REDUCTION OF MIGRAINES AFTER TREATMENT OF HEREDITARYHEMORRHAGIC TELANGIECTASIA (HHT)

Background: Pulmonary arteriovenous malformations (PAVMs) due to hereditaryhemorrhagic telangiectases (HHT) is associated with paradoxical strokes, brainabcesses, and increased prevalence of migraines. We report a patient in whom wefound a relationship between PAMVs and a reduction in frequency of migrainewith aura after the treatment of the first pulmonary malformation.Patient and methods: A 67-year-old woman developed migraine with visual auraand major epistaxis during childhood. A PAVM is discovered and surgically removedin 1969. Migraines nearly disappeared during several years, after which theystarted to reappear progressively. A HHT syndrome is diagnosed based on recurrentepistaxis, the development of cutaneous telangiectases and a positive family history.She suffered a left subcortical stroke in 2008. Perfusion CT, chest radiography,thoracic CT-angiography, contrast echocardiography, contrast transcranial Dopplerand cerebral MRI were performed.Results: Perfusion CT showed previous asymptomatic strokes in cerebellum andbasal ganglia. 4 PAMVs were confirmed on the chest x-ray whose structural conformationis identified on thoracic CT. Contrast echocardiography and transcranialDoppler showed a massive right to left shunt. It is planned to embolize the 4PAVMs, and migraine frequency will now be prospectively assessed.Conclusion: This patient with a pulmonary arteriovenous malformation showeda reduced migraine frequency after resection of her lung lesion. This suggests acausal relationship between a right to left shunt and migraine, as discussed inpatients with patent foramen ovale.

Efficacy And Safety Of Baerveldt Aqueous Shunts In Glaucoma Secondary To Anterior Segment Irradiation, For Uveal Melanoma

Purpose: Elevated IOP is commonly associated with iris and ciliary body melanoma. Traditional management requires the majority of eyes to undergo enucleation. The authors describe the first series of Baerveldt aqueous shunts in eyes with uveal melanoma, treated by total anterior segment irradiation.Methods: 25 consecutive patients with unilateral iris melanoma were prospectively recruited after obtaining informed consent. All patients underwent anterior segment proton beam irradiation, corneal limbal autografts and Baerveldt tube implantation at Jules Gonin Eye Hospital, Lausanne. Postoperative examinations were performed on day 1, weeks 1,3,6,9 and months 3,6,12 and annually thereafter. Success was defined as: IOP </=18mmHg (definition A); IOP </= 21mmHg and 20% reduction in IOP (definition B). All complications were recorded.Results: Mean age was 53; mean follow up, 10.3 months; mean interval to treatment following irradiation, 2.4 years; mean pre-op IOP was 29.9 mmHg; mean post-op IOP 14.1 mmHg; mean pre-op medications 3.0; post-op medications 1.3. Success rates were, definition A: 95%; definition B: 90%. Only11% had minor complications and there were no sight-threatening complications. Aggressive ocular hypertension was observed in the several eyes prior to shunt implantation. Two eyes were enucleated for non-glaucoma related sequelae.Conclusions: Baerveldt aqueous shunts are safe and efficacious following total anterior segment irradiation for uveal melanoma. The novel interdisciplinary approach improved ocular retention rates, offering a promising alternative to current management algorithms.

A new approach for potential drug target discovery through in silico metabolic pathway analysis using Trypanosoma cruzi genome information

The current drug options for the treatment of chronic Chagas disease have not been sufficient and high hopes have been placed on the use of genomic data from the human parasite Trypanosoma cruzi to identify new drug targets and develop appropriate treatments for both acute and chronic Chagas disease. However, the lack of a complete assembly of the genomic sequence and the presence of many predicted proteins with unknown or unsure functions has hampered our complete view of the parasite's metabolic pathways. Moreover, pinpointing new drug targets has proven to be more complex than anticipated and has revealed large holes in our understanding of metabolic pathways and their integrated regulation, not only for this parasite, but for many other similar pathogens. Using an in silicocomparative study on pathway annotation and searching for analogous and specific enzymes, we have been able to predict a considerable number of additional enzymatic functions in T. cruzi. Here we focus on the energetic pathways, such as glycolysis, the pentose phosphate shunt, the Krebs cycle and lipid metabolism. We point out many enzymes that are analogous to those of the human host, which could be potential new therapeutic targets.

