Thrombocytopenia as an Independent Prognostic Indicator Following Extradural Spinal Tumor Resection

BACKGROUND

Few studies have examined the prognosis for patients with baseline thrombocytopenia undergoing extradural spine tumor resection.

OBJECTIVE

To evaluate mortality, readmission, and other 30-day outcomes in patients with varying degrees of preoperative thrombocytopenia undergoing osseous extradural tumor excision.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was queried from 2011-2019. Patients were categorized according to baseline preoperative platelet count, in 25,000/μL increments: 125,000-149,000/μL, 100,000-125,000/μL, 75,000-100,000/μL, and < 75,000/μL. These were compared to a control group with platelet count >150,000/μL. Outcomes in each cohort were analyzed using multivariate logistic regression analysis.

RESULTS

The database search revealed 3,574 patients undergoing extradural tumor resection; 2,171 (4.8%) of patients with platelets 125,000-149,000/μL, 114 (3.2%) with 100,000-125,000/μL, 75,000-100,000/μL in 43 (1.2%), and < 75,000/μL in 42 (1.2%). Platelet counts <100,000/μL was associated with perioperative blood transfusion, cardiac complications, and non-home discharge, and 30-day mortality. On subgroup analysis for mortality, an interaction was present between individuals with moderate/severe thrombocytopenia and cervical tumors.

CONCLUSION

In patients undergoing surgery for extradural spine tumor, degree of baseline thrombocytopenia-rather than presence alone-is an independent predictor of several adverse events. Wherever possible, optimization of preoperative platelet count to at least 100,000/μL may improve outcomes.

Risk Factors for Medical and Surgical Complications After Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion

Background

The prevention of perioperative and postoperative complications is necessary to avoid poor postoperative outcomes and increased costs. Previous investigations have identified risk factors for complications after various spine procedures, but no such study exists in a population solely undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). The purpose of this study is to determine risk factors for the development of complications up to 2 years after MIS TLIF procedures.

Methods

Patients who underwent primary, single-level MIS TLIF from 2007 to 2016 were retrospectively reviewed. The incidence of medical and surgical complications up to 2 years postoperatively was determined. Patients were categorized according to demographic, comorbidity, and procedural characteristics. Bivariate Poisson regression with robust error variance was used to determine if an association existed between patient characteristics and complication incidence. A final multivariate model including all patient characteristics as controls was created using backwards, stepwise regression until only those variables with P < .05 remained.

Results

390 patients were analyzed. Upon bivariate analysis, age >50 years (P = .025), diabetes mellitus (P = .001), and operative duration >105 minutes (P = .016) were associated with increased medical complication rates. Regarding surgical complications, age ≤50 years (P < .001), obesity (P = .012), and diabetes mellitus (P = .042) were identified as risk factors on bivariate analysis. Upon final multivariate analysis, operative time >105 minutes (P = .009) and diabetes mellitus (P = .001) were independent risk factors for medical complications. Independent risk factors for surgical complications on multivariate analysis included age ≤50 years (P < .001), diabetes mellitus (P = .002), and obesity (P = .030).

Conclusions

Diabetic patients and those who underwent longer operations were at increased risk of medical complications, while younger patients, obese patients and those also with diabetes mellitus were at increased risk of surgical complications up to 2 years after MIS TLIF. Practitioners can use this information to identify patients who require preventative care before their procedure or increased postoperative vigilance and monitoring after single-level MIS TLIF.

Level of Evidence

3.

Static Versus Expandable Devices Provide Similar Clinical Outcomes Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

BACKGROUND

Few studies have analyzed differences in radiographic parameters and patient-reported outcomes (PROs) between expandable and static interbody devices in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

QUESTIONS/PURPOSES

To evaluate differences in radiographic parameters and PROs following MIS TLIF between static and expandable interbody devices.

METHODS

Patients undergoing primary, single-level MIS TLIF between 2014 and 2017 were retrospectively identified. Radiographic measurements including lumbar lordosis (LL), segmental lordosis (SL), disc height (DH), and foraminal height (FH) were performed on lateral radiographs before and after MIS TLIF with a static or expandable articulating interbody device. Radiographic outcomes and PROs were compared using paired and unpaired Student's t test.

RESULTS

Thirty patients received expandable interbody devices and 30 patients received static interbody devices. The expandable device cohort exhibited significantly greater improvement in DH and FH at final follow-up compared with those receiving a static device. Both device cohorts experienced significant improvements in PROs at 6 months post-operatively.

CONCLUSION

MIS TLIF with an expandable interbody device led to a greater increase of DH and FH than with a static interbody device. Patients undergoing MIS TLIF can expect similar improvements in PROs whether receiving a static or an expandable interbody device. Further studies are required to better understand improvements in clinical outcomes afforded by expandable interbody devices.

