The impact of obesity on perioperative complications in patients undergoing anterior lumbar interbody fusion

Access to the Lumbosacral Spine: A Current View

The surgical approach to the lumbosacral spine has been the subject of experimental and scientific anatomical studies since the Hippocratic era. However, it was in the 20th century that, with the evolution of asepsis and antibiotic therapy, spine surgery began to evolve at breakneck speed, and the various possibilities of access roads became objects of development and discussion. As a result, pathologies of the lumbosacral spine can be accessed in different ways and positions, from the traditional posterior approach in the prone position to the anterior, oblique, lateral, and endoscopic approaches. The current article brings state-of-the-art access routes to the lumbosacral spine. This article objective is to elucidate the possibilities of accesses the lumbar spine for any purposes, as decompression, fusion, tumour resections, reconstruction or deformity correction, despites type of implants or implants positioning.

Leveraging machine learning to ascertain the implications of preoperative body mass index on surgical outcomes for 282 patients with preoperative obesity and lumbar spondylolisthesis in the Quality Outcomes Database

OBJECTIVE

Prior studies have revealed that a body mass index (BMI) ≥ 30 is associated with worse outcomes following surgical intervention in grade 1 lumbar spondylolisthesis. Using a machine learning approach, this study aimed to leverage the prospective Quality Outcomes Database (QOD) to identify a BMI threshold for patients undergoing surgical intervention for grade 1 lumbar spondylolisthesis and thus reliably identify optimal surgical candidates among obese patients.

METHODS

Patients with grade 1 lumbar spondylolisthesis and preoperative BMI ≥ 30 from the prospectively collected QOD lumbar spondylolisthesis module were included in this study. A 12-month composite outcome was generated by performing principal components analysis and k-means clustering on four validated measures of surgical outcomes in patients with spondylolisthesis. Random forests were generated to determine the most important preoperative patient characteristics in predicting the composite outcome. Recursive partitioning was used to extract a BMI threshold associated with optimal outcomes.

RESULTS

The average BMI was 35.7, with 282 (46.4%) of the 608 patients from the QOD data set having a BMI ≥ 30. Principal components analysis revealed that the first principal component accounted for 99.2% of the variance in the four outcome measures. Two clusters were identified corresponding to patients with suboptimal outcomes (severe back pain, increased disability, impaired quality of life, and low satisfaction) and to those with optimal outcomes. Recursive partitioning established a BMI threshold of 37.5 after pruning via cross-validation.

CONCLUSIONS

In this multicenter study, the authors found that a BMI ≤ 37.5 was associated with improved patient outcomes following surgical intervention. These findings may help augment predictive analytics to deliver precision medicine and improve prehabilitation strategies.

Obesity: An Independent Risk Factor for Complications in Anterior Lumbar Interbody Fusion? A Systematic Review

STUDY DESIGN

Systematic Review and Meta-analysis.

OBJECTIVES

Raised patient BMI is recognised as a relative contraindication to posterior lumbar interbody fusion (PLIF) due to the anaesthetic challenges, difficult positioning and increased intraoperative and postoperative complications, with the relative risk rising in patients with a BMI >25 kg/m2. The impact of obesity defined as a BMI > 30 kg/m² on Anterior Lumbar Interbody Fusion (ALIF) outcomes is not yet established. The aim of this review was to evaluate if the presence of a raised BMI in patients undergoing ALIF procedures was an independent risk factor for intra- and postoperative complications.

METHODS

A systematic review of search databases PubMed; Google Scholar and OVID Medline was made to identify studies related to complications in patients with increased body mass index during anterior lumbar interbody fusion. PRISMA guidelines were utilised for this review. Complication rates in raised BMI patient cohort was compared to normal BMI complication rates with meta-analysis where available.

RESULTS

315 articles returned with search criteria applied. Six articles were included for review, with 2190 patients included for analysis. Vascular complications in obese vs. non-obese patients undergoing the anterior approach demonstrate no significant difference in complication rates (P = .62; CI = -.03-.02). Obesity is found to result in an increased rate of overall complications (P = .002; CI = .04-.16).

