Cranial ultrasound findings in preterm germinal matrix haemorrhage, sequelae and outcome

Germinal matrix-intraventricular haemorrhage (GMH-IVH), periventricular haemorrhagic infarction (PHI) and its complication, post-haemorrhagic ventricular dilatation (PHVD), are still common neonatal morbidities in preterm infants that are highly associated with adverse neurodevelopmental outcome. Typical cranial ultrasound (CUS) findings of GMH-IVH, PHI and PHVD, their anatomical substrates and underlying mechanisms are discussed in this paper. Furthermore, we propose a detailed descriptive classification of GMH-IVH and PHI that may improve quality of CUS reporting and prediction of outcome in infants suffering from GMH-IVH/PHI.

State-of-the-art neonatal cerebral ultrasound: technique and reporting

In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5-18 MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment.

Randomized Control Trial of Postnatal rhIGF-1/rhIGFBP-3 Replacement in Preterm Infants: Post-hoc Analysis of Its Effect on Brain Injury

Background: Postnatal insulin-like growth factor-1 (IGF-1) replacement with recombinant human (rh)IGF-1 and IGF binding protein-3 (rhIGF-1/rhIGFBP-3) is being studied as a potential treatment to reduce comorbidities of prematurity. We have recently reported on a phase II, multicenter, randomized, controlled trial comparing postnatal rhIGF-1/rhIGFBP-3 replacement with standard of care (SOC) in extremely preterm infants (NCT01096784). Maximum severity of retinopathy of prematurity was the primary endpoint of the trial and presence of GMH-IVH/PHI one of the pre-specified secondary endpoints. Infants therefore received serial cranial ultrasound scans (CUS) between birth and term age. In this post-hoc analysis we present a detailed analysis of the CUS data of this trial and evaluate the effect of postnatal rhIGF-1/rhIGFBP-3 replacement on the incidence of different kinds of brain injury in extremely preterm infants. Methods: This report is an exploratory post-hoc analysis of a phase II trial in which infants <28 weeks gestational age were randomly allocated to rhIGF-1/rhIGFBP-3 or SOC. Serial cranial ultrasounds were performed between birth and term-equivalent age. Presence of germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH), periventricular hemorrhagic infarction (PHI), post-hemorrhagic ventricular dilatation, and white matter injury (WMI) were scored by two independent masked readers. Results: The analysis included 117 infants; 58 received rhIGF-1/rhIGFBP-3 and 59 received SOC. A trend toward less grade II-III GMH-IVH and PHI was observed in treated infants vs. SOC. A subanalysis of infants without evidence of GMH-IVH at study entry (n = 104) showed reduced progression to GMH-IVH in treated infants (25.0% [13/52] vs. 40.4% [21/52]; not significant). No effects of rhIGF-1/rhIGFBP-3 on WMI were observed. Conclusion: The potential protective effect of rhIGF-1/rhIGFBP-3 on the occurrence of GMH-IVH/PHI appeared most pronounced in infants with no evidence of GMH-IVH at treatment start.

Preterm white matter injury: ultrasound diagnosis and classification

White matter injury (WMI) is the most frequent form of preterm brain injury. Cranial ultrasound (CUS) remains the preferred modality for initial and sequential neuroimaging in preterm infants, and is reliable for the diagnosis of cystic periventricular leukomalacia. Although magnetic resonance imaging is superior to CUS in detecting the diffuse and more subtle forms of WMI that prevail in very premature infants surviving nowadays, recent improvement in the quality of neonatal CUS imaging has broadened the spectrum of preterm white matter abnormalities that can be detected with this technique. We propose a structured CUS assessment of WMI of prematurity that seeks to account for both cystic and non-cystic changes, as well as signs of white matter loss and impaired brain growth and maturation, at or near term equivalent age. This novel assessment system aims to improve disease description in both routine clinical practice and clinical research. Whether this systematic assessment will improve prediction of outcome in preterm infants with WMI still needs to be evaluated in prospective studies.

Statistical analysis of MCC-IMS data for two group comparisons-an exemplary study on two devices

The Multi-capillary-column-Ion-mobility-spectrometry (MCC-IMS) technology for measuring breath gas can be used for distinguishing between healthy and diseased subjects or between different types of diseases. The statistical methods for classifying the corresponding breath samples typically neglects potential confounding clinical and technical variables, reducing both accuracy and generalizability of the results. Especially measuring samples on different technical devices can heavily influence the results. We conducted a controlled breath gas study including 49 healthy volunteers to evaluate the effect of the variables sex, smoking habits and technical device. Every person was measured twice, once before and once after consuming a glass of orange juice. The two measurements were obtained on two different devices. The evaluation of the MCC-IMS data regarding metabolite detection was performed once using the software VisualNow, which requires manual interaction, and once using the fully automated algorithm SGLTR-DBSCAN. We present statistical solutions, peak alignment and scaling, to adjust for the different devices. For the other potential confounders sex and smoking, in our study no significant influence was identified.

