A 53-year-old man developed severe acute systemic illness three weeks after an upper respiratory tract infection. Serial blood cultures grew Moraxella catarrhalis. During antibiotic treatment, fever and infectious parameters disappeared, but severe aortic regurgitation developed. Aortic valve replacement was performed, during which extensive destruction of the aortic valve was noted. Endocarditis due to M. catarrhalis is very rare with, to our knowledge, only six cases having been reported to date. M. catarrhalis is a normal commensal of the upper respiratory tract, but in unpredictable circumstances can become an important pathogen. Bacteremia due to this organism therefore requires prompt treatment, as serious organ complications, including endocarditis, can occur.

How to cite: Neumayer, U., Schmidt, H. K., Mellwig, K. P., & Kleikamp, G. (1999). Moraxella catarrhalis endocarditis: report of a case and literature review. The Journal of heart valve disease, 8(1), 114–117.

A 61-year-old male with degenerative aortic valve regurgitation, mitral valve regurgitation and chronic atrial fibrillation underwent a combined reparative procedure consisting of aortic valve repair, mitral valve repair and maze procedure. Surgery was successful and postoperatively the patient is in NYHA class I, without anticoagulation. To the best of our knowledge, this is the first clinical report of this combined reparative surgery. As advances are made in valve repair surgery, it is expected that similar combined procedures will be performed more frequently in future. The benefits of avoiding valve replacement and anticoagulation after such combination treatment is discussed.

How to cite: Izumoto, H., Sato, Y., Ogawa, M., Kamata, J., Eishi, K., & Kawazoe, K. (1999). Double valve repair and maze procedure for degenerative valvular disease and chronic atrial fibrillation. The Journal of heart valve disease, 8(1), 112–113.

Background and aim of the study: The Doppler color flow mapping techniques of the distal jet are influenced by the eccentricity of aortic regurgitation (AR). The aim of this study was to clarify screening variables for assessing AR severity in patients with an eccentric jet.

Methods: Fifty-four patients with eccentric AR were studied. Values of the radius and effective regurgitant orifice area (EROA) determined by the proximal isovelocity surface area (PISA) method using transthoracic echocardiography (TTE) were compared with measurements by multiplane transesophageal echocardiography (m-TEE), aortic angiography and regurgitant fraction.

Results: In patients with eccentric AR, values of PISA radius and EROA by TTE correlated well with values made by m-TEE (r = 0.87, p<0.001 and r = 0.86, p<0.001, respectively), angiographic grade (rs = 0.87, p<0.001 and rs = 0.88, p<0.001, respectively) and regurgitant fraction (r = 0.88, p<0.001 and r = 0.84, p<0.001, respectively). Values of PISA radius > or =0.70 cm and EROA > or =0.25 cm2 were always associated with a regurgitant fraction > or =0.40, while PISA radius <0.70 cm and EROA <0.25 cm2 were always associated with a regurgitant fraction <0.40.

Conclusions: Measurements determined by the PISA method, using either TTE or m-TEE, are reliable for assessing the severity of eccentric AR. PISA radius is easy to obtain and therefore widely applicable in clinical practice as a screening tool for evaluating eccentric AR severity.

How to cite: Sato, Y., Kawazoe, K., Nasu, M., & Hiramori, K. (1999). Clinical usefulness of the proximal isovelocity surface area method using echocardiography in patients with eccentric aortic regurgitation. The Journal of heart valve disease, 8(1), 104–111.

Background and aim of the study: Complications after replacement of diseased heart valves with mechanical prostheses have been shown to be related to the hemodynamics distal to the valve. For this reason, the velocity patterns have been disclosed in vitro with a variety of different techniques. This study introduces a magnetic resonance imaging (MRI) -based technique, which entails easy acquisition of fluid velocity field data with a high accuracy and spatial resolution.

Methods: A high-field magnetic resonance scanner equipped with short echo time phase-contrast velocity measurement software was applied in a detailed mapping of the axial velocity profile across the entire vessel area at two positions downstream of a bileaflet valve prosthesis inserted in a pulsatile flow system in vitro. The laminar shear forces were calculated from the fluid velocity field data.

