Retrospective clinical analysis of stented vs. stentless porcine aortic bioprostheses.

OBJECTIVE: The study was designed to compare hemodynamic performance, structural failure and survival of patients undergoing aortic valve replacement (AVR) with a composite aortic stented or stentless porcine bioprosthesis. METHODS: From January 1990 to June 1999, the clinical data of 725 patients undergoing AVR with stented porcine aortic bioprosthesis were reviewed. We defined two groups of patients with similar clinical characteristics: 202 patients receiving aortic stented and 205 patients stentless valves. The two patients groups were similar in age, sex, valve lesion, valve size, preoperative New York Heart Association (NYHA) class status and follow-up. RESULTS: The number of patients available for follow-up, excluding hospital and late mortality, reoperations and patients lost to follow-up, was 157 for the stented and 175 for the stentless group. There was a higher incidence of rheumatic heart disease in the stented (59%) vs. stentless group (44%), (P=0.003). Fewer patients had prior aortic bioprosthetic dysfunction in the stented (7.6%) compared to the stentless group (25%) (P<0.001). The mean intensive care unit stay, hospital mortality and late mortality were similar (P, NS). The total complication rate was higher in the stented (12%) than the stentless (3.4%)(P=0.005). Valve related death was higher in the stented (2.5%) than the stentless (0%) (P=0. 049). Postoperatively, the aortic effective orifice area (AEOA) was larger (P<0.001) and the transvalvular peak and mean gradients were lower in the stentless group (P<0.001). The leaflet tissue degeneration analysis was 8.0% in patients at risk for stented and 0. 6% for stentless (P=0.001). Actuarial analysis disclosed no statistical difference in patient survival between groups (P=0.18). Reoperations were less frequent in the stentless group (P=0.010). CONCLUSIONS: Hemodynamic benefits in the stentless group were evident and expressed by larger AEOA, lower gradients, better left ventricular remodeling with significant decrease of the left ventricular mass. Lower complication rates, lower reoperation rates, less leaflet tissue degeneration, and lower valve related mortality rates were seen in the stentless group. A controlled clinical comparison trial with longer follow-up will be required to confirm these clinical and hemodynamic benefits.

Use of bovine pericardial tissue for aortic valve and aortic root replacement: long-term results.

BACKGROUND AND AIMS OF THE STUDY: The study aimed to determine the clinical performance of bovine pericardial aldehyde-treated products alone or in combination with aortic leaflets of porcine origin. These included a composite porcine stentless aortic valve attached to a scalloped pericardial tube (BSAV), and valved and non-valved bovine pericardial conduits for use in left-sided heart lesions (BPG). METHODS: For BSAV grafts, between January 1990 and August 1996, 163 patients (119 males) had their aortic valves replaced by SJM Biocor BASV. Mean age was 37.9 +/- 17.6 years (range: 1 to 76 years). Rheumatic heart disease sequelae (n = 72) and replacement of a prosthetic heart valve (n = 46) were predominant. Preoperative NYHA functional class showed 90 patients (55.2%) in class III and 50 (30.7%) in class IV. BPVC and NVPC grafts were used in 166 patients: acute aortic dissection was the main indication in 52 (31.3%) and chronic in 36 (21/7%). The ascending aorta was involved in 141 patients (84.9%); grafts were seldom used at other sites. In most patients the graft implanted was either a non-valved (n = 79) or a valved (n = 75) pericardial conduit. Twelve patients had a localized lesion and required a patch repair. RESULTS: For BASV grafts, the non-valve-related hospital mortality rate was 4.9%. There were 14.7% non-fatal complications with full recovery of all patients. Mean follow up in 141 patients was 3.0 +/- 1.4 years (range: 1 month to 7.2 years); 14 patients were lost to follow up. Late, non-conduit-related, mortality occurred in seven patients (4.9%). Eight patients underwent reoperation. The current clinical follow up of 127 patients has shown 118 (92.9%) with competent valves and nine (7.0%) with mild stable aortic insufficiency. For BPVC and NVPC grafts, hospital mortality rate was 16.9%, death being related to poor preoperative clinical condition. Postoperative follow up was accomplished in 125 patients; reoperation was necessary in seven patients. Histology showed good tissue preservation up to five years; echocardiography revealed satisfactory findings. No valved conduit had to be reoperated for valve or pericardial tissue wear. CONCLUSIONS: Clinical results of left-sided heterologous pericardial grafts have shown excellent performance over time. The BASV (over seven years) and BPVC and NVPC (eight years) have demonstrated superior results as aortic valves alone or in combination with a pericardial conduit.

