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Biomedical subjects

D M Cosgrove

Publications and source records attributed to D M Cosgrove.

At least 19 recordsLinked to original sources
PubMed1996

Extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock.

BACKGROUND: Extracorporeal membrane oxygenation circuits have recently been introduced for extracorporeal life support (ECLS) in adult patients in cardiogenic shock and have been shown to provide excellent oxygenation and hemodynamic support. Heparin coating of the extracorporeal circuit provides a more biocompatible surface, which has been shown to minimize early surface-induced complement activation and platelet dysfunction and hence may improve patient survival. This report reviews our experience with extracorporeal membrane oxygenation to treat postcardiotomy cardiogenic shock using minimal to no systemic heparinization in 23 patients. METHODS: During the 22-month period September 1992 through July 1994, 23 patients in cardiogenic shock were placed on venoarterial ECLS using a heparin-bonded circuit. These patients' charts were retrospectively reviewed. A logistic regression analysis of the variables collected was performed to identify clear-cut predictors of ability to be weaned from ECLS. RESULTS: Average patient age was 47.3 +/- 16.4 years (range, 5 to 72 years). There were 17 male patients. Average time on ECLS was 58.4 +/- 35.1 hours (range, 0.5 to 144 hours). Statistical analysis revealed that patients unable to be weaned from ECLS were more likely to have a critically dilated left ventricle on echocardiography and were female. Ten patients (43.5%) died while on ECLS. Four patients were transferred to an implantable left ventricular assist device, and 3 underwent successful transplantation. The 9 other patients were successfully weaned from ECLS, and 4 were discharged home from the hospital. Overall, 7 patients (30.4%) who were placed on ECLS were successfully discharged home. CONCLUSIONS: Extracorporeal life support using an extracorporeal membrane oxygenation system provides excellent cardiac support with similar hospital survival rates as centrifugal mechanical support. Extracorporeal life support has complications unique to itself, but with time, these are likely to be overcome. Women and patients with persistent left ventricular dilatation are less likely to be weaned.

Acute Kidney Injury↗
PubMed1996

Mechanisms of hemolysis with mitral prosthetic regurgitation. Study using transesophageal echocardiography and fluid dynamic simulation.

OBJECTIVES: The aims of this study were to define the hydrodynamic mechanisms involved in the occurrence of hemolysis in prosthetic mitral valve regurgitation and to reproduce them in a numeric simulation model in order to estimate peak shear stress. BACKGROUND: Although in vitro studies have demonstrated that shear stresses > 3,000 dynes/cm2 are associated with significant erythrocyte destruction, it is not known whether these values can occur in vivo in conditions of abnormal prosthetic regurgitant flow. METHODS: We studied 27 patients undergoing reoperation for significant mitral prosthetic regurgitation, 16 with and 11 without hemolysis. We classified the origin and geometry of the regurgitant jets by using transesophageal echocardiography. By using the physical and morphologic characteristics defined, several hydrodynamic patterns were simulated numerically to determine shear rates. RESULTS: Eight (50%) of the 16 patients with hemolysis had paravalvular leaks and the other 8 had a jet with central origin, in contrast to 2 (18%) and 9 (82%), respectively, of the 11 patients without hemolysis (p = 0.12, power 0.38). Patients with hemolysis had patterns of flow fragmentation (n = 2), collision (n = 11) or rapid acceleration (n = 3), whereas those without hemolysis had either free jets (n = 7) or slow deceleration (n = 4) (p < 0.001, power 0.99). Numeric simulation demonstrated peak shear rates of 6,000, 4,500, 4,500, 925 and 950 dynes/cm2 in these five models, respectively. CONCLUSIONS: The distinct patterns of regurgitant flow seen in these patients with mitral prosthetic hemolysis were associated with rapid acceleration and deceleration or high peak shear rates, or both. The nature of the flow disturbance produced by the prosthetic regurgitant lesion and the resultant increase in shear stress are more important than the site of origin of the flow disturbance in producing clinical hemolysis.

Aged↗
PubMed1996

Surgical treatment of prosthetic valve endocarditis.

