Short and Mid-term Outcomes of Ductal Graft with Bilateral Pulmonary Banding in Hypoplastic Left Heart Syndrome and Variants.

This study evaluates a novel surgical technique inspired by the hybrid Norwood procedure, which involves ductal graft placement and bilateral pulmonary artery banding. This technique is designed to avoid the high-risk classical Norwood stage 1 operation and to avoid the need for first stage invasive catheter interventions and interstage catheter interventions when ductal stent placement is not feasible in developing countries with limited resources. Between June 2015 and December 2022, 14 patients with hypoplastic left heart syndrome and variants were treated using this procedure at our center. Polytetrafluoroethylene graft was used for ductal graft procedure and polytetrafluoroethylene bands were used for bilateral pulmonary banding. Atrial septectomy was done selectively. Patients with adequate left heart growth underwent biventricular repair and pulmonary debanding. Patients without left heart growth underwent cavopulmonary anastomosis or necessary intermediate surgical revisions. Seven patients out of 14 reached the second stage. Two received biventricular repair, three underwent bidirectional cavopulmonary anastomosis, and two required repeat palliations other than bidirectional cavopulmonary anastomosis. Modifications of the Norwood procedure is an ongoing process due to the complex nature of hypoplastic left heart syndrome and variants. As experience grows, the mortality associated with ductal graft and bilateral pulmonary banding procedure may decrease, making this technique an alternative for centers where classical Norwood operation or hybrid palliation is not possible, especially in developing countries with limited resources. We might predict promising outcomes, especially for patients with hypoplastic left heart complex where biventricular repair is expected.

Second harvest of Congenital Heart Surgery Database in Türkiye: Current outcomes.

Background: This second harvest of the Congenital Heart Surgery Database intended to compare current results with international databases. Methods: This retrospective study examined a total of 4007 congenital heart surgery procedures from 15 centers in the Congenital Heart Surgery Database between January 2018 and January 2023. International diagnostic and procedural codes were used for data entry. STAT (Society of Thoracic Surgeons and European Association for Cardiothoracic Surgery) mortality scores and categories were used for comparison of the data. Surgical priority status was modified from American Society of Anesthesiologist guidelines. Centers that sent more than 5 cases to the database were included to the study. Results: Cardiopulmonary bypass and cardioplegic arrest were performed in 2,983 (74.4%) procedures. General risk factors were present in 22.6% of the patients, such as genetic anomaly, syndrome, or prematurity. Overall, 18.9% of the patients had preoperative risk factors (e.g., mechanical ventilation, renal failure, and sepsis). Of the procedures, 610 (15.2%) were performed on neonates, 1,450 (36.2%) on infants, 1,803 (45%) on children, and 144 (3.6%) on adults. The operative timing was elective in 56.5% of the patients, 34.4% were urgent, 8% were emergent, and 1.1% were rescue procedures. Extracorporeal membrane oxygenation support was used in 163 (4%) patients, with a 34.3% survival rate. Overall mortality in this series was 6.7% (n=271). Risk for mortality was higher in patients with general risk factors, such as prematurity, low birth weight neonates, and heterotaxy syndrome. Mortality for patients with preoperative mechanical ventilation was 17.5%. Pulmonary hypertension and preoperative circulatory shock had 11.6% and 10% mortality rates, respectively. Mortality for patients who had no preoperative risk factor was 3.9%. Neonates had the highest mortality rate (20.5%). Intensive care unit and hospital stay time for neonates (median of 17.8 days and 24.8 days, respectively) were also higher than the other age groups. Infants had 6.2% mortality. Hospital mortality was 2.8% for children and 3.5% for adults. Mortality rate was 2.8% for elective cases. Observed mortality rates were higher than expected in the fourth and fifth categories of the STAT system (observed, 14.8% and 51.9%; expected, 9.9% and 23.1%; respectively). Conclusion: For the first time, outcomes of congenital heart surgery in Türkiye could be compared to the current world experience with this multicenter database study. Increased mortality rate of neonatal and complex heart operations could be delineated as areas that need improvement. The Congenital Heart Surgery Database has great potential for quality improvement of congenital heart surgery in Türkiye. In the long term, participation of more centers in the database may allow more accurate risk adjustment.

