Alessandro Fiorindi

Neuroendoscopic biopsy of ventricular tumors: A multicentric experience

OBJECT Although neuroendoscopic biopsy is routinely performed, the safety and validity of this procedure has been studied only in small numbers of patients in single-center reports. The Section of Neuroendoscopy of the Italian Neurosurgical Society invited some of its members to review their own experience, gathering a sufficient number of cases for a wide analysis. METHODS Retrospective data were collected by 7 centers routinely performing neuroendoscopic biopsies over a period of 10 years. Sixty patients with newly diagnosed intraventricular and paraventricular tumors were included. No patient harboring a colloid cyst was included. Data regarding clinical presentation, neuroimaging findings, operative techniques, pathological diagnosis, postoperative complications, and subsequent therapy were analyzed. RESULTS In all patients, a neuroendoscopic tumor biopsy was performed. In 38 patients (64%), obstructive hydrocephalus was present. In addition to the tumor biopsy, 32 patients (53%) underwent endoscopic third ventriculostomy (ETV), and 7 (12%) underwent septum pellucidotomy. Only 2 patients required a ventriculoperitoneal shunt shortly after the endoscopy procedure because ETV was not feasible. The major complication due to the endoscopy procedure was ventricular hemorrhage noted on the postoperative images in 8 cases (13%). Only 2 patients were symptomatic and required medical therapy. Infection occurred in only 1 case, and the other complications were all reversible. In no case did clinically significant sequelae affect the patients outcome. Tumor types ranged across the spectrum and included glioma (low- and high-grade [27%]), pure germinoma (15%), pineal parenchymal tumor (12%), primary neuroectodermal tumor (4%), lymphoma (9%), metastasis (4%), craniopharyngioma (6%), and other tumor types (13%). In 10% of patients, the pathological findings were inconclusive. According to diagnosis, specific therapy was performed in 35% of patients: 17% underwent microsurgical removal, and 18% underwent chemotherapy or radiotherapy. CONCLUSIONS This is one of the largest series confirming the safety and validity of the neuroendoscopic biopsy procedure. Complications were relatively low (about 13%), and they were all reversible. Neuroendoscopic biopsy provided meaningful pathological data in 90% of patients, making subsequent tumor therapy feasible. Cerebrospinal fluid pathways can be restored by ETV or septum pellucidotomy (65%) to control intracranial hypertension. In light of the results obtained, a neuroendoscopic biopsy should be considered a possible alternative to the stereotactic biopsy in the diagnosis and treatment of ventricular or paraventricular tumors. Furthermore, it could be the only surgical procedure necessary for the treatment of selected tumors.

Primary obstruction of the fourth ventricle outlets: neuroendoscopic approach and anatomic description.

OBJECTIVEPrimary obstruction of the foramina of Magendie and Luschka is an uncommon and still unclear cause of noncommunicating hydrocephalus. The aim of this work is the description, for the first time, of the inner aspect of these velar obstructions of the fourth ventricle outlets and the demonstration of the efficacy of neuroendoscopic treatment. METHODSOf 240 hydrocephalic patients treated in our institution with endoscopic third ventriculostomy, a subgroup of 10 cases with closure of the fourth ventricular outlets without associated Chiari malformation and syringomyelia was selected. In all of these cases, a transaqueductal endoscopic navigation of the fourth ventricle was performed, and the obstructed outlets were inspected. All of the clinical data and, in particular, the videotape records of endoscopic operations, as well as the cine-magnetic resonance imaging scans, were reviewed to evaluate their patency status. RESULTSVarious degrees of stenosis were found endoscopically: restriction of the Magendie contour with thick and opaque membrane, transparent spider web-like membrane, and dense membrane with fissures acting as valves. Endoscopic third ventriculostomy was effective in almost all patients, although we noticed an unforeseen high incidence of closure of the stoma. The restored normal cerebrospinal fluid flux after ventriculocisternostomy and magendieplasty was demonstrated by comparative study of cerebrospinal fluid flow measurements by cine-magnetic resonance imaging. CONCLUSIONThis report demonstrates the effectiveness of neuroendoscopic third ventriculostomy as well as magendiestomy in cases of tetraventricular hydrocephalus attributable to primary obstruction of the outlets of the fourth ventricle and, for the first time, presents direct images of various types of outlet obstructive pathology.

