Pediatric ranges of normality for 2D speckle-tracking echocardiography atrial strain: differences between p- and r-gating and among new (Atrial Designed) and conventional (Ventricular Specific) software's.

BACKGROUND: 2D speckle tracking echocardiography (STE) atrial strain (ε) analysis in children is gaining interest; however, pediatric nomograms remain limited. Comparison among conventional software's (designed for left ventricle and adapted to atria and using R-gating analysis) and new software's (designed for atria and allowing for both R- and P-gating) are lacking. The present study aims to establish pediatric nomograms for atrial ε using an atrial dedicated software and to compare values obtained by (a) R- and P-gating and, (b) R-gating with new and conventional software. METHODS: Echocardiographic measurements included STE left (LA) and right (RA) atrial longitudinal reservoir, conduit and contractile ε. Age/weigh/height/heart rate, and body surface area (BSA) were used as independent variables in the statistical analysis. RESULTS: In all, 580 healthy subjects (age range, 31 days-18 years; mean age 7.5 years; median age 7.1 years; inter-quartile range, 4.3-10.7 months; 45.5% female) were included. Feasibility of atrial ε measurements was high (98.9-96.8%). At lower age, atrial conduit ε was lower (p<0.001) while contractile ε was higher (p<0.001). All atrial ε values calculated with P-gating method were lower-than R-gating values (p<0.001). R-gated LA ε reservoir values generated with the new software were lower, and R-gated RA contractile ε higher than with the conventional software (p<0.011). CONCLUSION: We report pediatric atrial ε values from a dedicated atrial software. Maturational changes in STE atrial ε values were demonstrated. Significant differences were observed among ε values obtained with P- and R-gating and with different software's.

Neo-aortic posterior sinus of Valsalva reduction and closed coronary artery transfer as a method to approach aortopulmonary mismatch in transposition of great arteries.

OBJECTIVE: In transposition of great arteries (TGA), aortopulmonary mismatch (APM) can determine postoperative neo-aortic insufficiency after arterial switch operation (ASO). The distortion of sinu-tubular junction may be the geometric mechanism responsible. We developed a strategy able to reduce the mismatch at the timing of ASO, and in this study, we aimed to describe our indications and results. METHODS: Preoperative root circumferences at the level of the mid-portion of sinus of Valsalva and ascending aorta circumference were used to define APM. Indication to surgery was a neo-aortic root (NAR) to ascending aorta ratio ≥ 1.4. Along with standard ASO, posterior neo-aortic sinus inverted conal resection and punch technique for coronary reimplantation was used in all patients to re-establish the more geometric ratio possible between the two components. Hypoplastic aortic arch (HAA) and aortic coarctation (CA) were managed by aortic arch enlargement with an autologous pericardial patch. RESULTS: Twenty patients (20 male), 19 with diagnoses TGA (17 with ventricular septal defect, 85%) and 1 with Taussig-Bing anomaly underwent ASO. HAA was present in three (15%) and CA in two (10%). The mean preoperative neo-aortic to ascending aorta ratio was 1.8 versus 1.1 postoperatively (p < .01). No moderate or severe neo-aortic insufficiency was observed before discharge and at a mean follow-up of 4.3 years (interquartile range = 0.5-12 years). CONCLUSION: Neo-aortic reduction plasty with coronary reimplantation by punch technique is an effective strategy to approach preoperative APM in TGA. This technique confers a more harmonious geometry to NAR that can improve neo-aortic valve function.

The impact of native Fallot anatomy on future therapeutic requirements and outcomes at follow-up.

BACKGROUND: In patients with repaired Fallot, subsequent surgical or interventional procedures and adverse cardiac events are frequent. We aimed to evaluate the impact of a simple pre-operative anatomic classification based on the size of the pulmonary valve (PV) annulus and branches on future therapeutic requirements and outcomes. METHOD: This is a single-center retrospective analysis of patients operated for Fallot before the age of 2 years, from January 1990. Pre-operative anatomy, surgical and interventional procedures and adverse events were extrapolated from clinical records. RESULTS: Among the 312 patients, a description of the PV and pulmonary arteries (PAs) native anatomy was known in 239 patients (male:147, 61.5%), which were divided in the following 3 groups: group 1 (65 patients) with normal size of both PV and PAs; group 2 (108 patients) with PV hypoplasia but normal size PAs; group 3 (66 patients) with concomitant hypoplasia of the PV and PAs. During the 12.7 years (IQR 6.7-17) follow-up time, 23% of patients required at least one surgical or interventional procedure. At Kaplan-Meier analysis, there was a significant difference in requirement of future surgical or interventional procedures among the 3 groups (p < 0,001). At multivariate Cox regression analysis, hypoplasia of PV and PAs was an independent predictor of subsequent procedures (HR:3.1,CI:1.06-9.1, p = 0.03). CONCLUSION: Native anatomy in Tetralogy of Fallot patients affects surgical strategy and follow-up. It would be therefore advisable to tailor patient's counseling and follow-up according to native anatomy, rather than following a standardized protocol.

