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Right hepatectomy
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摘要
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.
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.
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媒體類型
 刊物
2001-12
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普通的
最愛
 音訊
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數位出版
WeBSurg.com, Dec 2001;1(12).
URL: http://www.websurg.com/doi-ot02en155.htm
URL: http://www.websurg.com/doi-ot02en155.htm
Right hepatectomy
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
• Anatomical relations
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.• Vascular supply
1. Hepatic artery2. 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.
• Segmentation
1. Right liver2. 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.
• Anatomical landmarks
1. Left liver2. 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
• Patient preparation
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.
• Intraoperative follow-up
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%.
• Intraoperative monitoring
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
• Patient
1. Rolls2. 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
• Team
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.
• Equipment
1. Anesthetic unit 2. Operating table
3. Instrument table
4. Electrocautery
5. Ultrasonography
6. Suction device
6. Instruments
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 principlesRight 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
• Subcostal incision
1. Tenth rib2. 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.
• Upper midline incision
1. Mercedes incisionIn 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.
• J-shaped incision
1. Xiphoid cartilage2. 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
• Exposure of the IVC
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 ligamentThe 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.
• Coronary ligament
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.
• Adhesions
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
• Pneumothorax
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.
• Coronary ligament
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.• Adrenal gland
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.• Tumors
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.
• Variation: adrenal adhesion
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.10. Approach/hepatic pedicle
• Cholecystectomy
Cholecystectomy is performed first in order to expose the superior portion of the right portal pedicle.The triangle of Calot is exposed by retracting Hartmann’s pouch caudad and to the right. The anterior and posterior peritoneal leaves are divided down to the inferior surface of the liver. The cystic duct and the cystic artery are identified and separated. The cystic artery is divided first, after ligation or cauterization of the gallbladder neck. The cystic duct is subsequently divided.
With the left hand, the first assistant pulls down the first duodenum to expose the anterior surface of the hepatoduodenal ligament. Segment 4 is lifted cephalad with a valve placed on its lower surface. This exposes the hilar plate, which is the reflection of the peritoneum of the porta hepatis on the capsule of segment 4, where the visceral peritoneum is slightly thickened.
• Incision
The peritoneum is opened at the level of the hilar plate parallel to the edge of segment 4, starting with the right part of the hilum. Only this right part should be divided. It is best to use bipolar cauterization before dividing the peritoneum with sharp scissors.
• Dissection
The decapsulated liver parenchyma appears at the upper part of the peritoneal incision. It is retracted slightly cephalad. The confluence of the right and left hepatic ducts is identified at the lower part of the incision, as well as the distal end of the right hepatic duct. This pulls the liver parenchyma off the right hepatic pedicle, which is lengthened artificially by this maneuver. The dissection of the right hepatic duct should be interrupted at this point.• Exposure
The peritoneum on the right inferior border of the porta hepatis is opened longitudinally, where the portal vein lies superficially. In order to facilitate the exposure, the first assistant slightly rotates the inferior part of the porta hepatis clockwise with the left hand. The portal vein lies just below the peritoneal layer.• Dissection
The anterior and posterior surfaces of the portal vein are dissected free. The portal vein receives no tributaries in this segment.The peritoneal incision is then extended cephalad along the right edge of the right portal vein. The superficial part of the hepatic pedicle is gently retracted cephalad with a small retractor. The dissection of the anterior surface of the portal vein and the exposure of the origin of the left portal vein is facilitated by a slight traction on the left portal vein. The areolar tissue situated between the main portal branches is cautiously retracted with the tip of blunt scissors to expose the origin of the right portal vein.
• Freeing
A tape can then be placed around the right portal vein. The dissecting instrument should be used with extreme caution around the right portal vein to avoid potential injury to the portal bifurcation or to the origin of the left portal vein.If the right portal vein is not sufficiently freed, the portal bifurcation may be injured during the passage of the dissector, potentially resulting in massive bleeding.
The repair of this injury is very difficult. It is best to clamp the portal vein to decrease the blood flow.
A small branch supplying the right part of segment 1 originates from the right or posterior surface of the right portal branch near the portal bifurcation. This branch can be accidentally injured during isolation of the right portal vein. It is therefore preferable to ligate and divide it before taping.
