[Percutaneous radiofrequency ablation of renal tumors: update 2015]

Analgesic effects of dexmedetomidine and remifentanil on periprocedural pain during percutaneous ablation of renal carcinoma

Background: Percutaneous ablation of renal carcinoma is frequently a favourable treatment alternative, especially in elderly patients suffering from co-morbidities. Also, it is less resource-demanding than conventional surgery of renal carcinoma, and one may, therefore, assume that the incidence of this procedure may increase. Analgesia is necessary during this intervention. The aim of this study was to explore the possibility of analgosedation and its relation to patient comfort and safety during percutaneous ablation of renal carcinoma.Methods: Forty-six patients, sedated with dexmedetomidine and remifentanil, supplemented with infiltration anaesthesia (lidocaine 1%), underwent percutaneous (radiofrequency or microwave) ablation of renal carcinoma in this prospective study.Results: The patients expected pain intensity around the numerical rating score (NRS) 4.5 (interquartile range [IQR] 3.5-5.5), which was slightly lower than pain experienced during the procedure NRS 5 (IQR 2-7; p = 0.49). Eight percent of the patients needed supplementary morphine during the ablation procedure. Sedation score did not differ during ablation, at arrival to or discharge from the recovery ward. Median periprocedural treatment time was 12 minutes (IQR 12-16). Treatment time did not correlate with experienced pain (R²=0.000074, p = 0.96). The median length of stay in the recovery room was 120 minutes (IQR 84-154). There were seven serious adverse events.Conclusions: This proof-of-concept study has shown that analgosedation during percutaneous ablation of renal carcinoma can be performed with a generally tolerable degree of patient satisfaction. However, pain occurs and should be managed adequately. Patient safety must be a major concern for the anaesthetic care.

[What can/should be treated in kidney tumors and when]

CLINICAL/METHODICAL ISSUE

In the treatment of localized renal cell carcinoma, the lack of randomization in controlled trials on thermal ablation is a major limitation. The latter leads to significant study bias and it ultimately remains unclear whether the improved overall survival in favor of partial nephrectomy can actually be attributed to the treatment method.

STANDARD RADIOLOGICAL METHODS

For T1a (≤4 cm) renal cell carcinoma without lymph node and distant metastases, excellent technical and clinical results have been described after imaging-guided radiofrequency ablation and cryoablation.

METHODICAL INNOVATIONS

Low major complication rates, preservation of renal function and three-dimensional confirmation of negative ablation margins (A0 ablation) are the advantages of computed tomography (CT)-guided thermal ablation.

PERFORMANCE

According to the results of controlled (non-randomized) trials on T1a renal cell cancer, the cancer-specific survival rates are comparable between ablative and surgical techniques.

ACHIEVEMENTS

It is high time for prospective randomized controlled trials to define the actual value of percutaneous thermal ablation and partial nephrectomy in the treatment of T1a renal cell carcinoma.

PRACTICAL RECOMMENDATIONS

Apart from localized renal cell carcinoma, angiomyolipoma and oncocytoma can be treated by thermal ablation. Transarterial embolization extends the radiological spectrum for the treatment of renal tumors, either as complementary embolization (e. g. before thermal ablation of T1a and T1b renal cell carcinoma), prophylactic embolization (e. g. angiomyolipoma >6 cm), preoperative embolization (e. g. before laparoscopic partial nephrectomy) or palliative embolization (e. g. in patients with symptomatic macrohematuria due to renal cell carcinoma).