Treatment efficacy of radiofrequency ablation of 338 patients with hepatic malignant tumor and the relevant complications

Radiofrequency ablation of hepatocellular carcinoma: long-term outcome and prognostic factors

PURPOSE

To investigate the efficacy of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), and the prognostic factors for post-RFA survival rate.

METHODS

From 1999 to 2006, 266 patients with 392 HCCs underwent ultrasound guided RFA treatment. They were 216 males and 50 females, average age 59.4+/-15.4 years (24-87 years). The HCC were 1.2-6.7 cm in diameters (average 3.9+1.3 cm). There were 158 patients with single tumor, and the rest had multiple (2-5) tumors. Univariate and multivariate analysis with 19 potential variables were examined to identify prognostic factors for post-RFA survival rate.

RESULTS

The overall post-RFA survival rates at 1st, 3rd, and 5th year were 82.9%, 57.9% and 42.9%, respectively. In the 60 patients with stage I HCC (AJCC staging), the 1-, 3-, 5-year survival rate were 94.8%, 76.4% and 71.6%, significantly higher than the 148 patients with stage II-IV tumors (81.8%, 57.6% and 41.2%, P=0.006). For the 58 patients with post-surgery recurrent HCC, the survival rates were 73.2%, 41.9% and 38.2% at the 1st, 3rd, and 5th year, which were significantly lower than those of stage I HCC (P=0.005). Nine potential factors were found with significant effects on survival rate, and they were number of tumors, location of tumors, pre-RFA liver function enzymes, Child-Pugh classification, AJCC staging, primary or recurrent HCC, tumor pathological grading, using mathematical protocol in RFA procedure and tumor necrosis 1 month after RFA. After multivariate analysis, three factors were identified as independent prognostic factors for survival rate, and they were Child-Pugh classification, AJCC staging and using mathematical protocol.

CONCLUSION

Identifying prognostic factors provides important information for HCC patient management before, during and after RFA. This long-term follow-up study on a large group of HCC patients confirmed that RFA could not only achieve favorable outcome on stage I HCC, but also be an effective therapy for stage II-IV or recurrent HCC.

Delayed Colonic Perforation After Percutaneous Radiofrequency Ablation of Hepatocellular Carcinoma

Radiofrequency ablation (RFA) is an effective treatment for hepatocellular carcinoma. Colonic perforation secondary to RFA of the liver is an uncommon complication that has been reported to have an incidence between 0.1% and 0.3%. Lesions adjacent (within 1 cm) to the colonic wall and those in patients with history of upper abdominal surgery or chronic cholecystitis are particularly at risk. More importantly, thermal injury leading to colonic perforation has proved to have a fatal outcome. We present a case of percutaneous RFA in a patient with hepatocellular carcinoma that was abutting the colonic hepatic flexure. Colonic perforation was diagnosed on the eighth day postablation when the patient was readmitted with peritonitis.

Bimodal electric tissue ablation-modified radiofrequency ablation with a le veen electrode in a pig model

Radiofrequency ablation (RFA) is a method of treating non-resectable liver tumors by use of a high-frequency alternating electrical current. Concerns have been raised as the local recurrence rates following treatment have been reported to be as high as 47%. The size of the ablation is limited by charring of adjacent tissues. It is hypothesized that by hydrating the liver, we can reduce charring, thus producing larger ablations, and that this can be achieved by addition of a direct electrical current to the electrical circuit. Using a pig model, standard RFA control ablations were created in the left lobe of the liver. Ablations using the modified circuit were created in the right lobe. At the end of the procedure, the pig was killed by lethal injection and the liver harvested. From the explanted liver, the diameter of each ablation was measured and the modified ablations were compared with controls using restricted maximum likelihood variance analysis. From 4 pigs, 14 controls and 12 modified ablations were produced. The mean diameter of the controls was 27.78 mm (+/- SE 3.37 mm). The mean diameter of the modified ablation was 49.55 mm (+/- SE 3.46 mm), which was significantly larger than the controls (P < 0.001). This study has shown that by modification of the standard RFA circuit with the addition of a direct electrical current, significantly larger ablations can be produced. By using this technique, the number of ablations required to treat one tumor would be less and it is anticipated this could reduce the rate of local recurrence.

Feasibility of percutaneous radiofrequency ablation for intrathoracic malignancies

BACKGROUND

Radiofrequency ablation (RFA) has become an accepted alternative for treating intrathoracic malignancies; however, the incidence and characteristics of peri- and postprocedural complications are not well described. The purpose of the study was to assess the safety and technical feasibility of percutaneous RFA in unresectable intrathoracic malignancies.

METHODS

Percutaneous RFA was performed in patients with intrathoracic malignancies between June 2001 and December 2004. In total, 366 tumors were treated in 137 patients in 211 sessions. All patients were nonsurgical candidates or had refused surgery. Three hundred and thirty-six lesions were subjected to RFA for the treatment of metastases and 30 lesions for primary lung carcinoma.

