Homografts for mitral valve replacement in florid endocarditis--an alternative to prosthetic replacement]

INTRODUCTION: Homografts for valve replacement are indicated in acute valve endocarditis. It is assumed that they possess anti-infective properties. Homografts are an established indication in aortic valve replacement. We present our early results with homografts for mitral valve replacement in acute endocarditis. PATIENTS AND METHODS: Between July 1996 and March 1998 we used cryopreserved homografts for mitral valve replacement in seven patients. In three cases (age 24, 42, and 34 years) the indication was an acute endocarditis with subsequent severe mitral valve insufficiency. The size of the required homograft was measured preoperatively using transesophageal echocardiography. For implantation the technique described by A. Carpentier was used; for stabilization of the mitral anulus a valvular ring (Physio) was implanted. Follow-up was done every six months including clinical and echocardiographical examinations. After the first postoperative year an Ultrafast-CT was done in addition. RESULTS: One patient had complete mitral valve replacement, in the other two cases the diseased parts of the valve were completely excised and the valve was repaired using a partial homograft. There were no perioperative deaths. In the follow-ups, up to 24 months of uneventful homograft function was documented by echocardiography; no insufficiency > degree I was seen on color Doppler echocardiography. At the last follow-up (mean follow-up 16 months, range 12 to 24 months) the average mitral valve orifice was 2.5 +/- 0.5 cm2, the mean pressure gradient 2.8 +/- 0.8 mm Hg. In Ultrafast-CT no morphological abnormalities of the mitral valves and no dilatation of the left ventricle were seen. There were no signs of a recurrence of the endocarditis in any patient during the follow-up period. CONCLUSION: Homografts for mitral valve replacement are an interesting alternative to prosthetic valve replacement, especially in younger patients. In cases with acute endocarditis, in which mechanical prosthesis should not be used, a reconstruction or repair of the mitral valve with preservation of the ventricular geometry is possible even if large parts of the mitral valve are infected.     

Mitral valve surgery utilizing homografts: early results

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair is superior to prosthetic valve replacement due to preservation of the subvalvular apparatus. We used cryopreserved homografts for mitral valve replacement in selected cases, in whom valve repair would not have been successful. METHODS: Cryopreserved homografts were used in 10 patients (four males, six females; mean age 47 +/- 8 years; range: 27-65 years), for either complete (n = 7) or partial (n = 3) mitral valve replacement. Surgery was indicated due to acute endocarditis (n = 3), stenosis (n = 4) or combined mitral valve disease (n = 3). Transesophageal echocardiography (TEE) was performed to determine correct homograft size; these values were compared with intraoperative measurements of valvular dimensions. The function of the implanted grafts was examined intraoperatively by TEE. Follow up included clinical examination, electrocardiography and echocardiography. RESULTS: All patients survived surgery. Intraoperative TEE revealed mild insufficiency (grade I) in six cases and no insufficiency in four. The papillary muscle-mitral annulus distance was the most reliable preoperative echocardiographic parameter to determine the required homograft. Mean pressure gradients were 3.2 +/- 0.7 mmHg for complete and 2.4 +/- 0.5 mmHg for partial homograft replacement. Sinus rhythm was present in all cases at discharge. Mean follow up was 24 months (range: 6-36 months). At six-month and one-year follow up, the pressure gradients had risen slightly to 3.4 +/- 0.6 mmHg (complete) and 2.8 +/- 0.6 mmHg (partial). To date, four patients had competent grafts, and six presented with an insufficiency (grade I). All patients had normal left ventricular function (EF 65 +/- 6%) at their last follow up; there were no signs of endocarditis during the follow up period. CONCLUSION: Mitral homografts for valve replacement or repair are recommended in selected cases in whom conservative reconstruction techniques are not possible. The avoidance of long-term anticoagulation therapy and preservation of left ventricular geometry are clear advantages to other mitral valve prostheses.     

