Claus Christian Pieper

Prospective Evaluation of Passive Expansion of Partially Dilated Transjugular Intrahepatic Portosystemic Shunt Stent Grafts-A Three-Dimensional Sonography Study.

PURPOSE To prospectively investigate early expansion kinetics of underdilated self-expanding stent grafts used for transjugular intrahepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS Twenty patients (7 female; mean age 66 y; range, 31-80 y) with liver cirrhosis undergoing TIPS creation for variceal bleeding (n = 5), refractory ascites (n = 14), or both (n = 1) with underdilation of 10-mm stent grafts received two-dimensional (2-D) and three-dimensional (3-D) ultrasound (US) examinations immediately after TIPS creation and 1 and 6 weeks later. Orthogonal views of the TIPS within the parenchymal tract were reconstructed from 3-D volume data sets acquired in longitudinal orientation of the stent. 2-D images and reconstructed 3-D images were used for blinded diameter measurements. Measurement technique was validated with intrainterventional plain radiographs with a sizing catheter as the gold standard. Diameter changes over time and interrelations with patient characteristics (null hypothesis: no expansion, no interrelation) were analyzed using a general linear model for repeated measures. RESULTS After dilation to 8-mm diameter, 2-D and 3-D measurements showed stent recoil (mean diameter 7.7 mm ± 0.21 and 7.6 mm ± 0.17, respectively). Diameter increased significantly from initial measurements to measurements at 1 and 6 weeks (2-D, 8.8 mm ± 0.24 and 9.4 mm ± 0.15, both P < .001; 3-D, 8.7 mm ± 0.27 and 9.4 mm ± 0.11, both P < .001). Validation measurements showed no significant differences between 2-D or 3-D US and gold standard. There were no statistically significant associations between stent expansion and clinical parameters (sex, P = .78; age, P = .82; etiology/grade of cirrhosis, P = .99; indication for TIPS, P = .78, liver stiffness, P = .70). CONCLUSIONS Underdilated self-expanding stent grafts used for TIPS creation significantly expand within first 6 weeks after intervention. These changes can be noninvasively monitored using 3-D US.

Yttrium-90 Radioembolization of Advanced, Unresectable Breast Cancer Liver Metastases—A Single-Center Experience

PURPOSE To determine value of transarterial radioembolization (TARE) for palliative treatment of unresectable liver-dominant breast metastases (LdBM) and to determine prognostic parameters. MATERIALS AND METHODS Records of patients undergoing TARE for progressing LdBM between June 2006 and March 2015 were retrospectively reviewed; 44 female patients (mean age 56.1 y; range, 34.9-85.3 y) underwent 69 TAREs (56 resin-based, 13 glass-based). Of 44 patients, 42 had bilobar disease. Mean administered activity was 1.35 GBq ± 0.71. Median clinical and imaging follow-up times were 121 days (range, 26-870 d; n = 42 patients) and 93 days (range, 26-2,037 d; n = 38 patients). Clinical and biochemical toxicities, imaging response (according to Response Evaluation Criteria In Solid Tumors), time to progression, and overall survival (OS) were evaluated. Data were analyzed with stratification according to clinical and procedural parameters. RESULTS Toxicities included 1 cholecystitis (grade 2) and 1 duodenal ulceration (grade 3); no grade ≥ 4 clinical toxicities were noted. Objective response rate (complete + partial response) was 28.9% (11/38); disease control rate (response + stable disease) was 71.1% (27/38). Median time to progression of treated liver lobe was 101 days (range, 30-2,037 d). During follow-up, 34/42 patients died (median OS after first TARE: 184 d [range 29-2,331 d]). On multivariate analysis, baseline Eastern Cooperative Oncology Group (ECOG) status of 0 (P < .0001, hazard ratio [HR] = 0.146) and low baseline γ-glutamyltransferase (GGT) levels (P = .0146, HR = 0.999) were predictors of longer OS. CONCLUSIONS TARE can successfully delay progression of therapy-refractory LdBM with low complication rate. Nonelevated baseline ECOG status and low GGT levels were identified as prognostic factors.

Evaluation of a Simplified Intravoxel Incoherent Motion (IVIM) Analysis of Diffusion-Weighted Imaging for Prediction of Tumor Size Changes and Imaging Response in Breast Cancer Liver Metastases Undergoing Radioembolization: A Retrospective Single Center Analysis.

