Caudal-to-cranial Approach in Laparoscopic Right Hemicolectomy with Complete Mesocolon Excision and D3 Lymph Node Dissection

Summary

Laparoscopic surgery is widely used in the treatment of right-sided colon cancer and offers numerous advantages. This paper describes the caudal-to-cranial surgical approach combined with complete mesocolic excision (CME) and D3 lymph node dissection, which may potentially reduce the technical difficulty and appear to be a safe approach.

Abstract

Laparoscopic right hemicolectomy (LRH) has been proven to be an effective and safe surgical approach. However, due to the numerous vessels involved in the right colon and the variability of individual anatomy, LRH still faces many challenges. In the early stages, two surgical approaches were reported in the literature: the lateral-to-medial and medial-to-lateral approaches. The lateral-to-medial approach is typically used in open surgery. Currently, with the development of technology, multiple surgical approaches for LRH are available. This paper reports on a caudal approach method, the caudal-to-cranial approach, combined with complete mesocolic excision (CME) and D3 lymph node dissection. The described procedural sequence-prioritizing the establishment of anatomical planes before vascular dissection-may facilitate precise vascular management by first defining the surgical landscape. This approach appears to enhance procedural safety and could potentially reduce operative difficulty by improving anatomical orientation. Our initial experience suggests that this method supports a thorough lymph node dissection, demonstrating its feasibility for performing CME and D3 lymph node dissection.

Introduction

Laparoscopic surgery is increasingly used in the treatment of right-sided colon cancer. It offers advantages such as minimal trauma and faster postoperative recovery compared with traditional open surgery. Laparoscopic right hemicolectomy (LRH) combined with complete mesocolon excision (CME) and D3 lymph node dissection has become the standard treatment for right-sided colon cancer^1,2. However, many controversies still exist in its application, including the surgical approach, the definition of the medial boundary of mesenteric resection, and the extent of lymph node dissection³. Traditional open surgery mainly employs the lateral-to-medial approach, whereas LRH differs and employs various approaches, primarily including the medial-to-lateral (medial) approach, the cranial-to-caudal approach (cranial), and the caudal-to-cranial (caudal) approach. Whether these different approaches impact patient oncological prognoses and surgical safety remains controversial and lacks consensus^4,5.

In the early stages of LRH, most practitioners applied the medial approach. The medial approach prioritizes vascular ligation before developing the dissection plane, which may better adhere to the principles of tumor-free operation and the No-touch Isolation Technique (NTIT)^6,7. Jiao et al.⁸ suggested that the cranial approach is an effective and safe surgical method that clearly exposes the branches of Henle's trunk, offering advantages such as less intraoperative bleeding, shorter operation time, and lower risk of vascular injury. However, due to the numerous vessels involved in right hemicolectomy and the variable vascular anatomy, both methods may have a steep learning curve for beginners⁸.

Currently, for right-sided colon cancer surgery, our center primarily employs the caudal approach. The caudal approach prioritizes plane dissection, first developing and expanding the dissection plane before ligating the central vessels. It provides excellent exposure to the Gerota's fascia, the posterior ureter and gonadal vessels, as well as the descending and horizontal portions of the duodenum and the pancreatic head⁹. This facilitates a more thorough exploration of the posterior area of the tumor, which is essential for T4-stage tumors. It may also assist the surgeon in achieving a comprehensive assessment of the entire surgical procedure at an early stage. This approach can also be applied to patients with a high Body Mass Index (BMI). In high-BMI patients, adipose tissue is more abundant, the mesentery is thick, and vascular dissection is relatively difficult¹⁰. After dissecting the dorsal aspect of the right colon mesentery from Gerota's fascia, the dorsal endpoints of the vascular anatomy can be exposed, which may facilitate vessel skeletonization and reduce the risk of vascular injury. However, in patients with a history of previous lower abdominal or pelvic surgery, or in those with persistent descending mesocolon (PDM), if severe adhesions are present at the dorsal membranous bridge of the right colon mesentery, this approach may not be suitable, and the medial or the cranial approach should be considered instead. From September 1, 2022, to June 30, 2025, we performed 33 cases of laparoscopic radical resection surgeries for right-sided colon cancer using the caudal approach, which appears to be a safe approach.

