To reduce unnecessary care and improve patient outcomes through bundled payments or population health management, healthcare organizations must define both the population for which they are assuming risk and the services that they will provide. Organizations also must be able to manage variations in cost and quality and demonstrate both the economic and clinical value they provide to the populations they serve. To effectively coordinate care across a patient population, providers--including physicians, hospitals, and postacute care facilities--must be willing to collaborate on efforts to reengineer care delivery.

Purpose: Minimally invasive surgery is associated with improved clinical outcomes and reduced costs. We hypothesize that in patients with similar preoperative characteristics, hysterectomy, colectomy, and thoracic resection performed via minimally invasive surgery (MIS) approach would be associated with fewer complex Diagnosis Related Group (cDRG) assignments and subsequently result in reimbursement savings. Methodology: Premier hospital database was used to examine inpatient discharges of open and MIS colectomy, hysterectomy and thoracic resection. Open and MIS groups were matched based on propensity score. Descriptive statistics and regression analysis were used to assess the impact of MIS on cDRG assignment. Potential reimbursement savings to the U.S. health care system, assuming a 10% increase in MIS utilization, was estimated using Medicare’s Fiscal Year (FY) 2013 national average reimbursement data and Premier’s procedure volume projections. Results: Compared with open surgery, the MIS group had a statistically significantly lower percent age of cDRG assignment (colectomy, 57% vs. 71%; hysterectomy, 15% vs. 19%; thoracic resection, 62% vs. 70%; P<.001 for each). Open surgery, when compared to MIS, increased the odds of cDRG assignment by 67% (odds ratio [OR], 1.67; 95% confidence in terval [CI], 1.62–1.71). We estimated that a 10% increase in MIS utilization would lead to annual payer reimbursement savings of about $24.4 million (colectomy, $17 million; hysterectomy, $5 million; thoracic resection, $2.4 million). Conclusion: Health care reform laws and economic pressures are causing a shift in focus from vol ume-based to value-based care. MIS approaches reduce payer expense based on fewer expensive cDRG assignments. Further adoption of MIS may lead to improved outcomes and additional savings.

A systematic approach targeting both the patients and physicians whose costs are above the norm is a sustainable way to effectively reduce costs of care. Finance leaders should build teams of specialists who can provide data on outliers in real time, make changes as problems are identified, and track improvements. Using a care map analytic framework hospitals can identify problem areas while establishing mechanisms to better control and manage costs in the long term.

Renal nuclear medicine is used to evaluate renal function and morphology. Renal scintigraphy is the best imaging modality for evaluation of functional parameters such as glomerular filtration rate and effective renal plasma flow. The commonly used renal radiopharmaceuticals are reviewed. Both imaging and non-imaging techniques are presented. Specific applications of renal nuclear medicine are discussed.

OBJECTIVE:To assess the survival of a free omental graft applied to an experimentally created wound on the distal extremity in dogs.STUDY DESIGN:A free omental graft was evaluated as a primary method of treatment for dogs with distal extremity wounds in an experimental model.ANIMALS OR SAMPLE POPULATION:Five adult intact female mixed breed dogs weighing 21.8 kg to 25.0 kg.METHODS:A free omental graft was harvested from the abdomen and transferred to a wound bed overlying the medial aspect of the tibia. A microvascular anastomosis was performed between the graft vessels and vessels at the recipient site. Daily clinical assessment of graft viability was performed. Angiography and 99mTechnetium labeled macroaggregated albumin (99mTc MAA) scintigraphic perfusion scans were performed on either day 4, 5, or 7. Postmortem collection of tissues for histopathologic analysis was performed immediately after imaging. Total operative time and graft ischemia time were evaluated for effects on graft survival.RESULTS:Two of seven grafts survived to the end of the study, three of seven grafts failed because of ischemia, and two of seven grafts failed because of self-trauma. There was no clinically significant morbidity associated with the abdominal portion of the procedure. Because of the small number of surviving grafts, the effects of operative time and graft ischemia time could not be statistically evaluated.CONCLUSIONS:Microvascular transplantation of a free omental graft can result in a viable tissue covering of a distal extremity wound, however, the failure rate is unacceptably high.CLINICAL RELEVANCE:A free omental graft may not have sufficient durability to be an acceptable wound covering by itself. Further studies combining omentum with a skin graft or other tissues may result in a clinically useful technique.

