Delve into the Science of NASS 2024: Thursday Best Paper Q&As
SpineLine is excited to continue our series of Q&As with the authors of the Best Papers from the NASS Annual Meeting. This series showcases the exceptional research and clinical innovations advancing the field of spine care. In this installment, we focus on the Thursday Best Paper authors. These researchers’ responses reveal the rigorous scientific approach and clinical relevance of their work. We invite you to explore the thoughtful and detailed responses from these experts, whose work continues to push the boundaries of spine research. Stay tuned for the final installment of this series, which will feature insights from the remaining Best Paper authors, ensuring a comprehensive overview of the top studies presented at NASS 2024. For more detailed information about the articles and the authors, please visit SpineLine and the NASS Annual Meeting page.
39. Impact of serum albumin levels on lumbar spine surgery outcomes: A MSSIC study
Author: Anisse Chaker, MD
What question is your research attempting to answer?
- Utilizing the Michigan Spine Surgery Improvement Collaborative (MSSIC) database, we are attempting to identify areas of preoperative optimization in surgical spine patients, specifically regarding preoperative nutritional status.
- We wanted to challenge the classic hypoalbuminemia cutoff of less than 3.5 g/dL for preoperative albumin levels. Our aim was to study if a higher preoperative albumin level within the borderline normal range of 3.5-4.0 g/dL leads to more ideal postoperative outcomes, and thus should be a new goal for preoperative optimization.
Please summarize your key findings and comment on the clinical significance.
- Over 15,000 patients who underwent elective lumbar spine surgery over a 2-year period were included in this study. These patients were grouped based on albumin ranges from <3.5g/dL, 3.5 – 3.7 g/dL, 3.8 – 4.0 g/dL, and > 4.0 g/dL. A multivariate analysis was conducted to control for various potential confounders.
- We found that the greatest risk of complications was seen within the <3.5 g/dL group. However, increased risks also were demonstrated for patients within the 3.5– 3.7 g/dL and 3.8-4.0 g/dL groups, including a significantly higher risk of 30- and 90-day readmissions and extended length of stay.
- Our findings suggest that a goal albumin of >3.7 g/dL for lumbar operations may improve postoperative outcomes and decrease healthcare costs in elective spine surgery.
What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?)
- We demonstrated that patients with borderline low serum albumin levels also have an increased risk of suboptimal postoperative outcomes in lumbar spine surgery. This challenges the prior hypoalbuminemia cutoff of <3.5 g/dL, and suggests patients may benefit from additional scrutiny in preoperative nutritional status and subsequent optimization.
- Our results also affirm that hypoalbuminemia (albumin level <3.5 g/dL) increases the risk of postoperative complications in spine surgery.
How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
This study can directly benefit our spine patients undergoing elective surgery via preoperative optimization. In an elective surgical setting, there is often a period of up to several months between a patient’s clinic visit and operative date where preoperative optimization could take place. This both benefits the patients’ overall clinical outcomes and satisfaction, while potentially saving overall costs by avoiding extended hospital stays and readmissions. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
- Though the suggestion of increasing the albumin cutoff to 3.7 g/dL may not appear to be a drastic change from < 3.5 g/dL, this may convince surgeons to not ignore borderline hypoalbunemia, such as from 3.2 or 3.3 up to 3.5 g/dL.
- Furthermore, obtaining preoperative albumin levels and involvement of a nutrition or dietary team could be a component of future efforts to establish multidisciplinary preoperative spine optimization initiatives.
41. Comparison of clinical and radiologic outcomes between oblique lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion in spondylolisthesis, a randomized controlled trial
Author: Assoc. Prof. Weerasak Singhatanadgige
What question is your research attempting to answer?
The research aims to compare clinical and radiologic outcomes between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and oblique lumbar interbody fusion (OLIF) procedures in patients diagnosed with low-grade spondylolisthesis. Please summarize your key findings and comment on the clinical significance.
The key findings of the study indicate that both MIS-TLIF and OLIF procedures resulted in significant improvements in patient-reported outcomes and radiologic parameters. There were no significant differences in clinical outcomes between the two procedures over the total follow-up period. However, OLIF demonstrated advantages in the restoration of disc height, foraminal height, and foraminal area, as well as lower intraoperative blood loss compared to MIS-TLIF. What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
Despite the differences in surgical approach and technique, both procedures can be equally effective in improving patient-reported outcomes for low-grade spondylolisthesis. There was significantly less blood loss in the OLIF group. Fluoroscopic time, O-arm Time, operative time, and hospital stay were comparable between groups.
