Gary S. Haas

Aortoventriculoplasty with the pulmonary autograft: The "Ross-Konno" procedure

BACKGROUND For patients with complex left ventricular outflow tract obstruction, including hypoplastic aortic anulus with or without severe diffuse subaortic stenosis, various aortoventriculoplasty procedures (e.g., Konno procedure and its modifications; extended aortic allograft root replacement) are important management options. In younger patients, however, reoperation for valve replacement is inevitably required, and anticoagulation issues pose additional problems. The pulmonary autograft provides a promising option for aortic valve replacement as part of the aortoventriculoplasty procedure in children. Long-term follow up shows that the pulmonary autograft functions well as the systemic arterial (neoaortic) valve and that valve growth occurs. METHODS Between July 1993 and May 1995, 11 patients 4 days to 17 years old (median 12 months) underwent aortoventriculoplasty with pulmonary autograft (Ross-Konno procedure). The diagnoses were aortic stenosis with or without subaortic stenosis (n = 8), Shone complex (n = 2), and interrupted aortic arch with subaortic stenosis (n = 1). On average, 1.9 previous interventions had been performed per patient, including a previous Konno procedure in one patient. The aortic root was replaced with a pulmonary autograft valve. The left ventricular outflow tract was enlarged with a Dacron polyester fabric patch in two patients, with an allograft aortic patch in two patients and a right ventricular infundibular free wall muscular extension harvested in continuity with the autograft in seven patients. RESULTS Intraoperative transesophageal echocardiographic assessment revealed mild aortic insufficiency in one patient. One patient had a residual left ventricular outflow tract gradient of 15 mm Hg. Significant complications were cardiac tamponade from bleeding (n = 1) and complete heart block necessitating a permanent pacemaker (n = 1). Follow-up ranged from 2 weeks to 16 months. To date, there have been no late deaths or reoperations. Follow-up echocardiography revealed mild autograft insufficiency in one patient and a 16 mm Hg residual left ventricular outflow tract gradient in one patient. CONCLUSIONS Initial experience suggests that aortoventriculoplasty with the pulmonary autograft is an excellent alternative for young patients with complex left ventricular outflow tract obstruction. Because the pulmonary autograft has been shown to grow after implantation, reoperation on the left ventricular outflow tract is likely to be avoided.

Intraoperative echocardiography for evaluation of congenital heart defects in infants and children

To determine the accuracy, utility, and limitations of intraoperative transesophageal echocardiography (TEE) in infants and children, we performed prebypass and postbypass TEE in 90 children undergoing surgical repair of congenital heart lesions, comparing the results to those obtained using intraoperative epicardial echocardiography and pre- and postoperative precordial echocardiography. Patients ranged in age from 4 days to 21 yr (mean 4.1 yr) and in weight from 3 to 68 kg (mean 15.4 kg). Prebypass, we obtained high-quality, two-dimensional TEE images in 86 patients, with correction of the preoperative precordial diagnosis in 3 and confirmation of the preoperative diagnosis in the rest. Adequate epicardial images were obtained in 78 patients, with confirmation of the preoperative diagnosis in all. Shunt lesions that were well delineated prebypass by both TEE and epicardial imaging included interatrial, interventricular, and atrioventricular septal defect lesions. TEE failed to detect the exact size and location of lesions involving the right ventricular outflow tract, i.e., doubly committed subarterial (supracristal) ventricular septal defects. Regurgitant lesions (n = 30) were identified and their severity evaluated in all patients by both TEE and epicardial imaging. Obstructive lesions (n = 33), excluding those involving the right ventricular outflow tract, were well defined by both echocardiographic approaches. Postbypass, we obtained high-quality, two-dimensional, color and Doppler TEE images in 86 patients and epicardial images in 78 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative echocardiography in infants and children with congenital cardiac shunt lesions: Transesophageal versus epicardial echocardiography

