Clinical Study
Effects of diabetes and smoking on lumbar spinal surgery outcomes

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Abstract

Smoking and diabetes have long been considered risk factors for poor surgical outcome. However, the precise role of smoking and diabetes in the development of poor outcome in lumbar spinal surgery remains ambiguous. This study was undertaken to determine the effects of diabetes and smoking specifically on lumbar spinal surgery outcomes. A retrospective cohort study studied 902 patients who underwent lumbar spinal surgery at the Royal Melbourne Hospital, Australia, between 2001 and 2005, inclusively. Four groups were formed: control; diabetic; positive smoking history; and diabetic and positive smoking history. Multivariate analysis was used to analyse the likelihood of developing complications with a history of diabetes and/or smoking. Our findings indicate that diabetes was significantly associated with an increased risk of developing complications. Patients in the diabetic groups were also significantly older and had a longer length of stay than the other patients (p < 0.05 for all significant findings). We conclude that diabetes does increase the risk of poor outcome following lumbar spinal surgery. However, we found no association between a positive smoking history and an increased rate of poor outcome.

Introduction

Smoking has been regarded as an independant risk factor for complications after surgery. It is associated with impaired tissue healing and an increased risk of pulmonary and cardiovascular complications after surgery.1, 2 With respect to spinal surgery, smoking has been demonstrated to increase the risk of lumbar disc degeneration, inhibit lumbar spinal fusion, and increase the risk of lumbar disc herniation. Smoking cessation, however, is associated with improved healing of spinal fusion compared to continued smoking. A study by Sanden et al. compared the surgical outcome of smoking and non-smoking patients who underwent lumbar decompression surgery after 2 years of follow-up. They found that although there were improvements in both groups, the smoking group showed less improvement in the form of higher analgesic use, poorer walking ability, and higher dissatisfaction with the surgery.2

The findings of Glassman et al. drew a similar conclusion with the non-union rate of spinal fusion being higher in smokers, lower in patients who ceased smoking, and even lower in patients who did not smoke.3 This is contradicted by Kim et al. who found no correlation between smoking history and increased risk of poor outcome.2, 4 Andersen et al. found that smoking cessation decreased the risk of non-union in spinal fusion and stated that smoking had a negative effect on spinal fusion.5 Another study by Hansraj et al. found no statistically significant association between smoking and the outcome of decompressive surgery for lumbar spinal stenosis.6 Delgado-Rodriguez et al. found no relationship between current smokers and risk of surgical site infection (SSI),7 whereas the results from Moller et al. indicated that smoking is one of the single most important risk factors for the development of wound complications such as impaired wound healing and SSI.1 Other findings in the literature agree with the conclusions of Moller et al. in that smoking is a risk factor for the development of SSI.4, 8, 9, 10, 11, 12, 13, 14

Diabetes mellitus is a chronic systemic disease that may damage small nerves and blood vessels. It can lead to a poor surgical outcome via impaired wound healing, due to local tissue ischaemia caused by damages to the microvasculature. Diabetes is also a known independant risk factor for SSI, and has been associated with increased infection rates.4, 8, 9, 10, 11, 12, 13, 14 Kim et al. suggested that diabetic patients have a higher risk of poor outcome, with neurological damage such as infarcts, demyelination, atrophy, and softening of the posterior spinal cord caused directly by diabetes, which cannot be resolved by decompression surgery.4

Kim et al. also suggested that diabetes and smoking have a synergistic effect that can adversely affect the outcome after cervical laminoplasties (odds ratio [OR] of 4.01 for patients positive for diabetes and smoking versus 2.92 for patients with only diabetes)4 However, Chen et al. found that diabetes is a definite risk factor for SSI after posterior spinal instrumentation whereas other variables such as smoking, age, sex, body mass index, estimated blood loss, and surgery time were not factors for the development of SSI.10

This study aimed to examine a relatively large number of patients who underwent spinal surgery at the Royal Melbourne Hospital, Melbourne, Australia, between 2001 and 2005, looking specifically at lumbar spinal surgery, to assess the effects of smoking and diabetes on the surgical outcome. It was hypothesised that patients with diabetes and/or a positive smoking history would have a higher rate of poor surgical outcome when compared to a control group.