Homografts in patients with combined disease of the aortic valve and the ascending aorta: an alternative to the classical Bentall procedure

BACKGROUND AND AIM OF THE STUDY: In patients with aneurysms or dissections of the ascending aorta and additional aortic valve disease, valve-containing composite grafts are used in clinical routine. The study aim was to present our experience with homografts for aortic valve replacement extended by a vascular prosthesis as an alternative to the classical Bentall procedure. METHODS: Thirty consecutive patients (mean age 46+/-14 years) were included in this study. Indications for valve replacement were aortic stenosis (n = 15), aortic insufficiency (n = 6), combined aortic valve disease (n = 6), endocarditis of the native valve (n = 1), and endocarditis of a previously placed bioprosthesis (n = 2). The mean diameter of the ascending aorta was 5.6+/-0.5 cm; one patient had an acute dissection (diameter 4.4 cm). For valve replacement, cryopreserved homografts (mean size 24+/-2 mm) were used in a mini-root technique, and the ascending aorta was replaced by collagen-coated vascular prostheses (mean diameter 28+/-3 mm). The size of the vascular prosthesis was adjusted to the diameter of the sinutubular junction of the implanted homograft. Follow up included annual clinical examinations, transthoracic echocardiography and ultrafast computed tomography (CT) scans. RESULTS: All patients survived surgery, and no deaths occurred during follow up. None of the patients had postoperative anticoagulation, and no thromboembolic events were noted. Follow up was complete, with an average 48 months (range: 6 to 84 months). Doppler echocardiography revealed trivial to mild aortic regurgitation in nine patients postoperatively, with no deterioration during follow up. No pathologic pressure gradients over the aortic valves were measured at Doppler echocardiography; the mean valvular orifice area was 2.5+/-0.3 cm2. At ultrafast CT, normal homograft anatomy including the sinotubular junction, no calcifications, and no signs of annular dilatation were seen. In the patient who had surgery for acute endocarditis of the native valve, ultrafast CT revealed a small pseudoaneurysm below the left coronary artery, without need for reoperation. CONCLUSION: Short- and mid-term results show that cryopreserved homografts extended by small-sized vascular prostheses can be used safely for Bentall procedures in selected cases where the diameter of the aortic valve annulus is moderately dilated.     

Is there an advantage in using homografts in patients with acute infective endocarditis of the aortic valve?

BACKGROUND AND AIM OF THE STUDY: Acute infective endocarditis is a surgical challenge, particularly when paravalvular abscesses and annular destruction are present. The choice of a homograft or mechanical valve prosthesis is an important issue in these patients. The study aim was to compare the outcome with homografts and mechanical valves in patients with acute infective endocarditis. METHODS: A total of 77 patients (mean age 49+/-9 years) operated on for acute endocarditis of the aortic valve was included in the study and analyzed retrospectively. The causative bacterium was isolated from blood cultures in 71 cases. Preoperatively, 21 patients required artificial ventilation and 24 had inotropic support due to hemodynamic instability. Aortic homografts were implanted in 43 patients, and mechanical valve prostheses in 34. The two patient groups were similar in terms of gender, age and preoperative inotropic support. In total, 31 patients (44%) had paravalvular abscesses, and a homograft was used significantly more often (77%, p <0.05) in these cases. Follow up examinations (clinical examination, ECG and transthoracic echocardiography) were performed six months postoperatively and continued on an annual basis. Endocarditis relapse was defined as persisting infection, whereas re-endocarditis indicated a new infection after an interval of at least six months. RESULTS: Perioperative mortality was 11.5% (5/43) in homograft patients. In the 38 survivors, follow up was complete and averaged 5.0+/-1.2 years. One patient had an endocarditis relapse three months after surgery. Re-endocarditis occurred in three patients after two or three years. One other patient had pseudoaneurysm formation without a need for intervention, and one had repeat aortic valve replacement due to dysfunction of the graft after four years. The other 33 patients had an uneventful follow up. Echocardiography revealed aortic insufficiency grade 1 in 12 cases (36%), with no progression during follow up. Perioperative mortality in mechanicat valve patients was 20.5% (n = 7) (p <0.05 versus homograft), and in those with paravalvular abscess, perioperative mortality was even higher than in homograft patients (4/7, 57.1% versus 3/24, 12.5%; p <0.05). When considering only patients without paravalvular abscess, there was no significant difference between groups (10.5% versus 12.5%). Three relapses occurred in mechanical valve patients (10.3%), but no endocarditis recurred during follow up. One late death (3.7%) occurred due to bleeding complicating long-term anticoagulation. CONCLUSION: The study results do not permit a general recommendation to be made for homograft use in patients with acute endocarditis. In cases with paravalvular abscesses, however, there was a trend towards improved outcome in the homograft group.     