AbstractTo investigate the value of a simplified intravoxel incoherent motion (IVIM) analysis for evaluation of therapy-induced tumor changes and response of breast cancer liver metastases (mBRC) undergoing radioembolization.In 21 females (mean age 54 years, range 43–72) with mBRC tumor size changes and response evaluation criteria in solid tumors (RECIST) response to 26 primary radioembolization procedures were analyzed. Standard 1.5-T liver magnetic resonance imaging including respiratory-gated diffusion-weighted imaging (DWI) with b0 = 0 s/mm2, b1 = 50 s/mm2, b2 = 800 s/mm2 before and 6 weeks after each treatment was performed. In addition to the apparent diffusion coefficient (ADC)(0,800), the estimated diffusion coefficient D′ and the perfusion fraction f′ were determined using a simplified IVIM approach. For each radioembolization, the 2 largest treated metastases (if available) were analyzed. Lesions were categorized according to size changes into group A (reduction of longest diameter [LD]) and group B (LD increase) after 3 months. Radioembolization procedures were further categorized into “response” (partial response and stable disease) and “nonresponse” (progressive disease) according to RECIST after 3 months. ADC and D′ are given in 10−6 mm2/s.Forty-five metastases were analyzed. Thirty-two lesions were categorized as A; 13 as B. Before therapy, group A lesions showed significantly larger f′-values than B (P = 0.001), but ADC(0,800) and D′ did not differ. After therapy, in group A lesions the ADC(0,800)- and D′-values increased and f′ decreased (P < 0.0001); in contrast in group B lesions f′ increased (P = 0.001). Groups could be differentiated by preinterventional f′ and by changes of D′ and f′ between pre and postinterventional imaging (area under the curve [AUC] of 0.903, 0.747 and 1.0, respectively).Preinterventional parameters did not differ between responders and nonresponders according to RECIST. ADC(0,800)- and D′-values showed a larger increase in responders compared with nonresponders (P = 0.013 and P = 0.001, respectively). After therapy f′-values decreased significantly in responders (P = 0.001). Good to excellent prediction of long-term RECIST response was possible by therapy-induced changes in LD, D′, and f′ (AUC 0.903, 0.879, and 0.867, respectively).A simplified IVIM model-based analysis of early post-treatment DWI can deliver additional information on tumor size changes and long-term RECIST response after radioembolization of mBRC. The estimated perfusion fraction f′ is better suited for response assessment than the conventional ADC(0,800) or D′. This can be useful to guide further treatment strategy.

Venous Obstruction in Asymptomatic Patients Undergoing First Implantation or Revision of a Cardiac Pacemaker or Implantable Cardioverter-Defibrillator: A Retrospective Single Center Analysis

PURPOSE To investigate the incidence and possible risk factors of upper deep vein obstruction in patients both prior to first cardiac device implantation and before device revision. MATERIALS AND METHODS Records of asymptomatic patients undergoing contrast venography prior to implantation or revision of a cardiac device from 09/2009 to 04/2012 were reviewed. Venograms were used to determine the presence of venous obstruction. Interrelations between the incidence of venous obstruction and patient- or device-related parameters were identified using Fishers exact test and univariate logistic regression. Multivariate logistic regression was used to identify independent predictors of venous obstruction. RESULTS 456 patients met the inclusion criteria (330 males, 126 females, 67.8  ±  12.9 years). 100 patients underwent first implantation, and 356 patients underwent device revision (mean time since implantation 82.5  ±  75.3 months). Venous obstruction was present in 11.0 % and 30.1 % before implantation and revision, respectively. Only presence of ventricular escape rhythm was significantly related to venous occlusion (p < 0.001) prior to first implantation. Prior to revision, significant predictors were male sex (p = 0.01), time since implantation (p < 0.0001), presence of escape rhythm (p = 0.02), compromised coagulation (p = 0.02), phenprocoumon (p = 0.005), and peripheral arterial disease (p = 0.01). CONCLUSION Although several risk factors could be identified, reliable prediction of venous obstruction was not possible. Therefore, we advocate performing venography in all patients prior to device revision or upgrade to avoid complications. In cases of first device implantation, the risks associated with venography should be weighed against the surprisingly high rate of deep upper vein obstruction.

Percutaneous CT-Guided Radiofrequency Ablation of Solitary Small Renal Masses: A Single Center Experience.

