腹腔镜右半结肠肿瘤（图文演示）

LAPAROSCOPIC   RIGHT   COLECTOMY   FOR   CANCER
Authors
J Leroy, J Marescaux
Abstract
Laparoscopic colorectal surgery has gained wide acceptance as a treatment in a variety of benign and malignant diseases. The reproducibility and safety of all the principal colorectal procedures has been demonstrated. Surgeons performing right hemicolectomy using the laparo-assisted technique consider it more difficult than open colectomy. It is possible to perform a completely laparoscopic right hemicolectomy in advanced laparoscopic centers with many benefits: less postoperative pain, short-term postoperative ileus, earlier return to daily activity. This chapter describes surgical anatomy, indications and techniques of laparoscopic right colon resection for cancer.


中文版：腹腔镜右半结肠肿瘤（中文图文）

1. Introduction
▶
Laparoscopic colon resection for malignancy is performed in advanced laparoscopic centers in order to have the patient benefit of the advantages of a minimally invasive procedure (smaller wounds, shorter hospital stay and earlier food intake). However, because an open right colectomy is a straightforward and simple procedure in comparison to the laparoscopic approach which demands more time, resources and equipment, many are questioning whether or not the laparoscopic approach offers any added benefits.
This chapter describes techniques for laparoscopic right colon resection for cancer. Although early studies report a high port-site recurrence rate, the most important randomized controlled multicenter studies such as Barcelona, COST, COLOR, CLASICC trials (Bonjer et al., 2007) appear to refute this risk and demonstrate that the oncological outcomes are at least equivalent. Additionally, the “Lacy” trial demonstrated improved cancer-related survival for stage III disease in the laparoscopic group (Lacy et al., 2008).
While the data for long-term survival still needs to be confirmed, the multiple short-term benefits of laparoscopy have been confirmed by many studies: these are smaller wounds, less postoperative pain, shorter hospital stay and earlier oral food intake.
The method used in this laparoscopic right colectomy will be analysed and discussed, thus allowing for a constructive comparison of the varying techniques utilized by other experts.
This chapter will describe the technique that was used for this intervention so that it may be reproduced, but it is important to note that the approach can vary according to each case.

2. Anatomy
• Attachments of the colon





The vasculature of the right colon is based on the superior mesenteric vessels.
There are two main arteries, the ileocolic and the right colic. These arteries anastomose to become the often fragile marginal artery network.
The venous network is denser. The draining veins coalesce into two main trunks, the ileocolic and the right colic.

• Arterial network

1. Superior mesenteric artery
2. Jejunal branches
3. Middle colic artery (gives right colic branch)
4. Right colic artery (isolated in 10% of cases)
5. Ileocolic artery
6. Marginal arteries
7. Ileal branch

• Venous network

1. Right colic vein
2. Right gastro-omental vein
3. Marginal veins
4. Pancreatic branch
5. Gastrocolic trunk (right colic pancreaticoduodenal veins)
6. Ileocolic vein
7. Superior mesenteric vein

• Gastrocolic trunk

Frontal view of the anatomy of the gastrocolic trunk (GT) and its tributaries:
PV: portal vein
SV: splenic vein
SMV: superior mesenteric vein
GT: gastrocolic trunk
RGOV: right gastro-omental vein

• Variations
• Right colic vessels

There are several anatomical variations concerning the right colic vessels.
See schematics of the right colic artery (RCA), ileocolic artery (ICA), superior mesenteric artery (SMA) and superior mesenteric vein (SMV).
A and B: positioning of the right colic arteries in relation to the SMV (Shatari et al., 2003)
A, with RCA; B, without RCA.

• Gastrocolic trunk and tributaries

(Mori et al., 1992; Lange et al., 2000)
There are several anatomical variations in the number and position of the vessels (see A, B, C, D). In the study by Lange et al., the CT-scan highlights that the gastrocolic trunk is not present in 10% of patients.