CONCLUSIONS

Obesity was demonstrated to have an impact on overall complication rates in Anterior Lumbar Interbody Fusion procedures, with postoperative complications including wound infections and lower fusion rates more common in patients in increased BMIs. Increased focus on patient positioning and reporting of outcomes in this patient cohort is warranted to further evaluate perioperative complications.

Role of obesity in less radiographic correction and worse health-related quality-of-life outcomes following minimally invasive deformity surgery

OBJECTIVE

Minimally invasive surgery (MIS) for adult spinal deformity (ASD) can offer deformity correction with less tissue manipulation and damage. However, the impact of obesity on clinical outcomes and radiographic correction following MIS for ASD is poorly understood. The goal of this study was to determine the role, if any, that obesity has on radiographic correction and health-related quality-of-life measures in MIS for ASD.

METHODS

Data were collected from a multicenter database of MIS for ASD. This was a retrospective review of a prospectively collected database. Patient inclusion criteria were age ≥ 18 years and coronal Cobb angle ≥ 20°, pelvic incidence-lumbar lordosis mismatch ≥ 10°, or sagittal vertical axis (SVA) > 5 cm. A group of patients with body mass index (BMI) < 30 kg/m2 was the control cohort; BMI ≥ 30 kg/m2 was used to define obesity. Obesity cohorts were categorized into BMI 30-34.99 and BMI ≥ 35. All patients had at least 1 year of follow-up. Preoperative and postoperative health-related quality-of-life measures and radiographic parameters, as well as complications, were compared via statistical analysis.

RESULTS

A total of 106 patients were available for analysis (69 control, 17 in the BMI 30-34.99 group, and 20 in the BMI ≥ 35 group). The average BMI was 25.24 kg/m2 for the control group versus 32.46 kg/m2 (p < 0.001) and 39.5 kg/m2 (p < 0.001) for the obese groups. Preoperatively, the BMI 30-34.99 group had significantly more prior spine surgery (70.6% vs 42%, p = 0.04) and worse preoperative numeric rating scale leg scores (7.71 vs 5.08, p = 0.001). Postoperatively, the BMI 30-34.99 cohort had worse Oswestry Disability Index scores (33.86 vs 23.55, p = 0.028), greater improvement in numeric rating scale leg scores (-4.88 vs -2.71, p = 0.012), and worse SVA (51.34 vs 26.98, p = 0.042) at 1 year postoperatively. Preoperatively, the BMI ≥ 35 cohort had significantly worse frailty (4.5 vs 3.27, p = 0.001), Oswestry Disability Index scores (52.9 vs 44.83, p = 0.017), and T1 pelvic angle (26.82 vs 20.71, p = 0.038). Postoperatively, after controlling for differences in frailty, the BMI ≥ 35 cohort had significantly less improvement in their Scoliosis Research Society-22 outcomes questionnaire scores (0.603 vs 1.05, p = 0.025), higher SVA (64.71 vs 25.33, p = 0.015) and T1 pelvic angle (22.76 vs 15.48, p = 0.029), and less change in maximum Cobb angle (-3.93 vs -10.71, p = 0.034) at 1 year. The BMI 30-34.99 cohort had significantly more infections (11.8% vs 0%, p = 0.004). The BMI ≥ 35 cohort had significantly more implant complications (30% vs 11.8%, p = 0.014) and revision surgery within 90 days (5% vs 1.4%, p = 0.034).

CONCLUSIONS

Obese patients who undergo MIS for ASD have less correction of their deformity, worse quality-of-life outcomes, more implant complications and infections, and an increased rate of revision surgery compared with their nonobese counterparts, although both groups benefit from surgery. Appropriate counseling should be provided to obese patients.

Identification of human-dependent routes of pathogen's transmission in a tertiary care hospital

Objectives

The purpose of the study was to validate the risk of patients' exposure to pathogenic flora carried on hands of students, visitors, and patients themselves, analyzing its density and genera and to compare them with the microflora of healthcare workers (HCWs).

