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At least 379 records · Page 21Linked to original sources
PubMed1998

G protein signaling and vein graft intimal hyperplasia: reduction of intimal hyperplasia in vein grafts by a Gbetagamma inhibitor suggests a major role of G protein signaling in lesion development.

Vein grafting results in the development of intimal hyperplasia with accompanying changes in guanine nucleotide-binding (G) protein expression and function. Several serum mitogens that act through G protein-coupled receptors, such as lysophosphatidic acid, stimulate proliferative pathways that are dependent on the G protein betagamma subunit (Gbetagamma)-mediated activation of p21ras. This study examines the role of Gbetagamma signaling in intimal hyperplasia by targeting a gene encoding a specific Gbetagamma inhibitor in an experimental rabbit vein graft model. This inhibitor, the carboxyl terminus of the beta-adrenergic receptor kinase (betaARK(CT)), contains a Gbetagamma-binding domain. Vein graft intimal hyperplasia was significantly reduced by 37% (P<0.01), and physiological studies demonstrated that the normal alterations in G protein coupling phenotypically seen in this model were blocked by betaARK(CT) treatment. Thus, it appears that Gbetagamma-mediated pathways play a major role in intimal hyperplasia and that targeting inhibitors of Gbetagamma signaling offers novel intraoperative therapeutic modalities to inhibit the development of vein graft intimal hyperplasia and subsequent vein graft failure.

Analysis of Variance↗
PubMed2005

Is duplex surveillance of value after leg vein bypass grafting? Principal results of the Vein Graft Surveillance Randomised Trial (VGST).

BACKGROUND: The purpose of this study was to assess the benefits of duplex compared with clinical vein graft surveillance in terms of amputation rates, quality of life, and healthcare costs in patients after femoropopliteal and femorocrural vein bypass grafts. METHODS AND RESULTS: This was a multicenter, prospective, randomized, controlled trial. A total of 594 patients with a patent vein graft at 30 days after surgery were randomized to either a clinical or duplex follow-up program at 6 weeks, then 3, 6, 9, 12, and 18 months postoperatively. The clinical and duplex surveillance groups had similar amputation rates (7% for each group) and vascular mortality rates (3% versus 4%) over 18 months. More patients in the clinical group had vein graft stenosis at 18 months (19% versus 12%, P=0.04), but primary patency, primary assisted patency, and secondary patency rates, respectively, were similar in the clinical group (69%, 76%, and 80%) and the duplex group (67%, 76%, and 79%). There were no apparent differences in health-related quality of life, but the average health service costs incurred by the duplex surveillance program were greater by 495 pound sterling (95% CI 83 pound sterling to 807 pound sterling) per patient. CONCLUSIONS: Intensive surveillance with duplex scanning did not show any additional benefit in terms of limb salvage rates for patients undergoing vein bypass graft operations, but it did incur additional costs.

Aged↗
PubMed1985

Femoral artery flow in deep vein thrombosis: hemodynamics of slow versus acute femoral vein occlusion.

There are many reports of reduced flow in the femoral artery following acute occlusion of the femoral vein. Poorer results might also be expected in arterial reconstructive surgery for obliterative vascular disease, in the event of deep vein thrombosis (DVT) of the limb. It is likely that patients develop DVT by a slow process that is totally different from experimental acute occlusion of the femoral vein, which leads to reduction of flow in the femoral artery. To test this hypothesis, a model with slow and gradual femoral vein occlusion was used. The results of this study showed that there was only 13.5% reduction in femoral artery flow during a four-hour gradual occlusion of the femoral vein. This excludes the possibility that in the presence of gradually occurring processes such as DVT, there is a hemodynamic basis for reduced flow through the femoral artery or through a bypass.

Animals↗
PubMed1996

Influence of angioscopic vein graft preparation on development of neointimal hyperplasia in an organ culture model of human saphenous vein.

