Surgical Techniques in Liver Resection: What Surgeons Should Know

Hepatic resection, also known as liver resection or hepatectomy, is a surgical procedure where a portion of the liver is removed. It is most commonly performed to treat liver tumors, both benign and malignant, but can also be indicated for other conditions such as trauma, liver abscesses, and certain metabolic diseases. This article provides an in-depth overview of hepatic resection, covering indications, preoperative evaluation, contraindications, surgical techniques, postoperative care, possible complications, different techniques, prognosis and outcomes, alternative options, average cost, recent advances, and more.

Indications for Hepatic Resection

The primary indication for hepatic resection is the presence of a hepatic tumor. These tumors can be benign, such as hepatic adenomas or focal nodular hyperplasia (FNH), or malignant, including hepatocellular carcinoma (HCC), cholangiocarcinoma, and metastatic liver cancer, particularly from colorectal cancer.

1. Hepatocellular Carcinoma (HCC): HCC is the most common primary liver cancer, often associated with chronic liver disease and cirrhosis. Hepatic resection is a preferred treatment for patients with a single tumor and well-preserved liver function.
2. Cholangiocarcinoma: This is a bile duct cancer that can be intrahepatic or extrahepatic. Hepatic resection is indicated for intrahepatic cholangiocarcinoma, especially if the tumor is localized.
3. Metastatic Liver Cancer: The liver is a common site for metastasis, particularly from colorectal cancer. Hepatic resection offers a potential cure for selected patients with isolated liver metastases.
4. Benign Liver Tumors: Although less common, hepatic resection may be indicated for large or symptomatic benign tumors like hepatic adenomas or large FNHs, particularly if there is a risk of rupture or hemorrhage.
5. Liver Trauma: In cases of severe liver trauma, particularly from blunt or penetrating injuries, hepatic resection may be necessary to control bleeding and remove devitalized tissue.
6. Liver Abscesses: In rare cases, hepatic resection may be indicated for refractory liver abscesses that do not respond to drainage and antibiotics.

Preoperative Evaluation

Preoperative evaluation for hepatic resection is crucial to assess the patient's overall health, liver function, and the extent of the disease. The following steps are typically involved:

1. Liver Function Tests: These include serum bilirubin, albumin, prothrombin time, and liver enzymes (AST, ALT). The Child-Pugh score or Model for End-Stage Liver Disease (MELD) score may also be used to assess liver function.
2. Imaging Studies: Cross-sectional imaging with contrast-enhanced CT or MRI is essential to assess the extent of the liver tumor, its relationship to vascular structures, and the presence of metastatic disease. In some cases, PET-CT may be indicated to evaluate for extrahepatic disease.
3. Indocyanine Green (ICG) Clearance Test: This test measures the liver's capacity to clear indocyanine green dye and is used to assess hepatic reserve before surgery.
4. Cardiopulmonary Assessment: A thorough evaluation of the patient’s cardiovascular and respiratory systems is necessary, particularly in older patients or those with comorbid conditions.
5. Portal Vein Embolization (PVE): In patients with borderline liver function, PVE may be performed preoperatively to induce hypertrophy of the future liver remnant (FLR), thereby reducing the risk of postoperative liver failure.
6. Nutritional Assessment: Malnutrition can significantly impact postoperative outcomes. Patients may require nutritional optimization preoperatively, including supplementation of protein, vitamins, and minerals.

Contraindications

While hepatic resection offers potential curative benefits, it is not suitable for all patients. Contraindications include:

1. Severe Cirrhosis: Patients with advanced cirrhosis (Child-Pugh C) are at high risk for postoperative liver failure and are generally not candidates for resection.
2. Extensive Bilateral Tumor Involvement: Patients with diffuse or bilobar involvement may not have enough residual liver function after resection.
3. Extrahepatic Disease: The presence of extrahepatic metastasis, especially in vital organs, usually contraindicates hepatic resection.
4. Severe Comorbidities: Patients with significant cardiovascular, respiratory, or renal disease may not tolerate major hepatic surgery.
5. Insufficient Liver Remnant: If the future liver remnant is inadequate (typically less than 20-25% in a normal liver or 40% in a cirrhotic liver), resection is contraindicated due to the high risk of postoperative liver failure.

