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Feng-Yu Kuo,
Wei-Chun Huang,
Kuan-Rau Chiou,
Guang-Yuan Mar, Chin-Chang Cheng,
Chen-Chi Chung,
Han-Lin Tsai,
Chen-Hung Jiang,
Shue-Ren Wann,
Shoa-Lin Lin,
Chun-Peng Liu
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ABSTRACT: BACKGROUND: Door-to-balloon (D2B) time is an important factor in the outcome of ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention. We aimed to use failure mode and effect analysis to reduce the D2B time for patients with STEMI and to improve clinical outcomes. METHODS: There were three stages in this study. In Stage 0, data collected from 2005-2006 was used to identify failures in the process, and during Stage 2 (2007) and Stage 3 (2008) the efficacy of intrahospital and interhospital strategies to reduce the D2B time were evaluated. This study enrolled 385 patients; 86 from 2005-2006; 80 in 2007; and 219 in 2008. RESULTS: By making improvements in these steps, the median D2B time was reduced from 146 min to 32 min for all patients. The proportion of patients with a D2B time of <90 min significantly increased from Stage 0 to Stage 1 and from Stage 1 to Stage 2, for all patients as well as for the non-transferred and transferred subgroups of patients (all p values <0.0001). For non-transferred patients, only reinfarction-free survival showed significant difference among the three stages (p=0.0225), and for transferred patients, only overall survival showed significant difference among the three stages (p=0.0322). Cox's proportional hazards regression analysis showed Stage 2 was associated with a lower risk of reinfarction and mortality compared with Stage 0. CONCLUSIONS: This study found that failure mode and effect analysis is a powerful method for identifying weaknesses in D2B processes and evaluating strategies to reduce the D2B time.
BMJ quality & safety 03/2013;
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ABSTRACT: BACKGROUND: Percutaneous vertebroplasty (PV) requires relatively lengthy fluoroscopic guidance, which might lead to substantial radiation exposure to patients or operators. The two-fluoroscopic technique (two-plane radiographs obtained using two fluoroscopes) during PV can provide simultaneous two-planar projections with reducing operative time. However, the two-fluoroscopic technique may expose the operator or patient to increased radiation dose. The aim of this study was to quantify the amount of radiation exposure to the patient or operator that occurs during PV using one- vs. two-fluoroscopic technique. METHODS: Two radiation dosimeters were placed on the right flank of each patient and on the upper sternum of each operator during 26 single-level PV procedures by one senior surgeon. The use of two-fluoroscopic technique (13 patients) and one-fluoroscopic technique (13 patients) were allocated in a consecutive and alternative manner. The operative time and mean radiation dose to each patient and operator were monitored and compared between groups. RESULTS: Mean radiation dose to the patient was 1.97 +/- 1.20 mSv (95% CI, 0.71 to 3.23) for the one-fluoroscopic technique group vs. 0.95 +/- 0.34 mSv (95% CI, 0.85 to 1.23) for the two-fluoroscopic technique group (P =0.031). Mean radiation dose to the operator was 0.27 +/- 0.12 mSv (95% CI, 0.17--0.56) for the one-fluoroscopic technique group vs. 0.25 +/- 0.14 mSv (95% CI, 0.06--0.44) for the two-fluoroscopic technique group (P = 0.653). The operative time was significantly different between groups: 47.15 +/- 13.48 min (range, 20--75) for the one-fluoroscopic technique group vs. 36.62 +/- 8.42 min (range, 21--50) for the two-fluoroscopic technique group (P =0.019). CONCLUSION: Compared to the one-fluoroscopic technique, the two-fluoroscopic technique used during PV provides not only shorter operative times but also reduces the radiation exposure to the patient. There was no significant difference between the two techniques with regards to radiation exposure to the operator.
BMC Musculoskeletal Disorders 01/2013; 14(1):38. · 1.58 Impact Factor
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ABSTRACT: The purpose of the study was to investigate dual-phase MDCT for assessing obstructive lesions and the extent and severity of the subtending myocardium at risk in patients presenting with chest pain syndromes 9 or more months after having undergone revascularization for the treatment of ST-segment elevation myocardial infarction (STEMI).
Dual-phase 64-MDCT was performed on 135 patients with recurring chest symptoms 9 months or more after revascularization (mean ± SD, 23 ± 11 months after index invasive angiogram for treatment of STEMI). Obstructive lesions (≥ 50% stenosis) were detected by MDCT angiography and the extent of myocardium at risk was detected by delayed phase 3D myocardium maps. A myocardium at-risk score based on MDCT findings was defined as the extent of myocardium at risk governed by the coronary lesion and weighted by lesion severity. Results were compared with stress-redistribution (201)Tl-SPECT and invasive angiography.
