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Biomedical subjects

U K Franzeck

Publications and source records attributed to U K Franzeck.

At least 19 recordsLinked to original sources

Microlymphatic aneurysms in patients with lipedema.

"Lipedema," a special form of obesity syndrome, represents swelling of the legs due to an increase of subcutaneous adipose tissue. In 12 patients with lipedema of the legs and in 12 healthy subjects (controls), fluorescence microlymphography was performed to visualize the lymphatic capillary network at the dorsum of the foot, at the medial ankle, and at the thigh. Microaneurysm of a lymphatic capillary was defined as a segment exceeding at least twice the minimal individual diameter of the lymphatic vessel. In patients with lipedema, the propagation of the fluorescent dye into the superficial lymphatic network of the skin was not different from the control group (p > 0.05). In all 8 patients with lipedema of the thigh, microaneurysms were found at this site (7.9 +/- 4.7 aneurysms per depicted network) and in 10 of the 11 patients with excessive fat involvement of the lower leg, multiple microlymphatic aneurysms were found at the ankle region. Two obese patients showed lymphatic microaneurysms in the unaffected thigh and in only 4 patients were microaneurysms found at the foot. None of the healthy controls exhibited microlymphatic aneurysms at the foot and ankle, but in one control subject a single microaneurysm was detected in the thigh. Multiple microlymphatic aneurysms of lymphatic capillaries are a consistent finding in the affected skin regions of patients with lipedema. Its significance remains to be elucidated although its occurrence appears to be unique to these patients.

Adipose Tissue↗

Lymphoedema, lymphatic microangiopathy and increased lymphatic and interstitial pressure in a patient with Parkinson's disease.

New microvascular findings in a woman with Parkinson's disease and lower leg oedema are presented. Microlymphography showed enhanced filling of the microlymphatic network with the fluorescent contrast medium comparable to the findings in lymphoedema. The microlymphatic and interstitial pressures of the skin were increased (27 mm Hg and 16 mm Hg respectively). The increased interstitial and microlymphatic pressures are the result of insufficient venous and lymphatic drainage due to impairment of calf muscle function during walking in Parkinson's disease. Manual lymph drainage and compression therapy, in combination with improvement of calf muscle function, resulted in regression of the oedema.

Aged↗

Dose-dependent increase of transcapillary diffusion of sodium fluorescein after histamine microinjections.

BACKGROUND: To study the dose-dependent effects of histamine on capillary permeability in human skin, using the microinjection technique. PATIENTS AND METHODS: Eight healthy volunteers (2 w, 6 m; mean age 33 years) were included in the study. On two separate occasions, glass microcannulas with a tip diameter of 7 to 9 microns were inserted into the subepidermal layer of the skin at the distal medial tibia surface of each lower limb with a micromanipulator. In each subject, 0.5 microliter of 3 different concentrations of histamine solution (0.1/1000, 0.01/1000 and 0.001/1000) were injected and compared to the solvent (0.9% NaCl). Transcapillary diffusion of intravenously administered Na-fluorescein was assessed simultaneously using two fluorescence videomicroscopy systems. Off-line video densitometry was performed in an area of 0.56 mm2 around the injection sites and fluorescence light intensities were measured in arbitrary units (AU) at 10, 30, 60, 120 and 600 s after dye appearance. RESULTS: Compared to the solvent histamine microinjections resulted in a dose-dependent increase of mean fluorescence light intensities (FLI). Whereas mean FLI for the 0.001/1000 histamine injection was only significantly elevated 10 min after dye appearance (p < 0.05) an increase of mean FLI was already observed 10 s after dye appearance following the 0.1/1000 histamine injection (p < 0.05), which was more pronounced at later time points (p < 0.001). Mean FLI's for the 0.01/1000 histamine solution were in between and resulted in significantly elevated values 1 min to 10 min after dye appearance (p < 0.05). CONCLUSIONS: We conclude that the microinjection technique together with fluorescence videomicroscopy described previously [6] is able to document a dose-dependent effect of histamine microinjections on skin capillary permeability. The technique may facilitate to determine appropriate dosages not only of histamine in order to test the effect of antagonists on human skin capillary permeability.

Adult↗

Lymphatic microangiopathy of the skin in systemic sclerosis.

