Aromatic amino acid biosynthesis impacts root hair development and symbiotic associations in Lotus japonicus.

Legume roots can be symbiotically colonized by arbuscular mycorrhizal (AM) fungi and nitrogen-fixing bacteria. In Lotus japonicus, the latter occurs intracellularly by the cognate rhizobial partner Mesorhizobium loti or intercellularly with the Agrobacterium pusense strain IRBG74. Although these symbiotic programs show distinctive cellular and transcriptome signatures, some molecular components are shared. In this study, we demonstrate that 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase 1 (DAHPS1), the first enzyme in the biosynthetic pathway of aromatic amino acids (AAAs), plays a critical role in root hair development and for AM and rhizobial symbioses in Lotus. Two homozygous DAHPS1 mutants (dahps1-1 and dahps1-2) showed drastic alterations in root hair morphology, associated with alterations in cell wall dynamics and a progressive disruption of the actin cytoskeleton. The altered root hair structure was prevented by pharmacological and genetic complementation. dahps1-1 and dahps1-2 showed significant reductions in rhizobial infection (intracellular and intercellular) and nodule organogenesis and a delay in AM colonization. RNAseq analysis of dahps1-2 roots suggested that these phenotypes are associated with downregulation of several cell wall-related genes, and with an attenuated signaling response. Interestingly, the dahps1 mutants showed no detectable pleiotropic effects, suggesting a more selective recruitment of this gene in certain biological processes. This work provides robust evidence linking AAA metabolism to root hair development and successful symbiotic associations.

Electroencephalographic guided propofol-remifentanil TCI anesthesia with and without dexmedetomidine in a geriatric population: electroencephalographic signatures and clinical evaluation.

Elderly and multimorbid patients are at high risk for developing unfavorable postoperative neurocognitive outcomes; however, well-adjusted and EEG-guided anesthesia may help titrate anesthesia and improve postoperative outcomes. Over the last decade, dexmedetomidine has been increasingly used as an adjunct in the perioperative setting. Its synergistic effect with propofol decreases the dose of propofol needed to induce and maintain general anesthesia. In this pilot study, we evaluate two highly standardized anesthetic regimens for their potential to prevent burst suppression and postoperative neurocognitive dysfunction in a high-risk population. Prospective, randomized clinical trial with non-blinded intervention. Operating room and post anesthesia care unit at Hospital Base San José, Osorno/Universidad Austral, Valdivia, Chile. 23 patients with scheduled non-neurologic, non-cardiac surgeries with age > 69 years and a planned intervention time > 60 min. Patients were randomly assigned to receive either a propofol-remifentanil based anesthesia or an anesthetic regimen with dexmedetomidine-propofol-remifentanil. All patients underwent a slow titrated induction, followed by a target controlled infusion (TCI) of propofol and remifentanil (n = 10) or propofol, remifentanil and continuous dexmedetomidine infusion (n = 13). We compared the perioperative EEG signatures, drug-induced changes, and neurocognitive outcomes between two anesthetic regimens in geriatric patients. We conducted a pre- and postoperative Montreal Cognitive Assessment (MoCa) test and measured the level of alertness postoperatively using a sedation agitation scale to assess neurocognitive status. During slow induction, maintenance, and emergence, burst suppression was not observed in either group; however, EEG signatures differed significantly between the two groups. In general, EEG activity in the propofol group was dominated by faster rhythms than in the dexmedetomidine group. Time to responsiveness was not significantly different between the two groups (p = 0.352). Finally, no significant differences were found in postoperative cognitive outcomes evaluated by the MoCa test nor sedation agitation scale up to one hour after extubation. This pilot study demonstrates that the two proposed anesthetic regimens can be safely used to slowly induce anesthesia and avoid EEG burst suppression patterns. Despite the patients being elderly and at high risk, we did not observe postoperative neurocognitive deficits. The reduced alpha power in the dexmedetomidine-treated group was not associated with adverse neurocognitive outcomes.