In restenotic, new, progressive, and previously obstructive lesions that are not currently progressive, analysis of assessable segments (1966/2025, 97.1%) obtained true-positive detection rates of 88.1%, 88.6%, 82.9%, and 100%, respectively; false-negative detection rates were 5.3%, 1.6%, 2.9%, and 8.8%. In 124 patients (91.9%) in whom all segments were assessable, the MDCT-based myocardium at-risk score correlated with the SPECT-based summed difference score (SDS) (r = 0.841, p < 0.001). For detecting SPECT-based SDS ≥ 1 and SDS > 3, areas under the receiver operating characteristic curve for the MDCT-based myocardium at-risk score were 0.874 (95% CI, 0.805-0.942) and 0.938 (95% CI, 0.895-0.981), with optimal cutoff values of 2.68 and 5.01, respectively.
Dual-phase MDCT is useful in detecting different patterns of obstructive lesions and the extent of myocardium at risk as an alternative for therapeutic planning in patients presenting with late symptoms after treatment for acute myocardial infarction.
American Journal of Roentgenology 03/2012; 198(3):548-62. · 2.78 Impact Factor
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ABSTRACT: Although E/e' (the ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity) is widely used to measure left ventricular filling pressure (LVFP), its accuracy is questionable in coronary artery disease patients.
Echocardiograms and LVFP were obtained from 174 patients with stable angina (Canadian Cardiovascular Society angina grade I-II) who had received interventions for angiography-confirmed coronary stenosis. Compared with single-vessel groups, the multiple-vessel group exhibited lower mitral annular velocities, higher LVFP, and stronger correlations between E/regional e' and LVFP. Additionally, stronger correlations between E/regional e' and LVFP existed in patients with systolic dysfunction or lower variation of myocardial performance index (MPI) among anterior, inferior and lateral borders of mitral annulus. Average e' was not superior to any regional e' for assessing LVFP by the E/e' method. E/e' and left atrial (LA) ejection fraction (EF) correlated linearly with LVFP, but the correlation between LA distensibility and LVFP was logarithmical. Compared with E/e', LA distensibility and LAEF were superior for identifying high LVFP.
E/e' is not completely satisfactory for assessing LVFP in patients with stable angina, especially those with single-vessel disease, preserved systolic function or high MPI variation. For identifying high LVFP, LA distensibility and LAEF are better than E/e'.
Circulation Journal 06/2011; 75(8):1942-50. · 3.77 Impact Factor
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ABSTRACT: Because left atrial (LA) volume plays a critical role in determining cardiovascular outcomes, it was hypothesized that this might be related to the distensibility of the left atrium and how this relates to left ventricular filling pressure (LVFP). Echocardiographic estimates of LVFP were compared to cardiac catheterization measurements in 521 consecutive patients with acute myocardial infarction and correlated with short- and long-term outcomes. Receiver-operating characteristic curve analysis was performed to investigate the sensitivity and specificity of echocardiographic parameters for predicting elevated LVFP (> 15 mm Hg). LA distensibility was calculated as (maximal volume - minimal volume) × 100%/minimal volume(.) and was found to be logarithmically associated with LVFP (p < 0.0001). LA distensibility was superior to mitral E/annular Em for identifying increased LVFP (area under the receiver-operating characteristic curve 0.92 vs 0.78). A total of 44 patients died during hospitalization, and 89 patients had died or experienced heart failure requiring rehospitalization at 12-month follow-up. In a multivariate Cox regression model, LA distensibility was an independent predictor of in-hospital mortality (hazard ratio 2.373 for LA distensibility ≤ 60%, p = 0.026), while LA volume was an independent prognostic factor of 1-year death or heart failure (hazard ratio 2.266 for LA volume ≥ 34 ml/m², p = 0.007). In conclusion, LA distensibility accurately identifies patients with increased LVFP after acute myocardial infarction and is an independent predictor of in-hospital mortality.
The American journal of cardiology 04/2011; 107(8):1117-24. · 3.58 Impact Factor
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ABSTRACT: Tissue Doppler imaging (TDI) data for acute inferior myocardial infarction (MI) patients who have received primary percutaneous coronary intervention (PCI) are sparse.