A Novel Scoring System for Term-Equivalent-Age Cranial Ultrasound in Extremely Preterm Infants

The role of term-equivalent-age (TEA) cranial ultrasound (cUS) in predicting outcome in preterm infants is increasingly being recognized. However, a detailed quantitative scoring system that allows comparison of groups and comparison with TEA magnetic resonance imaging (MRI) scoring systems is lacking. Eighty-four extremely preterm infants underwent cUS and MRI at TEA. Cranial US was evaluated using a novel detailed scoring system. Agreement between cUS and MRI scores was good (Spearman's ρ = 0.51, p < 0.001). Outcome at 30 mo corrected was assessed in 66 of 84 preterm and 85 term-born infants. Sensitivity was the same for cUS and MRI in prediction of cerebral palsy (75%) and severe cognitive delay (100%); the specificity was slightly higher for MRI (cerebral palsy: 97% vs. 90%, severe cognitive delay: 95% vs. 90%). The proposed novel cUS scoring system is a helpful tool in quantitative assessment of cUS at TEA and prediction of outcome at 30 mo.

A scoring system predicting the clinical course of CLPB defect based on the foetal and neonatal presentation of 31 patients

Recently, CLPB deficiency has been shown to cause a genetic syndrome with cataracts, neutropenia, and 3-methylglutaconic aciduria. Surprisingly, the neurological presentation ranges from completely unaffected to patients with virtual absence of development. Muscular hypo- and hypertonia, movement disorder and progressive brain atrophy are frequently reported. We present the foetal, peri- and neonatal features of 31 patients, of which five are previously unreported, using a newly developed clinical severity scoring system rating the clinical, metabolic, imaging and other findings weighted by the age of onset. Our data are illustrated by foetal and neonatal videos. The patients were classified as having a mild (n = 4), moderate (n = 13) or severe (n = 14) disease phenotype. The most striking feature of the severe subtype was the neonatal absence of voluntary movements in combination with ventilator dependency and hyperexcitability. The foetal and neonatal presentation mirrored the course of disease with respect to survival (current median age 17.5 years in the mild group, median age of death 35 days in the severe group), severity and age of onset of all findings evaluated. CLPB deficiency should be considered in neonates with absence of voluntary movements, respiratory insufficiency and swallowing problems, especially if associated with 3-methylglutaconic aciduria, neutropenia and cataracts. Being an important differential diagnosis of hyperekplexia (exaggerated startle responses), we advise performing urinary organic acid analysis, blood cell counts and ophthalmological examination in these patients. The neonatal presentation of CLPB deficiency predicts the course of disease in later life, which is extremely important for counselling.

Volvulus in term and preterm infants - clinical presentation and outcome

AIM

Our aim was to assess if term and preterm infants with volvulus showed different patterns with regard to pathogenesis, clinical presentation and outcome.

METHODS

We reviewed the medical records and imaging data of infants aged less than six months with volvulus treated in a single surgical referral centre from 2006-2013.

RESULTS

Volvulus was diagnosed in 19 infants, with no anatomical anomaly in three of the 12 preterm infants and one of the seven term infants. Most cases (74%) presented during the first eight days of life. Later presentations occurred exclusively in preterm infants, with only one of the five having no anatomic anomalies. Bilious vomiting was the leading symptom in six of the seven term infants, while the symptoms in preterm infants were rather nonspecific. Intestinal necrosis, with the need for bowel resection, occurred in one term (14%) infant and nine (75%) preterm infants.

CONCLUSION

The clinical presentation and outcome of volvulus differed between preterm and term infants, but the rate and distribution of underlying anomalies did not differ. Symptoms in preterm infants were often nonspecific and led to a delay in diagnosis. This might have contributed to the higher rate of intestinal necrosis in preterm infants.

Severe neonatal complication of transverse lie after preterm premature rupture of membranes

Both transverse lie and preterm premature rupture of membranes (PPROM) are associated with neonatal morbidity and mortality. We present a neonate born at 29 weeks gestation with severe birth trauma after PPROM and transverse lie. The patient had extensive swelling and areas of desquamated and necrotic skin of the right lower limb. Neonatal compartment syndrome (NCS) was suspected. Perfusion of the limb improved after decompressing subcutaneous incisions. A fetus in transverse lie may be mechanically damaged in the case of PPROM, especially at an early gestational age. Early recognition is of great interest in the management and prognosis of NCS.

Neonatal magnetic resonance imaging and outcome at age 30 months in extremely preterm infants

OBJECTIVE

To examine associations between brain white matter abnormalities, including diffuse excessive high signal intensities, detected on neonatal magnetic resonance imaging (MRI) with neurodevelopmental outcome at age 30 months.

STUDY DESIGN

This was a prospective, population-based study of infants born at <27 weeks gestation (n=117) undergoing conventional MRI at term equivalent age (n=107). At age 30 months corrected, 91 of the preterm infants (78%) and 85 term-born controls were assessed with the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III).

RESULTS

Cerebral palsy (CP) was present in 7% of the preterm group. On the BSID-III, mean composite scores were 96±9.5 for the cognitive scale, 97±14 for language scales, and 103±15 for motor scales, all within the normal range for age. Compared with the term-born controls, however, the preterm infants did not perform as well on all 3 scales, also when MRI was normal. Significant associations were seen between moderate to severe white matter abnormalities and CP (P<.001). The presence of diffuse excessive high signal intensities was not associated with performance on the BSID-III or with CP.

