An unusual case of retained bullet in the heart since World War II: a case report.

Although bullets penetrating into the heart are usually known as fatal, retained cardiac bullets can have a silent course without causing any cardiovascular complications. An 89 year-old patient with myocardial infarction was admitted to our department hemodynamically stable and widely awake. His electrocardiogram didn't show any evidence of ischemia. Cardiac catheterization revealed a three-vessel coronary artery disease. In addition, a circular structure projected on the area of the marginal branch and the V. magna cordis. Removal of the bullet showed that three quarters of myocardium were involved without any perforation. The history of the patient revealed an injury under the heavy fire during World War II. Thus, this case demonstrates that bullets can remain asymptomatic within in the heart for decades. The patient was dis-charged home at the 10th postoperative day after having an uneventful clinical course.

Deep vein thrombosis and novel oral anticoagulants: a clinical review.

Deep vein thrombosis (DVT) is a common disease associated with high rates of mortality and significant morbidity. The diagnostic approach of DVT has evolved over the years. Algorithmical use of pretest probability, D-Dimer testing and ultrasonography allow safe and accurate investigation of DVT. The anticoagulation therapy, used to treat DVT, includes vitamin K antagonists (VKAs) and low-molecular-weight heparin (LMWH) or unfractionated heparin (UF). The duration of anticoagulation therapy depends on the cause of DVT and patient's clinical profile. Although these conventional therapies are effective, narrow therapeutic index, need for frequent monitoring and various food-drug interactions cause difficulties for patients. In recent decades, new oral anticoagulants have been developed. These drugs focus directly on inhibiting either Factor Xa (rivaroxaban, apixaban, edoxaban) or thrombin (dabigatran). In contrast to warfarin, these new agents have shorter half-life, fewer drug or food interactions, no necessity for a close monitoring and ease of administration. This review summarizes current knowledge about deep vein thrombosis and new treatment aspects with novel oral anticoagulants.

Giant aneurysm of the right coronary artery with fistula to right atrium.

Coronary artery aneurysms are rare entities with a prevalence of 0.15%-4.9%. Giant coronary artery aneurysms are known as more than 2 to 5 cm in size. We present a case of 74 year-old female who was admitted to our clinic with chest pain and dyspnea. Coronary angiography demonstrated a giant right coronary artery (RCA) aneurysm with a significant left-to-right shunt. The patient underwent an open heart surgery. During the exploration, an aneurysm of 40 mm in diameter of the RCA was seen. The aneurysmatic RCA was excluded and continuously closed with the support of intra-aortic balloon pump (IABP). The patient was discharged on the 13th postoperative day without any complication.

Left anterior descending coronary artery: long-term angiographic results of CABG with endarterectomy.

AIM: The procedure of coronary bypass grafting (CABG) with coronary endarterectomy (CE) is controversial. However, in the setting of severely calcified coronary arteries CE may enable complete revascularization. Complete revascularization, especially of the left anterior descending artery (LAD), is important for long-term outcome. In this study we assessed long-term LAD graft patency and anterior wall function after CABG with CE of the LAD. METHODS: Between 1984 and 1992, 283 patients underwent CABG with CE of the LAD. In 50 patients (47 men), aged 59+/-7.6 (40-77), clinical reassessment and surveillance angiography were performed. In all patients complete revascularization had been achieved with 3.5+/-1 (1-5) grafts/patient with 1-3 CE/patient. The LAD was grafted either with a saphenous vein segment (N=38) or with left intern thoracic artery (N=12). A graft obstructed less than 50% in diameter was defined as patent. RESULTS: At follow-up 39 patients (78%) were in CCS class I/II and had improved significantly (P<0.000). Control angiography after 7.6+/-2.5 (3.5-11.7) years after CABG revealed a patent LAD graft in 30/50 patients (60%). Actuarial graft patency was 100%, 96%, and 56% after 2, 5, and 10 years and was lower in patients with diabetes (P=0.001). Deterioration of anterior wall motion was observed in 17 patients (34%) and was more frequent if anterior wall motion was preoperatively normal (P=0.002), irrespective of LAD graft patency. CONCLUSION: Clinical status and long-term graft patency of grafts on endarterectomized LAD is considerable. However, patients with preoperatively normal anterior wall function are at increased risk for myocardial damage in the long-term.

Successful single lung fontan operation in 2 children: case reports.

We report on 2 children, aged 3 and 4 years, with single ventricle physiology who underwent Fontan operation in the presence of a single right lung successfully with good midterm outcome. Therefore, the absence of one lung is not a contraindication for a Fontan palliation in selected patients with optimal hemodynamics.