• Anatomical variation
The most common anatomical variations are either the division of the portal trunk into three branches or a segmental right portal vein arising from the left portal vein. If there are two different portal branches coursing towards the right liver, tape should be placed around them.• Exposure
The right hepatic artery is searched for in the lymphatic tissue anterior to the right portal branch. This localisation is constant, even in cases of an anomalous pattern of the arterial tree (early division of the right hepatic artery, for example).• Dissection
The lymphatic tissue is cautiously opened after performing bipolar cauterization. The right hepatic artery might already be divided into segmental or subsegmental branches. All of the remaining lymphatic tissue surrounding the artery is divided and the artery and its branches (if present) are placed on tape.11. Division/portal vessels I
• Clamping test
Clamping of the right portal pedicle (right portal vein and right hepatic artery) results almost instantaneously in discoloration of the right liver and demarcation of the right and left lobes of the liver at the level of the interlobar fissure.• Right hepatic artery
The right hepatic artery or its segmental or subsegmental branches are ligated and divided. This allows the surgeon to better expose the right portal vein and pursue its dissection up to the liver. It is then possible to identify and dissect the origin of the anterior and posterior branches of the right portal vein. This allows better visualization of this vessel, which can then be ligated more safely. Any residual lymphatic tissue anterior to the right branch of the portal vein is divided. • Right portal vein
This operative step is crucial. Ligation of the right portal vein too close to its origin may result in a stenosis, leading to possible intraoperative or postoperative thrombosis of the portal vein with a high risk of hepatic failure and postoperative death. A light vascular clamp is placed on the origin of the right portal branch and one or two hemostatic clamps are placed on the distal part of the vein or at the origin of its segmental branches. The right portal vein is divided, taking care to leave a cuff on the proximal edge, which is oversewn with fine vascular suture. The distal part is ligated over the hemostatic clamp.• Posterior hilar plate
After the right portal branch has been divided, the right liver lobe remains attached to the hepatic pedicle by only the right hepatic duct and a band of fibrous tissue situated on the same plane as the duct extending towards the posterior edge of the liver (also called the posterior hilar plate). This band of fibrous tissue is divided with scissors. It often contains a small portal branch and more rarely a small bile duct.• Hepatic duct
Once the lower aspect of the right hepatic duct has been freed, it is possible to isolate it. The segmental right ducts join distally and thus the right hepatic duct is very short. Dissection should take place near the right and left hepatic duct confluence, because dissection of the right duct at a more proximal level is made difficult by the presence of segmental and subsegmental ducts. A tape is placed around the right hepatic duct. The right hepatic duct is clamped distally at the level of the right and left hepatic duct confluence, avoiding any obstruction of the left hepatic duct, and proximally at the level of the segmental duct confluence. The right hepatic duct is divided and the distal and proximal ends suture- ligated with absorbable suture. This ligature is essential as any loosening of the distal stump may cause massive bile leakage. At this point, the right liver is completely detached from the hepatic pedicle.
12. Division/portal vessels II
• Variation 1
The right hepatic pedicle is transected “en masse” in the hilum.Once the upper border of the right hepatic duct has been dissected, the inferior border of the right portal vein is exposed. An atraumatic clamp is passed between the hepatic parenchyma and the right hepatic duct, around the portal vein. The right hepatic pedicle is isolated with a tape. This maneuver can be dangerous, as bleeding may occur and distal vascular control is impossible to obtain in the deeper part of the operative field. After slight anterior traction on the tape, a mechanical stapler is applied to the entire right hepatic pedicle. Several firings of the mechanical stapler may be necessary to divide the right pedicle. It has been suggested that blood loss is less after “en masse” ligation of the right hepatic pedicle than after an isolated division of these vessels, ducts and bile duct.