Choroid plexus and aquaporin-1 : A novel explanation of cerebrospinal fluid production

Aquaporins are selective water channel proteins that play a central role in the homeostasis of human body water. The choroid plexus (CP) is considered to be the main cerebrospinal fluid (CSF)-producing structure. In this study, six specimens of normal human CP obtained during surgery were analyzed by immunohistochemistry techniques for aquaporin-1 (AQP1) expression and distribution. Intense, uniformly distributed AQP1 immunostaining was observable in the apical but not the basolateral side of cuboid cells of the CP. Moreover, this polarized expression of AQP1 was weakly detectable in the endothelial cells of choroid microvessels and, with a different pattern, in the cells lining the tubules shaped into crypts. Selective AQP1 expression on the surface of the normal human CP might explain the role of CSF production by this complex structure.

Endoscopic Anatomy of the Cerebral Aqueduct

OBJECTIVE What is known about the cerebral aqueduct is derived mainly from the legacy of classic histology and from the most recent advanced neuroimaging technologies. In fact, although this important structure is frequently glimpsed by neurosurgeons, only limited anatomic contributions have been added by microsurgery to its direct in vivo description. A review of our surgical experience in navigating the fourth ventricle prompted us to revisit the classical anatomic descriptions of the aqueduct and compare them using the novel perspective of neuroendoscopy. METHODS We reviewed video recordings of 65 transaqueductal explorations of the fourth ventricle using flexible endoscopes, which were performed in our center to treat various pathological conditions. Forty-one patients were selected as being more informative for anatomic description. They include 21 patients with communicating normal pressure hydrocephalus, 6 patients with intraventricular hemorrhage, 5 patients with membranous obstruction of the foramen of Magendie, 5 patients with trapped fourth ventricle as evidenced after aqueductoplasty, 3 patients with colloid cysts, and 1 patient with craniopharyngioma with apparently normal aqueduct, which was navigated to aspirate small fragments of colloid and tiny clots. RESULTS Patients with normal-sized third ventricles confirmed the typical triangular shape of the aqueductal adytum, whereas all pathological aqueducts invariably had an oval contour. The posterior commissure, a faint trace of the median sulcus, and the rubral eminences were the structures invariably noticed. Five segments of the aqueduct were always identifiable: the adytum, first constriction, ampulla, second constriction, and posterior part or egressus. CONCLUSION Neuroendoscopy provides a novel perspective into the inner aqueductal wall and supplies an incomparable view of the intracanalicular anatomic structures.

