Maciej Moll

The neoaortic root in children with transposition of the great arteries after an arterial switch operation

OBJECTIVES Neoaortic root changes in children with transposition of the great arteries (TGA) are reportedly risk factors for the development of neoaortic regurgitation (NeoAR). The aims of this study were to assess the neoaortic root diameter and relative proportion in children with TGA after surgical correction and to identify possible correlations with the development of neoaortic insufficiency. METHODS Of the 611 children who had the arterial switch operation performed in the Cardiology Department of the Polish Mothers Memorial Hospital, 172 consecutive patients were qualified for this study. The inclusion criteria were: anatomical correction performed during the neonatal period, more than 10 years of postoperative observation and at least two full echocardiographic examinations. RESULTS NeoAR increased during postoperative follow-up and at the end of the observation period, 76% of the patients had NeoAR (27%-trace, 42%-mild, 7%-moderate and 0.6%-severe). Among the analysed risk factors for NeoAR development, the significant ones were arterial valve discrepancy (OR = 2.05; 95% CI: 1.04-4.02; P = 0.031) and the non-facing commissures (OR = 4.05; 95% CI: 1.34-11.9; P = 0.01). The neoaortic root diameter was not statistically significantly correlated with the presence of NeoAR or with the heart defects associated with transposition. The neoaortic root was initially, on average, 37% (z-score = 1.58) bigger than the aortic root in healthy children. This disproportion increased during the follow-up evaluations to 57% (z-score = 2.09). CONCLUSIONS The neoaortic root in children after the arterial switch procedure develops differently from that in healthy children, but this is not evidently related to NeoAR development or associated heart defects.

Long-Term Outcome of Direct Neopulmonary Artery Reconstruction During the Arterial Switch Procedure

BACKGROUND Neopulmonary stenosis at anastomosis site is one of the most frequent complications after the arterial switch procedure for transposition of the great arteries. The surgical technique is a crucial factor associated with the frequency of stenotic complications. We present the outcomes of direct neopulmonary anastomosis during the arterial switch procedure in patients with simple transposition. This research was to assess the efficacy of this surgical technique based on the incidence of postprocedural supravalvular neopulmonary stenosis (SVPS). METHODS Among 545 patients operated on in our department between 1992 and 2009, the 346 consecutive survivors who had undergone simple transposition in the first month of life were included in this analysis. Switch procedures were performed with direct neopulmonary artery anastomosis in 318 patients (92%); in the remaining 28 (8%), the risk of coronary artery compression required the use of a pericardial patch for pulmonary reconstruction. RESULTS Neopulmonary stenosis occurred in 9 patients (2.6%): 5 had undergone direct neopulmonary reconstruction, and 4 had been treated with a patch. Balloon angioplasty of SVPS was performed twice in 1 patient. No patients required reoperation to treat neopulmonary stenosis. In multivariate analysis (logistic regression), patch reconstruction (odds ratio, 27.5; p=0.001) and nonfacing commissures (odds ratio, 11.1; p=0.004) were correlated significantly with the incidence of SVPS. CONCLUSIONS Direct neopulmonary artery anastomosis during arterial switch is an interesting alternative to patch reconstructions and ensures a good postoperative result with low rates of complications and SVPS.

Primary Ficolin-3 deficiency--Is it associated with increased susceptibility to infections?

Ficolin-3 (also called H-ficolin or Hakata antigen) is the most potent activator of the lectin pathway of complement in vitro. Its genetically determined deficiency in Caucasians is associated with a frame-shift mutation +1637delC (rs28357092) of the FCN3 gene. When it was described for the first time, it was postulated to be strictly associated with enhanced susceptibility to infections. At present, with our knowledge extended by several other patients that issue seems to be more complicated and less clear-cut. Two new cases of primary Ficolin-3 deficiency are reported here: a 50-year old male, suffering from membranous nephropathy and an 11-month old male infant who was operated on to repair congenital heart disease. Based on those cases and a literature review, we conclude that the clinical consequences of congenital Ficolin-3 deficiency are still unclear and such questions as whether it may be life-threatening or acts as a disease modifier remain to be elucidated.

Activation of the lectin pathway of complement by cardiopulmonary bypass contributes to the development of systemic inflammatory response syndrome after paediatric cardiac surgery.

