Injection of subphrenic saline during radiofrequency ablation to minimize diaphragmatic injury

Successful surgical rescue of delayed onset diaphragmatic hernia following radiofrequency ablation using a thoracoscopic approach for hepatocellular carcinoma: a case report

Background

Radiofrequency ablation (RFA) is widely used as a minimally invasive treatment for hepatocellular carcinoma (HCC). RFA has a low risk of complications, especially compared with liver resection. Nevertheless, various complications have been reported after RFA for HCC; however, diaphragmatic hernia (DH) is extremely rare.

Case presentation

A 78-year-old man underwent thoracoscopic RFA for HCC located at the medial segment adjacent to the diaphragm approximately 7 years before being transported to the emergency department due complaints of nausea and abdominal pain. Computed tomography revealed a prolapsed small intestine through a defect in the right diaphragm, and emergency surgery was performed. The cause of diaphragmatic hernia was the scar of RFA. We confirmed that the small intestine had prolapsed into the right diaphragm, and we resected the necrotic small intestine and repaired the right diaphragm. Herein, we report a case of ileal strangulation due to diaphragmatic hernia after thoracoscopic RFA.

Conclusions

Care should be taken when performing thoracoscopic RFA, especially for tumors located on the liver surface adjacent to the diaphragm. Patients should be carefully followed up for possible DH, even after a long postoperative interval.

The value of artificial pleural effusion for percutaneous microwave ablation of liver tumour in the hepatic dome: a retrospective case-control study

PURPOSE

The aim of this study was to evaluate the feasibility, safety, and efficiency of percutaneous microwave ablation (MWA) with artificial pleural effusion for liver tumours located in the hepatic dome.

MATERIALS AND METHODS

A total of 112 sessions of artificial pleural effusion performed on 102 liver tumour patients were summarised and analysed at our hospital. Among them, 31 hepatocellular carcinoma patients treated by percutaneous MWA were selected as the artificial pleural effusion group. The control group without artificial pleural effusion was matched with tumour size, tumour location and the histological grades of differentiation. The primary technique effectiveness rate, local tumour progression rate and tumour-free survival rate were compared.

RESULTS

Artificial pleural effusion was achieved successfully in 110 of 112 sessions (98.2%), which helped to improve the visibility in 98.8% (82/83) and acquire safe puncture path in 96.3% (26/27). There were no statistical differences between the artificial pleural effusion group and the control group in the primary technique effectiveness rate (p = 1.000), the 1-, 2-, and 3-year local tumour progression rates (p = 0.669), and the 1-, 2-, and 3-year tumour-free survival rates (p = 0.979).

CONCLUSIONS

Percutaneous MWA with artificial pleural effusion could be a feasible, safe, and effective technique for liver tumours located in the hepatic dome.

Percutaneous microwave ablation for liver cancer adjacent to the diaphragm

PURPOSE

The aim of the study was to prospectively evaluate the safety and effectiveness of percutaneous microwave (MW) ablation for liver cancer adjacent to the diaphragm.

MATERIALS AND METHODS

From May 2005 to June 2008, 89 patients with 96 hepatic lesions adjacent to the diaphragm (the shortest distance from the lesion margin to the diaphragm less than 5 mm), who underwent ultrasound (US)-guided percutaneous MW ablation, were included in the study group. A total of 100 patients with 127 hepatic lesions not adjacent to the diaphragm (the shortest distance from the lesion to the diaphragm and the first or second branch of the hepatic vessels more than 10 mm), who underwent US-guided percutaneous MW ablation, were included in the control group. During the ablation the temperature of marginal ablation tissue proximal to the diaphragm was monitored and controlled at 50°-60°C for more than 10 min in the study group. We compared the results of ablation between the two groups.

RESULTS

A total of 91 of 96 tumours (94.8%) in the study group and 123 of 127 tumours (96.9%) in the control group achieved complete ablation (P > 0.05). Local tumour progression was found in 18 of 96 tumours (18.8%) in the study group and 21 of 127 tumours (16.5%) in the control group during follow-up after MW ablation (P > 0.05). No major complications occurred in either group.