AtRAC7/ROP9 Small GTPase Regulates A. thaliana Immune Systems in Response to B. cinerea Infection.

Botrytis cinerea is a necrotrophic fungus that can cause gray mold in over 1400 plant species. Once it is detected by Arabidopsis thaliana, several defense responses are activated against this fungus. The proper activation of these defenses determines plant susceptibility or resistance. It has been proposed that the RAC/ROP small GTPases might serve as a molecular link in this process. In this study, we investigate the potential role of the Arabidopsis RAC7 gene during infection with B. cinerea. For that, we evaluated A. thaliana RAC7-OX lines, characterized by the overexpression of the RAC7 gene. Our results reveal that these RAC7-OX lines displayed increased susceptibility to B. cinerea infection, with enhanced fungal colonization and earlier lesion development. Additionally, they exhibited heightened sensitivity to bacterial infections caused by Pseudomonas syringae and Pectobacterium brasiliense. By characterizing plant canonical defense mechanisms and performing transcriptomic profiling, we determined that RAC7-OX lines impaired the plant transcriptomic response before and during B. cinerea infection. Global pathway analysis of differentially expressed genes suggested that RAC7 influences pathogen perception, cell wall homeostasis, signal transduction, and biosynthesis and response to hormones and antimicrobial compounds through actin filament modulation. Herein, we pointed out, for first time, the negative role of RAC7 small GTPase during A. thaliana-B. cinerea interaction.

Anaerobiosis, a neglected factor in phage-bacteria interactions.

IMPORTANCE: Many parameters affect phage-bacteria interaction. Some of these parameters depend on the environment in which the bacteria are present. Anaerobiosis effect on phage infection in facultative anaerobic bacteria has not yet been studied. The absence of oxygen triggers metabolic changes in facultative bacteria and this affects phage infection and viral life cycle. Understanding how an anaerobic environment can alter the behavior of phages during infection is relevant for the phage therapy success.

Comparative Genomics Identifies Conserved and Variable TAL Effectors in African Strains of the Cotton Pathogen Xanthomonas citri pv. malvacearum.

Strains of Xanthomonas citri pv. malvacearum cause bacterial blight of cotton, a potentially serious threat to cotton production worldwide, including in sub-Saharan countries. Development of disease symptoms, such as water soaking, has been linked to the activity of a class of type 3 effectors, called transcription activator-like (TAL) effectors, which induce susceptibility genes in the host's cells. To gain further insight into the global diversity of the pathogen, to elucidate their repertoires of TAL effector genes, and to better understand the evolution of these genes in the cotton-pathogenic xanthomonads, we sequenced the genomes of three African strains of X. citri pv. malvacearum using nanopore technology. We show that the cotton-pathogenic pathovar of X. citri is a monophyletic lineage containing at least three distinct genetic subclades, which appear to be mirrored by their repertoires of TAL effectors. We observed an atypical level of TAL effector gene pseudogenization, which might be related to resistance genes that are deployed to control the disease. Our work thus contributes to a better understanding of the conservation and importance of TAL effectors in the interaction with the host plant, which can inform strategies for improving resistance against bacterial blight in cotton.

Sigh Ventilation in Patients With Trauma: The SiVent Randomized Clinical Trial.

