Hypoalbuminemia as an Independent Risk Factor for Perioperative Complications Following Surgical Decompression of Spinal Metastases

Developmental and Validation of Machine Learning Model for Prediction Complication After Cervical Spine Metastases Surgery

STUDY DESIGN

This is a retrospective cohort study utilizing machine learning to predict postoperative complications in cervical spine metastases surgery.

OBJECTIVES

The main objective is to develop a machine learning model that accurately predicts complications following cervical spine metastases surgery.

SUMMARY OF BACKGROUND DATA

Cervical spine metastases surgery can enhance quality of life but carries a risk of complications influenced by various factors. Existing scoring systems may not include all predictive factors. Machine learning offers the potential for a more accurate predictive model by analyzing a broader range of variables.

METHODS

Data from January 2012 to December 2020 were retrospectively collected from medical databases. Predictive models were developed using Gradient Boosting, Logistic Regression, and Decision Tree Classifier algorithms. Variables included patient demographics, disease characteristics, and laboratory investigations. SMOTE was used to balance the dataset, and the models were assessed using AUC, F1-score, precision, recall, and SHAP values.

RESULTS

The study included 72 patients, with a 29.17% postoperative complication rate. The Gradient Boosting model had the best performance with an AUC of 0.94, indicating excellent predictive capability. Albumin level, platelet count, and tumor histology were identified as top predictors of complications.

CONCLUSIONS

The Gradient Boosting machine learning model showed superior performance in predicting postoperative complications in cervical spine metastases surgery. With continuous data updating and model training, machine learning can become a vital tool in clinical decision-making, potentially improving patient outcomes.

LEVEL OF EVIDENCE

Level III.

The utilization of hypoalbuminemia as a prognostic metric in patients with spinal metastases: A scoping review

Introduction

Hypoalbuminemia is associated with poor outcomes in cancer patients, but its role in spinal metastases remains unclear.

Research question

This study aimed to identify albumin cutoff values defining hypoalbuminemia and describe the association between serum albumin and outcomes in patients with spinal metastases.

Material and methods

A narrative review of articles up to December 2022 was conducted using PubMed/Medline, EMBASE, and Web of Science databases. Variables extracted included study design, patient characteristics, serum albumin levels, treatments, and levels of evidence. Outcomes included survival/mortality, complications, ambulatory status, readmission, length of stay, discharge disposition, and blood loss.

Results

Thirty-eight studies comprising 21,401 patients were analyzed. Most studies (92%) were Level of Evidence III. Albumin was evaluated as a continuous variable in 18% of studies and as a dichotomous variable in 76%, with 3.5 g/dL being the most common threshold for hypoalbuminemia. Primary outcomes evaluated were survival/mortality (71% of studies), complications (34%), and reoperation/readmission (11%). Of studies examining the association between hypoalbuminemia and survival/mortality, 74% found a significant association. An association between albumin levels and complications was found in 54% of relevant studies.

Discussion and conclusion

The findings of this study suggest that a threshold of 3.5 g/dL seems most appropriate to define hypoalbuminemia in patients with spinal metastases. However, evidence also supports a level-dependent effect. The most consistent significant association was between low albumin and survival at both fixed and continuous time points. There is less evidence to support an association between hypoalbuminemia and other endpoints such as perioperative complications.

Which Prognostic Model Best Predicts Poor Prognosis in Patients with Spinal Metastases? A Comparative Analysis of 8 Scoring Systems

BACKGROUND

Existing scoring system's comparative effectiveness in identifying patients with poor prognosis (i.e., <6 months survival) has not been thoroughly explored.

METHODS

We compared the predictive performance of 8 prognostic scoring systems (Tomita, modified Tokuhashi, modified Bauer, Rades, Oncological Spinal Prognostic Index, Lei, New England Spinal Metastasis Score, and the skeletal oncology research group [SORG] nomogram) with the area under the curve (AUC) from receiver operating characteristic curves and evaluated the predictive accuracy for 6-month survival across different primary tumor origins, and 1-month survival. Logistic regression was used to identify factors associated with 6-month survival.

RESULTS

Six hundred forty one patients with spinal metastasis treated between 1994 and 2022 were included. The SORG nomogram showed best performance with low discriminative power in predicting 6-month survival (AUC [95% confidence interval {CI}]: 0.664 [0.584-0.744]). Logistic regression analysis identified significant factors influencing 6-month survival, including primary cancer type in Lei's classification, preoperative Frankel grades C and D, or grades A and B compared with grade E, preoperative white blood cell, preoperative albumin, and preoperative chemotherapy. For 1-month survival predictions, both the SORG nomogram (AUC [95% CI]: 0.750 [0.648-0.851]) and modified Tokuhashi score (AUC [95% CI]: 0.667 [0.552-0.781]) showed significance, albeit with moderate to low discriminative power.

CONCLUSIONS

This study shows that most scoring systems have low discriminative power, with only the SORG nomogram having moderate power for predicting poor prognosis. Recent and future advances in treatment, laboratory markers, and our understanding of tumor biology should be incorporated into prognostic models to improve their accuracy.

Malnutrition in Spine Oncology: Where Are We and What Are We Measuring?

STUDY DESIGN

Scoping review.

OBJECTIVE

To identify which markers are used as surrogates for malnutrition in metastatic spine disease and which are the most studied outcomes associated with it.

METHODS

A scoping review was performed by searching the PubMed/Medline, EMBASE, and Web of Science databases up to July 2022. We searched for articles exploring markers of malnutrition in spine oncology patients including but not limited to albumin, body weight, weight loss, and nutrition indices. A narrative synthesis was performed.

RESULTS

A total of 61 articles reporting on 31,385 patients met inclusion criteria. There were 13 different surrogate markers of nutrition, with the most common being albumin in 67% of studies (n = 41), body weight/BMI in 34% (n = 21), and muscle mass in 28% (n = 17). The most common studied outcomes were survival in 82% (n = 50), complications in 28% (n = 17), and length of stay in 10% (n = 6) of studies. Quality of life and functional outcomes were assessed in 2% (n = 1) and 3% (n = 2) of studies, respectively. Out of 61 studies, 18% (n = 11) found no association between the examined markers and outcome.

CONCLUSION

Assessment of nutritional status in patients with spinal metastases is fundamental. However, there is lack of a comprehensive and consistent way of assessing malnutrition in oncologic spine patients and therefore inconsistency in its relationship with outcomes. A consensus agreement on the assessment and definition of malnutrition in spine tumor patients is needed.

Preoperative Serum Albumin and TLC as Predictors of Postoperative Complications in Spine Surgery

STUDY DESIGN

Narrative review.

PURPOSE

To investigate the state of literature regarding serum albumin and total lymphocyte count and their associations with postoperative complications after spine surgery.