Homografts für den Mitralklappenersatz bei florider Endokarditis - eine Alternative zum prothetischen Ersatz

Summary Introduction: Homografts for valve replacement are indicated in acute valve endocarditis. It is assumed that they possess anti-infective properties. Homografts are an established indication in aortic valve replacement. We present our early results with homografts for mitral valve replacement in acute endocarditis. Patients and methods: Between July 1996 and March 1998 we used cryopreserved homografts for mitral valve replacement in seven patients. In three cases (age 24, 42, and 34 years) the indication was an acute endocarditis with subsequent severe mitral valve insufficiency. The size of the required homograft was measured preoperatively using transesophageal echocardiography. For implantation the technique described by A. Carpentier was used; for stabilization of the mitral anulus a valvular ring (Physio^TM) was implanted. Follow-up was done every six months including clinical and echocardiographical examinations. After the first postoperative year an Ultrafast-CT was done in addition. Results: One patient had complete mitral valve replacement, in the other two cases the diseased parts of the valve were completely excised and the valve was repaired using a partial homograft. There were no perioperative deaths. In the follow-ups, up to 24 months of uneventful homograft function was documented by echocardiography; no insufficiency > °I was seen on color Doppler echocardiography. At the last follow-up (mean follow-up 16 months, range 12 to 24 months) the average mitral valve orifice was 2.5 - 0.5 cm², the mean pressure gradient 2.8 - 0.8 mm Hg. In Ultrafast-CT no morphological abnormalities of the mitral valves and no dilatation of the left ventricle were seen. There were no signs of a recurrence of the endocarditis in any patient during the follow-up period. Conclusions: Homografts for mitral valve replacement are an interesting alternative to prosthetic valve replacement, especially in younger patients. In cases with acute endocarditis, in which mechanical prosthesis should not be used, a reconstruction or repair of the mitral valve with preservation of the ventricular geometry is possible even if large parts of the mitral valve are infected. Zusammenfassung Einleitung: Da Homografts eine natürliche Infektresistenz zugeschrieben wird, stellen Endokarditiden eine besondere Indikation für dieses Klappenersatzverfahren dar. Für den Aortenklappenersatz sind sie inzwischen in der klinischen Routine fest etabliert. Wir stellen unsere ersten Ergebnisse mit Mitralhomografts bei florider Mitralklappenendokarditis vor. Patienten und Methoden: Im Zeitraum von Juli 1996 bis März 1998 setzten wir bei sieben Patienten kryopräservierte Homografts für den Mitralklappenersatz ein. Bei drei Patienten (Alter 24, 42 und 34 Jahre) bestand eine floride Endokarditis mit resultierender operationswürdiger Mitralinsuffizienz. Präoperativ wurde die Größe des benötigten Homografts mittels transösophagealer Echokardiographie bestimmt. Die Implantation erfolgte in der von A. Carpentier beschriebenen Technik; zur Stabiliserung des Mitralklappenringes wurde ein Klappenring (Physio^TM) implantiert. Die Patienten wurden in halbjährlichen Abständen klinisch und echokardiographisch nachuntersucht. Nach einem Jahr wurde zusätzlich ein Ultrafast-CT angefertigt. Ergebnisse: Bei einem Patienten wurde die Mitralklappe komplett ersetzt, bei zwei anderen die native Klappe mit Hilfe eines Teilhomografts rekonstruiert. Alle Patienten überlebten den Eingriff. In den postoperativen Nachkontrollen (12-24 Monate) konnten echokardiographisch unauffällige Homografts dokumentiert werden, insbesondere ergab die Farbdoppler-Echokardiographie bei keinem Patienten eine Mitralinsuffizienz > °I. Postoperativ (zum jeweils letzten Follow-up-Termin) betrug die mittlere Öffnungsfläche der Mitralklappe 2,5 - 0,5 cm², der mittlere Druckgradient lag bei 2,8 - 0,8 mm Hg. Es kam in keinem der Fälle zu einem Rezidiv der Endokarditis. Das Ultrafast-CT zeigte ebenfalls eine unauffällige Morphologie mit erhaltener Ventrikelgeometrie. Schlußfolgerung: Der Mitralklappenersatz mit Homografts stellt vor allem bei jungen Patienten eine interessante Alternative zum prothetischen Klappenersatz dar. Insbesondere bei florider Endokarditis mit ausgedehntem Befall der Mitralklappe wird eine Rekonstruktion beziehungsweise der Ersatz unter Erhaltung der Ventrikelgeometrie ermöglicht.     

Six-year experience with cryopreserved mitral homografts in the treatment of tricuspid valve endocarditis in HIV-infected drug addicts.

