Diagnostic Operation of the Liver and Techniques of Hepatic Resection

Percutaneous and Transjugular Liver Biopsy

Liver biopsy was originally described by Ehrlich in 1883 to determine glycogen stores in patients with diabetes. A variety of approaches and techniques have been described for performing liver biopsy, including percutaneous, transjugular, laparoscopic, and open techniques.

For focal lesions, percutaneous liver biopsies are often conducted under image guidance either with the use of ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI). The goal of percutaneous biopsy is to obtain a core of tissue with good preservation of the underlying hepatic architecture.

The presence of significant ascites or underlying coagulopathy is a relative contraindication to percutaneous biopsy. In this scenario a transjugular biopsy may be necessary. However, transjugular biopsies are best used for large and easily targetable lesions and are of limited use for small focal lesions because of the inability to accurately place the needle. Furthermore, the amount of tissue obtained is often smaller and more fragmented compared with percutaneous core needle biopsies, making pathologic assessment more difficult.

If multiple percutaneous attempts have failed to obtain adequate material, if there is suspicion that a liver lesion is highly vascularized and prone to bleeding, if there is a need to obtain tissue from multiple sites, or if it is otherwise preferable to biopsy the liver under direct vision, then either laparoscopic or open liver biopsy may be used.

Laparoscopy and Biopsy

Laparoscopy examination of the liver consists of visual inspection, palpation (using standard laparoscopic instruments is possible to appreciate any parenchymal nodularity or change in tissue consistency), and tissue biopsy. Superficial lesions can be biopsied under direct visualization using cupped biopsy forceps, whereas deeper lesions might require laparoscopic ultrasound guidance and the use of percutaneous core needle biopsy devices. The authors recommend performing core needle biopsy rather than fine-needle aspiration (FNA) because the former allows for the identification of the architectural structure of the underlying liver parenchyma and often delivers more reliable results compared with FNA. In addition, the direct laparoscopic visualization of the liver parenchyma allows for quick identification and treatment of any potential bleeding complications caused by a large needle biopsy.

Preoperative laparoscopy, as a diagnostic tool in hepatobiliary malignancies, has been discussed extensively during the past two decades. Although no definitive consensus has been achieved, with the improvement of modern radiographic imaging modalities its role appears to be limited to select cases. A particular case is represented by gallbladder and hilar cholangiocarcinoma where the yield of staging laparoscopy and ultrasonography is relatively high and the value of surgical palliation is relatively low, thus arguing in favor of laparoscopic staging in order to prevent an unnecessary laparotomy.

Open Liver Biopsy and Examination

An open liver biopsy can be performed through a limited right subcostal incision. The incision should be placed over the inferior edge of the liver but should be at least 3 cm below the costal margin to allow for adequate fascial closure. The liver can be examined both visually and by palpation, but care should be taken to not disturb any portosystemic collateral vessels. If these friable vessels are disrupted, or if the hepatic capsule is ruptured during examination, a major abdominal operation may be required to gain control. Visual inspection for gross evidence of cirrhosis, nodularity, abnormal color or texture, or neoplasm may be revealing. A laparoscopic ultrasound probe can be used through a small incision, or, if the incision is large enough, the regular probe may be used. A wedge biopsy can be obtained using a No. 15 scalpel and removing a specimen measuring 1 cm at its base. A core needle biopsy can be obtained through the same site, directed deeper into the liver parenchyma but away from the porta hepatis. If significant bleeding is expected, hemostatic 2-0 chromic catgut or Vicryl mattress sutures can be placed in an interlock V shape outside the biopsy site prior to biopsy. After the biopsies are taken, the base of the biopsy site is treated with the argon beam coagulator for hemostasis. The fascia should be closed with running permanent suture if ascites is anticipated. Similarly, the skin should be closed with a running long-lasting suture if ascites is anticipated.

Subcostal Approach

Most hepatectomies can be accomplished via a right subcostal incision made 3 to 4 cm below the right costal margin with an upper midline extension in a supine patient. The right rectus abdominis muscle is completely divided, as are the medial portions of the external oblique, internal oblique, and transversus abdominis muscles. Depending on the exposure required, the incision can be made up to and beyond the midaxillary line between the costal margin and the iliac bone. This incision exposes the anterior and inferior surfaces of the right and left liver and provides good access to the porta hepatis. For exposure of the dome of the liver, a midline extension over and above the xiphoid is performed and the xiphoid removed. For even more exposure, the incision can be extended under the left subcostal area ( Figs. 124.1 and 124.2 ). With this full incision, the surgeon has excellent exposure to the entire upper abdomen, including the liver as well as the retrohepatic and suprahepatic inferior vena cava (IVC). Because of the appearance when closed, this incision is often referred to as the Mercedes incision.

In extreme circumstances, a median sternotomy or right thoracotomy through the costal margin can even further increase access and exposure.

Midline Approach

The midline incision can be used in thin patients, especially when a pelvic procedure, such as a low anterior resection, is being performed at the same time, or if the hepatic resection will be limited to the left half of the liver. The patient is positioned supine. This approach does not generally allow good access to the retrohepatic vena cava, the right hepatic vein, or the right posterior sector of the liver until the liver is completely mobilized off the diaphragm and retroperitoneum. It is commonly used in exploration for trauma where hepatic injury may be found. If greater exposure is required, a median sternotomy or right thoracotomy through the costal margin can be performed.

Right Thoracoabdominal Approach

The thoracoabdominal incision is sometimes used in patients with large bulky lesions involving the right dome or right posterior section of the liver. It gives the best access to the suprahepatic and retrohepatic vena cava, as well as the right hepatic vein. In addition, it is sometimes used in instances of significant right diaphragmatic involvement. The patient is positioned on a bean bag with the chest in a lateral position but the hips at 45 degrees. The incision is made from the umbilicus to the right costal margin, and, depending on the location of the lesion, the seventh, eight, or even ninth rib interspace is opened. If keeping the right lung unventilated will help, then a double-lumen endotracheal tube should be used. The diaphragm should be incised circumferentially to avoid the neurovascular bundle supplying it. Care should be taken to leave 3 to 4 cm of diaphragm on the rib cage to allow for later closure.