To determine the utility and limitations of intraoperative transesophageal echocardiography in infants and children with congenital intracardiac shunts, intraoperative transesophageal (n = 50) and epicardial (n = 49) echocardiograms were performed before and after cardiopulmonary bypass in children from 4 days to 16 years old and 3 to 45 kg in body weight. A miniaturized transesophageal probe (6.9 mm maximal diameter) was used in 36 patients weighting less than or equal to 20 kg. Epicardial imaging was performed with a 5 MHz precordial probe. The intraoperative transesophageal echocardiographic findings before and after cardiopulmonary bypass were correct and complete in 94% of patients. Transesophageal echocardiography correctly identified atrial septal defects, most types of ventricular septal defects, anomalous pulmonary veins, atrioventricular septal defects, tetralogy of Fallot, truncus arteriosus and double inlet ventricles. It failed to provide a correct diagnosis in only three patients, all of whom had doubly committed subarterial ventricular septal defects. Epicardial echocardiography identified all cases that had a doubly committed subarterial ventricular septal defect. A correct and complete intraoperative diagnosis was obtained with the use of epicardial imaging in 92% before and after cardiopulmonary bypass, but this technique required interruption of surgery and could not be completed in three patients because of induced arrhythmias and hypotension. These results demonstrated that intraoperative transesophageal echocardiography consistently defined important morphologic, color and pulsed Doppler ultrasound features of most congenital shunt lesions. Lesions that involved the right ventricular outflow tract are sometimes difficult to image with uniplane transesophageal echocardiography. There were no complications in any of the 50 subjects.

Outcomes After Bidirectional Cavopulmonary Shunt in Infants Less Than 6 Months Old

OBJECTIVES We sought to assess the results after bidirectional cavopulmonary shunt (BCPS) in infants < 6 months old and to identify risk factors for poor outcome. BACKGROUND Although BCPS is a well established procedure for the palliation of patients with a single-ventricle heart, there have been very few reports of outcomes after BCPS in young infants. METHODS Since 1990, 42 infants between 0.8 and 6.0 months of age (mean [+/-SD] 3.7 +/- 1.4) have undergone BCPS for primary (n = 16) or secondary (n = 26) palliation of tricuspid atresia (n = 13), hypoplastic left heart syndrome (n = 10) or other forms of functional single-ventricle heart (n = 19). Accessory pulmonary blood flow was included in 18 patients. Preoperative and perioperative data were gathered on retrospective review of patient records, and follow-up was conducted by means of direct physician contact or record review. RESULTS The overall hospital mortality rate, including that associated with reoperations, was 4.8% (2 of 42 patients). Seven patients (17%) required reoperation related to the BCPS or pulmonary blood flow in the early postoperative period: Procedures included take-down of the BCPS in four patients, with one early death, and procedures to decrease pulmonary blood flow in three patients. Age < 1 month correlated significantly with early death and with early failure of the BCPS (death or take-down). Follow-up of the 37 patients discharged with intact BCPS was obtained at a mean +/-SD of 14.3 +/- 11.3 months postoperatively, during which time three patients died (at 6.5 +/- 2.5 months). The 2-year actuarial survival rate for patients undergoing BCPS at < 6 months of age was 86%. Overall freedom from death or take-down (including early and late events) was significantly lower in patients < 2 months old than in those > 2 months old. Four patients have undergone successful Fontan completion (18.3 +/- 2.9 months postoperatively), and one patient whose BCPS was taken down subsequently underwent successful restoration of a BCPS. CONCLUSIONS Outcomes after BCPS in young infants are comparable to those in older infants and children. However, our current preference is to defer this procedure until after 2 months of age.

Predicting feasibility of biventricular repair of right-dominant unbalanced atrioventricular canal.

