Progress in the investigation of chronic venous insufficiency.
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Blood Flow Velocity↗
Biomedical subjects
D Christopoulos
Publications and source records attributed to D Christopoulos.
Skin flow and swelling in post-phlebitic limbs.
It has been demonstrated that skin blood flow of postphlebitic limbs is increased. Also the venoarteriolar response (VAR), i.e. precapillary vasoconstriction present in normal limbs on standing up, is reduced in limbs with venous insufficiency, resulting in capillary hypertension. The supine skin resting flow (SF) and the skin flow on standing (SF) have been measured with laser-Doppler in 30 normal lower limbs and 70 postphlebitic limbs with ambulatory venous pressure greater than 65 mmHg; also, the rate of ankle swelling (RAS) has been measured with strain-gauge plethysmography. The VAR was derived from VAR = 100* (RF-SF)/RF. The reduction of VAR and the increase in SF, which has been demonstrated in the postphlebitic limbs, correlated well with the rate of ankle swelling (RAS). The measurements of SF, VAR and RAS evaluate objectively the degree of impairment of the microcirculation because of severe venous disease. They offer the possibility to study the natural history and the effect of treatment of venous hypertensive microangiopathy.
Adult↗
Pathogenesis of venous ulceration in relation to the calf muscle pump function.
Air plethysmography has been used to quantitate venous reflux by measuring the average filling rate of the veins (venous filling index; in milliliters per second) on standing from the supine position, the ejection fraction of the calf muscle pump as a result of one tip-toe movement, and the residual volume fraction after 10 tip-toe movements. Thirty normal limbs, 110 limbs with primary varicose veins, 34 limbs with reflux in the deep veins but without occlusion, and 31 limbs with deep venous occlusion, with or without reflux, have been studied. An increase in the incidence of ulceration occurred with increasing values of reflux and decreasing values of the calf muscle pump ejection fraction. A poor ejection fraction was the primary cause of venous ulceration in limbs with minimal reflux. A good ejection fraction, however, significantly reduced the incidence of ulceration in limbs with marked reflux (p less than 0.05). The residual volume fraction, which expresses the combined effect of venous reflux and ejection fraction with rhythmic exercise, showed a good correlation with the incidence of ulceration and the measurements of ambulatory venous pressure (r = 0.81). The air-plethysmographic measurements completely assess the calf muscle pump function and provide an accurate method to identify the predominant hemodynamic factor (ejection fraction, reflux, or both) responsible for the clinical picture of the patient.
Adult↗
A perioperative technique for detection of retained valve cusps in the in situ vein graft.
A problem of the in situ vein bypass technique is the retained value cusp. To ensure that maximum flow has been obtained through the vein graft after valvotomy, a simple perioperative technique has been developed. This consists of infusing normal saline solution into the vein and comparing the distal to proximal (antegrade) flow with the proximal to distal (retrograde) flow under the same conditions. Twelve consecutive in situ vein grafts have been assessed. Antegrade and retrograde flow measurements were similar in four of the grafts but different in eight (40% to 80% reduced retrograde flow). Valvotomy was repeated and subsequent measurements of retrograde flow were similar or greater than the antegrade. The technique described is simple, reproducible, inexpensive, and may prove useful for routine intraoperative evaluation of valvotomy of in situ vein grafts.
Aged↗
Venous reflux: quantification and correlation with the clinical severity of chronic venous disease.
Air-plethysmography has been used to measure, in ml and in ml 100 ml-1 of tissue, the blood volume that filled the leg veins on changing posture from the recumbent position to standing. The venous filling index (VFI) (average filling range) was measured in ml s-1 and in ml 100 ml-1 min-1. We studied 24 normal legs (N), 21 with primary varicose veins without chronic swelling, skin changes (liposclerosis, eczema, pigmentation) or ulceration (PVV) and 59 with chronic swelling and/or skin changes and/or ulceration; of these 59 legs, 31 had primary varicose veins (PVV/S) and 28 had popliteal reflux (PR). The classification was done according to clinical examination, Duplex scanning, ambulatory venous pressure measurements and venography. There was an increased incidence of sequelae with increasing values of VFI. The incidence of these sequelae was irrespective of whether reflux was in the deep or in the superficial veins. VFI is a practical non-invasive measurement of reflux. It should be used to study the effect of therapy and particularly to evaluate new reconstructive procedures designed to abolish reflux in the deep veins.
Adult↗
Objective noninvasive evaluation of venous surgical results.
The hemodynamic effect of conventional surgery for varicose veins has been evaluated with a new method of air-plethysmography. The functional venous volume of the leg, venous reflux, and calf muscle pump-ejecting capacity have been measured in 42 legs with primary varicose veins. The patients were studied clinically, with Doppler ultrasound, duplex scanning, and phlebography preoperatively. Doppler ultrasound was repeated postoperatively. Air-plethysmography was performed one day before surgery and 8 to 10 days after surgery. A decrease of the functional venous volume of 16% has been observed (p less than 0.001). The abolition of venous reflux has been shown in all the patients. An improvement in the calf muscle pump-ejecting capacity has also been shown, with a 30% increase of the ejection fraction of the calf muscle pump and with a 43% decrease of the residual volume fraction after 10 tiptoe movements (p less than 0.001). The results indicate that this new method of air-plethysmography apart from its diagnostic value offers a new and unique technique for a noninvasive, objective, and quantitative evaluation of the results of established and experimental venous surgery.