METHODS

Comprehensive search of the PubMed database was performed to find relevant articles addressing preoperative serum albumin, total lymphocyte count, or their respective composite scores and their associations with postoperative complications after spine surgery.

SUMMARY OF BACKGROUND DATA

Serum albumin level is frequently cited as a marker of patient nutritional status. Total lymphocyte count has more recently gained attention in the literature for similar reasons. Identification of modifiable preoperative patient risk factors for postoperative complications such as malnutrition may help minimize the incidence of postoperative complications.

RESULTS

Review of the literature revealed 10 studies that discussed the association between preoperative hypoalbuminemia and postoperative complications. Five studies examined the relationship between either prognostic nutritional index (PNI), controlling nutritional status (CONUT), or both and postoperative complications after spine surgery. Preoperative hypoalbuminemia, low PNI, and high CONUT scores were associated with increased risk of postoperative complications after spine surgery.

CONCLUSIONS

Preoperative malnourishment is a modifiable patient factor that is associated with an increased risk of postoperative complications after spine surgery.

Outcomes in Patients with Spinal Metastases Managed with Surgical Intervention

BACKGROUND

Spinal metastases are a significant cause of morbidity in patients with advanced cancer, and management often requires surgical intervention. Although prior studies have identified factors that influence outcomes with surgery, the ability of these factors to predict outcomes remains unclear in the era of contemporary therapies, and there is a need to better identify patients who are likely to benefit from surgery.

METHODS

We performed a single-center, retrospective analysis to evaluate risk factors for poor outcomes in patients with spinal metastases treated with surgery. The primary outcome was mortality at 180 days.

RESULTS

A total of 128 patients were identified. Age ≥ 65 years at surgery (p = 0.0316), presence of extraspinal metastases (p = 0.0110), and ECOG performance scores >1 (p = 0.0397) were associated with mortality at 180 days on multivariate analysis. These factors and BMI ≤ 30 mg/kg2 (p = 0.0008) were also associated with worse overall survival.

CONCLUSIONS

Age > 65, extraspinal metastases, and performance status scores >1 are factors associated with mortality at 180 days in patients with spinal metastases treated with surgery. Patients with these factors and BMI ≤ 30 mg/kg2 had worse overall survival. Our results support multidisciplinary discussions regarding the benefits and risks associated with surgery in patients with these risk factors.

Use of the Geriatric Nutritional Risk Index to Assess Risk for Postoperative Complications Following Posterior Cervical Decompression/Fusion

BACKGROUND

Posterior cervical decompression with or without fusion (PCD/F) is used to manage degenerative spinal conditions. Malnutrition has been implicated for poor outcomes in spine surgery. The aim of this study was to assess the ability of the Geriatric Nutritional Risk Index (GNRI) as a risk calculator for postoperative complications in patients undergoing PCD/F.

METHODS

The 2006 to 2018 American College of Surgeons National Surgery Quality Improvement Program Database was queried for patients undergoing PCD/F. Nutritional status was categorized as normal (GNRI greater than 98), moderately malnourished (GNRI 92-98), or severely malnourished (GNRI less than or equal to 92). Complications within 30 days of surgery were compared among the groups. Preoperative data that were statistically significant (P < 0.05) upon univariate χ2 analysis were included in the univariate then multivariate binary regression model to calculate adjusted ORs. All ORs were assessed at the 95% CI.

RESULTS

Of the 7597 PCD/F patients identified, 15.6% were severely malnourished and 19.1% were moderately malnourished. Severe and moderate malnourishment were independent risk factors for mortality (OR = 3.790, 95% CI 2.492-5.763, P < 0.001; OR = 2.150, 95% CI 1.351-3.421, P = 0.011). Severe malnourishment was an independent risk factor for sepsis/septic shock (OR = 3.448, 95% CI 2.402-4.948, P < 0.001).

CONCLUSIONS

In elderly patients undergoing PCD/F, severe malnutrition, as defined by the GNRI, was an independent risk factor for mortality and sepsis/septic shock.

CLINICAL RELEVANCE

The GNRI may be more useful than other indices for risk stratification in elderly patients because it accounts for confounding variables such as hydration status and paradoxical malnourishment in obese patients.

LEVEL OF EVIDENCE: 3

The prognostic nutritional index (PNI) is independently associated with 90-day and 12-month mortality after metastatic spinal tumor surgery

INTRODUCTION

Estimated postoperative survival is an important consideration during the decision-making process for patients with spinal metastases. Nutritional status has been associated with poor outcomes and limited survival in the general cancer population. The objective of this study was to evaluate the predictive utility of the prognostic nutritional index (PNI) for postoperative mortality after spinal metastasis surgery.

METHODS

A total of 139 patients who underwent oncologic surgery for spinal metastases between April 2012 and August 2022 and had a minimum 90-day follow-up were included. PNI was calculated using preoperative serum albumin and total lymphocyte count, with PNI < 40 defined as low. The mean PNI of our cohort was 43 (standard deviation: 7.7). The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed.

RESULTS

The 90-day mortality was 27% (37/139), and the 12-month mortality was 56% (51/91). After controlling for age, ECOG performance status, total psoas muscle cross-sectional area (TPA), and primary cancer site, the PNI was associated with 90-day mortality [odds ratio 0.86 (95% confidence interval 0.79-0.94); p = 0.001]. After controlling for ECOG performance status and primary cancer site, the PNI was associated with 12-month mortality [OR 0.89 (95% CI 0.82-0.97); p = 0.008]. Patients with a low PNI had a 50% mortality rate at 90 days and an 84% mortality rate at 12 months.

CONCLUSION

The PNI was independently associated with 90-day and 12-month mortality after metastatic spinal tumor surgery, independent of performance status, TPA, and primary cancer site.

Association between malnutrition and surgical site wound infection among spinal surgery patients: A meta-analysis

A surgical site infection (SSI) is one of the most common complications of spinal surgery. Malnutrition has also been linked to SSI after other surgical procedures. However, whether malnutrition is a risk factor for SSI after spinal surgery remains controversial. Therefore, we performed a meta-analysis to comprehensively evaluate the relationship between malnutrition and SSI. Relevant studies of the correlation between malnutrition and SSI were retrieved from the Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure and Wanfang Data from database inception to 21 May 2023. Two reviewers independently assessed the included studies, and a meta-analysis was performed using STATA 17.0 software. A total of 24 articles with 179 388 patients were included: 3919 and 175 469 cases comprised the SSI and control groups, respectively. The meta-analysis results showed that malnutrition significantly increased the SSI incidence (odds ratio, 1.811; 95% confidence interval, 1.512-2.111; p < 0.001). These results suggest that patients with malnutrition are at higher risk for SSI after surgery. However, because of significant differences in sample sizes among studies, and because some studies had limitations to their methodological quality, further validation of these results by additional high-quality studies with larger sample sizes is necessary.

