patterns than often seen in other segments of the colon. A study by Spinoglio and coauthors of 202 robotic vs. 101 laparoscopic right colectomies with CME indicated a lower rate of conversion to open surgery (0% vs. 6.9%) in robotic vs. laparoscopic surgery (p = 0.01), with no difference in 5-year overall or disease-free survival [17]. A recent literature review comparing laparoscopic vs. open CME included 1 RCT and 11 non-randomized studies (4 from Europe and 7 from Asia) [14]. As expected, laparoscopic surgery offered faster return of gastrointestinal function and less complications. There were no differences in the quality of the resected specimen based on lymph node harvest and distance from tumor to the mesenteric transection . The laparoscopic approach offered better 3-year overall survival (OR 2.02, p = 0.001) and disease-free survival (PR 1.45, p = 0.05) [14]. These results suggest that a minimally invasive approach is at least feasible, but the survival results need to be interpreted with some caution as these studies were fraught with selection bias, and in many instances, laparoscopic resections were offered to lower-risk tumors. Although little has been published on the learning curve during CME, the few publications on this topic have demonstrated a long learning curve as demonstrated by longer operative time and time to achieve CME specimens of satisfactory quality [18, 19].

Please refer to Chap. 13 on laparoscopic right colectomy for malignant disease for details on operative setup and techniques of laparoscopic right colectomy with CME.

Perioperative Outcomes of CME

The extensive dissection close to or around the root of the major blood vessels in both CME and D3 lymphadenectomy has led to understandable concerns about possible morbidity compared to conventional colon cancer resection which does not mandate as an extensive dissection. Tables 11.1 and 11.2 summarize publications to date where either CME or D3 resections were compared to either a concurrent or historical control group who underwent conventional or “standard” colon cancer resection. Operative blood loss was reported on in three studies, with one study reporting a significantly higher blood loss in the CME group, with no difference noted in the other two studies [20–22] (Table 11.1). A recent pooled analysis by Alhassan and coauthors comparing [23] conventional colectomy and CME for colon cancer found a similar rate of pooled overall complications for conventional resection of 19.6% (95% CI:13.6–25.5) and 22.5% (95% CI:18.4–26.6) for CME [20–22, 24, 25]. However, the sole paper to date to report on intraoperative complications did note a significantly higher rate of intraoperative organ injuries in patients undergoing CME resection (CME 9.1% vs. 3.6% conventional resection, p < 0.001), notably splenic and superior mesenteric vein injury [25]. These findings suggest that a surgeon should be careful in performing dissection close to the root of major feeding vessels, as there is a risk of injury to structures such as the duodenum, pancreas, and SMV.

Table 11.1

Studies comparing conventional colectomy and CME or D3 lymphadenectomy with respect to operative and 30-day outcomes

Study	Study period	Country	Surgical approach	Number	OR time (mins)	Blood loss (ml)	Complication rate (%)	30-day mortality (%)
West et al. [39]	1999–2008	Denmark	Conventional CME	170 93	– –	– –	– –	– –
Bertelson et al. [22]	2007–2009	Denmark	Conventional CME	93 105	– –	270 250	20 22.6	7. 6.
Galizia et al. [20]	2004–2012	Italy	Conventional CME	58 45	130* 178	200* 280	12.1 13.3	– –
Bertelson et al. [34]	2008–2011	Denmark	Conventional CME	1031 364	– –	– –	– –	4 5
Bertelson et al. [40]	2008–2013	Denmark	Conventional CME	1701 529	– –	– –	28.5 30.6	– –
Merkel et al. [24]	1978–2014	Germany	Conventional CME	429 1099	– –	– –	17.2* 21.3	3.7 2.7
Olofsson et al. [21]	2007–2009	Sweden	Conventional CME	390 1694	148 155	204 232	20.8 22.8	0.8 3.6*
Kotake et al. [26]	1985–1994	Japan	Conventional D3 resection	3425 3425	– –	– –	– –	– –
Kotake et al. [27]	1995–2004	Japan	Conventional D3 resection	463 463	– –	– –	– –	– –