Omphalocele and alveolar capillary dysplasia: a new association.

OBJECTIVE: First report of an infant with coexistent omphalocele and alveolar capillary dysplasia. DESIGN: Descriptive case report. SETTING: Neonatal intensive care unit of a tertiary care children's hospital. PATIENT: We describe a term infant with omphalocele and respiratory insufficiency attributable to pulmonary hypertension. The patient was placed on extracorporeal membrane oxygenation, but the pulmonary hypertension persisted. After 10 days on extracorporeal membrane oxygenation, a lung biopsy was performed. It showed alveolar capillary dysplasia. Because of the lethal prognosis, extracorporeal membrane oxygenation was withdrawn and the patient expired. CONCLUSIONS: This is the first description of an association between omphalocele and alveolar capillary dysplasia. In newborns with omphalocele who have severe respiratory insufficiency and pulmonary hypertension, alveolar capillary dysplasia should be considered.

Effect of bladderbox alarms during venoarterial extracorporeal membrane oxygenation on cerebral oxygenation and hemodynamics in lambs.

To determine the effects of bladderbox alarms during venoarterial extracorporeal membrane oxygenation (va-ECMO) on cerebral oxygenation and hemodynamics, six lambs were prospectively treated with va-ECMO and bladderbox alarms were simulated. Changes in concentrations of oxyhemoglobin (deltacO2Hb), deoxyhemoglobin (deltacHHb), and total Hb (deltactHb) were measured using near infrared spectrophotometry. Fluctuations in Hb oxygenation index (deltaHbD) and cerebral blood volume (deltaCBV) were calculated. Heart rate (HR), mean arterial pressure (MAP), blood flow in the left carotid artery (Qcar), and central venous pressure (CVP) were registered. Bladderbox alarms were simulated by increasing the ECMO flow or partially clamping the venous cannula and resolved by decreasing the ECMO flow, unclamping the cannula, or intravascular volume administration. CBV, HbD, MAP, and Qcar decreased significantly during bladderbox alarms, whereas HR and CVP increased. After the bladderbox alarms, CBV and HbD increased significantly to values above baseline. For HbD, this increase was higher during intravascular volume administration.MAP, Qcar, and CVP recovered to preexperiment values but increased further with volume administration. HR was increased at the end of our measurements. We conclude that Bladderbox alarms during va-ECMO treatment result in significant fluctuations in cerebral oxygenation and hemodynamics, a possible risk factor for intracranial lesions.

The effect of inhaled nitric oxide on the course of extracorporeal membrane oxygenation and the occurrence of hemorrhagic complications.

This study evaluated the relation between prior inhaled nitric oxide (iNO) and the time to initiation and duration of treatment with veno-arterial extracorporeal membrane oxygenation (ECMO) and the occurrence of hemorrhagic complications. A retrospective study was conducted in 59 human newborns treated for respiratory insufficiency with ECMO over a 5-year period. Patients received iNO before ECMO (iNO group) or not (control group). Both groups were compared for patient characteristics, postnatal age at the initiation of ECMO, duration of ECMO treatment, and hemorrhagic complications. There were no significant differences between the iNO group and the control group for patient characteristics and medication use before the ECMO treatment, except for norepinephrine. There was no significant difference for postnatal age at the initiation of ECMO and mean duration of ECMO treatment. We found no statistically significant difference in hemorrhagic complications between both groups. This persisted after correction for diagnosis and ECMO run-time in linear logistic regression analysis. Inhaled nitric oxide before ECMO did not result in a significant delay in the initiation of ECMO or longer duration of the ECMO. There was no significant relationship between the use of prior iNO and the occurrence of hemorrhagic complications during the ECMO treatment.

Decreased mortality but increased morbidity in neonates with jejunoileal atresia; a study of 114 cases over a 34-year period.