Pitfalls in surgical repair of Fallot's tetralogy: The "ventricular subaortic pouch".

Fallot-type ventricular septal defect (VSD) is characterized by anterior malalignment of the outlet septum with variable degree of aortic dextroposition. Correct identification of the borders of the defect is crucial to achieve an optimal surgical repair. We describe a particular postsurgical lesion, identified by cardiac magnetic resonance and cardiac computed tomography, which results from an improper surgical closure technique of anterior malaligned VSD. Based on its anatomical features we defined this entity "subaortic pouch." A comprehensive description of this defect is here provided along with an in-depth analysis of the proper operative technique for Fallot-type VSD repair.

The different surgical impact of the superior cavoatrial incision in children and adults.

INTRODUCTION: The single- and double-patch repairs are undoubtedly the most commonly used techniques for the surgical management of partial anomalous pulmonary venous connection associated with sinus venosus atrial septal defect. The aim of this study was to retrospectively compare early and long-term surgical outcomes in paediatric and adult patients, focusing in particular on the occurrence of ectopic atrial rhythm. MATERIAL AND METHODS: Seventy patients (male: 38, 54.2%) underwent surgical repair for partial anomalous pulmonary venous connection with sinus venosus atrial septal defect. Forty-nine patients (70%) underwent surgical repair in paediatric age (<16 years old), while 21 of (30%) patients were operated in adulthood. Thirty patients (42.8%) underwent single-patch repair and 39 patients (55.7%) underwent double-patch repair. In only one patient, the Warden procedure was performed (1.4%). Median follow-up time was 52 months (IQ 15.1-113). RESULTS: The type of surgical technique didn't affect the incidence of ectopic atrial rhythm (26.6% in single-patch group and 25.6% in double-patch groups, p = 0.9). At long-term follow-up, ectopic atrial rhythm, as an expression of sinoatrial node disturbance, was however significantly more frequent in the paediatric population (28.8% paediatric group and 4.7% adult group, p = 0.02). CONCLUSIONS: The higher incidence of ectopic atrial rhythm in children is probably related to the closer position of the sinus node to the superior cavoatrial incision, which makes irreversible iatrogenic traumatism more likely to occur. Surgical techniques that avoid any manipulation on the superior cavoatrial junction should, therefore, be preferred for children undergoing partial anomalous pulmonary venous connection repair.

Retrieval team-initiated early donor management increases the donor heart utilization rate for transplantation.

OBJECTIVES: Heart transplantation represents the most effective therapy that is currently available for end-stage heart failure. Despite the shortage of organ donors, many donor hearts are not accepted for transplantation due to poor function. Targeted donor management may increase the donor heart utilization rate. The aim of this study is to analyse a 2-year experience of early donor management through the 'scout programme' by a high-volume national cardiothoracic organ retrieval team. METHODS: A prospective cohort study was carried out between 2013 and 2015 on consecutive donation from brain-dead donors. A member of the cardiothoracic retrieval team travelled to the intensive care unit of the donor hospital to assist with early management. RESULTS: One hundred and seventy-eight cardiac donors were enrolled; 106 (59.5%) were 'scouted', and 72 (40.5%) were 'non-scouted'. Donor heart utilization rate in the 'scouted' group was 47.2% (50/106) compared with 30.6% (22/72) in the 'non-scouted' group (P = 0.03). On logistic regression analysis, early donor management by the scouts independently predicted donor heart utilization. The time in the operating theatre from donor arrival to skin incision was significantly reduced in the 'scouted' group. No differences were found in the 30-day graft failure rate or the 30-day, 1-year and 2-year survival rates of the recipients between the 2 groups. CONCLUSIONS: Early donor management delivered by the cardiothoracic retrieval team significantly increased the donor heart utilization rate from existing donors. Moreover, the time in the operating theatre from donor heart arrival to skin incision was significantly reduced.

Hybrid strategies for high-risk non-hypoplastic left heart syndrome patients.

