Application of Laparoscopic Hepatectomy Combined with Intraoperative Microwave Ablation in Colorectal Cancer Liver Metastasis

Summary

This protocol describes the laparoscopic resection of colorectal cancer liver metastases combined with ultrasound-guided microwave ablation. This technique can safely, effectively, and accurately treat refractory liver metastases <3 cm, reduce postoperative complications, and accelerate the postoperative rehabilitation of patients.

Abstract

Laparoscopic hepatectomy is a common treatment for colorectal cancer liver metastasis. Previously, a sufficient number of functional liver masses had to be maintained during laparoscopic hepatectomy, with a residual liver volume of >40% in cirrhotic patients and >30% in non-cirrhotic patients. The high incidence of complications such as bleeding, bile leakage, or liver failure due to the exposure and difficulty of the resection of specific liver segments such as S2 and S7 reduces the success rate of liver resection. At present, microwave ablation is mainly applied in the treatment of liver metastasis using a percutaneous approach, which makes it difficult to identify hidden parts or small lesions. For some liver segments, the percutaneous puncture of liver segment 7 (S7) is likely to pass through the thoracic cavity, and the percutaneous puncture of liver segment 2 (S2) adjacent to the diaphragm is likely to injure the diaphragm and heart; these issues restrict the application of percutaneous ablation in colorectal cancer liver metastasis. Considering multiple lesions, laparoscopic microwave ablation combined with hepatectomy was performed in this study. The location of the lesions was determined by contrast-enhanced ultrasound under laparoscopy, and small lesions that were difficult to detect before the operation were identified. For the scattered lesions, which had diameters less than 3 cm and were difficult to resect, ablation was adopted to substitute hepatectomy. This technique helped to more explicitly locate the tumors, simplified the operation procedures, reduced the risk of complications such as bleeding and bile leakage, shortened the operation time, accelerated the postoperative recovery, significantly improved the success rate of operation, and enhanced the clinical prognosis of colorectal cancer liver metastasis by surgical resection.

Introduction

Colorectal cancer is the third most common cause of cancer-related death worldwide¹, and the most common site of hematogenous metastases from colorectal cancer is the liver; this metastasis occurs in up to 50% of colorectal patients and is the leading cause of death in colorectal cancer patients². For colorectal cancer patients without liver metastases, survival can be prolonged by surgical resection and postoperative adjuvant chemotherapy, and interventional techniques. In the case of resectable liver metastases, those with a diameter of less than 3 cm can be treated by surgical local excision, radiological intervention, cryotherapy, radiofrequency ablation, and microwave ablation to improve the survival rate of patients³. For unresectable colorectal cancer liver metastases, conventional chemotherapy, interventional therapy, and other treatment strategies have limited survival benefits for the vast majority of patients.

Surgery is the gold standard for liver metastases from colorectal cancer, with a 5 year survival rate of 40%. Only 20%-30% of patients with colorectal liver metastases can benefit from surgical treatment, and most patients with unresectable colorectal liver metastases experience limited benefit from traditional conservative treatment⁴. An important method in the treatment of colorectal cancer liver metastases is thermal ablation, including microwave ablation and radiofrequency ablation; these two techniques induce cell death through coagulation necrosis caused by local hyperthermia. The main indications of thermal ablation include (i) unresectable liver lesions; (ii) combination with hepatectomy; (iii) patients with severe comorbidities or poor performance status (PS); (iv) small (<3 cm) solitary lesions otherwise requiring segmentectomy; and (v) patient preference⁵. Among them, microwave ablation (MWA) is a safe and effective treatment that can prolong the survival of patients. It has a wide range of active heating areas and does not depend on electrical conduction in the tumor tissue. This energy transfer is not limited by tissue scorching. Compared with radiofrequency ablation, microwave ablation has a higher temperature in the tumor tissue, shorter treatment time, and larger treatment range⁶.

Multiple intrahepatic metastases often occur in colorectal cancer liver metastases. In conventional treatment, chemotherapy, immunotherapy, interventional therapy, microwave therapy, radiofrequency ablation, and other methods can improve the survival rate of patients. The 5 year survival rate is 50%, but the survival rate is still low⁷. Surgical resection is still an important method for the treatment of liver metastases. Due to multiple liver metastases, small residual liver volume, postoperative bleeding, bile leakage, and inflow or outflow tract obstruction, which lead to the risk of liver failure, the surgical resection of multiple liver metastases is difficult. Three-quarters of patients are diagnosed with unresectable liver metastases⁸. Laparoscopic hepatectomy combined with microwave ablation in the treatment of colorectal cancer liver metastases can avoid the small amount of residual liver limiting the operation, reduce the adverse reactions of systemic chemotherapy, and overcome the electrical conduction barrier of radiofrequency ablation, thereby improving the success rate of surgery, prolonging the survival time of patients, and achieving a better prognosis of colorectal cancer liver metastases^3,9.

