VIII. Complications and treatment
Complications caused by RFA are classified into mild (grade A, B) and severe (grade C-F) according to the severity.
Grade A: no treatment required, no adverse consequences.
Grade B: treatment required, no adverse consequences, including overnight observation only.
Grade C: treatment required, length of stay <48h.
Grade D: treatment required, increased level of medical care, length of stay >48h.
Grade E: resulted in long-lasting sequelae.
Grade F: death.
It has been reported that the overall complication rate of RFA is 0-10.6%, the incidence of minor complications is about 4.7%, the incidence of serious complications is about 2.2%, and the morbidity and mortality rate is 0-1.4%. According to the time of occurrence, they are divided into immediate complications (<2424=""30="">30d after RFA), as follows.
1. Pain: generally occurs intraoperatively and l-2d postoperatively, and rarely lasts longer than 1 week. Mild pain does not require special treatment; moderate or severe pain is given sedative and analgesic treatment under the premise of excluding acute abdominal disease and other causes.
2.Post-ablation syndrome: including hypothermia and general discomfort, which are self-limiting symptoms. Its severity and duration are related to the volume of ablated tumor. Patients with small ablation tumor size may not have any symptoms. Most of the patients have symptoms lasting from 2 to 7 d. The symptoms of patients with larger ablation tumors can last from 2 to 3 weeks. The treatment of post-ablation syndrome is mainly symptomatic support, such as antipyretic, antiemetic and fluid replacement.
3.Bile heart reflex.
(1) Cause: Surgical stimulation of the biliary system causes coronary artery spasm and cardiac dysfunction due to vagal excitation, manifested as bradycardia, which may be accompanied by a drop in blood pressure, arrhythmia, myocardial ischemia or even ventricular fibrillation or cardiac arrest. Pain can also cause vagal excitation, resulting in bradycardia.
(2) Treatment: Stop RFA treatment immediately and administer intravenous atropine; give appropriate emergency resuscitation treatment to patients with decreased blood pressure, arrhythmia and cardiac arrest.
(3) Prevention: For patients whose tumors are adjacent to gallbladder and bile duct, preoperative atropine 0.5mg can be applied intravenously to reduce vagal excitability; sedative and analgesic drugs can be applied to control pain; RFA can be started from small power and gradually adjusted to predetermined parameters.
4. Pericardial tamponade.
(1) Cause: misinjury of pericardium when guiding needle, RF electrode needle puncture and unfolding sub needle.
(2) Treatment: small amount of pericardial effusion (<100>100m1): emergency pericardial puncture and drainage and corresponding resuscitation treatment.
(3) Prevention: For tumors adjacent to the heart, a detailed surgical treatment plan is developed preoperatively. Give priority to image-guided modalities that can guide puncture in real time to prevent mis-penetration.
5. Liver abscess.
(1) Cause: Liquefied necrosis of tissue in the RFA treatment area secondary to infection or formation of biliary tumor in the ablation area secondary to infection.
(2)Treatment: timely percutaneous abscess drainage and anti-infection treatment.
(3) Prevention: Strict aseptic operation and prophylactic application of antibiotics for patients with risk factors for infection (diabetes, post-duodenal papillotomy, etc.) and large ablation volume.
6. Liver failure.
(1) Cause: Serious postoperative complications, such as infection, bleeding, biliary tract injury, etc.
(2)Treatment: Active liver preservation and treatment of complications (anti-infection, abscess drainage, hemostasis, dilation, biliary drainage, etc.).
(3) Prevention: intraoperative avoidance of biliary tract and vascular injury; postoperative prevention of related complications and active hepatoprotective treatment.
7. Subperitoneal hematoma and abdominal hemorrhage.
(1) Cause: Tearing of liver pericardium and parenchyma, tumor rupture, vascular injury, inadequate needle tract ablation, etc.
(2) Treatment: monitor patient’s vital signs, conservative treatment for small amount of bleeding; arterial active epistaxis with simultaneous arterial embolization or ablation to stop bleeding; active anti-shock treatment for patients with hemorrhagic shock and surgical exploration to stop bleeding if necessary.
(3) Prevention: avoid puncture of larger vascular branches, reduce the number of punctures, leave the liver envelope to adjust the radiofrequency electrode needle and the needle channel must be ablated when retiring the needle after surgery.
8.Pneumothorax.
(1)Cause: Injury to the dirty layer of pleura or lung tissue during puncture.
(2) Treatment: Small amount of pneumothorax is treated conservatively. Medium to large amount of pneumothorax perform puncture to aspirate gas or closed drainage of the chest cavity.
(3) Prevention: preoperative breathing and breath-holding training for patients, routine puncture under calm breathing and breath-holding, avoid damaging the dirty pleura or lung tissue during puncture.
9. Pleural effusion.
(1) Cause: Ablation treatment of adjacent diaphragmatic tumor damages diaphragmatic guanidine and pleural tissue, necrotic tissue stimulates pleura after ablation, liquefaction of necrotic tissue or direct breakage of biliary tumor into pleural cavity.
(2)Treatment: Conservative treatment for small amount of pleural effusion, puncture aspiration or drainage for medium to large amount of pleural effusion.
(3) Prevention: When ablating adjacent diaphragmatic tumors, try to avoid diaphragmatic and pleural injury, and combine chemical ablation for tumor parts adjacent to the diaphragm.
10.Biliary duct and gallbladder injury.
(1) Cause: Mechanical injury or thermal injury to bile duct and gallbladder caused by radiofrequency electrode needle.
