Shugang Li

Intraoperative motor evoked potential monitoring to patients with preoperative spinal deficits: judging its feasibility and analyzing the significance of rapid signal loss

BACKGROUND CONTEXT Transcranial motor evoked potential (MEP) monitoring has been widely adopted in spine surgery, but so far the useful monitoring data for patients with preoperative spinal deficits (PPSDs) are limited. Originally we thought that they seemed technically more difficult and less reliable in performing the MEP monitoring to PPSDs. PURPOSE Our objective was to study (1) the feasibility of MEP monitoring in PPSDs and the (2) the significance of rapid MEP loss. STUDY DESIGN/SETTING A retrospective case notes study from a prospective patient register was used as the study design. PATIENT SAMPLE A total of 332 PPSDs who underwent posterior spine surgery with a reliable MEP monitoring were collected between September 2010 and December 2014. OUTCOME MEASURES Relevant MEP loss was identified as rapid amplitude reduction (more than 80% MEP) associated with high-risk surgical maneuvers or high-risk diagnoses. METHOD The muscles with higher strength were used to record the optimal MEP signal. MEP monitoring of these patients was considered to be feasible if reproducible signals had been obtained; moreover, sensitivity, specificity, positive predictive value (PPV), and negative predictive value were computed. The significance of the patients with rapid MEP loss was analyzed. RESULTS From a total of 332 PPSDs, 27 cases showed significant MEP loss (23 true positive, 4 false positive), and 21 showed new spinal deficits. Invalid MEP baselines were found in 11 paralysis and 6 severely incomplete paraplegia patients, and success rate of reliable MEP was 95.1% in PPSDs. The congenital kyphoscoliosis, tuberculous kyphoscoliosis, and thoracic spinal stenosis are considered high-risk diagnoses to result in MEP loss. The sensitivity of intraoperative MEP monitoring was 100%, the specificity 98.7%, the positive predictive value 85.2%, and the negative predictive value 100%. CONCLUSIONS Intraoperative MEP monitoring is feasible for most of the PPSDs. The rapid MEP loss during high-risk diagnoses and complicated surgical procedures may indicate new spinal deficits.

Unplanned Reoperation within 30 Days of Fusion Surgery for Spinal Deformity

No recent studies have analyzed the rates of or reasons for unanticipated revision surgery within 30 days of primary surgery in spinal deformity patients. Our aim was to examine the incidence, characteristics, reasons, and risk factors for unplanned revision surgery in spinal deformity patients treated at one institution. All patients with a diagnosis of spinal deformity presenting for primary instrumented spinal fusion at a single institution from 1998 to 2012 were reviewed. All unplanned reoperations performed within 30 days after primary surgery were analyzed in terms of demographics, surgical data, and complications. Statistical analyses were performed to obtain correlations and risk factors for anticipated revision. Of 2758 patients [aged 16.07 years (range, 2–71), 69.8% female] who underwent spinal fusion surgery, 59 (2.1%) required reoperation within 30 days after primary surgery. The length of follow up for each patient was more than 30 days. Of those that required reoperation, 87.0% had posterior surgery only, 5.7% had anterior surgery, and 7.3% underwent an anteroposterior approach. The reasons for reoperation included implant failure (n = 20), wound infection (n = 12), neurologic deficit (n = 9), pulmonary complications (n = 17), and coronal plane imbalance (n = 1). The risk factors for reoperation were age, diagnosis, and surgical procedure with osteotomy.

Genetic Polymorphism of lbx1 is Associated with Adolescent Idiopathic Scoliosis in Northern Chinese Han Population

Study Design. A case-control association study was performed to investigate the relationship between ladybird homeobox (LBX1) and adolescent idiopathic scoliosis (AIS) in northern Chinese Han population. Objective. To explore the prevalence and functional importance of LBX1 polymorphisms in patients with AIS within the northern Chinese Han population. Summary of Background Data. AIS is the most common subtype of idiopathic scoliosis. Genetic factors such as LBX1 polymorphisms have been recently proved to be associated with AIS in some populations. In this study we explored the prevalence and functional importance of the polymorphisms around LBX1 in patients with AIS within the northern Chinese Han population. Methods. Five tag single nucleotide polymorphisms (SNPs) around or in LBX1 were genotyped in 180 patients with AIS and 182 controls. And the luciferase assay was performed to explore the functional importance of the most significant SNPs. Results. We replicated that rs11190870, previously reported as the most significantly associated SNP, was enriched in our AIS cohort. In addition, we found that the T allele of rs1322331 was associated with a novel risk allele (odds ratio = 3.349, 95% confidence interval 1.742–6.436). In the following luciferase assay, the TT-type promoter showed significantly reduced transcription activity in vitro. Conclusion. Two SNPs around LBX1, rs11190870 and rs1322331 are associated with AIS in northern Chinese Han population. The T allele of rs1322331 is a novel risk allele. We hypothesize that rs1322331 might increase patients’ susceptibility to AIS by reducing LBX1-AS1 transcription and thus upregulating the function of LBX1. Level of Evidence: 3

Association Between rs11190870 Polymorphism Near LBX1 and Susceptibility to Adolescent Idiopathic Scoliosis in East Asian Population: A Genetic Meta-Analysis.