Surgical Techniques and Steps

Hepatic resection can be performed using various techniques, depending on the location and extent of the tumor, as well as the patient's anatomy and liver function. The most common approaches are open surgery, laparoscopic surgery, and robotic-assisted surgery.

1. Open Hepatic Resection: This traditional approach involves a large abdominal incision to access the liver. It is often preferred for large tumors, complex resections, or when major vascular structures are involved. The Pringle maneuver, which involves clamping the hepatoduodenal ligament, may be used to control intraoperative bleeding.
2. Laparoscopic Hepatic Resection: Minimally invasive techniques have become increasingly popular for hepatic resection. Laparoscopic surgery offers the advantages of reduced postoperative pain, shorter hospital stays, and faster recovery. However, it requires advanced surgical skills and may not be suitable for all patients, particularly those with large tumors or severe adhesions.
3. Robotic-Assisted Hepatic Resection: Robotic surgery is an emerging technique that provides enhanced precision and dexterity. It is particularly useful for complex resections in difficult-to-access areas of the liver.
4. Anatomical vs. Non-Anatomical Resection: Hepatic resection can be classified as anatomical or non-anatomical. Anatomical resection involves removing a specific liver segment or lobe along anatomical planes, while non-anatomical (or wedge) resection involves removing a tumor with a margin of healthy tissue, regardless of segmental anatomy.
5. Surgical Steps:
   • Patient Positioning: The patient is positioned supine, with the operating table tilted to optimize exposure.
   • Incision: An upper midline or right subcostal incision is made, with or without an extension to the left subcostal area (Chevron or Mercedes incision).
   • Exploration: The liver is mobilized, and the tumor is carefully examined to confirm resectability.
   • Parenchymal Transection: The liver parenchyma is divided using various techniques, including the use of a Cavitron Ultrasonic Surgical Aspirator (CUSA), bipolar electrocautery, or stapling devices. Hemostasis is meticulously maintained.
   • Resection and Hemostasis: The tumor-bearing segment is resected, and the resection margin is examined for adequate clearance. Hemostasis is achieved using sutures, clips, or topical agents.
   • Drain Placement: Drains may be placed to monitor for postoperative bleeding or bile leakage.
   • Closure: The abdominal incision is closed in layers.

Postoperative Care

Postoperative management focuses on monitoring for complications, managing pain, and supporting liver function. Key aspects include:

1. Pain Management: Adequate pain control is essential for early mobilization and recovery. Options include epidural analgesia, patient-controlled analgesia (PCA), and multimodal analgesia.
2. Liver Function Monitoring: Liver function tests are closely monitored in the immediate postoperative period. Any signs of liver failure, such as jaundice or coagulopathy, require prompt intervention.
3. Fluid and Electrolyte Management: Careful fluid management is essential to avoid fluid overload, which can exacerbate liver dysfunction.
4. Nutritional Support: Early enteral nutrition is encouraged, with a focus on providing adequate protein to support liver regeneration.
5. Prevention of Complications: Prophylactic antibiotics, thromboprophylaxis, and early mobilization are important to prevent infection, venous thromboembolism, and respiratory complications.
6. Surveillance Imaging: Postoperative imaging, usually with CT or MRI, is performed to assess for complications such as bile leaks, abscesses, or recurrence of the tumor.

