Johann Brink

New engineering treatment of bovine pericardium confers outstanding resistance to calcification in mitral and pulmonary implantations in a juvenile sheep model

OBJECTIVE To conduct a test of noninferiority for CardioCel (Admedus, Brisbane, Australia), a chemically engineered bovine pericardium over autologous pericardium treated intraoperatively with glutaraldehyde in a chronic juvenile sheep model of pulmonary valve (PV) and mitral valve (MV) reconstruction. METHODS We replaced the posterior leaflet of the MV and of 1 PV cusp with patches in ewes aged 10 months. There were 2 groups: CardioCel (n = 6) and control (n = 4). All valves were competent. Echocardiography was performed before euthanasia. The collected data were function, macroscopy, histology, and calcium contents. The primary end points were thickening and calcium content. RESULTS All animals survived until sacrifice after 7 months. The valves had normal echo. The macroscopic aspect of the valves was excellent. Examination of the slides for both groups revealed a continuous endothelium on both sides of the patch and a layer of new collagen developed on both sides between patch and endothelium and interstitial cells and smooth muscle cell in these layers. The patch had not thickened but the 2 layers of new collagen for the PV showed a median thickening of 37% in the CardioCel group and 111% in the control group (P = .01), and for the MV a thickening of 108% and 251%, respectively, was seen (P = .01). The median calcium content in the PV was 0.24 μg/mg (range, 0.19-0.30) in the CardioCel group versus 0.34 μg/mg (range, 0.24-0.62) in controls (P = .20). In the MV it was 0.46 μg/mg (range, 0.30-1.0) in the CardioCel group and 0.47 μg/mg (range, 0.29-1.9) in controls (P = 1.0). CONCLUSIONS In this growing lamb model the CardioCel patch allowed accurate valve repair at both systemic and pulmonary pressure. The mechanical properties of CardioCel after 7 months were preserved with a more controlled healing than the treated autologous pericardium and without calcification.

End-to-Side Repair for Aortic Arch Lesions Offers Excellent Chances to Reach Adulthood Without Reoperation

BACKGROUND The purpose of this study was to determine the rate of reinterventions from birth to adulthood after end-to-side anastomosis technique for interrupted and hypoplastic aortic arches. Multicenter data have shown that more than half of patients require arch reintervention in the 2 decades after repair. METHODS The follow-up of 170 consecutive patients undergoing end-to-side repair through sternotomy for interrupted aortic arch (95) or coarctation (75) in one institution between 1985 and 2012 was reviewed. Associated lesions included ventricular septal defect (143) and bicuspid aortic valve (50). One-stage repair was performed in 158 patients (93%). RESULTS There were 12 hospital deaths (7%), and 4 early arch reinterventions (2 for bronchial compression). Eleven hospital survivors (7%) were lost to follow-up. After a mean of 10 ± 6 years, there were 9 late deaths. Eighteen-year survival was 93% (95% confidence interval: 87 to 96). Eight patients had bronchial compression, 5 during initial stay and 3 after hospital discharge; 2 of them required surgery. Eighteen-year freedom from arch reoperation was 87% (95% confidence interval: 76 to 93). An additional 10 patients underwent balloon dilation, for an 18-year freedom from reintervention (balloon dilation or surgery) of 77% (95% confidence interval: 65 to 85). At last follow-up, 24 patients (16%) had an echocardiographic gradient greater than 25 mm Hg. Blood pressure was recorded in 105 patients, and only 11 (10%) were hypertensive. CONCLUSIONS The end-to-side anastomosis technique for repair of aortic arch lesions results in a low rate of mortality, arch reoperation, and late hypertension. The development of arch obstruction requiring balloon dilation warrants continuous follow-up of these patients.

Late primary arterial switch for transposition of the great arteries with intact ventricular septum in an african population.

