Risk Factors for Perioperative Complications in Morbidly Obese Patients Undergoing Elective Posterior Lumbar Fusion

Cellular and molecular mechanisms underlying obesity in degenerative spine and joint diseases

Degenerative spine and joint diseases, including intervertebral disc degeneration (IDD), ossification of the spinal ligaments (OSL), and osteoarthritis (OA), are common musculoskeletal diseases that cause pain or disability to the patients. However, the pathogenesis of these musculoskeletal disorders is complex and has not been elucidated clearly to date. As a matter of fact, the spine and joints are not independent of other organs and tissues. Recently, accumulating evidence demonstrates the association between obesity and degenerative musculoskeletal diseases. Obesity is a common metabolic disease characterized by excessive adipose tissue or abnormal adipose distribution in the body. Excessive mechanical stress is regarded as a critical risk factor for obesity-related pathology. Additionally, obesity-related factors, mainly including lipid metabolism disorder, dysregulated pro-inflammatory adipokines and cytokines, are reported as plausible links between obesity and various human diseases. Importantly, these obesity-related factors are deeply involved in the regulation of cell phenotypes and cell fates, extracellular matrix (ECM) metabolism, and inflammation in the pathophysiological processes of degenerative spine and joint diseases. In this study, we systematically discuss the potential cellular and molecular mechanisms underlying obesity in these degenerative musculoskeletal diseases, and hope to provide novel insights for developing targeted therapeutic strategies.

A New Neuroanesthetic Protocol of Rendering Specialized Care in Treating Degenerative Lumbar Spine Diseases in High-Risk Patients: Prospective Analysis of the Results

The aim of the study is to assess the effectiveness of a new neuroanesthetic protocol for treating degenerative lumbar spine diseases in high-risk patients.

Materials and Methods

Two groups of patients with a high risk of anesthesia and surgery determined by the authors' clinical decision support system (CDSS) have been prospectively studied. A new neuroanesthetic protocol was used in the experimental group (EG, n=25), while the control group (CG, n=25) underwent intravenous anesthesia based on propofol and fentanyl. Minimally invasive transforaminal lumbar interbody fusion was performed in all cases. Changes of the intraoperative mean arterial pressure and heart rate, intensity of the local pain syndrome, amount of the opiates used, presence of cognitive disorders, adverse effects of anesthesia, and surgical complications have been compared.

Results

The groups were representative (p>0.05) in terms of the age-gender parameters, anthropological data, comorbid background, involvement in smoking, preoperative characteristics of the lumbar spine, as well as the level of cognitive functions. No statistically significant changes of the mean arterial pressure (p=0.17) were registered in EG patients relative to the CG (p=0.0008). Intraoperative reduction of the heart rate in patients of the CG was not noted (p=0.49) in comparison with the EG (p=0.03). In the postoperative period, the best indicators of cognitive functions on the FAB test (p=0.02) and MoCA test (p=0.03) were revealed in EG. A significantly less amount of perioperative opiates (p=0.005) at a low level of the local pain syndrome was also noted (p=0.01). The intergroup analysis has shown fewer adverse effects of anesthesia in EG compared to CG (p=0.01) with a comparable number of postoperative surgical complications (p=0.42).

Conclusion

A new neuroanesthetic protocol of rendering a specialized care to patients with a high risk of anesthesia and surgery, assessed by the authors-developed CDSS, has resulted in effective elimination of the local postoperative pain syndrome, reduction of perioperative application of opioids, and stabilization of intraoperative indicators of cardiovascular activity. In addition, no postoperative cognitive disorders, anesthetic side-effects, adverse pharmacological consequences of the complex usage of non-steroidal anti-inflammatory drugs, prolonged local anesthetics, alpha-2-agonist, and non-narcotic analgesics have been registered.

