Post hemorrhagic ventricular dilation

Shanu chandran

• Progressive enlargement of ventricles following IVH until the ventricular width at intraventricular foramen exceeds 97th centile for gestational age.

• 20-30% of <34wks babies develop IVH and 50% of them can go for PVHD

Criteria for PVHD

• anterior horn width, measured diagonally (>4mm),

• third ventricular width, measured in the coronal plane (>3mm) and

• thalamo-occipital dimension, measured in the sagittal plane (>26mm)

Ventricular enlargement due to excessive build up of csf

Ventricular enlargement due to cerebral atrophy

Ventricles are usually round Ventricle are not round

Enlargement rapid Enlargement slow

Increased head enlargement No increased head enlargement

Pathophysiology

• Normally csf is absorbed through arachnoid villi and across the ependyma…..blocked by small blood clots

• Endogenous attempt to lyse blod clots…..ineffecient due to low plasminogen and high inhibitor of plasminogen activator

Role of TGFb1

• Released into CSF following IVH• Upregulates genes for extracellular matrix

proteins such as fibronectin and laminin- scar formation

• If Scar tissue block the exit from 4th ventricle-obstructive hydrocephalus; if blocks channels of reabsorption- communicating hydrocephalus

• Following dilation, periventricular wm gets damaged

rapid pressure and oedema free radical damage from iron proinflammatory cytokines

Reasons for ventricular dilation before rapid head growth

• Paucity of cerebral myelin• Relative excess of water in centrum semiovale• Relatively large subarachnoid space(this space

could be encroached on even after ventricular dilation, but before separation of sutures)

Effects of PHVD

Initial assessment

• Diagnosis using recognised criteria and measurement of ventricular width

• Clinical assessment-irritability, increased tendon reflex,tension in fontanelle,squamous sutue >5mm, head circumference)

• Ascertainment of parenchymal brain lesions that may affect infants prognosis

• Head circumference increases by about 1 mm daily between 26 and 32 weeks’ gestation; between 32 and 40 weeks it increases by 0.7 mm daily

• An increase of 2mm per day is considered excessive

Objectives of Mx

• To protect the infant from damage secondary to raised ICP

• To avoid the need for a permanent shunt –to prevent blockage and infection necessitating multiple revisions

Basic groups for management

Based on• USG progression of ventricular dilation• Rate of head growth• Signs of increased ICP• Resistance index and dRI

• Slowly progressive VD: moderate dilation, appropriate rate of head growth , stable RI, dRI, <2wk---- close follow up

• Persistent slowly progr VD: similar to I, except duartion is >2wks and increase in head growth and RI/dRI----close follow up till 4 wks;if rapid progression/>4wks, serial lumbar puncture

Rapidly progressive VD: moderate to severe dilation, clearly excessive rate of head growth,RI,dRI clearly increased

Management- serial lumbar punctures ventricular drainage- EVD, VSGS VP shunt

• Arrested progression: spontaneous arrest of ventricular dilation or arrest following lumbar puncture

• Management-close surveillance for 1 yr• Late progressive ventricular dilation can occur

in 5%

USG evaluation of ventricular size

• First sign of incr in ICP- rounding of frontal horns with increase in ant horn width-ballooning

• AHW-most sensitive marker for mild ventri enlargement

• A normal AHW is less than 3 mm, with the 95th percentile curve reaching 2 mm at 36 weeks and 3 mm at 40 weeks

• an AHW greater than 6 mm is generally considered abnormal

• Thalamo occipital distance-depth of occipital horn of lat ventricle

• visible before any increase in frontal horn dimensions

• dilated to a greater extent than the frontal horns

Levene index and ventricular index

• The Levene index is the absolute distance between the falx and the lateral wall of the anterior horn in the coronal plane at the level of the third ventricle.

• Up to 40 weeks of GA the Levene-index s and after 40 weeks the ventricular index-the ratio of the distance between the lateral sides of the ventricles and the biparietal diameter.

• Levine ventricular index 97th percentile + 4 mm curve- threshold for intervention for PHVD, increases from 14 to 15 to 16 mm at 27, 31, and 33 weeks

Resistive index

• RI of ant cerebral artery- assessment of raised ICP

• As the ICP increases it decreases the end diastolic velocity, thus causing the RI to increase towards 1.0.