Patients and methods

Between May and June 2018, five groups of participants were included. Each group consisted of eight individuals. Palmar skin imprints were obtained from dominant hands of doctors, nurses, students, visitors, and patients in orthopedics ward. Imprints were incubated at 37°C under aerobic conditions, and colony-forming units (CFU) on each plate were counted after 24, 48, and 72 h. Microorganisms were identified.

Results

Hands of doctors were colonized more often by Gram - positive non-spore-forming rods bacteria than hands of nurses (p<0.05). A higher number of Staphylococcus epidermidis CFUs was observed on doctors’ than on nurses’ hands (p<0.05), whereas Staphylococcus hominis was isolated from doctor’s and patients’ imprints, but was not from nurses’ and students’ imprints (p<0.05). Micrococcus luteus colonized patients’ hands more often than students’ (p<0.05), visitors’ hands than doctors’ (p<0.05), students’ than nurses’ (p<0.05), visitors’ than nurses’ (p<0.05) and patients’ hands (p<0.05). Staphylococcus aureus (S. aureus) was isolated only from one doctor and one nurse (203 and 10 CFUs/25 cm² ). Imprints taken from the hands of patients, students and visitors were S. aureus-free. No methicillin-resistant S. aureus (MRSA), vancomycin-resistant enterococci, nor expanded spectrum betalactamase-positive or carbapenemase-positive rods were isolated. The number of Gram-negative rods was the highest on visitors' hands, significantly differing from the number on patient’s, doctor’s, nurse’s, and student’s hands. Spore-forming rods from genus of Bacillus were isolated from representatives of all tested groups. Bacillus cereus occurred more commonly on visitors’ hands than doctors’ hands (p<0.05).

Conclusion

Patients, students, and visitors may play the causal role in the spread of pathogenic bacteria, particularly spore-forming rods. Our study results confirm the effectiveness of educational activities, that is the hospital's hand hygiene program among HCWs, patients, and visitors. Hand hygiene procedures should be reviewed to put much more effort into reducing the impact of all studied groups on the transmission of infectious diseases.

Increased risk of postoperative wound complications among obesity classes II & III after ALIF in 10-year ACS-NSQIP analysis of 10,934 cases

BACKGROUND CONTEXT

Anterior lumbar interbody fusion (ALIF) procedures for lumbar spine disease have been increasing amid a growing obese patient population with limited studies available focusing exclusively on risk-factors for post-operative ALIF complications.

PURPOSE

The objective of this study was to compare 30-day post-operative complications among different obesity World Health Organization classes according to body mass index (BMI) in comparison to non-obese patients who underwent an ALIF procedure.

STUDY DESIGN/SETTING

Retrospective cohort study of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) from 2009 to 2019.

PATIENT SAMPLE

A total of 10,934 patients undergoing an ALIF.

OUTCOME MEASURES

Primary outcome measures include 30 day cardiac, pulmonary, urinary, infectious, and wound complications. Secondary outcomes included rates of blood transfusion, reintubation, deep vein thrombosis, pulmonary embolism, 30-day return to the operating room (OR), and 30 day mortality.

METHODS

Patients were identified by use of the current procedural terminology codes 22558 and 22585 from 2009 to 2019. Patients were divided into the following groups: non-obese (BMI 18.5-29.9 kg/m²), Obese I (BMI 30-34.9 kg/m²), Obese II (BMI 35-39.9 kg/m²), and Obese III (BMI ≥40 kg/m²). Age, gender, race, American Society of Anesthesiologists status, smoking status, hypertension requiring medication, steroid used, chronic obstructive pulmonary disease, history of a bleeding disorder, and diabetes was identified as risk factors after a univariate analysis conducted for demographic variables and pre-operative comorbidities. A multivariate logistic regression analysis was then performed to adjust for these preoperative risk factors and compare obesity classes I-III to non-obese patients.

RESULTS

Obesity classes II and III had a significant odds ratio (OR) for superficial infection (OR:2.7, 95%CI(1.7-4.5); OR:2.8, 95%CI(1.5-5.2) respectively), organ space infection (OR:3.8, 95%CI(1.6-7.4); OR:3.2, 95%CI(1.1-9.9) respectively), wound disruption (OR:2.8, 95%CI(1.1-7.4); OR:4.6, 95%CI(1.6-13.6) respectively), and total wound complication (OR:2.6, 95%CI(1.8-3.9); OR:3.4, 95%CI(2.2-5.4) respectively) following a multivariate logistic regression analysis.