Impact of Iliac Crest Bone Grafting on Postoperative Outcomes and Complication Rates Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

The relationship between bone graft technique and postoperative outcomes for minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has not been well-defined. This study aims to determine the effect of iliac crest bone grafting (ICBG) on patient-reported outcomes (PROs) and complication rates following MIS TLIF.

METHODS

Primary, single-level MIS TLIF patients were consecutively analyzed. Patients that prospectively received a percutaneous technique of ICBG were compared to patients that retrospectively received bone morphogenetic protein-2 (BMP-2). Complication rates were assessed perioperatively and up to 1 year postoperatively. Changes in Oswestry Disability Index (ODI), visual analogue scale (VAS) back, and VAS leg pain were compared. Rates of minimum clinically important difference (MCID) achievement at final follow-up for ODI, VAS back, and VAS leg scores were compared.

RESULTS

One hundred forty-nine patients were included: 101 in the BMP-2 cohort and 48 in the ICBG cohort. The ICBG cohort demonstrated increases in intraoperative blood loss and shorter lengths of stay. ICBG patients also experienced longer operative times, though this did not reach statistical significance. No significant differences in complication or reoperation rates were identified. The ICBG cohort demonstrated greater improvements in VAS leg pain at 6-week and 12-week follow-up. No other significant differences in PROs or MCID achievement rates were identified.

CONCLUSION

Patients undergoing MIS TLIF with ICBG experienced clinically insignificant increases in intraoperative blood loss and did not experience increases in postoperative pain or disability. Complication and reoperation rates were similar between groups. These results suggest that ICBG is a safe option for MIS TLIF.

Swallowing Function Following Anterior Cervical Discectomy and Fusion With and Without Anterior Plating: A SWAL-QOL (Swallowing-Quality of Life) and Radiographic Assessment

Objective

Anterior cervical plating in anterior cervical discectomy and fusion (ACDF) procedures are associated with improved outcomes compared to stand-alone cages. However, concerns exist regarding increased rates of postoperative dysphagia following an ACDF. This study aims to quantify the effect of anterior plating on swallowing-quality of life (SWAL-QOL) scores and radiographic swelling assessments following a primary, single-level ACDF.

Methods

Patients retrospectively reviewed. Patients grouped into those receiving a cage or anterior plate. SWAL-QOL scores were recorded preoperatively and 6 weeks and 12 weeks postoperatively. Lateral radiographs were used to create a swelling index with a ratio of the prevertebral swelling distance to the anterior-posterior diameter of each involved vertebral body. An air index was created using the same methodology. Statistical analysis was performed using chi-square analysis and independent t-tests for categorical and continuous variables.

Results

Sixty-eight primary, single-level ACDF patients were included. Forty-one (60.3%) received a stand-alone cage and 27 (39.7%) received a cage with anterior plating. No differences in demographics, comorbidities, operative time, estimated blood loss, or length of hospital stay were identified between Cage and Plate cohorts. Finally, no differences were observed in postoperative SWAL-QOL scores or swelling and air indices between groups.

Conclusion

The results demonstrate that patients undergoing a primary, single-level ACDF with or without anterior plating experience similar operative times and lengths of stay. Patients that receive a cage with anterior plating did not experience significant increases in dysphagia as measured by the SWAL-QOL questionnaire compared to patients that received a stand-alone cage. Furthermore, radiographic assessments of swelling are comparable.

Does the Day of the Week Affect Length of Stay and Hospital Charges Following Anterior Cervical Discectomy and Fusion?

Background

To reduce the economic impact of excessive costs, risk factors for increased length of stay (LOS) must be identified. Previous literature has demonstrated that surgeries later in the week can affect the LOS and costs following joint arthroplasty. However, few investigations regarding the day of surgery have been performed in the spine literature. The present study attempts to identify the association between day of surgery on LOS and hospital charges following anterior cervical discectomy and fusion (ACDF) procedures.

Methods

A prospectively maintained surgical database of primary, level 1-2 ACDF patients between 2008 and 2015 was retrospectively reviewed. Patients were stratified by surgery day: early week (Tuesday) or late week (Friday) ACDF. Differences in patient demographics and preoperative characteristics were compared between cohorts using chi-square analysis or Student t test for categorical and continuous variables, respectively. Direct hospital costs were obtained using hospital charges for each procedure and subsequent care prior to discharge. Associations between date of surgery and costs were assessed using multivariate linear regression controlled for.

Results

Two hundred and ninety-five patients were included in the analysis. One hundred and fifty-three patients underwent early week ACDF, and 142 underwent late week ACDF. Surgery day cohorts reported similar baseline characteristics. There were no differences in operative characteristics or hospital LOS between cohorts. Additionally, no differences in total or subcategorical hospital costs were identified between surgery day cohorts.

