Ocular and orbital blood flow velocity in patients with peripheral vascular disease and diabetes treated with intravenous prostaglandin E1.

The purpose of this study was to evaluate the effect of intravenous prostaglandin E1 (PGE1) on the flow velocity of the ophthalmic artery and the central retinal artery in patients with peripheral vascular disease manifested by intermittent claudication. The flow velocity of these vessels is frequently decreased in vascular patients. Since these patients were already being treated with PGE1 for their intermittent claudication, the authors wanted to evaluate the effect on the flow velocity of the ocular vessels as well. A randomized 21-week study of two groups of vascular patients was performed. The first group had intermittent claudication. The second group had intermittent claudication and were also diabetics. Both groups were treated with intravenous PGE1 for their intermittent claudication. Using the color Doppler, the flow velocities of the ophthalmic artery and central retinal artery were measured before and after the intravenous treatment. Before treatment, the flow velocity of the ophthalmic artery and the central retinal artery was decreased when compared to that in the normals. After treatment, there was a significant increase in the systolic and diastolic phases of the flow velocity in both arteries. The systolic flow velocity increased by as much as 40%, and the diastolic flow velocity increased by as much as 80%. The flow velocities of the ophthalmic artery and the central retinal artery are frequently decreased in certain ocular diseases, and this decreased flow may contribute to the ocular pathology. If intravenous PGE1 is able to increase the flow velocity of these vessels in patients with peripheral vascular disease, it is possible that it is also able to increase the flow velocity of these vessels in patients with ocular disease as well. Intravenous PGE1 may prove to be a useful adjunct therapy in eyes when ischemia is part of the pathology.

Ocular and retrobulbar blood flow in ocular hypertensives treated with topical timolol, betaxolol and carteolol.

The purpose of this study was to evaluate the effect of topical timolol 0.5%, betaxolol 0.5% and carteolol 2% on the blood flow velocity of the central retinal artery (CRA), the posterior ciliary artery (PCA) and the ophthalmic artery (OA) in patients with ocular hypertension. A group of 14 patients with ocular hypertension and a group of 11 normals were studied. The color Doppler was used to measure the peak systolic flow velocity (PSFV) and the end diastolic flow velocity (EDFV) of the CRA, the PCA and the OA in the normals and in the patients. The normals were under no treatment, while the patients were studied before and after treatment with topical timolol 0.5%, betaxolol 0.5% and carteolol 2%. In the systolic phase, there was a significant increase in the flow velocity of the CRA with all three drugs. In the diastolic phase of the CRA, the increase was significant for timolol 0.5% and carteolol 2% but not for betaxolol 0.5%. The flow velocity of the PCA and OA remained unchanged. In this study of 14 patients with ocular hypertension, topical timolol 0.5%, betaxolol 0.5% and carteolol 2% led to a significant increase in the flow velocity of the CRA without creating a steal or decrease in the flow velocity of the PCA.

Ocular and orbital blood flow in cigarette smokers.

OBJECTIVE: To report the effect of cigarette smoking on the blood flow velocity of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery (PCA) in patients who smoke at least 20 cigarettes a day. METHODS: The color duplex scanner was used to measure the systolic and diastolic flow velocity of the OA, CRA, and PCA in 10 smokers and 11 nonsmokers. RESULTS: Both the systolic and diastolic flow velocity decreased in the OA, CRA, and PCA in smokers compared with nonsmokers. The systolic flow decreased by as much as 36% and the diastolic flow by as much as 52%. This decrease was significant for the flow velocity of the CRA and PCA but not for the OA. An increase in the resistance index was also found. CONCLUSION: The authors believe that the decrease in the flow velocity of these vessels may be due to an increase in the vascular resistance of the vessels of the retina and optic nerve head in smokers. This may be important in patients with eye disease in whom altered blood flow already contributes to the ocular or orbital pathology.

Ocular and orbital blood flow in patients with essential hypertension treated with trandolapril.

