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European Journal of Cardio-thoracic... Apr 2023Right ventricle to pulmonary artery anatomic discontinuity is common in complex congenital heart malformations. Handsewn conduits are a practised method of repair. In a...
OBJECTIVES
Right ventricle to pulmonary artery anatomic discontinuity is common in complex congenital heart malformations. Handsewn conduits are a practised method of repair. In a proof-of-concept study, we evaluated pulmonary valve replacement with a handsewn pericardial valved pulmonary conduit in vitro and in vivo.
METHODS
A pulsatile flow-loop model (in vitro) and an acute 60-kg porcine model (in vivo) were used. With echocardiography and pressure catheters, baseline geometry and fluid dynamics were measured. The pulmonary valve was replaced with a handsewn glutaraldehyde-treated pericardial valved pulmonary conduit corresponding to a 21-mm prosthetic valve, after which geometric measurements and fluid dynamics were reassessed.
RESULTS
In vitro, 15 pulmonary trunks at 4 l/min and 13 trunks at 7 l/min, and in vivo, 11 animals were investigated. The valved pulmonary conduit was straightforward to produce at the operating table and easy to suture in place. All valves were clinically sufficient in vitro and in vivo. The mean transvalvular pressure gradient in the native valve and the conduit was 8 mmHg [standard deviation (SD): 2] and 7 mmHg (SD: 2) at 4 l/min in vitro, 19 mmHg (SD: 3) and 17 mmHg (SD: 4) at 7 l/min in vitro and 3 mmHg (SD: 2) and 6 mmHg (SD: 3) in vivo.
CONCLUSIONS
Our proof-of-concept demonstrates no early evidence of structural damage to the conduit, and the fluid dynamic data were acceptable. The handsewn conduit can be produced at the operating table.
Topics: Animals; Swine; Heart Valve Prosthesis; Pulsatile Flow; Heart Defects, Congenital; Pulmonary Valve; Pulmonary Artery; Heart Ventricles; Bioprosthesis
PubMed: 37042717
DOI: 10.1093/ejcts/ezad143 -
Plant Physiology and Biochemistry : PPB May 2023Phosphorus is one of the most important essential mineral elements for plant growth and development. It has been widely recognized that phosphorus deficiency can lead to...
Phosphorus is one of the most important essential mineral elements for plant growth and development. It has been widely recognized that phosphorus deficiency can lead to the significant declines in leaf photosynthetic rate and leaf area. However, the internal mechanism associated with the leaf anatomical traits has not been well understood. In present study, a hydroponic experiment was conducted to study the effect of phosphorus deficiency on leaf growth and photosynthesis in Jimai 22 (JM22, Triticum aestivum L.) and Suk Landarace 26 (SL26, Triticum aestivum L.). With the decrease in phosphorus concentration, leaf photosynthetic rate and leaf area in SL26 and JM22 all decreased significantly, but the decrease in leaf area occurred earlier than that in leaf photosynthetic rate. The thresholds of phosphorus concentration to maintain a high photosynthesis were 145.5 and 138.7 mg m, respectively, in SL26 and JM22; and they were 197.5 and 212.0 mg m, respectively, for leaf growth. The decrease in leaf photosynthetic rate under low P conditions was mainly caused by the lowered stomatal conductance and mesophyll conductance, and to a less extent by the decrease in biochemical capacities. The decrease in stomatal conductance was attributed to the smaller vascular bundle area, xylem conduits area and the lower leaf hydraulic conductance. However, the reduction in mesophyll conductance was not related to either the cell wall thickness or the development of chloroplast.
Topics: Triticum; Plant Stomata; Mesophyll Cells; Carbon Dioxide; Photosynthesis; Plant Leaves; Phosphorus
PubMed: 37031546
DOI: 10.1016/j.plaphy.2023.107680 -
Journal of Surgical Case Reports Mar 2023Gastrointestinal complications following radical cystectomy (RC) are a common occurrence, with small bowel obstruction (SBO) a known complication. Limited cases have...
Gastrointestinal complications following radical cystectomy (RC) are a common occurrence, with small bowel obstruction (SBO) a known complication. Limited cases have been reported of SBO following RC due to internal herniation of the small intestine around the ureter, ileal conduit, obturator nerve and, as a consequence of retroperitoneal lymphadenectomy, even the abdominal vasculature. We present a rare case in which intestinal herniation beneath the external iliac artery (EIA) resulted in a closed-loop SBO with ischaemia and necrosis. Intra-operative transection of the unrecognised EIA occurred, necessitating primary arterial repair. This case highlights the importance of maintaining a high index of suspicion for complex pathology and anatomical variations in patients following RC and other operations involving retroperitoneal lymphadenectomy.