From 1975 through 1992, we reoperated on 146 patients for the treatment of prosthetic valve endocarditis. Prosthetic valve endocarditis was considered to be early (< 1 year after operation) in 46 cases and active in 103 cases. The extent of the infection was prosthesis only in 66 patients, anulus in 46, and cardiac invasion in 34. Surgical techniques evolved in the direction of increasingly radical débridement of infected tissue and reconstruction with biologic materials. All patients were treated with prolonged postoperative antibiotic therapy. There were 19 (13%) in-hospital deaths. Univariate analyses demonstrated trends toward increasing risk for patients with active endocarditis and extension of infection beyond the prosthesis; however, the only variables with a significant (p < 0.05) association with increased in-hospital mortality confirmed with multivariate testing were impaired left ventricular function, preoperative heart block, coronary artery disease, and culture of organisms from the surgical specimen. During the study period, mortality decreased from 20% (1975 to 1984) to 10% (1984 to 1992). For hospital survivors the mean length of stay was 25 days. Follow-up (mean interval 62 months) documented a late survival of 82% at 5 postoperative years and 60% at 10 years. Older age was the only factor associated (p = 0.006) with late death. Nineteen patients needed at least one further operation; reoperation-free survival was 75% at 5 and 50% at 10 postoperative years. Fever in the immediate preoperative period was the only factor associated with decreased late reoperation-free survival (p = 0.032). Prosthetic valve endocarditis remains a serious complication of valve replacement, but the in-hospital mortality of reoperations for prosthetic valve endocarditis has declined. With extensive débridement of infected tissue and postoperative antibiotic therapy, the extent and activity of prosthetic valve endocarditis does not appear to have a major impact on late outcome, and the majority of patients with this complication survive for 10 years after the operation.

Adult↗
PubMed1995

Pressure recovery in bileaflet heart valve prostheses. Localized high velocities and gradients in central and side orifices with implications for Doppler-catheter gradient relation in aortic and mitral position.

BACKGROUND: We investigate pressure recovery in central and side orifices of St Jude valves and the effect of mitral versus aortic position on the relation between Doppler- and catheter-derived pressure gradients. METHODS AND RESULTS: Maximum, transvalvular, and net pressure gradients are calculated and compared with Doppler-derived gradients in an in vitro model. Pressure recovery and pressure loss coefficients are calculated. Simultaneous Doppler and catheter gradients are obtained intraoperatively in five patients undergoing mitral valve replacement. Centerline Doppler gradients correspond closely with maximum catheter gradients but are higher than transvalvular and net pressure gradients. Thirty-six percent of the initial pressure drop is recovered between the valve leaflets and is independent of valve size or configuration. A variable amount of postvalvular pressure recovery is observed depending on aortic or mitral configuration. Side orifice velocities are 85 +/- 4% of the centerline velocities. Incorporation of the pressure loss coefficient in the simplified Bernoulli equation shows close agreement between centerline Doppler gradients and transvalvular gradients (r = .99, y = 1.11x-0.19). CONCLUSIONS: Gradients across the St Jude valve measured by Doppler ultrasound are higher than transvalvular or net catheter gradients due to downstream pressure recovery. This is more marked for Doppler gradients based on centerline velocities than side orifice velocities and is more pronounced for valves in an aortic than a mitral configuration. Therefore, to be comparable with invasive transvalvular catheter gradients, either Doppler gradients should be calculated based on side orifice velocity measurements or the Doppler gradient calculation should include the pressure loss coefficient when based on central orifice velocities.

Aortic Valve↗
PubMed1995

Quantification of mitral regurgitation by the proximal convergence method using transesophageal echocardiography. Clinical validation of a geometric correction for proximal flow constraint.

