Richard M Lynch1. 1. Accident and Emergency Department, Cavan General Hospital, Co. Cavan, Ireland. rlynch@tinyworld.co.uk
Abstract
BACKGROUND: Early detection of abdominal aortic aneurysms (AAA) is paramount to reducing the very high mortality rates associated with rupture. This literature review was undertaken to assess the accuracy of abdominal examination in the detection of non-ruptured AAA. METHOD: A comprehensive literature search was performed to retrieve prospective studies comparing the accuracy of physical examination (PE) in the diagnosis of non-ruptured AAA confirmed by the gold standard, ultrasonography. RESULTS: The sensitivity of PE in the diagnosis of AAA ranges from 33% to 100%, the specificity from 75% to 100%, and the positive predictive value from 14% to 100%. Detection rates increase with increasing aortic diameter, increasing age, male sex, presence of recognisable risk factors, examination by an experienced clinician, PE directed specifically towards the detection of AAA, prevalence of AAA in study population, and thin patients. CONCLUSION: Clinical examination cannot be relied upon to exclude AAA. Larger aneurysms are usually palpable and more likely to be detected on examination especially in thin patients. Due to the poor sensitivity of PE together with the high sensitivity and specificity of ultrasound, obese patients in whom there is difficulty palpating an aneurysm, despite a history suggestive of possible non-ruptured AAA, should be referred for ultrasound examination to assist with the diagnosis.
BACKGROUND: Early detection of abdominal aortic aneurysms (AAA) is paramount to reducing the very high mortality rates associated with rupture. This literature review was undertaken to assess the accuracy of abdominal examination in the detection of non-ruptured AAA. METHOD: A comprehensive literature search was performed to retrieve prospective studies comparing the accuracy of physical examination (PE) in the diagnosis of non-ruptured AAA confirmed by the gold standard, ultrasonography. RESULTS: The sensitivity of PE in the diagnosis of AAA ranges from 33% to 100%, the specificity from 75% to 100%, and the positive predictive value from 14% to 100%. Detection rates increase with increasing aortic diameter, increasing age, male sex, presence of recognisable risk factors, examination by an experienced clinician, PE directed specifically towards the detection of AAA, prevalence of AAA in study population, and thin patients. CONCLUSION: Clinical examination cannot be relied upon to exclude AAA. Larger aneurysms are usually palpable and more likely to be detected on examination especially in thin patients. Due to the poor sensitivity of PE together with the high sensitivity and specificity of ultrasound, obesepatients in whom there is difficulty palpating an aneurysm, despite a history suggestive of possible non-ruptured AAA, should be referred for ultrasound examination to assist with the diagnosis.