13q deletion syndrome and retinoblastoma in identical dichorionic diamniotic monozygotic twins.

PURPOSE: To report the case of identical dichorionic diamniotic female twins with unilateral retinoblastoma in 13q deletion syndrome. METHODS: Clinical and ophthalmoscopic evaluation, combination of multiple ligation-dependent probe amplification, array-comparative genomic hybridization analyses, and magnetic resonance imaging were performed. RESULTS: Peculiar facial features, marked hypotonia, gastroesophageal reflux, interatrial septal defect with left to right shunt and light dilatation of right chambers, 5th finger hypoplasia, 3rd-5th toes clinodactyly, 2nd toe overlapped to 3rd toe, and cutis marmorata were found. Ophthalmoscopic evaluation revealed unilateral retinoblastoma in both girls. Magnetic resonance imaging detected corpus callosum hypoplasia in both twins. A 34.4-Mb deletion involving bands 13q13.2-q21.33 and including the RB1 gene was identified in both twins. The deletion was not present in the DNA of their parents and older brother. CONCLUSIONS: Dysmorphic features in children must be always suspicious of 13q deletion syndrome and a short ophthalmoscopic follow-up is necessary to detect the presence of a retinoblastoma.

Sonication of catheter tips for improved detection of microorganisms on external ventricular drains and ventriculo-peritoneal shunts.

The diagnosis of infections involving internal or external neurosurgical drainage devices is challenging, and to our knowledge no single reliable microbiological test exists. We used sonication to study bacterial colonization in 14 explanted external ventricular drains (EVD) and 13 ventriculo-peritoneal shunt (VPS) devices. This technique dislodges biofilm bacteria from the surface of implanted materials before culture. Removed devices were sonicated in saline (40 kHz, 1 minute, 0.25 W/cm(2)), the resulting fluid was cultured aerobically and anaerobically at 37°C, and bacterial growth was counted. Ventricular cerebrospinal fluid (CSF) was cultured separately. In the EVD group, sonication cultures grew significantly more bacteria (64%, 9/14) than cultures of aspirated ventricular CSF (14%, 2/14). In the VPS group the difference was not significant. Positive sonication cultures of EVD catheters yielded a median of >100 colony forming units (CFU) (range, 60-800). For positive sonication cultures of VPS, the median was 1000 CFU (range, 20-100,000). All patients with bacteria in their CSF also had positive sonication cultures from the removed device. Of the five patients with sterile or presumably contaminated CSF cultures but positive sonication cultures of removed shunts, one became afebrile after removal of the EVD, two developed meningitis and two remained asymptomatic. Sonication culture of EVD appears to improve the microbiological assessment of device-related infection and it corroborates with CSF cultures of revision surgery for VPS. Sonication of the removed EVD tip may raise awareness for the onset of meningitis.

Monitoring switch-type sensors and powering autonomous sensors via inductive coupling: application to removable seats in vehicles