BACKGROUND: Proximal flow convergence is a promising method to quantify mitral regurgitation but may overestimate flow when the flow field is constrained. This has not been investigated clinically, nor has a correction factor been validated. METHODS AND RESULTS: Eighty-five patients were studied intraoperatively with transesophageal echocardiography and divided into two groups: central convergence (no constraining wall) and eccentric convergence (at least one constraining wall). Regurgitant stroke volume (RSV) and orifice area (ROA) were calculated by ROA = 2 pi r2 Va/Vp and RSV = ROA x VTIcw, where r and va are the radius and velocity of the aliasing contour and vp and VTIcw are the peak and integral of regurgitant velocity. In eccentric convergence patients, convergence angle (alpha) was measured from two-dimensional Doppler color flow maps, and ROA and RSV were corrected by multiplying by alpha/180. For reference, RSV was the difference between thermodilution and pulsed Doppler stroke volumes. In central convergence patients (n = 45), RSV (r = .95, delta = 2.5 +/- 10.8 mL) and ROA (r = .96, delta = 0.02 +/- 0.08 cm2) were accurately calculated, but significant overestimation was noted in the eccentric convergence patients (n = 40, delta RSV = 63.9 +/- 38.0 mL, delta ROA = 0.54 +/- 0.31 cm2), 68% of whom had leaflet prolapse or flail. delta RSV was correlated with alpha (r = -.69, P < .001). After correction by alpha/180, overestimation was largely eliminated (delta RSV = 15.5 +/- 19.3 mL and delta ROA = 0.14 +/- 0.14 cm2) with excellent correlation for the whole group (RSV, r = .91; ROA, r = .95). CONCLUSIONS: A simple geometric correction factor largely eliminates overestimation caused by flow constraint with the proximal convergence method and should extend the clinical utility of this technique.

Case-Control Studies↗
PubMed1995

Have PTCA failures requiring emergent bypass operation changed?

From 1980 through 1990, 9,145 patients had balloon angioplasty with failure of the procedure requiring emergent surgical revascularization within 24 hours occurring in 253 patients (2.8%). Patients were divided into two cohorts based on the date of the percutaneous transluminal coronary angioplasty (PTCA): 1980 to 1985 (n = 109) and 1986 to 1990 (n = 144). The incidence of PTCA failure was 3.8% during 1980 to 1985 (109/2,903) and decreased to 2.3% (144/6,242) for 1986 to 1990. Comparison of pre-PTCA patient characteristics between the two periods showed that only a history of a previous PTCA and class III or class IV symptoms were more common in the recent years (p < or = 0.05). In-hospital mortality after emergency operation was 4.6% (5/109) during 1980 to 1985 and 7.6% (11/144) from 1985 to 1990 (p = not significant). This trend toward increased mortality appeared to be related to an increased number of patients who underwent operation in a state of severe hemodynamic compromise in the more recent period. The in-hospital mortality rate for patients in shock or undergoing cardiopulmonary resuscitation was 28.3% (13/46) compared with 1.4% (3/207) for patients with less severe hemodynamic derangement (p < 0.001). Use of the intraaortic balloon pump preoperatively increased from 12.8% to 32.6% (p < 0.01). Late survival was 92% at 2 and 87% at 5 postoperative years. Although the incidence of PTCA failure necessitating emergent surgical intervention has decreased over time, there has been a trend toward an increased in-hospital mortality rate for those patients that does not appear to be related to more severe pre-PTCA characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1995

Initial experience with the Cosgrove-Edwards Annuloplasty System.

BACKGROUND: The mitral valve has a nonplanar shape and a sphincter action. Pathologic dilatation occurs along the posterior annulus. To preserve the physiologic function and correct annular dilatation, we developed an annuloplasty system that is universally flexible and produces a measured plication of the posterior annulus (Cosgrove-Edwards Annuloplasty System). METHODS: The results of 150 consecutive mitral valve repairs using this system were analyzed. Mean age was 58 +/- 13 years; 59% were men. The cause of the valve disease was degenerative in 75% of the patients, rheumatic in 13%, ischemic in 8%, and infectious in 4%. Associated procedures were performed in 61 patients (41%). RESULTS: Echocardiographic mitral regurgitation decreased from 3.7 +/- 0.6 before repair to 0.2 +/- 0.4 after repair (p < 0.0001). There were no hospital deaths and no cases of hemodynamically significant systolic anterior motion or other annuloplasty-related complications. Follow-up was 100% complete at a mean of 3.1 +/- 3.6 months. There were three late deaths, three transient ischemic attacks, and one episode of endocarditis. Five patients (3.3%) have undergone reoperation for recurrent mitral insufficiency; no reoperations were related to the annuloplasty system. At a mean of 9 months, three-dimensional reconstruction of the mitral annulus from multiple echocardiographic images confirmed the nonplanar shape and sphincter mechanism of the annulus. Annular orifice area decreased 19% during the cardiac cycle from a mean of 10.3 cm2 in diastole to 8.6 cm2 in systole. CONCLUSIONS: This annuloplasty system is effective for repair of insufficiency secondary to all causes, preserves physiologic annulus function, and is associated with a low incidence of valve-related complication.

