The role of transesophageal echocardiography in the diagnosis and management of patients with aortic perivalvular abscesses

Aortic valve abscesses (AVAs) are a devastating complication of aortic valve endocarditis. Over 8 years, 25 patients were diagnosed with AVA by transesophageal echo (TEE). Management and outcomes were then analyzed. Eleven (44%) AVAs involved prosthetic valves, and 6 (24%) occurred in congenitally malformed valves. Twenty patients (80%) underwent surgical intervention; the rest were treated medically. Eleven (44%) of the patients died [6 (30%) surgery patients and all the medical patients]. Eight of 11 (73%) patients who died were culture positive for Staphylococcus aureus. All patients with congenitally malformed aortic valves underwent surgical intervention and survived. We conclude that: (1) despite advances in therapy and diagnosis, patients with AVAs have a high mortality rate; (2) prognosis with AVA is especially poor when S aureus is the infectious organism; (3) patients with AVAs in congenitally malformed valves have a great outcome with surgery; (4) patients treated medically have a very poor prognosis; earlier identification by TEE may be critical to improving survival.     

Influence of the first assistant on abdominal aortic aneurysm surgery

The hypothesis that the type of first assistant who attends the surgeon influences the course and outcome of graft replacement for abdominal aortic aneurysm was tested. Surgical results were analyzed in 179 consecutive patients (149 men and 30 women; mean age, 69 +/- 7.5 years). All the operations were performed by the author-an experienced surgeon with a practice limited to general vascular surgery. The choice of first assistant was based solely on availability; 110 (61%) patients had a board-certified surgeon as the first assistant and 69 (39%) had an experienced registered nurse as the first assistant. Patients with intact aneurysms undergoing elective surgery were in Group 1, and patients with intact aneurysms undergoing urgent surgery were in Group 2. Group 3 patients included those who had ruptured aneurysms but were hemodynamically stable, and Group 4 patients had ruptured aneurysms and were in shock. The distribution of patients was similar in each first-assistant group, as was the use of straight and bifurcated graft reconstructions, associated visceral procedures, and other adjunctive procedures. The hospital mortality was 4% (6/149) for Group 1 patients, 12% (2/17) for Group 2,20% (1/5) for Group 3, and 50% (4/8) for Group 4 patients. The morbidity and mortality rates were independent of the type of assistant, as were the operative time, blood loss, and adjusted blood transfusion volume. These results suggest that the choice of either an MD-surgeon or an experienced RN as first assistant does not influence the course or outcome of abdominal aortic aneurysm surgery.     

Cardiac score. A semiquantitative measure of cardiac involvement that improves prediction of prognosis in systemic sclerosis

Cardiac involvement, assessed yearly by a semiquantitative cardiac scoring technique (the sum of 2 variables, scored 0 or 1 for left axis deviation, and 0 or 2 for moderate-large pericardial effusion) and outcome at 10 years were evaluated in 90 systemic sclerosis (SSc) patients enrolled in a 3-year prospective drug trial. Higher cardiac scores were associated with decreased survival. The inverse relationship of survival with cardiac score was more significant than the relationship between survival and any of the cardiopulmonary variables individually (P less than 0.0000003). Predicted 6-year survival was 79% in patients with a cardiac score of 0, 51% in those with a score of 1, 15% in those with a score of 2, and 0% in those with a score of 3. We conclude that a simple 2-variable weighted cardiac score, derived from routine electrocardiography and echocardiography, is a useful predictor of survival in patients with SSc, and we propose that the application of this cardiac score be tested in other populations of SSc patients.     

Distal radial artery (snuffbox) access for carotid artery stenting – Technical pearls and procedural set-up

PurposeTo report use of distal radial artery (dRA) access for carotid artery stenting (CAS) and to discuss procedural setup and technical considerations for a successful intervention.MethodsA retrospective review of our prospective neurointerventional database of CAS was conducted between May 2019 and March 2020. All CAS cases via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data was collected.Results22 CAS procedures in 20 patients via dRA were identified. Patients’ mean age was 69.4 years (range 53–87 years). 3 patients were female. Mean radial artery diameter was 2.1 mm (range 1.6–2.8 mm). dRA access was achieved in all cases. Conversion to femoral access was required in 2 cases (9.1%) due to persistent radial artery vasospasm resulting in patient discomfort despite multiple additional doses of intraarterial vasodilators and added intravenous sedation as well as tortuous vessel anatomy and limited support of the catheters in a type 3 aortic arch for left CAS.ConclusionOur preliminary experience with dRA access for CAS suggests this approach to be feasible and safe for patients. Technical considerations are important and preprocedural planning is necessary for a successful intervention. Catheter systems and devices specifically designed for radial access are needed to enable more interventionalists to safely perform neurointerventional procedures via wrist access.     

A ligand-binding pocket in the dengue virus envelope glycoprotein

Dengue virus is an emerging global health threat. Its major envelope glycoprotein, E, mediates viral attachment and entry by membrane fusion. A crystal structure of the soluble ectodomain of E from dengue virus type 2 reveals a hydrophobic pocket lined by residues that influence the pH threshold for fusion. The pocket, which accepts a hydrophobic ligand, opens and closes through a conformational shift in a beta-hairpin at the interface between two domains. These features point to a structural pathway for the fusion-activating transition and suggest a strategy for finding small-molecule inhibitors of dengue and other flaviviruses.     

Genomic changes associated with antigenic variation of visna virus durig persistent infection.

Visna virus undergoes antigenic change during persistent infection of sheep. Antigenic variants of visna virus were compared by using the genomic RNA and analyzing the large RNase T1-resistant oligonucleotides. Mutants isolated from a persistently infected sheep contained a small number of changes in their oligonucleotide patterns when compared with parental virus. To determine whether the changes in the nucleotide structure were clustered in one region of the genome, we determined the order of the oligonucleotides of the parental and mutant RNAs along the genome with respect to the 3' polyadenylylated end. All but one difference between the parental strain and the antigenic mutant used for mapping were located within 2 kilobases from the 3' terminus. Nucleotide sequence analyses showed that several of the oligonucleotides that differed in the parental and mutant RNAs could be accounted for by single base changes.