Complications of radiofrequency ablation in hepatocellular carcinoma

Minimally invasive treatment combined with cytokine-induced killer cells therapy lower the short-term recurrence rates of hepatocellular carcinomas

The recurrence of hepatocellular carcinoma (HCC) after minimally invasive therapy is frequent. Adoptive immunotherapy is thought to be an effective method to lower recurrence and metastasis rates of malignant tumors. Therefore, 85 HCC patients after transcatheter arterial chemoembolization and radiofrequency ablation therapy were randomized to immunotherapy group and no adjuvant therapy group. Autologous cytokine-induced killer (CIK) cells were transfused via hepatic artery to the patients. The alteration of levels of lymphocyte subsets in peripheral blood of patients was examined by flow cytometry. All patients were screened by computed tomography every 2 months to observe the tumor recurrent conditions. After CIK cell infusions, the percentages of CD3+, CD4+, CD56+, CD3+CD56+ cells, and CD4+/CD8+ ratio increased from 68.6+/-11.0%, 31.1+/-9.0%, 15.6+/-7.9%, 5.2+/-3.1%, and 1.1+/-0.5 to 70.7+/-10.1%, 33.5+/-8.0%, 18.4+/-9.4%, 5.9+/-2.8%, and 1.3+/-0.7, respectively (P<0.05); whereas the percentage of CD8 cells decreased from 31.1+/-7.8% to 28.6+/-8.3% (P<0.05). The 1-year and 18-month recurrence rates of the study group were 8.9% and 15.6%, compared with 30.0% and 40.0% of the control group (both P value<0.05). The data suggest that CIK cell transfusion is an effective treatment. It can boost the immunologic function in HCC patients and plays an important role in reducing the recurrence rate of HCC.

Thermal ablation of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cause of cancer, and its incidence is increasing worldwide because of the dissemination of hepatitis B and C virus infection. Patients with cirrhosis are at the highest risk of developing HCC and should be monitored every 6 months to diagnose the tumour at an early, asymptomatic stage. Patients with early-stage HCC should be considered for any of the available curative therapies, including surgical resection, liver transplantation and percutaneous image-guided ablation. Liver transplantation is the only option that provides cure of both the tumour and the underlying chronic liver disease. However, the lack of sufficient liver donation greatly limits its applicability. Resection is the treatment of choice for HCC in non-cirrhotic patients, who account for about 5% of the cases in western countries. However, in patients with cirrhosis, candidates for resection have to be carefully selected to reduce the risk of postoperative liver failure. It has been shown that a normal bilirubin concentration and the absence of clinically significant portal hypertension are the best predictors of excellent outcomes after surgery. However, less than 5% of cirrhotic patients with HCC fit these criteria. Image-guided percutaneous ablation is the best therapeutic choice for non-surgical patients with early-stage HCC. While ethanol injection has been the seminal percutaneous technique, radiofrequency ablation has emerged as the most effective method for local tumour destruction and is currently used as the primary ablative modality at most institutions.

Radiofrequency ablation prior to liver transplantation: focus on complications and on a rare but severe case

BACKGROUND

Radiofrequency ablation (RFA) is an established treatment for hepatocellular carcinoma (HCC) in patients awaiting liver transplantation, due to its comparably low rate of complication and high effectiveness. Complications are thought to be rare and mostly self-limiting. By contrast, we report on a life-threatening complication and discuss it in the context of other complications.

PATIENTS AND METHODS

Out of a total of 149 RFA procedures, the incidence of major complications was 4% on a per-procedure basis. Mortality was 0.67%. Major complications included intractable pain, intrahepatic hematoma, skinburn at the site of patch electrode, and sectorial bile duct stricture. All complications occurred after percutaneous RFA. Highlighted is a young patient listed for liver transplantation because of HCC recurrence following hepatic resection, who was treated by percutaneous RFA as a bridging therapy until a suitable graft became available. Post-operatively, gastric perforation occurred due to heat injury of the gastric wall.

CONCLUSIONS

The percutaneous RFA approach can occasionally lead to detrimental complications, particularly in patients with intra-abdominal adhesions, due to previous surgery if new intrahepatic malignant lesions accrue near the resection margin. Even widespread HCC disease can be treated effectively with orthotopic liver transplantation if the tumor growth is limited to the liver.

Bimodal electric tissue ablation-long term studies of morbidity and pathological change

BACKGROUND

Radiofrequency ablation is a popular method of treating unresectable liver tumors but tumors greater than 3 cm in diameter have a much greater risk of local recurrence after treatment. Bimodal electric tissue ablation is a modified form of radiofrequency ablation that creates significantly larger ablations by the addition of extra direct current circuitry. This may help to reduce the risk of local recurrence in these larger tumors. Prior to use in a clinical setting, a long term study was performed to assess associated morbidity and the pathological changes in the ablations.

METHODS

In eight pigs, six ablations were performed in each liver. Pigs were euthanized at 2 d, 2 wk, 2 mo, and 4 mo, and the ablations were assessed macroscopically and microscopically for pathological change. Regular blood tests were performed to assess changes in liver function. At death, any other abnormalities detected were reported.

