The ultrasound appearances of neonatal renal vein thrombosis

Sonographic features of umbilical catheter-related complications

Umbilical catheters are commonly used in the neonatal period for blood sampling or for administering medication or parenteral nutrition. The position of the catheter is usually confirmed with radiography. However, many complications associated with the use of umbilical catheters, such as liver collections from extravasation or vascular thrombosis, are not apparent on radiographs but can be easily diagnosed with ultrasound. This pictorial review illustrates the sonographic findings of complications that should be excluded in the sick neonate with an indwelling catheter.

Non Catether Induced Renal and Inferior Vena Cava Trombosis in a Neonate: A Case Report

BACKGROUND:

Neonatal renal vein thrombosis is the most common vascular condition in the newborn kidney, which could lead to serious complication in infants.

CASE REPORT:

We report a case of the unilateral renal vein and inferior vena cava thrombosis, presented with gross hematuria and thrombocytopenia in a neonate. The neonate was a macrosomic male born to a mother with hyperglycemia in pregnancy. The baby was born with perinatal asphyxia and early neonatal infection and massive hematuria. Clinical and laboratory examination showed enlarged kidney having corticomedullary differentiation diminished and azotemia. Diagnosis of renal vein thrombosis was suspected by renal ultrasound and confirmed by magnetic urography. Prothrombotic risk factors were evaluated. The child is being managed conservatively. Measures aimed at the prevention of end-stage renal disease because of its poor outcome were highlighted. Despite anticoagulant therapy, the right kidney developed areas of scarring and then atrophy.

CONCLUSION:

In this work, we present a patient with multiple entities in the aetiology of non-catheter induced renal and vena cava thrombosis in a neonate. Clinicians should suspect renal vein thrombosis in neonates when presented with early postnatal gross hematuria, palpable abdominal mass and thrombopenia.

Spontaneous neonatal renal vein thromboses: Should we treat them all? A report of five cases and a literature review

Renal vein thrombosis (RVT) is a rare but well-known neonatal entity for which several therapeutic modalities are reported in the literature because of the lack of consensus management guidelines.

POPULATION AND METHODS

A retrospective study of the medical records of children managed between January 1990 and December 2013, and whose final diagnosis was RVT. The diagnosis was initially clinical and subsequently confirmed by the abdominal ultrasonography (AUS) and Doppler imaging if necessary. The abdominal CT scan was performed when the AUS finding led to the suspicion of RVT extension to the inferior vena cava (IVC). Each patient's birth parameters (birth weight [BW], birth length [BL], and head circumference [HC]) and modalities were recorded. The treatment modalities, the outcome at follow-up along with results of etiological screening were also recorded.

RESULTS

Five newborn infants were diagnosed as having unilateral RVT at the mean postnatal age of 3.8 days (range, 1-11 days). All presented with a classical triad associated nephromegaly, thrombocytopenia, and gross hematuria. Two patients had genetic thrombophilic risk factors (1 heterozygous Leiden factor V mutation in case 4, and Activated Protein C resistance in case 5). Two infants were managed conservatively, and the other three received antithrombotic treatment (recombinant tissue plasminogen activator and heparin). All five patients had a similar course, leading to non-functioning renal atrophy, despite aggressive thrombolytic therapy or conservative treatment.

CONCLUSION

We suggest that simple unilateral RVT be managed conservatively, while antithrombotic therapy may be attempted for unilateral RVT extending into the inferior vena cava and for bilateral RVT.

Extensive Thrombosis of the Inferior Vena Cava and Left Renal Vein in a Neonate

Antenatal renal vein thrombosis is a rarely described diagnostic finding, with variable consequences on kidney function. We present the case of an affected fetus, born at 35-week gestation, with intrauterine oligohydramnios and two small kidneys. A renal ultrasound carried out after birth confirmed the presence of prenatal abnormalities. Renal vein thrombosis was not diagnosed at the time. The baby died 20 days later of kidney failure, metabolic acidosis, and polypnea with severe hypotrophy. Autopsy revealed atrophied kidneys and adrenal glands. The vena cava had thrombosis occupying most of its length. The right renal vein was normal, while the left renal vein was threadlike and not permeable. Histologically, there was necrosis of the left adrenal gland with asymmetrical bilateral renal impairment and signs of ischemic and hemorrhagic lesions. A review of thrombophilia was carried out and a heterozygous mutation in Factor V was found in both the mother and the child.