Aquesta tesi explora la possibilitat de fer servir enllaços inductius per a una aplicació de l’automòbil on el cablejat entre la centraleta (ECU) i els sensors o detectors és difícil o impossible. S’han proposat dos mètodes: 1) el monitoratge de sensors commutats (dos possibles estats) via acoblament inductiu i 2) la transmissió mitjançant el mateix principi físic de la potència necessària per alimentar els sensors autònoms remots. La detecció d'ocupació i del cinturó de seguretat per a seients desmuntables pot ser implementada amb sistemes sense fils passius basats en circuits ressonants de tipus LC on l'estat dels sensors determina el valor del condensador i, per tant, la freqüència de ressonància. Els canvis en la freqüència són detectats per una bobina situada en el terra del vehicle. S’ha conseguit provar el sistema en un marge entre 0.5 cm i 3 cm. Els experiments s’han dut a terme fent servir un analitzador d’impedàncies connectat a una bobina primària i sensors comercials connectats a un circuit remot. La segona proposta consisteix en transmetre remotament la potència des d’una bobina situada en el terra del vehicle cap a un dispositiu autònom situat en el seient. Aquest dispositiu monitorarà l'estat dels detectors (d'ocupació i de cinturó) i transmetrà les dades mitjançant un transceptor comercial de radiofreqüència o pel mateix enllaç inductiu. S’han avaluat les bobines necessàries per a una freqüència de treball inferior a 150 kHz i s’ha estudiat quin és el regulador de tensió més apropiat per tal d’aconseguir una eficiència global màxima. Quatre tipus de reguladors de tensió s’han analitzat i comparat des del punt de vista de l’eficiència de potència. Els reguladors de tensió de tipus lineal shunt proporcionen una eficiència de potència millor que les altres alternatives, els lineals sèrie i els commutats buck o boost. Les eficiències aconseguides han estat al voltant del 40%, 25% i 10% per les bobines a distàncies 1cm, 1.5cm, i 2cm. Les proves experimentals han mostrat que els sensors autònoms han estat correctament alimentats fins a distàncies de 2.5cm.