Single-stage repair of complex cardiac abnormalities in high-risk neonates presents formidable challenges. The majority of hybrid strategies involving bilateral pulmonary artery banding (bPAB) with or without patent ductus arteriosus (PDA) stenting is described in the setting of hypoplastic left heart syndrome. We present a series of cases describing two-stage repair with initial palliative hybrid procedures involving bPAB with or without PDA stenting. This allows weight gain and stabilization of circulation before complete repair, provides good results, and may overcome risk factors associated with single-stage repair in neonates.

Pulmonary endarterectomy is effective and safe in patients with haemoglobinopathies and abnormal red blood cells: the Papworth experience.

OBJECTIVES: Patients with haemoglobinopathies and congenital haemolytic anaemia constitute a unique population more predisposed to developing chronic thromboembolic pulmonary hypertension (CTEPH). Although pulmonary endarterectomy (PEA) is accepted as the best treatment for CTEPH, PEA in these patients poses significant practical challenges. Apart from a few case reports, the results of PEA in this patient population have not been previously reported. The aim of this study was to review the outcome of PEA in this patient population. METHODS: We performed a retrospective analysis, from our dedicated CTEPH database, of all patients who underwent PEA surgery and had abnormal haemoglobin or congenital haemolytic anaemia. We reviewed diagnosis, exchange transfusions on cardiopulmonary bypass, preoperative and postoperative pulmonary haemodynamic and functional data and outcomes for this group. Paired data analysis was performed by Student's t-test; P < 0.05 was statistically significant. RESULTS: Between the start of our PEA programme in 1997 and April 2015, we performed PEA in 19 patients with haemoglobinopathy or congenital haemolytic anaemia. The mean age was 52 ± 15 years. There were 9 patients with sickle cell trait, 2 with coexisting alpha+ thalassaemia trait, 2 patients with HbSC disease, 2 patients with beta-thalassaemia major, 3 patients with hereditary spherocytosis, 2 patients with stomatocytosis (one with the cryohydrocytosis subtype) and 1 patient with HbC trait. In the 9 HbAS patients, the mean HbS% was 31.9 ± 6%, and in the HbSC patients, the mean HbS% was 46.5 ± 1.3% preoperatively. To reduce this HbS to ≤20%, for safe PEA with deep hypothermic circulatory arrest, we used exchange blood transfusion. Immediately postoperatively, there was a significant improvement in pulmonary vascular resistance (938 ± 462 to 260 ± 167 dyne s cm(-5); P < 0.0001). One patient died 81 days following surgery; 18 patients are alive at a median follow-up of 3.4 ± 3 years. Six months postoperatively, the patients showed significant improvement in New York Heart Association status (P < 0.0001), and in 6-min walk distance from 251 ± 111 to 399 ± 69 m (P < 0.0001). CONCLUSIONS: Results of PEA in this complex patient group were satisfactory. Expert haematological advice is important and exchange blood transfusions may be necessary. The presence of abnormal haemoglobin does not contra-indicate PEA surgery.

Interdisciplinary approach to cell-biomaterial interactions: biocompatibility and cell friendly characteristics of RKKP glass-ceramic coatings on titanium.

In this work, titanium (Ti) supports have been coated with glass-ceramic films for possible applications as biomedical implant materials in regenerative medicine. For the film preparation, a pulsed laser deposition (PLD) technique has been applied. The RKKP glass-ceramic material, used for coating deposition, was a sol-gel derived target of the following composition: Ca-19.4, P-4.6, Si-17.2, O-43.5, Na-1.7, Mg-1.3, F-7.2, K-0.2, La-0.8, Ta-4.1 (all in wt%). The prepared coatings were compact and uniform, characterised by a nanometric average surface roughness. The biocompatibility and cell-friendly properties of the RKKP glass-ceramic material have been tested. Cell metabolic activity and proliferation of human colon carcinoma CaCo-2 cells seeded on RKKP films showed the same exponential trend found in the control plastic substrates. By the phalloidin fluorescence analysis, no significant modifications in the actin distribution were revealed in cells grown on RKKP films. Moreover, in these cells a high mRNA expression of markers involved in protein synthesis, proliferation and differentiation, such as villin (VIL1), alkaline phosphatase (ALP1), ß-actin (ß-ACT), Ki67 and RPL34, was recorded. In conclusion, the findings, for the first time, demonstrated that the RKKP glass-ceramic material allows the adhesion, growth and differentiation of the CaCo-2 cell line.

Sol-gel derived 45S5 bioglass: synthesis, microstructural evolution and thermal behaviour.

