Julia Dumfarth

Mechanisms of Failure and Outcome of Secondary Surgical Interventions After Thoracic Endovascular Aortic Repair (TEVAR)

BACKGROUND We evaluated mechanisms of failure and outcome of secondary surgical interventions after thoracic endovascular aortic repair (TEVAR). METHODS Between 1996 and 2009, 421 patients underwent TEVAR for the following indications: atherosclerotic aneurysms, type B dissections, penetrating ulcers and traumatic lesions. RESULTS Twenty-one patients underwent secondary surgical interventions. Indications were type I endoleak formation, retrograde type A dissection, distal aneurysm formation as well as infection. Retrospectively, by analysing referral computed tomography scans and by current knowledge, failure could have been foreseen in 72% of patients. Median interval to secondary surgical intervention was 24 months (IQR 8-40). Sixteen patients underwent thoracic or thoracoabdominal repair and five patients underwent ascending and hemiarch replacement. In-hospital mortality was 19%. Cause of death was multiorgan failure in all cases. CONCLUSIONS The need for secondary surgical intervention after TEVAR is low but carries risk. By analysing mechanisms of failure, the majority of these events could have been avoided by a more strict indication. Thereby, further critical evaluation and respecting limitations of TEVAR will help to reduce the need for these operations.

A New Mechanism by Which an Acute Type B Aortic Dissection Is Primarily Complicated, Becomes Complicated, or Remains Uncomplicated

BACKGROUND This study is to evaluate if different locations of the primary entry tear result in primary complicated, secondary complicated, or uncomplicated acute type B aortic dissection. METHODS Sixty-five patients were analyzed. Patients were stratified according to the location of the primary entry tear. Primary entry tears in axial computed tomographic scans at the upper circumference (180°) of the distal aortic arch were defined as convex (group A) and the remaining as concave (group B). Detailed morphometry was done and the clinical outcome, including need for thoracic endovascular aortic repair, was evaluated. RESULTS Forty-two patients (group A) had the primary entry tear at the convexity and 23 patients (group B) had the primary entry tear at the concavity of the distal aortic arch. There was a significant difference with regard to the incidence of primary complicated type B aortic dissection (group A 21% vs group B 61%, p = 0.003) and with regard to the development of complications in group A (9 days; 9 to 37) versus group B (0 days; 0 to 13, p = 0.03). Cox regression analysis revealed a primary entry tear at the concavity to be the only independent predictor of primary or secondary development of a complicated acute type B aortic dissection (hazard ratio, 1.8; 95% confidence interval, 1.0 to 3.2). CONCLUSIONS A primary entry tear at the concavity of the distal aortic arch is associated with a significant increase of the occurrence of complicated acute type B aortic dissection. Due to low procedural risk and high success rates, closure of the primary entry tear with thoracic endovascular aortic repair is strongly recommended in this newly defined high-risk subgroup of patients.

Long-term results of thoracic endovascular aortic repair in atherosclerotic aneurysms involving the descending aorta

OBJECTIVE This study evaluated long-term results of thoracic endovascular aortic repair for atherosclerotic aneurysms involving descending aorta. METHODS One hundred thirteen patients underwent thoracic endovascular aortic repair for this indication from 1996 to 2009. Mean follow-up was 54 ± 38 months (5-144 months). In-hospital mortality, neurologic injury, need for rerouting, occurrence of endoleaks and their treatment, and survival were recorded. RESULTS In-hospital mortality was 5.3%. Transient neurologic injury rate was 2.6%. Previous rerouting was performed in 51%. Assisted early and late type I and III endoleak rates were 7.9% and 5.7%, respectively. Five percent of patients required late surgical conversion. Actuarial survivals were 86%, 60%, and 42% at 1, 5, and 10 years, respectively. Aorta-related actuarial survivals were 94%, 90%, and 83% at 1, 5, and 10 years, respectively. Cox regression analysis revealed higher number of prostheses as independent risk factor for early (hazard ratio, 5.38; 95% confidence interval, 1.68-42.37) and late (hazard ratio, 8.49; 95% confidence interval, 1.09-66.06) endoleak formation. Female sex (hazard ratio, 0.35; 95% confidence interval, 0.13-0.99), no arch involvement (hazard ratio, 0.21; 95% confidence interval, 0.05-0.08), and higher number of prostheses (hazard ratio, 7.95; 95% confidence interval, 1.36-46.58) affected survival. CONCLUSIONS Aorta-related survival is excellent among patients undergoing thoracic endovascular aortic repair for atherosclerotic aneurysms involving the descending aorta. Life-long surveillance remains mandatory, with early and late failure uncommon but still needing consideration. Thoracic endovascular aortic repair in this group of patients remains attractive and has now proven durability.