Calculating sympathovagal balance from heart rate variability: are there alternatives in adolescents?

OBJECTIVE: Assessing sympathovagal balance by calculating LF/HF-ratio from power spectral analysis (PSA) of heart rate variability (HRV) may be difficult in adolescents as chaotic breathing leads to methodical bias and metronomic breathing is not easy to perform. Diastolic blood pressure variability (dBPV) is less influenced and may therefore offer more stable values for calculations. The present study was performed on 72 paediatric subjects to investigate possible alternative LF/HF-calculations from PSA of HRV and dBPV. METHODS AND RESULTS: Seventy-two paediatric individuals in three groups: 12 controls, 17 heart- and heart-lung-transplanted children (TX) and 43 adolescents born small for gestational age (SGA). Short-term beat-to-beat HRV and BP-recordings were made supine and during active standing. Ratios calculated: LF/HF from HRV, LF/HF from dBPV, LF-dBPV/HF-HRV and LF-HRV/HF-dBPV. LF/HF from dBPV as well as LF-HRV/HF-dBPV did not correlate with LF/HF-HRV. Correlation of LF/HF from HRV and LF-dBPV/HF-HRV was high especially in TX and in patients with resting heart rate of above 90 beats per minute. CONCLUSIONS: In adolescents, the ratio of LF-dBPV/HF-HRV may be an alternative method for calculating sympathicovagal balance being less influenced by breathing patterns. In younger patients with elevated resting heart rate, but also in patients with very low HRV such as TX-patients this method could be a supplemental diagnostic tool whenever autonomic nervous control on the cardiocirculatory system has to be assessed.

Surgical management of mitral regurgitation after repair of endocardial cushion defects: early and midterm results.

BACKGROUND: Mitral regurgitation (MR) represents the principal indication for reoperation in patients after repair of atrioventricular septal defects (AVSD). Reports of mitral valvuloplasty (MVP) in such patients are few; the alternative, mitral valve replacement (MVR), necessitates commitment to future valve replacement and long-term anticoagulation. We sought to determine the outcome of those patients who underwent either MVP or MVR between January 1, 1988, and December 31, 1998, for significant MR after repair of AVSD. Furthermore, we sought to identify (a) morphological predictors necessitating MVR, and (b) predictors of future reoperation within the MVP group. METHODS AND RESULTS: Retrospective review of clinical, operative, and echocardiographic data were performed. There were 46 patients identified (37 MVP and 9 MVR). The median age at initial AVSD repair was 0.6 years, and the age at subsequent mitral valve operation was 2.8 years. The early postoperative mortality rate was 2.2%, and survival at 1 and 10 years was 89.9% and 86.6%, respectively. A high rate of complete heart block was noted within the MVR group (37.5%). Freedom from later mitral valve reoperation for both groups was similar. No significant morphological predictors necessitating MVR were found. Predictors of reoperation within the MVP group included the presence of moderate or worse MR in the early postoperative period. In both groups New York Heart Association class, degree of MR, growth, and ventricular volumes improved. CONCLUSIONS: Mitral valve surgery significantly improves clinical status, with a sustained improvement in ventricular chamber size. MR can be successfully managed in patients after repair of AVSD independent of morphological type. Overall survival is acceptable, and further reoperation within the MVP group is influenced by early outcome of repair.

Early in vivo experience with tissue-engineered trileaflet heart valves.

BACKGROUND: Tissue engineering is a new approach in which techniques are being developed to transplant autologous cells onto biodegradable scaffolds to ultimately form new functional autologous tissue. Workers at our laboratory have focused on tissue engineering of heart valves. The present study was designed to evaluate the implantation of a whole trileaflet tissue-engineered heart valve in the pulmonary position in a lamb model. METHODS AND RESULTS: We constructed a biodegradable and biocompatible trileaflet heart valve scaffold that was fabricated from a porous polyhydroxyalkanoate (pore size 180 to 240 microm; Tepha Inc). Vascular cells were harvested from ovine carotid arteries, expanded in vitro, and seeded onto our heart valve scaffold. With the use of cardiopulmonary bypass, the native pulmonary leaflets were resected, and 2-cm segments of pulmonary artery were replaced by autologous cell-seeded heart valve constructs (n=4). One animal received an acellular valved conduit. No animal received any anticoagulation therapy. Animals were killed at 1, 5, 13, and 17 weeks. Explanted valves were examined histologically with scanning electron microscopy, biochemically, and biomechanically. All animals survived the procedure. The valves showed minimal regurgitation, and valve gradients were <20 mm Hg on echocardiography. The maximum gradient was 10 mm Hg with direct pressures. Macroscopically, the tissue-engineered constructs were covered with tissue, and there was no thrombus formation on any of the specimens. Scanning electron microscopy showed smooth flow surfaces during the follow-up period. Histological examination demonstrated laminated fibrous tissue with predominant glycosaminoglycans as extracellular matrix. 4-Hydroxyproline assays demonstrated an increase in collagen content as a percentage of native pulmonary artery (1 week 45.8%, 17 weeks 116%). DNA assays showed a comparable number of cells in all explanted samples. There was no tissue formation in the acellular control. CONCLUSIONS: Tissue-engineered heart valve scaffolds fabricated from polyhydroxyalkanoates can be used for implantation in the pulmonary position with an appropriate function for 120 days in lambs.

