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Scientific Reports Sep 2022The left inferior phrenic vein (LIPV) is a major drainage vessel of gastric varices and serves as an important conduit in endovascular treatment for gastric varices. The...
The left inferior phrenic vein (LIPV) is a major drainage vessel of gastric varices and serves as an important conduit in endovascular treatment for gastric varices. The narrowing of LIPV has been empirically demonstrated and sometimes hinders catheter insertion for the treatment of gastric varices. We herein investigated the morphology of narrowed LIPV in patients with portal hypertension. Venograms of LIPV on 25 patients with gastric varices (15 males; 10 females; age range, 45-79 years with a mean of 67 years) were retrospectively reviewed, the following four parameters were measured: the diameter of LIPV, the diameter of narrowed LIPV, the narrowing rate, and the distance to narrowed LIPV from the left renal vein. On all 25 venograms, a narrowing was detected just above the common trunk with the left adrenal vein. The diameter of LIPV was 9.0 ± 4.2 mm, the diameter of narrowed LIPV was 5.1 ± 2.3 mm, the narrowing rate was 40.6 ± 16.0%, and the distance to narrowed LIPV from the left renal vein was 20.0 ± 7.4 mm. This anatomical information about the narrowing of LIPV may contribute to the safe and efficacious treatment of gastric varices.
Topics: Aged; Esophageal and Gastric Varices; Female; Humans; Hypertension, Portal; Male; Middle Aged; Phlebography; Retrospective Studies; Venae Cavae
PubMed: 36088466
DOI: 10.1038/s41598-022-19610-w -
Journal of the American Society of... Feb 2023Adverse left atrial (LA) remodeling after ST-segment elevation myocardial infarction (STEMI) has been associated with poor prognosis. Flow impairment in the dominant...
BACKGROUND
Adverse left atrial (LA) remodeling after ST-segment elevation myocardial infarction (STEMI) has been associated with poor prognosis. Flow impairment in the dominant coronary atrial branch (CAB) may affect large areas of LA myocardium, potentially leading to adverse LA remodeling during follow-up. The aim of this study was to assess echocardiographic LA remodeling in patients with STEMI with impaired coronary flow in the dominant CAB.
METHODS
Of 897 patients with STEMI, 69 patients (mean age, 62 ± 11 years; 83% men) with impaired coronary flow in the dominant CAB (defined as Thrombolysis In Myocardial Infarction flow grade < 3) were retrospectively compared with an age- and sex-matched control group of 138 patients with normal dominant CAB coronary flow.
RESULTS
Patients with dominant CAB-impaired flow had higher peak troponin T (3.9 μg/L [interquartile range, 2.2-8.2 μg/L] vs 3.2 μg/L [interquartile range, 1.5-5.6 μg/L], P = .009). No differences in left ventricular ejection fraction or mitral regurgitation were observed between groups at baseline or at follow-up. LA remodeling assessment included maximum LA volume, speckle-tracking echocardiography-derived LA strain, and total atrial conduction time assessed on Doppler tissue imaging at baseline, 6 months, and 12 months. Patients with dominant CAB-impaired flow presented larger LA maximal volumes (26.9 ± 10.9 vs 18.1 ± 7.1 mL/m, P < .001) and longer total atrial conduction time (150 ± 23 vs 124 ± 22 msec, P < .001) at 6 months, remaining unchanged at 12 months. However, all LA strain parameters were significantly lower from baseline (reservoir, 20.3 ± 10.1% vs 27.1 ± 14.5% [P < .001]; conduit, 9.1 ± 5.6% vs 12.8 ± 8% [P < .001]; booster, 9.1 ± 5.6% vs 12.8 ± 8% [P < .001]), these differences being sustained at 6- and 12-month follow-up.
CONCLUSIONS
Atrial ischemia resulting from impaired coronary flow in the dominant CAB in patients with STEMI is associated with LA adverse anatomic and functional remodeling. Reduced LA strain preceded LA anatomic remodeling in early phases after STEMI.
Topics: Male; Humans; Middle Aged; Aged; Female; ST Elevation Myocardial Infarction; Stroke Volume; Retrospective Studies; Atrial Remodeling; Atrial Fibrillation; Ventricular Function, Left; Myocardial Infarction; Percutaneous Coronary Intervention
PubMed: 35977632
DOI: 10.1016/j.echo.2022.08.006 -
Aorta (Stamford, Conn.) Apr 2022Aortic valve infective endocarditis is a life-threatening condition. Patients frequently present profoundly unwell and extensive surgery may be required to correct the...
