Nikolas Kortes

Evaluation of the Plasmatic and Parenchymal Elution Kinetics of Two Different Irinotecan-Loaded Drug-Eluting Embolics in a Pig Model

PURPOSE To evaluate and compare irinotecan elution kinetics of two drug-eluting embolic agents in a porcine model. MATERIALS AND METHODS Embolization of the left liver lobe was performed in 16 domestic pigs, with groups of two receiving 1 mL of DC Bead M1 (70-150 µm) or Embozene TANDEM (75 µm) loaded with 50 mg irinotecan. Irinotecan plasma levels were measured at 0, 10, 20, 30, 60, 120, 180, and 240 minutes after completed embolization and at the time of euthanasia (24 h, 48 h, 72 h, or 7 d). Liver tissue samples were taken to measure irinotecan tissue concentrations. RESULTS The highest irinotecan plasma concentrations of both embolic agents were measured 10 and 20 minutes after embolization, and concentrations were significantly higher for DC Bead M1 versus Embozene TANDEM (P = .0019 and P = .0379, respectively). At 48 hours and later follow-up, no irinotecan was measurable in the plasma. For both embolic agents, the highest irinotecan tissue concentration was found after 24 hours and decreased in a time-dependent manner at later follow-up intervals. Additionally, SN-38 tissue levels for both agents were therapeutic at 24 hours, with therapeutic levels of SN-38 at 48 hours in one liver embolized with TANDEM particles. Histopathologic analysis revealed ischemic, inflammatory, and fibrotic tissue reactions. CONCLUSIONS Irinotecan is measurable in plasma and hepatic tissue after liver embolization with both types of irinotecan-eluting embolic agents. DC Bead M1 shows early burst elution kinetics, whereas Embozene TANDEM has a lower and slower release profile. The initial burst is significantly greater after embolization with DC Bead M1 than with Embozene TANDEM.

Therapeutic lymphangiography and CT-guided sclerotherapy for the treatment of refractory lymphatic leakage.

PURPOSE To evaluate therapeutic lymphangiography and computed tomography (CT)-guided sclerotherapy for the treatment of refractory inguinal, pelvic, abdominal, and thoracic lymphatic leakage. MATERIALS AND METHODS Between January 2008 and April 2011, 18 patients with refractory lymphatic leakage were treated with therapeutic lymphangiography. Additionally, 10 of these 18 patients underwent CT-guided sclerotherapy with injection of ethanol at the site of the leakage. In the delayed sclerotherapy group (n = 5), the sclerotherapy procedure was performed when the leak persisted after therapeutic lymphangiography. In the immediate sclerotherapy group (n = 5), sclerotherapy was performed on the same day as lymphangiography. The sites of the lymphatic leakage were as follows: inguinal leakage in 8 patients, pelvic leakage in 4 patients, abdominal leakage in 2 patients, and thoracic leakage in 4 patients. Data collected included technical success, clinical success, and procedural complications. RESULTS Lymphangiography was technically successful in all patients. In eight patients undergoing therapeutic lymphangiography alone, the clinical success rate was 75%, and the drainage catheter could be removed in six patients after the treatment. Lymphangiography followed by immediate sclerotherapy was clinically successful in four of five patients. Lymphangiography combined with delayed sclerotherapy was clinically successful in three of five patients. Overall, the clinical success rate was 72% (13 of 18 patients). One minor complication occurred. CONCLUSIONS Therapeutic lymphangiography alone or in combination with CT-guided sclerotherapy is a promising treatment option for the management of refractory lymphatic leakage.

Hepatic artery stent-grafts for the emergency treatment of acute bleeding

PURPOSE We evaluated the technical success and clinical efficacy of stent-graft implantation for the emergency management of acute hepatic artery bleeding. METHODS Between January 2010 and July 2013, 24 patients with hemorrhage from the hepatic artery were scheduled for emergency implantation of balloon expandable stent-grafts. The primary study endpoints were technical and clinical success, which were defined as successful stent-graft implantation with sealing of the bleeding site at the end of the procedure, and cessation of clinical signs of hemorrhage. The secondary study endpoints were complications during the procedure or at follow-up and 30-day mortality rate. RESULTS In 23 patients, hemorrhage occurred after surgery, and in one patient hemorrhage occurred after trauma. Eight patients had sentinel bleeding. In most patients (n=16), one stent-graft was implanted. In six patients, two overlapping stent-grafts were implanted. The stent-grafts had a target diameter between 4mm and 7 mm. Overall technical success was 88%. The bleeding ceased after stent-graft implantation in 21 patients (88%). The mean follow-up was 137 ± 383 days. In two patients, re-bleeding from the hepatic artery occurred during follow-up after 4 and 29 days, respectively, which could be successfully treated by endovascular therapy. The complication rate was 21% (minor complication rate 4%, major complication rate 17%). The 30-day mortality rate was 21%. CONCLUSIONS Implantation of stent-grafts in the hepatic artery is an effective emergency therapy and has a good technical success rate for patients with acute arterial hemorrhage.