CONCLUSIONS

Under strict temperature monitoring, percutaneous MW ablation is safe and can achieve a high complete ablation rate for the treatment of hepatic tumours adjacent to the diaphragm.

Radiofrequency ablation for hepatocellular carcinoma abutting the diaphragm: the value of artificial ascites

Ultrasound (US)-guided percutanoeus radiofrequency (RF) ablation is difficult to perform for treating a hepatic tumor abutting the diaphragm due to a poor sonic window and high risk of diaphragmatic thermal injury. RF ablation with assistance of the use of artificial ascites is a simple and safe technique for treating a hepatic dome tumor abutting the diaphragm. One can improve the sonic window and separate the RF ablation zone from the diaphragm by downward displacement of the liver with the use of a simple and inexpensive technique. Dextrose water solution is an ideal fluid due to its nonionic nature. Complications related to the use of artificial ascites including hemoperitoneum are rare. Peritoneal adhesion and tumor location in the bare area are the limitations for the application of this technique.

Percutaneous radiofrequency ablation of hepatocellular carcinoma abutting the diaphragm and gastrointestinal tracts with the use of artificial ascites: safety and technical efficacy in 143 patients

The purpose of this study was to assess the feasibility, safety and efficacy of radiofrequency ablation (RFA) with the use of artificial ascites for hepatocellular carcinoma (HCC) adjacent to the diaphragm and gastrointestinal tract. One hundred forty-three patients with 181 HCCs who underwent US-guided percutaneous RFA with the use of artificial ascites were retrospectively reviewed. Among the 181 HCCs, 148 HCCs were defined as problematic nodules for two major reasons: poor sonic window or possible thermal injury. We artificially induced ascites before performing RFA by dripping 5% dextrose in a water solution. We assessed the technical success of introducing artificial ascites, technical feasibility of the use of artificial ascites and complications. The technical success rate, as well as the primary and secondary technique success rate, was assessed by regular follow-up CT examinations. RFA with artificial ascites was successfully achieved in 130 of 143 patients. The primary technique effectiveness was 85.3%. During follow-up (mean, 20.4 months), remote intrahepatic recurrence occurred in 49 patients and local tumor progression occurred in 15 patients. Three (2.1%) of the 143 patients experienced major complications (hemoperitoneum, lobar infarction and biloma) related to the RFA procedure. The use of artificial ascites is a simple and useful technique to minimize collateral thermal injury and to improve the sonic window.

Percutaneous radiofrequency ablation for the hepatocellular carcinoma abutting the diaphragm: assessment of safety and therapeutic efficacy

Objective

To assess the safety and therapeutic efficacy of a percutaneous radiofrequency (RF) ablation for the hepatocellular carcinoma (HCC) abutting the diaphragm.

Materials and Methods

We retrospectively assessed 80 patients who underwent a percutaneous RF ablation for a single nodular (< 4 cm) HCC over the last four years. Each patient underwent an ultrasound-guided RF ablation using internally cooled electrodes for the first-line treatment. We divided patients into two subgroups based on whether the index tumor was abutting (less than 5 mm) the diaphragm or not: group A (abutting; n = 31) versus group B (non-abutting; n = 49). We compared the two subgroups for complications and therapeutic efficacy using image and the review of medical records. The statistical assessment included an independent t-test, Fisher's exact test, and chi-square test.

Results

The assessment of the diaphragmatic swelling at CT immediately following the procedure was more severe in group A than group B (mean thickness change:1.44 vs. 0.46 mm, p = 0.00). Further, right shoulder pain was more common in group A than B (p = 0.01). Although minor complications (hemothorax 1 case, pleural effusion 1 case) were noted only in group A, no major thoracic complication occurred in either group. The technical success rate was lower in group A than group B (84% vs. 98%, p = 0.03). As well, the primary and secondary technique effectiveness rates in group A and group B were 90% versus 98% (p = 0.29) and 79% versus 91% (p = 0.25), respectively. The local tumor progression rate was higher in group A than in group B (29% vs. 6%, p = 0.02).