Radionuclide ventriculography has been used in humans to evaluate valvular incompetency. The stroke volume ratio, derived from the radionuclide ventriculogram, is used to quantify the severity of mitral regurgitation (MR). Previous studies conducted in humans have shown that left to right stroke volume ratio increases as the severity of MR increases. In this study, we evaluated radionuclide ventriculography as a noninvasive method to detect MR in dogs with surgically created mitral insufficiency. Six male and three female adult, conditioned mongrel dogs were used. Scintigraphic studies were performed prior to and 4 weeks after surgically created MR. Because of the overlap of the left and right ventricles when viewed from a left lateral position, we combined data from a first-pass radionuclide angiocardiogram with the radionuclide ventriculogram to obtain a corrected stroke volume ratio. Blood flow transit parameters were also derived from the first-pass radionuclide angiocardiogram. Standard left ventricular functional indices were also measured from the radionuclide ventriculogram. On the left lateral view of the heart, 25 to 30% of the right ventricular volume overlaps the left ventricle. After correcting for the overlap, the stroke volume ratio of normal dogs was 1.17+/-0.178 (mean+/-SD), which increased to 2.06+/-0.41 (mean+/-SD) (p < .001) 4 weeks after creation of MR. The was no significant change in left ventricular ejection fraction or peak rate of ejection following MR. The transit times of blood through the left ventricle were measured from the first-pass radionuclide angiocardiogram and were expressed as half-time clearance, peak clearance rate, and time to peak clearance rate. The baseline half-time clearance was 2.07+/-0.71 s (mean+/-SD), which increased to 6.70+/-4.89 s (mean+/-SD) (p = .02) after creation of MR. The baseline peak clearance rate was 49.75+/-8.96 cts/s (mean+/-SD), which decreased to 23.12+/-6.84 cts/s (mean+/-SD) (p < .001) after creation of MR. Stroke volume ratios significantly increased following creation of MR. Blood flow transit through the left ventricle slowed following creation of MR. The variability of these parameters were small in the baseline studies, suggesting these techniques may be clinically useful to gauge the severity of MR in dogs.

Small diameter (⩽6mmID) synthetic vascular grafts, used as lower-limb vessel replacements in patients without suitable autologous saphenous veins, have a failure rate of 53% after 4 yr. Graft failure is due to thrombosis and intimal hyperplasia, an increase in smooth muscle cells in the lumen of the vessel which leads to progressive closing and ultimate occlusion of the vessel. In an effort to increase patency rates of synthetic grafts, investigators have seeded vascular grafts with endothelial cells prior to implantation in an attempt to control both thrombosis and smooth muscle proliferation. This technique has been successful for the development of an endothelial monolayer in animal trials, but has met with limited success in humans. The hydrophobicity, low surface energy, and weak electrical charge of expanded polytetrafluoroethylene (ePTFE) provides conditions which are not optimal for endothelial cell attachment. The purpose of this study is to evaluate the effect of vacuum ultraviolet (VUV) modification of ePTFE on endothelial cell adhesion and proliferation. Pieces of ePTFE graft material were exposed to 10, 20 or 40 W VUV radiation for 10, 20 or 40 min using a UV excimer lamp. Prior to cell adhesion and proliferation experiments, the grafts pieces were autoclaved and cut into pledgets. Half of the pledgets were precoated with fibronectin (20μg/ml). Cell adhesion was measured by seeding 3H-thymidine labeled human umbilical vein endothelial cells (HUVEC) onto the pledgets for 60 min. The pledgets were then washed and the remaining radioactivity assayed using scintillation counting. For the cell proliferation experiments, pledgets were seeded with unlabeled HUVEC which were allowed to adhere to the graft material for 18 h. The cells were then exposed to 3H-thymidine (1μCi/ml) for approximately 48 h and then washed to remove any unincorporated 3H-thymidine. Incorporation of 3H-thymidine was measured using scintillation counting. Four replicate samples each, with and without fibronectin, were evaluated for each power and exposure time for both the adhesion and proliferation experiments. VUV modification had no effect on cell adhesion for all power levels studied. In addition, it appears that cell adhesion is independent of the presence of fibronectin. Cell proliferation, on the other hand, is augmented by modification, especially in the presence of fibronectin. These results suggest that VUV modification may provide a better surface for endothelial cell colonization of synthetic vascular grafts.

