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At least 19 recordsLinked to original sources
PubMed1984

Promotion of vascular patency in dermal burns with ibuprofen.

Differences in the vascular response to burn and freeze injuries were investigated as a model for defining the mechanism and cause of vascular occlusion in rats after dermal burns. Concentrations of thromboxane and prostacyclin in wound fluid were elevated in both types of trauma. However, inhibition of prostaglandin synthesis by indomethacin failed to promote vascular patency in burn-injured animals. However, the systemic administration of ibuprofen and imidazole led to increased vascular patency. Ibuprofen promoted vascular patency even when given six hours after burn trauma. These studies indicate that ibuprofen and imidazole promote vascular patency by fostering fibrinolysis rather than by inhibiting prostaglandin synthesis and release.

6-Ketoprostaglandin F1 alpha↗
PubMed2005

Computerised analysis of auscultatory sounds associated with vascular patency of haemodialysis access.

Vascular access for renal dialysis is a lifeline for about 120 000 individuals in the United States. Stethoscope auscultation of vascular sounds has some utility in the assessment of access patency, yet can be highly skill-dependent. The objective of the study was to identify acoustic parameters that are related to changes in vascular access patency. The underlying hypothesis is that stenoses of haemodialysis access vessels or grafts cause vascular sound changes that are detectable using computerised data acquisition and analysis. Eleven patients participated in the study. Their vascular sounds were recorded before and after angiography, which was accompanied by angioplasty in most patients. The sounds were acquired using two electronic stethoscopes and then digitised and analysed on a personal computer. Vessel stenosis changes were found to be associated with changes in acoustic amplitude and/or spectral energy distribution. Certain acoustic parameters correlated well (correlation coefficient = 0.98, p < 0.0001) with the change in the degree of stenosis, suggesting that stenosis severity may be predictable from these parameters. Parameters also appeared to be sensitive to modest diameter changes (> 20%), (p < 0.005, Wilcoxon rank sum test). These results suggest that computerised analysis of vascular sounds may be useful in vessel patency surveillance. Further testing using longitudinal studies may be warranted.

Arteriovenous Shunt, Surgical↗
PubMed1992

[Angioscopic prediction of late vascular patency after transluminal balloon angioplasty for arteriosclerotic obstructions of the artery of the lower extremities].

Arterial occlusion or stenosis of the lower extremity due to arteriosclerosis obliterans (ASO) was treated by transluminal balloon angioplasty (TBA). Angioscopic observation of the vascular lumen, performed immediately after TBA, provided five major findings: (1) abrasion of the intima, (2) irregularity of the lumen due to poor expansion, (3) laceration of the wall, (4) mural thrombus and (5) calcification. The degree of each of these abnormalities was scored with a 3-grade scale (0, 1 and 2), and scores for the 5 abnormalities were totaled in each patient. Analysis of the relationship between scores and postoperative vascular patency demonstrated that patients without vascular patency in the early (within 6 months) or late period (6 months or more) after the operation had higher total scores as compared to those in whom the vessel remained patient in the corresponding postoperative periods (p less than 0.01, p less than 0.05). Among others, patients with a total score over 5 showed markedly lower patency rates in the early period (10%) as well as late period (0%) after the operation (p less than 0.01). These results indicate the usefulness of post-TBA angioscopic observation of vascular lumen in predicting the long-term patency of the vessels operated on.

Aged↗
PubMed1997

Antiplatelet effect of FK633, a platelet glycoprotein IIb/IIIa antagonist, on thrombus formation and vascular patency after thrombolysis in the injured hamster carotid artery.