Neuroendoscopic aspiration of hematocephalus totalis: Technical note

OBJECTIVE AND IMPORTANCE: Massive intraventricular hemorrhage requires aggressive and rapid management to decrease intracranial hypertension. The amount of intraventricular blood is a strong prognostic predictor, and its fast removal is a priority. Neuroendoscopy may offer some advantages over more traditional surgical approaches. We describe here the technical details and clinical outcomes of the neuroendoscopic management of massive tetraventricular hemorrhage in 25 consecutive patients, highlighting the potential pitfalls and the advantages of the technique. CLINICAL PRESENTATION: Twenty-five patients, aged 7 to 80 years, presenting with massive ventricular hemorrhage were admitted between January 1996 and May 2004 to our neurosurgery unit after an emergency computed tomographic scan. Severity of ventricular hemorrhage was graded according to the Graeb scale; the mean Graeb score was 9.8 ± 2.9. Hemorrhages were secondary to vascular malformation in 12 cases. INTERVENTION: Endoscopy was performed on the first day in 17 cases, with a delay of 1 to 5 days in the remaining 8 cases. A flexible endoscope with “free-hand” technique was always preferred. The ventricular cleaning proceeded in three phases: lateral ventricle, third ventricle, and then aqueduct and fourth ventricle. In selected patients, a catheter, both for intracranial pressure monitoring and for drainage, was positioned. The procedure was successfully completed in all cases. There was no surgery-related mortality. The mean length of intensive care unit stay after the operation was 18 ± 12 days. Short-term mortality (1 mo) was 12%, whereas long-term (>6 mo) mortality was 24%. Complete recovery (Glasgow Outcome Scale score, 5) was achieved in 40% of cases. A ventriculoperitoneal shunt was necessary in 12% of patients. CONCLUSION: Intraventricular hemorrhage, analogously to other ventricular diseases, can be treated successfully with flexible endoscopes. Obviously, the limitation of this study lies in its observational nature; however, the encouraging results reported here should prompt a randomized study to evaluate the effectiveness and efficiency of the endoscopic approach in comparison to the more established semiconservative management offered by external derivation with fibrinolytic agents.

Endoscopic treatment of brain abscesses

BackgroundStereotactic aspiration with external drainage has become widely accepted as the standard treatment for intracerebral abscesses. Although neuroendoscopic technique has only been occasionally adopted for this pathology, it introduces some advantages because it presents visual awareness that the pus has been removed.MethodsFour patients with cerebral abscess and one with a subdural empyema were operated using a neuroendoscopic technique in our Department between 1996 and 2003. A 4-mm flexible endoscope was introduced into the purulent collection through a burr hole, the pus was meticulously aspirated, and the cavity washed with isovolumetric antibiotic lavages using the working channel for both irrigation and suction.ConclusionNeuroendoscopic treatment of brain abscesses presents some additional advantages as a possible alternative to stereotactic aspiration, which still constitutes the gold standard for this pathology. The adoption of stereotactic or frameless guidance systems can probably be recommended particularly for deep, complex lesions.

Neuroendoscopic aspiration of tumors in the posterior third ventricle and aqueduct lumen: a technical update.

BackgroundSmall soft ventricular tumors are good candidates for complete removal by a purely endoscopic technique. This approach is particularly interesting for lesions located in the posterior third ventricle and aqueductal lumen.MethodsWe present our method of endoscospic aspiration through direct contact between the tumor and the working channel of a flexible scope.ResultsAspiration without the intermediate use of cannulas is safe and has proved to be effective in the apparently total or partial removal of three soft tumors of different pathologies located in the third ventricle or aqueductal lumen. In one case, a second neuroendoscopy a few months later to repeat endoscopic third ventriculostomy (ETV) offered a unique opportunity to observe the absence of the tumor and the restored anatomy.ConclusionsNeuroendoscopy provides a safe, effective way to radically resect small soft tumors in these troublesome locations and can be a valuable alternative to microsurgery.

Fluorescein-enhanced characterization of additional anatomical landmarks in cerebral ventricular endoscopy.