BACKGROUND In right-dominant unbalanced atrioventricular (AV) canal, there are no criteria to judge adequacy of the left ventricle for biventricular repair. The purpose of this study was to test the hypothesis that right ventricular volume overload in this condition results in right-to-left septal bowing and contributes to the appearance of a small left ventricle. METHODS Five consecutive neonates and young infants (age range, 23 days to 5 months; median age, 3 months) with right-dominant unbalanced complete AV canal underwent biventricular repair. Preoperative and postoperative echocardiographic measurements of left (LV) and right ventricular size and AV valve component size were made. Potential LV volume was assessed preoperatively using a theoretic model that assumed a normalization of septal bowing. RESULTS There was no perioperative mortality; 1 patient died 71 days postoperatively of problems related to the left AV valve. Preoperatively, all patients had severe LV hypoplasia, with a mean end-diastolic indexed true LV volume of 14.8 +/- 9.1 mL/m2, indexed potential LV volume of 32.0 +/- 18.8 mL/m2, left AV valve to total AV valve ratio of 0.30 +/- 0.06, and LV to right ventricular long-dimension ratio of 0.65 +/- 0.1. Postoperatively, all patients had indexed true LV volumes greater than 30 mL/m2 (mean volume, 35.6 +/- 3.9 mL/m2), and the left AV valve to total AV valve ratio and the LV to right ventricular long-dimension ratio increased to 0.42 +/- 0.03 and 0.88 +/- 0.11, respectively. Both preoperative potential and true LV volumes correlated well with postoperative true LV volumes: r = 0.90 (p = 0.040) and r = 0.93 (p = 0.023), respectively. Increases in LV length and left AV annulus size indicated contributions of volume loading and surgical patching to the right of the ventricular crest to the increase in LV size. CONCLUSIONS In our small series, preoperative indexed potential LV volume of 15 mL/m2 or greater (present in all patients) allowed biventricular repair of right-dominant unbalanced AV canal. Any previous criteria for LV hypoplasia in this condition need to be reconsidered. This study also has implications for other right-sided volume-loaded lesions in which the left ventricle initially is judged to be hypoplastic but in which biventricular repair may be feasible.

Morphologic determinants favoring surgical aortic valvuloplasty versus pulmonary autograft aortic valve replacement in children

UNLABELLED The pulmonary autograft is being used with increasing frequency to replace the diseased aortic valve in the pediatric population. Attempted surgical aortic valvuloplasty with an unacceptable result and return to cardiopulmonary bypass for aortic valve replacement with a pulmonary autograft results in prolonged bypass time and increased potential for morbidity. Therefore, the ability to predict an unsuccessful outcome for valvuloplasty would be of significant clinical benefit. This issue is addressed in the present study. METHODS Twenty-two patients (median age 5.7 years, range 3 weeks to 14 years) with bicuspid (n = 11), tricuspid (n = 9), or quadricuspid (n = 2) aortic valves underwent valvuloplasty for aortic stenosis (n = 9), aortic regurgitation (n = 7), or a combination (n = 6). Previous related procedures included balloon aortic valvuloplasty (n = 3) and open surgical valvotomy (n = 1). Median pressure gradient across the aortic valve was 80 mm Hg. Surgical valvuloplasty techniques included thinning of leaflets (n = 18), commissurotomy (n = 15), suspension of reconstructed leaflet to the aortic wall (n = 10), closure of leaflet fenestration (n = 5), shortening of free edge of prolapsed cusp (n = 4), repair of torn leaflets (n = 3), and augmentation of scarred leaflets with autologous pericardium (n = 3). Concomitant subvalvular and supravalvular stenosis were repaired in nine and four patients, respectively. In five patients, during the same hospital stay, a failed valvuloplasty was converted into a valve replacement with a pulmonary autograft because of residual or resultant stenosis (n = 3) or regurgitation (n = 2). RESULTS No early or late deaths occurred. At a median follow-up of 16.3 months the median pressure gradient across the aortic valve in the 15 patients with preoperative stenosis or combined stenosis and regurgitation was 16 mm Hg (p < 0.01 versus preoperative gradient). Of the 22 patients, the aortic valve functioned normally (defined as < or = mild stenosis or regurgitation, or both) in 14 patients (including five patients with valve replacement); four patients had stenosis (gradients 40, 45, 60, and 60 mm Hg), two patients had regurgitation, and two patients had combined stenosis (gradients 40 and 50 mm Hg) and regurgitation. Three of the patients with recurrent stenosis underwent secondary surgical valvuloplasty without improvement. Outcome after valvuloplasty was examined according to valve structure: six of nine tricuspid valves functioned normally, whereas only three of 13 nontricuspid valves functioned normally (P = 0.07). Patients with a nontricuspid aortic valve and regurgitation had a high probability of requiring immediate valve replacement (P = 0.009). The actuarial freedom from significant native valve stenosis or regurgitation at 24 months was 82% for tricuspid valves and 36% for nontricuspid valves (P = 0.007). CONCLUSIONS (1) Surgical aortic valvuloplasty should be the preferred approach when the aortic valve is tricuspid. (2) In contrast, aortic valve replacement with a pulmonary autograft should be the preferred strategy in the presence of a nontricuspid aortic valve (especially when the aortic valve is regurgitant) and after failed surgical valvuloplasty.