Results: The velocity profiles very close to the valve reflected the bileaflet design as also shown in previous studies, but the extent and velocities of the jet emanating from the slit between the leaflets were clearly better visualized. However, one diameter downstream of the valve the central jet was completely dispersed and the hemodynamic complexity was significantly reduced. Recirculation and retrograde flow regions that might be relevant for understanding typical long-term complications after implantation were observed close to the valve.

Conclusions: In one scan experiment the presented method provides information on flow characteristics that previously required application of different types of experiment. Thus, the method seems promising as a new technique for detailed and extensive mapping of the velocities and laminar shear stresses downstream of prosthetic heart valves in vitro.

How to cite: Ringgaard, S., Botnar, R. M., Djurhuus, C., Stodkilde-Jorgensen, H., Hasenkam, J. M., Boesiger, P., & Pedersen, E. M. (1999). High-resolution assessment of velocity fields and shear stresses distal to prosthetic heart valves using high-field magnetic resonance imaging. The Journal of heart valve disease, 8(1), 96–103.

Background and aim of the study: Steady and pulsatile flow models used to assess the hydrodynamic aspects of prosthetic heart valves are generally made of Plexiglas and Lucite tubing. They often allow continuous-wave and pulsed-wave Doppler ultrasound velocity measurements to be made parallel to the flow, but cannot be used as such for ultrasound scanning of valve inflow and outflow velocities because of ultrasonic reverberation and refraction by the tubing. The aim of the study was to develop a new flow model which allowed ultrasonic scanning of the prosthetic valve flow for three-dimensional (3D) reconstruction of color Doppler flow distributions.

Methods: The flow model, designed with left ventricular and aortic chambers composed of agar gel which mimics the ultrasound characteristics of biological tissues, was developed and tested for comparative in vitro hydrodynamic and Doppler ultrasonic studies of aortic prosthetic valves. An electromagnetic flowmeter and a pressure monitor provided the flow and pressure signals for the hydrodynamic tests. The Doppler ultrasonic evaluation was performed with an Ultramark 9 HDI ultrasound system and a 3D ultrasound imaging system. The model was designed to enable assessment of prosthetic valve performance by pulsed-wave and continuous-wave Doppler velocity measurements, as well as by 3D color Doppler velocity measurements obtained by ultrasonic scanning of the left ventricle or aortic chamber with an ultrasound probe mounted on a motorized translation assembly.

Results: The study results showed that this new flow model can provide 3D color Doppler velocity distributions as well as accurate comparisons of hydrodynamic parameters of mechanical and bioprosthetic heart valves derived from Doppler and catheter measurements, both under steady and pulsatile flow conditions.

Conclusion: This new flow model can be used to evaluate the usefulness of hydrodynamic parameters for the assessment of prosthetic heart valves using both conventional Doppler echocardiography, as currently used in patients, and 3D color Doppler ultrasonic imaging.

How to cite: Durand, L. G., Garcia, D., Sakr, F., Sava, H., Cimon, R., Pibarot, P., Fenster, A., & Dumesnil, J. G. (1999). A new flow model for Doppler ultrasound study of prosthetic heart valves. The Journal of heart valve disease, 8(1), 85–95.

Background and aims of the study: Composite graft replacement of the aortic root is still a complex operation, transgraft hemorrhage being one of the most severe complications. The aim of the study was to evaluate early results with the Carbo-seal composite conduit for aortic root replacement.

Methods: A retrospective review of 21 patients operated on for ascending aortic aneurysm and/or dissection with the open technique between August 1993 and February 1998 is presented; 12 patients had Marfan syndrome and nine were non-Marfan.

Results: There were two operative deaths (9.5%) due to low cardiac output. Two patients were re-explored for bleeding which was not due to transgraft hemorrhage. Postoperative complications were one hemothorax, one pneumothorax and two pericardial effusions. During the follow up, one patient died of rupture of a descending aortic aneurysm, and one patient in atrial fibrillation had a transient ischemic attack. At the closing of the follow up, the remaining patients were well and free of complications.

Conclusions: Carbo-seal may be considered a reliable device for use in aortic root replacement, though a longer follow up and a larger patient population are necessary to confirm these positive early results.