PURPOSE To analyze the outcome of patients undergoing percutaneous CT-guided radiofrequency ablation (RFA) of small renal masses (SRM) at a single center during a ten-year time period. MATERIALS AND METHODS Patient records of renal RFAs (07/2003 - 11/2013) were reviewed. Indications were SRM suspicious of malignancy on imaging and one of the following: severe comorbidity; old age; solitary kidney; impaired renal function; patient wish. Biopsy was performed at the time of RFA. Patients were excluded if no follow-up was available. Patient and procedural characteristics were recorded. Survival rates were calculated using the Kaplan-Meiers method and compared with log-rank or cox tests. RESULTS 38 patients (16 females, mean age 70.0 years [range 52 - 87]) presenting with a solitary SRM were included in the study. Biopsy showed malignancy in 29 patients; 9 had benign tumors. 26 patients suffered from cardiovascular, respiratory or hepatic comorbidities. Technical success (complete ablation on first follow-up) was achieved in 95 % of cases. Two major complications (bowel perforation; hematothorax) occurred. The 3- and 7-year overall survival (OS) [any cause] rates were 73.4 ± 0.8 % and 50.3 ± 1.0 %, respectively (mean follow-up 54.6 months, range 1 - 127). 4 recurrences and 2 metastases were observed. The presence of comorbidities was the only independent predictor of OS. There was no difference in survival between patients with benign and malignant tumors. CONCLUSION RFA of SRM is successful in a large percentage of cases with a low complication rate and durable local control. As RFA is typically performed in multimorbid patients, overall survival seems to depend primarily on comorbidities rather than cancer progression. Key Points • RFA of SRM is technically successful in the majority of cases. • RFA leads to a high degree of local tumor control. • Post-RFA most patients ultimately die of comorbidities. • Overall survival post-RFA does not significantly differ between benign and malignant tumors in multimorbid patients.

Efficacy and time-to-hemostasis of antegrade femoral access closure using the ExoSeal vascular closure device: a retrospective single-center study.

OBJECTIVE To retrospectively evaluate the efficacy and time-to-hemostasis of antegrade femoral access closure using the ExoSeal vascular closure device (VCD). DESIGN Retrospective, single-center analysis. MATERIALS AND METHODS Between September 2010 and February 2013, 148 ExoSeal VCD closures (5-7F) of antegrade femoral accesses were performed in 119 patients (70 males, mean age 71.6 years, range 40-97 years). In all cases initial diagnostic angiography was performed via an 18G/3.8F retrograde femoral access, which was left in place during intervention (in-house standard) and was used to obtain control angiography after successful closure of the antegrade access to determine hemostasis. Technical device success was defined as ExoSeal closure without major VCD-related complications; procedural success as hemostasis within 5 minutes. Statistical analysis was performed using a logistic regression model and correlation analyses. RESULTS 145/148 (98.0%) ExoSeal closures were technically successful (5F: n = 76; 6F: n = 65; 7F: n = 7). Angiographic control showed closure after 2 minutes in 130/145 cases. In a further 14 cases hemostasis was achieved after an additional 3 minutes MC, so that closure was successful within 5 minutes in 144/148 cases (97.3%). No major complication occurred. One minor complication was recorded in a 6F access case. Pre-interventional activated partial thromboplastin time (aPTT) was the only statistically significant predictor of necessary manual compression (MC) > 2 minutes (p = .01), but with an odds-ratio of only 1.038. The INR showed an odds-ratio of 2.455 for need for 5 minutes MC (NS). Significant correlations were found between the need for 5 minutes MC and medication with acetylsalicylic acid (p = .01), clopidogrel (p < .01), and abciximab (p < .001). CONCLUSION ExoSeal vascular closure of antegrade femoral punctures is safe and effective with a low complication rate. Two minutes of MC are sufficient to achieve hemostasis in the majority of cases. However, in patients on antiplatelet therapy, especially after abciximab, the authors advocate prolonging MC to 5 minutes.

Using the Multilayer Stent as a Supplement to EVAR in Combined Abdominal Aortic Aneurysm and Iliac Artery Aneurysm With Inadequate Distal Landing Zone—A Case Report

Combined abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) is a common condition. The recently approved Cardiatis Multilayer stent (Cardiatis, Isnes, Belgium) is an innovative stent system for peripheral aneurysm management that has been applied in several clinical cases. After deployment, the unique stent design reduces mean velocity and vorticity within the aneurysm sac, causing thrombus formation and thus exclusion of the aneurysm while the vessels branching from the aneurysm remain patent. We describe a case of combined AAA and IAA with successful endovascular aneurysm repair of the AAA and treatment of the internal iliac artery with the Cardiatis Multilayer stent at 12 months of follow-up.

