The effect of diabetes on perioperative complications following spinal surgery: a meta-analysis

Impact of preoperative haemoglobin A1c levels on postoperative outcomes in adults undergoing major noncardiac surgery: A systematic review

AIMS

Diabetes is known to increase morbidity and mortality after major surgery. However, literature is conflicting on whether elevated preoperative haemoglobin A1c (HbA1c) levels are associated with worse outcomes following major noncardiac surgery. We aimed to investigate the effect of incremental preoperative HbA1c levels on postoperative outcomes in adults who had undergone major noncardiac surgery.

METHODS

We systematically searched PubMed, EMBASE and the Cochrane Library databases for eligible studies published between January 2012 and July 2023. Randomised controlled trials and observational studies (cohort and case-control studies) which measured HbA1c within 6 months before surgery and compared outcomes between at least three incremental subgroups or analysed HbA1c as a continuous variable were included. The systematic review protocol was registered with PROSPERO (CRD42023391946).

RESULTS

Twenty observational studies investigating outcomes across multiple surgical types were included. Higher preoperative HbA1c levels were associated with increased odds of overall postoperative complications, postoperative acute kidney injury, anastomotic leak, surgical site infections and increased length of stay. Each 1% increase in preoperative HbA1c was associated with increased odds of these complications. No association with reoperations and 30-day mortality was identified. The literature was highly variable with respect to composite major complications, perioperative cardiovascular events, hospital readmissions, postoperative pneumonia and systemic thromboembolism.

CONCLUSIONS

Current evidence suggested that higher preoperative HbA1c levels were associated with increased odds of postoperative complications and extended length of stay in adults undergoing major noncardiac surgery. Further high-quality studies would be needed to quantify the risks posed and determine whether early intervention improves outcomes.

Superinfections of the Spine: A Single-Institution Experience

Background/Objectives: A superinfection occurs when a new, secondary organism colonizes an existing infection. Spine infections are associated with high patient morbidity and sometimes require multiple irrigations and debridements (I&Ds). When multiple I&Ds are required, the risk of complications increases. The purpose of this study was to report our experience with spine superinfections and determine which patients are typically affected. Methods: A retrospective case series of spine superinfections and a retrospective case-control analysis were conducted. Data were collected manually from electronic medical records. Spine I&Ds were identified. Groups were created for patients who had multiple I&Ds for (1) a recurrence of the same causative organism or (2) a superinfection with a novel organism. Preoperative demographic, clinical, and microbiologic data were compared between these two outcomes. A case series of superinfections with descriptive data was constructed. Lastly, two illustrative cases were provided in a narrative format. Results: A total of 92 patients were included in this analysis. Superinfections occurred after 6 out of the 92 (7%) initial I&Ds and were responsible for 6 out of the 24 (25%) repeat I&Ds. The preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) of the patients with a superinfection were significantly lower than those in the control group (p = 0.022 and p = 0.032). Otherwise, the observed differences in the preoperative variables were not statistically different. In the six cases of superinfection, the presence of high-risk comorbidities, a history of substance abuse, or a lack of social support were commonly observed. The superinfecting organisms included Candida, Pseudomonas, Serratia, Klebsiella, Enterobacter, and Staphylococcus species. Conclusions: Superinfections are a devastating complication requiring reoperation after initial spine I&D. Awareness of the possibility of superinfection and common patient archetypes can be helpful for clinicians and care teams. Future work is needed to examine how to identify, help predict, and prevent spine superinfections.

Racial Differences in Perioperative Complications, Readmissions, and Mortalities After Elective Spine Surgery in the United States: A Systematic Review Using AI-Assisted Bibliometric Analysis

STUDY DESIGN

Systematic Review and Meta-analysis.

OBJECTIVES

To evaluate the impact of race on post-operative outcomes and complications following elective spine surgery in the United States.

METHODS

PUBMED, MEDLINE(R), ERIC, EMBASE, and SCOPUS were searched for studies documenting peri-operative events for White and African American (AA) patients following elective spine surgery. Pooled odds ratios were calculated for each 90-day outcome and meta-analyses were performed for 4 peri-operative events and 7 complication categories. Sub-analyses were performed for each outcome on single institution (SI) studies and works that included <100,000 patients.