How to cite: Vitale, N., Owens, W. A., Hamilton, J. R., Forty, J., Dark, J. H., & Hasan, A. (1999). Early results with the Carbo-seal composite valve conduit for aortic root replacement. The Journal of heart valve disease, 8(1), 80–84.

Background and aim of the study: The study aim was to analyze predictive factors of long-term results after mechanical heart valve replacement in children.

Methods: Forty-four patients (19 males, 25 females; mean age 8.9+/-3.9 years, median 7.0 years, range: 1.3 to 15 years) underwent heart valve replacement with mechanical prostheses. Of these patients, 25 had left atrioventricular valve replacement (LavVR) (18 mitral, six tricuspid in corrected transposition of the great arteries (TGA), one common in a univentricular heart), 13 had aortic valve replacement (AVR) and six had tricuspid valve replacement (TVR). The etiology of the valvular disease was congenital in all patients, and complicated by infective endocarditis in seven (16%). Fifteen patients had undergone previous procedures and 16 required simultaneous repair of associated lesions. The mean size of the implanted prosthesis was 26 mm (range: 19-29 mm) for LavVR, 29.7 mm (range: 23-33 mm) for TVR, and 21.9 mm (range: 19-25 mm) for AVR. Postoperatively, all patients received oral anticoagulation. The mean follow up was 6.8+/-3.5 years (total 290 patient-years).

Results: There was no early mortality, but three patients (7%) died later; all late deaths occurred in patients with LavVR. There were two sudden deaths, both in patients with complex congenital heart disease and heart failure (before the ACE inhibitor era), and one valve-related death from thrombotic occlusion of a mitral prosthesis. Five patients were reoperated on; three for patient-prosthesis mismatch, one for periprosthetic leak, and one for aortic dissection due to Marfan's syndrome. Thrombotic obstruction occurred in three patients; two in the tricuspid position were treated successfully with thrombolysis, but one in the left atrioventricular position proved fatal. After seven years, the survival rate was 93.4%.

Conclusions: Mechanical heart valve replacement in children aged over one year with congenital heart disease can be performed with satisfactory early and late results. Mechanical valves of >23 mm diameter in the atrioventricular position in the systemic ventricle, and >21 mm in the aortic orifice, can offer excellent long-lasting hemodynamic performance. However, mechanical valves in the tricuspid position are prone to develop thrombotic occlusion.

How to cite: Lubiszewska, B., Rozanski, J., Szufladowicz, M., Szaroszyk, W., Hoffman, P., Ksiezycka, E., Rydlewska-Sadowska, W., & Ruzyllo, W. (1999). Mechanical valve replacement in congenital heart disease in children. The Journal of heart valve disease, 8(1), 74–79.

Homograft use for aortic valve replacement (AVR) in aortic valve acute bacterial endocarditis (ABE) has gained in popularity, due mainly to the relative resistance of homografts to infection. Recent success with mitral valve homograft use led us to apply homograft mitral valve replacement (MVR) in a patient with severe ABE that was not amenable to valve repair. Following surgery, the patient improved rapidly with normalization of infection parameters and chest radiography, and was discharged home on postoperative day 11. Follow up echocardiography showed good function of the homograft mitral valve with no regurgitation. After four months, the patient had normal valve function, with no evidence of infection. In conclusion, MVR with a mitral valve homograft in the setting of ABE was satisfactory, though patient follow up was relatively short (four months).

How to cite: Reardon, M. J., Vinnerkvist, A., & LeMaire, S. A. (1999). Mitral valve homograft for mitral valve replacement in acute bacterial endocarditis. The Journal of heart valve disease, 8(1), 71–73.

Background and aim of the study: Isolated cleft of the anterior mitral leaflet is a rare cause of mitral insufficiency. Although an established entity, due to its rarity the exact anatomic diagnosis is difficult to establish unless sought specifically.

Methods: Four patients (age range: 16 to 26 years) with isolated cleft of the anterior mitral leaflet were treated at the authors' institute. Clinical symptoms were typical of mitral insufficiency; the exact anatomic diagnosis was not established preoperatively in any patient. The cleft was directly sutured in all four patients and additional annuloplasty was performed in three.