PURPOSE: The aim of the study was to evaluate patient demographics, classification and location of the atresia, operative management, postoperative care, and outcome in 114 infants with jejunoileal atresia (JIA) over a period of more than 3 decades. METHODS: This was a retrospective case series in a tertiary care teaching hospital. Records of all patients with JIA treated at the authors' institution between 1971 and 2004 were examined. RESULTS: Sixty-two percent of atresia and stenosis was noted in the jejunum, 30% in the ileum, and 8% in both the jejunum and the ileum. Atresias and stenosis were classified as follows: 7% type 0, 16% type I, 21% type II, 24% type IIIa, 10% type IIIb, 22% type IV. Gastrointestinal anomalies were encountered in 24% of patients, genitourinary malformations in 9%, cystic fibrosis in 9%, neurologic anomalies in 6%, and congenital heart disease in 4%. Operative management included resection with primary anastomosis in 69% of all patients and temporary enterostomies in 26%. After operative management, 15% of children had resultant short bowel syndrome. Oral feeding was allowed on median day 7, and full energy expenditure via the enteric route was reached on median day 20. Forty-seven percent of infants required central venous line placement for total parenteral nutrition. Early postoperative complications occurred in 28% of patients with JIA and late postoperative complications in 17%. We observed a mortality rate of 11%. CONCLUSIONS: This is one of the largest series of neonates with JIA described. Short bowel syndrome seems to be the biggest problem resulting in longer hospital stay, more feeding problems, and higher morbidity and mortality rates. Management of children with short bowel syndrome has improved because of the use of total parenteral nutrition, new operative techniques, and better intensive care. In the last 15 years, survival has increased at the cost of the surviving children as we noted a higher percentage of late complications.

Pancreatic injury in children: good outcome of nonoperative treatment.

PURPOSE: Treatment of blunt injury of the pancreas in children remains controversial. Some prefer nonoperative treatment, whereas others prefer operative management in selected cases. This report reviews the treatment of patients with blunt pancreatic trauma admitted to a level I pediatric trauma center in The Netherlands. METHODS: Medical records of all children less than 15 years with blunt pancreatic trauma admitted to the University Medical Center St Radboud in the period 1975 to 2003 were retrospectively analyzed. RESULTS: Thirty-four children were included, age 3 to 14 years. Most injuries were because of bicycle accidents (58%). On admission, amylase was raised in 90% of the patients. Five patients had pancreatic duct injuries identified by imaging (endoscopic retrograde cholangiopancreaticography was used once, magnetic resonance cholangiopancreaticography twice) or at surgery. Thirty-one children were initially managed nonoperatively. Pancreatic surgery was performed in 3 children (1 Roux-Y, 2 drainage only). Mean hospital stay was 29 days in the operative group and 24 days in the nonoperative group. Fluid collections developed in 2 operated patients. Both resolved spontaneously. In 14 of the 31 nonoperated patients, a pseudocyst developed. Only 6 of these needed secondary intervention. Of these, 3 were drained percutaneously. There was no mortality and no long-term morbidity in both groups. CONCLUSIONS: Nonoperative management of pancreatic injury in children has good clinical outcome. Only 10% need secondary surgery. In 50%, pseudocysts develop of which half can be managed nonoperatively. The reliability of computed tomographic scan grading is of limited value to decide whether to operate primarily. There is little to gain with ERCP and stenting. The place of MRCP as a noninvasive diagnostic tool remains to be determined.

Intravascular volume administration: a contributing risk factor for intracranial hemorrhage during extracorporeal membrane oxygenation?

