Conquering the Rock-A Retrospective Single-Center Experience of the Transapical Petrosal Transtentorial (Kawase) Approach: Operative Technique and Impact on Cranial Nerve Function.

Since its description in 1985, the transapical petrosal transtentorial or Kawase approach has become a viable option of approaching lesions located in and around the apex of the petrous bone, Meckel's cave, and the anterolateral surface of the brain stem while preserving cranial nerve function. At the Brain Tumor Center, Erasmus MC, 25 patients were treated using the Kawase approach between 2004 and 2018 for various indications, including petroclival meningiomas, chondrosarcomas, pontine cavernomas, trigeminal schwannomas, and posterior circulation aneurysms. Hearing preservation was achieved in all patients; new abducens nerve and trochlear nerve palsies were present in three and six patients, respectively, of which a total of eight required ophthalmological correction. Seven patients experienced a cerebrospinal fluid fistula postoperatively, but this complication appeared self-limiting in all cases, with one patient experiencing secondary meningitis. After modifying our closure technique, the rate of fistulas dropped to zero. The observed direct postoperative mortality was 4% (one patient), although not related to the approach itself. In conclusion, the Kawase approach is a highly complex, but essential middle fossa approach, extremely robust, and able to serve a wide array of pathologies together with its extensions. It is very accurate for performing hearing preservation surgery, but not without caveats and inherent risk of complications.

Spinal meningiomas: Treatment outcome and long-term follow-up.

BACKGROUND: Spinal intradural tumors can be classified as intradural extramedullary or intramedullary tumors. Spinal meningiomas are among the most frequent intradural, extramedullary tumors (IDEMs), representing 12 % of all meningiomas and 25-45 % of all intradural spinal tumors. OBJECTIVE: To evaluate postoperative outcome, defined by mortality, tumor recurrence and modified Rankin Scale in patients with spinal meningiomas. Furthermore, to identify factors related to these outcome measures and define possible prognosticators. METHODS: A large single center retrospective analysis of 166 consecutive spinal meningioma patients during a 29-year period (1989-2018). RESULTS: Female to male ratio was 5.15 to 1. Of all 166 resected tumors, 159 were WHO grade I and seven were WHO grade II. Histopathologically, the psammomatous type was most common (42.8 %). The thoracic region was the most frequent location (71.1 %), followed by cervical and lumbar locations. A complete resection (Simpson I-III) was achieved in 88.7 %. In 12 cases (7.2 %) recurrences of a spinal meningioma occurred after an interval of 0.70-13.78 years. Postoperative complications consisted of CSF leakage and wound healing problems. Three patients died of direct postoperative complications (1.8 %), nine patients died in follow-up due to unrelated causes. Post-operative complications were related to the overall outcome (p = 0.029). Clinical outcome showed improvement in 117 patients out of 148 (79.1 %) according to modified Rankin Scale; 24 patients remained stable and 7 patients deteriorated. Patients with pre-existing bladder/bowel problems and incomplete resections had higher chance of recurrences. Younger patients also had a higher recurrence rate. Follow-up ranged from 0 to 23 years, median of 0.77 years, most were discontinued after 2 years. CONCLUSIONS: The primary treatment of spinal meningiomas remains surgery. Complete resection of spinal meningiomas is achieved in most of the cases, however preserving and improving neurological status has priority over complete tumor resection. Morbidity and mortality is relatively low. Longer follow-up periods are recommended, since recurrences can occur after 10-15 years.

The membrane of Liliequist-a safe haven in the middle of the brain. A narrative review.