Results: Postoperative echocardiography confirmed satisfactory results. After a mean follow up of 46.7 months (range: 3 to 84 months), one patient had mild mitral insufficiency and the remaining patients had no mitral regurgitation.

Conclusion: In severe mitral insufficiency with no obvious mitral valve pathology and an intact atrial septum, a cleft of the anterior mitral leaflet should be sought. Repair of the cleft can restore normal mitral valve function.

How to cite: Mohanty, S. R., Choudhary, S. K., Ramamurthy, S., & Kumar, A. S. (1999). Isolated congenital anterior mitral leaflet cleft: a rare cause of mitral insufficiency. The Journal of heart valve disease, 8(1), 67–70.

Background and aim of the study: The detection of left atrial thrombus (LAT) is especially important in patients being evaluated for percutaneous mitral valvuloplasty and elective cardioversion for atrial fibrillation. Transesophageal echocardiography (TEE) is widely used for this indication. This study was undertaken to validate the use of multiplane TEE to detect LAT in the setting of rheumatic mitral valve disease.

Methods: The study population comprised 262 patients (103 men, 159 women, mean age 42.2+/-13.1 years) who underwent open heart surgery for rheumatic mitral valvular disease between January 1994 and October 1997. Of these patients, 178 had mitral stenosis and 84 mitral regurgitation. All patients were examined with multiplane TEE less than three days before valvular surgery.

Results: The presence or absence of LAT was confirmed at surgery by direct inspection of the left atrium. Left atrial thrombi were detected by TEE in 34 patients (14 men, 20 women; mean age 51+/-8 years). The presence of all 34 thrombi found by multiplane TEE was confirmed during surgery. Only one thrombus was confirmed surgically among 228 patients shown thrombus-negative by multiplane TEE. The sensitivity, specificity, positive and negative predictive value and diagnostic accuracy for multiplane TEE were 97, 100, 100, 99.6 and 99.6%, respectively.

Conclusion: Multiplane TEE is exquisitely sensitive for the detection of LAT.

How to cite: Koca, V., Bozat, T., Akkaya, V., Sarikamis, C., Turk, T., Vural, H., & Ozdemir, A. (1999). Left atrial thrombus detection with multiplane transesophageal echocardiography: an echocardiographic study with surgical verification. The Journal of heart valve disease, 8(1), 63–66.

Background and aim of the study: Significant tricuspid regurgitation (TR) can contribute to increased morbidity and mortality in patients after mitral valve replacement (MVR), both in the immediate and late postoperative period. The aim of this study was to evaluate the prevalence and the clinical importance of TR late after MVR, as assessed both clinically and echocardiographically.

Methods: The study group comprised 65 patients (39 women, 26 men; mean age 61+/-12 years) with rheumatic heart disease who had undergone MVR without tricuspid valve surgery between one and 30 years (mean 11.3+/-8 years) before their last clinical examination. All patients underwent a complete color-Doppler echocardiographic examination. The predominant presurgical mitral lesion was stenosis in 44 patients and regurgitation in 21. The severity of the tricuspid valve disease was assessed echocardiographically using color-Doppler flow images and flow direction in the inferior vena cava or hepatic veins, and by clinical evaluation.

Results: Echocardiography revealed significant late TR in 44 patients (67%), which was moderate in 16 and severe in 28, and evident on physical examination in 24 cases (37%). Age (relative risk (RR) = 1.1; C.I. 1-1.1) and female sex (RR = 1.8; C.I. = 1.0-3.2) were identified as statistically significant predictors for late clinical TR development, but only age was found as a statistically significant predictor for echocardiographic TR development. An elevated RR for organic TR and predominant mitral regurgitation was found. In contrast, pre- and postoperative pulmonary artery pressure, predominant mitral lesion, prosthetic valve gradient and regurgitation were similar in patients with and without late TR.

Conclusions: Significant TR diagnosed by echocardiography late after MVR is common, and clinically evident in more than one-third of patients. Therefore, a lower threshold for tricuspid valve repair should be considered when mitral valve surgery is carried out.

How to cite: Porter, A., Shapira, Y., Wurzel, M., Sulkes, J., Vaturi, M., Adler, Y., Sahar, G., & Sagie, A. (1999). Tricuspid regurgitation late after mitral valve replacement: clinical and echocardiographic evaluation. The Journal of heart valve disease, 8(1), 57–62.