OBJECTIVE: The objective of this study was to determine the relationship between the frequency and total volume of intravascular volume administration and the development of intracranial hemorrhage during venoarterial extracorporeal membrane oxygenation. METHODS: In a retrospective, matched, case-control study, 24 newborns who developed an intracranial hemorrhage during venoarterial extracorporeal membrane oxygenation treatment were compared with 40 control subjects. Both groups were analyzed for gestational age, gender, race, Apgar scores at 1 and 5 minutes, birth weight, cardiopulmonary resuscitation before venoarterial extracorporeal membrane oxygenation, age at the start of treatment, duration of treatment, worst arterial blood gas sample preceding treatment, activated clotting time values, need for platelet transfusions, mean blood pressure, and the use of inotropics and steroids before the treatment. For both groups, total number and volume of intravascular infusions of normal saline, pasteurized plasma protein solution, erythrocytes, and platelets during the first 24 hours of treatment were determined. Variables were analyzed in their relationship to intracranial hemorrhage by using univariate and multivariate conditional logistic regression. RESULTS: The only statistically significant difference in patient characteristics between the case patients and control subjects was arterial blood gas values. Newborns who developed intracranial hemorrhage during the treatment received both a statistically significantly higher number and a statistically significantly higher total volume of intravascular volume administrations compared with control patients. After adjustment for pH, Paco(2), and Pao(2) in the multivariate analysis, we found a significant relation between the development of intracranial hemorrhage and >8 infusions or >300 mL of volume infusion in the first 8 hours and >10 infusions in the first 24 hours of treatment. CONCLUSIONS: The number and total volume of intravascular volume administration in the first 8 and 24 hours of venoarterial extracorporeal membrane oxygenation treatment are statistically significantly related to the development of intracranial hemorrhage.

Closure of giant omphaloceles by the abdominal wall component separation technique in infants.

BACKGROUND/PURPOSE: Several techniques have been described to repair giant omphaloceles. There is no procedure considered to be the criterion standard worldwide. The aim of the present prospective study was to analyze the early and late results of secondary closure of giant omphaloceles using the component separation technique (CST) in infants. METHODS: From January 2004 to January 2007, 10 consecutive pediatric patients with a giant omphalocele were treated at our department. Initially, patients were treated conservatively. After epithelialization of the omphalocele, the abdominal wall was reconstructed using CST. Patients were monitored for complications during admission, and all patients were seen for follow-up. RESULTS: Component separation technique was performed at median age of 6.5 months (range, 5-69 months). The median diameter of the hernia was 8 cm (range, 6-9 cm). There was no mortality. The postoperative course was uneventful in 7 patients. Complications were seen in 3 patients (infection, skin necrosis, and hematoma). Median hospital stay was 7 days. After median follow-up of 23.5 months (range, 3-39 month), no reherniations were found. CONCLUSIONS: The CST is a safe 1-stage procedure for secondary closure in children with a giant omphalocele without the need for prosthetic material and with good clinical outcome.

Long-term functional sequelae of sacrococcygeal teratoma: a national study in The Netherlands.

BACKGROUND: Long-term functional sequelae after resection of sacrococcygeal teratoma (SCT) are relatively common. This study determines the incidence of these sequelae associated clinical variables and its impact on quality of life (QoL). PATIENTS AND METHODS: Patients with SCT treated from 1980 to 2003 at the pediatric surgical centers in The Netherlands aged more than 3 years received age-specific questionnaires, which assessed parameters reflecting bowel function (involuntary bowel movements, soiling, constipation), urinary incontinence, subjective aspect of the scar, and QoL. These parameters were correlated with clinical variables, which were extracted from the medical records. Risk factors were identified using univariate analysis. RESULTS: Of the 99 posted questionnaires, 79 (80%) were completed. The median age of the patients was 9.7 years (range, 3.2-22.6 years). There were 46% who reported impaired bowel function and/or urinary incontinence (9% involuntary bowel movements, 13% soiling, 17% constipation), and 31% urinary incontinence. In 40%, the scar was cosmetically unacceptable. Age at completion of the questionnaire, Altman classification, sex, and histopathology were not risk factors for any long-term sequelae. Size of the tumor (>500 cm3) was a significant risk factor for cosmetically unacceptable scar (odds ration [OR], 4.73; confidence limit [CL], 1.21-18.47; P = .026). Long-term sequelae were correlated with diminished QoL. CONCLUSION: A large proportion of the patients with SCT have problems with defecation, urinary incontinence, or a cosmetically unacceptable scar that affects QoL. Patients who are at higher risk for the development of long-term sequelae cannot be clearly assessed using clinical variables.