One hundred and sixty-five patients received primary PCI for acute inferior MI were enrolled. Right ventricular infarction (RVI) was defined as a culprit lesion proximal to the right ventricular branch of right coronary artery (RCA). Echocardiograms and TDI were obtained within 6 h after primary PCI. The prevalence of multi-vessel disease in the RCA-P culprit group (50%) was higher than that in other groups (39% of RCA-D culprit, 43% of left circumflex artery (LCX) culprit). The myocardial performance index (MPI) of the lateral tricuspid annulus provides discriminatory power for identifying RVI, whereas systolic velocity (Sm) of the lateral tricuspid annulus does not. Lateral mitral annular MPI divided by the lateral tricuspid annular MPI is a reliable index for identifying a culprit lesion (>1.06 predicts culprit over LCX; <0.96 predicts culprit over RCA-P and RVI). Kaplan-Meier survival curves revealed that late cardiovascular events were more likely in RVI patients. However, multivariate Cox proportional hazards analysis revealed that the most important factor in hard events and all cardiovascular events was multivessel disease.
TDI is useful for identifying RVI and culprit lesions in inferior MI patients received primary PCI. RVI itself isn't associated with 1-year hard events and all cardiovascular events.
Circulation Journal 10/2010; 74(10):2173-80. · 3.77 Impact Factor
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ABSTRACT: Echocardiograms and left ventricular (LV) filling pressure were obtained from 95 patients with chronic severe mitral regurgitation (MR) and 16 patients with acute severe MR. All patients underwent catheterization for preoperative examinations and LV filling pressure measurements. A total of 52 age-, gender- and co-morbidity-matched patients with negative coronary angiographic results served as the controls. Echocardiography, including assessment of left atrial (LA) distensibility, was performed simultaneously. LA distensibility correlated logarithmically with the LV filling pressure. However, the early-diastolic mitral inflow velocity divided by the early-diastolic mitral annular velocity (mitral E/E') correlated linearly with the LV filling pressure. Bivariate correlation analysis revealed that LV filling pressure correlated positively with the maximum and minimum indexed LA volume, as well as the E/E', but the LV filling pressure correlated negatively with LA distensibility, LA ejection fraction, and LV ejection fraction. However, the MR regurgitation volume was associated only with the maximum and minimum indexed LA volume. Receiver operating characteristic curve analysis indicated that LA distensibility was not inferior to E/E' for identifying a LV filling pressure >15 mm Hg. However, to identify acute severe MR, LA distensibility was superior to E/E'. In conclusion, LA distensibility, as is E/E', is a valuable diastolic parameter. In patients with severe MR, it offers adequate power to assess the LV filling pressure and to identify acute severe MR.
The American journal of cardiology 03/2010; 105(5):709-15. · 3.58 Impact Factor
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ABSTRACT: To use the ratio of early mitral inflow peak velocity (E) to mitral flow propagation velocity (FPV) measured in the early phase of myocardial infarction (early phase E/FPV) to evaluate the training effects of 8 weeks' cardiopulmonary rehabilitation in patients post-myocardial infarction.
Single-blinded, randomized control trial.
Eighty-seven patients with acute myocardial infarction who had undergone primary coronary intervention.
Participants were enrolled randomly to either the cardiac rehabilitation or the control group. The rehabilitation group followed an 8-week supervised rehabilitation programme. All patients completed exercise testing and echo- cardiography at both the beginning and at 8-week follow-up.
The value of E/FPV was significantly reduced at 8-week follow-up in the rehabilitation group (p = 0.005). After cardiac rehabilitation, the increase in peak V(O2) (p = 0.002) and cardiac clinical outcome (composition of mortality, cardiac readmission rate, and revascularization rate) (p = 0.001) were significantly greater in patients with an early phase E/FPV < 1.5 than in patients with early phase E/FPV >or= 1.5. There were no significant differences in the increase in peak V (O2) and cardiac clinical outcome in patients with early phase E/FPV >or= 1.5.
Early phase E/FPV < 1.5 predicts more beneficial effects of cardiac rehabilitation in post-acute myocardial infarction patients who have undergone primary coronary intervention.
Journal of rehabilitation medicine: official journal of the UEMS European Board of Physical and Rehabilitation Medicine 03/2010; 42(3):232-8. · 1.88 Impact Factor
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ABSTRACT: Pseudomeningoceles are a rare complication after spinal surgery, and studies on these complex formations are few.