Camptodactyly-arthropathy-coxa vara-pericarditis syndrome and an unusual association with mitral stenosis.

BACKGROUND: Campotodactyly-artrhropathy-coxa vara-pericarditis (CACP) syndrome is a very rare autosomal recessive genetic disorder. It is characterized by flexion contracture of the fifth finger (camptodactyly); noninflammatory arthropathy; decreased angle between the shaft and the head of the femur (coxa vara) and pericarditis. Its association with mitral stenosis has not yet been reported. Hereby we report this unique association with CACP syndrome. CASE: An eleven-year-old girl presented with non-productive cough, dyspnea, and orthopnea. She was diagnosed CACP syndrome at the age of seven and a biallelic frameshift mutation in the PRG4 gene was determined. The physical examination revealed pectus excavatum, camptodactyly, genu valgum, tachypnea and orthopnea. The functional capacity was NYHA III-IV. She had 2/6 soft pansystolic murmur at 4th left intercostal space and a rumbling diastolic murmur at apex. Echocardiography revealed an enlarged left atrium, severe stenotic mitral valve with a mean diastolic transmitral gradient of 22.5 mmHg, mild mitral regurgitation and mild apical pericardial effusion. The patient had mitral comissurotomy and partial pericardiectomy operation. Her post-operative transmitral gradient decreased to 6.9 mmHg and the pulmonary pressure was 30 mmHg. Her functional capacity increased to NYHA I-II. CONCLUSIONS: The main defect is the proteoglycan 4 protein which acts like a lubricant in articular and visceral surfaces. Therefore, the leading clinical feature is arthropathy. Cardiac involvement other than clinically mild pericarditis is not usually expected. Three types of proteoglycans (decorin, biglycan, and versican) are present in the mitral valve. This could be the reason of mitral valve involvement in rare cases as like ours. It is important that these patients undergo echocardiographic examination regularly.

Mechanical characterization and torsional buckling of pediatric cardiovascular materials.

In complex cardiovascular surgical reconstructions, conduit materials that avoid possible large-scale structural deformations should be considered. A fundamental mode of mechanical complication is torsional buckling which occurs at the anastomosis site due to the mechanical instability, leading surgical conduit/patch surface deformation. The objective of this study is to investigate the torsional buckling behavior of commonly used materials and to develop a practical method for estimating the critical buckling rotation angle under physiological intramural vessel pressures. For this task, mechanical tests of four clinically approved materials, expanded polytetrafluoroethylene (ePTFE), Dacron, porcine and bovine pericardia, commonly used in pediatric cardiovascular surgeries, are conducted (n = 6). Torsional buckling initiation tests with n = 4 for the baseline case (L = 7.5 cm) and n = 3 for the validation of ePTFE (L = 15 cm) and Dacron (L = 15 cm and L = 25 cm) for each are also conducted at low venous pressures. A practical predictive formulation for the buckling potential is proposed using experimental observations and available theory. The relationship between the critical buckling rotation angle and the lumen pressure is determined by balancing the circumferential component of the compressive principal stress with the shear stress generated by the modified critical buckling torque, where the modified critical buckling torque depends linearly on the lumen pressure. While the proposed technique successfully predicted the critical rotation angle values lying within two standard deviations of the mean in the baseline case for all four materials at all lumen pressures, it could reliably predict the critical buckling rotation angles for ePTFE and Dacron samples of length 15 cm with maximum relative errors of 31% and 38%, respectively, in the validation phase. However, the validation of the performance of the technique demonstrated lower accuracy for Dacron samples of length 25 cm at higher pressure levels of 12 mmHg and 15 mmHg. Applicable to all surgical materials, this formulation enables surgeons to assess the torsional buckling potential of vascular conduits noninvasively. Bovine pericardium has been found to exhibit the highest stability, while Dacron (the lowest) and porcine pericardium have been identified as the least stable with the (unitless) torsional buckling resistance constants, 43,800, 12,300 and 14,000, respectively. There was no significant difference between ePTFE and Dacron, and between porcine and bovine pericardia. However, both porcine and bovine pericardia were found to be statistically different from ePTFE and Dacron individually (p < 0.0001). ePTFE exhibited highly nonlinear behavior across the entire strain range [0, 0.1] (or 10% elongation). The significant differences among the surgical materials reported here require special care in conduit construction and anastomosis design.