Abnormalities of coagulation related to the use of inhaled nitric oxide before extracorporeal membrane oxygenation.

OBJECTIVE: Evaluation of the influence of previous inhaled nitric oxide (iNO) treatment on the occurrence of clotting complications and disseminated intravascular coagulation during extracorporeal membrane oxygenation (ECMO). DESIGN: Retrospective study in newborns treated with venoarterial ECMO during a 5-yr period. SETTING: Neonatal intensive care unit of a university medical center. PATIENTS: A total of 59 newborns with severe respiratory insufficiency treated with venoarterial ECMO. INTERVENTIONS: Patients received iNO before ECMO (iNO group) or not (control group). MEASUREMENTS AND MAIN RESULTS: There were no differences between the groups for patient characteristics and medication use before ECMO, except for norepinephrine. After correction for diagnosis and duration of ECMO, significantly more clotting complications and disseminated intravascular coagulation as individual variables were seen in the iNO group. For the combination of clotting complications and disseminated intravascular coagulation, there was a significantly higher prevalence in the iNO group. CONCLUSIONS: In our population, we found a remarkable relationship between clotting complications or disseminated intravascular coagulation and iNO use before ECMO treatment, which needs further prospective research before conclusions can be drawn.

Anesthesia-related morbidity and mortality after surgery for muscle biopsy in children with mitochondrial defects.

BACKGROUND: Children with mitochondrial defects (MD) may have an increased risk for cardiorespiratory and neurological complications from anesthesia. The aim of this study was to determine the incidence of perioperative complications and adverse events in children with MD. METHODS: We performed a retrospective review of the anesthesia, surgical and medical records of 155 children up to 10 years who underwent a diagnostic surgical muscle biopsy for suspected mitochondrial and muscle disorders between 1999 and 2003. The data of the 122 patients where a definite MD diagnosis was found were analyzed. Anesthesia was conducted according to the discretion of the attending staff. In children with MD the activity of the different complexes of the oxidative phosphorylation system was measured. RESULTS: From the preoperative assessment, signs of encephalopathy were most frequent (n = 93), followed by muscle weakness (n = 32), lactic acidosis (n = 15), cardiomyopathy and/or conduction defects (n = 10) and chronic respiratory problems (n = 7). The mean age of the children with MD was 32.4 months (SD = 26.9). The mean duration of anesthesia was 36.0 min (SD = 12.6) and the mean length of stay in the recovery room was 33.0 min (SD = 24.0). There were no major changes in heart rate or blood pressure which required pharmacological intervention during anesthesia or postanesthesia care unit (PACU) stay. A short episode of SpO2 <80% with airway obstruction occurred once in the PACU. Biochemical analysis in the children with a MD showed an isolated deficiency of one of the five protein complexes of oxidative phosphorylation in 42 children, a combination of complex deficiencies in 41 and no definite localization in 39 children. CONCLUSION: With standard preoperative assessment, monitoring and anesthesia management, there were no major peroperative and postoperative anesthesia-related complications in children undergoing surgical muscle biopsy with a MD diagnosis.

Influence of volume replacement with colloids versus crystalloids in neonates on venoarterial extracorporeal membrane oxygenation on fluid retention, fluid balance, and ECMO runtime.

