Imaging features and prognostic factors in fetal and postnatal torcular dural sinus malformations, part II: synthesis of the literature and patient management

Infantile dural arteriovenous fistula: a reconsideration

BACKGROUND

Infantile-type dural arteriovenous shunts (IDAVS) are rare and heterogeneous vascular lesions, complicating their classification and management. The current tripartite classification of pediatric dural arteriovenous shunts (DAVS) into dural sinus malformation, infantile-type, and adult-type, does not stand up to scrutiny, given the variable presentations of the latter two types in children. We estimate the prevalence of IDAVS and evaluate the long term outcomes after endovascular treatment (EVT).

METHODS

A retrospective review of a pediatric cerebrovascular database between 2006 and 2023 was conducted. Clinical and radiographic data were analyzed to evaluate the presentation and long term outcomes of IDAVS.

RESULTS

IDAVS were identified in 8 (0.5%) of 1463 patients, with mean age at diagnosis of 34.7 months; male infants comprised 62.5%. The most common clinical presentations included macrocephaly (37.5%), seizures (25%), and dilated scalp veins (25%). EVT was performed in 87.5% of cases, averaging 5.8 procedures per patient. Radiographic obliteration was observed in 28.6%. Good clinical outcomes (modified Rankin Scale score of ≤2) were achieved in 85.7%. Our findings showcased discrepancies and limitations in the current classification of pediatric DAVS, prompting a re-evaluation.

CONCLUSION

IDAVS accounted for a small proportion of pediatric cerebrovascular pathologies, with markedly heterogeneous presentations. Stepwise selective embolization was associated with favorable outcomes, and is recommended over an aggressive approach with the goal of complete angiographic obliteration. Our proposed revised classification system bifurcates pediatric DAVS into dural sinus malformations and all other DAVS that are manifest in children, thereby enhancing diagnostic clarity and therapeutic approaches.

Anticoagulation helps shrink giant venous lakes and arteriovenous fistulas in dural sinus malformation

BACKGROUND

Dural sinus malformations (DSMs) associated with high flow arteriovenous shunts are a challenging disease in babies that can lead to severe neurological damage or death. We report our treatment strategy in seven consecutive DSMs.

METHODS

We performed a retrospective analysis of seven consecutive patients from four centres, treated with transarterial embolization and anticoagulants.

RESULTS

Mean clinical and imaging follow-up was 2.8 years (IQR1-3 1.8-5.3). At baseline, the median size of the dilated venous pouch (giant lake) was 35 mm (IQR1-3 24-41) that decreased to a normal or near normal venous collector diameter of median size 11.5 mm (IQR1-3 8.5-13.8). This was achieved after a median of two embolization sessions targeted on dural feeders (IQR1-3 1.5-2.5), leaving associated pial feeders untreated. There were no cerebral hemorrhagic complications during the anticoagulation treatment. Median percentage of shunt remaining after embolization was 30% (IQR1-3 12-30), which spontaneously decreased with anticoagulation and even after discontinuation of anticoagulation, in parallel with the reduction in diameter of the dilated sinus, up to healing (or near healing). At the last clinical assessment, the modified Rankin Scale score was 0 in four patients, 1 in one patient, and 3 in two patients.

CONCLUSIONS

Anticoagulants may help to potentiate transarterial embolization in DSMs in babies by decreasing venous dilatation and reducing the remaining arteriovenous shunt, particularly the pial feeders. We did not observe recurrence of arteriovenous shunts after treatment, especially during anticoagulation treatment. Further studies are needed to support our findings.