PubMed: 36942288
DOI: 10.1093/jscr/rjad118 -
European Journal of Cardio-thoracic... May 2023Endovascular treatment has been suggested as an alternative for open surgery for type A aortic dissection, but current devices have severe anatomical limitations. This...
Endovascular repair in type A aortic dissection: Anatomical candidacy for currently manufactured stent grafts and conceptual valve-carrying devices for an Endo-Bentall procedure.
OBJECTIVES
Endovascular treatment has been suggested as an alternative for open surgery for type A aortic dissection, but current devices have severe anatomical limitations. This study assesses the computed tomography-based anatomical suitability of currently manufactured stent grafts as well as 2 embodiments of valve-carrying devices.
METHODS
In a retrospective single-centre cohort of 200 consecutive ascending/arch operations between 2009 and 2018, a total of 112 patients with type A aortic dissections were identified and evaluated for endovascular candidacy based on the locations of the entries, the landing zone diameters/lengths and the supra-aortic vessel origins according to the anatomical instructions for use criteria of 6 commercially available (tubular, branched or fenestrated) stent grafts. Two suggested valve-carrying devices with inner branches or fenestrations for the coronary arteries and branches for the supra-aortic vessels were also evaluated.
RESULTS
The anatomical feasibility for commercial stent grafts ranged from 4% to 21%. The main limitations were proximal landing zone diameter (considering oversizing <15%), length due to dilatation and an entry too close to the sinotubular junction. For the valve-carrying conduits, anatomical feasibility was between 31% and 80%, with the main limiting factors being the diameter of the aortic annulus and its distance to the coronary arteries.
CONCLUSIONS
The anatomical applicability of currently manufactured stent grafts for the treatment of type A aortic dissection is limited mainly by the absence of a suitable proximal landing zone in the ascending aorta and might substantially be improved by anchoring in the aortic annulus using a valve-carrying device that uses either fenestrations or branches for the coronary arteries.
Topics: Humans; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Aortic Aneurysm, Thoracic; Stents; Retrospective Studies; Endovascular Procedures; Aortic Dissection; Prosthesis Design; Treatment Outcome
PubMed: 36916747
DOI: 10.1093/ejcts/ezad085 -
Minerva Cardiology and Angiology Mar 2023Percutaneous coronary intervention (PCI) of coronary chronic total occlusion (CTO PCI) is one of the most challenging but rewarding procedures in the portfolio of...
Percutaneous coronary intervention (PCI) of coronary chronic total occlusion (CTO PCI) is one of the most challenging but rewarding procedures in the portfolio of interventional cardiologists. Several challenges, however, still must be overcome and many questions need to be answered. After coronary artery bypass graft (CABG), disease of the conduits and concomitant progression of atherosclerotic disease to CTO of the subtended native coronary vessels are common and associated with onset of new anginal symptoms and worsening of the prognosis. Which is the best strategy for these post-CABG CTOs? Furthermore, what is the role of physiology in the setting of CTO PCI? In the last decades, many researchers tried to demystify the complex maze but technical limitations and the demanding procedure itself, for both the patient and the operator, do not allow extensive investigation of its impact on clinical practice. Can we enhance periprocedural planning of CTO PCI with a more tailored and multidimensional evaluation? Analysis of coronary computed tomography angiography (CCTA) scans is getting more and more incorporated into the clinical routine and training of interventional cardiologists but mainly focuses on structural valvular disease. Nevertheless, with the appropriate expertise, a lot of information can be derived for coronary intervention to improve procedural planning and potentially outcomes. Finally, in the era of drug-eluting stent, is there a place for strategies that minimize metal implantation in the coronaries to further reduce late-onset adverse events in CTO PCI? This approach could be attractive in CTOs due to the higher risk of target vessel failure and revascularization shown in literature but, at the same time, more challenging due to the histological and anatomical complexity of the disease. In this review, we aim to tackle these questions and concomitantly provide a vision of potential future application of new techniques and technology in CTO PCI that could allow further advancement in this field.
