Perioperative management - Liver resection, left lateral, laparoscopic

Whether a liver lesion can be laparoscopically resected depends less on the tumor entity than on the sensible feasibility of the laparoscopic resection procedure. The feasibility in turn depends essentially on technical-functional and anatomical parameters, which also apply in part to open liver surgery.

Technical-functional parameters

• Is an R0 resection possible?
• Is there sufficient volume of functional residual liver tissue after the resection?
• Number of (liver) surgical previous operations (adhesions)?
• Follow-up procedure after previous open liver surgery?

Anatomical parameters

• Tumor size?
• Number of lesions?
• Segment localization of the lesion(s)?

Particularly suitable for laparoscopic resection of benign or malignant processes are the so-called "laparoscopic segments" II, III, IVB, V and VI according to Couinaud.

The laparoscopic segment 2/3 resection can now be considered standard in centers, as the parenchymal bridges to segment 4 are often narrow and the supplying vessels in the liver hilum are easily accessible. A Pringle maneuver is usually not required.

Of great importance for the feasibility of a laparoscopic liver resection is the limited field of view of the operator, which is why the resection line should be linear and run in only one plane. An intraoperative change in the resection line as in open surgery is hardly possible with the minimally invasive procedure; here, the resection strategy must be determined preoperatively and can, if necessary, be slightly modified after performing intraoperative sonography.

Taking into account the aforementioned parameters, benign lesions such as adenomas, focal nodular hyperplasias, and symptomatic hemangiomas represent good indications for laparoscopic liver resection; for malignancies, these are predominantly colorectal liver metastases, but also hepatocellular carcinomas and metastases from breast carcinomas. From a technical aspect, wedge resections, segment resections, and left lateral resections are possible.

For malignancies, the following applies:

• peripheral solitary tumor max. 5 cm or for tumor > 5 cm localization in segment II/III
• Tumor localization in segments II, III, IVB, V or VI
• unilobar distribution, max. 3 foci
• R0 resection achievable with one resection line (left lateral resection, right or left hemihepatectomy)
• good distance of the lesion to central structures (V. cava inferior, hepatic veins, pedicle = branch from V. portae, A. hepatica, and D. hepaticus)
• no previous liver surgeries
• no planned concomitant procedures such as colon resection, incisional hernia repair, etc.

However, the indication for laparoscopic liver resection is not limited to tumor resection; it is also increasingly used for living liver donation.

• Pronounced liver cirrhosis (Child stage C, possibly also stage B)
• General inoperability of the patient due to underlying diseases; in particular, cardiac risks must be considered
• Significant adhesions, especially in the upper abdomen area
• Tumor infiltrations into neighboring tissue
• Large tumors that may be injured by the small vessel forceps and thus can trigger tumor cell dissemination
• In advanced liver cirrhosis and a tumor burden in hepatocellular carcinoma with no more than three lesions < 5 cm, liver transplantation should also be considered

Lesions in the posterior and superior sections of the liver, the so-called “non-laparoscopic segments” I, IVa andVIII do not represent a contraindication for a MIC procedure i.e.S., but are technically extremely difficult.

Likewise, patients are less suitable in whom an extensive oncological lymphadenectomy is required (e.g., in CCC) or in whom resectability is uncertain from the outset.

In hilar or vessel-near lesions, in addition to the increased bleeding risk, there is also an increased risk for the development of gas embolism in case of injury to larger hepatic veins.

History and Clinical Examination

Laboratory Diagnostics

• Preoperative routine laboratory including coagulation and blood group, possibly supplemented depending on the underlying disease
• Liver-specific: Transaminases, bilirubin, alkaline phosphatase, hepatitis serology (abnormal laboratory values do not fundamentally contribute to the differentiation of liver lesions)
• Tumor markers: AFP (Alpha-1-Fetoprotein), TPA (tissue polypeptide antigen), CEA, CA19-9

The AFP is the decisive tumor marker for hepatocellular carcinoma (HCC), in the case of an AFP increase of > 400 μl/l, the presence of an HCC can be assumed in 95% of cases. Caution: an AFP increase can also occur in chronic hepatitis B and C without HCC.

Ultrasound with and without Contrast Medium (CM)

The assessment of focal liver lesions with native B-mode ultrasound and color-coded duplex ultrasound enables a reliable classification of focal liver lesions in up to 60% of cases (e.g., cysts, typical hemangiomas, focal fat distribution disorders).

