Anatomy, Terminology and Treatment in Pediatric Neurosurgery Part I

Transcription

1 Anatomy, Terminology and Treatment in Pediatric Neurosurgery Part I John Ragheb, MD, FACS, FAAP Professor of Neurosurgery and Pediatrics, Affiliated Faculty of University of Miami, Miller School of Medicine Chief of Pediatric Neurosurgery, Nicklaus Children s Hospital, Miami Children s Health System Jackson Memorial Health System

2 Disclosure None relevant to this presentation Surgical mentor for Medtronic and NeuroPace

3 Overview Common surgical diseases of the nervous system in children Part I; hydrocephalus and spinal dysraphism (spina bifida) Anatomy and pathophysiology Surgical management and nomenclature Complications

4 Hydrocephalus

5 History of Hydrocephalus CSF Imhotep Hippocrates Dropsy of the brain Galen - A.D water on the brain Vesalius s - fluid within the ventricles Dandy pneumoencephalography CT Nulson first pressure regulated valve implanted

6 80% by choroid plexus endothelium 20%? ependyma or parenchyma CSF is an active secretion form ultrafiltrate of plasma Arachnoid villus bulk flow pressure dependent hydrostatic gradient Lymphatics Brain parenchyma Nerve root sleeve

7 Etiologic Classification of Hydrocephalus Absorption Obstruction to absorption Infection Hemorrhage Production Overproduction of CSF Choroid plexus papilloma Inflammation Obstruction of CSF flow Congenital malformations Neoplasms

8 Infectious Bacterial Viral Parasitic Fungal TB Non-Infectious Hemorrhage IVH SAH Chemical

9 Age of onset Rate of CSF accumulation Associated intracranial anomalies Etiology

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12 Shunts for hydrocephalus Ventriculo-venous shunts using polyethylene tubes 1940s Matson and Ingraham Frequent and easy occlusion with clots Use of the first shunt using a ball and spring valve (1952) Nulsen and Spitz

13 John Holter in laboratory with his wife Mary and their son Casey 1957

14 Historical Treatment of Shunts first pressure regulated valve Divert CSF to: Vascular system Peritoneum Pleura Less desirable spots.. Hydrocephalus

15 Everybody hates shunts. They become blocked and infected; they wander, ulcerate and perforate; they must be pumped or shut off; they must be taken out, put in again, replaced or removed *#+%^! Shunts anonymous

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19 Time to shunt failure Infection Malfunction

20 Shunt Complications Obstruction Shunt failure 30-40% in the first year (Sainte-Rose 1991, Piatt 1993, DiRocco 1994, Drake 1998); 4-5 % per year thereafter Risk increased in infants less than 6 months (47% vs 14%) Ventricular end most common cause of obstruction (63%); proximal end occlusion soon after insertion Shunt disconnection and migration late event Di Rocco et al, Survey of first complication after newly implanted shunt device for the treatment of hydrocephalus, ISPN survey. Childs Nerv System, 10: , 1994 Piatt et al. A search for determinants of cerebrospinal fluid shunt survival: a retrospective analysis. Pediatric Neurosurgery, 19: , 1993

21 Shunt Complications

22 Shunt Complications Over Drainage Extraaxial collections (3.4%) unrelated to type of valve (Drake 1998): most common with large ventricles Slit ventricles Chronic over drainage intracranial hypotension Slit ventricle syndrome Small ventricles and raised intracranial pressure (ICP): a consequence of over-shunting, poor intracranial compliance, symptoms of repeated shunt failure

23 Complications Infection Shunt infection 0.3% - 38% 90% present < 3 months - RARE after 1 year < 1 year of age, < 1.5 Kg, compromised host Bacteriology skin flora - staph epi < 6 months Gm negatives Necessitates 2 operations, 2-3 weeks of Abx Measurable consequences

24 1.0 Failure Rate by Age Group Proportion Failure Free > 10 yr 5-10 yr 1-5 yr 6 mos - 1 yr 1-6 mos < 1 mon Duration of Follow Up (years)

25 Better Shunts, fewer complications?

26 Randomized Trial of CSF Valve Design 344 children <18yo 12 centers Min 3 yr f/u Drake et al Nsurg 43:294, 1998

27 Randomized Trial of CSF Valve Design Drake et al 1998

28 Randomized Trial of CSF Valve Design

29 We need a better way.

30 Advances in Technology Endoscopy Imaging

31 Endoscopic Procedures Initial experience in ETV using ureteroscope Mixter 1923 Access through the lamina terminalis (Dandy) Advent of rod lenses, charge couple devices, optical fibers to transmit light from an outside source (Storz 1965)

