The correlation of age and extension length in DeBakey type I aortic dissection: are older patients over 70 years at a lower risk?

OBJECTIVES: Age-related atherosclerosis has been shown to cause aortic stiffness and wall rigidification. This analysis aimed to correlate age and dissection extension length in a large contemporary multicentre study. We hypothesize that younger patients suffer more extensive DeBakey type I dissection due to aortic wall integrity, allowing unhindered extension within the layers. METHODS: The perioperative data of 3385 patients from the German Registry for Acute Aortic Dissection Type A were retrospectively analyzed with regard to postoperative outcomes and dissection extension. Patients with DeBakey type I aortic dissection (n = 2510) were retrospectively identified and divided into 2 age groups for comparison: ≤69 years (n = 1741) and ≥70 years (n = 769). Patients with DeBakey type II dissection or connective tissue disease were excluded from the analysis. RESULTS: In younger patients (≤69 years), aortic dissection involved the supra-aortic vessels significantly more often (52.0% vs 40.1%; P < 0.001) and extended significantly further downstream the aorta: descending aorta (68.4% vs 57.1%; P < 0.001), abdominal aorta (54.6% vs 42.1%; P < 0.001) and iliac bifurcation (36.6% vs 26.0%; P < 0.001). Consequently, younger patients also presented with significantly higher incidences of preoperative cerebral (P < 0.001), spinal (P < 0.001), visceral (P < 0.001), renal (P = 0.013) and peripheral (P < 0.001) malperfusion. In older patients (≥70 years), dissection extent was significantly more often limited to the level of the aortic arch (40.9% vs 29.2%; P < 0.001). No significant difference was found with regard to 30-day mortality (20.7% vs 23.6%; P = 0.114). CONCLUSIONS: Extensive DeBakey type I aortic dissection is less frequent in older patients ≥70 years than in younger patients. In contrast, younger patients suffer more often from preoperative organ malperfusion and associated complications. Postoperative mortality remains high irrespective of age groups.

The TLR7/8 ligand resiquimod targets monocyte-derived dendritic cell differentiation via TLR8 and augments functional dendritic cell generation.

Imidazoquinolone compounds, such as resiquimod are Toll-like receptor (TLR) 7/8 ligands representing novel immune response modifiers undergoing clinical testing. Resiquimod has been reported to modulate conventional human monocyte-derived DC (moDC) differentiation, but the role of TLR7 and TLR8 is unclear. We directly dissected the TLR7- and TLR8-dependency by employing selective TLR7 ligands and resiquimod-coculture experiments with inhibitory oligonucleotides (iODN) suppressing TLR7, TLR7+8 or TLR7+8+9. Selective TLR7 ligands did not affect conventional moDC differentiation as analyzed by CD14/CD1a expression. iODN experiments confirmed that resiquimod's effects during DC differentiation were antagonized only with TLR8 iODNs. Direct comparison of resiquimod DC with TLR7- and control-DC revealed significantly higher T-cell costimulatory molecule and MHC class II expression. Resiquimod DC promoted significantly stronger allogeneic T-cell proliferation and stronger naïve CD4(+) T-cell proliferation. These results indicate the relevance of TLR8 for human monocyte-derived DC differentiation and maturation and may be relevant for clinical trials employing resiquimod.

Thoracic surgical procedures supported by a pumpless interventional lung assist.

BACKGROUND: For support of pulmonary function during complex thoracic surgical procedures, especially in respiratory compromised patients, a pumpless interventional lung assist (iLA) was applied. Feasibility and effectiveness for this novel indication were evaluated. METHODS: Ten patients underwent thoracic surgery with respiratory support by iLA. Indication for iLA application was the need for intraoperative prolonged discontinuation of ventilation (tracheal surgery and lung resections after pneumonectomy [n = 6], and emergency procedures in patients with acute respiratory failure [n = 4]. The pumpless extracorporeal system was inserted percutaneously into the femoral blood vessels before surgery. Blood flow through the iLA, cardiac output, and gas exchange were monitored. RESULTS: In all patients, the surgical procedure was successfully performed because of the support by the pumpless iLA. Mean blood flow across the iLA was 1.58 +/- 0.3 L/min (1.2 L/min to 2.2 L/min). Low-dose norepinephrine was required to maintain sufficient systemic blood pressure. There was a moderate improvement in oxygenation (49 mL/min transfer of O(2)) and a very efficient elimination of carbon dioxide (121 mL/min transfer of CO(2)). Thus, extended periods of apneic oxygenation were possible during surgery. The device was removed immediately after surgery in 6 patients. In 4 patients with severe respiratory insufficiency, the iLA was continued for a mean of 6.8 days to allow for protective postoperative ventilation. CONCLUSIONS: The application of pumpless iLA was hemodynamically well tolerated, and allowed for safe procedures in respiratory compromised patients, avoiding the application and consequences of cardiopulmonary bypass or pump-driven extracorporeal membrane oxygenation.

The metabolic and renal effects of adrenaline and milrinone in patients with myocardial dysfunction after coronary artery bypass grafting.

INTRODUCTION: Myocardial dysfunction necessitating inotropic support is a typical complication after on-pump cardiac surgery. This prospective, randomized pilot study analyzes the metabolic and renal effects of the inotropes adrenaline and milrinone in patients needing inotropic support after coronary artery bypass grafting (CABG). METHODS: During an 18-month period, 251 patients were screened for low cardiac output upon intensive care unit (ICU) admission after elective, isolated CABG surgery. Patients presenting with a cardiac index (CI) of less than 2.2 liters/minute per square meter upon ICU admission - despite adequate mean arterial (titrated with noradrenaline or sodium nitroprusside) and filling pressures - were randomly assigned to 14-hour treatment with adrenaline (n = 7) or milrinone (n = 11) to achieve a CI of greater than 3.0 liters/minute per square meter. Twenty patients not needing inotropes served as controls. Hemodynamics, plasma lactate, pyruvate, glucose, acid-base status, insulin requirements, the urinary excretion of alpha-1-microglobuline, and creatinine clearance were determined during the treatment period, and cystatin-C levels were determined up to 48 hours after surgery (follow-up period). RESULTS: After two to four hours after ICU admission, the target CI was achieved in both intervention groups and maintained during the observation period. Plasma lactate, pyruvate, the lactate/pyruvate ratio, plasma glucose, and insulin doses were higher (p < 0.05) in the adrenaline-treated patients than during milrinone or control conditions. The urinary excretion of alpha-1-microglobuline was higher in the adrenaline than in the control group 6 to 14 hours after admission (p < 0.05). No between-group differences were observed in creatinine clearance, whereas plasma cystatin-C levels were significantly higher in the adrenaline than in the milrinone or the control group after 48 hours (p < 0.05). CONCLUSION: This suggests that the use of adrenaline for the treatment of postoperative myocardial dysfunction - in contrast to treatment with the PDE-III inhibitor milrinone - is associated with unwarranted metabolic and renal effects.