Outcomes of the Ross procedure in young adults with previous aortic valve interventions.

OBJECTIVES: Contemporarily modified Ross procedure continues to deliver excellent outcomes and remains part of the treatment strategy for aortic valve disease in the young adult population. The aim of this study was to assess whether Ross procedure carried out as a second or subsequent intervention for aortic valve disease carries similar risk and long-term benefit, when compared to Ross procedure for the first-time aortic valve replacement. METHODS: A total of 158 patients aged 16-60 years from a single congenital cardiac centre between 1997 and 2020 were included. The sample was split into 2 subgroups, based on the history of previous aortic valve interventions prior to the Ross procedure. Primary outcomes were defined as survival and pulmonary autograft failure. Coarsened exact matching was used to balance for covariates. RESULTS: A total of 103 patients underwent primary Ross and 55 underwent secondary Ross with a mean follow-up of 7.8 years. Twenty-two patients underwent 28 reoperations during follow-up. Forty-nine well-matched pairs were obtained through matching. Freedom from pulmonary autograft failure at 10 years was 84.5% in the primary group vs 100% in the secondary group (P = 0.021). Five- and ten-year survival were identical, 97.5% in the primary group vs 95.6% in the secondary group (P = 0.53). Male sex and era were found to be predictors of neoaortic root dilatation. CONCLUSIONS: The lower incidence of graft failure seen in secondary Ross could justify a stepwise approach to aortic valve intervention. Ross procedure delivers excellent outcomes in the adult population with no difference in survival for primary or secondary Ross.

A novel approach to stenting a stenotic graft housing a Berlin Heart cannula by utilizing an adapted left ventricular assist device circuit.

BACKGROUND: A 9-year-old boy with Berlin Heart biventricular assist device for diagnosis of dilated cardiomyopathy developed progressive reduction in left ventricular assist device(VAD) emptying and evidence of low cardiac output despite alterations to the device settings. Computed tomography revealed that the Dacron graft attaching the systemic cannula to the ascending aorta was stenosed. METHOD & RESULT: A minimally invasive approach with novel circuit modification was used to achieve antegrade stenting of the stenosed graft. CONCLUSION: This proposed technique provides a large port for minimally invasive access via an adapted VAD circuit allowing stent insertion to the aortic graft with an excellent outcome.

Ventricular assist devices in transposition and failing systemic right ventricle: role of tricuspid valve replacement.

OBJECTIVES: Ventricular assist device (VAD) for systemic right ventricular (RV) failure patients post-atrial switch, for transposition of the great arteries (TGA), and those with congenitally corrected TGA has proven useful to reduce transpulmonary gradient and bridge-to-transplantation. The purpose of this study is to describe our experience of VAD in systemic RV failure and our move towards concomitant tricuspid valve replacement (TVR). METHODS: This is a single-centre retrospective study of consecutive adult patients receiving HeartWare VAD for systemic RV failure between 2010 and 2019. From 2017, concomitant TVR was performed routinely. Demographic, clinical variables and echocardiographic and haemodynamic measurements pre- and post-VAD implantation were recorded. Complications on support, heart transplantation and survival rates were described. RESULTS: Eighteen patients underwent VAD implantation. Moderate or severe systemic tricuspid regurgitation was present in 83.3% of patients, and subpulmonic left ventricular impairment in 88.9%. One-year survival was 72.2%. VAD implantation was technically feasible and successful in all but one. Post-VAD, transpulmonary gradient fell from 16 (15-22) to 10 (7-13) mmHg (P = 0.01). Patients with TVR (n = 6) also demonstrated a reduction in mean pulmonary and wedge pressures. Furthermore, subpulmonic left ventricular end-diastolic dimension (44.3 vs 39.6 mm; P = 0.03) and function improved in this group. After 1 year of support, 72.2% of patients were suitable for transplantation. CONCLUSIONS: VAD is an effective strategy as bridge-to-candidacy and bridge-to-transplantation in patients with end-stage systemic RV failure. Concomitant TVR at the time of implant is associated with better early haemodynamic and echocardiographic results post-VAD.

Evaluation of antibiotic susceptibility test results: how guilty a laboratory could be?