Functional living trileaflet heart valves grown in vitro.

BACKGROUND: Previous tissue engineering approaches to create heart valves have been limited by the structural immaturity and mechanical properties of the valve constructs. This study used an in vitro pulse duplicator system to provide a biomimetic environment during tissue formation to yield more mature implantable heart valves derived from autologous tissue. METHODS AND RESULTS: Trileaflet heart valves were fabricated from novel bioabsorbable polymers and sequentially seeded with autologous ovine myofibroblasts and endothelial cells. The constructs were grown for 14 days in a pulse duplicator in vitro system under gradually increasing flow and pressure conditions. By use of cardiopulmonary bypass, the native pulmonary leaflets were resected, and the valve constructs were implanted into 6 lambs (weight 19+/-2.8 kg). All animals had uneventful postoperative courses, and the valves were explanted at 1 day and at 4, 6, 8, 16, and 20 weeks. Echocardiography demonstrated mobile functioning leaflets without stenosis, thrombus, or aneurysm up to 20 weeks. Histology (16 and 20 weeks) showed uniform layered cuspal tissue with endothelium. Environmental scanning electron microscopy revealed a confluent smooth valvular surface. Mechanical properties were comparable to those of native tissue at 20 weeks. Complete degradation of the polymers occurred by 8 weeks. Extracellular matrix content (collagen, glycosaminoglycans, and elastin) and DNA content increased to levels of native tissue and higher at 20 weeks. CONCLUSIONS: This study demonstrates in vitro generation of implantable complete living heart valves based on a biomimetic flow culture system. These autologous tissue-engineered valves functioned up to 5 months and resembled normal heart valves in microstructure, mechanical properties, and extracellular matrix formation.

Results of Norwood stage I operation: comparison of hypoplastic left heart syndrome with other malformations.

OBJECTIVE: We compared the Norwood stage I operation for hypoplastic left heart syndrome and other complex malformations with ductus-dependent systemic circulation. METHODS: A retrospective study of 194 patients who underwent a Norwood stage I palliation between 1990 and 1998 was conducted. Malformations in 131 patients were classified as hypoplastic left heart syndrome, defined as aortic and mitral atresia or severe stenosis, normal segmental anatomy, intact ventricular septum, and hypoplasia of the left ventricle. Sixty three patients had other lesions: hypoplastic left ventricle with ventricular septal defect (n = 18), unbalanced complete atrioventricular canal (n = 9), complex double-outlet right ventricle (n = 14), double-inlet left ventricle (n = 11), tricuspid atresia with transposition of the great arteries (n = 6), and others (n = 5), including heterotaxia. RESULTS: Operative (>30 days) and 1-year survivals were lower for patients with hypoplastic left heart syndrome than for those with other lesions (63.4% vs 81%, P =.008, and 51.2% vs 71.4%, P =.02, respectively). The presence of a nonhypoplastic left ventricle (n = 27) was associated with higher operative and 1-year survivals (96.3% vs 64.7%, P =.002; 88.9% vs 52. 7%, P <.001). A restrictive atrial septal defect and prematurity tended to increase mortality across both groups. Cox proportional hazards regression indicated that a single right ventricle was the most important independent predictor of death (P <.001). Operative mortality for all patients undergoing the stage I procedure decreased from 38.5% (1990-1994) to 21.4% after 1994 (P =.02). CONCLUSIONS: The survival of patients with malformations other than hypoplastic left heart syndrome after the Norwood procedure is greater than for those with hypoplastic left heart syndrome. Staged palliation is valid surgical therapy in these patients, with good results in intermediate follow-up.