Adult↗
Total parenteral nutrition by intraperitoneal feeding in rabbits.
The possibility of intraperitoneal (IP) parenteral nutrition was suggested after the observation that glucose and amino acids pass from the peritoneal cavity into the systemic circulation. We used rabbits to study the characteristics of the transfer of glucose, lipids and amino acids. An IP injection of glucose 25% (1 g/kg) produced a peak level in the serum within 40 min. A 20% fat solution (1 g/kg) showed maximum serum levels of triglycerides and total lipid in 2.5 h, while a standard amino acid solution (1.5 g/kg) enriched with 25 14C-phenylalanine peaked serum levels in 16 min. The 4 rabbits survived for 28 days with IP glucose, amino acids and lipids as the only form of nutrition, apart from water. When sacrificed after 28 days histology of peritoneum, liver, spleen, gut and kidney showed no abnormality. We conclude that the basic nutritional components are adequately absorbed through the peritoneum, and that long-term nutritional support can be achieved uneventfully with IP administration of nutritional solutions.
Absorption↗
Duplex scanning in the assessment of deep venous incompetence.
A noninvasive method to evaluate deep venous incompetence by duplex scanning is presented. For this test, it was decided to have the patient standing so as to make the test less dependent on the need for patient cooperation and to allow gravity to produce reflux. Results were validated against ambulatory venous pressure measurements. The method described had a sensitivity of 84% and specificity of 88%. Duplex scanning is a useful screening test for detecting the presence and site of incompetence in patients with deep venous disease.
Humans↗
Congenital diverticula of the sigmoid colon.
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Child, Preschool↗
'On-line' alterations of contralateral jugular blood gas profile during carotid clamping.
The aim of this work was to record the metabolic status of the brain (pH, PCO(2) and PO(2)) during carotid endarterectomy (CEA), with the use of an intravascular multiparameter sensor (Paratrend 7) via retrograde catheterization of the contralateral jugular vein. Twenty-four patients with ASA grades II and III scheduled for CEA were included in the study. After induction of anesthesia, the contralateral internal jugular vein was punctured retrogradely and the sensor was introduced. During clamping, pH became persistently more acidotic (7.34-7.31; p < 0.05), PCO(2) was elevated (43.2-46.8 mm Hg; p < 0.05) while most of the patients showed a non-significant decrease in PjvO(2)/SjvO(2) (jv = jugular venous). Correlation with clamping time or stump pressure was not significant. Unclamping was followed by a short period (5- 9 min) of decrease in pH and elevation of PCO(2) (7.30-7.22; p < 0.05, and 48.0-52.5 mm Hg; p < 0.05, respectively). PjvO(2) was significantly elevated (51.8-58.0 mm Hg; p < 0.001) after the restoration of flow. The study suggests that local CO(2) creates conditions for compensation of flow after the application of a carotid clamp. We consider that this monitoring technique, after further validation, may provide useful information.
Aged↗
'Real' epidemiology of varicose veins and chronic venous diseases: the San Valentino Vascular Screening Project.
The aim of this study was to evaluate the prevalence and incidence of venous diseases and the role of concomitant/risk factors for varicose veins (VV) or chronic venous insufficiency (CVI). The study was based in San Valentino in Central Italy and was a real whole-population study. The study included 30,000 subjects in eight villages/towns evaluated with clinical assessment and duplex scanning. The global prevalence of VV was 7%; for CVI, the prevalence was 0.86% with 0.48% of ulcers. Incidence (new cases per year) was 0.22% for VV and 0.18% for CVI; 34% of patients with venous disease had never been seen or evaluated. The distribution of VV and CVI in comparison with duplex-detected incompetence (DI) indicates that 12% of subjects had only VV (no DI), 2% had DI but no VV, 7.5% had DI associated with VV, 2% apparent CVI without DI, 3% DI only (without CVI), and 1.6% both CVI and DI. VV associated with DI are rapidly progressive and CVI associated with DI often progresses to ulceration (22% in 6 years). VV without significant DI (3%) and venous dilatation without DI tend to remain at the same stage without progression for a lengthy time. New cases per year appear to have a greater increase in the working population (particularly CVI) possibly as a consequence of trauma during the working period. In older age (>80 years), the incidence of CVI tends to decrease. Ulcers increase in number with age. Only 22% of ulcers can be defined as venous (due to venous hypertension, increased ambulatory venous pressure, shorter refilling time, obstruction and DI). Medical advice for VV or CVI is requested in 164 subjects of 1,000 in the population. In 39 of 1,000, there is a problem but no medical advice is requested and in only 61 of 1,000, the venous problem is real. In VV in 78% of limbs, there is only reflux, in 8% only obstruction, and in 14% both. In CVI, 58% of limbs have reflux, 23% obstruction, and 19% both. In conclusion, VV and CVI are more common with increasing age. The increase with age is linear. There was no important difference between males and females. These results are the basis for future real, whole population studies to evaluate VV and CVI.