Importance: Among patients receiving mechanical ventilation, tidal volumes with each breath are often constant or similar. This may lead to ventilator-induced lung injury by altering or depleting surfactant. The role of sigh breaths in reducing ventilator-induced lung injury among trauma patients at risk of poor outcomes is unknown. Objective: To determine whether adding sigh breaths improves clinical outcomes. Design, Setting, and Participants: A pragmatic, randomized trial of sigh breaths plus usual care conducted from 2016 to 2022 with 28-day follow-up in 15 academic trauma centers in the US. Inclusion criteria were age older than 18 years, mechanical ventilation because of trauma for less than 24 hours, 1 or more of 5 risk factors for developing acute respiratory distress syndrome, expected duration of ventilation longer than 24 hours, and predicted survival longer than 48 hours. Interventions: Sigh volumes producing plateau pressures of 35 cm H2O (or 40 cm H2O for inpatients with body mass indexes >35) delivered once every 6 minutes. Usual care was defined as the patient's physician(s) treating the patient as they wished. Main Outcomes and Measures: The primary outcome was ventilator-free days. Prespecified secondary outcomes included all-cause 28-day mortality. Results: Of 5753 patients screened, 524 were enrolled (mean [SD] age, 43.9 [19.2] years; 394 [75.2%] were male). The median ventilator-free days was 18.4 (IQR, 7.0-25.2) in patients randomized to sighs and 16.1 (IQR, 1.1-24.4) in those receiving usual care alone (P = .08). The unadjusted mean difference in ventilator-free days between groups was 1.9 days (95% CI, 0.1 to 3.6) and the prespecified adjusted mean difference was 1.4 days (95% CI, -0.2 to 3.0). For the prespecified secondary outcome, patients randomized to sighs had 28-day mortality of 11.6% (30/259) vs 17.6% (46/261) in those receiving usual care (P = .05). No differences were observed in nonfatal adverse events comparing patients with sighs (80/259 [30.9%]) vs those without (80/261 [30.7%]). Conclusions and Relevance: In a pragmatic, randomized trial among trauma patients receiving mechanical ventilation with risk factors for developing acute respiratory distress syndrome, the addition of sigh breaths did not significantly increase ventilator-free days. Prespecified secondary outcome data suggest that sighs are well-tolerated and may improve clinical outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02582957.

The Phaseolus vulgaris Receptor-Like Kinase PvFER1 and the Small Peptides PvRALF1 and PvRALF6 Regulate Nodule Number as a Function of Nitrate Availability.

Legumes associate with Gram-negative soil bacteria called rhizobia, resulting in the formation of a nitrogen-fixing organ, the nodule. Nodules are an important sink for photosynthates for legumes, so these plants have developed a systemic regulation mechanism that controls their optimal number of nodules, the so-called autoregulation of nodulation (AON) pathway, to balance energy costs with the benefits of nitrogen fixation. In addition, soil nitrate inhibits nodulation in a dose-dependent manner, through systemic and local mechanisms. The CLE family of peptides and their receptors are key to tightly controlling these inhibitory responses. In the present study, a functional analysis revealed that PvFER1, PvRALF1, and PvRALF6 act as positive regulators of the nodule number in growth medium containing 0 mM of nitrate but as negative regulators in medium with 2 and 5 mM of nitrate. Furthermore, the effect on nodule number was found to be consistent with changes in the expression levels of genes associated with the AON pathway and with the nitrate-mediated regulation of nodulation (NRN). Collectively, these data suggest that PvFER1, PvRALF1, and PvRALF6 regulate the optimal number of nodules as a function of nitrate availability.

Unraveling Ce3+ detection at the surface of ceria nanopowders by UPS analysis.

A sequential analysis using Ultra-violet Photoelectron Spectroscopy (UPS) and X-ray Photoelectron Spectroscopy (XPS) on ceria nanopowders has been implemented to identify the influence of the X-ray beam on the surface of this oxide. For the first time, UPS analysis evidenced the photoreductive effect of XPS analysis on ceria after an oxidative in situ pretreatment, leading to an overestimation of the Ce3+/Ce4+ ratio obtained by XPS. Based on this spectroscopy methodology, UPS imposes itself as a leading technique for analyzing powders with minimal impact on the authentic chemical state, thus paving the way for identifying the real ratio of Ce4+ and Ce3+ of ceria after oxidative and reductive in situ treatments.

Inhibition of legume nodulation by Pi deficiency is dependent on the autoregulation of nodulation (AON) pathway.