Remodeling of venous drainage after the treatment of dural sinus malformation with arteriovenous shunts in a neonate: a case report and literature review

Dural sinus malformations (DSMs) are rare congenital vascular diseases characterized by a giant venous pouch with or without arteriovenous shunts. We present a neonatal case of DSM that was diagnosed prenatally and treated via endovascular intervention in the early postnatal period. The patient presented with a large DSM involving the torcular Herophilion prenatal magnetic resonance imaging (MRI). Enlargement of the head circumference and respiratory failure rapidly progressed after birth. On the 5th day after birth, the neonate underwent endovascular occlusion via the umbilical artery. The arteriovenous shunt was occluded, and the reflux from the enlarged venous pouch to the dural sinus was decreased. No additional procedure other than ventriculoperitoneal shunting was required. The neonate's development slowly caught up to normal parameters. Follow-up MRI demonstrated the successful development of the venous drainage system. DSMs are characterized by an abnormally dilated dural sinus, which can block the venous return and ultimately increase intracranial pressure and cerebral ischemia. Long-term follow-up indicates that an abnormally developed dural sinus can be reconstructed by appropriate and timely treatment.

Increasing precision in the management of pediatric neurosurgical cerebrovascular diseases with molecular genetics

Recent next-generation DNA and RNA sequencing studies of congenital and pediatric cerebrovascular anomalies such as moyamoya disease, arteriovenous malformations, vein of Galen malformations, and cavernous malformations have shed new insight into the genetic regulation of human cerebrovascular development by implicating multiple novel disease genes and signaling pathways in the pathogenesis of these disorders. These diseases are now beginning to be categorized by molecular disruptions in canonical signaling pathways that impact the differentiation and proliferation of specific venous, capillary, or arterial cells during the hierarchical development of the cerebrovascular system. Here, the authors discuss how the continued study of these and other congenital cerebrovascular conditions has the potential to replace the current antiquated, anatomically based disease classification systems with a molecular taxonomy that has the potential to increase precision in genetic counseling, prognostication, and neurosurgical and endovascular treatment stratification. Importantly, the authors also discuss how molecular genetic data are already informing clinical trials and catalyzing the development of targeted therapies for these conditions historically considered as exclusively neurosurgical lesions.

Torcular Dural Sinus Malformation: Fetal and Postnatal Imaging Findings and Their Associations With Clinical Outcomes

BACKGROUND

Torcular dural sinus malformations (tDSMs) are rare vascular malformations that present in fetuses and infants. Existing data on prognostic imaging features, as well as the associated morbidity and mortality, are limited and variable. We therefore reviewed cases of tDSMs diagnosed on fetal magnetic resonance imaging (MRI) at our referral center to identify pre- and postnatal MRI imaging features associated with long-term outcomes.

METHODS

We searched our imaging database for fetal and postnatal MRI reports of tDSM cases. The electronic medical record was then reviewed for pre- and postnatal clinical data, including follow-up imaging. Neurological outcomes were characterized using the previously reported scale based on the Bicêtre Score. Imaging features association with outcome scores were compared using the Fisher exact test.

RESULTS

Sixteen cases of tDMS diagnosed by fetal MRI with postnatal clinical follow-up were identified, 11 of whom underwent postnatal MRI. The majority of cases of tDSM (73%) decreased in size or resolved on postnatal follow-up study without treatment. Restricted diffusion and parenchymal hemorrhage on fetal MRI were the only imaging features identified significantly associated with unfavorable neurological outcome or death, present in two patients with poor outcomes (two of two) and only one with a normal outcome (one of 14) (P = 0.025).

CONCLUSIONS

Findings of tDSM on fetal MRI most often regress and/or resolve with normal or mild neurological outcomes, with the most significant predictor of poor outcome being the presence of parenchymal injury on fetal MRI. In addition, a subset will present with venolymphatic malformations.

Neonatal vascular anomalies manifesting as soft-tissue masses

The broad and heterogeneous spectrum of vascular anomalies ranges from an innocuous localized cutaneous discoloration to complex, extensive and life-threatening diagnoses. While many of these lesions are present at birth, smaller and deeper lesions might be clinically occult for months or years. Certain vascular anomalies commonly manifest in the prenatal or neonatal period and often have suggestive clinical and imaging features that can aid the radiologist in making a correct diagnosis. The characteristics of such lesions presenting very early in life, particularly those manifesting as soft-tissue masses, are the focus of this review.

