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Biomedical subjects

M Depairon

Publications and source records attributed to M Depairon.

33 records · Page 2Linked to original sources
PubMed1996

[Value of Doppler ultrasonic studies in the diagnosis of deep venous thrombosis of the lower limbs].

To compare the operating characteristics of the venous echo-doppler and that of venous phlebography in our setting, 90 consecutive patients admitted on suspicion of deep vein thrombosis of one leg underwent both examinations. Phlebography confirmed the diagnosis in 46 patients (51%). The sensitivity, specificity, and positive and negative predictive values of the echo-doppler were 91, 92, 94 and 90% respectively. For the subgroup of patients with proximal deep vein thrombosis, these values were 97, 97, 97 and 97%, respectively; for the subgroup with distal deep vein thrombosis, these values were 60, 95, 75 and 90%, respectively. This study confirms the excellent performance of the venous echo-doppler for the diagnosis of deep vein thrombosis of the leg in our hospital. However, in the subgroup of patients with distal deep vein thrombosis, only the sensitivity of the venous echo-doppler is relatively low and the diagnosis may still require color echo-doppler or phlebography.

Diagnosis, Differential↗
PubMed1996

The quantitation of blood flow/metabolism coupling at rest and after exercise in peripheral arterial insufficiency, using PET and 15-0 labeled tracers.

Regional blood flow and oxygen uptake of the lower limbs were studied in 11 patients with arterial insufficiency (10 with severe unilateral, 1 with bilateral intermittent claudication). Regional muscle blood flow (F), oxygen consumption rate (R), and oxygen extraction fraction (E) were evaluated by positron emission tomography (PET) and bolus inhalation of C15O2 and 15O2 by the patient. Tomograms were recorded at the greatest diameter of legs, at rest and ten minutes after a treadmill walk test leading to the development of ischemic pain in the affected leg. In 5 patients, F and E were correlated with the results of occlusive venous strain gauge plethysmography and with the measurements of blood gases in one brachial artery and in the femoral vein of the affected limb. Blood flow values measured at rest and after exercise by PET were poorly correlated with the plethysmographic findings. This may be because PET does not interfere with flow as venous occlusion plethysmography does in low peripheral pressure conditions. The results show that F, R, and E were not significantly different in normal and pathologic legs at rest. The values of F and R were significantly higher in pathologic than in normal lower limbs, ten minutes after exercise, whereas E was not significantly altered by exercise at any side. This suggests that, during the recovery from a walk test, the delayed increase in oxygen uptake is proportional to the delayed hyperemia in the ischemic muscles ("oxygen debt") and probably not linked to a luxury perfusion.

Aged↗
PubMed1992

[Hypothenar hammer syndrome: little-known etiology of secondary Raynaud's phenomenon].

Hypothenar hammer syndrome is an uncommonly encountered cause of Raynaud's phenomenon associated with professional or recreational activities. We report 6 consecutive cases seen in our angiology unit between 1988 and 1990. Clinical findings include a history of repeated microtraumatisms of the dominant hand, male sex, unilaterality, sudden onset, and severe Raynaud's phenomenon of the last three fingers. Investigations reveal an aneurysm or thrombosis of the distal cubital artery or of the superficial palmar branch, associated with occlusion of digital arteries. Avoidance of the aggravating conditions or resection and/or plasty of the affected vascular segment usually leads to disappearance of the symptoms.

Adult↗
PubMed1992

Prognostic significance of nailfold capillary microscopy in patients with Raynaud's phenomenon and scleroderma-pattern abnormalities. A six-year follow-up study.

The aim of this study was to assess the prognostic significance of scleroderma capillary pattern (SD-pattern) in patients with Raynaud's phenomenon. Thirty patients with a capillaroscopy examination suggestive of scleroderma (megacapillaries and/or avascularity) but without clinical criteria of scleroderma (ARA criteria) were reevaluated 6 years after the initial clinical and capillaroscopy examinations. SD-pattern abnormalities were classified according to a semiquantitative method. Eight out of the 28 evaluated patients (28%) developed a scleroderma spectrum disorder (SDS). The presence of avascularity and/or a mean of more than two megacapillaries digit greatly enhanced the percentage of evolution toward SDS (70%/88% respectively). Most of the patients with few enlarged capillaries and no capillary rarefaction at entry had primary acrocyanosis (11/15). None of them developed SDS. The microangiopathy disappeared during the follow-up period in most of these patients (14/15). These results confirm the prognostic value of SD-pattern capillary abnormalities for SDS. Primary acrocyanosis, a benign clinical entity should be considered in presence of few megacapillaries and without capillary rarefaction.