The use of bovine pericardium for pulmonary valve reconstruction or conduit replacement: long-term clinical follow up.

BACKGROUND AND AIMS OF THE STUDY: This study aimed to determine the clinical performance of bovine pericardial aldehyde-treated material alone or in combination with aortic leaflets of porcine origin. These were the porcine aortic stentless pulmonary valved bovine pericardial conduit (PSPVC), and porcine aortic monocusp attached to pericardial patch (PAMC), used to correct right-sided heart lesions. METHODS: Between November 1985 and October 1995, 33 patients underwent corrective congenital surgery with PSPVC. Mean patient age was 5.7+/-4.3 years (range: 15 days to 18 years). Pulmonary atresia with ventricular septal defect (VSD) was the most frequent disease (16/33, 48%). For PAMC, 45 patients with various congenital heart malformations underwent implantation between June 1989 and April 1996. Mean patient age was 4.8+/-4.7 years (range: 2 weeks to 18 years). RESULTS: With PSPVC, hospital mortality rate was 18.2% and related to poor preoperative clinical condition in six cases. Four patients were lost to follow up; 23 (85%) were followed for 3 months to 10 years (mean 4.8+/-3.0 years). Distal anastomotic scarring in four patients was probably due to retraction of the pericardial tissue. With PAMC, hospital mortality rate was 11% and related to patients' preoperative clinical condition. Three patients were lost to follow up; 37 survivors have been followed for 6 to 88 months (mean 38.5+/-19.0 months). There were no late deaths. Two patients underwent reoperation; intra-operative observation showed well-preserved monocusps with no signs of tissue degeneration. The remaining 35 patients remain asymptomatic by clinical examination and Doppler echocardiography. The monocusps remained mobile in every case. CONCLUSION: PSPVCs have shown excellent performance and durability in young patients with a low mean age (5 years). The monocusp graft has remained functional with good leaflet motion for up to seven years.

Porcine stentless valve/bovine pericardial conduit for right ventricle to pulmonary artery.

BACKGROUND AND OBJECTIVES: We assessed the long-term outcome of a glutaraldehyde-preserved bovine pericardial conduit containing a stentless composite porcine aortic valve. METHODS: Between November 1985 and May 1995, 33 stentless porcine valves attached to bovine pericardial conduits were used in 33 patients with complex congenital cardiac malformations. These patients required a conduit between the right ventricle and the pulmonary artery because of an absent or inadequate pulmonic artery. All patients were approached by midsternotomy. One patient with pulmonic atresia and an interventricular septal defect required left thoracotomy for ligation of collaterals. RESULTS: Of the initial 33 patients, clinical follow-up was performed in 23 discharged patients (70%) for 1.7 to 10.5 years. The echo-Doppler analysis performed in each of the 23 followed patients showed excellent conduit and valve function in all but 4 patients, in whom a valve gradient of 60 mm Hg was noted. There was no tissue structural failure noticed in this study. CONCLUSIONS: The SJM Biocor (Belo Horizonte, Brazil) bovine pericardial stentless valved conduit performed well as a substitute for the right ventricle to pulmonary artery connection.

Porcine mitral stentless valve mid-term clinical results.