Genome reconstruction and comparative genomics of pneumocystis jirovecii

Pneumocystis jirovecii is a fungus belonging to a basal lineage of the Ascomycotina, the Taphrinomycotina subphylum. It is a parasite specific to humans that dwells primarily in the lung and can cause severe pneumonia in individuals with debilitated immune system. Despite its clinical importance, many aspects of its biology remain poorly understood, at least in part because of the lack of a continuous in vitro cultivation system. The present thesis consists in the genome reconstruction and comparative genomics of P. jirovecii. It is made of three parts: (i) the de novo sequencing of P. jirovecii genome starting from a single broncho- alveolar lavage fluid of a single patient (ii) the de novo sequencing of the genome of the plant pathogen Taphrina deformans, a fungus closely related to P. jirovecii, and (iii) the genome scale comparison of P. jirovecii to other Taphrinomycotina members. Enrichment in P. jirovecii cells by immuno-precipitation, whole DNA random amplification, two complementary high throughput DNA sequencing methods, and in silico sorting and assembly of sequences were used for the de novo reconstruction of P. jirovecii genome from the microbiota of a single clinical specimen. An iterative ad hoc pipeline as well as numerical simulations was used to recover P. jirovecii sequences while purging out contaminants and assembly or amplification chimeras. This strategy produced a 8.1 Mb assembly, which encodes 3,898 genes. Homology searches, mapping on biochemical pathways atlases, and manual validations revealed that this genome lacks (i) most of the enzymes dedicated to the amino acids biosyntheses, and (ii) most virulence factors observed in other fungi, e.g. the glyoxylate shunt pathway and specific peptidases involved in the degradation of the host cell membrane. The same analyses applied to the available genomic sequences from Pneumocystis carinii the species infecting rats and Pneumocystis murina the species infecting mice revealed the same deficiencies. The genome sequencing of T. deformans yielded a 13 Mb assembly, which encodes 5,735 genes. T. deformans possesses enzymes involved plant cell wall degradation, secondary metabolism, the glyoxylate cycle, detoxification, sterol biosynthesis, as well as the biosyntheses of plant hormones such as abscisic acid or indole-3-acetic acid. T. deformans also harbors gene subsets that have counterparts in plant saprophytes or pathogens, which is consistent with its alternate saprophytic and pathogenic lifestyles. Mating genes were also identified. The homothallism of this fungus suggests a mating-type switching mechanism. Comparative analyses indicated that 81% of P. jirovecii genes are shared with eight other Taphrinomycotina members, including T. deformans, P. carinii and P. murina. These genes are mostly involved in housekeeping activities. The genes specific to the Pneumocystis genus represent 8%, and are involved in RNA metabolism and signaling. The signaling is known to be crucial for interaction of Pneumocystis spp with their environment. Eleven percent are unique to P. jirovecii and encode mostly proteins of unknown function. These genes in conjunction with other ones (e.g. the major surface glycoproteins) might govern the interaction of P. jirovecii with its human host cells, and potentially be responsible of the host specificity. P. jirovecii exhibits a reduced genome in size with a low GC content, and most probably scavenges vital compounds such as amino acids and cholesterol from human lungs. Consistently, its genome encodes a large set of transporters (ca. 22% of its genes), which may play a pivotal role in the acquisition of these compounds. All these features are generally observed in obligate parasite of various kingdoms (bacteria, protozoa, fungi). Moreover, epidemiological studies failed to evidence a free-living form of the fungus and Pneumocystis spp were shown to co-evolved with their hosts. Given also the lack of virulence factors, our observations strongly suggest that P. jirovecii is an obligate parasite specialized in the colonization of human lungs, and which causes disease only in individuals with compromised immune system. The same conclusion is most likely true for all other Pneumocystis spp in their respective mammalian host. - Pneumocystis jirovecii est un champignon appartenant à ine branche basale des Ascomycotina, le sous-embranchement des Taphrinomycotina. C'est un parasite spécifique aux humains qui réside principalement dans les poumons, et qui peut causer des pneumonies sévères chez des individus ayant un système immunitaire déficient. En dépit de son importance clinique, de nombreux aspects de sa biologie demeurent,largement méconnus, au moins en partie à cause de l'absence d'un système de culture in vitro continu. Cette thèse traite de la reconstruction du génome et de la génomique comparative de P. jirovecii. Elle comporte trois parties: (i) le séquençage de novo du génome de P. jirovecii à partir d'un lavage broncho-alvéolaire provenant d'un seul patient, (ii) le séquençage de novo du génome d'un champignon pathogène de plante Taphrina deformans qui est phylogénétiquement proche de P. jirovecii, et (iii) la comparaison du génome de P. jirovecii à celui d'autres membres du sous-embranchement des Taphrinomycotina. Un enrichissement en cellules de P. jirovecii par immuno-précipitation, une amplification aléatoire des molécules d'ADN, deux méthodes complémentaires de séquençage à haut débit, un tri in silico et un assemblage des séquences ont été utilisés pour reconstruire de novo le génome de P. jirovecii à partir du microbiote d'un seul échantillon clinique. Un pipeline spécifique ainsi que des simulations numériques ont été utilisés pour récupérer les séquences de P. jirovecii tout en éliminant les séquences contaminants et les chimères d'amplification ou d'assemblage. Cette stratégie a produit un assemblage de 8.1 Mb, qui contient 3898 gènes. Les recherches d'homologies, de cartographie des voies métaboliques et des validations manuelles ont révélé que ce génome est dépourvu (i) de la plupart des enzymes dédiées à la biosynthèse des acides aminés, et (ii) de la plupart des facteurs de virulence observés chez d'autres champignons, par exemple, le cycle du glyoxylate ainsi que des peptidases spécifiques impliquées dans la dégradation de la membrane de la cellule hôte. Les analyses appliquées aux données génomiques disponibles de Pneumocystis carinii, l'espèce infectant les rats, et de Pneumocystis murina, l'espèce infectant les souris, ont révélé les mêmes déficiences. Le séquençage du génome de T. deformans a généré un assemblage de 13.3 Mb qui contient 5735 gènes. T. deformans possède les gènes codant pour les enzymes impliquées dans la dégradation des parois cellulaires des plantes, le métabolisme secondaire, le cycle du glyoxylate, la détoxification, la biosynthèse des stérols ainsi que la biosynthèse d'hormones de plantes telles que l'acide abscissique ou l'acide indole 3-acétique. T. deformans possède également des sous-ensembles de gènes présents exclusivement chez des saprophytes ou des pathogènes de plantes, ce qui est consistent avec son mode de vie alternatif saprophyte et pathogène. Des gènes impliqués dans la conjugaison ont été identifiés. L'homothallisme de ce champignon suggère mécanisme de permutation du type conjuguant. Les analyses comparatives ont démontré que 81% des gènes de P. jirovecii sont présent chez les autres membres du sous-embranchement des Taphrinomycotina. Ces gènes sont essentiellement impliqués dans le métabolisme basai. Les gènes spécifiques au genre Pneumocystis représentent 8%, et sont impliqués dans le métabolisme de l'ARN et la signalisation. La signalisation est connue pour être cruciale pour l'interaction des espèces de Pneumocystis avec leur environnement. Les gènes propres à P. jirovecii représentent 11% et codent en majorité pour des protéines dont la fonction est inconnue. Ces gènes en conjonction avec d'autres (par exemple, les glycoprotéines de surface), pourraient être déterminants dans l'interaction de P. jirovecii avec les cellules de l'hôte humain, et être potentiellement responsable de la spécificité d'hôte. P. jirovecii possède un génome de taille réduite à faible pourcentage en GC et récupère très probablement des composés vitaux comme les acides aminés et le cholestérol à partir des poumons humains. De manière consistante, son génome code pour de nombreux transporteurs (22% de ses gènes), qui pourraient jouer un rôle essentiel dans l'acquisition de ces composés. Ces caractéristiques sont généralement observées chez les parasites obligatoires de plusieurs règnes (bactéries, protozoaires, champignons). De plus, les études épidémiologiques n'ont pas réussi à prouver l'existence d'ime forme vivant librement du champignon. Etant donné également l'absence de facteurs de virulence, nos observations suggèrent que P. jirovecii est un parasite obligatoire spécialisé dans la colonisation des poumons humains, ne causant une maladie que chez des individus ayant un système immunitaire compromis. La même conclusion est très probablement applicable à toutes les autres espèces de Pneumocystis dans leur hôte mammifère respectif.