Background and aim of the study: Abnormal passive elastic properties have been reported in patients with severe mitral stenosis and have been attributed to either: (i) chamber atrophy due to unloading; (ii) myocardial fibrosis; (iii) right and left ventricular (LV) interaction; or (iv) internal restrictions due to the rigid mitral valve apparatus. The study aim was to evaluate the effect of percutaneous mitral balloon valvuloplasty (PMV) on passive elastic properties in 19 patients with severe mitral stenosis. Ten patients with normal coronary arteries and LV function served as controls.

Methods: LV high-fidelity pressure measurements and simultaneous biplane LV angiograms were obtained before and after PMV (n = 11). The constant of chamber stiffness (b; ml(-1)) was calculated from the diastolic pressure-volume relationship and the constant of myocardial stiffness (beta) from the diastolic stress-strain relationship. The time constant of relaxation (T; ms) was calculated from the LV pressure decay during isovolumic relaxation. Regional ejection fraction (radial axis system) was determined in six regions of the right anterior oblique (RAO) and left anterior oblique (LAO) angiographic projections.

Results: Mitral valve area was increased from 1.0 to 2.2 cm2 after PMV, whereas diastolic pressure gradient was reduced from 14 to 4 mmHg. Global LV ejection fraction (EF) was slightly reduced (57% versus 63%; p<0.05) before valvuloplasty and normalized thereafter. Regional EF increased significantly (p<0.05) in the posterolateral region of the LAO projection after intervention. Myocardial stiffness was increased before, and decreased significantly after balloon valvuloplasty (from 16 to 11; p<0.05). The rate of relaxation and chamber stiffness remained unchanged.

Conclusions: Myocardial stiffness is increased in patients with mitral stenosis, but normalized after successful PMV. The improvement in passive elastic properties after valvuloplasty can be explained by the mobilization of the subvalvular apparatus with an improvement in regional LV function.

How to cite: Mayer, I. V., Fischer, A., Jakob, M., Mandinov, L., Hug, R., Vassalli, G., & Hess, O. M. (1999). Reversal of increased diastolic stiffness in mitral stenosis after successful balloon valvuloplasty. The Journal of heart valve disease, 8(1), 47–56.

Background and aims of the study: This report describes surgical indication and operative technique of complete preservation of the mitral valvular and subvalvular apparatus during mitral valve replacement.

Methods: Twenty patients, 12 with rheumatic lesions and eight with congenital lesions, were operated between 1991 and 1996. The left atrium was opened using a trans-septal approach through the right atrium in 17 patients, and at the intra-atrial groove in three. The valve was sized without excising any mitral valvular or subvalvular tissue. Teflon pledget-reinforced horizontal mattress valve sutures were passed from the left atrium, through the mitral annulus, around the free edge of mitral leaflet, and up through the prosthetic sewing ring. The prosthetic valve was seated and the sutures tied, reefing the native leaflets and compressing them between the sewing ring and native annulus. Thus, chordal tension on the ventricle was evenly maintained.

Results: There was no operative or late death. Postoperative results were excellent. Echocardiography showed that none of the patients had any observable anterior leaflet and redundant subvalvular tissue in the left ventricular outflow tract (LVOT); thus, neither LVOT obstruction nor interference with prosthetic valve function occurred.

Conclusions: Based on these findings, it is suggested that when mitral valve replacement is required in patients with mitral insufficiency (MI) or MI with mild stenosis, the mitral valvular and subvalvular tissue should be completely preserved.

How to cite:

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How to cite: Frater R. W. (1999). Chordal sparing mitral valve replacement. The Journal of heart valve disease, 8(1), 42–43.

Background and aim of the study: Stent mounting of a porcine aortic valve induces loss of mobility and reduces the effective orifice area. Any stentless design conserves the flexibility of the valvular apparatus, but unfortunately, these valves require a more elaborate implantation technique which is considered a major drawback by many surgeons. In an attempt to see if the insertion of the Toronto SPV stentless valve could be made easier, we altered the configuration by lowering the profile at the depth of both coronary sinuses. Theoretically, this could enable insertion of the valve by a single suture layer under the two coronary ostia, in addition to some fixation points at the commissures.