Adult↗
PubMed1995

Surgical and long-term antifungal therapy for fungal prosthetic valve endocarditis.

BACKGROUND: Fungal prosthetic valve endocarditis is an uncommon but serious disease. We have developed a strategy of treatment that includes perioperative amphotericin B, radical debridement of infected tissue, reconstruction using biologic tissue when possible, and prolonged oral suppressive antifungal therapy. METHODS: We retrospectively reviewed the charts of 12 patients reoperated on for fungal prosthetic valve endocarditis involving the aortic valve (10 patients: six porcine valves, two mechanical valves, two homografts) and the mitral valve (2 patients, both porcine valves). Prosthetic valve endocarditis developed in 7 within 12 months after the first valve procedure. The organisms included Candida species (9 patients), Scopulariopsis brevicaulis (1), Saccharomyces cervisiae (1), and histoplasmosis (1). RESULTS: At operation, all patients had prosthetic vegetations, 8 had abscesses, and 4 had sinus tracts. Seven received aortic homografts, 4 received porcine valves (two mitral), and 1 received a mechanical prosthesis. Two patients died in the hospital after prolonged illnesses (83% hospital survival). Four patients had recurrence an average of 25 months later and 3 underwent further surgical intervention. One patient had recurrence and died 17 months postoperatively. One other late death occurred 96 months after operation, and there was no evidence of recurrence. Eight patients (67%) are alive and well 51.5 +/- 61.0 months (range, 1 to 189 months) after the first redo procedure for fungal prosthetic valve endocarditis. CONCLUSIONS: We conclude that preoperative treatment with amphotericin B, radical resection of all infected tissue, cardiac reconstruction using biologic tissue when possible, and life-long oral antifungal therapy is effective for fungal prosthetic valve endocarditis.

Abscess↗
PubMed1995

Intraoperative validation of mitral inflow determination by transesophageal echocardiography: comparison of single-plane, biplane and thermodilution techniques.

OBJECTIVES: This study investigated the accuracy of mitral inflow quantification using biplane transesophageal echocardiography. BACKGROUND: Mitral stroke volume can be reliably quantified by transthoracic Doppler echocardiography, but previous studies involving monoplane transesophageal echocardiography have yielded mixed results. METHODS: Thirty patients without mitral regurgitation were prospectively examined immediately before cardiovascular surgery. Mitral annulus diameter was measured in the transverse (d1) and longitudinal views (d2) by biplane transesophageal echocardiography. Assuming an elliptic shape, the annular area was calculated as pi d1d2/4; area was also calculated from single-plane data assuming a circular annular shape as pi d2/4. The time-velocity integral of mitral annular Doppler velocity was then multiplied by annular area to yield stroke volume. These data were compared with simultaneous thermodilution measurements by linear regression. RESULTS: Good correlations were observed between thermodilution (x) and Doppler (y) measurements of stroke volume (SV) (r = 0.86, p < 0.01, delta SV [y-x] = 2.64 +/- 9.86 ml for single four-chamber view; r = 0.77, p < 0.01, delta SV = 1.82 +/- 12.59 ml for two-chamber view; r = 0.94, p < 0.001, delta SV = 1.78 +/- 5.90 ml for biplane measurements) with similar data for cardiac output (r = 0.82, r = 0.74 and r = 0.92, respectively). The biplane measurements were most accurate and had less variability in individual patients (p < 0.05). This finding was supported by a numerical model that demonstrated (for an ellipse of eccentricity 1.5:1) that even maximal misalignment of biplane diameters yielded only 8% area overestimation, whereas single-plane calculations assuming a circular shape produced a variation in area of 225%. CONCLUSIONS: This study validates the accuracy of measurements of mitral inflow using biplane transesophageal echocardiography with potential application for quantification of valvular regurgitation in the operating room. The results are further generalizable, indicating that orthogonal biplane measurements are both necessary and sufficient to ensure accuracy in area calculation for any elliptic structure.

