Successful Management of Arterial Pseudoaneurysm Caused by Stent Fracture.

Pseudoaneurysm is a relatively common complication of arterial injury. Arterial pseudoaneurysms have many different etiologies, including trauma, iatrogenic injury, vascular repair, infection, and vasculitides. In this case report, we present a pseudoaneurysm created by a fracture of superficial femoral artery (SFA) stent secondary to a mechanical fall. To our knowledge, this is the first report of a symptomatic pseudoaneurysm caused by a SFA stent fracture. The large, unruptured pseudoaneurysm in this case was successfully treated with a covered stent and pseudoaneurysm exclusion.

Low rehospitalization rate for vascular surgery patients.

OBJECTIVES: Reducing rehospitalization rates has been proposed to improve care, reduce costs, and as a pay-for-performance criterion. Recent review of Medicare claims data indicates that vascular surgery patients have among the highest rates of 30-day rehospitalization at 23.9%. METHODS: We retrospectively examined all live patient discharges (n = 799) from the vascular surgery service at a single university hospital over 12 months. Planned and unplanned 30-day rehospitalizations were distinguished, and predictors of unplanned 30-day rehospitalization were determined. To identify whether patients were readmitted to other hospitals, a prospective study of patient discharges (n = 66) over 1 month was also performed. RESULTS: Ninety-five (11.9%) of the 799 patient discharges from the vascular surgery service were rehospitalized within 30 days. Of these, 71 were unplanned; therefore, the unplanned rehospitalization rate was 8.9%. The most common causes of unplanned 30-day rehospitalization were related to wound complications. Diabetes (P = .039) predicted unplanned 30-day rehospitalization by multivariate analysis. Patients with the diagnosis of critical limb ischemia (14.9%) and patients undergoing open lower extremity revascularization (14.6%) had the highest rates of unplanned 30-day rehospitalization. In the prospective portion of this study, no patient was readmitted to any other hospital. CONCLUSIONS: Relatively low 30-day rehospitalization was accomplished in vascular surgery patients at a single university hospital. Moreover, planned rehospitalizations accounted for approximately 25% of readmissions in vascular surgery patients. Strategies designed to reduce rehospitalization in diabetics may be warranted.

Duplex ultrasound imaging alone is sufficient for midterm endovascular aneurysm repair surveillance: a cost analysis study and prospective comparison with computed tomography scan.

OBJECTIVE: Early in our experience with endovascular aortic aneurysm repair (EVAR) we performed both serial computed tomography scans and duplex ultrasound (DU) imaging in our post-EVAR surveillance regimen. Later we conducted a prospective study with DU imaging as the sole surveillance study and determined cost savings and outcome using this strategy. METHODS: From September 21, 1998, to May 30, 2008, 250 patients underwent EVAR at our hospital. Before July 1, 2004, EVAR patients underwent CT and DU imaging performed every 6 months during the first year and then annually if no problems were identified (group 1). We compared aneurysm sac size, presence of endoleak, and graft patency between the two scanning modalities. After July 1, 2004, patients underwent surveillance using DU imaging as the sole surveillance study unless a problem was detected (group 2). CT and DU imaging charges for each regimen were compared using our 2008 health system pricing and Medicare reimbursements. All DU examinations were performed in our accredited noninvasive vascular laboratory by experienced technologists. Statistical analysis was performed using Pearson correlation coefficient. RESULTS: DU and CT scans were equivalent in determining aneurysm sac diameter after EVAR (P < .001). DU and CT were each as likely to falsely suggest an endoleak when none existed and were as likely to miss an endoleak. Using DU imaging alone would have reduced cost of EVAR surveillance by 29% ($534,356) in group 1. Cost savings of $1595 per patient per year were realized in group 2 by eliminating CT scan surveillance. None of the group 2 patients sustained an adverse event such as rupture, graft migration, or limb occlusion as a result of having DU imaging performed as the sole follow-up modality. CONCLUSION: Surveillance of EVAR patients can be performed accurately, safely, and cost-effectively with DU as the sole imaging study.

Influence of the human parainfluenza virus 3 attachment protein's neuraminidase activity on its capacity to activate the fusion protein.

In order to examine functions of the hemagglutinin-neuraminidase (HN) protein that quantitatively influence fusion promotion, human parainfluenza virus 3 (HPIV3) variants with alterations in HN were studied. The variant HNs have mutations that affect either receptor binding avidity, neuraminidase activity, or fusion protein (F) activation. Neuraminidase activity was regulated by manipulation of temperature and pH. F activation was assessed by quantitating the irreversible binding of target erythrocytes (RBC) to HN/F-coexpressing cells in the presence of 4-GU-DANA (zanamivir) to release target cells bound only by HN-receptor interactions; the remaining, irreversibly bound target cells are retained via the fusion protein. In cells coexpressing wild-type (wt) or variant HNs with wt F, the fusion promotion capacity of HN was distinguished from target cell binding by measuring changes with time in the amounts of target RBC that were (i) reversibly bound by HN-receptor interaction (released only upon the addition of 4-GU-DANA), (ii) released by HN's neuraminidase, and (iii) irreversibly bound by F-insertion or fusion (F triggered). For wt HN, lowering the pH (to approach the optimum for HPIV3 neuraminidase) decreased F triggering via release of HN from its receptor. An HN variant with increased receptor binding avidity had F-triggering efficiency like that of wt HN at pH 8.0, but this efficiency was not decreased by lowering the pH to 5.7, which suggested that the variant HN's higher receptor binding activity counterbalanced the receptor dissociation promoted by increased neuraminidase activity. To dissect the specific contribution of neuraminidase to triggering, two variant HNs that are triggering-defective due to a mutation in the HN stalk were evaluated. One of these variants has, in addition, a mutation in the globular head that renders it neuraminidase dead, while the HN with the stalk mutation alone has 30% of wt neuraminidase. While the variant without neuraminidase activity triggered F effectively at 37 degrees C irrespective of pH, the variant possessing effective neuraminidase activity completely failed to activate F at pH 5.7 and was capable of only minimal triggering activity even at pH 8.0. These results demonstrate that neuraminidase activity impacts the extent of HPIV3-mediated fusion by releasing HN from contact with receptor. Any particular HN's competence to promote F-mediated fusion depends on the balance between its inherent F-triggering efficacy and its receptor-attachment regulatory functions (binding and receptor cleavage).