Pathophysiological Factors Associated with Left Ventricular Perforation in Transcatheter Aortic Valve Implantation by Transfemoral Approach.

BACKGROUND AND AIM OF THE STUDY: Left ventricular (LV) perforation is one of the rare and most serious complications of transcatheter aortic valve implantation (TAVI). The study aim was to determine the pathophysiological factors associated with this serious complication. METHODS: A retrospective study was conducted of pathophysiological factors shown in echocardiograms and computed tomography angiograms performed preoperatively in patients who developed LV perforation during transfemoral TAVI (study group) with regards to anatomic and functional variables. Results were then compared with data acquired from a randomly selected sample of patients without perforation (control group). Among 963 TAVI cases, LV perforation occurred in 11 patients (three males, eight females; mean age 79 years). These patients showed complications of LV perforation that required emergency sternotomy and repair of injury to the left ventricle. Ten patients were rescued by the procedure, but one patient died during surgery. RESULTS: Focus on preoperative factors and intraoperative steps was established in favor to identify possible predictors of LV perforation. A LV cavity size <4.2 cm and a hypercontractile ventricle were identified in 10 patients (90%). Only one patient had a dilated cardiomyopathic left ventricle, with a cavity size of 6.1 cm and an ejection fraction of 10%. The present study results revealed other specific patient-related factors, namely a narrow aorto-mitral angle and a thin ventricular muscular wall despite long-standing aortic stenosis. All 11 patients had an average mid-LV muscular wall thickness of 5 mm. An inverse proportional relationship between the aorto-mitral angle and the incidence of perforation was noted, where in all 11 patients the wire had directed itself towards the anterior free wall of the left ventricle, where it induced injury. CONCLUSIONS: A small LV cavity, a hypercontractile state, a thin muscular wall, and a narrow aorto-mitral angle may be considered potential predictors of the occurrence of LV perforation during TAVI.

Anticoagulation After Biological Aortic Valve Replacement: Is There An Optimal Regimen?

BACKGROUND: The anticoagulation of biological heart valves remains a 'hot spot' of discussion in various domains due to the risk of developing valve thrombosis and arterial thromboembolism. The situation has always been controversial, especially during the early postoperative phase. The American College of Cardiology/ American Heart Association and European Society of Cardiology guidelines recommend the use of warfarin for the first three months after biological aortic valve replacement (BAVR), although the American College of Chest Physicians guidelines suggest that these recommendations are experience-based and that the risk/benefit is unclear. The aim of the present study was to compare the efficacy of aspirin and warfarin in patients after BAVR. METHODS: A total of 863 patients who underwent BAVR between 2008 and 2015 was allocated to two groups. Each group was managed with a specific anticoagulation regimen, with 430 patients receiving warfarin during the first three postoperative months, and 433 receiving aspirin. The major study end points were bleeding, cerebral ischemic events, and survival. RESULTS: In total, 10 and 15 postoperative cerebral ischemic events occurred between 24 h and three months after surgery in patients treated with aspirin and warfarin, respectively. After three months the incidence of cerebral ischemic events did not differ greatly between the two groups. The rate of major bleeding events and rates of stroke-free survival and overall survival were not statistically significant between the warfarin and aspirin groups. CONCLUSIONS: Plasma anticoagulation with warfarin during the early postoperative phase was shown statistically to be inferior to platelet aggregation inhibition by aspirin with regards to postoperative bleeding risk, cerebral ischemic events, and survival.

Transcatheter Aortic Valve Replacement Without the Use of Contrast Medium: An Alternative Safe Implantation Technique.

BACKGROUND: New transcatheter equipment and accumulated experience have stimulated further refinements in implantation techniques. We aimed to compare the outcomes of transfemoral transcatheter aortic valve replacement (TF-TAVR) with and without the use of contrast medium (CM) in patients with glomerular filtration rate (GFR) <30 mL/min/1.73 m². METHODS: This single-center, retrospective study included all patients who underwent TF-TAVR procedure with Edwards Sapien balloon-expandable bioprostheses between September 2017 and September 2018 at the Zentralklinik Bad Berka Germany, and compared outcomes of TF-TAVR with and without the use of CM. RESULTS: A total of 98 consecutive patients were included in this study; 25 patients underwent TF-TAVR without the use of CM and 73 patients underwent TF-TAVR with the use of CM. Acute kidney injury was significantly higher in patients who received CM (15 patients [20.5%] in the control group vs 1 patient [4%] in the study group; P=.04). Other procedure-related complications were equally distributed between both groups. CONCLUSION: TF-TAVR without the use of CM can be considered a safe and reproducible alternative technique. Furthermore, it reduced the incidence of postoperative acute kidney injury in patients with GFR <30 mL/min/1.73 m².

The role of melanin as protector against free radicals in skin and its role as free radical indicator in hair.

Throughout the body, melanin is a homogenous biological polymer containing a population of intrinsic, semiquinone-like radicals. Additional extrinsic free radicals are reversibly photo-generated by UV and visible light. Melanin photochemistry, particularly the formation and decay of extrinsic radicals, has been the subject of numerous electron spin resonance (ESR) spectroscopy studies. Several melanin monomers exist, and the predominant monomer in a melanin polymer depends on its location within an organism. In skin and hair, melanin differs in content of eumelanin or pheomelanin. Its bioradical character and its susceptibility to UV irradiation makes melanin an excellent indicator for UV-related processes in both skin and hair. The existence of melanin in skin is strongly correlated with the prevention against free radicals/ROS generated by UV radiation. Especially in the skin melanin (mainly eumelanin) ensures the only natural UV protection by eliminating the generated free radicals/ROS. Melanin in hair can be used as a free radical detector for evaluating the efficacy of hair care products. The aim of this study was to investigate the suitability of melanin as protector of skin against UV generated free radicals and as free radical indicator in hair.