CONCLUSIONS

Risk for post-operative wound complications following an ALIF were found to be significantly higher for obesity classes II-III in comparison to non-obese patients. These findings can further support the use of additional wound care in the perioperative setting for certain levels of obesity.

Outcomes of anterior vs. posterior approach to single-level lumbar spinal fusion with interbody device: An analysis of the nationwide inpatient sample

BACKGROUND

Interbody devices have revolutionized lumbar spinal fusion surgery by improving mechanical stability and maximizing fusion potential. Several approaches for interbody fusion exist with two of the most common being anterior lumbar interbody fusion (ALIF) and posterior lumbar interbody fusion (PLIF). This study aims to compare patient data, hospital outcomes, and post-operative complications between an anterior vs. posterior approach to lumbar interbody fusion.

METHODS

This retrospective cohort study utilized the Nationwide Inpatient Sample (NIS) and International Classification of Diseases, 10th edition (ICD10) codes to identify patients (18 +) from 2016 to 2018 who underwent lumbar interbody fusion under an anterior or posterior approach. Patients missing identifiers were excluded from this study. Patients were further investigated by demographic data and the presence of comorbidities. Hospital outcome data was investigated by length of stay (LOS), total hospital charges, mortality, and post-operative complications.

RESULTS

373,585 patients were included in this study. 257,975 (69%) underwent fusion via a posterior approach, and 115,610 (31%) via an anterior approach. Patients undergoing posterior approach were found to have a greater number of comorbidities than anterior (3.5 vs. 2, respectively, p = <0.001). The posterior approach was associated with decreased LOS (3.59 vs 4.19 days, p = <0.0001) and decreased total hospital charges ($141,700 vs $211,015, p = <0.0001). A posterior approach was found to have lower rates of post-operative complications. For the anterior approach cohort, tobacco dependence (OR=1.31 [1.20-1.42, p = <0.001], diabetes (OR=2.41 [2.33-2.49, p = <0.001], and osteoporosis (OR=1.42 [1.30-1.54, p = <0.001] were found to be significant independent predictors of post-operative pseudoarthrosis. Obesity (OR=1.28 [1.14-1.42, p = <0.001], tobacco dependence (OR=1.48 [1.40-1.56, p = <0.001], diabetes (OR=2.21 [2.10-2.32, p = <0.001], congestive heart failure (OR=1.20 [1.01-1.39, p = 0.04], and osteoporosis (OR=1.65 [1.55-1.75, p = <0.001], were found to be independent predictors of post-operative pseudoarthrosis in the posterior cohort.

CONCLUSIONS

Patients who underwent the anterior approach suffered from increased hospital charges, length of stay, and increased risk of post-operative complications including mortality, wound dehiscence, hematoma/seroma, and pseudoarthrosis. Comorbid disease plays a significant role in the outcome of successful fusion with variable effect depending on the surgical approach. Increasing due diligence in patient selection should be considered when choosing an approach in pre-operative planning.

The Morphological Changes in Adjacent Segments Amongst Patients Receiving Anterior and Oblique Lumbar Interbody Fusion: A Retrospective Study

Adjacent segment disease (ASD) is troublesome condition that has proved to be highly related to spinal malalignment after spinal surgery. Hence, we aimed to evaluate the morphological changes after anterior lumbar interbody fusion (ALIF) and oblique LIF (OLIF) to establish the differences between the two surgical methods in terms of possible ASD avoidance. Fifty patients, half of whom received ALIF while the other half received OLIF, were analyzed with image studies and functional outcomes during the pre-operative and post-operative periods, and 2 years after surgery. Image measurements obtained included spinal-pelvic parameters, index lordosis (IL), segmental lordosis (SL), anterior disc height (ADH), posterior disc height (PDH) and adjacent segment disc angle (ASDA). The ADH and PDH in the adjacent segment decreased in the two groups while OLIF showed greater decrease without radiological ASD noted at 2-year follow-up. Both groups showed an increase in IL after surgery while ALIF showed greater improvement. No statistical difference was identified in functional outcomes between LIFs. We suggest that both ALIF and OLIF can restore adequate lordosis and prevent ASD after surgery. However, it should be noted that patient selection remains crucial when making any decision involving which of the two methods to use.

