Surgical Trunk Oriented Laparoscopic Right Hemicolectomy (ST-LRH) for Right-Sided Colon Cancer

Summary

This protocol describes Surgical Trunk-oriented Laparoscopic Right Hemicolectomy (ST-LRH), a modified laparoscopic right hemicolectomy designed to optimize vascular management and lymph node dissection, simplify surgical procedures, and improve surgical safety and efficiency.

Abstract

Laparoscopic right hemicolectomy is a commonly utilized surgical procedure for the treatment of right-sided colon cancer. However, the high degree of difficulty in separating adjacent structures and the frequent vascular variations present in laparoscopic right hemicolectomy contribute to ongoing challenges, including unclear dissection planes, increased intraoperative bleeding, and insufficient lymph node clearance. This article proposes a combined approach that employs the surgical trunk as a guide, providing a clearer anatomical perspective and safer procedural steps. The study demonstrates all the steps of Surgical Trunk-oriented Laparoscopic Right Hemicolectomy (ST-LRH). A 67-year-old male was diagnosed with ascending colon cancer via colonoscopy and biopsy. Surgery was performed using the ST-LRH approach. The operation lasted approximately 125 min with 20 mL of blood loss. Postoperatively, no complications occurred, and the patient was discharged 7 days later. ST-LRH offers clearer exposure to the vascular anatomy of the surgical trunk and Henle trunk while reducing the risk of intraoperative bleeding. This approach is more procedural and standardized, facilitating broader adoption. Additionally, it contributes to reducing the learning curve for junior surgeons in mastering laparoscopic-assisted radical resection of right-sided colon cancer.

Introduction

Laparoscopic right hemicolectomy represents a prevalent surgical modality for the treatment of right-sided colon cancer¹. The procedure is often challenging due to the intricate anatomical planes of the right colonic mesentery², the substantial difficulty in dissecting adjacent structures, and the frequent vascular anomalies in the Henle trunk and surgical trunk³. Consequently, laparoscopic right hemicolectomy may encounter issues such as indistinct dissection planes, increased intraoperative hemorrhage, and inadequate lymphadenectomy⁴. At present, the conventional approaches to laparoscopic right hemicolectomy include three distinct modalities: the cephalad approach, the central approach, and the caudal approach⁵. Employing a singular approach may not suffice to achieve comprehensive delineation of variant vascular structures, preservation of a clear anatomical plane, and thorough lymph node dissection -- all of which are paramount for surgical success.

Considering these challenges, this article introduces a combined approach centered around dissection and manipulation along the surgical trunk, named "Surgical Trunk-Guided Laparoscopic Radical Resection for Right Hemicolon Cancer." This approach reduces intraoperative bleeding, clearly delineates the anatomical plane, and ensures comprehensive lymph node dissection -- factors that offer significant advantages in shortening operative time and reducing blood loss compared to existing unilateral methods.

ST-LRH represents an innovative solution within the field of minimally invasive oncological surgery. This method provides a new perspective on the standard practice of laparoscopic right hemicolectomy. The present study elucidates the specific procedural steps involved in ST-LRH, enabling evaluation of its applicability in clinical practice.

Protocol

This protocol follows the guidelines of the Human Research Ethics Committee of Zhujiang Hospital, Southern Medical University. Written informed consent was obtained from the patients for participation in the study. The required consumables and equipment are listed in the Table of Materials.

1. Identification of the Henle's trunk and veins via cephalic approach

NOTE: Prior to the mobilization of the transverse mesocolon, ascertain the accurate position of the tumor. Position the patient with the head elevated and the feet lowered. Subsequently, the following steps are undertaken:

1. Preparation before laparoscopy
   1. Under general anesthesia (performed following institutionally approved protocols), perform routine disinfection and draping.
   2. Make a 1-cm transverse incision 5–6 cm below the umbilicus with a pointed knife. Insert a 10-mm trocar to establish pneumoperitoneum, maintaining an insufflation pressure threshold of 15 mmHg.
   3. Place a 12-mm operator's trocar at the intersection of the left midaxillary line and a point 2 cm superior to the umbilicus. Insert a 5-mm trocar at the intersection of the left midclavicular line and a point 4 cm inferior to the umbilicus. Position two additional 5-mm trocars at locations symmetrical to the operator's trocar.
2. Exposure of the omental bursa
   1. Commence lateral to the vascular arch at the midpoint of the greater gastric curvature.
   2. Incise the gastrocolic ligament to expose the omental bursa. Then, dissect along the greater omentum on the greater curvature towards the right, separating it up to the right margin of the omental bursa (Figure 2A).
3. Incising and separating the anterior leaf of the transverse mesocolon
   1. Continue the dissection by incising the anterior leaf of the transverse mesocolon and separate the fused mesentery between the duodenum and the transverse colon to the right, reaching the lateral abdominal wall. This maneuver facilitates entry into the right Toldt's space (Figure 2B).
4. Entering the retroperitoneal space anterior to the pancreas and duodenum
   1. Incise the anterior leaf of the transverse mesocolon to access the retroperitoneal space anterior to the pancreas and duodenum. Within this space, dissect inferiorly to the neck of the pancreas and laterally to the ligament of Treitz (Figure 2C).
5. Management of the Henle's trunk and its veins
   1. At this anatomical level, visualize the Henle's trunk and its tributary veins, which course anteriorly in the region of the pancreas.
   2. Ligate the relevant veins, such as the MCV and SRCV. Do not manipulate arterial structures at this step (Figure 2D).
6. Complete mobilization of the transverse mesocolon
   1. Complete the mobilization of the superior aspect of the transverse mesocolon in its entirety (Figure 2E). Place a gauze pad as a marker/

2. Dissection of the retrocolic space via caudal approach

NOTE: Reposition the patient with the head lowered and the feet elevated to facilitate the caudal approach.

