Outcome after catheter-directed thrombolysis of occluded prosthetic femoropopliteal bypasses. A prospective study.

PURPOSE: To evaluate the outcome after catheter-directed thrombolysis of occluded femoropopliteal prosthetic bypasses with the distal anastomosis above the knee. MATERIAL AND METHODS: Twenty-one patients were included in this prospective study. End-hole catheters, a bolus dose and continuous infusion of recombinant tissue-plasminogen activator (rt-PA) were used, with a median total dose of 10 mg (range 7-20 mg). RESULTS: With an intra-thrombotic position of the catheter, total or subtotal lysis was obtained in 19 of 21 patients (90%). No serious complications occurred. In 9 patients, the stenoses were successfully treated with balloon angioplasty (PTA, n=5), local thrombectomy/extension of bypass (n=3), or with a new bypass (n=1). After a median observation time of 18 months (6-24), 5 patients had open bypass. Re-occlusion occurred in all (6/6) bypasses in which no flow-limiting lesion was discovered, in all (4/4) bypasses treated twice with thrombolysis, as well as in all bypasses in which stenoses had not been adequately treated (3/3). One bypass re-occluded immediately due to poor runoff. CONCLUSION: In the present study, 19/21 infra-inguinal prosthetic bypasses were successfully treated with catheter-directed thrombolysis. However, re-occlusion often took place, especially in bypasses without flow-limiting lesions. If re-occlusion occurs in a bypass in which no stenoses were revealed during the primary thrombolysis procedure, a second catheter-directed thrombolytic treatment does not seem to be warranted. Our results confirm that treatment of flow-limiting lesions is a prerequisite for maintaining patency.

Mechanics of intraventricular filling: study of LV early diastolic pressure gradients and flow velocities.

This study investigates mechanisms of left ventricular (LV) intracavitary flow during early, rapid filling. In eight coronary artery disease patients with normal LV ejection fraction we recorded simultaneous LV apical and outflow tract pressures and intraventricular flow velocities by color M-mode Doppler echocardiography. In five anesthetized dogs we also recorded left atrial pressure and LV volume by sonomicrometry. In patients, as the early diastolic mitral-to-apical filling wave arrived at the apex, we observed an apex-outflow tract pressure gradient of 3.5 +/- 0.3 mmHg (mean +/- SE). This pressure gradient correlated with peak early apex-to-outflow tract flow velocity (r = 0.75, P < 0.05). The gradient was reproduced in the dog model and decreased from 3.1 +/- 0.3 to 1.7 +/- 0.5 mmHg (P < 0.05) with caval constriction and increased to 4.2 +/- 0.5 mmHg (P < 0.001) with volume loading. The pressure gradient correlated with peak early transmitral flow (expressed as time derivative of LV volume; r = 0.95) and stroke volume (r = 0.97). In conclusion, arrival of the early LV filling wave at the apex was associated with a substantial pressure gradient between apex and outflow tract. The pressure gradient was sensitive to changes in preload and correlated strongly with peak early transmitral flow. The significance of this gradient for intraventricular flow propagation in the normal and the diseased heart remains to be determined.

[Intra-arterial thrombolysis in peripheral bypass and arterial occlusions. Results and predictive factors for thrombolysis]. / Intraarteriell trombolyse ved perifere bypass- og arterieokklusjoner. Resultater og prediktive faktorer for trombolyse.

The purpose of the study was to reveal the association between successful intra-arterial thrombolysis in peripheral arterial and graft occlusions and the following factors: sex, age, symptoms, duration of symptoms, length of occlusion, conduit type, runoff and catheter localisation. Forty-six patients were treated with continuous intra-arterial infusion of streptokinase. Twelve patients were given tissue plaminogen activator (tPA). In the streptokinase-group successful lysis was achieved in 27 of 46 patients (59%). A significant association was found between successful thrombolysis and good runoff (p < 0.01). Catheter position above the occlusion resulted in lysis in only 1 of 11 patients. Lysis was achieved in nine of 12 patients (75%) treated with tPA. In this study, good runoff and intrathrombotic infusion were almost prerequisites for obtaining a positive immediate outcome. Other factors were less important.

Factors predicting the outcome of intraarterial thrombolysis in peripheral arterial and graft occlusions.

PURPOSE: To determine the association between successful intraarterial thrombolysis and the following factors: sex, age, symptoms, duration of symptoms, length of occlusion, conduit type, runoff, and catheter localization. MATERIAL AND METHODS: Forty-six patients with acute or subacute occlusions of peripheral native arteries and grafts were treated with continuous intraarterial infusion of streptokinase or urokinase. A univariate chi-square test and logistic regression analysis were used. RESULTS: Successful lysis was achieved in 27 of 46 patients (59%). The logistic regression analysis revealed a significant association between successful thrombolysis and good runoff (p < 0.01). A catheter position above the occlusion resulted in lysis in only one of 11 patients. The variables rest pain and claudication were slightly significant (p = 0.07). None of the other variables were significant, but a trend toward a separate effect of duration of occlusion was found. CONCLUSION: Good runoff and intrathrombotic infusion are virtual necessities in obtaining a positive immediate outcome in peripheral arterial and graft occlusions. In our study, other factors were less important.

