Compressione pneumatica intermittente negli stadi avanzati di arteriopatia periferica: studio delle modificazioni emodinamiche e della perfusione distale indotte da un dispositivo originale e confronto con uno strumento disponibile sul mercato

Introduction: Intermittent pneumatic compression (IPC) is a technique based on the application of pressure at the level of various points of the inferior limb, aimed at provoking haemodynamic modifications starting from the treatment zone. IPC devices, that are mainly used in the area of venous-lymphatic pathologies to reduce edema and for the prevention of venous thromboembolism, have also been applied for treatment of peripheral arterial occlusive disease (PAOD). An IPC device, “Gradient Pump” (GP), based on new haemodynamic concept and technical solutions, has been recently developed by the Vascular Diseases Center of the University of Ferrara-Italy. Aim of the present study in PAOD patients is a) to evaluate the effects of GP on haemodynamic parameters and foot perfusion during a single operative cycle and during a therapeutic cycle and b) to compare efficacy and compliance to the treatment of GP versus a traditional device for PAOD available on the market. Subjects and Methods: In the study were enrolled and evaluated a) 7 patients (12 diseased legs) with PAOD at III-IV Fontaine’s stage and b) 12 patients (21 diseased legs, 12 out of them affected by critical ischemia). The GP device is composed of a single inflatable cuff to be positioned at the thigh, including a rigid element to apply a proper pressure to the femoral vein. The cuff is connected to a compressor which produces periodic sequences of pressure at 1 operative cycle/minute (20 sec of compression, 40 sec of decompression). The therapeutic cycle is composed by a 5min working period followed by a 5min resting period repeated for 3-4 times, modifiable by a manual electromechanical timer. The pressure of cuff inflation is set by a manual pressure regulator to patient’s blood systolic pressure – 20 mmHg with maximal value at 120 mmHg. For the phase A of the study, haemodynamic measurements as Time Average Velocity (TAV) and Blood Flow (BF) were performed by Echo color doppler (ECD) at the femoral vein at different phases of the operative cycle, at rest (basal level), early compression (In1), full compression (In) and full decompression (Out). The haemodynamic measurements during a therapeutic cycle were performed before the start of the first working cycle (basal level), at the end of the second cycle and at the end of the last working period, during the phase Out of both operative cycles. The study of tissue perfusion at the foot was performed using a Near Infrared Spectroscopy (NIRS) device, in order to detect variations in total (tHb), oxygenated (O2Hb) and deoxygenated haemoglobin by means of probes positioned on the dorsum of the foot. The changes of these parameters were recorded and quantified by the calculation of the areas under the curve (AUC). Measurements were performed continuously for a 5min period before the treatment and for the whole treatment. For the phase B of the study, GP was compared to a device available on the market (Art Assist ACI Medical, LLC San Marcos, CA), with cuffs to be positioned at foot and calf sequentially inflating (foot cuff first and calf cuff after 3 seconds, 20 seconds of rest). The device operates for 3 cycles/min at a fixed pressure of inflation of 120 mmHg. Outcome measures: a) Ankle-Brachial Index (ABI) measured according to the standard at rest and after treatment b) Haemodynamic measurements by ECD, including TAV e BF evaluation at femoral vein and at popliteal artery, performed before treatment, after 30 min in the decompression phase of the operative cycle and at the end of the treatment c) Evaluation of Foot perfusion by NIRS device as above described, by measurements performed continuously for a 5 min period before the treatment and for the whole treatment with both devices.4) Compliance, measured by a properly developed questionnaire proposed to the patients before and after the treatment with both devices to evaluate symptoms reduction and satisfaction. The effects of the AA instrument and GP device were measured in the same subjects in supine position in two different days with an interval of 48 ± 2 hours between the two treatments and an alternate order for each device. AA was tested for two consecutive hours of treatment and GP for 35 minutes. Results: A): the treatment with GP was well tolerated, without reported negative symptoms. During a single operative cycle BF and TAV at the femoral vein significantly increased during In e In1 phases (p>0.01). During a therapeutic cycle (25 min) BF and TAV slightly increased during the phase “out” from the beginning to the end of the treatment (p=0,10 n.s.). The foot perfusion was improved, with a significant increase both of tHbAUC and HbO2AUC (p<0.005), correlated to the TAV variations from the basal level recorded at femoral vein during the phase “out” (p<0.05). B): all patients completed the treatment with GP, while three out of them interrupted the treatment for painful symptoms at the foot. ABI increased from the baseline after treatment with GP (n=21, p=0.005), being unmodified after treatment with AA. After 30min of GP treatment the ECD parameters (TAV e BF) increased significantly at the femoral vein (n=21, p<0.05) as well BF at popliteal artery (p=0.011), while no variations were observed after AA treatment. Following compression with GP an improved foot perfusion was observed, with increase of tHbAUC (p<0.0001) and Hb O2AUC (p=0.001) that instead decreased after AA treatment (p=0.03). Compared to the AA treatment, the compression therapy with GP obtained a higher score for compliance, reduction of symptoms, easy use of the device and patients’ satisfaction (p<0.0001). Conclusions: GP, a new device for IPC in PAOD, evokes favourable haemodynamic changes with increased foot perfusion. Haemodynamic changes, distal perfusion and compliance with GP are more relevant than those observed after treatment with a traditional IPC device available on the market