Laser Fenestration of Aortic Stent-Grafts Followed by Noncompliant vs Cutting Balloon Dilation: A Scanning Electron Microscopy Study.

PURPOSE: To examine the effects of in situ laser fenestration and subsequent balloon dilation (noncompliant vs cutting) on the graft fabric of 4 aortic stent-graft models. METHOD: In an in vitro setup, the Zenith TX2, Talent, Endurant, and Anaconda aortic stent-grafts (all made of polyester graft material) were subjected to laser fenestration with a 2.3-mm-diameter probe at low and high energy in a physiologic saline solution followed by balloon dilation of the hole. For the first series of tests, 6-mm-diameter noncompliant balloons were used and replaced for the second series by 6-mm-diameter cutting balloons. Each procedure was performed 5 times (5 fenestrations per balloon type). The fenestrations were examined visually and with light and scanning electron microscopy. RESULTS: Each fenestration demonstrated various degrees of fraying and/or tearing regardless of the device. The monofilament twill weave of the Talent endograft tore in the warp direction up to 7.09±0.46 mm at high energy compared with 2.41±0.26 mm for the Endurant multifilament device. The fenestrations of the 3 endografts with multifilament weave (Zenith, Anaconda, and Endurant) showed more fraying; fenestration areas in the multifilament Endurant were >10 mm2 at low and high energy. The fenestrations were free of melted fibers, but minor blackening of the filaments was observed in all devices. Overall, the cutting balloons resulted in worse tearing and damage. Of note, the edges of the dilated laser-formed fenestrations of the Talent and the Endurant grafts demonstrated evidence of additional shredded yarns. CONCLUSION: In situ fenestration does not cause any melting of the polyester; however, the observed structural damage to the fabric construction must be carefully considered. Cutting balloons caused various levels of tearing compared to the noncompliant balloons and cannot be recommended for use in this application. Rather, noncompliant balloons should be employed, but only with endografts constructed from multifilament yarns. The use of in situ fenestration must be restricted to urgent and emergent cases until long-term durability can be determined.

The use of EndoAnchors to rescue complicated TEVAR procedures.

BACKGROUND: The aim of this study was to assess the applicability and outcomes of EndoAnchor use in the endovascular repair of thoracic and thoracoabdominal aortic aneurysms. METHODS: A retrospective review was performed of all thoracic endovascular aortic repairs (TEVARs) performed with the use of EndoAnchors between December 2012 and January 2016. Primary study endpoints included freedom from migration, freedom from aortic- related intervention, and freedom from post-operative type I or type III endoleak. RESULTS: During this study period, a total of 54 patients underwent TEVAR for thoracic or thoracoabdominal aneurysm with the use of EndoAnchors at our institution. Twenty-seven cases were performed as the index operation. Twenty-seven cases were considered redo operations. EndoAnchors were deployed for therapeutic and prophylactic indications. Mean follow-up was 9.6±8.8 months. EndoAnchors were used for therapeutic indications in 31.5% of patients and for prophylactic indications in 68.5%. The technical success of EndoAnchor deployment was 99.8%. The overall initial technical success of the operation was 98.1%. There were no instances of graft migration. The overall endoleak rate was 5.4% with prophylactic EndoAnchor use and 11.8% with therapeutic use. Aortic-related reintervention was required in 13.5% of patients who received prophylactic EndoAnchor placement and 23.5% of patients who received therapeutic EndoAnchor placement. Only one reintervention was performed for EndoAnchor failure. A p value of <0.05 was considered significant. CONCLUSIONS: EndoAnchors can be safely utilized in TEVAR with high rates of technical success. These results demonstrate the potential to enhance thoracic endograft efficacy and durability with the use of therapeutic and prophylactic EndoAnchors. Long-term data is needed to further define the use of this technology in the thoracic aorta.

Bar Code Medication Administration Technology: Characterization of High-Alert Medication Triggers and Clinician Workarounds.

BACKGROUND: Bar code medication administration (BCMA) technology is gaining acceptance for its ability to prevent medication administration errors. However, studies suggest that improper use of BCMA technology can yield unsatisfactory error prevention and introduction of new potential medication errors. OBJECTIVE: To evaluate the incidence of high-alert medication BCMA triggers and alert types and discuss the type of nursing and pharmacy workarounds occurring with the use of BCMA technology and the electronic medication administration record (eMAR). METHODS: Medication scanning and override reports from January 1, 2008, through November 30, 2008, for all adult medical/surgical units were retrospectively evaluated for high-alert medication system triggers, alert types, and override reason documentation. An observational study of nursing workarounds on an adult medicine step-down unit was performed and an analysis of potential pharmacy workarounds affecting BCMA and the eMAR was also conducted. RESULTS: Seventeen percent of scanned medications triggered an error alert of which 55% were for high-alert medications. Insulin aspart, NPH insulin, hydromorphone, potassium chloride, and morphine were the top 5 high-alert medications that generated alert messages. Clinician override reasons for alerts were documented in only 23% of administrations. Observational studies assessing for nursing workarounds revealed a median of 3 clinician workarounds per administration. Specific nursing workarounds included a failure to scan medications/patient armband and scanning the bar code once the dosage has been removed from the unit-dose packaging. Analysis of pharmacy order entry process workarounds revealed the potential for missed doses, duplicate doses, and doses being scheduled at the wrong time. CONCLUSIONS: BCMA has the potential to prevent high-alert medication errors by alerting clinicians through alert messages. Nursing and pharmacy workarounds can limit the recognition of optimal safety outcomes and therefore workflow processes must be continually analyzed and restructured to yield the intended full benefits of BCMA technology.

Identification, localization and interaction of SNARE proteins in atrial cardiac myocytes.

Atrial cardiac myocytes secrete the vasoactive hormone atrial natriuretic peptide (ANP) by both constitutive and regulated exocytotic fusion of ANP-containing large dense core vesicles (LDCV) with the sarcolemma. Detailed information, however, regarding the identity and function of specific membrane fusion proteins (SNARE proteins) involved in exocytosis in the endocrine heart is lacking. In the current study, we identified SNARE proteins and determined their association with ANP-containing secretory granules using primary cultures of neonatal and adult rat atrial cardiac myocytes. Using RT-PCR, cardiac myocytes were screened for SNARE and SNARE-associated transcripts. Identified SNARE proteins that have been implicated in exocytosis in neuroendocrine cells were further characterized by Western blot analysis. Functional interaction between SNARE proteins was demonstrated using immunoprecipitation. Using cell fractionation and immunocytochemical methods, it was revealed that VAMP-1, VAMP-2 and synaptotagmin-1 (the putative Ca(2+) sensor) localized to subpopulations of ANP-containing secretory granules in atrial myocytes. Currently, there is conflicting data regarding the role of Ca(2+) in ANP exocytosis. To judge whether secretory activity could be evoked by intracellular Ca(2+) elevation, time-resolved membrane capacitance measurements were used in combination with the flash photolysis of caged compounds to follow the exocytotic activity of single neonatal atrial myocytes. These studies demonstrated that multiple SNARE proteins are present in neonatal and adult cardiac myocytes and suggest the importance of Ca(2+) in exocytosis of ANP from neonatal atrial cardiac myocytes.