Conclusion

We found that the percutaneous RF ablation for the HCC abutting the diaphragm is a safe procedure without major complications. However, it is less effective with regard to technical success and local tumor control.

Does artificial ascites induce the heat-sink phenomenon during percutaneous radiofrequency ablation of the hepatic subcapsular area?: an in vivo experimental study using a rabbit model

OBJECTIVE

To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model.

MATERIALS AND METHODS

A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05).

RESULTS

One rabbit from the "W" group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups "W" and "R" throughout the procedures (39.2+/-0.4 degrees C in group W and 33.4+/-4.3 degrees C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4+/-237.3 mL in group C, 1,172.0+/-468.9 mL in group R, and 1,030.6+/-665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group "C" rabbits (p = 0.030).

CONCLUSION

Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region.

Hepato-pericardial fistula following radiofrequency ablation (RFA) for liver metastasis: a case report and review of the literature

INTRODUCTION

Recent large-scale studies have demonstrated the efficiency and safety of radiofrequency ablation (RFA) for unresectable hepatic tumors. Nevertheless, severe side effects especially relating to non-target thermal injury have occurred after radiofrequency ablation.

CASE REPORT

We observed the development of a hepato-pericardial fistula leading to pericardial empyema after RFA of a metastatic hepatic lesion. Concerning the genesis of the fistula, development from thermal damages in the diaphragm and pericardium as well as abscess formation in the liver is assumed. Treatment consisted of percutaneous drainage and flushing via remaining hepatic and pericardial catheters. Recovery was achieved conservatively after 2 months. To the best of our knowledge, a hepato-pericardial fistula as a complication of RFA has not been reported so far. The review of the literature revealed several cases of intrahepatic abscess formation after RFA as well as one case of pericardial empyema due to perforation of hepatic amoebic abscess. Two cases of pericardial tamponade after RFA are reported in the literature leading to death. Treatment via percutaneous drainage has been successful in this case and correlates with the successful treatment of abscess formation after RFA of metastatic pancreatic cancer. Other authors suggest pericardectomy or thoracotomy in the treatment of pericardial empyema.

CONCLUSION

The management of hepatic abscess formation subsequent to RFA of metastatic hepatic malignancies is not well described. We regard the percutaneous drainage as treatment of pericardial empyema as well as hepatic abscess as less invasive and sufficient, as demonstrated in this case.

Percutaneous radiofrequency ablation of hepatic tumors against the diaphragm: frequency of diaphragmatic injury

PURPOSE

To retrospectively determine the frequency of diaphragmatic injury when percutaneous hepatic radiofrequency (RF) ablation is performed adjacent to the diaphragm.

MATERIALS AND METHODS

Institutional Review Board approval was obtained for our HIPAA-compliant study. Informed consent for the ablation procedure and for use of related data for future research was obtained from each patient. A retrospective review was conducted of 215 patients undergoing percutaneous RF ablation of hepatic tumors. Twenty-nine patients (21 men and eight women; age, 41-89 years) were identified with tumors abutting the diaphragm. Episodes of right shoulder pain were recorded. A panel of radiologists blinded to the patients' clinical histories reviewed their imaging for evidence of diaphragmatic injury and ablation success. A generalized estimating equation model and the Fisher exact test were used for statistical analysis.

RESULTS

The 29 patients had a total of 33 tumors abutting the diaphragm. Tumor size was 1.3-5.5 cm (mean, 3.2 cm +/- 1.1). After ablation, five (17%) patients reported right shoulder pain. In four, pain was mild or moderate, with symptoms lasting 2-14 days (median, 5.5 days). Three of these showed diaphragmatic thickening on postablation computed tomographic (CT) scans. One patient had severe pain lasting 2 weeks, followed by milder pain for 2 months. This patient's postablation CT images showed focal nodular diaphragmatic thickening. This patient was treated with a multitined device; the other four, with straight-needle devices. Local tumor progression was seen in 14 tumors (42.4%). Tumors 3 cm or smaller had a much lower local progression rate than tumors larger than 3 cm (12.5% vs 70.6%).

