Role of patent ductus arteriosus in preterms in long-term outcome.

OBJECTIVE: This study aimed to determine long-term neurodevelopmental outcome and cerebral oxygenation in extremely preterm infants, comparing those with a hemodynamic significant patent ductus arteriosus (hsPDA) to those without. STUDY DESIGN: We included infants born before 28 weeks of gestation from 2008 to 2010 with routine echocardiography. Prior to echocardiography, regional cerebral oxygen saturation was measured. At 5 years of age, we evaluated neurodevelopmental outcomes using the Movement Assessment Battery for Children 2nd Dutch edition for motor skills and the Wechsler Preschool and Primary Scale of Intelligence 3rd Dutch edition for cognition. RESULTS: A total of 66 infants (gestational age 26.6 ± 0.9 weeks, birth weight 912 ± 176 g) were included, 34 infants with a hsPDA (including treatment). The group infants with hsPDA showed lower pre-closure cerebral saturation levels (58.2 % ±7.8 % versus 62.8 % ±7.0 %; p = 0.01). At 5 years, impaired motor outcome occurred more often in infants with hsPDA (17 (53 %) vs. 7 (23 %); p = 0.01). In multivariate analysis existence of hsPDA remained unfavourably related to the motor subdomain "aiming and catching". There were no potential effects of hsPDA on cognitive performance at 5 years of age. CONCLUSION: Treatment-receiving infants with hsPDA appear to exhibit motor deficits, specifically in "aiming and catching", by the age 5. Persistent ductal patency could be a contributing factor.

Troubled Judging of Bronchus Compression Due to Contrast-Filled Balloon in Three-Dimensional Rotational Angiography.

Three-dimensional rotational angiography (3DRA) is a suitable technique to detect the risk of left main bronchus (LMB) compression during left pulmonary artery (LPA) stenting in partial cavopulmonary connection and total cavopulmonary connection (TCPC). We report on a case of a 4-year-old boy with hypoplastic left heart syndrome and TCPC in which 3DRA and bronchoscopy gave conflicting information on airway patency during balloon interrogation. The balloon with high contrast concentration created a severe artifact impeding visibility of the LMB. Simultaneous flexible bronchoscopy revealed an unobstructed LMB. Repeated 3DRAs with lower contrast concentration had no artifact and showed a patent airway in accordance with the bronchoscopy. Conventional LPA stenting was performed without indication for stent ovalization. The benefit of low contrast concentration in the interrogation balloon was demonstrated in a second case of an 11-year-old boy with TCPC. The margins of the LPA and LMB were clearly visible without blank-out artifact. Oval stent procedure was necessary to prevent LMB compression. When 3DRA is used for vessel-airway interrogation, the balloon contrast concentration should be low in order to avoid artifacts. When in doubt, simultaneous flexible bronchoscopy can overcome the dilemma in airway judgment.

Early and midterm outcomes of bare metal stenting in small children with recurrent aortic coarctation.

AIMS: The aim of this study was to report our experience with the Cook Formula stent in the treatment of (recurrent) coarctation of the aorta in children below 12 kg. METHODS AND RESULTS: In vitro study of the Cook Formula 418 (8 mm) and 535 (8 and 10 mm) stents demonstrated successful down-crimping on smaller balloons and predictable fracturing patterns. Between November 2012 and January 2019, one patient with native, one patient with post-interventional and thirteen patients with post-surgical coarctation of the aorta underwent implantation of a Cook Formula stent. Patient and procedural characteristics were obtained as well as procedural success, complications, and follow-up. Median age was 4.3 months and median weight 5.5 kg. Arterial sheath size ranged from 5 to 7 Fr. In-stent diameters of 3.7 to 8.8 mm were obtained with a median residual gradient of 0 mmHg. Major complications consisted of periprocedural haemodynamic instability (n=1), dissection of the iliac artery (n=1) and non-deployment with surgical removal (n=1). Re-dilations were performed after a median interval of 24.3 months. Median follow-up was 31.7 months. CONCLUSIONS: The bare metal Cook Formula stent provides a durable and effective alternative to reoperation and balloon dilatation for native as well as post-surgical aortic coarctation in children below 12 kg.

