Biomedical subjects

Mark D Rodefeld

Publications and source records attributed to Mark D Rodefeld.

At least 19 recordsLinked to original sources

PubMed2006

Outcomes in patients with interrupted aortic arch and associated anomalies: a 20-year experience.

OBJECTIVE: The surgical results for the repair of interrupted aortic arch (IAA) have evolved in recent years. We report our results for staged repair of this complex congenital malformation. METHODS: Sixty-five patients (mean age, 16.9+/-41.7 days) were diagnosed with IAA and referred for surgical therapy. The surgical management strategy at our institution between 1982 and 2005 has been one-stage complete repair (n=13) or staged repair (n=52) in selected patients. Non-complex patients (group I, n=51) had a ventricular septal defect (87%), aortopulmonary window (8%), and left ventricular outflow tract obstruction (27%). Group II (n=14) were patients with Taussig-Bing double outlet right ventricle (n=6) or truncus arteriosus (n=8). Method of staged repair of IAA was to transect and turn down the left carotid artery and anastomosis it to the descending aorta (n=41) or graft interposition (n=2) combined with a pulmonary artery (PA) banding followed in a few months by delayed ventricular septal defect (VSD) closure and PA de-banding. RESULTS: There were 5 early and 10 late deaths. The actuarial survival including early mortality was 92% at 1 year, 81% at 5 years, and 76% at 10 and 15 years. There was an 81% 15-year survival for children in group I compared with a 54% for children in group II (p<0.001). Risk factors for increased mortality by univariate analysis were as follows: (1) primary aortic anastomosis (p=0.03), (2) presence of complex anomalies (p=0.05), and (3) initial IAA repair performed before 1994 (p=0.05). Actuarial freedom from any type of aortic reoperation or intervention was 86% at 1 year, 69% at 5 years, and 60% at 10 and 15 years. Univariate and multivariate analyses identified no tested variables as risk factors for reoperation. The majority (86%) was in New York Heart Association (NYHA) class I, and 14% remained in NYHA class II. During the postoperative course there were no neurologic deficits, seizures, and growth disturbances in any patient. CONCLUSION: Staged repair of IAA using a left carotid artery turn down can be safely applied in IAA patients with and without other intracardiac anomalies with good results. Use of the left carotid artery for arch reconstruction did not result in any detectable neurological events or growth disturbances later in life. Associated anomalies played an important role in outcomes. The long-term probability for reoperation and/or reintervention remains high regardless of operative technique.

Aorta, Thoracic↗

PubMed2006

Evolution of aortic valve replacement in children: a single center experience.

BACKGROUND: The availability of an ideal prosthesis for aortic valve replacement (AVR) in children remains controversial due to an early degeneration of xenografts and the potential risks related to anticoagulation with mechanical prostheses. This has led many surgeons to the Ross procedure. This study outlines the evolution of our 30-year experience with AVR in children. METHODS: One hundred and forty-seven children, aged 10 days to 18 years (mean 11.9+/-5.7 years), underwent AVR between 1974 and June 2005. Preoperative diagnosis included aortic insufficiency (n=39), aortic stenosis (n=14), combined aortic stenosis with insufficiency (n=78), and complex left ventricular outflow tract obstruction (n=16). Xenografts (n=11) and mechanical prostheses (n=47) were used in 58 patients. The remaining 89 patients had placement of homografts (n=8) or underwent a Ross procedure (n=81). Of the 147 patients, 87 (59%) had previous procedures. RESULTS: Overall early and late mortality was 7.5% (11/147 pts). Overall survival estimated by the Kaplan-Meier method, including early mortality, was 94% at 1 year, and 93% at 5, 10, and 20 years. Univariate and multivariate analysis identified date of operation (before 1980) as a risk factor for death (p=0.002). Follow-up was complete in 136 patients (5 lost to follow-up), with a total follow-up of 2433.72 patient-years. The overall study group aortic valve-related reoperation rate was 20% (20/138 pts), the reoperation rate was highest in xenograft group (60%); followed by mechanical valves group (16%), homograft group (14%), and the Ross procedure group (9%). Ross patients showed significant increase of the annulus diameter (p=0.002) and the aortic sinus diameter (p=0.01) at the last follow-up. The actuarial rate for freedom from aortic valve-related reoperation was 99% at 1 year, 94% at 5 years, 88% at 10 years, and 85% at 20 years. Univariate and multivariate analysis identified the presence of a xenograft as a risk factor for aortic valve-related reoperation (p=0.001). CONCLUSION: AVR in children can be performed with acceptable mortality and minimal mid-term morbidity. The Ross procedure, although more complicated, has the advantage of not requiring anticoagulation. Pulmonary autograft, in our series, has demonstrated growth with no structural degeneration. The potential for development of significant autograft insufficiency and ascending aortic aneurysmal dilatation is small but warrants annual follow-up. Our data supports that the Ross procedure is the AVR of choice in children.