Cerebral neurovascular embryology, anatomic variations, and congenital brain arteriovenous lesions

Cerebral neurovascular development is a complex and coordinated process driven by the changing spatial and temporal metabolic demands of the developing brain. Familiarity with the process is helpful in understanding neurovascular anatomic variants and congenital arteriovenous shunting lesions encountered in endovascular neuroradiological practice. Herein, the processes of vasculogenesis and angiogenesis are reviewed, followed by examination of the morphogenesis of the cerebral arterial and venous systems. Common arterial anatomic variants are reviewed with an emphasis on their development. Finally, endothelial genetic mutations affecting angiogenesis are examined to consider their probable role in the development of three types of congenital brain arteriovenous fistulas: vein of Galen malformations, pial arteriovenous fistulas, and dural sinus malformations.

OUP accepted manuscript

Paediatric intracranial dural arteriovenous shunts have clinical presentations and evolutions, with angiographic characteristics that differ from those described in adults. We report our experience concerning their therapeutic management, emphasizing the relevance of early diagnosis and appropriate treatment for satisfactory neurocognitive development. Using a prospective database, we reviewed the clinical and radiological data of all children with dural arteriovenous shunts managed between 2002 and 2020. Dural shunts were categorized into three types: dural sinus malformations with arteriovenous shunts; infantile dural arteriovenous shunts; and adult-type dural arteriovenous shunts. Therapeutic strategies and outcomes were analysed depending on lesional subtypes. Modified Rankin Scale for the paediatric population was assessed pre-treatment and at last follow-up. Twenty-eight patients [16 girls (57.1%); 12 boys (42.9%)] were included: 17 dural sinus malformation [10 boys (58.8%); seven girls (41.2%)], three infantile shunts [three girls (100%)], eight adult-type shunts [four girls (50%)]; four boys (50%)], with a mean age of 19.2 ± 36.6 months at presentation. Twelve (42.9%) had a modified Rankin Scale score of 0–2, four (14.3%) had a score of 3, three (10.7%) had a score of 4 and eight (28.6%) had a score of 5. Embolization was performed in 22 children [78.6%; 12 girls (54.5%); 10 boys (45.5%)]. Fifteen patients could be cured (68.2%): 11 dural sinus malformations (73.3%), four adult-type lesions (100%) but no infantile shunt. Mean post-treatment follow-up was 39.5 months (max. 139 months): 14 patients (63.6%) presented a modified Rankin Scale score of 0–2 and eight (36.4%) had a score ≥3. In the dural sinus malformation group, the modified Rankin Scale score was improved in 11 patients (73.3%) and unchanged in three (20%). Only one patient with infantile subtype (33.3%) improved clinically. In the adult-subtype group, all children (100%) improved. Of six untreated patients [four girls (66.7%); two boys (33.3%)], four with adult-subtype shunts showed uneventful evolutions, one with dural sinus malformation died, and therapeutic abortion was conducted in an antenatally diagnosed dural sinus malformation. Paediatric dural fistulas comprise different subtypes with variable clinical courses. Proper diagnosis is mandatory for optimal therapeutic strategies within appropriate therapeutic windows.

Fetal Cerebral Sinovenous Thrombosis and Dural Sinus Malformation

BACKGROUND

Fetal cerebral sinovenous thrombosis (CSVT) and dural sinus malformation (DSM) are rare types of fetal cerebral venous pathology that are becoming increasingly recognized as fetal imaging advances. Fetal DSMs are a common source of fetal CSVT, although CSVT may occur without a DSM. The literature on these disorders is limited.

METHODS

Cases of fetal CSVT and DSM were identified retrospectively through a query of the Indiana University Health fetal imaging archive from 2007 to 2021.