BACKGROUND AND AIM OF THE STUDY: In the past, valve homografts have been used in the treatment of aortic endocarditis. This report details our experience in tricuspid valve replacement using cryopreserved mitral homografts in HIV-positive drug addicts with infective endocarditis. METHODS: Five HIV-1-infected drug addicts with active uncontrollable tricuspid valve endocarditis underwent tricuspid valve replacement with a cryopreserved mitral homograft. RESULTS: There was no early mortality, and median follow up was 5 years (range: 1 to 6 years). One late mortality occurred as a result of heroin overdose. Three of the five patients developed six episodes of recurrent bacterial tricuspid endocarditis on the homograft; these were cured successfully with antibiotics. All survivors remain in NYHA functional class I. The latest transthoracic echocardiography examination showed mild, moderate or severe regurgitation in one, two and two patients, respectively. To date, neither homograft calcification nor rupture of the papillary muscle has been detected. CONCLUSIONS: This novel technique is considered to be an adequate approach to these cases of uncontrollable infectious disease. Further episodes of valvular infection can be managed medically.     

Pseudoaneurysm complicating homograft aortic valve replacement--two different--courses and strategies

The courses of two patients with pseudoaneurysm formation following aortic valve replacement using homografts are reported. Both patients had aortic valve replacement due to acute infective endocarditis with paravalvular abscess formation. The first case had an uneventful postoperative course; but on routine echocardiography, a pseudoaneurysm located at the left coronary commissure was found at one year follow-up. As the pseudoaneurysm was completely asymptomatic, the patient was followed up carefully at six months intervals. The second patient also had pseudoaneurysm formation postoperatively, but he presented one year after surgery with fever and elevated leucocyte count. He had surgical revision of the pseudoaneurysm because no other reason for an infection could be found. Four months later he presented again with infection signs and pseudoaneurysm formation. This time, the homograft was completely excised and another homograft was implanted. One year after the final operation, he is now free from re-infection. The two presented courses show that pseudoaneurysms complicating aortic valve replacement should be managed according to attendant circumstances and symptoms.     

Bentall procedure using cryopreserved valved aortic homografts: mid- to long-term results

The Bentall procedure is the standard operation for patients who have lesions of the ascending aorta associated with aortic valve disease. In many cases, however, mechanical prosthetic conduits are not suitable. There are few reports in the English-language medical literature concerning the mid- to long-term outcome of Bentall operations with cryopreserved homografts. Therefore, we reviewed our experience with this procedure and valved homografts. From January 1997 through December 2002, 21 patients underwent a Bentall operation with cryopreserved homografts at our institution. There were 14 males and 7 females; the mean age was 36 +/- 21 years (range, 15-74 years). Eleven patients had undergone previous aortic valve surgery. All patients had aortic dilatation or aneurysms involving the ascending aorta. Indications for surgery included aortic valve stenosis or insufficiency, and aortic valve endocarditis (native valve or prosthetic). One patient had Takayasu's arteritis and 3 had Marfan syndrome. There was 1 hospital death (due to sepsis), but no other major postoperative complications. The mean hospital stay was 14 +/- 7 days. Follow-up echocardiographic and computed tomographic scans were performed yearly. The mean follow-up was 34 months (6-72 months). Follow-up imaging revealed no calcifications or degenerative processes related to the homograft. Four patients had minimal valve regurgitation. Two patients died during follow-up. The 3-year actuarial survival rate was 85.7%. Our data suggest that the Bentall procedure with a valved homograft conduit is a safe procedure with excellent mid- to long-term results, comparable to results reported with aortic valve replacement with a homograft.     

Mitral valve homograft for mitral valve replacement in acute bacterial endocarditis

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).     

Human valvular substitutes for the treatment of complex progressive endocarditis. Application to aortic, mitral and tricuspid valves

