Pharmacology of the Human Saphenous Vein

Nowadays, the great saphenous vein is the vascular conduit that is most frequently employed in coronary and peripheral revascularization surgery. It is known that saphenous vein bypass grafts have shorter patency than arterial ones, partly because the wall of the normal saphenous vein has different structural and functional characteristics. The features of this vein can be affected by the large distention pressures it is submitted to during its preparation and insertion into the arterial system. Indeed, a vein graft is subjected to considerable changes in hemodynamic forces upon implantation into the arterial circulation, since it is transplanted from a non-pulsatile, low-pressure, low-flow environment with minimal shear stress to a high-pressure system with pulsatile flow, where it undergoes cyclic strain and elevated shear. These changes can be responsible for functional and morphological alterations in the vessel wall, culminating in intima hyperproliferation and atherosclerotic degeneration, which contribute to early graft thrombosis. This review has followed a predetermined strategy for updating information on the human saphenous vein (HSV). Besides presenting the aspects relative to the basic pharmacology, this text also includes surgical aspects concerning HSV harvesting, the possible effects of the major groups of cardiovascular drugs on the HSV, and finally the interference of major cardiovascular diseases in the vascular reactivity of the HSV.

Echocardiographic identification of the oblique vein of the left atrium: its relationship to the persistent left superior caval vein

Thus far, little has been written concerning echocarchographic identification of the oblique of the left atrium, or Marshall`s vein. There is much discussion, nonetheless, on the potential significance of the vein, or its ligamentous remnant, as an arrhythmic substrate. We describe here four patients in whom transthoracic echocardiography revealed a venous structure protruding within the cavity of the left atrium. We discuss the possibility that these structures represent Marshall`s vein, albeit probably as part of a persistent left superior caval vein.

Coupling of composite resin cements to quartz fiber posts: A comparison of industrial and ""chairside"" treatments of the post surface

Purpose: To evaluate the influence of surface treatments on microtensile bond strength of luting resin cements to fiber posts. Materials and Methods: Forty-two quartz fiber posts (Light Post, RTD) were divided into 7 groups (n = 6) according to the surface treatment. I and 11: experimental patented industrial treatment consisting of zirconium oxide coating and silanization (RTD); III: industrial treatment followed by adhesive application (XPBond, Dentsply Caulk); IV: adhesive (XPBond); V: adhesive (Prime&Bond NT, Dentsply Caulk); VI: silane (Calibra Silane, Dentsply Caulk); VII: no treatment. Adhesives were used in the self-curing mode. Two cements (Sealbond, RTD - group 1, and Calibra, Dentsply Caulk - groups 11 to VII) were applied on the posts to produce cylindrical specimens. Post/cement interfaces were evaluated under SEM. The surface of the industrially coated posts was examined using energy dispersive analysis by x-ray. Cylinders were cut to obtain microtensile sticks that were loaded in tension at a crosshead speed of 0.5 mm/min until failure. Statistical analysis was performed using Kruskal-Wallis analysis of variance followed by Dunn`s multiple range test for post-hoc comparisons (p < 0.05). Weibull analysis was also performed. Results: The post/cement bond strength was significantly higher on fiber posts treated industrially (I: 23.14 +/- 8.05 MPa; II: 21.56 +/- 7.07 MPa; III: 22.37 +/- 7.00 MPa) or treated with XPBond adhesive (IV: 21.03 +/- 5.34 MPa) when compared to Prime&Bond NT application (V: 14.05 +/- 5.06 MPa), silanization (VI: 6.31 +/- 4.60 MPa) or no treatment (VII: 4.62 +/- 4.31) of conventional fiber posts (p < 0.001). Conclusion: The experimental industrial surface treatment and the adhesive application enhanced fiber post to resin cement interfacial strength. Industrial pretreatment may simplify the clinical luting procedure.

