Optimization of the Surgical Approach in AVMs Using MRI and 4D DSA Fusion Technique : A technical note.

PURPOSE: Previously published data demonstrated the possibility of displaying the angioarchitecture of intracranial vascular malformations using time-resolved 3D imaging (4D digital subtraction angiography [DSA]). The purpose of our study was to prove the technical feasibility of creating fused images of time-resolved 3D reconstructions and MPRAGE MRI data sets and to check the reliability of the correct anatomical display of the angioma nidus and the venous drainage in the fused images of patients with intracranial arteriovenous malformations (AVM). PATIENTS AND METHODS: In this study 20 patients with intracranial AVM underwent pretherapeutic DSA and time-resolved 3D DSA in addition to MRI including MPRAGE sequences. The images were post-processed with the fusion software tool on a dedicated research workstation. The fusion of both imaging modalities was done semi-automatically with automatic co-registration software followed by a manual co-registration. RESULTS: Co-registered DSA/MRI data sets of 20 untreated AVMs were evaluated independently by two reviewers. Image fusion was successful in all 20 cases with an acceptable additional set-up time. The fused images were highly scored by the two raters in respect to their congruency of the dedicated regions. Precise anatomical localization of the nidus, the feeding arteries and the draining veins were possible with the merged images. CONCLUSION: Creating fused images of time-resolved 3D DSA and contrast-enhanced T1-weighted MPRAGE MR images might be beneficial for the preoperative and intrasurgical workflow in patients with AVMs. This new software tool fulfils the required quality and accuracy of the merged images. The clinical validation has to be proven in further studies.

Application of Time-Resolved 3D Digital Subtraction Angiography to Plan Cerebral Arteriovenous Malformation Radiosurgery.

BACKGROUND AND PURPOSE: Time-resolved 3D-DSA (4D-DSA) enables viewing vasculature from any desired angle and time frame. We investigated whether these advantages may facilitate treatment planning and the feasibility of using 4D-DSA as a single imaging technique in AVM/dural arteriovenous fistula radiosurgery. MATERIALS AND METHODS: Twenty consecutive patients (8 dural arteriovenous fistulas and 12 AVMs; 13 men and 7 women; mean age, 45 years; range, 18-64 years) who were scheduled for gamma knife radiosurgery were recruited (November 2014 to October 2015). An optimal volume of reconstructed time-resolved 3D volumes that defines the AVM nidus/dural arteriovenous fistula was sliced into 2D-CT-like images. The original radiosurgery treatment plan was overlaid retrospectively. The registration errors of stereotactic 4D-DSA were compared with those of integrated stereotactic imaging. AVM/dural arteriovenous fistula volumes were contoured, and disjoint and conjoint components were identified. The Wilcoxon signed rank test and the Wilcoxon rank sum test were adopted to evaluate registration errors and contoured volumes of stereotactic 4D-DSA and integration of stereotactic MR imaging and stereotactic 2D-DSA. RESULTS: Sixteen of 20 patients were successfully registered in Advanced Leksell GammaPlan Program. The registration error of stereotactic 4D-DSA was smaller than that of integrated stereotactic imaging (P = .0009). The contoured AVM volume of 4D-DSA was smaller than that contoured on the integration of MR imaging and 2D-DSA, while major inconsistencies existed in cases of dural arteriovenous fistula (P = .042 and 0.039, respectively, for measurements conducted by 2 authors). CONCLUSIONS: Implementation of stereotactic 4D-DSA data for gamma knife radiosurgery for brain AVM/dural arteriovenous fistula is feasible. The ability of 4D-DSA to demonstrate vascular morphology and hemodynamics in 4 dimensions potentially reduces the target volumes of irradiation in vascular radiosurgery.

[Therapy of inherited diseases of platelet function. Interdisciplinary S2K guideline of the Permanent Paediatric Committee of the Society of Thrombosis and Haemostasis Research (GTH e. V.)]. / Therapie hereditärer Thrombozytopathien. Interdisziplinäre S2K-Leitlinie der Ständigen Kommission Pädiatrie der Gesellschaft für Thrombose- und Hämostaseforschung e. V.