In this retrospective study, we compared the effects of colloid versus crystalloid fluid replacement on the clinical signs of capillary leakage syndrome in 30 neonates with pulmonary hypertension due to meconium aspiration syndrome on venoarterial membrane oxygenation (VA-ECMO). Before 2000, 15 neonates received volume replacement with a pasteurized plasma protein solution (3.8% albumin); after 2000, 15 neonates received normal saline. Patient characteristics and pre-ECMO values did not differ between the two groups. Total fluid balance was also equal. Diuretic use was significantly higher in the colloid group (p < 0.001). The chest wall soft-tissue index was significantly higher in the crystalloid group (p < 0.005), as were the ventilator settings at the end of the ECMO runtime (p < 0.05). Serum colloid osmotic pressure, albumin, urea nitrogen, and creatinine were significantly higher in the colloid group (p < 0.0001, < 0.0001, < 0.001, and < 0.05, respectively). Duration of VA-ECMO, of artificial ventilation after ECMO treatment, and the mortality rate did not differ between the two groups. We conclude that volume replacement with crystalloids in neonates on VA-ECMO aggravated the edema in a preexisting situation of capillary leakage syndrome, whereas volume replacement with colloids could impair the kidney function.

Secondary closure of a giant omphalocele by translation of the muscular layers: a new method.

The current report describes a case of an infant girl with a giant omphalocele in whom a new surgical technique was used for closing the abdominal wall after epithelialization of the omphalocele for 16 months. The technique used was translation of the muscular layers of the abdominal wall. The functional and cosmetic results appear superior compared with other suggested treatments used for this abdominal wall defect.

Morphometric analysis of the lung vasculature after extracorporeal membrane oxygenation treatment for pulmonary hypertension in newborns.

Persistent pulmonary hypertension in the newborn (PPHN) is characterised by increased medial and adventitial thickness in the lung vasculature. This study describes morphometry of lung vasculature after extracorporeal membrane oxygenation (ECMO) in newborns with PPHN, due to meconium aspiration syndrome, sepsis or idiopathic persistent pulmonary hypertension of the newborn (i-PPHN). Three groups were studied: newborns with PPHN treated with ECMO (n=9), newborns with PPHN not treated with ECMO (n=12) and age-matched controls without PPHN (n=11). In pulmonary arteries with an external diameter of less than 150 microm, arterial media, adventitia and total wall thickness, expressed as a percentage of the external diameter, and their cross-sectional areas were calculated. Newborns with PPHN, compared with controls, demonstrated increased percentage of media thickness, adventitia thickness and total wall thickness, and increased medial, adventitial and total wall cross-sectional area. Newborns treated with ECMO, compared with those not treated so, showed a decreased percentage of media thickness and medial cross-sectional area in arteries with an external diameter less than 75 microm, and decreased percentage of media thickness and decreased medial, adventitial and total wall cross-sectional area in arteries with an external diameter of 75-150 microm. ECMO for persistent PPHN, due to meconium aspiration syndrome, sepsis or i-PPHN, reduces the abnormal morphometry of small pulmonary arteries. The underlying mechanisms contributing to this improved morphometry are yet unknown.

Oxygenation and hemodynamics in left and right cerebral hemispheres during induction of veno-arterial extracorporeal membrane oxygenation.

OBJECTIVE: Oxygenation and hemodynamics in the left and right cerebral hemispheres were measured during induction of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). STUDY DESIGN: Using near infrared spectrophotometry, effects of right common carotid artery (RCCA) and right internal jugular vein (RIJV) ligation and start of VA-ECMO on concentrations of oxyhemoglobin, deoxyhemoglobin, and cerebral blood volume (CBV) were evaluated in 10 newborn infants. Mean cerebral blood flow velocity (CBFV) in the major cerebral arteries was compared before and after the start of VA-ECMO (pulsed Doppler ultrasonography). RESULTS: RCCA ligation caused a decrease in oxyhemoglobin concentration and an increase in deoxyhemoglobin concentration. RIJV ligation caused no changes. Sixty minutes after the start of VA-ECMO, oxyhemoglobin concentration and CBV had increased, and deoxyhemoglobin concentration had decreased. There were no differences between the hemispheres. Mean CBFV had increased in the left internal carotid artery, and it increased equally in both middle cerebral arteries. Flow direction was reversed in the right internal carotid artery. Three patients had asymmetric cerebral lesions, not related to differences in the measurements between the cerebral hemispheres. CONCLUSION: The initiation of VA-ECMO causes changes in cerebral oxygenation and hemodynamics but without a difference in effect on left and right cerebral hemispheres.

Ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation: effects on cerebral oxygenation and hemodynamics.

OBJECTIVE: To investigate the effect on cerebral oxygenation and hemodynamics of a patent ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation in a lamb model. DESIGN: Prospective intervention study in animals. SETTING: Animal research laboratory of a university medical center. SUBJECTS: Six anesthetized newborn lambs with patent ductus arteriosus and left-to-right shunt, installed on venoarterial extracorporeal membrane oxygenation. INTERVENTIONS: Six lambs of 140 days gestational age were prepared to keep the ductus arteriosus open by infiltration of the vessel wall with formaline 10%. The animals were installed on standard venoarterial extracorporeal membrane oxygenation. With a mechanical occluder, the ductus was closed. MEASUREMENTS AND MAIN RESULTS: Changes of mean arterial blood pressure and carotid artery blood flow were measured simultaneously. Using near infrared spectrophotometry, we calculated changes in cerebral concentration of oxyhemoglobin and deoxyhemoglobin (reflecting changes in cerebral oxygen supply) and total hemoglobin (reflecting changes in cerebral blood volume). Also, cerebral oxygen delivery before and after ductus closure was calculated. Before ductus closure there was a left-to-right shunt with a mean +/- SEM of 41 +/- 20% of total body blood flow. Closure of the ductus resulted in an immediate increase in mean arterial blood pressure and carotid artery blood flow. The concentration of oxyhemoglobin increased and the concentration of deoxyhemoglobin decreased, representing increased cerebral oxygen supply. The concentration of total hemoglobin was unchanged, representing unchanged cerebral blood volume. There was an increase in cerebral oxygen delivery. CONCLUSIONS: In this lamb model, a considerable left-to-right shunt over the ductus during venoarterial extracorporeal membrane oxygenation reduced cerebral circulation and oxygenation.

Compartment syndrome, rhabdomyolysis and risk of acute renal failure as complications of the lithotomy position.

Compartment syndrome, rhabdomyolysis and the risk of acute renal failure are potential complications of the lithotomy position. A six-year-old girl is described who developed a compartment syndrome with rhabdomyolysis after prolonged surgery in the lithotomy position. This complication occurred three times over ten years in our hospital. Rhabdomyolysis may induce acute renal failure. The pathogenesis of rhabdomyolysis--induced renal failure has not yet been elucidated. However, forced diuresis by intravenous administration of mannitol and furosemide can prevent acute renal failure.

Cardiac diverticulum and omphalocele: Cantrell's pentalogy or syndrome.

Omphaloceles and left ventricular diverticulums are rare disorders. Although either is known to occur on its own, the combination is highly suggestive of the so-called pentalogy of Cantrell. This syndrome is a combination of deformities involving midline structures, with exteriorisation of the heart, or 'ectopia cordis', as the most severe malformation. A cause has yet to be identified, though genes located on the X-chromosome may be involved. We discuss a neonate who presented with an omphalocele and a palpable diverticulum of the left ventricle. An omphalocele, especially when above the umbilicus, is an indication for further investigation for deformities as seen in the spectrum of Cantrell's pentalogy, especially cardiac malformations and anterior diaphragmatic herniation. A left ventricular diverticulum is usually associated with Cantrell's syndrome. When found, it is usually accompanied by other intracardiac malformations, so that again further examination is indicated. In our patient, there was an atrial septal defect within the oval fossa, along with a ventricular septal defect and unobstructed albeit anomalous venous pulmonary return to the left atrium. Early surgical intervention seems to be indicated, as spontaneous rupture, arrhythmias, and thromobogenicity of the ventricular diverticulum have all been reported.