PubMed: 36912168
DOI: 10.23736/S2724-5683.23.06293-2 -
The Journal of Vascular Access May 2024Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG... (Comparative Study)
Comparative Study
BACKGROUND
Though arteriovenous grafts (AVG) mature more reliably than arteriovenous fistulae (AVF) and require fewer maturation procedures (MP) to obtain functional patency, AVG are thought to have worse function after maturation. We explored differences in post-maturation outcomes between the following groups: AVF patients who did (AS-AVF) and did not (unAS-AVF) require assisted maturation and AVG patients who did (AS-AVG) and did not (unAS-AVG) require assisted maturation.
METHODS
Using the US Renal Data System (2012-2017), we retrospectively identified patients who initiated dialysis with a central venous catheter, underwent AVF or AVG placement and achieved successful two-needle cannulation. Primary patency and access abandonment after maturation were compared across groups using competing risks regression methods, generating sub-hazards ratios (sHR).
RESULTS
We identified 42,664 AVF and 12,335 AVG that met inclusion criteria. A larger proportion of AVFs required interventions: 18,408 AVF (43.2%) versus 2594 AVG (21.0%; p < 0.01). Both AS-AVG and AS-AVF patients experienced patency loss at 1 year more frequently compared with unAS-AVG (67.5% & 57.5% vs 55.2% respectively). Patency loss was lowest in unAS-AVF (38.9%). These trends were robust on adjusted analysis (unAS-AVG reference, AS-AVG sHR = 1.44, p < 0.01; AS-AVF sHR = 1.08, p < 0.01, unAS-AVF sHR = 0.67, p < 0.01). AS-AVGs were more likely to be abandoned than unAS-AVGs (11.7% unAS-AVG vs 17.2% AS-AVG). Fistulae, assisted or not, had lower unadjusted rates of 1-year abandonment than grafts (8.9% AS-AVF vs 7.3% unAS-AVF). On adjusted analysis, AVF usage was protective against abandonment (unAS-AVG, reference; AS-AVF sHR = 0.67, p < 0.01; unAS-AVF sHR = 0.59, p < 0.01) while AS-AVG was not (AS-AVG sHR = 1.32, p < 0.01).
CONCLUSIONS
unAS-AVF have the best long-term outcomes. AS-AVF lose primary patency at a higher rate than unAS-AVG. AVGs may be a better choice than AVFs if veins are marginal and likely to require assisted maturation. Further research is needed to identify anatomic and physiologic factors that affect long-term performance and influence conduit choice.
Topics: Humans; Arteriovenous Shunt, Surgical; Vascular Patency; Renal Dialysis; Retrospective Studies; Male; Female; Graft Occlusion, Vascular; Middle Aged; Time Factors; Risk Factors; Treatment Outcome; Aged; Blood Vessel Prosthesis Implantation; United States; Databases, Factual; Blood Vessel Prosthesis; Risk Assessment; Adult
PubMed: 36847168
DOI: 10.1177/11297298231151365 -
Journal of Clinical Medicine Jan 2023(1) Background: Previous studies showed left ventricular (LV) and left atrial (LA) improvement and reverse remodeling after therapy with Sacubitril/Valsartan (S/V) in...
(1) Background: Previous studies showed left ventricular (LV) and left atrial (LA) improvement and reverse remodeling after therapy with Sacubitril/Valsartan (S/V) in patients affected by heart failure with reduced ejection fraction (HFrEF). Therefore, we sought to investigate predictors of LA structural and functional reverse remodeling (LARR) in this setting of patients after therapy with S/V, focusing on left atrial strain parameters, such as peak atrial longitudinal strain (PALS). (2) Methods: Patients with HFrEF underwent clinical and echocardiographic evaluation at baseline and after six months of therapy with S/V. Measures of LA structure (LA volume index, LAVi) and function (LA emptying fraction (LAEF), PALS, LA conduit strain and peak atrial contraction strain (PACS) were also analyzed. Patients were divided in two groups, those with a LARR (relative reduction in LAVi > 15%, LARR+) and those without (LARR-). (3) Results: A total of 47 consecutive patients (66 ± 8 years, 85% male, mean LVEF 28 ± 6%) were enrolled in the study and followed up. A significant increase of LAEF (46 ± 13 vs. 37 ± 11%, < 0.001) and a significant reduction of LAVi (42 ± 15 vs. 45 ± 15 mL/m, = 0.008) were found after 6 months of S/V therapy; 47% of the population showed LA reverse remodeling. LA strain parameters, PALS (19 ± 8 vs. 15 ± 7 %, < 0.001) and LA conduit (-9.7 ± 5.2% vs. -7.6 ± 4.1%, = 0.007) significantly improved after 6 months of S/V therapy. At multivariable stepwise regression analysis, changes in LV End Diastolic Volume (LVEDV) and PALS were significantly proportional to changes in LAVi values. (4) Conclusions: Six months of treatment with S/V in patients with HFrEF was associated with an improvement in LA functional reverse remodeling in a real-world scenario. LARR was not significantly correlated to baseline echocardiographic variables, but was proportional to changes in LV volumes and LA strain parameters. Finally, after S/V therapy, a strict connection between LA and LV reverse remodeling and between LA anatomical and functional reverse remodeling seems to be outlined.