Adolescent↗

PubMed2006

Twenty-four hour cardiopulmonary stability in a model of assisted newborn Fontan circulation.

BACKGROUND: Morbidity and mortality after stage-1 palliation of hypoplastic left heart syndrome is high as a result of adverse physiologic conditions imposed by the systemic-to-pulmonary arterial shunt. Conversion to a systemic venous source of pulmonary blood flow (Glenn/Fontan) substantially decreases instability and mortality risk. Cavopulmonary assist has the potential to eliminate critical dependence on the problematic systemic arterial shunt. We studied this support modality during a 24-hour period in a neonatal animal model of univentricular Fontan circulation. METHODS: Lambs (8.1 +/- 0.9 kg, 8.3 +/- 2.1 days, n = 7) underwent total cavopulmonary diversion. A miniature centrifugal pump was used to assist cavopulmonary flow. Control animals (6.6 +/- 1.0 kg, 7.3 +/- 2.1 days, n = 11) underwent placement of monitoring lines only. Hemodynamic and gas exchange data were measured. Within-group and between-group comparisons were made using two-way repeated measures analysis of variance. RESULTS: After an initial phase of reactivity, pulmonary vascular resistance returned to low levels and was not significantly different from baseline values after hour 13 or significantly different from control values after hour 4. Systemic venous pressure remained low. Oxygenation and ventilation remained normal with no histologic evidence of parenchymal lung injury. CONCLUSIONS: Pump-assisted cavopulmonary diversion is well tolerated up to 24 hours in the neonatal period. Despite initial reactivity, pulmonary vascular resistance trended toward normal and approached control values. Cavopulmonary assist holds the potential to serve as a bridge to neonatal Fontan repair of single ventricle. Chronic studies are warranted to determine the duration and rate of weaning of support to transition to an unassisted univentricular Fontan circulation.

Animals↗

PubMed2006

Closed transventricular aortic valvotomy for critical aortic stenosis in neonates: outcomes, risk factors, and reoperations.

BACKGROUND: Critical aortic stenosis (AS) in neonates necessitates urgent intervention for patient survival. The optimal treatment, however, continues to be controversial and still has high morbidity and mortality in many centers. This study examined our late outcome, risks, and reoperations after the treatment of critical AS in neonates. METHODS: Sixty-six neonates (47 boys and 19 girls) underwent closed transventricular aortic valvotomy for critical AS between 1978 and 2000. The mean age at the first intervention was 15.1 +/- 19.6 days (range, 1 to 78). Their weight ranged from 1.4 to 6.2 kg (mean, 3.5 +/- 0.9 kg). Sixteen patients (23%) had isolated critical AS and normal or dilated left ventricles, and 50 neonates (77%) had associated cardiovascular anomalies (ie, aortic annular hypoplasia, hypoplasia of the left ventricle, mitral valve abnormalities, and endocardial fibroelastosis, coarctation, or interruption of aorta). RESULTS: The hospital mortality was 29% (19 of 66). Kaplan-Meier 5- and 15-year survival was 61% and 58%, respectively. The operative mortality rates were 6% in neonates with isolated AS and 36% in patients with complex AS. The five risk factors significant for mortality on univariate analysis were (1) presence of endocardial fibroelastosis (p = 0.05), (2) presence of hypoplastic left ventricle (p = 0.003), (3) presence of associated cardiovascular anomalies (p = 0.04), (4) aortic valve annulus of less than 5.0 mm (p = 0.01), and (5) surgery before 1985 (p = 0.003). Of these five factors, only the presence of hypoplastic left ventricle (p = 0.001) and surgery before 1985 (p = 0.001) remain significant for mortality by multivariate analysis. At last follow-up (mean, 8.2 +/- 6.2 years), 36 of 47 of the long-term survivors were in New York Heart Association functional class I and II. Kaplan-Meier analysis showed 5- and 15-year freedom from aortic valve reoperation to be 83% and 60%, respectively. Univariate and multivariate analysis showed the presence of multilevel stenosis (p = 0.04) as the best preoperative predictor for the need for late reoperation in survivors. CONCLUSIONS: We conclude that critical AS in neonates continues to be associated with significant mortality. Reintervention such as surgical and balloon valvotomy are usually required within 10 years of initial surgery.