CONCLUSION

This 3-year cohort of extremely preterm infants had low rates of major brain injury and impaired outcome. Neonatal MRI provides useful information, but this information needs to be treated with caution when predicting outcome.

Cranial ultrasound and MRI at term age in extremely preterm infants

OBJECTIVES

Conventional MRI at term age has been reported to be superior to cranial ultrasound (cUS) in detecting white matter (WM) abnormalities and predicting outcome in preterm infants. However, in a previous study cUS was performed during the first 6 weeks only and not in parallel to MRI at term age. Therefore, the aim of the present work was to study brain injuries in preterm infants performing concomitant cUS and MRI at full-term age.

METHODS

In a population-based cohort of 72 extremely low gestational age infants paired cUS and conventional MRI were performed at term age. Abnormalities on MRI were graded according to a previously published scoring system. On cUS images the lateral ventricles, the corpus callosum, the interhemispheric fissure and the subarachnoidal spaces were measured and the presence of cysts, grey matter abnormalities and gyral folding were scored.

RESULTS

Moderate or severe WM abnormalities were detected on MRI in 17% of infants and abnormalities of the grey matter in 11% of infants. Among infants with normal ultrasound (n=28, 39%) none had moderate or severe WM abnormalities or abnormal grey matter on MRI. All infants with severe abnormalities (n=3, 4%) were identified as severe on MRI and cUS.

CONCLUSIONS

All severe WM abnormalities identified on MRI at term age were also detected by cUS at term, providing the examinations were performed on the same day. Infants with normal cUS at term age were found to have a normal MRI or only mild WM abnormalities on MRI at term age.

Late germinal matrix hemorrhage-like lesions in very preterm infants

In preterm infants, the germinal matrix is a common origin of hemorrhages during the first 7 days of life. Sonographically, germinal matrix hemorrhages present as subventricular echodensities evolving into pseudocysts. Similar lesions have been reported as incidental findings also beyond 7 days of life. They may result from vasculitis and ischemic infarction, rather than hemorrhage. To assess the occurrence, time course, and significance for neurodevelopment of such late germinal matrix hemorrhage-like lesions, we reviewed serial cerebral ultrasound examinations obtained in 86 sequentially admitted infants (gestational age <32 weeks or birth weight <1500 g). Neurodevelopment was assessed at 3 years (Bayley Scales of Infant Development). Nine infants had late isolated germinal matrix hemorrhage-like lesions. Their Psychomotor Development Index scores were significantly lower than that in infants without hemorrhage. Our results suggest that late isolated germinal matrix hemorrhage-like lesions are of clinical significance because of their notable incidence and association with neurodevelopmental outcome.

White matter changes in extremely preterm infants, a population-based diffusion tensor imaging study

AIM

To investigate cerebral white matter (WM) abnormalities (J Pediatr 2003; 143: 171) and diffuse and excessive high signal intensities (DEHSI), (J Pediatr 1999; 135: 351) in a cohort of extremely preterm infants born in Stockholm during a 3-year period, using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI).

METHODS

MRI at term-equivalent age was performed in 109 infants and DTI data were acquired in 54 infants. Survival rate in the entire cohort was 67%. Sixteen term-born healthy control infants were scanned for comparison.

RESULTS

No or mild WM abnormalities were seen in 86% of infants and 14% had moderate or severe WM abnormalities. DEHSI were seen in infants with all grades of white matter abnormalities and were present in 56% of infants. In the WM at the level of centrum semiovale, infants with any WM abnormalities or DEHSI had lower Fractional Anisotropy and higher Apparent Diffusion Coefficient compared with control infants. No significant differences in diffusion were seen in infants without DEHSI compared with the controls in this region. Compared with controls, the preterm infants had significantly altered diffusion in the corpus callosum.

CONCLUSION

Only 14% of the extremely preterm infants had moderate or severe WM abnormalities on MRI. However, the incidence of DEHSI was high. In the DEHSI regions, changes in diffusion parameters were detected, indicating altered WM organization.

The clinical presentation of preterm cerebellar haemorrhage

The objective of this study was to evaluate clinical symptoms and findings on cranial ultrasound (CUS) in preterm infants with cerebellar haemorrhage through retrospective analysis of all preterm infants with a postnatal CUS or MRI diagnosis of cerebellar haemorrhage admitted in a tertiary care centre between January 2002 and June 2009. Fifteen infants were identified; median gestational age was 25 2/7 weeks and median birth weight 730 g. We discerned six types of haemorrhage: subarachnoid (n = 3), folial (n = 1), lobar (n = 9, of which 4 bilateral), giant lobar (n = 1, including vermis) and contusional (n = 1). Especially in infants with lobar cerebellar haemorrhage, CUS showed preceding or concurrent lateral ventricle dilatation, mostly without intraventricular haemorrhage (IVH). Thirteen infants suffered from notable, otherwise unexplained motor agitation in the days preceding the diagnosis. In conclusion, motor agitation may be a presenting symptom of cerebellar haemorrhage in preterm infants. Unexplained ventriculomegaly can be a first sign of cerebellar haemorrhage and should instigate sonographic exploration of the cerebellum.