Epinephrine stress testing during cardiac catheterization in patients with aortic coarctation.

BACKGROUND: The severity of aortic coarctation (CoA) may be underestimated during cardiac catheterization. We aimed to investigate whether epinephrine stress testing improves clinical decision making and outcome in CoA. METHODS: We retrospectively evaluated CoA patients >50 kg with a peak systolic gradient (PSG) ≤20 mm Hg during cardiac catheterization who underwent epinephrine stress testing. Subsequent interventional management (stenting or balloon dilatation), complications, and medium-term clinical outcome were assessed. RESULTS: Fifty CoA patients underwent cardiac catheterization with epinephrine stress testing. Patients with a high epinephrine PSG (>20 mm Hg; n = 24) were younger and more likely to have a hypertensive response to exercise compared to patients with a low epinephrine PSG (≤20 mm Hg; n = 26). In total, 21 patients (88%) with a high epinephrine PSG underwent intervention, and 20 patients (77%) with a low epinephrine PSG were treated conservatively. After a mean follow-up of 25 ±â€¯18 months, there was a lower prevalence of hypertension in patients with a high epinephrine PSG who underwent intervention compared to patients with a low epinephrine PSG treated conservatively (19% vs. 76%; P = .001). In a multivariate model, intervention was independently associated with a 14.3-mm Hg reduction in systolic blood pressure (P = .001) and a decrease in the use of antihypertensive agents. CONCLUSIONS: In CoA patients with a low baseline PSG but high epinephrine PSG, percutaneous intervention is associated with a substantial reduction in systemic blood pressure and the use of antihypertensive medication. Accordingly, epinephrine stress testing may be a useful addition in the evaluation of CoA.

Oval stenting in left pulmonary artery stenosis: a novel double balloon technique to prevent airway compression in single ventricle.

AIMS: Left pulmonary artery (LPA) stenosis is common in patients with cavopulmonary connections. Stent implantation is the treatment of choice but may be complicated or contraindicated by left main bronchus (LMB) compression due to limited retro-aortic space after a Damus-Kaye-Stansel (DKS) or Norwood operation. This study describes a novel double balloon technique of LPA stenting in patients at risk of LMB compression. METHODS AND RESULTS: A cohort study was performed in 11 patients who underwent LPA stenting with an oval stent technique between 2015 and 2018. Retro-aortic anatomy was evaluated periprocedurally by three-dimensional rotational angiography (3DRA). Pre-existing LMB compression was demonstrated by 3DRA in seven out of eight patients who had undergone previous LPA stenting and in one patient without stenting. Primary ovalisation with immediate stent implantation on double balloons was performed in one patient. Ten patients had secondary ovalisation with single balloon stent implantation followed by the double balloon technique for ovalisation. The procedures were successful in all patients and guaranteed LMB patency without increasing pre-existing compression. CONCLUSIONS: The 3DRA-guided oval stent technique with double balloon inflation is successful in treating LPA stenosis after a DKS or Norwood operation in patients at risk of bronchial compression, guaranteeing LMB patency without increasing pre-existing compression.

Endovascular coil embolization of a complex aortic arch pseudoaneurysm following arch stenting.

Pseudoaneurysm formation is a life-threatening complication of thoracic aortic stenting due to the high risk of rupture. When located in the aortic arch, anatomic features may pose difficulties in choosing the optimal treatment strategy. Here, we describe the first poststenting aortic arch pseudoaneurysm treated by endovascular coil embolization. This approach, which we performed in a multidisciplinary setting, may be a feasible alternative in patients not considered suitable for open repair or stent-grafting. As an acute pseudoaneurysm may develop and rapidly expand during the first days after aortic stenting, early follow-up imaging is preferable.

Medium-term systemic blood pressure after stenting of aortic coarctation: a systematic review and meta-analysis.