BACKGROUND: The membrane of Liliequist is one of the best-known inner arachnoid membranes and an essential intraoperative landmark when approaching the interpeduncular cistern but also an obstacle in the growth of lesions in the sellar and parasellar regions. The limits and exact anatomical description of this membrane are still unclear, as it blends into surrounding structures and joins other arachnoid membranes. METHODS: We performed a systematic narrative review by searching for articles describing the anatomy and the relationship of the membrane of Liliequist with surrounding structures in MEDLINE, Embase and Google Scholar. Included articles were cross-checked for missing references. Both preclinical and clinical studies were included, if they detailed the clinical relevance of the membrane of Liliequist. RESULTS: Despite a common definition of the localisation of the membrane of Liliequist, important differences exist with respect to its anatomical borders. The membrane appears to be continuous with the pontomesencephalic and pontomedullary membranes, leading to an arachnoid membrane complex around the brainstem. Furthermore, Liliequist's membrane most likely continues along the oculomotor nerve sheath in the cavernous sinus, blending into and giving rise to the carotid-oculomotor membrane. CONCLUSION: Further standardized anatomical studies are needed to clarify the relation of the membrane of Liliequist with surrounding structures but also the anatomy of the arachnoid membranes in general. Our study supports this endeavour by identifying the knowledge hiatuses and reviewing the current knowledge base.

Systematic review of current randomised control trials in chronic subdural haematoma and proposal for an international collaborative approach.

BACKGROUND: Chronic subdural haematoma (CSDH) is a pathology that is frequently encountered by neurosurgeons. Nevertheless, there is a lack of guidelines based on solid evidence. There has been a recent and considerable increase in the interest on management and outcomes for CSDH. Therefore, we systematically reviewed all currently running randomised controlled trials (RCTs) in chronic subdural haematoma to understand the areas under investigation and plan future collaborative trials. METHODS: Clinical trials databases (Cochrane Controlled Register of Trials, WHO ICTRP and clinical trials.gov) were searched for trials relevant to chronic subdural haematoma. It was then established which trials were currently running and fulfilled robust research methodology for a RCT. RESULTS: There are 26 currently running RCTs in CSDH, with the most common topics covering application of steroids (7), surgical techniques (5) and tranexamic acid (5). Further to this, there are trials running on other pharmacological agents (4), middle meningeal artery (MMA) embolisation (2) and peri-operative management (3). CONCLUSIONS: Pharmacological agents are a particular focus of CSDH management currently, and a wealth of studies on steroids will hopefully lead to more harmonised, evidence-based practice regarding this in the near future. Surgical techniques and new procedures such as MMA embolisation are also important focuses for improving patient outcomes. There is an on-going need for future RCTs and evidence-based guidelines in CSDH, particularly including low- and middle-income countries, and it is hoped that the establishment of the iCORIC (International COllaborative Research Initiative on Chronic Subdural Haematoma) will help address this.

The importance of microsurgery in childhood meningioma: a case report.

INTRODUCTION: Although meningiomas are frequently diagnosed in adults, it is a rare (intracranial) tumor in the pediatric population, with an incidence of 0.06/100,000. The pathology and treatment of meningiomas in adulthood has been a topic of increasing investigation. So far, the treatment of pediatric meningiomas has been extrapolated from these results. The question remains, however, whether translation of adult meningioma data into the childhood population is legitimate. METHODS: We present the case of a 3-year-old girl diagnosed with an intraventricular malignant meningioma and type 2 neurofibromatosis. She was operated on multiple times to achieve complete resection and received adjuvant chemotherapy. Since, she has been stable with no neurological sequelae and/or recurrence of the meningioma. CONCLUSION: Pediatric meningiomas are rare tumors and differ from their adult counterparts in various aspects. We believe that gross total resection of meningioma in the pediatric population, when possible, is the treatment of choice. In the event of a subtotal resection, repeat resection is recommended. Any adjuvant treatment with chemotherapy or radiation therapy should be carefully considered during multidisciplinary meetings.

Ambivalence among neurologists and neurosurgeons on the treatment of chronic subdural hematoma: a national survey.

