Diameter Changes in Traumatic Aortic Injury: Implications for Stent-Graft Sizing.

OBJECTIVES: The aim of this study was to compare aortic diameters from admission computed tomography angiography (CTA) scans to postoperative aortic diameters in patients with traumatic aortic injury (TAI) and evaluate the influence of substantial blood loss on aortic diameter. METHODS: The aortic databases of two tertiary university centers were retrospectively screened for patients with TAI between February 2002 and February 2019. Concomitant organ injuries, bone fractures, blood loss, and clinical outcomes were evaluated. Aortic diameters were measured in CTA upon admission and were compared with the CTA before discharge at three different aortic levels (mid-ascending, 5 cm distal to the end of the stent graft, and at the celiac trunk level). RESULTS: We identified 45 patients, aged 43 (first quartile; third quartile [26; 55]) years with a TAI treated by thoracic endovascular aortic repair. The most frequent cause of TAI was a car accident (n = 24). Concomitant injuries were seen in all but one patient. Bone and pelvic fractures were seen in 40 (89%) and 15 (33%) patients, respectively. Type III aortic injury was present in 25 patients (56%). Increase of aortic diameter after stabilization was +1.7 mm (-0.6 mm; 2.5 mm; p = 0.004) at the mid-ascending aorta, +2.1 mm (0.2 mm; 3.8 mm; p < 0.001) 5 cm distal to the stent graft, and +1.5 mm (0.5 mm; 3.2 mm; p < 0.001) at the celiac trunk level. CONCLUSION: In patients with TAI, the aortic diameter is significantly reduced as compared with the aortic diameter at discharge. The reduction of aortic diameter might be caused by hemorrhagic shock and should be kept in mind for appropriate stent-graft sizing.

What Is the Best Method to Achieve Safe and Precise Stent-Graft Deployment in Patients Undergoing TEVAR?

Thoracic endovascular aortic repair (TEVAR) for aortic pathologies requires sufficient landing zone of ideally more than 25 mm for safe anchoring of the stent-graft and prevention of endoleaks. In the aortic arch and at the thoracoabdominal transition, landing zone length is usually limited by the offspring of the major aortic side-branches. Exact deployment of the stent-graft to effectively use the whole length of the landing zone and to prevent occlusion of one of the side-branches is key to successful TEVAR. There are numerous techniques described to lower blood pressure and to reduce or eliminate aortic impulse to facilitate exact deployment of stent-grafts including pharmacologic blood pressure lowering, adenosine-induced asystole, inflow occlusion, and rapid pacing. Aim of this review was to assess the current literature to identify which of the techniques is best suited to prevent displacement and allow for precise placement of the stent-graft and safe balloon-molding.

Hypertrophic cardiomyopathy is characterized by alterations of the mitochondrial calcium uniporter complex proteins: insights from patients with aortic valve stenosis versus hypertrophic obstructive cardiomyopathy.

Introduction: Hypertrophies of the cardiac septum are caused either by aortic valve stenosis (AVS) or by congenital hypertrophic obstructive cardiomyopathy (HOCM). As they induce cardiac remodeling, these cardiac pathologies may promote an arrhythmogenic substrate with associated malignant ventricular arrhythmias and may lead to heart failure. While altered calcium (Ca2+) handling seems to be a key player in the pathogenesis, the role of mitochondrial calcium handling was not investigated in these patients to date. Methods: To investigate this issue, cardiac septal samples were collected from patients undergoing myectomy during cardiac surgery for excessive septal hypertrophy and/or aortic valve replacement, caused by AVS and HOCM. Septal specimens were matched with cardiac tissue obtained from post-mortem controls without cardiac diseases (Ctrl). Results and discussion: Patient characteristics and most of the echocardiographic parameters did not differ between AVS and HOCM. Most notably, the interventricular septum thickness, diastolic (IVSd), was the greatest in HOCM patients. Histological and molecular analyses showed a trend towards higher fibrotic burden in both pathologies, when compared to Ctrl. Most notably, the mitochondrial Ca2+ uniporter (MCU) complex associated proteins were altered in both pathologies of left ventricular hypertrophy (LVH). On the one hand, the expression pattern of the MCU complex subunits MCU and MICU1 were shown to be markedly increased, especially in AVS. On the other hand, PRMT-1, UCP-2, and UCP-3 declined with hypertrophy. These conditions were associated with an increase in the expression patterns of the Ca2+ uptaking ion channel SERCA2a in AVS (p = 0.0013), though not in HOCM, compared to healthy tissue. Our data obtained from human specimen from AVS or HOCM indicates major alterations in the expression of the mitochondrial calcium uniporter complex and associated proteins. Thus, in cardiac septal hypertrophies, besides modifications of cytosolic calcium handling, impaired mitochondrial uptake might be a key player in disease progression.