• Variation 2
Intraparenchymal division of the right hepatic pedicle is performed.The principle of this technique is to divide the vessels and ducts as far from the porta hepatis as possible, thereby reducing the risk of injury to a vessel or main duct linked to the remaining liver, particularly in case of anatomical variations. The right hepatic artery and the right portal vein are dissected and isolated as described previously. The right hepatic duct is only partially dissected. The vessels are clamped. Parenchymal transection is carried out until the biliary confluence is reached. Transection should be performed slightly to the right of the usual plane. The vessels and ducts are dissected within the parenchyma and divided separately. This approach is not considered to be safer than extraparenchymal division. In the latter technique, division is performed on segmental branches that are sometimes difficult to isolate. In addition, the division of the pedicle within the parenchyma pushes the line of transection slightly to the right, making the last parenchymal division and right hepatic vein approach more difficult.
• Variation 3
Quite frequently, a subsegmental or segmental duct drains separately into the common hepatic duct slightly below the confluence of the right and left hepatic ducts. This variation should not be taken into account in the technique. The distance separating the right hepatic duct and this other branch is short enough for the clamp to be placed on the two ducts without the need to identify them.13. Dissection/suprahepatic vein
• Vascular approach
The cellular tissue between the right and middle hepatic vein is gently retracted with the tip of blunt scissors and divided. The left border of the right hepatic vein is exposed before it enters the IVC. The right liver is rotated towards the left upper quadrant in order to expose the IVC.• Dissections
• Hepatocaval ligament
The IVC is situated above the adrenal gland posterior to the liver. Its right surface is covered with a fibrous ligament called the hepatocaval ligament, which extends between the posterior border of the liver and the posterior surface of the vena cava. While it is very thin in most patients, it is thick in more than 20% of patients.This ligament is divided to expose the right surface of the superior part of the IVC. It is sometimes easy to separate it from the vein, but in about 15% of cases, it closely adheres to the venous wall, making the procedure difficult to perform.
• Hepatic branches
The right border and the right half of the anterior surface of the IVC are dissected. A certain number of small hepatic branches (also called Spiegelian veins) are observed from the posterior surface of the liver to the IVC; they are ligated and divided. This dissection should be performed gently since tearing of a branch may cause massive bleeding that is difficult to control before complete right mobilisation of the liver from the IVC. If hemostasis is necessary, it should be achieved with an X-shaped stitch using fine suture.
• Right hepatic vein
Once the hepatocaval ligament has been divided, the inferior border of the right hepatic vein is exposed. The left border of the vein is isolated using gentle caudad to cephalad dissection. An atraumatic dissector is passed around the vein caudad to cephalad so a tape can be placed. This maneuver must be performed with the utmost care to avoid injuring the middle or right hepatic veins. If complete isolation of the right hepatic vein is made impossible by an obstacle, further caudad to cephalad dissection of the left border of the vein should be performed. In our experience, it was possible to completely isolate the right hepatic vein with a tape in 99.5% of right liver resections, even in cases of voluminous tumors.• Dangers
• Injury
Injury to a main hepatic vein may cause major bleeding and gas embolism.The injury is packed with sponges to temporarily stop bleeding and stabilize the state of the patient. Hemostasis can later be performed with one or several interrupted stitches with fine suture. The pressure is low in the hepatic veins and as a result bleeding can be easily controlled.
Note: Hemostasis performed too rapidly when the exposure is poor can aggravate bleeding and venous injuries.
• Dissection
Dissection of the hepatocaval ligament from the right hepatic vein involves a risk of injury to the hepatic vein or the IVC. In about 5% of patients, this ligament is replaced by a bridge of hepatic parenchyma that should be divided. This bridge usually contains a small portal branch and a bile duct. This parenchymal bridge may be up to 10 mm thick.
