Nijaguna Mathad

The Natural History of Cranial Dural Arteriovenous Fistulae With Cortical Venous Reflux-The Significance of Venous Ectasia

BACKGROUND: The quoted risk of hemorrhage from dural arteriovenous fistulae with cortical venous reflux varies widely, and the influence of angiographic grade on clinical course has not previously been reported. OBJECTIVE: To assess the risk of hemorrhage and the influence of angiographic grade on this risk, compared with known predictors of hemorrhage such as presentation. METHODS: Seventy-five fistulae with cortical venous reflux identified in our arteriovenous malformations clinic between 1992 and 2007 were followed up clinically, and their angiograms were reviewed. RESULTS: There were 8 hemorrhages in 90 years of follow-up. The annual incidence of hemorrhage before any treatment was 13%, and 4.7% after partial treatment, giving an overall incidence of 8.9% before definitive treatment. Borden and Cognard grades were poor discriminators of risk for lesions with the exception of Cognard type IV lesions. These lesions, characterized by venous ectasia, had a 7-fold increase in the incidence of hemorrhage (3.5% no ectasia vs 27% with ectasia). Patients presenting with hemorrhage (20%) or nonhemorrhagic neurological deficit (22%) had a higher incidence of hemorrhage than those with a benign presentation (4.3%), but this may be directly linked to the presence of venous ectasia. CONCLUSION: In this series untreated dural arteriovenous fistulae with cortical venous reflux had a 13% annual incidence of hemorrhage after diagnosis. There was a significant difference between those with and without venous ectasia. This should be confirmed by further studies, but probably defines a high-risk subgroup of patients that requires rapid intervention.

Endoscopic third ventriculostomy in the treatment of childhood hydrocephalus: validation of a success score that predicts long-term outcome

OBJECT The goal of this study was to externally validate the proposed Endoscopic Third Ventriculostomy Success Score (ETVSS), which predicts successful treatment for hydrocephalus on the basis of a childs individual characteristics. METHODS The authors retrospectively identified 181 cases of consecutive endoscopic third ventriculostomy (ETV) performed in children at a single neurosurgery center in the United Kingdom. They compared actual success at both 6 and 36 months, with mean predicted probabilities for low, moderate, and high chance of success strata based on the ETVSS. Long-term success was calculated using Kaplan-Meier methods and comparisons were made by means of unpaired t-tests. RESULTS Overall, 166 primary ETVs were performed; ETV success was 72.9% at 6 and 64.5% at 36 months. At long-term follow-up, the mean predicted probability of success was significantly higher in those with a successful ETV (99 patients) than in those with a failed ETV (67 patients) (p = 0.001). The ETVSS accurately predicted outcome at 36 months; the low, medium, and high chance of success strata had mean predicted probabilities of success of 82%, 63%, and 36%, and actual success of 76%, 66%, and 42%, respectively. The overall complication rate was 6%. CONCLUSIONS The ETVSS closely predicted the overall long-term success rates in high-, moderate-, and low-risk groups. The results of this study suggest that the ETVSS will aid clinical decision making in predicting outcome of ETV.

Patient-reported nasal morbidity following endoscopic endonasal skull base surgery

Abstract Objective. To quantify the frequency and severity of nasal morbidity following endoscopic endonasal skull base surgery using patient-reported outcome measures. Methods. Retrospective review and follow-up of all patients who underwent endoscopic endonasal skull base surgery at University Hospital Southampton between January 2007 and December 2011. Demographic data were collated from case notes and patients were asked a standardised questionnaire by telephone interview. Statistical sub-analysis of pituitary and other anterior skull base pathology groups was performed using SPSS 1.8. Results. Out of 151 included patients, 85 had a pituitary pathology and the remaining had other anterior skull base pathologies. The mean age was 55.2 years, with 75 male and 76 female patients. Totally 124 patients were interviewed with a median follow-up of 15 months. Mild or no nasal crusting was reported by 77% of patients. In those experiencing crusting, more than 50% resolved within 4 weeks. The majority of patients reported no nasal blockage (52%), pain (83%) or nasal discharge (57%) post-operatively. Totally 71% reported no change in sense of smell post-operatively. The only statistically significant difference between the two pathology groups was that surgery on other anterior skull base pathology was associated with an increased rate of developing anosmia (p = 0.02). Conclusion. Endoscopic endonasal skull base surgery is associated with a low level of patient-reported post-operative nasal morbidity. There is no significant difference in frequency of crusting, blockage, pain or discharge between pituitary and other anterior skull base pathology groups. However, anterior skull base surgery would appear to be associated with an increased rate of anosmia post-operatively.