Possible Complications

While hepatic resection can be curative, it carries a risk of complications, some of which can be life-threatening. Common complications include:

1. Postoperative Liver Failure: The most serious complication, particularly in patients with underlying liver disease. It is characterized by jaundice, coagulopathy, and encephalopathy.
2. Bleeding: Intraoperative or postoperative bleeding is a significant risk, given the liver's vascularity. Blood transfusions or reoperation may be necessary.
3. Bile Leak: Bile leakage can occur if the bile ducts are injured or inadequately closed. It may require drainage or endoscopic intervention.
4. Infection: Intra-abdominal abscesses or wound infections can occur, requiring antibiotics and, in some cases, surgical drainage.
5. Respiratory Complications: Atelectasis, pneumonia, and pleural effusion are common postoperative issues, particularly in patients with preexisting respiratory conditions.
6. Venous Thromboembolism (VTE): The risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) is increased after major surgery, necessitating thromboprophylaxis.

Different Techniques

Several advanced techniques have been developed to improve the safety and efficacy of hepatic resection:

1. Laparoscopic and Robotic Techniques: These minimally invasive approaches reduce the surgical trauma associated with open resection, leading to quicker recovery times and less postoperative pain.
2. Radiofrequency Ablation (RFA) and Microwave Ablation (MWA): In some cases, these techniques are used adjunctively with resection to destroy small tumors or to treat tumors that are difficult to resect completely.
3. Portal Vein Embolization (PVE): Preoperative PVE is used to increase the size of the future liver remnant (FLR) by inducing hypertrophy in the contralateral liver lobe.
4. Intraoperative Ultrasound: This technique is used to delineate tumor margins and to guide the resection, especially in cases where the tumor is not well-defined on preoperative imaging.
5. Indocyanine Green (ICG) Fluorescence Imaging: ICG is used intraoperatively to assess liver perfusion and to help identify tumor margins, improving the accuracy of resection.

Prognosis and Outcome

The prognosis after hepatic resection depends on several factors, including the underlying liver condition, the extent of the resection, and the histological type of the tumor. Generally, patients with well-preserved liver function and a solitary tumor have the best outcomes.

1. Hepatocellular Carcinoma (HCC): The 5-year survival rate after resection for HCC ranges from 40% to 70%, depending on tumor size, number, and underlying liver disease.
2. Colorectal Liver Metastases: The 5-year survival rate after resection for colorectal liver metastases is approximately 40% to 60%, with better outcomes in patients with a limited number of metastases and no extrahepatic disease.
3. Cholangiocarcinoma: The prognosis for cholangiocarcinoma is generally poorer, with a 5-year survival rate of around 20% to 40% after resection.

Alternative Options

For patients who are not candidates for hepatic resection, alternative treatment options include:

1. Liver Transplantation: This is an option for patients with small, unresectable HCCs within the Milan criteria. It offers the potential for a cure but is limited by organ availability.
2. Ablative Therapies: Radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation can be used for small tumors, particularly in patients with poor liver function.
3. Transarterial Chemoembolization (TACE): TACE is a palliative treatment for unresectable HCC, delivering chemotherapy directly to the tumor while occluding its blood supply.
4. Systemic Chemotherapy: For patients with metastatic liver disease or advanced HCC, systemic chemotherapy or targeted therapy may be the only option.

Average Cost

The cost of hepatic resection can vary widely depending on the country, the complexity of the surgery, and the healthcare system. In the United States, the cost of hepatic resection can range from $50,000 to $100,000, including hospital stay, surgeon fees, and postoperative care. In other countries, the cost may be lower, but it is essential to consider the quality of care and availability of advanced surgical techniques.

Recent Advances

Recent advances in hepatic resection focus on improving surgical outcomes, reducing complications, and expanding the indications for surgery:

1. Enhanced Recovery After Surgery (ERAS) Protocols: ERAS protocols have been shown to reduce hospital stay, decrease complications, and improve patient outcomes after hepatic resection.
2. Robotic Surgery: The increasing use of robotic-assisted surgery allows for more precise and less invasive hepatic resections, particularly for complex cases.
3. Targeted Therapies: Advances in targeted therapies, such as sorafenib and lenvatinib, have improved the management of advanced HCC, potentially downstaging tumors to make them resectable.
4. Liver Regeneration Techniques: Research into enhancing liver regeneration, including stem cell therapy and growth factor administration, may offer future benefits for patients undergoing hepatic resection.