Smoking is rightfully regarded as the single largest preventable cause of several cardiovascular diseases (CVDs) and several types of cancer. The harmful effects of tobacco on health came to light in the mid-20th century and nowadays the public is largely well-informed of them. However, smoking rates are still unacceptably high, most notably in developing and undeveloped countries. Additionally, it should be kept in mind that the cardiovascular system and lungs are not the only organ systems affected. The lower extremities are one such example, and foot and ankle surgeons often fight a tough battle with their patients who experience higher rates of post-surgery complications and treatment failures than non-smokers.
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Tobacco smoking is associated with several complications arising in the perioperative period, connected both to the surgery itself and any comorbid conditions that might interfere with surgery success. The harmful effects range from low bone mineral density, peri-implant bone loss, delayed fracture union and implant failure to peripheral arterial disease or PAD, if we take a broader definition [1, 2]. The latter is a particularly serious condition on its own with complications that directly impact foot and ankle surgical procedures even in the absence of smoking.
Smoking is a well-known risk factor for PAD, second only to diabetes mellitus in harmful effects on prevalence, morbidity, and mortality in affected patients [3, 4]. Smokers are 2.3 times more likely to have PAD than non-smokers, and even former smokers are more than 2.6 times likely than their non-smoking counterparts to have the disease . Studies have also demonstrated that smoking dramatically increases the incidence of PAD in men and this association is 2 to 3 times stronger in comparison with coronary artery disease (CAD) .
Several mechanisms regulate how smoking increases the incidence of PAD, including the reduction of flow-mediated dilation (FMD) through damage to the endothelial cells due to chemicals in tobacco smoke, which is conductive to atherogenesis . Additionally, many smokers have other medical issues (diabetes, hyperlipidaemia, hypertension, etc.) or are subject to risk factors (male gender, advanced age, family history) that increase the probability and severity of atherosclerosis. However, not all individuals are affected equally.
The harmful effects of smoking on health are generally the same for both genders, although that cannot be said for the risk for specific diseases where there are significant differences such as within each gender and racial group. Focusing just on PAD, female smokers are 20 times more likely to have the disease than non-smokers . Moreover, from a racial perspective, black individuals are more at risk for PAD than white, and this is especially pronounced in black smokers [9, 10]. On top of that, black people have higher rates of comorbid conditions like insulin-dependent diabetes, renal insufficiency, and heart failure (HF) that aggravate PAD-related complications, including arterial ulcers, which are difficult to treat .
Chemical compounds in tobacco smoke, more than 4000 of them, have an adverse effect on wound healing, particularly nicotine, carbon monoxide, and hydrogen cyanide . The exact mechanism involved is not well understood, but it has been demonstrated to relate to impaired oxygen supply to tissues [13-15]. In PAD, this manifests as a greater incidence of non-healing wounds and worse outcomes in those with existing wounds, particularly in combination with diabetes [16-18]. Also, smoking is related to a higher rate of post-operative complications in patients who had undergone revascularisation with severity dependent on the daily consumption of cigarettes .
The effects on wounds incurred during foot and ankle surgery are similar. Studies have shown that smoking not only delays healing but also increases wound infection . Smoking can likewise cause destruction in recipients of autologous chondrocyte implantation, inhibiting healing and increasing the likelihood of graft failure . Even more serious are the effects on bone healing.
Despite different mechanisms at work, tobacco smoking complicates proper bone healing, even in fractures that are rarely associated with non-union . More specifically, it has been shown that the serum level of transforming growth factor-beta, was reduced in smokers compared to non-smokers following bone fracture . Fortunately, smoking cessation lessens the likelihood of said complications with one study demonstrating a decreased risk of post-operative complications due to smoking cessation during the first six weeks after acute fracture surgery .
The advantages of smoking cessation are numerous and generally proportional with time passed since the last cigarette [25-29]. When it comes to PAD, it decreases the risk of incidence in those who do not have the disease yet, improves claudication symptoms, and prevents or lessens the risk of disease progression, amputation, graft failure, restenosis after endovascular revascularisation, MI, and ultimately death [30-32].
Even if they don’t have PAD, or are recovering from it, those about to undergo foot and ankle surgery will benefit as well. A meta-analysis of the results of a systematic review involving 6 randomised controlled trials and 15 observational studies found that smoking cessation was associated with a decreased likelihood of post-operative complications, including total hip and total knee arthroplasty . The foot and ankle surgeon’s help in achieving that is vital. One study encompassing patients who underwent forefoot fusion and arthrodesis surgery demonstrated that 64% of smokers quit preoperatively after counselling by surgeons, and 16% reduced their smoking, i.e. 80% of patients responded to the request and encouragement to discontinue smoking .
Smoking cessation is an important factor in preventing complications and adverse outcomes due to foot and ankle surgery, particularly in patients with PAD. Together with selected other clinicians, foot and ankle surgeons are in a unique position to influence their patients to cease smoking and improve their overall health and decrease the incidence of several diseases.