In this work, the 45S5 bioactive glass was synthesized through an aqueous sol-gel method. Characteristic functional groups were evidenced by Fourier transform infrared spectroscopy, the thermal behaviour was investigated by thermogravimetric and differential thermal analysis, crystallization kinetics and phase evolution were followed by X-ray diffraction measurements. The sintering behaviour of the sol-gel derived 45S5 was then studied by dilatometry and the microstructural evolution was followed step-by-step, interrupting the thermal cycle at different temperatures. In vitro dissolution tests were performed in order to assess the degradation behaviour of sol-gel derived 45S5 samples thermally treated at different temperatures. A relevant influence of the calcination conditions (namely, dwelling time and temperature) of the as-prepared powder on the phase appearance and its sintering behaviour as well as on the porosity features, in terms of pore dimension and interconnectivity, of the fired materials was stated.

Extracorporeal hydroxyapatite-chamber for bone and biomaterial studies.

Hydroxyapatite (HA) spherules and autologous bone (AB) with a central vascular pedicle were housed inside an HA-chamber to form the skeletal segment of specific shape. Experimental chambers were then inserted in a pocket between medial thigh muscles in 13 New Zealand male rabbits for 3 months. Three graft group were scheduled: (A) HA and AB without vascular pedicle, (B) HA with vascular pedicle, (C) HA and AB with vascular pedicle. At term, histology showed tissue and cellular degeneration in group A chambers. Due to spherules coalescence, fibrous tissue is formed in group B chambers. Group C chambers contained living osteocytes in the implanted bone, several newly formed vessels in soft tissue, bone and partial hydroxyapatite erosions. New bone was formed in apposition to both autologous bone and hydroxyapatite. Our study suggests that this experimental model could be used to grow adequately sized vascularized skeletal segments.

Biomaterials for orthopedics: a roughness analysis by atomic force microscopy.

We conducted an AFM analysis of roughness on 7 materials widely used in bone reconstruction. Roughness was evaluated by measuring Root Mean Square (RMS) values and RMS/average height (AH) ratio, in different dimensional ranges, varying from 100 microns square to a few hundreds of nanometers. The results showed that Titanium presented a lower roughness than the other materials analyzed, frequently reaching statistical significance. On the contrary, bioactive materials, such as hydroxyapatite (HA) and bioactive glasses, demonstrated an overall higher roughness. In particular, this study focuses attention on AP40 and especially RKKP, which proved to have a significant higher roughness at low dimensional ranges. This determines a large increase in surface area, which is strongly connected with osteoblast adhesion and growth and to protein absorption. Therefore, the biointegration properties of bioactive glasses can also be given as answer in terms of surface structures in which chemical composition can influence directly the biological system (e.g. with chemical exchanges and development of specific surface electrical charge) and indirectly, via the properties induced on tribological behavior that expresses itself during the smoothing of the surfaces. We also test two new bioactive glasses, RBP1 and RBP2, with a chemical composition similar to AP40, but with some significant small additions and substitutions of components, in order to make preliminary considerations on their potential role in orthopedics.

The effect of pulsed electromagnetic fields on the osteointegration of hydroxyapatite implants in cancellous bone: a morphologic and microstructural in vivo study.

Effects of pulsed electromagnetic fields (PEMFs, 75 Hz. 1.6 mT) were investigated in 12 rabbits after placing hydroxyapatite (HA) implants in their femoral condyles. Six animals were stimulated with PEMFs for three consecutive weeks, 6 h/day, while the remaining animals were sham-treated (Control Group). Rabbits were sacrificed at 3 and 6 weeks (after a 3-week non-stimulation period) for histomorphometric analysis and microhardness testing (at 200, 500, 1,000, 2,000 microm from the implant) around the implants. Histomorphometric analysis did not highlight any significant changes. On the contrary, there were statistically significant differences between the effects produced by PEMFs and Control Groups (F = 149.70, p < 0.0005) on the Affinity Index results, as well as by the experimental time of 6 and 3 weeks (F = 17.12, p = 0.001) on the same results. In PEMF-stimulated animals the microhardness (HV) values measured in trabecular bone at a distance of 200 and 500 microm from the implants, were significantly higher with respect to controls. At 6 weeks, HV values at the bone-implant interface in PEMF-stimulated animals were not significantly different with respect to normal bone, while they remained significantly lower in control animals. Both morphological and structural results demonstrated a positive therapeutic effect of PEMFs in accelerating HA osteointegration in trabecular bone.