OBJECTIVE: Long-term prognosis of patients with coarctation of the aorta (CoA) is impaired due to the high prevalence of hypertension and consequent cardiovascular complications. Although stent implantation results in acute anatomical and haemodynamic benefit, limited evidence exists regarding the late clinical outcome. In this meta-analysis, we aimed to evaluate the medium-term effect of stent placement for CoA on systemic blood pressure (BP). METHODS: PubMed, EMBASE and Cochrane databases were searched for non-randomised cohort studies addressing systemic BP ≥12 months following CoA stenting. Meta-analysis was performed on the change in BP from baseline to last follow-up using a random-effects model. Subgroup analyses and meta-regression were conducted to identify sources of heterogeneity between studies. RESULTS: Twenty-six studies with a total of 1157 patients and a median follow-up of 26 months were included for final analysis. Meta-analysis showed a 20.3 mm Hg (95% CI 16.4 to 24.1 mm Hg; p<0.00001) reduction in systolic BP and an 8.2 mm Hg (12 studies; 95% CI 5.2 to 11.3 mm Hg; p<0.00001) reduction in diastolic BP. A concomitant decrease in the use of antihypertensive medication was observed. High systolic BP and peak systolic gradient at baseline and stenting of native CoA were associated with a greater reduction in systolic BP at follow-up. CONCLUSIONS: Stent implantation for CoA is associated with a significant decline in systolic and diastolic BP during medium-term follow-up. The degree of BP reduction appears to be dependent on baseline systolic BP, baseline peak systolic gradient, and whether stenting is performed for native or recurrent CoA.

Three-Dimensional Rotational Angiography in Pediatric Patients with Congenital Heart Disease: A Literature Review.

Cardiac catheterization is a commonly used form of imaging and treatment in pediatric patients with congenital heart disease. Traditionally, two-dimensional conventional angiography was the method used, but since 2000 three-dimensional rotational angiography (3DRA) is increasingly used in the field of cardiology in both adult and pediatric patients. To investigate the use and applications of 3DRA in pediatric congenital cardiology, literature was systematically reviewed and 29 eligible articles were found. Those showed that 3DRA is already a greatly valued diagnostic and therapeutic technique in pediatric cardiology. However, the literature misses well-designed clinical, homogeneous, multicenter, prospective studies recording data in a standardized manner. These studies are necessary to ensure proper data analysis and to investigate the true advantages of 3DRA and how it exactly benefits the patients.

Percutaneous Pulmonary Valve Implantation: Current Status and Future Perspectives.

Patients with congenital heart disease (CHD) with right ventricle outflow tract (RVOT) dysfunction need sequential pulmonary valve replacements throughout their life in the majority of cases. Since their introduction in 2000, the number of percutaneous pulmonary valve implantations (PPVI) has grown and reached over 10,000 procedures worldwide. Overall, PPVI has been proven safe and effective, but some anatomical variations can limit procedural success. This review discusses the current status and future perspectives of the procedure.

Dramatic Dose Reduction in Three-Dimensional Rotational Angiography After Implementation of a Simple Dose Reduction Protocol.

Previously, median effective dose (ED) of 1.6 mSv per three-dimensional rotational angiography (3DRA) has been reported. This study evaluated ED and image quality in 3DRA after implementation of a simple dose reduction protocol in pediatric catheterizations. Simple conversion factors between 3DRA ED and readily available parameters at the cathlab were determined. The dose reduction protocol consisted of frame reduction (60-30 frames/s (f/s)), active collimation of the X-ray beam, usage of a readily available low dosage program, and a pre-3DRA run check. EDs were calculated with Monte Carlo PCXMC 2.0. Three observers blindly assessed 3DRA image quality of the dose reduction and normal-dose cohort. Between October 2014 and October 2015, 84 patients (median age 4.3 years) underwent 100 3DRAs with a median ED of 0.54 mSv (0.12-2.2) using the dose reduction protocol. Median ED in the normal-dose cohort (17 3DRAs) was 1.6 mSv (1.2-4.9). Image quality in the dose reduction cohort remained excellent. Correlations between ED and dose area product (DAP) and ED and skin dose were found with a ρ of 0.82 and 0.83, respectively. ED exposure of the entire catheterization was reduced to 2.64 mSv. Introduction of a simple protocol led to 66% dose reduction in 3DRA and 79% in the entire catheterization. 3DRA image quality in this group remained excellent. In 3DRA ED correlates well with DAP and skin dose, parameters readily available at the cathlab.