No class I evidence exists about the optimal treatment of chronic subdural hematoma (CSDH). The aim of this study was to evaluate current practice of CSDH patients with different neurological grades, and probable ambivalence towards various treatment paradigms, especially primary treatment with high-dose corticosteroids, among vascular neurologists and neurosurgeons. A questionnaire survey containing 4 questions, 1 consisting of cases, was sent to every vascular neurologist (n = 83) and neurosurgical centre (n = 15) in the Netherlands. The various treatment options were related to the treating physician, geographical distribution, both in general and for individual case. Sixty-two percent of surveys were returned. The proportion of patients primarily treated with corticosteroids was 17.5 % in 2009 and 20.5 % in 2010. Surgery by either burr holes or craniotomy was favoured by 61.1 % as primary treatment, and conservative treatment with corticosteroids by 22.4 %. Case studies revealed that surgery was preferred in case of severe neurological symptoms, whereas wait-and-see policy was preferred in case of mild symptoms without midline shift, of which 28 % would administer corticosteroids. Variety in answers was obtained in less pronounced cases. In the Netherlands, neurologists and neurosurgeons appear to favour surgery in CSDH patients as primary treatment, especially in severe cases. An ambivalent approach towards treatment protocols was shown, especially in patients with mild symptoms, regardless of hematoma size. A regimen of high-dose corticosteroids only, is preferred by about a quarter and predominantly in milder cases, and might depend on geographical distribution. These results suggest the need for a well-designed randomized trial.

Endoscopic third ventriculocisternostomy in hydrocephalic children under 2 years of age: appropriate or not? A single-center retrospective cohort study.

PURPOSE: Treating hydrocephalus can be difficult in children under the age of 2 years because a high amount of uncertainty exists as to which treatment to perform. In this retrospective cohort study, we analyzed children under the age of 2 years with hydrocephalus undergoing an endoscopic third ventriculocisternostomy (ETV) with respect to ETV outcome. METHODS: In 59 consecutive patients under the age of 2 years, an ETV was performed between 1999 and 2010 at the Erasmus MC, Sophia Children's Hospital. Demographics, etiology of hydrocephalus, and radiological data were extracted retrospectively from the patients' medical records and operative reports and related to outcome. ETV Success Score (ETVSS) was used to retrospectively calculate the probability of success related to the actual outcome. RESULTS: In this series, 42.4 % of patients had a successful ETV. The only statistically significant finding concerned age. The failed ETV patients appeared to be younger (0.52 ± 0.60 vs. 0.86 ± 0.56 year, p = 0.005), and when using a cutoff age of 6 months only, five out of 32 infants had a successful ETV (p = 0.002). Of the children with an arachnoid cyst, 57.1 % were treated successfully with an ETV. Of the five patients with a high probability of ETV success, four (80 %) were indeed successfully treated with ETV (p = 0.049). CONCLUSIONS: Our data confirm the overall ineffectiveness of an ETV in children under the age of 6 months. Nevertheless, using the ETVSS is recommended to aid in the decision-making process even in patients under the age of 6 months.

The role of corticosteroids in the management of chronic subdural hematoma: a systematic review.

The role of corticosteroids in the management of chronic subdural hematoma (CSDH) remains a matter of debate. Standard surgical treatment has recurrence rates reported between 4 and 26%. We reviewed the safety and effectiveness of corticosteroids both as a monotherapy and as an adjunct to surgery in patients with CSDH. PubMed-MEDLINE, EMBASE and Cochrane databases were searched in July 2011 for randomized controlled trials and for prospective and retrospective cohort studies, reporting on 10 or more adult patients with CSDH. Quality was assessed according to the STROBE checklist. Corticosteroid monotherapy and surgery with corticosteroids as an adjunct were compared with no treatment or surgery only, with regard to lethality, neurological outcome, secondary intervention and complications. Five observational studies were included in this review. There was no randomized allocation of treatment in any study. Secondary intervention rates ranged from 3 to 28%, lethality rates ranged from 0 to 13%, and good outcome was seen in 83-100%. Hyperglycemia occurred more often in patients treated with corticosteroids. In only two studies, one case of gastrointestinal bleeding was observed. Five observational studies suggest that corticosteroids might be beneficial in the treatment of CSDH; however, there is a lack of well-designed trials that support or refute the use of corticosteroids in CSDH. These results encourage further randomized clinical trials to establish the role of corticosteroids in CSDH.