1. Dissection of the Toldt's space
   1. Initially, incise the peritoneum along the mesentery bridge to gain access to the Toldt's space for dissection (Figure 3A). During this process, ensure the assistant provides appropriate tension to help expose the loose reticular tissue between the gaps.
   2. Adjust the tissue as needed to enable separation. Meticulously dissect the Toldt's space from the bottom up using small gauze pads (Figure 3B).
   3. Upon completion of the dissection, place a gauze strip within the Toldt's space to guide subsequent procedures and protect the structures (Figure 3C).
2. Incising the fusion fascia and entering the anterior retroperitoneal space of the pancreas and duodenum
   1. Continue by incising the fusion fascia towards the left to facilitate entry into the anterior retroperitoneal space of the pancreas and duodenum (Figure 3D). Ensure the superior boundary connects with the cephalic gauze strip, and the medial boundary extends to the posterior projection of the superior mesenteric vein (Figure 3E).
   2. Upon completion of the dissection, place another gauze strip in the anterior retroperitoneal space of the duodenum and at the posterior projection of the superior mesenteric vein to guide the dissection of the surgical trunk and protect the posterior structures (Figure 3F).

3. Surgical trunk anatomy and separation

1. Flattening of the surgical trunk and localization of the preliminary incision line
   1. Have the assistant elevate the mesentery of the MCA and IMA/IMV to flatten the surgical trunk. Direct attention to the gauze strip placed at the ligament of Treitz on the cephalic side, which serves as the medial reference point for the peritoneal incision and dissection.
   2. Designate the area below the elevated ileocolic vessels as the lateral reference point (Figure 4A).
2. Peritoneal incision and preliminary dissection
   1. Begin the incision from the midpoint of the marked preliminary incision line, which often corresponds to the projection where the ileocolic vessels join the superior mesenteric vein.
   2. First, separate laterally, incising through to the posterior aspect where the gauze strip is visible. Continue the incision along the original preliminary incision line to the medial reference point (Figure 4B,C).
3. Identification and division of veins in the surgical trunk
   1. Enter the sheath of the superior mesenteric vein through the incision at the midpoint and perform intra-sheath separation. Ensure the dissection reaches the left boundary of the superior mesenteric vein.
   2. Identify the venous types of the surgical trunk at this stage (Figure 4D). After confirming the venous types of the surgical trunk, ligate and transect the ICV, ICA, MCA, and Henle's trunk at their bases (Figure 4E,F).
4. Lateral dissection and intestinal reconstruction
   1. Following the ligation and transection of the aforementioned vessels, dissect the ascending colon free from the lateral abdominal wall along the lateral aspect. Then, perform ileotransversostomy and abdominal closure.

4. Post-operative condition and management

NOTE: Treatment includes anti-infection measures, appropriate fluid replenishment, analgesia, inhibition of gastric acid secretion, and nebulization for supportive care.

1. Post-operative Day 1: Administer total parenteral nutrition. Give 5-10 mL of water every 1-2 h.
2. Post-operative Day 2: Continue total parenteral nutrition. Review subsequent examinations, including a complete blood count, blood biochemistry, and infection markers.
3. Post-operative Day 3: Initiate a full liquid diet. Remove the abdominal drainage tubes.
   NOTE: The criteria for removal of abdominal drainage tubes are: (1) The drainage fluid is clear, without blood, pus, sediment, etc.; (2) The drainage volume is less than 50 mL; (3) The patient's condition is stable, vital signs are stable, and re-examination results show no obvious abnormalities.
4. Post-operative Day 4: Transition to a semi-solid diet. Review subsequent examinations as on Day 2 and prepare the patient for discharge the following day.

Results

A 67-year-old male with controlled hypertension presented with rectal bleeding. A CT scan indicated right colon cancer with characteristic wall thickening (Figure 1A). Further colonoscopy and biopsy subsequently confirmed ascending colon cancer. The relevant pre-operative tests (e.g., blood count, urine analysis, blood sugar, blood electrolytes, serum creatinine, liver function tests, renal function tests, coagulation function tests, etc.) were completed. The function of the patient's vital ...

Discussion

When performing laparoscopic-assisted right hemicolectomy, the anatomical variations of the branch vessels of the surgical trunk and the Henle trunk are highly complex. Failure to accurately identify the origins of these vessels during the procedure may result in intraoperative hemorrhage, difficulty in achieving vascular ligation at the root, and even damage to the surgical trunk, leading to severe complications^7,8.

To address these c...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Electrocautery	YANLING Electronic	YLT1015
Hem-o-lok	Teleflex	544240
Laparoscopic	STORZ	26606 BCA
Laparoscopic trocar	KANGJI Medical	101Y.616
Lap-protector	KANGXIN Medical	KX09010002
Surgical stapler	Verykind Medical	0256
Surgical stapler	Verykind Medical	0516
Surgical sutures	Biomedical	10680
Surgical sutures	Johnson & Johnson	TJMQHK
Ultrasound knife	Johnson & Johnson	C9DY41