Postoperative Complications of Surgery for Cervical Spondylotic Myelopathy with and Without Athetoid Cerebral Palsy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: With the aging of the Japanese population, patients with athetoid cerebral palsy (ACP) are getting older, and the rate of surgery for CSM is increasing in ACP patients. However, postoperative complications of such surgery among adult patients with ACP have not been reported yet. We investigated postoperative complications of surgery for CSM with ACP and compared them with those of surgery for CSM without ACP using a national inpatient database of Japan. METHODS: Using the Diagnosis Procedure Combination database, we identified 61382 patients who underwent surgery for CSM from July 2010 to March 2018. We examined patient backgrounds, surgical procedures, and type of hospital, and a 4:1 propensity score matching was performed to compare the outcomes between the non-ACP and ACP groups. RESULTS: There were 60 847 patients without ACP and 535 patients with ACP. The mean age was 68.5 years in the non-ACP group and 55 years in the ACP group. The percentages of patients who underwent fusion surgery were 21.6% and 68.8% in the non-ACP and ACP groups, respectively. The 4:1 propensity score matching selected 1858 in the non-ACP group and 465 in the ACP group. The ACP group was more likely to have postoperative urinary tract infection (.4% vs 2.8%, P < .001), postoperative pneumonia (.4% vs 2.4%, P < .001), and 90-day readmission for reoperation (1.9% vs 4.3%, P = .003). CONCLUSIONS: We found that ACP patients were more vulnerable to postoperative complications and reoperation after CSM than non-ACP patients.

Inhibition of glucose use improves structural recovery of injured Achilles tendon in mice.

Injured tendons do not regain their native structure except at fetal or very young ages. Healing tendons often show mucoid degeneration involving accumulation of sulfated glycosaminoglycans (GAGs), but its etiology and molecular base have not been studied substantially. We hypothesized that quality and quantity of gene expression involving the synthesis of proteoglycans having sulfated GAGs are altered in injured tendons and that a reduction in synthesis of sulfated GAGs improves structural and functional recovery of injured tendons. C57BL6/j mice were subjected to Achilles tendon tenotomy surgery. The injured tendons accumulated sulfate proteoglycans as early as 1-week postsurgery and continued so by 4-week postsurgery. Transcriptome analysis revealed upregulation of a wide range of proteoglycan genes that have sulfated GAGs in the injured tendons 1 and 3 weeks postsurgery. Genes critical for enzymatic reaction of initiation and elongation of chondroitin sulfate GAG chains were also upregulated. After the surgery, mice were treated with the 2-deoxy-d-glucose (2DG) that inhibits conversion of glucose to glucose-6-phosphate, an initial step of glucose metabolism as an energy source and precursors of monosaccharides of GAGs. The 2DG treatment reduced accumulation of sulfated proteoglycans, improved collagen fiber alignment, and reduced the cross-sectional area of the injured tendons. The modulus of the 2DG-treated groups was higher than that in the vehicle group, but not of statistical significance. Our findings suggest that mucoid degeneration in injured tendons may result from the upregulated expression of genes involved the synthesis of sulfate proteoglycans and can be inhibited by reduction of glucose utilization.

Spinal cord swelling in patients with cervical compression myelopathy.

BACKGROUND: Intramedullary hyperintense lesions associated with spinal cord edema on T2-weighted MR images (T2WI) are rare findings in patients with cervical spondylosis and are poorly characterized. We investigated the clinical characteristics of spinal cord edema due to cervical spondylosis (SCECS). METHODS: In total, 214 patients with cervical spondylotic myelopathy who underwent surgery between April 2007 and March 2017 were divided into SCECS and non-SCECS groups with SCECS defined as follows: (1) intramedullary signal intensity (ISI) of the cervical spinal cord in sagittal T2WI extending to more than one vertebral body height; (2) "fuzzy" ISI, recognized as a faint intramedullary change with a largely indistinct and hazy border; and (3) a larger sagittal diameter of the spinal cord segment with ISI just above or below the cord compression area compared with areas of the cervical spine without ISI. Radiographic parameters, demographic characteristics, and the Japanese Orthopedic Association (JOA) surgical outcomes score were compared between the groups. RESULTS: Seventeen patients (7.9%) were diagnosed with SCECS. These patients were younger than those in the non-SCECS group [median (interquartile range), 64 (20) vs. 69 (15) years, respectively, p = 0.016], and the disease duration from onset to surgery was significantly shorter in the SCECS group than in the non-SCECS group [6 (7) vs. 20 (48) months, respectively]. No significant difference was observed between groups with respect to sex, radiologic findings, or surgical outcomes. CONCLUSION: The disease showed an earlier onset and more rapid progression in the patients with SCECS than in those without SCECS.

