Management and Outcome of Non-Aneurysmal Primary Aortic Infection.

INTRODUCTION: Aortic infection without prior intervention or aneurysm is exceedingly rare. We report the presentation, diagnosis, management, and outcome of patients with this unusual entity. METHODS: Retrospective chart and imaging review of patients with primary aortic infection. RESULTS: 5 patients (3 male, mean age 71.2 years) presented between 2014 and 2022. All had abdominal, back, or flank pain. Four had constitutional symptoms. All were evaluated with a complete blood count; 3 had leukocytosis. Both serum C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were elevated in the 4 patients evaluated with these tests. All were studied with peripheral blood culture on the first hospital day prior to any antibiotic administration. Blood culture was positive in only 1 patient. Computed tomography (CT) scan showed periaortic inflammation without aneurysm in all. Fluorodeoxyglucose positron emission tomography (PET) was obtained in 3 and a radiolabeled leukocyte single-photon emission CT (SPECT) scan was performed in 2. All demonstrated periaortic concentration of the radioisotope consistent with inflammation or infection. Intraoperative cultures were positive in 3. One patient who had a negative intraoperative culture was examined with broad range polymerase chain reaction (PCR) and DNA sequencing which identified a causative bacterium. The other patient with a negative intraoperative culture had periaortic abscess but was on antibiotics preoperatively, potentially confounding the culture. All patients underwent in-situ repair with rifampin impregnated polyester (N = 2), cryopreserved aortic allograft (N = 2), or autogenous femoral vein (N = 1). No patient developed recurrent infection or aortic related complications following surgery with an average follow up of 31.8 months (range 8-88 months). CONCLUSIONS: Patients with primary aortic infection present similarly with the triad of abdominal or back pain, laboratory markers of infection, and imaging demonstrating periaortic inflammation. Patients were treated successfully with in-situ repair. Preoperative identification of a causative organism was difficult, and PCR may be useful to help identify an organism.

Outcomes of great vessel debranching to facilitate thoracic endovascular aortic repair.

OBJECTIVE: With the expanding application of endovascular technology, the need to deploy into zone 0 has been encountered on occasion. In the present study, we evaluated the outcomes of great vessel debranching (GVD) as a method of extending the proximal landing zone to facilitate thoracic endovascular aortic repair (TEVAR). METHODS: We performed a single-center retrospective review of all patients who had undergone GVD followed by TEVAR between May 2013 and December 2020. The primary outcome was primary patency of all targeted vessels, with all-cause perioperative mortality as a secondary outcome. Kaplan-Meier analysis was used to account for censoring of mortality and primary patency. The extent of hybrid aortic repairs was characterized into type I (GVD plus TEVAR without ascending aorta or aortic arch reconstruction, type II (GVD plus TEVAR with ascending aorta reconstruction), and type III (GVD plus TEVAR with ascending aorta and aortic arch reconstruction with an elephant trunk (soft [surgical] or frozen [endovascular]]). RESULTS: A total of 42 patients (23 men [54.8%]; mean age, 62.2 ± 11.2 years) had undergone GVD, with 122 vessels revascularized (42 innominate, 42 left common carotid, and 38 left subclavian arteries). The indication for TEVAR was aneurysmal degeneration from aortic dissection in 32 patients (76.2%), a thoracic aneurysm in 9 patients (21.4%), and a perforated aortic ulcer in 1 patient (2.4%). The median duration between GVD and TEVAR was 82 days. The mean follow-up period was 25.7 ± 23.5 months. Type I repair was performed in 4, type II in 16, and type III in 22 patients. The perioperative mortality, stroke, and paraplegia rates were 9.5%, 7.1%, and 2.4%, respectively. Neither the extent of repair (P = .80) nor a history of aortic repair (P = .90) was associated with early mortality. Of the 38 patients who had survived the perioperative period, 6 had died >30 days postoperatively. At 36 months, the survival estimate was 68.6% (95% confidence interval, 45.7%-83.4%). The overall primary patency of the innominate artery, left common carotid artery, and left subclavian artery was 100%, 89.5%, and 94.1%, respectively. The primary-assisted patency rate was 100% for all the vessels. CONCLUSIONS: We found GVD to be a safe and effective method of extending the proximal landing zone into zone 0 with outstanding primary patency rates. Further studies are required to confirm the safety and longer term durability for these patients.