Inhibition of nodule development is one of the main adverse effects of phosphate (Pi) deficiency in legumes. Despite all of the efforts made over the last decades to understand how root nodules cope with Pi deficiency, the molecular mechanisms leading to the reduction in nodule number under Pi deficiency remain elusive. In the present study, we provide experimental evidence indicating that Pi deficiency activates the autoregulation of nodulation (AON) pathway, leading to a reduction in nodule numbers in both common bean and soybean. A transcriptional profile analysis revealed that the expression of the AON-related genes PvNIN, PvRIC1, PvRIC2, and PvTML is upregulated under Pi deficiency conditions. The downregulation of the MYB transcription factor PvPHR1 in common bean roots significantly reduced the expression of these four AON-related genes. Physiological analyses indicated that Pi deficiency does not affect the establishment of the root nodule symbiosis in the supernodulation mutant lines Pvnark and Gmnark. Reciprocal grafting and split-roots analyses determined that the activation of the AON pathway was required for the inhibitory effect of Pi deficiency. Altogether, these data improve our understanding of the genetic mechanisms controlling the establishment of the root nodule symbiosis under Pi deficiency.

Pseudocrossidium replicatum (Taylor) R.H. Zander is a fully desiccation-tolerant moss that expresses an inducible molecular mechanism in response to severe abiotic stress.

KEY MESSAGE: The moss Pseudocrossidium replicatum is a desiccation-tolerant species that uses an inducible system to withstand severe abiotic stress in both protonemal and gametophore tissues. Desiccation tolerance (DT) is the ability of cells to recover from an air-dried state. Here, the moss Pseudocrossidium replicatum was identified as a fully desiccation-tolerant (FDT) species. Its gametophores rapidly lost more than 90% of their water content when exposed to a low-humidity atmosphere [23% relative humidity (RH)], but abscisic acid (ABA) pretreatment diminished the final water loss after equilibrium was reached. P. replicatum gametophores maintained good maximum photosystem II (PSII) efficiency (Fv/Fm) for up to two hours during slow dehydration; however, ABA pretreatment induced a faster decrease in the Fv/Fm. ABA also induced a faster recovery of the Fv/Fm after rehydration. Protein synthesis inhibitor treatment before dehydration hampered the recovery of the Fv/Fm when the gametophores were rehydrated after desiccation, suggesting the presence of an inducible protective mechanism that is activated in response to abiotic stress. This observation was also supported by accumulation of soluble sugars in gametophores exposed to ABA or NaCl. Exogenous ABA treatment delayed the germination of P. replicatum spores and induced morphological changes in protonemal cells that resembled brachycytes. Transcriptome analyses revealed the presence of an inducible molecular mechanism in P. replicatum protonemata that was activated in response to dehydration. This study is the first RNA-Seq study of the protonemal tissues of an FDT moss. Our results suggest that P. replicatum is an FDT moss equipped with an inducible molecular response that prepares this species for severe abiotic stress and that ABA plays an important role in this response.

Synergy between Metallic and Oxidized Pt Sites Unravelled during Room Temperature CO†Oxidation on Pt/Ceria.

Pt-based materials are widely used as heterogeneous catalysts, in particular for pollutant removal applications. The state of Pt has often been proposed to differ depending on experimental conditions, for example, metallic Pt poisoned with CO being present at lower temperature before light-off, while an oxidized Pt surface prevails above light-off temperature. In stark contrast to all previous reports, we show herein that both metallic and oxidized Pt are present in similar proportions under reaction conditions at the surface of ca. 1 nm nanoparticles showing high activity at 30 °C. The simultaneous presence of metallic and oxidized Pt enables a synergy between these phases. The main role of the metallic Pt phase is to provide strong adsorption sites for CO, while that of oxidized Pt supposedly supplies reactive oxygen. Our results emphasize the complex dual oxidic-metallic nature of supported Pt catalysts and platinum's evolving nature under reaction conditions.

