Percutaneous microwave coagulation therapy for superficial hepatocellular carcinoma on the liver surface

Protection from injury of organs adjacent to a renal tumor during percutaneous cryoablation

Renal cryoablation has become accepted as treatment for small renal tumors as an alternative to surgery. However, parallel with the increase in the use of this therapy, there also has been increases in the number of reports of complications related to renal cryoablation. One potential complication is injury to important non-renal structures adjacent to the ablated renal tumor, such as the colon, duodenum, ureter, psoas muscle and so on. To prevent injury of adjacent organs, separating organs from the tumor is desirable. Over the past 15 years, several techniques have been developed to protect against injury of organs adjacent to renal tumors that are targets of cryoablation. The most commonly used technique for this purpose has been hydrodissection. Others include dissection with gas, balloon dissection and probe traction. To avoid injury of a ureter running near the renal tumor, pyeloperfusion is known to be useful. The rate of cases necessitating avoidance of organ injury by using these techniques is relatively high. In some cases, more than two techniques are combined. In the present review, we provided an overview of techniques currently available to protect against organ injuries, and discussed the advantages and disadvantages of each technique.

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.