The Y-stenting technique for pulmonary artery bifurcation stenosis: Initial results and mid-term outcomes.

BACKGROUND: Treatment for main or peripheral PBS is challenging. An interventional approach is generally preferred as surgical angioplasty often results in residual stenosis. However, there is limited data on the mid- and long-term results of the different interventional approaches. The aim of this study is to report on initial and mid-term results of the Y-stenting technique for pulmonary artery bifurcation stenosis (PBS). METHODS: A single centre retrospective study of all Y-stenting procedures for main or peripheral PBS was conducted. Patient and procedural data as well as mid-term outcomes were analysed. RESULTS: 11 Y-stenting procedures were performed, 9 in the main pulmonary bifurcation and 2 in the PA periphery. In 8 patients the bifurcation stents were connected, in 3 patients there was no connection between the stents. Y-stenting creates a geometry close to the physiological PA bifurcation anatomy with complete alignment to the vessel wall without flow separation. Control angiography showed unrestricted blood flow after all procedures. Median right/left ventricle pressure ratio decreased from 0.9 to 0.5. No immediate or delayed adverse events were seen. During a median follow-up of 33.5 months, 2 patients in the non-connected group and 3 patients in the connected group needed a total of 6 re-interventions. No intima proliferation was seen in patients with connected stents. CONCLUSIONS: Y-stenting is a safe and effective treatment for PBS. When both bifurcation stents are connected, this may result in lower rates of in-stent intima proliferation in comparison to other PBS stenting techniques.

Cardiac Valve Annulus Diameters in Extremely Preterm Infants: A Cross-Sectional Echocardiographic Study.

BACKGROUND: With the increasing incidence of births of very preterm very-low-birth-weight infants, there is a demand for echocardiographic reference values of cardiac dimensions. OBJECTIVES: The aim of this study was to provide reference values of cardiac valve annulus diameters in a cohort of extremely preterm very-low-birth-weight neonates and to correlate these with patient characteristics. METHODS: Valve diameters of 376 infants of < 32 weeks' gestation and with a birth weight of ≤2,000 g were measured using 2-dimensional echocardiography. Correlations between valve diameters and patient characteristics (birth length/weight, body surface area, gestational age, and sex) were assessed. Birth weight was used to establish linear regression models. Inter- and intraobserver agreement was assessed through intraclass correlation coefficient (ICC) analysis. RESULTS: Substantial variability was found (aortic valve mean [standard deviation; range]: 5.0 mm [0.6; 3.7-6.5]; pulmonic valve: 5.8 mm [0.8; 3.4-7.9]; mitral valve: 8.0 mm [1.0; 5.5-10.5]; tricuspid valve: 7.6 mm [1.2; 4.9-10.6]). There was a moderate correlation between birth weight and valve diameter (R2 aortic valve: 0.36; pulmonic valve: 0.20; mitral valve: 0.24; tricuspid valve: 0.24). Adequate intraobserver (ICC range 0.74-0.91) and interobserver agreement (ICC range 0.77-0.89) was found. CONCLUSIONS: Our study provides ready-to-use reference values for cardiac valve annulus diameters for extremely preterm infants.

Additional value of three-dimensional rotational angiography in the diagnostic evaluation and percutaneous treatment of children with univentricular hearts.