Branched renal calculi treated by percutaneous nephrolithotomy and extracorporeal shock waves.

Fifty-four renal staghorn calculi, 26 complete and 28 partial, were treated in 51 patients by percutaneous nephrolithotomy (PCN) in combination with extracorporeal shock wave lithotripsy (ESWL) when necessary. At an average time of observation of 11.1 months, 56% of the renal units were stone free. Twenty-two per cent had residual gravel of less than 2 mm in diameter and 15% contained residuals between 2 and 5 mm in diameter. Seven per cent of the kidneys had significant residual calculi. Additional endourological procedures were required in 13 cases. Complications were minimal and were all conservatively treated. PCN in combination with ESWL is an effective treatment of most branched renal calculi. The methods may be used repeatedly without increasing technical difficulty. The results compare well with open surgery.

Laser Doppler flux reappearance time (FRT) in patients with lower limb atherosclerosis and healthy controls.

Laser doppler flowmetry was used to examine the skin circulation in the lower limb during postischaemic reactive hyperaemia. Flux reappearance time (FRT), the time from tourniquet deflation to the start of the hyperaemic response, was determined from the recorded curves, and the aim of the study was to investigate whether FRT is dependent on total limb vascular resistance or to the resistance in a segment of the limb. FRT was first compared with the clinical situation of the examined subjects, and with the resting ankle blood pressure index (API). Controls had an immediate hyperaemic response (FRT less than or equal to 3 s), while patients with critical ischaemia had prolonged FRT (greater than 48 s). Among the claudicators there was no significant correlation between API or ankle blood pressure and FRT. When FRT was compared with angiography, all claudicators who only had significant atherosclerosis proximal to the tourniquet, had FRT values within the control range. Patients who only had distal atherosclerosis had prolonged values (greater than 15 s), indicating that FRT is independent of proximal atherosclerosis and reflects the vascular resistance in the arteries in the segment between the tourniquet and the measuring probe. This interpretation was supported by the reduction of pathologically prolonged FRT when the distance between the tourniquet and the measuring site was reduced. We conclude that FRT as measured by this technique seems to reflect the vascular resistance in the run off arteries distal to the tourniquet.

Measurements of common femoral artery flow velocity in the evaluation of aortoiliac atherosclerosis. Comparisons between pulsatility index, pressures measurements and pulse-volume recordings.

Blood flow velocity in the common femoral artery was measured in 52 limbs of 45 patients with radiologic signs of aortoiliac atherosclerosis. Group A limbs had significant obstruction of the aortoilac segment; group B had not. 'Significant' implied a transobstruction pressure gradient of greater than or equal to 10 mmHg at rest or greater than or equal to 20 mmHg after intra-arterial injection of papaverine. Pulse-volume recording (PVR) and non-invasive measurement of the common femoral artery pressure (FAP) were also performed. Pulsatility index (PI) less than 3.9 and PVR amplitude less than 13 mm indicated significant obstruction, whereas PI greater than 5.4 and PVR amplitude greater than 20 mm were observed only in limbs without significant pressure gradient across the aortoiliac segment. PI 3.9-5.4 and PVR amplitude 13-20 mm were found in both groups. FAP and flow velocity during reactive hyperemia did not adequately distinguish the two groups, because of value overlap. In assessing the hemodynamic significance of aortoiliac obstruction, PI and PVR in the common femoral artery may be useful supplements to clinical examination, but measurement of the pressure gradient across the aortoiliac obstruction before and after vasodilation probably is most reliable.

Water-soluble contrast media in radiography of small bowel obstruction. Comparison of ionic and non-ionic contrast media.

Fifty patients with possible gastrointestinal obstruction, referred for enteric follow-through examination, were randomized for a double-blind, parallel comparison of the hyperosmolar contrast medium Gastrografin and the low-osmolar Omnipaque. The result was that Omnipaque retained its radiographic density in the small bowel better than Gastrografin. Omnipaque was thus a better alternative than Gastrografin in follow-through examinations of intestinal obstruction. Also, 23 patients out of 28 with small bowel obstruction due to peritoneal adhesions, had spontaneous relief of symptoms during the observation period following contrast medium ingestion with no significant difference between the two media. This indicated that enteric follow-through procedures may have a therapeutic efficacy similar to the treatment of small bowel obstruction using nasogastric suction and gastrointestinal rest. Possible mechanisms for this action of the contrast media are discussed.

Hemodynamic effect of percutaneous transluminal angioplasty for lower limb atherosclerosis. A study based on pulsed Doppler ultrasound flowmetry.