Lysophosphatidic acids and their substrate lysophospholipids in cerebrospinal fluid as objective biomarkers for evaluating the severity of lumbar spinal stenosis.

Lysophospholipids (LPLs) are known to have potentially important roles in the initiation and maintenance of neuropathic pain in animal models. This study investigated the association between the clinical severity of lumbar spinal stenosis (LSS) and the cerebrospinal fluid (CSF) levels of LPLs, using human samples. We prospectively identified twenty-eight patients with LSS and fifteen controls with idiopathic scoliosis or bladder cancer without neurological symptoms. We quantified LPLs from CSF using liquid chromatography-tandem mass spectrometry. We assessed clinical outcome measures of LSS (Neuropathic Pain Symptom Inventory (NPSI) and Zurich Claudication Questionnaire (ZCQ)) and categorized patients into two groups according to their severity. Five species of lysophosphatidic acid (LPA), nine species of lysophosphatidylcholine (LPC), and one species of lysophosphatidylinositol (LPI) were detected. The CSF levels of all species of LPLs were significantly higher in LSS patients than controls. Patients in the severe NPSI group had significantly higher LPL levels (three species of LPA and nine species of LPC) than the mild group. Patients in the severe ZCQ group also had significantly higher LPL levels (four species of LPA and nine species of LPC). This investigation demonstrates a positive correlation between the CSF levels of LPLs and the clinical severity of LSS. LPLs are potential biomarkers for evaluating the severity of LSS.

Mental State Can Influence the Degree of Postoperative Axial Neck Pain Following Cervical Laminoplasty.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To investigate factors influencing the incidence of moderate to severe postoperative axial neck pain following cervical laminoplasty. METHODS: We reviewed 125 patients with cervical myelopathy who underwent double-door laminoplasty. The primary outcomes were the Numerical Rating Scale score (NRS score, 0-10) for neck pain, the Short Form 36 (SF-36) Health Survey score (Physical and Mental Component Summary scores [PCS and MCS, respectively]), and satisfaction. Imaging parameters on plain radiographs and magnetic resonance imaging were also evaluated. Patients with moderate to severe postoperative neck pain (NRS ≥ 5) were compared with those with no or mild neck pain (NRS ≤ 4). RESULTS: One hundred and three patients (82%) with complete data were eligible for inclusion. There were 67 men and 36 women, with a mean age of 65 years (32-89 years). Twenty-five patients (23%) had moderate to severe postoperative axial pain (NRS ≥ 5) and were compared with the other 78 patients (NRS ≤ 4), which revealed several predictive factors, including female sex, the presence of preoperative neck pain, low postoperative PCS, low preoperative and postoperative MCS, and satisfaction with the treatment. Multivariable logistic regression analysis revealed that the postoperative MCS (P = .002) was a risk factor for postoperative neck pain, although the preoperative MCS did not reach statistical significance (P = .06). CONCLUSIONS: Patients with a low mental state, possibly before surgery, are at a high risk for postoperative axial neck pain. None of the imaging parameters were statistically different.