Adult↗
PubMed1995

Surgical management of hypertrophic obstructive cardiomyopathy. Early and late results.

From 1975 through 1993, 178 patients underwent surgical management of hypertrophic obstructive cardiomyopathy. Operations included isolated septal myectomy (n = 95), septal myectomy and coronary artery bypass grafting (n = 41), septal myectomy plus a valve procedure (n = 25), septal myectomy, valve procedure, and coronary artery bypass grafting (n = 14), and mitral valve replacement without septal myectomy (n = 3). Recent myectomy results were monitored with transesophageal echocardiography. After initial myectomy, 32 patients (20%) underwent a second pump run for more extensive myectomy only (n = 22), mitral valve replacement only (n = 5), or both (n = 2). In-hospital mortality was 6% (n = 11) and 4% (n = 6) for patients undergoing septal myectomy or septal myectomy plus coronary artery bypass grafting, respectively. Heart block occurred in 17 patients (10%). Left ventricular outflow tract systolic gradients decreased from a mean of 93 mm Hg to 21 mm Hg after myectomy. Late survival was 86% and 70% at 5 and 10 postoperative years, respectively, and 93% and 79% for patients undergoing septal myectomy alone or septal myectomy plus coronary artery bypass grafting, respectively. Only 3 of 131 in-hospital survivors of septal myectomy or septal myectomy plus coronary artery bypass grafting died late cardiac deaths, for a yearly mortality of 0.6%. However, the 5-year late survival of patients undergoing valve operation plus septal myectomy was 51%, and multivariate testing confirmed the adverse influence on late survival (p = 0.008), as well as adverse influences of increasing age (p = 0.016) and return to cardiopulmonary bypass for mitral valve replacement (p = 0.038). At follow-up 136 patients (94%) had New York Heart Association class I or II symptoms. For patients with hypertrophic obstructive cardiomyopathy, septal myectomy alone or in combination with coronary artery bypass grafting produces effective symptom relief, excellent long-term survival, and a low risk of late cardiac death.

Aged↗
PubMed1995

The Carpentier-Edwards pericardial aortic valve. Ten-year results.

To evaluate the function of the Carpentier-Edwards pericardial valve in the aortic position, we analyzed the results of 310 aortic valve replacements performed between 1982 and 1985. Mean age was 64.2 +/- 10.8 years (range 22 to 95 years); 190 patients (61.3%) were male patients. There were 18 hospital deaths (5.8%), and none were valve related. Follow-up of the 292 survivors was 100% complete at a mean of 7.8 +/- 2.9 years; 2290 patient-years of follow-up were available for analysis. There were 133 late deaths (45.5%). Actuarial survivals at 5 and 10 years were 82.5% and 45.9%, respectively. The 10-year actuarial freedom from events was 88.7% +/- 2.1% for thromboembolism, 90.9% +/- 1.8% for hemorrhage, 94.3% +/- 1.6% for endocarditis, and 91.2% +/- 2.6% for structural deterioration. The 153 hospital survivors 65 years of age or older had an extremely low incidence of structural valve deterioration, with only four explants and 95.5% actuarial freedom from explantation at 10 years, and a linearized rate of 0.3 +/- 0.2 per patient-year compared with 88.6% and 0.7 +/- 0.2 for patients younger than 65 years of age. Twelve valves were explanted for structural deterioration. Of these, 11 (93%) had leaflet calcification causing stenosis and one had a wear-related leaflet tear. The Carpentier-Edwards pericardial valve has a low incidence of valve-related complications. The freedom from structural valve deterioration is low at 10 years, particularly in patients 65 years of age and older.

