Nam Lee

Clinical characteristics and prognostic factors of stress-induced cardiomyopathy

Background and Objectives Stress-induced cardiomyopathy (SCM) is characterized by a transient left ventricular (LV) dysfunction due to emotional and physical stress. There are limited data about the clinical characteristics in Korean patients. We sought to clarify the clinical features and prognosis in patients with SCM. Subjects and Methods We reviewed 39 cases diagnosed with SCM in a tertiary hospital. The SCM was diagnosed as: 1) no previous history of cardiac disease, 2) acute onset, 3) regional wall motion abnormality, typically in the takotsubo or inverted takotsubo shape by echocardiography, and 4) no significant stenosis in the coronary angiogram. We evaluated clinical characteristics, biomarkers, and prognosis. Results Mean age was 61.3±16.1 years (female 69%). The triggering factors were physical stress in 32 patients (82%) and emotional stress in 5 patients (13%). The initial symptom was dyspnea (n=18, 46%) rather than chest pain (n=10, 26%). An initial electrocardiogram (EKG) presented T-wave inversion (n=18, 46%), ST-elevation (n=11, 28%), and ST-depression (n=2, 5%). Multivariate logistic regression analysis showed that initial high sensitive C-reactive protein (hs-CRP) {odds ratio (OR) 1.41, 95% confidence interval (CI); 1.02-1.97} and initial left ventricular ejection fraction (LVEF) (OR 0.89, 95% CI; 0.80-0.98) were significantly associated with death or cardiogenic shock, respectively. Conclusion The major triggering factor of SCM is physical stress due to illness or surgical procedures, and the first manifestation is dyspnea rather than chest pain. Elevated hs-CRP and decreased LVEF at admission were independent risk factors for death or cardiogenic shock.

Relationship between T1 slope and loss of lordosis after laminoplasty in patients with cervical ossification of the posterior longitudinal ligament.

BACKGROUND CONTEXT Laminoplasty is a major surgical method used to treat patients with cervical ossification of the posterior longitudinal ligament (OPLL). Sometimes, patients with cervical OPLL demonstrate postoperative kyphosis despite sufficient preoperative lordosis. Recently, the impact of T1 slope has emerged as a predictor of kyphotic alignment change after laminoplasty. However, the relationship between T1 slope and postoperative cervical alignment change is not yet fully established. PURPOSE The goals of the present study were to investigate the relationship between T1 slope and loss of cervical lordosis (LCL), and to identify the role of T1 slope as a predictor of postoperative kyphosis after laminoplasty in patients with OPLL. STUDY DESIGN This is a retrospective case study. PATIENT SAMPLE Between January 2011 and January 2012, 64 consecutive patients who underwent cervical laminoplasty for OPLL were enrolled (male:female ratio=47:17; mean age=55.9 years). Cervical spine lateral radiographs in neutral, flexion, and extension were taken before surgery and at 2-year follow-up. OUTCOME MEASURES The C2-C7 Cobb angle, cervical range of motion (ROM), T1 slope, neck tilt, and C2-C7 sagittal vertical axis (SVA) were measured from lateral radiographs of the cervical spine preoperatively and postoperatively at 2-year follow-up. METHODS Patients were divided into two groups according to preoperative T1 slope, and the postoperative cervical alignment change was compared between the groups. Postoperative kyphosis and LCL incidence were also evaluated at 2-year follow-up. The relationships between postoperative cervical alignment change and preoperative variables, including age, T1 slope, cervical ROM, C2-C7 SVA, and T1 slope minus C2-C7 Cobb angle (T1S-CL), were investigated. RESULTS Patients were divided into two groups above and below median preoperative T1 slope (23.2°). There were no differences in age, sex, type of OPLL, or operation level between the two groups. Patients with higher preoperative T1 slope demonstrated significantly more lordotic preoperative cervical alignment (p=.001). Patients with higher preoperative T1 slope were more likely to exhibit postoperative LCL (p=.03), and when it occurred the degree of LCL was greater (p=.06). In multiple linear regression analysis, higher T1 slope (B=0.414, p=.04) and lower T1S-CL (B=-0.412, p=.03) were significantly associated with more postoperative LCL. In spite of these results, postoperative kyphosis did not occur more frequently in patients with higher T1 slope (p=.64). CONCLUSIONS Patients with higher T1 slope had more lordotic curvature before surgery and demonstrated more LCL at 2-year follow-up. Cervical alignment was compromised after laminoplasty, and the degree of LCL was correlated with preoperative T1 slope. After laminoplasty for cervical OPLL, patients with higher T1 slope tended to exhibit a greater LCL yet did not drift into frank postoperative kyphosis.

