Biomedical subjects

K Ouriel

Publications and source records attributed to K Ouriel.

At least 91 records · Page 5Linked to original sources

PubMed1995

Operative management of coexistent aortic disease and horseshoe kidney.

The presence of horseshoe kidney in conjunction with abdominal aortic disease significantly increases the technical difficulty of aortic reconstruction. Preservation of the renal blood supply and collecting system during the surgical procedure is the goal of operative management. The pertinent issues that remain unresolved include the need for specific preoperative studies, the optimal operative approach and the safety of isthmus division. From 1979 to 1994 eight patients with horseshoe kidney underwent operative intervention for aortic disease. Five men and three women who had a mean age of 66 years underwent seven reconstructions for aneurysmal disease and one for aortoiliac occlusive disease. All operations were elective and the transperitoneal approach was used in all cases. In the patients with aneurysmal disease the mean maximal aortic diameter was 7.3 cm. The mean preoperative serum creatinine value was 1.1 mg/dl. Preoperative identification of horseshoe kidney was accomplished in all seven patients with aneurysmal disease but not in the patient with occlusive disease. The anomaly was correctly identified by CT scan in seven of seven (100%) patients, arteriography in two of eight (25%) patients, ultrasonography in two of seven (29%) patients, and renal scan in one patient. In the three patients who underwent intravenous pyelography (IVP) the caliceal system was demonstrated to be completely separate from the isthmus. Renal artery anomalies were present in six (75%) patients; in three (50%) these anomalies could be not visualized on the preoperative arteriogram. Renal revascularization was accomplished by a variety of techniques, including reimplantation of multiple (one patient) and single (four patients) renal arteries and branch grafting to an individual renal artery (one patient).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Differential mechanisms of failure of autogenous and non-autogenous bypass conduits: an assessment following successful graft thrombolysis.

The advent of graft thrombolysis has provided an objective means for evaluating the etiology of graft occlusion. Over a 10-year period, intra-arterial urokinase (102 cases) or streptokinase (seven cases) was used in 109 infrainguinal conduits (30 autogenous and 79 non-autogenous) that failed 30 days or more after implantation. Thrombolysis was not achieved in 19 additional graft occlusions; these cases were excluded from study because of an inability to define the mechanism of failure. Non-invasive laboratory data were available within 6 months of graft occlusion in 82 (75%) of the cases, with Doppler segmental studies in 80 cases (73%) and duplex ultrasonography studies in 39 cases (36%). Pre-failure non-invasive laboratory abnormalities were detected more frequently in autogenous grafts (21 of 24 patients, 88%), while non-autogenous grafts usually occluded without prior hemodynamic change (11 of 58 patients had abnormalities, 19%) (P < 0.001). Thrombolysis uncovered anatomic defects responsible for thrombosis in 27 (90%) of 30 autogenous grafts compared with only 32 (41%) of non-autogenous conduits (P < 0.001). The most common lesions underlying autogenous graft failure comprised stenoses within the body of the graft (11 cases, 37%), while the most common lesions in failed non-autogenous grafts appeared to be stenoses at an anastomosis (21 cases, 27%). Thus, the mechanisms underlying the late failure of autogenous and non-autogenous grafts differ markedly; autogenous grafts most commonly fail as a result of the gradual development of lesions intrinsic to the graft, while non-autogenous grafts fail precipitously, presumably as a result of some non-anatomic mechanism.

Adult↗

PubMed1995

Long QT syndrome: an indication for cervicothoracic sympathectomy.