Aged↗
PubMed1992

Assessment of acute and old deep venous thrombosis in upper extremity by venous strain gauge plethysmography.

The purposes of this study were to evaluate the efficiency of occlusion strain gauge plethysmography in the diagnosis of symptomatic deep venous thrombosis in upper extremities, to compare early (one month) and late clinical evolution (many years) to plethysmography data and, finally, to set up normal and pathological values. Four groups of patients were tested. Sixteen patients with confirmed acute thrombosis, 6 patients with unconfirmed thrombosis, 15 with an old thrombosis (mean follow-up: 7 years) as well as 15 healthy volunteers. The outflows measurements were significantly lowered (p less than 0.05) in the arms with acute thrombosis compared to the contralateral arms, to the affected arms of patients with thrombosis excluded and to both volunteers' arms. Pathological values for the different outflow parameters could be defined as follows: Maximum venous output less than 110 ml/100 ml/minute, Outflow after 3 seconds less than 1.2 ml/100 ml, Strandness index less than 0.16. On month after the acute episode we found a good correlation between the usually favourable clinical evolution and venous haemodynamics assessed by plethysmography. The mild late post-thrombotic syndrome of most patients with an old thrombosis was not well demonstrated by plethysmography.

Adult↗
PubMed1991

Assessment of flow and oxygen delivery to the lower extremity in arterial insufficiency: a PET-scan study comparison with other methods.

The authors studied muscular blood flow (F), oxygen consumption rate (R), and oxygen extraction fraction (E) in 5 patients suffering from severe intermittent claudication (stage II). They applied the bolus technique of H2150 and 1502 with a detection by positron emission tomography (PET). Tomograms were recorded at the greatest diameter of the calves, at rest and ten minutes after a treadmill walk test leading to the development of ischemic pain in the affected extremity. F and E data were compared with the values obtained by more usual methods, namely occlusive venous strain gauge plethysmography and femoral venous blood sampling. During the study, these patients received naftidrofuryl, a vasodilatator drug, in an intravenous dose of 600 mg diluted in 250 mL saline infused over a six-hour period in a placebo-controlled, double-blind, crossover protocol (two consecutive experiments, a week apart). The results showed that all blood flow values measured at rest and after exercise by PET were in close correlation (r = 0.71) with the plethysmographic findings. The agreement between the two methods of measuring blood flow was less obvious with an Altman's presentation of the data: there was a tendency to measure higher values with PET scan. Concerning E, the correlation was poor at rest. After exercise, the values were more elevated with PET and no correlation was found with blood samples. The authors found no significant effect of naftidrofuryl either on flow or metabolic data.

Double-Blind Method↗
PubMed1988

[Regional blood flow and oxygen consumption in the leg muscles of normal subjects and in those with arterial insufficiency. Study of the distribution of C15O2 and of 15O2 using positron emission tomography].

We first studied the distribution of radioactivity during continuous inhalation of C15O2 and 15O2 in traverse tomograms of the greatest diameter of legs, at rest and immediately after exercise (ankle flexions). C15O2 and 15O2 were distributed homogeneously and symmetrically in both legs of normal subjects at rest. The activity accumulated in the anterolateral region after exercise. In patients, this pattern of distribution was similar but asymmetrical, depending on the arterial pathology. No systematic distribution of either C15O2 or 15O2 was observed. In a second step, we studied quantitatively blood flow (F), oxygen uptake (R) and oxygen extraction (E) in 11 subjects: 5 normals (23 +/- 1 years) and 6 patients (60 +/- 11 years) suffering from unilateral intermittent claudication. We used the bolus inhalation technique of C15O2 and 15O2. In the normal leg at rest, ranges were 2.5 to 8.0 ml/min.hg for F, 0.9 to 21.3 mumol/min.hg for R and 3.6 to 33.4% for E. In the pathological leg at rest, ranges were 3.7 to 11.3 ml/min.hg for F, 3.8 to 10.6 mumol/min.hg for R and 7.1 to 24.5% for E. After exercise, ranges were 6.4 to 62.8 ml/min.hg for F, 66.0 to 386.3 mumol/min.hg for R and 29.2 to 89.5% for E in both legs. There was no straight difference between normal and pathological legs soon after exercise. This study allows us to expect that the demonstration of such a difference implies a longer delay of data acquisition following the slow post-ischemia recovery.

Adult↗
PubMed1986

[Determination of the amputation level by transcutaneous PO2 measurement and distal arterial systolic pressure].

