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How to cite: Renzulli, A., Cerasuolo, F., Festa, M., Caruso, A., Cotrufo, M., & Vitale, N. (1997). Stentless fresh pulmonary homograft for recurrent mitral prosthetic valve endocarditis. The Journal of heart valve disease, 6(3), 329.

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How to cite: Moore, M. A., & Phillips, R. E. (1997). In response to "Formaldehyde Replaces Glutaraldehyde in Porcine Bioprosthetic Heart Valves". The Journal of heart valve disease, 6(3), 327–328.

Open-heart surgery in patients with recent cardiogenic embolic stroke represents a difficult management problem. We present a patient who developed thrombosis of a mitral tilting-disc prosthesis complicated by repeat cerebral embolic episodes that resulted in acute neurologic injury. We believe that in such patients the indication for reoperation must be individually evaluated but it is justified in young subjects, even in the presence of severe neurologic damage.

How to cite: Milano, A., Guglielmi, C., Tartarini, G., Grana, M., & Bortolotti, U. (1997). Reoperation for prosthetic thrombosis and acute neurologic injury. The Journal of heart valve disease, 6(3), 324–326.

Both in vivo and in vitro models have been developed to study the initiation and progression of dystrophic calcification of bioprosthetic heart valves. Circulatory in vivo models have proven to be the most predictive of the success of a new valve designs or anticalcification schemes; however, these experiments are time consuming and expensive. An appealing alternative to circulatory implantation is the sub-cutaneous rat implantation model. This model is inexpensive and calcification occurs rapidly. Recent studies have shown, however, that some anticalcification methods work well in the subcutaneous model but are ineffective in the circulatory model. In vitro models would provide the most convenient method for testing new anticalcification strategies but, to date, no in vitro test system has been developed which produces calcification of rates and with morphology comparable with that in vivo models. We have also studied the effects of collagen damage and cell extraction on the calcification of porcine aortic valve cusps both in vitro and in the subcutaneous rat model, and found significant differences in the patterns of mineralization. The objectives of this paper therefore are to compare and contrast the different experimental protocols and procedures reported in the literature to better define the effects of different model systems on the calcification process.

How to cite: Mako, W. J., & Vesely, I. (1997). In vivo and in vitro models of calcification in porcine aortic valve cusps. The Journal of heart valve disease, 6(3), 316–323.

Background and aims of the study: There is a need for a replacement cardiac valve constructed from non-immunogenic materials but incorporating living, and preferably autologous, cells. The object of this study was to colonize freeze-dried porcine valve leaflets with human fibroblasts and vascular endothelial cells.

Methods: Porcine pulmonary valve leaflets were freeze-dried to produce a porous matrix having communicating cavities of appropriate dimensions for fibroblast repopulation. Cultured human fibroblasts and vascular endothelial cells that had been cryopreserved by standard methods were added to freeze-dried leaflets. Following culture at 37 degrees C, the leaflets were examined by confocal scanning microscopy and transmission electron microscopy.

Results: Mechanical perforation of the leaflet surface permitted colonization of the freeze-dried matrix by fibroblasts; under the conditions we studied, the cell density did not reach physiologic levels but those cells that were present were well attached and metabolically active. Gentle cotton abrasion of the surface of the freeze-dried leaflets provided a suitable substrate for endothelial cell attachment and confluence was achieved in 10 days. Leaflets were perforated, cultured with human fibroblasts for 10 days, then gently rubbed with a cotton bud and cultured for a further 10 days with human endothelial cells. The endothelial cells formed a confluent layer on the surface and viable fibroblasts were present within the substance of the leaflet.

Conclusion: Although these results are preliminary, they demonstrate the basic feasibility of this approach to the production of xenogeneic valves that contain the patient's own cells.

How to cite: Curtil, A., Pegg, D. E., & Wilson, A. (1997). Repopulation of freeze-dried porcine valves with human fibroblasts and endothelial cells. The Journal of heart valve disease, 6(3), 296–306.

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How to cite: Vesely I. (1997). The hybrid autograft/xenograft aortic valve. The Journal of heart valve disease, 6(3), 292–295.

Background and aims of the study: Cerebral complications constitute a major source of morbidity and disability after cardiac valve surgery. These may be the result of macroembolization (air/debris) or inadequate perfusion pressure. In an attempt to reduce the incidence of cerebral vascular accident (CVA)/transient ischemic attack (TIA), we have routinely performed three minutes of passive retrograde cerebral perfusion (PRCP) on all valve cases. Here, we retrospectively determined our perioperative (0-30 day) incidence of CVA/TIA.