Chronic serous otitis media as a manifestation of temporal meningioma.

Chronic serous otitis media is a common problem in the daily routine of the otorhinolaryngologist. In the majority of cases, the cause is related to dysfunction of the eustachian tube due to viral or bacterial rhinitis and occasionally to nasopharyngeal tumors. We report a case of a patient presenting with chronic serous otitis media that was resistant to conventional therapy. MRI with gadolinium finally revealed that the middle ear fluid was caused by leakage of cerebrospinal fluid (CSF) due to bone destruction by a temporal meningioma. The CSF leakage was closed by surgery. Histopathology confirmed meningioma in the temporal bone.

Multi-slice computed tomographic angiography for stenosis detection in forearm hemodialysis arteriovenous fistulas.

PURPOSE: A method of diagnosing the extent and severity of arteriovenous fistula (AVF) stenoses is multislice computed tomographic angiography (MS-CTA). The aim of this prospective study was to assess the accuracy of MS-CTA for the detection and grading of stenoses in AVF in comparison to digital subtraction angiography (DSA), which was used as the gold standard of reference. METHODS: Fifteen hemodialysis (HD) patients with dysfunctioning forearm AVF were included. These AVFs were evaluated by both DSA and MS-CTA and were read in a prospective, blinded manner by two radiologists experienced in vascular imaging. RESULTS: ROC analysis revealed areas under the curve of 0.90+/-0.07 for observer I and 0.87+/-0.08 for observer II at a stenosis cut-off level of >or=50% diameter reduction. The combined results for MS-CTA showed sensitivity, specificity and positive and negative predictive values of 82%, 98%, 82% and 98% for stenoses>or=50% and 71%, 99%, 77% and 98% for stenoses>or=75%. Inter-observer agreement for the detection of stenoses>or=50% diameter reduction was 0.70 and 1.0, for MS-CTA and DSA, respectively. CONCLUSION: MS-CTA can provide good visualization of forearm HD access AVF and has moderate sensitivity, but high specificity for the detection of flow-limiting stenoses.

Risk factors for infections related to external ventricular drainage.

BACKGROUND: External ventricular drainage (EVD) is frequently used in neurosurgery for cerebrospinal fluid (CSF) drainage in patients with raised intracranial pressure. The major complication of this procedure is an EVD-related infection, i.e., meningitis or ventriculitis. The purpose of the present retrospective single centre study is to assess the possible causes of these infections. PATIENTS AND METHODS: Two hundred and twenty-eight patients were included in the period from January 1993 until April 2005. Patient and disease demographics, as well as EVD data, and the occurrence of infection were reviewed, compared, and included in a risk-analysis study. RESULTS: The population's mean age was 56 +/- 15 years and the sexes were equally distributed. Most frequently, the indication for EVD was hydrocephalus due to intraventricular haemorrhage (48.2%). An infection was documented in 23.2% of all patients. Duration of EVD drainage appeared to be a risk factor for infection (>11 days: OR 4.1; 95% CI 1.8-9.2, p = 0.001). CSF sampling frequency was also a significant risk-factor (no sampling: OR 0.2, 95% CI 0.2-0.5, p = 0.003). CONCLUSIONS: We found a relatively high percentage of EVD-related infections. After multivariate analysis there appears to be a relation with duration of drainage and frequent CSF sampling. As a result, a new EVD protocol is proposed in our institution that we believe will decrease the number of EVD-related infections to a minimum.

Safety and efficacy of frameless and frame-based intracranial biopsy techniques.