Transcutaneous oxygen partial pressure measurement (TcPO2) using a polarographic probe heating the skin at 44 degrees C provides informations about the capacity of blood to supply skin with oxygen. As oxygen is necessary for tissue survival, TcPO2 could constitute an adequate parameter for the determination of an amputation level. Among 67 amputations performed between 1983 and, 1984, we included in this study 34 patients (35 amputations), in whom TcPO2 was preoperatively measured (24 males, 10 females, mean age 67 years, range 19-86 years). Twenty two were diabetics. Twenty patients suffered from severe ischemia (stage Fontaine 4); 13 patients suffered from chronic diabetic lesions or/and osteomyelitis and two patients suffered from frostbite. The follow-up period lasted until operative wound was healed or a more proximal amputation was undertaken (mean 2.5 months, range 15 days to 10 months). Five operative wounds did not heal, so that a more proximal amputation was undertaken. TcPO2 was below 20 mm Hg in 3 of these 5 patients. TcPO2 was above 20 mm Hg in 24 among 30 patients in whom operative wound healed. When TcPO2 is above 20 mm Hg, the probability of operative wound healing is 92%. When TcPO2 is below 20 mm Hg, the risk of a more proximal amputation is 33%. Distal systolic blood pressure has no predictive value. It is concluded than when TcPO2 is above 20 mm Hg, the probability of healing of operative wound is clinically acceptable. When TcPO2 is below 20 mm Hg, 1 of 3 patients will be reamputated at a more proximal level, but healing does occur in 66% of patients.

Adult↗
PubMed1982

[Sequelae of unilateral deep venous thrombosis in plethysmography of the calf].

Twenty four patients suffering from unilateral venous disturbances revealed by Doppler and secondary to a deep venous thrombosis were examined. The calf venous haemodynamics was analyzed by use of a strain-jauge plethysmograph. We determined the increase in venous volume due to the inflation of a thigh pneumatic cuff (pressure at 20, 40 and 60 mm Hg; delta V20, delta V40, delta V60). The maximal venous output (Vout) was measured after a quick release of the 60 mm Hg pressure. The maximal venous drainage (VMM) was assessed during a rhythmic exercise (tiptoeing) while standing; delta V20, delta V40 and delta V60 were nearly constantly reduced on the abnormal side (t of Student respectively 3.49; 6.09 and 5.07). Vout dropped proportionaly to delta V60. Some abnormalities due to valvular insufficiency were frequently present in the beginning of the inflation curve at the level of the abnormal limbs. VMM was nearly always largely decreased on the affected side (t = 5.43). The unilateral flow disturbances displayed by the Doppler were regularly going with abnormalities of the capacitive system, well demonstrated by comparison with the non-affected limbs.

Blood Pressure↗
PubMedDate not supplied

Effect of exercise on the leg distribution of C15O2 and 15O2 in normals and in patients with peripheral ischemia: a study using positron tomography.

In order to evaluate regional muscle blood flow and oxygen utilization, we study with positron emission tomography (PET) the distribution of C15O2 and 15O2 in 17 subjects: 5 normals (24 +/- 3 years) and 12 patients (63 +/- 13.5 years). C15O2 and 15O2 are inhalated with a steady-state technique. Positron tomograms are recorded in supine position at the greatest diameter of the leg. Exercise consists in simultaneous ankle flexions. In all normals, C15O2 and 15O2 are distributed homogeneously and symmetrically in both legs. At rest, they concentrate in the region of vascular pedicle. After exercise, C15O2 and 15O2 are electively distributed in the anterolateral region of the leg. In patients, this pattern of distribution is similar but asymmetrical. Moreover, the regional uptake of C15O2 and 15O2 often dissociates. In conclusion, C15O2 and 15O2 allow to study repeatedly muscle blood flow and oxygen utilization in patients with peripheral ischemia, both at rest and after exercise. The broad spectrum of pathological changes observed in this study needs further metabolic investigations.

Adult↗
PubMedDate not supplied

[Prognosis and prevention of white atrophy].

White atrophy, defined by Milian, is a smooth ivory white plaque, slightly depressed, of variable dimensions, and surrounded by a pigmented telangiectasic area, several millimetres across. It is usually localised in the lower limbs and mostly affects middle-aged women. It is a symptom with multiple aetiopathology. It is to be bound in isolation, or forming part of the clinical picture of various affections caused by degeneration in the cutaneous vascularization. Sometimes it causes ulceration resistant to the available treatments. Some authors suggest an immunological pathology of vascular occlusion. Others consider that it is result of a localized disorder of coagulation or fibrinolysis.

Atrophy↗