Identification of CXCL16 as a diagnostic biomarker for obesity and intervertebral disc degeneration based on machine learning

Intervertebral disc degeneration (IDD) is the primary cause of neck and back pain. Obesity has been established as a significant risk factor for IDD. The objective of this study was to explore the molecular mechanisms affecting obesity and IDD by identifying the overlapping crosstalk genes associated with both conditions. The identification of specific diagnostic biomarkers for obesity and IDD would have crucial clinical implications. We obtained gene expression profiles of GSE70362 and GSE152991 from the Gene Expression Omnibus, followed by their analysis using two machine learning algorithms, least absolute shrinkage and selection operator and support vector machine-recursive feature elimination, which enabled the identification of C-X-C motif chemokine ligand 16 (CXCL16) as a shared diagnostic biomarker for obesity and IDD. Additionally, gene set variant analysis was used to explore the potential mechanism of CXCL16 in these diseases, and CXCL16 was found to affect IDD through its effect on fatty acid metabolism. Furthermore, correlation analysis between CXCL16 and immune cells demonstrated that CXCL16 negatively regulated T helper 17 cells to promote IDD. Finally, independent external datasets (GSE124272 and GSE59034) were used to verify the diagnostic efficacy of CXCL16. In conclusion, a common diagnostic biomarker for obesity and IDD, CXCL16, was identified using a machine learning algorithm. This study provides a new perspective for exploring the possible mechanisms by which obesity impacts the development of IDD.

Weight loss makes the difference: perioperative outcomes following posterior lumbar fusion in patients with and without weight loss following bariatric surgery

BACKGROUND CONTEXT

Morbid obesity (MO) has been associated with increased risk of adverse events following procedures such as posterior lumbar fusion (PLF). While preemptive bariatric surgery (BS) has been considered for those with MO (body mass index [BMI] ≥35 kg/m2), not all undergoing such intervention have significant weight loss, and the impact of BS has been shown to correlate with weight loss after different related procedures.

PURPOSE

To examine outcomes following isolated single level PLF among patients with history of BS who subsequently did and did not transition out of the morbidly obese category.

STUDY DESIGN/SETTING

Retrospective case-control study.

PATIENT SAMPLE

The PearlDiver 2010-Q1 2020 MSpine database was used to identify adult patients undergoing elective isolated PLF. Patients were excluded if they had a history of infection, neoplasm, or trauma in the 90-days prior to their PLF and if they were not active in the database for at least 90 days following their surgery. Three sub-cohorts were defined: 1) MO controls without a history of BS (-BS+MO), 2) patients with prior BS procedure who remained MO (+BS+MO), and 3) patients with prior BS who were no longer MO at the time of PLF (+BS-MO). Matched 1:1:1 populations were created for these three sub-cohorts based on age, sex and Elixhauser Comorbidity Index (ECI).

OUTCOME MEASURES

Ninety-day adverse events and readmission rates were assessed and compared between the three sub-cohorts (-BS+MO, +BS+MO, +BS-MO).

METHODS

Univariable analyses and multivariable logistic regression were performed on the matched population to compare 90-day adverse events and readmission rates controlling for age, sex, and ECI.

RESULTS

The current study identified PLF patients who were MO at the time of surgery but did not have a history of BS (-BS+MO, n=34,236), those who had BS and remained MO (+BS+MO, n=564), and those who had MS and were no longer MO (+BS-MO, n=209 which was only 27% of those who had BS). On multivariable analysis of the matched populations, those that had BS but remained MO (+BS+MO) were not at reduced odds of 90-day adverse events. However, those that had BS and were no longer MO (+BS-MO) were at reduced odds of 90-day any, severe, and minor adverse events (OR 0.41, 0.51, and 0.37, respectively with p<0.05 for all).

CONCLUSIONS

Only 27% of those with a history of BS prior to PLF transitioned out of the MO category. Compared to those who were morbidly obese without BS, those who had BS were only at reduced risk of 90-day adverse events if they actually lost weight sufficient to drop out of morbidly obesity. These findings should be taken into account when counseling patients and interpreting prior studies.