Aortic valve infective endocarditis is a life-threatening condition. Patients frequently present profoundly unwell and extensive surgery may be required to correct the underlying anatomical deficits and control sepsis. Periannular involvement occurs in more than 10% of patients with aortic valve endocarditis. Complex aortic valve endocarditis has a mortality rate of 10 to 40%. Longstanding surgical dogma suggests homografts represent the optimal replacement option in complex aortic valve endocarditis; however, there is a paucity of evidence and lack of consensus on the optimal replacement choice. A systematic review and meta-analysis was performed utilizing EMBASE, PubMed, and the Cochrane databases to review articles describing homografts versus aortic valve replacement and/or valved conduit graft implantation for complex aortic valve endocarditis. The outcomes of interest were mortality, reinfection, and reoperation. Eleven studies were included in this meta-analysis, contributing 810 episodes of complex aortic valve endocarditis. All included reports were cohort studies. There was no statistically significant difference in overall mortality (risk ratio [RR] 0.99; 95% confidence interval [CI], 0.61-1.59; = 0.95), reinfection (RR 0.89; 95% CI, 0.45-1.78; = 0.74), or reoperation (RR 0.91; 95% CI, 0.38-2.14; = 0.87) between the homograft and valve replacement/valved conduit graft groups. Overall, there was no difference in mortality, reinfection, or reoperation rates between homografts and other valve or valved conduits in management of complex aortic endocarditis. However, there is a paucity of high-quality evidence in the area, and comparison of valve types warrants further investigation.
PubMed: 35933984
DOI: 10.1055/s-0042-1743110 -
European Heart Journal Open Sep 2021To study flow-related energetics in multiple anatomical segments of the total cavopulmonary connection (TCPC) in Fontan patients from four-dimensional (4D) flow magnetic...
Segmental assessment of blood flow efficiency in the total cavopulmonary connection using four-dimensional flow magnetic resonance imaging: vortical flow is associated with increased viscous energy loss rate.
AIMS
To study flow-related energetics in multiple anatomical segments of the total cavopulmonary connection (TCPC) in Fontan patients from four-dimensional (4D) flow magnetic resonance imaging (MRI), and to study the relationship between adverse flow patterns and segment-specific energetics.
METHODS AND RESULTS
Twenty-six extracardiac Fontan patients underwent 4D flow MRI of the TCPC. A segmentation of the TCPC was automatically divided into five anatomical segments [conduit, superior vena cava (SVC), right/left pulmonary artery (LPA), and the Fontan confluence]. The presence of vortical flow in the pulmonary arteries or Fontan confluence was qualitatively scored. Kinetic energy (KE), viscous energy loss rate, and vorticity were calculated from the 4D flow MRI velocity field and normalized for segment length and/or inflow. Energetics were compared between segments and the relationship between vortical flow and segment cross-sectional area (CSA) with segment-specific energetics was determined. Vortical flow in the LPA ( = 6) and Fontan confluence ( = 12) were associated with significantly higher vorticity ( = 0.001 and = 0.015, respectively) and viscous energy loss rate ( = 0.046 and = 0.04, respectively) compared to patients without vortical flow. The LPA and conduit segments showed the highest KE and viscous energy loss rate, while most favourable energetics were observed in the SVC. Conduit CSA inversely correlated with KE ( = -0.614, = 0.019) and viscous energy loss rate ( = -0.652, = 0.011).
CONCLUSIONS
Vortical flow in the Fontan confluence and LPA associated with significantly increased viscous energy loss rate. Four-dimensional flow MRI-derived energetics may be used as a screening tool for direct, MRI-based assessment of flow efficiency in the TCPC.
PubMed: 35919267
DOI: 10.1093/ehjopen/oeab018 -
Planta Jul 2022In Dracaena draco trunks, the primary and secondary xylem conduits co-function. Both are resistant to embolism; however, secondary conduits are mainly involved in...
In Dracaena draco trunks, the primary and secondary xylem conduits co-function. Both are resistant to embolism; however, secondary conduits are mainly involved in mechanical support. Monocotyledonous dragon trees (Dracaena spp., Asparagaceae) possess in their trunks both primary and secondary xylem elements, organized into vascular bundles, that for dozens of years co-function and enable the plant to transport water efficiently as well as provide mechanical support. Here, based on the modified Hagen-Poiseuille's formula, we examined the functional anatomical xylem traits of the trunk in two young D. draco individuals to compare their function in both primary and secondary growth. We provided analyses of the: (i) conduits surface sculpture and their cell walls thickness, (ii) conduit diameter and frequency, (iii) hydraulically weighted diameter, (iv) theoretical hydraulic conductivity, (v) area-weighted mean conduit diameter, as well as (vi) vulnerability index. The conduits in primary growth, located in the central part of the trunk, were loosely arranged, had thinner cell walls, larger mean hydraulically weighted diameter, and significantly larger value of the theoretical hydraulic conductivity than conduits in secondary growth, which form a rigid cylinder near the trunk surface. Based on the vulnerability index, both primary and secondary conduits are resistant to embolism. Taking into account the distribution within a trunk, the secondary growth conduits seems to be mainly involved in mechanical support as they are twisted, form structures similar to sailing ropes and have thick cell walls, and a peripheral localization. D. draco has been adapted to an environment with water deficit by distinctive, spatial separation of the xylem elements fulfilling supportive and conductive functions.