Anatomical risk factors for mortality and cardiac morbidity after arterial switch operation.

BACKGROUND: The arterial switch operation (ASO) is the treatment of choice for transposition of the great arteries. METHODS: Anatomical risk factors on mortality and morbidity were analyzed retrospectively in 312 patients who underwent ASO between 1982 and 1997. RESULTS: Survival was 95%, 92%, and 92% after 30 days, 5, and 10 years, respectively. Operative survival improved after 1990 to 97% (p < 0.001). Risk factors for operative mortality were complex anatomy (p = 0.018), coronary anomalies (p = 0.008), and prolonged bypass time (p < 0.001). Determinants of late mortality were coronary distribution (p = 0.03), position of the great arteries (p = 0.0095), bypass time (p = 0.047), and aortic coarctation (p = 0.046). After a follow-up of 3.6 +/- 2.7 years (0.1 to 14.9 years), 98% had good left ventricle function, 94% were in sinus rhythm, 2.4% had moderate to severe pulmonary stenosis, 0.3% had significant aortic regurgitation, and 1% had coronary stenosis. Freedom from reoperation was 100%, 96%, and 94% after 1, 5, and 10 years, respectively. No preoperative anatomic parameter correlated with long-term morbidity. CONCLUSIONS: ASO can be performed with low operative mortality (< 5%) and long-term morbidity. Malformations associated with complex transposition of the great arteries influence early and late mortality.

Tissue engineering of heart valves: in vitro experiences.

BACKGROUND: Tissue engineering is a new approach, whereby techniques are being developed to transplant autologous cells onto biodegradable scaffolds to ultimately form new functional tissue in vitro and in vivo. Our laboratory has focused on the tissue engineering of heart valves, and we have fabricated a trileaflet heart valve scaffold from a biodegradable polymer, a polyhydroxyalkanoate. In this experiment we evaluated the suitability of this scaffold material as well as in vitro conditioning to create viable tissue for tissue engineering of a trileaflet heart valve. METHODS: We constructed a biodegradable and biocompatible trileaflet heart valve scaffold from a porous polyhydroxyalkanoate (Meatabolix Inc, Cambridge, MA). The scaffold consisted of a cylindrical stent (1 x 15 x 20 mm inner diameter) and leaflets (0.3 mm thick), which were attached to the stent by thermal processing techniques. The porous heart valve scaffold (pore size 100 to 240 microm) was seeded with vascular cells grown and expanded from an ovine carotid artery and placed into a pulsatile flow bioreactor for 1, 4, and 8 days. Analysis of the engineered tissue included biochemical examination, enviromental scanning electron microscopy, and histology. RESULTS: It was possible to create a trileaflet heart valve scaffold from polyhydroxyalkanoate, which opened and closed synchronously in a pulsatile flow bioreactor. The cells grew into the pores and formed a confluent layer after incubation and pulsatile flow exposure. The cells were mostly viable and formed connective tissue between the inside and the outside of the porous heart valve scaffold. Additionally, we demonstrated cell proliferation (DNA assay) and the capacity to generate collagen as measured by hydroxyproline assay and movat-stained glycosaminoglycans under in vitro pulsatile flow conditions. CONCLUSIONS: Polyhydroxyalkanoates can be used to fabricate a porous, biodegradable heart valve scaffold. The cells appear to be viable and extracellular matrix formation was induced after pulsatile flow exposure.

Cantrell's syndrome: a challenge to the surgeon.

We present a case of partial Cantrell's syndrome with ventricular septal defect, left ventricular diverticulum, dextrorotation of the heart, an anterior diaphragmatic defect, and a midline supraumbilical abdominal wall defect with omphalocele. At the age of 20 months, the patient underwent a successful cardiac surgical procedure. To detect risk factors and to define therapeutic strategies, we analyzed the spectrum and the frequency of malformations described in 153 patients with Cantrell's syndrome. Despite modern surgical standards, Cantrell's syndrome represents a challenge to the surgeon because of the wide spectrum of anomalies, the severity of the abdominal and cardiac malformations, and the high mortality.

Systemic right ventricular failure after atrial switch operation: midterm results of conversion into an arterial switch.