RESULTS

Although no procedural mortality occurred, 2 patients died during the course of the study because of intractable pneumothorax and massive hemoptysis (0.9%). The overall major complication rate was 17.1% (pneumothoraces requiring tube drainage in 25, pleuritis in 6, pleural effusion requiring tube drainage in 4, lung abscess in 1, and intrapulmonary hemorrhage with hemothorax in 1). Minor complications included pneumothoraces not requiring tube drainage in 108 sessions, pleural effusion without drainage in 34, hemosputum in 9, nausea and/or vomiting in 3, subcutaneous emphysema in 3, cough in 2, skin burn in 2, atelectasis in 1, and subileus in 1. High fever and/or chest pain were seen in 33.8% and 39.3% of patients, respectively.

CONCLUSIONS

With over 200 procedures, RFA appears to be a safe and minimally invasive option with negligible mortality and little morbidity in selected patients with unresectable intrathoracic malignancies.

Decreased portal flow volume increases the area of necrosis caused by radio frequency ablation in pigs

BACKGROUND/AIMS

Although radio frequency ablation (RFA) has been widely accepted as an effective treatment for hepatocellular carcinoma (HCC), severe complications are not uncommon. Major complications seem to occur as a result of over-ablation beyond the intended area. As most patients with HCC have underlying cirrhosis, we speculated that decreased portal flow might cause the necrosis associated with RFA. To confirm this hypothesis, we examined the area of necrosis resulting from RFA under varying conditions of portal flow in a porcine model.

METHODS

RFA was performed using ultrasonographic guidance in anesthetized pigs. During the RFA procedure, portal flow was regulated by a balloon catheter, which was set in a portal trunk. The necrosis area was measured after sacrifice and was compared with the hyperechoic area that appeared during ablation. In another session, RFA was performed close to the hepatic vein and endothelial damage was examined.

RESULTS

The necrosis area caused by RFA was significantly larger when the portal flow volume was decreased by 50% or more. The hyperechoic lesion was always larger than the area of pathological necrosis regardless of portal flow volume. Under conditions of decreased portal flow, the vessel endothelium near the ablated area was more readily damaged.

CONCLUSION

Decreased portal flow volume resulted in enlargement of the area of necrosis caused by RFA. Our results indicate that over-ablation could easily occur in patients with advanced cirrhosis, and that this could lead to major complications. Ultrasonographic guidance may be helpful for avoiding over-ablation.

Evaluation of mulitprobe radiofrequency technology in a porcine model

OBJECTIVE

We evaluated two new radiofrequency devices in an in vivo porcine model.

MATERIALS AND METHODS

Multiprobe radiofrequency ablation (RFA) was used in a porcine model with an impedance-based algorithm in one experiment and clustered probes with and without switcher controllers in another; a Pringle maneuver was used with half of the ablations.

RESULTS

The impedance experiment included 13 ablations, with a mean length of 7.0 cm and width of 2.9 cm (95% CI) and an average time of 596 s. Ablation volumes were significantly larger (54.1+/-11.7 cc(3) vs 34.9+/-4.8 cc(3), p<0.05) and ablation times were significantly shorter (359 s vs 834 s, p<0.05) for the Pringle group compared with the No Pringle group, respectively. The switcher controller experiment included 34 RFAs. Diameter (mm) (51.4 vs 40.3, p<0.0001), surface area (cm(2)) (22.4 vs 16.0, p<0.0002), and volume (cc) (66.1 vs 36.9, p<0.0001) were significantly larger for the combination probes with switcher controller compared with clustered probes, respectively. Ablation volumes for the Pringle vs No Pringle groups in the combination probes were 68.0 cc vs 64.3 cc and for the clustered probes 40.1 cc vs. 33.7 cc, respectively.

CONCLUSION

Multiprobe ablations using RFA are promising technologies that need further study to evaluate their clinical utility.

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.

Pre- and Postoperative Clinical Care of Patients Undergoing Interventional Oncology Procedures: A Comprehensive Approach to Preventing and Mitigating Complications

Interventional radiology (IR) is transforming itself into a fully fledged clinical specialty. Successful practices will have to adapt to this environment by developing the requisite clinical skills and acquiring the associated privileges. To thrive, an IR physician will have to develop strong clinical skills, be intimately familiar with the relevant disease, IR procedure, its possible complications and how to address them effectively. From an administrative point of view, successful practices will have to follow a multidisciplinary approach to treatment that involves other physician-specialists and develop a diverse IR group that can provide appropriate pre- and post-intervention clinical care. The above are especially necessary in order to offer interventions such as arterial embolizations and percutaneous ablations which are rapidly becoming the mainstay of treatment for non-surgical patients (and increasingly surgical patients as well) with cancer.