• Anatomical variation
In about 20% of patients, there is another large right hepatic vein close to the inferior edge of the liver. This is the right inferior hepatic vein. It is easier to divide this inferior hepatic vein between two hemostatic clamps to complete the dissection of the IVC.14. Transection/parenchyma
• Opening of the liver capsule
Before dividing the liver parenchyma, the fibrous capsule of the liver is incised over its entire length using electrocautery, along the interlobar fissure that can be distinguished by ischemic demarcation caused by vessel division. It is preferable to remain 2 mm to the right of this line so the parenchymal division can be done on the right flank of the middle hepatic vein, which is preserved, and to remain on the transection surface. The incision of the capsule starts from the superior surface of the liver on the left edge of the right hepatic vein over the hilum, and skirts around the anterior border of segment 1 (at its narrowed part). It is then continued cephalad to the posterior surface of the liver, along the IVC, up to the left edge of the right hepatic vein.• Operative technique
• Parenchymal division
The parenchymal division is started at the anterior border of the liver. It follows the interlobar fissure while keeping slightly to the right of the middle hepatic vein. The division is performed step-by-step through the entire thickness of the liver, which opens out like a book. Once the hilus is reached, division should start again from the anterior border of segment 1 and be pursued cephalad towards the superior and posterior surface of the liver.• Pediculization
On the superior part of the parenchymal division, the left border of the right hepatic vein is approached. The peritoneal leaf covering it is opened and the vein is skeletonized. A vascular clamp is placed on the vein at its precise junction with the IVC. The right hepatic vein is then divided.• Closure
After removing the operative specimen, the right hepatic vein stump is oversewn with fine vascular suture. Alternatively, the vein can be closed with a vascular stapler. Special care must be taken to achieve perfect hemostasis in closing the lateral wall of the IVC. 15. Transection techniques
• Principles and techniques
Numerous vessels and bile ducts run through the liver parenchyma. In order to transect the parenchyma without causing bleeding or bile leakage, it should be divided while preserving the blood vessels and ducts. These are ligated and divided as they are exposed.Finger fracture or digitoclasty (crushing the hepatic parenchyma between the thumb and the forefinger) was the first procedure used. This technique is rather traumatic and exposes smaller vessels to injury.
Finger fracture has been replaced by vascular clamp-assisted parenchymal dissection, also referred to as kellyclasty. This is a simple method. It is essential to progress slowly and to crush only thin parenchymal fragments, to avoid bleeding and injuries to small vessels.
• Ultrasonic dissection
Ultrasound emission from the tip of a handpiece gently dissociates the liver tissue.Ultrasonic dissectors are provided with an irrigation-suction device that is used to continually cleanse the dissection plane. The power of ultrasound must be adjusted to the firmness of the parenchyma. When the adjustment is correctly done, the risk of vascular or biliary injury is very low. The few properly designed studies comparing kellyclasty to ultrasonic dissection suggest that there is less blood loss with ultrasonic dissectors than with kellyclasty.
• High pressure water jet
Dissociation of liver tissue may also be performed with a high pressure water jet (2 to 3 bars). The saline solution, blood and micro tissue debris are aspirated through a suction cannula incorporated into the handpiece. The line of transection is flat and smooth. The pressure of the jet should be adapted to the firmness of the parenchyma. When the adjustments are properly done, even small vascular and biliary structures are preserved.• Techniques
These techniques permit “en masse” coagulation of a liver tissue fragment and the small pedicles running through it until necrosis and spontaneous division occur. The techniques that are currently available to surgeons use the heat produced by very high frequency vibrations applied to the blades of scissors. Only vessels and bile ducts measuring less than 3 mm in diameter may be divided using this technique.
• Division of pedicles
Division of intraparenchymal pedicles can be performed using fine suture, metal or absorbable clips, or bipolar coagulation. Bipolar coagulation is used more often nowadays for most pedicles. In a right liver resection, only a small number of collaterals of the middle hepatic vein need to be ligated or clipped.• Danger
If bleeding occurs during this division, it is most often due to the tearing or avulsion of a collateral from the middle hepatic vein.It is important to avoid poorly controlled reflexes such as abruptly separating the two parts of the liver or thrusting the suction-irrigation device into the dissection plane to better expose the hemorrhagic zone. These two maneuvers aggravate injuries and bleeding.
In the absence of a clear understanding of bleeding mechanisms, it is often better to place sponges between the two parts of the liver and exert manual pressure for one to two minutes. This can stop bleeding, or at least limit it, to permit better exposure and hemostasis.
16. Control/transection
• Simple transection
• Control/hemostasis
When the hepatic transection is uneventful and the division of biliary and vascular pedicles is done step by step, the cut surface of the liver is dry at the end of the resection and requires no additional maneuver. A thorough examination is still necessary. Hemostasis and biliostasis are checked one last time with the remaining liver back in place, as exposure maneuvers may conceal bleeding or minimal bile leaks.• Bleeding
Superficial bleeding is stopped by bipolar cautery. Deeper bleeding, whether arterial or portal, is stopped by suture ligatures with fine suture. The tightening of these stitches should be gradual so as not to tear the hepatic parenchyma.Hepatic venous bleeding usually stops after simple compression.