The antithrombotic and restenosis-preventing effects of FK633, an inhibitor of platelet aggregation via binding to the glycoprotein (GP) IIb/IIIa receptor, were studied, IC50 value of FK633 against platelet aggregation ex vivo induced by 2.5 microM adenosine diphosphate (ADP) was 5.4 x 10(-7) M as determined using hamster platelet rich plasma. The inhibitory effect was also investigated in vivo on thrombus formation at the carotid arterial wall injured by a modified catheter. As a control, the left carotid artery was injured and the time required to develop a thrombotic occlusion (3.9 +/- 1.1 min, mean +/- S.E.M., n = 18) was determined. Then, the right carotid artery of the same animal was injured while a continuous intravenous (i.v.) infusion of FK633 was administered at doses of 0 (saline), 0.1, 0.3 or 1.0 mg/kg/h. The time to occlusion was dose-dependently prolonged. In a separate experiment, 10% of the total tPA dose (0.52 mg/kg) was injected into the injured artery as a bolus and the remaining was infused i.v. at a constant rate for 30 min. When FK633 (0.3 or 1.0 mg/kg/h) was infused together with tPA, late patency of the reperfused artery was much improved as compared with that of treatment with tPA alone. Bleeding time, measured at the end of the tPA infusion, was markedly prolonged when the higher dose of FK633 (1.0 mg/kg/h) was coadministered, however coadministration of the lower dose of FK633 (0.3 mg/kg/h) was almost without prolongation on the bleeding time, despite a significant effect on the vascular patency after thrombolysis. Next, neointima formation was evaluated 2 weeks after the vascular injury. When FK633 (0.3 mg/kg/h) was continuously infused i.v. by an implanted osmotic pump for 3, 7 or 14 days after the vascular injury, the neointimal area formation was significantly suppressed in the treatment groups for 7 or 14 days. These findings suggest that FK633 inhibits platelet activation in the injured artery and improves vascular patency after thrombolysis with tPA with a concomitant suppression of neointima formation.

Animals↗
PubMed1989

An evaluation of the ability of the peripheral vasodilator buflomedil to improve vascular patency after acute frostbite.

The extent of microvascular damage from frostbite can be accurately demonstrated by vascular microcorrosion casting techniques (P. S. Daum, W. D. Bowers, Jr., J. Tejada, and M. P. Hamlet, Cryobiology 24, 65-73, 1987). In the present investigation, the peripheral vasodilator buflomedil was evaluated for its ability to ameliorate microcirculatory damage from acute experimentally induced freeze injury. This drug has been reported to decrease tissue loss in human frostbite patients when given intravenously during thawing (J. Foray, P. E. Baisse, J. P. Mont, and Cl. Cahen, Sem. Hop. Paris 56, 490-497, 1980). In seven groups of anesthetized rats, left hindpaws were cooled to heat of fusion; cooling continued until the temperature in the footpads fell to -15 degrees C. Prior to cooling, group 1 received a tail vein injection of 1 ml saline/kg, while group 2 received 10 mg buflomedil/kg. Immediately following cooling, group 3 received an injection of 10 mg buflomedil/kg. Hindpaws were rapidly rewarmed in a 40 degree C bath. During rewarming, left hindpaws from group 4 were immersed in deionized water, from group 5 in 24 mg buflomedil in deionized water, from group 6 in 30% dimethyl sulfoxide (Me2SO), and from group 7 in 24 mg buflomedil in 30% Me2SO. Right hindpaws served as controls. Vascular microcorrosion casts were made from left and right hindpaws of all groups. There was no significant difference in mean cast weights when frozen hindpaws of the seven groups were compared, although treatment with buflomedil increased the mean cast weight of control hindpaws from groups 3 and 7. It therefore appears that, in this acute model for frostbite, buflomedil does not improve vascular patency.

Animals↗
PubMed1989

Oxygen radical scavengers improve vascular patency and bone-muscle cell survival in an ischemic extremity replant model.

We examined the use of oxygen radical scavengers in preventing the no-reflow phenomenon and improving bone-muscle cell survival in an ischemic extremity replant model. A total of 70 Lewis rat modified hindlimb replants were performed after specific periods of cold ischemia and intraarterial perfusion with either superoxide dismutase and catalase, specific oxygen free-radical scavengers, or a control solution. Ischemic hindlimbs treated with superoxide dismutase and catalase showed a statistically significant (p less than 0.05) improvement in vascular patency after prolonged cold ischemia when compared to controls. Histologically, experimental extremities demonstrated greater osteoblast, osteocyte, and muscle cell survival in replanted hindlimbs with patent vascular anastomoses. The perfusion of severed limbs and digits and free vascularized tissue transfers with superoxide dismutase and catalase after a period of ischemia has already occurred may prolong the ischemic "time window" tolerated for successful tissue survival.

Animals↗
PubMed1995

Vincula tendinum of human hands with special reference to vascular patency.

