Richard Nolz

Type II endoleaks after endovascular repair of abdominal aortic aneurysms: fate of the aneurysm sac and neck changes during long-term follow-up.

Purpose To evaluate the frequency of type II endoleaks after endovascular aneurysm repair (EVAR) and to compare sac diameter and neck changes in patients with type II endoleak to endoleak-free patients with at least 3-year imaging follow-up. Methods Among 407 consecutive EVAR patients, 109 patients (101 men; mean age 72.1 years, range 55–86) had at least 3-year computed tomography (CT) data and no type I or III endoleak. In this cohort, 49 patients presented with a type II endoleak at some time and 60 patients had no endoleak. Patients with type II endoleaks were further divided into subgroups based on the vessel origin and the perfusion status (persistent or transient). The course of the perfusion status of type II endoleaks and changes in the aneurysm sac diameters, neck diameters, and renal to stent-graft distances (RSD) were evaluated in the defined groups. Reintervention and death rates were also reported. Results The mean follow-up was 68.1±23.8 months. Compared to the no endoleak group, overall sac diameter increased significantly in the type II endoleak group (p=0.007), but vessel origin did not have any influence. With regard to the perfusion status of type II endoleaks, aneurysm sac changes were significantly higher (p = 0.002) in the persistent endoleak group. During the study period, the increase in the proximal neck diameter was significantly higher in the no endoleak group compared to the type II endoleak group (p=0.025). No significant difference was found in RSD changes between the defined groups. Reinterventions were performed in 20 (18.3%) patients (13 for type II endoleak); 2 (1.8%) patients without type II endoleak died of ruptured aneurysm. Conclusion Persistent type II endoleaks led to significant aneurysm sac enlargement, but without increased mortality or rupture rates.

Diagnostic workup of primary sclerosing cholangitis: The benefit of adding gadoxetic acid-enhanced T1-weighted magnetic resonance cholangiography to conventional T2-weighted magnetic resonance cholangiography

AIM To evaluate the value of gadoxetic acid-enhanced T1-weighted (T1W) magnetic resonance cholangiography (MRC) versus conventional T2-weighted (T2W) MRC compared to endoscopic retrograde cholangiopancreatography (ERCP) in patients with primary sclerosing cholangitis (PSC). MATERIALS AND METHODS Based on T1W MRC, PSC patients were classified into a regular (RG) and a delayed (DG) excreting group, with an absence of gadoxetic acid in the common bile duct at 20 min. Beading, pruning, and gradation of central bile duct stenosis, evaluated by T1W and T2W MRC, were compared to ERCP. Liver parenchymal enhancement was measured in both study groups and compared to a reference group (n = 20) without a history of liver disease. Two readers performed all measurements. RESULTS Based on beading and pruning of the peripheral bile ducts, sensitivities, specificities, and accuracies for reader 1 were 0.17/0.43, 0/0.17, and 0.15/0.31 for T1W MRC, and 0.83/0.86, 1/0.83, and 0.85/0.85 for T2W MRC (p = 0.004). For reader 2 sensitivities, specificities, and accuracies were 0.25/0.57, 0/0.33, and 0.23/0.46 for T1W MRC, and 0.92/1, 1/0.83, and 0.92/0.92 for T2W MRC (p = 0.012). Compared to ERCP, central bile duct stenoses were significantly overestimated (p < 0.001) by T2W MRC. A significantly lower parenchymal enhancement was found in the DG (n = 7) compared to the RG (n = 13), and compared to the reference group (p < 0.001). CONCLUSION The combined performance of T2W and T1W MRC may provide a comprehensive imaging workup of PSC, including morphological and functional information resulting in optimal management.

Carotid artery stenting and follow-up: Value of 64-MSCT angiography as complementary imaging method to color-coded duplex sonography

