A surgical intervention might be highly variable amongst surgeons and centers. This variability has a potential relevance concerning clinical outcomes.

For right-sided colon cancer, the laparoscopic right hemicolectomy (LRHC) knows substantial variation. Especially since the surgical technique has been evolving during the latest decade with the introduction of intracorporeal anastomosis, a dissection technique within the correct embryological planes (complete mesocolic excision) and central vascular ligation of the segmental branches at its origin, resulting in an optimal lymph node dissection.

Given the insights from recent studies showing the association between quality of surgery and relevant clinical outcomes, there is a great need for a formative quality assessment of LRHC. Detailed objective assessment of the LRHC is currently not performed in clinical practice nor in surgical training. Quality assessment of LRHC has great potential to improve surgical training and furthermore, implementation of a standardized technique will ultimately lead to better quality of care for patients suffering from right-sided colon cancer.

The main objective of this study is to improve surgical outcomes for patient with right-sided colon cancer by a prospective sequential interventional cohort study that aims to standardize the surgical technique with subsequent controlled implementation after standardized review of the current practice in a nationwide multicenter setting. The primary endpoint is the 30-day morbidity according to the Clavien-Dindo classification system.

1. Prospective mapping of current practice with surgical variations in laparoscopic right hemicolectomy (total duration of inclusion 3 months) N= 40 centers N = 310 videos

   1. METC approval for the use of anonymized videos of a laparoscopic procedure and collection of corresponding clinical outcomes.
   2. Approaching hospitals for participation (high volume centers (50+ colon cancers).
   3. Prospective inclusion of consecutive patients undergoing laparoscopic right hemicolectomy in the participating hospitals in three months.

2. Development of Standard Laparoscopic Right Hemicolectomy: an (inter)national Delphi study

   1. Approaching specialists to participate in the Delphi method (from participating hospitals in step 1).
   2. Identification of crucial steps and measures according to literature and expert's opinion (Delphi method).
   3. Documentation of steps and the order in which they need to be performed, development of a competency assessment tool (CAT).

3. Skills center training facility

   a. Training the participating surgeons in the method of the standardized laparoscopic right hemicolectomy, as consented in the Delphi method.

4. Implementation of the standardized laparoscopic right hemicolectomy with proctoring during another period with prospective inclusion of consecutive patients with collection of surgical videos in all participating hospitals (N=40 centers, total 310 videos)

   1. Rating videos.
   2. Comparing with pre-implementation performance based on outcome measures reflecting oncological quality of surgery, and 30-day clinical outcomes.
   3. Comparing with pre-implementation performance based on the long-term outcomes. (3-year DFS and 5-year OS).

5. Implementing standardised lap right hemicolectomy (after learning curve without proctoring)

   1. Consecutive inclusion of patients (n=310)
   2. CT imaging
   3. Video analysis
   4. Competency analysis
   5. Variation analysis
   6. Clinico pathological data

Inclusion Criteria:

• Planned laparoscopic (extended) right hemicolectomy for colon cancer of the caecum, ascending colon or hepatic flexure;
• Age above 18 years;
• cTNM stage 1-3 (CT-staged);
• No prior midline or transverse laparotomy;
• ASA1-3;
• No immune modulating medication.

Exclusion Criteria:

• cT4b;
• Perforated disease;
• Acute obstruction;
• Emergency operation;
• Appendiceal cancer;
• Other primary malignancy treated within 5 years from diagnosis of colon cancer, except for curatively treated prostate, breast, skin and cervical cancer.