Michael D. Black

Single lung ventilation in children using a new paediatric bronchial blocker

As video‐assisted thoracoscopic surgery has become more common in paediatric patients, the use of single lung ventilation in children has also increased. Single lung ventilation in young children is performed by either advancing a tracheal tube into the mainstem bronchus opposite the side of surgery or by positioning a bronchial blocker into the mainstem bronchus on the operative side. Techniques for placing a variety of bronchial blockers outside the tracheal tube have been described. We describe a technique for placement of a new bronchial blocker through an indwelling tracheal tube using a multiport adaptor and a fibreoptic bronchoscope.

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

UNLABELLEDnThe 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.nnnMETHODSnTwenty-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).nnnRESULTSnNo 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).nnnCONCLUSIONSn(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.

Repair of isolated multiple muscular ventricular septal defects: the septal obliteration technique

BACKGROUNDnIsolated multiple ventricular septal defects (mVSDs) remain a surgical challenge. The dilemma of whether to perform a complete repair ultimately rests with the surgeon, who must decide if all significant septal defects can be located. Avoidance of a pulmonary arterial band (as part of a two-stage repair) will negate the need for future pulmonary arterial reconstruction and will reduce the incidence of late right ventricular diastolic dysfunction.nnnMETHODSnWe performed a retrospective analysis of hospital and echocardiographic data of eight children who underwent a septal obliteration technique (SOT) as part of their correction of mVSDs (with and without coarctation of the aorta).nnnRESULTSnEight children with a mean age of 10.5 months (range 1.5 to 36 months), and weight of 6.2 kg (range 2.1 to 13.5 kg), respectively, underwent correction of mVSDs. All had a single, large, perimembranous defect, additional VSDs within the muscular trabecular septum (juxtaposed to the moderator band), and apical mVSDs. All VSDs were repaired via the right atrium, with avoidance of either a right or left ventriculotomy. The posterior and apical defects were excluded from the right ventricular cavity with a pericardial patch (SOT). The follow-up period remains limited to a mean of 20.9 months (8 to 39 months). Two children repaired with SOT had previous pulmonary artery bands (neonatal coarctation repair). All children were successfully discharged home with a mean postoperative Qp:Qs of 1.09:1. One pacemaker was required, but this child has since reverted back to normal sinus rythm.nnnCONCLUSIONSnOur initial experience using the SOT in the treatment of apical VSDs as a component of isolated mVSDs has been rewarding. All children are currently alive, in normal sinus rhythm, and have no residual significant left-to-right shunts.

Extended aortic root replacement with aortic allografts or pulmonary autografts in children.

OBJECTIVESnTo evaluate the early results and effectiveness of left ventricular outflow tract enlargement with aortic allograft or pulmonary autograft in children with complex left ventricular outflow tract obstruction.nnnMETHODnThe records of 30 children who underwent aortic root enlargement and replacement with either an aortic allograft (22 patients) or pulmonary autograft (8 patients) between January 1987 and June 1997 were reviewed. The predominant diagnosis was complex left ventricular outflow tract obstruction (n = 19), associated with aortic incompetence in 11 children. Before root enlargement, 27 children underwent surgical valvotomy (14 patients), balloon dilatation (10 patients), or both interventions (3 patients). Mean age at root enlargement was 5.4 +/- 3.5 years (range, 2 days-16 years). Most of the children (27 patients) underwent a Konno aortoventriculoplasty. Concomitant septal myectomy was performed in 4 children, mitral valve procedure in 5 children, and endocardial fibroelastosis resection in 1 child.nnnRESULTSnFive children (17%) died in hospital. Four of these were infants less than 2 months old. All had acute aortic incompetence as the result of recent intervention necessitating urgent operation. The fifth child, aged 10 years, died of myocardial failure 2 weeks after the operation. During the follow-up period (mean length, 4.1 +/- 2.8 years), sudden death occurred in 1 child 3 months after the operation. Follow-up echocardiograms (obtained for 23 of the surviving 24 children within 3 +/- 2.3 years) showed a left ventricular outflow tract gradient reduced from a mean of 65 to 11 mm Hg (P =.001); Z value increased from a mean of -0.5 to 4.1 (P <. 001), and aortic incompetence was trivial or mild except in 2 children.nnnCONCLUSIONnUrgent aortic root enlargement in decompensating neonates carries higher mortality rates. In older children, the early results of root enlargement and implantation of allograft or autograft are good.

Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts

BACKGROUNDnResults of aortic arch reconstruction in the setting of biventricular physiology are well documented in the adult population, however, in children, surgical outcome of this subgroup of patients is less clear.nnnMETHODSnWe studied the clinical outcomes of 37 children aged 8 days to 15 years (median 26 months), who underwent aortic arch reconstruction for arch hypoplasia from 1982 to 1997. The children were divided into three groups: Group 1 (20 patients) had isolated aortic arch lesions, Group 2 (13 patients) had associated intra-cardiac pathology yet conserving a biventricular physiology, Group 3 (4 patients) had Williams Syndrome. Previous interventions for coarctation had been performed in 30 patients (81%). Arch repair consisted of a patch aortoplasty in the majority of patients (35 of 37 children).nnnRESULTSnOperative mortality occurred in 5 children, 4 in Group 2 (31%), 1 in Group 3 (25%) and none in Group 1. Permanent neurological complications occurred in 2 children (5 %). During the follow-up, which ranged from 1 month to 8 years, balloon angioplasty for arch obstruction was required in 1 child. There was one late death, associated with a subsequent intra-cardiac repair.nnnCONCLUSIONSnAortic arch surgery in children with isolated arch hypoplasia, is associated with excellent early and late survival in addition to a low reintervention rate. Alternative perfusion and operative strategies must be implemented in infants with associated intra-cardiac anomalies to improve results.

Total anomalous systemic venous drainage to the coronary sinus in association with hypoplastic left heart disease: more than a mere coincidence.

atrium. The pathologic diagnosis of the aneurysm was atherosclerotic and the follow-up CT scan showed normal atria and venae cavae. The postoperative course was uneventful and the patient was discharged on the twelfth postoperative day. Coronary artery aneurysm is a relatively rare disease, with the incidence being reported to be 0.3% to 4.9% of patients undergoing coronary angiography. 1 The most common sites of aneurysm are the proximal and middle portions of the RCA, followed by the proximal left anterior descending artery2; however, an aneurysm of the SA nodal branch of the RCA has not previously been reported. RCA aneurysm may cause angina, myocardial infarction, fistula into the cardiac chamber, and unexpected death as a result of thromboembolism or rupture.i, 30vrum, Froysaker, and Vatne 4 reported a single case of RCA aneurysm causing superior vena caval stenosis in 1984. Our case involved both caval obstructive symptoms without any of the aforementioned clinical features. In our case, the abnormally dilated SA nodal artery branched from the normal-sized RCA, 5 mm apart from the aorta. It ran behind the superior cavoatrial junction for about 2.5 cm and finally formed the giant aneurysm. Preoperative and postoperative electrocardiograms did not show any abnormality, and we could not confirm the SA nodal branch from the left coronary arterial system by angiography. Thus we concluded that it was indeed an aneurysm of the SA nodal artery as a result of the path it followed.

Isolated origin of the left subclavian artery from the left pulmonary artery

We describe two children with isolated origin of the left subclavian artery from the left pulmonary artery detected by echocardiography during the assessment of their congenital cardiac malformations. Both patients demonstrated pre-operative evidence of subclavian steal. This entity results from persistence of the dorsal segment of the sixth left arch, with regression of the left fourth arch and interruption of the left dorsal arch distal to the origin of the seventh left intersegmental artery. The significance of this finding relates to the potential for pulmonary overcirculation, which could have significant post-operative ramifications if not detected prior to surgical repair of an associated cardiac malformation. This entity differs from cases with a right aortic arch and aberrant left subclavian artery which has the potential to form a vascular ring, unlike cases with isolated origin of the left subclavian artery from the pulmonary artery that do not cause compression of the airway.

Surgical repair of complete atrioventricular septal canal defects with absent posterior leaflet

We report 2 cases of absence of the posterior (left mural) leaflet in complete atrioventricular septal defect. Closure of the atrioventricular septal defect was successfully accomplished in both cases. We describe the technique of left atrioventricular valve repair that led to a competent reconstructed valve.

Innovations and Future Directions in Pediatric Cardiac Anesthesia and Surgery

Minimally invasive pediatric cardiac surgery, although still evolving, lacks much of the corporate thunder directed to wards the adult patient. Because the majority of pediatric procedures remain open requiring cardiopulmonary bypass, innovations and/or modifications of already established tech niques might have important adult medical applications. The care of children born with congenital heart disease at our institution presently incorporates cardioscopy, active venous suction, epidural/spinal anesthesia, and, most recently, robotic video assistance. This mufti-disciplinary combination has not only optimized the cosmetics of the operation and use of hospital resources but also has maintained the safety and reproducibility of the surgical interventions.

Modification of an extracorporeal life support circuit for intraoperative correction of complex congenital heart disease

Extracorporeal life support (ECLS) was established in a newborn infant diagnosed with severe respiratory failure secondary to complex congenital heart disease. After 4 days of ECLS support in the intensive care unit, the infant was brought to the operating room for repair of the primary lesion. Due to concerns related to recurrent respiratory failure associated with blood contact to a new extracorporeal circuit, the existing ECLS circuit was modified for use in the operating room. This report describes the circuit modification steps and challenges related to running a modified ECLS circuit for cardiopulmonary support during cardiac surgery. Perfusion (2007) 22, 35—40.