Alprostadil↗

PubMed2006

Neonatal cavopulmonary assist: pulsatile versus steady-flow pulmonary perfusion.

BACKGROUND: Morbidity and mortality associated with single-ventricle physiology decrease substantially once a systemic venous, rather than systemic arterial, source of pulmonary blood flow is established. Cavopulmonary assist has potential to eliminate critical dependence on the problematic systemic-to-pulmonary shunt as a source of pulmonary blood flow in neonates. We have previously demonstrated feasibility of neonatal cavopulmonary assist under steady-flow conditions. We hypothesized that pulsatile pulmonary perfusion would further improve pulmonary hemodynamics. METHODS: Lambs (weight 7.2 +/- 1.1 kg, age 7.9 +/- 1.5 days) underwent total cavopulmonary diversion using bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to augment cavopulmonary flow. Pulsatility was created with an intermittently compressed compliance chamber in the circuit. Hemodynamic and gas exchange data were measured for 8 hours. Pulsatile (n = 6), steady-flow (n = 13), and control (n = 6) groups were compared using two-way analysis of variance with repeated measures. RESULTS: All animals remained physiologically stable with normal gas exchange function. Mean pulmonary arterial pressure was elevated in pulsatile and steady-flow groups compared with the control group and within-group baseline values. Pulmonary vascular resistance was elevated initially in both assist groups but decreased significantly over the last 4 hours of the study and normalized after hour 4 in the pulsatile perfusion group. Pulmonary vascular resistance also normalized to control in the steady-flow group after hour 7. CONCLUSIONS: Both steady-flow and pulsatile pulmonary perfusion demonstrated normalization of pulmonary vascular resistance to control in a neonatal model of univentricular Fontan circulation. These results suggest that there is no benefit to pulsatile flow in this model.

Animals↗

PubMed2006

Caval division technique for sinus venosus atrial septal defect with partial anomalous pulmonary venous connection.

BACKGROUND: Repair of sinus venosus atrial septal defect (ASD) with high partial anomalous pulmonary venous connection (PAPVC) using an internal patch may be complicated by obstruction of the superior vena cava (SVC) or pulmonary veins, or both, and sinus node dysfunction. In cases in which the anomalous veins insert more than 2 cm above the cavoatrial junction, we have adopted the technique of caval division in which the SVC is divided and the proximal end is anastomosed to the right atrial appendage, and the distal SVC serves as a conduit for pulmonary venous drainage to the left atrium through the ASD. We retrospectively compare the results of the internal patch repair versus the Warden technique. METHODS: Between 1991 and 2004, 54 patients diagnosed with sinus venosus ASD and PAPVC have undergone repair at our institution. Mean age was 13.4 years (range, 1.5 to 58). Thirteen patients (24%) had high insertion of anomalous veins and underwent the Warden technique. Follow-up averages 4.3 years (range, 1 to 13). RESULTS: There were no early or late deaths. All patients remain in normal sinus rhythm. Twelve of the 13 patients with Warden procedure have had postoperative echocardiograms, and 11 of these patients showed no evidence of SVC or pulmonary venous obstruction. In 1 patient, symptomatic pulmonary venous obstruction developed and required revision of a contracted intra-atrial pericardial baffle. CONCLUSIONS: Caval division for treatment of high PAPVC appears to be safe and is associated with low morbidity and mortality. The Warden procedure is an effective surgical option for patients undergoing correction of high PAPVC.

Abnormalities, Multiple↗

PubMed2006

Mitral valve replacement with Ross II technique: initial experience.