Association of preoperative hypoprotein malnutrition with spinal postoperative complications and other conditions: A systematic review and meta-analysis

BACKGROUND

Postoperative complications of spinal surgery are a common clinical problem, which impose significant economic and clinical burdens on patients and medical staff. Previous studies have suggested a close relationship between low-protein malnutrition and postoperative complications of surgery. However, the relationship between preoperative malnutrition and various orthopedic postoperative complications remains unclear.

PURPOSE

To investigate the association between protein malnutrition and postoperative complications and outcomes.

METHODS

We conducted a systematic search of the PubMed, Embase, Cochrane Library, and Web of Science databases for published research articles between the database inception and February 28th, 2023, that evaluated the association between malnutrition and the risk of postoperative complications and death in spinal surgery patients. Malnutrition was defined as low pre-albumin and albumin levels before surgery. Two evaluators independently extracted study data and assessed the risk of bias in each study. Fixed- or random-effect models were used to calculate the pooled effect estimates. Funnel plots and Egger's tests were used to detect publication bias, and the Trim-and -Fill method was conducted to evaluate the impact of publication bias on the results.

RESULTS

A total of 26 studies were included in this meta-analysis, comprising 17 retrospective cohort studies and 9 case-control studies. The study included more than 86,000 participants. Analysis of postoperative complications revealed that the overall incidence of malnutrition-related complications after surgery was 3.17 times higher (OR = 3.17, 95% CI 2.69-3.75, z = 13.57, P < 0.05). The incidence of surgical site infections was 2.08 times higher (OR = 2.08, 95% CI 1.66-2.62, z = 6.307, P < 0.05), and the incidence of postoperative urinary tract infections was 2.55 times higher (OR = 2.55, 95% CI 1.80-3.60, z = 5.30, P < 0.05). The incidence of postoperative sepsis was 3.31 times higher (OR = 3.31, 95% CI 2.31-4.75, z = 6.51, P < 0.05), and the incidence of postoperative pneumonia was 3.02 times higher (OR = 3.02, 95% CI 1.331-6.857, z = 2.64, P = 0.008 < 0.05). The incidence of postoperative cardiac complications was 4.24 times higher (OR = 4.24, 95% CI 2.45-7.35, z = 5.15, P < 0.05), and the incidence of postoperative renal complications was 4.04 times higher (OR = 4.04, 95% CI 2.06-7.93, z = 4.05, P < 0.05). The incidence of postoperative pulmonary complications was 2.38 times higher (OR = 2.38, 95% CI 1.46-3.87, z = 6.98, P < 0.05), while the incidence of postoperative thrombotic complications was 2.76 times higher (OR = 2.76, 95% CI 1.756-4.345, z = 4.40, P < 0.05). Furthermore, the incidence of transfusion during and after surgery was 1.33 times higher (OR = 1.33, 95% CI 1.13-1.56, z = 3.40, P = 0.001 < 0.05), the incidence of postoperative readmission was 1.67 times higher (OR = 1.67, 95% CI 1.24-2.27, z = 3.33, P = 0.001 < 0.05), and the risk of postoperative death was 6.01 times higher (OR = 6.01, 95% CI 4.51-8.01, z = 12.27, P < 0.05). After conducting a publication bias test and Trim-and -Fill method analysis, we found no evidence of publication bias, and the results remained stable.

CONCLUSION

Preoperative low protein malnutrition is closely related to the incidence of postoperative complications and postoperative status. More prospective multicenter studies should be conducted to validate this conclusion. Furthermore, more effective assessment and intervention of preoperative nutritional status should be carried out to prevent the occurrence of postoperative complications and mortality risk.

Hypoalbuminemia as a Predictor of Mortality, Disability, and Readmission in Patients Undergoing Spine Surgery: A Retrospective Analysis

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The objective of this study was to clarify the association between preoperative albumin status and mortality and morbidity in lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Hypoalbuminemia is a known marker of inflammation and is associated with frailty. Hypoalbuminemia is an identified risk factor for mortality following spine surgery for metastases, yet has not been well studied among spine surgical cohorts outside of metastatic cancer.

MATERIALS AND METHODS

We identified patients with preoperative serum albumin laboratory values who underwent lumbar spine surgery at a US public university health system between 2014 and 2021. Demographic, comorbidity, and mortality data were collected along with preoperative and postoperative Oswestry Disability Index (ODI) scores. Any cause readmission within 1 year of surgery was recorded. Hypoalbuminemia was defined as <3.5 g/dL in serum. We examined the Kaplan-Meier survival plots based on serum albumin. Multivariable regression models were used to identify the association between preoperative hypoalbuminemia with mortality, readmission, and ODI, while controlling for age, sex, race, ethnicity, procedure, and Charlson Comorbidity Index.

RESULTS

Of 2573 patients, 79 were identified as hypoalbuminemic. Hypoalbuminemic patients had a significantly greater adjusted risk of mortality through 1 year (odds ratio=10.2; 95% CI: 3.1-33.5; P <0.001), and 7 years (hazard ratio=4.18; 95% CI: 2.29-7.65; P <0.001). Hypoalbuminemic patients had ODI scores 13.5 points higher (95% CI: 5.7-21.4; P <0.001) at baseline. Adjusted readmission rates were not different between groups through 1 year (odds ratio=1.15; 95% CI: 0.5-2.62; P =0.75) or through full surveillance (hazard ratio=0.82; 95% CI: 0.44-1.54; P =0.54).

CONCLUSIONS

Preoperative hypoalbuminemia was strongly associated with postoperative mortality. Hypoalbuminemic patients did not have demonstrably worse outcomes in their functional disability beyond 6 months. Within the first 6 months following surgery, the hypoalbuminemic group improved at a similar rate to the normoalbuminemic group despite having a greater preoperative disability. However, causal inference is limited in this retrospective study.

Life-threatening perioperative complications among older adults with spinal metastases: An analysis based on a nationwide inpatient sample of the US

INTRODUCTION

We aimed to investigate the prognostic determinants of life-threatening and fatal complications in patients <80 and ≥ 20 years of age and those ≥80 years who were undergoing surgery for spinal metastases.

MATERIALS AND METHODS

Based on data between 2005 and 2018 extracted from National Inpatient Sample as the largest longitudinal hospital inpatient databases in the United States, statistical analyses were performed to identify prognostic factors (age, sex, household income, insurance status, major comorbidities, primary site of malignancy, types of surgery, surgical approaches, types of hospital admission, and hospital-related characteristics) for major and fatal perioperative complications among older adult patients.