Intrawound low-dose vancomycin is superior to high-dose in controlling the risk of wound dehiscence in spine surgeries

Wound complications in spine surgeries are common and serious. This study aimed to determine the risk of wound dehiscence with a low-dose of intrawound vancomycin compared to that with a high-dose and no-vancomycin and its effectiveness in the prevention of surgical site infection. Patients were categorized into 3 groups. The first group did not receive any intrawound vancomycin. In the second, patients received a high-dose of vancomycin (1 g). The third group included patients who received a low-dose of intrawound vancomycin (250 mg). Patient demographics, clinical data, and surgical data were also collected. Multivariate linear regression analysis was used to examine factors associated with dehiscence or infection. Of the 391 patients included in our study, 56 (14.3%) received a high-dose of intrawound vancomycin, 126 (32.2%) received a low-dose, and 209 (53.5%) did not receive any treatment. The overall incidence of wound dehiscence was 6.14% (24 out of 391 patients). Wound dehiscence was significantly higher (P = .039) in the high-dose vancomycin group than in the low-dose vancomycin group. The overall incidence of postoperative infection was 2.05% (8 patients) and no statistically significant differences were observed between the low-dose and high-dose vancomycin groups. Patients with higher body mass index were more likely to experience wound dehiscence and postoperative infection, irrespective of the dose of vancomycin used. The use of low-dose intrawound vancomycin (250 mg) resulted in less wound dehiscence compared with high-dose vancomycin. Further trials are required to evaluate the effectiveness of the low-dose in preventing postoperative infections.

Risk Factors for 30-day Unplanned Readmission following Surgery for Lumbar Degenerative Diseases: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

Surgical procedures for lumbar degenerative diseases (LDD), which have emerged in the 21-century, are commonly practiced worldwide. Regarding financial burdens and health costs, readmissions within 30days following surgery are inconvenient. We performed a systematic review to integrate real-world evidence and report the current risk factors associated with 30-day readmission following surgery for LDD.

METHODS

The Cochrane Library, Embase, and Medline electronic databases were searched from inception to April 2022 to identify relevant studies reporting risk factors for 30-day readmission following surgery for LDD.

RESULTS

Thirty-six studies were included in the review. Potential risk factors were identified in the included studies that reported multivariate analysis results, including age, race, obesity, higher American Society of Anesthesiologists score, anemia, bleeding disorder, chronic pulmonary disease, heart failure, dependent status, depression, diabetes, frailty, malnutrition, chronic steroid use, surgeries with anterior approach, multilevel spinal surgeries, perioperative transfusion, presence of postoperative complications, prolonged operative time, and prolonged length of stay.

CONCLUSIONS

There are several potential perioperative risk factors associated with unplanned readmission following surgery for LDD. Preoperatively identifying patients that are at increased risk of readmission is critical for achieving the best possible outcomes.

Effect of obesity on short- and long-term complications of shoulder arthroplasty

BACKGROUND

The proportion of patients undergoing total shoulder arthroplasty (TSA) with obesity continues to grow every year in the United States. Although comorbid obesity is common among TSA patients, the relationship of obesity on medical and surgical complications remains debated. The goal of this study was to evaluate a national database for postoperative medical and surgical complications in patients undergoing TSA with comorbid obesity.

METHODS

Patients undergoing anatomic and reverse TSA were studied in the PearlDiver database. Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes were used to compare patients with and without preoperative obesity who underwent TSA, and they were stratified based on body mass index (BMI) into nonobese, obese, morbidly obese, and superobese. A matched comparison was performed at a 1:1 ratio based on age, sex, diabetes, smoking, tobacco use, and Charlson Comorbidity Index.