OBJECTIVES: Time testing is essential with any valvular procedure, especially when a new concept is introduced such as the mitral stentless valve. Our purpose is to evaluate the results obtained over 4 years with this operation, particularly to attest the impact of preservation of annulo ventricular continuity on the long term results of these patients. METHODS: From March 1992 to August 1996, 120 patients had their mitral valves replaced with a porcine stentless mitral valve. The observation period was 54 months with total patients follow-up of 3424 months with a mean of 28.5 months. The age ranged from 11 to 72 years (mean 35.22 +/- 14.98). There were 73 females (60.8%) and 47 males (39.2%). The predominant etiology was rheumatic heart disease. Associated procedures were performed in 12 patients (10%), and the great majority of the patients were in functional class III and IV (NYHA). RESULTS: Hospital mortality occurred in seven patients (5.83%) non valve related except for one early case of endocarditis. Early reoperation related to technical failure were necessary in 4 patients without mortality. Follow-up was accomplished in 101 patients and ranged from 2 to 54 months. Late reoperations were required in 16 patients (nine due to mitral insufficiency, five because of endocarditis and two for mitral stenosis). Most reoperations were related to technical failure. Among the 82 patients presently in control, 72 showed a competent mitral stentless valve, eight with stable mild mitral regurgitation and in two a decreased mitral orifice. Hemodynamic performance of the valve has been excellent in this group, particularly in patients with left ventricular dysfunction. CONCLUSION: Although technical complexity remains the main cause of reoperations with this valve, experience has shown that it not only provides preservation of the left ventricular function but also promised significant increase of the ejection fraction in patients with poor left ventricular function.

Late complications after surgical exclusion of the thoracic aorta.

Two patients who underwent surgical exclusion of the thoracic aorta for chronic dissecting aneurysms of the descending aorta died 4 and 8 years after surgery due to complications in part related to the operative technique. One patient developed pseudoaneurysm of the proximal aortic stump with fatal exsanguination through an aortapulmonary fistula. The other patient developed progressive dilatation of the remaining abdominal aorta with subsequent rupture. The surgical approach in this case was extremely difficult because of the previous exclusion procedure which determined a highly demanding reoperation. Although surgical exclusion of the thoracic aortic may be a useful technique in some situations, we must be aware of its early and late complications and, in our opinion, it should be seen only as an alternative treatment for very special patients with diseases of the descending thoracic aorta.

[Ventricular fibrillation in a patient with the permanent form of junctional reciprocating tachycardia]. / Fibrilação ventricular em paciente com forma permanente da taquicardia juncional reciprocante.

A case of a 20 year old young man having the permanent form of junctional reciprocating tachycardia complicated by ventricular fibrillation (VF) is reported. A number of antiarrhythmic drugs either as single or combined therapy fail to control tachycardia. Paroxisms of a faster palpitation which never lasted longer than a few minutes were felt over the last six months before the occurrence of VF. At admission, a narrow QRS tachycardia 250 beats/min was recorded and soon degenerated into VF. After electrical shock with 350J permanent form of junctional tachycardia resumed. Electrophysiologic evaluation identified an accessory pathway with long conducting times in postero-septal location, enhanced atrioventricular node conduction and inducible atrial flutter. The patient underwent successful radiofrequency ablation and is doing well after 18 months of follow-up, being off antiarrhythmic drug and tachycardia free.

Fibrilação; ventricular em pacientes com forma permanente da taquicardia juncional reciprocante / Ventricular fibrillation in a patient with the permanent form of junctional reciprocating tachycardia

Homem de 20 anos, portador de taquicardia de apresentaçäo incessante há longos anos, sem resposta a medicaçöes antiarrítmicas. Seis meses antecedendo a admissäo referia paroxismos de taquicardia mais rápida, de duraçäo curta, autolimitada. Na admissäo apresentava flutter atrial com conduçäo 1:1 (250 bpm) que degenerou em fibrilaçäo ventricular, revertida com 350J. O estudo eletrofisiológico identificou taquicardia atrioventricular, utilizando conexäo anômala "oculta" de localizaçäo póstero-septal deita com conduçäo lenta e propriedade decremental, conduçäo atrioventricular acelerada, observando-se precipitaçäo de fibrilaçäo atrial com resposta rápida pós-atropinizaçäo. Foi submetido a ablaçäo por cateter pro radiofrequência com sucesso. Esta assintomático, 18 meses após o procedimento.

Surgical technique of implanting the stentless porcine mitral valve.