The value of intravoxel incoherent motion model-based diffusion-weighted imaging for outcome prediction in resin-based radioembolization of breast cancer liver metastases

Purpose To evaluate prognostic values of clinical and diffusion-weighted magnetic resonance imaging-derived intravoxel incoherent motion (IVIM) parameters in patients undergoing primary radioembolization for metastatic breast cancer liver metastases. Subjects and methods A total of 21 females (mean age 54 years, range 43–72 years) with liver-dominant metastatic breast cancer underwent standard liver magnetic resonance imaging (1.5 T, diffusion-weighted imaging with b-values of 0, 50, and 800 s/mm2) before and 4–6 weeks after radioembolization. The IVIM model-derived estimated diffusion coefficient D’ and the perfusion fraction f’ were evaluated by averaging the values of the two largest treated metastases in each patient. Kaplan–Meier and Cox regression analyses for overall survival (OS) were performed. Investigated parameters were changes in f’- and D’-values after therapy, age, sex, Eastern Cooperative Oncology Group (ECOG) status, grading of primary tumor, hepatic tumor burden, presence of extrahepatic disease, baseline bilirubin, previous bevacizumab therapy, early stasis during radioembolization, chemotherapy after radioembolization, repeated radioembolization and Response Evaluation Criteria in Solid Tumors (RECIST) response at 6-week follow-up. Results Median OS after radioembolization was 6 (range 1.5–54.9) months. In patients with therapy-induced decreasing or stable f’-values, median OS was significantly longer than in those with increased f’-values (7.6 [range 2.6–54.9] vs 2.6 [range 1.5–17.4] months, P<0.0001). Longer median OS was also seen in patients with increased D’-values (6 [range 1.6–54.9] vs 2.8 [range 1.5–17.4] months, P=0.008). Patients with remission or stable disease (responders) according to RECIST survived longer than nonresponders (7.2 [range 2.6–54.9] vs 2.6 [range 1.5–17.4] months, P<0.0001). An ECOG status ≤1 resulted in longer median OS than >1 (7.6 [range 2.6–54.9] vs 1.7 [range 1.5–4.5] months, P<0.0001). Pretreatment IVIM parameters and the other clinical characteristics were not associated with OS. Classification by f’-value changes and ECOG status remained as independent predictors of OS on multivariate analysis, while RECIST response and D’-value changes did not predict survival. Conclusion Following radioembolization of breast cancer liver metastases, early changes in the IVIM model-derived perfusion fraction f’ and baseline ECOG score were predictive of patient outcome, and may thus help to guide treatment strategy.

A new robotic assistance system for percutaneous CT-guided punctures: Initial experience

Abstract Purpose: To evaluate the feasibility of CT-guided bone biopsies using a novel robotic needle guide. Material and methods: The robotic needle guide iSYS 1.3 (iSYS Medzintechnik, GmbH, Kitzbuehel, Austria) mounted on the standard table of a CT scanner was used for all studies. For preclinical testing, eight vertebral bodies of dead swine were biopsied, trying to place the needle in the center of the vertebral body via a transpedicular access. For clinical evaluation, bone biopsies were taken in three different patients with ambiguous bone lesions. All biopsies were performed under general anesthesia, using a 12G bone biopsy needle. Results: The animal studies demonstrated that the biopsy needle could be placed accurately in the center of the vertebral body in all cases. No readjustment was necessary, the CT scans demonstrated an intrapedicular trajectory avoiding the spinal canal or the neural foramina. Subsequently, following the animal studies, all biopsies could be performed successfully. Needle placement was accurate without any need for readjustment. No complications occurred during the procedure. Conclusion: Using the iSYS 1.3 allows for accurate and simple stereotactic biopsies of bone lesions, avoiding the need for needle readjustment. The systems may offer even less experienced teams to take biopsies in regions which are difficult to access.

Successful Minimally Invasive Treatment of Intractable, Postoperative Chylous Ascites Via Percutaneous Lymph Vessel Embolization.

The accumulation of chyle—a milky-fluid rich in triglycerides ([200 mg/dl)—within the peritoneal cavity, commonly referred to as chylous ascites or chyloperitoneum, is a rare condition. Up to two thirds of the patients can be successfully treated conservatively [1]. In case conservative management options fail, invasive surgical therapy is indicated. Surgical approaches, however, can be technically challenging for the surgeon and are associated with a high morbidity and mortality [1]. In recent years, interventional radiological treatment of chylous leakages, such as chylothoraces, has been increasingly used and evaluated [1, 2]. Most approaches include embolization or disruption of the thoracic duct above the level of the cisterna chyli which is an adequate technique in the treatment of chylothoraces [2]. In chylous ascites, however, thoracic duct embolization alone would not resolve the chylous leakage in many cases because the leakage site may be below the embolized segment, with even possible worsening of ascites due to blockage of the lymphatic runoff [2]. There is only a small number of reported cases of interventional treatment of chylous ascites to date [1–5]. We report a case of successful percutaneous transabdominal embolization in a case of otherwise uncontrollable chylous ascites after Whipple surgery for cholangiocellular carcinoma. Case Report