Section snippets

Study design

A retrospective cohort study which looked at distinctive and separate cohorts of patients who underwent lumbar spinal surgery at the Royal Melbourne Hospital between 2001 and 2005 was conducted. Ethics approval was granted by the Royal Melbourne Hospital Ethics Committee.

Patient inclusion criteria

Potential participants were identified by searching the electronic medical record database using procedure codes specific to lumbar spinal surgery and diagnosis codes specific to conditions that use lumbar spinal surgery as

Data analysis

The relevant information was extracted from the electronic medical records and clinical notes and edited into an Excel (Microsoft, Redmond, WA, USA) database created for the project. The data were analysed to compare overall outcomes and the rate of good and poor outcomes between the cohorts. With respect to patients who developed a poor outcome, each individual event was analysed to determine its significance and relation to the relevant exposure of diabetes, smoking, or both.

All patients who

Results

A total of 902 patients underwent lumbar spinal surgery at the Royal Melbourne Hospital between 2001 and 2005, inclusive (Suppl. Table 1). Details of the patient populations in each group are shown in Table 1. Of the 902 patients, 115 (12.75%) patients had a diagnosis of either insulin or non-insulin-dependent diabetes and 383 (42.46%) patients had a positive smoking history. The 40 (4.43%) patients who were both diabetic and had a positive smoking history were placed in a separate group,

Discussion

In our patient population, the overall rate of complication development was 27.83%, with 251 of 902 patients developing at least a single complication following lumbar spinal surgery. The overall rate of developing multiple complications was 5.43% (49/902). Patients who underwent spinal fusion procedures had an overall rate of complication development of 39.09% (77/197) compared to patients who underwent decompression surgery without fusion, with an overall rate of 24.68% (174/705). Patients in

Limitations

This study’s main limitation was its retrospective nature. All of the clinical patient information was obtained through review of clinical notes. Unfortunately, not all physicians input the same degree of detail in the medical records, which may result in incomplete clinical information. However, since the size of the cohort was relatively large, we had enough power to accommodate the data and overcome some of these deficiencies.

Electronic coding databases are also subject to error based on

Conclusions

We conclude that diabetes independently increases the rate of poor outcome following lumbar spinal surgery. Diabetic patients had a significantly higher rate of developing single and multiple complications, especially those of the infectious and cardiovascular nature as defined in this study. A positive smoking history was not associated with a higher rate of poor outcome following lumbar spinal surgery, whether as an independant variable or as a co-dependent variable with diabetes.

Conflicts of interest/disclosures

The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.

References (18)

  • A.M. Møller et al.

    Effect of smoking on early complications after elective orthopaedic surgery

    J Bone and Joint Surg Br

    (2003)
  • B. Sanden et al.

    Smokers show less improvement than non-smokers 2 years after surgery for lumbar spinal stenosis

    Spine

    (2011)
  • S.D. Glassman et al.

    The effect of cigarette smoking and smoking cessation on spinal fusion

    Spine

    (2000)
  • H.J. Kim et al.

    Diabetes and smoking as prognostic factors after cervical laminoplasty

    J Bone and Joint Surg Br

    (2008)
  • T. Andersen et al.

    Smoking as a predictor of negative outcome in lumbar spinal fusion

    Spine

    (2001)
  • K.K. Hansraj et al.

    Decompressive surgery for typical lumbar spinal stenosis

    Clin Orthop Relat Res

    (2001)
  • M. Delgado-Rodríguez et al.

    A prospective study of tobacco smoking as a predictor of complications in general surgery

    Infect Control Hosp Epedemiol

    (2003)
  • A.F. Pull ter Gunne et al.

    Incidence of surgical site infection following adult spinal deformity surgery: an analysis of patient risk

    Eur Spine J

    (2010)
  • A.F. Pull ter Gunne et al.

    Incidence, prevalence, and analysis of risk factors for surgical site infection following adult spinal surgery

    Spine

    (2009)
There are more references available in the full text version of this article.

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