How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
This research has several implications for spine patients. Firstly, it suggests that both MIS-TLIF and OLIF procedures can provide satisfactory clinical outcomes for patients with low-grade spondylolisthesis. Secondly, the findings highlight the potential benefits of OLIF in terms of reduced intraoperative blood loss and improved restoration of spinal alignment. Ultimately, this research may contribute to better treatment decision-making for spondylolisthesis patients, leading to improved surgical outcomes and quality of life. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
The findings of this research may influence future directions in spine-related research, clinical practice in several ways. Firstly, it may encourage further investigation into the comparative effectiveness of different minimally invasive spinal fusion techniques for specific patient populations. Additionally, it may inform the development of clinical guidelines and protocols for the management of low-grade spondylolisthesis. Is there anything else you would like readers to know about this paper?
This study represents the first randomized controlled trial comparing outcomes between MIS-TLIF and OLIF specifically for low-grade spondylolisthesis. This study has some limitations. First, we were unable to blind the surgeon, however the surgeon was not involved in assessing the study outcomes. Second, we analyzed the data up to only one year after the operations. This period may not be long enough to detect differences in patient-reported outcomes and late sequelae. Third, this study was conducted at a single tertiary referral center, so the results may not be generalizable.
42. Class 2/3 obesity leads to significantly worse outcomes following minimally invasive transforaminal lumbar interbody fusion
Author: Pratyush Shahi, MBBS, MS(Ortho)
What question is your research attempting to answer?
The study aimed to analyze whether a BMI of 35 and above (class 2/3 obesity) negatively impacts the outcomes of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for degenerative conditions of the lumbar spine. Please summarize your key findings and comment on the clinical significance.
We found that class 2/3 obese patients undergoing MIS TLIF had worse clinical outcomes compared to the other BMI groups. They also took longer to be discharged from the hospital and return to driving following surgery. No significant difference was seen in fusion rates and complication/reoperation rates. What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
While some previous reports have analyzed postoperative outcomes in obese patients following MIS TLIF, evidence on outcomes in morbidly obese class 2/3 patients remains largely lacking. These patients represent a significant percentage of the global population and remain understudied in the spine literature. How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
The findings of this study will help in presurgical patient education and shared decision-making. These findings also support the need for preoperative optimization through weight loss in morbidly obese patients undergoing MIS TLIF. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
This study lays the background for further research looking at outcomes in morbidly obese patients after other spinal surgeries. Future cohort studies analyzing the impact of preoperative optimization of obesity on clinical outcomes after elective spine surgery could change clinical practice.
43. Incidence of postoperative urinary retention and associated risk factors in a male population after minimally invasive spine surgery
Author: Mitali Sakharkar, BA
What question is your research attempting to answer?
We are trying to understand whether the rate of postoperative urinary varies by spinal level and other risk factors. Please summarize your key findings and comment on the clinical significance.
Our study shows that in male patients undergoing lumbar MIS-ATP surgeries have an increased risk of POUR. L2-L4 fusion levels specifically had increased risk compared to lower lumbar fusions. Interestingly, single-level fusions had an increased incidence of POUR as compared to multilevel fusions.
What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
This is the first work to the author's knowledge to delineate differences in urinary complications within MIS-ATP surgeries by spinal level, in line with expected pelvic splanchnic anatomy. Furthermore, it brings up an interesting result of increased POUR risk in single-level fusion.
How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
This research can be utilized to benefit spine patients by aiding in surgical planning and pointing for operative risk minimization in single compared to multiple level surgeries.
In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
We envision this research points towards a large gap in knowledge regarding elucidating reasons behind single-level fusion complications, requiring additional research into the etiologies of POUR complications in this patient cohort.
44. Go big or go home? What to do with Parkinsons patients needing thoracolumbar fusion
Author: Matthew Lindsey, MD
What question is your research attempting to answer?
When treating patients with Parkinsons disease requiring thoracic fusion, should one pursue a conservative or an aggressive fusion strategy? Please summarize your key findings and comment on the clinical significance.