RESULTS

A total of 31,925 patients aged ≥ 20y who were undergoing surgery for spinal metastasis were identified (< 80 y: n = 28,448; ≥ 80 y: n = 35,37). After adjustment, age ≥80 y was significantly associated with greater risk of perioperative cardiac arrest (adjusted odds ratio [aOR]: 1.34, 95% confidence interval [CI]: 1.03-1.73) and acute kidney injury (AKI) (aOR: 1.23, 95% CI: 1.07-1.41) but lower risk of venous thromboembolic event (VTE) (aOR: 0.80, 95% CI: 0.66-0.96) than <80y. Factors predicting life-threatening complications among patients ≥ 80y were: male sex (<80 y: aOR = 1.14; ≥ 80 y: aOR = 1.35), higher score on Charlson Comorbidity Index (CCI) (80 y, aOR = 1.21-2.67; ≥ 80 y: aOR = 1.25-2.55), open surgery (<80 y: aOR = 1.24; ≥ 80 y: aOR = 1.35), and greater Metastatic Spinal Tumor Frailty Index (MSTFI) (<80 y: aOR = 2.48-10.03; ≥ 80 y: aOR = 2.69-11.21). Among patients <80y, factors predicting life-threatening complications were: male sex, Black race, greater CCI score, primary tumor at kidney, hematologic cancer, other/unspecified primary site, certain surgical procedures, open surgery, greater MSTFI, emergent admission, and low hospital volume.

DISCUSSION

This study identifies a list of independent risk factors for the presence of life-threatening complications among patients <80 and ≥ 80y who were undergoing surgery for spinal metastasis. The findings contribute to the development of clinical strategies for the surgical management of spinal metastasis, especially for octogenarians, and lower the risk of unfavorable inpatient outcomes.

Development and External Validation of the Spinal Tumor Surgery Risk Index

BACKGROUND

Patients undergoing surgical procedures for spinal tumors are vulnerable to major adverse events (AEs) and death in the postoperative period. Shared decision making and preoperative optimization of outcomes require accurate risk estimation.

OBJECTIVE

To develop and validate a risk index to predict short-term major AEs after spinal tumor surgery.

METHODS

Prospectively collected data from multiple medical centers affiliated with the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2020 were reviewed. Multiple logistic regression was used to assess sociodemographic, tumor-related, and surgery-related factors in the derivation cohort. The spinal tumor surgery risk index (STSRI) was built based on the resulting scores. The STSRI was internally validated using a subgroup of patients from the American College of Surgeons National Surgical Quality Improvement Program database and externally validated using a cohort from a single tertiary center.

RESULTS

In total, 14 982 operations were reviewed and 4556 (16.5%) major AEs occurred within 30 days after surgery, including 209 (4.5%) deaths. 22 factors were independently associated with major AEs or death and were included in the STSRI. Using the internal and external validation cohorts, the STSRI produced an area under the curve of 0.86 and 0.82, sensitivity of 80.1% and 79.7%, and specificity of 74.3% and 73.7%, respectively. The STSRI, which is freely available, outperformed the modified frailty indices, the American Society of Anesthesiologists classification, and the American College of Surgeons risk calculator.

CONCLUSION

In patients undergoing surgery for spinal tumors, the STSRI showed the highest predictive accuracy for major postoperative AEs and death compared with other current risk predictors.

Racial Disparities in Perioperative Morbidity Following Oncological Spine Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess the impact of race on complications following spinal tumor surgery.

METHODS

Adults with cancer who underwent spine tumor surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program datasets from 2012 to 2016. Clavien-Dindo Grade I-II (minor complications) and Clavien-Dindo Grade III-V (major complications including 30-day mortality) complications were compared between non-Hispanic Whites (NHW) and Black patients. A multivariable analysis was also conducted.

RESULTS

Of 1,226 identified patients, 85.9% were NHW (n = 1,053) and 14.1% were Black (n = 173). The overall rate of Grade I-II complications was 16.2%; 15.1% for NHW patients and 23.1% for Black patients (P = .008). On multivariable analysis, Black patients had significantly higher odds of having a minor complication (OR 1.87; 95% CI, 1.16-3.01; P = .010). On the other hand, the overall rate of Grade III-V complications was 13.3%; 12.5% for NHW patients and 16.2% for Black patients (P = .187). On multivariable analysis, Black race was not independently associated with major complications (OR 1.26; 95% CI, 0.71-2.23; P = .430). Median length of stay was 8 days (IQR 5-13) for NHW patients and 10 days (IQR 6-15) for Black patients (P = .011).

CONCLUSION

Black patients who underwent metastatic spinal tumor surgery were at a significantly increased risk of perioperative morbidity compared to NHW patients independent of baseline and operative characteristics. Major complications did not differ between groups. Race should be further studied in the context of metastatic spine disease to improve our understanding of these disparities.

Performance assessment and external validation of specific thresholds of total psoas muscle cross-sectional area as predictors of mortality in oncologic spine surgery for spinal metastases

PURPOSE

The purpose of this study was to assess the utility of low muscle mass (LMM) in predicting 90-day and 12-month mortality after spinal tumor surgery.

METHODS

We identified 115 patients operated on for spinal metastases between April 2012 and August 2022 who had available perioperative abdominal or lumbar spine CT scans and minimum 90-day follow-up. LMM was defined as a total psoas muscle cross-sectional area (TPA) at the L4 pedicle level less than 10.5 cm² for men and less than 7.2 cm² for women based on previously reported thresholds. A secondary analysis was performed by analyzing TPA as a continuous variable. The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed.

RESULTS

The 90-day mortality was 19% for patients without and 42% for patients with LMM (p = 0.010). After multivariate analysis, LMM was not independently associated with increased odds of 90-day mortality (odds ratio 2.16 [95% confidence interval 0.62 to 7.50]; p = 0.223). The 12-month mortality was 45% for patients without and 71% for patients with LMM (p = 0.024). After multivariate analysis, LMM was not independently associated with increased odds of 12-month mortality (OR 1.64 [95% CI 0.46 to 5.86]; p = 0.442). The secondary analysis showed no independent association between TPA and 90-day or 12-month mortality.

CONCLUSION

Patients with LMM had higher rates of 90-day and 12-month mortality in our study, but this was not independent of other parameters such as performance status, hypoalbuminemia, or primary cancer type.

Hypoalbuminemia and Elevated CRP are Risk Factors for Deep Infections and Urinary Tract Infections After Lumbar Spine Surgery in a Large Retrospective Patient Population

STUDY DESIGN

Retrospective cross-sectional study.

OBJECTIVES

To determine if pre-operative albumin and CRP can predict post-operative infections after lumbar surgery.

METHODS

Patients who underwent an anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), or lumbar discectomy were identified using a patient record database (PearlDiver) and were included in this retrospective study. Patients were stratified by Charlson Comorbidity Index (CCI) scores and pre-operative albumin and CRP status. Post-operative complications included deep infections and urinary tract infections within 3 months of the surgery and revisions within 1 year of the surgery.