As persisting parts of the mesotendon, Vinculum breve and Vinculum longum are known to serve as transport and conduction pathways to the intravaginal segments of flexor tendons. For morphological evaluation of their constancy, they were dissected out of, measured, and histologically examined on the 2nd-5th fingers in 53 hands of donated cadavers. The Vincula brevia existed in all cases more or less in association with the insertion of the superficialis as well as profundus flexor tendon, meanwhile the Vincula longa varied in number from 0 to 3 per tendon from one finger to the others, even 4 in the case of the index superficialis tendon. Light microscopic investigation of vascular patency was carried out on semithin resin sections of 137 Vincula longa obtained from the flexor superficialis and profundus tendons of 53 index fingers. Up to 5 or more arterial and venous vessels were counted per Vinculum longum. The complete absence of a patent artery was recognized in 6 out of 62 Vincula longa of the flexor superficialis and in 22 out of 75 of the profundus flexor. Most frequently, the Vincula longa had a single artery and a single vein. Considering the constant presence of vessels on the cross section, the Vinculum breve is regarded as essential for maintaining the tendons at work. In contrast, the significance of Vinculum longum will be variable for the microcirculation of intravaginal segments of the flexor tendons individually and also in the course of aging.

Adult↗
PubMed1976

Factors influencing postoperative vascular patency.

In summary, we have briefly examined the pathogenesis of arterial thrombosis, the importance of vessel wall injury and alteration of blood flow in this process, and finally the rationale for use of various agents in an attempt to promote postoperative vascular patency. At present, as in the past, the most important factor toward ensuring patency after arterial reconstruction is a technically perfect operation which allows vigorous inflow and runoff and rapid linear flow (25).

Blood Vessels↗
PubMed1988

Vascular patency of fibular free graft: assessment by Doppler color-flow imager: a case report.

Viability of a vascularized free fibula transfer can be difficult to establish. It is possible, however, to assess patency of the involved microvascular anastomoses and blood flow in the vessels of the transposed fibula. A Doppler color-flow imager can be used to evaluate blood flow and vascular patency. The imager potentially can be employed in the operating room, during the immediate postoperative period, and for long term follow-up. It is non-invasive and produces a permanent record of vascular anatomy and flow characteristics.

Adolescent↗
PubMed1994

Failure of thrombolytic therapy to improve long-term vascular patency.

PURPOSE: Few data are available on long-term follow-up of arterial segments subjected to thrombolysis. We reviewed all cases of vascular occlusion treated with urokinase to identify early success and determine the influence of postlysis intervention and the nature of the thrombosed segment (i.e., artery vs graft) on long-term patency. METHODS: Data on 134 cases (58 arteries, 76 grafts) treated with high-dose urokinase infusion in the lower limbs over a 7-year period were analyzed. Limbs were divided into five groups on the basis of therapy after lytic infusion to determine long-term efficacy: group I, success with no additional therapy; group II, percutaneous angioplasty alone; group III, limited surgical procedure (operative angioplasty, jump graft); group IV, extensive procedure (new bypass); and group V, revascularization after lytic failure. Long-term results were assessed by life-table analysis and groups compared by log-rank test (Mantel-Haenszel). RESULTS: Initial patency was established in 87 (64.9%) of 134 cases with 5 deaths (3.7%), 11 amputations (8.2%), and 16 complications (11.9%). Follow-up was available in 68.6% of cases for a mean of 10.9 months. No difference was seen between grafts and native arteries. Patency was analyzed at 6, 12, 18, and 24 months. The 24-month patency rate after lysis alone (group I-25.9%) was inferior (p < 0.05) to results after lysis and any subsequent intervention (groups II, III, and IV). The type of intervention did not influence subsequent patency. Twenty-four-month patency of procedures performed after failed thrombolysis (group V, 41.4%) was not different from those after successful lysis (groups I to IV). Twenty-four-month patency in groups II and III (minor interventions, 62.9%) was not significantly different from that of groups IV and V (major interventions, 53.2%) (p > 0.25). CONCLUSIONS: Operative intervention is required to produce long-term arterial patency, even after successful thrombolysis. No statistically significant benefit of thrombolysis on vascular patency was seen in our series.

Angioplasty↗
PubMed1993

The determination of dual pancreatic and renal transplant graft vascular patency with Tc-99m HMPAO.