Can Elective Spine Surgery Be Performed Safely Among Nonagenarians?: Analysis of a National Inpatient Database in Japan.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare morbidity and mortality between nonagenarians and other older adult patients who underwent elective spine surgery. SUMMARY OF BACKGROUND DATA: There is a lack of information of the perioperative risks of nonagenarians undergoing spine surgery. METHODS: Data of patients aged ≥65 years who underwent elective spine surgery from July 2010 to March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide administrative inpatient database in Japan. Clinical outcomes included mortality, occurrence of major complications (cardiac events, respiratory complications, pulmonary embolism, stroke, and acute renal failure), urinary tract infection, and postoperative delirium. These clinical outcomes in nonagenarians were compared with those in patients aged 65 to 79 years and octogenarians. A multivariate logistic regression model fitted with a generalized estimation equation was used to evaluate the influence of advanced age on 90-day mortality and postoperative major complications. RESULTS: Of 88,370 patients identified in the database, 418 were nonagenarians. Compared with patients aged 65 to 79 years and octogenarians, nonagenarians had the highest rates of 90-day mortality (0.2%, 0.3%, and 1.7%, respectively; P < 0.001) and at least one major complication (3.7%, 5.0%, and 7.4%, respectively; P < 0.001). Nonagenarians had the highest proportions of cardiac events, respiratory complications, urinary tract infections, and delirium. The multivariable logistic regression analyses revealed that nonagenarians had increased risks of both 90-day mortality (odds ratio, 8.65; 95% confidence interval, 3.62-20.6) and postoperative major complications (odds ratio, 2.32; 95% confidence interval, 1.61-3.36) compared with patients aged 65 to 79 years. CONCLUSION: Nonagenarians had increased morbidity and mortality following elective spine surgery compared with other older adult patients. Among the complications, cardiac events, respiratory complications, urinary tract infection, and delirium were more likely to occur in nonagenarians. LEVEL OF EVIDENCE: 3.

In-hospital mortality and morbidity of pediatric scoliosis surgery in Japan: Analysis using a national inpatient database.

Several previous reports have elucidated the mortality and incidence of complications after pediatric scoliosis surgery using nationwide databases. However, all of these studies were conducted in North America. Hence, this study aimed to identify the incidence and risk factors for in-hospital mortality and morbidity in pediatric scoliosis surgery, utilizing the Diagnosis Procedure Combination database, a national inpatient database in Japan.We retrospectively extracted data for patients aged less than 19 years who were admitted between 01 June 2010 and 31 March 2013 and underwent scoliosis surgery with fusion. The primary outcomes were in-hospital death and postoperative complications, including surgical site infection, ischemic heart disease, acute renal failure, pneumonia, stroke, disseminated intravascular coagulation, pulmonary embolism, and urinary tract infection.We identified 1,703 eligible patients (346 males and 1,357 females) with a mean age of 14.1 years. There were no deaths among the patients. At least one postoperative complication was found in 49 patients (2.9%). The most common complication was surgical site infection (1.4%). The multivariable logistic regression analysis showed that male sex (odds ratio, 2.22; 95% confidence interval, 1.28-3.70), comorbid diabetes (7.00; 1.56-31.51), and use of allogeneic blood transfusion (3.43; 1.86-6.41) were associated with the occurrence of postoperative complications. The present nationwide study elucidated the incidence and risk factors for in-hospital mortality and morbidity following surgery for pediatric scoliosis in an area other than North America. Diabetes was identified for the first time as a risk factor for postoperative complications in pediatric scoliosis surgery.

In-hospital complication rate following microendoscopic versus open lumbar laminectomy: a propensity score-matched analysis.

BACKGROUND CONTEXT: The incidence of postoperative complications after microendoscopic laminectomy (MEL) has not been compared with that after open laminectomy in a large study, so it is not clear whether MEL is a safer procedure. PURPOSE: The objective of this study was to compare postoperative morbidity and mortality following lumbar laminectomy between patients treated with MEL and with open laminectomy. STUDY DESIGN: This is a retrospective cohort study with propensity score-matched analysis. PATIENT SAMPLE: Data of patients who underwent elective spinal surgery between July 2010 and March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan. OUTCOME MEASURES: Clinical outcomes included length of hospital stay, occurrence of major complications (cardiac events, respiratory complications, pulmonary embolism, stroke, and acute renal failure), surgical site infection (SSI), postoperative delirium, and in-hospital death. MATERIALS AND METHODS: Propensity score matching was performed to adjust for measured confounding factors, including patient age, sex, Charlson Comorbidity Index, body mass index, smoking status, blood transfusion, duration of anesthesia, number of operated disc levels, and type of hospital and hospital volumes. The clinical outcomes of one-to-one propensity-matched pairs of the MEL and the open laminectomy groups were compared. RESULTS: Of 23,317 patients identified in the database, 1,536 underwent MEL (6.6%). By one-to-one propensity score matching, 1,536 pairs were selected. The distributions of patient backgrounds were closely balanced between the MEL and the open laminectomy groups. An analysis of 1,536 pairs revealed that there was a significantly lower incidence of major postoperative complications in those who underwent MEL (1.0% vs. 2.8% for open laminectomy, risk difference 1.8%, 95% confidence interval [CI] 0.9%-2.9%), SSI (0.5% vs. 1.6% for open laminectomy, risk difference 1.1%, 95% CI 0.4%-1.9%), and postoperative delirium (1.1% vs. 2.3% for open laminectomy, risk difference1.2%, 95% CI 0.3%-2.1%). The length of hospital stay was significantly shorter in those treated with MEL (12 days vs. 16 days for open laminectomy, p<.001). There was no significant difference in in-hospital mortality between the groups. CONCLUSIONS: Patients who underwent MEL were significantly less likely to experience major postoperative complications and were less likely to develop SSI and postoperative delirium than those who underwent open laminectomy.

