Cost-consequence analysis of different active flowable hemostatic matrices in cardiac surgical procedures.

BACKGROUND: A recent retrospective comparative effectiveness study found that use of the FLOSEAL Hemostatic Matrix in cardiac surgery was associated with significantly lower risks of complications, blood transfusions, surgical revisions, and shorter length of surgery than use of SURGIFLO Hemostatic Matrix. These outcome improvements in cardiac surgery procedures may translate to economic savings for hospitals and payers. OBJECTIVE: The objective of this study was to estimate the cost-consequence of two flowable hemostatic matrices (FLOSEAL or SURGIFLO) in cardiac surgeries for US hospitals. METHODS: A cost-consequence model was constructed using clinical outcomes from a previously published retrospective comparative effectiveness study of FLOSEAL vs SURGIFLO in adult cardiac surgeries. The model accounted for the reported differences between these products in length of surgery, rates of major and minor complications, surgical revisions, and blood product transfusions. Costs were derived from Healthcare Cost and Utilization Project's National Inpatient Sample (NIS) 2012 database and converted to 2015 US dollars. Savings were modeled for a hospital performing 245 cardiac surgeries annually, as identified as the average for hospitals in the NIS dataset. One-way sensitivity analysis and probabilistic sensitivity analysis were performed to test model robustness. RESULTS: The results suggest that if FLOSEAL is utilized in a hospital that performs 245 mixed cardiac surgery procedures annually, 11 major complications, 31 minor complications, nine surgical revisions, 79 blood product transfusions, and 260.3 h of cumulative operating time could be avoided. These improved outcomes correspond to a net annualized saving of $1,532,896. Cost savings remained consistent between $1.3m and $1.8m and between $911k and $2.4m, even after accounting for the uncertainty around clinical and cost inputs, in a one-way and probabilistic sensitivity analysis, respectively. CONCLUSIONS: Outcome differences associated with FLOSEAL vs SURGIFLO that were previously reported in a comparative effectiveness study may result in substantial cost savings for US hospitals.

Paradoxical response of plasma lipoprotein(a) in patients undergoing cardiopulmonary bypass.

Plasma lipid, lipoprotein and apolipoprotein levels are known to decrease after major surgery. Coronary artery bypass surgery additionally involves use of extracorporeal circulation by use of a cardiopulmonary bypass pump, which necessitates hemodilution due to saline dextrose infusion to prime the pump. To investigate changes in lipids, lipoproteins and apolipoproteins as well as changes in C-reactive protein and albumin we conducted a study on 22 patients undergoing cardiac surgery involving cardiopulmonary bypass. Timed arterial blood samples were taken before, during and after cardiopulmonary bypass. At the onset and during cardiopulmonary bypass a rapid and significant fall was observed in all lipids and lipoproteins except lipoprotein(a) with recovery to near basal levels by 72 h for cholesterol, triglycerides, high density lipoprotein cholesterol and albumin, while apolipoproteins AI and B remained below basal levels during the postoperative period up to 72 h. In contrast, lipoprotein(a) levels increased at the onset, doubled during cardiopulmonary bypass and remained elevated postoperatively. On the other hand, C-reactive protein levels fell at the onset and during cardiopulmonary bypass but they became markedly elevated postoperatively. When results were corrected for hemodilution, the response patterns remained unchanged. As lipoprotein(a) is both atherogenic and thrombogenic, its elevation during cardiopulmonary bypass may be clinically important.

Influence of cytokines and immunosuppressive drugs on major histocompatibility complex class I/II expression by human cardiac myocytes in vitro.

Human cardiac myocytes do not express detectable levels of major histocompatibility complex (MHC) class II antigens and express low levels, if any, of MHC class I antigens. During rejection episodes, cardiac biopsies show massive increases of MHC antigens, which are thought to be induced by cytokines released by donor-sensitized recipient mononuclear cells. In efforts to determine the nature of the cytokines that induce MHC expression on cardiac myocytes, human fetal cardiac myocyte cultures were established. Interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma), interleukin (IL)-1, IL-2, IL-3, IL-4, and tumor necrosis factor (TNF)-alpha were added to these cultures and dose/kinetics of MHC class I/II induction quantitated. Data show that IFN-gamma induces both MHC class I and II expression, and all the other cytokines (except IL-2) induce only MHC class I but not class II. Cytokines used in combination showed that IFN-alpha with TNF-alpha was the only combination that induced MHC class II expression. Addition of immunosuppressive drugs such as cytoxan, azathioprine, cyclosporine-A, and FK-506, even when added at the initiation of the cultures, did not appreciably affect the ability of the appropriate cytokines to induce MHC expression by the myocytes in vitro.