A retrospective analysis of dexmedetomidine and morphine in the fast-track and ultra-fast-track extubation protocol after congenital cardiac surgery.

BACKGROUND AND AIM OF THE STUDY: After congenital cardiac surgery, the duration of mechanical ventilation (MV) is related to the clinical status, type of operation, and the sedative-analgesic agents used postoperatively. This study aims to examine the effects of dexmedetomidine and morphine on the fast-track extubation (FTE) and ultra-fast-track extubation (UFTE) protocol after congenital cardiac surgery. METHODS: A total of 251 pediatric patients were divided into two groups: 118 patients in the morphine group (Group M) and 133 patients in the dexmedetomidine group (Group D). We retrospectively reviewed medical data including hemodynamic parameters, duration of MV and cardiovascular intensive care unit (CICU), additional sedative/analgesic requirement, adverse events, the need for reintubation, and noninvasive MV, sedation, and pain scores. RESULTS: The mean mechanical ventilation duration of Group D was significantly shorter than Group M (3.74 ± 0.83 h in Group D, 5.72 ± 1.54 h in Group M, respectively) (p = .001; p < .05). In Group D, the success rate of FTE was 92.5% (n = 123) and UFTE was 7.5% (n = 10) (p = .001). In Group M, the success rate of FTE was 72.9% (n = 86) and UFTE was 0% (n = 0) (p > .05). CONCLUSIONS: Dexmedetomidine and morphine have clinical benefits which encourage their use for FTE protocol. Dexmedetomidine has more benefits compared to morphine. It can be used in UFTE protocol, besides its use in FTE protocol with fewer side effects.

Measuring potassium level in packed red blood cells before using: Word of caution for congenital cardiac surgery.

BACKGROUND AND AIM OF THE STUDY: Transfusion-associated hyperpotassemia is a serious complication of packed red blood cell (PRBC) transfusion after congenital cardiac surgery. Our study aimed to identify risk factors and potential preventive measures of transfusion-associated hyperpotassemia in neonates and infants after congenital cardiac surgery. METHODS: Pediatric patients who underwent congenital cardiac surgery and need transfusion were enrolled in this prospective study. The potassium concentration of PRBC was checked from the sample taken from the segment. The volume of transfusion, age of PRBC, potassium concentration of unit were recorded. The estimated increment of potassium level in patients after PRBC transfusion was calculated. RESULTS: Seventy-four individual patients, 95 distinct transfusions, 112 blood products were evaluated. The mean age of the blood unit was 3.8 ± 1.4 days. The mean potassium concentration in the PRBCs was 9.9 ± 2.4 mmol/L. A weak correlation was observed between the potassium value of the PRBC and the age of PRBC (p = 0.049, r = 0.2, y = 0.24 × x + -0.68). There was a weak correlation between the potassium value of PRBCs and the age of the unit (p < 0.001, r = 0.37, y = 2.8 × x + -3.6). CONCLUSIONS: Before transfusion, even PRBC is fresh, measuring the potassium level of PRBC and the potassium that will be given to the pediatric patient with transfusion can prevent transfusion-related hyperpotassemia and related complications. Otherwise, high potassium levels, which may be overlooked despite being fresh, may cause serious complications, even cardiac arrest, especially in neonates and infants.

Surgical procedures for coronary arteries in pediatric cardiac surgery: Risk factors and outcomes.