The aim of this study was to assess the immediate and long-term results of human valvular substitutes (homografts and autografts) in the treatment of complex progressive endocarditis in aortic, mitral and tricuspid valves. Since 1992, 80 patients (64 men, 16 women) aged 44 +/- 16 years (range 15 to 76 years), were treated. In 53 patients, the endocarditis involved native valves, 4 on previously plastified valves, or prosthetic valves in 27 patients. The endocarditis was recurrent 6 patients. The lesions were situated on the aortic valve (N = 59), mitral valve (N = 5), aortic and mitral valves (N = 12), aortic and tricuspid valves (N = 3), mitral and tricuspid valves (N = 1). The peroperative findings confirmed the lesions diagnosed at echocardiography: prosthetic valve dehiscence (27 patients), prosthetic cusp tear (N = 7), vegetations (N = 61), perforations (N = 48), periannular abscess (N = 47), aorto-ventricular discontinuity (N = 12), aorto-mitral discontinuity (N = 7), right ventricular aortic fistula (N = 1), aorto-pulmonary fistula (N = 1), pseudo-aneurysm (N = 1), ventricular septal defect (N = 1). Eighty-six human valvular substitutes were used (double homograft in 6 patients): aortic homograft (N = 63), pulmonary in the aortic position (N = 1), the mitral position (N = 12), of which 8 were in the mitral and 4 in the tricuspid position, pulmonary autograft (N = 10). Ten mitral valve repairs were performed on infected lesions. Associated procedures included mitral valve repair (N = 5), tricuspid valve repair (N = 1) for non-infarcted valve lesions, replacement of the ascending aorta (N = 2), the aortic arch (N = 1), coronary bypass surgery (N = 2) and one nephrectomy. The hospital mortality was 5% (4 patients). The causes of death were: infarction (N = 2), myocardial failure (N = 1) and multiorgan failure (N = 1). Four early reoperations were required for technical problems, none for endocarditis. Seventy-three of the 76 survivors were followed up for 43 +/- 24 months (range 1 to 84 months). Eight patients died during follow-up, but only 1 of cardiac causes (operation for recurrent endocarditis in a drug abuser). Seven operations were performed, 3 for technical problems or structural failure, 4 for recurrent endocarditis. At 5 years' follow-up, the survival was 81 +/- 5%; 88 +/- 6% of patients were free of endocarditis, 77 +/- 6% had no reoperation: no patient had thromboembolic complications. These results show that human valvular substitutes are adapted for the treatment of complex, progressive aortic, mitral and tricuspid valve endocarditis when techniques of valvular repair are no longer feasible.     

Evaluation of the decellularized pulmonary valve homograft (SynerGraft)

BACKGROUND AND AIM OF THE STUDY: Rejection is thought to contribute to the degeneration of valved homografts. A novel cryopreserved decellularized homograft valve (SynerGraft; CryoLife, Inc.) offers the unique opportunity to gain new insight into the immunology of homograft implantation and its significance for valve function. METHODS: Twenty-four patients (group I; mean age 37 +/- 11 years) underwent implantation of a pulmonary SynerGraft and were examined at one and six months postoperatively; 22 patients (group II; mean age 41 +/- 17 years) with conventional homografts served as controls. Temperature, C-reactive protein (CRP) levels and white blood cell count (WBC) were studied perioperatively. Follow up included echocardiography and anti-human leukocyte antigen (HLA) class I antibody determination. RESULTS: Significantly lower temperatures were measured in group I (p = 0.019). CRP level and WBC each increased postoperatively, but did not differ between groups. During follow up, none of the SynerGraft patients became positive for anti-HLA antibodies, compared with 66% of controls (p = 0.011). Homograft diameter and valve orifice area were decreased significantly at one month after surgery in groups I and II (25 +/- 1 versus 18 +/- 3 mm; 25 +/- 1 versus 19 +/- 2 mm, respectively; p <0.001 both groups). Transvalvular pressure gradients significantly increased during follow up. CONCLUSION: Implantation of the SynerGraft pulmonary homograft appeared safe, and though evidence was found of a reduced immunologic response after SynerGraft implantation this (unexpectedly) did not translate into any hemodynamic advantage. Hence, factors other than rejection appear as the main contributions to the observed functional changes.     

Two years' clinical experience with a quadrileaflet stentless bioprosthesis in the mitral position