RESULTS

53 studies (5,589,069 patients, 9.8% AA) were included. Eleven included >100,000 patients. AA patients had increased rates of 90-day readmission (OR 1.33, P = .0001), non-routine discharge (OR 1.71, P = .0001), and mortality (OR 1.66, P = .0003), but not re-operation (OR 1.16, P = .1354). AA patients were more likely to have wound-related complications (OR 1.47, P = .0001) or medical complications (OR 1.35, P = .0006), specifically cardiovascular (OR 1.33, P = .0126), deep vein thrombosis/pulmonary embolism (DVT/PE) (OR 2.22, P = .0188) and genitourinary events (OR 1.17, P = .0343). SI studies could only detect racial differences in re-admissions and non-routine discharges. Studies with <100,000 patients replicated the above findings but found no differences in cardiovascular complications. Disparities in mortality were only detected when all studies were included.

CONCLUSIONS

AA patients faced a greater risk of morbidity across several distinct categories of peri-operative events. SI studies can be underpowered to detect more granular complication types (genitourinary, DVT/PE). Rare events, such as mortality, require larger sample sizes to identify significant racial disparities.

Strong association of lumbar disk herniation with diabetes mellitus: a 12-year nationwide retrospective cohort study

Background

Despite reports on the association between diabetes mellitus (DM) and lumbar disk herniation (LDH), large-scale, nationwide studies exploring this relationship are lacking. We aimed to examine the profiles of DM in individuals with LDH and explore the potential mechanisms underlying the development of these disorders.

Methods

This retrospective, population-based study was conducted between 2008 and 2019 using data from the National Health Insurance (NHI) research database in Taiwan. The primary outcome was the date of initial LDH diagnosis, death, withdrawal from the NHI program, or end of the study period.

Results

In total, 2,662,930 individuals with and 16,922,546 individuals without DM were included in this study; 719,068 matched pairs were established following propensity score matching (1:1 ratio) for sex, age, comorbidities, smoking, alcohol consumption, antihyperglycemic medications, and index year. The adjusted risk for developing LDH was 2.33-fold (95% confidence interval: 2.29-2.37; P<0.001), age-stratified analysis revealed a significantly greater risk of LDH in every age group, and both males and females were approximately twice as likely to develop LDH in the DM compared with non-DM cohort. Individuals with DM and comorbidities had a significantly higher risk of developing LDH than those without, and the serial models yielded consistent results. Treatment with metformin, sulfonylureas, meglitinides, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, or alpha-glucosidase inhibitors was associated with a more than 4-fold increased risk of LDH in the DM cohort. DM was strongly associated with the long-term development of LDH; over the 12-year follow-up period, the cumulative risk of LDH was significantly higher in patients with than without DM (log-rank P<0.001).

Conclusion

DM is associated with an increased risk of LDH, and advanced DM may indicate a higher risk of LDH.

The surgical patient of yesterday, today, and tomorrow-a time-trend analysis based on a cohort of 8.7 million surgical patients

BACKGROUND

Global healthcare delivery is challenged by the aging population and the increase in obesity and type 2 diabetes. The extent to which such trends affect the cohort of patients the authors surgically operate on remains to be elucidated. Comprising of 8.7 million surgical patients, the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database can be analyzed to investigate the echo of general population dynamics and forecast future trends.

MATERIAL AND METHODS

The authors reviewed the ACS-NSQIP database (2008-2020) in its entirety, extracting patient age, BMI, and diabetes prevalence. Based on these data, the authors forecasted future trends up to 2030 using a drift model.

RESULTS

During the review period, median age increased by 3 years, and median BMI by 0.9 kg/m2. The proportion of patients with overweight, obesity class I, and class II rates increased. The prevalence of diabetes rose between 2008 (14.9%) and 2020 (15.3%). The authors forecast the median age in 2030 to reach 61.5 years and median BMI to climb to 29.8 kg/m2. Concerningly, in 2030, eight of ten surgical patients are projected to have a BMI above normal. Diabetes prevalence is projected to rise to 15.6% over the next decade.

CONCLUSION

General population trends echo in the field of surgery, with the surgical cohort aging at an alarmingly rapid rate and increasingly suffering from obesity and diabetes. These trends show no sign of abating without dedicated efforts and call for urgent measures and fundamental re-structuring for improved future surgical care.

Early Experience With an Endocrinology Preoperative Fast-Track Program for Optimizing Spine Surgery Candidates With Poorly Controlled Diabetes Mellitus

INTRODUCTION

Previous studies demonstrated an increase in adverse outcomes for patients undergoing elective surgeries with poorly controlled diabetes mellitus. At a large, tertiary-care spine center with a notable population of patients with poorly controlled diabetes, an Endocrinology Fast-Track (EFT) program was developed to improve patient optimization before elective spine surgery. The purpose of this study was to report our early experience.

