Hemorheological Aspects in The Microvasculature of Several Pathologies

Abstract

We evaluated morphological changes in several pathologies using computerized videocapillaroscopy, and related hemorheological patterns using the laser assisted optical rotational red cell analyzer (LORCA). In addition, tissue oxygenation was measured using two oximeters with Combi sensors (Periflux 5000, Perimed).

The study included four groups of patients (pts) that were compared with a control group. Group A Controls (n=25: 15 males [M] and 10 females [F] aged 36 ± 3 years); Group B Diabetic pts n=32 (IDDM pts n=20: 12 M and 8 F aged 43 ± 4 years; NIDDM pts n=12: 6 M and 6 F aged 45 ± 3 years); Group C Glaucoma pts n=30 (16 M and 14 F aged 42 ± 5 years); Group D Liver failure pts n=6 (3 M and 3 F aged 44 ± 5 years); Group E Hypertensive pts n=50 (smokers n=28: 12 M and 16 F aged 40 ± 4 years, and non-smokers n=22: 12 M and 10 F aged 38 ± 3 years). In all patients hemorheological measurements were made using the LORCA (including red blood cell [RBC] deformability and aggregability), morphology was evaluated using computerized videocapillaroscopy (magnification 200 x), and transcutaneous oxygen partial pressure measurements (TcpO ₂) were made with the Periflux 5000.

In patients with diabetic microangiopathy: the capillary loops in 50% (16/32) of these pts showed formations such as ‘deer horns’, 72% (23/32) showed formations such as ‘elephant nose’, and in 45% (14/32) formations such as a ‘cork screw’; in diabetics with POAD an important capillary rarefaction was found in 26% (9/32) of the pts. In glaucoma patients, in 84% (25/30) we observed ‘capillary meandering’ and images such as ‘a comb’. In patients with more complicated pathology capillary rarefaction was found in 70% (21/30) of the patients. An improvement in the perfusion of non-functional loops was found in deceased patients who had suffered liver failure one week after liver transplantation in 90% (5/6) of the studied cadavers. In non-smoking hypertensives morphological changes were found in 25% (6/22) of the patients, and in hypertensive smokers in 47% (13/28). RBC deformability was detected using LORCA and expressed as the Elongation Index (EI), and RBC aggregability was detected using LORCA and expressed in t ½(seconds) indicating the RBC aggregability peak. Group A controls: EI 0.59 ± 0.02; t 3 ± 1 sec; Group B: IDDM EI 0.55 ± 0.01; t : 2 ± 0.5 sec p <0.05; NIDDM EI 0.56 ± 0.01; t 2 ± 0.2 sec p < 0.04; Group C glaucoma: EI 0.56 ± 0.01; t 2 ± 0.3 sec p < 0.05; Group D liver failure: EI 0.56 ± 0.02; t 2 ± 0.4 sec p < 0.03; Group E hypertensives: smokers EI 0.56 ± 0.02; t 2 ± 0.6 sec p < 0.04; non-smokers EI 0.57 ± 0.02; t 2 ± 0.6 sec p < 0.04 compared with controls. We also measured the TcpO ₂ at the dorsum of the right foot as a standard site representing peripheral control of microvasculature perfusion. Group A 96 ± 11 mmHg; Group B IDDM 74 ± 9 mmHg p < 0.05; NIDDM 76 ± 8 mmHg p < 0.05; Group C glaucoma 75 ± 9 mmHg p < 0.05; Group D liver failure 69 ± 6 mmHg p < 0.05; Group E hypertensives: smokers 70 ± 5 mmHg p < 0.05, non-smokers 77 ± 9 mmHg p < 0.05 compared with controls.

This study presents an interesting and complete methodology to evaluate the microcirculation in different pathologies that induce changes in the microvasculature.