Percutaneous computerized tomography guided renal cryoablation using local anesthesia: pain assessment

Recent Perspectives on the Mechanism of Recurrence After Ablation of Hepatocellular Carcinoma: A Mini-Review

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Hepatectomy, liver transplantation, and ablation are the three radical treatments for early-stage hepatocellular carcinoma (ESHCC), but not all patients are fit for or can tolerate surgery; moreover, liver donors are limited. Therefore, ablation plays an important role in the treatment of ESHCC. However, some studies have shown that ablation has a higher local recurrence (LR) rate than hepatectomy and liver transplantation. The specific mechanism is unknown. The latest perspectives on the mechanism of recurrence after ablation of HCC were described and summarized. In this review, we discussed the possible mechanisms of recurrence after ablation of HCC, including epithelial–mesenchymal transition (EMT), activating autophagy, changes in non-coding RNA, and changes in the tumor microenvironment. A systematic and comprehensive understanding of the mechanism will contribute to the research and development of related treatment, combined with ablation to improve the therapeutic effect in patients with ESHCC.

Percutaneous cryoablation in early stage hepatocellular carcinoma: analysis of local tumor progression factors

PURPOSE

We aimed to evaluate the effectiveness and safety of percutaneous cryoablation (PC) for early or very early stage hepatocellular carcinoma (HCC) and assess the risk factors for local tumor progression (LTP) after PC.

METHODS

A total of 45 treatment-naïve patients treated with PC for early or very early stage HCCs were included in this retrospective study. The safety of PC was assessed by evaluating procedure-related complications and comparing hepatic function before and after the procedure. The effectiveness was assessed by evaluating technical success, LTP rates, and disease progression (DP) rates. Prognostic factors associated with LTP after PC were also analyzed.

RESULTS

Technical success and complete response were achieved in all patients (100%) by 1 month after PC. During a mean of 28.1±15.6 months of follow-up, the incidences of LTP and DP were 11.1% and 37.8%, respectively. The LTP-free and DP-free survival rates were 93.3% and 84.4% at 1 year and 88.9% and 62.2% at 2 years, respectively. Hepatic function was normalized within 3 months after PC. There were no major complications and only one minor complication of small hematoma. On univariate and multivariate analysis, minimal ablative margin <5 mm was the only significant risk factor associated with LTP.

CONCLUSION

PC is a safe and effective therapy for patients with early or very early stage HCC. Minimal ablative margin <5 mm was a significant prognostic factor for LTP.

Safety and effectiveness of percutaneous renal cryoablation with conscious sedation

OBJECTIVE

To investigate complications and treatment failure rates of percutaneous renal cryoablation (PRC) for small renal masses under local anaesthesia and conscious sedation (LACS), to assess the safety and effectiveness of this approach, as PRC is typically performed under general anaesthesia (GA).

PATIENTS AND METHODS

We retrospectively reviewed PRC under LACS from 2003 to 2017. We analysed perioperative parameters between patients who successfully underwent PRC under LACS and patients with post-procedural complications or treatment failure (renal mass enhancement after successful intraoperative tumour ablation). Two-sided non-parametric and Fisher's exact tests were performed to compare uncomplicated or disease-free PRC with the complication or treatment failure group, respectively.

RESULTS

A total of 100 PRCs under LACS were performed during the study period. Of these patients, six patients had at least one postoperative complication (6%), and treatment failure was diagnosed in nine patients (9%) after PRC [mean (SD) follow-up of 42.7 (26.6) months]. The procedural failure rate was 1%. No ablations were converted to GA. The mean tumour size was smaller in patients who had no complications during PRC compared to those who did, at a mean (SD) of 2.2 (0.6) cm vs 3.0 (1.0) cm (P = 0.039). The use of more intraoperative probes during the PRC was also associated with complications, at a mean (SD) 3.0 (1.4) vs 1.8 (0.8) (P = 0.021).

CONCLUSIONS

PRC under LACS is an effective and safe procedural approach for managing small renal masses with low complication, treatment failure, and procedural failure rates. Larger renal masses and intraoperative use of multiple probes is associated with an increased risk of PRC complications.