The arterial switch operation (ASO) is the optimal management of transposition of the great arteries with intact ventricular septum (TGA-IVS) within the first 3 weeks of life; beyond this age optimal treatment is debatable. The authors adopted a strategy of primary ASO for TGA-IVS in the first 10 weeks of life regardless of left ventricular (LV) status. This report reviews the early outcomes with this management approach. Between August 2006 and December 2009, 22 patients with TGA-IVS underwent the primary ASO. Sixteen of them were less than 21 days old (early switch group) and 6 were between 31 and 66 days old (late switch group). A review of their hospital records was performed to determine outcomes in the 2 groups. Operative variables and postoperative outcomes were recorded. There was 1 hospital death in the early switch group (6.3%) but none in the late group (0%). Temporary mechanical circulatory support was required in 1 patient (6.3%) in the early switch group and in 2 of the 6 (33.3%) in the late switch group. One late death of undetermined cause occurred in the late switch group 8 weeks after discharge. No significant difference could be demonstrated between the 2 groups in terms of operative variables and the measured postoperative outcomes. It is concluded that the age limit for the primary ASO can be extended to at least 10 weeks; temporary mechanical circulatory support may be required as a rescue.

Surgery for scimitar syndrome: the Melbourne experience.

OBJECTIVES To evaluate the outcomes associated with surgical repair of scimitar syndrome. METHODS From 1974 to 2012, 21 patients with scimitar syndrome underwent corrective surgery. Outcomes included mortality, reoperation rate, hospital length of stay and long-term functional status. RESULTS The mean age of surgery was 5.4 years (2.5 months to 16.7 years). Sixteen (76.2%) patients were symptomatic at presentation. Fifteen (71.4%) patients presented with the infantile form and 6 (28.6%) with the adult form of scimitar syndrome. Operative techniques included baffle repair in 15 (71.4%) patients, reimplantation in 5 (23.8%) patients and pneumonectomy in 1 (4.8%) patient. Six (28.6%) patients were operated in infancy at a mean of 4 months (2.5-9.6 months) of age. There was 1 (4.8%) hospital death and 3 (15%) late deaths. The risk factors for mortality included preoperative pulmonary hypertension (P = 0.006) and surgery during infancy (P = 0.003). The incidence of postoperative pulmonary vein stenosis was 23.8% (n = 5). Three (14.3%) patients underwent reoperation for pulmonary vein stenosis. Neither baffle (P = 0.6) nor reimplantation (P = 0.55) surgical techniques influenced the rate of stenosis. The follow-up was complete in 15 (88%) survivors at a mean of 13.7 years (1.3-38.5 years). All surviving patients were asymptomatic and had a New York Heart Association functional status Class I. CONCLUSIONS Mortality was highest in patients who had preoperative pulmonary hypertension and those who were operated on before 1 year of age. Surgical technique did not influence the occurrence of pulmonary vein stenosis. Survivors were asymptomatic at the long-term follow-up.

Long-term results of anatomic correction for congenitally corrected transposition of the great arteries: A 19-year experience

Objective: The surgical indication, timing, strategy, and surgical technique for anatomic correction of congenitally corrected transposition of the great arteries are challenging. We evaluated the long‐term results at The Royal Childrens Hospital Melbourne. Methods: Review of 32 successive anatomic corrections between 1996 and 2015. Results: Twenty‐one double‐switch (66%), 6 Senning/Bex‐Nikaidoh (19%), and 5 Senning/Rastelli (16%) procedures were performed (median age, 1.9 years). Median follow‐up was 5.4 years with 4 deaths and 1 heart transplant. Cumulative incidence of late reoperation was 8%, 29%, and 59% at 1, 5, and 10 years, respectively. Twenty‐six patients had full follow‐up with native hearts. Nineteen had normal left ventricle (LV) function. Late LV dysfunction, mostly mild, was not related to needing a pacemaker (P = .4) or a pulmonary artery band (PAB) (P = .08). Previous PAB was linked to the need for aortic valve surgery or neoaortic regurgitation moderate or greater (P = .03). Six required Senning revision. The introduction of the Shumacker modification of the Senning has generated stable pulmonary venous pathways. Six patients developed postoperative iatrogenic atrioventricular block dependent on a permanent pacemaker. Conclusions: Anatomic correction is a surgical challenge. It provides excellent functional outcomes in survivors with a significant need for reoperation and a definite risk of death or transplantation. Normal LV function should be expected in most patients. LV dysfunction was not linked to PAB or pacemaker requirement but surgery without LV training had better long‐term LV function. The Shumacker modification provided stable venous pathways. Iatrogenic atrioventricular block remains a challenge.