Direct epicardial shock wave therapy improves ventricular function and induces angiogenesis in ischemic heart failure

OBJECTIVES Direct application of low-energy unfocused shock waves induces angiogenesis in ischemic soft tissue. The potential effects of epicardial shock wave therapy applied in direct contact to ischemic myocardium are uncertain. METHODS For induction of ischemic heart failure in a rodent model, a left anterior descending artery ligation was performed in adult Sprague-Dawley rats. After 4 weeks, reoperation with (treatment group, n = 60) or without (control group, n = 60) epicardial shock wave therapy was performed. Low-energy shock waves were applied in direct contact with the infarcted myocardium (300 impulses at 0.38 mJ/m(2)). Additionally, healthy animals (n = 30) with normal myocardium were studied. Angiogenesis, ventricular function upregulation of growth factors, and brain natriuretic peptide levels were analyzed. RESULTS Histologic analysis revealed significant angiogenesis 6 weeks (treatment group: 8.2 +/- 3.7 vs control group: 2.9 +/- 1.9 vessels per field, P = .016) and 14 weeks (treatment group: 7.1 +/- 3.1 vs control group: 3.2 +/- 1.8 vessels per field, P = .011) after shock wave treatment. In the treatment group ventricular function improved throughout the follow-up period (6 weeks: 37.4% +/- 9% [P < .001] and 14 weeks: 39.5% +/- 9% [P < .001]). No improvement of ventricular function was observed in the control group (6 weeks: 28.6% +/- 5% and 14 weeks: 21.4% +/- 5%). Rat brain natriuretic peptide 45 levels were lower in the treatment group compared with those in the control group 6 and 14 weeks after treatment. Vascular endothelial growth factor, Fms-related tyrosine kinase 1, and placental growth factor levels were upregulated after 24 and 48 hours and 7 days in the treatment group. No effects on healthy myocardium were observed. CONCLUSION Direct epicardial low-energy shock wave therapy induces angiogenesis and improves ventricular function in a rodent model of ischemic heart failure.

Midterm Results of Thoracic Endovascular Aortic Repair in Patients With Aneurysms Involving the Descending Aorta Originating From Chronic Type B Dissections

BACKGROUND Midterm results of TEVAR (thoracic endovascular aortic repair) in patients with aneurysms involving the descending aorta originating from chronic type B dissections are not known. METHODS Between 2004 and 2009, 14 patients with a median age of 63 years (79% male) with this pathology were treated. Seven patients underwent supraaortic transpositions in various extents prior to TEVAR in order to gain a sufficient proximal landing zone. RESULTS Median time from dissection to treatment was 19 months (4 to 84 months). All patients had an uneventful in-hospital course. The median covered length of the aortic arch and descending aorta was 190 mm (100 to 250 mm). Primary success rate defined as absence of type Ia endoleakage was 86%. No patient, where visceral or renal vessels originated from the false or from both lumina sustained ischemic injury by TEVAR. The median follow-up period is 34 months to date (6 to 64 months). Aortic-related morbidity and mortality during follow-up was low (14%). CONCLUSIONS Midterm results of TEVAR in patients with aneurysms involving the descending aorta originating from chronic type B dissections are good. The self-expanding capability of the stent grafts is sufficient over time. However, extensive coverage of the descending aorta is warranted to achieve success. Further studies are needed to extend our knowledge in this particular subgroup of patients.

Prophylactic Low-Energy Shock Wave Therapy Improves Wound Healing After Vein Harvesting for Coronary Artery Bypass Graft Surgery: A Prospective, Randomized Trial

BACKGROUND Wound healing disorders after vein harvesting for coronary artery bypass graft surgery increase morbidity and lower patient satisfaction. Low-energy shock wave therapy (SWT) reportedly improves healing of diabetic and vascular ulcers by overexpression of vascular endothelial growth fractor and downregulation of necrosis factor kappaB. In this study, we investigate whether prophylactic low-energy SWT improves wound healing after vein harvesting for coronary artery bypass graft surgery. METHODS One hundred consecutive patients undergoing coronary artery bypass graft surgery were randomly assigned to either prophylactic low-energy SWT (n = 50) or control (n = 50). Low-energy SWT was applied to the site of vein harvesting after wound closure under sterile conditions using a commercially available SWT system (Dermagold; Tissue Regeneration Technologies, Woodstock, GA). A total of 25 impulses (0.1 mJ/mm(2); 5 Hz) were applied per centimeter wound length. Wound healing was evaluated and quantified using the ASEPSIS score. (ASEPSIS stands for Additional treatment, presence of Serous discharge, Erythema, Purulent exudate, Separation of the deep tissue, Isolation of bacteria, and duration of inpatient Stay). Patient demographics, operative data, and postoperative adverse events were monitored. RESULTS Patient characteristics and operative data including wound length (SWT 39 +/- 13 cm versus control 37 +/- 11 cm, p = 0.342) were comparable between the two groups. We observed lower ASEPSIS scores indicating improved wound healing in the SWT group (4.4 +/- 5.3) compared with the control group (11.6 +/- 8.3, p = 0.0001). Interestingly, we observed a higher incidence of wound healing disorders necessitating antibiotic treatment in the control group (22%) as compared with the SWT group (4%, p = 0.015). No SWT-associated adverse events were observed in the treatment group. CONCLUSIONS As shown in this prospective randomized study, prophylactic application of low-energy SWT improves wound healing after vein harvesting for coronary artery bypass graft surgery.