Influence of Filling Materials on the Bonding Interface of Thin-walled Roots Reinforced with Resin and Quartz Fiber Posts

Introduction: A common complication during the restoration of severely destroyed teeth is the loss of coronal root dentine. The aim of this study was to evaluate the influence of different sealers on the bonding interface of weakened roots reinforced with resin and fiber posts. Methods: Sixty extracted maxillary canines were used. The crowns were removed, and the thickness of root dentine was reduced in the experimental (n = 40) and positive control (n = 10) groups. The specimens of experimental group were assigned to four subgroups (n = 10) according to the filling material: gutta-percha + Grossmann`s sealer, gutta-percha + AH Plus (Dentsply De Trey Gmbh, Konstanz, Germany), gutta-percha + Epiphany (Pentron Clinical Technologies, Wallingford, CT), and Resilon (Resilon Research LLC, Madison, CT) + Epiphany. In the negative control group (n = 10), canals were not filled. After post space preparation, the roots were restored with composite resin light-activated through a translucent fiber post. After 24 hours, specimens were transversally sectioned into 1-mm-thick slices. Push-out test and scanning electron microscopic (SEM) analyses of different regions were performed. Data from push-out test were analyzed by using Tukey post hoc multiple comparison tests. The percentage of failure type was calculated. Data from SEM analysis were compared by Friedman and Kruskal-Wallis tests (alpha = 0.05). Results: The mean bond strength was significantly higher in the negative control group as compared with the other groups (P < .05). In all groups, the most frequent type of failure was adhesive. Overall, apical and middle regions presented a lower density of resin tags than the coronal region (P < .05). Conclusions: The push-out bond strength was not affected by sealer or region. The canal region affected significantly the resin tag morphology and density at the bonding interface. (J Endod 2011;37:531-537)

Microstructural evolution of the Serido Belt, NE-Brazil: the effect of two tectonic events on development of c-axis preferred orientation in quartz

The polyphase evolution of the Serido Belt (NE-Brazil) includes D, crust formation at 2.3-2.1 Ga, D-2 thrust tectonics at 1.9 Ga and crustal reworking by D-3 strike-slip shear zones at 600 Ma. Microstructural investigations within mylonites associated with D-2 and D-3 events were used to constrain the tectono-thermal evolution of the belt. D-2 shear zones commenced at deeper crustal levels and high amphibolite facies conditions (600-650 degreesC) through grain boundary migration, subgrain rotation and operation of quartz Q-prism slip. Continued shearing and exhumation of the terrain forced the re-equilibration of high-T fabrics and the switching of slip systems from (c)-prism to positive and negative (a)-rhombs. During D-3, enhancement of ductility by dissipation of heat that came from syn-D-3 granites developed wide belts of amphibolite facies mylonites. Continued shearing, uplift and cooling of the region induced D-3 shear zones to act in ductile-brittle regimes, marked by fracturing and development of thinner belts of greenschist facies mylonites. During this event, switching from (a)-prism to a basal slip indicates a thermal path from 600 to 350 degreesC. Therefore, microstructures and quartz c-axis fabrics in polydeformed rocks from the Serido Belt preserve the record of two major events, which includes contrasting deformation mechanisms and thermal paths. (C) 2003 Elsevier Ltd. All rights reserved.

Treatment by splenectomy of a portal vein aneurysm in hepatosplenic schistosomiasis

Portal vein aneurysm is a rare medical entity that can be caused by chronic hepatic diseases with portal hypertension. We describe a 45-year-old man with variceal bleeding from hepatosplenic schistosomiasis and an incidentally found intrahepatic aneurysm. Diagnosis was confirmed with non-invasive imaging exams, arteriography and liver biopsy. Following splenectomy, the aneurysm diameter decreased substantially.

Kidney function after left renal vein ligation in the dog

The ligature of the left renal vein is an alternative whenever this vessel is injured. The purpose of this study was to evaluate the capacity of the affluents of the left renal vein, proximal to the ligature, to maintain tissue vitality and function of the left kidney. Fifteen mongrel male dogs were divided in 3 groups of 5 dogs: Group I (control) - a laparotomy was performed, and the abdominal structures were only identified; Group II - the left renal vein was tied, close to vena cava; Group III - the same procedure as for Group II and a right nephrectomy. Blood urea nitrogen and serum creatinine levels were measured before the procedure, and every 3 days during 4 weeks in the postoperative period. Renal arteriography and an excretory urogram were performed on the animals that survived 60 days. Thereafter, or immediately after precocious death, the kidneys were removed for histological examination. All the animals of Group III died before two months (mean = 10.5 +-3.2 days), while the animals of Group II survived during that period. There was a complete exclusion of the left kidney in all dogs that underwent renal vein ligature. In the animals of Group II, the renal cortico-medullary limits could not be identified. At microscopy, the aspect was suggestive of nephrosclerosis. In the animals of Group III, the left kidney was enlarged, and a great amount of intravascular and intrapelvic blood clots were observed. At microscopy, extensive areas of necrosis, inflammatory infiltration, and hemorrhage were identified. In conclusion, the tributaries of the renal vein were not sufficient to maintain the tissue vitality and function of the left kidney after ligature of its main vein.