The new stentless porcine mitral valve was developed to serve as an anatomically correct substitute for a diseased mitral valve. Extensive acute animal experimentation was performed, and from this the logical sequence for selecting the correct valve size and the specific technique for implanting it were determined. The following are the major steps to successfully implant a mitral stentless valve: First, mitral valve complex analysis must be done to determine the correct procedure to be performed and the feasibility of using the stentless mitral valve. Second, the correct size of stentless mitral valve must be chosen. Third, the papillary muscle anatomy must be assessed to determine the site and number of sutures necessary for securely holding the new origin of the new chordae. Fourth, the papillary muscle sutures must be anchored to the free pericardial edge of the new chordal origin. Fifth, the chordal alignment with both trigonal areas must be perfect. Sixth, the annulus may be sutured using either continuous or interrupted sutures. Perioperative echocardiography, preferably transesophageal echocardiography, should be done in every patient. Although reoperation was necessary in 5 patients (non-valve-related), the results in 74 patients (3 early and 3 late non-valve-related deaths excluded) followed up for at most 26 months (mean, 14 months) have been excellent. The quality of the results obtained in this initial clinical trial has reinforced our current preference for this valve in patients requiring mitral valve replacement. Longer follow-up is required to confirm that these good results continue.

Porcine stentless aortic valve in re-replacements and acute aortic valve endocarditis.

Between June 1990 and June 1993, 135 patients received a porcine stentless aortic valve (PSAV) at our institution. In this group, there were 33 patients in whom the stentless valve was used to replace a previously inserted malfunctioning aortic valve prosthesis (n = 19) or to treat acute aortic valve endocarditis (n = 14, five native, nine prosthetic endocarditis). There was one hospital death caused by multiple organ failure in a patient with endocarditis and preoperative cerebral stroke. Two patients died after hospital discharge; one suffered sudden death following a pacemaker failure four month after surgery and the other died due to Candida albicans sepsis after a prolonged antibiotic treatment. There were two reoperations; one to correct a dehiscence of the proximal suture line and the other to replace a degenerated valve 3.5 years after implantation in a 14 year old boy. All operative survivors were followed clinically with serial color Doppler echocardiography. No recurrence of endocarditis was detected. Aortic root reconstruction was achieved even in the presence of multiple abscesses. All but one patients showed a normally functioning valve with none or minimal aortic insufficiency. In our opinion the PSAV is an excellent aortic valve substitute for patients with damaged aortic annulus, because it promotes aortic root remodeling, decreases the incidence of postoperative paravalvular leaks and helps to prevent endocarditis recurrence.

Heterologous mitral valve transplant: the first 50 patients clinical analysis.

From March 1992 to August 1993, 50 patients underwent mitral valve replacement with the new heterologous stentless mitral bioprosthesis in our institution. The development of this heart valve substitute, its technique of implantation and the results observed in the first group of 50 patients have had us to review the initial experience. The surgical protocol included an accurate mitral valve complex analysis, adequate valve size selection, attachment of the papillary muscle to the new chordal origin and approximation of the stentless mitral to the patient's annulus. There was one hospital death (2%), not related to the valve or to the technique and four reoperations: two due to endocarditis, one because of a perivalvular leak and one due to a mismatched stentless valve. The late mortality (4%) was not valve-related. The follow-up has shown excellent valve performance with improved left ventricular function in the great majority of the patients. Based on the current analysis, it can be stated that reproducibility of the surgical technique and the excellence of the clinical follow-up may contribute favorably to a better quality of life and longer valve durability in patients requiring mitral heart valve replacement.

Replacement of the ascending aorta and aortic arch with bovine pericardial grafts. A preliminary report.

Bovine pericardial (BP) grafts have been clinical use at Biocor Hospital since 1989 for replacement or repair of the ascending aorta (AsAo) and initial segment of the aortic arch (AoAr). The main advantages of BP grafts that have justified their clinical application are much easier surgical technique, perfect hemostasis and low cost. From Feb/89 to Feb/94, 88 BP grafts were implanted in the AsAo or the AoAr. There were 33 valved conduits, 47 non-valved conduits and 8 patches. The main indication for the procedure was acute dissection of the aorta, accounting for 50% of the cases. The total hospital mortality was 20.4%. Follow-up was obtained in all but two patients. Patients who survived 2 or more years postoperatively (n = 31) underwent either an echocardiographic or an angiographic study in order to access the behavior of the graft, which was perfect in all of them. The current follow-up is short and complications such as calcification may still develop. However the present study has clearly shown the superior handling and better hemostasis of BP grafts compared to the classical Dacron prosthesis.

