NF2 status of meningiomas is associated with tumour localization and histology.

In approximately 60% of sporadic meningiomas, the tumour suppressor gene NF2, located on chromosome 22q, is inactivated. Mutations in the NF2 gene have been specifically reported in transitional and fibrous, but not meningothelial, meningiomas. Since meningothelial meningiomas frequently occur in anterior parts of the skull base, the association between tumour localization, size, histological subtype and NF2 status was investigated in a group of 42 sporadic meningiomas. NF2 status was determined by LOH analysis, karyotyping and FISH. Tumour size and site were evaluated by CT scans and MRIs. A strong correlation between tumour localization in the anterior skull base and intact 22q was revealed (p=0.003). On the other hand, tumour localization at the convexity was associated with disruption of NF2 (p=0.023). Furthermore, an association between chromosome 22 status and histological subtype was observed: abnormalities of chromosome 22q were more frequent in transitional and fibrous meningiomas than in the meningothelial variant (p<0.001). Also, the meningothelial meningiomas were more often located in the anterior skull base (p<0.006). Based on these findings, it is concluded that an alternative histogenesis and genetic pathway is likely to exist for meningiomas arising in the anterior skull base.

Interobserver variability of cisternal blood on CT after aneurysmal subarachnoid hemorrhage.

Interobserver variability in the prediction of delayed cerebral ischemia by means of blood on CT was investigated in 159 patients with aneurysmal subarachnoid hemorrhage, admitted within 72 hours after the bleed. The authors found considerable interobserver variability in the assessment of the amount of blood in the individual cisterns. A high sum score was an independent predictor for delayed cerebral ischemia only for rater 1 (rater 1: hazard ratio, 3.26; 95% confidence interval [CI], 1.14 to 7.75; rater 2: hazard ratio, 1.72; 95% CI, 0.72 to 4.09). The authors conclude that interobserver variability limits the predictive power of the amount of blood on CT for the occurrence of cerebral ischemia.

The effect of balloon angioplasty on hypertension in atherosclerotic renal-artery stenosis. Dutch Renal Artery Stenosis Intervention Cooperative Study Group.

BACKGROUND: Patients with hypertension and renal-artery stenosis are often treated with percutaneous transluminal renal angioplasty. However, the long-term effects of this procedure on blood pressure are not well understood. METHODS: We randomly assigned 106 patients with hypertension who had atherosclerotic renal-artery stenosis (defined as a decrease in luminal diameter of 50 percent or more) and a serum creatinine concentration of 2.3 mg per deciliter (200 micromol per liter) or less to undergo percutaneous transluminal renal angioplasty or to receive drug therapy. To be included, patients also had to have a diastolic blood pressure of 95 mm Hg or higher despite treatment with two antihypertensive drugs or an increase of at least 0.2 mg per deciliter (20 micromol per liter) in the serum creatinine concentration during treatment with an angiotensin-converting-enzyme inhibitor. Blood pressure, doses of antihypertensive drugs, and renal function were assessed at 3 and 12 months, and patency of the renal artery was assessed at 12 months. RESULTS: At base line, the mean (+/-SD) systolic and diastolic blood pressures were 179+/-25 and 104+/-10 mm Hg, respectively, in the angioplasty group and 180+/-23 and 103+/-8 mm Hg, respectively, in the drug-therapy group. At three months, the blood pressures were similar in the two groups (169+/-28 and 99+/-12 mm Hg, respectively, in the 56 patients in the angioplasty group and 176+/-31 and 101+/-14 mm Hg, respectively, in the 50 patients in the drug-therapy group; P=0.25 for the comparison of systolic pressure and P=0.36 for the comparison of diastolic pressure between the two groups); at the time, patients in the angioplasty group were taking 2.1+/-1.3 defined daily doses of medication and those in the drug-therapy group were taking 3.2+/-1.5 daily doses (P<0.001). In the drug-therapy group, 22 patients underwent balloon angioplasty after three months because of persistent hypertension despite treatment with three or more drugs or because of a deterioration in renal function. According to intention-to-treat analysis, at 12 months, there were no significant differences between the angioplasty and drug-therapy groups in systolic and diastolic blood pressures, daily drug doses, or renal function. CONCLUSIONS: In the treatment of patients with hypertension and renal-artery stenosis, angioplasty has little advantage over antihypertensive-drug therapy.