Initial Experience in Chile with Stent Implantation in the Right Ventricle Outflow Tract in High-Risk Patients with Tetralogy of Fallot.

Tetralogy of Fallot (ToF) treatment is difficult in patients with surgical risk factors or unfavorable anatomy. Stent implantation in the right ventricular outflow tract (RVOT) is an option for these patients. We report our initial experience in Chile with RVOT stenting in patients with ToF. Retrospective and descriptive study conducted in three pediatric cardiovascular centers in Chile between 2012 and 2015, including all ToF patients with stent in the RVOT as first procedure. Clinical records, echocardiographic, interventional, and surgical reports were reviewed for demographics and information of RVOT and pulmonary arteries. 12 newborns with ToF were included (75% female). Median age was 20 days (1-70) and mean weight was 2178 g (1400-3414). Saturations increased after the procedure from 74.3% (55-88) to 88.5% (80-98%), (p < 0.01). No complications or mortality were related to interventions. Follow-up was 11 months (7-36). Median right and left pulmonary arteries Z-score increased from - 4.0 (- 5.2 to - 0.3) and - 1.5 (- 4.8 to - 0.26) to + 0.53 (0.0 to 2.2) and + 1.1 (0.5 to 2.9), (p < 0.05), respectively. Nakata index increased from 63 mm2/mm2 (35 to 143) to 162 mm2/mm2 (107 to 197), (p < 0.05). Surgical repair was performed at a median of 4 months (2-7). Transannular patch repair was necessary in all patients and there was no surgical mortality. RVOT stenting is a safe and useful option for patients with ToF and surgical risk factors or unfavorable anatomy. It increases the pulmonary blood flow, improving saturation and pulmonary artery growth as a bridge for surgical repair.

Actin Depolymerizing Factor Modulates Rhizobial Infection and Nodule Organogenesis in Common Bean.

Actin plays a critical role in the rhizobium-legume symbiosis. Cytoskeletal rearrangements and changes in actin occur in response to Nod factors secreted by rhizobia during symbiotic interactions with legumes. These cytoskeletal rearrangements are mediated by diverse actin-binding proteins, such as actin depolymerization factors (ADFs). We examined the function of an ADF in the Phaseolus vulgaris-rhizobia symbiotic interaction (PvADFE). PvADFE was preferentially expressed in rhizobia-inoculated roots and nodules. PvADFE promoter activity was associated with root hairs harbouring growing infection threads, cortical cell divisions beneath root hairs, and vascular bundles in mature nodules. Silencing of PvADFE using RNA interference increased the number of infection threads in the transgenic roots, resulting in increased nodule number, nitrogen fixation activity, and average nodule diameter. Conversely, overexpression of PvADFE reduced the nodule number, nitrogen fixation activity, average nodule diameter, as well as NODULE INCEPTION (NIN) and EARLY NODULIN2 (ENOD2) transcript accumulation. Hence, changes in ADFE transcript levels affect rhizobial infection and nodulation, suggesting that ADFE is fine-tuning these processes.

An Autophagy-Related Kinase Is Essential for the Symbiotic Relationship between Phaseolus vulgaris and Both Rhizobia and Arbuscular Mycorrhizal Fungi.

Eukaryotes contain three types of lipid kinases that belong to the phosphatidylinositol 3-kinase (PI3K) family. In plants and Saccharomyces cerevisiae, only PI3K class III family members have been identified. These enzymes regulate the innate immune response, intracellular trafficking, autophagy, and senescence. Here, we report that RNAi-mediated downregulation of common bean (Phaseolus vulgaris) PI3K severely impaired symbiosis in composite P. vulgaris plants with endosymbionts such as Rhizobium tropici and Rhizophagus irregularis Downregulation of Pv-PI3K was associated with a marked decrease in root hair growth and curling. Additionally, infection thread growth, root-nodule number, and symbiosome formation in root nodule cells were severely affected. Interestingly, root colonization by AM fungi and the formation of arbuscules were also abolished in PI3K loss-of-function plants. Furthermore, the transcript accumulation of genes encoding proteins known to interact with PI3K to form protein complexes involved in autophagy was drastically reduced in these transgenic roots. RNAi-mediated downregulation of one of these genes, Beclin1/Atg6, resulted in a similar phenotype as observed for transgenic roots in which Pv-PI3K had been downregulated. Our findings show that an autophagy-related process is crucial for the mutualistic interactions of P. vulgaris with beneficial microorganisms.