Beta-blockade represents the primary treatment modality in patients with long QT syndrome, but left cervicothoracic sympathectomy (LCS) has been employed in refractory cases and in cases with malignant arrhythmias. LCS was performed in ten patients (six male, four female) with long QT syndrome, ranging in age from 1 month to 40 years (median 15 years). Familial long QT syndrome was present in seven patients (70%). The mean(s.e.m.) (range) preoperative corrected QT interval (QTc) was 0.52(0.01) (0.46-0.60)s. The mean(s.e.m.) duration of symptoms was 4.4(1.1) years with a mean(s.e.m.) of 4.1(0.9) syncopal episodes and 1.2(0.2) cardiac arrests per patient. LCS was carried out for refractory symptoms on beta-blockers in nine cases; a single patient was unable to tolerate beta-blockers and LCS represented the primary treatment modality. A left supraclavicular approach was utilized in each patient, resecting a portion of the stellate and all of the T2 and T3 ganglia. The median(range) length of hospitalization following operation was 2(2-6) days. There were no unexpected complications of operation, although nine (90%) of the patients developed Horner's syndrome. The QTc decreased a mean(s.e.m.) of 0.03(0.01)s following operation (P < 0.01). The frequency of symptomatic episodes decreased from a mean(s.e.m.) of 7.1(3.1)/year before LCS to 0.1(0.1) after operation (P < 0.001). Patients have been followed for a mean of 1.3(0.3) years, and all but one patient remains symptom-free; the youngest patient died suddenly 10 months after surgery. These results suggest that LCS is associated with significant clinical benefits in patients with long QT syndrome and the procedure should be considered when symptoms are refractory and malignant, or when contraindications to beta-blockers are present.

Adolescent↗

PubMed1995

Thrombus formation on polytetrafluoroethylene surfaces: the importance of von Willebrand factor.

The importance of von Willebrand factor (vWf) in the formation of platelet-fibrin thrombi on expanded polytetrafluoroethylene (ePTFE) surfaces was studied in an in vitro system, perfusing non-anticoagulated human blood over ePTFE grafts for 3 min at varying shear rates (100, 500 and 1500/s shear). Platelet (111In) and fibrin (125I) deposition was assessed on ePTFE surfaces in the presence and relative absence of vWf, achieved by use of polyclonal anti-vWf antibody (anti-vWf Ab). A total of 29 perfusions were performed. Increasing shear rate was associated with greater platelet deposition in the presence of vWf (p < 0.001). This shear-dependent rise in platelet deposition was not observed when vWf was blocked by anti-vWf Ab (P < 0.1), confirming the role of vWf in platelet deposition at high shear rates. Fibrin deposition increased with increasing shear rate in the presence of vWf (P < 0.01). Inhibiting vWf abolished the shear-dependent increase in fibrin deposition. These data suggest that vWf plays a critical role in platelet and fibrin thrombus formation on ePTFE surfaces. These effects are particularly important under conditions of high shear rate. These mechanisms may lead to the observed pathologic thrombus formation and platelet-dependent neointimal processes occurring at areas of high shear rate within the anastomotic regions of ePTFE grafts.

Blood Platelets↗

PubMed1995

Appropriate frequency of carotid duplex testing following carotid endarterectomy.

BACKGROUND: The value of carotid duplex analysis is well proven for the diagnosis of carotid bifurcation occlusive disease, but its use in the postoperative setting is less well defined. PATIENTS AND METHODS: A series of 281 carotid endarterectomies were performed in 222 patients. A protocol of serial duplex examinations was established, with tests performed at the time of the first postoperative clinic visit and every 6 months thereafter. The goal of postoperative surveillance was to identify critical restenotic carotid lesions of greater than 80% diameter reduction and determine the incidence of subsequent carotid occlusion and neurologic events. RESULTS: Critical restenoses developed in 25 (8.9%) of the arteries and occlusions occurred in 12 (4%). Restenosis occurred with greatest frequency during the first year after operation (5%), but continued to develop with a frequency of approximately 2% per year thereafter. Postoperative carotid occlusions occurred at a rate of approximately 1% per year. Known restenotic lesions progressed to occlusion over a mean duration of 11 months. Stroke was infrequent in patients with critical restenoses (4%) until the lesions progressed to occlusion (33%). CONCLUSIONS: These observations suggest that a protocol of semiannual duplex testing into the late postoperative period may identify critical carotid restenotic lesions prior to the development of carotid occlusion and stroke.

Adult↗

PubMed1995

Economic implications of thrombolysis or operation as the initial treatment modality in acute peripheral arterial occlusion.