BACKGROUND: Limited data exist regarding the coronary revascularization procedures needed during the repair of several congenital and pediatric cardiac malformations. We aimed to determine risk factors for in-hospital mortality and long-term outcomes of various pediatric coronary revascularization procedures. METHODS: We retrospectively reviewed the records of 32 consecutive pediatric patients who underwent coronary revascularization procedures at our institution between May 1995 and June 2020. In-hospital mortality, risk factors, surgical indications, revascularization patency, and mid- and long-term follow-up data were investigated. Patients were categorized into the coronary artery bypass grafting (n = 11) and other coronary artery procedure (n = 21) groups. RESULTS: The median age and weight of patients at the time of surgery were 9 months and 4.8 kg, respectively. There were five in-hospital deaths (5/32, 15.6%). The mortality rates were 27.2% (3/11) in the coronary artery bypass grafting group and 9.5% (2/21) in the other coronary artery procedure group (p = .206; 95% confidence interval: 0.496-25.563). The mortality rates for planned and rescue procedures were 8.3% (2/24) and 37.5% (3/8) (p = .06), respectively. The median follow-up time was 12.5 years. Control imaging studies for coronary patency were performed in 70.3% (19/27) of surviving patients. The overall coronary patency rate was 94.7% (18/19). CONCLUSIONS: Pediatric coronary revascularization procedures with elective-planned indications can be performed with good outcomes. Young age and rescue and emergency procedures may carry an increased risk of in-hospital mortality, although not found to be statistically significant. Surviving patients require lifelong follow-up regarding the patency of reperfused coronary arteries.

Noninvasive monitoring of central venous oxygen saturation by jugular transcutaneous near-infrared spectroscopy in pediatric patients undergoing congenital cardiac surgery

Background and aim: In patients undergoing congenital cardiac surgery, it is crucial to maintain oxygen demand-consumption balance. Central venous oxygen saturation (ScvO2) is a useful indicator of oxygen demand and consumption balance which is an invasive method. Near-infrared spectroscopy (NIRS) is a noninvasive, continuous monitoring technique that measures regional tissue oxygenation. NIRS that is placed over the internal jugular vein cutaneous area (NIRSijv) has the potential to show ScvO2 indirectly. In this study, we aimed to determine the correlation between ScvO2 with NIRSijv in pediatric patients undergoing congenital cardiac surgery. Materials and methods: Fifty children participated in the study. Four patients were excluded for the inability of internal jugular vein (IJV) catheterization due to technical difficulties. After anesthesia induction, NIRS probes were placed on the IJV site with ultrasound guidance for the measurement of continuous transcutaneous oxygen saturation. The catheter insertion was also done through the IJV from the other side using ultrasound guidance. Cerebral oxygenation monitoring was done using NIRS with a single pediatric probe placed on the right forehead. Values of NIRSijv, cerebral NIRS (NIRSc) and ScvO2, were recorded at certain times until postoperative 24th hour. Results: Data were collected at 8 different time points. There was a significant correlation between ScvO2 and NIRSijv in all measurement time points (r = 0.91), (P = 0.001). The mean bias between ScvO2 and NIRSijv was 2.92% and the limits of agreement were from 11% to ­5.2%. There was a moderate correlation between ScvO2 and NIRSc (r = 0.45), (P = 0.001). The mean bias between ScvO2 and NIRSc was 2.7% and the limits of agreement were from +26% to ­20%. Conclusions: In this study, we found a strong correlation between ScvO2 and NIRS measurements taken from the internal jugular vein site. Accordingly, continuous noninvasive monitoring with transcutaneous NIRSijv can be an alternative method as a trend monitor for the central venous oxygen saturation in pediatric cardiac patients undergoing congenital cardiac surgery.

Transcatheter Closure of Left Ventricular Pseudoaneurysm After Mitral Valve Replacement.

Left ventricular pseudoaneurysm (LVPA) is a rare but lethal complication of mitral valve replacement (MVR) or myocardial infarction. Early correction is necessary for patients with extensive and expanding LVPA. We report a transcatheter closure of LVPA after MVR. A 63-year-old woman presented with an LVPA 2 months after MVR. The repeated computed tomographic scan and transthoracic echocardiography showed enhancement of pseudoaneurysm. The LVPA was closed successfully with Amplatzer Vascular Plug using a transcatheter approach.