Actuarial Analysis↗
PubMed1995

Complications of extracorporeal life support systems using heparin-bound surfaces. The risk of intracardiac clot formation.

Extracorporeal life support with heparin-coated extracorporeal membrane oxygenation circuits are being used with increased frequency in patients who have cardiogenic shock. We report our experience in 30 patients with cardiogenic shock, looking specifically at the complications associated with this form of life support. Thirty patients with a mean age of 46.5 +/- 16.6 years received extracorporeal life support for a mean of 62.8 +/- 41.1 hours (range 0.5 to 159 hours). Twenty-three patients had postcardiotomy cardiogenic shock, five had acute myocardial infarction, and one each had acute cardiac deterioration after a balloon coronary angioplasty and another after pulmonary artery balloon angioplasty. Peripheral (femoral vein to femoral artery) cannulation was used in 24 patients. Limb ischemia developed in 21 patients (70%), renal failure in 17 patients (57%), oxygenator failure requiring change in 13 patients (43%), bleeding requiring reexploration in 12 (40%), and infection in 9 patients (30%). Transesophageal echocardiography revealed intracardiac thrombus formation in 6 patients (20%) and clot was visualized grossly in the pump head in 2 patients (6%) necessitating pump-head change. Nine patients (30%) were discharged home. We conclude that the use of heparin-coated extracorporeal life support without systemic heparinization, especially after protamine has been used to reverse systemic heparinization in patients having postcardiotomy cardiogenic shock, may be dangerous. Extracorporeal life support has introduced new complications unique to itself specifically limb ischemia, oxygenator failure, and pump-head thrombus.

Adolescent↗
PubMed1995

Axillary artery: an alternative site of arterial cannulation for patients with extensive aortic and peripheral vascular disease.

The increasing number of patients with extensive aortic and peripheral vascular atherosclerosis or aneurysms who are undergoing cardiac operations present difficult decisions as to the optimal site of arterial cannulation for cardiopulmonary bypass. Femoral artery cannulation is the most common alternative to ascending aortic cannulation, but severe iliofemoral disease or the danger of atheroemboli caused by retrograde perfusion through an atherosclerotic or aneurysmal descending aorta may make this approach impossible or undesirable. We have used axillary artery cannulation for cardiac operations in 35 patients for indications including severe aortic atherosclerosis (n = 16), extensive aortic aneurysms (n = 11), and aortic dissection (n = 8). The cardiac operations performed were coronary artery bypass grafting (n = 9) aortic valve replacement (n = 1), aortic valve replacement and coronary artery bypass grafting (n = 5), repair of mitral valve periprosthetic leak (n = 1), and resection of ascending and/or aortic arch (n = 19). Deep hypothermia with circulatory arrest was used in 26 patients and retrograde cerebral perfusion in 18. All patients awoke from the operation and no patient had a cerebrovascular accident. One patient required axillary artery thrombectomy and one patient had a mild ipsilateral brachial plexus paresis after the operation. Four patients died in the hospital. We conclude that axillary artery cannulation is a safe and effective means of providing antegrade arterial flow during cardiopulmonary bypass in patients with severe atherosclerotic or aneurysmal disease. This strategy may lower the prevalence of stroke associated with cardiopulmonary bypass in these patients.

Adult↗
PubMed1995

Systemic hypothermia and circulatory arrest combined with arterial perfusion of the superior vena cava. Effective intraoperative cerebral protection.