Balloon dilation strategy does not affect outcomes for transcarotid artery revascularization in prospective trials.

OBJECTIVES: Strategies of balloon dilation during transfemoral carotid artery stenting include prestent dilation only (PRE), post-stent dilation only (POST), or both predilation and postdilation (PRE+POST). Concerns over higher neurological risk have been raised with POST and PRE+POST during transfemoral carotid artery stenting. Whether these concerns are applicable to transcarotid artery revascularization (TCAR), which uses proximal clamping and cerebral blood flow reversal during stent deployment and balloon angioplasty remains unknown. Our aim is to analyze outcomes of PRE, POST, or PRE+POST balloon dilation strategies during TCAR. METHODS: We analyzed the prospectively collected data from the ROADSTER1 (pivotal), ROADSTER2 (US Food and Drug Administration indicated postmarket), and ROADSTER Extended Access TCAR trials. All trial patients had a high risk anatomic or clinical factors for carotid endarterectomy and were included, unless they did not undergo stent deployment or balloon dilation. For trial inclusion, asymptomatic patients had a carotid stenosis of more than 80%, and symptomatic patients had stenosis of more than 50%. Primary outcome measures were stroke, death, and myocardial infarction (MI) at 30 days. Data were statistically analyzed with χ2, analysis of variance, and multivariable analysis, as appropriate. RESULTS: There were 851 patients (566 male) who underwent dilation by PRE (n = 216), POST (n = 249), or PRE+POST (n = 386). Patients had carotid stenosis of greater than 70% (n = 828, 97%), and 207 (24%) were symptomatic. Flow reversal times were longer in the PRE+POST group (PRE 10.2 minutes, POST 9.8 minutes, and PRE+POST 13.3 minutes; P < .001). The 30-day stroke rate for the whole cohort was 1.9%, mortality was 0.5%, and MI rate was 0.94%. Stroke rates for the PRE cohort (1.9%), POST cohort (2.0%), and PRE+POST cohort (1.8%; P = .98) were similar. Also, death rates at 30 days, and composite stroke, death, and MI rates were similar in the three cohorts. No significant differences in adverse outcomes were noted among the various dilation strategies for both symptomatic and asymptomatic patients. CONCLUSIONS: Based on these prospective trial data, there is no difference in neurological complications owing to balloon dilation strategy during TCAR. The balloon dilation technique best suited to the patient's specific lesion morphology should be used. Further studies are needed to evaluate the relationship of these dilation strategies to long-term outcomes, including stent patency, restenosis, and reintervention.

Transport rate of EAAT2 is regulated by amino acid located at the interface between the scaffolding and substrate transport domains.

Excitatory Amino Acid Transporters (EAATs) are plasma membrane proteins responsible for maintenance of low extracellular concentrations of glutamate in the CNS. Dysfunction in their activity is implicated in various neurological disorders. Glutamate transport by EAATs occurs through the movement of the central transport domain relative to the scaffold domain in the EAAT membrane protein. Previous studies suggested that residues located within the interface of these two domains in EAAT2, the main subtype of glutamate transporter in the brain, are involved in regulating transport rates. We used mutagenesis, structure-function relationship, surface protein expression and electrophysiology studies, in transfected COS-7 cells and oocytes, to examine residue glycine at position 298, which is located within this interface. Mutation G298A results in increased transport rate without changes in surface expression, suggesting a more hydrophobic and larger alanine results in facilitated transport movement. The increased transport rate does not involve changes in sodium affinity. Electrophysiological currents show that G298A increase both transport and anion currents, suggesting faster transitions through the transport cycle. This work identifies a region critically involved in setting the glutamate transport rate.