Protocol

This study and surgical protocol were approved by the Medical Ethics Committee of the Second Affiliated Hospital of Zhengzhou University (Ethics Approval No: KYS2021096, October 11, 2021). All patients provided written informed consent forms. All procedures were performed by the same core surgical team, led by attending surgeons with extensive experience in laparoscopic colorectal surgery. This study is retrospective.

1. Patient selection (Figure 1)

1. Inclusion criteria: Include patients with preoperative examination confirmed right-sided colon cancer without distant metastasis, preoperative stage I-III, who underwent the caudal approach surgical method, preoperative multidisciplinary team (MDT) assessment indicated no significant contraindications, and pathological report indicated adenocarcinoma.
2. Exclusion criteria: Exclude patients with severe cardiopulmonary dysfunction, unable to tolerate laparoscopic surgery, tumor stage IV or locally advanced (e.g., tumor invading duodenum, ureter, etc.), emergency surgery was performed due to tumor hemorrhage, enterobrosis, etc., the medial approach, the cranial approach, and the other approaches were performed in LRH.

2. Preoperative preparation

1. Complete the preoperative tests, including blood routine test, liver function, renal function, infectious disease screening, and coagulation function. Complete colonoscopy and pathological examination, and all relevant imaging examinations, including contrast-enhanced Computed Tomography.
2. Carry out an MDT discussion involving oncologists, gastrointestinal surgeons, radiologists, radiation oncologists, gastroenterologists, and anesthesiologists to determine the best procedure. Carry out bowel preparation routinely in patients (except those with intestinal obstruction). Assess nutritional risk preoperatively and administer enteral nutritional supplements as appropriate.
3. At 30 min preoperatively, administer intravenous antibiotic prophylaxis for infection (Cefoxitin 2.0 g in normal saline).