Tracing craniosynostosis to its developmental stage through bone center displacement.

In metopic and coronal suture synostosis, the involved bone centers are abnormally situated just next to the affected suture. Bone centers are the starting point of ossification during embryogenesis from which bone growth spreads radially. In this paper, we describe a similar observation for sagittal suture synostosis, with both parietal bone centers located almost completely cranially. The (reduced) distance between the bone centers of a synostotic suture reflects the time during embryogenesis at which fusion took place. We suggest that in craniosynostosis the bone centers arise in their normal position, and initial outgrowth is undisturbed until the bone fronts meet. It is during this developmental stage that fusion occurs instead of suture formation. Due to the fusion, growth can only occur at the free bony rims from then on. The bone centers remain located at a fixed distance from one another in the middle of the fused bones, becoming relatively more displaced with time. This implies that the distance between the involved bone centers directly indicates the developmental period during which sutural growth was arrested. The same phenomenon of bone center displacement is found in types of craniosynostosis with and without fibroblast growth factor receptor (FGFR) or TWIST gene mutations.

Validity of prediction of the site of ruptured intracranial aneurysms with CT.

OBJECTIVE: We studied the diagnostic power of blood distribution on CT (performed within 72 hours after the bleed) for the site of ruptured aneurysm in 168 consecutive patients with subarachnoid hemorrhage with either a single aneurysm or no aneurysm on the four-vessel angiogram or postmortem examination. METHODS: A neurosurgeon and a neuroradiologist blind to the results of the angiography independently scored the distribution of blood on the CT and predicted the site of the ruptured aneurysm. RESULTS: Overall agreement among raters was 52% and chance-adjusted agreement (kappa) was 0.42 (weighted kappa value 0.47). A parenchymal cerebral hematoma was an excellent predictor for the site of a ruptured aneurysm but was present in only a minority of cases (15%). The next most valid predictor was blood distribution on CT in patients with a ruptured anterior cerebral artery aneurysm or anterior communicating artery aneurysm (sensitivity 0.79, specificity 0.96, and positive predictive value 0.79 for rater 1; sensitivity 0.77, specificity 0.97, and positive predictive value 0.90 for rater 2). The validity of the predictive value of blood distribution on CT in patients with a ruptured aneurysm of the middle cerebral artery, internal carotid artery, or posterior circulation arteries was either inconsistent between raters or low. CONCLUSION: With the exception of the presence of a parenchymal hematoma, the site of the ruptured aneurysm can be predicted by CT only in ruptured anterior cerebral artery or anterior communicating artery aneurysms.

Inter-observer variability in the angiographic assessment of renal artery stenosis. DRASTIC study group. Dutch Renal Artery Stenosis Intervention Cooperative.

OBJECTIVE: To assess inter-observer agreement in the interpretation of renal angiograms. DESIGN: Comparison of the assessment of renal angiograms by three experienced radiologists, who evaluated the number of renal arteries and the presence, location, aspect and severity of a renal artery stenosis. SETTING: General hospital and university hospital serving urban and rural populations. PATIENTS: Patients with difficult-to-treat hypertension referred for diagnostic work-up; 312 angiograms with the intra-arterial digital subtraction technique were obtained from 289 consecutive patients. MAIN OUTCOME MEASURES: Inter-observer agreement was tested for the following parameters: number of arteries per kidney, presence of stenosis, location of stenosis (truncal, ostial), aspect of stenosis (concentric, eccentric, post-stenotic dilatation), severity of stenosis (reduction of lumen diameter in categories of 30%, 40%, etc. to 100%), and overall quality of the angiographic images. Kappa (kappa) values and weighted kappa between the three pairs of radiologists were used as estimates of inter-observer agreement RESULTS: Agreement about the number of renal arteries was reasonable (kappa = 0.50-0.72), as was agreement about the presence of stenosis (kappa = 0.68-0.86). Agreement about stenosis location and aspect was poor (kappa = 0.26-0.47 and kappa = 0.15-0.26, respectively). There was general agreement about the severity of stenosis (weighted kappa = 0.65-0.70), but it was not possible to distinguish between 50 and 60% stenosis or between 60 and 70% stenosis (kappa < 0.40). No correlation was found between agreement on severity of stenosis and the quality of the images. CONCLUSIONS: It is not realistic to make statements about what degree of renal artery stenosis is clinically significant, as long as the intra-arterial angiogram with digital subtraction remains the gold standard. It is likewise risky to rely too strongly on stenosis morphology as visualized by renal angiography in choosing between balloon angioplasty and stent deployment.