PURPOSE: Angioscopy for in situ vein graft preparation has been criticized on the basis that the trauma of instrumentation may predispose to accelerated intimal hyperplasia, jeopardizing patency rates following infrainguinal revascularization. The aim of this study was to assess the effects of angioscopic preparation on endothelial integrity and smooth muscle cell (SMC) behavior in an established organ culture model of human saphenous vein (HSV). METHODS: HSV was harvested from 12 patients during bypass surgery before and after angioscopic preparation. Endothelial integrity was evaluated by immunohistochemical staining with JC-70 and scanning electron microscopy (SEM); remaining segments of pre- and postangioscopy vein were maintained in culture for 14 days in medium supplemented with 30% fetal calf serum. Viability was confirmed by measurement of tissue adenosine triphosphate on day 14 and thickness of the neointima was measured by computerized image analysis of histologic sections. Monoclonal antibodies to proliferating cell nuclear antigen (PCNA) were used as an immunohistochemical marker for proliferating SMCs. RESULTS: There was a significant reduction in the percentage staining by JC-70 (71.3% versus 20.4%) in pre- versus postangioscopy vein (p = 0.002 by Wilcoxon's rank test; n = 12). This was supported by SEM images. Despite this, there were no significant differences between the pre- and postangioscopy HSVs after 14 days of culture with respect to neointimal thickness (61 versus 56 microns) and staining with PCNA (4.80 versus 4.08 nuclei per 10 microns), all according to Wilcoxon's rank test. CONCLUSIONS: Angioscopic vein graft preparation is associated with endothelial cell loss but does not induce additional neointimal hyperplasia in HSV in vitro. These results suggest that angioscopic manipulation does not alter SMC behavior.

Adenosine Triphosphate↗
PubMed1976

Scanning electron microscope study of human veins and aorta-coronary artery vein grafts.

Scanning electron microscope study of two vein grafts which were removed after 50 months of implantation as aorta-coronary artery vein grafts showed considerable subendothelial thickening, which consisted of relatively cell-poor fibrous layer. In one of the grafts the endothelial surface was intact; the second graft showed focal loss of endothelial cells. Sections of two fresh human veins, studied prior to their insertion as aorta-coronary artery vein grafts, have shown that they retained an intact endothelial layer. A third fresh vein, however, showed focal damage with missing endothelial cells and adherent fibrin.

Autopsy↗
PubMedDate not supplied

Cephalic vein cutdown for inserting indwelling subclavian vein catheters in gynecologic oncology patients.

To decide on an alternate procedure for placement of central vein catheters other than percutaneous access of the subclavian vein, we conducted a study of 46 women who underwent placement of a central venous catheter utilizing the cephalic vein procedure at Ruby Memorial Hospital at West Virginia University in Morgantown. Of these patients, 96% had a successful placement of a catheter into the subclavian vein following dissection of the cephalic vein within the deltopectoral groove. There were no cases of pneumothorax or injury to the great vessels during the surgical procedure, which is a significant advantage for women who often have significant pleural effusions.

Adult↗
PubMedDate not supplied

Middle hepatic vein tributary reconstruction could not act as a complete substitute for an entirely preserved middle hepatic vein.

BACKGROUND/AIMS: The necessity of the middle hepatic vein for living donor liver transplantation using right lobe graft is still controversial. METHODOLOGY: We reviewed 7 long-term surviving right-lobe recipients in whom middle hepatic vein tributaries were not reconstructed (group A, n=4) or were reconstructed (group B, n=3). Volume regeneration of the right paramedian (segments V+VIII) and right lateral (segments VI+VII) sectors was assessed by computed tomography at 3, 6, 9, and 12 postoperative months. The right paramedian sector was further subdivided into the ventral portion in relation to the anterior branch of the right portal vein and dorsal portion. RESULTS: The volume regeneration ratio was significantly lower in group A than in group B persistently after 6 postoperative months in regard to the right paramedian sector, the dorsal portion, and especially the ventral portion (0.64 +/- 0.19 vs. 1.22 +/- 0.17, p=0.034, 12 postoperative months). However, volume regeneration was impaired in the ventral portion as compared to other areas in group B. CONCLUSIONS: In conclusion, middle hepatic vein tributary reconstruction improves the volume regeneration of the right paramedian sector in right lobe living donor liver transplantation However, it could not act as a complete substitute for an entirely preserved middle hepatic vein.

Adolescent↗
PubMed1990

[Morphologic studies of the conductive veins of the leg in superficial varicose veins].

Issuing from the thesis of Fischer and Siebrecht that the epifascial varicosis can be accompanied by an insufficiency of the conducting and muscle veins for the first time morphological investigations on the profound venous system were carried out with the questioning whether the non-thrombotic insufficiency of the profound conducting veins of the leg an adequate morphological correlate is underlying which is to be recognized and proved histologically. On the basis of this first pilot study can be shown that similar forms of reaction take place in the part of the superficial and profound veins which are free from varices. Hitherto it is still unclear which factors are leading for the causes in the pathological mosaic. The insufficiency of the conducting veins, age-conditioned and functional changes and the arteriosclerotic venopathy are discussed. The conception of the insufficiency of the conducting veins also in the field of morphological research proves to be the initiator of exact and further analyses.