BACKGROUND: The selection of an appropriate antimicrobial is a challenging task for clinicians. The Kirby-Bauer disk diffusion method is one of the most widely practiced antimicrobial susceptibility tests (AST). It is affected by many factors among which are the media used. Mueller-Hinton agar (MHA) is the standard medium recommended in guidelines. However, these guidelines are not strictly adhered to in some developing countries. OBJECTIVES: Validation of AST results on nutrient agar (NA) medium used as a substitute for MHA by some microbiology laboratories in Alexandria, Egypt. METHODS: A total of 149 clinical bacterial isolates and 3 reference strains: Staphylococcus aureus (S. aureus) ATCC® 25923, Escherichia coli (E. coli) ATCC®25922, and Pseudomonas aeruginosa (P. aeruginosa) ATCC®27853 were comparatively challenged to antibiotics employing MHA and NA. RESULTS: All antibiotics-reference bacterial strain challenges on NA compared to MHA were unacceptable (> 3 out of limit zones in 30 consecutive days). Considering clinical isolates, the frequency of very major, major, and minor errors on NA was highest in the case of P. aeruginosa (8.98%, 4.08%, and 14.7% respectively) followed by S. aureus (7.6%, 6%, and 8.8% respectively). On the other hand, the least frequency of errors was in the case of Enterobacteriaceae (0%, 0.4%, and 3.2% respectively). CONCLUSIONS AND RECOMMENDATIONS: Using NA in AST resulted in multiple errors and the high discrepancy in results compared to MHA making it unreliable for susceptibility testing. MHA should not be replaced by NA in AST. Following guidelines and QC measures for AST must be neither bypassed nor underestimated.

Ventricular function and vascular dimensions after Norwood and hybrid palliation of hypoplastic left heart syndrome.

OBJECTIVE: Norwood and hybrid procedure are two options available for initial palliation of patients with hypoplastic left heart syndrome (HLHS). Our study aimed to assess potential differences in right ventricular (RV) function and pulmonary artery dimensions using cardiac magnetic resonance (CMR) in survivors with HLHS. METHODS: 42 Norwood (mean age 2.4±0.8) and 44 hybrid (mean age 2.0±1.0 years) patients were evaluated by CMR after stage II palliation prior to planned Fontan completion. Initial stage I Norwood procedure was performed using a modified Blalock-Taussig shunt, while the hybrid procedure consisted of bilateral pulmonary artery banding and arterial duct stenting. Need for reinterventions and subsequent outcomes were also assessed. RESULTS: Norwood patients had larger RV end-diastolic dimensions (91±23 vs 80±31 mL/m2, p=0.004) and lower heart rate (90±15 vs 102±13, p<0.001) than hybrid patients. Both Norwood and hybrid patients showed preserved global RV pump function (59±9 vs 59%±10%, p=0.91), while RV strain, strain rate and intraventricular synchrony were superior in the Norwood group. Pulmonary artery size was reduced (lower lobe index 135±74 vs 161±62 mm2/m2, p=0.02), and reintervention rate was significantly higher in the hybrid group whereas subsequent outcome did not differ significantly (p=0.24). CONCLUSIONS: Norwood and hybrid strategy were associated with equivalent and preserved global RV pump function while development of the pulmonary arteries and reintervention rate were superior using the Norwood approach. Impaired RV myocardial deformation as a potential marker of early RV dysfunction in the hybrid group may have a negative long-term impact in this population.

Is the medical treatment for arterial hypertension after primary aortic coarctation repair related to age at surgery? A retrospective cohort study.

BACKGROUND: Hypertension following primary coarctation repair affects up to a third of subjects. A number of studies suggest that future hypertension risk is reduced if primary repair is performed at a younger age. OBJECTIVES: The objective of this study was to evaluate the risk of future medical treatment for hypertension depending on age of primary coarctation repair. METHODS: This study was carried out at a tertiary paediatric cardiology referral centre. Retrospective database evaluation of children aged 28 days and ⩽12 months), and children (>12 months). Main outcome measure is the need for long-term anti-hypertensive medication. The risk for re-coarctation was also evaluated. RESULTS: A total of 87 patients were analysed: 60 neonates, 17 infants, 10 children. Among them, 6.7% neonates, 29.4% infants, and 40% children required long-term anti-hypertensive medications. Group differences were statistically significant (p=0.004). After adjustment for type of repair, the risk of long-term anti-hypertensive therapy was 4.5 (95% confidence interval 1.2-16.9, p=0.025) and 10.5 times (95% confidence interval 2.6-42.3, p=0.001) higher if primary repair was carried out in infancy and childhood, respectively, compared with neonates. Among all, 13 patients developed re-coarctation: 21.7% in the neonatal group, 5.9% in the infant group, and 20% in the child group. We could not demonstrate a significant difference between these proportions or calculate a reliable risk for developing re-coarctation. CONCLUSIONS: Risk of medical treatment for hypertension was lowest when primary repair was carried out during the neonatal period, rising 10-fold if first operated on as a child. Knowing the likelihood of hypertension development depending on age of primary repair is useful for long-term surveillance and counselling.

