Noninvasive investigations in vascular disease. St Mary's Fellows. ISVI (Italian Society for Vascular Investigations)

Effects of Shock Waves on Microcirculation, Perfusion, and Pain Management in Critical Limb Ischemia

Shock waves (SW) are used to control pain in different clinical conditions (eg, painful knee, elbow, and shoulder, etc). The effects of SWs may be due to cellular “stunning” (particularly nervous components). It may also be the consequence of unknown metabolic actions on tissues, which may include changes in cellular permeability, the liberation of proteins and mediators locally acting on pain and nerve endings. The aim of this study was to evaluate the reduction in pain and the improvement in microcirculation induced by SW treatment in a 2-week study in patients with chronic limb ischemia (CLI). Of the 32 patients with CLI, 30 (20 with rest pain only, 10 with necrosis) completed the study. The treatment was well tolerated. Foot radiographs performed before and after treatment indicate no bone damage after treatment. Foot (tibial arteries) blood pressure was unchanged after 2 weeks. The increase in laser Doppler flux was significant (p<0.05) after treatment. The ORACLE score at 2 weeks was decreased (p<0.05). The same trend was observed with the analogue scale line for pain (p<0.05). Partial pressure of oxygen (PO2) increased (p<0.05) and partial pressure of carbon dioxide (PCO2) decreased (p<0.05). In all patients an increase in pain-free walking distance was observed (the distance increased on average 2.4 times). Flux improvement was still present after 1 month. The outcome at 3 months in these patients indicates that the improvement (concerning the survival of the limbs) was persistent. In conclusion SWs treatment in CLI produced changes both on the microcirculation and pain. These results are very interesting, confirming previous observations, and opening new treatment options in CLI. The skin flow improvement did not relate to an increase in pressure.

Pre- and postoperative evaluation by photoplethysmography in patients receiving surgery for lower-limb varicose veins

Objective. To evaluate the effectiveness of surgery in treating primary varicose veins in the lower limbs by photoplethysmography (PPG) and duplex mapping (DM). Method. Forty-eight lower limbs were clinically evaluated according to the CEAP classification system and subjected to PPG and DM exams. Each limb had a venous refill time (VRT) of <20 seconds and a normal deep vein system (DVS) by DM. Results. The mean pre- and postoperative VRTs were 13.79 and 26.43 seconds, respectively (P < 0.0001). After surgery, 42 limbs (87.50%) had normal results by PPG (VRT > 20 seconds). Four limbs (8.33%) showed improved VRTs, but the VRTs did not reach 20 seconds. In the 2 limbs (4.17%) that maintained their original VRTs, the DM exams showed the presence of insufficient perforating veins. Conclusion. In most cases, PPG allows for a satisfactory evaluation of the outcome of varicose vein surgery.

The reliability of toe systolic pressure and the toe brachial index in patients with diabetes

BACKGROUND

The Ankle Brachial Index is a useful clinical test for establishing blood supply to the foot. However, there are limitations to this method when conducted on people with diabetes. As an alternative to the Ankle Brachial Index, measuring Toe Systolic Pressures and the Toe Brachial Index have been recommended to assess the arterial blood supply to the foot. This study aimed to determine the intra and inter-rater reliability of the measurement of Toe Systolic Pressure and the Toe Brachial Index in patients with diabetes using a manual measurement system.

METHODS

This was a repeated measures, reliability study. Three raters measured Toe Systolic Pressure and the Toe Brachial Index in thirty participants with diabetes. Measurement sessions occurred on two occasions, one week apart, using a manual photoplethysmography unit (Hadeco Smartdop 45) and a standardised measurement protocol.

RESULTS

The mean intra-class correlation for intra-rater reliability for toe systolic pressures was 0.87 (95% LOA: -25.97 to 26.06 mmHg) and the mean intra-class correlation for Toe Brachial Indices was 0.75 (95% LOA: -0.22 to 0.28). The intra-class correlation for inter-rater reliability was 0.88 for toe systolic pressures (95% LOA: -22.91 to 29.17.mmHg) and 0.77 for Toe Brachial Indices (95% LOA: -0.21 to 0.22).

CONCLUSION

Despite the reasonable intra-class correlation results, the range of error (95% LOA) was broad. This raises questions regarding the reliability of using a manual sphygmomanometer and PPG for the Toe Systolic Pressure and Toe Brachial Indice.

Effects of shock waves on the microcirculation in critical limb ischemia (CLI) (8-week study)

