Prophylactic Gelatin Sponge Tract Injection to Prevent Bleeding after Percutaneous Renal Cryoablation in a Swine Model

Abstract

Achievement of hemostasis can be a challenge during percutaneous renal cryoablation (PRC). This study describes the use of a porcine model to test the ability of gelatin sponge injection into the tract to limit bleeding at the site of cryoprobe puncture. A total of nine swine (18 kidneys) underwent bilateral ultrasound-guided PRC with double freeze/thaw cycle protocol with use of a 2.4-mm cryoprobe. The cryoablation location and protocol were applied identically to both kidneys in each pig; however, only one side received gelatin sponge injection after cryoablation through a coaxial sheath (3 mm). After removal of the sheath, a midline laparotomy incision was performed and sponges were placed around the kidneys. Blood loss was measured by calculating the change in weight of the sponges after 30 minutes of absorption time. Acute blood loss was compared between the two groups. The kidneys treated with gelatin sponge were removed and grossly and histologically examined to identify the gelatin sponge at the puncture cryolesion. The use of gelatin sponge resulted in significantly less blood loss (mean, 8.24 mg +/- 4.68) compared with the control kidneys (mean, 20.24 mg +/- 8.14; P = .001). Gross and histopathologic results confirmed that the gelatin sponge was in the cryoablation puncture sites. Mean diameters of cryoablation ice balls on the gelatin sponge and control sides were 3.9 cm +/- 0.2 and 3.8 cm +/- 0.4, respectively. The lesions were not significantly different between sides. Percutaneous tract injection of gelatin sponge appears promising as a method to decrease acute blood loss from PRC.