Pneumodissection Prior to Percutaneous Cryoablation of a Small Renal Tumor

Introduction

Percutaneous cryoablation (PCA) is an emerging treatment option for small renal tumors instead of surgery. It offers a low morbidity rate, minimal convalescence and maximal preservation of renal function (Atwell TD, Farrell MA, Leibovich BC et al. J Urol. 2008; 179: 2136–2140). It is a well-accepted, minimally invasive and nephron-sparing CT- or MRI-guided treatment option that can be conducted under local instead of general anesthesia. Thus, it can be used in a wide range of patients who cannot receive general anesthesia due to their comorbidities. Furthermore, the large majority of complications are minor and require observation only (Atwell TD, Farrell MA, Leibovich BC et al. J Urol. 2008; 179: 2136–2140). Even though the procedure is minimally invasive, injury to organs adjacent to the renal tumor is a potentially dangerous, yet preventable complication during the intervention. The kidney, ureter and adrenal gland are surrounded by fat and a fibrotic capsule (Gerota fascia). This complex is adjacent to the intestines on both sides. The kidneys are adjacent to the liver on the right side and to the stomach, spleen and pancreas on the left side. Especially in lean people, unintended injury to thermosensitive adjacent tissue during PCA can lead to devastating complications, such as significant hemorrhage or bowel perforation. In order to prevent damage to neighboring structures caused by the ice ball, thermal isolation of the tumor by pneumodissection of the peritumoral tissue prior to the intervention is a convenient technique.