Conclusions

Patients undergoing ACDF later in the week exhibit similar LOS and hospital costs compared to those undergoing ACDF early in the week. These results suggest that outpatient procedures with short postoperative stays are likely not affected by the changes in hospital work efficiency that occur during the transition to the weekend. As such, hospitals should not restrict outpatient procedures to specific days of the week.

Level of Evidence

3.

Narcotic Consumption Following Minimally Invasive Lumbar Decompression: A Comparison Between Hospital and Ambulatory-Based Surgery Centers

Background

Several studies have compared outcomes between hospital-based centers (HBCs) and ambulatory surgery centers (ASCs) following minimally invasive lumbar decompression (MIS LD). However, the association between narcotic consumption and pain in the immediate postoperative period has not been well characterized. As such, this study aims to examine pain, narcotic consumption, and length of stay (LOS) among patients discharged on postoperative day 0 following a 1-level MIS LD between HBCs or ASCs.

Methods

Patients who underwent a primary, 1-level MIS LD were retrospectively reviewed and stratified by operative location. Differences between groups in patient demographics were assessed using independent-sample t tests for continuous variables and χ² analysis for categoric variables. The operative location and its effect on perioperative characteristics, inpatient pain scores, and narcotics consumption were analyzed using multivariate linear regression adjusted for significant patient characteristics.

Results

There were 235 patients identified, of whom 90 and 145 underwent surgery at an HBC or ASC, respectively. The HBC cohort exhibited an increased comorbidity burden and had a greater percentage of privately insured patients. The HBC cohort recorded shorter operative time and greater total estimated blood loss. Patients in the HBC cohort experienced prolonged LOS, and consumed greater total oral morphine equivalents compared with the ASC cohort. No differences were observed in the remaining outcomes.

Conclusions

The results of the current study suggest that patients who underwent MIS LD at an ASC received fewer narcotics than patients treated at an HBC, which may contribute to shortened LOS. Additionally, there was no difference in patient-reported pain between cohorts despite the differences in narcotic use. As such, postoperative narcotics administration varied, indicating HBC patients perhaps required more narcotic pain medications to achieve the same pain scores that were sufficient enough to allow patient discharge, thus prolonging LOS.

Level of Evidence

III.

The Patient-Reported Outcomes Measurement Information System in spine surgery: a systematic review

OBJECTIVE

The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed to provide a standardized measure of clinical outcomes that is valid and reliable across a variety of patient populations. PROMIS has exhibited strong correlations with many legacy patient-reported outcome (PRO) measures. However, it is unclear to what extent PROMIS has been used within the spine literature. In this context, the purpose of this systematic review was to provide a comprehensive overview of the PROMIS literature for spine-specific populations that can be used to inform clinicians and guide future work. Specifically, the authors aimed to 1) evaluate publication trends of PROMIS in the spine literature, 2) assess how studies have used PROMIS, and 3) determine the correlations of PROMIS domains with legacy PROs as reported for spine populations.

METHODS

Studies reporting PROMIS scores among spine populations were identified from PubMed/MEDLINE and a review of reference lists from obtained studies. Articles were excluded if they did not report original results, or if the study population was not evaluated or treated for spine-related complaints. Characteristics of each study and journal in which it was published were recorded. Correlation of PROMIS to legacy PROs was reported with 0.1 ≤ |r| < 0.3, 0.3 ≤ |r| < 0.5, and |r| ≥ 0.5 indicating weak, moderate, and strong correlations, respectively.

RESULTS

Twenty-one articles were included in this analysis. Twelve studies assessed the validity of PROMIS whereas 9 used PROMIS as an outcome measure. The first study discussing PROMIS in patients with spine disorders was published in 2012, whereas the majority were published in 2017. The most common PROMIS domain used was Pain Interference. Assessments of PROMIS validity were most frequently performed with the Neck Disability Index. PROMIS domains demonstrated moderate to strong correlations with the legacy PROs that were evaluated. Studies assessing the validity of PROMIS exhibited substantial variability in PROMIS domains and legacy PROs used for comparisons.

CONCLUSIONS

There has been a recent increase in the use of PROMIS within the spine literature. However, only a minority of studies have incorporated PROMIS for its intended use as an outcomes measure. Overall, PROMIS has exhibited moderate to strong correlations with a majority of legacy PROs used in the spine literature. These results suggest that PROMIS can be effective in the assessment and tracking of PROs among spine populations.