Comparison of angiography and intravascular ultrasound before and after balloon angioplasty of the femoropopliteal artery.

PURPOSE: To compare angiographic and intravascular ultrasound (IVUS) data before and after balloon angioplasty (PTA) of the femoropopliteal artery. METHODS: Qualitative and quantitative analyses were performed on corresponding angiographic and IVUS levels obtained from 135 patients. RESULTS: IVUS detected more lesions, calcified lesions, and vascular damage than angiography. Sensitivity of angiography was good for the presence of a lesion (84%), moderate for eccentric lesions (53%) and for vascular damage (52%), and poor for calcified lesions (30%). The increase in angiographic diameter stenosis was associated with a decrease in lumen area and increase in percentage area stenosis on IVUS. CONCLUSIONS: Angiography is less sensitive than IVUS for detecting lesion eccentricity, calcified lesions, and vascular damage. Presence of a lesion and amount of plaque were underestimated angiographically. Only before PTA was good agreement found between angiographic diameter stenosis and lumen size on IVUS.

Intravascular ultrasound predictors of restenosis after balloon angioplasty of the femoropopliteal artery.

OBJECTIVES: To determine intravascular ultrasound parameters related to restenosis following percutaneous transluminal balloon angioplasty (PTA) of the femoropopliteal artery. DESIGN: Prospective study. MATERIALS AND METHODS: Patients were studies with intravascular ultrasound before and after angiographic successful PTA (n = 114). Intravascular ultrasound cross-sections obtained with 1 cm interval in the dilated segment were analysed. A distinction was made between anatomic (duplex scanning) and clinical (Rutherford criteria) restenosis assessed within 1 month and at 6 months after PTA. RESULTS: Intravascular ultrasound predictors of 1 month anatomic outcome were lumen area stenosis after PTA, lumen area increase, plaque area decrease, and area stenosis decrease; predictor of 6 months anatomic outcome was area stenosis after PTA. Multivariate analysis revealed that area stenosis after PTA was the only independent predictor of both 1 and 6 months anatomic outcome. Intravascular ultrasound predictors of 1 month clinical outcome were the presence of hard lesion and the mean arc of hard lesion. Multivariate analysis revealed that the mean arc of hard lesion was the only independent predictor of 1 month clinical outcome. No predictors for 6 months clinical outcome were found. CONCLUSIONS: Intravascular ultrasound can elucidate parameters predictive of restonosis after PTA. The strongest intravascular ultrasound parameter predictive of anatomic restenosis was a large area stenosis after PTA.

Effect of balloon angioplasty in femoropopliteal arteries assessed by intravascular ultrasound.

OBJECTIVE: To study the effects of balloon angioplasty (PTA) of the femoropopliteal artery with intravascular ultrasound (IVUS). MATERIALS AND METHODS: Corresponding IVUS cross-sections (n = 1033) obtained before and after PTA from 115 procedures were analysed. Vascular damage including plaque rupture, dissection and media rupture was assessed. Free lumen area (FLA), media-bounded area (MBA) and plaque area (PLA) were measured. RESULTS: After PTA vascular damage was seen at the target site in 83 (72%) arteries: plaque rupture in 30 (26%), dissection in 66 (57%) and media rupture in 20 (17%) arteries. The FLA increased from 5.4 +/- 3.4 mm2 to 14.1 +/- 5.0 mm2 (p < 0.001), MBA increased from 26.9 +/- 10.0 mm2 to 32.9 +/- 10.7 mm2 (p < 0.001) and PLA decreased from 21.6 +/- 8.5 mm2 to 18.8 +/- 8.0 mm2 (p < 0.001). The increase in MBA accounted for 68% of lumen gain. The frequency of vascular damage and the relative contribution of MBA increase and PLA decrease to luminal gain were not different in procedures with balloon diameter < or = 5 mm and > or = 6 mm. CONCLUSIONS: Vascular damage is common following PTA. Lumen gain is mainly due to vessel expansion and, to a lesser extent, to a decrease in plaque area.