Porcine stentless aortic heart valve substitute mid-term clinical follow-up.

From May 1990 to January 1994, 120 patients underwent aortic valve replacement with the use of the Biocor porcine aortic stentless heart valve (BPASHV). There were 83 male and 3 female patients. The age ranged from 11 seventy-six (76) years with a mean of 36. Eighty-five patients were under 40 years of age. Sixty-four patients underwent their first aortic valve replacement due to rheumatic heart disease, 30 because of prosthetic valve failure and of those: 20 were due to primary tissue failure and in 10 due to prosthetic endocarditis, native aortic bicuspid valve in 11 and senile calcificant aortic valve disease in four. Thirty-three patients had aortic annular related pathology. Their preoperative functional class revealed 61 patients in class III and 59 in class IV. The longest follow-up in this aortic group was 42 months with a mean of 26. The surgical technique used rendered consistent and reproducible results. There was a hospital mortality of six patients (5%). The mortality was not valve related. The hospital morbidity in 14 revealed full recovery of all patients. There were four late reoperations, in two due to recurrent endocarditis and in the last two because of paravalvar leak. There was a late mortality of four patients (non valve related). The follow-up of these patients revealed full competent aortic stentless valve in 97 patients and only minor jet in nine. Most patients are in functional class I and II. The Aortic stentless concept has proven to be outstanding with the use of the Biocor Aortic stentless valve throughout the current follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Porcine stentless mitral heart valve substitute: short term clinical data.

Beginning March 1992 to February 1994, 65 patients were submitted to mitral valve replacement using the porcine mitral stentless heart valve. This group took in 65 patients, their age ranged from four to 65 with a mean of 26 years. Forty patients were below years of age. The major indication was rheumatic heart disease sequelae in 50 patients, mitral valve endocarditis in six, myomatous degeneration in four and in five previous mitral prosthetic valve was replaced due to tissue failure. The preoperative functional class revealed 35 patients in class III and 30 in class IV. The longest follow-up was 23 months with a mean of 12. The surgical technique used rendered consistent and reproducible results. There was a hospital mortality of two patients or 3.1%. The hospital morbidity revealed full recovery of all patients. There were three patients reoperated because of valve endocarditis in two and in one due to partial dehiscence of the suture at the annular level. All three patients had full recovery after a reoperation. There was a late mortality of two patients, non valve related. The follow-up of these patients revealed full competent stentless mitral valve in 50 patients and in nine minor to mild jets were encountered by color echo-Doppler. Most patients are in functional class I and II. The stenless concept has prove to be outstanding in the mitral position throughout the current follow-up of close to 2 years.(ABSTRACT TRUNCATED AT 250 WORDS)

The new stentless aortic valve: clinical results of the first 100 patients.

From May 1990 to August 1993, 100 patients underwent aortic valve replacement using the stentless porcine aortic valve. There were 69 males and 31 females. The mean age was 36 (range 11-76) years. Of 70 patients under 40 years of age, 20 were less than 20 years old. Indications included rheumatic heart sequelae in 55 patients (first valve replacement), prosthetic failure in 20, endocarditis in 13, congenital aortic bicuspid valve in four, degenerative disease in four and senile calcified aortic valves in four. Twenty patients had aortic annular related pathology. There were 15 associated surgical procedures. Forty-three patients required aortic root enlargement. There were approximately equal numbers of patients in New York Heart Association (NYHA) functional classes III and IV. The hospital mortality rate was 6%; 14 patients who experienced hospital morbidity had a full recovery. Two late reoperations were performed in patients with primary valve endocarditis; their recovery was uneventful. Four late deaths were not valve related. Comparative echo Doppler analysis before and after operation demonstrated good improvement of left ventricular function in nearly all patients. The valve was competent in 96% of patients and the remainder displayed minor jets without haemodynamic significance. The valve coaptation was stable in all patients. Use of the stentless porcine aortic valve in this first 100 patients has provided excellent clinical results with a follow-up of 41 months. Further follow-up and close observation will be required to analyse the outcome of this new valve and procedure with time.