Successful management of neonatal renal venous thrombosis

Renal vein thrombosis is the most common vascular condition involving the newborn kidney and it can result in severe renal damage. We report a newborn with renal vein thrombosis treated with continuous infusion of unfractionated heparin who had normal total renal function after 3 years of follow up, despite reduction of the functional contribution of the affected kidney.

Unusual Presentation of Renal Vein Thrombosis in a Preterm Infant

Neonatal renal vein thrombosis is the most common vascular condition in the newborn kidney, which could lead to serious complication in infants undergoing intensive care. In this study, we report the case of a preterm infant with left renal vein and inferior vena cava thrombosis, presented with gross hematuria, thrombocytopenia, transient hypertension, and adrenal hemorrhage. Supportive care was offered instead of heparin therapy or thrombolytic agents. In conclusion, our case teaches that, despite the lack of a clinically obvious shock event, renal vein thrombosis should be considered in a macrohematuric newborn without renal failure.

Abdominal thromboses of splanchnic, renal and ovarian veins

Thromboses of abdominal veins outside the iliac-caval axis are rare but clinically relevant. Early deaths after splanchnic vein thrombosis occur in 5-30% of cases. Sequelae can be liver failure or bowel infarction after splanchnic vein thrombosis, renal insufficiency after renal vein thrombosis, ovarian infarction after ovarian vein thrombosis. Local cancer or infections are rare in Budd-Chiari syndrome, and common for other sites. Inherited thrombophilia is detected in 30-50% of patients. Myeloproliferative neoplasms are the main cause of splanchnic vein thrombosis: 20-50% of patients have an overt myeloproliferative neoplasm and/or carry the molecular marker JAK2 V617F. Renal vein thrombosis is closely related to nephrotic syndrome; finally, ovarian vein thrombosis can complicate puerperium. Heparin is used for acute treatment, sometimes in conjunction with systemic or local thrombolysis. Vitamin K-antagonists are recommended for 3-6 months, and long-term in patients with Budd-Chiari syndrome, unprovoked splanchnic vein thrombosis, or renal vein thrombosis with a permanent prothrombotic state such as nephrotic syndrome.

Neonatal renal vein thrombosis

Neonatal renal vein thrombosis (RVT) continues to pose significant challenges for pediatric hematologists and nephrologists. The precise mechanism for the onset and propagation of renal thrombosis within the neonatal population is unclear, but there is suggestion that acquired and/or inherited thrombophilia traits may increase the risk for renal thromboembolic disease during the newborn period. This review summarizes the most recent studies of neonatal RVT, examining its most common features, the prevalence of acquired and inherited prothrombotic risk factors among these patients, and evaluates their short and long term renal and thrombotic outcomes as they may relate to these risk factors. Although there is some consensus regarding the management of neonatal RVT, the most recent antithrombotic therapy guidelines for the management of childhood thrombosis do not provide a risk-based algorithm for the acute management of RVT among newborns with hereditary prothrombotic disorders. Whereas neonatal RVT is not a condition associated with a high mortality rate, it is associated with significant morbidity due to renal impairment. Recent evidence to evaluate the effects of heparin-based anticoagulation and thrombolytic therapy on the long term renal function of these patients has yielded conflicting results. Long term cohort studies and randomized trials may be helpful to clarify the impact of acute versus prolonged antithrombotic therapy for reducing the morbidity that is associated with neonatal RVT.

[Neonatal renal venous thrombosis: the recent experience of Robert-Debré hospital]

Neonatal renal venous thrombosis (NRVT) is a rare disease, with variable consequences on kidney function. We report a retrospective study of 9 newborns with NRVT admitted to our hospital from 1996 to 2005. The median age at diagnosis was 2 days (range, 1-10 days). In 7 patients, diagnosis was suspected based on one classical clinical or biological sign and was confirmed by ultrasound. Seven newborns had at least one known obstetrical or neonatal risk factor. NRVT was unilateral in three cases, was bilateral in 6 cases, and was associated with inferior vena cava thrombosis in 5 patients, with surrenal hemorrhage in 3 patients. Three patients did not receive specific treatment. The median delay between diagnosis and specific treatment was 20 h (range, 3-36 h). Three patients were treated by fibrinolysis, including 2 with bilateral NRVT, 2 newborns received heparins, and 1 patient was treated with a vitamin K antagonist. With a median evaluation time of 5 years and 2 months for 6 patients, 5 patients recovered their kidney function completely and the 6th child has moderate renal failure. It seems illusory to wait for randomized control studies to appreciate the potential long-term benefit of treatments on kidney function after a NRVT, whose bilateral forms appear to be more severe. A case-by-case approach appears better adapted. These results reinforce recommendations that suggest an early pediatric nephrologic follow-up for all newborns with a NRVT.