Persistence of the embryonic lateral marginal vein: report of two cases

PURPOSE: Congenital venous malformations of the lower limbs represent a particular challenge for the vascular surgeon. Persistence of fetal veins is a rare malformation, and the most common is the persistence of the lateral marginal vein usually observed in patients with Klippel-Trenaunnay Syndrome. The persistence of this embryonic vein as an isolated venous malformation without the other characteristics of the Klippel-Trenaunnay Syndrome has not yet been reported. This paper describes two cases. METHODS: Two patients, a 17-year-old male patient and a 16-year-old female, have had since their birth a large venous trunk in the lateral aspect of the right leg and thigh. The limbs underwent duplex scanning and phlebography. The surgical removal of the lateral marginal vein was performed. RESULTS: Surgical treatment resulted in very good functional and aesthetic results. Follow-up at 26 months showed no evidence of varicose vein recurrence. CONCLUSIONS: To achieve good results, surgical intervention may be indicated in cases of orthopedic deformity, hemorrhage, symptomatic, and unaesthetic lesions.

Coronary bilateral ostial enlargement using the saphenous vein in a patient with syphilitic aortitis

A patient with tertiary syphilis presenting with bilateral coronary ostial lesions and aortic regurgitation underwent surgical reconstruction of the coronary ostia by the anterior approach with autogenous saphenous vein grafting and substitution of the aortic valve with a bovine bioprosthesis. The procedure was easily performed and had good outcomes both early and late. The rarity of the association of a lesion in both coronary ostia with aortic regurgitation in syphilis and the surgical technique employed are discussed.

Fetal tachyarrhythmia with 1:1 atrioventricular conduction. Adenosine infusion in the umbilical vein as a diagnostic test

This is the report of a case of fetal tachyarrhythmia with 1:1 atrioventricular conduction detected by pre-natal echocardiography in a fetus at 25-weeks gestation. Adenosine infusion via cordocentesis was performed as a diagnostic test to differentiate between atrioventricular nodal reentrant supraventricular tachyarrhythmia and atrial flutter. After infusion, transient 2:1 atrioventricular dissociation was obtained and the diagnosis of atrial flutter was made. Transplacental therapy with digoxin and amiodarone was then successfully used.

The use of primary stenting or balloon percutaneous transluminal coronary angioplasty for the treatment of acutely occluded saphenous vein grafts. Results from the Brazilian National Registry - CENIC

OBJECTIVE: We conducted a comparative analysis of the in-hospital outcomes of patients who underwent primary percutaneous transluminal angioplasty (PTCA) or stent implantation because of an acute myocardial infarction (AMI) related to an acute vein graft occlusion. METHODS: Since 1991 the Brazilian Society of Hemodynamic and Interventional Cardiology has maintained a large database (CENIC). From these, we selected all consecutive patients, who underwent primary PTCA or stenting in the first 24 hours of AMI, with the target vessel being an occluded vein graft. Immediate results and major coronary events occurring up until hospital discharge were analyzed. RESULTS: During this period, 5,932 patients underwent primary PTCA or stenting; 158 (3%) of the procedures were performed because of an acute vein graft occlusion. Stenting was performed in 74 (47%) patients. Patients treated with stents had a higher success rate and lower mean residual stenosis compared with those who underwent primary balloon PTCA. The incidence of reinfarction and death were similar for stenting and balloon PTCA. CONCLUSION: Primary percutaneous treatment of AMI related to acute vein graft occlusion is still an uncommon practice. Primary stenting improved luminal diameter and offered higher rates of success; however, this strategy did not reduce the in-hospital reinfarction and death rate, compared with that occurring with PTCA treatment.