A Mouse Intervertebral Disc Degeneration Model by Surgically Induced Instability.

STUDY DESIGN: An experimental study to develop a mouse model of lumbar intervertebral disc degeneration (IDD). OBJECTIVE: The aim of this study was to develop a mouse lumbar IDD model using surgically induced instability and to compare the findings of this model to those in human IDD. SUMMARY OF BACKGROUND DATA: Previously, various kinds of inducers have been used to reproduce IDD in experimental animals; however, there is yet no standard mouse lumbar IDD model without direct injury to intervertebral disc. METHODS: A total number of 59 C57BL/6J male mice at 8 weeks old were used. Instability of lumbar spine was induced by surgical resection of posterior elements, including facet joints, supra- and interspinous ligaments. We then analyzed time course changes in radiographical (n = 17) and histological analyses (n = 42), and compared these findings with those in human IDD. RESULTS: Radiographical analyses showed that the disc height began to decrease in the first 2 weeks after the surgery, and the decrease continued throughout 12 weeks. Bone spurs at the vertebral rims were observed in the late stage of 8 and 12 weeks after the surgery. Histological analyses showed that the disorder of the anterior anulus fibrosus (AF) was initially obvious, followed by posterior shift and degeneration of the nucleus pulposus (NP). Proteoglycan detected in inner layer of AF and periphery of NP was decreased after 8 weeks. Immunohistochemistry displayed the increase of type I and X collagen, and matrix metalloproteinase 13 in the anterior AF. CONCLUSION: Surgical resection of posterior elements of mouse lumbar spine resulted in reproducible IDD. Because the present procedure does not employ direct injury to intervertebral disc and the radiological and histological findings are compatible with those in human IDD, it may contribute to further understanding of the native pathophysiology of IDD in future. LEVEL OF EVIDENCE: N/A.

Is high T-1 slope a significant risk factor for developing interlaminar bony fusion after cervical laminoplasty? A retrospective cohort study.

OBJECTIVE Several investigators have reported the occurrence of interlaminar bony fusion after cervical laminoplasty, which is reportedly associated with reduced postoperative cervical range of motion (ROM). However, to the authors' knowledge, no previous study has investigated the characteristics of patients who were likely to develop interlaminar bony fusion after cervical laminoplasty. Therefore, the objective of this study was to investigate the risk factors for interlaminar bony fusion in patients with cervical spondylotic myelopathy (CSM) following cervical laminoplasty and to investigate the effect of interlaminar bony fusion on surgical outcomes. METHODS The authors retrospectively reviewed data from 92 patients with CSM (63 men and 29 women) after cervical laminoplasty. The presence of interlaminar bony fusion was evaluated by functional radiographs 2 years after surgery. The patients were divided into 2 groups according to the presence of postoperative interlaminar bony fusion: a fusion group (at least 1 new postoperative interlaminar bony fusion) and a nonfusion group (no new interlaminar bony fusion). Potential risk factors for postoperative interlaminar bony fusion were assessed, including diabetes mellitus, smoking status, whether the C-2 lamina was included in the surgical treatment, C2-7 Cobb angle in each cervical position, preoperative cervical ROM, and T-1 slope. The differences in each variable were compared between the fusion and nonfusion groups. Thereafter, multivariate logistic regression analysis was performed to identify the risk factors for postoperative interlaminar bony fusion. For surgical outcomes, the recovery rate based on Japanese Orthopaedic Association scores and the reduction rate of cervical ROM were evaluated 2 years after surgery. RESULTS Interlaminar bony fusion was observed in 60 cases, 52 of which were observed at the C2-3 level. Patients in the fusion group were significantly older, had a significantly larger C2-7 angle in flexion, and had a significantly lower preoperative cervical ROM than those in the nonfusion group. A high T-1 slope was significantly more frequent in the fusion group. Multivariate analysis revealed that the significant risk factors for postoperative interlaminar bony fusion were high T-1 slope (odds ratio 4.81; p = 0.0015) and older age (odds ratio 1.05; p = 0.025). The Japanese Orthopaedic Association recovery rate in patients with interlaminar bony fusion did not differ significantly from those without bony fusion (45% vs 48%; p = 0.73). However, patients with bony fusion showed significantly reduced postoperative cervical ROM compared with those without bony fusion (50% vs 25%; p < 0.001). CONCLUSIONS High T-1 slope and older age were significant risk factors for developing interlaminar bony fusion after cervical laminoplasty in patients with CSM. Interlaminar bony fusion was associated with reduced postoperative cervical ROM, but it did not affect neurological outcomes.

