Background: Major limbs loss and high mortality rate were observed in the management of Thai patients with atherosclerosis obliterans (ASO) of the lower extremities. These were the results of delayed diagnosis and treatment together with the associated morbidities. There is a lack of information of this disease resulting in a lack of knowledge and awareness of this problem among general practitioners in Thailand.
Objectives: The purposes of this study were (1) to identify the prevalence of this disease in a tertiary care hospital, (2) to enumerate the risk factors and comorbidities, (3) to identify clinical characteristics of the disease and (4) to evaluate the outcomes of treatment.
Material and method: A prospective study ofpatients with ASO of the lower extremities was carried out between January 2000 and December 2004. Patients having clinical manifestations of chronic and acute arterial occlusion with the absence of ankle pulse were included in the present study. Evidence of atheromatous plaque by angiography, operative finding, and histopathology of arterial wall from amputated specimens were used to confirm the diagnosis. The selection of surgical treatments for this disease such as revascularization, major amputation, minor amputation and debridement depended on the severity of limb ischaemia, the status of distal artery and the patients' general condition. The risk factors, comorbidities, clinical manifestations, site of arterial occlusion, severity of ischaemia, types of surgical treatment and outcomes of management were analyzed.
Results: Four hundred and fourteen consecutive patients with ASO were diagnosed in the present study with a prevalence of 1.02:1,000. Femoro-popliteal arterial segment was the most common site (221 cases, 53.4%) of the affected arteries. Diabetes mellitus (253 cases, 61. 1%) was the most common risk factor of ASO followed by hypertension (217 cases, 52.4%), smoking (195 cases, 47.1%) and hyperlipidemia (172 cases, 41.5%). Ischaemic heart disease (108 cases, 26.1%) was the most common comorbidity of ASO followed by major stroke (56 cases, 13.5%) and chronic renal failure (20 cases, 4.8%). Patients with ASO presented mostly as chronic manifestations (385 cases, 93%) or with limb-threatening condition (326 cases, 78.7%). The clinical manifestations were ischaemic ulcer and/or digital gangrene (251cases, 60.6%), rest pain (182 cases, 44.0%) incapacitating claudication (62 cases, 15.0%) and acute ischaemic pain (29 cases, 7.0%). One hundred and thirty eight (33.3%) patients had significant lower limb infection at the time of admission. One hundred and seventy one (41.3%) patients underwent revascularization procedures as the major primary treatments to salvage the limbs. The success rate of limb salvage after revascularization was 76.6% (13 1/171). Major amputation after revascularization was 16. 9%(29/ 171). Perioperative mortality rate of revascularization procedure was 8.2 %(14/171). Major amputation was required as the primary treatment due to infective (18.4%, 76/414) and ischaemic process (6.5%, 27/414). The mortality rate of primary major amputation for infection and ischaemia were 19.7%(15/76) and 25.9%(7/2 7) respectively. The total mortality rate in the present study was 11.3% (47/414). The common causes of death were sepsis and ischaemic heart disease.
Conclusion: ASO of the lower extremities is one of the major problems for national health care causing major limb loss and death. Arterial bypass surgery was the most effective treatment for limb salvage. Management of this disease at the terminal stage causes high morbidity and mortality. Hence, early detection of this disease and correction of the risk factors should be the most effective strategy to improve the overall outcome of the management of this complicated problem.