Is there a variance in complication types associated with ALIF approaches? A systematic review

Purpose

Anterior lumbar interbody fusion (ALIF) is a well-established alternative to posterior-based interbody fusion techniques, with approach variations, such as retroperitoneal, transperitoneal, open, and laparoscopic well described. Variable rates of complications for each approach have been enumerated in the literature. The purpose of this study was to elucidate the comparative rates of complications across approach type.

Methods

A systematic review of search databases PubMed, Google Scholar, and OVID Medline was made to identify studies related to complication-associated ALIF. PRISMA guidelines were utilised for this review. Meta-analysis was used to compare intraoperative and postoperative complications with ALIF for each approach.

Results

A total of 4575 studies were identified, with 5728 patients across 31 studies included for review following application of inclusion and exclusion criteria. Meta-analysis demonstrated the transperitoneal approach resulted in higher rates of retrograde ejaculation (RE) (p < 0.001; CI = 0.05–0.21) and overall rates of complications (p = 0.05; CI = 0.00–0.23). Rates of RE were higher at the L5/S1 intervertebral level. Rates of vessel injury were not significantly higher in either approach method (p = 0.89; CI =  − 0.04–0.07). Rates of visceral injury did not appear to be related to approach method. Laparoscopic approaches resulted in shorter inpatient stays (p = 0.01).

Conclusion

Despite the transperitoneal approach being comparatively underpowered, its use appears to result in a significantly higher rate of intraoperative and postoperative complications, although confounders including use of bone morphogenetic protein (BMP) and spinal level should be considered. Laparoscopic approaches resulted in shorter hospital stays; however, its steep learning curve and longer operative time have deterred surgeons from its widespread adaptation.

Predictors of Extended Hospitalization and Early Reoperation After Elective Lumbar Disc Arthroplasty

BACKGROUND

Lumbar disc arthroplasty (LDA) has emerged as a motion-sparing alternative to lumbar fusion. Although LDA may be amenable to the ambulatory surgical setting, to date no study has identified the factors predisposing patients to extended hospital stay.

METHODS

A national surgical quality improvement database was queried from 2011 to 2019 for patients undergoing elective, single-level, primary LDA. Univariate and multivariate logistic regression analyses were performed to elucidate predictors of length of stay (LOS) at or above the 90th percentile of the study population (3 days). Secondary study endpoints included rates of complications, as well as predictors and reasons for unplanned reoperation within 30 days.

RESULTS

A total of 630 patients met eligibility criteria for the study, of whom 517 (82.1%) had LOS <3 days and 113 (17.9%) had LOS ≥3 days. Multivariate logistic regression revealed associations between prolonged hospitalization and postoperative diagnosis of degenerative disk disease, obesity, Hispanic identity, and operation length >120 minutes. Before discharge, patients with LOS ≥3 days were more likely to have venous thromboembolisms, pneumonia, surgical site infections, and reoperations. Independent predictors of reoperation were wound infections, diabetes, and smoking.

CONCLUSIONS

Complications following elective single-level LDA are relatively rare, with few extended hospitalizations being attributable to any specific complication. Risk factors for prolonged LOS appear to be related to diagnosis and surgical time rather than to modifiable preoperative comorbidities. Conversely, unplanned reoperations within 30 days are associated with optimizable perioperative factors such as smoking, diabetes, and surgical site infection.

The effect of anterior lumbar interbody fusion staging order on perioperative complications in circumferential lumbar fusions performed within the same hospital admission

OBJECTIVE

Anterior lumbar interbody fusion (ALIF) is a powerful technique that provides wide access to the disc space and allows for large lordotic grafts. When used with posterior spinal fusion (PSF), the procedures are often staged within the same hospital admission. There are limited data on the perioperative risk profile of ALIF-first versus PSF-first circumferential fusions performed within the same hospital admission. In an effort to understand whether these procedures are associated with different perioperative complication profiles, the authors performed a retrospective review of their institutional experience in adult patients who had undergone circumferential lumbar fusions.