RESULTS

74,280 patients were included in this study. 21,903 had pre-operative albumin or CRP lab values. 7,191 (33%), 12,183 (56%), and 2,529 (12%) patients underwent an ALIF, PLIF, and a lumbar discectomy, respectively. 16,191 did not have any complication (74%). The most common complication was UTI (16%). Among all patients, hypoalbuminemia was a significant risk factor for deep infection and UTI after ALIF, deep infection, UTI, and surgical revision after PLIF, and deep infection after lumbar discectomy. Elevated CRP was a significant risk factor for deep infection after ALIF, UTI after PLIF, and deep infection after lumbar discectomy in patients with a CCI ≤ 3.

CONCLUSIONS

Pre-operative hypoalbuminemia and elevated CRP were significant risk factors for deep infection, UTI, and/or revision, after ALIF, PLIT, and/or lumbar discectomy. Future studies with a larger population of patients with low albumin and high CRP values are needed to further elaborate on the current findings.

Nutritional Optimization for Post-Spinal Surgery Recovery

Adequate nutritional intake is a key component of uncomplicated recovery from spinal surgery. Though much in the literature exists regarding its importance, specific dietary regimens for spinal surgery remain understudied, and little is available in compiling both preoperative and postoperative nutritional recommendations for patients. The complexity that may exist with these recommendations -- especially in the context of patients with diabetes or those who use substances -- has led in recent years to the development of protocols such as Enhanced Recovery After Surgery (ERAS), which gives providers a guideline upon which to base their nutritional counselling. More innovative regimens, such as the use of bioelectrical impedance analyses to assess nutritional status, have also emerged, resulting in a vast array of dietary recommendations and protocols for spinal surgery. In the following paper, we aim to compile a few of these guidelines, comparing various preoperative and postoperative nutritional strategies as well as making note of special considerations, like patients with diabetes or those who use substances. We also work to overview several such dietary "protocols" available in the literature, with a special focus on ERAS and more recent regimens like the Northwestern High-Risk Spine Protocol. We briefly mentioned preclinical work on novel nutritional recommendations as well. Ultimately, we hope to highlight the importance of nutrition in spinal surgery and address the need for greater cohesion of dietary strategies already in existence.

The predictive ability of routinely collected laboratory markers for surgically treated spinal metastases: a retrospective single institution study

PURPOSE

We aimed to identify effective routinely collected laboratory biomarkers for predicting postoperative outcomes in surgically treated spinal metastases and attempted to establish an effective prediction model.

METHODS

This study included 268 patients with spinal metastases surgically treated at a single institution. We evaluated patient laboratory biomarkers to determine trends to predict survival. The markers included white blood cell (WBC) count, platelet count, neutrophil count, lymphocyte count, hemoglobin, albumin, alkaline phosphatase, creatinine, total bilirubin, calcium, international normalized ratio (INR), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR). A nomogram based on laboratory markers was established to predict postoperative 90-day and 1-year survival. The discrimination and calibration were validated using concordance index (C-index), area under curves (AUC) from receiver operating characteristic curves, and calibration curves. Another 47 patients were used as a validation group to test the accuracy of the nomogram. The prediction accuracy of the nomogram was compared to Tomita, revised Tokuhashi, modified Bauer, and Skeletal Oncology Research Group machine-learning (SORG ML).

RESULTS

WBC, lymphocyte count, albumin, and creatinine were shown to be the independent prognostic factors. The four predictive laboratory markers and primary tumor, were incorporated into the nomogram to predict the 90-day and 1-year survival probability. The nomogram performed good with a C-index of 0.706 (0.702-0.710). For predicting 90-day survival, the AUC in the training group and the validation group was 0.740 (0.660-0.819) and 0.795 (0.568-1.000), respectively. For predicting 1-year survival, the AUC in the training group and the validation group was 0.765 (0.709-0.822) and 0.712 (0.547-0.877), respectively. Our nomogram seems to have better predictive accuracy than Tomita, revised Tokuhashi, and modified Bauer, alongside comparable prediction ability to SORG ML.

CONCLUSIONS

Our study confirmed that routinely collected laboratory markers are closely associated with the prognosis of spinal metastases. A nomogram based on primary tumor, WBC, lymphocyte count, albumin, and creatinine, could accurately predict postoperative survival for patients with spinal metastases.

Systemic considerations for the surgical treatment of spinal metastatic disease: a scoping literature review

Systemic assessment is a pillar in the neurological, oncological, mechanical, and systemic (NOMS) decision-making framework for the treatment of patients with spinal metastatic disease. Despite this importance, emerging evidence relating systemic considerations to clinical outcomes following surgery for spinal metastatic disease has not been comprehensively summarised. We aimed to conduct a scoping literature review of this broad topic. We searched MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and CINAHL databases from Jan 1, 2000, to July 31, 2021. 61 articles were included, accounting for a total of 22 335 patients. Preoperative systemic variables negatively associated with postoperative clinical outcomes included demographics (eg, older age [>60 years], Black race, male sex, low or elevated body-mass index, and smoking status), medical comorbidities (eg, cardiac, pulmonary, hepatic, renal, endocrine, vascular, and rheumatological), biochemical abnormalities (eg, hypoalbuminaemia, atypical blood cell counts, and elevated C-reactive protein concentration), low muscle mass, generalised motor weakness (American Spinal Cord Injury Association Impairment Scale grade and Frankel grade) and poor ambulation, reduced performance status, and systemic disease burden. This is the first comprehensive scoping review to broadly summarise emerging evidence relevant to the systemic assessment component of the widely used NOMS framework for spinal metastatic disease decision making. Medical, surgical, and radiation oncologists can consider these findings when prognosticating spinal metastatic disease-related surgical outcomes on the basis of patients' systemic condition. These factors might inform a shared decision-making approach with patients and their families.

A retrospective study evaluating the association between hypoalbuminemia and postoperative outcomes for patients receiving open rotator cuff repair

PURPOSE

Malnutrition has historically been shown to influence surgical outcomes. Although the diagnosis of malnutrition can be multifactorial, serum albumin levels serve as a useful indicator of malnutrition in patients undergoing orthopaedic surgery. The purpose of this study is to examine the prevalence of post-operative complications in patients with malnutrition (hypoalbuminemia) who underwent open rotator cuff repair. We hypothesized that patients with low preoperative albumin levels will have an increased risk for postoperative complications, readmission, reoperation, and prolonged hospital stay.