UPS and UV spectroscopies combined to position the energy levels of TiO2 anatase and rutile nanopowders.

An accurate experimental determination of electronic structures in semi-conductor nanopowders is a challenging task. We propose here to combine UPS and UV-Vis spectroscopies in order to get the full description of the electronic band alignment of powder samples, TiO2 rutile and anatase. For UPS measurements, two preparation methods, namely the dropping method and electrophoretic deposition, were used to prepare layers of titania powders on a conducting substrate, ITO or Ag. Both methods lead to comparable results, with a quantitative description of the energy levels from the valence band. Combining these results with the UV-Vis spectra of the same powders enables the determination of the absolute position of the valence band maximum and the conduction band minimum. Combined UPS-UV-Vis spectroscopy provides a better insight into the properties of a powdered material which can differ from single crystal model systems. It can also be used to predict the electronic transfer in mixed phase systems during photocatalytic processes.

Legume NADPH Oxidases Have Crucial Roles at Different Stages of Nodulation.

Plant NADPH oxidases, formerly known as respiratory burst oxidase homologues (RBOHs), are plasma membrane enzymes dedicated to reactive oxygen species (ROS) production. These oxidases are implicated in a wide variety of processes, ranging from tissue and organ growth and development to signaling pathways in response to abiotic and biotic stimuli. Research on the roles of RBOHs in the plant's response to biotic stresses has mainly focused on plant-pathogen interactions; nonetheless, recent findings have shown that these oxidases are also involved in the legume-rhizobia symbiosis. The legume-rhizobia symbiosis leads to the formation of the root nodule, where rhizobia reduce atmospheric nitrogen to ammonia. A complex signaling and developmental pathway in the legume root hair and root facilitate rhizobial entrance and nodule organogenesis, respectively. Interestingly, several reports demonstrate that RBOH-mediated ROS production displays versatile roles at different stages of nodulation. The evidence collected to date indicates that ROS act as signaling molecules that regulate rhizobial invasion and also function in nodule senescence. This review summarizes discoveries that support the key and versatile roles of various RBOH members in the legume-rhizobia symbiosis.

Regulation of Small RNAs and Corresponding Targets in Nod Factor-Induced Phaseolus vulgaris Root Hair Cells.

A genome-wide analysis identified the set of small RNAs (sRNAs) from the agronomical important legume Phaseolus vulgaris (common bean), including novel P. vulgaris-specific microRNAs (miRNAs) potentially important for the regulation of the rhizobia-symbiotic process. Generally, novel miRNAs are difficult to identify and study because they are very lowly expressed in a tissue- or cell-specific manner. In this work, we aimed to analyze sRNAs from common bean root hairs (RH), a single-cell model, induced with pure Rhizobium etli nodulation factors (NF), a unique type of signal molecule. The sequence analysis of samples from NF-induced and control libraries led to the identity of 132 mature miRNAs, including 63 novel miRNAs and 1984 phasiRNAs. From these, six miRNAs were significantly differentially expressed during NF induction, including one novel miRNA: miR-RH82. A parallel degradome analysis of the same samples revealed 29 targets potentially cleaved by novel miRNAs specifically in NF-induced RH samples; however, these novel miRNAs were not differentially accumulated in this tissue. This study reveals Phaseolus vulgaris-specific novel miRNA candidates and their corresponding targets that meet all criteria to be involved in the regulation of the early nodulation events, thus setting the basis for exploring miRNA-mediated improvement of the common bean-rhizobia symbiosis.