Endoscopic Biopsy and Third Ventriculostomy for the Management of Pineal Region Tumors

OBJECTIVE To assess the histologic accuracy of endoscopic biopsy samples of the pineal region. Pineal region tumors usually present with acute hydrocephalus. Histologic diagnosis is paramount, as it greatly influences treatment. Endoscopic techniques can combine histologic diagnosis with relief of the obstructive hydrocephalus in a single operation. Because pineal region tumors can be heterogeneous, initial biopsy samples may not represent the most aggressive portion of the tumor. METHODS This retrospective study reviews our experience of endoscopic third ventriculostomy combined with biopsy of the lesion. The histologic diagnosis as a result of the initial biopsy was compared with the final histologic diagnosis to establish the accuracy of the endoscopic biopsy sample in aiding diagnosis. RESULTS Forty-seven patients underwent an endoscopic third ventriculostomy. All but 1 patient underwent a concurrent biopsy of the space-occupying lesion and 39 of 46 patients (85%) had a histologic diagnoses. In the remaining 7 patients (15%), the histology was negative; in 6 cases, the second attempt to obtain a histologic diagnosis was successful (2 repeat endoscopic biopsy samples, 2 resections, 2 stereotactic biopsy samples). In 1 patient a presumed low-grade tectal tumor was followed up with sequential scanning. Twenty-eight patients underwent subsequent operations (24 resections, 4 stereotactic biopsies). In 6 of 28 patients (21%), the histologic report was amended after the second procedure. CONCLUSIONS The endoscopic biopsy sample yields an accurate histologic diagnosis for most pineal region tumors, with a positive histologic sample in about 85% of patients. However, the results must be interpreted cautiously, as the heterogeneous nature of these tumors may lead to an approximately 21% error rate in the initial tumor diagnosis.

Giant prolactinoma causing cranio-cervical junction instability: a case report.

Prolactinomas are common secretory pituitary tumours, usually managed with dopamine agonists. There have previously been case reports of rarer giant prolactinomas causing invasion of surrounding structures. We describe a case report of an exceptionally aggressive giant prolactinoma that eroded the occipital condyles causing cranio-cervical joint instability mandating surgical fixation.

Fibrin Sealant Injection: An Aid to Reduce Venous Bleeding during Jugular Bulb and Sigmoid Sinus Dissection in Glomus Jugulare (Jugulotympanic Paraganglioma) Surgery.

Glomus jugulare (jugulotympanic paraganglioma) surgery requires tumor dissection in the region of the jugular bulb, upper internal jugular vein, and sigmoid sinus. Despite ligation or external compression of the sigmoid sinus proximally and ligation of the internal jugular vein distally, troublesome venous bleeding can arise from the inferior petrosal sinus or condylar veins at the medial wall of the jugular bulb. Excessive packing in this area can place the integrity of the lower cranial nerves at risk. We report a technique in which Tisseel(®) fibrin sealant is injected into the ligated sigmoid sinus and internal jugular vein. This forms an internal cast around the tumor in the sigmoid-jugular complex and helps seal the inferior petrosal sinus and condylar veins. This allows for safer dissection with reduced venous bleeding. Our experience in five cases has shown this technique to be effective.

Endoscopic endonasal resection of large skull base schwannoma

Abstract Schwannomas of the skull base can pose a surgical challenge due to their anatomical location. To date extensive craniofacial approaches have had to be used to access these lesions. We present a patient where an expanded endoscopic endonasal approach was used to address a large skull base schwannoma with good results. The approach confers significantly less morbidity and a substantially shorter hospital stay.

Hydrocephalus outcome: validation of endoscopic third ventriculostomy success score

Aims To externally validate the Endoscopic Third Ventriculostomy Success Score (ETVSS) recently found by Kulkarni et al1 to predict successful ETV for hydrocephalus, that is, child not requiring shunt or repeat ETV, on the basis of a childs individual characteristics. The ETVSS is based upon patient age, aetiology and presence of a previous shunt. To date there has been no external validation of this model. We consider both short term and long term outcome, using a detailed large single centre series of paediatric patients with a long period of follow-up. Methods We retrospectively identified consecutive children undergoing ETV at a single regional neurosurgery centre. We compared actual success at both 6 and 36 months with mean predicted probabilities for low, moderate and high chance of success strata based on the ETVSS. Long-term success was calculated using Kaplan Meier methods and comparisons made by unpaired t tests. Results In total 166 primary ETV were performed at a median age of 39 (range 0.03–230) months. There was a greater number of patients in younger age groups in this series; 49 patients were under 6 months of age (29.5%) compared to 129 (20.9%) in the model dataset (difference 8.6%, CI 1.0 to 16.3; p=0.07). Overall, ETV success was 72.9% at 6 and 64.5% at 36 months. Although derived to predict outcome at 6 months, the model predicted outcome better on long-term follow-up than at 6 months. At long-term follow-up, the mean predicted probability was significantly higher in those with a successful ETV (n=99) than in those who failed (n=67) (p=0.001). The ETVSS accurately predicted long term success rates; the low, medium and high groups had mean predicted probabilities of 82%, 63% and 36% and overall success at 36 months of 76%, 66%, 42% respectively. The overall complication rate was 6%. Conclusion The ETVSS closely predicted the overall long term success rates in high, moderate and low risk groups. Our study suggests the ETVSS will be useful in the clinical decision-making in predicting long term outcome of ETV but further refinement of the model, validation and comparison with shunt treatment is required.