OBJECTIVE:To determine the short-term hemodynamic effects associated with circumferential mitral annuloplasty (CMA) in dogs with mitral regurgitation.STUDY DESIGN:Prospective experimental study. Animals-Seven healthy adult mongrel dogs.METHODS:Mitral regurgitation was surgically induced, and annular dilation occurred. Echocardiography and cardiac catheterization were used to determine forward ejection fraction (FEF), regurgitant fraction (RF), pulmonary capillary wedge pressure (PCWP), and annular diameter before and immediately after CMA in five dogs. FEF and RF were also evaluated 7 days after annuloplasty.RESULTS:Mean annular diameter and PCWP were significantly reduced immediately after CMA. Significant increases in FEF of 19% and 22% were shown immediately and 7 days after CMA. Significant reductions in RF of 19% and 22% were also shown immediately and 7 days after annuloplasty.CONCLUSIONS:Sustained hemodynamic benefits and a reduction in annular diameter were achieved by CMA in a canine model of mitral regurgitation.CLINICAL IMPLICATIONS:CMA may be a suitable treatment for heart failure because of mitral regurgitation when early signs of cardiovascular decompensation persist despite appropriate medical management.

= 10) or CG (n= 10) placement in the infrarenal aorta after balloon injury with harvest at 1 and 6 weeks. Endothelial repaving, intima-to-media height ratios (IMHR), and inflammatory stains were performed. Endothelial repaving was greater in 6-week SG compared to CG (51% ± 5.0 versus 10% ± 5.0, p≤ 0.05). IMHR was less in 6-week SG compared to CG at the proximal (1.22 ± 0.16 versus 1.82 ± 0.16, p≤ 0.05) and distal anastomosis (0.81 ± 0.25 versus 1.33 ± 0.25, p≤ 0.05). Smooth muscle cell (SMC) α-actin was greater in 1-week SG compared to CG at the distal anastomosis (121.5 ± 7.2 versus 94.0 ± 7.2, p≤ 0.05). Proliferating cell nuclear antigen (PCNA) was less in 6-week SG compared to CG at the proximal (5.6 ± 1.4 versus 9.4 ± 1.1, p≤ 0.05) and distal anastomosis (3.8 ± 0.6 versus 11.2 ± 1.1, p≤ 0.05). Macrophage CD-44 was less in 6-week SG compared to CG at the proximal (10.4 ± 1.6 versus 32.6 ± 3.6, p≤ 0.05) and distal anastomosis (8.6 ± 0.9 versus 35.6 ± 3.6, p≤ 0.05). Intraarterial SG placed after balloon injury exhibited significantly greater endothelialization and less intimal hyperplasia when compared to CG.

Endothelial seeding of vascular grafts has been shown to decrease graft thrombogenicity and prolong longevity when implanted in vivo. Previous studies have utilized anatomic grafts to study endothelialization and healing. Anatomic thoracoabdominal grafts do not allow for sequential biopsy for evaluation of individual grafts nor do they approximate the environment for long bypass grafts used in limb salvage. This study evaluated the use of an extra-anatomic aortic bypass graft to assess the healing of endothelial cell seeded expanded polytetrafluoroethylene (ePTFE). Radionuclide angiography was used to evaluate graft patency and quantify blood flow through the graft. Dogs underwent placement of an extra-anatomic 60 cm long, 8 mm internal diameter, graft seeded with autologous endothelium. Grafts were biopsied from 2 weeks up to 1 year. Radionuclide studies were performed postimplantation and following each graft biopsy. Graft placement and biopsies were well tolerated in all dogs. Biopsied segments of graft allowed for sequential studies of the healing of implanted grafts by scanning electron and light microscopy. Flow through the implanted graft was close to 50% of the total caudal abdominal aortic flow. No significant difference in graft flow was noted either between animals or over time.