Single-centre vs. population-based outcome data of extremely preterm infants at the limits of viability

AIM

In response to the disappointing outcome data of the population-based EPICure study published in 2000, we compared the outcome of infants 22 0/7 to 25 6/7 weeks of gestational age (GA) in a single tertiary care centre 2000-2004 with that of EPICure.

METHODS

EPICure tools and definitions, including 30 months' Bayley Scales.

RESULTS

Of 83 infants <26 weeks born alive, more were admitted to intensive care--82% vs. 68% (p < 0.0001)--and more infants survived to discharge (57% vs. 26%, p < 0.0001; 69% vs. 39%, p < 0.01, of those admitted to intensive care). More infants, as a percentage of live births, survived without severe (41%, 34/83 vs. 20%, 233/1185, p < 0.0001) or overall disability (22%, 18/83 vs. 13%, 155/1185, p = 0.03). However, at the border of viability--GA 23 and 24 weeks--the rate of infants surviving without overall disability was not significantly higher (13%, 6/45 vs. 9%, 56/623).

CONCLUSION

In infants <26 weeks of GA, increased rates of survival and survival without disability were observed in a single-centre inborn cohort born 5-8 years later than the EPICure cohort. This did not translate into increased survival without overall disability in infants of 23-24 weeks of GA.

The acoustic hood: a patient-independent device improving acoustic noise protection during neonatal magnetic resonance imaging

BACKGROUND

Magnetic resonance imaging (MRI) is today the imaging modality of choice to investigate the neonatal brain. However, the acoustic noise during scanning is very loud, often exceeding 100 dBA.

AIM

To reduce the acoustic noise during MRI for neonatal patients. If effective, this would create a safer environment and also result in fewer aborted examinations due to poor image quality from patient motion.

METHODS

A passive acoustic noise protector, the acoustic hood, was built out of dampening material. Sound pressure measurements with and without the acoustic hood were performed using our clinical neonatal scan protocol, consisting of eight imaging sequences. The acoustic hood is placed over the newborn inside the MR scanner tunnel during the examination to absorb acoustic noise.

RESULTS

The acoustic noise level was substantially reduced using the acoustic hood. Peak sound pressure was reduced 16.18-22.21 dBA depending on the pulse sequence. For the entire frequency spectra, reduction were between 4-13.59 dBA again varying with the pulse sequence.

CONCLUSION

Acoustic noise can be reduced further than before by using the patient-independent acoustic hood in addition to other noise protection. We recommend the use of three passive hearing protections during neonatal MRI: (1) dental putty, (2) paediatric ear muffs, and (3) the acoustic hood.

Lateral ventricular size in extremely premature infants: 3D MRI confirms 2D ultrasound measurements

Ventriculomegaly at term age is an important predictor of neurologic outcome in preterm infants. Previous studies have found only poor correlations between two-dimensional (2D) cranial ultrasound (US) measurements of lateral ventricles and volume measurements using three-dimensional (3D) magnetic resonance imaging (MRI). Paired cranial MRI and US scans in a population based cohort of 28 extremely preterm infants were obtained at term equivalent age. A 3D MRI volume and five different 2D ultrasound measurements were assessed for each lateral ventricle. Correlations and interobserver variability were calculated. Reliability of US measurements and correlations between MRI volumes and US measurements of the frontal horns and ventricular midbody were consistently good. The highest correlation was achieved by combining the coronal frontal horn measurements to a frontal horn product (r(2) = right 0.94, left 0.95). Our study underlines the value of cranial ultrasound measurements in neonatal care and follow-up.

Blood sampling via umbilical vein catheters decreases cerebral oxygenation and blood volume in preterm infants

AIM

We have shown previously that blood sampling via umbilical artery catheters decreases cerebral oxygenation and cerebral blood volume in preterm infants. To evaluate alternative methods, we assessed the effects of blood sampling via umbilical vein catheters in a cohort of preterm infants.

METHODS

Twenty neonates (median birth weight 900 g [range 410-1900 g], median gestational age 27 weeks [24-31 weeks]) were studied during routine blood sampling via umbilical vein catheters by near-infrared spectroscopy. Tissue oxygenation index and changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured and changes in cerebral oxygenation and cerebral blood volume were calculated. Oxygen saturation and heart rate were recorded simultaneously.

RESULTS

There was a significant drop of cerebral oxygenation (-2.135 +/- 0.532 micromol/L) and cerebral blood volume (-0.037 +/- 0.019 mL/100 g tissue) during umbilical vein blood sampling. Although peripheral arterial oxygen saturation remained unchanged, cerebral tissue oxygenation index decreased from 64.8 +/- 2.5% to 62.4 +/- 2.6% (p < 0.01), accompanied by a slight increase in heart rate (from 140 +/- 2.9 to 144 +/- 2.9 beats/min, p < 0.01).