Successful atrioventricular valve repair improves long-term outcomes in children with unbalanced atrioventricular septal defect

Background: Atrioventricular valve regurgitation is a significant cause of morbidity and mortality in patients with unbalanced atrioventricular septal defect. However, knowledge of the outcomes of atrioventricular valve repair in children with unbalanced atrioventricular septal defect and univentricular physiology is limited. Methods: We conducted a retrospective review of all patients with unbalanced atrioventricular septal defect treated with single‐ventricle palliation who underwent atrioventricular valve surgery at The Royal Childrens Hospital. Results: Between 1976 and 2016, 139 children with unbalanced atrioventricular septal defect underwent single‐ventricle palliation, of whom 31.7% (44/139) required atrioventricular valve surgery. Repair of the atrioventricular valve was attempted in 97.7% (43/44) of patients, of whom 4.7% (2/43) were converted to replacement during the initial operation. Replacement of the atrioventricular valve without attempted repair was performed in 2.3% (1/44) of patients. Early mortality was 18.2% (8/44). Freedom from death or transplantation at 10 years was 66.0% (95% confidence interval, 49.1–78.5) and at 20 years was 53.3% (95% confidence interval, 32.1–70.6). In multivariable analysis, significant predischarge atrioventricular valve regurgitation (hazard ratio, 6.4; P = .002), age less than 1 year (hazard ratio, 8.3; P = .01), and repair before stage II palliation (hazard ratio, 3.4; P = .04) were associated with death. Freedom from reoperation at 10 years was 61.9% (95% confidence interval, 41.9–76.8) and at 20 years was 56.3% (95% confidence interval, 35.3–72.8). Moderate or greater atrioventricular valve regurgitation at discharge was associated with an increased risk of reoperation (hazard ratio, 1.8; P = .03). Of transplant‐free survivors, atrioventricular valve regurgitation was less than moderate in 60.0% (15/25) at the most recent follow‐up. Conclusions: Atrioventricular valve surgery in patients with unbalanced atrioventricular septal defect is associated with substantial mortality and a high rate of reoperation. Successful atrioventricular valve repair is associated with better survival and freedom from reoperation.

Complications of Extra-Anatomic Aortic Bypass for Complex Coarctation and Aortic Arch Hypoplasia

BACKGROUND We have adopted the extra-anatomic bypass graft as the procedure of choice for the treatment of coarctation and aortic arch hypoplasia in the adult-sized patient. However, we have experienced prolonged chest drainage and have decided to investigate this complication and the morbidity related to this procedure. METHODS Between 1996 and 2010, 15 extra-anatomic bypass grafts of the aorta were performed in 14 patients. Their hospital records and follow-up data were retrospectively reviewed and compared with those of 14 consecutive patients operated with other conventional techniques over the same time period. RESULTS There was no hospital mortality. After the extra-anatomic bypass procedure, patients had longer hospital stay because of prolonged pleural effusions. Four patients developed complications related to persistent effusions leading to reinterventions, which led to mediastinitis in 2 instances. At last follow-up, 2 of 14 patients with extra-anatomic bypass remained hypertensive, while 8 of the 14 patients who underwent other types of repair had arch obstruction, were hypertensive, or both. CONCLUSIONS In the adult-sized patient extra-anatomic bypass of the aortic arch relieves arch obstruction more effectively than conventional techniques. However, this technique is fraught with complications related to prolonged effusion drainage that may lead to mediastinitis and reintervention. Its indication should be weighted carefully.

Impact of arch reobstruction and early hypertension on late hypertension after coarctation repair

OBJECTIVES Late hypertension after coarctation repair is associated with high mortality, but its risk factors remain unclear. This study aims to determine early and late postoperative risk factors for late hypertension after coarctation repair. METHODS A cross-sectional study including transthoracic echocardiogram and 24-h blood pressure (BP) monitoring was performed in 144 patients aged ≥10 years with previous coarctation repair. Median age at repair was 39 days (interquartile range 0-3 years). Early postoperative hypertension was evaluated by calculating the mean of BP measurements taken on the same day before hospital discharge or the need for antihypertensives prior to discharge. Multivariable analyses were performed to adjust for gender, surgical age, and follow-up age. RESULTS After a mean follow-up period of 22 ± 7 years, 59% (84/142) of patients were hypertensive: 58% (82/142) on 24-h BP monitoring and 1% (2/142) on antihypertensives. Early postoperative hypertension was present in 58% (73/126): 39% (49/126) on BP measurements and 19% (24/126) on antihypertensives. Early and late arch reobstruction (transthoracic echocardiogram peak gradient ≥25 mmHg) was present in 37% (23/62) and 23% (33/144), respectively. On multivariable logistic analysis, early postoperative hypertension and maximum descending arch velocity on echocardiography were associated with late hypertension on 24-h BP monitoring (odds ratio 2.21, 95% confidence interval 1.05-4.66, P = 0.04; and odds ratio 2.28, 95% confidence interval 1.08-4.81, P = 0.03; respectively). CONCLUSIONS There is a high prevalence of late hypertension after coarctation repair. Arch reobstruction may be a major determinant of late hypertension. Early postoperative hypertension may identify very early in life those at risk of developing late hypertension.