Study Design. Meta-analysis to collect all the relevant studies to date to further investigate whether or not the rs11190870 polymorphism is associated with susceptibility to adolescent idiopathic scoliosis (AIS) in East Asian population. Objective. To investigate whether or not the rs11190870 polymorphism is associated with susceptibility to AIS in East Asian population. Summary of Background Data. To date, the single nucleotide polymorphism rs11190870 was identified as the most significant common variant in Japanese females. Three association studies conducted in Chinese Han population from Hong Kong, Yangtze River region, and Southern region of mainland China replicated the association between AIS and rs1190870. However, there is limited published data about the association of rs11190870 with AIS in East Asian population. Methods. A systematic search of all relevant studies published through August 2013 was conducted using the MEDLINE, EMBASE, OVID, and ScienceDirect. Single nucleotide polymorphism of rs11190870 was evaluated. The included studies were assessed in the analysis of the following allele model: T allele versus C allele for the allele-level comparison; (b) TC + TT versus CC for dominant model of T allele; (c) TT versus TC + CC for recessive model of T allele, and (d) TT versus CC for extreme genotype. Results. Four studies with 8415 total participants (2889 patients with AIS and 5526 controls), who were all East Asian population, were eligible for inclusion. We searched for genotypes T allele versus C allele, TT versus TC + CC, TC + TT versus CC, and TT versus CC in a fixed/random-effects model. The effect summary odds ratios and 95 % confidence intervals were obtained, which shows significant association between rs11190870 and AIS in East Asian populations (all genetic models P < 0.001). Subgroup analyses were conducted according to sex. The results showed a significant association between rs11190870 and AIS in female (all genetic models, P < 0.001) but not in male (all genetic models, P > 0.05). Conclusion. The present meta-analysis demonstrated that the T allele of single nucleotide polymorphism rs11190870 may be a major susceptibility locus in the East Asian population with AIS, especially in female. Level of Evidence: 1

A randomized controlled trial on the effects of collagen sponge and topical tranexamic acid in posterior spinal fusion surgeries

BackgroundThis is a randomized controlled trial research to assess the hemostatic efficacy of gelatin sponge, collagen sponge, and topical use of tranexamic acid (TXA) on postoperative blood loss in posterior spinal fusion surgeries.MethodsWe recruited patients with spinal degenerative diseases into the study from November 2013 to October 2016. All the participants were assigned to 3 groups using a simple, equal-probability randomization scheme: group A is a control group utilizing gelatin sponge, while groups B and C are experimental groups, applying collagen hemostatic sponge and topical TXA respectively. Postoperative blood loss, rates of transfusion, and hospitalization were compared among the 3 groups.ResultsIn our study, the volume of drainage and blood content in drainage on the first postoperative day (POD 1) of patients in the experimental groups were significantly less than those in the control group, as well as rates of transfusion and postoperative hospitalization (P < 0.05). When compared with the control group, the volume of drainage decreased by 22.7% in group B and 56.2% in group C, while the blood content in drainage decreased by 28.8 and 75% respectively.ConclusionsIn this study, collagen and topical use of TXA have both proven to be effective and safe for patients undergoing posterior spinal fusion surgeries, while TXA has exhibited better efficacy. The total amount of perioperative blood loss reduced significantly without increasing incidence of related complications.Trial registrationA randomized controlled trial for effects of collagen sponge and topical tranexamic acid in posterior lumbar fusion surgeries. ChiCTR-IIR-17010785.

Can tranexamic acid conserve blood and save operative time in spinal surgeries? a meta-analysis