Methods: In all cases, the extracorporeal circuit consisted of an ascending aortic cannula and either one two-stage or two single-stage venous cannulae. Three minutes of PRCP was instituted in all cases upon discontinuation of anterograde cardiopulmonary bypass (CPB) via a shunt distal to the heart/lung machine between the arterial and venous cannulae. Mean systemic blood pressure was maintained at 60 mmHg with Neo-Synephrine. Central venous pressure never exceeded 25 mmHg. In 10 cases, transcranial Doppler ultrasonography (TCD) was used to assess middle cerebral artery (MCA) blood flow. In total, 209 consecutive valve procedures with PRCP (group A) were compared with 164 consecutive valve procedures with no PRCP (group B). All data were compared using Fisher's exact probability test. The incidence of CVA/TIA was also compared with published retrospective and prospective data.

Results: TCD demonstrated blood flow reversal in the MCA after a minimum of 30 s. The incidence of CVA/TIA was 0% (0/209) in group A, and 2.4% (4/165) in group B (p = 0.0386). The incidence of CVA/TIA in published retrospective data is 0.7-3.8% and 4.8-5.2% in prospective data.

Conclusions: We have demonstrated in 209 consecutive valve cases that, upon discontinuation of CPB, routine three-minute PRCP not only reversed MCA blood flow, but also reduced the incidence of neurologic events.

How to cite: Quigley, R. L., Fuller, B. C., Sampson, L. N., & Reitknecht, F. L. (1997). Passive retrograde cerebral perfusion during routine cardiac valve surgery reverses middle cerebral artery blood flow and reduces the risk of stroke. The Journal of heart valve disease, 6(3), 288–291.

Background and aims of the study: Reoperations for periprosthetic leaks (PL) and valve dehiscence (VD) are associated with high mortality and substantial recurrence rate. Standard methods of repair are often not feasible due to friability of the annulus tissue or lack of space to locate the sutures. We have therefore used a variety of unconventional methods to close the leaks securely.

Clinical material and methods: The clinical records of 25 patients reoperated for PL and VD between 1989 and 1995 were reviewed. Eighteen patients had aortic and seven mitral PL. Patients with mechanical heart valves were more frequently reoperated than those with bioprostheses (2.1% versus 0.7%). The PL was repaired in 16 cases, and the prosthesis was exchanged in nine cases with VD or large leaks. Six of the latter nine patients had active prosthetic endocarditis. A variety of surgical techniques was used to repair the leaks, including placing sutures from outside the aortic wall, through the atrial and ventricular septum, through the free left atrial wall and closure by single or double patch technique.

Results: Hospital mortality was 4% (1/25 patients) and one-year mortality 12.5%. None of the patients except one with active prosthetic endocarditis needed a second reoperation.

Conclusions: If PLs are difficult to close with standard surgical technique, the alternative methods described might be useful. These methods can also be used during primary valve replacements where leaks remain.

How to cite: Konstantinov, I. E., Franzen, S. F., & Olin, C. L. (1997). Periprosthetic leaks and valve dehiscence: alternative methods of repair. The Journal of heart valve disease, 6(3), 281–287.

Background and aims of the study: Preservation of the mitral valve and subvalvular apparatus was introduced clinically in the early 1960s, but for two decades the technique for mitral valve replacement included excision of both leaflets and their attached chordae tendineae. Lately, emphasis has been replaced on retaining the mitral subvalvular apparatus during valve replacement because of its role in left ventricular function. Hence, during the past six years, when performing mitral valve replacement we have, when possible, preserved the valvular and sub-valvular mitral apparatus.

Methods: Between January 1990 and November 1996, complete retention of all mitral tissue in connection with mitral valve replacement was performed in 58 patients (23 women and 35 men). Mean age was 63 years (range: 23 years to 77 years). Coronary bypass was a concomitant procedure in 19 patients; both the mitral and aortic valve was replaced in four cases. Calcified and/or stenotic valves were not a contraindication for the procedure; calcified plaques were removed. Adhesion between anterior and posterior leaflets was treated with sharp dissection. Valve and subvalvular tissue were preserved. The leaflets were reefed within the valve-sutures and compressed between the sewing ring and the native annulus when implanting the valve prosthesis. Chordal tension on the ventricle is thus maintained and the chordae pulled away from the valve effluent.

Results: Six patients died in the postoperative period and three had transient neurological symptoms. In no patient was death or transient neurological symptoms a consequence of the retention of mitral leaflets with subvalvular apparatus.

