Difficult withdrawal of an inferior vena cava filter: Technical considerations and associated variables.

OBJECTIVE: To analyse the efficacy of the procedure for withdrawing an inferior vena cava (IVC) filter and the clinical and radiological factors associated with difficult withdrawal. MATERIAL AND METHODS: This retrospective observational study included patients who underwent IVC filter withdrawal at a single centre between May 2015 and May 2021. We recorded demographic, clinical, procedural, and radiological variables: type of IVC filter, angle with the IVC > 15°, hook against the wall, and legs embedded in the IVC wall > 3 mm. The efficacy variables were fluoroscopy time, success of IVC filter withdrawal, and number of attempts to withdraw the filter. The safety variables were complications, surgical removal, and mortality. The main variable was difficult withdrawal, defined as more than 5 min fluoroscopy or more than 1 attempt at withdrawal. RESULTS: A total of 109 patients were included; withdrawal was considered difficult in 54 (49.5%). Three radiological variables were more common in the difficult withdrawal group: hook against the wall (33.3% vs. 9.1%; p = 0.027), embedded legs (20.4% vs. 3.6%; p = 0.008), and >45 days since IVC filter placement (51.9% vs. 25.5%; p = 0.006). These variables remained significant in the subgroup of patients with OptEase IVC filters; however, in the group of patients with Celect IVC filters, only the inclination of the IVC filter >15 ° was significantly associated with difficult withdrawal (25% vs 0%; p = 0.029). CONCLUSION: Difficult withdrawal was associated with time from IVC placement, embedded legs, and contact between the hook and the wall. The analysis of the subgroups of patients with different types of IVC filters found that these variables remained significant in those with OptEase filters; however, in those with cone-shaped devices (Celect), the inclination of the IVC filter >15° was significantly associated with difficult withdrawal.

Retirada difícil de filtro de vena cava inferior (FVCI). Consideraciones técnicas y variables asociadas / Difficult withdrawal of an inferior vena cava filter: technical considerations and associated variables

Objetivo: Analizar la eficacia del procedimiento de retirada de los filtros de la vena cava inferior (FVCI), así como los factores clínico-radiológicos asociados a una retirada difícil. Material y método: Estudio retrospectivo, observacional y unicéntrico de pacientes tratados mediante retirada de FVCI entre mayo del 2015 y mayo del 2021. Se recogieron variables clínico-demográficas, del procedimiento y radiológicas: tipo de FVCI, angulación respecto a la vena cava inferior (VCI) >15°, gancho contra la pared y patas del dispositivo incrustadas en la pared de VCI> 3mm. Las variables de eficacia fueron: tiempo de fluoroscopia, éxito en la retirada del FVCI y número de intentos hasta la retirada. Como variables de seguridad: presencia de complicaciones, retirada quirúrgica y mortalidad. La variable principal fue la retirada difícil, definida como más de 5min de fluoroscopia o más de un intento de retirada. Resultados: Se incluyó a 109 pacientes, 54 (49,5%) fueron considerados retirada difícil. Las variables radiológicas gancho contra la pared (33,3% vs. 9,1%; p=0,027), patas incrustadas (20,4% vs. 3,6%; p=0,008) y> 45 días desde la colocación (51,9% vs. 25,5%; p=0,006) fueron significativamente más frecuentes en el grupo de retirada difícil. Estas variables mantienen la asociación al analizar los FVCI Optease®. En los FVCI Celect® solo se asoció con retirada difícil la inclinación del FVCI> 15° (25% vs. 0%; p=0,029).Conclusión: Se ha encontrado asociación entre una retirada difícil y las siguientes variables: tiempo desde colocación del FVCI, patas incrustadas y contacto del gancho con la pared de VCI. Al analizar según el tipo de FVCI, estas variables se mantienen en el tipo Optease®, en cambio, la inclinación de más de 15° dificulta la retirada de los dispositivos de morfología cónica (Celect®).(AU)

Objective: To analyze the efficacy of the procedure for withdrawing an inferior vena cava (IVC) filter and the clinical and radiological factors associated with difficult withdrawal. Material and methods: This retrospective observational study included patients who underwent IVC filter withdrawal at a single center between May 2015 and May 2021. We recorded demographic, clinical, procedural, and radiological variables: type of IVC filter, angle with the IVC> 15°, hook against the wall, and legs embedded in the IVC wall> 3mm. The efficacy variables were fluoroscopy time, success of IVC filter withdrawal, and number of attempts to withdraw the filter. The safety variables were complications, surgical removal, and mortality. The main variable was difficult withdrawal, defined as more than 5minutes fluoroscopy or more than 1 attempt at withdrawal. Results: A total of 109 patients were included; withdrawal was considered difficult in 54 (49.5%). Three radiological variables were more common in the difficult withdrawal group: hook against the wall (33.3% vs. 9.1%; p=0.027), embedded legs (20.4% vs. 3.6%; p=0.008), and>45 days since IVC filter placement (51.9% vs. 25.5%; p=0.006). These variables remained significant in the subgroup of patients with OptEase IVC filters; however, in the group of patients with Celect IVC filters, only the inclination of the IVC filter>15° was significantly associated with difficult withdrawal (25% vs 0%; p=0.029). Conclusion: Difficult withdrawal was associated with time from IVC placement, embedded legs, and contact between the hook and the wall. The analysis of the subgroups of patients with different types of IVC filters found that these variables remained significant in those with OptEase filters; however, in those with cone-shaped devices (Celect), the inclination of the IVC filter>15° was significantly associated with difficult withdrawal.(AU)