[Secondary sternotomy in pediatric heart surgery]. / Esternorrafia secundária em cirurgia cardíaca pediátrica.

PURPOSE: To analyze the results observed in children who underwent surgical correction of congenital anomalies, in whom the sternotomy was left open to avoid postoperative heart compression. METHODS: Fourteen children with mean age of 11 months, with different kind of congenital malformations who underwent definitive correction were submitted to the technique of delayed sternal closure. The indication was: hemodynamic instability due to sternal approximation (8), uncontrolled bleeding (4) and preventive (2). In all patients a bovine pericardial patch was sutured to the skin edges allowing a good decompression of the heart. RESULTS: Among the 14 children, two died in the immediate postoperative period, before the secondary sternal closure. There were two other deaths in the remaining 12 children who underwent sternal approximation, one due to acute pneumothorax and the other due to low cardiac output. The incision was closed after hemodynamic stabilization was achieved, and happened usually around the 3rd postoperative day. There were no cases of mediastinal infection. CONCLUSION: The technique of delayed sternal closure is an important approach in pediatric cardiac surgery and can be life saving. In our experience a bovine pericardial patch proved to be effective in decompressing the heart and also in protecting the mediastinal cavity.

Surgical repair of transposition of great arteries and total anomalous pulmonary venous return to the coronary sinus (TGA with TAPVR).

The association of transposition of the great arteries (TGA) and total anomalous pulmonary venous return (TAPVR) is very rare; we report one case of this malformation with an intracardiac type of TAPVR draining into the coronary sinus. The surgical repair was performed directing the coronary sinus blood flow to the tricuspid valve. The proximity of the anatomical structures allowed an intra-atrial patch repair similar to a modified Mustard procedure. In the postoperative period the child developed low cardiac output for 2 days, requiring inotropic support and mechanical ventilation. Her recovery was otherwise uneventful. The postoperative echocardiogram showed an intact repair with perfect flow through the patch from the pulmonary veins to the right ventricle. Almost 2 years after surgery, the patient underwent cardiac catheterization that showed integrity of the surgical repair with normal pressures in all heart chambers. To our knowledge this is the first report in the medical literature of surgical treatment of this association.

[Atriofascicular connection with slow conduction and longitudinal dissociation. Electrophysiologic evidence and clinical implications]. / Conexão átrio-fascicular com condução lenta e dissociação longitudinal. Comprovação eletrofisiológica e implicações clínicas.

We report on a patient with paroxysmal left bundle branch block-like tachycardia with electrophysiologic findings suggestive of nodoventricular pathway (ventricular pre-excitation dependent on slowing of AV conduction, and accessory pathway with exclusive anterograde conduction). There was no pre-excitation during sinus rhythm but it was brought on by intravenous verapamil. Atrioventricular node conduction curves showed no signs of duality. Diagnosis of an atriofascicular pathway with decremental properties was based on the following findings: 1) absence of AV dissociation during reciprocating tachycardia; 2) absence of fusion beats or narrowing QRS complexes during tachycardia; 3) advancement of right ventricular activation with late atrial extrastimuli delivered during antidromic tachycardia at a time of low right atrium refractoriness; 4) observation that earliest ventricular endocardial electrogram during tachycardia (activation mapping) was simultaneous with the right bundle potential; 5) surgical ablation of the accessory pathway by endocardial incision at the right anterior aspect of the tricuspid ring, far away from the AV node region. Evidences showing anterograde longitudinal dissociation of the accessory pathway included cycle length alternation during tachycardia and duality of accessory pathway conduction times and refractory periods. We hypothesize that reentry occurring in such AV node-like structure could give to a pre-excited tachycardia with AV dissociation mimicking antidromic tachycardia associated with nodoventricular pathway.