RESULTS

From 2010 to 2020, a total of 113,634 patients undergoing anatomic or reverse TSA were identified in a national database. During this time, the percentage of TSA patients with obesity increased every year. Matched cohort analysis demonstrated higher odds of readmission, deep vein thrombosis and pulmonary embolism, superficial infection, and prosthetic joint infection at 90 days postoperatively in the obesity group. There were no increased odds of mechanical complications or revision surgery at 2 years in the obesity group when matched to nonobese patients with similar comorbidities.

CONCLUSION

The number of patients undergoing TSA with obesity is rising. Medical complications and infection after TSA are greater in obese patients even when matching for medical comorbidities, age, and sex, and rates of complication increase as BMI increases. Obesity is not an independent risk factor for mechanical surgical complications and revision surgery, and the relatively higher rates are likely due to an increased burden of other comorbidities. Surgeons should counsel obese patients appropriately regarding their perioperative risk of medical complication, but they should not expect higher rates of mechanical complication or revision surgery at 2-year follow-up when compared to a matched control group with similar comorbidities.

Clinical Outcomes of Bariatric Surgery Before Spinal Fusion: A Systematic Review

INTRODUCTION

Morbidly obese patients are at increased risk for intraoperative and postoperative complications following spinal fusion. Preoperative weight loss can improve clinical outcomes. The present systematic literature review is aimed to evaluate the hypothesis that bariatric surgery before spinal fusion surgery is associated with higher rates of complications and revisions.

METHODS

Three databases were queried for literature pertaining to bariatric surgery prior to spinal fusion. A 2-author screening process was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Methodologic index for non-randomized studies criteria was used to objectively assess the methodologic quality of the studies reviewed. Retrospective cohort studies in which the patients underwent bariatric surgery were included.

RESULTS

Four retrospective cohort studies consisting of a total of 180,090 patients were included. Length of stay was significantly shorter for the bariatric surgery (BS) group patients than the control (C) groups patients (P = 0.009). There were no significant differences in 1-year mortality rate (P = 1.0), readmission rate (P = 0.86), overall postoperative complications (P = 0.83), and postoperative infections (P = 0.97) between the BS and C groups.

CONCLUSIONS

There were no consistent differences in rates of postoperative complications, infections, hospital readmission, and mortality between obese patients with bariatric surgery prior to spinal fusion and control group patients. The present study does not support the hypothesis that bariatric surgery before spinal fusion contributes to a higher rate of postoperative complications in patients undergoing spinal fusion.

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.

Adverse Events After Posterior Lumbar Fusion Are Not Sufficiently Characterized With 30-day Follow-up: A Database Study

INTRODUCTION

Many studies track outcomes after procedures, such as posterior lumbar fusion (PLF), for only 30 days because of database limitations. However, adverse events may not have plateaued by this time. Thus, this study used an alternate database to evaluate the timing of adverse events for 90 days after PLF.

METHODS

Adult PLF patients were identified from the 2010 to 2020 Q2 M53Ortho PearlDiver administrative data set. Ninety-day rates of multiple adverse events were determined. The time of diagnosis for each event in the 90-day postoperative period was determined. Data were dichotomized by occurrence in days 0 to 30 and 31 to 90. Median, interquartile range, and middle 80% for the time of diagnosis were determined for each adverse event.

RESULTS

Of 51,915 patients undergoing PLF, 7,141 (13.8%) had an adverse event within 90 days of PLF. Of these, 5,174 (72.5%) experienced an event within 30 days and 2,544 (35.6%) after 30 days. For individual adverse outcomes studied, the percent that occurred 31 to 90 days after surgery ranged from 9% to 42%. The time of diagnosis (median; interquartile range; middle 80%) for each adverse event was as follows: transfusion (2 days; 2 to 5 days; 1 to 26 days), acute kidney injury (9; 2 to 29; 1 to 60), hematoma (9; 4 to 20; 3 to 39), cardiac event (11; 3 to 43; 1 to 71), pneumonia (12; 4 to 38; 2 to 68), venous thromboembolism (15; 6 to 33; 3 to 62), sepsis (19; 9 to 39; 4 to 63), surgical site infection (21; 14 to 34; 8 to 48), urinary tract infection (22; 8 to 49; 4 to 72), and wound dehiscence (27; 17 to 39; 9 to 54).