Absorbable pulmonary artery banding: a strategy for reducing reoperations†

Objectives Pulmonary artery banding (PAB) remains in the armamentarium of techniques for several congenital cardiac anomalies, but necessitates a reoperation for eventual removal. We sought to assess the efficacy of an absorbable PAB in obviating the requirement for reoperation. Methods From 2003 to 2015, 45 consecutive patients with a median age of 1.6 months (2 days-11 months) underwent placement of a polydioxanone absorbable PAB. In 28 patients (62%), the band was placed concomitantly to a ventricular septal defect (VSD) closure and in 17 (38%), the band was the sole procedure for the VSDs. Fourteen patients had additional cardiac anomalies and 9 patients had aortic arch anomalies, which were repaired at the time of absorbable PAB placement. Results There was 1 hospital death. The band was removed early in 3 patients. Mean time to follow-up was 5.2 ± 3.5 years. Overall, 32 of the 41 patients discharged from hospital with absorbable PABs did not require reoperation on the VSDs or the band, resulting in a single-stage definitive repair of 78%. Median time to absorbable PAB resorption was 7.2 months (interquartile range, 5.0-10.4). Freedom from reoperation related to residual VSDs or PAB obstruction was 78% (95% CI: 61-87%) at 10 years. Conclusions The use of absorbable polydioxanone PABs is an effective method of reducing reoperations for multiple VSDs. Their use should be incorporated in the surgical strategy for repair of muscular and residual VSDs.

Laryngeal ultrasound detects a high incidence of vocal cord paresis after aortic arch repair in neonates and young children

Objectives: To determine the incidence of vocal cord paresis (VCP) after neonatal aortic arch repair/Norwood‐type procedure, and the effectiveness of noninvasive laryngeal ultrasound in detecting VCP compared with gold standard invasive nasoendoscopy. Methods: Fifty‐two patients who underwent an arch repair (39 of 52; 75%) or Norwood‐type procedure (13 of 52; 25%) via sternotomy between April 1, 2015, and April 30, 2017 underwent laryngeal ultrasound (50 of 52; 96%) and/or flexible fiber optic nasoendoscopy (39 of 52; 75%) at 48 to 72 hours after endotracheal extubation. Primary arch diagnoses were coarctation in 56% (29 of 52), hypoplastic left heart syndrome in 17% (9 of 52), isolated hypoplastic arch in 17% (9 of 52), and interrupted aortic arch in 10% (5 of 52). The median patient age at surgery was 5.5 days (interquartile range, 4.0–12.5 days). Fifteen patients (15 of 52; 29%) required preoperative intubation. Results: Left VCP was present in 59% (23 of 39) of patients on nasoendoscopy and in 59% (27 of 46) of patients on laryngeal ultrasound, and 4 additional patients had inconclusive ultrasound results. There was agreement between the results of nasoendoscopy and conclusive ultrasound in all cases. The overall sensitivity, specificity, positive and negative predictive values, and Cohens kappa coefficient of laryngeal ultrasound compared with nasoendoscopy for the detection of left VCP were 95%, 88%, 91%, 93%, and 0.83, respectively. On multivariable analysis, preoperative intubation and arch repair techniques other than the Norwood procedure were associated with left VCP (odds ratio, 12.7; P = .03; and 14.1; P = .03, respectively). Conclusions: There is a high incidence of VCP after arch repair via sternotomy. Laryngeal ultrasound seems to be an effective and noninvasive method for detecting VCP in neonates and young children.