CONCLUSIONS

Umbilical vein blood sampling reduces cerebral oxygenation and cerebral blood volume. The magnitude of the effects is similar to those during umbilical artery blood sampling.

Resting-state networks in the infant brain

In the absence of any overt task performance, it has been shown that spontaneous, intrinsic brain activity is expressed as systemwide, resting-state networks in the adult brain. However, the route to adult patterns of resting-state activity through neuronal development in the human brain is currently unknown. Therefore, we used functional MRI to map patterns of resting-state activity in infants during sleep. We found five unique resting-states networks in the infant brain that encompassed the primary visual cortex, bilateral sensorimotor areas, bilateral auditory cortex, a network including the precuneus area, lateral parietal cortex, and the cerebellum as well as an anterior network that incorporated the medial and dorsolateral prefrontal cortex. These results suggest that resting-state networks driven by spontaneous signal fluctuations are present already in the infant brain. The potential link between the emergence of behavior and patterns of resting-state activity in the infant brain is discussed.

Combined endovascular stent-graft repair and adjunctive visceral vessel reconstruction for complex thoracoabdominal aortic aneurysms

AIM

This study demonstrates the therapeutic value of the hybrid open and endovascular procedure in anatomically challenging thoracoabdominal aortic aneurysms (TAAAs) in high-risk patients.

METHODS

Between January 2000 and February 2006, 8 patients were treated with open visceral vessel revascularization and endovascular repair for TAAAs. Patient data were available from medical records. Pre- and postoperative physical examination, intra-arterial angiography, and spiral computed tomography scanning was performed in prearranged examinations.

RESULTS

A total of 28 visceral bypasses were performed in the 8 patients: 6 patients with complete visceral vessel revascularization and 2 with an aorto-mesenteric-celiac bypass. Aneurysm exclusion was achieved through the deployment of in total 23 stent-grafts. Seven out of the 8 procedures were conducted electively and one under urgent conditions. The mean follow-up period was 21 months. We recorded one procedure-related death due to postoperative hemorrhage resulting from diffuse retroperitoneal bleeding with consecutive multiorgan failure. Moreover, one patient developed acute renal insufficiency, but returned to normal values after temporary hemodialysis. Major adverse events included 2 cases of pneumonia and one myocardial infarction. Two reoperations were performed due to one mesenteric bypass occlusion and one groin hematoma. No neurological complications were observed.

CONCLUSION

The combined hybrid endovascular and open surgical approach in the treatment of complex TAAAs remains a feasible and effective operation technique. The less invasive character of the procedure and avoidance of aortic-cross clamping are clear advantages. Nevertheless, further study is mandatory to establish this alternative therapeutic option for complex TAAAs.

Vacuum assisted wound closure in postoperative periprosthetic groin infections: a new gold standard?

AIM

This study was designed to control the results of conservative treatment using vacuum assisted wound closure (VAWC) applied exclusively to cases of deep groin infections with involvement of alloplastic graft material.

METHODS

During a 2 year period 10 patients with 11 deep inguinal infections involving alloplastic graft material were treated with supportive VAWC. Intraoperative management included extensive debridement, sartorius myoplastic and VAWC application. A retrospective case-note review was performed. Variables comorbidity, surgical management of the infection, microbiological results, complications and Doppler results were analysed.

RESULTS

Six early graft infections (< 30 days after implantation) and 5 late infections were treated. In 3 cases (27.3%) the infected graft material was replaced by a silver-coated Dacron prosthesis. The mean duration of VAWC was 16+/-7.7 days; postoperative mean hospital stay was 25.3+/-8.5 days. Mean postoperative follow-up was 13.1 months with no procedure-related mortality.

CONCLUSION

Even in the presence of synthetic vascular graft material, negative pressure therapy can greatly simplify challenging wound healing problems under maintenance of the alloplastic grafts. These preliminary results demonstrate the safety and effectiveness of VAWC for the treatment of deep alloplastic graft infections.

Brain abnormalities in extremely low gestational age infants: a Swedish population based MRI study

AIMS

Brain abnormalities are common in preterm infants and can be reliably detected by magnetic resonance (MR) imaging at term equivalent age. The aim of the present study was to acquire population based data on brain abnormalities in extremely low gestational age (ELGA) infants from the Stockholm region and to correlate the MR findings to perinatal data, in order to identify risk factors.

METHODS

All infants with gestational age <27 weeks, born in the Stockholm region between January 2004 and August 2005, were scanned on a 1.5 T MR system at term equivalent age. Images were analysed using a previously established scoring system for grey and white matter abnormalities.

RESULTS

No or only mild white matter abnormalities were observed in 82% and moderate to severe white matter abnormalities in 18% of infants. The Clinical Risk Index for Babies (CRIB II) score, use of inotropes, the presence of high-grade intraventricular haemorrhages and posthaemorrhagic ventricular dilatation were associated with white matter abnormalities.

CONCLUSION

The incidence of moderate to severe white matter abnormalities in a population-based cohort of ELGA infants from the Stockholm region was 18%. To examine the clinical relevance of these promising results, neurodevelopmental follow up at 30 month corrected age, is ongoing.