Genetically recombinant endothelial cells (rEC) may improve the patency of small diameter vascular grafts by preventing thrombosis or limiting neointimal hyperplasia. Previous work has shown that rEC have reduced adhesion to vascular bypass graftsin vivo.Poor adhesion may be due to altered adhesion (integrin) receptors. This study evaluated the expression of the α5β1(fibronectin), α2β1(collagen IV), and αvβ3(vitronectin) integrin subunits on rEC. Human umbilical vein EC or canine jugular vein EC were transduced with neoR, neoR and human tPA or hygromycin resistance genes using retroviral vectors. Naive EC and EC exposed to empty viral particles (mEC) were controls. Naive EC, mEC, and all rEC's were evaluated for α and β subunits for each integrin receptor studied using immunoblotting. Blotting for α2, α5, and αvexhibited expression of the α integrin subunits in all cells. The β1and β3subunits were present in mEC and nEC but were absent or truncated in all rEC. The decreased adhesion of rEC's to synthetic vascular grafts may be accounted for by their altered β1and β3integrin subunit expression. The β subunit is critical for organization of the cytoskeleton and cellular signal transduction. Diminished β subunit expression in rEC is neither vector specific nor related to retroviral exposure alone. Alteration of β integrin expression may be to associated with the over-expression of phosphotransferase genes such as neoR or hygromycin B used as selectable markers in gene transfer protocols.

Purpose: We investigated the mechanical characteristics of lyophilized human saphenous vein valves to determine their suitability for use as allogeneic transplants to treat chronic venous insufficiency.Methods: Fresh cadaveric veins were lyophilized in vacuum bottles within 24 hours of harvest and were stored at room temperature. The veins were reconstituted in saline solution and then were placed in an in vitro flow circuit for evaluation. At varied how rates, pressures proximal and distal to valves during prograde and retrograde now were measured. Valve closure times were determined with Doppler examination and spectral analysis. The valves were also stressed to 350 mm Hg on a separate apparatus.Results: All pressures proximal and distal to the valves remained less than 10 mm Hg during prograde flow. A pressure gradient developed immediately on the reversal of flow. Pressure as high as 200 mm Hg applied against the dosed valves was not transmitted beyond the valve. Valve closure times had a mean of 0.31 +/- 0.03 seconds and 0.21 +/- 0.01 seconds for the Doppler examination and spectral analysis, respectively. All valves withstood stress pressures to 350 mm Hg.Conclusions: The in vitro mechanical characteristics of the valves of lyophilized veins are similar to known values for normal in vivo valves.

Background. Incomplete luminal endothelialization may contribute to small diameter vascular graft failure. Vascular endothelial growth factor (VEGF) can be used to stimulate endothelialization without provoking smooth muscle cell (SMC) proliferation. Heparin and VEGF in a fibrin glue (FG) were investigated for their ability to promote selective human aortic endothelial cell (HAEC) proliferation and human aortic smooth muscle cell (HASMC) inhibition.Methods. HAECs and HASMCs were seeded on FG containing VEGF (2.5, 10, 30, 100 ng/ml) or VEGF and heparin (5, 50, 500 units/ml). Proliferation assays were performed with tritiated thymidine on days 1 and 3. Results were analysed by ANOVA, with p less than or equal to 0.05 significant.Results. HAEC proliferation on FG with 10, 30, and 100 ng/ml VEGF significantly increased HAEC proliferation to greater than FG with VEGF alone at day 1. Human aortic SMC proliferation was not stimulated by the addition of VEGF. The addition of 5, 50, and 500 units/ml heparin significantly inhibited HASMC proliferation regardless of VEGF concentration.Discussion. VEGF at 10 ng/ml combined with heparin at 50 units/ml exhibited maximal stimulation of HAECs with inhibition of HASMCs. VEGF and heparin in a biologic glue may improve patency by selectively promoting HAEC proliferation without HASMC growth on synthetic vascular bypass grafts.