We have used retrograde arterial perfusion of the superior vena cava as an adjunct to deep hypothermia and systemic circulatory arrest for intraoperative cerebral protection in 43 adult patients (18 of whom were 70 years old or older). The indications for the use of circulatory arrest were thoracic aortic operations (37 patients) and atherosclerosis or calcification of the ascending aorta (6 patients) in patients needing aortic valve or coronary operations. In all patients systemic hypothermia (16 degrees to 18 degrees C) was achieved with cardiopulmonary bypass and the systemic arterial circulation was arrested. Retrograde arterial perfusion of the superior vena cava was established through a wire-reinforced venous cannula (with a superior vena cava tourniquet) at a temperature of 15 degrees C. In 36 patients a separate roller pump system was used for the retrograde cerebral perfusion. Central venous pressure was monitored at 25 to 30 mm Hg; mean flow rate was 250 ml/min. Periods of circulatory arrest and retrograde cerebral perfusion ranged from 4 to 110 minutes (mean 38 minutes), and for seven patients the period of circulatory arrest was longer than 60 minutes. Four postoperative deaths occurred, one related to stroke in a patient who had an aortic dissection during coronary surgery and the others related to noncerebral complications. Three nonfatal cerebral complications occurred, although all had completely resolved by late follow-up. Advantages of retrograde cerebral perfusion are (1) simplicity of use and avoidance of vascular trauma, (2) excellent exposure, (3) retrograde flow that minimizes embolization of air and atherosclerotic debris, and (4) effective cerebral oxygen delivery. Retrograde cerebral perfusion appears to be an important adjunct to hypothermia and circulatory arrest not only for patients undergoing operation for ascending aorta and aortic arch disease but also for patients with diffuse aortic atherosclerosis undergoing coronary or valve operations.

Adult↗
PubMed1995

Flow characteristics of aortic cannulae.

Atheroembolism from the ascending aorta is an emerging cause of noncardiac complications after open heart surgery. We designed a new arterial cannula specifically to reduce the exit force and velocity of blood flow, thereby reducing the "sandblasting" effect of the exiting blood jet. The cannula has a closed tip and an internal cone that diffuses blood flow such that it enters the aorta via multiple side holes. Fluid dynamics of the cannula were tested against five frequently used cannulae: Sarns High-Flow (3M Sarns High-Flow, Ann Arbor, MI, USA), DLP 83024 (DLP Inc., Grand Rapids, MI, USA), RMI ARS 024C (Research Medical Inc. of Research Industries Corp., Midvale, UT, USA), Bard 1966 (C.R. Bard Inc., Haverhill, MA, USA), and Argyle THI (Sherwood Medical Co. Sub American Home Products Corp., St. Louis, MO, USA). All cannulae had an 8.0-mm external diameter. The new cannula demonstrated a similar pressure drop and internal tip diameter as the others. The exit force (newtons) of the Soft Flow cannula was significantly less than the Sarns High-Flow (p < 0.05), DLP (p < 0.001), RMI (p < 0.01), Bard (p < 0.001), and the Argyle (p < 0.001) cannulae. Peak velocity (cm/s) of the Soft Flow cannula was significantly less than the DLP (p < 0.01), RMI (p < 0.01), Bard (p < 0.01), and Argyle (p < 0.001). The cannulae all had similar hemolysis rates. The new arterial cannula produced the lowest exit force and flow velocity with no increase in hemolysis and may help to decrease the incidence of atheroemboli and its sequelae.

Cardiac Surgical Procedures↗
PubMed1995

Homografts in the treatment of prosthetic valve endocarditis.

Homografts may provide unique technical advantages in the setting of aortic root destruction from prosthetic valve endocarditis. Viable cryopreserved homografts are relatively resistant to infection, do not require anticoagulation, and exhibit satisfactory long-term durability. In a group of 33 patients undergoing homograft replacement for active prosthetic valve endocarditis, left aortoventricular discontinuity was present in 11 patients, periannular abscesses were found in 21 patients, 15 patients had vegetations covering most of the prosthesis, and severe valve dehiscence was present in 10 patients. The homograft proved versatile in allowing various techniques for aortic root reconstruction. All patients survived operation. Two late hospital deaths accounted for a hospital mortality rate of 6%. Of 31 hospital survivors, 26 (83%) remained free of major events at a mean of 20.1 months. Overall late survival including all deaths was 73.1% +/- 11.98%. All but one patient is FC 1. In addition to the technical advantages offered by the homograft, the relatively low morbidity and mortality incidence associated with its use in prosthetic valve endocarditis makes it an appealing alternative in this setting.

Abscess↗