Impact of concomitant replacement of the ascending aorta in patients undergoing aortic valve replacement on operative morbidity and mortality.

OBJECTIVES: The aim of this study was to evaluate the impact of concomitant ascending aortic replacement on operative morbidity and mortality in patients undergoing aortic valve replacement (AVR). METHODS: We retrospectively analysed our institutional database for all patients undergoing elective isolated AVR and AVR with concomitant replacement of the ascending aorta between January 2009 and May 2020. Patients undergoing surgery for infective endocarditis or requiring hypothermic circulatory arrest were excluded. A 3:1 propensity matching was performed for 688 patients to compare isolated AVR (120 patients) with AVR + ascending aortic replacement (40 patients). RESULTS: There were significant differences in median cardiopulmonary bypass (CPB) time [92.5 (75-114) vs 118.5 (104-131) min; P < 0.001], median aortic cross-clamp time [65.0 (51.5-78.5) vs 84.5 (77-94) min; P < 0.001] and median intensive care unit stay [1 (1-3) vs 2 (1-6) days; P < 0.01]. There was no significant difference in the use of intraoperative and postoperative blood products, re-exploration for bleeding, postoperative atrial fibrillation, acute renal failure, incidence of stroke, perioperative myocardial infarction and 30-day mortality. CONCLUSIONS: Concomitant replacement of the ascending aorta significantly prolongs CPB and aortic clamp times but does not increase operative morbidity and mortality. Therefore, replacement of a dilated ascending aorta appears to be the most durable and safest treatment option in patients undergoing AVR with an aneurysmatic ascending aorta.

Lower hemisternotomy: infrequently used but versatile.

BACKGROUND: A lower hemisternotomy is an infrequently used approach in cardiac surgery. This single center report evaluates applicability and clinical outcomes of procedures performed through a lower hemisternotomy. METHODS: The institutional database was reviewed. From 2014 to 2019, 55 consecutive patients had undergone minimally invasive procedures through a lower hemisternotomy (median follow-up 34 months). Demographic as well as outcome data were retrieved from our prospectively maintained institutional database. RESULTS: Performed procedures included mitral and tricuspid repairs, aortic valve replacement as well as coronary artery bypass grafting. The median patient age was 72 years. Out of the 55 patients, 55% were male. Predominantly mitral valve procedures (11 isolated, 30 combined) had been performed. Mitral valve procedures (N.=41) consisted of 36 repairs and 5 replacements. Repair rate for degenerative mitral insufficiency was 97.6%. Median EuroScore II was 3.4% (2.1-6.0). Median cross-clamp time was 67 (44-99) min. Median procedural length was 169 (138-201) min. Reoperation rate for bleeding was 1.8%. Major vascular complications occurred in two patients. Freedom from valve related reoperation was 96.1% during follow-up. Thirty-day mortality and overall mortality during follow-up was 3.6% and 10.9%. CONCLUSIONS: In properly selected cases the lower hemisternotomy allows for a variety of cardiac procedures. It permits central aortic cannulation and a direct vision of intracardiac structures and therefore should be kept in mind as an alternative minimally invasive approach.

An Alternative Approach to Build a "Biologic Bentall" From a Pericardial Tube and a Sutureless Valve.