RESULTS

Seven cases were identified, all of whom were alive at birth. A DSM was present in six. Treatments after birth included enoxaparin sodium (3), embolization (3), and shunt placements (1). Five cases had documented regression or complete resolution of the thrombus and/or malformation. One was lost to follow-up, one died from complications of hydrocephalus at nine months, one was receiving physical and occupational therapy at last follow-up at three months, one had concern for autism and mild gait abnormality at 21 months, two had concern for speech delay (18 months and 24 months), and one had normal development at most recent follow-up (four years).

CONCLUSIONS

Positive short-term outcomes may occur for some cases of fetal CSVT and DSM. However, risk factors and best treatments are not clear, and long-term outcome data are limited. There is a need for further study.

Fetal imaging of a rare case of dural sinus malformation: a case report

Background

Dural sinus malformations (DSM) are rare congenital anomalies, accounting for less than 2% of all intracranial vascular malformations. Fetal MRI plays an important role in the confirmation of the diagnosis, prognostication, and planning of treatment strategies. Here, we present a rare case of dural sinus malformation without thrombosis, diagnosed by prenatal ultrasound and fetal MRI. In addition to this, fetal intracranial 3D gradient recalled echo Dixon-based MRA was done which, to the best of our knowledge, is a first.

Case presentation

A 24-year-old multigravida with no known comorbidities underwent a routine second trimester anomaly scan in which an unusual posterior interhemispheric cyst was diagnosed. Further evaluation with fetal MRI revealed dilated posterior sinuses and torcula, normal internal jugular vein, and maintained flow voids with no mass effect. Fetal Dixon-based MRA and correlated Doppler revealed supply to the lesion by bilateral occipital arteries and posterior cerebral arteries. With these imaging features, a midline dural sinus malformation was diagnosed.

Conclusion

Dural sinus malformations should be considered in the differential diagnosis of unusual posterior fossa cystic lesions detected on antenatal ultrasound coupled with a colour Doppler examination. Prompt fetal MRI is essential to establish the diagnosis, identify intracranial complications and decide the postnatal treatment strategy, thereby possibly improving the postnatal outcome.

Staged embolisation of a giant torcular dural sinus malformation in a neonate

Torcular dural sinus malformations (tDSMs) represent a rare subset of paediatric cerebrovascular malformations and are often diagnosed antenatally via ultrasound. The management of these in utero lesions remains controversial as previous studies suggested elective termination of the pregnancy because of their presumably high mortality and severe long-term morbidity. However, more recent evaluations have suggested that the overall prognosis for infants harbouring these lesions may be much better than previously believed. As such, we present the case of a neonate with a giant tDSM, diagnosed in utero, who was treated postnatally via staged transarterial and transvenous embolisation to alleviate worsening obstructive hydrocephalus and brainstem compression. We provide details regarding the surgical approach and long-term neurological outcomes for this patient. To the best of our knowledge, this is one of the largest reported tDSM presented in the literature.

Neonatal giant dural sinus ectasia: a multimodality imaging approach

Dural venous sinus ectasia is a rare anomaly characterised by the formation of a large vascular lake within the leaves of the dural sinuses, usually associated with thrombosis. These lesions can cause brain compression, cardiac insufficiency and disseminated intravascular coagulation, which may lead to poor prognosis. We present the case of a neonate who presented with an intracranial mass on prenatal ultrasound. Postnatal transcranial ultrasonography, cranial CT and cranial MRI demonstrated a large lesion predominantly occupying the dural sinus confluence, extending into the sagittal sinus, straight sinus and right transverse sinus. The left marginal sinus remains unfused and patent. Concomitant arteriovenous malformations were evident in the median interhemispheric fissure and the left Sylvian fissure. There are several published case reports and case series describing malformations of the dural sinuses in perinatal and neonatal patients in recent years, but this case is unique in that: (1) there is the presence of a vascular malformation concomitant to the dural sinus ectasia and (2) it highlights the importance of imaging in clinching the diagnosis of giant dural venous sinus ectasia, as it is often misdiagnosed as more common conditions such as extra-axial intracranial haemorrhage.