BACKGROUND: Pulmonary autograft mitral valve replacement (PA-MVR) was introduced clinically by Ross in 1967, but has been rarely utilized in North America and Europe. The aim of this study is to review our early experience with PA-MVR. METHODS: Since June 2002, 8 patients (7 female and 1 male) between 12 to 46 years of age with outgrown mechanical valves (n = 3) failed MV repair for rheumatic or congenital MV disease (n = 4) and irreparable bileaflet myxoid prolapse (n = 1), underwent PA-MVR. The pulmonary autograft was harvested and replaced using a pulmonary homograft. The autografts were mounted within a woven Dacron graft 6-8 mm greater in diameter than the autograft annulus diameter on a preoperative echocardiogram. The graft's external surface was covered with fresh autologous pericardium. RESULTS: There were no deaths. Intraoperative echocardiography confirmed a mean MV gradient of 4 mm Hg with trivial (n = 7) or mild (n = 1) regurgitation. Follow-up (range, 13 to 36 months) echocardiography in 4 patients showed no increase in MV gradient or regurgitation. One patient with severe myxoid degeneration and one patient with rheumatic disease, both with systemic hypertension, developed progressive regurgitation due to stretching of a single autograft leaflet producing prolapse. One patient developed a moderate gradient due to retention of excessive native mitral leaflet and subannular chordal tissue. Three of 4 patients have required PA-MVR replacement with mechanical valves 6 to 14 months post-PA-MVR. One asymptomatic patient with mild to moderate mitral regurgitation is being followed after treatment of her systemic hypertension. CONCLUSIONS: Pulmonary autograft mitral valve replacement offers selected patients a potentially lifelong autologous valve without the need for long-term anticoagulation. The PA-MVR technique deserves careful consideration in younger patients in sinus rhythm. Postoperative systemic hypertension should be treated aggressively to prevent excessive stress on the pulmonary autograft particularly in the early postoperative months.

Adolescent↗

PubMed2006

Valved bovine jugular vein conduits for right ventricular outflow tract reconstruction in children: an attractive alternative to pulmonary homograft.

BACKGROUND: Pulmonary homografts (PH) have been the preferred valved conduits for right ventricular outflow tract (RVOT) reconstruction in the US since the mid-1980s. Although PHs have worked well for Ross patients, many PH extracardiac conduits used for congenital heart surgery suffer from degeneration and develop regurgitation and obstruction within months after implantation and require replacement within 4 to 6 years. Recently a valve-containing bovine jugular vein (Contegra, Medtronic, Inc, Minneapolis, MN) was introduced for clinical trials for a variety of patients requiring RVOT reconstruction. METHODS: The early results of RVOT reconstruction utilizing the Contegra conduit were retrospectively analyzed in 62 patients. This series consisted of 9 newborns with truncus arteriosus, 39 patients with failed PHs, 6 with pulmonary atresia and 2 with tetralogy of Fallot with absent pulmonary valve, 2 with transposition of great arteries with ventricular septal defect and pulmonary stenosis, and 4 undergoing a Ross procedure. The patients ages ranged from 2 weeks to 18 years (mean, 7.3 +/- 6.0 years) and weights were from 2 to 83 kg (mean, 28.1 +/- 22.3 kg). The Contegra conduit sizes varied in diameter between 12 and 22 mm (mean, 18.2 +/- 4.1 mm). RESULTS: There were two early (3%) and four (7%) late deaths and none of them was conduit related. There has been one conduit explantation, and seven patients have required reinterventions to relieve stenosis at or beyond the distal anastomosis of the conduit to pulmonary artery bifurcation (8 of 60; 13%). Six of the 7 patients had balloon dilatation of the branch pulmonary arteries for preexisting stenosis. One patient developed distal anastomotic stenosis that did not yield to balloon angioplasty and she underwent surgical patch arterioplasty of the distal anastomosis. The interval from conduit implantation to reintervention ranged from 3 to 27 months (mean, 11.1 +/- 7.8 months). Of these, three patients required placement of a stent in the left (n = 1) or both branch pulmonary arteries (n = 2). During the short to intermediate follow-up in our series we have not observed, on echocardiography, shrinkage of the Contegra as we and others have reported with PHs. CONCLUSIONS: The Contegra conduit offers a promising alternative for RVOT reconstruction. Early hemodynamic performance compares favorably with PHs. Clinical advantages are greater availability in sizes from 12 to 22 mm and natural continuity between the valve and conduit that allows proximal infundibular shaping without additional materials. The price of the bovine jugular venous valve is approximately one-half that of many PHs in the US. Short-term freedom from dysfunction is at least as good as PHs. Long-term durability must be determined for this new conduit. The Contegra conduit is currently our conduit of choice for RVOT reconstruction in infants, children, and young adults.

Adolescent↗

PubMed2006

The Ross-Konno procedure in children: outcomes, autograft and allograft function, and reoperations.