Incidence and risk factors for Contegra graft infection following right ventricular outflow tract reconstruction: long-term results.

OBJECTIVES: The aim of this study was to evaluate the risk factors associated with Contegra graft (Medtronic Minneapolis, MN, USA) infection after reconstruction of the right ventricular outflow tract. METHODS: One hundred and six Contegra grafts were implanted between April 1999 and April 2010 for the Ross procedure (n = 46), isolated pulmonary valve replacement (n = 32), tetralogy of Fallot (n = 24), double-outlet right ventricle (n = 7), troncus arteriosus (n = 4), switch operation (n = 1) and redo of pulmonary valve replacement (n = 2). The median age of the patients was 13 years (range 0-54 years). A follow-up was completed in all cases with a median duration of 7.6 years (range 1.7-12.7 years). RESULTS: There were 3 cases of in-hospital mortality. The survival rate during 7 years was 95.7%. Despite the lifelong endocarditis prophylaxis, Contegra graft infection was diagnosed in 12 (11.3%) patients at a median time of 4.4 years (ranging from 0.4 to 8.7 years). Univariate analysis of preoperative, perioperative and postoperative variables was performed and the following risk factors for time to infection were identified: female gender with a hazard ratio (HR) of 0.19 (P = 0.042), systemic-to-pulmonary shunt (HR 6.46, P < 0.01), hypothermia (HR 0.79, P = 0.014), postoperative renal insufficiency (HR 11.97, P = 0.015) and implantation of permanent pacemaker during hospitalization (HR 5.29, P = 0.075). In 2 cases, conservative therapy was successful and, in 10 patients, replacement of the infected valve was performed. The Contegra graft was replaced by a homograft in 2 cases and by a new Contegra graft in 8 cases. Cox's proportional hazard model indicated that time to graft infection was significantly associated with tetralogy of Fallot (HR 0.06, P = 0.01), systemic-to-pulmonary shunt (HR 64.71, P < 0.01) and hypothermia (HR 0.77, P < 0.01). CONCLUSION: Contegra graft infection affected 11.3% of cases in our cohort, and thus may be considered as a frequent entity that can be predicted by both intraoperative and early postoperative factors. After the diagnosis of infection associated with the Contegra graft was confirmed, surgical treatment was the therapy of choice.

