Impact of Smoking on 30-day Morbidity and Mortality in Adult Spinal Deformity Surgery

Influence of smoking on patient-reported outcome measures (PROMs) in patients undergoing surgery for adult spinal deformity: a propensity score-matched analysis

PURPOSE

The purpose of this study was to determine the isolated influence of smoking in patient-reported outcome measures (PROMs) for adult spinal deformity (ASD) surgery excluding known tobacco-related complications.

METHODS

Retrospective analysis of a prospective multicenter ASD database. Patients operated on ASD with 2 year post-operative follow-up were included. Former smokers (non-active smokers) and patients developing mechanical or infectious complications were excluded. Changes of PROMs over time were analyzed using mixed models for repeated measures (MMRM). Propensity score matching (PSM) (1:1 ratio, caliper 0.10) was performed without replacement using optimum algorithm, tolerance ≤ 0.001, and estimated with 95% confidence interval (CI). PROMS in both groups were compared by paired t test or Wilcoxon signed-rank test.

RESULTS

692 out of 1246 surgical patients met our inclusion criteria. 153 smokers were matched with 153 non-smokers according to age, BMI, number of fused levels, and global tilt. After PSM both groups were homogeneous regarding baseline parameters, surgical data, and complications (mechanical complications and infection excluded). Smokers had worse baseline results for SRS-total, SRS-pain COMI-back, and ODI; smokers also showed worse 2-year outcomes for SRS-total, SRS-function, SRS-pain, SRS-self-image, and ODI. However, no differences between the two groups were found in the improvement from baseline to 2-year follow-up or in the timing of this improvement (MMRM). The proportion of patients reaching the minimal clinically important difference (MCID) after surgery was similar in the two groups, but the proportion of patients reaching patient acceptable symptom state (PASS) was significantly lower in smokers for SRS-Subtotal, SRS-function, and SRS-image.

CONCLUSION

Even in the absence of smoking-related complications, smokers had worse PROMs at baseline and 2 years after surgery with less patients achieving PASS, but similar degrees on improvement compared to non-smokers. The proportion achieving MCID was also similar between the two cohorts.

Preoperative Optimization for Adult Spinal Deformity Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

The purpose of this review is to identify modifiable risk factors in patients undergoing adult spinal deformity surgery and compile literature recommendations for the preoperative optimization of these risk factors.

SUMMARY OF BACKGROUND DATA

Optimization of modifiable risk factors not only benefits the patient but also lessens resource and cost burdens on the health care system, allowing for better quality and value-based care. There is limited but applicable literature discussing preoperative optimization in adult spinal deformity surgery patients specifically.

METHODS

We searched PubMed for studies that looked at one of the variables of interest (eg, osteoporosis, prehabilitation and functional status, multidisciplinary preoperative screening, infection, obesity, nutrition, smoking, diabetes, blood loss, chronic opioid use, and psychosocial factors) in adult patients with spinal deformity according to Preferred Reporting Items for Systematic Reviews and Meta-Analyse guidelines.

RESULTS

Seventy studies were included in the final review and synthesis of information. Guidelines and recommendations from these studies were compared and compiled into evidence-based action items for preoperative optimization of modifiable risk factors before adult spinal deformity surgery.

CONCLUSIONS

While the approach of preoperative optimization of modifiable risk factors may incur additional planning efforts and patient care time, it has the potential to significantly reduce perioperative complications and reduce morbidity and mortality during surgery, thus allowing for improved outcomes, increased quality of life, and satisfaction from this patient population.

LEVEL OF EVIDENCE

3.

Put Down the Tin: Chewing Tobacco Use Is Associated With Worse Outcomes After Primary Lumbar Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

This study evaluated the impact of chewing tobacco on both medical and spine-related complication rates after spinal lumbar fusions in comparison to both a control cohort and a smoking cohort.

SUMMARY OF BACKGROUND DATA

Smoking is a prevalent modifiable risk factor that has been demonstrated to be associated with increased complications after lumbar fusion. Although smoking rates have decreased in the United States, chewing tobacco use has not similarly reduced. Despite chewing tobacco delivering up to 4 times the dose of smoking, the impact of chewing tobacco is incompletely understood.

METHODS

A retrospective cohort study was conducted using the PearlDiver database. Patients who underwent lumbar spine fusion and used chewing tobacco were matched with a control cohort and a smoking cohort. Medical complications within 90 days after primary lumbar fusion were evaluated, including deep venous thrombosis, acute kidney injury, pulmonary embolism, transfusion, acute myocardial infarction, and inpatient readmission. Spine-related complications were evaluated at 2 years postoperatively, including pseudoarthrosis, incision and drainage (I&D), instrument failure, revision, and infection.