Normative Values and Correlates of Mean Common Carotid Intima-Media Thickness in the Korean Rural Middle-aged Population: The Atherosclerosis RIsk of Rural Areas iN Korea General Population (ARIRANG) Study

Carotid intima-media thickness (CIMT) is considered as a surrogate marker for cardiovascular disease (CVD). We determined the normative value of CIMT and correlates of CVD risk factors and Framingham risk score (FRS) in Korean rural middle-aged population. We measured CIMT with a B-mode ultrasonography in 1,759 subjects, aged 40 to 70 yr, in a population-based cohort in Korea. A healthy reference sample (n = 433) without CVD, normal weight and normal metabolic parameters was selected to establish normative CIMT values. Correlates between CIMT and conventional CVD risk factors were assessed in the entire population. Mean values of CIMT (in mm) for healthy reference sample aged 40-49, 50-59, and 60-70 yr were 0.55, 0.59, and 0.66 for men and 0.48, 0.55, and 0.63 for women, respectively. In multivariate regression analysis, CIMT was correlated with older age, higher BMI, male gender, higher LDL-cholesterol level and history of diabetes mellitus. The mean CIMT was also correlated with FRS in both gender (r2 = 0.043, P < 0.01 for men; r2 = 0.142, P < 0.01 for women). We identified normative value of CIMT for the healthy Korean rural middle-aged population. The CIMT is associated with age, obesity, gender, LDL-cholesterol, diabetes mellitus and FRS.

Feasibility Study of Utilization of action camera, GoPro Hero 4, Google Glass and Panasonic HX-A100 in Spine Surgery.

Study Design. Study for feasibility of commercially available action cameras in recording video of spine. Objective. Recent innovation of the wearable action camera with high-definition video recording enables surgeons to use camera in the operation at ease without high costs. The purpose of this study is to compare the feasibility, safety, and efficacy of commercially available action cameras in recording video of spine surgery. Summary of Background Data. There are early reports of medical professionals using Google Glass throughout the hospital, Panasonic HX-A100 action camera, and GoPro. This study is the first report for spine surgery. Methods. Three commercially available cameras were tested: GoPro Hero 4 Silver, Google Glass, and Panasonic HX-A100 action camera. Typical spine surgery was selected for video recording; posterior lumbar laminectomy and fusion. Three cameras were used by one surgeon and video was recorded throughout the operation. The comparison was made on the perspective of human factor, specification, and video quality. Results. The most convenient and lightweight device for wearing and holding throughout the long operation time was Google Glass. The image quality; all devices except Google Glass supported HD format and GoPro has unique 2.7K or 4K resolution. Quality of video resolution was best in GoPro. Field of view, GoPro can adjust point of interest, field of view according to the surgery. Narrow FOV option was the best for recording in GoPro to share the video clip. Google Glass has potentials by using application programs. Connectivity such as Wi-Fi and Bluetooth enables video streaming for audience, but only Google Glass has two-way communication feature in device. Conclusion. Action cameras have the potential to improve patient safety, operator comfort, and procedure efficiency in the field of spinal surgery and broadcasting a surgery with development of the device and applied program in the future. Level of Evidence: N/A