• Bile leak
When a bile leak is detected near the left hepatic duct, its origin should be absolutely identified and the wound repaired by fine X-shaped monofilament absorbable sutures.• Complicated transection
• Risks
When the parenchymal division is long and difficult, especially in diseased livers with steatosis or fibrosis, or in patients who have undergone chemotherapy, the dissection plane can be hemorrhagic at the end of the resection.• Limited bleeding
In the absence of major bleeding, either arterial or portal, it is best to apply compression with sponges and moderate manual pressure for a few minutes. Complete hemostasis can usually be achieved. Placing sponges soaked with coagulation factors on the area can help obtain permanent hemostasis.• Bile leaks
The injection of a dye in the bile ducts via a cystic cannula does not improve the screening for a bile leak in the region and is therefore not recommended. An intraoperative cholangiography performed via the cystic duct is useful only when major injury to the upper biliary confluence is suspected. This is very unlikely during a right hepatectomy if the technique has been carefully followed.• Abdominal drainage
Abdominal drainage after hepatic resection has evolved in the same manner as it has for other types of abdominal surgery. If the surgical procedure is performed properly, the ligature of the main vessels is reliable and the cut surface of the liver is dry, abdominal drainage is not useful. Many surgeons still prefer to leave an abdominal drain. A small aspiration drain is most convenient.• Variation
The use of biological glue sprayed onto the line of transection at the end of the procedure is controversial. In our experience, it does not allow the surgeon to seal a bile leak or to stop bleeding that compression alone cannot manage.17. Postop period
The IV is left in place until bowel function is restored. This generally occurs 2 to 4 days after the procedure. Oral food intake can be started as soon as the bowel function resumes. Although antibiotic prophylaxis is generally advised, there is no evidence that it is useful. It is preferable to wait for 24 hours after surgery before starting anticoagulant therapy, to avoid bleeding at the parenchymal dissection plane. Early ambulation of the patient is recommended, as for all surgical procedures. Postoperative follow-up is essentially clinical. 18. Results
Liver resection is a well-tolerated procedure in patients with a normal liver, as long as the volume of remaining parenchyma is greater than 30% of whole liver volume. Liver function tests
Postoperative alteration of liver function test results is early and short-term. After major liver resections such as right or extended right hepatectomy, serum bilirubin concentration can rise to 50 micromoles/L and is at its highest level on the second or third postoperative day. Prothrombin time decreases to a mean of 40%. SGOT and SGPT levels increase to about 5 to 10 times their normal value. Increase in liver transaminases depends not only on the size of the parenchymal resection but also on intraoperative bleeding and the duration of portal triad clamping. Changes in serum bilirubin concentration, prothrombin time and transaminases beyond these values or for a more prolonged period of time are predictive of postoperative complications and should prompt investigations.
Operative mortality
Operative mortality now averages 1% in patients with a normal liver parenchyma. It is higher following major liver resection and resection of malignant tumors than following minor resection and treatment of benign tumors (Belghiti et al., 2000). Estimated mortality in living donor liver transplantation, the best case for liver resection, is less than 0.2% (Renz and Roberts, 2000).
Other complications
The overall complication rate still averages 40%, and includes pneumonia, urinary tract infection and peripheral venous thrombosis. Severe complications occur in about 15% of patients. Abdominal complications occur in about 10% of cases. They require reoperation in about 3% of patients who undergo liver resection. The most frequent complications are bleeding from the remaining liver or from small vessels, bile leakage and subphrenic abscess. Right pleural effusion is particularly common and may occur independently of a subphrenic abscess or hematoma.
19. Reference
Belghiti J, Hiramatsu K, Benoist S, Massault P, Sauvanet A, Farges O. Seven hundred forty-seven hepatectomies in the 1990s: an update to evaluate the actual risk of liver resection. J Am Coll Surg 2000;191:38-46.Renz JF, Roberts JP. Long-term complications of living donor liver transplantation. Liver Transpl
2000;6:S73-6.