Multicenter Retrospective Registry of Anterior Communicating Artery Aneurysms with Endovascular Therapy (MACAARET): safety and efficacy study according to morphological considerations and spatial orientations.

AIM: To analyse the safety and efficacy parameters of endovascular treatment of anterior communicating artery (ACoA) aneurysms, according to their morphological considerations and three-dimensional orientation in a multicentric registry. MATERIALS AND METHODS: A retrospective analysis was undertaken of a prospective database of consecutive patients that underwent endovascular embolisation for ACoA aneurysm in four high-volume neuroradiology interventional departments. The study has been registered in ClinicalTrial.gov. Data were collected regarding the clinico-demographic variables of the patients, anatomical variations of the circle of Willis, morphological considerations and spatial orientation of ACoA aneurysms were recorded. Safety and efficacy variables were also recorded. Associations between anatomical variations of the circle of Willis, morphological considerations, and spatial orientation of the ACoA aneurysms and safety and efficacy variables were assessed. RESULTS: Data from 122 consecutive patients were collected in the MACAARET study (mean age (±SD) was 55 (±14) and 50.8% (62/122) were male). One hundred and five patients (86.1%) presented with subarachnoid haemorrhage (SAH). ACoA aneurysms with a neck size of >4 mm had less chance of having successful endovascular treatment than those of ≤4 mm (19.8% versus 46.7%; p=0.002) and were also more likely to recanalise during follow-up (61.5% versus 19.5%; p=0.003). Moreover, ACoA aneurysms with an aspect ratio of >1.7 had more chance of having immediate therapeutic success than those with a ratio of ≤1.7 (70.7% versus 44.8%; p=0.012). There were no other associations between the anatomical variables of the ACoA aneurysms and the safety-efficacy variables. CONCLUSION: ACoA aneurysms are suitable for both endovascular and microsurgical approaches, but more data are required to determine which is the best approach regarding the morphological and spatial orientation of the aneurysm and the anatomical variations of the circle of Willis.

Value of Posterior circulation ASPECTS and Pons-Midbrain Index on non-contrast CT and CT Angiography Source Images in patients with basilar artery occlusion recanalized after mechanical thrombectomy. / Valor de la escala ASPECTS de circulación posterior y del índice puente-mesencéfalo en imágenes de TC sin contraste y angiografía por TC en pacientes con oclusiones de la arteria basilar recanalizados tras trombectomía mecánica.

PURPOSE: Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy. METHODS: Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.<8) and PMI (≥3vs.<3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate. RESULTS: CTASI pc-ASPECTS, dichotomized at <8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived. CONCLUSION: PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.

Identification and characterization of novel angiotensin-converting enzyme inhibitors obtained from goat milk.

The aim of the present study was to identify and characterize new inhibitory peptides of angiotensin I-converting enzyme (ACE) from goat milk and to analyze the effect of long-term intake of a goat milk hydrolysate-supplemented (GP-hyd) diet on the development of hypertension in spontaneously hypertensive rats (SHR). Three new inhibitory peptides for ACE (TGPIPN, SLPQ, and SQPK) were isolated. The inhibitory concentration 50% (IC50) values of individual peptides were 316, 330, and 354 micromol/L, respectively. Only TGPIPN was found to pass intact a monolayer of Caco-2 cells in small amounts. The SHR fed for 12 wk a diet (GP-hyd) enriched in a hydrolysate containing these peptides (estimated intake of TGPIPN was 230 mg/kg per d) showed lower (approximately 15 mmHg) systolic blood pressure than animals fed a control diet. The ACE activities in the aorta, left ventricle, and kidney were significantly decreased in the GP-hyd group compared with those of the control group and were similar to those found in SHR fed captopril (130 mg/kg per d). Impaired endothelium-dependent relaxation to acetylcholine by aortic rings from SHR was improved in those fed the GP-hyd diet. The left ventricle weight and kidney weight index were significantly reduced in the GP-hyd group and captopril groups. Moreover, long-term treatment of SHR with a diet enriched in goat milk hydrolysate, or captopril, attenuated the development of hypertension, cardiac and renal hypertrophy, and endothelial dysfunction. These effects might be related to the in vivo inhibitory effects of the hydrolysate on tissue ACE activity.

