Safety and feasibility of endovascular aortic aneurysm repair as day surgery.

OBJECTIVE: The adoption of endovascular aneurysm repair (EVAR) during the past two decades has led to significantly shorter length of stay as well as lower hospital resource use. Currently, most patients are admitted to the hospital after EVAR; however, there are no standard observation periods, and timing of discharge is based on clinical judgment. The aim of this study was to confirm the safety and feasibility of performing EVAR as outpatient surgery. METHODS: We developed criteria to identify patients for potential same-day discharge (infrarenal aneurysm, low perioperative risk, to be accompanied for first 24 hours). We then implemented a prospective trial that observed patients planned for same-day discharge and compared them with a historical control group (patients who had undergone EVAR during the previous 2 years and met same-day discharge criteria). Basic demographic and operative data as well as length of stay, inpatient and perioperative complications, emergency department visits, readmissions, reinterventions, and deaths were collected. The primary outcome was the 30-day complication rate, and the study was powered to assess noninferiority. RESULTS: Prospectively, we assessed 266 patients and planned 110 (41%) for outpatient EVAR (62% of historical controls met outpatient criteria). Demographic characteristics were similar between planned outpatients and historical controls. In planned outpatients, hospital stay was significantly shorter (0.7 ± 2.6 days vs 2.5 ± 6.9 days; P < .01), and 79% were discharged the same day of surgery. The 30-day follow-up was available for all study patients and 94% of control patients; there were no differences in complication (11% vs 9%), readmission (2% vs 4%), reintervention (4% vs 4%), or mortality (1% vs 1%) rates, but study patients had significantly more emergency department visits (15% vs 6%; P < .05). Unsuccessful same-day discharge was associated with longer operative times, increased blood loss, and use of general anesthesia. CONCLUSIONS: In selected patients undergoing elective EVAR, same-day discharge is feasible without increasing complication rates. Health resource utilization remains a challenge in transitioning to an outpatient model.

Characterization of a degradable polar hydrophobic ionic polyurethane with circulating angiogenic cells in vitro.

This study investigated the interaction of human circulating angiogenic cells (CACs) with a degradable polar hydrophobic ionic polyurethane (D-PHI) which has been previously shown to exhibit anti-inflammatory character and favorable interactions with human endothelial cells (ECs). Given the implication of the CACs in microvessel development it was of intrinsic interest to expand our knowledge of D-PHI biocompatibility with this relevant primary cell involved in angiogenesis. The findings will be compared to a well-established benchmark substrate for CACs, fibronectin-coated tissue culture polystyrene (TCPS). Immunoblotting analysis showed that CACs were a heterogeneous population of cells composed mostly of monocytic cells expressing the CD14 marker. Assessment of the cytokine release profile, using ELISA, showed that D-PHI supported a higher concentration of interleukin-10 (IL-10) when compared to the concentration of tumor necrosis factor alpha, which is indicative of an anti-inflammatory phenotype, and was different from the response with TCPS. It was found that the CACs were attached to D-PHI and remained viable and functional (nitric oxide production) during the seven days of culture. However, there did not appear to be any significant proliferation on D-PHI, contrary to the CAC growth on fibronectin-coated TCPS. It was concluded that D-PHI displayed some of the qualities suitable to enable the retention of CACs onto this substrate, as well as maintaining an anti-inflammatory phenotype, characteristics which have been reported to be important for angiogenesis in vivo.

Intramyocardial delivery of mesenchymal stem cell-seeded hydrogel preserves cardiac function and attenuates ventricular remodeling after myocardial infarction.

BACKGROUND: To improve the efficacy of bone marrow-derived mesenchymal stem cell (MSC) therapy targeted to infarcted myocardium, we investigated whether a self-setting silanized hydroxypropyl methylcellulose (Si-HPMC) hydrogel seeded with MSC (MSC+hydrogel) could preserve cardiac function and attenuate left ventricular (LV) remodeling during an 8-week follow-up study in a rat model of myocardial infarction (MI). METHODOLOGY/PRINCIPAL FINDING: Si-HPMC hydrogel alone, MSC alone or MSC+hydrogel were injected into the myocardium immediately after coronary artery ligation in female Lewis rats. Animals in the MSC+hydrogel group showed an increase in cardiac function up to 28 days after MI and a mid-term prevention of cardiac function alteration at day 56. Histological analyses indicated that the injection of MSC+hydrogel induced a decrease in MI size and an increase in scar thickness and ultimately limited the transmural extent of MI. These findings show that intramyocardial injection of MSC+hydrogel induced short-term recovery of ventricular function and mid-term attenuation of remodeling after MI. CONCLUSION/SIGNIFICANCE: These beneficial effects may be related to the specific scaffolding properties of the Si-HPMC hydrogel that may provide the ability to support MSC injection and engraftment within myocardium.

Developing cell therapy techniques for respiratory disease: intratracheal delivery of genetically engineered stem cells in a murine model of airway injury.

Interest has increased in the use of exogenous stem cells to optimize lung repair and serve as carriers of a therapeutic gene for genetic airway diseases such as cystic fibrosis. We investigated the survival and engraftment of exogenous stem cells after intratracheal injection, in a murine model of acute epithelial airway injury already used in gene therapy experiments on cystic fibrosis. Embryonic stem cells and mesenchymal stem cells were intratracheally injected 24 hr after 2% polidocanol administration, when epithelial airway injury was maximal. Stem cells were transfected with reporter genes immediately before administration. Reporter gene expression was analyzed in trachea-lungs and bronchoalveolar lavage, using nonfluorescence, quantitative, and sensitive methods. Enzyme-linked immunosorbent assay quantitative results showed that 0.4 to 5.5% of stem cells survived in the injured airway. Importantly, no stem cells survived in healthy airway or in the epithelial lining fluid. Using 5-bromo-4-chloro-3-indolyl-beta-d-galactopyranoside staining, transduced mesenchymal stem cells were detected in injured trachea and bronchi lumen. When the epithelium was spontaneously regenerated, the in vivo amount of engrafted mesenchymal stem cells from cell lines decreased dramatically. No stem cells from primary culture were located within the lungs at 7 days. This study demonstrated the feasibility of intratracheal cell delivery for airway diseases with acute epithelial injury.