Sonography of renal venous thrombosis in neonates and infants: can we predict outcome?

BACKGROUND

The relationship between sonographic features of renal venous thrombosis (RVT) and outcome has not been described in a large series of patients.

OBJECTIVE

To analyze sonographic findings of RVT and their evolution in a large series of patients and to attempt to identify features that might predict outcome.

MATERIALS AND METHODS

Retrospective analysis of sonograms and medical records of neonates and infants diagnosed with RVT during the period 1998-2007.

RESULTS

Of 22 children (mean age: 3 days; age range: 0-107 days), RVT was bilateral in 12. Of 34 affected kidneys, thrombus in the main renal vein was seen in 17 and typical RVT sonographic findings without main renal vein thrombus were seen in the remaining 17. All children had US follow-up (range: 0.6-97.2 months). Three children with bilateral RVT died. Nine kidneys atrophied. Imaging findings associated with subsequent kidney atrophy included markedly reduced perfusion at diagnosis, subcapsular collections, patchy cortical echotexture and profoundly hypoechoic and irregular renal pyramids. Six patients (eight kidneys) presented with renal calcifications on initial sonogram before 7 days of life, suggesting antenatal RVT.

CONCLUSION

Sonography is useful in neonatal and early infant RVT and might help predict renal atrophy. Antenatal RVT appears to be relatively common.

Renal pyramids: focused sonography of normal and pathologic processes

In neonates and children, sonographic examinations of the renal pyramids may depict a spectrum of unique changes in echogenicity due to the effects of physiologic processes or a wide variety of pathologic processes that may affect the collecting ducts or interstitium of the pyramids. Focused sonographic evaluation of the pyramids with high-frequency transducers produces the most detailed images of the pyramids, revealing some appearances not previously reported, to the authors' knowledge. The authors highlight the clinical settings in which they have documented detailed changes in the echogenicity of the pyramids. The patterns of altered echogenicity alone may reflect a specific cause but in many instances are nonspecific, with clinical and biochemical correlation required to establish a more precise diagnosis. However, there is a lack of histologic data to completely explain the mechanism of many of these changes in echogenicity in all of the processes. As the authors have expanded their use of the focused sonographic technique, they have been able to depict altered echogenicity in the pyramids in greater numbers of children in whom an explanation for the changes is not always immediately apparent; for now, the cause must be considered idiopathic. More work is required to expand the use of this focused technique together with clinical, biochemical, and histologic correlation in an attempt to offer more complete explanations for the changes in echogenicity of the pyramids.

Fatal pulmonary embolism in a premature neonate after twin-to-twin transfusion syndrome

Thrombotic events are being increasingly recognized during the neonatal period. An infant girl was born at 29 weeks' gestation after a pregnancy complicated by twin-to-twin transfusion syndrome. After an initial uncomplicated clinical course, her oxygen requirement increased, which was interpreted as an early sign of bronchopulmonary dysplasia. At 3 weeks of age, she suddenly collapsed and died of severe pulmonary hypertension. At autopsy, multiple pulmonary artery emboli and several older renal vein thromboses were found. Results of genetic analyses of the infant and her family were negative for thrombophilia. Although embolism represents a frequent emergency in adults, fatal pulmonary embolism has never, to our knowledge, been described for premature infants. This case suggests that thrombotic events are underdiagnosed and that additional studies are needed to define infants at risk and optimal treatment strategies.

[Neonatal renal vein thrombosis: early diagnosis using Doppler ultrasonography and long-term sequelae]

OBJECTIVE

To describe the physiopathological mechanisms in perinatal renal vein thrombosis and the associated risk factors, with emphasis on the clinical and radiological characteristics and on the long-term evolution.