3. Surgical anatomy
• Generalities

1. Attachment site
2. Toldt's fascia
3. Superior aspect of the transverse mesocolon
4. Inferior aspect of the transverse mesocolon
5. Posterior aspect of the right mesocolon
6. Anterior aspect of the right mesocolon
7. Mesentery
The vessels are located in the mesocolon, often hidden in the adipose tissue. Therefore, in obese patients, it is harder to identify them. To find them, it is important to have good anatomical landmarks. Good landmarks are the virtual line between the duodenojejunal and ileocecal junction (root of the mesentery), and the exposure of the inferior aspect of the right and transverse mesocolon.
The peritoneum is initially incised along or lateral to the superior mesenteric vessels. This maneuver is the key to early vascular control.
The vessels are approached cephalad along or lateral to the anterior surface of the superior mesenteric vein. This reveals sequentially the ileocolic vessels, followed by the right colic vessels.

• Middle colic artery

The right branch of the middle colic artery, which is the first branch of the superior mesenteric artery, is situated to the left of the gastrocolic trunk and superior mesenteric vein. The right branch must be divided separately to preserve the vascular supply of the left transverse colon. The trunk of the middle colic artery, which is often quite long, must be dissected in order to see the right branch. The lymph nodes present along the right colic artery are also dissected.

• Gastrocolic trunk

The gastrocolic trunk results from the junction of the right colic and right gastro-omental veins. It drains into the superior mesenteric vein on the inferior margin of the pancreatic head, above the third portion of the duodenum. Fragile pancreatic branches join it.
The right colic vein can be clipped electively (see step 10-Vascular division) preserving the gastrocolic trunk. This maneuver also applies to colectomies performed for malignancies.
In 10% to 30% of cases, an additional right colic vein can be found, arising from the ascending colon and draining into the superior mesenteric vein below the third portion of the duodenum.

• Ileocolic vessels

The ileocolic vein is exposed by incising the peritoneum overlying the superior mesenteric vein caudad to cephalad. This vein can sometimes be quite large and is located on the right border of the superior mesenteric vein. It is mostly situated inferior to the ileocolic artery. The latter crosses behind the superior mesenteric vein in 70% of cases (in front of it in the remaining 30%) after originating from the superior mesenteric artery.

4. Indications

▶
Laparoscopic colon resection for malignancy is gradually gaining acceptance in select centers of expertise with highly skilled surgical teams. Because of the ease and simplicity of open right colectomy, many have questioned if the laparoscopic approach offers any added benefits. In some subgroups of patients such as obese patients, the laparoscopic approach gives more advantages with a lower morbidity (Leroy et al., 2005). Whether performed totally laparoscopically or in a laparoscopic-assisted fashion, it reduces parietal trauma and thus minimizes the immediate morbidities related to a large abdominal incision. A good operative strategy is important to minimize the difficulties of the laparoscopic approach.
Accepted indications for laparoscopic right colectomy include:
- inflammatory bowel diseases;
- polyps;
- angiodysplasia;
- right colonic diverticulosis;
- malignant tumors < T3, with no evidence of local metastasis (Veldkamp et al., 2004).
In cancer, the worldwide consensus is to respect oncologic principles: primary vascular approach, large lymph node resection depending on the bowel segment to be removed, 5cm distal margin, and 10cm proximal margin, and R0 resection.

5. Basic principles

We perform a MEDIAL POSTERIOR RIGHT COLECTOMY. The surgeon, standing between the patient’s legs, separates the right and left colon respecting oncological principles.
The vascular division will be performed first. Then the colon and ileum will be divided followed by complete mobilization of the right colon. Finally, the anastomosis is done before or after the specimen’s removal in or out of the abdominal cavity.