This protocol describes the precision treatment of laparoscopic hepatectomy combined with microwave ablation for tumors <3 cm, occult liver metastases, and multiple liver metastases with positioning using laparoscopic ultrasound.

Protocol

This study was approved by the Ethics Committee of the Sixth Affiliated Hospital, Sun Yat-sen University. The diagnostic criteria and treatment strategies refer to Chinese guidelines for the diagnosis and comprehensive treatment of colorectal liver metastases (version 2018) and the Shanghai International Consensus on Diagnosis and Comprehensive Treatment of Colorectal Liver Metastases (Version 2019). The patient had clinical symptoms such as hematochezia, intestinal obstruction, liver pain, and weight loss. Patients with unresectable multiple liver metastases diagnosed by CT, MR, B-ultrasound, liver function, CEA, AFP, and other tumor markers were included in the study. The representative patient and their family have been informed of the contents of this agreement, the video shooting, and other relevant content; a signed informed consent form and authorization have been obtained from the patient.

1. Instruments for operation

1. Before surgery, ensure that the surgical instruments mentioned in the Table of Materials are sterile, the surgical materials are complete, and the surgical equipment is normal.

2. Preparation for operation

1. Prepare the belly button and skin for abdominal surgery. Clean the belly button and shave the belly hair.
2. Bowel preparation: Ask patients to start consuming a residual-free diet, such as porridge and liquid foods, within 3 days before surgery, and guide them to take laxatives such as 139.12 g of compound polyethylene glycol electrolyte powder in 2,000 mL of warm water 1 day before the surgery. Ask the patient to have a clean enema on the night before surgery and in the morning on the day of surgery until all feces are discharged. The feces should be water samples without fecal residues. No food or drink is allowed for 8 h before the surgery. Insert a gastric tube for gastrointestinal decompression before the surgery.
3. Ask the patient to lie supine on the operating table, and give general anesthesia with endotracheal intubation.
4. Ensure the surgeons wash their hands during surgery, disinfect the operating area twice with 5% iodophenol, deiodize it once with 70% alcohol, and place surgical towels.
5. At 30 min before the operation, administer 2.5 g of cefoperidine and sulbactam sodium and 100 mL of 0.9% sodium chloride solution intravenously.

3. Laparoscopic hepatectomy combined with intraoperative microwave ablation for colorectal cancer liver metastases

1. Insert a 12 cm trocar into the navel and abdominal cavity for aeration. Maintain the abdominal pressure at 12-15 mmHg, place 12 cm trocars under the xiphoid process and 15 cm below the costal margin of the right midclavicular line, and place two additional 5 cm trocars on the left and right sides (Figure 1).
2. Place the laparoscope into the navel trocar to explore the cavity organs, such as the intestine, and the parenchymal organs, such as the liver in the abdominal cavity (Figure 2A). Separate the round and falciform ligaments associated with the abdominal wall and diaphragm of the liver using an ultrasonic knife (Figure 2B).
3. Inject the contrast agent intravenously during the operation, and then place the laparoscopic ultrasound probe into the abdominal cavity from the two trocars 12 cm to explore the whole liver (Figure 3B).
4. Under the effect of the contrast agent, locate the metastatic tumors in the S5 and S7 segments of the liver by ultrasound, and make localization markers on the liver surface (Figure 3A).
5. For liver segments or liver lobes with less than three liver metastases, perform anatomic lobe or liver segment resection with an ultrasonic knife as per the portal vein drainage (Figure 4). Dissect the liver parenchyma of the left lateral lobe (Figure 4A), and sever the branch of the umbilical fissure vein (Figure 4B). Expose the hepatic pedicles between segment II and segment III (Figure 4C), and sever the left lateral lobe of the liver with a nail gun (Figure 4D).
6. Use laparoscopic ultrasound to locate the boundaries of the tumor and to mark the surface of the liver (Figure 5A). Keep the margin of resection >1 cm from the tumor, and perform the local liver parenchymal resection with an ultrasonic scalpel (Figure 5B).
7. Detect liver metastases using laparoscopic ultrasound pressed to the liver surface (Figure 6A). Enter the microwave ablation needle into the abdominal cavity through the percutaneous puncture. This ensures that the laparoscopic puncture path avoids the thorax and surrounding organs and that ultrasound can be used to guide the microwave ablation needle into the tumor center for ablation. At the same time, microwave ablation under abdominal ultrasound can avoid important blood vessels and bile ducts in the liver (Figure 6B).
8. Determine the metastatic lesions and the puncture site of microwave ablation by CT or B-ultrasound before the operation, and mark the surface puncture. After the localization of the metastasis, insert the microwave ablation needle into the abdominal cavity under direct laparoscopy.
9. For metastatic tumors less than 3 cm in diameter, perform microwave ablation at 55 W power for 5 min by inserting a microwave ablation needle into the center of the metastatic tumor under the guidance of a laparoscopic ultrasound probe.
   NOTE: Colorectal cancer liver metastases are mainly multiple liver metastases, and different treatments can be performed for different metastatic lesions. For metastatic lesions in the left lateral lobe, surgical resection can be performed if the remaining liver volume is sufficient. Microwave ablation can be used for metastatic lesions in occult sites that are difficult to resect or cannot be resected. Taking the ablation of a metastatic tumor in the S7 segment of the liver as an example, if the lesion is not easy to find with laparoscopic ultrasound, or the percutaneous puncture path needs to pass through the thorax or organs, it is necessary to free the perihepatic tough band (Figure 7A) and rotate the liver downward (Figure 7B) to expose the S7 segment of the liver. In this study, the metastatic tumor in segment S7 of the liver was re-located by ultrasound (Figure 7C), and thoracotomy was avoided. Microwave ablation needles were inserted into the center of the metastatic tumor, and ablation was performed under a specific power microwave ablation machine. Successful ablation was defined as liver tissue necrosis 3 cm away from the tumor center (this video is liver S7 segment ablation; Figure 7D).
10. Electocoagulate the liver parenchyma sections with an ultrasonic scalpel, and place a hemostatic gauze (Figure 8A). Clean the abdominal cavity, and place a drainage tube (Figure 8D). Close the trocar pinhole with 2-0 polyglactin 910 sutures.