DISCUSSION

This study highlights the importance of looking past the 30-day mark for adverse events after PLF because approximately one-third of adverse events in this study were diagnosed 31 to 90 days after surgery. This can affect research studies, patient counseling about the incidence of specific adverse events, and the development of mechanisms for surveillance at key time points.

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.

[Study of modified subcutaneous lumbar spine index as a predictor for short-term effectiveness in transforaminal lumbar interbody fusion]

Objective

To explore the value of modified subcutaneous lumbar spine index (MSLSI) as a predictor for short-term effectiveness of transforaminal lumbar interbody fusion (TLIF) in treatment of lumbar degenerative disease (LDD).

Methods

Between February 2014 and October 2019, 450 patients who were diagnosed as LDD and received single-segment TLIF were included in the study. Based on the MSLSI measured by preoperative lumbar MRI, the patients were sorted from small to large and divided into three groups ( n=150). The MSLSI of group A was 0.11-0.49, group B was 0.49-0.73, and group C was 0.73-1.88. There was no significance in gender, age, disease duration, diagnosis, surgical segment, and improved Charlson comorbidity index between groups ( P>0.05). There were significant differences in the subcutaneous adipose depth of the L ₄ vertebral body and body mass index (BMI) between groups ( P<0.05). The operation time, intra-operative blood loss, length of incision, drainage tube placement time, drainage volume on the 1st day after operation, drainage volume on the 2nd day after operation, total drainage volume, antibiotic use time after operation, walking exercise time after operation, hospital stay, the incidences of surgical or non-surgical complications in the three groups were compared. Pearson correlation analysis was used to analyze the correlation between MSLSI and BMI, and partial correlation analysis was used to study the relationship between MSLSI, BMI, improved Charlson comorbidity index, subcutaneous adipose depth of the L ₄ vertebral body and complications. The Receiver Operating Characteristic (ROC) curve was used to evaluate the value of SLSI and MSLSI in predicting the occurrence of complications after TLIF in treatment of LDD.

Results

There was no significant difference in operation time, length of incision, antibiotic use time after operation, walking exercise time after operation, drainage tube placement time, drainage volume on the 1st day after operation, drainage volume on the 2nd day after operation, and total drainage volume between groups ( P>0.05). The amount of intra-operative blood loss in group C was higher than that in groups A and B, and the hospital stay was longer than that in group B, with significant differences ( P<0.05). Surgical complications occurred in 22 cases (14.7%), 25 cases (16.7%), and 39 cases (26.0%) of groups A, B, and C, respectively. There was no significant difference in the incidence between groups ( χ ²=0.826, P=0.662). The incidences of nerve root injury and wound aseptic complications in group C were higher than those in groups A and B, and the incidence of nerve root injury in group B was higher than that in group A, with significant differences ( P<0.05). There were 13 cases (8.7%), 7 cases (4.7%), and 11 cases (7.3%) of non-surgical complications in groups A, B, and C, respectively, with no significant difference ( χ ²=2.128, P=0.345). There was no significant difference in the incidences of cardiovascular complications, urinary system complications, central system complications, and respiratory system complications between groups ( P>0.05). There was a correlation between MSLSI and BMI in 450 patients ( r=0.619, P=0.047). Partial correlation analysis showed that MSLSI was related to wound aseptic complications ( r=0.172, P=0.032), but not related to other surgical and non-surgical complications ( P>0.05). There was no correlation between BMI, improved Charlson comorbidity index, subcutaneous adipose depth of the L ₄ vertebral body and surgical and non-surgical complications ( P>0.05). ROC curve analysis showed that the area under ROC curve (AUC) of MSLSI was 0.673 (95%CI 0.546-0.761, P=0.025), and the AUC of SLSI was 0.582 (95%CI 0.472-0.693, P=0.191).