Failure of intravascular ultrasound to predict dissection after balloon angioplasty by using plaque characteristics.

Intravascular ultrasound (IVUS) is more sensitive than angiography in the assessment of plaque characteristics before intervention and vascular damage after balloon angioplasty. On the basis of IVUS data, this finding may improve clinical treatment by reducing the incidence of severe dissections after balloon angioplasty. We therefore studied the relation between plaque characteristics and dissections after balloon angioplasty. First, an in vitro study on atherosclerotic arteries (n = 42) was performed in which IVUS images were compared with histologic sections to validate the IVUS technique; second, the in vitro findings were compared with IVUS findings obtained in vivo (n = 73). Dissections were observed in 37 histologic sections and visualized on IVUS in 22 (59%) of the corresponding ultrasonic cross-sections; in vivo dissections were demonstrated by IVUS in 46 (63%) cases. Dissections were generally seen at the thinnest region of the plaque on both histologic sections (92%) and IVUS cross-sections (in vitro 83%; in vivo 93%). No significant relation was found between pre-interventional plaque characteristics such as composition features and eccentricity and the incidence, location, and extent of postinterventional dissections. Thus IVUS is able to identify dissections after balloon angioplasty, generally occurring at the site of the thinnest plaque diameter. However, neither the incidence nor the severity of these dissections was related to any of the preinterventional plaque characteristics.

The value of pre-operative ultrasound mapping of the greater saphenous vein prior to 'closed' in situ bypass operations.

OBJECTIVE: The aim of this study was to test pre-operative ultrasound mapping for the detection of duplications and narrow vein segments of the greater saphenous vein (GSV) used as bypass for occlusive arterial disease surgery. PATIENTS AND METHODS: In 44 patients pre-operative ultrasound findings of duplications and lumen assessment of GSV were compared to the per-operative findings. RESULTS: In nine patients (20%) the pre-operative ultrasound examination showed a duplication. Pre-operative ultrasound had missed a duplication in two cases but had instead shown a narrow segment in both. The pre-operative ultrasound assessment of lumen diameter showed a narrow lumen segment in 10 of the 44 patients. In one patient a per-operatively narrow lumen had not been seen on pre-operative ultrasound. CONCLUSION: Pre-operative ultrasound mapping of the GSV is a sensitive tool for detection of duplications and narrow vein segments. Since these anatomical variations provide important information for the vascular surgeon, before performing a 'closed' in situ bypass operation, pre-operative vein mapping should be considered when planning such a procedure.

The diagnostic value of magnetic resonance imaging in combination with angiography in patients with vascular malformations: a prospective study.

Vascular birthmarks are common lesions that can be divided into hemangiomas and vascular malformations (arterial, venous, capillary, and lymphatic malformations or a combination of these, according to Mulliken. Thirty-four patients with a vascular malformation were evaluated prospectively with magnetic resonance imaging (MRI) during a 6-year period in a combined study of the departments of radiology and plastic and reconstructive surgery. Hemangiomas were not part of this study, as they regress spontaneously in childhood. MRI and angiographic findings are described and the value of MRI is investigated for its usefulness in conjunction with angiography. MRI turns out to be superior as the initial diagnostic test for vascular malformations. Further investigations are not necessary in low-flow lesions. In case of high-flow and combined-flow lesions, angiography is indicated following MRI to show the exact angioarchitecture, which is essential for therapy planning. A flowchart, based on radiodiagnostic features, is proposed for diagnostic evaluation of patients with vascular birthmarks.