RESULTS

After primary lumbar fusion, the chewing tobacco cohort demonstrated significantly higher rates of pseudoarthrosis [odds ratio (OR): 1.41], revision (OR: 1.57), and any spine-related complication (OR: 1.32) compared with controls. The smoking cohort demonstrated significantly higher rates of pseudoarthrosis (OR: 1.88), I&D (OR: 1.27), instrument failure (OR: 1.39), revision (OR: 1.54), infection (OR: 1.34), and any spine-related complication (OR: 1.77) compared with controls. The chewing tobacco cohort demonstrated significantly lower rates of pseudoarthrosis (OR: 0.84), I&D (OR: 0.49), infection (OR: 0.70), and any spine-related complication (OR: 0.81) compared with the smoking cohort.

CONCLUSIONS

This study demonstrated that chewing tobacco is associated with higher rates of both spine-related and medical complications after primary lumbar fusion. However, chewing tobacco use is associated with less risk of complications compared with smoking.

LEVEL OF EVIDENCE

Level III.

The Risk of Adverse Events in Smokers Undergoing Spinal Fusion: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Determine if tobacco use is associated with increased risk of postoperative adverse events within 90 days in patients undergoing spinal fusion surgery.

METHODS

Databases were queried to identify cohort studies that directly compared smokers with non-smokers and provided the absolute number of adverse events and the population at risk. Data quality was evaluated using the Quality in Prognosis Studies tool. Risk ratios (RR) and 95% confidence intervals were calculated and compared between studies. The grading of recommendation, assessment, development and evaluation (GRADE) criteria were used to assess the strength of the evidence.

RESULTS

Seventeen studies assessing 37 897 participants met the inclusion criteria. Of these, 10 031 (26.5%) were smokers and 27 866 (73.5%) were nonsmokers. The mean age for the study population was 58 years, and 45% were males. Smoking was not associated with increased risk of one or more major adverse events within 90 days following spine surgery (seven studies, pooled RR 1.13, 95% CI [.75-1.71], I2 = 41%). However, smoking was significantly associated with one or more major adverse events in ≤2 level fusion (three studies, pooled RR 2.46, 95% CI [1.18-5.12], I2 = 0%), but not in fusions of ≥3 levels (four studies, pooled RR .87, 95% CI [.70-1.08], I2 = 0%). Additionally, there was no statistically significant association between smoking and any adverse event, nor increased reoperation risk due to adverse events.

CONCLUSIONS

In this meta-analysis, tobacco use was not associated with a statistically significant increased risk of adverse events within 90 days in patients undergoing spinal fusion surgery. Our results are limited by the variable reporting methodology for both complication rates as well as smoking incidence between the included individual studies.

Relationship between smoking and postoperative complications of cervical spine surgery: a systematic review and meta-analysis

To determine whether smoking has adverse effects on postoperative complications following spine cervical surgery (PROSPERO 2021: CRD42021269648). We searched PubMed, Embase, Cochrane Library, and Web of Science through 13 July 2021 for cohort and case–control studies that investigated the effect of smoking on postoperative complications after cervical spine surgery. Two researchers independently screened the studies and extracted data according to the selection criteria. The meta-analysis included 43 studies, including 27 case–control studies and 16 cohort studies, with 10,020 patients. Pooled estimates showed that smoking was associated with overall postoperative complications (effect estimate [ES] = 1.99, 95% confidence interval [CI]: 1.62–2.44, p < 0.0001), respiratory complications (ES = 2.70, 95% CI: 1.62–4.49, p < 0.0001), reoperation (ES = 2.06, 95% CI: 1.50–2.81, p < 0.0001), dysphagia (ES = 1.49, 95% CI: 1.06–2.10, p = 0.022), wound infection (ES = 3.21, 95% CI: 1.62–6.36, p = 0.001), and axial neck pain (ES = 1.98, 95% CI: 1.25–3.12, p = 0.003). There were no significant differences between the smoking and nonsmoking groups in terms of fusion (ES = 0.97, 95% CI: 0.94–1.00, p = 0.0097), operation time (weighted mean difference [WMD] = 0.08, 95% CI: −5.54 to 5.71, p = 0.977), estimated blood loss (WMD = −5.31, 95% CI: −148.83 to 139.22, p = 0.943), length of hospital stay (WMD = 1.01, 95% CI: −2.17 to 4.20, p = 0.534), Visual Analog Scale-neck pain score (WMD = −0.19, 95% CI: −1.19 to 0.81, p = 0.707), Visual Analog Scale-arm pain score (WMD = −0.50, 95% CI: −1.53 to 0.53, p = 0.343), Neck Disability Index score (WMD = 11.46, 95% CI: −3.83 to 26.76, p = 0.142), or Japanese Orthopedic Association Scores (WMD = −1.75, 95% CI: −5.27 to 1.78, p = 0.332). Compared with nonsmokers, smokers seem to be more significantly associated with overall complications, respiratory complications, reoperation, longer hospital stay, dysphagia, wound infection and axial neck pain after cervical spine surgery. It is essential to provide timely smoking cessation advice and explanation to patients before elective cervical spine surgery.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Surgical Risk Assessment

BACKGROUND

Patient factors (increased body mass index [BMI], smoking, and diabetes) may impact outcomes after spine surgery. There is a lack of consensus regarding which factors should be screened for and potentially modified preoperatively to optimize outcome.