PURPOSE: To study the effect of essential hypertension on flow velocity in the central retinal (CRA) and posterior ciliary arteries (PCA). Flow velocity was also evaluated in these arteries in patients with hypertension treated with trandolapril, an oral angiotensin-converting enzyme inhibitor. METHODS: Using the duplex scanner, flow velocity of the CRA and PCA was measured in 12 medication-free patients with hypertension and 10 normal controls. The hypertensive patients were then treated with oral trandolapril, 1 mg/day for 1 week. After 1 week of treatment, flow velocity was again measured in the arteries of the patients with hypertension. RESULTS: There was a significant reduction in systolic and diastolic flow velocity of the vessels tested in the medication-free hypertensive patients when compared with those in the normal controls. In controls, the CRA had a peak systolic flow velocity (PSFV) of 34 cm/sec and an end diastolic flow velocity (EDFV) of 14 cm/sec; the PCA had a PSFV of 38 cm/sec and an EDFV of 16 cm/sec. In the hypertensive patients off medication, the CRA had a PSFV of 16 cm/sec and an EDFV of 6 cm/sec; the PCA had a PSFV of 17 cm/sec and an EDFV of 5 cm/sec. The diastolic component also was significantly decreased in the patients with hypertension. Flow velocity significantly increased in the hypertensive patients treated with trandolapril for 1 week, but did not reach the level of flow measured in normal controls. CONCLUSION: The decreased flow velocity in hypertensive patients may result from a peripheral vasospasm in the vessels of the eye and orbit. This decreased flow velocity may be important in eyes that already have ocular disease. Improvement in flow velocity was noted with oral trandolapril but it did not reach the levels seen in normal controls.

Doppler ultrasonography of the central retinal artery by duplex scanning.

PURPOSE: To present duplex scanning of the central retinal artery, which the authors have termed duplex scanner imaging, as an alternative to color Doppler imaging in the evaluation of retinal blood flow velocity, and to show the difference in measurements obtained with the two different techniques. METHODS: The high-resolution ATL-Ultramark 4 duplex scanner (Advanced Technology Laboratories, Bothell, WA) with the variable focus access probe was used to measure blood flow velocity of the central retinal artery in the eyes of 48 healthy volunteers. RESULTS: Using this technique the peak systolic flow velocity (+/- standard deviation [SD]) of the central retinal artery was 36.6 +/- 10.8 cm/sec, and the end diastolic flow velocity was 12.6 +/- 3.7 cm/sec. CONCLUSION: The flow velocity measurements of the central retinal artery obtained with this technique were much higher than those obtained by other authors using color Doppler imaging (9.6 cm/sec for the peak systolic flow velocity, and 4.7 cm/sec for the end diastolic flow velocity). The authors propose duplex scanner imaging as an alternative to color Doppler imaging for evaluating retinal blood flow velocity. The duplex scanner also can be used to measure the flow velocity of orbital vessels.

Acute effects of intermittent sequential compression in venous hypertension.

Chronic venous hypertension produces microangiopathy which often progresses to ulceration. It has been recently observed that intermittent sequential compression (ISC) increases the rate of healing of venous ulcers. The aim of this study was to investigate the effect of this form of therapy on the microcirculation in limbs with venous hypertension. Skin blood flow at rest (RF) was measured by laser Doppler flowmetry at the perimalleolar region at rest (horizontal position) and on standing in 34 limbs with chronic venous hypertension (17 with ulcerations) and 20 limbs of healthy volunteers. The venoarteriolar response (VAR = the vasoconstrictory response on standing) was also measured. Also 8 limbs with venous hypertension not treated with ISC were studied to evaluate the effects of supine resting alone on the microcirculation. Two treatment protocols were used. In Study 1 intermittent sequential compression was applied for 30 minutes. Laser-Doppler measurements were performed at time 0 (before intermittent sequential compression) and after 30, 60 and 90 minutes. In Study 2 intermittent sequential compression was applied for 60 minutes and measurements were performed at time 0 and after 60 and 120 and 180 minutes. In patients of Study 1 RF was 1.45 +/- 0.8, significantly higher than in normals (p < 0.05) and the venoarteriolar response only 7%, significantly lower than in normals. At the end of the compression period there was a marked change towards normality as RF decreased (1.1 +/- 0.2) while the change in venoarteriolar response was not significant. At 60 and 90 minutes the changes in RF were still significant (p < 0.05) and the VAR was significantly increased (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Microcirculation in systemic hypertension.

In 40 patients with idiopathic systemic hypertension, skin blood flow was evaluated with laser-Doppler flowmetry, transcutaneous measurements of partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2), and determination of capillary permeability before and after treatment with nifedipine (10 mg tid for four weeks). Also 35 normal subjects matched for age and sex distribution were studied. Before treatment, microcirculatory studies showed a significant decrease in skin flow and venoarteriolar response in hypertensive patients in comparison with normal subjects. Moreover, PO2, PCO2, and capillary permeability were significantly lower in hypertensives. All these microcirculatory parameters significantly increased after nifedipine treatment while both systolic and diastolic pressures decreased. In conclusion, laser-Doppler flowmetry used with other microcirculatory techniques was able to discriminate between normal subjects and hypertensive patients, and it was able to show the improvement in the microcirculation after nifedipine treatment.

Colour duplex scanning and phlebography in deep vein thrombosis.