Dural Sinus Arteriovenous Malformation in the Fetus. Case Report and Discussion of the Literature

Sonographic findings of cerebral arteriovenous malformations in the fetus are uncommon and usually regard aneurysm of the Galen vein. Outcome of arteriovenous malformations is usually severe. We report a case of a fetus at 21 weeks' gestation with a rarer arteriovenous malformation, referred to us for echocardiography on account of a suspicious cardiomegaly at obstetrical scan. Upon examination, we found cardiomegaly, together with an associated moderate tricuspid regurgitation, however, there were no clear features of tricuspid dysplasia. Considering an unusually dilated superior vena cava, we found via color Doppler imaging a systodiastolic flow at Color Doppler progressing. Subsequent MRI of the central nervous system determined the localization in the sinus dura mater. Due to an already evident hemodynamic impact, the parents opted for the termination of the pregnancy. Autopsy confirmed a voluminous arteriovenous malformation of the transverse sinus of the dura mater, severe cardiomegaly, mainly of the ventricles, and hypoplasia of the lungs.

Improving long-term outcomes in pediatric torcular dural sinus malformations with embolization and anticoagulation: a retrospective review of The Hospital for Sick Children experience

OBJECTIVE

Torcular dural sinus malformations (tDSMs) are rare pediatric cerebrovascular malformations characterized by giant venous lakes localized to the midline confluence of sinuses. Historical clinical outcomes of patients with these lesions were poor, though better prognoses have been reported in the more recent literature. Long-term outcomes in children with tDSMs are uncertain and require further characterization. The goal of this study was to review a cohort of tDSM patients with an emphasis on long-term outcomes and to describe the treatment strategy.

METHODS

This study is a single-center retrospective review of a prospectively maintained data bank including patients referred to and cared for at The Hospital for Sick Children for tDSM from January 1996 to March 2019. Each patient's clinical, radiological, and demographic information, as well as their mother's demographic information, was collected for review.

RESULTS

Ten patients with tDSM, with a mean follow-up of 58 months, were included in the study. Diagnoses were made antenatally in 8 patients, and among those cases, 4 families opted for either elective termination (n = 1) or no further care following delivery (n = 3). Of the 6 patients treated, 5 had a favorable long-term neurological outcome, and follow-up imaging demonstrated a decrease or stability in the size of the tDSM over time. Staged embolization was performed in 3 patients, and anticoagulation was utilized in 5 treated patients.

CONCLUSIONS

The authors add to a growing body of literature indicating that clinical outcomes in tDSM may not be as poor as initially perceived. Greater awareness of the lesion's natural history and pathophysiology, advancing endovascular techniques, and individualized anticoagulation regimens may lead to continued improvement in outcomes.

Prenatal findings and postnatal follow-up of a midline dural sinus malformation

Dural sinus malformation is a rare condition. We describe a prenatally detected case followed by repeated ultrasound scans and a prenatal magnetic resonance imaging examination. A substantial spontaneous regression was observed, which is associated with a favorable outcome. We believe that our observations, including a long postnatal follow-up, will add to the present knowledge of prenatally detected cases, and thus improve management of the pregnancies as well as our possibilities to counsel the parents-to-be.

Endovascular management of torcular dural sinus malformations in children: the role of straight sinus occlusion

BACKGROUND

Torcular dural sinus malformations (tDSMs) with arteriovenous shunts are rare congenital intracranial vascular malformations that carry a high rate of neurologic impairment and death in the neonatal, infant and young pediatric population. Their impact on brain venous drainage, especially the deep venous system, is one of the key factors in the clinical prognosis and natural history of the disease. We describe our therapeutic strategy for tDSMs, disconnecting the reflux into the deep venous system by performing an endovascular straight sinus occlusion.

METHODS

Among all children with dural sinus malformations seen between 2002 and 2020, we retrospectively reviewed those with tDSM in whom straight sinus occlusion had been performed.