4. Postoperative care

1. Ask the patient to fast, take parenteral nutrition, and perform early ambulation at 48 h after surgery.
2. Perform ECG monitoring, pay attention to the patient's blood pressure, pulse, blood oxygen, and other vital signs, and review routine bloods, liver function, coagulation function, electrolytes, etc.
3. Bleeding is likely to occur within 48 h after surgery. Closely observe whether there is abdominal pain, abdominal distension, tenderness, or rebound tenderness, and pay attention to the quantity, color, and character of the drainage fluid from the abdominal drainage tube. Note whether the patient has defecation exhaust.
4. At 1 week after the surgery, discharge the patient from the hospital and instruct the patient to return to the hospital 1 month later for chemotherapy and an abdominal ultrasound review and to undergo microwave ablation again if necessary.

Results

For patients with liver metastases from past colorectal cancer, patients with unilateral liver metastases, or patients with few liver metastases can undergo surgical resection and obtain a good prognosis. Nevertheless, in patients with unresectable colorectal cancer with multiple liver metastases in both lobes, conservative treatment has a poor prognosis and a low 5 year survival rate. However, hepatectomy combined with microwave ablation can further improve the survival rate of patients and achieve a good prognosis comp...

Discussion

The main metastatic site of colorectal cancer metastasis is the liver. Liver resection is the treatment for colorectal cancer liver metastases, and liver resection can improve the survival rate of patients¹¹. As colorectal cancer metastasizes to the liver through the blood, resulting in multiple liver metastases in both lobes, and the remaining liver volume is small, about 75% of liver metastases in colorectal cancer patients cannot be surgically removed¹². Systemic chemoth...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.9% sodium chloride solution	Foshan Shuanghe Commercial Co., Ltd	H20013095	Dilute antibiotics, irrigate.
2-0 polyglactin 910 sutures	Johnson & Johnson Medical Devices	W8400	Close the Trocar hole.
3 D laparoscopic	STORZ	26605BA	Surgical treatment under direct vision, minimally invasive
Absorbable Hemostat	ETHICON	1962	wound hemostasis
BiClamp E Lap	ERBE Elektromedizin GmbH	20195-136	Intraoperative wound hemostasis
Cefoperazone Sulbactam Sodium	Pfizer Pharmaceuticals Ltd	H20020597	infection prevention
Laparoscopic ultrasound probe	HITACHI	ALOKA-UST5418	Intraoperative localization of liver metastases
LIGACLIP Multiple Clip Applier and Ligating Clips	Ethicon Endo - Surgery, LLC	ER320	Clamp tiny blood vessels and bile ducts
Microwave ablation System	Nanjing Yigao Microwave System Engineering Co., Ltd, China	ECO-100A110	Microwave ablation of liver metastases
Polymer ligation clips	Teleflex Medical, USA	Hem-lock544233	Clipping of broken ends of blood vessels and bile ducts
Silica gel drainage tube	BAINUS MEDICAL	YY-Fr16	Drainage of peritoneal fluid
Ultrasonic knife	Johnson & Johnson Medical Devices	HAR36	Tissue cutting, microvascular hemostasis