Operative fusion of patients with metabolic syndrome increases risk for perioperative complications

The Predictive Potential of Nutritional and Metabolic Burden: Development of a Novel Validated Metric Predicting Increased Postoperative Complications in Adult Spinal Deformity Surgery

STUDY DESIGN

A retrospective cohort review.

OBJECTIVE

To develop a scoring system for predicting increased risk of postoperative complications in adult spinal deformity (ASD) surgery based on baseline nutritional and metabolic factors.

BACKGROUND

Endocrine and metabolic conditions have been shown to adversely influence patient outcomes and may increase the likelihood of postoperative complications. The impact of these conditions has not been effectively evaluated in patients undergoing ASD surgery.

MATERIALS AND METHODS

ASD patients 18 years or above with baseline and two-year data were included. An internally cross-validated weighted equation using preoperative laboratory and comorbidity data correlating to increased perioperative complications was developed via Poisson regression. Body mass index (BMI) categorization (normal, over/underweight, and obese) and diabetes classification (normal, prediabetic, and diabetic) were used per the Centers for Disease Control and Prevention and the American Diabetes Associates parameters. A novel ASD-specific nutritional and metabolic burden score (ASD-NMBS) was calculated via Beta-Sullivan adjustment, and Conditional Inference Tree determined the score threshold for experiencing ≥1 complication. Cohorts were stratified into low-risk and high-risk groups for comparison. Logistic regression assessed correlations between increasing burden score and complications.

RESULTS

Two hundred one ASD patients were included (mean age: 58.60±15.4, sex: 48% female, BMI: 29.95±14.31, Charlson Comorbidity Index: 3.75±2.40). Significant factors were determined to be age (+1/yr), hypertension (+18), peripheral vascular disease (+37), smoking status (+21), anemia (+1), VitD hydroxyl (+1/ng/mL), BMI (+13/cat), and diabetes (+4/cat) (model: P <0.001, area under the curve: 92.9%). Conditional Inference Tree determined scores above 175 correlated with ≥1 post-op complication ( P <0.001). Furthermore, HIGH patients reported higher rates of postoperative cardiac complications ( P =0.045) and were more likely to require reoperation ( P =0.024) compared with low patients.

CONCLUSIONS

The development of a validated novel nutritional and metabolic burden score (ASD-NMBS) demonstrated that patients with higher scores are at greater risk of increased postoperative complications and course. As such, surgeons should consider the reduction of nutritional and metabolic burden preoperatively to enhance outcomes and reduce complications in ASD patients.

Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery

STUDY DESIGN/SETTING

Retrospective cohort study.

OBJECTIVE

Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery.

METHODS

ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility.

RESULTS

By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001).

CONCLUSIONS

The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.

The Effect of Hyperlipidemia as a Risk Factor on Postoperative Complications in Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To analyze the effect of hyperlipidemia (HLD) on postoperative complications in patients who underwent anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

ACDF represents the standard procedure performed for focal anterior nerve root or spinal cord compression with low complication rates. HLD is well known as a risk factor for major complications after vascular and transplant surgery, and orthopedic surgery. To date, there have been no studies on HLD as a risk factor for cervical spine surgery.

PATIENTS AND METHODS

Patients who underwent ACDF from 2010 through quarter 3 of 2020 were enrolled using the MSpine subset of the PearlDiver Patient Record Database. The patients were divided into single-level ACDF and multilevel ACDF groups. In addition, each group was divided into subgroups according to the presence or absence of HLD. The incidence of surgical and medical complications was queried using relevant International Classification of Disease and Current Procedural Terminology codes. Charlson Comorbidity Index was used as a broad measure of comorbidity. χ 2 analysis, with populations matched for age, sex, and Charlson Comorbidity Index, was performed.

RESULTS

A total of 24,936 patients who underwent single-level ACDF and 26,921 patients who underwent multilevel ACDF were included. In the multilevel ACDF group, wound complications were significantly higher in the patients with HLD. Among medical complications, myocardial infarction, renal failure, and urinary tract infection/urinary incontinence were significantly higher in the patients with HLD in both groups. Revision surgery and readmission were significantly higher in the patients with HLD who underwent multilevel ACDF.

CONCLUSIONS

In patients who underwent ACDF, several surgical and medical complications were found to be higher in patients with HLD than in patients without HLD. Preoperative serum lipid concentration levels and management of HLD should be considered during preoperative planning to prevent postoperative complications in patients undergoing ACDF.