Mortality and morbidity after spinal surgery in patients with Parkinson's disease: a retrospective matched-pair cohort study.

BACKGROUND CONTEXT: There is a lack of information about postoperative outcomes and related risk factors associated with spinal surgery in patients with Parkinson's disease (PD). PURPOSE: This study aimed to investigate the postoperative morbidity and mortality associated with spinal surgery for patients with PD, and the risk factors for poor outcomes. STUDY DESIGN: This is a retrospective matched-pair cohort study. PATIENT SAMPLE: Data of patients who underwent elective spinal surgery between July 2010 and March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan. OUTCOME MEASURES: In-hospital mortality and occurrence of postoperative complications. METHODS: For each patient with PD, we randomly selected up to four age- and sex-matched controls in the same hospital in the same year. The differences in in-hospital mortality and occurrence of postoperative complications were compared between patients with PD and controls. A multivariable logistic regression model fitted with a generalized estimation equation was used to identify significant predictors of major complications (surgical site infection, sepsis, pulmonary embolism, respiratory complications, cardiac events, stroke, and renal failure). Multiple imputation was used for missing data. RESULTS: Among 154,278 patients undergoing spinal surgery, 1,423 patients with PD and 5,498 matched controls were identified. Crude in-hospital mortality was higher in patients with PD than in controls (0.8% vs. 0.3%, respectively). The crude proportion of major complications was also higher in patients with PD (9.8% vs. 5.1% in controls). Postoperative delirium was more common in patients with PD (30.3%) than in controls (4.3%). Parkinson's disease was a significant predictor of major postoperative complications, even after adjusting for other risk factors (odds ratio, 1.74; 95% confidence intervals, 1.37-2.22; p<.001). CONCLUSIONS: Patients with PD had a significantly increased risk of postoperative complications following spinal surgery. Postoperative delirium was the most frequently observed complication.

Seasonal Variations in the Risk of Reoperation for Surgical Site Infection Following Elective Spinal Fusion Surgery: A Retrospective Study Using the Japanese Diagnosis Procedure Combination Database.

STUDY DESIGN: A retrospective study of data abstracted from the Diagnosis Procedure Combination (DPC) database, a national representative database in Japan. OBJECTIVE: The aim of this study was to examine seasonal variations in the risk of reoperation for surgical site infection (SSI) following spinal fusion surgery. SUMMARY OF BACKGROUND DATA: Although higher rates of infection in the summer than in other seasons were thought to be caused by increasing inexperience of new staff, high temperature, and high humidity, no studies have examined seasonal variations in the risk of SSI following spinal fusion surgery in the country where medical staff rotation timing is not in summer season. In Japan, medical staff rotation starts in April. METHODS: We retrospectively extracted the data of patients who were admitted between July 2010 and March 2013 from the DPC database. Patients were included if they were aged 20 years or older and underwent elective spinal fusion surgery. The primary outcome was reoperation for SSI during hospitalization. We performed multivariate analysis to clarify the risk factors of primary outcome with adjustment for patient background characteristics. RESULTS: We identified 47,252 eligible patients (23,659 male, 23,593 female). The mean age of the patients was 65.4 years (range, 20-101 yrs). Overall, reoperation for SSI occurred in 0.93% of the patients during hospitalization. The risk of reoperation for SSI was significantly higher in April (vs. February; odds ratio, 1.93; 95% confidence interval, 1.09-3.43, P = 0.03) as well as other known risk factors. In subgroup analysis with stratification for type of hospital, month of surgery was identified as an independent risk factor of reoperation for SSI among cases in an academic hospital, although there was no seasonal variation among those in a nonacademic hospital. CONCLUSION: This study showed that month of surgery is a risk factor of reoperation for SSI following elective spinal fusion surgery, nevertheless, in the country where medical staff rotation timing is not in summer season. LEVEL OF EVIDENCE: 3.