Methods: Two modified 20 mm Toronto SPV valves were tested in vitro for hydrodynamics in a computer-controlled pulse duplicator system and compared with two standard 20 mm valves. Animal implant studies using three standard versus three modified valves (21, 23 and 25 mm) were conducted in juvenile sheep for durability and biocompatibility over a period of three months.

Results: The standard Toronto SPV valve provided excellent hemodynamics. The altered configuration performed less optimally during hydrodynamic testing with increased transvalvular gradients. In animal implant studies, cusps adjacent to all reduced-height sinuses showed markedly accelerated fibrosis and substantial calcification, in contrast to only mild fibrosis on the inflow aspects of the standard leaflets.

Conclusions: The more pronounced the deformation of the stentless valve, the faster the calcification of the leaflets adjacent to the distorted sinuses. As both valves types were prepared using an identical preservation technique, the role of loss of mobility in leading to early failure is clearly demonstrated. These findings also underline the extreme importance of correct implantation technique for all stentless valves in order to prevent degeneration.

How to cite: 

Background and aim of the study: In a previous study, we used magnetic resonance (MR) imaging to reconstruct, three-dimensionally, porcine bioprosthetic heart valve (PBHV) cusp geometry. Initial results using three valves indicated that accelerated testing induced changes in cuspal shape, including focal regions of high curvature. Since for thin-walled shell structures, such as the PBHV cusp, curvature changes can affect the stress distribution independently from changes to mechanical properties, shape changes might have adverse effects on PBHV durability.

Methods: The MR technique was applied to an expanded valve database to explore more fully shape change with fatigue. The spatial curvature distribution was compared across valves subjected to a range of accelerated test times.

Results: Results confirmed our initial findings that PBHV cusps undergo a continuous, non-recoverable deformation with accelerated testing. This deformation resulted in an increase in the portion of cuspal surface exhibiting high curvature values. In one cusp we mapped structural information obtained by small-angle light scattering back to the three-dimensional cuspal surface using an interpolation technique. Results from the mapped cusp demonstrated a strong spatial correlation between elevated curvatures and structural damage.

Conclusions: The observed changes in cuspal shape accelerate PBHV damage due to an increase in flexural strains induced by an increase in curvature reversal during operation, rather than an increase in tension during closure.

Background and aim of the study: The long-term (18 years) results after aortic (AVR), mitral (MVR) and double (aortic/mitral, DVR) valve replacement with Hancock II bioprosthesis were investigated.

Methods: Between 1978 and 1996, 279 Hancock II bioprostheses were implanted in 269 patients (166 males, 113 females; mean age 61.8+/-13.3 years). There were 135 AVR (48.4%), 122 MVR (43.8%) and 22 DVR (7.8%). Preoperatively, 208 patients (77.3%) were in NYHA functional class III/IV, 53 (19.7%) had previous cardiac surgery, and 19 (7.1%) underwent concomitant coronary artery bypass. Follow up (mean seven years) was 96% complete, with a total of 1,857 patient-years.

Results: There were 20 early (7.3%), and 78 (29.0%) late deaths. At the last follow up, 68.3% of patients were in NYHA functional class I/II. The actuarial survival rate of patients at 10 and 18 years after discharge was 67.7+/-5.0% and 44.7+/-8.8% after AVR and 64.5+/-5.6% and 32.7+/-11.5% after MVR, respectively; survival after DVR was 74.0+/-11.2% at 12 years. At 10 and 18 years, actuarial freedom from thromboembolism was 83.5+/-4.5% and 73.1+/-10.5% after AVR and 82.1+/-4.3% and 73.2+/-7.3% after MVR; it was 78.4+/-15.0% after DVR at 12 years. At these times, actuarial freedom from hemorrhage was 88.7+/-3.8% and 83.5+/-6.2% after AVR and 79.0+/-4.9% and 32.6+/-23.3% after MVR; freedom after DVR was 36.2+/-26.6%. Probability of freedom from endocarditis at 10 and >15 years was 93.4+/-3.5% and 85.9+/-7.8% after AVR and 97.0+/-2.1% and 97.0+/-2.1% for MVR, respectively; freedom at 10 years after DVR was 75.0+/-21.6%. Freedom from structural deterioration at 10 and 18 years was 77.9+/-5.3% and 18.7+/-14.6% after AVR and 78.3+/-6.0% and 32.1+/-10.2% after MVR; freedom at 10 and 12 years after DVR was 64.0+/-17.5% and 32.0+/-24.2%. A low incidence of structural valve deterioration was found in AVR patients aged >65 years (p = 0.0478). Hemorrhage and paravalvular leak were more frequent in MVR (p = 0.0296 and 0.0309, respectively). No difference was seen in thromboembolism after anticoagulation for one or three months after AVR. Actuarial freedom from explantation at 10 and 18 years was 73.1+/-5.9% and 15.9+/-13.5% after AVR and 77.1+/-6.1% and 37.3+/-9.7% after MVR; freedom at 10 and 12 years after DVR was 72.0+/-17.8% and 24.0+/-20.4%.