Reperfusion modification with a simplified blood cardioplegia system compared with oxygenated crystalloid cardioplegia.

A simplified system was developed for administration of blood cardioplegia with reperfusion modification. This system utilizes a single pass stainless steel coil to eliminate the need for a separate heat exchanger circuit. This system was compared with an oxygenated crystalloid cardioplegia system which was utilized in a manner which allowed warm blood perfusion of the heart for the last three minutes of the crossclamp interval. Both of these systems were compared with regard to mortality, spontaneous defibrillation, myocardial temperature, blood usage and peak CK-MB levels. In this series of patients, no significant advantage of either system could be identified.

Catastrophic thrombosis of porcine aortic bioprostheses.

Hemodynamically critical thrombotic stenosis of porcine bioprosthetic valves in the aortic position without thrombotic predisposition is rare. Two patients at our institution abruptly manifested thrombotic stenosis of porcine bioprosthetic valves in the aortic position within 3 months of implantation without apparent predisposing factors. Clinicians should consider this rare but catastrophic complication in the appropriate setting.

Characterization of human cardiac infiltrating cells posttransplantation: II. CD4+ cloned T-cell lines with "anti-idiotype"-like reactivity.

CD4+ T cells were cultured from posttransplant cardiac biopsies placed on irradiated feeder cells of autologous cloned donor major histocompatibility complex class II-specific T-cell lines cultured and grown from previous biopsies. Fourteen of the CD4+ T-cell cultures were expanded and cloned using the same feeder cells. Two of the 14 cloned T-cell lines were examined in detail for their ability to proliferate in vitro. Clones 7E4 and 8G2 proliferated (as determined by primed lymphocyte testing) only when cocultured with a series of distinct autologous cloned T-cell lines from previous biopsies that were specific for donor-specific HLA-DR3 and HLA-DR4, respectively. In addition, when HLA-DR-specific T-cell lines were established using recipient peripheral blood mononuclear cells and a series of HLA-DR-expressing homozygous typing cells, clone 7E4 only responded to the series of distinct HLA-DR3-specific autologous cloned T-cell lines but not to autologous HLA-DR2 and -DR4, and clone 8G2 responded to 3 of 8 distinct autologous HLA-DR4-specific T-cell lines, but not HLA-DR2-specific T-cell lines. These data demonstrate that cardiac biopsies contain CD4+ T cells of recipient origin which show anti-idiotype-like reactivity against T-cell receptors specific for donor-specific major histocompatibility complex class II molecules.

Catastrophic consequences of internal mammary artery hypoperfusion.

Inappropriate use of the internal mammary artery for complex coronary artery bypass operations may have disastrous yet avoidable consequences. In 712 consecutive coronary artery bypass operations performed between January 1985 and September 1986, five patients had an intraoperative course suggesting internal mammary artery hypoperfusion. In three, coronary artery bypass was performed as a reoperative procedure. The following similarities were noted in all five patients: a technically satisfactory internal mammary artery anastomosis, a left anterior descending coronary artery having critical proximal stenosis (greater than or equal to 90%), a distal artery at least 2.0 mm diameter free of disease, satisfactory left ventricular function, a catastrophic clinical outcome (death in three, cardiac transplantation in one, 3-month hospitalization in one), and all patients could be weaned from cardiopulmonary bypass only after insertion of a saphenous vein graft distal to the internal mammary artery graft. Bilateral internal mammary grafts were used in four of five patients. In both patients without prior coronary artery bypass, there was a discrepancy in internal mammary artery flow and myocardial demand: cardiac hypertrophy, large (2.5 mm) distal left anterior descending supplied by a small (less than 2.0 mm) internal mammary artery, and sequentially grafted arteries. All three patients having reoperative coronary artery bypass had normal anterior wall motion, and in two of the three patients, the left anterior descending-saphenous vein graft was arteriographically normal and the sole source of blood to the anterior, septum, and inferior myocardium. In two patients the normal left anterior descending-saphenous vein graft supply a large left anterior descending (greater than 2.0 mm) was replaced with a small left internal mammary artery. Internal mammary artery hypoperfusion typically occurred 30 to 40 minutes after discontinuation of cardiopulmonary bypass but was also seen in the intensive care unit. The condition may be confused with internal mammary artery or coronary artery spasm. It may be avoided by careful prebypass planning of the operation, intraoperative assessment of internal mammary artery flow and size with prudent use of sequential internal mammary artery grafting, avoiding use of the terminal left anterior descending (unless large), retaining nonobstructed saphenous vein grafts when the internal mammary artery has marginal flow or size, and placement of a saphenous vein graft distal to the left internal mammary artery when size or flow in the latter is small.