The systemic inflammatory response is a challenge in the management of paediatric patients undergoing cardiac surgery. Although multi‐factorial, a contribution by the lectin pathway of complement activation has been postulated. We therefore investigated the changes in serum levels of mannose binding lectin (MBL) and activities of MBL–MBL‐associated serine protease (MASP)‐1 and MBL–MASP‐2 complexes immediately before and during surgery, throughout the first postoperative day and at discharge from the hospital. These changes were analysed in relation to postoperative complications. Blood samples were obtained from 185 children with congenital heart disease undergoing surgical correction with the use of cardiopulmonary bypass: preoperatively (MBL‐1), 15 min after initiation of cardiopulmonary bypass (CPB) (MBL‐E), 30 min (MBL‐2), 4 h (MBL‐3), 12 h (MBL‐4) and 24 h (MBL‐5) post‐CPB and at discharge from hospital (MBL‐K). Alterations in serum MBL levels were calculated as a ratio of its serum level at subsequent time‐points (MBL‐2, ‐3, ‐4, ‐5) to the preoperative (MBL‐1) value. Decreases in MBL and MBL–MASP complexes were observed in all samples, correlating with a decrease in C4 and increase in C4a, confirming activation of the lectin pathway. Changes in MBL levels between children with an uncomplicated postoperative course and those suffering from infection or low cardiac output syndrome did not differ significantly, but significant differences were observed between the SIRS and non‐SIRS groups. Paediatric cardiac surgery with the use of cardiopulmonary bypass activates the complement system via the lectin pathway and the latter contributes to the development of the post‐bypass systemic inflammatory response.

Reoperations and catheter interventions in patients with transposition of the great arteries after the arterial switch operation

OBJECTIVES: Reoperations and catheter interventions after the arterial switch operation (ASO) are relatively rare, but their frequency varies among different centres. They significantly impact the postoperative course of children with transposition of the great arteries (TGA). The aim of this study was to assess the frequency of reoperations and catheter interventions in patients with TGA after the ASO and to identify the potential risk factors. METHODS: For this retrospective case review study we included all consecutive 715 patients with TGA who underwent the ASO in the Department of Cardiac Surgery between the years 1991 and 2015. All of the surgical procedures were performed by one cardiac surgery team led by J.J.M., using the same surgical technique with his own specific modifications. RESULTS: The overall early mortality after the ASO was 7.4%; late mortality occurred in 15 cases (2.3%) and the mean clinical follow-up of our cohort was 10.5 years. Early reoperations (<30 days after surgery) were performed in 37 patients (5.1%). Reoperations were performed in 31 patients (4.7% of survivors), and their risk factors were previous early reoperation and left ventricle outflow tract obstruction, while isolated TGA reduced the risk of reoperations. Catheter interventions were performed in 25 patients (3.8% of survivors). In the majority of the cases, the indications for percutaneous procedures were pulmonary stenosis and recoarctation of the aorta. The statistically significant risk factors were aortic arch anomalies associated with TGA and neopulmonary artery anastomosis with a patch, while isolated TGA decreased the risk of reintervention. Freedom from cumulative reinterventions after the ASO was 90.4% at 5 years; 88.0% at 10 years; 86.5% at 15 years and 86.5% from 20 to 25 years. CONCLUSION: The frequency of reoperations and percutaneous interventions in patients with TGA after the ASO remains low. The majority of the procedures are performed because of pulmonary stenosis and recoarctation of aorta. Cardiac anomalies associated with TGA have a significant impact on the incidence of reoperation and reintervention.

Mannose-binding lectin (MBL) insufficiency protects against the development of systemic inflammatory response after pediatric cardiac surgery

We investigated MBL2 and MASP2 genotypes, serum MBL (mannose-binding lectin) levels and activities of its complexes with associated serine proteases (MASP-1, MASP -2), in relation to complications following cardiac surgery in 195 children. The incidence of SIRS was lower in patients carrying MBL2 A/O and O/O genotypes (p=0.024). Children with MBL levels <500ng/ml had a lower risk of SIRS (p=0.014) and fever (p=0.044). Median MBL concentration was higher in patients who developed SIRS (p=0.048) but lower in those with post-operative infections (p=0.046). MBL-MASP-2 activities <100mU/ml protected from SIRS (p=0.007), low cardiac output syndrome (p=0.03) and multiorgan failure (p=0.012). In contrast, MBL2 YA/YA genotypes were associated with SIRS (p=0.018), low cardiac output syndrome (p=0.018), fever (p=0.018) and high inotropic score (VIS>30) (p=0.021). Thus, low MBL concentrations and associated genotypes may protect patients from systemic inflammation while high MBL serum levels and corresponding genotypes are risk factors of postoperative complications.

