Colorectal cancer is a major disease threatening human health (1–3), with its diagnosis and treatment arousing immense concern worldwide (4–6). Laparoscopic radical colorectal resection has become an established technique for treating colorectal cancer. It includes complete mesocolic excision (CME) and total mesocolic excision (TME) (7–9), which are two surgical methods that have become gradually standardized in the recent years. However, the choice of access for laparoscopic radical colorectal resection remains controversial.

Compared with laparoscopic radical rectal cancer resection, laparoscopic radical right hemicolectomy is more complicated, and the surgical approach and criteria for its selection has undergone many changes, owing to factors such as vascular variation, difficulties in locating vital, adjacent tissues and organs and performing colon lymph node dissection (10, 11). Among the possible surgical approaches, the “intermediate approach” proposes ligation of the dissociated mesenteric vessels first, and better aligns with the principle of the no touch isolation technique in surgical oncology (12–14). Due to the aforementioned difficulties, surgeons experienced with laparoscopic techniques often prefer the intermediate approach when performing laparoscopic radical right hemicolectomy. However, the disadvantage of the intermediate approach is that the complexity of colon anatomy may lead to difficulties in performing operation steps (15, 16), such as those involving separating and revealing mesenteric-related vessels in obese patients, accessing the correct anatomical plane, and disconnecting the vessels in areas where lesions are located. Before it become clear whether a tumor can be radically resected, the operator may be very passive.

Additionally, the risk of injury to both Henle's stem and superior mesenteric vessels is increased due to large anatomical variations after right hemicolectomy (Figure 1). The transition from the duodenum to the pancreas head surface is also prone to damage by inadvertent entry into the pancreatic tissue, resulting in bleeding (17).

Finally, the approach is challenging for novice surgeons to perform; thus, surgeons are constantly exploring new surgical approaches and improved points of access (18, 19). In this study, we compared the clinical data from patients who underwent the small bowel mesenteric priority approach and the traditional intermediate approach for radical right hemicolectomy.

Right colon cancer includes malignant tumors occurring in the cecum, ascending colon, and hepatic flexure. With the popularization and development of laparoscopic surgery, laparoscopic D3 lymph node dissection and CME for radical right hemicolectomy has become the standard for right colon cancer treatment (21) due to many procedural advantages, such as less trauma, accurate access at an anatomical level, standardized ligation of the mesenteric root vessels and lymph node dissection, and fewer complications and shorter recovery time for patients (22, 23). However, radical resection of right hemicolectomy includes its drawbacks, particularly vascular variation and difficulty in removing colonic lymph nodes. Furthermore, it involves several important organs and tissues such as the ureter, pancreas, and duodenum (24, 25), hence that the selection of an appropriate approach is vital to surgery success.

The traditional intermediate approach is currently the most widely used approach. However, this approach has many disadvantages. First, when searching for the Toldt gap, the mesentery must to be incised from below the ileocolic vessels. Due to the large vascular variation, bleeding during the separation of the vessels leads to an unclear field, and it is easy to enter the wrong level which results, in bleeding and injury to the ureteral genital vessels and retroperitoneal organs such as the anterior renal fascia. Furthermore, the integrity of the colonic mesentery is damaged. The anatomy of the middle approach from the duodenum to the anterior space of the pancreatic head may cause accidental injury the stem of Henle and entry into the pancreatic tissue, resulting in hemorrhage and unclear vision. Another disadvantage is that in obese patients, as it is challenging to enter the correct level through the middle approach in these patients. As the anatomical layers of obese patients are not well demarcated, they can lead to bleeding and complications during the operation (26). Finally, the complexity of the operation of the intermediate approach creates a steep learning curve for novice surgeons, thus requiring both experienced surgeons and surgical assistants.

This study retrospectively analyzed the clinical data of patients undergoing laparoscopic radical right hemicolectomy for right colon cancer in our gastrointestinal surgery department from 2019 to 2022. The clinical results were compared between patients who underwent the small bowel mesenteric priority approach and those who underwent the traditional intermediate approach for radical right hemicolectomy. The results showed that the operation time of the small bowel mesenteric priority approach (experimental group) was shorter than that of the traditional intermediate approach (control group). Although the difference in intraoperative bleeding was not statistically significant, the scatter plot analysis showed that the priority small bowel mesenteric approach reduced the risk of intraoperative hemorrhage, compared with that of the intermediate approach. The two approaches were consistent in terms of the number of lymph nodes cleared and postoperative recovery.

The feasibility and favorable clinical results of the priority access to the small intestine mesentery are well demonstrated. This may be because when compared with the traditional intermediate approach, the small intestine mesenteric approach has several advantages. The small intestine mesentery at the expected dissection point is cut first, which is conducive to judging the blood supply at the dissected small intestine after completion of the right hemicolectomy, thus preventing the occurrence of anastomotic leak due to the loss of blood supply at the anastomosis. Additionally, because the anatomical position of the ileocolic vein is relatively fixed, the first large vessel revealed after vertically cutting the small intestinal mesentery is the ileocolic vein. This avoids the difficulty in determining the location and course of the right hemi-colon vessels and reduces bleeding caused by accidental damage to vessels and tissues during surgery. Another advantage of the small intestine mesenteric priority approach is that it opens the small intestine mesentery first, which prepares for the subsequent step with the genetic branches of the mesenteric vessels. It also clears the operation field as the Toldt gap is expanded while dissecting the vessels. Furthermore, the small intestine mesentery is opened first, so the operator can cut the small intestine mesentery and can extend the Toldt gap to the caudal side by cutting the “hole” in the small intestine mesentery. This approach also opens the medial gap at the largest level, which is more convenient for the implementation of total colonic mesocolic resection. In this study, the surgical operations in both the control and experimental groups were performed by an experienced surgeon, and the learning curve for this surgeon who was proficient in the traditional method (25 cases) and on the learning curve for the new method (13 cases). The new method has been widely promoted and studied among young surgeons in our hospital, and for surgeons who mastered laparoscopic operations and were proficient in gastrointestinal anatomy, the learning curve was concentrated in 10–15 cases The learning curve for the traditional method in our hospital is 25–30 cases, which is also more aligned with the global learning curve markers (27, 28). Therefore, it can also be concluded that the new method is more simple for novices to learn and master. However, due to the small number of young surgeons in our hospital, CUSUM analysis has not been used for the time being, and the accurate learning curve of the new method needs to be further analyzed.

The approach avoids the need to turn the intestinal canal to find the caudal approach gap to expand the right colonic gap, reducing both operation time and patient discomfort, especially for patients who have obesity and mesenteric hypertrophy. It also reduces the risk of damaging blood vessels on the surface of Henle's stem and the pancreatic head. Even if there are accidental injuries to the vessels, it will be easier to handle due to greater exposure.

This study has some limitations. First, it is limited to the intermediate approach and the small bowel mesenteric priority approach. Future studies can explore the comparison of the therapeutic efficacy of the small bowel mesenteric priority approach with other approaches or combined approaches, and the results may improve the precision of laparoscopic techniques and clinical outcomes. Second, this is a single-center, retrospective study with a relatively small sample size and a limited study duration. It is necessary to validate the results of this study through conducting future studies with longer duration and large sample sizes.

In conclusion, compared with the traditional intermediate approach, the small bowel mesenteric priority approach in laparoscopic right hemicolectomy has the advantages of safety, minimal invasiveness, simplicity, and good operability. It is more conducive to ensuring an adequate surgical field and accurate anatomical positioning, and it can ensure similar clinical treatment results while better reducing the operating time, intraoperative bleeding, and other indicators.