METHODS

Seventy-five patients who were scheduled for elective spine surgery were noted to have Hgb A1c > 7 on preoperative evaluation. Thirty-two patients accepted referral to the EFT program and 43 declined (non-EFT). Mean preoperative Hgb A1c was similar between groups (EFT: 8.79 versus non-EFT: 9.26, P = 0.221). The Fast-Track program included counseling, education, and medical management.

RESULTS

Patients in the two groups were similar in number of females (EFT: 17 versus non-EFT: 17, P = 0.348), age (EFT: 57.7 versus non-EFT: 60.6, P = 0.280), and body mass index (EFT: 34.6 versus non-EFT: 33.0, P = 0.341). A smaller number of smokers were there in the EFT group (1) compared with the non-EFT group (15, P = 0.003). The proportion of patients on insulin (EFT: 19 versus non-EFT: 23, P = 0.814) and oral hypoglycemics (EFT: 29 versus non-EFT: 39, P = 0.983) was similar between the two groups. Surgical clearance for patients with a documented preoperative Hgb A1c of < 7 or equivalent fructosamine level was significantly better in the Fast-Track group compared with the non-Fast-Track group (91% versus 42%, P = 0.000). Although most patients who declined the Fast-Track program did not obtain clearance for surgery, mean Hgb A1c was improved at the latest follow-up in both groups for those who obtained surgical clearance (7.10 versus 6.78, P = 0.470).

DISCUSSION

A novel EFT program was successful in obtaining acceptable blood glucose control in patients recommended for spine surgery who had poorly controlled diabetes mellitus on preoperative evaluation. The improved blood glucose control was maintained at the latest follow-up.

Current understanding of tandem spinal stenosis: epidemiology, diagnosis, and surgical strategy

Tandem spinal stenosis (TSS) is defined as the concomitant occurrence of stenosis in at least two or more distinct regions (cervical, thoracic, or lumbar) of the spine and may present with a constellation of signs and symptoms. It has four subtypes, including cervico-lumbar, cervico-thoracic, thoraco-lumbar, and cervico-thoraco-lumbar TSS. The prevalence of TSS varies depending on the different subtypes and cohorts.

The main aetiologies of TSS are spinal degenerative changes and heterotopic ossification, and patients with developmental spinal stenosis, ligament ossification, and spinal stenosis at any region are at an increased risk of developing TSS.

The diagnosis of TSS is challenging. The clinical presentation of TSS could be complex, concealed, or severe, and these features may be confusing to clinicians, resulting in an incomplete or delayed diagnosis. Additionally, a consolidated diagnostic criterion for TSS is urgently required to improve consistency across studies and form a basis for establishing treatment guidelines.

The optimal treatment option for TSS is still under debate; areas of controversies include choice of the decompression range, choice between simultaneous or staged surgical patterns, and the order of the surgeries.

The present study reviews publications on TSS, consolidates current awareness on prevalence, aetiologies, potential risk factors, diagnostic dilemmas and criteria, and surgical strategies based on TSS subtypes. This is the first review to include thoracic spinal stenosis as a candidate disorder in TSS and aims at providing the readers with a comprehensive overview of TSS.

The impact of diabetes mellitus on spinal fracture with diffuse idiopathic skeletal hyperostosis: A multicenter retrospective study

BACKGROUND

Patients with diffuse idiopathic skeletal hyperostosis (DISH) are susceptible to spinal column injuries with neurological deterioration. Previous studies indicated that the prevalence of diabetes mellitus (DM) in patients with DISH was higher than that in patients without DISH. This study investigates the impact of DM on surgical outcomes for spinal fractures in patients with DISH.

METHODS

We retrospectively evaluated 177 spinal fractures in patients with DISH (132 men and 45 women; mean age, 75 ± 10 years) who underwent surgery from a multicenter database. The subjects were classified into two groups according to the presence of DM. Perioperative complications, neurological status by Frankel grade, mortality rate, and status of surgical site infection (SSI) were compared between the two groups.

RESULTS

DM was present in 28.2% (50/177) of the patients. The proportion of men was significantly higher in the DM group (DM group: 86.0% vs. non-DM group: 70.1%) (p = 0.03). The overall complication rate was 22.0% in the DM group and 19.7% in the non-DM group (p = 0.60). Poisson regression model revealed that SSI was significantly associated with DM (DM group: 10.0% vs. non-DM group: 2.4%, Relative risk: 4.5) (p = 0.048). Change in neurological status, mortality rate, instrumentation failure, and nonunion were similar between both groups. HbA1c and fasting blood glucose level (SSI group: 7.2% ± 1.2%, 201 ± 67 mg/dL vs. non-SSI group: 6.6% ± 1.1%, 167 ± 47 mg/dL) tended to be higher in patients with SSI; however, there was no significant difference.