MATERIAL AND METHODS

We retrospectively studied a total of 11 cases of neonatal renal vein thrombosis; the mean age of patients at diagnosis was 3 days. We analyzed the type of presentation, the clinical manifestations, and the findings at B-mode and Doppler ultrasonography, as well as the treatment undertaken and the long-term sequelae.

RESULTS

At the time of diagnosis, the triad of a palpable mass, unequivocal hematuria, and thrombocytopenia was present in only 63.63% of patients. A prothrombotic risk factor was identified in the newborn or mother in 45.45% of cases. At ultrasonographic examination, all newborns had enlarged kidneys and in all cases it was impossible to differentiate between the renal cortex and the renal medulla. In 4 of the 11 cases, hyperechogenic intramedullary linear images characteristic of the initial stage of thrombosis were identified. Functional follow-up studies using DMSA (dimercaptosuccinic acid) and MAG-3 (mercaptoacetyltriglycine acid) revealed morphological abnormalities in all patients; 7 patients had a nonfunctioning kidney.

CONCLUSIONS

Visualizing echogenic bands within the medulla should alert radiologists to the initial phase of renal vein thrombosis and enable the appropriate treatment to be administered. With the exception of cases discovered before birth, renal vein thrombosis has a poor prognosis, with atrophy and renal failure in the long term.

Renal venous thrombosis in a newborn with prothrombotic risk factors

Renal venous thrombosis (RVT) is a rare but a well recognized entity in children and neonates. The clinical signs of neonatal RVT include hypertension, enlarged kidney(s), hematuria, renal insufficiency, proteinuria, thrombocytopenia, or all. Persisting impairment of kidney function and hypertension are serious and common complications in patients with RVT. Risk factors for the development of RVT include maternal diabetes mellitus, pathologic states associated with thrombosis (e.g., shock, dehydration, perinatal asphyxia, polycythemia), and sepsis. Inherited prothrombotic abnormalities have been described in some reports of RVT. We report the case of a male newborn with left RVT and associated homozygosity for both factor V Leiden (G1691A) and methylenetetrahydrofolate reductase C677T mutations in addition to elevated serum lipoprotein (a). The patient was treated with heparin. We believe our case to be the first reported case in the English medical literature of such an association between neonatal RVT and homozygosity for both factor V Leiden and methylenetetrahydrofolate reductase. This case and other studies clearly demonstrate that neonatal RVT should be evaluated for thrombophilia conditions.

Power Doppler imaging in acute renal vein occlusion and recanalization: a canine model

OBJECTIVE

To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model.

MATERIALS AND METHODS

We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified.

RESULTS

We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant.

CONCLUSION

The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion.

Antithrombotic therapy in neonates and children: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

This chapter about antithrombotic therapy in neonates and children is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs, and Grade 2 suggests that individual patient values may lead to different choices (for a full understanding of the grading, see Guyatt et al in this supplement, pages 123S-131S). In this chapter, many recommendations are based on extrapolation of adult data, and the reader is referred to the appropriate chapters relating to guidelines for adult populations. Within this chapter, the majority of recommendations are separate for neonates and children, reflecting the significant differences in epidemiology of thrombosis and safety and efficacy of therapy in these two populations. Among the key recommendations in this chapter are the following: In children with first episode of venous thromboembolism (VTE), we recommend anticoagulant therapy with either unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) [Grade 1B]. Dosing of IV UFH should prolong the activated partial thromboplastin time (aPTT) to a range that corresponds to an anti-factor Xa assay (anti-FXa) level of 0.35 to 0.7 U/mL, whereas LMWH should achieve an anti-FXa level of 0.5 to 1.0 U/mL 4 h after an injection for twice-daily dosing. In neonates with first VTE, we suggest either anticoagulation or supportive care with radiologic monitoring and subsequent anticoagulation if extension of the thrombosis occurs during supportive care (Grade 2C). We recommend against the use of routine systemic thromboprophylaxis for children with central venous lines (Grade 1B). For children with cerebral sinovenous thrombosis (CSVT) without significant intracranial hemorrhage (ICH), we recommend anticoagulation initially with UFH, or LMWH and subsequently with LMWH or vitamin K antagonists (VKAs) for a minimum of 3 months (Grade 1B). For children with non-sickle-cell disease-related acute arterial ischemic stroke (AIS), we recommend UFH or LMWH or aspirin (1 to 5 mg/kg/d) as initial therapy until dissection and embolic causes have been excluded (Grade 1B). For neonates with a first AIS, in the absence of a documented ongoing cardioembolic source, we recommend against anticoagulation or aspirin therapy (Grade 1B).