BACKGROUND: Failure of the systemic right ventricle after atrial switch operation can be treated by conversion into an arterial switch operation. METHODS: Four patients, age 38 to 59 months, presented with right ventricular failure after Senning operation and ventricular septal defect closure. One patient had elevated left ventricular pressure; in the other three patients the left ventricle was retrained to a left ventricular/right ventricular pressure ratio of 0.8 or greater by pulmonary artery banding in 12 to 24 months. RESULTS: Postoperative course after arterial switch operation was prolonged, but clinical condition was good at discharge. Fractional shortening ranged from 20% to 28%. Trace-to-moderate aortic regurgitation was present; only 1 patient had preserved sinus rhythm. After a mean follow-up of 43.5 months 1 patient had died due to left ventricular dysfunction. The survivors are in New York Heart Association functional class I to II. Fractional shortening has improved (29% to 37%); aortic regurgitation has not increased. No patient has undisturbed sinus rhythm. CONCLUSIONS: Conversion of an atrial into an arterial switch is an alternative to cardiac transplantation in childhood. However, the procedure is demanding. Long-term morbidity is caused by rhythm disturbances. Aortic valve performance and left ventricular function require close observation.

Anatomically positioned aorta ascending-descending bypass grafting via left posterolateral thoracotomy for reoperation of aortic coarctation.

OBJECTIVE: Operation for aortic recoarctation and/or residual hypoplastic arch represents a surgical challenge because of surrounding scar tissue in the coarctation area, hazard of spinal cord ischemia due to aortic cross-clamping, laceration of the recurrent nerve, and the choice of the best approach. We demonstrate the first results of an anatomically guided technique via the prior left thoracotomy approach without establishment of cardiopulmonary bypass. METHODS: Since 1989, five patients underwent anatomically positioned ascending-descending bypass grafting for treatment of recoarctation. Indication was a non-dilatable hypoplastic aortic arch segment; in two cases an additional isthmic restenosis was present. Inclusion criteria for our technique was an aorta ascending diameter large enough to allow partial clamping. Primary repair of aortic coarctation was end-to-end anastomosis in four patients and patch angioplasty in one. Mean age at primary repair was 5.5 years and at reoperation 16.1 years. Systolic pressure gradients at rest ranged from 35 to 70 mmHg; upper extremity hypertension was present in all patients. Operative technique consisted of performing a dacron or PTFE aorta ascending-descending bypass graft parallel to the aortic arch, size 18 or 20 mm in diameter, via the prior left thoracotomy. RESULTS: There were no intraoperative complications and all patients survived. Postoperative complications were left lung atelectasis with necessity of reintubation, pericardial effusion, and transient left diaphragm elevation, each in one patient. After 7-90 months all patients are free of symptoms, have normal blood pressure (with two patients being under anti-hypertensive medication), and have no echocardiographically measurable pressure gradients. CONCLUSIONS: Anatomically positioned aorta ascending-descending bypass grafting via the prior left posterolateral thoracotomy without cardiopulmonary bypass is a safe and efficient method for operation of complex recoarctation in patients with an acceptable size of the aorta ascendens.

Twenty years experience with pediatric pacing: epicardial and transvenous stimulation.

OBJECTIVE: Permanent cardiac pacing in children and adolescents is rare and often occurs by means of epicardial pacing. Based on two decades of experience, operative and postoperative data of patients with epicardial and transvenous pacing were analyzed retrospectively. METHODS: Between October 1979 and December 1998, 71 patients (mean age, 5.3+/-4.2, range, 1 day-16.2 years; mean body weight, 18+/-12; range, 8-56 kg) underwent permanent pacemaker implantation. Indications were sinus node dysfunction and atrio-ventricular block following surgery for congenital heart disease (69%), or congenital atrioventricular block (31%). Pacing was purely atrial (1.4%), purely ventricular (73%), ventricular with atrial synchronization (5. 6%), or atrioventricular synchronized (20%). Epicardial pacing was established in 49 (69%), transvenous in 22 (31%) patients. Follow-up was 3.4+/-3.8 years (epicardial) and 3.0+/-4.0 years (transvenous). RESULTS: Epicardial leads were implanted in younger patients (mean age: 4.5 vs. 7.0 years, P<0.05) and preferably after surgery induced atrioventricular block (78 vs. 46%, P<0.05). The youngest patient with transvenous pacing was 1.3 years old (weight, 8.5 kg). At implantation epicardial ventricular stimulation threshold at 1.0 ms was 1.07+/-0.46 vs. 0.53+/-0.31 V (transvenous) (P<0.05). The age-adjusted rate of lead-related reoperations was significantly higher in patients with epicardial leads (P<0.05), mainly due to increasing chronic stimulation thresholds resulting in early battery depletion. In three patients who received steroid-eluting epicardial leads initial low thresholds persisted after five month to one years. In two patients with recurrent epicardial threshold increase, steroid-eluting epicardial leads led to good acute and chronic thresholds after nine to 15 month. Two post-operative death (2.8%) were probably due to a dysfunction of the (epicardial) pacing system. CONCLUSIONS: Transvenous pacing in the pediatric population is associated with a lower acute stimulation threshold and a lower rate of lead-related complications. If epicardial pacing is necessary (e. g. small body weight, special intracardiac anatomy (e.g. Fontan), impossible access to superior caval vein), steroid-eluting leads may be considered.