Matched Comparison of Fusion Rates between Hydroxyapatite Demineralized Bone Matrix and Autograft in Lumbar Interbody Fusion

Objective To compare the fusion rate of a hydroxyapatite demineralized bone matrix (DBM) with post-laminectomy acquired autograft in lumbar interbody fusion surgery and to evaluate the correlation between fusion rate and clinical outcome. Methods From January 2013 to April 2014, 98 patients underwent lumbar interbody fusion surgery with hydroxyapatite DBM (HA-DBM group) in our institute. Of those patients, 65 received complete CT scans for 12 months postoperatively in order to evaluate fusion status. For comparison with autograft, we selected another 65 patients who underwent lumbar interbody fusion surgery with post-laminectomy acquired autograft (Autograft group) during the same period. Both fusion material groups were matched in terms of age, sex, body mass index (BMI), and bone mineral density (BMD). To evaluate the clinical outcomes, we analyzed the results of visual analogue scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey (SF-36). Results We reviewed the CT scans of 149 fusion levels in 130 patients (HA-DBM group, 75 levels/65 patients; Autograft group, 74 levels/65 patients). Age, sex, BMI, and BMD were not significantly different between the groups (p=0.528, p=0.848, p=0.527, and p=0.610, respectively). The HA-DBM group showed 39 of 75 fused levels (52%), and the Autograft group showed 46 of 74 fused levels (62.2%). This difference was not statistically significant (p=0.21). In the HA-DBM group, older age and low BMD were significantly associated with non-fusion (61.24 vs. 66.68, p=0.027; -1.63 vs. -2.29, p=0.015, respectively). VAS and ODI showed significant improvement after surgery when fusion was successfully achieved in both groups (p=0.004, p=0.002, HA-DBM group; p=0.012, p=0.03, Autograft group). Conclusion The fusion rates of the hydroxyapatite DBM and Autograft groups were not significantly different. In addition, clinical outcomes were similar between the groups. However, older age and low BMD are risk factors that might induce non-union after surgery with hydroxyapatite DBM.

Paradoxical Radiographic Changes of Coflex Interspinous Device with Minimum 2-Year Follow-Up in Lumbar Spinal Stenosis

OBJECTIVES Studies have yet to investigate long-term radiologic changes in lumbar spinal stenosis patients treated with interspinous device (Coflex). This study aimed to evaluate which radiologic parameters change significantly after surgery with Coflex and identify which parameter most affects the radiologic outcome. METHODS Of 101 patients with lumbar spinal stenosis treated by Coflex insertion on L4-5, the radiologic parameters of 30 patients were measured before and at least 2 years after surgery. On the basis of the development of bony erosion around Coflex, patients were divided into the erosion group (n = 14) or the nonerosion group (n = 16). RESULTS The mean anterior disc height (ADH) and range of motion (ROM) were significantly decreased after surgery (15.161 mm vs. 13.788 mm and 9.63° vs. 7.13°). The erosion group showed substantially higher values in preoperative ADH, postoperative posterior disc height (PDH), and intervertebral foramen height (6.52 mm vs. 8.05 mm; 5.80 mm vs. 8.03 mm; 19.20 mm vs. 21.06 mm). Postoperative ROM and ROM ratio were higher in the erosion group (5.95° vs. 8.47° and 0.659 vs. 0.938). However, only ADH showed a significant change in the erosion group after surgery (15.86 mm vs. 14.29 mm). On the contrary, ADH and PDH, as well as ROM, were significantly decreased in the nonerosion group (14.55 mm vs. 13.34 mm; 6.52 mm vs. 5.82 mm; 9.46° vs. 5.95°). CONCLUSION The preoperative state including relatively higher ADH, PDH, and larger ROM could induce erosion. The long-term preservation of disc height and ROM may also induce erosion. That reduction of most radiologic parameters seems to be natural after surgery, and insufficient reduction of disc height and ROM may induce adverse effects, which can increase the possibility of spinous process fracture or device malposition.