Combined pancreatic-renal transplants promise the restoration of physiologic control of serum glucose and normal renal function. As pancreatic transplantation becomes more common, there is an increased need for rapid, noninvasive evaluation of vascular graft patency and function. Pancreatic transplants share the renal transplant's complications of ischemia at harvest but are at greater risk. Tc-99m HMPAO is a lipophilic complex that clears rapidly from the blood after intravenous injection, and tissue accumulation is proportional to regional perfusion. Using Tc-99m HMPAO to monitor the vascular competency has the advantage of a high count rate during dynamic scintigrams but, in contrast to Tc-99m DTPA, has excellent delayed static images. Four patients who received combined cadaveric pancreatic-renal transplants and had a total of eight Tc-99m HMPAO scintigraphic examinations were reviewed.

Adult↗
PubMed1998

Effect of GR144053, a fibrinogen-receptor antagonist, on thrombus formation and vascular patency after thrombolysis by tPA in the injured carotid artery of the hamster.

The antithrombotic effect of GR144053, which inhibits platelet aggregation by binding to the fibrinogen receptor (glycoprotein IIb/IIIa), was investigated in vitro and in vivo by using hamsters. This compound inhibited the platelet aggregation induced by adenosine diphosphate (ADP; 2.5 microM) with a mean inhibitory concentration (IC50) value of 2.2 +/- 0.4 x 10(-5) M. Vascular injury was inflicted in one carotid artery by using a modified catheter to produce endothelial denudation. In the control group, arterial blood flow was interrupted 4.4 +/- 2.3 min (n = 12) after the injury. When GR144053 continuously infused intravenously at doses of 0 (saline) 0.1, 0.3, and 1.0 mg/kg/h (n = 8, each), the time that elapsed before the vessel became completely obstructed was prolonged in a dose-dependent manner. In separate experiments, reperfusion could be obtained by continuous infusion of tissue-type plasminogen activator (tPA; 0.52 mg/kg) starting 30 min after the initiation of thrombus formation. When GR144053 (0.3 and 1.0 mg/kg/h) was infused in addition to tPA, the incidence of reperfusion and the later patency of the reperfused artery were much improved as compared with tPA alone. The bleeding time at the end of tPA infusion was significantly prolonged in the presence of the highest dose of GR144053. Next, neointima formation was evaluated 2 weeks after the vascular injury. When GR144053 (0.3 mg/kg/h) was continuously infused i.v. by an implanted osmotic pump for 14 days, the neointimal area was significantly reduced. In separate hamsters, the proliferating index of smooth muscle cells (SMCs) by using bromodeoxyuridine (BrdU) was investigated, and treatment with both tPA and GR144053 significantly decreased the SMC proliferation index in vivo. However, in the in vitro experiments using a hamster SMC line, GR144053 did not have an inhibitory effect on SMC proliferation. These findings suggest that GR144053 inhibits platelet activation on the injured artery and improves vascular patency after thrombolysis with tPA, which furthermore results in suppression of neointima formation.

Animals↗
PubMed1999

A method to evaluate microcirculatory vascular patency of full thickness burn in an animal model.

BACKGROUND: In cases of thermal injuries it is always difficult to predict the extent of necrosis to the peripheral ischemic zone. Practically, full-thickness skin burn also affects the underlying muscle, panniculus carnosus, which adheres tightly to the skin. In this proposed model, the muscle which was always partly damaged also covers the ischemic zone of full-thickness burn injury. To evaluate the deeper levels of injury, the status of the micro circulation of thermally affected muscle was evaluated by counting the accumulated radioactive agent, 99mTc methoxyisobutylisonitril (MIBI) in the muscle cells. METHODS: 370 MBq/kg (10 mCi/kg) MIBI was administered intravenously to the animals having burn injuries by a comb device as described in previous literature. Then, 20 minutes after injection, whole burned areas were excised and placed under a gamma camera. Each thermally injured area showed four rectangular defects with lower tracer uptakes than the three adjacent interspaces. The tracer uptake of the burned sites and interspaces was analyzed from the acquired images on a computer, and the degree of injury could be assessed quantitatively. Additionally, specimen counts were obtained from selected burned stripes, interspaces and normal tissue for comparison. RESULTS: Burned sites were evident with lower tracer uptakes whereas interspaces with higher uptakes. Captured activity in interspaces indicated that capillary patency mostly maintained and it permitted the arrival of the radiopharmaceutical to the muscle cells. CONCLUSIONS: Muscle layer, where just below the burn area and tightly attached to the skin, could be assessed as a representative of the extension of the injury.