Single-Position Oblique Lumbar Interbody Fusion and Percutaneous Pedicle Screw Fixation under O-Arm Navigation: A Retrospective Comparative Study

The insertion of pedicle screws in the lateral position without a position change has been reported. We completed a retrospective comparison of the radiologic and clinical outcomes of 36 patients who underwent either single-position oblique lateral lumbar interbody fusion (SP-OLIF) using the O-arm (36 cases) or conventional OLIF (C-OLIF) using the C-arm (20 cases) for L2-5 single-level lumbar degenerative diseases. Radiological parameters were analyzed, including screw accuracy (Gertzbein-Robbins classification system; GRS), segmental instability, and fusion status. Screw misplacement was defined as a discrepancy of ≥2 mm. Clinical outcomes, including visual analog scale, Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), and postoperative complications, were assessed. The spinal fusion rate was not different between the SP-OLIF and C-OLIF groups one year after surgery (p = 0.536). The ODI score was lower (p = 0.015) in the SP-OLIF than the C-OLIF group. Physical (p = 0.000) and mental component summaries (p = 0.000) of the SF-36 were significantly higher in the SP-OLIF group. Overall complication rates, including revision, surgical site infection, ipsilateral weakness, and radicular pain/numbness, were not significantly different. SP-OLIF using the O-arm procedure is feasible, with acceptable accuracy, fusion rate, and complication rate. This may be an alternative to conventional two-stage operations.

Obesity and Spine Surgery: A Qualitative Review About Outcomes and Complications. Is It Time for New Perspectives on Future Researches?

STUDY DESIGN

Literature review.

OBJECTIVES

An increasing number of obese patients requires operative care for degenerative spinal disorders. The aim of this review is to analyze the available evidence regarding the role of obesity on outcomes after spine surgery. Peri-operative complications and clinical results are evaluated for both cervical and lumbar surgery. Furthermore, the contribution of MIS techniques for lumbar surgery to play a role in reducing risks has been analyzed.

METHODS

Only articles published in English in the last 10 years were reviewed. Inclusion criteria of the references were based on the scope of this review, according to PRISMA guidelines. Moreover, only paper analyzing obesity-related complications in spine surgery have been selected and thoroughly reviewed. Each article was classified according to its rating of evidence using the Sacket Grading System.

RESULTS

A total number of 1636 articles were found, but only 130 of them were considered to be relevant after thorough evaluation and according to PRISMA checklist. The majority of the included papers were classified according to the Sacket Grading System as Level 2 (Retrospective Studies).

CONCLUSION

Evidence suggest that obese patients could benefit from spine surgery and outcomes be satisfactory. A higher rate of peri-operative complications is reported among obese patients, especially in posterior approaches. The use of MIS techniques plays a key role in order to reduce surgical risks. Further studies should evaluate the role of multidisciplinary counseling between spine surgeons, nutritionists and bariatric surgeons, in order to plan proper weight loss before elective spine surgery.

Metabolic syndrome increases risk for perioperative outcomes following posterior lumbar interbody fusion

The present study is a retrospective cohort study. Metabolic syndrome (MetS) is a clustering of clinical findings that has been shown to increase the risk of the surgical outcomes. Our study aimed to evaluate whether MetS was a risk factor for increased perioperative outcomes in patients undergoing posterior lumbar interbody fusion (PLIF).We retrospectively analyzed patients over 18 years following elective posterior lumbar spine fusion from January 2014 to December 2018. Emergency procedures, infections, tumor, fracture, and revision surgeries were excluded. Patients were divided into 2 groups with and without MetS. The MetS was defined by having 3 of the following 4 criteria: obesity (body mass index ≥30 kg/m), dyslipidemia, hypertension, and diabetes. The follow-up period lasted up to 30 days after surgery. The outcomes of demographics, comorbidities, perioperative complications, and length of stay were compared between the 2 groups. Multivariate logistic regression analysis was used to identify perioperative outcomes that were independently associated with MetS.The overall prevalence of MetS was 12.5% (360/2880). Patients with MetS was a significantly higher risk factor for perioperative complications, and longer length of stay cmpared with patients without MetS (P < .05). The MetS group had a higher rate of cardiac complications (P = .019), pulmonary complication (P = .035), pneumonia (P = .026), cerebrovascular event (P = .023), urinary tract infection (P = .018), postoperative ICU admission (P = .02), and deep vein thrombosis (P = .029) than non-MetS group. The patients with MetS had longer hospital stays than the patients without MetS (22.16 vs 19.99 days, P < .001). Logistic regression analysis revealed that patients with MetS were more likely to experience perioperative complications (odds ratio [OR] 1.31; 95% confidence interval [CI]: 1.06-2.07; P < .001), and extend the length of stay (OR: 1.69; 95% CI: 1.25-2028; P = .001).The MetS is a significant risk factor for increased perioperative complications, and extend length of stay after PLIF. Strategies to minimize the adverse effect of MetS should be considered for these patients.