METHODS

The National Surgical Quality Improvement Program database was queried for patients undergoing open rotator cuff repair from 2006 to 2019. Two patient cohorts were defined: patients with hypoalbuminemia (<3.5 g/dL) and patients with normal preoperative serum albumin (≥3.5 g/dL), with the former being an indicator for malnutrition. In this analysis, demographics, comorbidities, and postoperative complications were compared between the two cohorts using bivariate analyses. Confounding factors found in the control group included sex, race, age, body mass index, smoking status, chronic obstructive pulmonary disease, hypertension, dialysis, diabetes, and dyspnea. To eliminate potential biases, multivariable logistic regression was used to adjust for these confounding factors.

RESULTS

Of 3,052 patients undergoing open rotator cuff repair with serum albumin levels recorded within 90 days before the surgery, 2,914 patients (95.5%), with an age range of 21-90 years, had normal albumin levels and 138 patients (4.5%), with an age range of 24-87 years, were hypoalbuminemic. Following adjustment on multivariate analyses, compared to patients with normal preoperative serum albumin, those with hypoalbuminemia had an increased risk of extended length of hospital stay (OR 7.47; p < 0.001) and hospital readmission (OR 4.16; p = 0.002).

CONCLUSION

Hypoalbuminemia is associated with extended length of stay and readmission after receiving open rotator cuff repair surgery.

Association between preoperative serum albumin and prognosis in patients with adrenocortical carcinoma after primary resection: a retrospective study

Background

Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with a poor prognosis. Given the limited treatment options, prognostic assessment of ACC is increasingly crucial. In this study, we aim to assess the correlation between preoperative serum albumin and prognosis in patients with ACC after primary resection.

Methods

We retrospectively collected and reviewed medical information about 71 ACC patients who underwent primary resection. Survival analysis was performed by Kaplan–Meier analysis with log-rank test or Breslow test. Receiver operating characteristic (ROC) curve and Jordan index was generated to explore optimal cut-off value of albumin. Univariate and multivariate analysis was conducted using Cox’s hazards model. Statistical significance was defined as P < 0.05.

Results

Among included patients, 33 patients (46.5%) relapsed at the end of follow-up, while 39 patients (54.9%) died. The median overall survival (OS) of included patients was 17 (range 1–104) months, and median recurrence-free survival (RFS) was 10 (range 0–104) months. In univariate analysis, the albumin was significantly associated with OS (HR:0.491, 95% CI: 0.260–0.930, P = 0.029) and RFS (HR: 0.383, 95% CI: 0.192–0.766, P = 0.007). In multivariate analysis, serum albumin as an independent prognostic factor of OS was confirmed (HR: 0.351, 95% CI: 0.126–0.982, P = 0.046).

Conclusions

Preoperative albumin might be a significant prognostic factor for ACC patients after primary resection. This result may be useful for risk stratification and management of this rare malignancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08689-5.

Comparison of Two Malnutrition Assessment Scales in Predicting Postoperative Complications in Elderly Patients Undergoing Noncardiac Surgery

Background: The present study was designed to investigate the relationship between two malnutrition assessment scales, perioperative nutrition screen (PONS) and Nutritional Risk Screening 2002 (NRS2002), with postoperative complications in elderly patients after noncardiac surgery.

Methods: This was a secondary analysis of a prospective cohort study. Elderly patients (65–90 years) undergoing noncardiac surgery were enrolled in Peking University First Hospital. Malnutrition was screened by PONS and NRS2002 at the day before surgery. Multivariable analysis was employed to analyze the relationship between PONS and NRS2002 and postoperative 30-day complications. Receiver operating characteristic (ROC) curve was generated to evaluate the predictive value of PONS and NRS2002 in predicting postoperative complications.

Results: A total of 915 patients with mean age of 71.6 ± 5.2 years were consecutively enrolled from September 21, 2017, to April 10, 2019. The incidence of malnutrition was 27.3% (250/915) by PONS ≥ 1 and 53.6% (490/915) by NRS2002 ≥ 3. The overall incidence of complications within postoperative 30 days was 45.8% (419/915). After confounders were adjusted, malnutrition by PONS ≥ 1 (OR 2.308, 95% CI 1.676–3.178, P < 0.001), but not NRS2002 ≥ 3 (OR 1.313, 95% CI 0.973–1.771, P = 0.075), was related with an increased risk of postoperative complications. ROC curve analysis showed that the performances of PONS [area under the ROC curve (AUC) 0.595, 95% CI 0.558–0.633] showed very weak improvement in predicting postoperative complications than NRS2002 score (AUC 0.577, 95% CI 0.540–0.614).

Conclusion: The present study found that malnutrition diagnosed by PONS was related with an increased risk of postoperative complications. The performances of PONS and NRS2002 were poor in predicting overall postoperative complications.

Clinical Trial Registration:www.chictr.org.cn, identifier: ChiCTR-OOC-17012734.

Consensus statement for perioperative care in lumbar spinal fusion: Enhanced Recovery After Surgery (ERAS®) Society recommendations

BACKGROUND

Enhanced Recovery After Surgery (ERAS) evidence-based protocols for perioperative care have led to improvements in outcomes in numerous surgical areas, through multimodal optimization of patient pathway, reduction of complications, improved patient experience and reduction in the length of stay. ERAS represent a relatively new paradigm in spine surgery.

PURPOSE

This multidisciplinary consensus review summarizes the literature and proposes recommendations for the perioperative care of patients undergoing lumbar fusion surgery with an ERAS program.

STUDY DESIGN

This is a review article.

METHODS

Under the impetus of the ERAS® society, a multidisciplinary guideline development group was constituted by bringing together international experts involved in the practice of ERAS and spine surgery. This group identified 22 ERAS items for lumbar fusion. A systematic search in the English language was performed in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Systematic reviews, randomized controlled trials, and cohort studies were included, and the evidence was graded according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Consensus recommendation was reached by the group after a critical appraisal of the literature.

RESULTS

Two hundred fifty-six articles were included to develop the consensus statements for 22 ERAS items; one ERAS item (prehabilitation) was excluded from the final summary due to very poor quality and conflicting evidence in lumbar spinal fusion. From these remaining 21 ERAS items, 28 recommendations were included. All recommendations on ERAS protocol items are based on the best available evidence. These included nine preoperative, eleven intraoperative, and six postoperative recommendations. They span topics from preoperative patient education and nutritional evaluation, intraoperative anesthetic and surgical techniques, and postoperative multimodal analgesic strategies. The level of evidence for the use of each recommendation is presented.

CONCLUSION

Based on the best evidence available for each ERAS item within the multidisciplinary perioperative care pathways, the ERAS® Society presents this comprehensive consensus review for perioperative care in lumbar fusion.

Preoperative malnutrition increases odds of hospital admission and extended length of stay following arthroscopic rotator cuff repair

BACKGROUND

Rotator cuff repair (RCR) is a common orthopedic procedure frequently performed in the outpatient setting. Malnutrition, as assessed by preoperative serum albumin <3.5 g/dL, has been independently associated with significantly higher risks of multiple adverse outcomes in several orthopedic procedures. The effect of preoperative hypoalbuminemia on short-term outcomes of RCR was previously unknown.