ABBREVIATIONS

BMI: body mass index; CCI: Charlson Comorbidity Index; GA: general anaesthesia; LACS: local anaesthesia and conscious sedation; PRC: percutaneous renal cryoablation; R.E.N.A.L.: Radius, Exophytic/Endophytic, Nearness, Anterior/Posterior, Location.

Current State of Tumor Ablation Therapies

The most common primary liver malignancy, hepatocellular carcinoma (HCC), has a high likelihood of mortality, and much effort into early detection and treatment has occurred. Multiple staging systems have surfaced of which some guide treatment. Curative intent is a goal of early-staged HCC treatment, and this can be achieved with surgical resection, liver transplantation, and minimally invasive percutaneous therapies such as tumor ablation. Many of the newer ablation techniques have evolved from shortcomings of prior methods which have resulted in an expanded number of applications for tumor ablation. Our review focuses on current mainstream image-guided percutaneous ablation modalities which are commonly performed as an alternative to surgery.

Percutaneous cryoablation for hepatocellular carcinoma

Local ablation therapy is considered as a conventional treatment option for patients with early stage hepatocellular carcinoma (HCC). Although radiofrequency (RF) ablation is widely used for HCC, the use of cryoablation has been increasing as newer and safer cryoablation systems have developed. The thermodynamic mechanism of freezing and thawing used in cryoablation is the Joule-Thomson effect. Cryoablation destroys tissue via direct tissue destruction and vascular-related injury. A few recent comparative studies have shown that percutaneous cryoablation for HCCs is comparable to percutaneous RF ablation in terms of long term therapeutic outcomes and complications. Cryoablation has several advantages over RF ablation such as well visualization of iceball, no causation of severe pain, and lack of severe damage to great vessels and gallbladder. It is important to know the advantages and disadvantages of cryoablation compared with RF ablation for improvement of therapeutic efficacy and safety.

Cryoablation of Hepatocellular Carcinoma with High-Risk for Percutaneous Ablation: Safety and Efficacy

PURPOSE

The aim of this study was to evaluate the safety and effectiveness of cryoablation in the treatment of subcapsular hepatocellular carcinoma (HCC) adjacent to various organs.

MATERIALS AND METHODS

Twenty-eight patients with subcapsular HCC were treated with cryoablation in our institution. The degree of peri-procedural pain was measured using the visual analog scale (VAS). Technical success, local tumor progression, and overall disease progression rates were calculated. Procedure-related complications were identified by reviewing electronic medical records. Biochemical data, including serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin levels before and after the procedure were collected.

RESULTS

Subcapsular HCC tumors were located near the gallbladder, colon, stomach, kidney, diaphragm, or abdominal wall. The technical success rate of cryoablation was 96.4 % (27/28). Local recurrence- and progression-free survival rates were 96 and 84 % at 6 months, and 82 and 43 % at 1 year, respectively. All patients survived during the follow-up period. The VAS pain score ranged from 0 to 3 (mean, 1.57). A major complication occurred in one patient (3.6 %) and minor complications occurred at a rate of 17.9 %. Transient elevations of serum AST, ALT, and bilirubin levels were observed.

CONCLUSION

Cryoablation is a safe and an effective procedure for the treatment of subcapsular HCC adjacent to various major organs.

Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why?

Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients.

Percutaneous renal cryoablation: current status

Over the last 13 years, renal cryoablation has emerged as a promising technique for the treatment of solid renal tumors. The improvement in imaging modalities such as ultrasound, computed tomography and MRI, as well as the introduction of thinner probes, has led to the spread of the minimally invasive percutaneous approach. We review the historical background of percutaneous renal cryoablation (PRC), present its basic principles, mention the contemporary clinical data and outcomes of this technique and suggest future directions for its wider application in renal tumors. Early results have demonstrated that it may offer an alternative for the treatment of small renal masses with the advantages of minimal complications, spared renal function, decreased overall costs and equivalent oncologic efficacy. Long-term results are required in order to apply this minimally invasive technique to a broader spectrum of patients.