Could craniometric measurements explain the growth of the superior sagittal sinus?

Pilot study of intracranial venous physiology in craniosynostosis

OBJECTIVE In addition to craniocerebral disproportion, other factors, such as Chiari malformation type I, obstructive sleep apnea, and venous outflow obstruction, are considered to have a role in the occurrence of intracranial hypertension in craniosynostosis. This pilot study examined cerebral venous flow velocity to better characterize the complex intracranial venous physiology of craniosynostosis. METHODS The authors performed a prospective cohort study of craniosynostosis patients (n = 34) referred to a single national (tertiary) craniofacial unit. Controls (n = 28) consisted of children who were referred to the unit's outpatient clinic and did not have craniosynostosis. Transfontanelle ultrasound scans with venous Doppler flow velocity assessment were performed at the first outpatient clinic visit and after each surgery, if applicable. Mean venous blood flow velocities of the internal cerebral vein (ICV_v) and the superior sagittal sinus (SSS_v) were recorded and blood flow waveform was scored. RESULTS Preoperatively, SSS_v was decreased in craniosynostosis patients compared with controls (7.57 vs 11.31 cm/sec, p = 0.009). ICV_v did not differ significantly between patients and controls. Postoperatively, SSS_v increased significantly (7.99 vs 10.66 cm/sec, p = 0.023). Blood flow waveform analyses did not differ significantly between patients and controls. CONCLUSIONS Premature closure of cranial sutures was associated with decreased SSS_v but not ICV_v; indicating an effect on the superficial rather than deep venous drainage. Further Doppler ultrasound studies are needed to test the hypothesis that at an early stage of craniosynostosis pathology SSS_v, but not pulsatility, is abnormal, and that abnormality in both SSS_v and the superficial venous waveform reflect a more advanced stage of evolution in suture closure.

Cerebrospinal fluid spaces between intracranial venous sinuses and overlying dura mater: magnetic resonance imaging

Purpose The intracranial venous sinuses are thought to lie interdurally, circumferentially contacting the dura maters. There has been no report documenting the cerebrospinal fluid spaces intervening between the venous sinuses and overlying dura mater. Here, we explored such structures using magnetic resonance imaging. Methods A total of 206 patients underwent magnetic resonance imaging with a T2-weighted or constructive interference steady-state sequence. Imaging data were analysed on a workstation. Results The peri-superior sagittal sinus cerebrospinal fluid spaces were identified in 100% of 133 patients who underwent coronal and sagittal T2-weighted imaging and in 98.6% of 73 with a constructive interference steady-state sequence. Among the 205 patients, the cerebrospinal fluid spaces were distributed over the frontoparietal region in 84% and the parietal region in 16%. On sagittal sections performed for 58 patients, the cerebrospinal fluid spaces were identified between the superior sagittal sinus and overlying dura mater. The peri-sinus spaces were found in 91% of the identified transverse sinuses, 29% of the straight and 70% of the occipital sinuses. The peri-superior sagittal sinus cerebrospinal fluid spaces were classified into five distinct appearances. The circumferential type was the most predominant and was found in 68.7%, followed by lateral in 10.2%, lateral plus inferior in 7.5%, lateral plus superior in 6.8% and superior in 6.8%. Conclusions The intracranial venous sinuses do not circumferentially contact with the dura maters. Instead, they are adjacent to the cerebrospinal fluid spaces intervening between the walls and overlying dura maters. These spaces are critical when considering tumour extensions contralateral to the superior sagittal sinus and safe surgical manoeuvres around it.

Transcranial Doppler in the evaluation of infants treated with retrograde ventriculosinus shunt

INTRODUCTION

Hydrocephalus is a prevalent condition among infants. Retrograde ventriculosinus shunt (RVSS) proposes a feasible option to treat hydrocephalus according to the principles presented by El-Shafei. In this essay, we analyze nuances and application of transcranial Doppler (TCD) in patients submitted to RVSS.

METHODS

We consecutively enrolled patients diagnosed with hydrocephalus after surgical repair of myelomeningocele from January 2010 to January 2012, users of Hospital das Clinicas, University of Sao Paulo. They were treated with RVSS. Patients enrolled to the study were consecutively evaluated in an outpatient basis with TCD in preoperative, immediate postoperative period, and late postoperative period (1 year).

RESULTS

Except for patient 3, there was an increase in mean flow velocity, decreased pulsatility index, and decreased resistance index in all vessels analyzed.

DISCUSSION

In our sample, transcranial Doppler could be used as a diagnostic and follow-up tool to evaluate hemodynamics and hydrodynamics in the preoperative and postoperative phases of RVSS. It was technically feasible in all patients, had close relation with other clinical and image parameters, and was sensitive to identify system malfunction.

Failed Ventriculoperitoneal Shunt: Is Retrograde Ventriculosinus Shunt a Reliable Option?

BACKGROUND

Currently, the treatment of hydrocephalus is mainly carried out through a ventriculoperitoneal shunt (VPS) insertion. However, in some cases, there may be surgical revisions and requirement of an alternative distal site for shunting. There are several described distal sites, and secondary options after VPS include ventriculopleural and ventriculoatrial shunt, which have technical difficulties and harmful complications.

OBJECTIVES

In this preliminary report we describe our initial experience with retrograde ventriculosinus shunt (RVSS) after failed VPS.

RESULTS

In 3 consecutive cases we applied RVSS to treat hydrocephalus in shunt-dependent patients who had previously undergone VPS revision and in which peritoneal space was full of adhesions and fibrosis. RVSS was performed as described by Shafei et al., with some modifications to each case. All 3 patients kept the same clinical profile after RVSS, with no perioperative or postoperative complications. However, revision surgery was performed in the first operative day in 1 out of 3 patients, in which the catheter was not positioned in the superior sagittal sinus.

CONCLUSIONS

We propose that in cases where VPS is not feasible, RVSS may be a safe and applicable second option. Nevertheless, the long-term follow-up of patients and further learning curve must bring stronger evidence.

Surgical technique of retrograde ventricle-sinus shunt is an option for the treatment of hydrocephalus in infants after surgical repair of myelomeningocele

ABSTRACT Introduction Treatment of hydrocephalus is accomplished primarily through a ventricular-peritoneal shunt (VPS). This study aims to describe the application of retrograde ventricle-sinus shunt (RVSS) in patients with hydrocephalus after surgical treatment of myelomeningocele. Method A prospective, randomized and controlled pilot study. We consecutively enrolled 9 patients with hydrocephalus after surgical repair of myelomeningocele from January 2010 to January 2012. These patients underwent elective RVSS or VPS. Five underwent RVSS and 4 underwent VPS. Patients were followed for one year with quarterly evaluations and application of transcranial Doppler. Results RVSS group showed outcomes similar to those of VPS group. Doppler revealed significant improvement when comparing preoperative to postoperative period. RVSS group had significantly higher cephalic perimeter than VPS group. Neuropsychomotor development, complications and subjective outcomes did not differ between groups. Conclusion RVSS shunt is viable; it is an alternative option for the treatment of hydrocephalus.