Peripheral Artery Disease (PAD) is a complex and serious cardiovascular disease (CVD), but like many (but not all) CVDs, it can be effectively managed using conservative methods so long as the condition is diagnosed in a timely manner. This is most easily achieved through an ABI or TBI assessment, which have, particularly the latter, diagnostic applications that are beyond those connected with PAD.
In 2010 there were at least 202 million patients with PAD (or LEAD, Lower Extremity Artery Disease, as it is increasingly also referred to as) – that number increased to 236.62 million in 2015 and today, in light of this rising trend, the prevalence is likely even higher, primarily due to ageing of the population and an increase in several important risk factors [1, 2]. However such worrisome estimates don’t really translate into numbers of definite diagnoses, as PAD is far more likely to be asymptomatic (40 % of patients) than symptomatic (10 % of all cases) or is ‘masked’ by other, unrelated medical conditions (atypical pain felt by the remaining half of patients) [3, 4]. Basing diagnosis solely on the presence of overt symptoms (intermittent claudication) or (unreliable) physical examination is foolhardy at best and bordering on malpractice as there are far better diagnostic methods available .
The Ankle-Brachial (Pressure) Index (ABPI or ABI) assessment is a prime example as it offers a level of accuracy and specificity in comparison with other, far more expensive methods (i.e. angiography). Cost-efficiency is coupled with the time-saving nature of the procedure (speed of assessment), particularly if performed with an oscillometric-plethysmographic diagnostic device in lieu of Doppler probe/sphygmomanometer combination [6, 7, 8]. But, despite its usability, particularly in general practice settings, it is greatly underutilised, even in at-risk patients. A comprehensive study of patients receiving wound care in the UK found that about 40 % of patients with lower-extremity ulcers had either not received an ABI assessment or it was unclear whether a recording had been taken – significant chance they might have been given inappropriate treatment .
Complications and the adverse outcomes of PAD are numerous and their severity greatly depends on timeliness of diagnosis and the presence of comorbid diseases, whether they are cardiovascular in nature or of another etiology/pathophysiology, with diabetes mellitus being a good example. This metabolic disorder is rapidly growing in prevalence (projected to affect at least 629 million individuals by 2045) and is also responsible for preventing accurate diagnosis of PAD (using ABI) in many patients through its contribution to the calcification (hardening) of arteries [10, 11].
Incompressible arteries can also be found in individuals with renal insufficiency and rheumatoid arthritis [12, 13]. Although toe arteries are rarely affected by calcification, they can be used as substitutes for blood pressure at dorsalis pedis/posterior tibial artery in the Toe-Brachial Index (TBI) assessment . Additionally, like ABI, TBI has a diagnostic value beyond diagnosing PAD and even has an application in postoperative monitoring of vascular surgery patients and predicting the possibility of adverse outcomes in beneficiaries of revascularisation surgery.
Nearly any type of vascular surgery carries with it a substantial risk of adverse outcomes, particularly if major blood vessels are involved. Introduction and refinement of percutaneous procedures has mitigated (in patients that are suitable candidates for such procedures) many of possible complications associated with open surgery (for respective conditions) [15, 16, 17]. There remains a greater risk of complications still persisting in high-risk patients of an advanced age with comorbid cardiac and/or renal issues . Comprehensive postoperative monitoring of vascular patients is therefore a must and should also include the use of ABI and TBI assessments, which have an added diagnostic value if performed as a part of preoperative screening.
The TBI is a valuable tool for the perioperative assessment and monitoring of vascular surgery patients, particularly those with incompressible arteries or other conditions that preclude the use of an ABI assessment.