Animals↗
PubMed1992

Effects of vapiprost, a novel thromboxane receptor antagonist, on thrombus formation and vascular patency after thrombolysis by tissue-type plasminogen activator.

1. A thrombus was induced in the rat femoral artery by endothelial damage due to the photochemical reaction between systemically-injected Rose Bengal and transillumination with green light (wavelength: 540 nm). The artery of the control rat was completely occluded in 302.8 +/- 27.0 s after the initiation of the reaction. 2. Pretreatment with vapiprost (0.1, 0.3 and 1.0 mg kg-1, i.v., 5 min before the reaction) prolonged the time required to occlude the femoral artery in a dose-dependent manner. The efficacy of vapiprost on the time required for occlusion was over 10 times higher than that of aspirin which was administered 30 min before the reaction. 3. The thrombolytic effects of tissue-type plasminogen activator (tPA) on the established arterial thrombus in the presence and absence of vapiprost were also studied in the same model. When vapiprost (0.3 mg kg-1, i.v.) was administered just before tPA infusion (100 micrograms kg-1 min-1 for 30 min), the time required to reperfuse the occluded artery was reduced, the incidence of the reperfusion was increased and the arterial blood flow after reperfusion was improved. 4. When vapiprost (1.0 mg kg-1 daily p.o.) was administered for 1 week after the establishment of reperfusion by tPA combined with vapiprost, the patency of the reperfused artery was improved and the femoral arterial blood flow was better preserved than after treatment with only tPA. 5. These findings suggest that this thromboxane receptor antagonist may be a useful adjunct to anti-thrombotic therapy. The combination therapy with tPA may be more effective than treatment with tPA alone and provides greater protection against reocclusion after reperfusion.

Animals↗
PubMed2003

Plasminogen supports tumor growth through a fibrinogen-dependent mechanism linked to vascular patency.

The growth of Lewis lung carcinoma (LLC) was sustained in plasminogen-deficient mice when transplanted into the dorsal skin but was dramatically suppressed in another anatomic location, the footpad. This unanticipated negative effect of plasminogen deficiency on footpad tumor growth was entirely relieved by superimposing a deficit in fibrinogen. This finding was not simply an unusual feature of LLC tumors--T241 fibrosarcoma growth in the footpad was also restricted by plasminogen deficiency in a fibrinogen-dependent manner. The probable mechanistic basis for suppression of tumor growth was revealed through transmission electron microscopy studies of tumor tissues. Occlusive microvascular thrombi were commonplace within footpad tumors from plasminogen-deficient mice, whereas no such lesions were observed within either dorsal skin tumors from plasminogen-deficient mice or footpad tumors from mice that also lacked fibrinogen. The data infer that tumor growth in the footpad of plasminogen-deficient mice is compromised as a function of the formation and persistence of vaso-occlusive thrombi that limit tumor blood supply. These studies indicate that plasminogen and fibrinogen can serve as critical determinants of tumor growth, but their relative importance is dependent on the tumor microenvironment. Furthermore, these studies suggest that one target of plasmin(ogen) relevant to tumor progression in vivo is intravascular fibrin.

Animals↗
PubMed1987

Interventional radiology for restoration of vascular patency in the postoperative patient--case reports.

The postoperative patient may present with one or more of a variety of problems amenable to management by interventional radiologic techniques, which may be curative by themselves or may, in addition, require or allow successful surgical intervention. To optimize patient care, a good working relationship between the vascular surgeon and the interventional radiologist is essential. Consideration should be given to the patient's presenting signs and symptoms, the surgical history with its alteration of anatomy, the results of available noninvasive studies, and knowledge of various therapeutic alternatives. Vascular radiologic interventions include angioplasty, thrombolytic therapy, a combination of both angioplasty and thrombolysis, and newer techniques such as percutaneous valvectomy. In this report, examples of some of the experience at Indiana University are presented. Emphasis is placed on the appropriate approach to the patient.

Adult↗