Endovascular repair in type A aortic dissection: Anatomical candidacy for currently manufactured stent grafts and conceptual valve-carrying devices for an Endo-Bentall procedure.

OBJECTIVES: Endovascular treatment has been suggested as an alternative for open surgery for type A aortic dissection, but current devices have severe anatomical limitations. This study assesses the computed tomography-based anatomical suitability of currently manufactured stent grafts as well as 2 embodiments of valve-carrying devices. METHODS: In a retrospective single-centre cohort of 200 consecutive ascending/arch operations between 2009 and 2018, a total of 112 patients with type A aortic dissections were identified and evaluated for endovascular candidacy based on the locations of the entries, the landing zone diameters/lengths and the supra-aortic vessel origins according to the anatomical instructions for use criteria of 6 commercially available (tubular, branched or fenestrated) stent grafts. Two suggested valve-carrying devices with inner branches or fenestrations for the coronary arteries and branches for the supra-aortic vessels were also evaluated. RESULTS: The anatomical feasibility for commercial stent grafts ranged from 4% to 21%. The main limitations were proximal landing zone diameter (considering oversizing <15%), length due to dilatation and an entry too close to the sinotubular junction. For the valve-carrying conduits, anatomical feasibility was between 31% and 80%, with the main limiting factors being the diameter of the aortic annulus and its distance to the coronary arteries. CONCLUSIONS: The anatomical applicability of currently manufactured stent grafts for the treatment of type A aortic dissection is limited mainly by the absence of a suitable proximal landing zone in the ascending aorta and might substantially be improved by anchoring in the aortic annulus using a valve-carrying device that uses either fenestrations or branches for the coronary arteries.

Applicability of endovascular branched and fenestrated aortic arch repair devices to treat residual type A dissection after ascending replacement.

OBJECTIVE: Endovascular repair of post-type A aortic dissection (PTAD) after open ascending replacement has recently been shown as safe and feasible, but with limited anatomic applicability because only one stent graft was evaluated. We assessed anatomic and clinical applicability of six commercially available branched/fenestrated stent grafts for endovascular repair of PTAD. METHODS: On postoperative CT scans of 101 patients, we measured the aortic diameter at the sinutubular junction, supra-aortic vessels, and descending aorta, as well as the distances between these landmarks along the outer curvature of the arch and the diameters of the supra-aortic vessel. Anatomic applicability was evaluated according to the instructions for use, clinical applicability with regard to supra-aortic and iliac arteries. Assessed devices were the Cook aortic double branch, Terumo double branch, Najuta fenestrated, Endospan Nexus, Medtronic Mona LSA, and Gore TAG thoracic branch. RESULTS: Single devices were anatomically and clinically applicable between 19 of 101 (Mona LSA) and 83 of 101 (Najuta) cases. Reasons for rejection varied considerably across devices. With all devices available, anatomic applicability was 97 of 101 and clinical applicability 95 of 101. Combinations of a fenestrated and a branched device showed the most favorable clinical applicability for a pair of two devices, ranging from 86 of 101 to 94 of 101. CONCLUSIONS: Anatomic and clinical applicability of endovascular devices for the repair of PTAD is high for fenestrated and branched devices, and very high for the combination of fenestrated and branched devices. Manufacturers should amend specific device requirements for PTAD. Surgeons should emphasize the need for a sufficiently long and straight graft as a potential landing zone.

Branched versus fenestrated thoracic endovascular aortic repair in the aortic arch: A multicenter comparison.