OBJECTIVE

The purpose of this evidence-based clinical practice guideline is to determine if preoperative patient factors of diabetes, smoking, and increased BMI impact surgical outcomes.

METHODS

A systematic review of the literature for studies relevant to spine surgery was performed using the National Library of Medicine PubMed database and the Cochrane Library. Clinical studies evaluating the impact of diabetes or increased BMI with reoperation and/or surgical site infection (SSI) were selected for review. In addition, the impact of preoperative smoking on patients undergoing spinal fusion was reviewed.

RESULTS

A total of 699 articles met inclusion criteria and 64 were included in the systematic review. In patients with diabetes, a preoperative hemoglobin A1c (HbA1c) >7.5 mg/dL is associated with an increased risk of reoperation or infection after spine surgery. The review noted conflicting studies regarding the relationship between increased BMI and SSI or reoperation. Preoperative smoking is associated with increased risk of reoperation (Grade B). There is insufficient evidence that cessation of smoking before spine surgery decreases the risk of reoperation.

CONCLUSION

This evidence-based guideline provides a Grade B recommendation that diabetic individuals undergoing spine surgery should have a preoperative HbA1c test before surgery and should be counseled regarding the increased risk of reoperation or infection if the level is >7.5 mg/dL. There is conflicting evidence that BMI correlates with greater SSI rate or reoperation rate (Grade I). Smoking is associated with increased risk of reoperation (Grade B) in patients undergoing spinal fusion.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/2-preoperative-surgical-risk-assessement.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Pulmonary Evaluation and Optimization

BACKGROUND

There are no current recommendations for preoperative pulmonary evaluation and management of patients undergoing elective spine surgery.

OBJECTIVE

The aim of this guideline is to determine preoperative risk factors for perioperative and postoperative pulmonary adverse events and to determine the optimal preoperative evaluation and management of at-risk patients.

METHODS

A systematic review of the literature was performed using the National Library of Medicine PubMed database and the Cochrane Library for studies relevant to postoperative pulmonary adverse events in patients undergoing spine surgery. Clinical studies evaluating preoperative patient risk factors and preoperative diagnostic and treatment interventions were selected for review.

RESULTS

The literature search yielded 152 abstracts relevant to the PICO (patient/population, intervention, comparison, and outcomes) questions included in this chapter. The task force selected 65 articles for full-text review, and 24 were selected for inclusion in this systematic review. Twenty-three articles addressed preoperative patient risk factors. One article addressed preoperative diagnostic studies of pulmonary function. There were no studies meeting the inclusion criteria for preoperative pulmonary treatment.

CONCLUSION

There is substantial evidence for multiple preoperative patient factors that predict an increased risk of a postoperative pulmonary adverse event. Individuals with these risk factors (functional dependence, advanced age [≥65 yr], chronic obstructive pulmonary disease, congestive heart failure, weight loss, and obstructive sleep apnea) who are undergoing spine surgery should be counseled regarding the potential increased risk of a perioperative and postoperative pulmonary adverse events. There is insufficient evidence to support any specific preoperative diagnostic test for predicting the risk of postoperative pulmonary adverse events or any treatment intervention that reduces risk. It is suggested, however, to consider appropriate preoperative pulmonary diagnostic testing and treatment to address active pulmonary symptoms of existing or suspected disease.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/5-preoperative-pulmonary-evaluation-optimization.

The impact of smoking on outcomes following anterior cervical fusion-nonfusion hybrid surgery: a retrospective single-center cohort study

BACKGROUND

There is mixed evidence for the impact of cigarette smoking on outcomes following anterior cervical surgery. It has been reported to have a negative impact on healing after multilevel anterior cervical discectomy and fusion, however, segmental mobility has been suggested to be superior in smokers who underwent one- or two-level cervical disc replacement. Hybrid surgery, including anterior cervical discectomy and fusion and cervical disc replacement, has emerged as an alternative procedure for multilevel cervical degenerative disc disease. This study aimed to examine the impact of smoking on intermediate-term outcomes following hybrid surgery.

METHODS

Radiographical and clinical outcomes of 153 patients who had undergone continuous two- or three-level hybrid surgery were followed-up to a minimum of 2-years post-operatively. The early fusion effect, 1-year fusion rate, the incidence of bone loss and heterotopic ossification, as well as the clinical outcomes were compared across three smoking status groups: (1) current smokers; (2) former smokers; (3) nonsmokers.

RESULTS

Clinical outcomes were comparable among the three groups. However, the current smoking group had a poorer early fusion effect and 1-year fusion rate (P < 0.001 and P < 0.035 respectively). Both gender and smoking status were considered as key factors for 1-year fusion rate. Upon multivariable analysis, male gender (OR = 6.664, 95% CI: 1.248-35.581, P = 0.026) and current smoking status (OR = 0.009, 95% CI: 0.020-0.411, P = 0.002) were significantly associated with 1-year fusion rate. A subgroup analysis demonstrated statistically significant differences in both early fusion process (P < 0.001) and the 1-year fusion rate (P = 0.006) across the three smoking status groups in female patients. Finally, non-smoking status appeared to be protective against bone loss (OR = 0.427, 95% CI: 0.192-0.947, P = 0.036), with these patients likely to have at least one grade lower bone loss than current smokers.