BACKGROUND CONTEXT It is widely accepted that tranexamic acid (TXA) effectively reduces blood losses and transfusions in major surgeries. However, limited studies investigated the role of TXA in conserving blood and saving operative time in spine surgeries. PURPOSE This meta-analysis was conducted to gather scientific evidence for TXA efficacy on conserving blood and saving operative time in spine surgeries. STUDY DESIGN A meta-analysis was performed. PATIENT SAMPLE Eighteen RCTs and 18 non-RCT studies involving 2,572 patients were included in the final analyses, comparing the effectiveness of intravenous TXA with a placebo/no treatment group. OUTCOME MEASURES Outcomes of interest included intraoperative, postoperative, and perioperative blood losses, allogeneic blood transfusion rates, cell salvage transfusion amounts, operative time, and the number of postoperative thrombosis events. METHODS An exhaustive literature search was conducted in the MEDLINE and EMBASE databases from January 2000 through March 2017. Meta-analysis was performed using Review Manager (RevMan) version 5.0. For continuous outcomes, the means and standard deviations were pooled to a mean difference and 95% confidence interval (CI). Odds ratios (OR) and 95% CI were calculated for dichotomous outcomes. The quantity of heterogeneity was assessed using I2 statistics. When there was no statistical evidence of substantial heterogeneity (I2≤50%), a fixed-effect model was adopted; otherwise, a random-effect model was chosen. Subgroup analysis was performed when more than three studies were included on one issue, based on low or high the dose of TXA. Beijing Talent Fund (2016) was received to support this work. RESULTS Significantly reduced intraoperative (weighted mean difference [WMD]=-280.09.00, p<.00001), postoperative (WMD=-120.15, p<.00001), perioperative (WMD=-310.86, p<.00001) blood losses, cell salvage transfusion amount (WMD=-471.79, p=.01), perioperative transfusion rate (odds ratio [OR], 0.33 [0.17, 0.65], p=.001), and operative time (WMD=-4.69, p=.003) were observed in TXA group. Furthermore, subgroup analysis revealed that high-dose TXA could reduce both intraoperative-perioperative allogeneic transfusion rates and operative time, whereas low dose of the drug does not convey such effects. CONCLUSIONS With the most comprehensive literature inclusion up to the present, this meta-analysis suggests that intravenous TXA use constitutes an important measure for conserving blood and saving operative time in spinal surgeries. High-dose TXA significantly reduces intraoperative-perioperative allogeneic transfusion rates and operative time, whereas low-dose TXA does not convey such efficacies. Larger prospective trials are still required to define the optimal regimen and to confirm the safety of TXA use in such surgeries.

Posterior-only Hemivertebra Resection With Anterior Structural Reconstruction With Titanium Mesh Cage and Short Segmental Fusion for the Treatment of Congenital Scoliokyphosis: The Indications and Preliminary Results

Study Design. Perspective study. Objectives. To evaluate indications and preliminary results of posterior hemivertebra resection with anterior structural reconstruction with titanium mesh cage and short segmental fusion. Summary of Background Data. There exist a lot of reports on posterior hemivertebra resection for the early surgical intervention of congenital scoliosis because of hemivertebra. However, a few reports describe the procedure of the anterior structural reconstruction after posterior hemivertebra resection. Methods. In this study, 18 selected children of mean age 5.4 years (range, 2–12 yrs) with scoliokyphosis because of hemivertebra were treated with posterior hemivertebra resection with anterior structural reconstruction and short segmental fusion. They were followed for an average of 37.1 (24–85) months. Radiograghs, operative reports, and patient charts were studied to evaluate the correction and complications. Results. Average fused segments were 1.67 (1–3). The segmental scoliosis was 40.1° before surgery, 4.1° postsurgery, and 5.7° at the latest the follow up. Moreover, the segmental kyphosis (difference to normal segmental alignment) was improved from 27.6° to 3.9°. The correction of the compensatory cranial and caudal curve was 74.7% and 82.4%. The trunk shift improved from 17.7 mm to 5.3 mm. No complications occurred until the latest follow up. Conclusion. Posterior hemivertebra resection with anterior structural reconstruction and short segmental fusion is a reliable procedure for selected patients with scoliokyphosis because of hemivertebra. A structural reconstruction is essential to the avoidance of overcorrection of the segmental scoliosis and resultant postoperative coronal imbalance with limited fused levels in some patients, increasing chances of short segmental fusion and saving mobile segments. As a fulcrum, anterior reconstruction with a titanium mesh cage could help to improve the correction of segmental kyphosis. Furthermore, the cage may help to stabilize the level of hemivertebra resection like a structural autograft, enhancing the postoperative stability and decreasing the stress of the pedicle and implants. Level of Evidence: 4

Efficacy and Safety of Topical Use of Tranexamic Acid in Reducing Blood Loss During Primary Lumbar Spinal Surgery: A Retrospective Case Control Study