Inherited disorders of platelet function are a heterogeneous group. For optimal prevention and management of bleeding, classification and diagnosis of the underlying defect are highly recommended. An interdisciplinary guideline for a diagnostic approach has been published (AWMF # 086-003 S2K; Hämostaseologie 2014; 34: 201-212). Underlying platelet disorder, platelet count, age and clinical situation modify treatment. Exclusive transfusion of platelet concentrates may be inappropriate as potentially adverse effects can outweigh its benefit. A stepwise and individually adjusted approach for restitution and maintenance of haemostasis is recommended. Administration of antifibrinolytics is generally endorsed, but is of particular use in Quebec disease. Restricted to older children, desmopressin is favourable in storage pool disease and unclassified platelet disorders. Although licensed only for patients with Glanzmann thrombasthenia and alloantibodies, in clinical practice rFVIIa is widely used in inherited platelet disorders with severe bleeding tendency. This guideline aims at presenting the best available advice for the management of patients with inherited platelet function disorders.

[Diagnosis of inherited diseases of platelet function. Interdisciplinary S2K guideline of the Permanent Paediatric Committee of the Society of Thrombosis and Haemostasis Research (GTH e. V.)]. / Diagnose angeborener Störungen der Thrombozytenfunktion. Interdisziplinäre S2K-Leitlinie der Ständigen Kommission Pädiatrie der Gesellschaft für Thrombose- und Hämostaseforschung e. V.

Congenital disorders of platelet function are a heterogeneous group of disorders that are often not detected until bleeding occurs. In clinical settings only a few methods have proven to be useful for identification and classification of inherited platelet disorders. For a rational diagnostic approach, a stepwise algorithm is recommended. Patient history and clinical investigation are mandatory. Von Willebrand disease and other coagulation disorders should always be ruled out prior to specific platelet testing. Platelet count, size, volume (MPV) and morphology may guide further investigations. The PFA-100® CT is suited for screening for severe platelet defects. Platelet aggregometry allows assessment of multiple aspects of platelet function. Flow cytometry enables diagnosis of thrombasthenia Glanzmann, Bernard-Soulier syndrome and storage pool defects. Molecular genetics may confirm a putative diagnosis or pave the way for identifying new defects. We present an unabridged version of the interdisciplinary guideline.

Phamacokinetics of rivaroxaban in adolescents.

BACKGROUND: The direct factor Xa inhibitor rivaroxaban is approved for venous thromboembolism (VTE) treatment in adults. However, in all phase-III trials children or adolescents have not been included. For under-aged VTE patients, current standard treatment consists of low molecular weight heparin or Vitamin K antagonists. Rivaroxaban could be an attractive alternative, however, no data on the pharmacokinetics (PK) of rivaroxaban in adolescents are currently available. PATIENT, METHODS: We report PK data for rivaroxaban derived from a girl (age:15 years), who presented three month after acute deep vein thrombosis, already receiving rivaroxaban therapy. In the steady state of rivaroxaban therapy (20 mg once daily), plasma levels at baseline, 3 and 6 hours after intake of rivaroxaban were measured to evaluate the pharmacokinetics and changes of global coagulation tests. RESULTS: At baseline, a very low trough level of only 9.9 ng/ml rivaroxaban was found. At 3 hours, a peak concentration of 137.76 ng/ml rivaroxaban was observed with a rapid decrease within 6 hours after drug intake, when plasma levels of 34.45 ng/ml were measured. The patients INR and aPTT values reacted correspondingly. CONCLUSION: Our data indicate that adolescents may exhibit lower peak and trough levels after rivaroxaban intake compared to adult patients, but seem to have similar PK curves during the elimination phase. While our case is the first published case of a successful VTE treatment in an under-aged patient, we strongly discourage the routine use of rivaroxaban in non-adult patients, until data from phase II and III trials are available.

Therapy refractory menorrhagia as first manifestation of Hermansky-Pudlak syndrome.