BACKGROUND: Frameless stereotaxy or neuronavigation has evolved into a feasible technology to acquire intracranial biopsies with good accuracy and little mortality. However, few studies have evaluated the diagnostic yield, morbidity, and mortality of this technique as compared to the established standard of frame-based stereotactic brain biopsy. We report our experience of a large number of procedures performed with one or other technique. PATIENTS AND METHODS: We retrospectively assessed 465 consecutive biopsies done over a ten-year time span; Data from 391 biopsies (227 frame-based and 164 frameless) were available for analysis. Patient demographics, peri-operative characteristics, and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and of it being followed by death. RESULTS: On average, nine tissue samples were taken with either stereotaxy technique. Overall, the biopsy led to a diagnosis on 89.4% of occasions. No differences were found between the two biopsy procedures. In a multiple regression analysis, it was found that left-sided lesions were less likely to result in a non-diagnostic tissue sample (p = 0.023), and cerebellar lesions showed a high risk of negative histology (p = 0.006). Postoperative complications were seen after 12.1% of biopsies, including 15 symptomatic haemorrhages (3.8%). There was not a difference between the rates of complication after either a frame-based or a frameless biopsy. Overall, peri-operative complications (p = 0.030) and deep-seated lesions (p = 0.060) increased the risk of biopsy-related death. Symptomatic haemorrhages resulting in death (1.5% of all biopsies) were more frequently seen after biopsy of a fronto-temporally located lesion (p = 0.007) and in patients with a histologically confirmed lymphoma (p = 0.039). CONCLUSIONS: The diagnostic yield, complication rates, and biopsy-related mortality did not differ between a frameless biopsy technique and the established frame-based technique. The site of the lesion and the occurrence of a peri-operative complication were associated with the likelihood of failure to achieve a diagnosis and with death after biopsy. We believe that using intraoperative frozen section or cytologic smear histology is essential during a stereotactic biopsy in order to increase the diagnostic yield and to limit the number of biopsy specimens that need to be taken.

Systemic dilation diathesis in patients with abdominal aortic aneurysms: a role for matrix metalloproteinase-9?

INTRODUCTION: Accumulating evidence suggests that patients with abdominal aortic aneurysm (AAA) suffer from a systemic dilating condition affecting all arteries. Matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), appear to be involved in aneurysm formation, as evidenced by increased aortic tissue MMP activity and plasma MMP levels in patients with AAA. Hypothesizing that an imbalance in plasma MMP/TIMP level might be associated with a systemic dilation diathesis, we studied mechanical vessel wall properties of non-affected arteries of patients with either AAA or aorto-iliac obstructive lesions in association with plasma MMP-9 and TIMP-1 levels. METHODS: Twenty-two patients with AAA and 12 with aorto-iliac occlusive disease (AOD) were included. Diastolic diameter (d) and distension (Deltad) were measured at the level of the common carotid artery (CCA) and suprarenal aorta (SA) using ultrasonography. Distensibility (DC) and compliance (CC) were calculated from d, Deltad and brachial pulse pressure. Plasma MMP-9 and TIMP-1 were determined with specific immunoassays. RESULTS: The average (+/-SD) age was 72.3+/-5.6 and 65.0+/-8.2 years for the AAA and AOD patients, respectively, (P=0.005). CCA diameter was 9.1+/-1.3mm in AAA patients and AOD 7.8+/-1.4mm in AOD patients, P=0.009. This difference persisted after correction for age. Plasma MMP-9 and TIMP-1 did not differ significantly between AAA and AOD patients. In the total 34 patients, the MMP-9/TIMP-1 ratio was correlated inversely with distensibility (r=-0.74, P=0.002) and to compliance (r=-0.58, P=0.024) of the suprarenal aorta. CONCLUSIONS: The CCA diameter was larger in AAA patients compared to AOD patients. MMP-9/TIMP-1 ratio was associated with decreased distensibility and compliance of the suprarenal aorta. These data support the idea that AAA patients exhibit a systemic dilation diathesis, which might be attributable to MMP/TIMP imbalances.

Upper extremity ischemia and hemodialysis vascular access.