AIMS: Complex single ventricle topography, changes in vessel geometry after surgical steps and subsequent stenoses are difficult to visualise with biplane conventional angiography (CA). This study aimed to investigate the additional value of three-dimensional rotational angiography (3DRA) compared to CA for diagnostic and interventional purposes in children with univentricular hearts. METHODS AND RESULTS: Demographic data, clinical data and catheterisation details of both imaging techniques were collected retrospectively. Image quality, interventional success and the additional value of 3DRA were reviewed and scored. Between January 2003 and March 2017, 140 patients underwent 183 CAs and 107 3DRAs. 3DRA image quality was superior to CA with fewer diagnostic angiographies performed (p<0.001). Intervention rate (p<0.001) and interventional success (p=0.03) were higher with 3DRA, while complication rates were similar. Mean radiation was lower in the 3DRA group, reaching significance pre-PCPC. 3DRA was considered of additional value in imaging of cardiovascular anatomy, collaterals, stenoses, and vessel-vessel and vessel-bronchi interactions. CONCLUSIONS: In univentricular hearts, 3DRA provides superior image quality when compared to CA. Furthermore, 3DRA is performed with fewer diagnostic angiographies, less radiation and higher interventional success.

Primary coronary stent implantation is a feasible bridging therapy to surgery in very low birth weight infants with critical aortic coarctation.

BACKGROUND: Surgical treatment of critical aortic coarctation (CoA) is difficult in very low birth weight (VLBW) infants ≤1500 g and preferably postponed until 3 kg with prostaglandins (PGE). OBJECTIVES: To investigate the procedure and outcome of primary coronary stent implantation as bridging therapy to surgery in VLBW infants with CoA. METHODS: Retrospective evaluation of primary CoA stenting in VLBW infants from 2010 to 2015. RESULTS: Five VLBW infants with a median gestational age of 29 weeks (27-32) underwent primary CoA stenting. Indication was cardiac failure in 4 and severe hypertension in 1 patient. Age and weight at intervention were 14 days (range 12-16) and 1200 g (680-1380), respectively. Stent diameter ranged 3-5 mm. The femoral artery used for intervention was occluded in all infants without clinical compromise. Severe restenosis and aneurysm occurred in 1 VLBW infant and was successfully treated with covered coronary stents. Median age at surgical correction was 200 days (111-804) and weight 5500 g (4500-11,400). No reinterventions were required during a median postoperative follow-up of 2.8 years (0.1-5.0). Neurodevelopmental outcomes were normal and comparable between patients and siblings (4/5 gemelli). CONCLUSIONS: Primary coronary stent implantation in VLBW infants with critical CoA is a feasible bridging therapy to surgery.

Normative Values of Aortic Arch Structures in Premature Infants.

BACKGROUND: Aortic arch abnormalities represent 5% to 8% of all congenital heart disease. Measurements of the aortic arch dimensions on two-dimensional echocardiographic images remain of critical importance in the diagnosis of aortic arch pathology. To define aortic hypoplasia or coarctation, measured dimensions must be compared with normal values. Normal values have been described for children of all ages in earlier studies. However, normative data for premature infants are not yet available. Therefore, the aim of this study was to develop normative data in a cohort of premature infants, which could be used in the diagnosis of aortic arch abnormalities. METHODS: A single-center study was conducted in a large population of premature infants with gestational ages of ≤32 weeks without hemodynamically important congenital heart disease, chromosomal abnormalities, and/or major cerebral congenital malformations. Two-dimensional echocardiographic measurements of four aortic arch structures were made on the second, fourth, and sixth days after birth. RESULTS: Three hundred eighty-five preterm patients were included. No differences in dimensions were found among days 2, 4, and 6. The dimension of the isthmus showed no significant relation to the existence of a patent ductus arteriosus. Reference intervals with mean and SD were calculated across the range of birth weight. Regression analysis was performed with multiple determinants in different models. The best predictive value was found for birth weight in a cubic model. CONCLUSIONS: This work provides regression equations for the calculation of Z scores and reference intervals for aortic arch dimensions in a cohort of preterm infants born at gestational ages of ≤32 weeks. The normative data can be used in diagnosis and decision making involving aortic arch pathology in premature infants.

Cerebral oxygenation and echocardiographic parameters in preterm neonates with a patent ductus arteriosus: an observational study.

