Electrochemical Effects after Transarterial Chemoembolization in Combination with Percutaneous Irreversible Electroporation: Observations in an Acute Porcine Liver Model.

PURPOSE: To evaluate the effects of combined use of transarterial chemoembolization and irreversible electroporation (IRE) for focal tissue ablation in an acute porcine liver model. MATERIALS AND METHODS: Two established interventional techniques were combined: IRE with zones of irreversible and reversible electroporation and chemoembolization with microspheres, iodized oil, and doxorubicin. IRE was performed before chemoembolization in two pigs (pigs 1 and 2; IRE/chemoembolization group), chemoembolization was performed before IRE in two pigs (pigs 3 and 4; chemoembolization/IRE group), and only IRE was performed in two pigs (pigs 5 and 6). Five study groups were defined: IRE/chemoembolization (pigs 1 and 2), chemoembolization/IRE (pigs 3 and 4), IRE only (pigs 5 and 6), chemoembolization only (tissue outside the IRE zones in pigs 1-4), and control (untreated liver tissue outside the IRE zones in pigs 5 and 6). Animals were euthanized 2 hours after intervention. Size and shape of IRE zones on contrast-enhanced computed tomography, cell death on light microscopy, and doxorubicin tissue concentrations on chromatography and fluorescence microscopy were analyzed. RESULTS: Size and shape of IRE zones were not significantly different (eg, P = .067 for volume). A histologic marker for irreversible cell death was positive in IRE/chemoembolization, chemoembolization/IRE, and IRE groups only in the macroscopically visible IRE zones. Doxorubicin tissue concentrations were not significantly different (P = .873). However, in the reversible electroporation (RE) zones, broad areas with intense intranuclear doxorubicin accumulation were observed in IRE/chemoembolization but not in chemoembolization/IRE and chemoembolization groups. CONCLUSIONS: IRE before chemoembolization enhances the intranuclear accumulation of doxorubicin in the RE zone.

Efficacy and nontarget effects of transarterial chemoembolization in bridging of hepatocellular carcinoma patients to liver transplantation: a histopathologic study.

PURPOSE: To histologically evaluate the efficacy and nontarget effects induced by transarterial chemoembolization as a "bridge" treatment of hepatocellular carcinoma (HCC) before liver transplantation (LT) and its relation to patient survival. MATERIALS AND METHODS: Between October 2003 and January 2011, 51 patients with HCC underwent LT after chemoembolization with iodized oil, small spherical particles, and carboplatin. The decision for LT was made according to national guidelines. The efficacy and nontarget effects of chemoembolization were determined histologically in explanted livers, and their impact on patients' survival after LT was analyzed. RESULTS: A total of 126 chemoembolization procedures were performed in 51 patients; the median number of procedures per patient was three (range, one to six). The extent of HCC necrosis was less than or equal to 50% in 32% of treated HCCs, more than 50% and less than or equal to 90% in 17%, and more than 90%-99% in 14%; 38% showed complete necrosis of the lesion. The most common nontarget effects were focal necrosis of the liver parenchyma adjacent to the embolized HCC nodule (28%), intralesional (micro)abscess (26%), intralesional hemorrhage (22%), and peritumoral bile duct necrosis (12%). Based on histopathologic examination, 35% of patients had HCC that did not meet Milan criteria. None of these findings was significantly associated with patient survival after LT. CONCLUSIONS: Transarterial chemoembolization induces histopathologically confirmed HCC necrosis with a high degree of efficacy, but histologically proven complete HCC necrosis was not predictive of survival in this cohort of patients. Although histopathologic examination revealed (clinically relevant) nontarget effects in a subset of patients, they did not impair survival.

Optimisation of the coagulation zone for thermal ablation procedures: a theoretical approach with considerations for practical use.

PURPOSE: This paper outlines a theoretical approach for optimisation of the coagulation zone for thermal ablation procedures and considerations for its practical application. METHODS: The theoretical approach is outlined in the Cartesian coordinate system. Considerations for practical application are implemented. The optimised coagulation zone is defined as the bare coverage of tumour mass plus a safety margin. The eccentricity of coagulation centre (ECC) is defined as the distance between the coagulation centre and the tumour centre. The direction of the applicator shaft is determined based on the x-axis direction. The tumour centre and coagulation centre are defined within the x/y-plane. The distance between coagulation margin (applicator tip) and tumour margin is called parallel offset (PAO). RESULTS: For spherical coagulation shapes, a linear relationship exists between optimised coagulation diameter and ECC. An exponential relationship exists between optimised coagulation volume and ECC. A complex relationship was found between PAO and determinants of ECC, which are ex and ey. PAO is an extremely important parameter, which allows for determination of the optimal applicator tip position in relation to the tumour margin. It can be calculated in such a manner that the optimised coagulation zone is minimised by neutralising dislocation of the coagulation centre in applicator shaft direction. The latter can be realised by withdrawing or further inserting the applicator shaft. CONCLUSIONS: The presented concept can be used to optimise the extent of the coagulation zone for thermal ablation procedures after positioning of the applicator. Its inherent advantage is the simple adjustment of the applicator shaft, which obviates the need for a repuncture.

Portal vein embolization using a Histoacryl/Lipiodol mixture before right liver resection.

PURPOSE: The purpose of this retrospective study was to evaluate the efficacy and safety of percutaneous transhepatic portal vein embolization (PVE) of the right liver lobe using Histoacryl/Lipiodol mixture to induce contralateral liver hypertrophy before right-sided (or extended right-sided) hepatectomy in patients with primarily unresectable liver tumors. METHODS: Twenty-one patients (9 females and 12 males) underwent PVE due to an insufficient future liver remnant; 17 showed liver metastases and 4 suffered from biliary cancer. Imaging was performed prior to and 4 weeks after PVE. Surgery was scheduled for 1 week after a CT or MRI control. The primary study end point was technical success, defined as complete angiographical occlusion of the portal vein. The secondary study end point was evaluation of liver hypertrophy by CT and MRI volumetry and transfer to operability. RESULTS: In all the patients, PVE could be performed with a Histoacryl/Lipiodol mixture (n = 20) or a Histoacryl/Lipiodol mixture with microcoils (n = 1). No procedure-related complications occurred. The volume of the left liver lobe increased significantly (p < 0.0001) by 28% from a mean of 549 ml to 709 ml. Eighteen of twenty-one patients (85.7%) could be transferred to surgery, and the intended resection could be performed as planned in 13/18 (72.3%) patients. CONCLUSION: Preoperative right-sided PVE using a Histoacryl/Lipiodol mixture is a safe technique and achieves a sufficient hypertrophy of the future liver remnant in the left liver lobe.