肝右叶切除术（图文演示）

中文版：肝右叶切除术（中文图文演示）

RIGHT   HEPATECTOMY
Authors
D Franco
Abstract
The description of the right hepatectomy covers all aspects of the surgical procedure used for the management of hepatic tumors.
Operating room set up, position of patient and equipment, instruments used are thoroughly described. The technical key steps of the surgical procedure are presented in a step by step way: incisions, mobilization of right liver, approach of hepatic pedicle, division of portal vessels, dissection of suprahepatic vein, transection of parenchyma, transection techniques, control of transection.
Consequently, this operating technique is well standardized for the management of this condition.

1. Introduction
The technique of liver resection has benefited during recent years from a better knowledge of both radiological and surgical liver anatomy. It is now possible to separately remove any single segment of the liver, or to remove very large parts of the liver, using new procedures for dividing liver parenchyma and methods for decreasing blood loss during surgery. At the same time, new developments in general anesthesia and intraoperative monitoring have decreased operative risks.
Nevertheless, major intraoperative or postoperative complications that are directly related to the surgical procedure can still occur. It is possible to minimize these risks by carefully following a step-by-step technique.
The types of liver resection are defined according to Couinaud’s anatomical classification (liver segments). Major procedures involve the resection of at least three segments. The most commonly performed procedures are right liver resection and left liver resection. In right liver resection, segments 5, 6, 7 and 8 are removed. This can be extended to include segment 4 or segment 1, or both, and is then considered a very large liver resection. In left liver resection, segments 2, 3 and 4 are removed. This can be extended to include segment 1, segment 5, segment 8, segments 5 and 8 or even segments 5, 8 and 1. The last case is one of the largest liver resections, as it leaves only the right posterior lateral segment unaffected.
In minor liver resections, only one liver segment or two adjacent segments are resected. Each liver segment may be removed separately or in combination with an adjacent segment. Bisegmentectomy 2 and 3 corresponds to the left lobectomy of older nomenclature. Resection of anterior segments (3, anterior 4, 5) is easier than resection of posterior segments.
Right liver resection and left liver resection form the basis of liver resection techniques. If these two techniques are mastered, other resections can be performed easily.

2. Surgical anatomy

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The liver is a voluminous organ. It is situated below the costal margin in the right subphrenic region. It is fixed to the abdominal wall by several ligaments: the falciform ligament anteriorly, the left and right coronary ligaments, and the left and right triangular ligaments posteriorly. It lies immediately anterior to the inferior vena cava (IVC) creating a groove to the posterior surface of the liver. It is attached to the IVC by the three large main hepatic veins whose extra-hepatic portions are very short and drain into the uppermost part of the abdominal IVC.

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1. Hepatic artery
2. Portal vein
3. Common hepatic duct
The liver is irrigated by the hepatic artery and by the portal vein draining blood from abdominal organs to the liver. The bile is drained by the common hepatic duct, which results from the confluence of the right hepatic duct and the left hepatic duct in the porta hepatis. The hepatic artery, the portal vein and the common bile duct constitute the porta hepatis attached to the liver on its inferior surface.

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1. Right liver
2. Left liver
3. Caudal surface
4. IVC
The liver is divided into 8 segments. There is a pedicle comprised of an arterial branch, a portal branch and a bile duct leading into each of the eight segments. The left liver is made up of segments 2, 3 and 4. The right liver is made up of segments 5, 6, 7 and 8. Segment 1 is the posterior part of the liver that is situated immediately anterior to the IVC; only its left part is bordered by true anatomical structures.
The right and left liver are divided by the interlobar fissure that is part of the plane going through the middle hepatic vein. The umbilical fissure of the liver separates the left lateral lobe (segments 2 and 3) from the rest of the liver. The plane of the right hepatic vein separates anterior medial segments from posterior lateral segments of the right liver.

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1. Left liver
2. Right liver
3. Caudal surface
4. IVC
The surface of the liver gives little indication of its internal segmentation except for the left lateral lobe (segments 2 and 3, which are situated to the left of the falciform ligament and the round ligament).
Although the limit between the right liver and the left liver is not traced on the surface of the liver, it corresponds to the plane of the middle hepatic vein coursing from the middle of the anterior edge of the gallbladder bed to the left half of the suprahepatic IVC. The separation between the posterior segments of the right liver (segments 6 and 7) and the anterior segments (5 and 8) corresponds to the plane of the right hepatic vein. Segment 4 is situated between the interlobar fissure and the falciform ligament. It then divides into two parts: a part anterior to the hilum and formerly called the caudate lobe, and a deeper posterior part with a sharp edge. The limit between the superior segments of the right liver (7 and 8) and the inferior segments (5 and 6) is a transversal plane crossing the hilum of the liver.
Intraoperative ultrasonography shows these vascular landmarks, and as a result each hepatic segment. The results of preoperative radiological studies facilitate the precise localization of hepatic tumors and enable the surgeon to decide on the type of liver resection before the intervention.