Recurrent stroke predictors differ in medically treated patients with pathogenic vs. other PFOs.

OBJECTIVE: To examine predictors of stroke recurrence in patients with a high vs a low likelihood of having an incidental patent foramen ovale (PFO) as defined by the Risk of Paradoxical Embolism (RoPE) score. METHODS: Patients in the RoPE database with cryptogenic stroke (CS) and PFO were classified as having a probable PFO-related stroke (RoPE score of >6, n = 647) and others (RoPE score of ≤6 points, n = 677). We tested 15 clinical, 5 radiologic, and 3 echocardiographic variables for associations with stroke recurrence using Cox survival models with component database as a stratification factor. An interaction with RoPE score was checked for the variables that were significant. RESULTS: Follow-up was available for 92%, 79%, and 57% at 1, 2, and 3 years. Overall, a higher recurrence risk was associated with an index TIA. For all other predictors, effects were significantly different in the 2 RoPE score categories. For the low RoPE score group, but not the high RoPE score group, older age and antiplatelet (vs warfarin) treatment predicted recurrence. Conversely, echocardiographic features (septal hypermobility and a small shunt) and a prior (clinical) stroke/TIA were significant predictors in the high but not low RoPE score group. CONCLUSION: Predictors of recurrence differ when PFO relatedness is classified by the RoPE score, suggesting that patients with CS and PFO form a heterogeneous group with different stroke mechanisms. Echocardiographic features were only associated with recurrence in the high RoPE score group.

Disposition of venlafaxine enantiomers in rats with hepatic encephalopathy after chronic drug treatment.

Portacaval shunted (PCS) rats, a model of hepatic encephalopathy, and control animals were administered racemic venlafaxine for 14 days (10 mg/kg). The levels of the S- and R-enantiomers and the S/R-enantiomer ratios of venlafaxine and its metabolites were assessed by an enantiomer-selective chromatographic assay in serum, brain parenchyma, and brain dialysate of both groups. Higher levels of the S- and R-enantiomers of venlafaxine were found in serum and brain of PCS vs. normal rats (median values of S- and R-venlafaxine in serum: 290 and 201 nM in PCS; 97 and 66 nM in normal rats; median values of S- and R-venlafaxine in cortex: 956 and 939 nM in PCS; 357 and 318 nM in normal rats). Interestingly, similar S/R-venlafaxine ratios were observed in PCS and normal rats both in serum (S/R = 1.4) and brain compartments (S/R = l.0-1.1). These findings may have clinical relevance for the safety of venlafaxine in chronic hepatic encephalopathy.

Suprapineal recess: an alternate site for third ventriculostomy? Case report.

This 30-year-old woman presented with clinical symptoms and signs of intracranial hypertension and Parinaud syndrome secondary to ventriculoperitoneal shunt dysfunction. Magnetic resonance (MR) imaging revealed gross triventricular hydrocephalus with a large suprapineal recess due to aqueductal stenosis. Using an endoscopic approach, a ventriculostomy was performed within the floor of the dilated suprapineal recess. Following this procedure the patient experienced alleviation of all her neurological symptoms and signs. Postoperative MR imaging and cerebrospinal fluid flow studies demonstrated a functioning ventriculostomy. The anatomy of the suprapineal recess and its suitability for endoscopic ventriculostomy are discussed.

Liver segmentation: Practical tips.

The liver segmentation system, described by Couinaud, is based on the identification of the three hepatic veins and the plane passing by the portal vein bifurcation. Nowadays, Couinaud's description is the most widely used classification since it is better suited for surgery and more accurate for the localisation and monitoring of intra-parenchymal lesions. Knowledge of the anatomy of the portal and venous system is therefore essential, as is knowledge of the variants resulting from changes occurring during the embryological development of the vitelline and umbilical veins. In this paper, the authors propose a straightforward systematisation of the liver in six steps using several additional anatomical points of reference. These points of reference are simple and quickly identifiable in any radiological examination with section imaging, in order to avoid any mistakes in daily practice. In fact, accurate description impacts on many diagnostic and therapeutic applications in interventional radiology and surgery. This description will allow better preparation for biopsy, portal vein embolisation, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy for transplantation. Such advance planning will reduce intra- and postoperative difficulties and complications.