3. Surgery procedure

1. Perform general anesthesia with endotracheal intubation. Perform central venous catheterization after anesthesia.
2. Patient position: Place the patient in the supine position with legs apart. Have the surgeon stand on the patient's left side, the first assistant stands on the patient's right side, and the laparoscopic mirror operator stands between the patient's legs. Place the monitor on the patient's head side (Figure 2A).
3. Use a five-port technique: Cut the skin with a blade. Place a 10 mm trocar 4-5 cm below the umbilicus as the observation port. Establish pneumoperitoneum and set the pressure at 11-13 mmHg. Place a 5-mm trocar at the midpoint between the left anterior superior iliac spine and the umbilicus as the surgeon's auxiliary operating port. Place a 12 mm trocar symmetrically opposite the auxiliary port at the umbilical level as the surgeon's main operating port. Place a 10 mm trocar at McBurney's point as the assistant's main operating port. Place the assistant's auxiliary operating port (5 mm trocar) symmetrically opposite the main operating port at the umbilical level. See Figure 2B for the trocar layout.
4. Adjust the table position as follows: For the caudal approach plane dissection, apply a head-down tilt of 30° and a left tilt of 15°. For dissecting central compartment lymph nodes and separating the transverse colonic mesentery from the mesogastrium, apply a head-up tilt of 30° and a left tilt of 15°.
   NOTE: For the caudal approach plane dissection, this position shifts the small bowel to the left upper abdomen, facilitating the exposure of the root of the small bowel mesentery. For central compartment lymph node dissection, this position shifts the small bowel to the left lower abdomen, facilitating flattening of the right mesocolon.
5. Dissect and develop the right retro-colic space and the pre-pancreatoduodenal space with the caudal approach.
   1. Apply head-down tilt 30° and left tilt 15°. Use an ultrasonic knife to perform layer dissection, tissue incision, and vascular anatomy. Apply traction to the ileocecal region and the root of the small bowel mesentery, reflecting them cranially to expose the membranous bridge between the right mesocolon and the retroperitoneum (Figure 3A). Incise the membranous bridge along the avascular line (line of Toldt) approximately 1 cm above the right common iliac artery to enter the right retro-colic space. Expand the space cranially until the horizontal part of the duodenum is visible medially (Figure 3B).
      NOTE: Under counter-traction, maintaining tension, entry into the right retro-colic space is easy. Using the horizontal duodenum as a guide avoids entering the space posterior to the duodenum. The method of blunt and sharp dissection can be adopted.
   2. Use the vessels on the medial side of the duodenum as landmarks (Figure 3C). Perform a deliberate crawling up maneuver to identify the pancreas. Dissect the pre-pancreatoduodenal space to expose the pancreas. Proceed with medial dissection to reveal the superior mesenteric vein (SMV; Figure 3D). Incise the Toldt's fusion fascia lateral to the duodenum (Figure 3E) to connect the right retro-colic space and the pre-pancreatoduodenal space. Dissect cranially near the colon hepatic flexure. Incise the parietal peritoneum of the right colon (Figure 3F). This completes the plane dissection for the caudal approach (Figure 3G).
      NOTE: Dissection from the duodenum to the pancreatic surface is a challenging step in the caudal approach, with risk of injuring vessels between the duodenum and pancreatic head.
6. Divide the right mesocolon medially, dissect the surgical trunk, and remove the D3 lymph node
   1. Apply head-up tilt of 30° and left tilt of 15°. Return the ileocecal region and push the small bowel towards the lower left abdomen. Have the assistant's left forceps pull the middle colic vessels cranially, and the right forceps lift the ileocolic vascular pedicle. Incise the mesentery at the oblique fold below the ileocolic vascular pedicle (Figure 4A), connecting with the previously dissected right retro-colic space. Continue incising the mesentery medially and expose the SMV (Figure 4B).
      NOTE: Identifying the SMV is key in this step. Depending on anatomical variations, the SMV may lie medial, lateral, or crisscrossed with the superior mesenteric artery (SMA)⁹. The medial oblique extension line of the incision below the ileocolic vascular pedicle will intersect the projection line of the SMV in the mesentery.
   2. Use the line from the root of the ileocolic vein (ICV) to the medial edge of the middle colic artery (MCA) as the cutting line, incise the right mesocolon. Open the SMV vascular sheath and dissect within the sheath to expose the main right colonic vessels: ileocolic vein/artery (ICV/ICA), right colic artery (RCA), and MCA (Figure 4C). Perform mesenteric resection and D3 lymph node dissection along the medial border of the SMV. Use the disposable ligation clip for ligation. Ligate the ICV/ICA, RCA, and MCA using disposable ligation in a stepwise manner. For tumors of the cecum/ascending colon, only the right branch of the MCA required ligation (Figure 4D).
      NOTE: The RCA arises independently in approximately 33.4% of cases¹⁰. The MCA usually arises from the SMA approximately 2 cm below the pancreatic neck. Care must be taken to avoid injuring large jejunal veins that may run above or below it.
   3. Dissect the Henle's trunk and its branches, then ligate the colic venous tributaries. Henle's trunk is often short, so dissect its branches and clearly expose it before ligating the RCV to avoid injuring the anterior superior pancreatoduodenal vein (ASPDV) and right gastroepiploic vein (RGEV; Figure 4E). This completes all medial approach steps (Figure 4F).
      NOTE: Henle's trunk anatomy is complicated with frequent variations^9,10 and is a common site of intraoperative bleeding. Extreme care is required during dissection.
7. Transition to the cranial approach dissection
   1. Open the gastrocolic ligament outside the gastroepiploic vascular arch (Figure 5A). Separate the transverse colonic mesentery from the mesogastrium, connecting with the medial dissection plane (Figure 5B). Dissect rightwards to the hepatic flexure, entering the right retro-colic space and connecting with the caudal approach plane, and completing the excision of the right mesocolon. Trim the mesocolon and ileal mesentery at the planned transection lines. Perform transection using a 60 mm endoscopic linear stapler.
8. Perform digestive tract reconstruction and specimen extraction
   1. For intracorporeal digestive tract reconstruction: Place the specimen in an endoscopic retrieval bag. Make a hole in the taenia coli 6 cm from the transverse colon stump. Make a hole 2 cm from the ileal stump. Perform a side-to-side isoperistaltic anastomosis (overlap technique) between the ileum and transverse colon using a 60 mm endoscopic linear stapler (Figure 6A). Close the common opening with a continuous 3-0 barbed suture (full thickness) followed by seromuscular imbrication. Extend the infra-umbilical observation port incision approximately 3-5 cm (Figure 6B) according to tumor size for specimen extraction.
      NOTE: Intracorporeal digestive tract reconstruction requires a strict aseptic and non-touch technique. Placing the specimen on the liver surface helps expose the surgical field of vision and avoid obstruction.
   2. Extracorporeal digestive tract reconstruction: Make a 5 cm midline mini laparotomy in the upper abdomen. Incise the abdominal wall layer by layer and place a wound protector. Extract the specimen extracorporeally. Using the same reconstruction method as above: make holes and perform a side-to-side isoperistaltic ileotransverse anastomosis (overlap) using a 60 mm linear stapler. Close the common opening with a continuous 3-0 barbed suture.
9. Irrigate the abdominal cavity, place a drain, and close the wound
   1. Re-establish pneumoperitoneum. Irrigate the abdominal cavity with normal saline (500-1000 mL). Place one drain near the anastomosis, and another in the pelvis. Suture the abdominal incision in two layers: first, close the peritoneum and linea alba continuously with a No. 2 barbed suture; then, interruptedly suture the skin with 2-0 silk sutures. For trocar holes, close the peritoneal layer with 1-0 silk sutures, followed by closing the skin with 2-0 silk sutures.