PURPOSE To compare 64-multi-slice-CT angiography (64-MSCTA) to color-coded duplex sonography (CCDS) in the follow-up after carotid artery stenting (CAS). METHODS Thirty patients who had an MSCTA and CCDS examination prior and after CAS were included. Twelve closed-cell and 24 open-cell stents were implanted. Neointimal surface, in-stent-restenosis (ISR), stent expansion, and fracture were evaluated. In addition, the occurrence of atherosclerotic lesions leading to a>50% stenosis in supraaortic vessels was assessed. RESULTS With MSCTA, >50% ISR was found in 5.6% of cases during a mean follow-up of 41.7 months. Comparing MSCTA and CCDS, grading of ISR and absolute diameters of neointimal surface correlated moderately (Spearman=0.402, p=0.015; Pearson=0.404, p=0.03). Assessment of the neointimal surface was significantly better with MSCTA (100% vs. 80.6%; p=0.011). Stent expansion was significant, compared to the basic value, with both modalities and stent types (p<0.001). Of 237 additionally assessed vessel segments, a>50% stenosis was detected in 38 (16.0%) vessel segments. Findings were stable in 25 (10.5%) and progressed in 11 (4.6%) vessel segments. Five small intracranial aneurysms were detected in four (13.3%) patients. Of 21 incidental findings in 16 (51.6%) patients there was one with malignancy (4.8%). CONCLUSION With regard to ISR and stent expansion, no significant difference was found, when MSCTA and CCDS were compared. CTA is quite applicable as a complementary imaging method for the follow-up of patients with carotid artery stents. Additional advantages are the detection of supraaortic vessel pathologies and incidental findings.

Complete ten-year follow-up after endovascular abdominal aortic aneurysm repair: Survival and causes of death

PURPOSE To analyze the hazard and causes of death after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms during a complete ten year follow-up. METHODS This is a retrospective clinical study of 130 consecutive patients undergoing EVAR between 1995 and 1998. One-hundred twenty-one patients (93.1%) were treated with first-generation stentgrafts and nine patients (6.9%) received second-generation devices. All patients completed a follow-up of at least 10 years, unless death occurred before then. Time and causes of death were provided by the Austrian central register of deaths. RESULTS The median follow-up was 7.6 years, and the 130 patients had 968.5 person-years of follow-up. The ten-year mortality rate was 62.3%. Cardiovascular events were the most frequent causes of death, with a 3.9 incidence rate per 100 person-years. Cancer death and death due to other causes occurred in 2.1 and 1.8 cases per 100 person-years, respectively. Lethal late aneurysm rupture happened in 4.6% (n=6), which corresponds to an annual incidence rate of 0.6 per 100 person-years. All of those patients had been treated with first-generation devices. CONCLUSIONS Cardiovascular events were the most frequent cause of death after EVAR, followed by malignancy and other diseases. The risk of dying from secondary rupture was clearly lower than that of death due to other reasons during ten years after EVAR, even in patients with first-generation stentgrafts.

Evaluation of [18F]-FDG-Based Hybrid Imaging Combinations for Assessment of Bone Marrow Involvement in Lymphoma at Initial Staging

The purpose of our study was to determine the value of different hybrid imaging combinations for the detection of focal and diffuse bone marrow infiltration in lymphoma. Patients with histologically proven lymphoma, who underwent both [18F]-FDG-PET/CT and whole-body MRI (including T1- and diffusion-weighted [DWI] sequences) within seven days, and a subsequent bone marrow biopsy, were retrospectively included. Three hybrid imaging combinations were evaluated: (1) [18F]-FDG-PET/CT; (2) [18F]-FDG-PET/T1; and (3) [18F]-FDG-PET/DWI. The presence of focal or diffuse bone marrow infiltration was assessed by two rater teams. Sensitivity, specificity, and accuracy for the detection of overall, focal, and diffuse bone marrow involvement were compared between the three hybrid imaging combinations. Overall, lymphomatous bone marrow involvement was found in 16/60 patients (focal, 8; diffuse, 8). Overall sensitivity, specificity, and accuracy were 81.3%, 95.5%, and 91.7% for [18F]-FDG-PET/CT; 81.3%, 97.7%, and 93.3% for [18F]-FDG-PET/T1; and 81.3%, 95.5%, and 91.7% for [18F]-FDG-PET/DWI. No statistically significant differences between the three imaging combinations were observed, based on overall bone marrow involvement, focal involvement, or diffuse involvement. The sensitivity of all three imaging combinations for detecting diffuse bone marrow involvement was only moderate (62.5% for all three combinations). Although the combination of [18F]-FDG-PET and T1-weighted MRI generally showed the best diagnostic performance for the detection of bone marrow involvement in lymphoma, it was not significantly superior to the two other hybrid imaging combinations. Since the sensitivity of all imaging combinations for the detection of diffuse bone marrow involvement was only moderate, bone marrow biopsy cannot be replaced by imaging as yet.