CONCLUSIONS

Smoking is associated with poor outcomes following hybrid surgery for multilevel cervical disc disease. Current smokers had the poorest fusion rate and most bone loss, but no statistically significant differences were seen in clinical outcomes across the three groups.

Complications After Adult Spinal Deformity Surgeries: All Are Not Created Equal

BACKGROUND

Data on timing of complications are important for accurate quality assessments. We sought to better define pre- and postdischarge complications occurring within 90 days of adult spinal deformity (ASD) surgery and quantify the effect of multiple complications on recovery.

METHODS

We performed a review of 1040 patients who underwent ASD surgery (age: 46 ± 23; body mass index: 25 ± 7, American Society of Anesthesiologists [ASA] score: 2.5 ± 0.6, levels: 10 ± 4, revision: 9%, 3-column osteotomy: 13%). We assessed pre- and postdischarge complications and risk factors for isolated versus multiple complications, as well as the impact of multiple complications.

RESULTS

The 90-day complication rate was 17.7%. 85 patients (8.2%) developed a predischarge complication, most commonly ileus (12%), and pulmonary embolism (PE; 7.1%). The most common causes of predischarge unplanned reoperation were neurologic injury (12.9%) and surgical site drainage (8.2%). Predictors of a predischarge complication included smoking (odds ratio [OR]: 2.2, P = .02), higher ASA (OR: 1.8, P = .008), hypertension (HTN; OR: 2.0, P = .004), and iliac fixation (OR: 4.3, P < .001). Ninety-nine patients (9.5%) developed a postdischarge complication, most commonly infection (34%), instrumentation failure (13.4%), and proximal junctional failure (10.4%). Predictors of postdischarge complications included chronic obstructive pulmonary disease (OR: 3.6, P < .0001), congestive heart failure (OR: 4.4, P = .016), HTN (OR: 2.3, P < .0001), and multiple rod construct (OR: 1.8, P = .02). Patients who developed multiple complications (9.3%) had a longer length of stay, and increased risk for readmission and unplanned reoperation.

CONCLUSIONS

Knowledge regarding timing of postoperative complications in relation to discharge may better inform quality improvement measures. PE and implant-related complications play a prominent role in perioperative complications and need for readmission, with several modifiable risk factors identified.

LEVEL OF EVIDENCE

Level 3.

CLINICAL RELEVANCE

Advances in surgical techniques and instrumentation have improved postoperative radiographic and clinical outcomes after ASD surgery. The rate of complications after complex ASD surgery remains high, both at early postoperative and long term follow-up. This study reviews complications within 90 days of surgery, with an assessment of patient and surgical risk factors. We found that modifiable risk factors for early complications after ASD surgery include COPD, and current smoking. The data presented in this study also provide surgeons with knowledge of the most common complications encountered after ASD surgery, to aid in preoperative patient discussion.

How Does Smoking Influence Patient-reported Outcomes in Patients After Lumbar Fusion?

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The goal of this study was to determine the effect of smoking on patient-reported outcome measurements (PROMs) after lumbar fusion surgery.

SUMMARY OF BACKGROUND DATA

Although smoking is known to decrease fusion rates after lumbar fusion, there is less evidence regarding the influence of smoking on PROMs after surgery.

METHODS

Patients undergoing between 1 and 3 levels of lumbar fusion were divided into 3 groups on the basis of preoperative smoking status: never smokers (NS); current smokers (CS); and former smokers (FS). PROMs collected for analysis include the Physical Component Score (PCS-12), Mental Component Score (MCS-12), Oswestry Disability Index (ODI), and Visual Analogue Scale back (VAS back) and leg (VAS leg) pain scores. Preoperative and postoperative PROMs were compared between groups. A multiple linear regression analysis was performed to determine whether preoperative smoking status was a predictor of change in PROM scores.

RESULTS

A total of 220 (60.1%) NS, 52 (14.2%) CS, and 94 (25.7%) FS patients were included. Patients in most groups improved within each of the PROMs analyzed (P<0.05). VAS leg pain (P=0.001) was found to significantly differ between groups, with NS and FS having less disability than CS (3.6 vs. 2.0, P=0.010; and 3.6 vs. 2.4, P=0.022; respectively). Being a CS significantly predicted less improvement in ODI (P=0.035), VAS back (P=0.034), and VAS leg (P<0.001) compared with NS. In addition, NS had a significantly lower 30-day readmission rate than CS or FS (3.2% vs. 5.8% and 10.6%, respectively, P=0.029).

CONCLUSION

CS exhibited worse postoperative VAS leg pain and a lower recovery ratio than never smokers. In addition, being in the CS group was a significant predictor of decreased improvement in ODI, VAS back, and VAS leg scores.

LEVEL OF EVIDENCE

Level III.