HYPOTHESIS

we hypothesized that preoperative serum albumin <3.5 g/dL would be associated with higher odds of post-operative admission and prolonged length of stay.

METHODS

This study represents a retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program database (NSQIP) for patients undergoing RCR between 2011 and 2015.

RESULTS

Multivariate regression analysis adjusted for sex, ASA classification, age, BMI, and diabetes status (Table 3) showed preoperative hypoalbuminemia conferred a significantly increased adjusted odds ratio of postoperative admission (adjusted odds ratio 1.711, CI 1.134-2.583, p = 0.011) and extended length of stay (adjusted odds ratio 2.073, CI 1.073-4.003, p = 0.030).

CONCLUSION

Malnutrition as assessed by preoperative serum albumin <3.5 g/dL is significantly associated with increased odds of hospital admission and extended length of stay following arthroscopic RCR. This has clinical implications in surgical patient selection and risk stratification.

LEVEL OF EVIDENCE

III, Retrospective cohort study.

A Novel Clinical Scoring System for Perioperative Morbidity in Metastatic Spinal Tumor Surgery: The Spine Oncology Morbidity Assessment Score

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate a scoring system to predict morbidity for patients undergoing metastatic spinal tumor surgery (MSTS).

SUMMARY OF BACKGROUND DATA

Multiple scoring systems exist to predict survival for patients with spinal metastasis. The potential benefits and risks of surgery need to be evaluated for patients with disseminated cancer and limited life expectancy. Few scoring systems exist to predict perioperative morbidity after MSTS.

METHODS

We reviewed records of patients who underwent MSTS at our institution between 2013 and 2019. All perioperative complications occurring within 30 days were recorded. A clinical scoring system consisting of five variables (age ≥ 70 yr, hypoalbuminemia, poor preoperative functional status [Karnofsky ≤ 40], Frankel Grade A-C, and multilevel disease ≥2 continuous vertebral bodies) was evaluated as a predictive tool for morbidity; every parameter was assigned a value of 0 if absent or 1 if present (total possible score = 5). The effect of the scoring system on morbidity was evaluated using stepwise multiple logistic regression. Model accuracy was calculated by receiver operating characteristic analysis.

RESULTS

One hundred and five patients were identified, with a male prevalence of 58.1% and average age at surgery of 61 years. The overall 30-day complication rate was 36.2%. The perioperative morbidity was 4.6%, 30.0%, 53.9%, and 64.7% for patients with scores of 0, 1, 2, and ≥3 points, respectively (P < 0.001). On multiple logistic regression analysis controlling for covariates not present in the model, the scoring system was significantly associated with 30-day morbidity (OR 3.11; 95% CI, 1.72-5.59; P < 0.001). The model's accuracy was estimated at 0.75.

CONCLUSION

Our proposed model was found to accurately predict perioperative morbidity after MSTS. The Spine Oncology Morbidity Assessment (SOMA) score may prove useful for risk stratification and possibly decision-making, though further validation is needed.Level of Evidence: 4.

Surgical Duration Implicated in Major Postoperative Complications in Total Hip and Total Knee Arthroplasty: A Retrospective Cohort Study

Total hip and knee arthroplasties are two of the most commonly performed orthopaedic surgeries and are expected to increase in incidence in the coming decades. We sought to examine whether the duration of these procedures is related to various postoperative complications using data from 2010 to 2017 from the American College of Surgeons National Surgical Quality Improvement Program database.

Which Objective Nutritional Index Is Better for the Prediction of Adverse Medical Events in Elderly Patients Undergoing Spinal Surgery?

OBJECTIVE

The relationship of preoperative malnutrition with perioperative adverse medical events (PAMEs) has not been well studied in elderly patients undergoing spinal surgery (SS). We aimed to compare the Prognostic Nutritional Index (PNI), Controlling Nutritional Status (CONUT) score, and Geriatric Nutritional Risk Index (GNRI) for prediction of PAMEs in elderly patients undergoing SS.

METHODS

Data of 454 patients ≥65 years old undergoing SS were reviewed. PAMEs were defined as death, cardiopulmonary complications, respiratory failure, acute kidney injury, pneumonia, delirium, cerebrovascular events, and sepsis. The area under the receiver operating characteristic curve was used to compare the predictive value of each nutritional index for PAMEs.

RESULTS

Incidence of PAMEs was 15.3%. Patients who had PAMEs had significantly lower GNRI and PNI but higher CONUT score before surgery compared with patients without PAMEs. Multivariate analysis showed that age (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.01-4.75, P = 0.014), chronic renal failure (OR 1.34, 95% CI 1.03-3.82, P = 0.002), coronary artery disease (OR 1.12, 95% CI 1.11-3.54, P = 0.028), PNI <45.4 (OR 2.12, 95% CI 1.16-4.80, P = 0.011), CONUT score >5 (OR 2.17, 95% CI 1.03-3.76, P = 0.001), and GNRI <92 (OR 2.68, 95% CI 1.20-6.45, P < 0.001) were significant predictors of PAMEs. The receiver operating characteristic curve showed that GNRI had much greater discriminatory ability regarding PAMEs than PNI and CONUT score.

CONCLUSIONS

Preoperative malnutrition is associated with PAMEs in elderly patients undergoing SS. GNRI had the highest accuracy for predicting PAMEs among the nutritional indices studied.

Predicting tumor-specific survival in patients with spinal metastatic renal cell carcinoma: which scoring system is most accurate?

OBJECTIVE

Although several prognostic scores for spinal metastatic disease have been developed in the past 2 decades, the applicability and validity of these models to specific cancer types are not yet clear. Most of the data used for model formation are from small population sets and have not been updated or externally validated to assess their performance. Developing predictive models is clinically relevant as prognostic assessment is crucial to optimal decision-making, particularly the decision for or against spine surgery. In this study, the authors investigated the performance of various spinal metastatic disease risk models in predicting prognosis for spine surgery to treat metastatic renal cell carcinoma (RCC).

METHODS

Data of patients who underwent surgery for RCC metastatic to the spine at 2 tertiary centers between 2010 and 2019 were retrospectively retrieved. The authors determined the prognostic value associated with the following scoring systems: the Tomita score, original and revised Tokuhashi scores, original and modified Bauer scores, Katagiri score, the Skeletal Oncology Research Group (SORG) classic algorithm and nomogram, and the New England Spinal Metastasis Score (NESMS). Regression analysis of patient variables in association with 1-year survival after surgery was assessed using Cox proportional hazard models. Calibration and time-dependent discrimination analysis were tested to quantify the accuracy of each scoring system at 3 months, 6 months, and 1 year.