INTRODUCTION: Oculocutaneous albinism (OCA) in combination with a platelet function defect caused by a disturbed release reaction from platelet δ-granules (storage pool defect - SPD) is typical for the autosomal recessive inherited Hermansky-Pudlak syndrome (HPS). CASE REPORT: A girl (age: 13 years) with OCA was hospitalized with transfusion-requiring menorrhagia. The suspicion of HPS was confirmed by results of lumi-aggregometry. Suspecting a disorder in primary haemostasis treatment with tranexamic acid (10 mg/kg body weight every 8 h i. v.), desmopressin (0.3 µg/kg body weight every 8 to 12 h) and hormonal therapy (norethisterone) was started but the menorrhagia persisted. Clinical response was finally achieved by a single injection of 100 µg/kg body weight recombinant factor VIIa (rFVIIa). CONCLUSION: The diagnosis of HPS should be suspected in patients with OCA and bleeding symptoms and is confirmed by the proof of SPD. In case of absent clinical response to desmopressin the application of rFVIIa should be considered. Hormones and antifibrinolytics are useful options in the treatment of extensive menorrhagia.

Surface acoustic wave resonators as novel tools for multiparametric blood analysis.

In this paper a new tool to assess viscoelastic and dielectric properties of human fluids is presented. Shear horizontal polarized surface acoustic waves (SH-SAW) are used to detect the viscoelastic properties of coagulating blood and blood plasma samples. One-port SAW resonators, with fundamental modes of 85, 170 und 340 MHz were developed. Additionally, their electrode structures can be used simultaneously to detect the dielectric behavior of the whole system by impedance spectroscopy while the frequency ranges from kHz to MHz. The combination of both methods offers the detection of clinical relevant blood parameters like the blood coagulation time and the hematocrit value within one measurement.

[Evaluation of haemostasis in children treated with valproic acid]. / Untersuchungen zur Hämostase bei Kindern unter Valproatbehandlung.

UNLABELLED: Coagulation parameters were determined in children with valproic acid mono- and valproic acid-lamotrigin combination therapy. PATIENTS, METHODS: Monotherapy group (n = 22; mean age: 10.5 years) was compared to combination therapy (n = 7; 12.9 years) and a control group (n = 22; 8.7 years). The following parameters were measured: aggregation and ATP-release in whole blood (ADP: 20 µmol/l, collagen: 1 µg/ml, thrombin: 0.5 U/ml), PFA-100® closure times (CT), blood cell counts, global tests, VWF:Ag, VWF:CBA, factors VIII and XIII as well as fibrinogen. Bleeding symptoms were evaluated by using a questionnaire. RESULTS: For ADP- and collagen-induced aggregation as well as for ATP release no significant differences between the groups were detected. The combined therapy group showed significantly prolonged CT. Von Willebrand disease was not detected in any of the patients. The platelet count was significantly decreased in the monotherapy group. In six children a mild bleeding tendency was observed, mostly epistaxis. CONCLUSION: A clinically relevant influence of valproic acid on haemostasis was found only in few cases. However, before surgical procedures an extended coagulation diagnostics is recommended in patients with valproic acid therapy.

[Clinical and laboratory aspects of the Aspirin-like defect as hereditary thrombocytopathy]. / Klinische und labordiagnostische Aspekte des Aspirin-like Defekts als hereditäre Thrombozytopathie.

UNLABELLED: The Aspirin-like defect (ALD) is caused by defects in the intraplatelet arachidonic acid (AA)-metabolism. We here present the characteristics of a larger cohort in a single centre. PATIENTS, METHODS: Based on 17 ALD index patients bleeding symptoms, agonist-induced platelet aggregation and closure times in the PFA-100 test were analysed in a family cohort of altogether 52 individuals from 17 families. Absent aggregation to AA (maximal aggregation or=1 bleeding symptoms. CONCLUSION: In case of a bleeding tendency diagnostic procedures should rule out primary haemostatic defects. Hereditary platelet function defects including ALD are an important differential diagnosis. Family studies are reasonable.

Deep vein and isolated calf muscle vein thrombosis following long-haul flights: pilot study.

The risk of venous thromboembolism associated with long-haul flights is the subject of controversy. In a prospective, controlled study, we examined 160 passengers before and after return from a long-haul flight and 160 age-matched and sex-matched, non-travelling volunteers using venous compression ultrasound. Deep vein thrombosis was not observed in either group. Isolated calf muscle vein thrombosis (ICMVT) was present in 4/160 (2.5%) flight passengers and in 1/160 (0.6%) controls. All subjects with ICMVT were clinically asymptomatic, and ICMVT was located in the soleal muscle veins in all four subjects. Three of the four passengers with ICMVT had other risk factors for thrombosis.