Are the surgeon’s movements repeatable? An analysis of the feasibility and expediency of implementing support procedures guiding the surgical tools and increasing motion accuracy during the performance of stereotypical movements by the surgeon

The developments in surgical robotics suggest that it will be possible to entrust surgical robots with a wider range of tasks. So far, it has not been possible to automate the surgery procedures related to soft tissue. Thus, the objective of the conducted studies was to confirm the hypothesis that the surgery telemanipulator can be equipped with certain routines supporting the surgeon in leading the surgical tools and increasing motion accuracy during stereotypical movements. As the first step in facilitating the surgery, an algorithm will be developed which will concurrently provide automation and allow the surgeon to maintain full control over the slave robot. The algorithm will assist the surgeon in performing typical movement sequences. This kind of support must, however, be preceded by determining the reference points for accurately defining the position of the stitched tissue. It is in relation to these points that the tools trajectory will be created, along which the master manipulator will guide the surgeons hand. The paper presents the first stage, concerning the selection of movements for which the support algorithm will be used. The work also contains an analysis of surgical movement repeatability. The suturing movement was investigated in detail by experimental research in order to determine motion repeatability and verify the position of the stitched tissue. Tool trajectory was determined by a motion capture stereovision system. The study has demonstrated that the suturing movement could be considered as repeatable; however, the trajectories performed by different surgeons exhibit some individual characteristics.

Successful Late Recruitment of the Occluded Left Main Coronary Artery After Initial Arterial Switch Operation

We describe a surgical technique for late recruitment of the proximally occluded left main coronary artery (LMCA) after initial arterial switch operation, which had been complicated by severe left ventricular dysfunction. This technique allowed for LMCA recanalization, using the patent conal artery branching off the LMCA close to the ostium. It is particularly useful in small children, where surgical options for coronary arteries are limited and associated with a high risk of restenosis. It was successfully used in a two-month-old boy with successful revascularization confirmed by angiography.

Usefulness of Routine Coronary CT Angiography in Patients with Transposition of the Great Arteries After an Arterial Switch Operation

Coronary complications in patients with transposition of the great arteries (TGA) after an arterial switch operation (ASO) are relatively rare, but of all the possible postoperative adverse events, they are potentially the most dangerous. The fate of the coronary arteries, which are transplanted during the neonatal ASO, remains uncertain. There is also no consensus regarding their postoperative evaluation, especially in asymptomatic patients. The aim of this study was to present the early results of routinely performed coronary computed tomography angiography (CCTA) in asymptomatic adolescents and young adults with TGA after an ASO. An initial series of 50 CCTAs performed in asymptomatic patients with TGA after an ASO were evaluated. In each case, a detailed examination of the coronary anatomy, its relationship to the surrounding structures, its exact position in the neoaortic sinus, and the presence of significant coronary abnormalities was performed. The CT scans revealed significant coronary abnormalities in 12 asymptomatic patients: three had acute proximal angulation and stenosis, four had an intra-arterial course, seven had a muscular bridge, one had a left anterior descending artery with an intramuscular course, and one had coronary fistulas to the pulmonary arteries. Additionally, in 25 patients, proximal acute angulation of at least one coronary artery was detected, and four of them had a high ellipticity index. Most of the potentially severe anatomical features were related to the left coronary artery or the left anterior descending artery. CCTA routinely performed on asymptomatic patients with TGA after an ASO provides accurate and useful information for postoperative management. The frequency of coronary anomalies and potentially dangerous anatomical features in this group of patients is high, and their impact on postoperative follow-up remains unknown.

Deposition of mannose‐binding lectin and ficolins and activation of the lectin pathway of complement on the surface of polyurethane tubing used for cardiopulmonary bypass

The artificial surface used for cardiopulmonary bypass (CPB) is a crucial factor activating the complement system and thus contributing to the generation of a systemic inflammatory response. The activation of classical and alternative pathways on this artificial surface is well known. In contrast, lectin pathway (LP) activation has not been fully investigated, although noted during CPB in several studies. Moreover, we have recently proved the contribution of the LP to the generation of the systemic inflammatory response syndrome after pediatric cardiac surgery. The aim of this study was to assess LP-mediated complement activation on the surface of polyurethane CPB circuit tubing (noncoated Chalice ® ), used for CPB procedures in children with congenital heart disease. We found deposition of mannose-binding lectin, ficolin-1, -2, and -3 on the surface of unused tubing and on tubing used for CPB from a small minority of patients. Furthermore, we observed deposition of complement C4 activation products on tubing used for CPB and previously unused tubing after incubation with normal serum. The latter finding indicates LP activation in vitro on the polyurethane surface.