Conclusions: We find the described technique to be useful not only in valve insufficiency but also in valve stenosis when preserving the mitral leaflets with sub-valvular apparatus during valve replacement. The technique is without procedure-related complications and prevents obstruction of left ventricular outflow tract.

How to cite: Aagaard, J., Andersen, U. L., Lerbjerg, G., Andersen, L. I., & Thomsen, K. K. (1997). Mitral valve replacement with total preservation of native valve and subvalvular apparatus. The Journal of heart valve disease, 6(3), 274–280.

Background and aims of the study: In vivo hemodynamic assessment of bileaflet aortic valve prostheses using standardized echocardiography is still uncommon; hence, adequate comparison of valve types can rarely be made. We compared the postoperative hemodynamics of St. Jude Standard valves (SJS) with those of Sorin Bicarbon valves (BC) implanted in the aortic position, using pulsed, continuous and color Doppler echocardiography.

Methods: The examination was performed four months after aortic valve prosthesis implantation in 76 patients (39 SJS valves, 37 BC valves). Valve sizes varied from 19 mm to 25 mm. Maximal and mean instantaneous pressure gradients were measured by Doppler echocardiography. Effective valve orifice area (EOA) was calculated and prosthetic valve regurgitation was assessed by color Doppler flow imaging.

Results: At valve sizes of 21 mm, 23 mm and 25 mm, SJS valves had a significantly lower EOAs than BC valves (p < 0.05). However, for a given nominal size, BC valves are larger, i.e. they have a larger anatomic (AOA) and geometric orifice area (GOA) than SJS valves. Consequently, BC valves were implanted in patients with a larger left ventricular outflow tract (p < 0.05). When EOA is related to the corresponding AOA, BC valves still show a larger EOA than SJS valves (p < 0.05). Prosthetic valve regurgitation is low in both valve types.

Conclusions: (a) Nominal valve size is not always a good basis for comparison of hemodynamic profiles between valve types. (b) Using the relationship between EOA and AOA, the hemodynamic profile of BC valves in the aortic position is shown to be superior to that of SJS valves.

How to cite: Flameng, W., Vandeplas, A., Narine, K., Daenen, W., Herijgers, P., & Herregods, M. C. (1997). Postoperative hemodynamics of two bileaflet heart valves in the aortic position. The Journal of heart valve disease, 6(3), 269–273.

Background and aims of the study: Previous studies have implicated a number of characteristics that predict strut fracture in Björk-Shiley convexo-concave heart valves, including valve size and position, opening angle, and weld date. This study examines whether the specific batch (shop order) with which a valve is associated during manufacture is related to the risk of fracture.

Material and methods: Our case-control study of CC60 degrees valves obtained detailed information on the manufacturing characteristics of 147 case and 1094 control valves used. Shop order fracture rate for each valve (percentage of other valves in the same shop order with a fracture) was obtained from the research database maintained by the valve manufacturer.

Results: Shop order was associated with fracture risk. Valves originating from shop orders with the highest two categories of fracture rate were at approximately twice the risk of fracture as other valves, after accounting for the effect of known risk factors.

Conclusions: Shop order information may provide additional data for assessing the likelihood of valve fracture in individuals being considered for prophylactic explant of heart valves.

How to cite: Walker, A. M., Funch, D. P., Bianchi, L., & Blot, W. J. (1997). Shop order fracture rate as a risk factor for strut fracture in Björk-Shiley CC60 degrees heart valves. The Journal of heart valve disease, 6(3), 264–268.

Background and aims of the study: Echocardiography and cineradiography are both valuable for the evaluation of prosthetic valve function, especially of mechanical valves. Although Doppler echocardiography data are available for the recently developed ATS valve, cineradiographic evaluation of leaflet movement of the valve has not been performed.

Materials and methods: Five patients received aortic and another five mitral valve replacement with the open pivot ATS bileaflet prosthetic valve. There were three men and seven women; mean patient age was 58.8 years. Cineradiographic and Doppler echocardiographic evaluations of the ATS valve were performed early after surgery in all 10 patients.

Results: There were no early deaths after surgery or after discharge from the hospital. No valve-related complications were seen, and no clinical symptoms or signs of prosthetic malfunction were observed during the follow up period. Doppler-derived values of the ATS valve were comparable with those previously reported; however, cineradiography of the valve demonstrated that the mean angle enclosed by the two open leaflets was 37.6 degrees (range: 34 degrees to 44 degrees) in the aortic position and 29.7 degrees (range: 20 degrees to 35 degrees) in the mitral position. Mean leaflet mobility was 93.0 degrees (range: 86 degrees to 96 degrees) in the aortic position and 100.0 degrees (range: 92 degrees to 110 degrees) in the mitral position. Thus, the opening of the normally functioning ATS valves in vivo was less than that observed in vitro and reported by the manufacturer.