When performing TL fusion on patients with Parkinsons, those who had longer construct fusions had less proximal and distal hardware and junctional failures. One should carefully consider the possibility of the development of proximal or distal complications. If indicated, an extended fusion may be a more durable plan. Longer construct fusions did not have significantly more morbid post op courses. What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
In an area where there is little data, this can help guide treatment for complicated patients. It agrees with some data that failures are common, and disagrees with others that indicate that complications are much more common. How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
Again, it can help support a more robust construct if there is a question as to whether a short, conservative plan or a more aggressive fusion are both possible treatment plans. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
I hope that it helps providers to consider carefully the levels of fusion in these complex patients. In the long run, doing more surgically may be the more conservative plan because it can prevent future failures. Is there anything else you would like readers to know about this paper?
We thank all that helped with the completion of this paper and all the patients who we treated.
45. Predictors of clinical failure after endoscopic lumbar spine surgery during the initial learning curve
Author: Daniel B. Scherman, B.Sc (Hons 1), B.Pharm, MBBS (Hons 1)
What question is your research attempting to answer?
Our research aimed to answer whether there were specific factors (ie, type of approach [transforaminal vs interlaminar], location of disc herniation, type of surgery, presence of disc calcification, presence of other pathology [spondylolisthesis, scoliosis, adjacent segment disease for example]) that may predict failed endoscopic lumbar spine surgery, particularly when surgeons are in the early stages of the endoscopic spine surgery learning curve. Please summarize your key findings and comment on the clinical significance.
To our knowledge, this is the first multi-centre, multi-surgeon study which evaluated the clinical outcomes of both transforaminal and interlaminar endoscopic approaches in patients with a wide range of lumbar spondylotic conditions to identify factors which may predict failed endoscopic spine surgery during the initial learning curve. Overall, the outcomes of endoscopic spine surgery are encouraging with a low complication and reoperation rate. However, those with calcified disc herniations, central canal stenosis or a disc herniation with a concurrent degenerative stenosis may benefit from traditional open or other minimally invasive techniques, particularly when surgeons are in the early stages of their endoscopic career. What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
This study supports endoscopic spine surgery as an effective procedure for a wide range of lumbar spondylodic conditions and serves as a useful guide to assist surgeons in patient selection whilst they are new to the endoscopic technique. How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
The current literature supports endoscopic spine surgery as an alternative to traditional open surgery and is associated with less postoperative pain, analgesia requirements, and need for rehabilitation. However, the steep learning curve associated with endoscopic spine surgery is well-documented. We hope that this paper will help guide surgeons in patient selection, particularly when they are new to endoscopic spine surgery, in order to minimize reoperation rates and improve patient outcomes. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
We hope that our research leads to improved patient selection and outcomes for those undergoing endoscopic spine surgery and ultimately leads to further use and development this surgical technique. Is there anything else you would like readers to know about this paper?
This study is published in World Neurosurgery, Volume 182, February 2024, Pages e506-e516. Do you have any photos or images that could help a reporter understand this research and explain it to their audience?
Below are two specific examples demonstrating pre- and postoperative imaging of failed endoscopic cases.
Example of a right paracentral calcified disc at the L5/S1 level for a interlaminar endoscopic discectomy. (A) Pre-operative axial CT scan demonstrating the calcified disc (white arrow). (B) Pre-operative axial T2-weighted MRI scan. (C) Post-operative axial demonstrating residual disc protrusion
Preoperative (A) and postoperative (B) axial MRI demonstrating residual, albeit improved, right L4-5 subarticular stenosis following attempted left L4-5 endoscopic unilateral laminotomy for bilateral decompression, despite adequate intraoperative visualization of traversing right L5 root (C).
46. Is MIS-ATP lumbosacral fusion safe in patients with aortoiliac calcification?
Authors: Tony Tannoury, MD; Chadi Tannoury, MD
What question is your research attempting to answer?
Are patients with aorto-iliac calcification at higher risk for developing complications following minimally invasive antepsoas (MIS-ATP) lumbosacral fusion?
Please summarize your key findings and comment on the clinical significance.