BACKGROUND: A haemodynamically significant patent ductus arteriosus (hsPDA) is clinically suspected and confirmed by echocardiographic examination. A hsPDA decreases cerebral blood flow and oxygen saturation by the ductal steal phenomenon. AIM: To determine the relationship between echocardiographic parameters, cerebral oxygenation and a hsPDA in preterm infants. METHODS: 380 preterm infants (<32 weeks gestational age) born between 2008 and 2010 were included. Blinded echocardiographic examination was performed on the second, fourth and sixth day after birth. Examinations were deblinded when hsPDA was clinically suspected. Regional cerebral oxygen saturation (rScO2) was continuously monitored by near-infrared spectroscopy during 72 h after birth, and afterwards for at least 1 h before echocardiography. Echocardiographic parameters included ductal diameter, end-diastolic flow in the left pulmonary artery, left atrium/aorta ratio and ductal flow pattern. RESULTS: rScO2 was significantly related only to ductal diameter over time. Mixed modelling analysed the course of rScO2 over time, where infants were divided into four groups: a closed duct, an open haemodynamically insignificant duct (non-sPDA), a hsPDA, which was successfully closed during study period (SC hsPDA) or a hsPDA, which was unsuccessfully closed during study period (UC hsPDA). SC hsPDA infants showed the highest rScO2 on day 6, while UC hsPDA infants had the lowest rScO2 values. CONCLUSIONS: Ductal diameter is the only echocardiographic parameter significantly related to cerebral oxygenation over time. Cerebral oxygenation takes a different course over time depending on the status of the duct. Low cerebral oxygenation may be suggestive of a hsPDA.

Effective radiation dosage of three-dimensional rotational angiography in children.

AIMS: Three-dimensional rotational angiography (3DRA) is a relatively new but promising imaging technique in the paediatric catheterization laboratory. However, data on effective dose (ED) of this technique in children are lacking. The purpose of this study is to provide ED of 3DRA and to correlate this with parameters readily available in daily practice. Furthermore, the effect of dose-reducing techniques is evaluated. METHODS AND RESULTS: Effective doses were calculated with Monte Carlo PCXMC 2.0 in 14 patients who underwent a total of 17 3DRAs at our paediatric catheterization laboratory. Median age was 5.7 years (range 1 day-16.6 years). Median ED was 1.6 milliSievert (mSv) (range 0.7-4.9). Effective dose did not correlate with age and body surface area but did correlate with dose area product (DAP) and milliGray (mGy) with r(2) of 0.75 and 0.83, respectively. Reduction of the total amount of frames from 248 to 133 per rotation resulted in further dose reduction of over 50% with preserved image quality. CONCLUSION: The median ED of 3DRA in children is 1.6 mSv and correlates with DAP and mGy. This dose can be halved by applying frame reduction. A significant further dose reduction can be achieved by obtaining additional knowledge of the equipment used.

Early detection of prenatal cardiocirculatory compromise in small for gestational age infants.

BACKGROUND: Impairment of gas and substrate exchange through the placenta leads to fetal hypoxia and growth restriction. Oxygenation of vital organs is maintained with preferential perfusion at the expense of less vital organs, challenging the fetal cardiovascular system. OBJECTIVES: To identify cardiovascular compromise in preterm small for gestational age (SGA) infants using the cardiac biomarker B-type natriuretic peptide (BNP), which indicates the workload of the myocardium. METHODS: In this retrospective case-control study, 26 SGA infants born at less than 32 weeks of gestation from October 2009 to October 2010 were matched for gestational age and month of birth with 26 appropriate for gestational age (AGA) infants. Antenatal Doppler ultrasound was used to identify fetal hemodynamic changes by determination of the pulsatility index (PI) of the middle cerebral artery (MCA-PI), umbilical artery (UA-PI) and veins of the ductus venosus (DV-PIV). These indices were compared with BNP levels obtained within 6 h after birth. RESULTS: Antenatal PIs of MCA, UA and DV were significantly related to elevated BNP levels after birth in SGA infants, but not in AGA infants (SGA: MCA-PI = r(2) 0.23, p < 0.05; UA-PI = r(2) 0.46, p < 0.01; DV-PIV = r(2) 0.31, p < 0.05). Furthermore, signs of perinatal (chronic) asphyxia coincided with elevated levels of BNP. SGA was related to more postnatal cardiocirculatory complications. No significant relations between postnatal cardiac ultrasound measurements, placenta size and BNP were found. CONCLUSION: BNP levels were elevated early after birth in SGA infants and corresponded positively with Doppler indices of circulatory compromise. This suggests an increased workload of the myocardium.