Comparison of self-expandable and balloon-expanding stents for hybrid ductal stenting in hypoplastic left heart complex.

OBJECTIVES: We aimed to compare the procedural and mid-term performance of a specifically designed self-expanding stent with balloon-expandable stents in patients undergoing hybrid palliation for hypoplastic left heart syndrome and its variants. BACKGROUND: The lack of specifically designed stents has led to off-label use of coronary, biliary, or peripheral stents in the neonatal ductus arteriosus. Recently, a self-expanding stent, specifically designed for use in hypoplastic left heart syndrome, has become available. METHODS: We carried out a retrospective cohort comparison of 69 neonates who underwent hybrid ductal stenting with balloon-expandable and self-expanding stents from December, 2005 to July, 2014. RESULTS: In total, 43 balloon-expandable stents were implanted in 41 neonates and more recently 47 self-expanding stents in 28 neonates. In the balloon-expandable stents group, stent-related complications occurred in nine patients (22%), compared with one patient in the self-expanding stent group (4%). During follow-up, percutaneous re-intervention related to the ductal stent was performed in five patients (17%) in the balloon-expandable stent group and seven patients (28%) in self-expanding stents group. CONCLUSIONS: Hybrid ductal stenting with self-expanding stents produced favourable results when compared with the results obtained with balloon-expandable stents. Immediate additional interventions and follow-up re-interventions were similar in both groups with complications more common in those with balloon-expandable stents.

Comparison of paracorporeal and continuous flow ventricular assist devices in children: preliminary results.

Objectives: With the scarcity of organs, a durable, reliable ventricular assist device (VAD) is required. The Berlin Heart EXCOR ® (BH) remains the most established VAD in the paediatric population. Implantable continuous flow (CF) VADs have been introduced to the paediatric field with encouraging early results. In this study, we compared the results of a newly introduced CF VAD (HeartWare VAD [HVAD] ® ) to results in a matched group of BH recipients. Methods: The study included patients aged <16 years who received mechanical left VAD (LVAD) support between December 2005 and January 2016. The preimplant characteristics and postimplant outcomes of patients who received the HVAD were compared with those of a matched group who received the BH. Patients with congenital heart disease were excluded. Results: Thirty patients were included in the study: 13 had received the HVAD and were matched with 17 patients who had received the BH LVAD. The only difference in preimplant characteristics was the need for higher inotropic support in the BH group. There was no difference in the need for right ventricular (RV) support (58.8% for BH vs 53.8% for HVAD, P = 1.00) or in the incidence of cerebrovascular accidents (12.5% vs 7.7%, respectively, P = 1.00), though the BH group showed prolonged mechanical ventilation (31.3% vs 0%, P = 0.047). There were no deaths while on VAD support in either group. Patients with the HVAD showed a bimodal distribution for the primary end point (transplant/explant): All HVAD recipients who also required early RV support reached this end point within 30 days of receiving the implant. Conclusions: Our early experience with the CF intracorporeal LVAD system (HVAD) indicates outcomes comparable to those with the well-established pulsatile flow paracorporeal LVAD (BH). The theoretical durability of the CF device, which might also allow for the possibility of hospital discharge and better quality of life, is yet to be proven.

Bootlace Technique for Delayed Sternal Closure in Pediatric Cardiac Surgery.

Delayed sternal closure is commonly required following cardiac surgery. This strategy has proven itself very helpful, especially after cardiac transplantation with significant donor/recipient size mismatch. However, at the time of chest closure, acute changes in intrathoracic pressure may be challenging. In this study, we describe our technique of gradual chest approximation, which facilitates closure in difficult situations.

Second stage after initial hybrid palliation for hypoplastic left heart syndrome: Arterial or venous shunt?