Collagen↗
PubMed1985

[A case of abdominal aortic aneurysm ruptured into the left common iliac vein with symptoms resembling deep vein thrombosis].

A 59 years old male with abdominal aortic aneurysm ruptured into the left common iliac vein was transferred to us with symptoms resembling deep vein thrombosis of the left lower extremity, such as leg pain, swelling and dilatation of the superficial veins. At operation, a Fogarty's occlusion catheter was inserted through the right greater saphenous vein into the inferior vena cava and inflated concomitantly during aortic clamp to prevent pulmonary embolism which may be caused by the dislodged thrombi from the aneurysm, and as well as to control back-flow-bleeding from the central. The fistula (3.0 X 1.0cm) was closed from inside of the aneurysm using the inferior wall of the aneurysm. The blood from the fistula was collected by the Cell Saver and re-transfused to the patient. The abdominal aorta was replaced with a Dacron Y-shaped prosthesis. The postoperative course was uneventful. CTR on chest X-ray subsided from 51% to 42%, cardiac output normalized from 11l/min to 6l/min, and symptoms resembling the deep vein thrombosis disappeared.

Aorta, Abdominal↗
PubMed1983

Collateral veins in left renal vein stenosis demonstrated via CT.

Twelve patients with left renal vein stenosis from tumor compression were studied with CT. All had distended collateral veins in the perirenal space which either formed a radiating or a cobweb pattern or appeared as marked longitudinal veins. Inferior phrenic vein branches were seen in seven patients and were considerably enlarged in two. Other major veins possibly taking part in collateral circulation could not be recognized due to obliteration of fat planes. The renal fascia was thickened in eleven patients, probably due to edema. A close study of the perirenal space with CT may give valuable information about collateral development.

Adolescent↗
PubMed1993

A comparative study of branch retinal vein occlusion and central vein occlusion amongst Malaysian patients.

A retrospective study of 95 patients with retinal vein occlusion was carried out to determine the clinical presentation and pattern of distribution in the local Malaysian population. There was no significant difference found in its distribution with regards to sex. In comparing branch retinal vein occlusion with central retinal vein occlusion, no significant differences were found in its racial distribution. Branch retinal vein occlusion occurred more commonly among the older patients whereas the converse is true for central retinal vein occlusion. Reduced vision represents the commonest mode of presentation. Hypertension, diabetes mellitus, hyperlipidaemia and haematological disorders are important associated systemic conditions.

Adult↗
PubMed1993

Testicular vein and peripheral vein testosterone, follicle stimulating hormone, luteinizing hormone, and prolactin concentrations in a patient with androgen insensitivity syndrome.

Androgen insensitivity syndrome (testicular feminization) is classically diagnosed by history, physical examination, karyotype and ultimately exploratory laparotomy. In this case, the diagnosis was verified by amenorrhea, female phenotype, Barr body negative buccal smear, and finally, exploratory laparotomy which revealed bilateral abdominal testes. Testicular vein blood samples obtained at the time of surgery were analyzed for testosterone, follicle stimulating hormone, luteinizing hormone, and prolactin and compared to peripheral vein blood samples. The testosterone concentration in the testicular vein was twice the concentration in the peripheral sample, reflecting gonadal function. The other testicular vein hormone concentrations mirrored the peripheral vein concentrations.

Adolescent↗
PubMed1994

Hemodynamic changes after ligation of a major branch of the portal vein in rats: comparison with rats with portal vein constriction.

In chronic portal-hypertensive rat models, such as portal vein constriction or cirrhosis, the portal blood flow that effectively perfuses the hepatocytes is substantially reduced because of anatomical or functional shunts. It is possible therefore that a feedback mechanism from the liver to the splanchnic bed is responsible for the splanchnic hyperemia observed in chronic portal hypertension. To investigate the possible role of such a feedback mechanism, we examined the chronological changes in both portal and systemic hemodynamics in rats after ligation of a major branch of the portal vein that supplies about 80% of the liver circulation. Rats submitted to sham surgery and portal vein-constricted rats were also studied. Blood flow and portal-systemic shunting were measured by radioactive microsphere techniques. For 7 days after portal-branch ligation, transient portal hypertension resulted from an elevated portal resistance. However, no significant changes in portal venous inflow or splanchnic arteriolar resistance were found in the portal branch-ligated rats, whereas in the portal vein-constricted rats significant hyperdynamic changes in these parameters were noted. On the other hand, transient hyperdynamic changes occurred in the systemic circulation during the period from the fourth to the sixth day after portal-branch ligation, similar to those observed in the portal vein-constricted rats. The lack of hyperdynamic changes in the portal territory of the portal branch-ligated rats suggests that the splanchnic hyperemia found in chronic portal-hypertensive states is unlikely to be caused by a feedback mechanism from the ischemic hepatic parenchyma.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Saphenous vein biopsy: a predictor of vein graft failure.