[Standard procedures in hemodialysis shunt surgery]

Native arteriovenous (AV) fistula are the first choice for primary hemodialysis access. It is essential to save as much vein as possible, and therefore distal AV shunts should be tried first. In patients with diabetes, primary brachiocephalic shunts are indicated and show better results than distal AV fistulae. The major complication of AV fistulae is shunt thrombosis. Immediate surgical repair is necessary, with the aim of preserving enough puncture sites to allow prompt continuation of the hemodialysis therapy. It is important to avoid central venous catheters, because these cause infectious complications more frequently. Shunt infections occur more often in polytetrafluoroethylene grafts than in native AV fistulae and represent a life-threatening situation for dialysis patients.

Umbilical artery catheter blood sampling volume and velocity: impact on cerebral blood volume and oxygenation in very-low-birthweight infants

AIM

Blood sampling from umbilical artery catheters decreases cerebral blood volume and cerebral oxygenation. The aim of this study was to assess the impact of sampling volume and velocity.

METHODS

Forty-eight infants, median birthweight 965 g (480-1500 g), median gestational age 27 wk (23-34 wk), were studied during routine blood sampling from umbilical artery catheters. The sampling procedure was performed following a strict protocol for draw-up volume (1.6 ml), sampling volume (1.7 ml or 0.2 ml), re-injection volume (1.6 ml) and flushing volume (0.6 ml), time of aspiration (40 s or 80 s), re-injection (30 s) and flushing (6 s). In each infant, sampling volume and aspiration time were subject to sequential variation in a randomized fashion (1.7 ml/40 s, 1.7 ml/80 s, 0.2 ml/30 s). Using near-infrared spectroscopy, changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured, and changes in cerebral blood volume and cerebral oxygenation were calculated.

RESULTS

During all three sampling procedures, oxygenated haemoglobin decreased significantly from baseline, whereas deoxygenated haemoglobin did not change. Correspondingly, a decrease in cerebral blood volume and cerebral oxygenation occurred. This decrease was not affected significantly by extending the sampling time from 40 s to 80 s, whereas it was blunted by reducing the amount of blood withdrawn.

CONCLUSION

Blood sampling from umbilical artery catheters induces a decrease in cerebral blood volume and cerebral oxygenation. The magnitude of the decrease depends on the blood volume withdrawn but not on sampling velocity.

Ultrasound diagnosis of brain atrophy is related to neurodevelopmental outcome in preterm infants

BACKGROUND

Intraventricular haemorrhage and periventricular leukomalacia are associated with poor outcome of very preterm infants, while the role of more subtle cerebral alterations, as detected by cranial ultrasound, is less clear.

AIM

In this study, we related periventricular echodensities and signs of brain atrophy to neurodevelopmental outcome at 3 y of age.

PATIENTS AND METHODS

All preterm infants born in 1997 in our institution with a gestational age <32 wk or birthweight <1500 g were subjected to repeated standardized cranial ultrasound examinations until discharge. Survivors were examined at 3 y of age employing the Bayley Scales of Infant Development II.

RESULTS

Eighty-seven infants were enrolled (birthweight 430-2500 g (median 1200 g), gestational age 24-34 wk (median 29 wk)). Periventricular echodensities were detected in 42 infants (48%); in 12 cases persisting <7 d, in 30 cases >7 d. At discharge, 18 infants (22%) had signs of brain atrophy. Neurodevelopmental outcome was assessed in 64 infants. Infants with signs of brain atrophy scored significantly lower on MDI (atrophy 91.8, no atrophy 101.9; p=0.02), PDI (atrophy 91.4, no atrophy 106.5; p=0.001) and Behaviour Rating Scale (atrophy 41.1, no atrophy 66.4; p=0.01) than infants without atrophy. Periventricular echodensities were not related to outcome.

CONCLUSION

Our data show that infants with sonographic signs of brain atrophy at discharge achieve lower scores in neurodevelopmental testing at 3 y.

Ginkgo biloba special extract EGb 761 in the treatment of peripheral arterial occlusive disease (PAOD)--a review based on randomized, controlled studies

OBJECTIVE

The present review gives an overview and evaluation of clinical studies proving the efficacy of EGb 761 in patients with PAOD.

METHODS

Relevant original papers and reports on this topic were identified by means of a literature search. Only randomized, double-blind, placebo-controlled clinical trials in patients with the indication peripheral arterial occlusive disease in stage II according to Fontaine were included (only treatment with the oral form of EGb 761). For the selected studies the ratio theta of the walking distance between EGb 761 and placebo was calculated and a test for relevant superiority of EGb 761 was performed (according to the guidelines of the Deutsche Gesellschaft für Angiologie (German Society of Angiology) [Heidrich et al. 1996]). Furthermore, a pooled estimation of the ratio was carried out.

RESULTS

Nine studies complied with the criteria. The methodological quality and design of the trials were heterogeneous. In the majority of the studies, there was an advantage of EGb 761 in the increase of pain-free walking distance compared to placebo. For 7 studies, the advantage was found to be statistically significant. Testing the relevant superiority showed a significant result in 6 of the selected studies. The pooled estimator of the ratio amounts to theta = 1.23 (95% CI: 1.16, 1.31) and demonstrates the efficacy of EGb 761 over placebo as well.