Cervical Anterolisthesis: A Predictor of Poor Neurological Outcomes in Cervical Spondylotic Myelopathy Patients After Cervical Laminoplasty.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To clarify the influence of cervical spondylolisthesis on neurological outcomes in cervical spondylotic myelopathy (CSM) patients after cervical laminoplasty. SUMMARY OF BACKGROUND DATA: Studies focusing on the surgical outcomes in CSM patients with cervical spondylolisthesis are limited. METHODS: We retrospectively reviewed 125 CSM patients after cervical laminoplasty. Neurological outcomes were evaluated by calculating the Japanese Orthopedic Association (JOA) recovery rate at 2 years after surgery. We defined anterolisthesis as a more than 3-mm anterior vertebral displacement in a flexion radiograph and retrolisthesis as a more than 3-mm posterior vertebral displacement in an extension radiograph. We further assessed potential risk factors for poor neurological outcomes after cervical laminoplasty, including cervical alignment, degree of spinal cord compression, duration of myelopathic symptoms, diabetes mellitus, and preoperative JOA score. Multivariate logistic regression analysis was performed to investigate the risk factors for poor outcomes (JOA recovery rate <50%) after cervical laminoplasty. RESULTS: Our study included 86 men and 39 women with mean age of 64 (range, 30-89) years. Average JOA scores were 9.9 and 13.3 points before and at 2 years after surgery, respectively. Average recovery rate was 47.2% (range, -68% to 100%), with 62 patients having poor outcomes (JOA recovery rate <50%) at 2 years after surgery. Anterolisthesis and retrolisthesis were observed in 13 and 24 patients, respectively. Multivariate logistic regression analysis revealed that the anterolisthesis was a significant risk factor for poor outcomes (JOA recovery rate <50%) after cervical laminoplasty (P = 0.01), whereas retrolisthesis did not affect the neurological outcomes (P = 0.6). CONCLUSION: Anterolisthesis, but not retrolisthesis, is a significant risk factor for and predictor of poor neurological outcomes after cervical laminoplasty. Cervical laminoplasty should not be considered in CSM patients with anterolisthesis. LEVEL OF EVIDENCE: 2.

Does the microendoscopic technique reduce mortality and major complications in patients undergoing lumbar discectomy? A propensity score-matched analysis using a nationwide administrative database.

OBJECTIVE Although minimally invasive spinal surgery has recently gained popularity, few nationwide studies have compared the adverse events that occur during endoscopic versus open spinal surgery. The purpose of this study was to compare perioperative complications associated with microendoscopic discectomy (MED) and open discectomy for patients with lumbar disc herniation. METHODS The authors retrospectively extracted from the Diagnosis Procedure Combination database, a national inpatient database in Japan, data for patients admitted between July 2010 and March 2013. Patients who underwent lumbar discectomy without fusion surgery were included in the analysis, and those with an urgent admission were excluded. The authors examined patient age, sex, Charlson Comorbidity Index, body mass index, smoking status, blood transfusion, duration of anesthesia, type of hospital, and hospital volume (number of patients undergoing discectomy at each hospital). One-to-one propensity score matching between the MED and open discectomy groups was performed to compare the proportions of in-hospital deaths, surgical site infections (SSIs), and major complications, including stroke, acute coronary events, pulmonary embolism, respiratory complications, urinary tract infection, and sepsis. The authors also compared the hospital length of stay between the 2 groups. RESULTS A total of 26,612 patients were identified in the database. The mean age was 49.6 years (SD 17.7 years). Among all patients, 17,406 (65.4%) were male and 6422 (24.1%) underwent MED. A propensity score-matched analysis with 6040 pairs of patients showed significant decreases in the occurrence of major complications (0.8% vs 1.3%, p = 0.01) and SSI (0.1% vs 0.2%, p = 0.02) in patients treated with MED compared with those who underwent open discectomy. Overall, MED was associated with significantly lower risks of major complications (OR 0.62, 95% CI 0.43-0.89, p = 0.01) and SSI (OR 0.29, 95% CI 0.09-0.87, p = 0.03) than open discectomy. There was a significant difference in length of hospital stay (11 vs 15 days, p < 0.001) between the groups. There was no significant difference in in-hospital mortality between MED and open discectomy. CONCLUSIONS The microendoscopic technique was associated with lower risks for SSI and major complications following discectomy in patients with lumbar disc herniation.