CONCLUSIONS

In spinal fracture in patients with DISH, although DM was an associated factor for SSI with a relative risk of 4.5, DM did not negatively impact neurological recovery. Perioperative glycemic control may be useful for preventing SSI because fasting blood glucose level was high in patients with SSI.

Predictors of Pain and Disability Outcomes Following Spinal Surgery for Chronic Low Back and Radicular Pain: A Systematic Review

OBJECTIVES

Success rates of spinal surgeries to treat chronic back pain are highly variable and useable prognostic indicators are lacking. We aimed to identify and evaluate preoperative predictors of pain and disability after spinal surgery for chronic low back/leg pain.

METHODS

Electronic database (01/1984-03/2021) and reference searches identified 2622 unique citations. Eligible studies included adults with chronic low back/leg pain lasting ≥3 months undergoing first elective lumbar spine surgery, and outcomes defined as change in pain (primary)/disability (secondary) after ≥3 months. We included 21 reports (6899 participants), 7 were judged to have low and 14 high risks of bias. We performed narrative synthesis and determined the quality of evidence (QoE).

RESULTS

Better pain outcomes were associated with younger age, higher education, and no spinal stenosis (low QoE); lower preoperative pain, fewer comorbidities, lower pain catastrophizing, anxiety and depression (very low QoE); but not with symptom duration (moderate QoE), other sociodemographic factors (low QoE), disability, or sensory testing (very low QoE). More favorable disability outcomes were associated with preoperative sensory loss (moderate QoE); lower job-related resignation and neuroticism (very low QoE); but not with socioeconomic factors, comorbidities (low QoE), demographics, pain, or pain-related psychological factors (very low QoE).

DISCUSSION

In conclusion, absence of spinal stenosis potentially predicts greater pain relief and preoperative sensory loss likely predicts reduction in disability. Overall, QoE for most identified associations was low/very low.

Racial Disparities in Outcomes After Spine Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

Racial disparities are a major issue in health care but the overall extent of the issue in spinal surgery outcomes is unclear. We conducted a systematic review/meta-analysis of disparities in outcomes among patients belonging to different racial groups who had undergone surgery for degenerative spine disease.

METHODS

We searched Ovid MEDLINE, Scopus, Cochrane Review Database, and ClinicalTrials.gov from inception to January 20, 2021 for relevant articles assessing outcomes after spine surgery stratified by race. We included studies that compared outcomes after spine surgery for degenerative disease among different racial groups.

RESULTS

We found 30 studies that met our inclusion criteria (28 articles and 2 published abstracts). We included data from 20 cohort studies in our meta-analysis (3,501,830 patients), which were assessed to have a high risk of observation/selection bias. Black patients had a 55% higher risk of dying after spine surgery compared with white patients (relative risk [RR], 1.55, 95% confidence interval [CI], 1.28-1.87; I² = 70%). Similarly, black patients had a longer length of stay (mean difference, 0.93 days; 95% CI, 0.75-1.10; I² = 73%), and higher risk of nonhome discharge (RR, 1.63; 95% CI, 1.47-1.81; I² = 89%), and 30-day readmission (RR, 1.45; 95% CI, 1.03-2.04; I² = 96%). No significant difference was noted in the pooled analyses for complication or reoperation rates.

CONCLUSIONS

Black patients have a significantly higher risk of unfavorable outcomes after spine surgery compared with white patients. Further work in understanding the reasons for these disparities will help develop strategies to narrow the gap among the racial groups.

Pathway for enhanced recovery after spinal surgery-a systematic review of evidence for use of individual components

BACKGROUND

Enhanced recovery in spinal surgery (ERSS) has shown promising improvements in clinical and economical outcomes. We have proposed an ERSS pathway based on available evidence. We aimed to delineate the clinical efficacy of individual pathway components in ERSS through a systematic narrative review.