Patients with persistent APC-resistance without factor V Leiden mutation.

BACKGROUND: Activated protein C (APC) resistance and factor V Leiden mutation are major risk factors for deep venous thrombosis. Previous work has led to the view that the coagulation phenotype and the genetic defect are associated in almost all patients. It has been reported about single APC-resistant patients without associated factor V Leiden, but significance and thrombotic risk of this constellation have not yet been established. PATIENTS AND METHODS: We tested 486 consecutive patients with deep venous thrombosis, arterial disease or other than vascular disease for APC-resistance with a factor VIII based assay. RESULTS: 149 patients (31%) showed a pathological APC-ratio. Sensitivity and specificity for detection of factor V Leiden were 100% and 40%, respectively. At 6 months follow-up APC-ratio returned to normal in 55% of the patients with initial pathological APC-resistance. At 12 months follow-up 91% of the patients with persistent APC-resistance showed a pathological ratio as well. CONCLUSIONS: Patients with APC-resistance not due to factor V Leiden can be attributed to one subset with reversible APC-resistance--possibly due to a hypercoagulable state in an acute thrombotic situation, and to another with persistent APC-resistance.

Eight novel LDL receptor gene mutations among patients under LDL apheresis in Dresden and Leipzig.

LDL apheresis is highly efficient in reducing elevated plasma cholesterol. Due to strict indications only patients with severe, refractory hypercholesterolemia are treated with this method. Mutations in the LDL receptor gene are major genetic causes for severe hypercholesterolemia. Screening the entire gene in LDL apheresis patients from Saxony should determine whether an increased frequency of defined mutations is responsible for the atherogenic hypercholesterolemia in this group. 31 unrelated patients (15 male, 16 female, age 33-71 yrs.) were included in the analysis. The LDL-R gene was screened using SSCP and/or automated sequencing. The familial defective apolipoprotein B-100 (FDB) mutation was genotyped using established PCR techniques. Nineteen of 31 patients were carriers of an LDL-R mutation. Ten missense and two nonsense mutations, three insertions and two deletions were detected. The mutations C74S, C74R, T87M, 660delC, 662insCCCCG, 680insGGACAAATCTGA, 1428insC and 2167delG have not been previously described. One patient was compound heterozygous for two missense mutations. Two further patients were heterozygous for FDB. No mutations were found among controls. A genetic background for hypercholesterolemia in the LDL-R could be established in about 61% of the patients examined. Therefore, methods of DNA analysis allow to recognize and adequately treat a large portion of high-risk individuals at an early stage.

Method-dependent influence of certain polymorphisms in the factor V B-domain on the response to activated protein C.

The factor V (FV) B-domain is extremely important to the cofactor function of native FV for activated protein C (APC) in the inactivation of factor VIII (FVIII). In a previous study, we found that in the B-domain coding portion of DNA, the polymorphisms at nucleotide positions 2391, 2663, 2684, and 2863 were associated. In the major allele, all bases are A (A allele) and those in the minor allele are G (G allele). This study concerns itself with the question of whether or not there are differences in the APC response between the A allele and the G allele in plasma samples from persons without the FV Leiden. The APC ratios of homozygous carriers of the major A allele and the minor G allele do not differentiate themselves in classical activated partial thromboplastin time-based assays. In contrast, a test based on the deactivation of FVIII in the tenase complex in homozygous carriers of the minor G allele showed significantly lower APC ratios (P = 0.001) in comparison with the major A allele. The results of the investigation after modification of the test indicate that mutative changes in the B-domain apparently influence the interaction among phospholipids, APC, FV, and protein S. An increase in FVIII through the introduction of the FVIII concentrate Kogenate to the plasma samples was associated with a drop in the APC ratios of both genotypes. After defining 59 age- and sex-based matched pairs without the FV Leiden, the observed frequency of the minor G allele was higher in the non-thrombotic group (33.0%) than in the thrombotic group (22.8%). However, the difference did not reach the level of significance (odds ratio, 0.53; 95% confidence interval, 0.26-1.12). It does, nevertheless, appear possible that a homozygous condition for the minor allele in combination with a defect known to be associated with thrombophilia represents an additional thrombogenetic risk factor.