Between October 2000 and March 2008, 11 patients who developed symptomatic pseudomeningoceles after spinal surgery were recruited. In this retrospective study, we reported our experiences in the management of these complex, symptomatic pseudomeningoceles after spinal surgery. A giant pseudomeningocele was defined as a pseudomeningocele >8 cm in length. We also evaluated the risk factors for the formation of giant pseudomeningoceles.
All patients were treated successfully with a combined treatment protocol of open revision surgery for extirpation of the pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage. Surgery-related complications were not observed. Recurrence of pseudomeningocele was not observed for any patient at a mean follow-up of 16.5 months. This result was confirmed by magnetic resonance imaging.
We conclude that a combined treatment protocol involving open revision surgery for extirpation of pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage is safe and effective to treat giant pseudomeningoceles.
BMC Musculoskeletal Disorders 03/2010; 11:53. · 1.58 Impact Factor
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ABSTRACT: Abstract
Background
Severely collapsed vertebral compression fracture (VCF) is usually considered as a contraindication for vertebroplasty because of critically decreased vertebral height (less than one-third the original height). However, osteoporotic VCF can possess dynamic mobility with intravertebral cleft (IVC), which can be demonstrated on supine lateral radiographs (SuLR) and standing lateral radiographs (StLR). The purposes of this study were to: (1) evaluate the efficacy of SuLR to detect IVCs and assess the intravertebral mobility in VCFs, and (2) evaluate the short-term results of vertebroplasty in severely collapsed VCFs with IVCs.
Methods
We enrolled 37 patients with 40 symptomatic osteoporotic VCFs for vertebroplasty; 11 had severely collapsed VCFs with concurrent IVCs detected on the SuLR, the others had not-severely collapsed VCFs. A preoperative StLR, SuLR, magnetic resonance imaging (MRI), and postoperative StLR were taken from all patients. Radiographs were digitized to calculate vertebral body morphometrics including vertebral height ratio and Cobb's kyphotic angle. The intensity of the patient's pain was assessed by the visual analogue scale (VAS) on the day before operation and 1 day, 1 month, and 4 months after operation. The patient's VAS scores and image measurement results were assessed with the paired t -test and Pearson correlation tests; Mann-Whitney U test was used for VAS subgroup comparison. Significance was defined as p < 0.05.
Results
IVCs in patients with not-severely collapsed VCFs were detected in 21 vertebrae (72.4%) by MRI, in 15 vertebrae (51.7%) by preoperative SuLR, and in 7 vertebrae (24.1%) by preoperative StLR. Using the MRI as a gold standard to detect IVCs, SuLR exhibit a sensitivity of 0.71 as compared to StLR that yield a sensitivity of 0.33. In patients with VCFs with IVCs detected on SuLR, the average of the postoperative restoration in vertebral height ratio was significantly higher than that in those without IVCs (17.1% vs. 6.4%). There was no statistical difference in the VAS score between severely collapsed VCFs with IVCs detected on SuLR and not-severely collapsed VCFs at any follow-up time point.
Conclusions
The SuLR efficiently detects an IVC in VCF, which indicates a better vertebral height correction after vertebroplasty compared to VCF without IVC. Before performing a costly MRI, SuLR can identify more IVCs than StLR in patients with severely collapsed VCFs, whom may become the candidates for vertebroplasty.
BMC Musculoskeletal Disorders. 01/2010;
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ABSTRACT: Severely collapsed vertebral compression fracture (VCF) is usually considered as a contraindication for vertebroplasty because of critically decreased vertebral height (less than one-third the original height). However, osteoporotic VCF can possess dynamic mobility with intravertebral cleft (IVC), which can be demonstrated on supine lateral radiographs (SuLR) and standing lateral radiographs (StLR). The purposes of this study were to: (1) evaluate the efficacy of SuLR to detect IVCs and assess the intravertebral mobility in VCFs, and (2) evaluate the short-term results of vertebroplasty in severely collapsed VCFs with IVCs.
We enrolled 37 patients with 40 symptomatic osteoporotic VCFs for vertebroplasty; 11 had severely collapsed VCFs with concurrent IVCs detected on the SuLR, the others had not-severely collapsed VCFs. A preoperative StLR, SuLR, magnetic resonance imaging (MRI), and postoperative StLR were taken from all patients. Radiographs were digitized to calculate vertebral body morphometrics including vertebral height ratio and Cobb's kyphotic angle. The intensity of the patient's pain was assessed by the visual analogue scale (VAS) on the day before operation and 1 day, 1 month, and 4 months after operation. The patient's VAS scores and image measurement results were assessed with the paired t-test and Pearson correlation tests; Mann-Whitney U test was used for VAS subgroup comparison. Significance was defined as p < 0.05.