METHODS

We included systematic reviews and meta-analysis, randomized controlled trials, non-randomized controlled studies, and observational studies in adults and pediatric patients evaluating any one of the 22 pre-defined components. Our primary outcomes included all-cause mortality, morbidity outcomes (e.g., pulmonary, cardiac, renal, surgical complications), patient-reported outcomes and experiences (e.g., pain, quality of care experience), and health services outcomes (e.g., length of stay and costs). Following databases (1990 onwards) were searched: MEDLINE, EMBASE, and Cochrane Library (Cochrane Database of Systematic Reviews and CENTRAL). Two authors screened the citations, full-text articles, and extracted data. A narrative synthesis was provided. We constructed Evidence Profile (EP) tables for each component of the pathway, where appropriate information was available. Due to clinical and methodological heterogeneity, we did not conduct a meta-analyses. GRADE system was used to classify confidence in cumulative evidence for each component of the pathway.

RESULTS

We identified 5423 relevant studies excluding duplicates as relating to the 22 pre-defined components of enhanced recovery in spinal surgery. We included 664 studies in the systematic review. We identified specific evidence within the context of spinal surgery for 14/22 proposed components. Evidence was summarized in EP tables where suitable. We performed thematic synthesis without EP for 6/22 elements. We identified appropriate societal guidelines for the remainder of the components.

CONCLUSIONS

We identified the following components with high quality of evidence as per GRADE system: pre-emptive analgesia, peri-operative blood conservation (antifibrinolytic use), surgical site preparation and antibiotic prophylaxis. There was moderate level of evidence for implementation of prehabilitation, minimally invasive surgery, multimodal perioperative analgesia, intravenous lignocaine and ketamine use as well as early mobilization. This review allows for the first formalized evidence-based unified protocol in the field of ERSS. Further studies validating the multimodal ERSS framework are essential to guide the future evolution of care in patients undergoing spinal surgery.

A Multi-Functional Implant Induces Bone Formation in a Diabetic Model

Patients with diabetes mellitus (DM) have defective healing of bone fractures. It was previously shown that nonviral gene delivery of plasmid DNA (pDNA) that independently encodes bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2), acts synergistically to promote bone regeneration in a DM animal model. Additionally, both insulin (INS) and the hormonally active form of vitamin D3, 1α,25-dihydroxyvitamin D3 (1α,25(OH)₂ D₃ ) (VD3) have independently been shown to play key roles in regulating bone fracture healing in DM patients. However, these individual therapies fail to adequately stimulate bone regeneration, illustrating a need for novel treatment of bone fractures in diabetic patients. Here, the ability of local delivery of INS and VD3 along with BMP-2 and FGF-2 genes is investigated to promote bone formation ectopically in Type-2 diabetic rats. A composite consisting of VD3 and INS is developed that contains poly(lactic-co-glycolic acid) microparticles (MPs) embedded in a fibrin gel surrounded by a collagen matrix that is permeated with polyethylenimine (PEI)-(pBMP-2+pFGF-2) nanoplexes. Using a submuscular osteoinduction model, it is demonstrated that local delivery of INS, VD3, and PEI-(pBMP-2+pFGF-2) significantly improves bone generation compared to other treatments, thusimplicating this approach as a method to promote bone regeneration in DM patients with bone fractures.

The Effects of Type 2 Diabetes and Postoperative Pneumonia on the Mortality in Inpatients with Surgery

OBJECTIVE

The aim of the study was to explore the relationship between type 2 diabetes (T2DM) and postoperative pneumonia, and the effects of T2DM and postoperative pneumonia on the mortality in inpatients with surgery.

METHODS

A retrospective study was conducted on 43,174 inpatients with surgery in The First Hospital of Qinhuangdao. These patients were divided into four groups according to T2DM and postoperative pneumonia, Group A subjects without T2DM and postoperative pneumonia, Group B subjects with T2DM only, Group C subjects with postoperative pneumonia only and Group D subjects with T2DM and postoperative pneumonia. In-hospital mortality was collected.

RESULTS

The incidences of postoperative pneumonia were higher in patients with T2DM than patients without T2DM (T2DM 3.2% vs Non-diabetes 1.7%, χ ²=36.219, P<0.001). The mortalities were 0.3% in Group A, 0.3% in Group B, 4.6% in Group C and 8.6% in Group D. In multiple logistic regression analysis, adjusted for sex, age, emergency admissions, coronary heart disease, heart failure, chronic kidney disease, hypoproteinemia, stroke and transient ischemic attack, the mortalities of Group C and Group D were 4.515 (95% CI: 2.779～7.336, P<0.001) times and 8.468 (95% CI: 3.567～20.099, P<0.001) times than the mortality of Group A.

CONCLUSION

T2DM is susceptible to postoperative pneumonia. The mortality increased in patients with postoperative pneumonia. When patients with T2DM and postoperative pneumonia at the same time, the mortality increased further. In T2DM patients with postoperative pneumonia, perioperative management should be improved for patient safety.