BACKGROUND AND AIMS OF THE STUDY: Currently available bioprosthetic mitral valves do not provide sufficient durability. A new stentless pericardial prosthesis was designed for better hemodynamic performance and reduction of stress load compared with current stented bioprostheses. METHODS: Between September 1997 and August 1999, the Quadrileaflet mitral valve (QMV) was implanted in 17 patients at our institution. Four patients had minimally invasive mitral valve replacement. Mean patient age was 62.2 +/- 16.3 years; preoperative NYHA class was 3.06 +/- 0.2; ejection fraction was 64.1 +/- 14.7%. Echocardiography was performed pre-, intra- and postoperatively, and at 3-6, 12 and 24 months follow up. RESULTS: Fifteen patients had an uneventful intra- and postoperative course. Two patients died, one from acute left heart failure at 6 h after surgery, and one on the first postoperative day after resuscitation for ventricular fibrillation. A small-sized prosthesis was implanted in four patients, medium-sized in eight and large-sized in five. The mean duration of cardiopulmonary bypass was 138.3 +/- 37.0 min; mean cross-clamp time was 91.3 +/- 26.3 min. Postoperative control echocardiography showed a mean valve orifice area of 2.5 +/- 0.4 cm2, transvalvular velocity (Vmax) was 1.6 +/- 0.4 m/s, and mean pressure gradient 3.6 +/- 2.0 mmHg. Echocardiographic evaluation after 3, 6 and 12 months showed no significant difference compared with the intraoperative data. Three patients had a minor mitral regurgitation (grade I-II). At 12 months all patients were in NYHA class I or II. CONCLUSION: The implantation technique of the QMV is more demanding, but the prosthesis is a promising alternative to conventional biological mitral valve replacement. Further follow up is needed to confirm these favorable mid-term results.     

Doppler echocardiographic comparison of the Carpentier and Duran anuloplasty rings versus no ring after mitral valve repair for mitral regurgitation

To compare the hemodynamic results of different anuloplasty techniques of primary valve repair for mitral regurgitation, 122 patients were prospectively studied with Doppler echocardiograms 5 to 10 days after operation. Seventy-seven patients had mitral valve prolapse, 27 had coronary artery disease, 13 patients had rheumatic mitral valve lesions and 5 patients had infective endocarditis. Forty-eight patients received the flexible Duran ring, 46 received the more rigid Carpentier ring and 28 patients received no ring. Doppler echocardiography demonstrated a significant decrease in mitral valve area estimated by the pressure half-time method in patients who received either a Carpentier (2.6 +/- 0.8 cm2) or Duran ring (2.8 +/- 0.8 cm2) when compared with patients who received no ring (3.2 +/- 0.7 cm2) (p = 0.01). No significant differences were observed for peak transmitral diastolic velocity, peak transmitral diastolic gradient, or the grade of mitral regurgitation by color flow Doppler mapping between patients with and without rings. The etiology of mitral disease and concomitant surgical procedures accompanying mitral valve repair did not significantly influence mitral valve area, peak velocity or peak gradient. These data suggest that Carpentier and Duran rings decrease the hemodynamic mitral valve area; however, the decrease in valve area is small and not associated with a clinically important increase in transvalvular gradient.     

Left ventricular outflow obstruction: a complication of mitral valvuloplasty

Thirty-two patients with severe mitral regurgitation underwent Carpentier mitral valvuloplasty. Postoperatively, three of these patients developed clinical and echocardiographic evidence of left ventricular outflow tract obstruction. None of these patients had asymmetric septal hypertrophy or preoperative echocardiographic demonstration of systolic anterior motion of the mitral valve. Outflow obstruction postoperatively was caused by systolic anterior motion of the mitral valve. Because this potential complication of Carpentier mitral valvuloplasty produced significant hemodynamic effects in two patients, echocardiography should be routinely performed after this operation.     

Aortic root enlargement with glycerol-preserved homologous dura mater patch during aortic valve replacement

Aortic root enlargement with a patch is sometimes indicated either to prevent aortic homograft valve distortion during implantation or to facilitate easy, tension-free closure of the aortotomy. Patches made of prosthetic material have been widely used for this purpose. The use of autogenous pericardium has recently been reported. Although dura mater has been shown to have great strength, low antigenicity, athrombogenicity, easy availability in large sizes and rapid bonding to most tissues, its use for patch enlargement of the aortic root has not been previously documented. From 1979 to 1983, 38 patients had dura mater aortic root gussets placed during aortic valve replacement at the Southampton General Hospital. In all cases, the patches were placed to facilitate aortic closure, or to prevent homograft valve distortion by enlarging the non-coronary sinus. Aortic homografts were implanted in 11 patients, Carpentier Edwards' Xenograft valves in 16, Bj?rk-Shiley valves in 8 and Wessex Xenografts in 3 patients. All the patients survived and in a mean follow-up of 30 +/- 12.8 months (range 3 to 48 months) there has been no clinical evidence of patch failure due to leakage, rupture or aneurysm formation. These results suggest that glycerol-preserved dura mater is a satisfactory patch material for aortic root enlargement during aortic valve replacement.     

