Felippe Saad

Ultrastructural study of the filum terminale and its elastic fibers.

OBJECTIVE:The filum terminale (FT) is a fibrovascular band involved in the pathophysiology of tethered cord syndrome (TCS). Its morphological and ultrastructural properties remain largely unknown even though they are thought to play a role in the generation of TCS in adult patients with normal level conus medullaris. MATERIALS AND METHODS:Twenty fresh adult human cadavers had their fila measured and removed. Transversal and longitudinal sections of the proximal, middle, and distal thirds of FT were submitted to light microscopy analysis with four different techniques. Five fila were selected for longitudinal and transversal scanning electron microscopy analysis. RESULTS:The bulk of the FT is composed of 5- to 20-&mgr;m thick longitudinal bundles of Type 1 collagen separated by 3- to 10-&mgr;m intervals, although capillaries and other elements may be present. A delicate (0.05–1.5 &mgr;m) meshwork of predominantly Type 3 collagen transversal fibers connects these bundles. Abundant longitudinally oriented elastic and elaunin fibers are found inside collagen bundles. A complex tridimensional structure is evidenced on electron microscopy. CONCLUSION:The longitudinal arrangement of collagen bundles and the impressive amount of elastic and elaunin fibers should elicit considerable elastic properties to the FT. An altered elasticity mechanism has been proposed for TCS; further studies are needed with TCS patients to define whether the collagen structure, Type 1/Type 3 proportion, or elastic fiber content are altered, which could lead to new histopathological definitions of TCS, helping neurosurgeons in the difficult management of TCS patients with normal level conus medullaris.

Role of endoscopic third ventriculostomy and ventriculoperitoneal shunt in idiopathic normal pressure hydrocephalus: preliminary results of a randomized clinical trial.

BACKGROUND Currently, the most common treatment for idiopathic normal pressure hydrocephalus (INPH) is a ventriculoperitoneal shunt (VPS), generally with programmable valve implantation. Endoscopic third ventriculostomy (ETV) is another treatment option, and it does not require prosthesis implantation. OBJECTIVE To compare the functional neurological outcome in patients after 12 months of treatment with INPH by using 2 different techniques: ETV or VPS. METHODS Randomized, parallel, open-label trial involving the study of 42 patients with INPH and a positive response to the tap test, from January 2009 to January 2012. ETV was performed with a rigid endoscope with a 30° lens (Minop, Aesculap), and VPS was performed with a fixed-pressure valve (PS Medical, Medtronic). The outcome was assessed 12 months after surgery. The neurological function outcomes were based on the results of 6 clinical scales: mini-mental, Berg balance, dynamic gait index, functional independence measure, timed up and go, and normal pressure hydrocephalus. RESULTS There was a statistically significant difference between the 2 groups after 12 months of follow-ups, and the VPS group showed better improvement results (ETV = 50%, VPS = 76.9%). CONCLUSION Compared with ETV, VPS is a superior method because it had better functional neurological outcomes 12 months after surgery.

Programmable valve represents an efficient and safe tool in the treatment of idiopathic normal-pressure hydrocephalus patients

UNLABELLED Idiopathic normal pressure hydrocephalus (iNPH) is characterized by gait disturbance, dementia and /or urinary incontinence, dilation of the ventricular system and normal opening cerebrospinal fluid pressure. Shunt surgery is the standard treatment of iNHP. Diversions with programmable valves are recommended, once drainage pressure can be changed. However, well-defined protocols still lack guiding the steps to attain proper pressure for each patient. METHODS In our study, we reported the experience of shunting 24 patients with iNPH using Strata® (Medtronic) valve, following a protocol based on a positive Tap Test. RESULTS We observed clinical improvement in 20 patients and stability/worsening in 4 patients. Complications occurred in five patients, including one death. The results display improvement, and complications occurred at a lower rate than reported in other studies. CONCLUSIONS The Strata® valve used in the proposed protocol represents an efficient and safe tool in the treatment of iNPH.

Performance of fixed-pressure valve with antisiphon device SPHERA® in hydrocephalus treatment and overdrainage prevention

Patients with hydrocephalus and risk factors for overdrainage may be submitted to ventricular shunt (VS) implant with antisiphon device. The objective of this study was to prospectively evaluate for two years the clinical and tomographic results of the implant of fixed-pressure valves with antisiphon device SPHERA(®) in 35 adult patients, with hydrocephalus and risk factors for overdrainage. Of these, 3 had congenital hydrocephalus in adult patients with very dilated ventricles (Evans index >50%), 3 had symptomatic overdrainage after previous VS implant (subdural hematoma, hygroma or slit ventricle syndrome), 1 had previous chronic subdural hematoma, 15 had normal pressure hydrocephalus with final lumbar pressure <5 cm H(2)O after tap test (40 mL), 6 had pseudotumor cerebri, and 7 had hydrocephalus due to other causes. Clinical improvement was observed and sustained in 94.3% of the patients during the two-year period with no computed tomography (CT) evidence of hypo or overdrainage, and no immediate early or late significant complications.