RESULTS

A total of 86 metastatic RCC patients were included (median age 64 years [range 29-84 years]; 63 males [73.26%]). The 1-year survival rate was 72%. The 1-year survival group had a good performance status (Karnofsky Performance Scale [KPS] score 80%-100%) and an albumin level > 3.5 g/dL (p < 0.05). Multivariable-adjusted Cox regression analysis showed that poor performance status (KPS score < 70%), neurological deficit (Frankel grade A-D), and hypoalbuminemia (< 3.5 g/dL) were associated with a higher risk of death before 1 year (p < 0.05). The SORG nomogram, SORG classic, original Tokuhashi, and original Bauer demonstrated fair performance (0.7 < area under the curve < 0.8). The NESMS differentiates survival among the prognostic categories with the highest accuracy (area under the curve > 0.8).

CONCLUSIONS

The present study shows that the most cited and commonly used scoring systems have a fair performance predicting survival for patients undergoing spine surgery for metastatic RCC. The NESMS had the best performance at predicting 1-year survival after surgery.

Low Preoperative Albumin Levels Predict Adverse Outcomes After Total Joint Arthroplasty

BACKGROUND

Low albumin levels have previously been shown to be a risk factor for increased complications in the 30-day postoperative period after total hip or knee arthroplasty. In this study, we examined the effect that albumin levels have on complications in all total joint primary arthroplasties or revisions (shoulder, elbow, wrist, hip, knee, ankle, and fingers).

METHODS

Patients who underwent a primary total joint arthroplasty or revision from 2005 to 2015 and who had preoperative serum albumin concentration levels recorded were identified from the U.S. National Surgical Quality Improvement Program (NSQIP) database. Patients were grouped into those with normal serum albumin concentrations (≥3.5 g/dL) and those who were hypoalbuminemic (<3.5 g/dL); hypoalbuminemia was subdivided into quartiles for statistical analysis. Univariate analyses were conducted with use of the Student t test for categorical outcomes and the chi-square test for continuous variables. Following univariate analysis, all significant comorbidity variables for both the primary and revision arthroplasty groups were used in a multivariate regression analysis to determine independent association of hypoalbuminemia and postoperative outcomes.

RESULTS

Using available data from 2005 to 2015, 135,008 patients fit the eligibility criteria, including those who had undergone primary arthroplasty (n = 125,162) and those who had undergone revision arthroplasty (n = 9,846). The revision arthroplasties included the shoulder (2%), hip (46%), and knee (52%), and the primary arthroplasties included the shoulder (3%), hip (39%), knee (57%), and other (1%). We found that patients who had lower albumin levels had a greater rate of postoperative complications including cardiac arrest, myocardial infarction, cerebrovascular accident, organ or space surgical site infection, sepsis, septic shock, pneumonia, renal insufficiency in general, unplanned intubation, return to the operating room within 30 days, urinary tract infection, and wound infection (all p < 0.005).

CONCLUSIONS

There was a significant difference in 30-day postoperative complications between patients with normal preoperative albumin levels and those with low albumin levels after all primary total joint arthroplasties or revisions. Patients with low albumin levels were at significantly increased risk for infection, pneumonia, sepsis, myocardial infarction, and other adverse outcomes. Further research is needed to develop interventions to improve serum albumin concentrations preoperatively to mitigate adverse outcomes.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Rates, Risk Factors, and Complications of Red Blood Cell Transfusion in Metastatic Spinal Tumor Surgery: An Analysis of a Prospective Multicenter Surgical Database

OBJECTIVE

To identify rates, risks, and complications of red blood cell (RBC) transfusion in metastatic spinal tumor surgery.

METHODS

The multicenter prospective American College of Surgeons National Quality Improvement Program database was queried for the years 2012-2016. Adult patients with disseminated cancer who underwent metastatic spinal tumor surgery were identified. Transfusion was defined as having received at least 1 intraoperative/postoperative RBC transfusion within the first 72 hours of surgery start time. A stepwise multiple logistic regression model with backward elimination was used.

RESULTS

Of 1601 patients identified, 623 patients (38.9%) received a RBC transfusion. Independent predictors of RBC transfusion included higher American Society of Anesthesiologists class (odds ratio [OR] = 1.54), preoperative anemia (OR = 3.10), instrumentation (OR = 1.63), and longer operative time (OR = 1.52). The overall complication rate was significantly higher in patients who received a transfusion compared with patients who did not receive a transfusion (22.3% vs. 15.0%, P < 0.001). Individual complications that were more common in patients who received a transfusion were sepsis (3.5% vs. 1.9%, P = 0.050), deep vein thrombosis (6.1% vs. 3.3%, P = 0.007), and prolonged ventilation (3.9% vs. 1.3%, P = 0.001). RBC transfusion (OR = 1.65), hypoalbuminemia (OR = 1.53), and anterior/anterolateral approaches for corpectomy (OR = 2.11) were independent risk factors for developing a postoperative complication.

CONCLUSIONS

RBC transfusion after metastatic spinal tumor surgery may increase the risk of early postoperative complications. Future research into preoperative patient optimization and decreasing intraoperative blood loss is needed.

Risk Factors for Wound-Related Complications After Surgery for Primary and Metastatic Spine Tumors: A Systematic Review and Meta-Analysis

OBJECTIVE

We systematically reviewed the literature to compare risk factors for postoperative complications at the surgical wound site in primary and metastatic tumor operations.

METHODS

We screened English-language publications on the outcomes of primary and metastatic spinal tumor operations. Pooled analyses and meta-analyses with random-effects modeling were performed comparing patients with and without wound complications, which were defined as surgical site infection or sterile wound dehiscence.

RESULTS

Our search identified 5471 unique citations, from which we included 23 studies describing 5104 patients. A total of 1936 patients underwent surgery for primary tumors, with a wound complication rate of 8.1%. Subgroup analysis of benign and malignant primary tumors yielded significantly different wound complication rates of 7.8% and 26.9%, respectively. The metastatic tumor cohort included 168 patients and a complication rate of 6.6%. In a pooled analysis of primary tumors, higher wound complication rates were associated with sacral operations and the use of instrumentation. In the metastatic tumor cohort, higher complication rates were associated with female sex, smoking history, preoperative chemotherapy, preoperative radiotherapy, corticosteroid use, and previous spine surgery. Instrumentation remained a statistically significant risk factor for primary tumors with the addition of random-effects meta-analysis.

CONCLUSIONS

Risk factors for wound complications after primary tumor operations were related to tumor histology and the spinal location of the operation. Risk factors for metastatic tumors may be related to several systemic preoperative treatments and baseline comorbidities. Random-effects meta-analysis showed the limited generalizability of these findings because of the small heterogenous primary literature.