Genetically modified endothelial cells (ECs) seeded on synthetic vascular grafts offer the potential to improve small diameter vascular graft patency. Despite encouraging results with naive ECs, cells transduced with retroviral vectors appear impaired in their ability to adhere to and stably colonize vascular grafts in vivo. This study addresses changes in retrovirally transduced EC adhesion as the cause of cell loss. Endothelial cells were retrovirally transduced with the bacterial neoR gene or "mock" transduced with empty viral particles. Cells were allowed to adhere to collagen IV (CIV) or fibronectin (FN) prior to exposure to 20 or 90 dyn/cm2 using a parallel plate apparatus. Cell detachment was evaluated using time lapse videomicroscopy. Fibronectin was a significantly better adhesive protein for naive EC than CIV at both shear stresses. NeoR-transduced EC had significantly greater detachment from FN than either naive or "mock"-transduced EC. Transduced EC attachment to FN was no greater than to CIV. Flow cytometric analysis of the fibronectin receptor (FNR) showed that transduced cells have reduced receptor expression compared to naive and "mock"-transduced EC. These results indicate retrovirally transduced EC have altered FNR and adhesion to FN and that these changes may account for transduced EC loss in vivo.

Osseous metaplasia of the pericardium causing effusive-constrictive pericardial disease has not, to our knowledge, been reported in dogs. Clinical signs of right-sided congestive heart failure prompted examination of the dog of this report. Documented causes of constrictive pericardial disease in dogs include trauma and actinomycotic, mycobacterial, and fungal infections. These causes were ruled out in this dog. Immune-mediated disorders, as have been reported in people, also were considered unlikely on the basis of test results. It was concluded that this dog had idiopathic osseous metaplasia of the pericardium and pleura. Signs of right-sided congestive heart failure resolved after subtotal pericardiectomy was performed.

Unique characteristics of endothelium make it an attractive target cell for gene transfer. Genetically modified endothelial cells (ECs) seeded on synthetic vascular grafts offer the potential to control neointimal hyperplasia, decrease graft thrombogenicity and improve small diameter graft patency. This study addresses the issue of synthetic vascular graft colonization with endothelial cells transduced with noninducible retroviral marker genes in the dog. Autologous endothelial cells were enzymatically harvested and transduced with either the bacterial NeoR gene or human growth hormone gene using retroviral vectors. All transduced cells were positive by polymerase chain reaction (PCR) amplification for the transduced gene sequence prior to graft seeding. Transduced ECs were seeded on Dacron grafts (n = 3) preclotted with autologous blood. These grafts exhibited complete endothelialization at times from 250 to 360 days. Recovered DNA, however, was negative for the transduced gene sequence when analyzed by PCR and Southern blotting. Expanded polytetrafluoroethylene (ePTFE) was evaluated (n = 8) using several different cell seeding protocols. Grafts were seeded at 3 densities (ranging from 6 × 103 to 1.5 × 105 cells/cm2) and 2 different adherence times. Seeding substrate was also evaluated. Grafts were either preclotted with whole blood or incubated with 20 or 120 μg/ml fibronectin for 60 min. Graft biopsies were evaluated from 2 to 52 wk. Limited endothelialization was present in 4 dogs as early as 2 wk, but never progressed to full luminal coverage. The remaining dogs failed to ever exhibit any luminal EC adherence. Two dogs with limited EC coverage had positive DNA by PCR for the NeoR gene sequence at 2 and 3 wk. In contrast to transduced EC's, nontransduced EC colonization of ePTFE was complete at 2 wk when seeded under conditions that transduced cells had failed to persist. Neither seeding density, adherence time, seeding substrate or retroviral vector used influenced the uniformly poor graft coverage seen with transduced cells. Results of this study indicate that despite successful gene transfer using 4 different retroviral vectors, transduced endothelial cells seeded under varying conditions appear altered in their ability to stably adhere and colonize synthetic vascular grafts in vivo.