Topics: Adaptation, Physiological; Dracaena; Trees; Water; Xylem
PubMed: 35906444
DOI: 10.1007/s00425-022-03966-4 -
Frontiers in Plant Science 2022High-elevation ecosystems are one of the most sensitive to climate change. The analysis of growth and xylem structure of trees from marginal populations, especially the...
High-elevation ecosystems are one of the most sensitive to climate change. The analysis of growth and xylem structure of trees from marginal populations, especially the ones growing at the treeline, could provide early-warning signs to better understand species-specific responses to future climate conditions. In this study, we combined classical dendrochronology with wood density and anatomical measurements to investigate the climate sensitivity of L., a typical European high-elevation tree species distributed in isolated patches in the Carpathians. Samples were collected from the Retezat Mountains, South-Western Romania. We analyzed ring width (TRW), maximum density (MXD), xylem anatomical traits [cell number per ring (CNo), cell density (CD), conduit area (CA), and cell wall thickness (CWT)] time series, split into ring sectors and assessed the relationships with monthly and daily climate records over the last century (1901-2015). The analysis showed a strong dependency of TRW on CNo and MXD on CWT. Summer temperature positively correlated with MXD and CWT [monthly correlation ( were 0.65 and 0.48 respectively] from the early to late wood but not TRW ( = 0.22). CA positively correlated with water availability ( 0.37) and negatively correlated with temperature ( -0.39). This study improves our general understanding of the climate-growth relationships of a European high-elevation tree species and the results could be considered for forecasting population dynamics on projected changes in climate.
PubMed: 35755705
DOI: 10.3389/fpls.2022.855003 -
The Thoracic and Cardiovascular Surgeon Dec 2022The aim of this study was to evaluate the long-term outcome and freedom from pulmonary valve replacement (PVR) after initial repair of tetralogy of Fallot (TOF).
BACKGROUND
The aim of this study was to evaluate the long-term outcome and freedom from pulmonary valve replacement (PVR) after initial repair of tetralogy of Fallot (TOF).
PATIENTS AND METHODS
The cohort of 306 patients treated between 1980 and 2017 was divided into anatomical subgroups according to the diagnosis of TOF-pulmonary stenosis, TOF-pulmonary atresia and TOF-double outlet right ventricle. Patients were treated with transannular patch (TAP), valve sparing repair (VSR), or conduits from the right ventricle to the pulmonary arteries (RVPA conduits).
RESULTS
There were 21 deaths (6.9%), 14 being hospital deaths (4.6%) after primary correction and four deaths (1.3%) occurred after PVR. One patient died after a non-cardiac operation (0.3%). There were two late deaths (0.7%). During the past 12 years no early mortality has been observed. Ninety-one patients (30.4%) received PVR after a median of 12.1 ± 7.0 years with an early mortality of 4.4% ( = 4) and no late mortality. A significant difference in freedom from reoperation after TAP, VSR, and RVPA-conduits could be identified. Multivariate analysis displayed transannular repair ( = 0.016), primary palliation ( <0.001), the presence of major aortopulmonary collateral arteries (MAPCA; = 0.023), and pulmonary valve -scores < - 4.0 ( = 0.040) as significant risk factors for PVR.
CONCLUSION
TOF repair has a beneficial long-term prognosis with low morbidity and mortality. Pulmonary valve -scores < - 4.0, transannular repair, and presence of MAPCAs are associated with earlier PVR. Non-VSRs and TOF-pulmonary atresia lead to earlier reoperation but have no negative impact on survival.
Topics: Cardiac Surgical Procedures; Humans; Infant; Pulmonary Atresia; Pulmonary Valve; Reoperation; Retrospective Studies; Tetralogy of Fallot; Treatment Outcome
PubMed: 35752174
DOI: 10.1055/s-0042-1749098 -
Plant Biology (Stuttgart, Germany) Dec 2022Climate change is expected to increase the frequency and intensity of summer droughts. Sufficient drought resistance, the ability to acclimate to and/or recover after...