The influence of smoking in minimally invasive spinal fusion surgery

Background

The impact of smoking on spinal surgery has been studied extensively, but few investigations have focused on minimally invasive surgery (MIS) of the spine and the difference between complication rates in smokers and non-smokers. We evaluated whether a history of at least one pack-year preoperatively could be used to predict adverse peri- and postoperative outcomes in patients undergoing minimally invasive fusion procedures of the lumbar spine. In a prospective study, we assessed the clinical effectiveness of MIS in an unselected population of 187 patients.

Methods

We evaluated perioperative and postoperative complication rates in MIS fusion techniques of the lumbar spine in smoking and non-smoking patients. MIS fusion was performed using interbody fusion procedures and/or posterolateral fusion alone.

Results

Smokers were significantly younger than non-smokers. We did not encounter infection at the site of surgery or severe wound healing disorder in smokers. We registered no difference between the smoking and non-smoking groups with regard to peri- or postoperative complication rate, blood loss, or length of stay in hospital. We found a significant influence of smoking (p = 0.049) on the overall perioperative complication rate.

Conclusion

MIS fusion techniques seem to be a suitable tool for treating degenerative spinal disorders in smokers.

A National Surgical Quality Improvement Program Analysis of Postoperative Major and Minor Complications in Patients with Spinal Metastatic Disease

BACKGROUND

Major complications after spine metastasis surgery are prioritized in the literature with little consideration of the more frequent minor events such as pneumonia or urinary tract infection. We analyzed incidence and risk factors of postsurgical complications in patients with spinal metastasis extracted from the National Surgical Quality Improvement Program (NSQIP). We also developed a useful predictive model to estimate the probability of occurrence of complications.

METHODS

A total of 1176 patients diagnosed with spinal metastasis were extracted from NSQIP. Variables screened included age, sex, tumor location, patient's functional status, comorbidities, laboratory values, and case urgency. Two multivariate logistic regression models were designed to evaluate risk factors and likelihood of event occurrence.

RESULTS

Minor events occurred twice as frequently compared with major complications (36% vs. 18% of patients). The most common major event was death (10%); the most frequent minor event was need for postoperative transfusion (29.4%). In the multivariate analysis, elderly age, emergency case, preoperative leukocytosis, and smoking status retained significance for major complications; American Society of Anesthesiologists classes 4-5, low hematocrit levels, and intradural extramedullary location of the tumor retained significance for minor complications. The predictive models designed explained 72% of the variability in major complications occurrence and 67% for minor events.

CONCLUSIONS

Smoking status and emergent surgery were found to be the strongest independent predictors of major complications, whereas higher American Society of Anesthesiologists class showed a greater association with minor events. The predictive models produced can be a useful aid for surgeons to identify those patients who are at greater risk of developing postoperative adverse events.

Effects of smoking on pedicle screw-based dynamic stabilization: radiological and clinical evaluations of screw loosening in 306 patients

OBJECTIVE

Cigarette smoking has been known to increase the risk of pseudarthrosis in spinal fusion. However, there is a paucity of data on the effects of smoking in dynamic stabilization following lumbar spine surgery. This study aimed to investigate the clinical outcomes and the incidence of screw loosening among patients who smoked.

METHODS

Consecutive patients who had lumbar spondylosis, recurrent disc herniations, or low-grade spondylolisthesis that was treated with 1- or 2-level surgical decompression and pedicle screw-based Dynesys dynamic stabilization (DDS) were retrospectively reviewed. Patients who did not complete the minimum 2 years of radiological and clinical evaluations were excluded. All screw loosening was determined by both radiographs and CT scans. Patient-reported outcomes, including visual analog scale (VAS) scores of back and leg pain, Japanese Orthopaedic Association (JOA) scores, and Oswestry Disability Index (ODI), were analyzed. Patients were grouped by smoking versus nonsmoking, and loosening versus intact screws, respectively. All radiological and clinical outcomes were compared between the groups.

RESULTS

A total of 306 patients (140 women), with a mean age of 60.2 ± 12.5 years, were analyzed during an average follow-up of 44 months. There were 34 smokers (9 women) and 272 nonsmokers (131 women, 48.2% more than the 26.5% of smokers, p = 0.017). Postoperatively, all the clinical outcomes improved (e.g., VAS back and leg pain, JOA scores, and ODI, all p < 0.001). The overall rate of screw loosening was 23.2% (71 patients), and patients who had loosened screws were older (61.7 ± 9.6 years vs 59.8 ± 13.2 years, p = 0.003) and had higher rates of diabetes mellitus (33.8% vs 21.7%, p = 0.038) than those who had intact DDS screws. Although the patients who smoked had similar clinical improvement (even better VAS scores in their legs, p = 0.038) and a nonsignificantly lower rate of screw loosening (17.7% and 23.9%, p = 0.416), the chances of secondary surgery for adjacent segment disease (ASD) were higher than for the nonsmokers (11.8% vs 1.5%, p < 0.001).

CONCLUSIONS

Smoking had no adverse effects on the improvements of clinical outcomes in the pedicle screw-based DDS surgery. For smokers, the rate of screw loosening trended lower (without significance), but the chances of secondary surgery for ASD were higher than for the nonsmoking patients. However, the optimal surgical strategy to stabilize the lumbar spine of smoking patients requires future investigation.