Usefulness of 3-dimensional Measurement of Ossification of the Posterior Longitudinal Ligament (OPLL) in Patients With OPLL-induced Myelopathy

Study Design. Retrospective study. Objective. To evaluate the usefulness of 3-dimensional (3D) measurement of ossification of the posterior longitudinal ligament (OPLL), and identify the reliability of a novel 3D method of measurement. Summary of Background data. OPLL is not a 2-dimensional (2D) disease, but rather a 3D disease. Therefore, conventional measurement of parameters using radiography may not be suitable for evaluating OPLL. However, there is no study that investigated the correlation between 3D parameters of OPLL and clinical outcomes. Methods. 50 patients (40 males and 10 females; mean age 57.2 yr) with symptomatic OPLL were enrolled. Neurological and clinical outcome scales were measured using the Japanese Orthopedic Association (JOA) score, visual analogue scale, short-form health survey (SF-36) and neck disability index. A 3D model was reconstructed with digital imaging and communications in medicine files from axial computed tomographic images using software (MIMICS; Materialise, Leuven, Belgium) to obtain the following parameters: 3D volume of OPLL, 3D volume of the spinal canal (confined to the vertebral level involving OPLL), spinal canal diameter, thickness of OPLL, and length of OPLL. All patients were divided into 2 different groups, the mild myelopathy group (JOA score ≥18, n = 11) and the severe myelopathy group (JOA score ⩽17, n = 23). Results. The 3D OPLL volume did not correlate with clinical outcomes (r =−0.275, P = 0.116). 3D OPLL ratio and OPLL thickness had a significant negative relationship with JOA score (r =−0.502, P < 0.005 and r =−0.437, P < 0.05, respectively). In particular, 3D OPLL ratio was an independent risk factor for increased severity of myelopathy (B =−29.71, P < 0.05). The mild myelopathy group showed lower 3D OPLL ratio than the severe myelopathy group (0.092 vs. 0.148, P < 0.05). Conclusion. 3D method of measurement is superior to the conventional method in terms of evaluating the clinical state of symptomatic patients with OPLL. Higher 3D OPLL ratio has an adverse effect on the spinal cord. Level of Evidence: 3

Progression of Coronal Cobb Angle After Short-Segment Lumbar Interbody Fusion in Patients with Degenerative Lumbar Stenosis.

OBJECTIVE The progression of scoliosis after fusion surgery is a poor prognostic factor of long-term outcomes in patients with degenerative lumbar stenosis (DLS). In this study we aimed to investigate changes in coronal alignment and identify risk factors related to progression of scoliosis after fusion. METHODS There were 540 patients with symptomatic DLS treated by short-segment lumbar fusion surgery. Among them, 50 patients had coronal Cobb angles >10° at the final follow-up. Sixteen patients had increases >5° (progression group), and 34 patients had increases <5° (nonprogression group). Radiologic parameters that may affect the progression of scoliosis were compared. RESULTS The mean progression of the Cobb angle was 7.92° in the progression group and 1.25° in the nonprogression group. The progression group had significantly longer follow-up periods and a lower preoperative Cobb angle. The apical vertebra (AV) of the major curve was more frequently thoracic in the progression group. Progression of the Cobb angle was correlated with the follow-up period, preoperative Cobb angle, and location of the AV. Multivariate regression analysis showed that progression of the Cobb angle was significantly associated with a lower preoperative Cobb angle, and both facet degeneration of the upper instrumented vertebra at the fusion site and vertebral spur formation on the concave side also appeared to be associated with progression of the Cobb angle. CONCLUSIONS The global magnitude of progression of the Cobb angle after short-segment lumbar fusion surgery in patients with DLS is similar to the natural curve progression of adult degenerative scoliosis.