Clinical evaluation of deep venous thrombosis is often unreliable. Recently it has been shown that deep venous thrombosis may be detected with colour duplex scanning which is safer than phlebography. However it is not clear how colour duplex correlates with phlebography. One hundred and twenty consecutive patients with suspected deep vein thrombosis were studied by colour duplex scanning and phlebography to compare the two methods. Both tests were positive in 102 limbs and negative in 16 limbs. In two cases of below-knee thrombosis colour duplex was negative while phlebography showed small localised thrombosis. The sensitivity of colour duplex was 98%, its specificity and positive predictive value 100% and its negative predictive value 88.8%. In conclusion colour duplex appears to be as effective as phlebography in detecting deep venous thrombosis above knee.

Improvement of capillary permeability in patients with venous hypertension after treatment with TTFCA.

The VSC (vacuum suction chamber) device, a new system to evaluate local capillary permeability, was used with laser Doppler flowmetry to study variations of permeability and of the microcirculation in 10 normal subjects; in 22 patients with moderate, superficial venous hypertension; and in 12 patients with postphlebitic limbs and severe venous hypertension. All these patients had distal (ankle and foot edema) in the evening. After a first assessment these subjects were studied again after two weeks without treatment and after two weeks' treatment with total triterpenic fraction of centella asiatica (TTFCA), tablets, 60 mg, tid. The VSC produces a wheal on the skin of the perimalleolar region that disappears (in average) in less than sixty minutes in normal subjects. The disappearance time (DT) is greater in conditions of increased capillary filtration and permeability. The three groups of subjects (normal and those with superficial and severe venous hypertension) had significantly different, increasing disappearance time of the wheals at the first observation. There were no significant changes after two weeks' observation, but after 2 weeks' treatment with TTFCA, there was a significant decrease of DT both in limbs with superficial and with deep venous incompetence. The improvement (decrease) of the abnormally increased capillary permeability was associated with a significant improvement of the microcirculation and symptoms (studied by an analogue scale line). In conclusion this study showed a combined improvement of the microcirculation and capillary permeability after treatment with TTFCA and the possibility of using the VSC to evaluate the effects of drugs (or other treatment) on local capillary permeability in patients with venous hypertension.

Capillary filtration and ankle edema in patients with venous hypertension treated with TTFCA.

The variation of capillary filtration rate (CFR), ankle circumference (AC), and ankle edema (AE) was evaluated in three groups of patients with venous hypertension (ambulatory venous pressure greater than 42 mmHg) and in a group of normal subjects before and after treatment for four weeks with Total Triterpenic fraction of Centella Asiatica (TTFCA), a venoactive drug acting on the microcirculation and on capillary permeability. Group A (20 patients) was treated with TTFCA 60 mg tid; Group B (20 patients) was treated with 30 mg tid; Group C (12 patients) was treated with placebo; and Group D (10 normal subjects) was treated with TTFCA 60 mg tid in an open study. Capillary filtration rate was assessed by venous occlusion plethysmography, ankle edema by a new system called AECT (Ankle edema coin tester). Subjective symptoms of venous hypertension were assessed by an analogue scale line considering four symptoms: swelling sensation, restless lower extremity, pain and cramps, and tiredness. CFR, AC, and AE were significantly higher in patients in comparison with normal subjects. After four weeks of TTFCA treatment there was a significant decrease of the abnormally increased CFR, AC, and AECT time in patients. This was also greater in the higher dose group. No significant change was observed in the placebo group and in normal subjects treated with TTFCA. Symptoms were also significantly improved in the two groups treated with the active drug according to the dose. No significant changes were observed in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Plication of the sapheno-femoral junction. An alternative to ligation?

Plication of the long saphenous vein at the sapheno-femoral junction (SFJ) is an interesting alternative to flush ligation and stripping in superficial venous incompetence. This technique abolishes venous reflux at the SFJ without altering the vein which may be useful for peripheral arterial surgery or coronary artery bypass grafting. The selection of the ideal candidate for plication must be done by ambulatory venous pressure measurements, Doppler and duplex scanning which indicate and quantify the superficial vein incompetence. The plication of the SFJ reduces the calibre of the vein to 60%-70% of its calibre for a length of 1.5 cm allowing the valve cusps to close when flow in the femoral vein is reversed (i.e. by Valsalva manoeuvre). In this series of ten patients, evaluated 6 months after plication of the SFJ, venous reflux was significantly reduced (at Doppler and duplex examination and ambulatory venous pressure measurements) and the improvement of haemodynamic data was associated with improvement of symptoms. In conclusion, considering these data, SFJ plication is an effective physiological alternative to flush ligation but long term results must be evaluated before using it for the treatment of incompetence of the long saphenous vein.