Intraoperative transesophageal echocardiography of atrioventricular septal defect

To determine the accuracy and utility of single-plane transesophageal echocardiography in analyzing atrioventricular (AV) septal defect, intraoperative transesophageal echocardiography was performed before and after institution of cardiopulmonary bypass in 16 patients (age 24 days to 14 years, weight 3 to 47 kg). Prebypass transesophageal echocardiography (including two-dimensional echocardiography, Doppler color flow mapping and pulsed wave Doppler ultrasound) correctly diagnosed divided AV valve, common AV valve and unbalanced AV valve, as well as atrial or ventricular septal defect, or both, in all cases. It correctly analyzed AV valve regurgitation in all 10 patients with right and all 14 with left AV valve regurgitation and correctly analyzed 30 of 33 additional cardiac anomalies. Transesophageal echocardiography was able to detect the absence of normal pulmonary venous connections but failed to demonstrate all of the complex anomalous pulmonary venous connections in three patients with atrial isomerism. Postbypass transesophageal echocardiography documented the absence of a significant residual shunt in 11 of 11 patients undergoing corrective surgery and verified residual AV valve regurgitation in 7 of 9 patients with tricuspid regurgitation and 11 of 13 with mitral regurgitation. Transesophageal echocardiographic information that altered or refined the surgical treatment was obtained in 5 (31%) of 16 patients. Epicardial and transesophageal echocardiography results were concordant in all 13 patients in whom both were performed. Transesophageal echocardiography provides useful and accurate imaging of the important two-dimensional, pulsed wave Doppler ultrasound and Doppler color flow mapping features in AV septal defect.

Extracardiac fontan operation with adjustable communication

A modified technique for the Fontan operation is described in which an adjustable communication between the extracardiac conduit (systemic venous chamber) and the right atrium (pulmonary venous chamber) is constructed. Potential advantages of this technique consist of minimization of surgical manipulation of atrial tissue, reduction or elimination of myocardial ischemia, creation of a uniform and stable inferior vena cava-to-pulmonary artery conduit, and increased flexibility and safety in certain high-risk patients such as those with increased pulmonary vascular resistance, pulmonary hypertension, and impaired ventricular function.

Modified surgical techniques for relief of aortic obstruction in {S,L,L} hearts with rudimentary right ventricle and restrictive bulboventricular foramen

Modified techniques of aortopulmonary anastomosis were performed in six neonates with atrioventricular and ventriculoarterial discordance [S,L,L], double-inlet left ventricle, and restrictive bulboventricular foramen area (mean index 1.10 cm2/m2) with unobstructed aortic arch (n = 3) or with hypoplasia (n = 2) or interruption (n = 1) of the aortic arch. In cases of unobstructed aortic arch, a flap of autogenous aortic tissue was used to augment the posterior aspect of the anastomosis of the main pulmonary artery to the ascending aorta, thus creating the potential for anastomotic growth; this technique is applicable regardless of the position of the ascending aorta relative to the main pulmonary artery. In case of levo-transposition of the aorta with hypoplasia or interruption of the aortic arch, a modified Norwood procedure was performed, in that the proximal ascending aorta was divided at the same level as the main pulmonary artery with subsequent homograft patch augmentation from the main pulmonary artery-ascending aorta anastomosis to the level of the proximal descending aorta; this technique avoids a spiraling incision of the aorta and therefore reduces the risk of torsion of the aortic root with its inherent risks of obstruction of the coronary circulation and aortic or pulmonary valve regurgitation. There was no early or late mortality. At a mean follow-up of 16 months, in all patients, there was unobstructed aortic outflow, as evidenced by echocardiographic absence of a significant ventricular-aortic systolic gradient (mean 4.5 +/- 4 mm Hg) and absence of distal aortic arch obstruction. There was no evidence of aortic or pulmonary valve regurgitation. The reported modified techniques provide effective relief of restrictive bulboventricular foramen and aortic obstruction in [S,L,L] hearts.

Organized Thrombus in Left Main Coronary Artery in Hypoplastic Left Heart Syndrome

A neonate is reported in whom, during Norwood stage I correction for hypoplastic left heart syndrome with mitral stenosis, an organized thrombus was found to protrude from the left coronary ostium into the aortic root. With ventricular assist device support the patient survived despite severe left ventricular ischemia. The presumed origin of the thrombus is from left ventriculocoronary arterial connections that serve to decompress the blind left ventricular cavity.