OBJECTIVE: For thoracic endovascular aortic repair of the arch, branched and fenestrated endografts are available with different limitations regarding anatomy and extent of the pathology. Comparisons are lacking in the literature. The aim of this study was to compare the results of 2 currently commercially available devices for branched thoracic endovascular aortic repair and fenestrated thoracic endovascular aortic repair. METHODS: In a retrospective, multicenter cohort study, a consecutive patient series treated with branched thoracic endovascular aortic repair or fenestrated thoracic endovascular aortic repair for aortic arch pathologies was assessed. Baseline characteristics, procedural fenestrated thoracic endovascular aortic repair, and outcome were analyzed. Furthermore, the potential anatomic feasibility of the respective alternate device was assessed on the preoperative computed tomography scans. RESULTS: The branched thoracic endovascular aortic repair and fenestrated thoracic endovascular aortic repair cohorts consisted of 20 and 34 patients, respectively, with similar comorbidities; indication was aneurysm in 65% and 79%, penetrating aortic ulcer in 20% and 9%, and dissection in the remaining procedures, respectively. Technical success was achieved in all but 1 patient. Perioperative mortality and major stroke rate were both 10% in branched thoracic endovascular aortic repair and 0% and 3% in fenestrated thoracic endovascular aortic repair, respectively. During follow-up of 31 and 40 months, 1 branch occlusion occurred in the branched thoracic endovascular aortic repair cohort, and 2 late endoleaks occurred in the fenestrated thoracic endovascular aortic repair group. One aortic death occurred. Although 35% of patients undergoing branched thoracic endovascular aortic repair were anatomically suitable for fenestrated thoracic endovascular aortic repair, 91% of those undergoing fenestrated thoracic endovascular aortic repair were suitable for branched thoracic endovascular aortic repair. CONCLUSIONS: Both branched thoracic endovascular aortic repair and fenestrated thoracic endovascular aortic repair show excellent technical success and acceptable complication rates, whereas branched thoracic endovascular aortic repair tends toward higher morbidity, especially stroke rates. By offering fenestrated thoracic endovascular aortic repair along with branched thoracic endovascular aortic repair, aortic centers could potentially lower complication rates and simultaneously still treat a wide range of anatomies.

Structural failure in bridging stentgrafts for branched endovascular aneurysm repair: a case-control study.

OBJECTIVE: To present a case series of spontaneous structural failure of bridging stentgrafts (BSGs) after branched endovascular aortic repair (bEVAR), as well as their failure types and their detection. While bEVAR is a safe and effective procedure, one main limitation is the reintervention rate associated with the BSGs. Structural failure of BSGs, defined as fabric disruption, stent fracture with leak or complete separation is a major cause for reinterventions and difficult to detect in computed tomography angiography (CTA). METHODS: From a multicenter bEVAR complication database, structural BSG failures were identified. Patient and BSG characteristics, detection mode, failure type, treatment and outcome were recorded and compared with bEVAR patients with intact BSGs. RESULTS: Twenty-three BSG failures were detected in 12 patients with only 43% directly identified in CTA, after a mean of 21.4 months after implantation. The BSGs were Advanta (n = 4), E-Ventus (n = 16) and BeGraft (n = 3) in 10 renal, 9 superior mesenteric, and 4 celiac branches. Religning with another BSG was successful in 20/22 cases, one BSG failure necessitated renal branch embolization (organ loss), and one mesenteric bypass surgery. Two reintervention-related mortalities occurred. CONCLUSION: Structural failure of BSGs is a serious limitation for bEVAR, which can result in high reintervention rates and serious complications. BSG failure typically occurs in single-layer types and events are clustered in patients. The necessary reinterventions carry serious morbidity and mortality. Since the use as BSG in bEVAR is off-label with all current BSG manufacturers, caution is advised regarding patient-informed consent.

Assessment of left and right ventricular functional parameters using dynamic dual-tracer [13N]NH3 and [18F]FDG PET/MRI.

BACKGROUND: Cardiac positron emission tomography/magnetic resonance imaging (PET/MRI) can assess various cardiovascular diseases. In this study, we intra-individually compared right (RV) and left ventricular (LV) parameters obtained from dual-tracer PET/MRI scan. METHODS: In 22 patients with coronary heart disease (69 ± 9 years) dynamic [13N]NH3 (NH3) and [18F]FDG (FDG) PET scans were acquired. The first 2 minutes were used to calculate LV and RV first-pass ejection fraction (FPEF). Additionally, LV end-systolic (LVESV) and end-diastolic (LVEDV) volume and ejection fraction (LVEF) were calculated from the early (EP) and late-myocardial phases (LP). MRI served as a reference. RESULTS: RVFPEF and LVFPEF from FDG and NH3 as well as RVEF and LVEF from MRI were (28 ± 11%, 32 ± 15%), (32 ± 11%, 41 ± 14%) and (42 ± 16%, 45 ± 19%), respectively. LVESV, LVEDV and LVEF from EP FDG and NH3 in 8 and 16 gates were [71 (15 to 213 mL), 98 (16 to 241 mL), 32 ± 17%] and [50 (17 to 206 mL), 93 (13 to 219 mL), 36 ± 17%] as well as [60 (19 to 360 mL), 109 (56 to 384 mL), 41 ± 22%] and [54 (16 to 371 mL), 116 (57 to 431 mL), 46 ± 24%], respectively. Moreover, LVESV, LVEDV and LVEF acquired from LP FDG and NH3 were (85 ± 63 mL, 138 ± 63 mL, 47 ± 19%) and (79 ± 56 mL, 137 ± 63 mL, 47 ± 20%), respectively. The LVESV, LVEDV from MRI were 93 ± 66 mL and 153 ± 71 mL, respectively. Significant correlations were observed for RVFPEF and LVFPEF between FDG and MRI (R = .51, P = .01; R = .64, P = .001), respectively. LVESV, LVEDV, and LVEF revealed moderate to strong correlations to MRI when they acquired from EP FDG and NH3 in 16 gates (all R > .7, P = .000). Similarly, all LV parameters from LP FDG and NH3 correlated good to strongly positive with MRI (all R > .7, and P < .001), except EDV from NH3 weakly correlated to EDV of MRI (R = .54, P < .05). Generally, Bland-Altman plots showed good agreements between PET and MRI. CONCLUSIONS: Deriving LV and RV functional values from various phases of dynamic NH3 and FDG PET is feasible. These results could open a new perspective for further clinical applications of the PET examinations.

