CME consists in the removal of an intact package of the tumor and its main lymphatic drainage. It was described by Werner Hohenberger in 2009 and derived from the concept of TME, developed 27 years earlier by Richard J. Heald. The technique entails sharp dissection of the visceral fascial layer from the parietal one, complete mobilization of the mesocolon with an intact fascia and true high ligation of the supplying arteries and draining veins at their origin, ensuring a maximal harvest of regional lymph nodes.
The vessels to ligate will depend on the location of the tumor and the theoretical pattern of lymphatic spread. A distance of 10 cm from the tumor must be respected.
For cancer in the Cecum and Ascendant colon, the procedure entails ligation of the Ileocolic, right colic vessels (when present) and right branch of the middle colic artery.
Hohenberger’s results showed a reduction of 5-year locoregional recurrence rate and an improvement in oncological outcomes. Many other studies have been published, suggesting better oncological outcomes, but possibly higher surgical morbidity rates for CME, without changes in surgical mortality.
In our hospital we perform CME in right colon cancer selectively, according to patient and disease characteristics. The most common elements we take in consideration are: age, comorbidities and node status.
The procedure is performed in 7 sequential steps:
1. Identification of the tumor and exposure of the mesocolon
2. Dissection of the mesocolon just above the SMV with identification and ligation of:
a. Ileocolic vessels
b. Right colic vessels (when present)
c. Middle colic vessels
At the origin, sequentially.
3. Dissection of the gastro-colic ligament and take-down of the hepatic flexure
4. Dissection of the transverse mesocolon and division of the transverse colon
5. Dissection of the mesentery 10 cm from the ileocecal valve and division of the terminal ileum.
6. Dissection of the Toldt’s fascia and complete mobilization of the right colectomy specimen.
7. Creation of an isoperistaltic latero-lateral ileo-colic anastomosis.
The specimen is removed at the end after inspection of the trocars, using a Pfannenstiel incision or an incision of a previous procedure the patient may have.