METHODS: The cutaneous capillary lymphatic system in patients with systemic sclerosis was investigated using fluorescence microlymphography. The distal upper limbs of 16 healthy controls (mean age 62.3+/-13.1 yr) and 16 patients with systemic sclerosis (mean age 58.9+/-13.6 yr) were examined and the following parameters were evaluated: (a) single lymphatic capillaries; (b) lymphatic capillary network and cutaneous backflow; (c) extension of the stained lymphatics; (d) diameter of single lymphatic capillaries. RESULTS: At the finger level, lymphatic capillaries were lacking in five patients, while they were present in all controls (P < 0.05). Extension of the stained lymphatics was increased in 11 patients (8.1+/-6.0 mm) compared to the 16 healthy controls (2.0+/-1.2 mm) (P < 0.0001). Cutaneous backflow was observed in three patients (P < 0.05). At the hand level, lymphatic network extension was significantly different between patients (3.8+/-2.4 mm) and controls (1.2+/-0.8 mm) (P < 0.01); however, no significant differences were found at the forearm level. CONCLUSION: Lesional skin in patients with systemic sclerosis exhibits evidence of lymphatic microangiopathy.

Adult↗

[Prospective 12-year follow-up study of clinical and hemodynamic sequelae of deep venous thromboses in patients with low risk (Zurich Study)].

No prospective study of the long-term sequelae of more than 10 years after acute deep vein thrombosis exists so far. Therefore, 28 patients with DVT were included in a prospective study to evaluate the natural history of postthrombotic syndrome. Clinical and hemodynamic examinations were performed at the time of admission; after 3, 6 and 12 months; after the 2nd, 3rd, 4th, 5th; and finally after the 12th year. All patients received unfractionated heparin initially and oral anticoagulants subsequently. After 12 years, 64% of the patients exhibited normal findings. Mild skin changes were found in 28%, marked trophic changes in 5%, and only 1 venous ulcer occurred. Regular use of compression stockings was reported by 54% of the patients with multilevel disease. Although mean maximum venous outflow was significantly reduced from the acute event to 2 years later (p < 0.003) compared with the contralateral leg, a significant (p < 0.05) improvement was observed 6 months later. Recanalization of calf vein thrombosis was detected by Doppler sonography after 3 months. 64% of the multilevel thromboses were recanalized completely or in part after 1 year; in 69%, valvular incompetence was found. In conclusion, in contrast to earlier reports, this prospective study up to 12 years after DVT demonstrates a low incidence of PTS by administration of initially unfractionated heparin, oral anticoagulation and compression therapy. However, the adverse clinical event rate (mortality 14%) and recurrency rate of 24% show that the prognosis after DVT does not appear favorable even in low-risk patients.

Adult↗

Fluorescence microlymphography of the upper extremities. Evaluation with a new computer programme.

BACKGROUND: To evaluate the initial lymphatics of the superficial skin in healthy volunteers using fluorescence microlymphography and to establish controls values for comparison with lymphedema patients. METHODS: Fluorescence microlymphography was performed on the hand dorsum, on the lower and the upper arm in 12 healthy subjects (58.7+/-8.0 years). At each of these sites 10 microl FITC-dextran was injected subepidermally using a steel cannula. The studies were recorded on video tape using a fluorescence microscope and a CCD video camera. Final magnification was 24 and 62. The maximum spread of the fluorescent contrast medium was measured 10 minutes after injection. The area of the visualized lymph capillaries was determined using a computer programme. SETTING: University Hospital, Department of Medicine, Division of Vascular Medicine (Angiology). RESULTS: The mean area of the visualised lymph capillary network 95.3+/-41.3 mm2 (42-174 mm) at the upper and 89.4+/-45.5 mm2 (44-171 mm). The maximum spread was 4.8+/-3.5 mm (1.9-13.6 mm) and 4.4+/-3.7 mm, respectively. The mean diameter of the lymph capillaries was 84.1+/-19.9 microm and 75.5+/-14.8 microm, respectively. CONCLUSIONS: The extension of the lymph capillary network at the upper and lower arm are comparable to those at the lower extremities. Considering the two-dimensional nature and the irregular shape of the network the area measurement seems to be more appropriate than the maximum spread in one direction.

