Laparoscopic right radical hemicolectomy: Central vascular ligation and complete mesocolon excision vs D3 lymphadenectomy - How I do it?

Abstract

In colon cancer surgery, ensuring the complete removal of the primary tumor and draining lymph nodes is crucial. Lymphatic drainage in the colon follows the vascular supply, typically progressing from pericolic to paraaortic lymph nodes. While NCCN guidelines recommend the removal of 10-12 lymph nodes for adequate oncological resection, achieving complete oncological resection involves more than just meeting these numerical targets. Various techniques have been developed and studied over time to attain optimal oncological outcomes. A key technique central to this goal is identifying the ileocolic vessels at their origin from the superior mesenteric vessels. Complete excision of the visceral and parietal mesocolon ensures the intact removal of the specimen, while D3 lymphadenectomy targets all draining regional lymph nodes. Although these principles emphasize different aspects, they ultimately converge to achieve the same goal of complete oncological resection. This article aims to simplify the surgical steps that align with the principle of central vascular ligation and mesocolon mobilization while ensuring adequate D3 dissection.

Key Words: Carcinoma caecum; Carcinoma ascending colon; Right hemicolectomy; Extended right hemicolectomy; Central vascular ligation; Complete mesocolon excision; D3 lymphadenectomy; Laparoscopic right hemicolectomy; Minimally invasive hemicolectomy

Core Tip: Despite many decades of research, there is no consensus on standard surgical techniques for right-side colon cancer. The complete oncological resection is much more than simple number of harvested lymph nodes. Identifying the ileocolic vessels at their origin from superior mesenteric vessels is the central technique to serve this purpose. Complete visceral and parietal mesocolon excision removes the intact specimen. D3 lymphadenectomy removes all draining regional lymph nodes. Both principles serve the same goal with different emphases. So addressing adequate lymphadenectomy with complete negative margin R0 resection is central to this article.

INTRODUCTION

Radical right hemicolectomy remains the preferred treatment for right-sided colon cancers, with the removal of draining lymph nodes being a crucial step for long-term survival. Despite decades of research, controversies persist regarding which lymph node stations should be removed and the establishment of universal nomenclature. The Japanese classification for colon cancer categorizes regional lymph nodes into D1 (pericolic lymph nodes), D2 (pericolic and intermediate lymph nodes), and D3 (nodes at the origin of blood supply)[1]. In right hemicolectomy, D3 dissection entails removing lymph nodes along the ileocolic (ICL) artery, the right colic artery if present, and the right branch of the middle colic artery (MCA). Extended right hemicolectomy includes resection of lymph nodes along the MCA, including its left branch[2] (Figure 1). The JCOG0205 study, comparing oral with intravenous fluorouracil as adjuvant chemotherapy for stage III colorectal cancer, reported a 5-year overall survival rate of 87.5% in the D2/D3 dissection group[3].

Figure 1 Line of resection for ascending colon/ caecum malignancy (blue line) & malignancy near hepatic flexure (purple line). Resection areas are shaded.

An oncologically appropriate surgery with R0 resection and adequate lymphadenectomy significantly improves the survival of colon cancer patients[4,5]. Complete mesocolon excision (CME) with central vascular ligation (CVL) has been associated with a 15% better overall survival at 5 years, with this improvement reaching up to 27% in stage III cases[6]. The fundamental principle is to remove the cancer-bearing segment of the colon along with the intact fascia and lymphovascular drainage[5]. The Japanese Society recommends D2 dissection for early-stage and D3 dissection for higher stages, with a focus on retrieving more affected lymph nodes. European centers advocate for CME + CVL, with an emphasis on embryological planes of surgery. Both principles have been developed independently to achieve the best possible survival outcomes and are the result of constant efforts by dedicated cancer surgeons, evolving from simply ligating feeding vessels. In this paper, we describe our surgical technique involving CME + CVL while also addressing D3 lymph node removal.

SURGICAL TECHNIQUE

Preoperative preparation and patient position

Before surgery, patients undergo preoperative bowel preparation with a laxative, along with prophylactic intravenous third-generation cephalosporin and metronidazole administered 30 min prior. Patients are positioned in a low lithotomy position, with a body warmer blanket and belt applied over the chest. Shoulder supports are utilized, and the legs are secured in lithotomy poles along with deep vein thrombosis pumps. A 12-mm camera port is inserted just above the umbilicus, and two 5-mm ports are inserted along the midclavicular line in the epigastric and left iliac regions. An additional 5-mm port may be used in the right iliac region for retraction. The table is positioned in the Trendelenburg position with the right side upwards.

Exposure of superior mesenteric vessels

The mesentery of the ascending colon and terminal ileum is retracted upwards and laterally, creating tension on the ICL pedicle. This maneuver induces a stretch in the midline at the origin of the ICL pedicle from the superior mesenteric vessels, facilitating identification of the superior mesenteric vein (SMV). The mesentery is incised along an appropriate line over the SMV, below the third part of the duodenum and approximately opposite the falciform ligament. Fibrofatty and lymphatic tissue are reflected towards the right, exposing the right side of the SMV. The origin of the ICL pedicle is identified, and further dissection superiorly over the SMV reveals the MCA.