RESULTS

Histopathological examination of ablation zones revealed tissue death by coagulative necrosis and healing by fibrotic scarring. Transient rises in serum liver enzymes were seen in the postoperative period. Skin necrosis was noted at the site of the positive electrode of the direct electrical current but no other form of morbidity was seen associated with the procedure.

CONCLUSIONS

Although the positive electrode placement requires further consideration, bimodal electric tissue ablation appears to be safe and behaves in a similar fashion to other thermal therapies such as standard radiofrequency ablation.

Hemobilia after radiofrequency ablation of hepatocellular carcinoma

OBJECTIVE

The purpose of this study was to report on the clinical course and imaging findings of hemobilia after radiofrequency (RF) ablation in four patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From July 2000 to December 2005, we experienced four cases of hemobilia after 1574 sessions of ultrasonography (US)-guided RF ablation in 1037 patients with HCCs. All ablation procedures were percutaneously performed with an internally cooled RF electrode system. The diagnosis of hemobilia was made if the patient complained of melena after RF ablation and biliary dilatation with high attenuating bile was noted at CT obtained immediately after RF ablation. We evaluated the clinical course and imaging findings of hemobilia caused by RF ablation.

RESULTS

All patient well tolerated RF ablation procedures without any incident during the procedure. Three of four patients complained of melena with an interval from 1 day to 4 days after RF ablation. One patient was asymptomatic. The melena symptom in all symptomatic patients spontaneously improved in 2 days. None of the patients showed substantial change in vital sign and the level of hemoglobin during the admission period. In all four patients, biliary (including GB) dilatation with high attenuating bile was noted at immediate follow-up CT. The CT findings in all four patients disappeared at 1 month follow-up CT.

CONCLUSION

Hemobilia is a rare potential complication of RF ablation with a favorable prognosis. Clinicians who use this technique should be aware of the characteristic CT findings and clinical course of hemobilia after RF ablation for liver tumors.

Bleeding after percutaneous radiofrequency ablation: Successful treatment with transcatheter embolization

PURPOSE

This knowledge will provide an ability to earlier detect bleeding complications after radiofrequency ablation (RFA), to manage these complications appropriately with endovascular procedures and minimize the sequelae.

MATERIALS AND METHODS

From 2002 to 2005, 96 patients with 150 hepatic tumours underwent 126 RFA sessions. Fifty-eight patients had HCC, 34 had liver colorectal metastases and 4 had cholangiocellular carcinoma. Sixty-one patients were men and 35 were women (mean age 69.82 years, age range 39-89). The lesions number ranged from 1 to 7 per patients (mean 1.6 nodules) with a mean diameter of 28.5 mm (range 80-10 mm). Seventy-seven patients underwent a single ablative session, 13 patients underwent 2 sessions, 4 patients underwent 3 sessions and 2 patients underwent 4 sessions. The number of tumours treated in each ablative session was 1 in 106, 2 in 18 and 4 in 2 patients.

RESULTS

Two cases of serious haemorrhages occurred after the procedures in two patients treated for liver metastases. An endovascular embolization was proposed for both patients using polyvinyl-alcohol and micro-coils. The absence of bleeding was first confirmed during angiography and then by CT performed the day after the angiographic procedure.

CONCLUSION

Transarterial embolization (TAE) represents the treatment of choice in the management of iatrogenic bleeding after RFA since it is minimally invasive, have a high success rate and a low incidence of complications compared to the more complex and dangerous surgical or laparoscopic options in patients who are often haemodynamically unstable and therefore at high anaesthetic and surgical risk.

Radiofrequency ablation of the liver in a rabbit model: creation of artificial ascites to minimize collateral thermal injury to the diaphragm and stomach

PURPOSE

To assess whether the creation of artificial ascites during radiofrequency (RF) ablation of the subcapsular portion of the liver can minimize collateral thermal injury to the diaphragm and stomach.

MATERIALS AND METHODS

A total of 20 percutaneous RF ablation procedures were performed in the livers of 10 rabbits (control, n = 5; experimental, n = 5) with use of an internally cooled electrode (1-cm active tip). In the experimental group, artificial ascites was established before RF ablation by dripping 320 mL of normal saline solution via a 20-gauge sheathed needle to separate the liver from the diaphragm and stomach. In each rabbit, two subcapsular ablation zones were made in the inferior tip of the left lobe of the liver adjacent to the stomach and in the far dome of the right lobe next to the diaphragm consecutively. After the animals were killed 3 days after the procedure, the frequency, size, and degree of thermal injury were compared between the experimental and control groups. The degree of thermal injury was graded by visual inspection according to a four-point scoring system. Representative cases underwent gross and histologic analysis.

RESULTS

Artificial ascites was achieved successfully with a single puncture in all rabbits in the experimental group. Mean procedure time for the formation of artificial ascites was 9 minutes. There was no difference in the size of the RF ablation zones in the liver between the two groups (P > .05). Thermal injury in the adjacent organs was observed significantly more frequently in the control group compared with the experimental group (diaphragm, 100% vs 0; stomach, 80% vs 20%; P < .05).

CONCLUSION

Creation of artificial ascites may be a simple and useful technique that can be used to reduce the frequency and severity of thermal injury during RF ablation of subcapsular hepatic tumors.