Is Radiofrequency Ablation Better than Venous Stripping for Management of Chronic Venous Insufficiency?

Chronic venous insufficiency (CVI) is a disease of the vein due to valve dysfunction, venous obstruction, or both. This results in increased vein pressure and related to disruption in the vein system.

Anatomical Study of the Hepatic Veins in Segment 4 of the Liver Using Three-Dimensional Visualization

Objective: The current study aimed to examine the anatomical structure of the hepatic vein of segment IV liver (S4) of the liver using three-dimensional (3D) visualization technology in order to explore the surgical value of the middle hepatic vein (MHV) manipulation and highlight the importance of current research in hepatic surgery.Methods: Between January 2014 and December 2019, 52 patients with abdominal diseases(not including hepatic disease) were selected for multiphasic computed tomography-enhanced scans of the upper abdomen. A 3D visualization system was utilized to display the structural details of the hepatic veins in S4 of their livers. Couinaud's eight-segment classification system was used to denote the liver' sections.Results: The constructed 3D model clearly displayed vascular morphological characteristics and their location in the liver, hepatic artery and vein system, and portal vein system. Of the 52 patients, 43 had an umbilical fissure vein (UFV) (82.7%), 19 had an accessory S4 liver vein (36.5%), 16 had both a UFV (30.8%) and an accessory S4 liver vein, and 6 had neither (11.5%). A total of 79% of the patients with a UFV and 74.2% of those with an accessory S4 liver vein had venous blood returning into the left hepatic vein.Conclusion: 3D visualization technology was used to determine hepatic venous return of S4 hepatic veins and was found to improve the safety of evaluation in hepatic surgery.

Cellular remains in a ~3.42-billion-year-old subseafloor hydrothermal environment

Subsurface habitats on Earth host an extensive extant biosphere and likely provided one of Earth’s earliest microbial habitats. Although the site of life’s emergence continues to be debated, evidence of early life provides insights into its early evolution and metabolic affinity. Here, we present the discovery of exceptionally well-preserved, ~3.42-billion-year-old putative filamentous microfossils that inhabited a paleo-subseafloor hydrothermal vein system of the Barberton greenstone belt in South Africa. The filaments colonized the walls of conduits created by low-temperature hydrothermal fluid. Combined with their morphological and chemical characteristics as investigated over a range of scales, they can be considered the oldest methanogens and/or methanotrophs that thrived in an ultramafic volcanic substrate.

Ultrasonographic characteristics and outcome of Type III umbilical-portal-systemic venous shunt

Aims: According to a novel in-utero classification termed “umbilical-portal-systemic venous shunt (UPSVS)” recently proposed for an abnormal umbilical, portal and ductal venous system, the portal-systemic shunt belongs to type III UPSVS. This study was designed to examine the ultrasonographic characteristics and outcome of type III UPSVS.Material and methods: All cases of Type III UPSVS diagnosed at our department from April 2016 to December 2020 were retrospectively studied.Results: Seventeen patients with type III UPSVS including 12 type IIIa and 5 IIIb cases were identified. Sonography showed a shunt between the inferior left portal vein and the left hepatic vein in all type IIIa cases. Three cases of type IIIb had a combination of another shunt (2 with type I and one with type IIIa). Integrate intrahepatic portal vein system was not seen in those 2 cases of type IIIb combined with type I UPSVS, leading to termination of pregnancy (TOP). TOP occurred in 4 patients with type IIIa as requested by the parents. Two cases (type IIIa and type IIIb each) underwent surgical procedure for the closure of the shunt. Spontaneous complete closure in 4 type IIIa cases and partial closure in one type IIIb case occurred during a period of 3-16 months.Conclusions: The majority of patients had type IIIa UPSVS presenting a good outcome. The lack of integrate intrahepatic portal vein system was the main reason for TOP in patients with type IIIb UPSVS. These data suggest the UPSVS classification is a useful tool for a prognosis prediction of type III UPSVS.

Role of Basement Structural Inheritance and Strike-Slip Fault Dynamics in the Formation of the Pataz Gold Vein System, Eastern Andean Cordillera, Northern Peru

New regional- to vein-scale geologic mapping and structural analysis of the Carboniferous Pataz gold vein system (~10 Moz Au) reveal critical insights into the structural control on gold mineralization along the Eastern Andean Cordillera of northern Peru. The Pataz basement comprises continental volcanic arc and marginal to marine sedimentary rocks, which experienced intensive D2 deformation associated with Late Famatinian northeast to southwest compressive fold-and-thrust belt development. The D2 event produced an E-NE–dipping structural grain, including (1) tilted and F2 folded S1 foliations, (2) local F2 axial planar S2 foliations, and (3) subparallel D2 thrust faults. Intrusions, constituting the ca. 342 to 332 Ma (Mississippian) Pataz batholith, were emplaced along strike of the prominent Río Marañón fault and inherited the D2 basement structures, as evident in the orientation of suprasolidus magmatic flow zones and intrusive contacts within the batholith. Progressive horst-and-graben development affecting the volcanic carapace of the Pataz batholith records late syn- to postmagmatic uplift and transition into a NW-SE–extensional regime. We show that the E-NE–dipping, batholith-hosted gold vein system formed through synchronous activation of two geometric fault-fill vein types, following (1) the moderately E-NE–dipping D2 basement-inherited competency contrasts within the batholith and (2) shallow NE-dipping Andersonian footwall thrusts, during NE-directed shortening (D3a). Both geometric vein types display an early paragenetic stage (I) of quartz-pyrite, progressing texturally from hydraulic breccia into crack-seal laminated shear veins. A second (II), undeformed quartz-pyrite-sphalerite-galena paragenetic stage is observed to fill previously established dilational sites adjacent to newly formed D3b normal faults, which likely formed during regional NW-SE–extensional horst-graben development. Kinematics and relative timing indicate that, upon batholith solidification, D3a transpressional dextral strike-slip ruptures along the Río Marañón fault superimposed a lower-order Riedel-type fault system. Fluid-assisted fault activation preferentially impinged on the D2 basement-inherited competency contrasts within the batholith. Subsequent transition into a transtensional regime led to the D3b normal faulting, providing a feeder system for stage II fluid influx. The tectonic switch may be explained either by increasing tensile strain accommodation upon progressive strike-slip movement within a regional dilational jog or by larger-scale crustal relaxation of the late Gondwana margin upon final Pangea assembly. Our new structural model for the Pataz vein system evolution highlights the importance of basement structural inheritance in controlling the localization of gold mineralization along polycyclic supercontinent margins. We provide valuable insights for exploration targeting of complex vein arrays within rheologically heterogeneous host rocks.