BACKGROUND: The Ross aortic valve replacement with a modified Konno-type enlargement Ross-Konno procedure of the aortic annulus and subannular region allows an autograft aortic valve replacement for children with significant annular and subannular hypoplasia. The potential for growth and the proven durability of the autograft make the Ross-Konno procedure an ideal aortic valve replacement for this subgroup with multilevel left ventricular outflow tract obstruction. We reviewed our institutional midterm experience to assess autograft and homograft hemodynamics, and management after a Ross-Konno procedure. METHODS: Between 1995 and 2005, 14 consecutive children (mean age, 6.4 +/- 5.9 years; range, 1 month to 17 years) underwent the Ross-Konno procedure. All children had severe to critical aortic stenosis or multilevel left ventricular outflow tract obstruction. RESULTS: There was 1 early and 1 late death with a mean follow-up of 5.7 +/- 3.6 years. Actuarial survival at 10 years was 86%. Three patients underwent right ventricular outflow tract reoperation for conduit replacement for homograft dysfunction and one patient required redo aortic root replacement with a mechanical valves for progressive aortic insufficiency. Freedom from right ventricular outflow tract and autograft reoperation at 10 years is 77% and 92%, respectively. Aortic annular dilation was not observed in all patients. Univariate and multivariate analysis identified no risk factors for autograft or homograft valve-related reoperation. CONCLUSIONS: The Ross-Konno procedure is an excellent technique to treat complex multilevel left ventricular outflow tract obstruction in children with significant annular and subannular hypoplasia. The autograft demonstrated durability without development of aortic stenosis or progressive dilation and a low incidence of developing progressive aortic insufficiency. Enlargement of the aortic annulus appear to parallel somatic growth in most instances.

Adolescent↗

PubMed2006

Surgical treatment of absent pulmonary valve syndrome associated with bronchial obstruction.

BACKGROUND: Absent pulmonary valve syndrome (APVS) is a relatively rare anomaly that is usually associated with a ventricular septal defect and a restrictive pulmonary annulus with severe pulmonary regurgitation. The to-and-fro flow across the right ventricular outflow tract produces enormously dilated and pulsatile pulmonary arteries (PAs) that cause severe respiratory distress and tracheomalacia by compression of the trachea and primary bronchi. This retrospective study summarizes our 20-year experience of surgical treatment in patients with APVS. METHODS: Between 1984 and 2005, 20 patients underwent repair of APVS using a valved conduit (n = 9), transannular patch (TAP) insertion alone (n = 5), or TAP with monocusp valve (n = 6) with PA reduction arterioplasty. Median age was 7 months (range, 6 days to 9 years). RESULTS: There were one perioperative and two late deaths. All deaths were related to airway complications. Survival was 90% at 1 year and 85% at 10 and 15 years. In a multivariate analysis only preoperative ventilator dependency was associated with a worse outcome (p = 0.02). Follow-up was available in 18 operative survivors (mean follow-up, 7.3 +/- 5.2 years). Six patients (33%) underwent reoperation for pulmonary valve incompetence and right ventricular dysfunction. Three patients (17%) had episodic bronchospasm of mild to moderate severity that were responsive to sympathomimetic bronchodilators. CONCLUSIONS: Morbidity associated with perioperative respiratory complications and ventilator dependency due to underlying tracheobronchomalacia is an important problem in patients with APVS. These infants may require multiple hospitalizations for recurrent respiratory infections secondary to their tracheobronchomalacia. Complete repair with a valved conduit and reduction pulmonary arterioplasty at the onset of symptoms and a definitive diagnosis is our procedure of choice for infants with APVS. With this approach, the airway can be optimized to give the best patient outcome.

Airway Obstruction↗

PubMed2006

Fate of the autograft and homograft following Ross aortic valve replacement: reoperative frequency, outcome, and management.