BACKGROUND: Thrombolytic agents have been used to treat arterial occlusion for almost 40 years. Recently, an investigation of the costs associated with two treatment options for acute peripheral arterial occlusions, thrombolysis and surgical intervention, was completed. The availability of hospital cost data for patients enrolled in the thrombolytic and operative treatment groups provided a basis with which to accurately assess the financial impact of the different treatment strategies, both from a purely financial standpoint and in relation to outcome. METHODS: The patient base was composed of 114 patients with acute limb ischemia of less than 7 days' duration. The patients were randomly assigned to receive urokinase (n = 57) or to undergo an operation (n = 57) as the initial therapeutic intervention. Patients in the thrombolytic group underwent standard intraarterial diagnostic arteriography, and patients with embolic events, in whom complete lysis of all embolic and propagated thrombotic material was achieved, were subsequently treated with heparin and long-term warfarin (Coumadin) therapy. The economic analysis was undertaken after the completion of the trial. Statistical comparisons between groups were made with the Student t test for continuous, normally distributed data. Mortality and limb salvage rates were calculated from Kaplan-Meier curves, appropriate for the censored nature of the data. RESULTS: The total treatment costs did not differ significantly between the two treatment groups ($22,171 +/- $4,959 in the thrombolytic group and $19,775 +/- $5,253 in the operative group). The total hospital charges were similar between the two groups. Overall, the total charges were remarkably similar between the two treatment groups, averaging $40,823 +/- $8,764 in the thrombolytic group and $41,930 +/- $10,398 in the operative group. CONCLUSIONS: An economic analysis of the data confirmed that the total economic impact of thrombolysis approximated that of initial operative therapy. The improved clinical outcome in patients treated with thrombolysis suggests that this modality may be appropriate as the initial therapeutic intervention in the select group of patients seen within the first few hours of an acute peripheral arterial occlusive event.

Acute Disease↗

PubMed1995

Thrombolysis in the treatment of lower extremity occlusive disease.

The development of new thrombolytic agents and increased experience in the use of these drugs has enhanced limb salvage, especially in patients who have undergone multiple lower extremity bypass procedures. This article reviews the indications for such therapy and critically assesses both complications and efficacy of treatment.

Arterial Occlusive Diseases↗

PubMed1995

Comparison of streptokinase, urokinase, and recombinant tissue plasminogen activator in an in vitro model of venous thrombolysis.

PURPOSE: Presumed differences in the thrombolytic activity and fibrinolytic specificity of the three commonly used thrombolytic agents, streptokinase, urokinase, and recombinant tissue plasminogen activator (rt-PA), are based on clinical study results, where variability renders meaningful comparisons difficult. An in vitro model of catheter-directed venous thrombolysis was used to compare the three agents. METHODS: Retracted iodine 125-radiolabeled clots that simulate those observed in the venous system were infused with thrombolytic agents at doses analogous to those used clinically. Perfusion with heparinized, whole human blood was undertaken for 60 minutes, measuring the efficacy of thrombolysis through serial quantification of radio tracer released into the circuit. Fibrinolytic specificity was determined by following decrements in perfusate fibrinogen concentration. RESULTS: Streptokinase was the agent associated with the slowest rate of clot lysis (p = 0.01 vs urokinase and rt-PA). Urokinase was associated with an intermediate rate of lysis but appeared to be the agent with the greatest degree of fibrinolytic specificity (p = 0.02 vs streptokinase, p = 0.05 vs rt-PA). Although rt-PA was associated with improved efficacy early in the perfusions, the differences between rt-PA and urokinase dissipated after 30 minutes. CONCLUSIONS: These laboratory observations suggest that urokinase may be the most appropriate agent for catheter-directed venous thrombolysis, offering an advantageous compromise between fibrinolytic specificity and thrombolytic speed.

Analysis of Variance↗

PubMed1995

Outpatient echocardiography as a predictor of perioperative cardiac morbidity after peripheral vascular surgical procedures.

