Atherosclerosis Obliterans of the Lower Extremities in Thai Patients
Pramook Mutirangura MD*, Chanean Ruangsetakit MD*, Chumpol Wongwanit MD*, Nuttawut Sermsathanasawadi MD*, Khamin Chinsakchai MD*
Affiliation : * Vascular Surgery Unit, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University
Background : Major limbs loss and high mortality rate were observed in the management of Thai patients with atherosclero-
sis 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.
Materials and Methods : A prospective study of patients 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 manage-
ment 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% (131/171). 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%(7/27) 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.
Keywords : Atherosclerosis obliterans, Peripheral arterial disease, Lower extremities