(2) Treatment: Conservative treatment for minor bile duct dilatation without symptoms and signs; percutaneous transhepatic or retrograde biliary drainage and bile duct angioplasty for obstructive jaundice; percutaneous drainage for symptomatic and gradually increasing bile tumors.
(3) Prevention: avoid damaging the large intrahepatic bile ducts and gallbladder during ablation; bile duct placement is also feasible, and saline is pumped to protect the bile ducts during ablation.
11.Hepatic artery and portal vein or hepatic artery and hepatic vein fistula.
(1) Cause: damage to the hepatic artery and portal vein or hepatic vein branches.
(2) Treatment: Hepatic artery with small flow rate. Portal vein or hepatic artery. Hepatic vein fistula does not need treatment, for large fractional flow is feasible spring coil embolization treatment.
12, gastrointestinal tract injury.
(1) Cause: When ablating the tumor adjacent to the gastrointestinal tract, it causes damage to the gastrointestinal tract and even perforation.
(2) Treatment: In case of gastrointestinal tract perforation, abstain from diet, gastrointestinal decompression and timely surgical treatment.
(3) Prevention: precise positioning and reasonable setting of ablation parameters, ablation treatment can be performed after separating tumor from adjacent gastrointestinal tract by injecting gas (filtered air or carbon dioxide:) or liquid (5% glucose or water for injection), and chemical ablation can also be combined for tumor adjacent to gastrointestinal tract. RFA is prohibited for those whose tumors have invaded the gastrointestinal tract.
13.Diaphragm injury.
(1) Cause: Tumor is adjacent to diaphragm, ablation treatment causes thermal injury to diaphragm.
(2)Treatment: For those who have formed pneumothorax or pleural effusion, the treatment is described in the treatment of “pneumothorax” and “pleural effusion”.
(3) Prevention: The diaphragm can be protected by injecting liquid (5% glucose or water for injection) under the diaphragm or pleural cavity, and chemical ablation can be combined with the tumor adjacent to the diaphragm.
14.Tumor implantation.
(1) Cause: mainly due to repeated multiple punctures and inadequate ablation of needle tracts.
(2) Treatment: Ablation therapy of implanted tumor is feasible.
(3) Prevention: avoid direct puncture of tumor; precise positioning, reduce the number of punctures of tumor; after puncturing tumor with radiofrequency electrode needle, if the position needs to be adjusted, it should be adjusted after ablation of tumor in situ.
15.Skin injury.
(1) Cause: The loop electrode plate is not pasted solidly or asymmetrically, one side of the loop electrode plate falls off, etc., which makes the local current load too large; the guiding needle contacts with the active end of the RF electrode needle during ablation treatment, which causes damage to the tissue and local skin through which the guiding needle passes.
(2) Treatment: apply scald cream, symptomatic treatment and prevent infection.
(3) Prevention: paste the negative plate tightly and symmetrically; cool the negative plate with local ice bag; find the cause immediately when one side of the negative plate is overheated; avoid contact between the guiding needle and the active end of the RF electrode needle during ablation treatment.
16.Other rare complications: intercostal artery and intercostal nerve injury, bile duct-bronchial fistula, etc.
(I) Cause: Puncture injury to intercostal artery, intercostal nerve and lung tissue, etc.
(2) Treatment: intercostal artery injury can be applied to hemostatic drugs. Local compression, embolization or ablation to stop the bleeding; intercostal nerve injury application of nerve-nourishing drugs and symptomatic treatment; bile duct a bronchial fistula feasible drainage or surgical treatment.
(3) Prevention.
Avoid intercostal artery and intercostal nerve travel area during RFA puncture, and fully ablate the needle tract to reduce the risk of intercostal artery bleeding; tumor at the top of the diaphragm should be treated by puncturing the tumor through the liver tissue during RFA, and can also be combined with artificial pleural fluid and pneumothorax to avoid puncturing the lung tissue to prevent bile duct a bronchial fistula.
Efficacy assessment and follow-up
1.Efficacy assessment: Enhanced CrI_ or enhanced Mm is the current standard method to evaluate the ablation effect, PET.CT can be used if available, ultrasonography can be used to initially evaluate the ablation effect after the treatment. Complete ablation of tumor: no enhancement of tumor and ablation edge, with or without concentric, homogeneous and smooth circular enhancement band. Tumor residual or recurrence: ablation margins show scattered, nodular, irregular eccentric intensification.
2.Later follow-up: ultrasound and enhanced cT or enhanced MRI, tumor markers and liver function were reviewed every l to 3 months within 1 year after surgery; every 3 months after 1 year. The main observation is whether the local lesions have progressed, whether there are new intrahepatic lesions and extrahepatic metastases.
X. Summary
RFA treatment for liver tumor should be strictly mastered in terms of indications, contraindications, operation points, precautions and prevention of complications. Image-guided precise puncture and accurate complete ablation are the keys to successful treatment. In order to reduce the chance of tumor recurrence and metastasis, the ablation scope should include the tumor and peritumor 0.5-1.0 cm liver tissue to obtain the ablation margin. For intermediate and advanced hepatocellular carcinoma and metastatic carcinoma, TACE or TAE treatment can be performed first, and then RFA treatment can be performed at an optional stage to achieve tumor reduction or even radical treatment effect. Ablation therapy should also focus on the protection of liver function. For multiple tumors and large tumors, RFA can be superimposed in multiple points to effectively control tumors in a short period of time. In addition to RFA treatment, chemotherapy, radioimmunotherapy, molecular targeting drugs and chemical ablation should be combined to further improve the overall effect of liver malignancy treatment.