Measurements of ankle pressure index (API) and arterial flow velocity including calculation of pulsatility index (PI) from the common femoral and pedal arteries were performed in 89 limbs of 75 patients before and after percutaneous transluminal angioplasty (PTA) (63 iliac and 26 femoropopliteal). A pulsed wave Doppler ultrasound flowmeter was used. An increase of API at rest of at least 0.15 or the absence of pressure drop after exercise following PTA was used as criteria for a hemodynamically successful angioplasty. In patients with hemodynamically successful PTA of an iliac obstruction PI increased from 4.2 to 8.6 (p less than 0.001); 91 per cent of these patients improved clinically. When iliac angioplasty was hemodynamically unsuccessful, PI remained unchanged; 11 per cent of these patients improved clinically. All limbs with hemodynamically successful PTA of a femoropopliteal obstruction improved clinically and PI increased from 3.1 to 8.7 (p less than 0.001). After hemodynamically unsuccessful femoropopliteal PTA, PI remained unchanged though 25 per cent of these patients improved clinically. These results illustrate that measurement of arterial flow velocity with calculation of PI may be a useful supplement for the functional evaluation of the effect of PTA, since symptomatic response alone may be unreliable.

The femoral arterial flow velocity pattern in patients with atherosclerotic obstruction of the femoropopliteal segment. A study based on pulsed Doppler ultrasound flowmetry.

The flow velocity pattern in the common femoral artery was analyzed in 107 limbs with femoropopliteal atherosclerotic obstruction and a normal aortoiliac segment. A pulsed wave Doppler ultrasound flowmeter was used. The highest (Va), the lowest (Vb) and the time average of the mean (V mean) velocities were obtained, and the pulsatility index (PI = Va-Vb/V mean) was calculated. In limbs with occluded (PI = 6.2) or greater than 50% stenotic (PI = 5.8) femoropopliteal segment, the flow velocity curve was slightly damped, with PI lower than in a control group (PI = 8.2). Neither stenosis of the profunda femoris artery nor the number of occluded leg arteries influenced the hemodynamic values in limbs with occluded femoropopliteal segment. Dampening of the femoral arterial flow velocity curve and reduced PI may indicate a stenotic (greater than 50%) or an occluded femoropopliteal segment. This flow pattern is also seen in aortoiliac atherosclerosis. In 76 limbs studied after femoropopliteal bypass, PI normalized when the bypass was patent, but was unchanged when the graft was occluded. Analysis of femoral arterial flow velocity pattern with calculation of PI may be useful in postoperative evaluation of femoropopliteal reconstruction.

The femoral arterial flow velocity pattern in patients with aortoiliac atherosclerosis. Studies with a pulsed Doppler ultrasound flowmeter.

The femoral arterial flow velocity pattern in 164 limbs with aortoiliac atherosclerosis was analyzed preoperatively, using a pulsed wave Doppler ultrasound flowmeter. Following aortoiliac reconstruction, 32 limbs were studied. The highest (Va), the lowest (Vb) and the time average of the mean velocities (V mean) were obtained, and pulsatility index (PI = Va-Vb/V mean) was calculated. The aortoiliac obstruction was radiologically graded as reduction in cross-sectional area (less than 25%, 25-50%, greater than 50%) or complete occlusion. With increasing grade of stenosis, progressive reduction of PI (from 7.6 to 2.1) was observed. PI differed according to degree of obstruction. In 30 extremities with clinical improvement after vascular reconstruction, PI showed significant postoperative rise (from 2.7 to 6.9). In the two limbs without clinical benefit of surgery, PI was largely unaffected. A monophasic, flattened curve of femoral arterial flow velocity and reduced PI may indicate aortoiliac atherosclerosis. Normalization of PI and biphasic curve following aortoiliac reconstruction suggest successful treatment.

Iohexol in phlebography of the leg. A comparative investigation with meglumine metrizoate.

Comparing iohexol 240 mg I/ml, iohexol 300 mg I/ml and meglumine-Ca metrizoate 200 mg I/ml in phlebography of the leg in patients on or without anticoagulants, no sign of postphlebographic thrombosis was found using the 125I-fibrinogen uptake test and repeat phlebography. More adverse reactions occurred with metrizoate than with iohexol. Metrizoate provided significantly poorer demonstration than the two iohexol concentrations with higher iodine content.

Iohexol in phlebography of the leg. A comparative investigation with meglumine metrizoate.

Comparing iohexol 240 mg I/ml, iohexol 300 mg I/ml and meglumine-Ca metrizoate 200 mg I/ml in phlebography of the leg in patients on or without anticoagulants, no sign of post-phlebographic thrombosis was found using the 125I-fibrinogen uptake test and repeat phlebography. More adverse reactions occurred with metrizoate than with iohexol. Metrizoate provided significantly poorer demonstration than the two iohexol concentrations with higher iodine content.

Ruptured Baker's cyst: a radiological diagnosis.

Rupture of a Baker's cyst may mimic thrombophlebitis of the leg clinically. Differentiation of these two entities is important because of therapeutic implications. A history of previous disease involving the knee, especially rheumatoid arthritis, or the finding of joint effusion are suggestive of the diagnosis of ruptured Baker's cyst. This may be confirmed by arthrography. We describe a series of eight patients with the "pseudothrombophlebitis" syndrome. Arthrography showed seven as having a ruptured Baker's cyst, while in one an intact cyst was found.