PubMed: 36769734
DOI: 10.3390/jcm12031086 -
Journal of the American Society of... May 2023Greater interest in imaging the superior vena cava (SVC) in recent years has arisen because of increased focus on disorders of the right heart; the growing use of... (Review)
Review
Greater interest in imaging the superior vena cava (SVC) in recent years has arisen because of increased focus on disorders of the right heart; the growing use of transvenous access lines, dialysis catheters, and device leads; and the emergence of right ventricular mechanical circulatory support systems via the transcatheter approach. As a low-pressure venous conduit in the right upper mediastinum, the SVC is prone to compression by various pathologic processes, to invasion by malignancies originating in nearby structures, and to complications arising from intraluminal device leads and indwelling catheters. Computed tomography and magnetic resonance venography are the modalities of choice for structural imaging of the SVC. Ultrasound allows a reasonable, yet less detailed anatomic assessment of this venous conduit. Spectral and color Doppler imaging by ultrasound are the most valuable noninvasive tools for the interrogation of SVC blood flow, a marker of the filling pattern of the right heart. Analysis of the velocity, duration, and direction of the Doppler waveforms and their phasic response to respiration makes it possible to distinguish normal from abnormal flow patterns and offers diagnostic insights into disorders that affect right heart function. The aims of this review are to demonstrate the added value SVC imaging provides during transthoracic and transesophageal echocardiographic studies, to outline its usefulness for the detection and evaluation of structural abnormalities, and to detail the role of spectral Doppler imaging in aiding the diagnosis of various disorders that affect the right heart.
Topics: Humans; Vena Cava, Superior; Echocardiography, Transesophageal; Heart Ventricles; Ultrasonography, Doppler
PubMed: 36754099
DOI: 10.1016/j.echo.2023.01.017 -
BMC Plant Biology Feb 2023Nonstructural carbohydrates (NSCs) reflect the carbon supply status and affect the construction and development of plants. Previous studies have focused on the dynamics...
Drought- and soil substrate-induced variations in root nonstructural carbohydrates result from fine root morphological and anatomical traits of Juglans mandshurica seedlings.
BACKGROUND
Nonstructural carbohydrates (NSCs) reflect the carbon supply status and affect the construction and development of plants. Previous studies have focused on the dynamics of NSCs among plant organs, however, few studies have paid attention to the synergistic variations between fine root traits and NSCs under drought based on the perspective of branch order roots. This study aims to explore the responses of fine root traits and NSCs among root orders of Juglans mandshurica seedlings under different drought intensities and soil substrates. The 2-year-old J. mandshurica potted seedlings were planted in three different soil substrates (humus, loam and sandy-loam soil) and subjected to four drought intensities (CK, mild drought T1, moderate drought T2 and severe drought T3) for 60 days.
RESULTS
The root biomass of seedlings in sandy-loam soil under the same drought intensity was higher than that of seedlings in humus soil. With an increase in drought, the root biomass, average diameter, root tissue density and cortex thickness decreased significantly, and the specific root length, stele diameter and conduit density increased. The root NSC contents in humus soil were higher than those in sandy-loam soil. The fine root soluble sugar content in all soil substrates decreased with increasing drought intensity, while the root starch and total NSC contents varied among the different soil substrates. Compared with transportive roots, the morphological and anatomical traits jointly explained the higher variation in NSC contents of the absorptive roots. The anatomical traits explained the higher variation in the NSC content of first five order roots.
CONCLUSION
Our results suggest that coordinated adaptation of the root traits and NSCs of Manchurian walnut seedlings exposed to water gradients in different soil substrates.
Topics: Juglans; Seedlings; Soil; Plant Roots; Droughts; Carbohydrates; Sand
PubMed: 36750810
DOI: 10.1186/s12870-022-03987-x