Conclusion

MSLSI can predict the short-term effectiveness of TLIF in treatment of LDD. Patients with high MSLSI suffer more intra-operative blood loss, longer hospital stay, and higher incidence of nerve root injury and postoperative incision complications.

[Research progress in effect of obesity on the effectiveness of posterior lumbar fusion]

Objective

To review the effect of obesity on the effectiveness of posterior lumbar fusion in patients with lumbar degenerative diseases (LDD).

Methods

The related literature at home and abroad was extensively reviewed. And the difficulty of operation, risk of complications, and long-term effectiveness of posterior lumbar fusion for obese patients with LDD were summarized.

Results

Although some relevant literature suggest that the posterior lumbar fusion for obese patients is difficult and the risk of postoperative complications is high, the overall research results do not suggest that obesity is a risk factor for the implementation of posterior lumbar fusion. By assessing the physical condition of patients and strictly grasping the surgical indications, obese patients can obtain good surgical efficacy.

Conclusion

Posterior lumbar fusion is an effective method for the treatment of LDD in obese patients. However, relevant studies need to be completed to further evaluate the safety and efficacy of posterior lumbar fusion for obese patients.

Risk Factors for 30- and 90-Day Readmission due to Intestinal Bowel Obstruction after Posterior Lumbar Fusion

Study Design

A retrospective analysis of data from the Healthcare Cost and Utilization Project Nationwide Readmissions Database (HCUP-NRD).

Purpose

To identify the perioperative characteristics associated with 30-day and 90-day readmission due to intestinal bowel obstructions (IBOs) following posterior lumbar fusion (PLF) procedure.

Overview of Literature

PLF procedures are used to repair spinal injuries and curvature deformities. IBO is a common surgical complication and its repair often necessitates surgery that increases the readmission rates and healthcare costs. Previous studies have identified the preoperative risk factors for 30-day readmissions in PLF; however, no study has specifically investigated IBO or identified risk factors for 90-day readmissions.

Methods

Data on demographic characteristics and medical comorbidities of patients who underwent PLF with subsequent readmission were obtained from the HCUP-NRD. The perioperative characteristics that were significantly different between patients readmitted with and without an active diagnosis of IBO were identified with bivariate analysis for both 30-day and 90-day readmissions. The significant characteristics were then included in a multivariate analysis to identify those that were independently associated with 30-day and 90-day readmissions.

Results

Drug abuse (odds ratio [OR], 4.00), uncomplicated diabetes (OR, 2.06), having Medicare insurance (OR, 1.65), age 55–64 years (OR, 2.42), age 65–79 years (OR, 2.77), and age >80 years (OR, 3.87) were significant risk factors for 30-day readmission attributable to IBO after a PLF procedure.

Conclusions

Of the several preoperative risk factors identified for readmission with IBO after PLF surgery, drug abuse had the strongest association and was likely to be the most clinically relevant factor. Physicians and care teams should understand the risks of opioid-based pain management regimens, attempt to manage pain with a multimodal approach, and minimize the opioid use.

The impact of long-term corticosteroid use on acute postoperative complications following lumbar decompression surgery

BACKGROUND

Corticosteroids have a negative impact on the human immune system's ability to function at an optimal level. Studies have shown that patients on long-term corticosteroids have higher infection rates. However, the rates of infection and other complications following lumbar decompression surgery remains under-investigated. The aim of our study was to determine the impact of preoperative long-term corticosteroid usage on acute, 30-day postoperative complications in a subset of patients undergoing lumbar spine decompression surgery, without fusion or instrumentation. We hypothesize that patients on long-term corticosteroids will have higher rates of infection and other postoperative complications after undergoing lumbar decompression surgery of the spine.