Conclusion: Over an 18-year follow up, the Hancock II bioprosthesis has shown satisfactory results, with a low incidence of valve-related complications, especially in elderly patients in the aortic position.

How to cite: Legarra, J. J., Llorens, R., Catalan, M., Segura, I., Trenor, A. M., de Buruaga, J. S., Rabago, G., & Sarralde, A. (1999). Eighteen-year follow up after Hancock II bioprosthesis insertion. The Journal of heart valve disease, 8(1), 16–24.

Background and aim of the study: Heart valve substitutes have been in use for over 30 years. Bioprosthetic heart valves have many advantages, but unfortunately suffer tissue degeneration and calcification. Many approaches, such as antimineralization treatment to prevent or delay these changes, have been tried. We present the morphologic findings from a series of Hancock II (antimineralization-treated) porcine bioprostheses.

Methods: Forty-five Hancock II porcine valve bioprostheses (16 mitral, 29 aortic) surgically explanted between March 1991 and December 1995 at the Toronto Hospital were analyzed for morphologic findings and causes of failure. The prostheses were implanted in 36 adults (mean age 55+/-14.7 years, range: 27 to 75 years) and had been in place between one month and 11 years (mean 5.1+/-3.3 years).

Results: Structural valve deterioration (SVD) characterized by tissue degeneration, calcification, cusp tears and increased stiffness, was the single most significant finding and cause of failure, affecting 56% of valves. Some degree of calcification was seen in 55% of prostheses, with severe calcification (grade 3 or 4) in 18%. Aortic bioprostheses showed more severe and earlier calcification than mitral ones (p = 0.03). Compared with the standard Hancock valve, the low incidence of significant calcification suggests a beneficial protective effect of antimineralization treatment. Severe pannus (grade 3 or 4) was seen in 60% of these prostheses. The pattern of pannus growth differs between mitral and aortic sites; mitral prostheses showed pannus on the flow and non-flow surfaces, often associated with cusp tears, mitral regurgitation and mitral leaflet preservation. A similar degree of pannus on aortic prostheses was invariably present on the flow surface and extended onto the valve cusps, leading to changes in the orifice which may cause clinical aortic stenosis. Infective endocarditis was seen in 15 prostheses (five mitral, 10 aortic) from 11 patients, and comprised the second most important cause of prosthesis failure. The risk of recurrent endocarditis was particularly high in patients who had infective endocarditis before valve replacement, even at five and six years post implantation.

Conclusions: SVD is the major finding in explanted Hancock II bioprostheses and is associated with cusp tears and calcification. The incidence of tissue calcification appears lower at the mitral site. These findings suggest that the antimineralization treatment had some beneficial effect. Pannus associated with prosthesis dysfunction at the mitral sites is a prominent finding and on the non-flow surface may be related to the native mitral valve-conserving procedure.

How to cite: Butany, J., Yu, W., Silver, M. D., & David, T. E. (1999). Morphologic findings in explanted Hancock II porcine bioprostheses. The Journal of heart valve disease, 8(1), 4–15.

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How to cite: Thiene, G., Bortolotti, U., & Valente, M. (1999). The Hancock II xenograft: a step forward in bioprosthetic valve longevity?. The Journal of heart valve disease, 8(1), 1–3.