Aortouni-iliac endografting as an alternative salvage procedure to open conversion in failed endovascular aneurysm repair.

Purpose To present a single-center experience with failed EVAR requiring conversions comparing open surgery to a minimally invasive procedure modifying the existing stent-graft into an aortouni-iliac (AUI) configuration. Methods A prospectively maintained database at our tertiary care university hospital was interrogated to identify all patients with failed EVAR who had undergone either stent-graft modification into an AUI configuration or open conversion between March 1995 and January 2012. Patients with late aneurysm ruptures were excluded. The search found 30 patients (one had initial treatment elsewhere) who required conversion among the 688 patients who had undergone EVAR in that time period. Before conversion, 16 (53%) patients had prior endovascular corrections to maintain aneurysm exclusion. Results An average time of 52.2 months (median 46.9, IQR 0.0–92.5) elapsed between initial EVAR and conversion. There were 11 early conversions (including 7 on-table), while 19 procedures were done <30 days post EVAR. Twenty-two (73%) patients underwent AUI endografting, while open conversions were carried out in 8 (27%). Mean hospital stay after conversion was 19.5 days (median 13.0, IQR 8.0–17.0). Overall mortality after conversion was 3.3% (1 patient after on-table open conversion), but since the introduction of AUI endografting as an alternative treatment approach, 30-day mortality following conversions fell to zero. Conclusion Modification of a failed stent-graft into an AUI configuration serves as a less invasive treatment option compared to open conversion and allows salvage of the failed device. With the implementation of this alternative approach, mortality after conversion parallels the mortality of elective abdominal aneurysm repair.

Endovascular Treatment of Delayed Rupture Following Prior Abdominal Aortic Aneurysm Repair Achieves Better Survival Rates

Purpose To test the hypothesis that endovascular treatment of delayed aneurysm rupture achieves significantly better survival rates compared to surgical conversion. Methods All patients sustaining delayed rupture following prior exclusion of an abdominal aortic aneurysm (AAA) either by endovascular aneurysm repair (EVAR) or open graft replacement from March 1995 through December 2011 were retrieved from a prospectively maintained database at a tertiary care university hospital. During the study period, 35 patients (32 men; mean age 72.9 years) presented with delayed rupture at a median 2.4 years (interquartile range 1.3–4.3) after initial AAA repair by EVAR (n=22) or open surgery (n=13). Causes of post-EVAR rupture were graft-related endoleaks, while ruptures after open repair occurred at anastomotic suture sites. Patients were divided into groups regarding type of treatment for delayed rupture: 20/35 (57%) underwent successful EVAR (10 redo procedures), 13/35 (37%) had surgery (3 redo procedures), and 2/35 (6%) patients received comfort care only. The primary endpoint was 30-day mortality. Results The 30-day mortality after curative treatment was 25% (5/20) for endovascular treatment compared to 54% (7/13) for surgery (p=0.14). Including additional deaths beyond 30 days, the overall in-hospital mortality was 52% (17/33). The Kaplan-Meier survival estimate for patients undergoing endovascular treatment was significantly higher (p=0.011). Conclusion Endovascular treatment of delayed rupture is feasible and helps to reduce mortality. Our data suggest that endovascular procedures are a superior treatment option for EVAR-suitable patients with delayed rupture compared with surgical conversion.

Anastomotic pseudoaneurysms after surgical reconstruction: Outcomes after endovascular repair of symptomatic versus asymptomatic patients