PURPOSE: A variety of preoperative provocative tests have been used to define the risk of cardiac morbidity and mortality after peripheral vascular procedures, including dipyridamole myocardial scintigraphy and dobutamine stress echocardiography. Although highly sensitive, these tests are time-consuming and associated with significant expense. We investigated outpatient echocardiography as a less resource-intensive means of assessing cardiac risk with operation. METHODS: Over a 2-year period 250 consecutive patients underwent outpatient transthoracic echocardiography before elective peripheral vascular operation was performed. The accuracy of the Goldman, Detsky, and the American Society of Anesthesiologists' Physical Status Classification clinical indexes of cardiac risk were assessed with regard to the development of cardiac complications such as unstable angina, myocardial infarction, life-threatening ventricular arrhythmias, severe congestive heart failure, and cardiogenic shock. The accuracy of echocardiographically determined left ventricular ejection fraction was determined at threshold values between 20% and 60%. RESULTS: Perioperative cardiac events developed in 23 (9.2%) of the patients, and nine (3.6%) of the patients died as a result of these complications. Clinical indexes lacked sensitivity in the preoperative prediction of cardiac complications. Receiver operating curve analysis defined a left ventricular ejection fraction of less than 50% as an appropriate threshold for defining patients at high risk, with a sensitivity of 78% and a specificity of 81% in the identification of patients who had cardiac morbidity. The positive predictive value was 27%, and the negative predictive value was 97%. The economic impact of outpatient echocardiography was well below that of dipyridamole myocardial scintigraphy or dobutamine stress echocardiography. CONCLUSIONS: Outpatient echocardiography appears to offer a cost-efficient compromise between clinical criteria alone and provocative cardiac testing such as dipyridamole myocardial scintigraphy and dobutamine stress echocardiography in the preoperative screening of patients undergoing peripheral vascular surgical procedures.

Adult↗

PubMed1995

Atherosclerosis of the lower extremity and free-tissue reconstruction for limb salvage.

Atherosclerosis of the lower extremity frequently leads to limb-threatening ischemic soft-tissue wounds. Over the past 44 months, 30 selected patients with arterial disease documented by angiography were treated with combined vascular reconstruction and free-tissue transfer for limb salvage. Soft-tissue defects occurred on the plantar and dorsal surfaces of the foot and distal tibia with significant bone, tendon, or joint exposure. Thirteen patients had osteomyelitis. Eighteen patients underwent simultaneous soft-tissue and vascular reconstruction, while 12 patients underwent delayed soft-tissue reconstruction. The free-flap tissues included the rectus abdominis flap in 13, the latissimus dorsi flap in 7, the radial forearm flap in 5, the scapular flap in 3, and the omentum flap in 2. Autogenous venous bypass was performed to the popliteal segment in 6 patients and the infrapopliteal arteries in 18. Five patients had inadequate outflow for complete vascular reconstruction and were treated with proximal vein grafts directed into the free flap. Twenty-two patients (73 percent) had successful free-tissue transfer and bypass graft patency and were independent ambulators over the mean follow-up period of 22 months. Of the 8 unsuccessful reconstructions, 3 patients had early free-flap and graft failure. Five patients developed new areas of ischemic disease despite graft and flap patency. All 8 patients were treated with amputation; 7 never regained ambulation. The combined application of vascular and free-flap soft-tissue reconstruction for the threatened ischemic lower extremity has produced excellent functional results in the majority of our patients.

Adult↗

PubMed1994

Thrombolysis in acute peripheral arterial occlusion: predictors of immediate success.