Important anatomical and physiological considerations in performance of complex mammary-coronary artery operations.

One or more internal mammary artery (IMA) anastomoses were performed in 87% of 692 consecutive coronary artery bypass operations performed over a 20-month period. One IMA was used in 68% (N = 469) and both IMAs were used in 19% (N = 130). Only saphenous vein grafts were used in 13% (N = 93). The mean number of anastomoses (all types) was 3.5. Fifty-seven patients were having a reoperation; bilateral IMA grafting was performed in 23% (N = 13). In 60 patients, 3 or more IMA anastomoses were performed: 3 IMA anastomoses, 50 patients; 4, 9 patients; and 5, 1 patient. In 27 patients, repeat coronary arteriography was performed within 30 days of operation to evaluate dynamics of IMA, saphenous vein, and native coronary artery flow. Major flow or all flow was through the graft (vs. the native coronary artery) in 62% of in situ IMA bypass grafts, 86% of free IMA grafts and 94% of saphenous vein grafts. Hospital mortality excluding patients having reoperation was 1.7% (11/635); it was less than 1% for patients having either single IMA grafting procedures (4/437) or bilateral IMA grafting procedures (1/117). Hospital mortality for patients receiving only saphenous vein grafts was surprisingly high, 7.4% (6/81). Major determinants of flow through the in situ IMA sequential graft are the size and flow of the IMA, the degree of proximal native coronary artery narrowing, the distally grafted to proximally grafted coronary artery size ratio, and probably the size of the side-to-side anastomosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Peritoneal dialysis in infants and children.

Pediatric renal failure patients can be restored to health with peritoneal dialysis more easily, more comfortably, and more safely than with hemodialysis. During the past 3.5 years, we have treated 22 children with either acute (less than 30 days) or chronic (greater than 30 days) peritoneal dialysis (PD) at Henrietta Egleston Hospital for Children. They ranged in age from 2 weeks to 15 1/6 years, mean 5.2 years. The indications for acute dialysis were renal failure following cardiac surgery (4); hemolytic-uremic syndrome (4); and renal failure associated with bromide intoxication (1), congenital urethral stricture (1), or bronchopulmonary dysplasia (1). Chronic dialysis was utilized for end-stage renal disease caused by glomerulonephritis (5), chronic infection (2), hemolytic-uremic syndrome (1), cystinosis (1), congenital renal artery stenosis (1), and unknown etiology (1). Thirty-four adult or pediatric Tenckhoff catheters were utilized to deliver PD for from 6 to 551 days (18 months). Pediatric Tenckhoff catheters must be pre-measured in order to have the Dacron cuffs glued to the appropriate position on the catheter (7-12 cm from the end) to fit the child. There were seven catheter-related infections in four patients; three required catheter revision and four were treated medically. There were eight catheter-related mechanical problems, all of which required re-operation. All of those on chronic PD and seven of those on acute PD survived for an overall survival of 82 per cent. All surviving patients have been restored to health either by recovery of renal function (6 patients), renal transplantation (8 patients), or maintenance of chronic ambulatory peritoneal dialysis (4 patients).

Hemodynamic consequences of severe pancreatitis.

Fifteen patients with severe pancreatitis underwent cardiovascular monitoring in an intensive care unit. The principal findings were a high cardiac index and a decrease in systemic vascular resistance. A significant negative correlation was found to exist between these two parameters (p less than 0.001). Severe pancreatitis apparently results in hemodynamic changes similar to those observed in sepsis. The mechanisms responsible for these observations are not known, although circulating vasoactive compounds resulting from pancreatic necrosis remain a strong possibility. Despite demonstrating a significant decrease in left ventricular stroke work index and an abnormal elevation in pulmonary capillary wedge pressure, the existence of a myocardial depressant factor could not be conclusively proved from these data.