Aortic root replacement with a new stentless aortic valve xenograft conduit: preliminary hemodynamic and clinical results

BACKGROUND AND AIM OF THE STUDY: Beside aortic valve-sparing surgery, a composite graft, homograft or (more rarely) an autograft are the most common options to replace a diseased or destroyed aortic root in adults. Recently, a new stentless xenograft valved conduit (Shelhigh, No-React) was introduced in Europe. This totally biologic conduit is glutaraldehyde cross-linked, detoxified and heparin-treated with No-React; this process eliminates residual glutaraldehyde and ensures stable tissue cross-linking. The initial clinical and hemodynamic results with this porcine valved conduit in the aortic position are presented herein. METHODS: Among 308 patients who underwent thoracic aorta surgery during a 30-month period, 127 had aortic root repair or replacement. The Shelhigh stentless aortic valve conduit was implanted in 35 patients (30 males, 5 females; mean age 68 +/- 7.2 years; mean body mass index 27.5 +/- 4.1 kg/m2). Of these patients, 15 had aortic valve stenosis and ascending aortic aneurysm, 10 had a dilated aortic root with or without aortic regurgitation, four had acute aortic dissection type A, and six had a complex pathology (destructive endocarditis or re-do surgery). RESULTS: One patient with prosthetic valve endocarditis died on postoperative day 1 from uncontrolled septicemia (30-day mortality, 2.7%). There were no conduit-related adverse events in the surviving patients, but one re-exploration was required for bleeding in a re-do case. Transthoracic echocardiography was available in 30 patients after six months, and in 15 patients after 12 months. The mean gradient across the aortic valve was 8.5 +/- 5.1 mmHg (range: 6 to 14 mmHg for conduit sizes 21 to 29 mm). CONCLUSION: The Shelhigh valved conduit shows promising hemodynamic properties. As the conduit contains no fabric or mechanical components, it is ideal for treatment of the infected aortic root, and an excellent alternative to homografts. In older patients, this conduit has the additional advantage that no long-term anticoagulation is required.     

Mitral homograft in the tricuspid position, aortic homograft and mitral plasty in a drug addict with multiple valve endocarditis

The case is reported of multiple valve surgery using as little prosthetic material as possible in a drug addict with recurrent right and left bacterial endocarditis. The patient underwent aortic valve replacement with a cryopreserved aortic homograft, mitral repair and tricuspid valve replacement with a mitral homograft, using a modified technique. The indications and surgical options for tricuspid valve endocarditis in this patient group are discussed, with particular focus on technical aspects of using mitral homografts in the tricuspid position.     

Aortic valve replacement with the Sorin Pericarbon Freedom stentless valve: five-year follow up

BACKGROUND AND AIM OF THE STUDY: Presumed benefits from stentless bioprostheses include larger orifice areas with lower transvalvular gradients, and improved hemodynamic flow characteristics and annular mechanics. Herein are reported the results of a large series of the Sorin Pericarbon Freedom stentless valve implanted in the aortic position. METHODS: Between July 1998 and June 2003, a total of 102 consecutive patients (58 males, 44 females; mean age 71.7+/-7.8 years; range: 28-87 years) requiring aortic valve replacement (AVR), including those undergoing concomitant procedures of coronary artery bypass, mitral valve repair and mini-maze, was recruited. The predominant lesion was aortic stenosis (n = 92; 90.2%); aortic regurgitation (AR) occurred in five patients (4.9%) (including three with endocarditis), and mixed aortic valve disease in five (4.9%). Six patients (5.9%) had undergone previous cardiac surgery. The median preoperative NYHA class was III. Thirsty-six patients (35.3%) underwent AVR alone. The mean valve size was 25 mm (range: 21-29 mm). Sixty-three patients (61.8%) had concomitant coronary artery disease that required a mean of 2.4+/-1.1 bypass grafts; three patients (3.0%) had combined AVR and mitral valve repair. The study end points observed were mortality, valve failure due to degeneration or endocarditis, reoperation, thromboembolism, transvalvular gradients and left ventricular (LV) mass regression. RESULTS: The median follow up for all patients was 31 months (range: 12 months to 5 years). The mean total cross-clamp time was 71.7+/-17.6 min without associated procedures, and 93.9+/-19.7 min with concomitant procedures. Early mortality was 4/102 (3.8%); actuarial survival over five years was 89.2%. Freedom from thromboembolism over five years was 95.9%, from reoperation 100%, and from endocarditis 99.98%. Fifty-seven patients (56.4%) had no AR detected postoperatively, and 34 (33.3%) had trivial or mild AR. A significant decline was observed in indexed LV mass regression within six months of surgery, from 190+/-72 g/m(2) at baseline to 152+/-47 g/m(2) (p = 0.01). CONCLUSION: In an elderly population with a high incidence of coronary artery disease, the Sorin Pericarbon Freedom stentless valve offers excellent hemodynamics, resulting in significant regression of left ventricular hypertrophy, together with acceptable operation times, morbidity and mortality in the medium term.     