Frequency of polymorphisms in the B-domain of factor V gene in APC-resistant patients.

In this study we investigated a group of patients in whom a resistance to APC (activated protein C) was found but no Leiden mutation existed in the presence of missense mutations in the first 1200 bp of the Exon 13 (B-domain) in the factor V (FV) gene. The determination of the APC response was performed using the Immunochrom(R) APC response Test Kit. The mutations were determined by temperature gradient gel electrophoresis and DNA sequencing. In the APC-resistant patients without the FV Leiden, we found 4 silent mutations (2298C>T, 2325T>C, 2379A>G, 2391A>G) and 4 missense mutations (2540A>C, 2663A>G, 2684A>G, 2863A>G), which code for the amino acids N789T (GenBank Accession # AF119360), K830R, H837R, and K897E. In all of the patients and controls, the polymorphisms at nucleotide positions 2391, 2663, 2684, and 2863 appeared to be associated. In the major allele all bases are A (A allele) and in the minor allele are G (G allele). A significantly lower G allele frequency was observable in the patient group than in the control group (0.14 vs. 0.31; p<0.05). The frequency of the 2540C allele, which is associated with the 2379G and the 4070G allele (non-Leiden!), did not differ significantly between the patient and the control groups. We suggest that the G allele, which is not associated with the FV Leiden mutation, as well as the [2379G; 2540C; 4070G] allele have no influence on the APC cofactor function itself, or only subtly as determined in the test systems used.

Mutations of the human hepatic lipase gene in patients with combined hypertriglyceridemia/hyperalphalipoproteinemia and in patients with familial combined hyperlipidemia.

Hepatic lipase is an enzyme which hydrolyzes triglycerides from plasma lipoproteins and thus takes part in the metabolism of intermediate density lipoproteins and high-density lipoproteins. The search described here concentrated on mutations of the HL gene in 129 patients with combined hypertriglyceridemia/hyperalphalipoproteinemia and in 184 members of 19 families with familial combined hyperlipidemia. Controls were 100 subjects with favorable lipid values (age 46-51 years). Mutation screening and analysis were performed by temperature-gradient gel electrophoresis, allele-specific restriction genotyping, and sequencing. Six different missense mutations and four different silent mutations were found in the HL gene. The alleles Phe-267 and Gln-343 were detected only once in the patient group with hypertriglyceridemia and hyperalphalipoproteinemia and were not detected in the control group. The allele Met-383 was rare in both patients and controls. We found 9.3% of the patients and only 3.0% of controls to be carrying the Val-73-Met missense mutation. The allele Phe-334 was found in 5.43% of patients and in 2.0% of controls. The difference between the frequencies of these alleles was significant between male patients and male controls (Met-73 P=0.044; Phe-334 P=0.047). Also, the summarized odds ratio of 3.28 (95% confidence interval 1.23-8.73) demonstrates that mutation carriers are significantly more prevalent in the patients. Fifteen carriers of the Met-73 allele were found in six families of the familial combined hyperlipidemia group. Furthermore, six carriers of the Phe-334 allele were found in three families of the same group. In comparison to the controls the summarized odds ratio of 2.45 (95% confidence interval 0.89-6.71) barely missed the level of significance. The linkage between genotype and phenotype was incomplete. These results show an association of the missense mutations Val-73-Met and Leu-334-Phe as susceptibility alleles for combined forms of hyperlipidemia.

The gene structure of the human growth factor bound protein GRB2.

The growth factor bound protein GRB2, a 25-kDa cytosolic protein, plays a key role in two separate pathways of the insulin signal transduction system leading from the insulin receptor to the Ras proteins and thus affecting mitogenic signaling. GRB2 regulates Ras activation through association with the guanine nucleotide exchange factor Sos. The GRB2/Sos complex can connect with insulin receptor substrate 1 (IRS-1), which is one of the primary targets of the insulin and insulin-like growth factor receptors. In a second pathway, independent of IRS-1, GRB2 links the insulin receptor to Ras signaling through another adapter protein, called Shc. In protooncogenic and other noninsulin signaling systems, GRB2 appears to link receptor tyrosine kinases to Ras in similar pathways as well. This study presents the exon-intron organization of the human GRB2 gene. After primers were placed across the known mRNA sequence, Long PCR products spanning introns and their adjacent splice sites were amplified and adequately sequenced to establish the splice sites and flanking regions. The gene was found to consist of five exons (ranging from 78 to 186 bp) and of four introns (from approximately 1 to approximately 7 kb). Intron primers for the respective exons were generated using the newly found flanking sequences. All exons were successfully amplified and sequenced, and the data obtained from Long PCR sequencing were confirmed.