Thrombolytic therapy is frequently used for the treatment of peripheral arterial occlusion, but clinical predictors of success have not yet been defined. We prospectively evaluated 80 consecutive patients receiving intra-arterial urokinase for acute (< 14 days) ischemia. Fifty-five patients (69%) were treated for bypass graft occlusion and 25 patients (31%) for native arterial occlusion. Two primary outcome measures were evaluated using multivariate techniques (stepwise logistic regression) to determine the independent predictors of immediate arteriographic success: successful (> 80%) thrombolysis and avoidance of adjuvant operative or endovascular procedures. Independent variables examined included age, sex, comorbid conditions, severity, duration, etiology and location of the ischemic process, and positioning of the infusion catheter and guidewire. Overall, successful lysis was achieved in 57 patients (71%) and adjuvant procedures were avoided in 22 patients (28%). Successful outcome was more frequent in prosthetic graft (78%) and native arterial (72%) occlusions than in vein graft occlusions (53%, p = 0.017) and in nondiabetics than in diabetics (80% vs. 52%, p = 0.031). Lysis was dependent on placement of the catheter into the substance of the thrombus (85% vs. 0% success, p = 0.004) and passage of a guidewire through the occlusive process (92% vs. 10% success, p = 0.001). The only parameter independently predictive of successful outcome without the use of adjuvant procedures was the location of the occlusion; additional procedures were necessary in 88% of aortoiliac and 82% of infrainguinal occlusions vs. only 17% of upper extremity occlusions (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1994

Infrarenal aortic aneurysm structure: implications for transfemoral repair.

PURPOSE: The structure of infrarenal aortic aneurysm was studied as a basis for design of a transfemoral system of aneurysm repair. This information was particularly important because endovascular techniques, unlike conventional techniques, afford little opportunity for intraoperative adjustments. METHODS: Three-dimensional computer reconstructions of the distal aorta, the renal arteries, the aneurysm and the iliac arteries were generated from computed tomography scanning data in 22 patients with aortic aneurysms. RESULTS: The proximal neck of the aneurysm was longer than 20 mm in 14 patients, and the mean length (of all 22) was 26.7 +/- 4.1 mm. In contrast, only one patient had a distal cuff longer than 20 mm and 14 of the others had no measurable distal cuff. The mean distal cuff length (of all 22) was 4.2 +/- 1.6 mm. There was no significant difference between mean aneurysm diameter in the anteroposterior direction (58.0 +/- 3.2 mm) and the transverse direction (56.4 +/- 3.3 mm), although corresponding values in individual patients were often different. Aneurysm diameter correlated with aneurysm length (r = 0.79, p < 0.001). The proximal right common iliac artery deviated from the axis of the distal aorta by 40.0 +/- 5.8 degrees, whereas the left deviated by 47.8 +/- 5.4 degrees. One of the iliac arteries deviated by more than 45 degrees in 12 cases. Eleven common iliac arteries in seven patients were aneurysmal. Fifteen patients had no aneurysm of the common iliac arteries, and another three had segments of nondilated common iliac artery distal to iliac aneurysms on both sides. CONCLUSIONS: Computerized three-dimensional reconstruction facilitated interpretation of anatomic information from computed tomography scans, particularly the length of the aneurysm neck and shape of the iliac arteries. On the basis of this information, we expect that few patients will have too short an aneurysm neck for endovascular aneurysm repair, but many will require a bifurcated graft for secure, hemostatic implantation distally.

Aortic Aneurysm, Abdominal↗

PubMed1994

Use of the activated coagulation time and heparin dose-response curve for the determination of protamine dosage in vascular surgery.

The activated coagulation time (ACT) can be used to construct a two-point heparin dose-response curve (HDRC) from the ACT values at baseline and 5 minutes after heparin administration. The ACT value at any subsequent time interval can then be used to estimate the residual heparin activity from the HDRC. The protamine dose is calculated to be the amount of residual heparin multiplied by a correction factor (1.3 was suggested for cardiac surgery). In vascular surgery, heparin and protamine dosing remain empirical, ACT monitoring is not standard, and use of the HDRC has not been previously investigated. Forty-five patients were prospectively randomized to one of three groups. ACT was measured before heparinization (1 mg/kg, 1 mg = 100 U), 5 minutes later, and then every 30 minutes until just prior to and after protamine administration. Group I received 1 mg/kg of protamine. In Groups II and III the residual heparin activity was interpolated from the HDRC and multiplied by 1.3 or 1.0, respectively, to derive the protamine dosage. Randomization created balanced groups with respect to demographic data. The individual peak effect of heparin ranged from 177% to 401% of control. The ACT returned to control after protamine in all groups. The protamine dose was significantly less when the HDRC was used (P < 0.05). Group III received the least protamine (0.64 +/- 0.07 mg/kg, P < 0.05). No adverse protamine reactions or postoperative bleeding occurred. It is concluded that ACT monitoring and use of the HDRC provides a safe and easy method to individualize protamine dosage in vascular surgery.

