PubMed HealthSearch

Biomedical subjects

E Wahlberg

Publications and source records attributed to E Wahlberg.

9 recordsLinked to original sources

Changes in postocclusive reactive hyperaemic values as measured with laser Doppler fluxmetry after infrainguinal arterial reconstructions.

OBJECTIVES: The aim of the present study was to evaluate microcirculartory changes of the postocclusive reactive hyperaemia test measured with Laser Doppler fluxmetry to detect results of arterial reconstructions. DESIGN: Prospective open study. SETTING: Vascular laboratory of a University Hospital. MATERIAL: Sixty patients with peripheral arterial occlusive disease who underwent infrainguinal reconstruction were examined the day before and 1-2 days after surgery. CHIEF OUTCOME MEASURES: The values were obtained during postocclusive reactive hyperaemia induced by release of a 3 min arterial occlusion with a cuff at ankle level with the laser Doppler probe placed dorsally on the first toe. The alterations after surgery in these hyperaemia parameters were compared to changes in ankle/brachial index and clinical improvement at 30 days postoperatively. MAIN RESULTS: Patients improved by surgery according to ankle/brachial index had significantly reduced time to peak (p < 0.001) and significantly increased resting flux value (p < 0.05) and peak flux value (p < 0.05). There was a significant correlation between the change after surgery in time to peak flux and increment of ankle/brachial index (r = 0.63, p < 0.001). CONCLUSIONS: Changes in reactive hyperaemia values as measured with laser Doppler fluxmetry, especially the time to peak flux, seem to detect circulatory changes caused by arterial reconstructions.

Aged

PAS-Port: a new implantable vascular access device for arm placement: experiences from the first two years.

OBJECTIVE: To evaluate the performance of a new subcutaneous infusion port for placement in the arm. DESIGN: Retrospective study. SETTING: Karolinska Hospital, Stockholm, Sweden. SUBJECTS: 85 of 90 consecutive patients referred for implantation of a subcutaneous infusion port. Five records were missing. Implantation was successful in 81 cases (95%). INTERVENTIONS: Implantation of a PAS-Port (Kabi Pharmacia Deltec) subcutaneously on the forearm. Vascular access was obtained by cut-down. MAIN OUTCOME MEASURES: Success rate, complications and reliability in routine use. RESULTS: After a follow-up time of 1-24 months (median 5), 42 ports were still in use, 21 patients had died with functioning ports, two ports had been removed at the end of treatment, 11 had been removed because of complications and because they malfunctioned; and 3 patients were lost to follow-up. The overall infection rate was 0.08/100 catheter days. CONCLUSIONS: PAS-Port is a safe alternative to chest-placed port systems where there is a need for long term vascular access in adult patients.

Adolescent

Limb loss in association with vascular surgery--a five-year series of major lower-limb amputation.

OBJECTIVE: To evaluate the type, timing and number of vascular reconstructions that preceded amputation; to compare the characteristics of amputees who had had reconstructions with those of amputees who had not, and to compare the results of amputation. DESIGN: Retrospective study of case notes. SETTING: University hospital, Sweden. SUBJECTS: All 219 patients who underwent amputation between 1987 and 1992. MAIN OUTCOME MEASURES: Incidence of amputations; presenting features, and type and results of vascular reconstructions. RESULTS: The number of amputations decreased after 1988, and that of vascular reconstructions increased. 56 of the 99 who had amputations after reconstruction (57%) had had their last procedure within a month. This group had had a mean of three operations, had worse run-off as assessed by angiography, and 2 of them (5%) had amputations after failed suprainguinal reconstruction for claudication alone. 68 of the total (31%) had amputations without first being assessed by a vascular surgeon. 52 (24%) required reamputation. CONCLUSION: Better objective methods are needed for the assessment of patients before primary as well as secondary vascular reconstructions. All patients should be seen by a vascular surgeon before amputation is recommended.

Adult

Effects of local hyperemia and edema on the biological zero in laser Doppler fluxmetry (LD).

The method of laser Doppler (LD) fluxmetry records the flux of moving blood cells and particles in a small tissue volume. However, also during complete arterial occlusion a flux-independent signal can be recorded, which is sometimes significantly different from the electrical zero of the instrument. This part of the signal has been called the biological zero (BZ), and can sometimes represent up to 80% of the total LD signal. In the present study, we investigated the influence of induced hyperemia produced by methylnicotinate and histamine respectively, both vasodilators but only histamine giving edema. Eleven legs of nine healthy subjects were studied. Test sites on the dorsal skin of the foot were prepared with a) histamine (10 mg/ml), b) methylnicotinate (0.1 mol/l) and c) saline. The substances were administered onto the skin with a lancet as the prick test procedure. The basal LD was measured before, and the BZ during an arterial occlusion obtained with a cuff at the ankle. Histamine induced a wheal and edema in all subjects, while methylnicotinate only caused erythema. Basal LD was significantly (p less than 0.01) increased by both substances compared to saline. The BZ was significantly higher (p less than 0.01) with histamine than with both saline and methylnicotinate. The results show that BZ is increased by vasodilation, and still more so by edema formation. It is concluded that the BZ value must always be recorded and taken into consideration when LD blood cell flux is measured in the skin.

Adult

The influence of reactive hyperemia and leg dependency on skin microcirculation in patients with peripheral arterial occlusive disease (PAOD), with and without diabetes.

The increase in venous pressure during leg dependency causes a vasoconstriction of the distal vascular bed in healthy subjects, which is due to the so-called veno-arteriolar reflex. The aim of the present study was to investigate if this reflex is disturbed in patients with severe peripheral arterial occlusive disease (PAOD), with and without diabetes. The total skin microcirculation during rest and postocclusive reactive hyperemia (PRH) after a three minute arterial occlusion at the ankle was studied by laser Doppler (LD) fluxmetry. The LD probe was attached to the dorsal region of the foot in 10 legs of healthy control subjects, patients with PAOD, and patients with PAOD and diabetes respectively. No vasoconstriction was seen in the PAOD group when the leg was moved from the supine to the dependent position. The PRH response was also significantly (p less than 0.05-0.01) impaired compared to the controls in both positions. The diabetic PAOD patients had an almost normal reactivity in spite of an equally reduced arterial circulation as the non-diabetic patients. The results show that patients with PAOD have a significantly disturbed reactivity of the skin microcirculation in the ischemic foot, while the reactivity in diabetic PAOD patients is almost normal.

Aged

Spatial and temporal variation in laser Doppler flux values in healthy lower limbs: comparison between the standard and the multiprobe.

Skin flow recordings with a laser Doppler instrument have not proven useful for evaluation of patients with peripheral arterial occlusive disease. The introduction of a probe using seven fibers suggested a reduction in spatial variation, but few studies using this multiprobe have been published. The present study was designed to compare the multiprobe to the standard probe placed between the knee and the first toe, chosen to fit a future study for amputation levels. The aim was to evaluate the multiprobe for that purpose. A laser Doppler fluxmeter with a standard and a multiprobe was used. Measurements were made in five probe sites in lower limbs of healthy volunteers. Each subject was studied by 30-second recordings during 60 min with both probes. Statistically (p < 0.001) lower flux values were obtained with the multiprobe than with the standard probe. The flux variation between the five probe sites was significantly (p < 0.01) higher with the standard probe than with the multiprobe, but the temporal variation was similar with both probes. The results suggest that the spatial variation in widely separated probe sites is reduced with the multiprobe. The temporal variation was not found to be reduced.

Adult