Percutaneous mechanical circulatory support from the collaborative multicenter Mechanical Unusual Support in TAVI (MUST) Registry.

OBJECTIVES: To evaluate the use and outcomes of percutaneous mechanical circulatory support (pMCS) utilized during transcatheter aortic valve implantation (TAVI) from high-volume centers. METHODS AND RESULTS: Our international multicenter registry including 13 high-volume TAVI centers with 87 patients (76.5 ± 11.8 years, 63.2% men) who underwent TAVI for severe aortic stenosis and required pMCS (75.9% VA-ECMO, 19.5% Impella CP, 4.6% TandemHeart) during the procedure (prior to TAVI 39.1%, emergent rescue 50.6%, following TAVI 10.3%). The procedures were considered high-risk, with 50.6% having severe left ventricular dysfunction, 24.1% biventricular dysfunction, and 32.2% severe pulmonary hypertension. In-hospital and 1-year mortality were 27.5% and 49.4%, respectively. Patients with prophylactic hemodynamic support had lower periprocedural mortality compared to patients with rescue insertion of pMCS (log rank = 0.013) and patients who did not undergo cardiopulmonary resuscitation during the TAVI procedure had better short and long term survival (log rank <0.001 and 0.015, respectively). CONCLUSIONS: Given the overall survival rate and low frequency of pMCS-related complications, our study results support the use of pMCS prophylactically or during the course of TAVI (bailout) in order to improve clinical outcomes in high-risk procedures or in case of acute life-threatening hemodynamic collapse.

Safety and image quality of cardiovascular magnetic resonance imaging in patients with retained epicardial pacing wires after heart transplantation.

BACKGROUND: Temporary epicardial pacing wires, implemented in patients during heart transplantation, are routinely removed before discharge. However, in some cases, these wires may remain in situ and are often considered as a contraindication for cardiovascular magnetic resonance (CMR) imaging in the future. Therefore, we aimed to provide data about safety and image quality of CMR in these patients. METHODS: This is a report on a subpopulation out of 88 patients after heart transplantation that were included in a prospective cohort study and underwent multiple CMR in their post-transplant course. During CMR, patients were monitored by electrocardiogram and all examinations were observed by a physician to document potential adverse events. Additionally, image quality was assessed by an imaging specialist. RESULTS: Nineteen of 88 patients included had temporary pacing wires in situ. These patients underwent a total of 51 CMR studies. No major adverse event and only one single, mild sensory event could be documented. All CMR studies showed preserved diagnostic image quality. Temporary pacing wires were visible in 100% of HASTE and cine sequences. In less than 50% of the examinations, temporary pacing wires were also visible in T1 and T2 mapping, short tau inversion recovery (STIR), and late gadolinium enhancement (LGE) sequences, without any impairment of image quality. CONCLUSIONS: With a low event rate of only one mild adverse event during 51 CMR examinations (2%), CMR appears to be safe in patients with retained temporary epicardial pacing wires after heart transplantation. Moreover, image quality was not impaired by the presence of pacing wires.