Atrial septal defect closure via mini-thoracotomy in pediatric patients: Postoperative analgesic effect of intercostal nerve block.

BACKGROUND: In this study, we evaluated the efficacy of intercostal nerve block for postoperative pain management in pediatric patients undergoing atrial septal defect closure through a right lateral mini-thoracotomy. METHODS: Between January 2016 and January 2019, a total of 63 pediatric patients (37 males, 26 females; mean age 34.8±26.8 months; range, 2 to 96 months) who underwent corrective congenital heart surgery for atrial septal defect closure through a right lateral mini-thoracotomy were retrospectively reviewed. The patients were divided into two groups as those (Group 1, n=33) receiving intercostal nerve block and general anesthesia and those (Group 2, n=30) receiving general anesthesia alone. Intravenous morphine at a dose of 0.03 mg/kg was applied as rescue analgesia to the patients with a Ramsay Sedation Scale score of >4 and Children"s Hospital of Eastern Ontario Pain Scale score of >7. The total analgesic requirement, adverse effects, duration of mechanical ventilation and length of stay in the intensive care unit were recorded. RESULTS: The mean duration of mechanical ventilation and intensive care unit stay was shorter in Group 1 compared to Group 2 (3.6±1.3 vs. 9.4±2.1 h; 23±2.6 vs. 30±7.2 h, respectively) (p<0.0001). The need for postoperative rescue analgesia was statistically significantly lower in Group 1 compared to Group 2 (0.3±0.5 mg vs. 1.1±0.9 mg, respectively) (p=0.003). The mean total morphine consumption was also lower in Group 1 compared to Group 2 (4.0±2.2 mg vs. 9.0±3.4 mg, respectively) (p<0.0001). CONCLUSION: Intercostal nerve block before thoracotomy closure in pediatric patients undergoing atrial septal defect repair under mini-thoracotomy provides early extubation, shorter mechanical ventilation duration and intensive care unit stay, and reduced analgesic requirements.

Pulmonary valve replacement in patients with repaired tetralogy of Fallot: early results for recovery of right ventricular dilatation and QRS duration

Background/aim: Although pulmonary valve replacement (PVR) improves ventricular function and symptoms, the benefit and optimal timing of PVR are controversial. This study aimed to evaluate early response to PVR for right ventricle (RV) dilatation and QRS duration. Materials and methods: Retrospective analysis was performed for 32 patients with repaired tetralogy of Fallot (TOF) between March 2005 and October 2017. The differences between preoperative and postoperative changes in echocardiographic parameters, clinical symptoms, and QRS duration were evaluated. Results: There were no in-hospital or late deaths. Mean age at the time of PVR was 16.57 ± 7.97 years. The interval between TOF repair and PVR was 12.99 ± 7.06 years. Postoperative echocardiographic findings showed significant reduction in indexed RV end-diastolic diameter (RV-EDDI) and the ratio of RV/LV-EDDI (P = 0.001 and P = 0.001, respectively). Higher preoperative RV-EDDI was associated with decreased change in RV-EDDI after PVR (r = 0.63; P = 0.001). Normalization of RV diameters was found to be independent of age at PVR, interval between TOF repair and PVR, preoperative QRS duration, and preoperative RV-EDDI. Conclusion: Significant improvement in RV diameter and symptoms could be obtained with PVR in patients with severe pulmonary regurgitation.

Monitoring Left Atrial Pressure With a Useful Epidural Catheter.