Fetal and Neonatal Thrombophilia

Thrombophilia of the fetus and neonate may contribute to higher prevalence of perinatal thrombosis. Due to the potential interaction between thrombophilic risk factors of the neonate and maternal thrombophilia and placental vasculopathy, we recommend thrombophilia assessment be performed in any child and in the mother in case of perinatal thrombosis. Further attention and larger prospective studies are required to establish the role of thrombophilic risk factors in the pathogenesis of any other perinatal complications.

Perinatal renal venous thrombosis: presenting renal length predicts outcome

BACKGROUND

Renal venous thrombosis (RVT) is the most common form of venous thrombosis in neonates, causing both acute and long term kidney dysfunction. Historical predisposing factors include dehydration, maternal diabetes, and umbilical catheters, but recent reports highlight associations with prothrombotic abnormalities.

STUDY

Twenty three patients with neonatal RVT were analysed over 15 years. Predisposing factors, presentation, and procoagulant status were compared with renal outcome using multilevel modelling.

RESULTS

Median presentation was on day 1: 19/23 (83%) had pre/perinatal problems, including fetal distress (14), intrauterine growth retardation (five), and pre-identified renal abnormalities (two); 8/18 (44%) had procoagulant abnormalities, particularly factor V Leiden mutations (4/18). Long term abnormalities were detected in 28/34 (82%) affected kidneys; mean glomerular filtration rate was 93.6 versus 70.2 ml/min/1.73 m2 in unilateral versus bilateral cases (difference 23.4; 95% confidence interval 6.4 to 40.4; p = 0.01). No correlation was observed between procoagulant tendencies and outcome, but presenting renal length had a significant negative correlation: mean fall in estimated single kidney glomerular filtration rate was 3 ml/min/1.73 m2 (95% confidence interval 3.7 to -2.2; p = 0.001) per 1 mm increase, and kidneys larger than 6 cm at presentation never had a normal outcome.

CONCLUSIONS

This subgroup of neonatal RVT would be better termed perinatal RVT to reflect antenatal and birth related antecedents. Prothrombotic defects should be considered in all patients with perinatal RVT. Kidney length at presentation correlated negatively with renal outcome. The latter, novel observation raises the question of whether larger organs should be treated more aggressively in future.

Neonatal renal venous thrombosis: clinical outcomes and prevalence of prothrombotic disorders

OBJECTIVE

To determine clinical outcomes and the prevalence of prothrombotic conditions in patients who had neonatal renal venous thrombosis (RVT).

STUDY DESIGN

A retrospective cohort of neonates with RVT who were admitted to 4 pediatric centers from 1980 to 2001 was identified. Information on clinical presentation, laboratory and radiological investigation, and treatment were abstracted. Survivors were evaluated for renal status and prothrombotic conditions.

RESULTS

Forty-three patients with neonatal RVT were identified. RVT was unilateral in 24 patients (56%) and associated with 2thrombi at other sites in 32 patienets (74%). Clinical presentations included renal failure in 24 patients (56%), thrombocytopenia, anemia, or both in 22 patients (51%), and renal mass in 21 patients (49%). Neonatal interventions included anti-coagulants in 28 patients (65%), antihypertensive medications in 9 patients (21%), peritoneal dialysis in 2 patients (5%), and nephrectomy in 2 patients (5%). The median age at follow-up was 3.7 years (range, 0.5-20.2 years). Thirteen patients (34%) had hypertension, and 11 patients (29%) had renal failure. End-stage renal disease developed in 3 patients, and they underwent live-related renal transplants. Twelve of the 28 patients (43%) examined had prothrombotic abnormalities.

CONCLUSION

Neonatal RVT is associated with significant renal morbidity and a high prevalence of prothrombotic abnormalities.