Assessment of Myocardial Viability in Ischemic Heart Disease by PET/MRI: Comparison of Left Ventricular Perfusion, Hibernation, and Scar Burden.

RATIONALE AND OBJECTIVES: Hybrid positron emission tomography-magnetic resonance (PET-MR) is a novel imaging technology that enables a comprehensive assessment of myocardial viability. The aim of this study was to intra-individually compare simultaneously acquired viability parameters from MRI and PET to determine complementary and redundant information. MATERIALS AND METHODS: Thirty-nine patients with ischemic heart disease (IHD) underwent cardiac PET-MR for myocardial viability assessment. Cardiac magnetic resonance (CMR), including late gadolinium enhancement (LGE), and PET, including a dynamic dual-tracer acquisition of [13N]ammonia ([13N]NH3)/[18F]fluorodeoxyglucose ([18F]FDG), were performed simultaneously. Allocation, extent, and transmural degree of left ventricular (LV) scars were measured from LGE. Perfusion, viability, and hibernation were assessed by PET. RESULTS: A comparison of scar location revealed six more areas of infarction on MR than on PET. Mean LV scarring by CMR was 14% (range, 2% to 42%) and 14% (range, 1% to 46%) by PET (CMR vs. PET: p = 0.9). An intra-individual comparison of scarring showed a good inter-method correlation (r = 0.7), which was also evident in the subgroup with low ejection fraction (EF) (r = 0.6). Hibernation and transmural degree of scars showed a moderate to weak correlation (r = 0.4), which was even worse in the low EF group (r = 0.1). CONCLUSIONS: In patients with IHD, there was a good correlation between PET and CMR for the LV scar extent using hybrid cardiac PET-MR. The degree of transmural scarring by CMR showed no correlation to PET hibernation. Therefore, cardiac PET-MR might be a suitable tool for a comprehensive assessment of myocardial viability if used to predict response to cardiac reperfusion strategies.

Assessment of attenuation correction for myocardial PET imaging using combined PET/MRI.

OBJECTIVE: To evaluate the frequency of artifacts in MR-based attenuation correction (AC) maps and their impact on the quantitative accuracy of PET-based flow and metabolism measurements in a cohort of consecutive heart failure patients undergoing combined PET/MR imaging. METHODS: Myocardial viability studies were performed in 20 patients following a dual-tracer protocol involving the assessment of myocardial perfusion (13N-NH3: 813 ± 86 MBq) and metabolism (18F-FDG: 335 ± 38 MBq). All acquisitions were performed using a fully-integrated PET/MR system, with standard DIXON-attenuation correction (DIXON-AC) mapping for each PET scan. All AC maps were examined for spatial misalignment with the emission data, total lung volume, susceptibility artifacts, and tissue inversion (TI). Misalignment and susceptibility artifacts were corrected using rigid co-registration and retrospective filling of the susceptibility-induced gaps, respectively. The effects of the AC artifacts were evaluated by relative difference measures and perceived changes in clinical interpretations. RESULTS: Average respiratory misalignment of (7 ± 4) mm of the PET-emission data and the AC maps was observed in 18 (90%) patients. Substantial changes in the lung volumes of the AC maps were observed in the test-retest analysis (ratio: 1.0 ± 0.2, range: 0.8-1.4). Susceptibility artifacts were observed in 10 (50%) patients, while six (30%) patients had TI artifacts. Average differences of 14 ± 10% were observed for PET images reconstructed with the artifactual AC maps. The combined artifact effects caused false-positive findings in three (15%) patients. CONCLUSION: Standard DIXON-AC maps must be examined carefully for artifacts and misalignment effects prior to AC correction of cardiac PET/MRI studies in order to avoid misinterpretation of biased perfusion and metabolism readings from the PET data.

The "Paper Roll": A Simple but Useful Tool for Minimal Invasive Mitral Valve Repair Surgery.

