USE OF BLOCKING CRYOPROBE FOR EXCEPTION OF HEAT RETURN FROM LARGE (D=10 MM) VESSEL DURING PERCUTANEOUS CRYOABLATION OF LIVER METASTASIS
Authors: P.V. Balakhnin, A.S. Shmelev, E.G. Shachinov, V.I. Malkevich,A.A. Meldo, V.V. Egorenkov, V.M. Moiseyenko
Background. A significant shortcoming of percutaneous cryoablation (PC) is its low efficiency of the treatment of malignant liver tumors adjacent to large (more than 3 mm) blood vessels. The transfer of heat from the blood to the tumor does not allow the creation of lethal hypothermia near the wall of a large vessel. This leads to incomplete necrosis of pathological tissue or the formation of an insufficient minimal ablation margin (less than 5 mm), fraught with local progression. In this regard, the feasibility of performing the PC of primary and metastatic liver tumors adjacent to large
vessels is being questioned.
Aim. To demonstrate the case of a technically successful PC of colorectal liver metastasis adjacent to the large (d=10mm) vessel using an additional cryoprobe which temporarily blocks the blood flow in this vessel (blocking cryoprobe).
Case presentation. The patient M 73 years old hospitalized in our clinic for the treatment of newly diagnosed metachronous solitary unresectable (in connection with concomitant diseases) colorectal liver metastasis 25 mm in diameter, localized in the IVA segment and closely adjacent to a large vessel – the middle hepatic vein (MHV) 10 mm in diameter. The multidisciplinary team was decided to carry out the PC of this metastasis under the local anesthesia. For the temporary cessation of blood flow over the MHV (in order to exclude heat transfer to the tumor) during the PC, it was decided to positioning an additional cryoprobe in the immediate vicinity of the MHV (blocking cryoprobe) under the US and FDCT during hepatic arteriography. The insertion of blocking cryoprobe allowed to create «ice ball» in the lumen of the MHV and completely block the blood flow in this vessel during PC. Due to this, the effect of heat return to the tumor
was excluded and an ablation zone of the required volume was created. As a result, the procedure of PC was technicallyeffective. After PC a complete recovery of blood flow through the MHV and its branches was noted, with no complications
after the intervention.
Conclusion. The use of one or more blocking cryoprobes can increase the technical efficiency of PC of liver tumors
closely adjacent to the large blood vessels, improve the long-term results of treatment of such tumors, and extend the
indications for the PC of liver tumors in the future.