Conclusions: These results suggest that unevenly distributed blood flows with different velocities through the two side orifices and the central orifice may result in incomplete opening of the ATS leaflets, which respond with great sensitivity to localized blood flow. Our findings appear to be important to avoid the removal of a normally functioning ATS valve only because the leaflet opening appears to be 'restricted'.

How to cite: Aoyagi, S., Kawara, T., Fukunaga, S., Mizoguchi, T., Nishi, Y., Kawano, H., & Arinaga, K. (1997). Cineradiographic evaluation of ATS open pivot bileaflet valves. The Journal of heart valve disease, 6(3), 258–263.

Background and aims of the study: Relatively high resting flow velocities are occasionally seen in asymptomatic patients with apparently normal mechanical aortic prostheses. Doppler echocardiography in conjunction with bicycle exercise or dobutamine have been used to 'unmask' symptoms or abnormal hemodynamics in these patients. The aim of this study was to compare the Doppler-derived hemodynamic response to exercise and to dobutamine in patients with normally functioning mechanical aortic prostheses.

Methods: Bicycle ergometry (from 200-400 kg x m/min) and dobutamine (from 5-40 micrograms/kg/min) in conjunction with Doppler echocardiography were performed in 25 asymptomatic patients (21 men, four women; mean age 61 years) with mechanical aortic prostheses (range: 19 mm to 27 mm) who had normal resting hemodynamics and normal left ventricular function. Aortic valve area (continuity equation) and maximal instantaneous and mean gradients were estimated at rest and at peak stress.

Results: Target heart rate was achieved in 10/25 (40%) patients with exercise, and in 21/25 (84%) with dobutamine (p < 0.005). At peak stress, exercise induced a 25% increase in peak flow velocity, a 55% increase in valve gradients, and no significant change in valve area. In comparison, dobutamine induced a 48% increase in peak flow velocity, a 105% increase in valve gradients, and also no significant change in valve area. The flow velocity and pressure gradients at peak stress were significantly higher with dobutamine than with exercise.

Conclusions: In normally functioning aortic valve prostheses, the target heart rate can be reached more often with dobutamine than with supine bicycle exercise. Despite significant increase in the transvalvular gradients, the valve area remained unchanged. The clinical significance of exercise or dobutamine in symptomatic patients with mechanical prostheses is yet to be proven.

How to cite: Zabalgoitia, M., Kopec, K., Oneschuk, L., Linn, W., Herrera, C. J., & O'Rourke, R. A. (1997). Use of dobutamine stress echocardiography in assessing mechanical aortic prostheses: comparison with exercise echocardiography. The Journal of heart valve disease, 6(3), 253–257.

Background and aims of the study: The benefits of transesophageal echocardiography (TEE) may depend on the clinical likelihood of infective endocarditis, but little data exist on patients at low risk.

Methods and results: We studied 32 patients with renal failure with either a low (n = 21) or high (n = 11) level of clinical suspicion for infective endocarditis. In the low-risk cases, TEE provided no new information whether the transthoracic echo was normal or abnormal, although it did confirm that an echogenic mass was more likely to be a calcific deposit than a vegetation. In the high-risk cases, transthoracic echocardiography was always abnormal but TEE added new information in seven out of 11 cases-positively in six, and by exclusion in one. TEE detected signs of complications of infective endocarditis in one case.

Conclusions: We conclude that, when the clinical suspicion of endocarditis is low, TEE is rarely necessary.

How to cite: Wu, E. B., Witherspoon, M. L., Gillmore, J. D., Pattison, J. M., & Chambers, J. B. (1997). The role of transesophageal echocardiography in patients with chronic renal failure at low and high risk of endocarditis. The Journal of heart valve disease, 6(3), 249–252.

Background and aims of the study: Previous studies have demonstrated the benefit of indexing body surface area (BSA) with ventriculo-arterial orifice diameters (or calculated effective surface dynamics) and with nominal external diameters of valves in order to study hemodynamic profiles in vivo or determine the clinical influence of this parameter. This study analyzes the relationship between BSA and nominal external diameter of mechanical valves implanted in the aortic position. It also evaluates the potential interest of using these diameters indexed to BSA in an echo-Doppler study of valves.