METHODS

A retrospective cohort study was conducted using data collected from the National Surgical Quality Improvement Program database data from 2005 to 2016. Lumbar decompression surgeries, including discectomies, laminectomies, and others were identified using CPT codes. Chi-square analysis was used to evaluate differences among the corticosteroid and non-corticosteroid groups for demographics, preoperative comorbidities, and postoperative complications. Logistic regression analysis was done to determine if long-term corticosteroid use predicts incidence of postoperative infections following adjustment.

RESULTS

26,734 subjects met inclusion criteria. A total of 1044 patients (3.9%) were on long-term corticosteroids prior to surgical intervention, and 25,690 patients (96.1%) were not on long-term corticosteroids. Patients on long-term corticosteroids were more likely to be older (p < 0.001), female (p < 0.001), nonsmokers (p < 0.001), and have a higher American Society of Anesthesiologist class (p < 0.001). Multivariate analysis demonstrated that long-term corticosteroid usage was associated with increased overall complications (odds ratio [OR]: 1.543; p < 0.001), and an independent risk factor for the development of minor complications (OR: 1.808; p < 0.001), urinary tract infection (OR: 2.033; p = 0.002), extended length of stay (OR: 1.244; p = 0.039), thromboembolic complications (OR: 1.919; p = 0.023), and sepsis complications (OR: 2.032; p = 0.024).

CONCLUSION

Long-term corticosteroid usage is associated with a significant increased risk of acute postoperative complication development, including urinary tract infection, sepsis and septic shock, thromboembolic complications, and extended length of hospital stay, but not with superficial or deep infection in patients undergoing lumbar decompression procedures. Spine surgeons should remain vigilant regarding postoperative complications in patients on long-term corticosteroids, especially as it relates to UTI and propensity to decompensate into sepsis or septic shock. Thromboembolic risk attenuation is also imperative in this patient group during the postoperative period and the surgeon should weigh the risks and benefits of more intensive anticoagulation measures.

A Comparison of the Elixhauser and Charlson Comorbidity Indices: Predicting In-Hospital Complications Following Anterior Lumbar Interbody Fusions

OBJECTIVE

The Elixhauser Comorbidity Index (ECI) and Charlson Comorbidity Index (CCI) are commonly used measures that use administrative data to characterize a patient's comorbidity burden. The purpose of this study was to compare the ability of these measures to predict outcomes following anterior lumbar interbody fusion.

METHODS

The National Inpatient Sample was queried for all ALIF procedures between 2013 and 2014. The area under the receiver operating curve (AUC) was used to compare the ECI and CCI in their ability to predict postoperative complications when incorporated into a base model containing age, sex, race, and primary payer. Percent superiority was computed using AUC values for ECI, CCI, and base models.

RESULTS

A total of 43,930 hospitalizations were included in this study. The ECI was superior to the CCI and baseline models in predicting minor (AUC 71 vs. 0.66, P < 0.0001) and major (AUC 0.74 vs. 0.67, P < 0.0001) complications. When evaluating individual complications, the ECI was superior to the CCI in predicting airway complications (65% superior, AUC 0.85 vs. 0.72, P = 0.0001); hemorrhagic anemia (83% superior, AUC 0.71 vs. 0.66, P < 0.0001); myocardial infarction (76% superior, AUC 0.86 vs. 0.67, P < 0.0001); cardiac arrest (75% superior, AUC 0.85 vs. 0.67, P < 0.0001); pulmonary embolism (105% superior, AUC 0.91 vs. 0.71, P < 0.0001); and urinary tract infection (43% superior, AUC 0.76 vs. 0.73, P = 0.046).

CONCLUSIONS

The ECI was superior to the CCI in predicting 6 of the 15 complications analyzed in this study. Combined with previous results, the ECI may be a better predictive model in spine surgery.

How Does Body Mass Index Influence Outcomes in Patients After Lumbar Fusion?

STUDY DESIGN

Retrospective study.