Adult↗

PubMed1994

Plasminogen acceleration of urokinase thrombolysis.

PURPOSE: A relative deficiency of plasminogen within the thrombus may be the rate limiting factor in clot lysis. METHODS: To investigate this hypothesis, we used an in vitro perfusion system and expanded polytetrafluoroethylene graft segments filled with radiolabeled human thrombus. Three groups of five perfusions were compared: (1) urokinase infusion (333 IU/min) into clots laced with buffer, (2) urokinase infusion (333 IU/min) into clots laced with plasminogen (44 CU), and (3) control, D5W infusion into clots laced with buffer. Two end points were measured over time: the amount of lysed thrombus and the flow through the graft. RESULTS: Urokinase infusion resulted in augmented flow through the graft when compared with control (p < 0.05). Lacing with plasminogen resulted in more rapid restoration of flow when compared with urokinase infusion alone (p < 0.05). Similarly, the rate of clot dissolution was significantly greater in plasminogen-laced thrombi (p < 0.05) when compared with the control and urokinase groups. Embolization of particles of thrombus was uniformly observed in the urokinase group, resulting in a temporary decrease in flow through the thrombosed graft. This event characteristically occurred after 60 minutes of infusion but was never seen in the urokinase/plasminogen treatment group. CONCLUSIONS: These results suggest that plasminogen supplementation of urokinase thrombolysis may result in significant clinical benefits with respect to the rate of clot lysis and the uniformity of clot dissolution with a lower likelihood of secondary embolization.

Analysis of Variance↗

PubMed1994

The posterior approach to popliteal-crural bypass.

PURPOSE: An evaluation of the posterior approach to popliteal-crural bypass was performed to assess the feasibility and results of this technique. METHODS: A posterior approach to the popliteal and crural vessels was performed in 21 patients in the prone position over a 24-month period, with use of lesser saphenous vein and a novel exposure of the crural arteries through the vein harvest incision. RESULTS: Diabetes mellitus was present in 17 (81%) patients, and all had limb-threatening ischemia with rest pain (15 patients, 71%), ulceration (7 patients, 33%), and gangrene (8 patients, 38%). The inflow site was the supragenicular popliteal artery in four patients (19%) and the infragenicular popliteal artery in 17 patients (81%). The outflow sites were the tibioperoneal trunk in six patients (29%), the peroneal artery in nine patients (43%), the posterior tibial artery in four patients (19%), and the anterior tibial artery in two patients (10%). The distal anastomosis was performed in the proximal one third of the crural artery in 16 (76%) of the patients, with a mean lesser saphenous vein graft length of 11.2 +/- 1.7 cm. The toe-brachial pressure indexes rose from 0.20 +/- 0.07 to 0.77 +/- 0.16 (p = 0.001), all wounds healed without complication, and 19 patients (90%) were discharged with open bypass grafts and salvaged extremities. The 6-, 12-, and 18-month primary graft patency rates were 88%, 88%, and 83%, respectively (Kaplan-Meier methods). CONCLUSIONS: Thus the posterior approach to infragenicular occlusive disease represents a durable alternative to traditional approaches; sparing the greater saphenous vein, facilitating exposure of the proximal crural arteries, and minimizing the wound healing problems commonly experienced with standard techniques.

Aged↗

PubMed1994

A comparison of thrombolytic therapy with operative revascularization in the initial treatment of acute peripheral arterial ischemia.