Common complications following anterior lumbar fusions include acute kidney injury, acute blood loss anemia, and ileus. In our analysis, patients with aortoiliac calcifications had a higher number of complications and were more likely to experience >1 complication. Despite controlling for confounding medical comorbidities and patient characteristics, subjects with any abdominal aortic calcification were at significantly higher odds (OR = 3) of perioperative complications compared to patients without. These findings are clinically relevant and will solicit surgeons to take preventative measures and counsel patients with aortoiliac calcification regarding possible post-operative complications following anterior lumbosacral fusion. However, there was no difference in vascular injuries between groups. What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
No existing literature investigated a scoring system quantifying the degree of aortoiliac calcification in patients undergoing the MIS-ATP fusion. We analyzed the impact of the presence, and the extent of, abdominal vascular calcification on the clinical outcomes. This affirms that patients with aortoiliac calcification are at higher risk of developing a medical complication following surgery but, counterintuitively, not at a higher risk for vascular injuries. How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
While patients with aortoiliac calcification are at a higher risk of perioperative complications, they may continue to require lumbosacral fusion to alleviate their symptoms. Our findings can serve as a patient counseling tool for surgeons performing the MIS-ATP fusion, or other alternative anterior spine surgeries. By doing so, surgeons can also implement preventative strategies to mitigate such complications, and subsequently improve patients’ outcomes and expedite their hospital length of stay. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
We hope the findings of this research are considered when managing patients with aortoiliac calcification who require MIS-ATP, or other anterior or posterior techniques for lumbosacral fusion. Integrating this knowledge into clinical decision-making may improve future patient outcomes. Finally, we hope that further advanced studies are conducted on patients with aortoiliac calcification undergoing different techniques of anterior spinal fusions. Is there anything else you would like readers to know about this paper?
Counterintuitively, manipulating the calcified vessels and elongating the anterior surface of the spine does not increase risk of injury to these vessels.
Preoperative and postoperative lateral X-ray of the lumbosacral spine of a patient with extensive aortoiliac calcification.
47. Surgical resection of spinal chordoma: overall survival and local recurrence
Authors: Daniel Lubelski, MD; Yuanxuan Xia, MD
What question is your research attempting to answer?
Spinal chordomas are rare and challenging tumors to manage. Limited evidence-based guidelines exist. Our goal was to review our institutional series to better understand overall survival, progression, prognostic factors, and impact of radiation. Here, we characterize long-term outcomes over 20 years for spinal chordomas managed at a quaternary care center specialized in spinal oncology. All data was collected from time of initial resection and all analyses were benchmarked to that index surgery. Please summarize your key findings and comment on the clinical significance.
In a cohort of 101 patients with average follow-up of 6.0±4.2 years, surgery achieved Enneking Appropriate (EA) criteria in 88/101 cases. There were 10/101 mortalities (average survival 7.3±5.3 years) and 25/101 recurrences (average recurrence at 4.0±3.2 years). Tracking symptoms over multiple postoperative timeframes, more patients became pain-free from 0-4 months to 4-12 months after surgery.
Rates of sensory deficits, motor weakness, and bowel/bladder dysfunction did not change. Tumor sizes ≥100cm3 predicted decreased local recurrence-free survival (LRFS, HR=2.57, 95% CI 1.04−6.35, p=0.041) while being ≥65 years old was associated with decreased overall survival (OS) time after surgery (HR=12.82, 95% CI 2.46−66.74, p=0.002).
These findings add to the existing evidence that tumor size is associated with LRFS and age is related to OS. Moreover, the data can inform providers as they counsel patients.
What is surprising/exciting/different about your research results? (For example, do they affirm or debunk any existing spine treatment or diagnosis?
This data validates the impact of age and tumor size on LRFS and OS. Interestingly, EA resection was not predictive of the primary outcome variables, though this may be related to limited statistical power. Adjuvant radiation was not related to outcomes but neoadjuvant SBRT may improve LRFS. How can this research ultimately apply to or benefit spine patients? (Will it make diagnosis/treatment/payment any easier/less expensive/better in the future?)
These data can inform providers as they counsel patients with spinal chordoma on what to expect after surgery in terms of survival, recurrence, and complications. It also adds to the growing body of evidence on the synergistic effect of SBRT in treating spinal chordoma. In what ways do you envision your research influencing or shaping future directions in spine-related research, clinical practice, or health policy?
We hope this report helps guide treatment paradigms for patients with spinal chordoma. Is there anything else you would like readers to know about this paper?
Spinal chordoma management remains a challenging entity to treat and multidisciplinary care is essential. We welcome the promise of new treatments, including noninvasive systemic and radiation options.