CONCLUSION

Of 29 patients who had ablation of hepatic tumors adjacent to the diaphragm, five (17%) had diaphragmatic injury, which was clinically apparent with right shoulder pain.

Intermittent hepatic vein balloon occlusion during radiofrequency ablation in the liver

The purpose of the study was to assess the feasibility of intermittent hepatic vein balloon occlusion during percutaneous radiofrequency (RF) ablation. Eight non-anticoagulated patients who had primary (n = 2) and metastatic (n = 6) liver tumors with a mean diameter of 4.2 cm (range 2.4-6.5 cm) were treated, resulting in a mean ablation diameter of 6.3 cm (range 4.3-9.3 cm). Six of 9 (67%) of the balloon-occluded hepatic veins were patent. No clinical sequelae of thrombosis were noted. Mean length of follow-up with CT and/or MRI was 12 months. Local tumor control was achieved in 5 of 8 patients. Intermittent hepatic vein balloon occlusion could potentially be a low-risk adjunctive maneuver for thermal ablation therapy in the treatment of large tumors and tumors adjacent to large vessels.

Thermal protection with 5% dextrose solution blanket during radiofrequency ablation

A serious complication for any thermal radiofrequency ablation is thermal injury to adjacent structures, particularly the bowel, which can result in additional major surgery or death. Several methods using air, gas, fluid, or thermometry to protect adjacent structures from thermal injury have been reported. In the cases presented in this report, 5% dextrose water (D5W) was instilled to prevent injury to the bowel and diaphragm during radiofrequency ablation. Creating an Insulating envelope or moving organs with D5W might reduce risk for complications such as bowel perforation.

The surgical approach for radiofrequency ablation of liver tumors

Radiofrequency ablation for the treatment of liver tumors is one of the best alternative treatment modalities when surgical resection is not possible. To find the right indication for the treatment, every patient should be treated in a high-volume center for the treatment of liver tumors in an interdisciplinary conference consisting of liver surgeons, interventional radiologists, medical oncologists, and gastroenterologists. With a multimodal approach including anatomic segmental and wedge resection of the liver, RFA, and chemotherapy, a median survival of 36 months was achieved in technically unresectable patients with colorectal liver metastases (Elias et al. 2005). This survival doubles the survival rate of any other treatment modality in this group of patients. These interdisciplinary conferences also serve to determine the approach for RFA, whether it should be percutaneous, laparoscopic, or open surgery. The safest ablation with the fewest adverse events from RFA is the open surgical approach, followed by the laparoscopic approach. The approach with the highest risk of injury to organs in proximity to the liver is the percutaneous approach. Therefore, many variables must be evaluated before making definite decisions. After choosing RFA as the best alternative treatment option after evaluation of all variables for a particular patient, it offers a treatment option with a potential cure. A major advantage is the possible combination with liver resection, which extends the indication for surgical or ablative therapy.

MR-guided percutaneous ethanol injection for hepatocellular carcinoma in a 0.2T open MR system

The purpose of this work is to describe our experience with single-session percutaneous ethanol injection (PEI) under the guidance of 0.2-T open MRI for hepatocellular carcinomas (HCC) that were not suitable for ablation under ultrasound (US) or computed tomography (CT) guidance. None of the lesions (N = 7) were detectable on US. MRI was chosen over CT as the guidance modality because the nodules were located in the hepatic dome (N = 4) or were invisible on noncontrast CT (N = 3). All of the nodules were targeted successfully, and apparently complete tumor necrosis was achieved in six nodules (86%). During a follow-up of one to 41 months, only one patient developed local recurrence four months after PEI. MR-guided PEI is feasible and effective for treating HCC when other imaging guidance methods are not appropriate.