Study Design. A retrospective case-control study. Objective. To compare postoperative blood loss, amount of allogeneic blood transfusion, removal time of drainage tube, length of hospital stay, and complications associated with tranexamic acid (TXA). Summary of Background Data. Spinal fusion surgery can be associated with significant blood loss. To the best of our knowledge, very few published studies exist reporting the effect of topical use of tranexamic acid (tTXA) on decreasing the blood loss in patients undergoing posterior lumbar spinal fusions. Methods. We conducted a retrospective nonrandomized case-control study of 100 adults undergoing posterior lumbar spinal fusion surgery. In the tTXA group (n = 50), wound surface was soaked with TXA (1 g in 100 mL saline solution) for 5 minutes before wound closure. In the control group (n = 50), wound surface was soaked with the same volume of normal saline. The postoperative blood loss, removal time of drainage tube, amount of allogeneic blood transfusion, and length of hospital stay were compared between the two groups. And the complications of TXA were also collected. Results. In the tTXA group, the postoperative blood loss, removal time of drainage tube, postoperative length of hospital stay were significantly lower than those in the control group (155.2 ± 104.3 mL vs. 278.6 ± 124.1 mL, 2.0 ± 0.6 d vs. 2.4 ± 0.5 d, 4.7 ± 1.4 d vs. 5.6 ± 2.3 d, P < 0.05, respectively). There was no significant difference in blood transfusion between two groups. No significant changes were noticed in terms of coagulation function, and no complications associated with TXA were observed. Conclusion. tTXA can significantly reduce postoperative blood loss, accelerate removal of drainage tube, shorten the duration of hospital stay, while not increasing the complication incidence in patients undergoing posterior lumbar spinal fusion surgery. Level of Evidence: 3

The further exploration of hidden blood loss in posterior lumbar fusion surgery

PURPOSE Hidden blood loss (HBL) plays an important role in lumbar fusion surgery. However, there was huge computation error when calculating hidden loss in previous studies because they regarded the volume of drainage as postoperative blood loss. We should not ignore the fact that the composition of drainage varies from person to person and also with time-lapse after operation. The purpose of this study was to demonstrate a more accurate HBL calculation formula by comparing it with previous formula and to address the importance of HBL in patients undergoing posterior lumbar fusion surgeries. METHODS For each patient, the HBL was calculated by previous formula and our recommendable formula. We compared the result of HBL calculated by two different methods. At the same time, we explored the HBL in patients undergoing posterior lumbar fusion surgeries with various levels. RESULTS In our study, the average total blood loss was 771ml. The mean intraoperative blood loss was 268ml, and the total volume of post-operative drainage is 276ml. The mean hidden loss of 90 patients calculated with previous method was 227ml and 29.4% of total loss. When taking change of drainage HCT into account, the mean hidden loss calculated with our recommendable method was 362.8ml and 47% of total loss. The results were significantly different (P<0.01). There was no significant difference in the percentage of the HBL between patients with single or multiple surgical levels. CONCLUSIONS There is often a substantial unmeasured blood loss in lumbar fusion surgeries. However, the component of drainage changed radically with time, we should take the true blood contained in drainage into considerations when calculating the HBL. LEVEL OF EVIDENCE Our research is a case-control study and the level of proof is III.

Topical use of tranexamic acid can effectively decrease hidden blood loss during posterior lumbar spinal fusion surgery: A retrospective study.

Abstract In spinal fusion surgery, total blood loss (TBL) is composed of visible blood loss from the surgical field and wound drainage, and hidden blood loss (HBL). Until now, no published studies exist reporting the effect of topical use of tranexamic acid (tTXA) on HBL in patients undergoing posterior lumbar spinal fusion surgery. This study aimed to explore the effect of tTXA on HBL during primary posterior lumbar spinal fusion surgery. Between September 2014 and September 2016, 100 adult patients (age > 18 years) with lumbar disc herniation or lumbar spinal stenosis undergoing primary posterior lumbar instrumented spinal fusions at 1 institution were divided into tTXA and control groups. The primary outcome was HBL. Secondary outcomes include TBL, intraoperative blood loss (IBL), postoperative blood loss (PBL), hemoglobin (HGB) levels on preoperative (Pre-op) and postoperatively (days 1–3, POD1, POD2, POD3, respectively), and amount of allogeneic blood transfusion. Complications occurring perioperatively until hospitalization discharge were also collected. In the tTXA group (n = 50 patients), wound surface was soaked with TXA (1 g in 100 mL saline solution) for 5 minutes before wound closure. For the control group (n = 50 patients), wound surface was soaked with the same volume of normal saline. There were no significant differences in demographics, surgical traits between the 2 groups. There were no significant differences in IBL or perioperative blood transfusion requirements between the 2 groups. However, in the tTXA group, TBL, PBL, and HBL were significantly lower than those in the control group (550 ± 268 vs 833 ± 298 mL, 53.5 ± 43.9 vs 136.7 ± 87.9 mL, 356.7 ± 254.8 vs 501.1 ± 216.9 mL, P < .001, respectively). HGB levels were significantly higher in the tTXA group (P < .001) on POD1 and had a slower decline on POD2 and POD3 than the control group. No complications associated with TXA were observed. From these data, we conclude that tTXA can effectively reduce HBL, without significant complications in adult patients undergoing posterior lumbar spinal fusion surgery.