Adult↗

Comparison between clinical examination, cw-Doppler ultrasound and colour-duplex sonography in the diagnosis of incompetent perforating veins.

OBJECTIVES: This study was conducted to investigate the accuracy and agreement between clinical examination, continuous wave (cw)-Doppler ultrasound and colour-duplex sonography (CDS) in diagnosing incompetent perforating veins (ICPV). DESIGN: Observational cohort study. MATERIAL AND METHODS: Nineteen patients with chronic venous insufficiency (CVI) were examined clinically, by hand-held cw-Doppler ultrasound in combination with tourniquet compression and CDS. RESULTS: The low accuracy of the clinical examination and the diagnosis of ICPV by cw-Doppler were surprising. The specificity was 15% and sensitivity 29%, when CDS was taken as the "gold standard". Furthermore the results show clearly that the application of a tourniquet cannot provide reliable results. CONCLUSIONS: In patients with CVI, clinical and cw-Doppler cannot accurately diagnose ICPV when compared to CDS.

Adult↗

Microvascular changes in venous disease: an update.

In an overview the microvascular involvement in chronic venous insufficiency (CVI) is described. Microangiopathy in the lower leg areas is characterized by the presence of typical enlarged and ramified blood capillaries, reduced capillary number, microvascular thrombosis and obliterations, and/or increased permeability of microlymphatics. Transcutaneous oxygen tension (tcPO2) is decreased and directly correlated to the number of perfused capillaries, whereas laser Doppler flux is enhanced. This apparent paradox may be explained by hyperperfusion in the deeper skin layers (mainly shunt vessels) and hypoperfusion in the superficial nutritive vessels. Microvascular changes are of patchy distribution. Trophic changes up to overt venous ulceration are mainly caused by microvascular ischemia and edema formation due to increased capillary permeability and deficient lymphatic drainage.

Capillary Permeability↗

On the relationship between changes in the deep veins evaluated by duplex sonography and the postthrombotic syndrome 12 years after deep vein thrombosis.

In a prospective study we performed color duplex ultrasonography to evaluate patency and valvular function of previous thrombosed veins 12 years after the acute thrombosis. Normal clinical findings were found in 64% of the patients, mild postthrombotic skin changes in 28%, and marked trophic changes in 5%; only 1 venous ulcer occurred. In 39 patients, 114 initially thrombosed vein segments were evaluated. Thirty-seven of 72 proximal segments were completely recanalized (23 with valvular incompetence) and 21 segments exhibited partial recanalization (19 with valvular incompetence). Superficial femoral vein segments were completely occluded in 19%, however, excellent collateralization was provided via the deep femoral vein. Thromboses of the posterior tibial vein demonstrated a high rate of recanalization with development of valvular incompetence in 52%. Whereas obstruction and valvular incompetence as single factors led to a postthrombotic leg in 8.5% and 33%, respectively, the most frequent cause for the development of the postthrombotic syndrome was the combination of reflux plus obstruction in the deep veins (50%). Compression therapy with elastic compression stockings is recommended for at least 5 years after the acute thrombosis.

Adult↗

Diurnal and long-term variations of lymph capillary pressure in healthy subjects.

The variability of pressure in the cutaneous lymph capillaries on the forefoot was determined in 2 groups of healthy volunteers. In group A, including 12 healthy subjects (8 men, 4 women; mean age 28 years, range 22 to 37 years), measurements were performed in the morning and late afternoon of the same day. In group B (12 healthy subjects, 5 women, 7 men; mean age 53 years, range 23 to 72 years), measurements of lymph capillary pressure were repeated with an interval of 7 weeks. The superficial microlymphatics were visualized by intravital fluorescence microlymphography, cannulated with glass micropipettes, and the lymph capillary pressure was measured using a servonulling pressure system. In group A, lymph capillary pressure measured in the morning (mean 7.5 +/- 4.4 mmHg; range -4 to 16 mmHg) did not differ (p > 0.05) from the pressure in the late afternoon (mean value 5.6 +/- 3.4 mmHg; range-1 to 13 mmHg). In group B, initial lymph capillary pressure (mean 3.9 +/- 2.9 mmHg, range -1.1 to 9.7 mmHg) was not different (p > 0.05) compared with the pressure after 7 weeks (2.9 +/- 2.7 mmHg, range -1.0 to 6.8 mmHg). We conclude that lymph capillary pressure in healthy subjects does not exhibit significant changes during the daytime or over the long term.