Mid-term follow up of mitral valve reconstruction due to active infective endocarditis

BACKGROUND AND AIM OF THE STUDY: Mitral valve reconstruction in patients with acute endocarditis (AE) is a challenging operation which prompts the surgeon into immediate action. This report summarizes the mid-term results of 22 patients who required mitral valve reconstruction due to AE. METHODS: Mean patient age was 46 years (range: 20-79 years); mean follow up was 46 months (range: 1-90 months). Preoperatively, >70% of patients had severe mitral regurgitation and were in NYHA functional class III. Surgical techniques used were annuloplasty (n = 16; 10 with Carpentier ring, five Wooler-Kay and one Frater); suture closure of the perforation (n = 1), patch closure of the perforation (n = 5), leaflet resection with primary closure (n = 2), leaflet resection with patch closure (n = 8), and chordal transfer (n = 3). Additional surgery included CABG (n = 3) and De Vega plasty (n = 4). Aortic valve replacement or reconstruction (n = 9) included one mechanical valve, one bioprosthesis, one reconstruction and six homografts. Patients were followed up annually in our outpatient department and/or by questionnaires. RESULTS: Two patients died perioperatively due to either low output syndrome or uncontrolled sepsis. There were three reoperations; two of these were successful, and one patient subsequently died. In addition, one patient died six years after operation due to prostatic cancer, and one seven years later due to progressive heart failure. At the last follow up, 15 patients were in NYHA class I (68%) and five in class II (23%); no or only mild mitral insufficiency was seen on transthoracic echocardiography (91%). The estimated survival rate at 60 months was 87 +/- 12.7%, and 12 patients were followed up for >60 months. No incidence of recurrent valve infection occurred. CONCLUSION: Mitral valve reconstruction in patients with AE shows a low incidence of valve-related complications with promising postoperative functional results and mid-term survival. On this basis, mitral valve reconstruction for mitral insufficiency secondary to AE may be recommended as a valve salvage treatment, when it is technically possible.     

Ten years' experience in aortic valve replacement with homografts in 389 cases

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement using homografts is an accepted alternative to the use of other replacement devices, and has been established at the authors' institution for more than 10 years. METHODS: Since 1992, a total of 389 homografts was implanted, and 332 patients (mean age 54 years, 72% males) were followed up. The initial patients (n = 75) had subcoronary implantation, all subsequent patients had root replacement. Both aortic grafts (AG) and pulmonary grafts (PG) were used. Follow up was conducted with regard to the factors 'graft origin', 'implantation technique' and 'gender', and included clinical examination, ECG and transthoracic echocardiography on an annual basis. RESULTS: Overall 30-day mortality was 5.4% (AG patients 3.9%, PG patients 13.5%; p = 0.09). Among late deaths (n = 22), six were valve-related (all prosthetic infection). Four minor thrombembolic events were recorded due to amaurosis fugax and transient ischemic attacks (TIA). Freedom from reoperation was 86.5%. Indication for graft replacement was greater after subcoronary implantation than after root implantation (p = 0.04). Reoperation was necessary in 24 patients due to restenosis (n = 4), regurgitation grade >II (n = 5), paravalvular leak (n = 2) and prosthetic infection (n = 13). At the latest echocardiographic follow up, mean peak pressure gradient was 15.60 +/- 11.76 mmHg, homograft regurgitation grade was 0.82 +/- 0.66, left ventricular end-diastolic diameter (EDD) was 49.1 +/- 7.54 mm, and mean aortic root diameter was 30.54 +/- 5.48 mm. When comparing parameters at a mean of five years postoperatively, the pressure gradient increased from 10.26 to 15.02 mmHg, regurgitation grade increased from 0.53 to 0.81, and EDD decreased from 52.3 to 50.4 mm. Other variables showed no significant differences. CONCLUSION: The present results confirmed good midterm-results for aortic valve replacement with homografts. These prostheses are vulnerable to infection, and root replacement was superior to the subcoronary implantation technique.