Climate change is expected to increase the frequency and intensity of summer droughts. Sufficient drought resistance, the ability to acclimate to and/or recover after drought, is thus crucial for forest tree species. However, studies on the hydraulics of mature trees during and after drought in natura are scarce. In this study, we analysed trunk water content (electrical resistivity: ER) and further hydraulic (water potential, sap flow density, specific hydraulic conductivity, vulnerability to embolism) as well as wood anatomical traits (tree ring width, conduit diameter, conduit wall reinforcement) of drought-stressed (artificially induced summer drought via throughfall-exclusion) and unstressed Picea abies and Fagus sylvatica trees. In P. abies, ER indicated a strong reduction in trunk water content after 5 years of summer drought, corresponding to significantly lower pre-dawn leaf water potential and xylem sap flow density. Vulnerability to embolism tended to be higher in drought-stressed trees. In F. sylvatica, only small differences between drought-stressed and control trees were observed. Re-watering led to a rapid increase in water potentials and xylem sap flow of both drought-stressed trees, and to increased growth rates in the next growing season. ER analyses revealed lower trunk water content in P. abies trees growing on throughfall-exclusion plots even 1 year after re-watering, indicating a limited capacity to restore internal water reserves. Results demonstrated that P. abies is more susceptible to recurrent summer drought than F. sylvatica, and can exhibit long-lasting and pronounced legacy effects in trunk water reserves.
Topics: Fagus; Droughts; Picea; Abies; Seasons; Trees; Pinus; Water
PubMed: 35611757
DOI: 10.1111/plb.13444 -
Plant Physiology Aug 2022Understanding mass transport of photosynthates in the phloem of plants is necessary for predicting plant carbon allocation, productivity, and responses to water and...
Understanding mass transport of photosynthates in the phloem of plants is necessary for predicting plant carbon allocation, productivity, and responses to water and thermal stress. Several hypotheses about optimization of phloem structure and function and limitations of phloem transport under drought have been proposed and tested with models and anatomical data. However, the true impact of radial water exchange of phloem conduits with their surroundings on mass transport of photosynthates has not been addressed. Here, the physics of the Munch mechanism of sugar transport is re-evaluated to include local variations in viscosity resulting from the radial water exchange in two dimensions (axial and radial) using transient flow simulations. Model results show an increase in radial water exchange due to a decrease in sap viscosity leading to increased sugar front speed and axial mass transport across a wide range of phloem conduit lengths. This increase is around 40% for active loaders (e.g. crops) and around 20% for passive loaders (e.g. trees). Thus, sugar transport operates more efficiently than predicted by previous models that ignore these two effects. A faster front speed leads to higher phloem resiliency under drought because more sugar can be transported with a smaller pressure gradient.
Topics: Biological Transport; Carbohydrates; Phloem; Plants; Sugars; Water
PubMed: 35588257
DOI: 10.1093/plphys/kiac231 -
Plant Physiology Aug 2022Embolism spreading in xylem is an important component of plant drought resistance. Since embolism resistance has been shown to be mechanistically linked to pit membrane...
Embolism spreading in xylem is an important component of plant drought resistance. Since embolism resistance has been shown to be mechanistically linked to pit membrane characters in stem xylem, we speculate that similar mechanisms account for leaf xylem. We conducted transmission electron microscopy to investigate pit membrane characters in leaf xylem across 18 Neotropical tree species. We also conducted gold perfusion and polar lipid detection experiments on three species covering the full range of leaf embolism resistance. We then related these observations to previously published data on embolism resistance of leaf xylem. We also incorporated previously published data on stem embolism resistance and stem xylem pit membranes to investigate the link between vulnerability segmentation (i.e. difference in embolism resistance) and leaf-stem anatomical variation. Maximum pit membrane thickness (Tpm,max) and the pit membrane thickness-to-diameter ratio (Tpm,max/Dpm) were predictive of leaf embolism resistance, especially when vestured pits were taken into account. Variation in Tpm,max/Dpm was the only trait predictive of vulnerability segmentation between leaves and stems. Gold particles of 5- and 10-nm infiltrated pit membranes in three species, while the entry of 50-nm particles was blocked. Moreover, polar lipids were associated with inner conduit walls and pits. Our results suggest that mechanisms related to embolism spreading are determined by Tpm, pore constrictions (i.e. the narrowest bottlenecks along pore pathways), and lipid surfactants, which are largely similar between leaf and stem xylem and between temperate and tropical trees. However, our mechanistic understanding of embolism propagation and the functional relevance of Tpm,max/Dpm remains elusive.
Topics: Droughts; Embolism; Gold; Lipids; Plant Leaves; Trees; Water; Xylem
PubMed: 35567500
DOI: 10.1093/plphys/kiac223