Impact of local steroid application in a minimally invasive transforaminal lumbar interbody fusion: results of a prospective, randomized, single-blind trial

OBJECTIVE

Local epidural steroid application may be associated with decreased pain and narcotic use in the immediate postoperative period following lumbar discectomy. However, local steroid delivery following lumbar fusion procedures has not been well characterized. This study aims to characterize the effect of local intraoperative depomedrol application on perioperative and postoperative outcomes following a single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

METHODS

A prospective, randomized, single-blinded study was performed. A priori power analysis determined that 86 patients were needed to detect a difference of 1 point in the visual analog scale (VAS) pain score between groups. Ninety-three patients were randomized into depomedrol (DEPO) and no depomedrol (NODEPO) cohorts. Prior to surgical closure, DEPO patients received 1 ml depomedrol (80 mg) applied directly to the surgical site by using a Gelfoam carrier. NODEPO patients received 1 ml saline on the same Gelfoam carrier. Perioperative outcomes including acute postoperative pain and narcotic use were assessed for the duration of inpatient stay. Patient-reported outcomes (PROs) questionnaires including VAS back and leg pain scores, and Oswestry Disability Index (ODI) were administered preoperatively and at 6-week, 12-week, and 6-month follow-up. Outcomes for DEPO and NODEPO cohorts were compared using linear regression controlled for sex.

RESULTS

Of the 93 patients, 45 (48.4%) were randomized to DEPO and 48 (51.6%) to NODEPO. A greater percentage of DEPO patients were female (53.3% vs 27.1%, p = 0.010). There were no other significant differences in patient baseline characteristics. Similarly, operating time, estimated blood loss, and length of inpatient stay did not differ between cohorts. Patients in the DEPO cohort consumed fewer hourly narcotics on postoperative day 0 (5.3 vs 6.3 oral morphine equivalents/hour, p = 0.034). However, no differences in acute postoperative pain or total narcotics consumption were observed between groups. Preoperative VAS leg scores were statistically different between cohorts (p = 0.027). However, preoperative ODI and VAS back scores did not differ between groups. Additionally, DEPO and NODEPO groups experienced similar improvements in PROs at all postoperative time points.

CONCLUSIONS

Local depomedrol use did not lead to decreases in acute postoperative pain or narcotics consumption after MIS TLIF. Additionally, local depomedrol was not associated with postoperative improvements in PROs. The findings of this randomized trial suggest that surgical and clinical outcomes following MIS TLIF may not be impacted by intraoperative application of depomedrol.

Clinical trial registration no.: NCT03308084 (clinicaltrials.gov)

Validity of PROMIS in minimally invasive transforaminal lumbar interbody fusion: a preliminary evaluation

OBJECTIVE

Patient-reported outcomes are commonly used to evaluate treatment efficacy. Inefficiencies in standard measurement tools often prove to be a barrier to data collection. The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed to overcome these limitations. This tool implements computer-adaptive testing, which enables the assessment of physical function in fewer questions than those required for “static” metrics. In spine surgery patients, moderate to strong correlations with Oswestry Disability Index (ODI) and the 36-Item Short Form Survey (SF-36) scores have been reported for PROMIS. However, to date, data regarding the efficacy of this tool for patients undergoing minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) have been limited.

METHODS

A prospectively maintained registry of patients who have undergone primary 1- or 2-level MIS TLIF was reviewed retrospectively. Patients with incomplete PROMIS data were excluded. Changes in PROMIS physical function scores 6 weeks, 12 weeks, and 6 months after surgery were analyzed using paired t-tests. PROMIS scores were compared with traditional outcome measures, including SF-12 physical function, ODI, and visual analog scale (VAS) back and leg scores. Correlations were tested using the Pearson correlation coefficient, and the strength of association was interpreted as follows: small, 0.1 ≤ |r| < 0.3; moderate, 0.3 ≤ |r| < 0.5; and large, |r| ≥ 0.5. Statistical significance was set at p < 0.05.

RESULTS

Seventy-four patients were included in this analysis after the exclusion of those without PROMIS scores. The mean preoperative PROMIS score was 35.92 ± 6.98. Significant improvements were demonstrated in PROMIS scores 12 weeks (41.33, p < 0.001) and 6 months (43.58, p < 0.001) after surgery. PROMIS scores demonstrated a significant correlation with SF-12, ODI, and VAS leg scores (p < 0.05). Strong associations with PROMIS scores were observed for SF-12 (r = 0.650 to 0.854), ODI (r = −0.525 to −0.831), and 6-month VAS back (r = −0.693) scores.

CONCLUSIONS

Physical function as measured by PROMIS improves significantly 12 weeks and 6 months after MIS TLIF. In addition, PROMIS scores have strong correlations with SF-12 and ODI scores. These results suggest that PROMIS scores can be used as a valid assessment of physical function in MIS TLIF patients. Further work is required to determine the full benefits of this measure in other spine populations.