Risk of infectious complications associated with blood transfusion in elective spinal surgery-a propensity score matched analysis.

BACKGROUND CONTEXT: Although the negative aspects of blood transfusion are increasingly recognized, less is known about transfusion-related risks in spinal surgery. PURPOSE: This study was designed to determine whether perioperative allogeneic blood transfusion is associated with increased risk of infectious complications after elective spinal surgery. STUDY DESIGN: A retrospective cohort study with propensity score matched analysis was carried out. PATIENT SAMPLE: Data of patients with spinal canal stenosis and spondylolisthesis who underwent elective lumbar surgeries (decompression or fusion) were obtained from the Diagnosis Procedure Combination database, a nationwide administrative inpatient database in Japan. OUTCOME MEASURES: Clinical outcomes included in-hospital death and the occurrence of infectious complications (surgical site infection [SSI], respiratory tract infection, urinary tract infection, and sepsis). METHODS: Patients' clinical information, including sex, age, type of hospital, preoperative comorbidities, duration of anesthesia, cell saver use, and volume of allogeneic blood transfused, were investigated. Patients transfused with >840 mL (6 units) were excluded. Propensity scores for receiving transfusion were calculated, with one-to-one matching based on estimated propensity scores to adjust for patients' baseline characteristics. The proportions of complications were compared in patients with and without transfusions. This study was funded by grants from the Ministry of Health, Labour and Welfare, Japan. RESULTS: Of the 84,650 patients identified, 5,289 patients (6.1%) received transfusions, with 4,436 (5.2%) receiving up to 840 mL. One-to-one propensity score matching resulted in 4,275 pairs with and without transfusion. Patients transfused were at increased risk of SSI (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.4-2.5; p<.001) and urinary tract infection (OR, 2.5; 95% CI, 1.5-4.2; p<.001) than those not transfused. CONCLUSIONS: Allogeneic blood transfusion after elective lumbar surgery was associated with increased risks of SSI and urinary tract infection.

Evaluation of Comorbidity Indices for a Study of Patient Outcomes Following Cervical Decompression Surgery: A Retrospective Cohort Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study was to investigate the predictive validity of 2 comorbidity indices in a study of patient outcomes following cervical decompression surgery. The comorbidity indices evaluated were the Charlson comorbidity index (CCI) and the self-administered comorbidity questionnaire (SCQ). SUMMARY OF BACKGROUND DATA: Comorbidities have been shown to have independent prognostic factors for HRQOL outcome in patients with spinal disorders. However, no appropriate evaluation method of comorbidity has been established in spinal research. METHODS: We retrospectively reviewed 86 cervical myelopathy cases treated by decompression surgery between 2004 and 2010. Health-related quality of life (HRQOL) outcomes were measured using the short form 36 physical component summary (PCS) and the neck disability index (NDI), administered both pre- and postoperatively. Patient comorbidity was evaluated by the CCI and SCQ. The CCI was calculated by the medical record review, whereas the SCQ was obtained from patients' self-reports. The correlations between HRQOL outcomes and comorbidity indices were investigated. Thereafter, multiple liner regression analyses were performed to assess the performance of these comorbidity indices for predicting postoperative HRQOL. RESULTS: The SCQ significantly correlated with both pre- and postoperative PCS scores and both pre- and postoperative NDI scores. The CCI did not correlate significantly with any outcome measure. On regression analysis, the CCI was a poor predictor of postoperative HRQOL, demonstrating only 0.2% of variance in the PCS score (P = 0.25) and only 0.4% of variance in the NDI score (P = 0.59). In comparison, the SCQ was a significant predictor of postoperative HRQOL, demonstrating 4.0% of variance in PCS score (P = 0.011) and 10.2% of variance in NDI score (P = 0.0001). CONCLUSION: The SCQ, but not the CCI, was a robust predictor of postoperative HRQOL. Our study suggests that the SCQ score is a more appropriate adjustment for HRQOL outcomes following cervical decompression surgery. LEVEL OF EVIDENCE: 3.

