I. B. Faris

Incidence of the radial steal syndrome in patients with Brescia fistula for hemodialysis: Its clinical significance

The Brescia fistula is the method of choice for providing vascular access in patients who have chronic kidney failure that requires hemodialysis. This study investigated hand hemodynamics in patients with Brescia fistulas to determine the incidence of radial steal and its relationship to symptoms of arterial insufficiency of the hand. Twenty-three patients, one of whom had symptoms of arterial insufficiency, were studied. Thumb systolic blood pressure was determined by photoplethysmography under resting conditions and with the fistula, radial, and ulnar arteries occluded successively by digital pressure. The brachial pressure was determined by Doppler ultrasonography and the thumb/arm pressure ratio was determined for each experimental condition. The presence of a Brescia fistula resulted in a 40% reduction of the thumb blood pressure (median thumb/arm ratio = 0.61), which returned to normal (median ratio = 1.03) when the fistula was occluded. Occlusion of the radial artery distal to the fistula resulted in a significant increase in thumb blood pressure (median ratio = 0.89; p less than 0.001), indicating the presence of radial steal. This phenomenon occurred in 21 of the 24 fistulas (88%) studied. This study demonstrated that the radial steal phenomenon occurs in most patients with Brescia fistulas but in only a small number of these patients do symptoms of arterial insufficiency develop.

Upper extremity arterial injuries: Experience at the Royal Adelaide Hospital, 1969 to 1991

PURPOSE A review of upper extremity arterial injuries managed at the Royal Adelaide Hospital between 1969 and 1991 was undertaken because the optimal management of complex upper extremity trauma, particularly in proximal injuries, remains unclear. METHODS Patients were identified from the computer registry of patients treated by the vascular unit at the Royal Adelaide Hospital. They were studied in three groups: (1) subclavian and axillary artery, (2) brachial artery, and (3) radial and ulnar artery injuries. The mechanism of injury, associated injuries, treatment and outcome were reviewed. RESULTS There were 114 patients with upper extremity arterial injuries: 28 with subclavian and axillary, 62 with brachial, and 24 with radial and ulnar artery injuries. Good upper limb function was obtained in 32% of subclavian and axillary artery injuries, 79% of brachial artery injuries, and all radial and ulnar artery injuries. Amputation was performed in 14% of the proximal injuries and 8% of the brachial artery injuries. Three deaths occurred in this study group. CONCLUSION Blunt proximal injuries were usually associated with neurologic, soft tissue, and bony damage, which was responsible for the poor functional outcome. Critical limb ischemia or severe hemorrhage rarely occurred. Complete brachial plexus lesions resulted in uniformly poor outcomes. More distal injuries were associated with fewer nerve and soft tissue injuries, resulting in a more satisfactory outcome.

Intra-arterial streptokinase therapy to relieve acute limb ischemia

One hundred two patients with acute lower limb ischemia were treated with intra-arterial streptokinase. Thirty-seven patients had occluded vascular grafts and sixty-five had had no previous vascular surgery. Eighty-six limbs were acutely threatened. Intra-arterial streptokinase was given as an initial loading dose with a lower maintenance dose given afterward. The mean duration of therapy was 59 hours and hematologic monitoring was meticulous. Indications for intra-arterial streptokinase therapy were contraindication to surgery, anticipation of technically difficult surgery, and multiple occlusions that required separate surgical approaches. Seventy-two legs were saved (71%) and 30 amputated. Morbidity was low and only 1 of the 11 deaths was attributable to streptokinase. No leg was lost that would otherwise have been saved by straightforward surgery and no leg was lost that had not been previously threatened. In 46 patients for whom emergency femorotibial bypass would have been necessary, 35 legs (76%) were saved. Forty-three patients had vascular reconstruction immediately after streptokinase therapy was stopped, to bypass occlusive lesions that had been demonstrated by the thrombolytic therapy in 28 patients, and because streptokinase had produced no response in 15 patients. The advantages of intra-arterial streptokinase in the management of the acutely ischemic leg are that the leg may be saved without surgery, that surgery is not precluded, that the patient can be made as fit as possible for surgery during the streptokinase infusion, and that streptokinase can facilitate surgery by delineating underlying vascular pathologic conditions and clearing distal runoff vessels.

Femorocrural grafting and regrafting: Does polytetrafluoroethylene have a role?