RESULTS

Our databank included nine patients with tDSM that were embolized. Mean age at the clinical onset was 8.9±9.6 months (min-max=0-31). Five patients presented a significant reflux in the straight sinus on digital subtraction angiography. Those patients were initially clinically worse (mean modified Rankin Scale (mRS) 3.8) than those who did not present with reflux (mean mRS 2.25), this reflux being responsible for intraventricular hemorrhage in three patients. The reflux was suppressed by transarterial embolization in one patient and by transvenous straight sinus occlusion in four patients. Staged endovascular treatment resulted in a complete cure in six patients without complications, and clinical improvement in all patients.

CONCLUSION

Straight sinus occlusion is a feasible technique that needs to be considered in the treatment strategy for tDSM with deep venous reflux in order to avoid or minimize brain damage.

Torcular dural sinus malformations: a grading system proposal

BACKGROUND

Torcular dural sinus malformations (tDSMs) are congenital complex vascular anomalies often referred as a single unit. Nevertheless, they possess distinct anatomical features, clinical diversity, and markedly different outcomes.

OBJECTIVE

On the basis of our institutional experience and analysis of published data, we propose a grading system.

METHODS

We have identified 44 papers to which we added our four institutional cases for a total of 126 patients. Eight predictor variables were studied. In order to assess their individual impact on mortality and possible correlations, a logistic regression model was constructed through a stepwise forward process.

RESULTS

Overall mortality was 22.1%. Mortality was higher in tDSM patients diagnosed postnatally, 40.7% versus a 15.6% in prenatally found cases (p = 0.007). We divided the patients into four grades. Grade I comprised patients with no feeder evidence and possessed the best outcomes (mortality of 7.55%). Mortality rose for grades II and III defined respectively by scarce and multiple feeders. Brain damage was the defining feature of grade IV. A mortality of 75% could be observed within this grade. Grade IV was further divided into grades IVa (antenatal) and IVb (postnatal cases). Furthermore, our logistic regression model found that brain damage (OR 11.3, p < 0.001, 95% CI 2.97-42.91) and patent feeders (OR 4, p = 0.03, 95% CI 1.15-13.86) were major determinants of poor outcome (area under ROC curve of 81.44%).

CONCLUSION

The grading system (tDSM-GS) streamlines classification into four different grades facilitating both diagnosis, clinical decision-making, and proper prognostication.

Venous pathologies in paediatric neuroradiology: from foetal to adolescent life

The interpretation of cerebral venous pathologies in paediatric practice is challenging as there are several normal anatomical variants, and the pathologies are diverse, involving the venous system through direct and indirect mechanisms. This paper aims to provide a comprehensive review of these entities, as their awareness can avoid potential diagnostic pitfalls. We also propose a practical classification system of paediatric cerebral venous pathologies, which will enable more accurate reporting of the neuroimaging findings, as relevant to the underlying pathogenesis of these conditions. The proposed classification system comprises of the following main groups: arterio-venous shunting-related disorders, primary venous malformations and veno-occlusive disorders. A multimodal imaging approach has been included in the relevant subsections, with a brief overview of the modality-specific pitfalls that can also limit interpretation of the neuroimaging. The article also summarises the current literature and international practices in terms of management options and outcomes in specific disease entities.

Nationwide survey of pediatric intracranial arteriovenous shunts in Japan: Japanese Pediatric Arteriovenous Shunts Study (JPAS)

The authors performed a nationwide study in Japan to evaluate the annual detected rate of pediatric intracranial arteriovenous (AV) shunts such as brain AV malformations (BAVMs), pial AV fistulas (PAVFs), vein of Galen aneurysmal malformations (VGAMs), and dural AV fistulas (DAVFs). These rates were revealed for the first time and showed that VGAM, DAVF, and PAVF were relatively common but that BAVMs were extremely rare in neonates and infants.