Perioperative Implications of Vaping

Over the past 10 - 15 years, there has been a significant increase in the use of electronic cigarettes. These devices are generally used to deliver nicotine through inhalation by aerosolization. While the long-term risk of lung cancer is yet to be known, the chemicals and impurities in the solutions may have other acute and chronic effects on the respiratory system including respiratory failure from adult respiratory distress syndrome. Recent concerns have been raised regarding the potential for significant acute and chronic health care risks of these devices including pneumonitis, airway reactivity and respiratory failure. Given that many of the acute effects are related to the respiratory system, anesthetic care may be required during diagnostic procedures including bronchoscopy to investigate the etiology of acute respiratory symptomatology. We present an adolescent who presented to the operating room for bronchoscopy and bronchoalveolar lavage to investigate the etiology of respiratory involvement following an episode of vaping. The healthcare and end-organ effects of nicotine, tobacco smoke and vaping are discussed, and potential anesthetic implications are presented.

The Effect of Tobacco Smoking on Adverse Events Following Adult Complex Deformity Surgery: Analysis of 270 Patients From the Prospective, Multicenter Scoli-RISK-1 Study

STUDY DESIGN

Post-hoc analysis of a prospective, multicenter cohort study.

OBJECTIVE

To analyze the impact of smoking on rates of postoperative adverse events (AEs) in patients undergoing high-risk adult spine deformity surgery.

SUMMARY OF BACKGROUND DATA

Smoking is a known predictor of medical complications after adult deformity surgery, but the effect on complications, implant failure and other AEs has not been adequately described in prospective studies.

METHODS

Twenty-six patients with a history of current smoking were identified out of the 272 patients enrolled in the SCOLI-RISK-1 study who underwent complex adult spinal deformity surgery at 15 centers, with 2-year follow-up. The outcomes and incidence of AEs in these patients were compared to the nonsmoking cohort (n = 244) using univariate analysis, with additional multivariate regression to adjust for the effect of patient demographics, complexity of surgery, and other confounders.

RESULTS

The number of levels and complexity of surgery in both cohorts were comparable. In the univariate analysis, the rates of implant failure were almost double (odds ratio 2.28 [0.75-6.18]) in smoking group (n = 7; 26.9%)) that observed in the nonsmoking group (n = 34; 13.9%), but this was not statistically significant (P = 0.088). Surgery-related excessive bleeding (>4 L) was significantly higher in the smoking group (n = 5 vs. n = 9; 19.2% vs. 3.7%; OR 6.22[1.48 - 22.75]; P = 0.006). Wound infection rates and respiratory complications were similar in both groups. In the multivariate analysis, the smoking group demonstrated a higher incidence of any surgery-related AEs over 2 years (n = 13 vs. n = 95; 50.0% vs. 38.9%; OR 2.12 [0.88-5.09]) (P = 0.094).

CONCLUSION

In this secondary analysis of patients from the SCOLI-RISK-1 study, a history of smoking significantly increased the risk of excessive intraoperative bleeding and nonsignificantly increased the rate of implant failure or surgery-related AEs over 2 years. The authors therefore advocate a smoking cessation program in patients undergoing complex adult spine deformity surgery.

LEVEL OF EVIDENCE

2.

Effects of smoking on cervical disc arthroplasty

Objective

Cigarette smoking can adversely affect bone fusion in patients who undergo anterior cervical discectomy and fusion. However, there is a paucity of data on smoking among patients who have undergone cervical disc arthroplasty (CDA). The present study aimed to compare the clinical and radiological outcomes of smokers to those of nonsmokers following CDA.

Methods

The authors retrospectively reviewed the records of consecutive patients who had undergone 1- or 2-level CDA for cervical disc herniation or spondylosis and had a minimum 2-year follow-up. All patients were grouped into a smoking group, which consisted of those who had consumed cigarettes within 6 months prior to the CDA surgery, or a nonsmoking group, which consisted of those who had not consumed cigarettes at all or within 6 months of the CDA. Clinical outcomes were evaluated according to the visual analog scale for neck and arm pain, Neck Disability Index, Japanese Orthopaedic Association Scale, and Nurick Scale at each time point of evaluation. Radiological outcomes were assessed using radiographs and CT for multiple parameters, including segmental range of motion (ROM), neutral lordotic curve, and presence of heterotopic ossification (HO).

Results

A total of 109 patients completed at least 2 years of follow-up and were analyzed (mean follow-up 42.3 months). There were 89 patients in the nonsmoking group and 20 in the smoking group. The latter group was younger and predominantly male (both p < 0.05) compared to the nonsmoking group. The two groups had similar improvements in all clinical outcomes after CDA compared to preoperatively. Radiological evaluations were also very similar between the two groups, except for two factors. The smoking group had well-preserved segmental ROM after CDA at an average of 8.1° (both pre- and postoperation). However, while the nonsmoking group remained mobile, segmental ROM decreased significantly (8.2° to 6.9°, p < 0.05) after CDA. There was a trend toward more HO development in the nonsmoking group than in the smoking group, but the difference was without significance (59.6% vs 50.0%, p = 0.43).