METHODS

The electronic medicals records of patients who had undergone ALIF and PSF on separate days within the same hospital admission at a single academic center were retrospectively analyzed. Patients carrying a diagnosis of tumor, infection, or traumatic fracture were excluded. Demographics, surgical characteristics, and perioperative complications were collected and assessed.

RESULTS

A total of 373 patients, 217 of them women (58.2%), met the inclusion criteria. The mean age of the study cohort was 60 years. Surgical indications were as follows: degenerative disease or spondylolisthesis, 171 (45.8%); adult deformity, 168 (45.0%); and pseudarthrosis, 34 (9.1%). The majority of patients underwent ALIF first (321 [86.1%]) with a mean time of 2.5 days between stages. The mean number of levels fused was 2.1 for ALIF and 6.8 for PSF. In a comparison of ALIF-first to PSF-first cases, there were no major differences in demographics or surgical characteristics. Rates of intraoperative complications including venous injury were not significantly different between the two groups. The rates of postoperative ileus (11.8% vs 5.8%, p = 0.194) and ALIF-related wound complications (9.0% vs 3.8%, p = 0.283) were slightly higher in the ALIF-first group, although the differences did not reach statistical significance. Rates of other perioperative complications were no different.

CONCLUSIONS

In patients undergoing staged circumferential fusion with ALIF and PSF, there was no statistically significant difference in the rate of perioperative complications when comparing ALIF-first to PSF-first surgeries.

The anterior-to-psoas approach for interbody fusion at the L5-S1 segment: clinical and radiological outcomes

OBJECTIVE

Over the last few decades, many surgical techniques for lumbar interbody fusion have been reported. The anterior-to-psoas (ATP) approach is theoretically supposed to benefit from the advantages of both anterior and lateral approaches with similar complication rates, even in L5-S1. At this segment, the anterior lumbar interbody fusion (ALIF) requires retroperitoneal dissection and retraction of major vessels, whereas the iliac crest does not allow the lateral transpsoas approach. This study aimed to investigate clinical-radiological outcomes and complications of the ATP approach at the L5-S1 segment in a single cohort of patients.

METHODS

This is a prospective single-center study, conducted from 2016 to 2019. Consecutive patients who underwent ATP at the L5-S1 segment for degenerative disc disease or revision surgery after previous posterior procedures were considered for eligibility. Complete clinical-radiological documentation and a minimum follow-up of 12 months were set as inclusion criteria. Clinical patient-reported outcomes, such as the visual analog scale for low-back pain, Oswestry Disability Index, and 36-Item Short Form Health Survey (SF-36) scores, as well as spinopelvic parameters, were collected preoperatively, 6 weeks after surgery, and at the last follow-up visit. Intraoperative and perioperative complications were recorded. The fusion rate was evaluated on CT scans obtained at 12 months postoperatively.

RESULTS

Thirty-two patients met the inclusion criteria. The mean age at the time of surgery was 57.6 years (range 44-75 years). The mean follow-up was 33.1 months (range 13-48 months). The mean pre- and postoperative visual analog scale (7.9 ± 1.3 vs 2.4 ± 0.8, p < 0.05), Oswestry Disability Index (52.8 ± 14.4 vs 22.9 ± 6.0, p < 0.05), and SF-36 (37.3 ± 5.8 vs 69.8 ± 6.1, p < 0.05) scores significantly improved. The mean lumbar lordosis and L5-S1 segmental lordosis significantly increased after surgery. The mean pelvic incidence-lumbar lordosis mismatch and pelvic tilt significantly decreased. No intraoperative complications and a postoperative complication rate of 9.4% were recorded. The fusion rate was 96.9%. One patient needed a second posterior revision surgery for residual foraminal stenosis.

CONCLUSIONS

In the present case series, ATP fusion for the L5-S1 segment has resulted in valuable clinical-radiological outcomes and a relatively low complication rate. Properly designed clinical and comparative trials are needed to further investigate the role of ATP for different L5-S1 conditions.