A study recently published in the World Journal of Surgery claims to be the first to provide comprehensive population-level data on the epidemiology of lower extremity amputation (LEA) in a Latin American low- and middle-income country (LMIC). The investigators write that their data, which focus on the Brazilian state of Sao Paulo, are “crucial to plan strategies to reduce the burden of LEA”.
“Lower limb amputations represent a high social, economic and health burden,” Rodrigo Bruno Biagioni (Hospital do Servidro Público Estadual de São Paulo, São Paulo, Brazil) et al write. According to the authors, most lower limb amputations are preventable, and reflect areas for improvement in healthcare. For these reasons, they stress that it is “essential” to know the epidemiology of these amputations, underscoring the rationale behind their study.
The investigators detail that LEA rates are “highly variable” across the world and that LEA trends are “conflicting”. These factors, they say, necessitate population-based studies in particular, “not only to truly know the local epidemiology of LEA, which reflects the quality of the health system, but also to build a global panorama in order to establish standards and goals.”
According to the authors, several countries in Europe, North America and Australasia have reported their amputation epidemiology, with most data coming from high-income countries (HICs). “Data from [LMICs] are scarce,” they write, noting that in Latin America no such study existed before the present analysis, to the best of their knowledge. “The paucity of data on LEA in LMICs is of particular concern,” the researchers note, “as the burden of PAD and [diabetes mellitus] is increasing in rates higher in LMICs than those observed in HICs.”
Biagioni et al’s study was a retrospective, population-based, cross-sectional analysis on all lower limb amputations performed in public hospitals in Sao Paulo—the most populous Brazilian state—between 2009 and 2020. The authors relay that they used a public database to evaluate types, rates and trends of the amputations performed, main aetiologies leading to the indication for amputation, hospital length of stay and in-hospital mortality rates, demographics of the amputees and procedure costs.
The study included data on 180,595 lower limb amputations and surgical revisions of amputations, with toe amputations (45%) and major amputations (33%) being the most frequent types of surgeries. Biagioni and colleagues report a significant increase in the rates of both of these procedures. They add that peripheral arterial disease (PAD) was found to be the most frequent underlying diagnosis for LEA, followed by diabetes mellitus, with an increasing trend for both over the last 12 years. Furthermore, they also observed seasonality in procedure rates, with peaks in August in all years.
The authors also reveal that most patients were male (69.3%), Caucasians (55.6%) and elderly. Other findings included a 6.6% rate of in-hospital mortality and lower limb amputations and total of US$67,675,875.55 reimbursed by the government.
Based on these findings, the authors propose some preventive strategies—namely foot ulcer screening, multidisciplinary diabetic foot care, and encouraging revascularisation procedures, which, they claim, have not significantly increased in the city of São Paulo, the capital of the state of Sao Paulo, since 2008.
In the discussion of their results, the research team considers some possible explanations for PAD being the main underlying diagnosis for all LEA in Sao Paulo, one of which is that Brazil is “late in the epidemiological transition concerning LEA”. They predict that it is likely Brazil will reach similar statistics to those found in most recent nationwide studies—which point to diabetes mellitus as the most common underlying cause of LEA—in the coming years, as the prevalence of smoking is reducing and that of diabetes mellitus is rising.
Furthermore, Biagioni et al address the finding that August showed the highest number of amputations in all years of their study. They write that, although this contrasts a previously reported finding from Hong Kong of higher LEA frequency due to diabetes mellitus during the summer, in this study the main underlying diagnosis was PAD, and it is possible there may be a worsening in PAD during winter. They elaborate: “Even though impaired circulation of lower limbs is documented for venous insufficiency, it is reasonable to think it may also play a role in arterial insufficiency.”
The authors recognise there are some limiting factors to their study, including the accuracy of their findings being “susceptible to inherent miscoding or data entry errors,” as with any database-driven study. In addition, they acknowledge that their data represent only the state of Sao Paulo, which depends solely on the public health system. “An integrated database covering data from public and private health systems would be more comprehensive,” they note.
Speaking to Vascular News, corresponding authors Andressa Cristina Sposato Louzada and Nelson Wolosker (both Hospital Israelita Albert Einstein, São Paulo, Brazil) comment on the study findings: “Knowledge of the data is essential for decision-making by public policy managers. Knowing the real amputation rates, increased investment in risk factor controls, and increased access to revascularisation become the most obvious attitudes. Soon, adopting such attitudes, amputation rates will probably decrease. This way, Brazilian society can evolve, an example for other countries.”