Conclusions

During an average 3.5 years of follow-up after 1- and 2-level CDA, cigarette smokers and nonsmokers had similar improvements in clinical outcomes. Moreover, segmental mobility was slightly better preserved in smokers. Since smoking status did not negatively impact outcomes, CDA may be a reasonable option for selected patients who have smoked.

Abbreviations

ACDF = anterior cervical discectomy and fusion; ASD = adjacent-segment degeneration; CDA = cervical disc arthroplasty; FDA = Food and Drug Administration; HO = heterotopic ossification; JOA = Japanese Orthopaedic Association; NDI = Neck Disability Index; ROM = range of motion; VAS = visual analog scale.

The Role of Potentially Modifiable Factors in a Standard Work Protocol to Decrease Complications in Adult Spinal Deformity Surgery: A Systematic Review, Part 1

STUDY DESIGN

Structured Literature Review.

OBJECTIVES

We sought to evaluate the peer-reviewed literature for potentially modifiable patient and surgical factors that could be incorporated into a Standard Work protocol to decrease complications in adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

Lean Methodology uses Standard Work to improve efficiency and decrease waste and error. ASD is known to have a high surgical complication rate. Several patient and surgical potentially modifiable factors have been suggested to affect complications, including preoperative hemoglobin, bone density, body mass index (BMI), age-appropriate realignment, preoperative albumin/prealbumin, and smoking status. We sought to evaluate the literature for evidence supporting these factors to include in a Standard Work protocol to decrease complications.

METHODS

Each of these six factors was developed into an appropriate clinical question that included the patient population, surgical intervention, a comparison group, and outcomes measure (PICO question). A comprehensive literature search was then performed. The authors reviewed abstracts and analyzed data from included studies. From 456 initial citations with abstract, 173 articles underwent full-text review. The best available evidence for clinical questions regarding the influence of these factors was provided by 93 included studies.

RESULTS

We found fair evidence supporting a low preoperative hemoglobin level associated with increased transfusion rates and decreased BMD and increased BMI associated with increased complication rates. Fair evidence supported low albumin/prealbumin associated with increased complications. There was fair evidence associating smoking exposure to increased reoperations, but conflicting evidence associating it with increased complications. There was no evidence in the literature evaluating age-appropriate realignment and complications.

CONCLUSION

Preoperative hemoglobin, bone density, body mass index, preoperative albumin/prealbumin, and smoking status all are potentially modifiable risk factors that are associated with increased complications in the adult spine surgery population. Developing a Standard Work Protocol for patient evaluation and optimization should include these factors.

LEVEL OF EVIDENCE

Level II.

Risk factors for increased postoperative drainage of calcaneal fractures after open reduction and internal fixation: An observational study

Sufficient drainage is very important for preventing wound complications after open reduction and internal fixation (ORIF) of calcaneal fractures. However, the drainage amount varies among patients. The objective of this study was to identify factors associated with increased postoperative drainage after ORIF of calcaneal fractures.A retrospective study including 87 patients with 92 calcaneal fractures in our hospital was performed. Patients were divided into 2 groups based on whether they had increased drainage, which was defined as a total drainage of ≥340 mL (50th percentile). We gathered the following data on each patient: age; sex; smoking history; body mass index (BMI); American Society of Anesthesiologists (ASA) classification; fracture type; the time from injury to surgery; operative time; bone grafting; preoperative labs including prothrombin time (PT), activated partial thromboplastin time (APTT), hematocrit, and D-dimer level; and histories for hypertension, diabetes, and heart disease. Univariate analysis and multivariate logistic regression analysis were used to analyze the risk factors associated with increased drainage.Total drainage ranged from 105 to 1185 mL, and the average drainage for this cohort was 393.6 ± 232.4 mL (mean ± standard deviation). 57.6% (n = 53) of patients had increased drainage. Smoking history, Sanders type, operative time, and bone grafting were significantly associated with increased drainage on univariate analysis. Multivariate logistic regression analysis then demonstrated that active smoking and higher Sanders type were independent risk factors for increased drainage.Patients with calcaneal fractures who smoked or had a higher level of Sanders type had a higher risk of increased postoperative drainage. Therefore, we suggest that active precautions be taken for these patients to reduce the rate of postoperative wound complications.

The Effect of Cigarette Smoking on Wound Complications After Single-Level Posterolateral and Interbody Fusion for Spondylolisthesis

OBJECTIVE

To evaluate the impact of cigarette smoking on the development of wound complications, including wound dehiscence, superficial infection, deep infection, or organ space infection, within the first 30 postoperative days in patients undergoing surgery for spondylolisthesis.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for the years 2012-2014 was used to identify adult patients who underwent single-level posterolateral fusion (PLF) or interbody fusion for spondylolisthesis. Wound complications occurring within 30 days were compared between current smokers and nonsmokers.