Perioperative stroke in patients undergoing elective spinal surgery: a retrospective analysis using the Japanese diagnosis procedure combination database.

BACKGROUND: Although a few studies on perioperative stroke following spinal surgery have been reported, differences in the incidence of perioperative stroke among various surgical procedures have not been determined. The purpose of this retrospective analysis was to investigate the incidence of perioperative stroke during hospitalization in patients undergoing elective spinal surgery, and to examine whether the incidence varied according to the surgical procedure. METHODS: A retrospective analysis of data from the Diagnosis Procedure Combination database, a nationwide administrative impatient database in Japan, identified 167,106 patients who underwent elective spinal surgery during 2007-2012. Patient information extracted included age, sex, preoperative comorbidity, administration of blood transfusion, length of hospitalization, and type of hospital. Clinical outcomes included perioperative stroke during hospitalization, and in-hospital death. RESULTS: The overall incidence of perioperative stroke was 0.22 % (371/167,106) during hospitalization. A logistic regression model fitted with a generalized estimating equation showed perioperative stroke was associated with advanced age, a history of cardiac disease, an academic institution, and resection of a spinal tumor. Patients who underwent resection of a spinal cord tumor (reference) had a higher risk of stroke compared with those undergoing discectomy (odds ratio (OR), 0.29; 95 % confidence interval (CI), 0.14-0.58; p = 0.001), decompression surgery (OR, 0.44; 95 % CI, 0.26-0.73; p = 0.001), or arthrodesis surgery (OR, 0.55; 95 % CI, 0.34-0.90); p = 0.02). Advanced age (≥80 years; OR, 5.66; 95 % CI, 3.10-10.34; p ≤ 0.001), history of cardiac disease (OR, 1.58; 95 % CI, 1.10-2.26; p = 0.01), diabetes (OR, 1.73; 95 % CI, 1.36-2.20; p ≤ 0.001), hypertension (OR, 1.53; 95 % CI, 1.18-1.98; p = 0.001), cervical spine surgery (OR, 1.44; 95 % CI, 1.09-1.90; p = 0.01), a teaching hospital (OR, 1.36; 95 % CI, 1.01-1.82; p = 0.04), and length of stay (OR, 1.008; 95 % CI, 1.005-1.010; p ≤ 0.001) were also risk factors for perioperative stroke. CONCLUSIONS: Perioperative stroke occurred in 0.22 % of patients undergoing spinal surgery. Resection of a spinal cord tumor was associated with increased risk of perioperative stroke as well as advanced age, comorbidities at admission, cervical spine surgery, surgery in a teaching hospital, and length of stay.

Spondylodiscitis concurrent with infectious aortic aneurysm caused by Candida tropicalis: a case report.

We report a case of spondylodiscitis concurrent with infectious aortic aneurysm caused by Candida tropicalis in a 79-year-old immunocompromised man. The patient underwent percutaneous drainage of the abscess and endoluminal exclusion of the aneurysm using a bifurcated stent graft. Micafungin was administered intravenously for 8 weeks, followed by a prolonged course of oral fluconazole. At the one-year follow-up, no recurrence was noted, and the patient could walk with a cane without low back pain.

Concurrent spinal schwannoma and meningioma mimicking a single cervical dumbbell-shaped tumor: case report.

Dumbbell-shaped tumors consisting of 2 different tumors are extremely rare. Herein, the authors present a case of concurrent spinal schwannoma and meningioma mimicking a single cervical dumbbell-shaped tumor. A 64-year-old man presented with a 5-year history of gradually exacerbating left occipital pain without clinical evidence of neurofibromatosis. Magnetic resonance imaging showed an extradural tumor along the left C-2 nerve root with a small intradural component. The tumor was approached via a C-1 hemilaminectomy. The intradural tumor was resected together with the extradural tumor after opening the dura mater. The intradural tumor was attached to the dura mater around the exit point of the C-2 nerve root. Intraoperative biopsy revealed that the extradural tumor was a schwannoma and that the intradural tumor was a meningioma. The dura mater adjacent to the tumor was then coagulated and resected. Postoperative pathological examination confirmed the same diagnoses with no evidence of continuity between the intra- and extradural components. The patient's postoperative clinical course was uneventful. Clinicians should be aware that cervical dumbbell-shaped tumors can consist of 2 different tumors.