Treatment of Symptomatic Coral Reef Aorta by Endovascular Stent-Graft Placement

We report 2 patients who were referred for treatment of hemodynamically significant symptomatic stenosis of the aorta at the thoracoabdominal transition (coral reef aorta) that was causing abdominal angina and intermittent claudication. Both patients underwent successful transfemoral endovascular stent-graft placement and are free of symptoms, with regular findings at 6-month follow-up completion computed tomography scan.

Atypical aortic arch branching variants: A novel marker for thoracic aortic disease

OBJECTIVE To examine the potential of aortic arch variants, specifically bovine aortic arch, isolated left vertebral artery, and aberrant right subclavian artery, as markers for thoracic aortic disease (TAD). METHODS We screened imaging data of 556 patients undergoing surgery due to TAD for presence of aortic arch variations. Demographic data were collected during chart review and compared with a historical control group of 4617 patients. RESULTS Out of 556 patients with TAD, 33.5% (186 patients) demonstrated anomalies of the aortic arch, compared with 18.2% in the control group (P < .001). Three hundred seventy (66.5%) had no anomaly of the aortic arch. Bovine aortic arch emerged as the most common anomalous branch pattern with a prevalence of 24.6% (n = 137). Thirty-five patients (6.3%) had an isolated left vertebral artery, and 10 patients (1.8%) had an aberrant right subclavian artery. When compared with the control group, all 3 arch variations showed significant higher prevalence in patients with TAD (P < .001). Patients with aortic aneurysms and anomalous branch patterns had hypertension less frequently (73.5% vs 81.8%; P = .048), but had a higher rate of bicuspid aortic valve (40.8% vs 30.6%; P = .042) when compared with patients with aneurysms but normal aortic arch anatomy. Patients with aortic branch variations were significantly younger (58.6 ± 13.7 years vs 62.4 ± 12.9 years; P = .002) and needed intervention for the aortic arch more frequently than patients with normal arch anatomy (46% vs 34.6%; P = .023). CONCLUSIONS Aortic arch variations are significantly more common in patients with TAD than in the general population. Atypical branching variants may warrant consideration as potential anatomic markers for future development of TAD.

Indications and imaging for aortic surgery: size and other matters.

OBJECTIVES To review the current general concepts and understanding of the natural history of thoracic aortic aneurysm and their clinical implications. METHODS Data on the the normal thoracic aortas were derived from the database of the Multi-Ethnic Study of Atherosclerosis (n = 3573), representative of the general population. Data on diseased thoracic aorta were derived from the database of the Aortic Institute at Yale-New Haven Hospital (n = 3263), representative of patients with thoracic aortic aneurysm and dissection. RESULTS Our studies have shown that the normal aorta in the general population is small (3.2 cm for the ascending aorta). Aortas larger than 5 cm are rare in the real world. The aneurysmal aorta grows at a mean of 0.2 cm/y, and larger aneurysms grow faster than do smaller ones. The dissection size paradox (which shows some aortic dissections occurring at small aneurysm sizes) is explained by the huge number of patients with small aortas in the general population. Genetic testing of patients with thoracic aortic disease helps identify genes responsible for aortic aneurysm and dissection. New imaging techniques such as 4-dimensional magnetic resonance imaging may add engineering data to our decision making. CONCLUSIONS Size continues to be a strong predictor of natural complications and a suitable parameter for intervention. As we enter the era of personalized aneurysm care, it is likely that specific genetic mutations will facilitate the determination of the appropriate size criterion for surgical intervention in individual cases.

Symptomatic spinal cord malperfusion after stent-graft coverage of the entire descending aorta

OBJECTIVE The study aims to identify risk constellations for symptomatic spinal cord malperfusion in patients undergoing extensive stent-graft coverage of the thoracic aorta. METHODS From 1997 through 2009, 26 patients (mean age 70 years) underwent extensive stent-graft coverage of the thoracic aorta. Indications for stent-graft placement were atherosclerotic aneurysms (n=18) and penetrating atherosclerotic ulcers (PAUs) (n=8). In 16 patients, a re-routing procedure was required to gain sufficient proximal landing zone length. Cerebrospinal fluid (CSF) drainage was not routinely applied owing to the necessity of maintaining continuing anti-platelet therapy due to severe cardiovascular co-morbidities. RESULTS Technical success was 100%. Five patients developed symptomatic spinal cord malperfusion. All symptomatic patients had impaired spinal cord blood supply by acute or chronic occlusion of at least two major blood-supplying vascular territories of the spinal cord. Secondary CSF drainage improved neurologic symptoms in all patients without causing any anti-platelet therapy-related collateral injury. CONCLUSIONS Extensive stent-graft coverage of the entire thoracic aorta can be performed with a high rate of success. If collateral blood supply to the spinal cord is maintained, occlusion of the intercostal arteries does not cause symptomatic malperfusion. However, if acute or chronic occlusion of the subclavian, lumbar or hypogastric arteries is present, likelihood of symptomatic malperfusion dramatically increases.