BACKGROUND Fluorescein enhancement to detect retinal disorder or differentiate cancer tissue in situ is a well-defined diagnostic procedure. It is a visible marker of where the blood-brain barrier is absent or disrupted. Little is reported in the contemporary literature on endoscopic fluorescein-enhanced visualization of the circumventricular organs, and the relevance of these structures as additional markers for safe ventricular endoscopic navigation remains an unexplored field. OBJECTIVE To describe fluorescein sodium-enhanced visualization of circumventricular organs as additional anatomic landmarks during endoscopic ventricular surgery procedures. METHODS We prospectively administered intravenously 500 mg fluorescein sodium in 12 consecutive endoscopic surgery patients. A flexible endoscope equipped with dual observation modes for both white light and fluorescence was used. During navigation from the lateral to the fourth ventricle, the endoscopic anatomic landmarks were first inspected under white light and then under the fluorescent mode. RESULTS After a mean of 20 seconds in the fluorescent mode, the fluorescein enhanced visualization of the choroid plexus of the lateral ventricle, median eminence-tuber cinereum complex, organum vasculosum of the lamina terminalis, choroid plexus of the third and fourth ventricles, and area postrema. CONCLUSION Fluorescein-enhanced visualization is a useful tool for helping neuroendoscopists recognize endoscopic anatomic landmarks. It could be adopted to guide orientation when the surgeon deems an endoscopic procedure unsafe or contraindicated because of unclear or subverted anatomic landmarks. Visualization of the circumventricular organs could add new insight into the functional anatomy of these structures, with possible implications for the site and safety of third ventriculostomy.

Neuroendoscopic options in the treatment of mesencephalic expanding cysts: Report of four cases and review of the literature

OBJECTIVE Mesencephalic expanding cysts, also called lacunae, are rare intraparenchymal, multilobulated cavities of variable diameter mostly localized in the thalamo-mesencephalic region. In symptomatic cases, usually presenting with hydrocephalus or midbrain syndrome, surgical treatment is required and, considering their position, a minimally invasive approach should be preferred. METHODS Four cases of expanding mesencephalic cysts endoscopically treated in three different Italian centers are described. Other possible causes of intracerebral cyst were excluded in all cases by complete neuroimaging and laboratory screening. All patients presented with signs and symptoms of midbrain compression and a slight to moderate ventricular dilation was present in three cases. RESULTS All patients underwent endoscopic cyst fenestration into the ventricle, associated with endoscopic third-ventriculostomy (ETV) in two cases and with cyst wall biopsy in one case. One patient suffered from transient worsening of her hemiparesis due to intraoperative bleeding. All patients showed clinical improvement and a reduction in cyst size on follow-up magnetic resonance images (MRI). CONCLUSION Neuroendoscopy appears to be an effective, probably definitive surgical option in the treatment of symptomatic mesencephalic expanding cysts. Associating ETV with cyst fenestration seems to offer more complete treatment. Deep intracystic navigation and cyst wall biopsy should be avoided.

Fluorescein-Guided Neuroendoscopy for Intraventricular Lesions: A Case Series

BACKGROUND The benefits of neuroendoscopy in the pathological diagnosis of intra- and paraventricular tumors have already been shown in many neurosurgical studies. However, most authors agree that neuroendoscopic biopsies are not infrequently inconclusive due to small or inadequate samples, prompting the need for new diagnostic strategies. OBJECTIVE To describe a technique not previously reported in the literature, combining neuroendoscopy with angiofluorescein guidance for the pathological diagnosis of intra- and paraventricular tumors. METHODS The 4-mm steerable fiberscope used was equipped with dual observation modes for white light and fluorescein. Access was by the classical precoronal burr hole. After inspecting the ventricular system in white light, a 10-mg/kg dose of fluorescein sodium (FS) was administered intravenously to the patient. The endoscope was then switched to the blue light fluorescent mode to better localize the pathological tissue. The protocol had been submitted to the local ethics committee. RESULTS From September 2011 to March 2015, 9 consecutive patients (aged 1-56 yr) harboring intra- and paraventricular lesions prospectively underwent angiofluorescein-guided endoscopy. In all cases, a pathological diagnosis was obtained without complications. In 5 patients, an endoscopic third ventriculostomy, and, in 1 patient, a septostomy was performed during the same procedure. Fluorescein guidance definitely modified our site of biopsy in 4 cases. CONCLUSION In our experience, FS has proven to be a strong enhancer of all ventricular lesions presenting with a disrupted blood-brain barrier, including inflammatory processes. Fluorescein-guided neuroendoscopy appears to be a safe, economic method to improve diagnostic potential in ventricular lesions.