3. Indications
Liver resection is indicated in the treatment of certain tumors affecting the liver and the bile ducts, and more rarely for inflammatory lesions.
Accepted indications for liver resection for tumors include hepatocellular carcinoma (HCC) with or without concomitant liver cirrhosis, adenomas, hepatic metastases and especially metastases of colorectal cancer. Other indications are more rare, particularly metastases of other types of cancer.
In proximal bile duct carcinoma, liver resection must often be associated with biliary resection.

Contraindications are those related to anesthesia for long and potentially hemorrhagic operations. In patients with hepatocellular carcinoma and concomitant liver cirrhosis, contraindications are related to the condition of the liver.

4. General anesthesia

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Liver resections are always performed under general anesthesia with intubation.
Patients are premedicated with hydroxyzine 2 mg/kg bw orally, 2 hours before surgery.
General anesthesia is induced with thiopenthal 4-6 mg/kg IV and sufentanil 0.3 micrograms/kg IV. Anesthesia is maintained with 0.5-1.5% end-tidal isoflurane and 60% nitrous oxide in oxygen, together with continuous infusion of sufentanil 0.3 micrograms/kg/h and bolus doses of vecuronium 1 mg as required. Hydroxyethylstarch 10 mL/kg is infused systematically over a period of 1 hour after induction of anesthesia.
Vecuronium 0.1 mg/kg is administrated to facilitate tracheal intubation.

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Lactated Ringer's solution is infused during the operation at a basal rate of 5 mL/kg/h. Ventilation is controlled throughout anesthesia. Tidal volume is set on 10 mL/kg and frequency is adjusted to maintain expired carbon dioxide at 4.5 ± 0.5 KPa.
Esophageal temperature is maintained at over 35.5°C with a heating pad.
Intraoperative blood loss is carefully measured by adding the volume of blood in suction canisters and the weight of the sponges used during surgery. Red blood cells are transfused if the intraoperative hematocrit is less than 28%.

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A catheter is placed in a radial artery for monitoring of arterial pressure.
Invasive cardiac monitoring is not routinely used. It is only intended for very large liver resections, for resections of large tumors and for high-risk patients, especially those suffering from cardiac insufficiency.
Expired carbon dioxide, expired isoflurane, inspired oxygen fraction, tidal volume and pulse oxymetry are measured continuously.
The electrocardiogram, mean arterial pressure and heart rate are monitored continuously.

5. Operative room set-up

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1. Rolls
2. Arm positioned at right angle
3. Arm maintained with drape
- supine position;
- legs together;
- one roll below the right hemithorax and another one below the right buttock;
- the left arm at a right angle;
- the right arm alongside the body, maintained with a drape;
It is important to make sure that nerve and arterial compression is avoided on all parts of the body, and that there is no stretching of the nerves due to overextension of the arm.
There must be sufficient room on the right side of the operating table for the second assistant, who stands to the left of the surgeon during all the steps of the procedure involving the porta hepatis.
Sterile drapes are placed on both sides of the patient, low on each side, high above the xiphoid process and slightly below the umbilicus

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1. The surgeon is on the right side of the patient.
2. The first assistant stands opposite the surgeon, on the left side.
3. A second assistant is required to grasp the liver with one or two valves during all steps involving the inferior surface of the liver, particularly during dissection of the porta hepatis.
4. A scrub nurse is mandatory and stands on the opposite side of the surgeon.
5. The anesthesiologist and his or her nurse stand at the head of the patient.

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1. Anesthetic unit
2. Operating table
3. Instrument table
4. Electrocautery
5. Ultrasonography
6. Suction device

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Few instruments are used. Nonetheless, liver resection involves several steps that require the following:
1. Scalpel
2. Atraumatic scissors
3. Bipolar coagulation
4. Suction-irrigation device
5. Surgical tapes
6. Mechanical linear stapler
7. Dissector
8. Vascular clamp
9. High pressure water jet dissector
10. Kelly clamp
11. Hemostatic clamp

7. Main principles

▶
Main principles
Right liver resection is usually performed in accordance with the following principles:
1. The right liver is mobilized first.
2. The right portal branch, the right branch of the hepatic artery and the right hepatic duct are identified, dissected and divided.
3. The right hepatic vein is controlled.
4. The liver parenchyma is transected along an anatomical line from the anterior edge of the liver down to the vena cava, to the right of the middle hepatic vein.