OBJECTIVE

The purpose of the present study is to determine how body mass index (BMI) affects patient-reported outcome measurements (PROMs) after lumbar fusions.

SUMMARY OF BACKGROUND DATA

Although greater preoperative BMI is known to increase the rates of adverse events after surgery, there is a paucity of literature assessing the influence of BMI on PROMs after lumbar fusion.

METHODS

Patients undergoing lumbar fusion surgery between 1 and 3 levels were retrospectively identified. PROMs analyzed were the Short Form-12 Physical Component Score, Mental Component Score, Oswestry Disability Index (ODI), and Visual Analog Scale Back and Leg pain scores. Patients were divided into groups based on preoperative BMI: class 1, BMI <25.0; class 2, BMI 25.0 to 29.9; class 3, BMI 30.0 to 34.9; and class 4, BMI ≥35.0. Absolute PROM scores, the recovery ratio, and the percentage of patients achieving minimum clinically important difference between groups were compared.

RESULTS

A total of 54 (14.8%) patients in class 1, 140 (38.2%) in class 2, 109 (29.8%) in class 3, and 63 (17.2%) in class 4 were included. All patients improved after surgery across all outcome measures (P < 0.001) except for class 4 patients, who did not improve in terms of Short Form-12 Mental Component Score scores after surgery (P = 0.276). Preoperative Short Form-12 Physical Component Score (P = 0.002) and Oswestry Disability Index (P < 0.0001) scores were significantly different between BMI groups-with class 4 having worse disability than class 1 and 2. BMI was not a significant predictor for any outcome domain. Overall 30- and 90-day readmission rates were similar between groups, with a higher revision rate in the class 4 group (P = 0.036), due to a higher incidence of postoperative surgical site infections (P = 0.014).

CONCLUSION

All patients undergoing short-segment lumbar fusion for degenerative disease improved to a similar degree with respect to PROMs. Those in the highest class of obesity (BMI ≥35.0) were, however, at a greater risk for postoperative surgical site infection.

LEVEL OF EVIDENCE

3.

Risk factors for post-discharge complications and readmissions in home-discharges after elective posterior lumbar fusions

OBJECTIVES

Previous literature has studied overall post-operative outcomes following lumbar fusions. We examined the rates and risk factors for adverse outcomes in patients who are being discharged home.

PATIENTS AND METHODS

The 2012-2016 ACS-NSQIP database was used to query for patients undergoing 1- to 2-level posterior lumbar fusions (PLFs) for degenerative spinal pathology. Patients discharged to a destination other than home were removed from the database.

RESULTS

Out of a total of 19,179 home-discharge patients, 546 (2.8%) experienced any adverse event (AAE), 276 experienced a severe adverse event (SAE) and 321 (1.7%) experienced a minor adverse event (MAE). Overall re-admission and re-operation rate in home-discharged patients was 4.4% and 2.5%. Multivariate analysis identified the following predictors for experiencing an AAE - Bleeding disorder (OR 2.25), BMI ≥ 35.0 vs. BMI < 25 (OR 1.96), chronic steroid use (OR 1.89), a LOS > 3 days (OR 1.53), insulin-dependent diabetes mellitus (OR 1.44), hypertension (OR 1.28) and female gender (OR 1.24). Patients with a pre-discharge complication (OR 2.12), bleeding disorders (OR 1.84), chronic steroid use (OR 1.55), age>75 (OR 1.49), age>65 (OR 1.26), history of severe COPD (OR 1.43), total operative time >210 min. (OR 1.26), ASA > II (OR 1.26) and undergoing a 2-level fusion (OR 1.21) were likely to be re-admitted from home.

CONCLUSIONS

Providers should utilize the data to risk-stratify and better understand the need of provision of supplemental health-care services, in home-discharged patients, and/or regular clinic follow-up to minimize the rate of adverse events and reduce costs in a bundled-payment environment.