OBJECTIVE: Hybrid palliation for hypoplastic left heart syndrome has been developed as an alternative to neonatal Norwood surgery. At the second stage, a source of pulmonary blood flow has to be established. Options include an arterial modified Blalock-Taussig or a venous superior cavopulmonary shunt. METHODS: We retrospectively reviewed patients who received second-stage palliation after the initial hybrid. Patients were stratified according to the source of pulmonary blood supply into the arterial shunt (n = 17 patients) or venous shunt (n = 26 patients). RESULTS: Age and weight at second stage were lower in the arterial group (85 [45-268] days vs 152.5 [61-496] days, P = .001 and 3.6 [2.7-9.4] kg vs 5.1 [2.97-9.4] kg, P = .001, respectively). All recorded surgical times were shorter in the arterial group. Mechanical ventilation and intensive care stay were shorter in the venous group (5.82 [2.01-14.9] days vs 2.42 [0.56-13.67] days, P = .005 and 8.5 [3.6-23.7] vs 5.75 [0.8-17.6] days, P = .036, respectively) There was no difference in mortality (2/17 vs 5/26; P = .685) or incidence of complications between the 2 groups. There was a tendency toward a higher need for intervention in the immediate postoperative period in the venous group, but this did not reach significance (6/17 vs 13/26, P = .342). The arterial group has shown better development of the branch pulmonary arteries with a higher lower lobe index (158.38 ± 39.43 mm(2)/m(2) vs 113.33 ± 43.96 mm(2)/m(2), respectively, P = .037). CONCLUSIONS: Both arterial and venous shunts are viable options with mortality and morbidity results comparable to those in the literature. The arterial shunt pathway (2-stage Norwood I) may offer better pulmonary arterial growth than the venous shunt (comprehensive/combined Norwood I and II).

De novo obstruction after supravalvular aortic stenosis repair in Williams-Beuren syndrome.

Williams-Beuren syndrome is characterized by diffuse arteriopathy due to elastin gene deficiency. We present a patient with de novo supravalvular stenosis due to excessive intimal hyperplasia after a previous repair. This case report supports in vitro and animal studies that have linked elastin deficiency to increased cellular proliferation in the vessel wall with the subsequent development of obstructive lesions.

Technical and anatomical factors affecting the size of the branch pulmonary arteries following first-stage Norwood palliation for hypoplastic left heart syndrome.

OBJECTIVES: Branch pulmonary artery (BPA) size is one of the factors that influence the efficacy of the Fontan circulation. Central pulmonary artery stenosis and small left pulmonary artery (LPA) are well-known problems following Norwood palliation for hypoplastic left heart syndrome (HLHS). We investigated anatomical and technical factors that may stand behind these problems. METHODS: A total of 47 consecutive patients were included in the study. All had complete magnetic resonance imaging (MRI) study pre-second-stage palliation. Measurements were taken using a first-pass 3D angiography technique after intravenous injection of an extravascular contrast agent. Factors investigated included the following: size and site of the pulmonary artery bifurcation stump in relation to the Damus-Kaye-Stansel (DKS) anastomosis, interaortic distance/ratio (neoaorta to descending aorta distance/antero-posterior dimension of the chest) (IAD/IAR), distance from the under surface of the arch and the size of native aorta and pulmonary artery. IAD/IAR were compared between two different arch reconstruction techniques. RESULTS: Stenosis occurred either centrally, at the origin of the BPA, or more distally, in the mid-LPA (posterior to DKS). There was a significant lower incidence of central BPA stenosis when the pulmonary artery stump was placed in the mid-position compared with right/left position (26 vs 67%; P = 0.011). A more bulky pulmonary artery stump was also found in those patients with central BPA stenosis (186 vs 137 mm(2)/m(2); P = 0.047). The mid-LPA consistently showed antero-posterior compression (mean cranio-caudal diameter 3.82 mm vs mean antero-posterior diameter 3.07 mm, P < 0.001). Indexed mid-LPA area was only correlated with IAD/IAR (r = 0.49 and 0.51, P < 0.001). No correlation was shown with the distance to the under surface of the arch (r = 0.14, P = 0.37), again confirming antero-posterior compression of the LPA rather than cranio-caudal. In multivariable analysis, the only predictor of indexed mid-LPA area was the IAR (P < 0.001). There was no significant difference in the IAD or IAR between the two arch reconstruction techniques [mean IAD 15.5 vs 13.5 mm (P = 0.14)]; [mean IAR 0.17 vs 0.19 (P = 0.21)]. CONCLUSIONS: Of all studied factors, IAR and the size and position of the pulmonary artery bifurcation plays the main role in LPA growth and central BPA stenosis.