Ligation of ICL pedicle

The duodenum is identified, and the mesentery overlying it is reflected, revealing an avascular plane. Continued inferior dissection over the SMV allows for the skeletonization of the ICL pedicle origin. All lymphatic tissue is reflected towards the right, and the ICL pedicle is doubly ligated at its origin with hemoclip and then cut (Figure 2).

Figure 2 Ileocolic pedicle skeletonized and ligated at origin.

Ligation of the right branch of MCA or MCA at the origin

The MCA is identified through previous dissection, and the transverse colon is retracted upwards to expose both the right and left branches of the MCA. In cases where the primary tumor is located in the cecum or ascending colon, the right branch of the MCA is ligated and cut (Figure 3). Alternatively, in cases where the primary tumor is around the hepatic flexure, the MCA is ligated at its origin. These resection lines allow for the removal of all draining lymph nodes up to D3 stations (Figure 4).

Figure 3 Right branch of middle colic artery ligated at division.

Figure 4 Middle colic artery origin from superior mesenteric artery.

Medial to lateral mobilization of mesocolon

The ligated ICL pedicle is lifted upwards, and dissection is performed along the fascia above the retroperitoneum, identifying Toldt’s fascia, a thin white fascia between the ascending colon anteriorly and the retroperitoneum posteriorly[7]. By pushing the mesocolon above the duodenum upwards and the duodenum downwards, mobilization in an avascular plane is achieved. This embryological fascial plane that lines between the ascending colon anteriorly and the duodenum and pancreas posteriorly is Fredet’s fascia[8]. This mobilization, starting at the origin of the vascular pedicle along the right border of the SMV, proceeds laterally to the abdominal wall. Thin white fascia is kept intact towards the mesocolon and lifted above from the retroperitoneum, duodenum, and pancreas posteriorly. A mesenteric cut is made along the terminal ileum at 7-10 cm, depending on the location of the primary tumor and vascular supply. Mesocolon is cut along the MCA superiorly, and medial to lateral mobilization is completed above the duodenum and pancreas up to the hepatic flexure.

Supracolic and lateral dissection

The gastrocolic omentum is divided, entering the lesser sac and completing the mobilization of the hepatic flexure. Lateral dissection of the already mobilized ascending colon along Toldt’s line is performed, completing the dissection (Video 1).

Anastomosis and specimen delivery

The umbilical port is enlarged by 2-3 cm, and a wound protector is applied. The mobilized colon is delivered out, mesenteric cuts are identified, and the ileum is positioned alongside the transverse colon. Enterotomy is made towards the ascending colon, and a linear cutter stapler is introduced into the ileum and transverse colon, performing side-to-side anastomosis with the first fire. Subsequently, the linear cutter stapler is placed beyond the enterotomy towards the anastomosis, and anastomosis is completed with the second fire. The specimen is delivered out, and the ileotransverse anastomosis segment is positioned internally. This technique minimizes stapler usage and is cost-effective. Alternatively, intracorporeal anastomosis can be performed using Endo GIA staplers.

DISCUSSION

Studies on CME have demonstrated a survival advantage of > 10% with the adoption of this technique[9]. Similarly, research focusing on D3 lymphadenectomy has shown a relative risk reduction in mortality by 18%[10]. Despite originating from different understandings and evolving in various regions globally, both approaches ultimately aim for the same outcome of improved cure rates and follow similar surgical principles. CME emphasizes the complete excision of the mesocolon fascia on both sides, while D3 lymphadenectomy focuses on removing lymph nodes along major feeding blood vessels. However, both techniques ultimately dissect along embryological fusion planes. Surgeons have meticulously confirmed the existence of colonic mesentery along the full length of the colon, which can be separated from the retroperitoneum along an avascular areolar tissue[11,12]. Goligher described the separation of this mesocolon towards the midline starting from Toldt’s line and along Toldt’s fascia[13]. Despite these universally recognized embryological principles, there remains a lack of consensus on what constitutes radical optimal right hemicolectomy. CVL is the surgical principle that is widely accepted across studies[14-16]. The distinction between D3 Lymphadenectomy and CME primarily lies in the extent of longitudinal bowel length dissection.

Our study seeks to underscore the importance of modern surgical principles in right hemicolectomy for malignancy. In the contemporary era, all advancements should be integrated, and efforts should be made to standardize surgical techniques for colon cancer globally. These principles should be incorporated into the teaching curriculum of medical colleges. By incorporating crucial cure-defining steps into a consensus definition, there could be broader adoption of those surgical techniques. The incorporation of important surgical techniques has led to oncological benefits worldwide, such as total mesocolon excision for rectal cancer and D2 Lymphadenectomy for gastric cancer[14,17]. Recognizing these potential benefits, we propose that the nomenclature for standard right radical hemicolectomy surgery should reflect survival-improving steps. It is suggested to use “Central Vascular Ligation with Complete Mesocolon Excision (CVL + CME) with D3 lymphadenectomy” for right-sided colon cancer surgery. This emphasis on nomenclature may lead to better adoption of key surgical principles in this procedure, resulting in proven better overall survival rates globally.

CONCLUSION

Surgical techniques are refined based on embryology and tumor biology, with the adoption of these techniques resulting in better survival and cure rates in oncology. We advocate for the adoption of CME + CVL with D3 lymphadenectomy as the standard approach for carcinoma of the right side of the colon. Both open and minimally invasive approaches can be utilized when performing this surgery.