A Comparison of Efficacy of Treatment and Time to Administration of Naloxone by BLS and ALS Providers.

INTRODUCTION: The administration of naloxone therapy is restricted by scope of practice to Advanced Life Support (ALS) in many Emergency Medical Services (EMS) systems throughout the United States. In Delaware's two-tiered EMS system, Basic Life Support (BLS) often arrives on-scene prior to ALS, but BLS providers were not previously authorized to administer naloxone. Through a BLS naloxone pilot study, the researchers sought to evaluate BLS naloxone administration and timing compared to ALS. HYPOTHESIS: After undergoing specialized training, BLS providers would be able to appropriately administer naloxone to opioid overdose patients in a more timely manner than ALS providers. METHODS: This was a retrospective, observational study using data collected from February 2014 through May 2015 throughout a state BLS naloxone pilot program. A total of 14 out of 72 state BLS agencies participated in the study. Pilot BLS agencies attended a training session on the indications and administration of naloxone, and then were authorized to carry and administer naloxone. Researchers then compared vital signs and the time of BLS arrival to administration of naloxone by BLS and ALS. Data were analyzed using paired and independent sample t-tests, as well as chi-square, as appropriate. RESULTS: A total of 131 incidents of naloxone administration were reviewed. Of those, 62 patients received naloxone by BLS (pilot group) and 69 patients received naloxone by ALS (control group). After naloxone administration, BLS patients showed improvements in heart rate (HR; P < .01), respiratory rate (RR; P < .01), and pulse oximetry (spO2; P < .01); ALS patients also showed improvement in RR (P < .01), and in spO2 (P = .005). There was no significant improvement in HR for ALS providers (P = .189).There was a significant difference in arrival time of BLS to the time of naloxone administration between the two groups, with shorter times in the BLS group compared to the ALS group (1.9 minutes versus 9.8 minutes; P < .01); BLS administration was 7.8 minutes faster when compared to ALS administration (95% CI, 6.2-9.3 minutes). CONCLUSIONS: Patients improved similarly and received naloxone therapy sooner when treated by BLS agencies carrying naloxone than those who awaited ALS arrival. All EMS systems should consider allowing BLS to carry and administer naloxone for an effective and potentially faster naloxone administration when treating respiratory compromise related to opiate overdose.

Immediate Stress Echocardiography for Low-Risk Chest Pain Patients in the Emergency Department: A Prospective Observational Cohort Study.

BACKGROUND: Evaluation and disposition of low-risk chest pain (CP) patients in the emergency department (ED) is time consuming and expensive. Low-risk CP often results in hospital admission to rule out myocardial infarction, which leads to additional costs and delays. OBJECTIVE: Our aim was to assess whether an immediate exercise stress echocardiogram (IESE) in the ED will allow safe, efficient, and cost-effective evaluation and discharge of patients with low-risk CP. METHODS: Low-risk CP patients (TIMI [Thrombolysis in Myocardial Infarction] score 0-1) presenting to the ED with normal electrocardiogram, no history of coronary artery disease, and negative troponin T received IESE. We followed these patients for major adverse cardiac events and compared them to a control cohort of similar-risk patients admitted with traditional care at 1 and 6 months. RESULTS: We enrolled 216 patients, 117 IESE and 109 control. We obtained follow-up at 1 and 6 months in 94% of the IESE group and 88% in the control group. There was no difference in diagnostic catheterization or percutaneous coronary intervention between the 2 groups (6.0% and 1.7% vs. 6.4% and 1.8%; p = 0.89). Median time from triage to discharge was significantly shorter with IESE (572.6 min vs. 1466.0 min), resulting in significantly lower cost ($4380.50 vs. $6191.70). There were no adverse events related to IESE or early discharge. CONCLUSIONS: In our study, IESE for low-risk CP patients presenting to the ED has the potential to be equally safe, more expeditious, and more cost effective than admission to an observation unit.