Low-pressure environment and remodelling of the forearm vein in Brescia-Cimino haemodialysis access.

BACKGROUND: The aim of the study was to determine which, and to what extent, haemodynamic parameters contribute to the remodelling of the venous limb of the Brescia-Cimino haemodialysis access. METHODS: The dimensions of the radial artery and the venous limb of the haemodialysis access were measured by an echo-tracking technique. In six ESRD patients undergoing primary arteriovenous fistula (AVF) formation, vessel diameter, wall thickness, blood pressure and blood flow were measured after the operation, and at 1 and 3 months follow-up. The contralateral forearm vessels in their native position served as baseline values for comparison. RESULTS: The diameter of the proximal antecubital vein progressively increased over the study period without reaching significant differences (4430, 5041 and 6620 microm at weeks 1, 4 and 12 respectively), whereas the intima-media thickness remained unchanged. The venous dilatation was associated with a reduction of the mean shear stress that culminated after the operation and progressively returned to normal venous values at 3 months (24.5 vs 10.4 dyne/cm(2), P<0.043). Thus the venous limb of the AVF undergoes eccentric hypertrophy as demonstrated by the increase in wall cross-sectional area (4.42 vs 6.32 mm(2) at week 1 vs week 12, P<0.028). At the time of the operation, the blood pressure in the AVF was 151+/-14/92.4+/-11 mmHg vs 49+/-19/24.5+/-6 mmHg (means+/-SEM) for the radial artery and the venous limb of the vascular access, respectively. One year after the operation the blood pressure in the venous limb had not changed: 42+/-14/25.3+/-7 mmHg (means+/-SEM). Under these conditions, the systolo-diastolic diameter changes observed in the radial artery and the antecubital vein were within a similar range at all time points: 56+/-17 vs 90+/-26 microm (means+/-SEM) at week 12. CONCLUSIONS: The increased circumferential stress resulting from the flow-mediated dilatation rather than the elevation of blood pressure appears to represent the main contributing factor to the eccentric hypertrophy of the venous limb of Brescia-Cimino haemodialysis access.

Lumboperitoneal shunting for pseudotumor cerebri.

To clarify the appropriate role of lumboperitoneal (LP) shunting in the surgical management of pseudotumor cerebri (PTC), we retrospectively analyzed the clinical data from 30 patients who underwent this procedure. We found LP shunting to be an effective means of acutely lowering intracranial pressure. Symptoms of increased intracranial pressure improved in 82% of patients. Among 14 eyes with impaired visual acuity, 10 (71%) improved by at least two lines. Worsening of vision occurred in only one eye. Of 28 eyes with abnormal Goldmann perimetry, 18 (64%) improved and none worsened. The incidence of serious complications was low. The major drawback of LP shunting was the need for frequent revisions in a few patients. The reason for poor shunt tolerance in certain individuals is unclear. In PTC, LP shunting should be considered as the first surgical procedure for patients with severe visual loss at presentation or with intractable headache (with or without visual loss). After shunting it is important to identify patients who are shunt intolerant.

Asymptomatic high flow subclavian steal in a patient with hemodialysis access.

Subclavian steal phenomenon due to proximal subclavian artery stenosis or occlusion is not un-common but often remains asymptomatic. We describe the case of a 66-year-old man with end-stage renal disease hemodialysed through a brachio-brachial loop graft of the left forearm. Echo-Doppler precerebral examination showed a high reversed flow of 570 ml/min in the ipsilateral vertebral artery. After successful endovascular recanalization of the subclavian artery, access blood flow increased and vertebral flow decreased to 30 ml/min. Complete neurological examination was normal both before and after endovascular treatment. This case demonstrates how high a subclavian steal can be without causing symptoms and how well precerbral and cerebral circulation can adapt to hemodynamic changes.