[Effect of metabolic uncontrolled diabetes mellitus (DM) on the resistance index of renal (IR) Interlobar arteries assessed with pulsed Doppler]. / Efecto del descontrol metabólico de la diabetes mellitus (DM) sobre el índice de resistencia (IR) de las arterias renales interlobares evaluado con Doppler pulsado.

BACKGROUND: Diabetes mellitus is a chronic degenerative disease characterized by elevated hyperglycemia, triggering a series of processes and culminating in chronic, uncontrolled, cellular and vascular damage in different organs. OBJECTIVE: To assess whether the elevated glycosylated hemoglobin, microalbuminuria, and the time evolution of more than 10 years of diabetes mellitus are associated with elevated resistance index of the interlobar renal arteries assessed with pulsed Doppler in patients with metabolic uncontrolled diabetes mellitus. MATERIAL AND METHODS: Transversal-analytical, observational, prospective study that included diabetic patients attending UMAE abdominal ultrasound in 25 of IMSS, from October 15, 2014 to November 15, 2014, which was performed for pulsed Doppler index resistance of vascular interlobar renal arteries and was collected from electronic medical records: age, sex, glycated hemoglobin, and microalbuminuria. The association between metabolic uncontrolled diabetes mellitus was analyzed with the elevation of resistance index by χ(2) test or Fisher, being significant with a value of p < 0.05, and to assess the magnitude of the association that was measured with a response magnitude of 95%. RESULTS: 63 patients with type 2 diabetes were examined, with an average age of 52.3 ± 14.2 years, 41 were older than 50 years (65.0%), 26 with hypertension (41.2%), 32 with higher levels of glycated hemoglobin 7 (50.8%), 35 with normoalbuminuria (55.6%), 28 with microalbuminuria (44.4%), and 39 with a time evolution of diabetes of more than 10 years (61.9%). We observed a statistically significant difference between microalbuminuria and increased duration of diabetes mellitus with high resistance index. CONCLUSION: The alterations in renal microvasculature conditioned by the occurrence of microalbuminuria in diabetic nephropathy and the duration of diabetes are strongly associated with higher resistance index.

Use of the amplatzer vascular plug II device to occlude different types of patent ductus arteriosus in pediatric patients.

INTRODUCTION: Transcatheter patent ductus arteriosus (PDA) closure is difficult in small patients in part due to the diverse PDA morphology. We describe a multicenter pediatric experience using the Amplatzer Vascular Plug II device (AVP II) to occlude PDA. METHODS: All patients undergoing transcatheter closure of PDA with AVP II from April 2008 until May 2012 were included. Clinical, angiographic, and echocardiographic data were collected. RESULTS: One hundred and seventy-seven procedures were performed. Median age was 14 months (2-180) with median weight 9.7 kg (4.7-68). The morphological PDA classification was Type A in 66 (37.1%), Type C in 27 (15.3%), Type D in 17 (9.6%), and Type E in 67 (37.9%). The median minimum PDA diameter was 2.6 mm (1.2-7.7 mm). The implanted device sizes were: 4 mm in 17 patients (9.6%), 6 mm in 81 (45.8%), 8 mm in 56 (31.6%), 10 mm in 18 (10.2%), and 12 mm in 5 (2.8%). The implanted device was mean of 2.6 + 0.7 times the ductus narrowest diameter and mean of 1 + 0.5 times the ductus largest diameter. Complications included: one severe left pulmonary artery stenosis and one device embolization. No aortic obstruction occurred. Closure was complete in the 175 remaining patients. CONCLUSIONS: The AVP II is an effective and safe device for PDA closure. It is particularly useful when dealing with nontypical PDA shapes and in small infants where it eliminated the risk of device-related aortic obstruction. The AVPII is an addition to the PDA device closure armamentarium in pediatric patients.