This report describes a technique to create a biologic Bentall from a pericardial tube and a rapid deployment valve. This technique facilitates reimplantation of the coronary arteries because the proximal anastomosis is sewn before valve implantation and allows suturing of the coronary ostia from inside and outside, given that there is no interference with the implanted valve. Indications for this technique include complex redo cases and patients with contraindications to a conventional Bentall procedure. This technique has been used in 2 patients with good results.

Distal Stent Graft-Induced New Entries After the Frozen Elephant Trunk Procedure.

BACKGROUND: This study sought to evaluate the incidence of and identify risk factors for distal stent graft-induced new entries (dSINEs) after the frozen elephant trunk (FET) procedure. METHODS: Patient characteristics and radiographic and follow-up data on 126 patients treated for aortic dissections with the Thoraflex (Vascutek Ltd, Inchinnan, United Kingdom) FET device in 2 centers between November 2013 and December 2018 were evaluated. Stress-strain behavior and load-displacement curves of the Thoraflex and the E-Vita Open (Jotec Inc, Hechingen, Germany) FET prosthesis were evaluated by applying axial load to the most distal ring of the prostheses. RESULTS: dSINEs were diagnosed in 16 patients (13%). There was no difference in the underlying disease, aortic features, or FET stent graft dimension between patients with and without dSINEs. No predictors for dSINE occurrence in patients treated with the Thoraflex device were identified. The risk for dSINE development was 14% (95% confidence interval [CI], 0% to 22%), 16% (95% CI, 0% to 24%), and 25% (95% CI, 0% to 45%) after 12, 24, and 36 months, respectively. When prostheses were loaded axially to 2-mm maximal displacement, the Thoraflex prosthesis exhibited strongly nonlinear behavior with maximal stiffness for minimal displacements, whereas the E-Vita prosthesis showed nearly constant stiffness. In addition, the Thoraflex prosthesis showed an increase in stiffness when confined. CONCLUSIONS: dSINEs may develop at any time after the FET procedure, and the risk for dSINE development is high. No clinical or patient-specific risk factors were identified in this study. The design of the Thoraflex graft with a stiff distal ring may be a potential reason for the occurrence of dSINEs.

Multicentre experience with two frozen elephant trunk prostheses in the treatment of acute aortic dissection†.

OBJECTIVES: The aim of this study was to evaluate early- and mid-term outcome and aortic remodelling in patients undergoing implantation of 2 different frozen elephant trunk prostheses, either the Thoraflex™ hybrid (Vascutek, Inchinnan, UK) and the E-vita Open (Jotec Inc., Hechingen, Germany) for acute aortic dissection. METHODS: All consecutive patients [n = 88; median age 59 (49-67) years; 69% male] undergoing surgery with a frozen elephant trunk prosthesis for acute aortic dissection from August 2005 until March 2018 were included in this study. The Thoraflex™ device was implanted in 55 patients and the E-vita Open graft in 33 patients. RESULTS: Preoperative characteristics did not differ significantly between groups. There was also no statistically significant difference in postoperative outcome: in-hospital mortality (11% vs 12%; P > 0.99), stroke (18% vs 6%; P = 0.12) and spinal cord injury (6% vs 6%; P > 0.99). While there was no statistically significant difference in the occurrence of distal stent graft-induced new entries (16% vs 18%; P = 0.77), there was a significantly higher rate of secondary endovascular aortic interventions in the Thoraflex™ hybrid group (22% vs 0%; P = 0.003). There was a trend towards a higher rate of false lumen thrombosis at the level of the stent graft (74% vs 95%; P = 0.085) and was comparable at the thoraco-abdominal transition (53% vs 80%; P = 0.36) 1 year after implantation of the prostheses. CONCLUSIONS: In this comparison of 2 frozen elephant trunk prostheses, there is no evidence that different surgical techniques influence in-hospital outcome. At 1-year follow-up, patients who underwent implantation of the E-vita Open prosthesis showed a significantly reduced rate of secondary aortic interventions and a trend towards a higher rate of false lumen thrombosis which might be attributed to a longer coverage of the descending aorta due to a longer stent graft design and significantly more frequent implantation in zone 3.