32 Endoscopic Third Ventriculostomy the Canadian Experience (Drake 2007) 368 patients - aqueductal stenosis (34%), tumor associated hydrocephalus (29%), IVH (10%), prior shunts (22%) Five year success in <1 mth - 28%, >10 yr - 68%; age was most important variable for success (p< MMC, post-infectious had the least chance for success Age Etiology

33 Endoscopic Third Ventriculostomy 10 y/o boy presented with acute h/a, n/v, papilledema ETV performed 10/4/2005 Asymptomatic post-op with improvement in school grades (straight A s) and concentration Pre-op Post-op

34 Classification of Hydrocephalus Communicating Hydrocephalus block to CSF flow or absorption at the basal cisterns or arachnoid villi Non-communicating Hydrocephalus block to CSF flow at or proximal to the outlet of the fourth ventricle

35 ETV in Infants? ETV in the infant population in Uganda 550 patients underwent ETV; 266 ETV and CPC, 284 ETV alone Majority of patients were postinfectious, non postinfectious or associated with MMC Success rate: ETV-CPC - 66% vs ETV alone 47% (p<0.0001) In MMC, ETV-CPC was more helpful than ETV alone (76% vs 35%, p=0.0045) In patients older than one year, CPC did not add Warf any et al significant, JNS 2005 benefit

36 Infection Rate % infection rate per procedure < 1 mos 1-6 mos 6 mos - 1 yr > 1yr Average Shunt ETV Age Group

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38 Neural Tube Defects Normal and Abnormal Development of the Spine and Spinal Cord

39 Normal Early CNS Development

40 Normal Early CNS Development Neurulation 18 days

41 Normal Early CNS Development

42 Abnormal Early CNS Development Craniorachischisis Anencephaly Holoprosencephaly Hydrocephalus Dandy-Walker Malformation Encephalocele

43 Encephaloceles Cranial NTD 1 in 5000 live births Basal Anterior skull base Sincipital Anterior Convexity Atretic

44 Encephaloceles Prognosis Location Sicipital > basal > convexity Contents Size Associated malformations

45 Sub-Occipital Encephalocele

46 Spina Bifida Embryology

47 Primary Neurulation formation of neural tube of brain and spinal cord begins a stage 10 ~ day 18 at medulla rostral neuropore at stage 11 ~ day 22 Spina Bifida Embryology Secondary Neurulation formation of caudal neural tube sacral and coccygeal segments caudal neuropore closes at stage 12 day 26

48 Spina Bifida Embryology The teratogenic event must occur by the 26th day (stage 12 )- the time of posterior neuropore closure

49 The Spectrum of Spina Bifida

50 Abnormal Early CNS Development Craniorachischisis Spina Bifida Cystica Myelomeningocele Terminal Myelocysotocele Spina Bifida Occulta Lipomyelomeningocele Tight Filum Split Cord Malformation

51 II. Identification of Cutaneous Abnormalities Myelomeningocele

52 II. Identification of Cutaneous Abnormalities Capillary Hemangioma

53 II. Identification of Cutaneous Abnormalities Subcutaneous Lipoma

54 II. Identification of Cutaneous Abnormalities Myelocystocele

55 II. Identification of Cutaneous Abnormalities Skin Appendage

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57 Functional Outcome in Spina Bifida In 163 Adults By Neurological Level Ambulatory vs. Wheelchair 77/163 = 47%

58 Spina Bifida Outcome IQ in 75 Hydrocephalic and Non-hydrocephalic Myelomeningocele Patients

59 Functional Outcome in Spina Bifida Prospect for Living Independently for 69 Survivors

60 Spina Bifida / Myelomeningocele Complex spectrum of CNS anomalies Hydrocephalus Chiari-II Malformation Abnormal spinal cord Hydromyelia

61 Chiari II Malformation Bony anomalies small post fossa large foramen magnum Hydrocephalus Cerebral anomalies polygira interdigitation occip. lobes Cervical anomalies Klippel-Feil Low-lying tentorium Abnormal venous sinuses Brainstem anomalies caudal displacement of CM jn tectal beaking CM kink small cerebellum

62 Chiari II Malformation

63 Spina Bifida Etiology - Folic Acid O.4mg daily PRIOR to conception risk 50% to 70% risk of 2nd child with SB by 72% The Bad News <50% of pregnancies in the US are unplanned

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