BACKGROUND AND AIM OF THE STUDY: The optimal hemodynamic performance and potential for growth of the pulmonary autograft has led to expanded indications for the Ross aortic valve replacement (AVR) procedure in some centers. The authors' institutional mid-term experience was reviewed to assess autograft and homograft hemodynamics, growth profile of the autograft, and reoperative frequency following Ross AVR. METHODS: Between June 1993 and June 2005, 167 consecutive patients (mean age 24.9 +/- 15.5 years; range: 1 month to 61 years) underwent Ross AVR: 48% of patients were aged < 19 years. Additional procedures (n = 78) were performed in 55 patients (33%) at the time of the Ross procedure. In total, 151 patients had isolated aortic valve disease and 16 pediatric patients had more complex, multi-level left ventricular outflow tract obstruction. RESULTS: There were two early deaths (1.2%) and one late death (0.6%) over a mean follow up of 5.1 +/- 3.0 years (range: 1 month to 11 years). Actuarial survival at 10 years was 98%. In pediatric patients with Konno procedure (n = 16), the pulmonary autograft mean annulus diameter increased from 10.2 to 19.9 mm. Twelve patients underwent 12 reoperations without mortality for autograft insufficiency or an ascending aortic aneurysm at a median interval of 5 years (range: 2 to 8 years): aortic annuloplasty and ascending aorta replacement (n = 4), composite aortic root replacement (n = 7), and repair of left ventricular pseudoaneurysm (n = 1). Freedom from replacement of the pulmonary autograft was 96% at 10 years. Five of the 164 surviving patients (3%) developed significant obstruction of the pulmonary homograft and required conduit replacement at a median of four years. CONCLUSION: The Ross AVR can be performed with good mid-term results, including the pediatric age group. The potential for development of significant autograft insufficiency and homograft stenosis warrants annual follow up through the intermediate and late terms.

Adolescent↗

PubMed2005

Staged surgical repair of functional single ventricle in infants with unobstructed pulmonary blood flow.

OBJECTIVE: The infant with a functional single ventricle (SV) and unobstructed pulmonary blood flow (UPBF) requires early protection of the pulmonary vascular bed to ensure suitability for a subsequent Fontan procedure. Systemic obstruction by aortic arch obstruction, subaortic stenosis, or combination of both, has been widely recognized as an important risk factor for poor outcome in children with SV-UPBF who are palliated with pulmonary artery banding (PAB). We reviewed our experience with primary PAB in the subset of patients with SV-UPBF to identify risk factors for subsequent palliative procedures and Fontan completion. METHODS: Between January 1990 and May 2004, 80 patients (median age, 14 days) with functional SV and UPBF underwent PAB as their primary palliative procedure. Thirty-five neonates had concomitant aortic coarctation or interrupted aortic arch repair (44%). A Damus-Kaye-Stansel procedure was subsequently performed in 19 patients, and subaortic resection or ventricular septal defect or bulboventricular foramen enlargement was performed in five. RESULTS: There were 4 operative deaths, and 15 late deaths. The actuarial overall survival is 84% at 1 year, 76% at 5 and 15 years. Follow-up is complete in all but six children at a mean interval of 4.9+/-3.7 years (range, 2 months-15 years). Thirty-seven patients (49%; 37 of 76) have undergone the hemi-Fontan procedure (with three hospital deaths) and 40 patients (53%; 40 of 76; 12 children without previous hemi-Fontan) have undergone the completion Fontan procedure without mortality or Fontan takedown. CONCLUSION: In infants with single ventricle physiology with or without systemic outflow obstruction and unobstructed pulmonary blood flow, a strategy of pulmonary artery banding carries acceptable operative and mid-term mortality in a high-risk group of patients. Pulmonary artery banding does not compromise performance of subsequent Damus-Kaye-Stansel procedure or completion Fontan palliation.

Female↗

PubMed2005

Operative results and outcomes in children with Shone's anomaly.

BACKGROUND: The outcome of children with multilevel left heart obstructions with mitral valve involvement (Shone's anomaly) is generally poor. This study reviews our results and outcomes in patients with staged repair for left ventricular outflow tract obstruction (LVOTO) and mitral valve reconstruction. METHODS: A total of 27 children underwent staged repair for Shone's anomaly between 1978 and 2003. The mean age at the first operation was 9.0 months (range, 2 days to 3 years). Mitral stenosis was present in all; with supravalvular mitral ring (n = 11), mitral valve abnormalities including parachute mitral valve, fused chordae, single papillary muscle (n = 10), and "typical" (Ruckman & Van Praagh) congenital mitral stenosis (n = 14). The LVOT obstruction features included subaortic stenosis (n = 16), valvar aortic stenosis (n = 7), bicuspid aortic valve (n = 24), and coarctation (n = 18). All 27 patients underwent 94 surgical procedures, including 22 mitral operations and 48 LVOT operations. RESULTS: There were no operative deaths at the first operation. Mean follow-up was 4.7 +/- 4.4 years (range, 6 months to 15 years). There were three late deaths (11%). All late deaths were secondary to severe mitral valve disease. Overall 15-year actuarial survival was 89%. All surviving patients are in New York Heart Association functional class I or II. CONCLUSIONS: Patients with Shone's anomaly are seen with a wide spectrum of major anatomic and hemodynamic abnormalities. A favorable outcome is possible for most. Operative mortality is adversely affected by the severity of mitral valve disease, the degree of left ventricular hypoplasia, and the need for multiple operative procedures.