Microwave Ablation in Porcine Livers Applying 5-minute Protocols: Influence of Deployed Energy on Extent and Shape of Coagulation

PURPOSE To evaluate the influence of deployed energy on extent and shape of microwave (MW)-induced coagulation in porcine livers applying 5-minute protocols. MATERIALS AND METHODS MW ablations (n = 25) were performed in ex vivo porcine livers (n = 8). Ablation time was 5 minutes. Five study groups were defined, each with different power output: I, 20 W (n = 5); II, 40 W (n = 5); III, 60 W (n = 5); IV, 80 W (n = 5); and V, 105 W (n = 5). Extent and shape of white coagulation was evaluated macroscopically, including short diameter, volume, front margin, coagulation center (distance between center of short diameter of coagulation and applicator tip), and ellipticity index (short diameter/long diameter). Deployed energy was also analyzed. RESULTS Short diameter and volume were significantly different (P<.001 and P<.001) between the groups: I, 23.0 mm and 11.1 cm(3); II, 12.4 mm and 12.4 cm(3); III, 27.0 mm and 17.6 cm(3); IV, 31.0 mm and 29.2 cm(3); and V, 35.0 mm and 42.3 cm(3). Front margin and coagulation center were also significantly different (P<.05 and P<.001): I, 6.0 mm and 13.0 mm; II, 8.0 mm and 11.0 mm; III, 8.0 mm and 14.0 mm; IV, 8.0 mm and 18.0 mm; and V, 10.0 mm and 19.0 mm. Ellipticity index was not significantly different. Deployed energy was significantly different (P<.001): I, 5.7 kJ; II, 11.0 kJ; III, 15.5 kJ; IV, 21.6 kJ; and V, 26.6 kJ. CONCLUSIONS Extent, but not shape, of MW-induced coagulation depends on the deployed energy. Applying the protocols described in this study, significantly different coagulation volumes can be created with an ablation time of 5 minutes but different power output.

Super-micro-bland particle embolization combined with RF-ablation: Angiographic, macroscopic and microscopic features in porcine kidneys

PURPOSE To describe angiographic, macroscopic and microscopic features of super-micro-bland particle embolization in combination with RF-ablation in kidneys. Thereby, a special focus was given on the impact of the sequence of the different procedural steps. MATERIALS AND METHODS In ten pigs, super-micro-bland particle embolization combined with RF-ablation was carried out. Super-micro-bland embolization was performed with spherical particles of very small size and tight calibration (40 ± 10 μm). In the left kidneys, RF-ablations were performed before embolization (I). In the right kidneys, RF-ablations were performed after embolization (II). The animals were killed three hours after the procedures. Angiographic (e.g. vessel architecture), macroscopic (e.g. long and short axes of the RF-ablations) and microscopic (e.g. particle distribution) study goals were defined. RESULTS Angiography detected almost no vessels in the center of the RF-ablations in I. In II, angiography could not define the RF-ablations. Macroscopy detected significantly larger long and short axes of the RF-ablations in II compared to I (52.2 ± 3.2 mm vs. 45.3 ± 6.9 mm [P<0.05] and 25.1 ± 3.5mm vs. 20.0 ± 1.9 mm [P<0.01], respectively). Microscopy detected irregular particle distribution at the rim of the RF-ablations in I. In II, microscopy detected homogeneous particle distribution at the rim of the RF-ablations. Microscopy detected no particles in the center of the RF-ablations in I and II. CONCLUSION The sequence of the different procedural steps of super-micro-bland particle embolization combined with RF-ablation impacts angiographic, macroscopic and microscopic features in kidneys in the acute setting.

Endovascular repair of a complex splenic artery aneurysm using a multilayer stent.

To the Editor, Based on autopsy studies, the prevalence of visceral artery aneurysms has been estimated to be up to 10 % [1], with up to 25 % complicated by rupture and a mortality rate of up to 70 % [2]. Splenic artery aneurysms (SAA) account for *60 % of visceral artery aneurysms [2]. Asymptomatic SAA larger than 2 cm should be treated either by operation or endovascular techniques [3, 4]. In recent years, exclusion of aneurysms by implanting multilayer stents is considered an attractive, minimally invasive treatment option [5–9]. Due to the multilayer design of this vascular prosthesis, the tubular, self-expanding multilayer stent (Cardiatis, Isnes, Belgium) is supposed to decrease velocity and vorticity of intra-aneurysmal blood flow. Thereby, thrombus formation within the aneurysm sac shall be deemed over time. The affected main artery and moreover branching vessels deriving from the aneurysm or the proximal and distal landing zones are expected to remain patent due to preserving laminar flow. We hereby report a successful minimally invasive treatment of a complex SAA with a multilayer stent. In a 46-year-old woman, a SAA was incidentally found after ultrasound examination at her general practitioner. Computed tomography angiography (CTA) showed a fusiform aneurysm in the distal part of the splenic artery with a maximum diameter of 2 cm and an ectatic transformation of the proximal and especially distal subsequent splenic artery over a total length of *4 cm. In a first angiographic effort in an attempt to use a balloonexpandable stent-graft, elongation and consecutive tortuosity of the splenic artery made any attempt for pushing the stent-graft forward impossible. In a multidisciplinary consensus, endovascular repair with the new multilayer stent was favored over open surgery. Before interventional therapy, the patient gave written informed consent. Digital subtraction angiography was performed using a left transbrachial approach. A 90-cm long, 7F sheath (Destination, Terumo, Tokyo, Japan) was introduced, and the splenic artery was engaged via a 4F catheter in multipurpose configuration (Cordis Corporation, Bridgewater,

Occlusion of a Long-Term Transpleural Biliary Drainage Tract Using a Gelatin Pledget (Hep-Plug ™ )

This case describes a technique used to close a long-term 14F transpleural biliary drainage catheter tract to prevent biliopleural fistula and further complications. We deployed a compressed gelatin foam pledget provided in a pre-loaded delivery device (Hep-Plug™) along the intrahepatic tissue tract for sealing it against the pleural cavity. The device used is easy to handle and gives the Interventional Radiologist the possibility to safely manage and prevent complications after percutaneous transhepatic interventions.