• Not sensitive, not specific

Repeated lumbar punctures

• simplest way to reduce ventricular size and intracranial pressure

• limit CSF removal to a maximum of 20 mL / kg so as to minimise the risk of cardiovascular disturbance

• Repeated LPs or ventricular taps do not reduce the risk of requiring formal CSF diversion, have no effect on neuromotor impairment and are associated with a significant risk of ventriculitis, (Ventriculomegaly Trial Group study)

• Repeated lumbar punctures are frequently associated with high rate of infection and the amount of cerebrospinal fluid drained may be insufficient

• External ventricular drainage - more effective than lumbar punctures in evacuating sufficient volumes of cerebrospinal fluid

Temporary Csf diversion

• A ventricular access device provides an easy and safe route for repeated aspiration of ventricular CSF, with low infection rates

• Insertion, through a frontal burr hole, requires a brief anaesthetic

• VSGshunt alternative• Timing – controversial

Ommaya VAD

Temporary csf diversion devices-merits/demerits

• The ventricular reservoir is a ventricular catheter capped by a reservoir.

• The reservoir is tapped through the scalp on a regular basis to remove CSF and maintain a stable clinical condition.

• VSG shunt- allows continuous CSF diversion, and thus sustained relief of elevated ICP, rather than the intermittent diversion provided by ventricular reservoir taps

• The family must be prepared for the subgaleal fluid collection that forms in the scalp

When to act??

• In a retrospective study done in Dutch NICUs(devries et al), early insertion, before crossing the 97th + 4mm ventricular index line, showed lower rates of ventriculoperitoneal shunt(odds ratio- 0.22)

• The Early versus Late Ventricular Intervention Study (ELVIS) is currently randomising between the two treatment thresholds, with death or shunt dependence and disability at two years the main treatment outcomes

De vries et al Acta Paediatr. 2002

ELVIS

• Preterms<34 wks with IVH 3/4- serial cus 1-3 times weekly till 21 days

• Intervention-surgical placement of VAD• Standard threshold arm- intervene if Levene

index>97 cent +4 or diagnonal frontal horn width >10mm

• Low threshold- LI >97 centile, FHW 7-10, TOD >24• VP shunt if csf removal still required at 44 wks

Other treatment options

• DRIFT( drainage , irrigation and fibrinolytic therapy)

• Drugs that decrease CSF production

DRIFT• A catheter is inserted into rt ventricle frontally

and another into lt ventricle posteriorly• Rh tPA is (0.5mg/kg) is injected into right

ventricle and left for 8 hours• Artificial CSF is inserted into right ventricle at

20ml/kg/hr• Old blood and debris are drained from left

ventricular drain to keep ICP below 7• Irrigation is continued till draining fluid is clear

of old blood.

• Aims to decompress the distended ventricles early

• Reducing pressure and distortion and• Removing intraventricular blood,

inflammatory cytokines, and iron, thereby reducing secondary injury to the cerebral hemispheres

RCT comparing DRIFT and std treatment

• Despite an increase in secondary intraventricular bleeding, DRIFT reduced severe cognitive disability in survivors and overall death or severe disability

Whitelaw et al .Pediatrics April 2010

Drug therapy• Carbonic anhydrase inhibitor acetazolamide reduces CSF

production• RCT compared standard therapy with std + drug

therapy( 100mg/kg/day acetazolamide +1mg/kg/day furosemide)

• Infants enrolled at mean post natal age of 3.6wks• 85% who were allocated to drug therapy either died or

were disabled or impaired at 1 year compared with 70% who were treated with standard therapy

Kennedy et al Pediatics 2001 sept

• Acetazolamide and furosemide therapy is neither effective nor safe in treating post hemorrhagic ventricular dilatation

• Increase the risk of motor impairment at 1yr• Increase the risk of nephrocalcinosis(RR-5.31)• No significant increase in combined outcome of

death/disability

Cochrane database systematic review 2001

• Ineffective in decreasing shunt placement• Increased neurological morbidity? Carb anhydrase is involved in myelination

and glial differentiation.

Streptokinase inj• Effect of intraventricular streptokinase after IVH on the risk of

permanent shunt dependence, neurodevelopmental disability or death

• When intraventricular streptokinase was compared with conservative management of PHVD, the number of deaths and babies with shunt dependence were similar in both groups

• Cannot be recommended

Cochrane database systematic review 2007

VP shunt

• Once baby reaches 2 kg• CSF protein <1.5g/dl• Early shunt-more risk of infections,shunt block

and revisions• ETV with choroid plexus cauterization

alternative

Prognosis

• Quadriparesis and significant cognitive impairment if associated PVL or PVHI

References

• Volpes tb of neurology of newborn 5 th ed• Chloherty manual of nb care 7th ed• Ultrasound measurements of the lateral ventricles

in neonates: why, how and when? A systematic review. Acta pediatrics 2010

• IVH in newborn.ACNR 2011• PHVD-review article -Arch Dis Child Fetal Neonatal

Ed 2002;86• Radiology assisstant.com/ emedicine

Thank you