Between 1980 and 1988, 263 patients received 307 femorocrural bypass grafts. 180 were primary infrainguinal grafts, 106 secondary, 18 tertiary and three quaternary. Rest pain or tissue loss was the indication in 96% of cases. Outflow vessels were the tibioperoneal trunk (n = 34), posterior tibial artery (n = 115), peroneal artery (n = 89) and anterior tibial artery (n = 69). 88 primary vein grafts were completed. 201 polytetrafluoroethylene (PTFE) grafts were inserted (92 primary and 109 subsequent reconstructions). There were no direct PTFE to crural vessel anastomoses. A Miller cuff was used in the majority (n = 175). The three year primary patency for primary vein grafts (36%) was similar to primary PTFE grafts (29%), but significantly higher than subsequent PTFE grafts (20%) (p = 0.03). Three year foot salvage for primary vein grafts (65%) was similar to primary PTFE (64%), but significantly better than subsequent PTFE (42%) (p = 0.02). The results support both redo femorocrural grafting for critical ischaemia, as judged by foot salvage rates, and the use of PTFE with a distal vein cuff in primary and subsequent femorocrural reconstruction if autologous vein is not available.

Martorell's hypertensive ischemic leg ulcers are secondary to an increase in the local vascular resistance * **

In 1945 Martorell described ischemic leg ulcers in patients with hypertension and suggested that the ischemic necrosis was secondary to hypertensive arteriolar disease. The aim of the study was to examine the minimum vascular resistance in the skin of patients with these ulcers. Twelve control subjects (median age 52 years), eight patients with peripheral vascular disease (PVD) (median age 73 years), and six patients with hypertensive ulcers (median age 74 years) were studied. The minimum vascular resistance (MVR) and skin perfusion pressure (SPP) were determined by an isotope clearance method. Presence and severity of PVD were assessed by ankle/arm pressure ratios. The ulcer patients had a higher ankle/arm pressure ratio than the PVD group (p = 0.026) but had similar SPP (p = 0.47). When compared with the control group they had a similar pressure ratio (p = 0.09) but lower SPP (p = 0.001). The MVR was higher in the ulcer patients than the control subjects (p = 0.005) and the PVD group (p = 0.01). The study shows that patients with hypertensive ulcers have a high vascular resistance. This increase in resistance may interfere with the compensatory relaxation that normally occurs distal to an arterial narrowing, resulting in poor tissue perfusion and subsequent ulcer development.

Monitoring of heparin in vascular surgery

In patients heparinized for surgery on the infrarenal aorta, the degree of anticoagulation by heparin of stasis blood (taken from below the aortic clamp) was compared with that obtained in circulating blood taken from a forearm artery. A measurement of activated partial thromboplastin time (APTT) was made on a venous blood sample taken from each patient before 5000 units of heparin was administered intravenously. Further measurements of APTT from static blood and from circulating arterial blood were made at 3, 15, 30, and 60 minutes after heparinization. Samples taken below the aortic clamp showed measurements of APTT lower than those from circulating arterial blood at 15, 30, and 60 minutes (p less than 0.05 paired Wilcoxon rank sum test). Current methods for administering and monitoring heparin may not provide an adequate degree of anticoagulation in static blood during vascular surgery. The consequences, if any, of inadequate anticoagulation in vascular surgery need further study.

The fate of the aortofemoral graft

OBJECTIVE To determine the incidence and cause for reoperation following aortofemoral bypass surgery. DESIGN This paper describes the results of all aortofemoral grafts performed in the years 1978-1991, 251 of these patients underwent an aortobifemoral graft (ABF) whilst the remaining 50 had an aortounifemoral graft (AUF). RESULTS The aortofemoral bypass was the only operation performed in fewer than half of the patients. Sixteen per cent of ABF and 50% of the AUF patients had surgery before the index operation. Subsequently 33% of the ABF patients and 60% of the AUF group had one or more additional vascular procedures. Graft infections and false aneurysms continued to present in about 1% patients per year at least up to 10 years following surgery. The 5 year actuarial survival was 73% in the ABF group and 38% in the AUF patients. The primary patency at 5 years was 85% in the ABF patients and 81% in the AUF group. Amputation was performed in 6% of the ABF patients and in 20% of the AUF patients. CONCLUSIONS The frequent need for later surgery (1:3 for the ABF patients) should be considered in the decision to undertake the initial aortofemoral operation when the patient presents with intermittent claudication.