Adolescent↗
Foam-sclerotherapy, surgery, sclerotherapy, and combined treatment for varicose veins: a 10-year, prospective, randomized, controlled, trial (VEDICO trial).
The study compared, by a prospective, randomized method, 6 treatment options: A: Sclerotherapy; B: High-dose sclerotherapy; C: Multiple ligations; D: Stab avulsion; E: Foam-sclerotherapy; F: Surgery (ligation) followed by sclerotherapy. Results were analyzed 10 years after inclusion and initial treatment. Endpoints of the study were variations in ambulatory venous pressure (AVP), refilling time (RT), presence of duplex-reflux, and number of recurrent or new incompetent venous sites. The number of patients, limbs, and treated venous segments were comparable in the 6 treatment groups, also comparable for age and sex distribution. The occurrence of new varicose veins at 5 years varied from 34% for group F (surgery + sclero) and ligation (C) to 44% for the foam + sclero group (E) and 48% for group A (dose 1 sclero). At 10 years the occurrence of new veins varied from 37% in F to 56% in A. At inclusion AVP was comparable in the different groups. At 10 years the decrease in AVP and the increase in RT (indicating decrease in reflux), was generally comparable in the different groups. Also at 10 years the number of new points of major incompetence was comparable in all treatment groups. These results indicate that, when correctly performed, all treatments may be similarly effective. "Standard," low-dose sclerotherapy appears to be less effective than high-dose sclero and foam-sclerotherapy which may obtain, in selected subjects, results comparable to surgery.
Adult↗
Prevention of venous thromboembolism. European Consensus Statement, 1-5 November 1991, developed at Oakley Court Hotel, Windsor, UK.
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Humans↗
[Non-invasive evaluation of venous obstruction. Reflux and function of the muscular mass of the calf with air plethysmography].
An study about the use of Air Plethysmography on venous occlusions is presented. Also, a comparison between Plethysmography and others non-invasive methods was made.
Air↗
Natural history of chronic bilateral internal carotid artery occlusion.
Chronic bilateral ICA occlusion was found in 15 of 3200 patients studied with duplex scanning during a six years period. Ten of these patients had a history of stroke. Mean follow-up was 28.9 months. Six patients died during follow-up, coexisting cardiac ischaemia being the major cause of death. Two patients suffered a stroke (one fatal) resulting in an annual stroke rate of 5.5%, three patients continued to have TIAs and 5 remained asymptomatic. Chronic bilateral ICA occlusion is not always associated with neurological deficit. Coronary ischaemia, more than stroke is the leading cause of death in these patients.
Adult↗
["Determination of venous hemodynamics". Contribution of air plethysmography].
Plethysmographic techniques based on the variation of a parameter linked to venous stasis, have permitted an approach to venous hemodynamics. The use of a new technique of air-plethysmography, which cold be quantified in volume variation, and permitting to study the progression of the venous stasis from a static as well as a dynamic standpoint, enable us to better assess the overall venous function. The first results obtained in healthy patients, are presented and the advantages of this new technique are discussed.
Humans↗
Evaluation of the effects of elastic compression in patients with postphlebitic limbs by laser-Doppler flowmetry.
Laser-Doppler flowmetry has been used to study the skin microcirculation in 20 normal limbs and 80 limbs of patients with venous hypertension and leg ulceration due to deep venous reflux. It was found that limbs with venous hypertension had a high skin resting blood flow (BRF) and an impaired veno-arteriolar reflex (VR). There was a marked improvement in both BRF and VR after elastic compression for three weeks and an association between this improvement and the rate of healing of the leg ulcers. The results indicate that elastic compression may affect the microcirculation even though it does not alter the venous pressure measurements when the elastic stockings are removed.
Adult↗
Noninvasive diagnosis and quantitation of popliteal reflux in the swollen and ulcerated leg.
Air-plethysmography was used to study 25 normal legs (N), 25 legs with primary varicose veins (PVV) without sequelae of venous disease (chronic swelling, skin changes, ulceration), 32 legs with primary varicose veins with sequelae of venous disease (PVV/S) and 32 legs with reflux in the popliteal vein (PR). The blood volume that filled the leg veins on standing from recumbent position (venous volume [VV]) in ml and the time needed for 90% filling of the veins (venous filling time [VFT90]), in seconds were measured. The ratio 90% of VV/VFT90 was defined as venous filling index (VFI) in ml/sec. VFI is a measurement of reflux. The measurements were repeated with a 2.5 cm wide tourniquet (T) placed at the knee level to occlude the superficial veins only. The method, apart from its diagnostic accuracy, can measure reflux separately in the superficial and the deep venous system and has indicated that the magnitude of reflux is related to chronic swelling and ulceration of the leg, irrespective of whether it is in the superficial or deep system.
Adult↗