CT mapping of the distribution of saline during radiofrequency ablation with perfusion electrodes

PURPOSE

During radiofrequency (RF) ablation, adjunctive saline increases the size of the ablation zone and therefore electrodes that simultaneously deliver current and saline have been developed, but the addition of saline also results in an irregular ablation zone. Our aim was to study the distribution of saline during RF ablation.

METHODS

Four patients were treated: 3 with liver metastases and 1 with hepatocellular carcinoma (HCC). Two different perfusion electrodes were used: a high-perfusion-rate, straight electrode (Berchtold, Germany) and a low-perfusion-rate, expandable electrode (RITA Medical Systems, USA). The saline perfusate was doped with non-ionic contrast medium to render it visible on CT and the electrical conductivity was measured. CT scans were obtained of each electrode position prior to ablation and repeated after ablation. Contrast-enhanced CT was performed 18-24 hr later to demonstrate the ablation zone. All treatments were carried out according to the manufacturer's recommended protocol.

RESULTS

The addition of a small quantity of non-ionic contrast did not alter the electrical conductivity of the saline. Contrast-doped saline extravasated beyond the tumor in all 3 patients with metastases but was limited in the patient with HCC. In some areas where saline had extravasated there was reduced enhancement on contrast-enhanced CT consistent with tissue ablation. One patient treated with the high-perfusion-rate system sustained a jejunal perforation requiring surgery.

CONCLUSION

Saline can extravasate beyond the tumor and with the high-perfusion-rate system this resulted in an undesirable extension of the ablation zone and a complication.

Thermoablation of Liver Metastases: Efficacy of Temporary Celiac Plexus Block

PURPOSE

To determine the efficacy of celiac plexus block during thermoablation of liver metastases.

METHODS

Fifty-five consecutive patients underwent thermoablation therapy of liver tumors by laser-induced thermotherapy. Twenty-nine patients received a temporary celiac plexus block, 26 patients acted as control group. In both groups fentanyl and midazolam were administered intravenously upon request of the patient. The duration of the intervention, consumption of opiates, and individual pain sensations were documented.

RESULTS

No complications resulting from the celiac plexus block were recorded. Celiac plexus block significantly reduced the amount of pain medication used during thermoablation therapy of liver tumors (with block, 2.45 mug fentanyl per kg body weight; without block, 3.58 mug fentanyl per kg body weight, p < 0.05; midazolam consumption was not reduced) in patients with metastases < or = 5 mm from the liver capsule. For metastases farther away from the capsule no significant differences in opiate consumption were seen. Celiac plexus block reduced the time for thermoablation significantly (178 min versus 147 min, p < 0.05) no matter how far the metastases were from the liver capsule. Average time needed to set the block was 12 min (range 9-15 min); additional costs for the block were marginal. As expected (as pain medications were given according to individual patients' needs) pain indices did not differ significantly between the two groups.

CONCLUSION

In patients with liver metastases < or = 5 mm from the liver capsule, celiac plexus block reduces the amount of opiates necessary, simplifying patient monitoring. In addition celiac plexus block reduces intervention time, with positive effects on overall workflow for all patients.

Palliation of Painful Perineal Metastasis Treated with Radiofrequency Thermal Ablation

We report a case of painful perineal metastasis from urinary bladder carcinoma in a 73-years-old woman, treated with CT-guided radiofrequency ablation (RFA). The pain was immediately relieved and follow-up at 1 and 6 months showed total necrosis of the mass. One year later, the patient has no pain and her quality of life is improved.

Bronchobiliary Fistula after Radiofrequency Thermal Ablation of Hepatic Tumor

A broad spectrum of complications can occur after radiofrequency (RF) ablation of hepatic tumors, even though it has been accepted as a safe and effective technique for unresectable hepatic tumors. Recently, the rare complication of brochobiliary fistula was encountered after RF ablation in a patient with a metastatic tumor from stomach cancer. It was assumed to have developed from collateral damage to the adjacent diaphragm and lung base as well as biloma formation at the ablation zone. Symptomatic improvement was achieved by conservative management with an external drainage catheter, but the fistula was still persistent on a 2-month follow-up image.