CONCLUSIONS

This review confirms the efficacy of Ginkgo biloba special extract EGb 761. It demonstrates not only the statistical significance of the difference with respect to placebo but also the clinical relevance for the treatment of patients with PAOD.

Effect of doxapram on cerebral blood flow velocity in preterm infants

BACKGROUND

Doxapram is used to treat apnea of prematurity when there is an insufficient response to methylxanthine treatment. As an unwanted side effect, reduced cerebral perfusion has been seen in methylxanthine-treated infants while effects of doxapram on the cerebral perfusion have not been studied yet.

PATIENTS AND METHODS

Fifteen preterm infants treated with doxapram were included in the study. Birth weight ranged from 380 g to 1150 g (median 740 g), gestational age from 24 to 27 weeks (median 26 weeks). Infants received a doxapram loading dose (2.5 mg/kg) over a 30-minute period, followed by a continuous infusion of 0.5 mg/kg/h. Using Doppler sonography, blood flow velocities and the resistance index were measured in the anterior cerebral artery. Measurements were performed at baseline and 30 and 120 minutes after the start of doxapram.

RESULTS

Maximal systolic blood flow velocity (V(max)) decreased significantly after the infants had received the loading dose (V(max) baseline: 40.7 cm/s +/- 6.9 [mean +/- SD]; V(max) 30 min: 35 cm/s +/- 8.9; p = 0.0017) but returned to near baseline values at 120 min (38.5 +/- 9.0, p = 0.22). End-diastolic, time-averaged, and time-averaged maximal velocities did not change significantly at 30 or 120 min.

CONCLUSIONS

Doxapram induced a significant decrease in maximal cerebral blood flow velocity. Further studies are needed to assess whether this decrease may be critical to cerebral white matter perfusion in the vulnerable preterm infant.

Favourable outcome after biopsy and decompression of a holocord intramedullary spinal cord astrocytoma in a newborn

A 4-month-old male infant presented with hydrocephalus as the initial clinical symptom due to a holocord intramedullary low-grade astrocytoma. This case illustrates a possible alternative treatment to radical surgery with a benign long-term course over a 4.5 year follow-up period.

Prophylactic urgent revascularization of the internal carotid artery in the symptomatic patient

BACKGROUND

The symptomatic patient showing a string sign or ulcerative stenosis of the internal carotid artery (ICA) is subject to a high risk of arterial thrombosis or persisting intracranial embolization during the waiting period before operative revascularization.

PATIENTS AND METHODS

During one year 186 operative revascularization procedures of the ICA were performed on the symptomatic patient. 26 of them fulfilled the prophylactic urgency criteria: symptoms of the cerebrovascular insufficiency and a string sign or ulcerative stenosis of the ICA with ulceration greater than 2 mm in depth. These results were compared to the control group of the 157 procedures under elective circumstances.

RESULTS

Mean clamping time of the urgency and the elective patients were 23.8 min vs. 24.5 min and operation time 50.1 min vs. 54.3 min. None of our urgency patients presented new neurological defects in the postoperative phase, while this occurred in 3.8% in the elective group. Mortality rate in the elective group was 2.7% and 0% in the urgency group. Furthermore, there were fewer local complications in the urgency group.

CONCLUSION

The urgent indication for the desobliteration of the ICA showing a symptomatic string sign or ulcerative stenosis can be recommended. Early thrombosis or neurological defects during the waiting period may be prevented without increasing complication rates.

[Comparison of effects of endotracheal suction and surfactant administration on hemodynamics and oxygenation of premature infants--a near infrared spectroscopy study]

BACKGROUND

Aim of this study was to assess whether the decrease in heart rate and oxygen saturation occurring acutely after bolus administration of surfactant is different from the effect of endotracheal suctioning and whether there are effects on cerebral haemodynamics and oxygenation.

METHODS

Twelve premature infants, birth weight 720-1560 g (Median 935 g), gestational age 25-30 weeks (Median 28 weeks), were investigated during surfactant administration (Curosurf) as a single bolus and a preceding endotracheal suctioning procedure. Using near infrared spectroscopy changes in cerebral blood volume and cerebral oxygenation index were assessed. Heart rate, arterial oxygen saturation, PCO2, and arterial blood pressure were registered continuously. Data were compared at 30, 60 and 120 seconds after the beginning of suctioning and surfactant administration.

RESULTS

Endotracheal suctioning and surfactant administration induced a similar decrease in heart rate (-29/min, SD 25, p < 0.01 and -30/min, SD 23, p < 0.001) during the first 30 seconds and in oxygen saturation at the 30 seconds datapoint (-3%, SD 2, p < 0.01 and -3%, SD 6, p < 0.05). The decrease in oxygen saturation persisted at 60 seconds after the start of suctioning (-4%, SD 5, p < 0.05). In contrast, oxygen saturation was no longer different from baseline levels 60 seconds after surfactant administration (+1%, SD 6, p = 0.5). After suctioning, cerebral oxygenation index had decreased significantly from baseline levels at 30, 60, and 120 seconds. In contrast, after surfactant administration, no significant difference from baseline was noted at 30 and 60 seconds and a significant increase occurred at 120 seconds. Mean arterial blood pressure, PCO2, and cerebral blood volume did not change significantly during endotracheal suctioning and during surfactant administration.