During minimal invasive mitral valve repair, excessive valve tissue, as in myxomatous or Barlow disease, might be cumbersome to analyze and treat the subvalvular mitral valve apparatus. We developed a new, adaptive, flexible, and easy-to-use technique for better visualization of the subvalvular apparatus. After visualization of the mitral valve, a simple sterile paper ruler was curled up to a roll 1 cm in diameter and inserted through the mitral valve. By means of two endo forceps, the paper roll was uncurled to the desired diameter, thus pushing the valve leaflets away, allowing for a direct view onto the subvalvular apparatus. This technique was successfully used in 34 consecutive patients (mean ± SD age = 57.2 ± 11.5 years; 22 male). The calculated risk score for additive EuroScore, logistic EuroScore, and EuroScore II was 4 ± 2, 3.2 ± 2.1, and 2.5 ± 5.4, respectively. No patient died within the first 30 days. All patients presented mitral valve insufficiency grade 0 to 1 postoperatively. Artificial chords were implanted in all patients (3.6 ± 1.8 chords per patient). This simple, adaptive, and cheap technique facilitates the approach to the subvalvular apparatus, especially in patients with myxomatous or Barlow disease. The ease of use allows for prompt approach to the papillary muscles and quick removal.

The megaaortic syndrome: Progression of ascending aortic aneurysm or a disease of distinct origin?

BACKGROUND: Thoracic aortic aneurysm (TAA) is an often asymptomatic disease with fatal outcome, such as dissection or rupture. The megaaortic syndrome (MAS) is an extensive dilatation of the whole aorta with low incidence but high lethal outcome with unknown pathophysiology so far. METHODS AND RESULTS: We compared aortic tissue of patients with sporadic TAAs and MAS of the ascending aorta with non-aneurysmal control tissues. Specimens of MAS patients showed a significantly reduced thickness of the media but an increased thickness of the intima compared to control tissue and TAAs with moderate dilatation. Advanced media degeneration however was detectable in both, TAAs with enhanced luminal diameter and MAS specimens, accompanied by reduced medial smooth muscle cell-density. Further specimens of MAS were characterized by massive atherosclerotic lesions in contrast to specimens of sporadic TAA patients. Infiltrations of macrophages in atherosclerotic lesions but also in the media adjacent to the adventitia were significantly elevated in tissue of TAAs with dilatation ≤6cm. Of note, atherosclerotic plaque-associated macrophages as well as those in the external media produce huge amounts of MMP-9 which is possibly involved in media degeneration and tissue destruction. CONCLUSIONS: Taken together these results demonstrate that the pathology of MAS shows similarities with that of TAAs but pathological differences in the ascending aorta, suggesting that MAS might be a disease of different origin.

Thoracic endovascular aortic repair in 300 patients: long-term results.

BACKGROUND: The aim of this analysis was to assess short and mid-term results of patients undergoing thoracic endovascular aortic repair (TEVAR) for 4 different indications. METHODS: From 1996 to 2010, 300 patients (80 female, 220 male, median age 67 years [20 to 88]) underwent TEVAR at our department. Among them were 137 descending thoracic aneurysms (DTA), 80 type B dissections (60 acute, 20 chronic), 59 perforating aortic ulcer (PAU), and 24 traumatic aortic transections (ATAT). Hospital mortality and mid-term survival among different indications for TEVAR were evaluated. RESULTS: Overall hospital mortality in our series was 5% (n = 15). Seven patients with DTA (5%), 4 patients with type B dissections (5%), 2 patients with PAU (3.4%), and 2 ATAT (8%) patients died during their hospital stay. Kaplan-Meier survival analysis revealed significant differences in survival rates according to the various indications for TEVAR (p < 0.001). Overall long-term mortality was 86%, 63%, and 44% at 1, 5, and 10 years. Early and late endoleak rate was 18% and 8%, respectively. CONCLUSIONS: The TEVAR has evolved into a safe and effective therapy for different aortic pathology resulting in promising long-term results. Nevertheless, the indication for TEVAR has direct impact on the success of the procedure. Patients with acute type B aortic dissections and acute traumatic aortic lesions seem to benefit the most from TEVAR.

IgG deposition and activation of the classical complement pathway involvement in the activation of human granulocytes by decellularized porcine heart valve tissue.

Decellularization treatment of heart valves has been thought to eliminate tissue immunogenicity. Early failure of tissue-engineered xenogeneic heart valves was seen in children and has been a major drawback in this promising field of research. This study was designed to characterize the effects of acellular porcine heart valve tissue on immune activation in vitro. Incubation of decellularized porcine tissue with human plasma led to adsorption of IgG, activation of the classical complement pathway and adhesion of activated polymorphonuclear leukocytes (PMN). This inflammatory response was strongly inhibited by proteins extracted from native porcine tissue which might indicate that inhibitors of PMN activation present in the extracellular matrix (ECM) are lost during the decellularization process.