PURPOSE: To determine why some vein grafts fail, we prospectively studied the relationship between the histologic condition of the greater saphenous vein (GSV) at the time of grafting and subsequent stenosis of the vein graft. METHODS: Ninety-four remnant segments of GSVs were obtained at the time of infrainguinal bypass in 91 patients and were perfusion fixed before histologic and ultrastructural examination. All bypass grafts were evaluated clinically and by duplex ultrasonography at regular intervals from 1 to 30 months after operation. All 24 grafts that developed lesions that caused thrombosis (failed grafts) or flow reduction (failing grafts) underwent arteriography and appropriate operative or other interventional correction of the causative lesion. RESULTS: There was no significant difference in the incidence of coronary artery disease, kidney disease, hypertension, or history of smoking in patients with normally functioning and failed or failing grafts. Diabetes occurred with an increased frequency in failed or failing grafts (p = 0.056). At the time of their insertion, GSVs that subsequently developed significant lesions had thicker walls (0.72 +/- 0.33 mm) compared with normally functioning grafts (0.58 +/- 21 mm; p < 0.02). Most of this difference was related to a significantly thicker intima (0.27 +/- 0.17 vs 0.11 +/- 0.7 mm; p < 0.0001). Another significant finding was the presence of subendothelial spindle-shaped cells greater than five cell layers thick. This occurred more often in pregraft biopsies from grafts that developed significant lesions (70.4% vs 7.5%, p < 0.0001). Electron microscopic examination of these cells demonstrated a subpopulation of poorly differentiated cells with few fibers and many vesicles. Four of 24 (17%) failed or failing grafts had evidence of vein wall calcification at the time of vein grafting. This was seen in only one (1.4%) of 70 normally functioning grafts without lesions (p < 0.005). CONCLUSIONS: We conclude that GSVs with thick and calcified walls or hypercellular intima at the time of grafting are at increased risk of developing intragraft lesions that may lead to graft failure. Frequent duplex ultrasonography surveillance is particularly warranted for such high-risk grafts.

Aged↗
PubMed1976

[Dynamic pressure in the superficial and deep crural veins in uncomplicated varicosity without incompetence of communicant veins].

Synchronous phlebotonometry was performed on 30 lower extremities in 27 patients. Various pressure dynamics was observed in the proximal and distal segments of profound veins. Dynamic phlebohypertension was found not only in superficial but also in deep-seated veins. The escape of superficial veins resulted in normalization of pressure in both systems. The more intensive muscle contractions under conditions of normal blood circulation the greater a reduction of pressure phases in the crural vein distal segment this factor may be used as a test for estimation of the vein-muscle pump function.

Female↗
PubMed1994

Internal jugular to axillary vein bypass for subclavian vein thrombosis in the setting of brachial arteriovenous fistula.

Placement of central venous catheter is the most common cause of subclavian vein thrombosis. In the setting of a functioning ipsilateral brachial arteriovenous fistula, venous hypertension symptoms may be exacerbated. We report successful decompression of severe venous hypertension in the right arm of a patient whose only access for hemodialysis was a functioning right brachial arteriovenous fistula and in whom proximal subclavian vein occlusion developed from a previous percutaneous dialysis catheter. Transposition of the right internal jugular vein and end-to-side anastomosis to the right axillary vein provided prompt and effective venous outflow, with complete resolution of venous engorgement of the affected limb and preservation of the dialysis fistula.

Arteriovenous Shunt, Surgical↗
PubMed1996

Total anomalous pulmonary venous connection to the portal and splenic vein associated with unilateral hypoplasia of pulmonary veins.

Total anomalous pulmonary venous return (TAPVR) represents a rare congenital anomaly with wide anatomical and physiological variability. We report a case of a newborn with a challenging form of obstructed infracardiac TAPVR, in whom left and right pulmonary veins drained separately into the portal system. The right pulmonary venous sinus connected to the left branch of the portal vein, whereas the left venous sinus connected to the splenic vein. Surgical repair consisted of the creation of a common retrocardiac venous trunk which was anastomosed to the left atrium. The postoperative course was characterized by persisting congestion of the right lung. Two months later, right pulmonary vein hypoplasia was successfully enlarged with autologous pericardium.

Angiography↗