6. Operating room set-up
&#8226; Organization

An organized operating room, along with good positioning of the patient and surgical team, plays a crucial role in the success of the surgical procedure.
The operating room should be spacious to provide ample room for all the equipment required in this type of surgery.
The surgeon’s position is very important. In a total right colectomy, he/she stands between the patient’s legs in order to dissect along a straight axis. In a partial segmental resection (ileocecectomy), the surgeon and the 1st assistant stand on the left side of the patient. The second assistant stands between the patient's legs.

&#8226; Patient

The patient is in supine position with his left arm alongside his body, his right arm abducted at a 90° angle to the body, his legs are slightly bent, abducted, and in stirrups.
- left tilt;
- reverse Trendelenburg;
- pressure areas are protected;
- pneumatic compression stockings;
- orogastric tube;
- urinary catheter.

&#8226; Team

1. Surgeon
2. First assistant
3. Second assistant
4. Scrub nurse

&#8226; Equipment

Use of a laparoscopic ultrasound is recommended for proper staging of the liver.
1. Anesthetic unit
2. Instrument table
3. Electronic equipment

7. Trocars
&#8226; Anatomical landmarks

1. Costal margin
2. Anterior superior iliac spine (ASIS)
3. Pubic symphysis
4. Umbilicus
A. Midline
B. Mid-clavicular line
C. Anterior axillary line

&#8226; Trocar types and positions

The number of ports varies from 3 to 5 depending on the surgeons and operative difficulties. Their position is also variable, but our standard approach uses the following protocol.
Ports are introduced according to the following order of appearance numbered on the schematic (from P1 to P5).
The optical port, a 0 degree scope, (P1) is placed on the midline above the umbilicus at the beginning of the procedure. An angled laparoscope (30-45 degrees) may be useful to mobilize the hepatic flexure. After a panoramic exploration of the abdominal cavity, the optical port (P2) is placed on the midline underneath the umbilicus.
We use 2 operating ports (P3 and P5), and one retracting port (P4).

8. Exploration

Abdominal cavity inspection:
After the introduction of the first trocar, the abdominal cavity is inspected. Based on this exploration, the decision on whether or not to pursue the operation laparoscopically is made, and the ideal trocar positioning determined. Indications for conversion to laparotomy at this operative stage include:
- extensive, dense adhesions;
- inability to locate the lesion;
- evidence of a T4 malignancy (invasion of adjacent structures).
Further inspection:
The abdominal cavity is scrutinized for the presence of secondary lesions or adhesions. The quality of the preoperative bowel preparation, which facilitates the procedure, is also assessed.

9. Exposure
&#8226; Pneumoperitoneum


The pressure induced by the pneumoperitoneum (12mmHg) creates the operative space but also pushes the visceral organs downwards.
A perfect control of this pressure ensures a good exposure.

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The use of gravity is the simplest way to retract the mobile organs. Exposure of the right colon and its mesentery is greatly assisted by placing the patient in a left lateral tilt, head up, causing the small intestine and sigmoid colon to slide into the left lower part of the abdominal cavity.

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The superior mesenteric vascular axis is exposed with blunt retraction following these steps:
The greater omentum is retracted cephalad toward the subphrenic space. The transverse colon is then elevated to expose the inferior aspect of the transverse mesocolon.
The grasping instrument must never be used directly on the colon, but on the mesentery or omental folds to retract and stretch anteriorly the transverse mesocolon.

&#8226; Operating field view

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After exploring the abdominal cavity through the supra-umbilical trocar, the laparoscope (0° or 30°) is inserted into the subumbilical trocar. This allows excellent visualization of the root of the mesentery, the right mesocolon, the superior mesenteric axis and the base of the transverse mesocolon. In this position, complete visualization of the abdominal cavity is possible, from the ileocecal region up to the transverse colon, allowing 90% of the operation to be performed with a 0° laparoscope

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Inserting the laparoscope in a supra-umbilical position is sometimes useful to free the hepatic flexure. However, this can be avoided by using a 30 degree scope.