Large tumors
A new anterior approach has been developed for patients with large tumors encased in the right upper quadrant. This anterior approach is performed as follows:
1. The portal branch, arterial branch and bile duct are divided.
2. The liver parenchyma is transected from the anterior edge towards the vena cava without previous mobilization of the right liver.
3. The right hepatic vein is controlled and divided.
4. The right liver is mobilized, starting from the IVC and ending with the division of the lateral liver attachments.
This approach is perfectly suited to laparoscopic liver resection.

8. Incisions

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1. Tenth rib
2. External border of left rectus muscle
3. Posterior axillary line
4. Rolls
5. Retraction of costal margin using strong retractors
This approach is appropriate for most right liver resections. The incision extends from the tip of the tenth rib on the right to the lateral border of the left rectus muscle. It is shifted to the right or to the left depending on the location and size of the tumor, and on the patient’s morphology. Extension of the incision beyond the tip of the tenth rib towards the mid or posterior axillary lines can be done to help mobilize the right liver.
By lifting the right chest and buttock with rolls, the incision can be extended laterally. Retraction of the costal margin using strong retractors provides excellent exposure of the liver.

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1. Mercedes incision
In the case of large tumors, particularly those in close contact with the hepatic vein-IVC junction, an upper midline incision may be added to the subcostal incision resulting in a Mercedes incision. This exposes the suprahepatic IVC in its short course between the liver and the diaphragm.
A specific danger related to the Mercedes incision is that it creates a weakness at the junction of the subcostal and midline incisions, potentially causing ascites leak in patients with cirrhosis, and wound dehiscence.

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1. Xiphoid cartilage
2. Tenth rib
The J-shaped incision involves a median laparotomy from the xiphoid cartilage, curving down towards the right at the middle of the xipho-umbilical line and extending laterally below the anterior part of the tenth rib.
The J-shaped incision results in less pain and fewer respiratory complications than the subcostal incision.

9. Mobilization/right liver

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1.Division of round and falciform ligaments
The round ligament and the falciform ligament are divided. With the left hand, the first assistant lowers and exposes the anterior layer of the right coronary ligament to divide it until the anterior surface of the suprahepatic IVC is exposed at the level of the confluence of the right hepatic vein.
Division of the peritoneum is then continued over the right surface of the right hepatic vein towards the diaphragm, down to the right surface of the vena cava. Bipolar coagulation and atraumatic scissors are used.

• Freeing of the right liver
• Subphrenic space
1. Division of hepatorenal ligament
The liver is then lifted upwards with the first assistant’s right hand. The hepatorenal ligament is divided with scissors after electrocoagulation, exposing the lower border of the right liver.
The liver is slightly retracted to the left by the first assistant’s left hand in order to expose the right subphrenic space. The inferior border of the triangular ligament is exposed, then divided upwards either using monopolar coagulation or bipolar coagulation and scissors.

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The anterior layer of the coronary ligament is opened caudad to cephalad to reach the plane dissected earlier, lateral to the IVC. Its posterior layer is opened to the retrohepatic IVC. The opening of the coronary ligament permits the freeing of the right liver from the diaphragm and from the retroperitoneal space.
The inferior and superior leaves of the coronary ligament are then opened alternately to the IVC.

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The liver is progressively freed from the retroperitoneal space to which it is attached by loose adhesions.
It is separated from the anterior surface of the right adrenal gland. The adrenal vein is preserved.
Once the liver is totally free from the right subphrenic space, it is rotated medially into the left upper quadrant. This maneuver exposes the right border of the IVC.

• Danger

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The coronary ligament is often short. In these cases, the diaphragm is in close contact with the liver.
Retracting the liver caudad and to the left can cause the diaphragm to be moved along and accidentally opened, resulting in a pneumothorax. If this happens, the edges of the diaphragmatic injury must be identified and closed with interrupted sutures or a running suture. The pneumothorax is evacuated using aspiration while the last stitch is being completed.

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Although the vascularization of this plane is generally quite poor, large vessels may be present in cirrhotic patients and in patients with large vascular tumors.

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Great care must be taken when freeing the adrenal gland to avoid tearing it and potentially causing bleeding that is difficult to control due to the friability of the adrenal tissue.

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Some large tumors invade the diaphragm, which may be retracted inside the tumor.
When the invasion involves a large surface, the diaphragm is incised longitudinally and a patch of diaphragm is left on the tumor. The diaphragm is closed immediately using interrupted sutures or a running suture.
When the invaded surface is small, it is possible to isolate the area and to cut and close the diaphragm using a mechanical linear stapler.

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In some patients, the adrenal gland is adherent to the liver parenchyma from which it should be carefully separated. A vein may drain directly into the hepatic parenchyma from the adrenal gland; it should be ligated and divided.