4. Postoperative management

1. Provide no food or drink on postoperative day (POD) 1. Administer total parenteral nutrition (TPN), paying attention to fluid, electrolyte, and acid-base balance. Start small by taking frequent sips of water on POD 2. Initiate a liquid diet, mainly consisting of oral nutritional supplements (ONS), after passing flatus. Give peptide-based nutritional supplements as needed.
2. Assess risk of venous thromboembolism (VTE) postoperatively. Use the Caprini risk assessment model to assess the risk of VTE. Implement preventive measures such as pneumatic compression devices. Administer low molecular weight heparin (LMWH) for anticoagulation if necessary.
3. Use prophylactic antibiotics for no longer than 48 h postoperatively. Remove the drainage tube when the following standards are met: The heart rate, breath, and blood pressure are stable. The body temperature and gas expulsion are normal. The volume and color of the drainage fluid are normal, and the volume is less than 100ml per day. Remove the pelvic drain on POD 3-5. Assess anastomotic fistula risk on POD 7. Remove the perianastomotic drain on POD 7-8.

5. Statistical analysis

1. This is a descriptive study. Present continuous variables as mean ± standard deviation, and categorical variables as number (percentage).

Results

From September 1, 2022, to June 30, 2025, we performed a total of 129 right hemicolectomy cases. According to the inclusion and exclusion criteria, 33 patients were included in the study. No cases required conversion to open surgery. The mean patient age was 64.42 ± 10.46 years. Mean BMI was 22.80 ± 3.26 kg/m². Seven patients (21.21%) had a history of abdominal surgery. One patient (3.03%) presented with preoperative intestinal obstruction (Table 1). Mean operative time was 181.25 ± 25.91 min. Mean intra...

Discussion

The development of membrane anatomy theory has promoted the progress of laparoscopic gastrointestinal oncology surgery, transforming the focus from vessel-oriented to plane-oriented anatomy. This not only improves surgical safety but also leads to better oncological prognoses. CME and D3 lymph node dissection hold significant research value and clinical importance in laparoscopic right-sided colon cancer surgery^11,12. CME, based on embryology and anatomy, emphasi...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Abdominal Trocar	Golden Stapler Surgical Co.,Ltd	JW12TLV; 5mm, 10mm, 12mm	Establishing operative channels through abdominal puncture
Absorble surgical suture	Jian Shi Surgical Instrument Co.,Ltd	3-0	Close the common opening of the small intestine and colon
Absorble surgical suture	Jian Shi Surgical Instrument Co.,Ltd	No. 2	Close the peritoneum and linea alba continuously
Absorble surgical suture	B.Braun Surgical.S.A	3-0	Suture the intestinal stump
Disposable ligation clip	Kang Ji Medical Instrument Co.,Ltd	KJ-JZJ06L, KJ-JZJ06ML	Ligation of blood vessels
Disposable medical drainage tube	Chen Sheng Medical Technology Co.,Ltd	Type G	Drainage and Irrigation
Endoscopic linear stapler	Reach Surgical Instrument Co.,Ltd	IM60WHT	Digestive tract reconstruction
HD laparoscope	KARL STORZ SE & Co. KG	TC200	——
Laparoscopic instruments	Tonglu youshi medical equipment co., Ltd	——	——
Silk braided non-absorbable suture	Johnson & Johnson Medical (China) Ltd.	2-0	Suture the skin
Surgical hemostasis   ablation electrotome	Yi Boleiming Medical Technology Co.,Ltd	LM-A5	Perform a mini-laparotomy on the abdomen
Ultrasound knife	Innolcon Medical Technology Co.,Ltd	SG35 Model, 5mm diameter	Surgical procedure