BACKGROUND: Left atrial pressure (LAP) monitoring provides a valuable option for management of hemodynamic status in pediatric congenital heart surgery during the postoperative period. METHODS: We used a Perifix Soft Tip 701 filter set catheter (B. Braun Melsungen AG 34209 Melsungen, Germany), which is commonly used for continuous epidural anesthesia. The catheter was placed into the left atrium to provide LAP monitoring. The study included 33 children, who needed LAP monitoring during and post-surgery between January 2016 and September 2017. Patients retrospectively were reviewed for ease of catheter placement, effectivity, accurate LAP, postoperative stability, and complications after removal of the catheter, including bleeding, air embolism, or thromboembolic events. RESULTS: Patients ranged in age from 2 days to 131.27 months (Mean 11.80 days ± 25.76 days). Fifteen patients were newborn. Of the newborn patients, 39.4% (N = 13) were female. Catheters successfully were implanted in all patients, and there were no procedural complications. Left atrial catheters were removed between 1 to 12 days, with an average of 3.55 days ± 3.39 days before chest tube removal. During follow-up, patients did not suffer complications, such as thrombus formation, catheter-related infection, systemic embolism or stroke. Also, after the catheter was withdrawn, patients did not suffer from bleeding, haemodynamic deterioration, catheter retention, or require the need for intervention. During the stay in ICU, catheter nonfunction was the most frequent complication at 12.1 percent (N = 4). CONCLUSION: This is a simple, easy, and safe technique for wide use in congenital cardiac surgery patients.

Effect of modified Blalock-Taussig shunt anastomosis angle and pulmonary artery diameter on pulmonary flow.

OBJECTIVE: This study aimed to identify the best graft-to-pulmonary artery (PA) anastomosis angle measuring pulmonary blood flow, wall shear stress (WSS), and shunt flow. METHODS: A tetralogy of Fallot with pulmonary atresia computer model was used to study three different modified Blalock-Taussig shunt (mBTS) anastomosis angle configurations with three different PA diameter configurations. Velocity and WSS were analyzed, and the flow rates at the right PA (RPA) and left PA (LPA) were calculated. RESULTS: A 4-mm and 8-mm diameter of RPA and LPA, respectively with vertical shunt angle produces the highest total flow. In the RPA larger diameter than the LPA configutations, the left-leaning shunt produces the lowest total PA flow whereas in the LPA larger diameter than the RPA configuratios, the right-leaning shunt produces the lowest total PA flow. Therefore, the shunt anastomosis should not be leaned through the narrow side of PA to reach best flow. As the flow inside the shunt increased, WSS also increased due to enhanced velocity gradients. CONCLUSION: The anastomosis angle between the conduit and PA affects the flow to PA. Vertical anastomosis configurations increase the total PA flow; thus, these configurations are preferable than the leaned configurations.

Coronary artery bypass grafting in children.

BACKGROUND: We present our clinical experience with coronary artery bypass grafting (CABG) in children. METHODS: Ten children who underwent CABG between July 1995 and August 2017 were retrospectively analyzed. Data including congenital cardiac malformations, previous surgical procedures, age and sex, type of coronary complications, ischemic events preceding surgery, and ventricular function before and after CABG were recorded. RESULTS: The study population consisted of five males and five females with a median age of 2.5 years (range, 88 days to 15 years). Eight internal mammary arteries (IMAs) and two saphenous veins were used for grafting. Indications for bypass grafting were coronary artery (CA) complications related to the post-arterial switch operation in six, CA complications during the Ross procedure in two, and an iatrogenic CA injury during complete repair of tetralogy of Fallot with abnormal CA, crossing the right ventricular outflow tract in two patients. Six of the grafts were performed as rescue procedures. Three patients died during hospitalization. The mean follow-up time was 6.8 years (range, 3 months to 18 years). Anastomoses were evaluated by coronary angiography in four patients, and were all patent. Echocardiography revealed normal myocardial function in all patients. CONCLUSION: Our study suggests that the IMA should be the graft of choice in children due to its growth potential and long-term patency.

Surgical Repair of Congenital Left Atrial Aneurysm and Mitral Valve Insufficiency in a Four-Year-Old Child.

Left atrial aneurysm is an extremely rare anomaly, which can be associated with supraventricular arrhythmia, compression of coronary arteries, intracardiac thrombus, life-threatening systemic embolization, pulmonary venous obstruction, mitral valve insufficiency, and congestive heart failure. Herein, we report a four-year-old boy who had a giant aneurysm of the left atrium and severe mitral regurgitation. The aneurysm and mitral valve cleft causing severe mitral regurgitation were successfully repaired.