Kinetic properties and inhibition of the dimeric dUTPase-dUDPase from Leishmania major.

Kinetic properties of the dimeric enzyme dUTPase from Leishmania major were studied using a continuous spectrophotometric method. dUTP was the natural substrate and dUMP and PPi the products of the hydrolysis. The trypanosomatid enzyme exhibited a low K(m) value for dUTP (2.11 microM), a k(cat) of 49 s(-1), strict Michaelis-Menten kinetics and is a potent catalyst of dUDP hydrolysis, whereas in other dUTPases described, this compound acts as a competitive inhibitor. Discrimination is achieved for the base and sugar moiety showing specificity constants for different dNTPs similar to those of bacterial, viral, and human enzymes. In the alkaline range, the K(m) for dUTP increases with the dissociation of ionizable groups showing pK(a) values of 8.8, identified as the uracil moiety of dUTP and 10, whereas in the acidic range, K(m) is regulated by an enzyme residue exhibiting a pK(a) of 7.1. Activity is strongly inhibited by the nucleoside triphosphate analog alpha-beta-imido-dUTP, indicating that the enzyme can bind triphosphate analogs. The existence of specific inhibition and the apparent structural and kinetic differences (reflected in different binding strength of dNTPs) with other eukaryotic dUTPases suggest that the present enzyme might be exploited as a target for new drugs against leishmaniasis.

New crystal forms of Trypanosoma cruzi dUTPase.

The dUTPase from Trypanosoma cruzi has been crystallized in two crystal forms, both belonging to space group P6(3)22, with unit-cell parameters a = b = 134.67, c = 148.66 A (form I, two molecules per asymmetric unit) and a = b = 136.43, c = 68.71 A (form II, one molecule per asymmetric unit). Single-wavelength data have been collected using synchrotron radiation to 3.0 A for crystal form I and to 2.4 A for crystal form II and structure solution is under way. T. cruzi dUTPase is a potential target for anti-protozoan drug design.

Trypanosomal dUTPases as potential targets for drug design.

Parasites of the Trypanosomatidae family are responsible for diseases that afflict several million people worldwide. Currently there is an urgent need for new drugs against these diseases and an approach to drug discovery is the study of biochemical and structural properties of a potential target and the subsequent design of specific compounds. Trypanosomatid genes coding for enzymes which distinctively hydrolyze dUTP have been isolated by genetic complementation in Escherichia coli mutants defective in dUTPase activity. An analysis of these sequences from Leishmania major and Trypanosoma cruzi showed that no significant similarity could be established with the family of known dUTPases and that the five consensus motifs were absent. However, limited similarity was identified for three motifs present in an enzyme related in function the dCTPase-dUTPase from T phages and 35 percent identity with a putative dUTPase identified in the eubacteria Campylobacter jejuni. T. cruzi and L. major dUTPases were highly similar and catalyzed in a specific fashion the hydrolysis of dUTP. A detailed kinetic study of both enzymes revealed that dUDP is also an efficient substrate of the enzyme while other nucleotides are poorly hydrolyzed. The enzyme is essential for viability in Leishmania and is up-regulated by inhibitors of dTMP synthesis. Thus, a new family of dUTPases might exist in certain organisms that bear no sequence or structure similarity with eukaryotic enzymes accomplishing the same function and that may constitute potential drug targets for the development of specific inhibitors.

Properties of Leishmania major dUTP nucleotidohydrolase, a distinct nucleotide-hydrolysing enzyme in kinetoplastids.

We have previously reported the presence, in the parasitic protozoan Leishmania major, of an enzyme involved in controlling intracellular dUTP levels. The gene encoding this enzyme has now been overexpressed in Escherichia coli, and the recombinant enzyme was purified to homogeneity. Biochemical and enzymic analyses of the Leishmania enzyme show that it is a novel nucleotidohydrolase highly specific for deoxyuridine 5'-triphosphate. The enzyme has proved to be a dimer by gel filtration and is able to hydrolyse both dUTP and dUDP quite efficiently, acting as a dUTP nucleotidohydrolase (dUTPase)-dUDP nucleotidohydrolase but has a limited capacity to act upon other nucleoside di- or triphosphates. The reaction products are dUMP and PP(i) when dUTP is the substrate and dUMP and P(i) in the case of dUDP. The enzyme is sensitive to inhibition by the reaction product dUMP but not by PP(i). dUTPase activity is highly dependent on Mg(2+) concentrations and markedly sensitive to the phosphatase inhibitor, NaF. In summary, Leishmania dUTPase appears to be markedly different to other proteins characterized previously that accomplish the same function.