Ultrasound-guided central venous cannulation: is there a difference between Doppler and B-mode ultrasound?

STUDY OBJECTIVE: To compare the success of Doppler and B-mode ultrasound-guided internal jugular vein (IJV) catheterization with respect to body mass index (BMI). STUDY DESIGN: Prospective, randomized study. SETTING: Section for cardiovascular anesthesia of a university hospital. PATIENTS: 338 consenting patients were analyzed. INTERVENTIONS: Subjects receiving central venous catheters for scheduled cardiac surgery were divided into two groups. After induction of general anesthesia, the right or left IJV was assessed for midcervical cannulation approach. In the Doppler group (n = 189), a SonoGuide2 with a 5.0-MHz probe was used. In the B-mode group (n = 149), the SiteRite II ultrasound system with a 7.5-MHz transducer was used. MEASUREMENTS AND MAIN RESULTS: There was a significant difference in the success rate of first needle pass between the two groups: Doppler group, 91% (172/189); B-mode group, 96.6% (144/149) (P = 0.045). A BMI of 30 and greater was associated with a significantly lower first needle pass success rate in the Doppler group (Doppler group, 77.1% [27/35]; B-mode group, 97.4% [38/39]; P = 0.011). The success rates in patients with a BMI below 30 for both methods were not different (Doppler group, 94.2% [145/154]; B-mode group, 96.4% [106/110]; P = 0.567). Arterial punctures occurred three times under Doppler guidance and twice under B-mode guidance. CONCLUSION: Cannulation of the IJV can be ensured and first needle pass success rate maximized by both ultrasound techniques. In patients with a BMI greater than 30, B-mode technique is superior to Doppler ultrasound.

HPLC analysis of vitamin E isoforms in human epidermis: correlation with minimal erythema dose and free radical scavenging activity.

The content and composition of different vitamin E isoforms was analyzed in normal human skin. Interestingly the epidermis contained 1% alpha-tocotrienol, 3% gamma-tocotrienol, 87% alpha-tocopherol, and 9% gamma-tocopherol. Although the levels of tocotrienol in human epidermis appear to be considerably lower than reported in the hairless mouse, the presence of significant amounts of tocotrienol levels leads to speculation about the physiological function of tocotrienols in skin. Besides antioxidant activity and photoprotection, tocotrienols may have skin barrier and growth-modulating properties. A good correlation was found for epidermal alpha-tocopherol (r = 0.7909, p <.0003), gamma-tocopherol (r = 0.556, p <.025), and the total vitamin E content (r = 0.831, p <.0001) with the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging in epidermis, as assessed by electron paramagnetic resonance (EPR) spectroscopy. In human epidermis, alpha-tocopherol is quantitatively the most important vitamin E isoform present and comprises the bulk of first line free radical defense in the lipid compartment. Epidermal tocotrienol levels were not correlated with DPPH scavenging activity. The minimal erythema dose (MED), an individual measure for sun sensitivity and a crude indicator for skin cancer susceptibility, did not correlate with the epidermal content of the vitamin E isoforms. Hence it is concluded that vitamin E alone is not a determinant of individual photosensitivity in humans.

Kinetic measurements using EPR imaging with a modulated field gradient.

EPR imaging with modulated field gradient was applied for the investigation of fast diffusion processes. Three different imaging methods are possible: spectral-temporal, spatio-temporal, and spectral-spatial imaging. The time resolution is on the order of seconds and the spatial resolution is in the micrometer region. The efficiency of this imaging technique is demonstrated for the penetration of the spin probe Tempol in the skin of hairless mice biopsies. The skin is normally protected against the penetration of water soluble substances by the horny layer, a resistive thin lipophilic layer. Overcoming this horny layer for water soluble ingredients is one of the main practical problems for the topical application of pharmaceutics which could be investigated by EPR imaging. Different images represent the penetration behavior of the water soluble Tempol in the skin after treatment with the penetration enhancer DMSO (Dimethylsulfoxide) and after removing the horny layer.

Morbidity risk in HFE associated hereditary hemochromatosis C282Y heterozygotes.

Hereditary hemochromatosis (HHC) is a late-onset, autosomal recessive disorder leading to a chronic iron overload syndrome, finally causing diabetes, cardiomyopathy and liver disease. HHC is the most common single gene disorder in northern Europeans that occurs with a frequency of approximately 0.5%, and most of these patients carry the C282Y and H63D mutation in the HFE gene on chromosome 6p21.3. The vast majority of HHC patients are homozygous for the C282Y mutation, but HHC phenotypes are observed in other genotypes. Expression of the disease, in those homozygous for the C282Y mutation, is highly variable depending on the various features of the population studied. C282Y heterozygotes have slightly increased iron stores and in absence of other genetic and/or environmental factors do usually not develop the HHC phenotype. It is currently a matter of debate whether C282Y heterozygotes may have an increased risk for morbidity. Different studies investigating the association of C282Y heterozygocity with morbidity have given conflicting results, as is exemplified by extrahepatic cancers, cardiovascular diseases, alcoholic liver disease, and diabetes. However, there are examples of clear and unambiguous disease associations, such as with sporadic pophyria cutanea tarda. It remains to be seen whether a strong correlation between the C282Y heterozygous state and distinct pathological conditions will exist and large-scale genotyping studies will help to identify such potential risk groups in the future.