Adult↗

Effect of postural changes on human lymphatic capillary pressure of the skin.

1. The influence of postural changes on cutaneous lymphatic capillary pressure and venous pressure was measured at the dorsum of the foot in twelve healthy volunteers. Measurements were performed in the supine and sitting positions. 2. Lymphatic skin capillaries were visualized by fluorescence microlymphography with fluorescein isothiocyanate (FITC)-Dextran 150000. Subsequently a lymphatic capillary was punctured with a glass micropipette and pressure was measured using the servo-nulling technique. Lymphatic capillary pressure, venous pressure, heart and respiration rates were recorded simultaneously. 3. Mean lymphatic capillary pressure was significantly higher (P = 0.0096) in the sitting (9.9 +/- 3.0 mmHg) than in the supine (3.9 +/- 4.2 mmHg) position. There was no significant difference (P = 0.09) between lymphatic capillary pressure and venous pressure (6.8 +/- 3.4 mmHg) in the supine position. During sitting mean lymphatic capillary pressure was significantly lower (P = 0.0022) than mean venous pressure (53.3 +/- 4.1 mmHg). The smaller increase in lymphatic capillary pressure may be caused by the discontinuous fluid column in the lymphatic system and enhanced orthostatic contractile activity of lymphatic collectors and precollectors. Spontaneous low frequency pressure fluctuations occurred in 89% of recordings during sitting, which was significantly (P = 0.02) higher than in the supine position (54%). 4. The present results support the suggestion of enhanced intrinsic contractile activity of lymph precollectors and collectors in the dependent position. This mechanism is primarily responsible for the propulsion of lymph from the periphery to the thoracic duct during quiet sitting, when extrinsic pumping by the calf muscles is not active.

Adult↗

Prospective 12-year follow-up study of clinical and hemodynamic sequelae after deep vein thrombosis in low-risk patients (Zürich study).

BACKGROUND: No prospective study of the long-term sequelae of more than 10 years after acute deep vein thrombosis exists so far. Therefore, 58 low-risk patients with DVT were included in a prospective study to evaluate the natural history of postthrombotic syndrome. METHODS AND RESULTS: Clinical and hemodynamic examinations were performed at the time of admission; after 3, 6, and 12 months; after the 2nd, 3rd, 4th, 5th years; and finally after the 12th year. All patients received heparin initially and oral anticoagulants subsequently. After 12 years, 64% of the patients exhibited normal findings. Mild skin changes were found in 28%, marked trophic changes in 5%, and only one venous ulcer occurred. Regular use of compression stockings was reported by 54% of the patients with multilevel thrombosis. Although mean maximum venous outflow was significantly reduced from the acute event to 12 years later (P<.003) compared with the contralateral leg, a significant (P<.05) improvement was observed 6 months later. Recanalization of calf vein thrombosis was detected by Doppler sonography after 3 months. Sixty-four percent of the multilevel thromboses were recanalized completely or in part after 1 year; in 69%, valvular incompetence was found. CONCLUSIONS: In contrast to earlier reports, this prospective study up to 12 years after deep vein thrombosis demonstrates a low incidence of postthrombotic syndrome by administration of oral anticoagulants and regular compression therapy. However, the adverse clinical event rate (mortality 14%) and a recurrence rate of 24% show that the prognosis after deep vein thrombosis does not appear favorable even in low-risk patients.

Administration, Oral↗

Microinjection technique for pharmacological evaluation of microvascular permeability in human skin.