Femoropopliteal venous bypass studied with intravascular ultrasound: a case report.

PURPOSE: To describe the ability of intravascular ultrasound (IVUS) to document the status of the greater saphenous vein during bypass surgery, the long-term changes in the bypass, and the effects of balloon angioplasty on vein graft stenoses. METHODS: An 80-year-old female underwent in situ femoropopliteal venous bypass grafting. Vein graft stenosis developed 6 months later, necessitating balloon angioplasty. The angioplasty failed, and a polytetrafluoroethylene (e-PTFE) interposition graft was placed. Ten months after bypass surgery, balloon angioplasty was performed for new stenoses. This procedure also failed, and the venous bypass and interposition graft were removed and replaced by an e-PTFE graft. IVUS images obtained during the first surgery were compared with those obtained 10 months later. Histologic sections were used to confirm the IVUS findings. RESULTS: IVUS detected a distinct narrowed venous segment, pre-existent intimal thickening, and disrupted valves. Over the follow-up period, both the pre-existent intimal thickening and the narrowed segment evolved into stenoses, necessitating treatment. Luminal gain after balloon angioplasty of graft stenosis was associated with vascular damage. CONCLUSIONS: This report shows that IVUS has the ability to document long-term venous bypass alterations and to demonstrate the effect of balloon angioplasty on venous bypass stenoses.

[Cushing's disease: successful surgery through improved preoperative tumor localization]. / Ziekte van Cushing: succesvollere chirurgie door verbeterde preoperatieve tumorlokalisatie.

OBJECTIVE: To study the effect of improved preoperative tumour localisation on the outcome of transsphenoidal surgery for Cushing's disease. DESIGN: Retrospective. SETTING: University Hospital Rotterdam, the Netherlands. METHODS: The case records were studied of 61 patients, operated on for Cushing's disease due to a corticotrophin-secreting microadenoma (diameter < 10 mm), in the period January 1985-September 1995. From 1985, preoperative tumour localisation was performed with computed tomography (CT), from 1989 with Magnetic Resonance Imaging (MRI) and Bilateral Simultaneous Inferior Petrosal Sinus Sampling (BSIPSS). The definition of a successful operation was: morning serum cortisol < 500 nmol/l, and of cure: morning serum cortisol < 140 nmol/l or 24-hr cortisoluria < 250 nmol. RESULTS: In 1985-1988, a microadenoma was localised preoperatively in 8/22 patients (36%), the operation was successful in 12 (55%), of which 4 (18%) were cured. In 1989-1991, a microadenoma was localised in 12/15 patients (80%), the operation was successful in 11 (73%), of which 4 (27%) were cured. In 1992-1995 a microadenoma was localised preoperatively in 23/24 patients (96%), the operation was successful in 19 (79%), of which 17 (71%) were cured. In the cured group, there was a low incidence (< 10%) of postoperative hypopituitarism in all three periods. There were 1, 0 and 1 recurrences of Cushing's disease respectively after initial cure. CONCLUSION: In our institution, improved preoperative localisation of corticotrophin-secreting hypophyseal microadenomas was associated with an important increase of success and cure rate of transsphenoidal surgery, while there was no increase in postoperative hypopituitarism or recurrences of Cushing's disease.

The role of bone centers in the pathogenesis of craniosynostosis: an embryologic approach using CT measurements in isolated craniosynostosis and Apert and Crouzon syndromes.

This paper describes the role of the displacement of bone centers, i.e., the tubers, in the pathogenesis of craniosynostosis. This displacement was studied in 54 patients with isolated or syndromic craniosynostosis in the form of CT scans as well as in two dry neonate skulls with Apert syndrome. For comparison, 49 fetal and 8 normal infant dry skulls were studied. Our investigation was restricted to the coronal and metopic sutures. The results showed a significantly more occipital localization of the frontal bone center and a more frontal localization of the parietal bone center at the side of a synostotic coronal suture in the isolated form as well as in Apert syndrome. In contrast, this was not the case in Crouzon syndrome, thus showing that these two syndromes have a different pathogenesis. For trigonocephaly, a more anteromedial localization of the frontal bone centers was found.