PURPOSE: Despite the widespread use of intraarterial thrombolytic therapy for peripheral arterial occlusive disease, a randomized study comparing its efficacy with that of operative intervention has never been performed. This study evaluates the potential of intraarterial urokinase infusion to provide clinical benefits in patients with acute peripheral arterial occlusion. METHODS: Patients with limb-threatening ischemia of less than 7 days' duration were randomly assigned to intraarterial catheter-directed urokinase therapy or operative intervention. Anatomic lesions unmasked by thrombolysis were treated with balloon dilation or operation. The primary end points of the study were limb salvage and survival. RESULTS: A total of 57 patients were randomized to the thrombolytic therapy group, and 57 patients were randomized to the operative therapy group. Thrombolytic therapy resulted in dissolution of the occluding thrombus in 40 (70%) patients. Although the cumulative limb salvage rate was similar in the two treatment groups (82% at 12 months), the cumulative survival rate was significantly improved in patients randomized to the thrombolysis group (84% vs 58% at 12 months, p = 0.01). The mortality differences seemed to be primarily attributable to an increased frequency of in-hospital cardiopulmonary complications in the operative treatment group (49% vs 16%, p = 0.001). The benefits of thrombolysis were achieved without significant differences in the duration of hospitalization (median 11 days) and with only modest increases in hospital cost in the thrombolytic treatment arm (median $15,672 vs $12,253, p = 0.02). CONCLUSIONS: Intraarterial thrombolytic therapy was associated with a reduction in the incidence of in-hospital cardiopulmonary complications and a corresponding increase in patient survival rates. These benefits were achieved without an appreciable increase in the duration of hospitalization and with only modest increases in hospital cost, suggesting that thrombolytic therapy may offer a safe and effective alternative to operation in the initial treatment of patients diagnosed with acute limb-threatening peripheral arterial occlusion.

Acute Disease↗

PubMed1994

Acute peripheral arterial occlusion: predictors of success in catheter-directed thrombolytic therapy.

PURPOSE: To determine predictors of clot dissolution in patients undergoing catheter-directed urokinase thrombolysis for peripheral arterial occlusion (PAO). MATERIALS AND METHODS: The study included 103 patients with limb-threatening symptoms of embolism lasting 14 days or less and resulting from embolism (n = 20) or thrombosis (n = 83). Successful lysis was defined as restitution of antegrade flow with less than 20% diameter reduction by residual thrombus. Stepwise logistic regression was used to analyze the data. RESULTS: Relevant clinical variables were diabetic status (odds ratio, 0.75; P = .04 for diabetic patients), conduit type (1.25; P = .04 for native artery and 1.51; P = .02 for prosthetic graft), and number of arterial segments involved (1.60; P = .02 for one level and 1.42; P = .03 for two levels). Important procedural variables included intrathrombus positioning of catheter ports (odds ratio, 7.40; P = .001) and guide wire passage through the occlusion (3.10; P = .003). Absolute thrombus volume was nonpredictive but correlated with reperfusion time (P = .02) and infusion time (P = .01). CONCLUSION: Predictive parameters may help in the selection of candidates with PAO for thrombolytic therapy.

Acute Disease↗

PubMed1994

Thrombolytic therapy for acute arterial occlusion.

The standard treatment of peripheral arterial occlusion has been operative, employing embolectomy, thrombectomy, or bypass grafting to restore blood flow to the compromised extremity. Intra-arterial thrombolysis has been advocated as an initial intervention designed to unmask the anatomic lesion responsible for the occlusive event, with a directed or endovascular modality thereafter. Four thrombolytic agents are in clinical use: streptokinase, urokinase, recombinant tissue plasminogen activator, and acylated plasminogen streptokinase activator complex. The agents differ with respect to efficacy of thrombolysis, fibrin specificity, and cost. At present, urokinase is the most widely used. Recent randomized clinical trials suggest a benefit of thrombolytic therapy in the initial management of acute peripheral arterial occlusion, with improved patient survival and similar amputation rates compared with immediate open intervention. Each modality has its place in specific patient subcategories; the determination of which patients are best served by a specific modality awaits the results of large clinical trials.

Angiography↗