Renal venous thrombosis in neonates: prothrombotic risk factors and long-term follow-up

The present study was designed to evaluate prothrombotic risk profiles in 59 consecutively recruited white neonates with renal venous thrombosis (RVT). The rates of prothrombotic risk factors (PRs)—for example, the factor V (FV) 1691G> A mutation, the factor II (FII) 20210G> A variant, antithrombin (AT), protein C (PC), protein S (PS), elevated lipoprotein(a) (Lp(a)), total fasting plasma homocysteine (tHcy) levels, and anticardiolipin antibodies (ACAs)—were compared with those of 118 healthy control children. At onset, 32 (54.2%) of the 59 neonates showed underlying clinical conditions; 40 (67.8%) of them and 23 (85.2%) of the 27 infants with idiopathic RVT showed at least one PR. Univariate analysis revealed significantly elevated odds ratios/95% confidence intervals (ORs/95% CIs) for FV and Lp(a). Additionally, PC/AT deficiency and ACAs were found significantly more often in the patient group (P = .04). Multivariate analysis calculated significant ORs/95% CIs only for FV (OR, 9.4; 95% CI, 3.3-26.6) and elevated Lp(a) (OR, 7.6; 95% CI, 2.4-23.8). Of the 59 neonates investigated, 53 revealed renal atrophy, and 13 children additionally suffered from severe arterial hypertension. In conclusion, the present study demonstrates the significance of genetic PR—especially the FV mutation and elevated Lp(a)—for the etiology of neonatal RVT.

Antithrombotic Therapy in Children*

This article about antithrombotic therapy in children is part of the 7th American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh the risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this article are the following. In neonates with venous thromboembolism (VTE), we suggest treatment with either unfractionated heparin or low-molecular-weight heparin (LMWH), or radiographic monitoring and anticoagulation therapy if extension occurs (Grade 2C). We suggest that clinicians not use thrombolytic therapy for treating VTE in neonates, unless there is major vessel occlusion that is causing the critical compromise of organs or limbs (Grade 2C). For children (ie, > 2 months of age) with an initial VTE, we recommend treatment with i.v. heparin or LMWH (Grade 1C+). We suggest continuing anticoagulant therapy for idiopathic thromboembolic events (TEs) for at least 6 months using vitamin K antagonists (target international normalized ratio [INR], 2.5; INR range, 2.0 to 3.0) or alternatively LMWH (Grade 2C). We suggest that clinicians not use thrombolytic therapy routinely for VTE in children (Grade 2C). For neonates and children requiring cardiac catheterization (CC) via an artery, we recommend i.v. heparin prophylaxis (Grade 1A). We suggest the use of heparin doses of 100 to 150 U/kg as a bolus and that further doses may be required in prolonged procedures (both Grade 2 B). For prophylaxis for CC, we recommend against aspirin therapy (Grade 1B). For neonates and children with peripheral arterial catheters in situ, we recommend the administration of low-dose heparin through a catheter, preferably by continuous infusion to prolong the catheter patency (Grade 1A). For children with a peripheral arterial catheter-related TE, we suggest the immediate removal of the catheter (Grade 2C). For prevention of aortic thrombosis secondary to the use of umbilical artery catheters in neonates, we suggest low-dose heparin infusion (1 to 5 U/h) (Grade 2A). In children with Kawasaki disease, we recommend therapy with aspirin in high doses initially (80 to 100 mg/kg/d during the acute phase, for up to 14 days) and then in lower doses (3 to 5 mg/kg/d for > or = 7 weeks) [Grade 1C+], as well as therapy with i.v. gammaglobulin within 10 days of the onset of symptoms (Grade 1A).

Neonatal thrombosis and its treatment

Thromboembolic disease (TE) has been described as the new epidemic of tertiary paediatrics, and no where is this more evident than in the neonatal population. As survival of premature and sick newborns has improved, the frequency of complications associated with intensive supportive therapy and monitoring has increased. Clinically significant thrombosis is emerging as one of the more common complications associated with improved neonatal outcome. The long-term implications of neonatal thrombosis are only just being realised. This systematic review will consider the epidemiology, diagnostic strategies, and outcome for both arterial and venous TE in neonates. The role of inherited thrombophilic abnormalities, and the evidence for anticoagulation therapy will also be considered. The lack of high level evidence in determining optimum therapy is obvious. Further research regarding diagnostic strategies, and optimal therapies is urgently needed.