Serial plasma concentrations of atrial natriuretic peptide, plasma renin activity, aldosterone, and antidiuretic hormone in neonates on extracorporeal membrane oxygenation.

To obtain information on water and salt regulating hormones and volume homeostasis during neonatal extracorporeal membrane oxygenation (ECMO), serial determinations of atrial natriuretic peptide (ANP), plasma renin activity (PRA), aldosterone (Aldo), antidiuretic hormone (ADH), colloid-osmotic pressure (COP), osmolality (Osmol), and central venous pressure (CVP) before, during, and after neonatal ECMO in 10 neonates with meconium aspiration syndrome (MAS) were carried out. Mean gestational ages and birth weights were 41(+3) weeks (39(+6) - 42(+4)) and 4,063 gm (3,500-4700), respectively; mean age at start and duration of ECMO 29.3 (14-69) and 152.6 hr (92-267), respectively. Plasma ANP (mean +/- SD) was 67.8+/-69.1 pmol/L before, decreased to 33.3+/-22.1 (not significant) pmol/L during, and significantly increased to 274.6+/-131.8 pmol/L after ECMO (p < 0.05). ANP correlated positively with CVP (r = 0.63; p < 0.001). Pre-ECMO PRA, Aldo, and ADH were comparable to those described earlier in normal neonates, decreased during (p < 0.001 for Aldo; p < 0.05 for PRA and ADH) and either remained elevated (PRA, p < 0.001; Aldo, p < 0.05) or decreased (ADH) after ECMO. COP and Osmol remained unchanged. Neonatal ECMO for MAS is characterized by circulatory and osmotic equilibrium. It is suggested that circulating volume contracts during and expands after neonatal ECMO for MAS.

Hemodynamic changes during opening of the bridge in venoarterial extracorporeal membrane oxygenation.

OBJECTIVE: To investigate the cause of the hemodynamic changes occurring during opening of the bridge in venoarterial (VA) extracorporeal membrane oxygenation (ECMO). DESIGN: Prospective intervention study in animals. SETTING: Animal research laboratory of a university medical center. SUBJECTS: Eight anesthetized lambs installed on VA-ECMO. INTERVENTIONS: During VA-ECMO the bridge was randomly opened during 1, 2.5, 5, 7.5, 10, and 15 secs at ECMO flow rates of 500, 400, 300, 200, 100, and 50 mL/min. Flows in the ECMO circuit between venous cannula and bridge and bridge and arterial cannula, mean arterial blood pressure, mean left carotid artery blood flow, central venous pressure, superior sagittal sinus pressure, inline mixed venous oxygen saturation, heart rate, and arterial oxygen saturation were measured continuously. Using near infrared spectrophotometry, changes in concentrations of cerebral oxygenated and deoxygenated hemoglobin and cerebral blood volume were also measured. Values during bridge opening were compared with values before opening. The same variables were determined with a roller pump on the bridge with a flow over the bridge at various flow rates. MEASUREMENTS AND MAIN RESULTS: Bridge opening resulted in a change of flow direction between venous cannula and bridge and bridge and arterial cannula. A biphasic response with initial decrease and secondary increase occurred in mean arterial blood pressure and mean left carotid artery blood flow. Central venous pressure, superior sagittal sinus pressure, deoxygenated hemoglobin, and cerebral blood volume increased, whereas cerebral oxygenated hemoglobin decreased. These effects occurred in each combination of ECMO flow rate and opening time. These effects could be abolished by installing a roller pump on the bridge. CONCLUSIONS: Bridge opening in VA-ECMO resulted in significant cerebral hemodynamic changes caused by an arteriovenous shunt over the bridge. The decreased cerebral perfusion pressure may contribute to the occurrence of cerebral ischemia, and the venous congestion may result in intracranial hemorrhages. These could be prevented by installing a roller pump on the bridge.