Shock waves (SWs) are used to control and decrease pain in several clinical conditions (e.g., painful elbow and shoulder, etc). This clinical effect may be due to cellular stunning of the tissues (particularly nervous components) in the area treated with SW. It may also be the consequence of unknown metabolic actions on tissues, which may include changes in cellular permeability and the liberation of proteins and mediators locally acting on pain and nerve endings. The aim of this study was to evaluate the reduction in pain and the microcirculation improvement induced by SWs treatment in an 8-week study in patients with chronic limb ischemia (CLI). Patients with CLI (15 with rest pain only and 15 with rest pain and limited distal necrosis) were included. The treatment was based on a 30-minute SWs session, three times weekly for 2 weeks. Clinical and microcirculatory evaluation were performed with laser Doppler Po2 and Pco2 measurements. Pain was measured with an analogue scale line. A Minilith SL1 (Storz Medical, Switzerland) litotriptor was used. The parabolic reflector is coupled to the skin with a silicon water cushion. Focal pressure was adjusted between 6 and 70 Mpa in eight steps. The energy flux density was variable from 0.03 to 0.5 mJ/mm2. Focal diameter and distance were defined (depth of target within the patient's foot of about 70 mm). The coded intensity used in this study was between 6 and 8 and the application time was 20 min (at four impulses per second). Twenty-eight of the 30 patients with CLI (15 with rest pain only and 13 with necrosis) completed the study. The treatment was well tolerated. Blood pressure was unchanged after 8 weeks while the increase in laser Doppler flux was significant (p<0.05) (at all measurements after treatment). The ORACLE score at 1 and 8 weeks was decreased (p<0.05). The same trend was observed with the analogue scale line for pain (p<0.05). PO2 increased (p<0.05) and Pco2 decreased (p<0.05). Tibial pressure did not change. All patients observed an increase in their subjective pain-free walking distance. The improvement was still present after 8 weeks. In a separate subset of 37 patients (mean age 60+/-9 years; males) with CLI, a SWs dose-finding evaluation was performed. Flux changes were measured at the dorsum of the foot. Three treatment plans were used: (a) 20-minute SW treatment only once; (b) 20-minute SWs treatment every 2 days for 1 week; (c) 20 minutes every day for 1 week. Treatments were well tolerated. A different increase in flux was observed on the basis of different treatments. Flux variations generally indicated that increased SWs dosage was associated with proportional flux increase. Flux improvement was still present after 4 weeks. SWs treatment in CLI produced changes both in the microcirculation and on pain. These preliminary results are comforting and open new research options to be explored in the near future.

Nomograms used to define the short-term treatment with PGE(1) in patients with intermittent claudication and critical ischemia. The ORACL.E (Occlusion Revascularization in the Atherosclerotic Critical Limb) Study Group. The European Study

Infusional, cyclic PGE1 treatment is effective in patients with intermittent claudication and critical limb ischemia (CLI). One of the problems related to chronic PGE1 treatment in vascular diseases due to atherosclerosis is to evaluate the variations of clinical conditions due to treatment in order to establish the number of cycles per year or per period (in severe vascular disease reevaluation of patients should be more frequent) needed to achieve clinical improvement. In a preliminary pilot study a group of 150 patients (mean age 67+/-12 years) with intermittent claudication (walking range from 0 to 500 m) and a group of 100 patients with CLI (45% with rest pain, and 55% gangrene; mean age 68 +/-11 years) the number of PGE1 cycles according to the short-term protocol (STP) needed to produce significant clinical improvement was preliminarily evaluated. Considering these preliminary observations, the investigators established a research plan useful to produce nomograms indicating the number of cycles of PGE1-STP per year needed to improve the clinical condition (both in intermittent claudication and CLI). A significant clinical improvement was arbitrarily defined as the increase of at least 35% in walking distance (on treadmill) and/or the disappearance of signs and symptoms of critical ischemia in 6 months of treatment in at least 75% of the treated patients. With consideration of the results obtained with the preliminary nomograms a larger validation of the nomograms is now advisable. A cost-effectiveness analysis is also useful to define the efficacy of treatment on the basis of its costs. The publication of this report in two angiological journals (Angeiologie and Angiology) will open the research on nomograms to all centers willing to collaborate to the study. The data are being collected in the ORACL.E database and will be analyzed within 12 months after the publication of this report.

Pressure and microcirculatory effects of treatment with lercanidipine in hypertensive patients and in vascular patients with hypertension

The aim of this study was to evaluate the macrocirculatory and microcirculatory effects of treatment with lercanidipine, a new antihypertensive agent acting both on blood pressure and microcirculation in patients with moderate essential hypertension and without vascular disease and in patient with hypertension and vascular disease. In hypertensive subjects target-organ damage associated with high blood pressure may now be objectively documented by noninvasive tests. These alterations constitute a model to evaluate not only the pressure effects of antihypertensive treatment but also the normalization of the peripheral microcirculatory network. With color duplex scanning, flow velocity in the central retinal artery and retinal flow velocity can be measured and with use of laser-Doppler-flowmetry, it is also possible to evaluate microcirculation alterations in hypertensive subjects. These evaluation methods are completely noninvasive and may be used to assess the microcirculatory effects of antihypertensive drugs.

Endovascular sclerotherapy, surgery, and surgery plus sclerotherapy in superficial venous incompetence: a randomized, 10-year follow-up trial--final results

The study was planned to evaluate efficacy and costs of endovascular sclerotherapy (ES) in comparison with surgery and surgery associated with sclerotherapy in a prospective (10-year follow-up), good-clinical-practice study. Patients with varicose veins and pure, superficial venous incompetence were included. Of the patients randomized into the three groups 39 (group A) were treated with ES, 40 (B) with surgery + sclerotherapy, and 42 with surgery only (C). Surgery consisted of ligation of the SFJ (saphenofemoral junction) and of incompetent veins detected with color duplex. Of the preselected 150 patients, 121 subjects entered the study; 96 completed the 10-year follow-up (mean age 52.6 +/- 6 years; 51 men, 45 women). Dropouts were due to nonmedical problems. At 10 years no incompetence was observed in subjects treated with SPJ ligation (B and C). In the ES group 18.8% of the SFJs were patent and incompetent and in 43.8% of limbs the distal (below-knee) venous system was still incompetent [16.1% in the surgery + sclerotherapy group (p < 0.05) and 36% in the group treated with surgery only (p < 0.05 vs B and 0.05 vs A)]. Color duplex of the long saphenous vein indicated atrophy or obstruction of a segment (average 6.7 cm) after SFJ ligation (4.2 cm after ES). The cost of ES was 68% of surgery while the cost of surgery and sclerotherapy was 122% of surgery only. Endovascular sclerotherapy is an effective, cheaper treatment option, but surgery after 10 years is superior.