Early end-tidal carbon monoxide levels, patency of the ductus arteriosus and regional cerebral oxygenation in preterm infants.

BACKGROUND: Carbon monoxide (CO), a relaxant regulator of muscle tone and marker of oxidative stress and inflammation, can be measured in exhaled air by determination of end-tidal CO corrected for CO in ambient air (ETCOc). OBJECTIVE: Increased endogenous production of CO may influence patency of the ductus arteriosus, cerebral perfusion and, subsequently, cerebral oxygenation. The aim was to study the relation between early ETCOc levels, hemodynamically significant patent ductus arteriosus (hsPDA) and cerebral oxygenation (rScO2) in preterm infants <32 weeks' gestational age and determine predictive values of ETCOc for hsPDA. METHODS: ETCOc was measured in 91 infants within the first 24 h after birth. A hsPDA was diagnosed according to echocardiographic indices. In 78/91 infants, rScO2 was monitored with near-infrared spectroscopy to assess cerebral oxygenation. RESULTS: ETCOc values were significantly higher in infants who subsequently developed hsPDA (2.3 ± 0.7 ppm) vs. no-hsPDA (1.7 ± 0.6 ppm), p < 0.001. With a cut-off value of 2.5 ppm, positive and negative predictive values of ETCOc for hsPDA were 55 and 88%, respectively. rScO2 values were not different between the two groups (64 ± 1 vs. 65 ± 3%, NS). CONCLUSIONS: The higher ETCOc values in hsPDA infants early after birth reflect the early relaxant state of ductal muscular tone. ETCOc <2.5 ppm within 24 h after birth may predict the subsequent absence of hsPDA. ETCOc showed no correlation with cerebral oxygenation in both groups.

Is cerebral oxygen supply compromised in preterm infants undergoing surgical closure for patent ductus arteriosus?

BACKGROUND: A haemodynamically important patent ductus arteriosus (PDA) is a risk factor for brain damage in preterm infants. The authors previously reported lower regional cerebral oxygen saturation (rScO(2)) in infants with PDA, which recovered after administration of indomethacin. However, PDA ligation has been reported to pose an even higher risk of neurodevelopmental impairment. OBJECTIVE: To investigate the impact of surgical closure of PDA on rScO(2) and cerebral fractional tissue oxygen extraction (cFTOE), measured by near-infrared spectroscopy, and on amplitude-integrated electro-encephalography (aEEG) measured brain activity. DESIGN/METHODS: In 20 preterm infants (gestational age 24.7-30.4 weeks; birth weight 630-1540 g), blood pressure, arterial saturation, rScO(2), cFTOE and aEEG were monitored before, during and up to 24 h after surgery. RESULTS: Before surgery, median (range) rScO(2) was 53% (41-68%), and during surgery, but before ductal clipping, it was 46% (31-89%). Eleven infants showed a drop in blood pressure and 13 infants a drop in rScO(2) during surgery (range 2-21%), accompanied by a decrease in aEEG amplitude. Twelve infants had rScO(2) values below 50% during surgery, with five being below 40%. Only at 24 h after surgery was rScO(2) higher (61% (36-85%), p<0.05) and cFTOE values lower (0.38 (0.09-0.61); p<0.05) compared with preclipping values. CONCLUSION: Ductal ligation poses a risk for a further decrease in already compromised cerebral oxygenation in preterm infants.