PURPOSE To compare perioperative and follow-up outcomes of symptomatic versus asymptomatic patients following endovascular repair of anastomotic pseudoaneurysms (APAs) of the abdominal aorta and iliac arteries. METHODS We retrospectively evaluated 17 patients (two women), with a mean age of 66.2 years (range 30-83 years). Endovascular treatment was performed in ten symptomatic, and seven asymptomatic patients electively. Data included technical success, perioperative (within 30 days) mortality and morbidity, as well as stent graft-related complications, reinterventions, and survival in follow-up. RESULTS Bifurcated (n = 13), aortomonoiliac (n = 3) endoprosthesis and one aortic cuff were implanted with a primary technical success rate of 100%. The overall in-hospital mortality and morbidity rate was 11.8% and 35.3%. The mean survival was 36.5 (range 0-111) months. There was a clear trend toward a lower overall survival within hospital and at one and three years for symptomatic patients compared to asymptomatic patients. (47.7 (CI: 0-138.8) versus 52.6 (CI: 28.5-76.8) months (p = 0.274)). During follow-up, late stent graft related complications were observed in six patients (35.3%) necessitating eight endovascular reinterventions. Additional three patients with primary fistulas between the APA and the intestine were treated by late surgical revision. CONCLUSION Endovascular therapy of APAs represents a considerable alternative to open surgical repair. Short proximal anchoring zones still pose a risk for endoleaks and unintentional overstenting of side branches with commercially available devices, but this might be overcome by use of fenestrated and branched stent grafts in elective cases.

Low-Dose High-Pitch CT Angiography of the Supraaortic Arteries Using Sinogram-Affirmed Iterative Reconstruction

Objective To prospectively evaluate image quality and radiation dose using a low-dose computed tomography angiography protocol and iterative image reconstruction for high-pitch dual-source CT-angiography (DSCTA) of the supraaortic arteries. Material and Methods DSCTA was performed in 42 patients, using either 120 kVp tube voltage, 120 mAS tube current, 2.4 pitch and filtered back projection, or 100 kVp tube voltage, 100 mAs tube current, 3.2 pitch, and sinogram affirmed iterative reconstruction. Measurements of vessel attenuation, of the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were performed to objectively evaluate image quality. Two readers evaluated subjective image quality and image noise, using a four-point scale. Effective dose was used to compare the differences in radiation dose. Results Low-dose protocol application showed significantly higher vessel opacification (p = 0.013), and non-significantly higher CNR and SNR values. There was no difference in the subjective image quality and image noise reading between the protocols. Effective dose was significantly lower using the low-dose protocol (1.29±0.21 mSv vs. 2.92±0.72 mSv; p<0.001). Conclusion The combined use of reduced tube voltage, reduced tube current, and iterative reconstruction reduces radiation dose by 55.4% in high-pitch DSCTA of the supraaortic arteries without impairment of image quality.

Effects of Portal Hypertension on Gadoxetic Acid–Enhanced Liver Magnetic Resonance: Diagnostic and Prognostic Implications

Objective The aim of this study was to investigate the impact of portal hypertension (PH) on gadoxetic acid–enhanced liver magnetic resonance imaging (MRI) and assess diagnostic and prognostic implications in comparison to established imaging features of PH. Materials and Methods Institutional review board–approved retrospective study of 178 patients (142 men; median age, 59.4 years) with chronic liver disease undergoing MRI and hepatic venous pressure gradient (HVPG) measurement between January 2008 and April 2015. Magnetic resonance imaging was assessed for established features of PH (splenic and portal vein diameters, portosystemic collaterals, ascites) and for features on 20 minutes delayed T1-weighted gadoxetic acid–enhanced MRI, that is, relative liver enhancement (RLE), biliary contrast excretion, or portal vein hyperintensity or isointensity (ie, portal vein hyperintensity sign, PVHS). Statistics encompassed linear regression, logistic regression, and survival analysis. Results There was an inverse correlation between HVPG and RLE (r2 = 0.18, P < 0.0001). On univariate analysis, clinically significant PH (ie, HVPG ≥ 10 mm Hg, n = 109) and severe PH (ie, HVPG ≥ 12 mm Hg, n = 99) were associated with delayed biliary contrast excretion (n = 33) and the PVHS (n = 74) (P < 0.01 for all). Multivariate analysis demonstrated significant associations between the PVHS and severe PH (odds ratio [OR], 3.33; P = 0.008), independently of spleen size (OR, 1.26; P = 0.002), portosystemic collaterals (n = 81; OR, 5.46; P = 0.0001), and ascites (n = 88; OR, 3.24; P = 0.006). Lower RLE and the PVHS were associated with lower 3-year, transplantation-free survival (hazards ratios, 0.98 and 3.99, respectively, P = 0.002 for all), independently of the Child-Pugh and Model for End-Stage Liver Disease scores. Conclusions The presence of the PVHS on gadoxetic acid–enhanced MRI is an independent indicator of severe PH and may enable more accurate diagnosis. This feature and decreased hepatic contrast uptake may also comprise prognostic information.