Methods: During 1994, a prospective echo-Doppler study of three models of mechanical valves in the aortic position was carried out.

Results: The echo-Doppler parameters of the aortic St. Jude Medical, Sorin Bicarbon and Dideco Monostrut prostheses have been studied with regard to nominal external diameters and were found identical to published data. There were no significant differences in these parameters between the three valves. In 128 patients, prosthetic external diameters were evenly distributed heterogeneously with regard to BSA. Indexing of nominal external diameter with BSA appeared a more reliable reference to study different echo-Doppler parameters, minimizing the effect of cardiac output.

Conclusion: The in vivo echo-Doppler determination at rest of valve hemodynamic profiles should be carried out with reference to the nominal external diameter indexed to the BSA.

How to cite: Bailly, P., Camilleri, L., Legault, B., Fleury, J. P., D'Agrosa, E. M., & de Riberolles, C. (1997). Doppler echocardiographic study of three different mechanical valves in the aortic position: the use of external nominal diameter indexed to body surface area. The Journal of heart valve disease, 6(3), 236–248.

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How to cite: Shah P. M. (1997). Early diagnosis of obstructed aortic valve prostheses: a clinical challenge. The Journal of heart valve disease, 6(3), 234–235.

Mitral valve repair has become the operation of choice for mitral regurgitation. It is often technically more demanding than valve replacement. The role of echocardiography has now extended beyond the identification of severe mitral regurgitation that would benefit from surgical correction. It helps the surgeon to assess valve reparability preoperatively, to assess the need for valve surgery in equivocal cases of ischemic mitral regurgitation, to plan the operation, and to assess valve function after repair. This article aims to discuss the role of echocardiography in providing the information needed by the surgeon for successful mitral valve repair. The echocardiographer must understand the surgeon's needs, while surgeons should understand both the benefits and limitations of echocardiography.

How to cite: Lee, E. M., Shapiro, L. M., & Wells, F. C. (1997). Echocardiography in mitral valve repair for mitral regurgitation: the surgeon's needs. The Journal of heart valve disease, 6(3), 228–233.

Left ventricular (LV) mass is affected by cardiovascular diseases and disorders. An increase in LV mass during a disease process may suggest disease progression, while a decrease in mass may suggest disease regression. Thus, LV mass can be used to follow the natural history of a disease or disorder and to evaluate the effect of therapeutic interventions. Although several methods have been used to determine LV mass in clinical practice, their application requires knowledge of their limitations and advantages. Most such techniques are insufficiently sensitive or specific to define LV mass changes in individual patients. Consequently, it may be more beneficial to evaluate therapy-related changes in LV mass in large patient groups.

How to cite: Boudoulas H. (1997). Determination of left ventricular mass in clinical practice. The Journal of heart valve disease, 6(3), 222–227.

Background and aims of the study: Bovine and porcine pericardial tissues stabilized by dye-mediated photooxidation have found application as bioprosthetic heart valve material.

Methods: To help predict clinical performance, a series of tests were performed to assess the biocompatibility and immunologic properties of these materials.

Results and conclusions: Photooxidized bovine or porcine pericardium sterilized with an iodine-based solution were found to be non-cytotoxic, non-hemolytic, and non-mutagenic. Oil or saline extracts of these tissues passed tests for intracutaneous toxicity (irritation), acute systemic toxicity, and subchronic toxicity. Histopathology of 90-day implants of these tissues in the rabbit model demonstrated no significant macroscopic reaction and only slight microscopic response. Using a rabbit model to assess immune response, both bovine and porcine pericardial tissues elicited low levels of antibody. Furthermore, tissue photooxidation or iodine sterilization did not increase the overall level of antibodies. Glutaraldehyde-treated tissue also elicited low antibody levels which were higher than photooxidized tissue-induced levels. Absorption studies indicated that the photooxidation process may generate new epitopes, possibly collagen cross-links. Using the juvenile sheep model to assess in vivo performance, bioprosthetic valves made with photooxidized tissue were implanted and allowed to serve as functional implants for up to two years. Upon explant, the photooxidized pericardial leaflets were found to be non-calcific and partially covered with a layer of host cells. Histological cross-sections stained with von Willebrand's factor confirmed this layer as endothelial cells.

How to cite: Moore, M. A., & Phillips, R. E. (1997). Biocompatibility and immunologic properties of pericardial tissue stabilized by dye-mediated photooxidation. The Journal of heart valve disease, 6(3), 307–315.