RESULTS

A total of 1688 patients who underwent single-level PLF or interbody fusion for spondylolisthesis were identified, among whom 271 were current smokers (16.1%). The overall wound complication rate was 3.3% for smokers versus 1.8% for nonsmokers (P = 0.095). When stratified by operative technique, the rate of wound complications was not significantly different between smokers and nonsmokers undergoing PLF (2.4% vs. 2.6%; P = 1.00); however, smokers who underwent interbody fusion were more likely to experience a wound complication compared with nonsmokers undergoing interbody fusion (3.7% vs. 1.3%; P = 0.028). On multivariate analysis, smoking was an independent predictor of organ/space infection irrespective of fusion technique used (odds ratio, 15.4; 95% confidence interval, 1.34-175.4; P = 0.028).

CONCLUSIONS

The rate of wound complications was not higher in smokers undergoing PLF alone, but was significantly higher in smokers who underwent interbody fusion. However, multivariate analysis identified smoking as an independent predictor of organ/space infection irrespective of fusion technique used.

Do Former Smokers Exhibit a Distinct Profile Before and After Lumbar Spine Surgery?

STUDY DESIGN

Retrospective longitudinal cohort.

OBJECTIVES

To determine if former smokers undergoing lumbar spine surgery have distinct baseline and postoperative patient-reported outcomes (PROs) compared with never smokers and current smokers.

SUMMARY OF BACKGROUND DATA

Smoking has known deleterious effects on patients undergoing lumbar spine surgery. However, former smokers have not been extensively evaluated. There are few studies regarding the relationship between pack-years or duration of smoking cessation, and subsequent clinical outcome.

METHODS

Patients undergoing lumbar spine surgery at three Quality Outcomes Database participating sites were identified. Demographic, surgical and PRO data including pre-op and 12-month post-op back and leg pain scores, Oswestry Disability Index (ODI) and EuroQOL-5D were collected. Smoking status was assessed from individual medical records. Three cohorts, never smokers, former smokers and current smokers, were compared. Association between PROs and quantitative smoking history and duration of pre-op smoking cessation were evaluated in the former smokers.

RESULTS

Of 1187 eligible cases, 843 (71%) had complete data, with 477 never, 250 former, and 116 current smokers. Among patients who had a fusion, baseline and 12-month post-op PROs were significantly different between cohorts, with former smokers having intermediate scores between current and never smokers. In the decompression only group, 12-month ODI was worse in the Current smokers, but overall the effects were much less pronounced. There was a significant negative correlation between smoke-free days before surgery and baseline back pain, ODI, 12-month leg pain and ODI and improvement in ODI. However, the correlation coefficients were small.

CONCLUSION

Former smokers have distinct baseline and 12-month post-op PROs that are intermediate between those of never smokers and current smokers. Smoking cessation does not entirely mitigate the negative effects of smoking on baseline and postoperative PROs for patients undergoing lumbar fusion surgery. This effect is less pronounced in patients undergoing decompression alone.

LEVEL OF EVIDENCE

2.

Reduced Impact of Smoking Status on 30-Day Complication and Readmission Rates After Elective Spinal Fusion (≥3 Levels) for Adult Spine Deformity: A Single Institutional Study of 839 Patients

BACKGROUND

Smoking status has been shown to affect postoperative outcomes after surgery. The aim of this study was to determine whether patients' smoking status impacts 30-day complication and readmission rates after elective complex spinal fusion (≥3 levels).

METHODS

The medical records of 839 adult spinal deformity patients undergoing elective complex spinal fusion (≥3 levels) at a major academic institution from 2005 to 2015 were reviewed. We identified 124 (14.8%) smokers and 715 (85.2%) nonsmokers. Patient demographics, comorbidities, intraoperative and postoperative complications, and 30-day readmission rates were collected for each patient. The primary outcome investigated in this study was the rate of 30-day postoperative complication and readmission rates.

RESULTS

Patient demographics and comorbidities were similar between both groups, including age, sex, and body mass index. Median [interquartile] number of fusion levels and operative time were similar between the cohorts (smoker: 5 [4-7] vs. nonsmoker: 5 [4-8], P = 0.58) and (smoker: 309.6 ± 157.9 minutes vs. nonsmoker: 287.5 ± 131.7 minutes, P = 0.16), respectively. Both cohorts had similar postoperative complication rates and lengths of hospital stay. There was no significant difference in 30-day readmission between the cohorts (smoker: 12.9% vs. nonsmoker: 10.8%, P = 0.48). There were no observed differences in 30-day complication rates, including pain (P = 0.46), UTI (P = 0.54), hardware failure (P = 0.36), wound dehiscence (P = 0.29), and wound drainage (P = 0.86). Smokers had greater rates of 30-day cellulitis (smoker: 1.6% vs. nonsmoker: 0.3%, P = 0.05) and DVT (smoker: 0.8% vs. nonsmoker: 0.0%, P = 0.02).

CONCLUSIONS

Our study suggests that smoking does not significantly affect 30-day readmission rates after complex spinal surgery requiring ≥3 levels of fusion. Further studies are necessary to corroborate our findings.