HEPARIN-INDUCED LDL PRECIPITATION IN A NONDIABETIC DIALYSIS PATIENT AS RESCUE THERAPY FOR CRITICAL ISCHEMIC FOOT: A CASE REPORT

Abstract Background and Aims Dialysis per se represents an independent risk factor for peripheral arterial obliterating disease and in particular for critical ischemic limb. Conventional by-pass surgery or endovascular revascularization frequently did not avoid major limb amputation in dialysis patients or are excluded for wild calcificating atherosclerosis. Extracorporeal LDL-apheresis by means of Heparin-induced LDL Precipitation (H.E.L.P.) is proposed in some cases in combination to the traditional clinical approach. Method Here we describe the case of a 83-year old patient who undergoes thrice weekly hemodialysis from 1 year and who is affected by COPD, ischemic cardiopathy, previous stroke and had a Charson score of 6. He was also affected by dry necrosis of the second toe and parcel of the third toe of the right foot. The patient was not affected by diabetes. Lower limb arteriography showed right tibial artery obstruction anterior to the distal and dorsal third and severe stenosis with short sub-obstruction in subarticular area of the left popliteal artery. The plan foot x-ray excluded osteomyelitis. The vascular surgery consultant found the arterial lesions not suitable for revascularization advising monitoring and dressing of lesions. Nonetheless the patient complained of pain and opioid analgesics were administered. Cardioaspirin and atorvastatin were also administered. The patient was considered eligible for (H.E.L.P.) apheresis for the rescue of his limb. The patient underwent 8 sessions of H.E.L.P. apheresis once a week for eight weeks in a non-dialysis day. His vascular access was a permanent cuffed hemodialysis catheter. H.E.L.P. consists firstly in plasma separation, then apolipoprotein B-containing lipoproteins and fibrinogen are precipitated at a pH-value of 5.12 by the addition of a mixed acetate-heparin buffer to plasma. Before returning the plasma to the patient, the excess heparin is adsorbed and the pH normalized by a bicarbonate dialysis. A total of 3 litres of plasma per session was treated. Each session lasted 3 hours and was carried out in the Dialysis ward. Blood samples were obtained directly before and immediately after each H.E.L.P. apheresis for laboratory measurements. Results A C-reactive protein of 4 mg/dL reflected systemic inflammation. At baseline (prior to H.E.L.P. apheresis), fibrinogen was 394 mg/dL, LDL cholesterol was 122 mg/dL, lipoprotein(a) was 50.5 mg/dL. Total cholesterol was fairly normal even before H.E.L.P. apheresis with concentrations of 170 mg/dL. The pre vs post H.E.L.P. values were significantly reduced for all the parameters considered (p<0.0001). The median reduction rate (RR) per session for fibrinogen was 63.8% (range 57.1-75.3%), for lipoprotein(a) 66.1% (range 54.6-76.5), for LDL-cholesterol 50.8% (range 40-59.3%), for total cholesterol 40.7% (range 35.4-43.5%) (Figure 1). C reactive protein RRs was 61.2% (range 56.2-63.2%). Nonetheless, in the period between the H.E.L.P. apheresis a rebound was observed: for fibrinogen it was 64.9% (range 52.5-73.4%), for total cholesterol 29.2% (range -4 – 54.3%), for LDL cholesterol 36.4% (range -20 – 68.8%), for lipoprotein(a) 69.1% (range 44.1-73.9%). After the 8 sessions of H.E.L.P. apheresis, fibrinogen RR was 21%, LDL cholesterol RR was 75.4%, total cholesterol RR was 64%, lipoprotein(a) RR was 17%. After 6 months the patient underwent minor amputation of the second toe of the right foot, the third toe healed completely. The lesions of the foot before and after 1 year after HELP are showed in Figure 2. Conclusion Drastic reductions of fibrinogen, LDL cholesterol and lipoprotein(a), together with an adequate wound care, reduced the risk of major limb amputation in this dialysis patient with critically ischemic foot that was not qualified for revascularization.