Digital ischemia in dialysis patients due to arteriovenous fistulas (AVF) is a rare condition, occurring in 4% of patients. The etiology is different from lower limb ischemia. Blood shunting through the AVF may cause stealing of blood and hypoperfusion in distal tissues, leading to pain, discolorisation and ulcers. High-flow AVFs have greater risk on ischemia than normal flow AVFs, however combined with peripheral arteriosclerotic disease the latter may also leads to ischemia. A non-invasive and angiographic diagnosis is of importance to determine treatment options. Augmentation of arterial inflow by interventional techniques and/or AVF bloodflow-reducing surgical procedures may eliminate pain and heal ulcers. The best results are obtained by bypassing the arteriovenous anastomotic site and interruption of steal phenomenon by ligation of the artery distal to the AV anastomosis.

Central vein obstruction in hemodialysis patients: results of radiological and surgical intervention.

BACKGROUND/AIMS: Symptomatic central venosus obstruction (CVO) in dialysis patients with arteriovenous fistulas (AVFs) leads to significant morbidity and patient inconvenience. We evaluated the results of surgical and radiological interventional treatment of symptomatic central venous obstruction. METHODS: Clinical data, site and length of vein obstruction, type and outcome of intervention were obtained from patient records. Patency rates of radiological and surgical treatment were calculated using Life Table survival analysis. RESULTS: In 28 patients with VH, 45 interventions (percutaneous intervention 30; surgical reconstruction 10; AVF closure five) were performed. Mean vessel obstruction length was 4.9 cm, mainly localized in the subclavian vein (55%). Initial clinical success rate of PTA and surgery was 92%, with complications after percutaneous transluminal angioplasty (PTA) on six occasions. Restenosis after PTA was observed in 39%. One-year primary and secondary patency after PTA was 50 and 63%, respectively. One-year primary patency after surgical reconstruction was 75%. CONCLUSION: Symptomatic CVO in dialysis patients with AVFs can be treated with a high success rate through radiological intervention. Surgical reconstruction is an appropriate alternative method in case of failed PTA.

[Real-time registration of flow-mediated dilatation for the assessment of endothelial function]. / Echtzeit-Registrierung der flussabhängigen Dilatation der A. brachialis zur Endothelfunktionsbestimmung.

UNLABELLED: Flow-mediated dilatation (FMD) is used to qualify vascular endothelial function. AIM: To evaluate the feasibility of real-time assessment of the stimulus-to-response (i. e. flow-velocity-to-diameter) relationship, repeated FMD was assessed in healthy subjects. METHODS: Brachial artery diameter and flow velocity were measured simultaneously in 10 healthy male subjects lying in the supine position. These parameters were registered in real-time mode and beat-to-beat by means of a 7.5 MHz linear array transducer attached to a custom-built Wall Track System and an 8 MHz continuous wave Doppler. RESULTS: Post-ischaemic increase in arterial diameter amounted to 5.9 +/- 2.9 % with an average increase in blood flow velocity of 487 +/- 174 %. The relative change in diameter was not correlated to the relative increase in flow velocity. CONCLUSION: Continuous registration of FMD can be performed. Motion artefacts, however, interfere with the real-time registration of FMD.

The effect of chronic flow changes on brachial artery diameter and shear stress in arteriovenous fistulas for hemodialysis.

BACKGROUND: Vessel wall adaptation to acute or chronic flow changes is regulated by shear stress (SS) at the endothelium. This hypothesis was tested in the brachial artery (BA) of patients receiving an arteriovenous fistula (AVF) for hemodialysis vascular access. METHODS: The acute and sustained effects were evaluated in 13 patients. Pre-operatively and postoperatively on predetermined time-points BA diameter and shear rate (SR) were measured. SS was calculated from whole blood viscosity and SR. Analysis was performed with Wilcoxon's test and ANCOVA multivariate analysis. RESULTS: Acutely, mean SS increased (475%, p<0.05), peak-to-peak SS decreased (37%, p<0.05) and peak SS remained constant. BA diameter increased (15%, p<0.05). After one year a further increase was observed (r=0.59, p<0.001), plus an increase in mean SS (r=0.78, p<0.001). Peak-to-peak SS remained constant. CONCLUSION: Our results indicate that after AVF placement an acute increase in SS results in an acute increase of vessel diameter. However, one year of sustained high blood flow does not result in restoration of mean SS.