The Aristotle score: a complexity-adjusted method to evaluate surgical results.

OBJECTIVES: Quality control is difficult to achieve in Congenital Heart Surgery (CHS) because of the diversity of the procedures. It is particularly needed, considering the potential adverse outcomes associated with complex cases. The aim of this project was to develop a new method based on the complexity of the procedures. METHODS: The Aristotle project, involving a panel of expert surgeons, started in 1999 and included 50 pediatric surgeons from 23 countries, representing the EACTS, STS, ECHSA and CHSS. The complexity was based on the procedures as defined by the STS/EACTS International Nomenclature and was undertaken in two steps: the first step was establishing the Basic Score, which adjusts only the complexity of the procedures. It is based on three factors: the potential for mortality, the potential for morbidity and the anticipated technical difficulty. A questionnaire was completed by the 50 centers. The second step was the development of the Comprehensive Aristotle Score, which further adjusts the complexity according to the specific patient characteristics. It includes two categories of complexity factors, the procedure dependent and independent factors. After considering the relationship between complexity and performance, the Aristotle Committee is proposing that: Performance = Complexity x Outcome. RESULTS: The Aristotle score, allows precise scoring of the complexity for 145 CHS procedures. One interesting notion coming out of this study is that complexity is a constant value for a given patient regardless of the center where he is operated. The Aristotle complexity score was further applied to 26 centers reporting to the EACTS congenital database. A new display of centers is presented based on the comparison of hospital survival to complexity and to our proposed definition of performance. CONCLUSION: A complexity-adjusted method named the Aristotle Score, based on the complexity of the surgical procedures has been developed by an international group of experts. The Aristotle score, electronically available, was introduced in the EACTS and STS databases. A validation process evaluating its predictive value is being developed.

Evaluation of biodegradable, three-dimensional matrices for tissue engineering of heart valves.

A crucial factor in tissue engineering of heart valves is the type of scaffold material. In the following study, we tested three different biodegradable scaffold materials, polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), and poly-4-hydroxybutyrate (P4HB), as scaffolds for tissue engineering of heart valves. We modified PHA and P4HB by a salt leaching technique to create a porous matrix. We constructed trileaflet heart valve scaffolds from each polymer and tested them in a pulsatile flow bioreactor. In addition, we evaluated the cell attachment to our polymers by creating four tubes of each material (length equals 4 cm; inner diameter, 0.5 cm), seeding each sample with 8,000,000 ovine vascular cells, and incubating the cell-polymer construct for 8 days (37 degrees C and 5% CO2). The seeded vascular constructs were exposed to continuous flow for 1 hour. Analysis of samples included DNA assay before and after flow exposure, 4-hydroxyproline assay, and environmental scanning electron microscopy (ESEM). We fabricated trileaflet heart valve scaffolds from porous PHA and porous P4HB, which opened and closed synchronously in a pulsatile bioreactor. It was not possible to create a functional trileaflet heart valve scaffold from PGA. After seeding and incubating the PGA-, PHA-, and P4HB-tubes, there were significantly (p < 0.001) more cells on PGA compared with PHA and P4HB. There were no significant differences among the materials after flow exposure, but there was a significantly higher collagen content (p < 0.017) on the PGA samples compared with P4HB and PHA. Cell attachment and collagen content was significantly higher on PGA samples compared with PHA and P4HB. However, PHA and P4HB also demonstrate a considerable amount of cell attachment and collagen development and share the major advantage that both materials are thermoplastic, making it possible to mold them into the shape of a functional scaffold for tissue engineering of heart valves.

Surgical management in paediatric patients with left abnormal subclavian artery and right aortic arch.

Left abnormal subclavian artery and right aortic arch is described as a rare cause of dyspnoea and dysphagia in paediatric patients. The optimal surgical management of such cases is not clearly established. We propose a single-stage repair by transection of the patent ductus arteriosus or ligamentum arteriosum and an additional transection of the left abnormal subclavian artery with reimplantation into the common carotid artery.