Application of cryoablation for the treatment of atrial fibrillation in patients undergoing cardiac surgery: Our mid-term results.

BACKGROUND: In this study, we aimed to present mid-term results of concomitant argon-based cryoablation in patients undergoing cardiac surgery. METHODS: Between August 2014 and May 2016, 33 patients (17 males, 16 females; mean age 63.9 years; range 45 to 82 years) underwent the Maze procedure using cryoablation for the treatment of atrial fibrillation during a concomitant open cardiac operation. Robot-assisted procedures were used in 12 patients. Biatrial or isolated left atrial ablation was performed according to the underlying pathology. The rhythm assessment with 12-lead electrocardiography and 24-hour Holter, and recordings of atrial fibrillation-related medications, stroke or other thromboembolic events were evaluated by the cardiologist at 3 and 12 months postoperatively. RESULTS: Thirty patients (90.9%) were in sinus rhythm and three (9.1%) were in atrial fibrillation at the time of discharge. Cryoablation failed in three patients (n=2, 8.3% in isolated left atrial and n=1, 11.1% in biatrial group) following the operation in the mid-term. Among the patients, there was no in-hospital mortality and no major postoperative complications such as stroke, sepsis, renal failure requiring dialysis, and prolonged respiratory failure. CONCLUSION: Concomitant surgical cryoablation is an effective method for the treatment of atrial fibrillation, when performed concomitantly with other cardiac surgical procedures and results in very low atrial fibrillation recurrence, even in robotic surgery.

Double switch operations: Should we perform physiologic or anatomic repair in congenitally corrected transposition of the great arteries.

The seeking for the optimal surgical treatment of congenitally corrected transposition of the great arteries (cTGA) is ongoing. Physiologic (conventional) repair approaches, leaving the morphologic right ventricle (MRV) on the systemic circulation side, cause systemic ventricle and tricuspid valve failure, particularly in the long-term. Double Switch operations (anatomic repair) were aimed to convert the morphologic left ventricle to systemic ventricle and MRV to pulmonic ventricle. Gradual improvement in the early and midterm results of double switch operations in the last 20 years rendered anatomic repair to become a preferred procedure. Thanks to the preservation of ventricular functions through anatomic repair, patients with congenitally cTGA may survive longer with normal/near normal functional capacity. However, studies with larger sample size and longer follow-up duration are required to establish a more definite judgement.

Tetralogy of Fallot Surgical Repair: Shunt Configurations, Ductus Arteriosus and the Circle of Willis.

In this study, hemodynamic performance of three novel shunt configurations that are considered for the surgical repair of tetralogy of Fallot (TOF) disease are investigated in detail. Clinical experience suggests that the shunt location, connecting angle, and its diameter can influence the post-operative physiology and the neurodevelopment of the neonatal patient. An experimentally validated second order computational fluid dynamics (CFD) solver and a parametric neonatal diseased great artery model that incorporates the ductus arteriosus (DA) and the full patient-specific circle of Willis (CoW) are employed. Standard truncated resistance CFD boundary conditions are compared with the full cerebral arterial system, which resulted 21, -13, and 37% difference in flow rate at the brachiocephalic, left carotid, and subclavian arteries, respectively. Flow splits at the aortic arch and cerebral arteries are calculated and found to change with shunt configuration significantly for TOF disease. The central direct shunt (direct shunt) has pulmonary flow 5% higher than central oblique shunt (oblique shunt) and 23% higher than modified Blalock Taussig shunt (RPA shunt) while the DA is closed. Maximum wall shear stress (WSS) in the direct shunt configuration is 9 and 60% higher than that of the oblique and RPA shunts, respectively. Patent DA, significantly eliminated the pulmonary flow control function of the shunt repair. These results suggests that, due to the higher flow rates at the pulmonary arteries, the direct shunt, rather than the central oblique, or right pulmonary artery shunts could be preferred by the surgeon. This extended model introduced new hemodynamic performance indices for the cerebral circulation that can correlate with the post-operative neurodevelopment quality of the patient.