CONCLUSIONS

Acute decreases in heart rate and oxygen saturation during bolus administration of surfactant are equal to effects occurring during endotracheal suctioning. However, the decrease in oxygen saturation is shorter and more importantly, no decrease in cerebral oxygenation occurs.

[Small premature infants do not tolerate axillary temperature measurement any better than rectal measurement. Study of the effect of axillary and rectal temperature measurement on vital parameters and cerebral hemodynamics and oxygenation]

BACKGROUND

Aim of this study was to assess, by use of monitoring parameters and near infrared spectroscopy (NIRS), whether premature infants tolerate axillary temperature measurement better than rectal.

METHODS

Twenty-one infants were studied. Birth weight was 540-1680 g (median 840 g), weight at the time of investigation 470-1500 g (Median 920 g), gestational age 24-31 weeks (median 29 weeks), age at time of investigation 4-25 days (median 11 days). Four pairs of axillary/rectal temperatures were taken in every infant. Heart rate and oxygen saturation were monitored. Using NIRS cerebral oxygenated and deoxygenated hemoglobin were measured and total cerebral hemoglobin and the cerebral oxygenation index were calculated.

RESULTS

Mean heart rate increased slightly but significantly from baseline during axillary and rectal temperature measurement (axillary: +6/min (+/- 7); p < 0.0001; rectal: +4/min (+/- 6); p < 0.0001). Peak increase in heart rate was significantly higher during axillary than during rectal temperature measurement (axillary: +18/min (+/- 10); rectal: +14/min (+/- 8); axillary versus rectal: p = 0.02). There was no difference in the number of measurements during which oxygen saturation dropped intermittently below 88% (rectal: 21% of measurements; axillary: 20% of measurements). NIRS parameters were not significantly different between axillary and rectal measurements: cerebral oxygenated hemoglobin and the oxygenation index showed a decrease in cerebral oxygenation during both, axillary and rectal measurement.

CONCLUSIONS

Axillary temperature measurement is not better tolerated than rectal in premature infants.

Umbilical artery catheter blood sampling decreases cerebral blood volume and oxygenation in very low birthweight infants

The aim of this study was to assess whether blood sampling from umbilical artery catheters reduces cerebral blood volume and cerebral oxygenation in very low birthweight infants. A total of 20 infants, median birthweight 890 g (530-1,500 g), median gestation age 26 +4 wk (range: 22 +5 to 30 +6 wk) were studied from 10 min before until 10 min after routine blood sampling from umbilical artery catheters placed in the high position. Using near infrared spectroscopy, changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured, and changes in cerebral blood volume and cerebral oxygenation index were calculated. Heart rate, oxygen saturation, transcutaneous PO2 and PCO2 were registered continuously. Mean arterial blood pressure was measured before and after sampling. Oxygenated haemoglobin decreased significantly from baseline during blood sampling, whereas deoxygenated haemoglobin did not change significantly. This resulted in a decrease in cerebral blood volume and cerebral oxygenation index. Heart rate increased slightly, but significantly, from baseline. Oxygen saturation, blood pressure, transcutaneous PO2 and PCO2 did not change significantly.

CONCLUSION

Blood sampling from umbilical artery catheters induces a significant decrease in cerebral blood volume and cerebral oxygenation.

Carotid endarterectomy prior to major abdominal aortic surgery

BACKGROUND

Major aortic surgery carries a high risk of stroke. Carotid artery occlusive disease (CAOD) has been identified as one of the contributing risk factors. Regarding the long-term prevention of stroke, carotid endartectomy (CEA) seems to be superior to the best medical treatment in patients with high-grade CAOD. However, the role of CEA prior to major aortic surgery has not been studied.

METHODS

DESIGN

Prospective study, observational design.

SUBJECTS AND SETTING

201 patients referred to a community hospital for major aortic surgery.

INTERVENTION

The patients were non-invasively screened by continuous-wave and duplex Doppler ultrasonography for the presence of CAOD. In 41 patients with angiographically confirmed high-grade CAOD, CEA was performed prior to major aortic surgery.

MAIN OUTCOME MEASURE

Combined mortality and major morbidity from CEA and abdominal aortic surgery.

RESULTS

There was no mortality or morbidity related to CEA. Total perioperative mortality related to major aortic reconstruction was 3.5%. No new perioperative focal neurologic deficits occurred except for one fatal stroke in a patient in whom CEA had been judged not to be indicated.

CONCLUSIONS

CEA can be performed safely prior to major aortic surgery resulting in excellent overall neurologic outcome in patients with high-grade CAOD. We propose that patients scheduled for major aortic surgery be screened for the presence of high-grade CAOD and that CEA be performed first, if indicated according to published guidelines.