Adolescent↗

PubMed2005

Right ventricular outflow tract reconstruction with an allograft conduit in non-ross patients: risk factors for allograft dysfunction and failure.

BACKGROUND: Allograft conduits (AC) are used for reconstruction of the right ventricular outflow tract (RVOT) in children with RVOT hypoplasia or atresia and for pulmonary valve replacement in children undergoing Ross aortic valve replacement (AVR). Children undergoing the Ross AVR are generally older and have their AC inserted in the orthotopic position as opposed to the heterotopic position used for most cases of complex RVOT obstruction. The orthotopic position of the AC combined with the fact that the AC in the Ross patients are larger and can be oversized are the three factors that increase the right ventricular-pulmonary artery (RV-PA) conduit durability in the Ross AVR group. A retrospective evaluation of our experience with use of AC in non-Ross patients for reconstruction of the RVOT was conducted to determine the risk factors for failure. METHODS: Between January 1985 and December 2003, 117 non-Ross patients received AC (94 pulmonary and 23 aortic) for RVOT reconstruction. Median age at implantation was 8 months (mean 4.3 +/- 7.1 years; range, 6 days to 43 years). There were 57 children (49%) less than 12 months of age. Endpoints were AC failure (valve explant, balloon dilatation), and AC dysfunction (AC stenosis >40 mm Hg and AC insufficiency more than 2+). There were no device-related deaths. RESULTS: Overall patient survival was 80% at 15 years. Freedom from AC failure was 60% at 5 years and 43% at 15 years. Freedom from failure was worse in infants (42% and 34% at 5 and 15 years, respectively). Freedom from AC dysfunction was 40% at 5 years and 23% at 15 years. Freedom from dysfunction was worse in infants (21% and 16% at 5 and 15 years, respectively). Univariate analysis identified younger patient age, smaller AC size, diagnosis of truncus arteriosus, and the presence of aortic AC as risk factors for AC dysfunction and failure. Multivariate analysis identified smaller AC size and the presence truncus arteriosus as risk factors for AC dysfunction and failure. CONCLUSIONS: Right ventricular outflow tract reconstruction with an AC in non-Ross patients has poor performance at midterm follow-up with AC dysfunction and failure of, respectively, 60% and 40% for the entire group and 79% and 58% in the infant group at 5 years. An alternate conduit for this application must be considered.

Adolescent↗

PubMed2005

Pulmonary arteriovenous malformations in children after the Kawashima operation.

BACKGROUND: Pulmonary arteriovenous malformations are a major cause of progressive late cyanosis in patients treated with cavopulmonary anastomoses. Previous experience suggests that exclusion of the hepatic venous effluent from the pulmonary circulation may cause the development of pulmonary arteriovenous malformations after the Kawashima operation in children with interrupted inferior vena cava with azygous continuation. METHODS: From January 1990 to November 2004, 21 children (median age, 2 years) with heterotaxy syndrome and interrupted inferior vena cava with azygous continuation underwent Kawashima operation. The average preoperative arterial oxygen saturation was 76% +/- 7% (range, 64% to 90%). RESULTS: Follow-up was complete in all survivors except 1 at a median duration of 4.5 years. Pulmonary arteriovenous malformations were diagnosed at a median of 5 years after Kawashima operation in 11 patients (58%). Completion Fontan operation has been performed in 15 (79%). Five children who underwent a completion Fontan procedure 1 to 1.5 years after Kawashima operation did not have pulmonary arteriovenous malformations. There were 2 late deaths due to chronic congestive heart failure 4 months and 7 years after Kawashima operation. Overall survival at 10 years is 90%. Univariate and multivariate analysis demonstrated presence of bilateral superior vena cavae (p = 0.002) and interval longer than 2 years between Kawashima operation and completion Fontan operation (p = 0.04) as predictors of developing pulmonary arteriovenous malformations. CONCLUSIONS: In most patients with heterotaxy and interrupted inferior vena cava with azygous continuation, clinical evidence of pulmonary arteriovenous malformations will develop after Kawashima operation if they are followed up long enough. Early redirection of the hepatic venous effluent to the pulmonary arterial circulation may prevent or lead to regression of pulmonary arteriovenous malformations, with low mortality and morbidity.

