Dear Sir,
This is in response to points raised in a letter to the editor regarding our article, ‘Two-year clinical outcomes post lower limb endovascular revascularisation for chronic limb-threatening ischemia at a tertiary Asian vascular centre in Singapore’.[1] We thank the authors for taking the time to read and provide their valuable comments[2] on our article. In the study population, 80/207 (38.6%) patients were smokers, and approximately 14.4% had a history of chronic obstructive pulmonary disease (COPD) or pneumonia. We have looked at COPD as a factor of outcome, but no correlation between COPD and post-operative patient mortality or morbidity was found.
However, we acknowledge that our small sample size (207) may not be representative of the larger population of patients with chronic limb-threatening ischemia (CLTI) in Singapore. Hence, the small sample size may suffer from a type II error. The fact that the entire group underwent endovascular revascularisation, which does not require a general anaesthetic or a surgical incision that may splint the diaphragm, would mean that the risk of complications, especially from respiratory issues would be less. Common risk factors such as smoking and old age cause patients to often have concomitant COPD and cardiovascular diseases. Patients with COPD and peripheral arterial disease (PAD) are likely to have a more impaired functional capacity than PAD patients without COPD,[3] due to the airflow limitations in these patients. The impaired functional capacity will then increase the mortality risk.[4] Conversely, PAD also has a considerable effect on exercise intolerance in COPD.[5] A study conducted in the USA found that the risks of major adverse cardiac events and respiratory-related adverse events were higher in PAD patients with COPD, as compared to those without.[6]
Hence, it is important to evaluate patients with COPD with severe PAD or CLTI to identify their functional status pre-operatively. Efforts should be made to optimise their functional capacity, such as via the pulmonary rehabilitation, prior to any surgical intervention.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
REFERENCES
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