Intravascular sonographic evaluation of iliac artery angioplasty: what is the mechanism of angioplasty and can intravascular sonography predict clinical outcome?

OBJECTIVE: The purpose of this study was to establish the arterial responses of the iliac artery after percutaneous transluminal angioplasty (PTA), using intravascular sonography, and to correlate intravascular sonography parameters with clinical outcome. SUBJECTS AND METHODS: The study included 21 patients studied with intravascular sonography before and after PTA of the iliac artery. Distinction was made between intravascular sonography cross sections collected from the common iliac and those from the external iliac artery. First, qualitative and quantitative intravascular sonography data obtained at the most stenotic site were compared with data derived from all corresponding cross sections of the dilated segment. Second, the predictive value of intravascular sonography parameters for the patient outcome was assessed. RESULTS: The free lumen and media-bounded areas seen in the common iliac artery were larger than those seen in the external iliac artery. Qualitative and quantitative effects of PTA observed with intravascular sonography on the two types of artery were not different. Vascular damage occurred in 81% of the patients. The frequency of vascular damage at the most stenotic site was slightly lower than in each dilated segment studied. The reduction in area stenosis after intervention was associated with an increase in the free lumen and media-bounded areas, whereas the plaque area reduced only slightly. The increase in the free lumen and media-bounded areas and the decrease in the plaque area at the most stenotic site after intervention were larger than the mean values. Qualitative data seen with intravascular sonography at the most stenotic site before and after intervention were not predictive of the patient outcome. In patients with an uneventful outcome after intervention, the free lumen area measured at the most stenotic site after PTA was larger and the area stenosis was smaller than in patients with a failure. CONCLUSION: This study of intravascular sonography established that although the common iliac artery is larger than the external iliac artery, the qualitative and quantitative effects of PTA in both types of artery were similar. The size of the free lumen area and the degree of stenosis seen with intravascular sonography after PTA at the most stenotic site may be predictive of a patient outcome.

Sagittal sinus occlusion, caused by an overlying depressed cranial fracture, presenting with late signs and symptoms of intracranial hypertension: case report.

A case of delayed signs of intracranial hypertension after open depressed cranial fracture occluding the superior sagittal sinus is reported. Elevating depressed fractures overlying a cranial venous sinus is hazardous. Conservative management of the intracranial hypertension, including repeated lumbar punctures, led to an unimpaired outcome. The options of management of delayed problems caused by traumatic venous occlusion are discussed.

[Transjugular placement of an intrahepatic portosystemic shunt as current treatment for complications of portal hypertension]. / Transjugulaire plaatsing van een intrahepatische portosystemische shunt als nieuwe behandeling voor complicaties van portale hypertensie.

OBJECTIVE: To analyse the results in 31 patients who underwent transjugular intrahepatic portosystemic shunting (TIPS). DESIGN: Retrospective study. SETTING: University Hospital Rotterdam-Dijkzigt, Rotterdam, the Netherlands. METHOD: Data of all patients who underwent a TIPS procedure from February 1992 to September 1994 were analysed. Indications for TIPS included recurrent variceal bleedings and refractory ascites. TIPS was performed under general anaesthesia. After TIPS heparin was given during one week. RESULTS: TIPS creation succeeded in 29 out of 31 patients. The mean portosystemic pressure gradient after TIPS was 9.6 mmHg. After 1.5 years the cumulative percentage of recurrent variceal bleeding was 44. The quantity of ascites decreased in 73% of the patients. During recatheterisation shunt dysfunction was seen in 16 out of 21 patients. Mortality was 13% within 30 days. The actuarial percentage of patients who died was 43 after 1.5 years. Mortality depended on Child-Pugh classification. CONCLUSION: TIPS is a new, safe and fast treatment for patients with complications of portal hypertension. The number of recurrent variceal bleedings was substantial. Intensive control examinations are imperative to discern shunt dysfunction. Long-term survival rates and morbidity depend on the seriousness of the pre-existing liver disease.