HCCs can exhibit various echo patterns. Approximately 75% of HCCs < 2 cm appear as hypoechoic, round structures. The detection of arterial perfusion in color-coded duplex ultrasound is indicative of an HCC. Contrast-enhanced ultrasound is suitable for further diagnostics of liver lesions that are unclear on native ultrasound. To enable differentiation between malignant and benign findings and to make a differential diagnostic classification, the assessment of vascular geometry and especially the contrast medium dynamics in the tissue is required:

• Benign liver lesions are characterized by persistent contrast enhancement in the portal venous and sinusoidal perfusion phases.
• The HCC typically appears contrast-sonographically as early arterial hyperperfused, i.e., it shows rapid CM influx. Well-differentiated HCCs wash out the CM slowly, moderately to poorly differentiated ones wash it out quickly.
• The intrahepatic CCC shows no characteristic behavior in ultrasound and is thus hardly clearly distinguishable sonographically from other intrahepatic space-occupying lesions. In extrahepatic localization, ultrasound provides indirect clues, for example, dilatation of the bile ducts.
• Duplex ultrasound can often provide information on tumor-related vascular infiltrations and compressions, especially when the portal venous system is affected.

Contrast-Enhanced CT

The performance of a contrast-enhanced CT with a native, arterial, and portal venous phase is considered the standard today in the diagnostics of HCC. In the arterial phase, the HCC appears as a hyperdense space-occupying lesion, whereas it presents as iso- or hypodense in the portal venous phase.

Magnetic Resonance Imaging

An MRI should be performed in cases of unclear CT findings and especially in suspected HCC.

Intrahepatic CCCs present unspecifically in MRI. An important diagnostic tool for extrahepatic CCCs is MR cholangiopancreatography (MRCP), which allows better assessment of suprahilar tumor extension than ERCP.

Positron Emission Tomography in Combination with CT

The "18-F-fluorodeoxyglucose positron emission tomography", abbreviated FDG-PET, is increasingly used in combination with CT in diagnostics and therapy monitoring of solid malignancies. The method is based on increased accumulation of FDG in tumor tissues.

In HCC, increased accumulation indicates a low degree of differentiation, which is associated with a poorer prognosis. The absence of FDG accumulation indicates a differentiated tumor.

In the diagnostics of CCCs, FDG-PET plays an important role in the detection of locoregional lymph nodes as well as in the detection of distant metastases, where the method is clearly superior to CT alone.

A PET-CT is also considered when a complete environmental diagnostics is required for extrahepatic primary tumors.

Endoscopic Retrograde Cholangiopancreatography

ERCP plays a rather subordinate role in the diagnostics of an HCC. Therapeutically, stent insertion using ERCP is used in tumor obstruction of the common hepatic duct.

In CCC, ERCP is used both diagnostically and therapeutically: In proximal and distal localization, the tumor can be very well localized, and ERCP also allows sample collection for cytological examination.

Liver Biopsy

In suspected HCC, there is an indication for biopsy under certain conditions. This should be performed according to the guidelines of the American Association for the Study of Liver Diseases (AASLD) in:

• Intrahepatic space-occupying lesions between 1 and 2 cm in diameter
• Absence of clear characteristics of the space-occupying lesion in imaging procedures

In findings characteristic of an HCC in imaging procedures, a biopsy can be dispensed with.

An intrahepatic tumor with a diameter > 2 cm should be biopsied if the space-occupying lesion does not present typically in imaging procedures and the AFP is < 200 ng/ml. In extrahepatic CCCs, histological confirmation can be obtained as part of an ERCP. Brush cytology, forceps biopsy, and bile aspiration are available for this, whereby the sensitivity can be increased by combining the mentioned procedures.

• In case of increased cardiopulmonary risk, clarification of the surgical risk through further diagnostics (stress ECG, cardiac echocardiography, coronary angiography, pulmonary function diagnostics)
• Sufficient intensive care capacity for high-risk patients
• Provide 4-6 RBCs, if necessary FFP or PCs
• Perioperative antibiotic administration as single-shot, e.g. 2nd generation cephalosporin + metronidazole 30 minutes before skin incision

A special preparation of the patient is generally not required, enema recommended.

For informing the patient, standardized informed consent forms should be used; anatomical drawings are also available here, into which the findings can be entered. Alternatives and additional treatment options should be explained, in particular, interventional measures including intraoperative radiofrequency ablation or an extension of the primary procedure should always be discussed.

Before every planned liver resection, information should also be provided about a cholecystectomy, and in laparoscopic procedures about the possibly required conversion to open surgery.

General Risks

• Bleeding
• Postoperative bleeding
• Necessity of transfusions with corresponding transfusion risks
• Thromboembolism
• Wound infection
• Abscess
• Injury to neighboring organs/structures (stomach, esophagus, spleen, diaphragm)
• Burst abdomen
• Incisional hernia
• Follow-up procedure
• Lethality

Specific Risks

• Liver parenchyma necrosis
• Bile fistula
• Bilioma
• Hemobilia
• Biliary peritonitis
• Bile duct stenosis
• Pleural effusion
• Gas embolism (due to unintended or unnoticed opening of hepatic veins)
• Portal vein thrombosis
• Hepatic artery thrombosis
• Chronic liver insufficiency
• Liver insufficiency with hepatic failure and coma
• Tumor recurrence