Arteriovenous Malformations↗

PubMed2005

Long-term results of apical aortic conduits in children with complex left ventricular outflow tract obstruction.

BACKGROUND: Apical aortic conduits were used in children with complex left ventricular outflow tract obstruction at our institution before we adopted the Ross and Ross-Konno procedures. The early results with apical aortic conduits were quite good when we used a porcine xenograft conduit and were less satisfactory when we converted to an aortic homograft valve as the conduit valve. This report summarizes our clinical experience with apical aortic conduits in children with an emphasis on hemodynamic results, reoperation, and long-term follow-up. METHODS: Records of 28 patients (age range, 2 weeks to 19 years) who underwent insertion of apical aortic conduit between September 1979 and June 1993 were reviewed. All patients had complex multilevel left ventricular outflow tract obstruction. All were symptomatic, and 22 (79%) had had one or two previous aortic valvotomies or left ventricular outflow tract operations, or both. RESULTS: Hospital mortality was 11% (3 of 28). Twenty-five children survived the perioperative period and improved, and 21 have had one or more cardiac catheterization from 6 to 18 months (mean, 1.2 years) after the initial operation. Reduction or resolution of resting mean left ventricular-to-aortic peak gradient in the early postoperative period from 81.8 +/- 24.0 to 15.4 +/- 8.9 mm Hg was demonstrated (p < 0.001). Overall 25-year survival was 57%. Fourteen surviving patients (56%) have undergone subsequent procedures (n = 18) from 5 months to 16 years postoperatively (mean, 6.9 years) because they developed a recurrent left ventricular-to-aortic gradient of 58 +/- 28 mm Hg (p < 0.002). One patient underwent heart transplantation. All other late survivors have normal left ventricular function as determined by serial echocardiography. CONCLUSIONS: Apical aortic conduit is effective in relieving complex left ventricular outflow tract obstruction and improving left ventricular performance with acceptable short-term and midterm results, but late complications caused primarily by conduit tissue valve dysfunction are frequent in children. Since the early 1990s, the apical aortic conduit procedure has been largely replaced with the Ross or Ross-Konno procedure in our pediatric practice.

Adolescent↗

PubMed2004

Cavopulmonary assist in the neonate: an alternative strategy for single-ventricle palliation.

BACKGROUND: Cavopulmonary blood flow, rather than a systemic arterial source of pulmonary blood flow, stabilizes Norwood physiology. We hypothesized that pump-assisted cavopulmonary diversion would yield stable pulmonary and systemic hemodynamics in the neonate. This was tested in a newborn animal model of total cavopulmonary diversion and univentricular Fontan circulation. METHODS: Lambs (n = 13; mean weight, 5.6 +/- 1.5 kg; mean age, 6.8 +/- 4.0 days) were anesthetized and mechanically ventilated. Baseline hemodynamic parameters were measured. Total cavopulmonary diversion was performed with bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to assist cavopulmonary flow. Support was titrated to normal physiologic parameters. Hemodynamic data, arterial blood gases, and lactate values were measured for 8 hours. Baseline, 1-hour, and 8-hour time points were compared by using analysis of variance. RESULTS: All animals remained stable without the use of volume loading, inotropic support, or pulmonary vasodilator therapy. Cardiac index, systemic arterial pressure, left atrial pressure, and lactate values were similar to baseline values 8 hours after surgery. Mean pulmonary arterial pressure and pulmonary vascular resistance were modestly increased 8 hours after surgery. Mean arterial pH, Po(2), and Pco(2) values remained stable throughout the study. CONCLUSIONS: Cavopulmonary assist is feasible in a neonatal animal model of total cavopulmonary diversion and univentricular Fontan circulation with acceptable pulmonary arterial pressures and without altering regional volume distribution or cardiac output. Pump-assisted cavopulmonary diversion, in combination with Norwood aortic arch reconstruction, could solve several major problems associated with a systemic shunt-dependent univentricular circulation, including hypoxemia, impaired diastolic coronary perfusion, and ventricular volume overload.

Animals↗

PubMed2004

Mitral valve replacement with the pulmonary autograft: Ross II procedure with Kabanni modification.

We report our experience with pulmonary autograft replacement of the mitral valve in eight patients. Hospital mortality of 0% was reported, and there has been one autograft failure requiring replacement (mean follow-up 12 +/- 6 months). We also review the world's experience with this technique. Mitral valve replacement with a pulmonary autograft (Ross II) is safe, reproducible, and possible warranted for selected patients.

Adolescent↗