Thromboembolic disease and antithrombotic therapy in newborns

This update uses an evidence based approach to analyze and present the epidemiology of neonatal thrombosis, etiologies, currently used techniques for diagnosis with their limitations, and current therapeutic approaches. In addition, the approaches to both prevention and optimal therapies are discussed. In Section I Dr. Paul Monagle addresses the epidemiology of neonatal thrombosis outside of the central nervous system in both arterial and venous locations, and those that occur in utero. The specific contributions of catheters and congenital prothrombotic disorders are delineated. Dr. Monagle also describes currently used techniques for the diagnosis of thrombotic events as well as their limitations and the current therapeutic approaches. In Section II, Dr. Gabrielle deVeber reviews the epidemiology of neonatal thrombosis within the central nervous system, in both arterial and venous locations and those that occur in utero. The neurological presentation, risk factors including congenital prothrombotic disorders, anatomical distribution, diagnostic tests, use of antithrombotic therapy and neurologic outcome of neonates with either sinovenous thrombosis or arterial ischemic stroke are discussed. In Section III, Dr. Anthony Chan reviews the current approaches to the prevention and treatment of neonatal thrombosis. Information on the differences in the response of neonates compared to adults to antithrombotic therapy and new approaches to the prevention and treatment of thrombosis in neonates are emphasized.

Congenital adrenal hyperplasia presenting as hematuria and acute renal faliure

We present a neonate who presented with hematuria and acute renal failure. Classical 21 hydroxylase deficiency was diagnosed on the basis of features of salt wasting, response to treatment with corticosteroids and mineralocorticoids and a positive ACTH stimulation test. Renal vein thrombosis secondary to hemoconcentration due to salt wasting was attributed as the cause of hematuria. Follow-up revealed clinical improvement and normalization of renal parameters. This is the first report of congenital adrenal hyperplasia presenting as hematuria and renal failure to the best of our knowledge.

Evaluation and treatment of thrombosis in the neonatal intensive care unit

Thromboses are infrequent but serious complications of patients in the NICU. Thromboses tend to occur in very sick neonates, particularly preterm neonates, and the majority of such thromboses are related to central vascular catheters. Other risk factors for neonatal thromboses include infants of diabetic mothers, sepsis, small for gestational age, congenital heart disease, maternal antiphospholipid syndrome, and possibly inherited prothrombotic disorders. Appropriate treatment, dosage, and duration of therapy for neonatal thromboses has not been studied in clinical trials. Treatment options include observation, anticoagulation, thrombolysis, and surgical thrombectomy. Regardless of the treatment chosen, all neonates with thromboses require frequent reassessment of the thromboses by angiography, echocardiography, or ultrasound until thrombus resolution occurs.

Sonographic evaluation of renal failure

Sonography is a critical component of the evaluation of both acute and chronic renal failure; however, most nephrologists have a limited knowledge of this procedure. The acoustic properties, limited spectrum of pathological changes, and ease of visualization of the kidneys, coupled with the safety, simplicity, and low cost of sonography, make it the modality of choice for renal imaging. This review discusses the basics of sonography as they apply to the kidney and describes the findings encountered in the more common causes of renal failure. Although many sonographic findings are nonspecific, their diagnostic use is greatly enhanced by a familiarity with the clinical presentation and a thorough understanding of renal pathophysiological characteristics. Therefore, nephrologists should be knowledgeable about renal sonography and participate in its interpretation.

Coexisting renal vein thrombosis and bilateral adrenal hemorrhage: renoscintigraphic demonstration

A rare case of simultaneous renal vein thrombosis and bilateral adrenal hemorrhage is presented, showing the utility of Tc-99m DTPA and DMSA renal scans to identify the condition and to assess renal function. The characteristic appearances of suprarenal tracer-free areas encircled by peripheral radioactive rims over the inferiorly displaced kidneys on a Tc-99m DTPA renal scan, and that of the flattened upper poles of the kidneys on a Tc-99m DMSA scan, were pathognomonic and strongly indicative of bilateral adrenal hemorrhage. These two scans also showed markedly diminished tracer uptake in the poorly functioning right thrombosed kidney. Follow-up imaging using these two renal scans well demonstrated the functional and morphologic alterations and recovery of the kidneys.

Neonatal vascular catheters and their complications

There has been an evolution in vascular access in the neonate. Newer types of materials and catheters, such as PICC lines and ECMO catheters, are now available. The frequency of line placement has increased, and radiologists now perform many of these procedures. This places the radiologist in the position of not only diagnosing complications, but actually causing them. Knowledge of these complications can help the practitioner avoid them and diagnose them as quickly as possible when they occur.