A new technique which combines skin microinjection of minute amounts of drugs (0.5 microliter) and measurement of capillary permeability by intravital fluorescence videomicroscopy and densitometry is introduced. Glass micropipettes with a tip diameter of 7-9 microns are inserted by a micromanipulator into the stratum papillare containing the capillary loops and used for microinjection by microsyringe and special dispenser. Transcapillary diffusion of sodium fluorescein applied by intravenous bolus injection is visualised by fluorescence videomicroscopy and stored on videotape. Perivascular fluorescent light intensity (FLI) is measured in arbitrary units (AU) by videodensitometry around the site of microinjection during playback of the videotapes. The method was tested by microinjection of 0.5 microliter histamine (1% solution) at the distal tibial plateau. Mean FLI values representing microvascular permeability were 2186 AU 10 min after microinjection of histamine, 420 AU after physiologic saline and 1228 AU after histamine combined with oral intake of 20 mg cetirizine. Cetirizine significantly reduced (P < 0.01) the increased permeability induced by histamine. However, the mean values after injection of the H1-blocker were still significantly enhanced (P < 0.01) when compared to the mean values observed after injection of physiologic saline solution, which provoked only minor microtrauma. The technique offers new scope for pharmacological testing in man.

Adult↗

Flow velocity of single lymphatic capillaries in human skin.

The purpose of this study was to investigate the previously unknown flow velocity in single lymphatic capillaries of humans in the supine position. Fifteen healthy subjects (10 women and 5 men; mean age 35.8 +/- 13.1 yr) were studied. Ten microliters of fluorescein isothiocyanate-dextran (150,000 mol wt) were injected into the subepidermal layer of the foot dorsum. The filling of the microlymphatics from the resulting depot was visualized by fluorescence video microscopy and stored on videotape. Flow velocity in the microlymphatics was determined on the video screen by direct measurement of the advancement of dyed lymph during a given time. The following median velocities were obtained: 0.51 mm/s (0.27 and 0.61 mm/s for lower and upper quartiles, respectively) for velocity during initial network filling and 9.7 microns/s (6.9 and 14.2 microns/s for lower and upper quartiles, respectively) for resting velocity at the end of the filling period. Mean lymphatic capillary diameter was 54.8 +/- 8.2 microns, and mean network extension was 8.3 +/- 3.2 mm. The high filling velocities are probably due to increased interstitial pressure and volume caused by dye microinjection, whereas the values measured during the end of network filling seem to approach resting flow velocities.

Adult↗

Microvascular changes in arterial occlusive disease: target for pharmacotherapy.

The main techniques which have been used to study skin microcirculation in patients with peripheral arterial occlusive disease include intravital microscopy with and without the use of fluorescent dyes, laser Doppler fluxmetry and transcutaneous oximetry. In patients with severe ischaemia (rest pain or incipient gangrene) the number of perfused skin capillaries is reduced. Parallel to the decreased number of microvessels containing blood, transcutaneous oxygen tension is low or even approaches the zero level. The tendency to oedema formation is documented by increased leakage of intravenously injected sodium fluorescein at the capillary apex of foot skin ('candlelight phenomenon'). Laser Doppler flux at rest may still be within the normal range even in advanced disease, since the sample volume of these instruments also contains non-nutritive shunt vessels. However, reactive hyperaemia after arterial occlusion is decreased and delayed in peripheral ischaemia. Whereas rhythmic low-frequency vasomotion is significantly enhanced in patients with intermittent claudication, vasoparalysis with no flux fluctuations prevails in patients with critical ischaemia.

Arterial Occlusive Diseases↗

[Color duplex ultrasonography in the diagnosis of deficient perforating veins in comparison to cw-Doppler ultrasonography and clinical examination].

The study was conducted to investigate the accuracy and agreement between clinical examination, cw-Doppler ultrasound and color-duplex sonography in diagnosing incompetent perforating veins. Nineteen patients with chronic venous insufficiency (CVI) were examined clinically, by hand-held cw-Doppler ultrasound in combination with tourniquet compression and color-coded duplex sonography CDS. The accuracy of the clinical examination and the diagnosis of ICPV by cw-Doppler were surprisingly low. The specificity was 15% and sensitivity 29%, when CDS was taken as gold standard. Furthermore the results show clearly that the application of a tourniquet cannot provide reliable results. It is concluded that in patients with CVI clinical and cw-Doppler examinations are not sufficient for an accurate diagnosis of incompetent perforating veins. Color-duplex provides a new noninvasive approach for accurate anatomical and functional diagnosis, which is of great importance prior to surgical interventions and/or sclerotherapy.

Adult↗