Common mutations of the lipoprotein lipase gene and their clinical significance.

The accumulation of triglyceride-rich lipoproteins is an independent factor for an increased risk for premature arteriosclerosis. Common mutations in the lipoprotein lipase (LPL) gene are at least in part inherited susceptibility factors involved in the age- and sex-dependent phenotypic expression of hypertriglyceridemia. It can be estimated that about 20% of patients with hypertriglyceridemia are carriers of common LPL gene mutations (Asp9Asn, Asn291Ser, Trp86Arg, Gly188Glu, Pro207Leu, Asp250Asn) associated with the HLP. Genotyping of these LPL gene mutations is recommended especially in patients with high risk for premature arteriosclerosis. A comparably high number of individuals are carriers of common mutations (Ser447X) or silent mutations (Thr361) associated with low favorable lipids.

Clinical importance of prothrombotic risk factors in pediatric patients with malignancy--impact of central venous lines.

UNLABELLED: To evaluate the role of inherited thrombophilia in the development of central venous line (CVL)-related thrombosis, the following parameters were determined in 77 pediatric-oncologic patients with CVL: activated protein C (APC)-ratio, factor V (FV) G1691A and prothrombin G20210A mutation, protein C, protein S, antithrombin, coagulation factor XII, lipoprotein (a) and homocysteine. An inherited prothrombotic risk factor was found in 17 patients (23%). Four out of 14 patients with a single detect (hyperlipoproteinemia, heterozygous FV G1691A and prothrombin G20210A mutation, protein C deficiency type I) and all three patients with combined defects (heterozygous FV G1691A mutation combined with heterozygous prothrombin G20210A variant, protein S deficiency or hyperlipoproteinemia) suffered from CVL-related thrombosis. In 11 out of 77 patients (14%) a CVL-related thrombosis was detected. In 2 children thrombosis occurred a few days after asparaginase therapy and in another three thrombosis was associated with CVL-related septicemia caused by Staphylococcus epidermidis. After removal of CVL, thrombosis was detected in 5 children, in 2 without clinical symptoms but in the presence of inherited prothrombotic risk factors. CONCLUSION: The present study demonstrates the clinical importance of CVL in combination with inherited thrombophilia in the development of thrombosis in pediatric-oncologic patients. Before or shortly after insertion of CVL, patients should be tested for the presence of factor V G1691A mutation, prothrombin G20210A variant and increased lipoprotein (a) values.

18 bp insertion/duplication with internal missense mutation in human hepatic lipase gene exon 3. Mutations in brief no. 181. Online.

Human hepatic lipase (hHL) plays an important role in hydrolysis of triglycerides from plasma lipoproteins. The enzyme also hydrolyzes HDL2 lipids resulting in smaller HDL particles with a lower cholesterol content and properties similar to HDL3. hHL is localized in liver sinusoids, ovary and adrenal gland. These findings propose an influence on processing of cholesterol. Here we report an insertion mutation in exon 3 of hHL. The 18 bp duplication contains an additional internal point mutation (GenBank-Accession #AF037404). The female mutation carrier suffered from severe adiposity with total cholesterol of 291,6mg/dl, HDL-cholesterol of 55,3mg/dl, LDL-cholesterol of 206,8mg/dl and triglycerides of 80,8mg/dl. Following cloning of a PCR-amplified fragment the mutation was confirmed by cycle sequencing. Sequence analysis revealed an inserted repeat of 18 nucleotides. Furthermore the patient carries an additional missense mutation A-->G at nucleotide 9 of the repeat which results in an amino acid exchange from Ile-->Val at codon 4 of the repeat. These data enable us to report the insertion of HisTyrThrValArgVal which might be responsible for the moderate shift in lipid metabolism of the heterozygous patient.