IVCs in patients with not-severely collapsed VCFs were detected in 21 vertebrae (72.4%) by MRI, in 15 vertebrae (51.7%) by preoperative SuLR, and in 7 vertebrae (24.1%) by preoperative StLR. Using the MRI as a gold standard to detect IVCs, SuLR exhibit a sensitivity of 0.71 as compared to StLR that yield a sensitivity of 0.33. In patients with VCFs with IVCs detected on SuLR, the average of the postoperative restoration in vertebral height ratio was significantly higher than that in those without IVCs (17.1% vs. 6.4%). There was no statistical difference in the VAS score between severely collapsed VCFs with IVCs detected on SuLR and not-severely collapsed VCFs at any follow-up time point.
The SuLR efficiently detects an IVC in VCF, which indicates a better vertebral height correction after vertebroplasty compared to VCF without IVC. Before performing a costly MRI, SuLR can identify more IVCs than StLR in patients with severely collapsed VCFs, whom may become the candidates for vertebroplasty.
BMC Musculoskeletal Disorders 01/2010; 11:164. · 1.58 Impact Factor
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ABSTRACT: Minimally invasive total knee or hip replacement has been increasingly adopted in recent years. However, literature indicates that minimally invasive joint arthroplasty may not always reduce pain or tissue trauma. We hypothesized that the tissue damage would be reduced in minimal access surgery (MAS) than the conventional open surgery (OS) for anterior lumbar disorders through quantifying measurement of serum actin-free Gc-globulin (Af-Gc), myoglobin (MG), and total creatine kinase (CK).
This prospective study enrolled 23 patients, including 10 who underwent MAS and thirteen who underwent conventional OS. Blood samples for Af-Gc, MG, and CK were taken simultaneously before surgery and then at intervals of 12, 24, 48, 72, 120, and 168 h thereafter.
All serum level changes in Af-Gc, MG, and CK were significantly lower in the MAS than in the OS group. A significant negative correlation was noted between changes in Af-Gc and MG levels (P = 0.012), and a significant positive correlation was noted between changes in CK and MG levels (P < 0.001). However, at 12 h postop, CK level was transiently higher in MAS group than the OS group.
The changes of Af-Gc, MG, and CK levels indicate that MAS is less tissue invasive than OS. Further, Af-Gc proved to be a more sensitive marker than MG or CK in response to surgical trauma. The transiently higher CK level at 12 h postop in MAS patients may indicate that a more soft tissue manipulation is required in MAS than the OS patients for the initial surgical approach.
Journal of Surgical Research 02/2009; 164(1):105-9. · 2.25 Impact Factor
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Chin-Chang Cheng,
Wei-Chun Huang,
Kuan-Rau Chiou,
Shih-Hung Hsiao,
Shih-Kai Lin,
Ling-Ying Lu,
Jui-Cheng Tseng,
Jui-Chieh Hu,
Guang-Yuan Mar,
Chuen-Wang Chiou,
Shoa-Lin Lin,
Chun-Peng Liu
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ABSTRACT: Evaluating right ventricular dysfunction, pulmonary artery systolic pressure (PASP), and exercise tolerance is critical in patients with systemic lupus erythematosus (SLE) because of the high mortality rate in such patients with pulmonary arterial hypertension (PAH). The aim of this study was to use the flow propagation velocity (FPV) of early diastolic tricuspid inflow to evaluate exercise tolerance and PAH severity and to predict readmission in patients with SLE.
A total of 66 patients with SLE with or without PAH and 30 healthy control subjects were enrolled. Controls were age-matched to patients with SLE and without PAH. All patients completed the 6-minute walking distance (6MWD) test and underwent standard echocardiography. Tricuspid FPV was measured in the modified parasternal short-axis view using the color M-mode technique. PAH was defined as PASP > 35 mm Hg using the tricuspid regurgitant method.
Patients with SLE and PAH had significantly lower tricuspid FPVs and 6MWDs than patients in the other 2 groups (both P values < .001). Tricuspid FPV was well correlated with 6MWD (r = 0.748, P < .001). In multivariate analysis, right atrial pressure was the only independent factor affecting tricuspid FPV (R(2) = 0.394, P < .001), and 6MWD was affected only by tricuspid FPV and PASP (R(2) = 0.629, P < .001). Patients with SLE who had been readmitted had lower tricuspid FPVs than those who had not (P = .035). Furthermore, FPV > or = 35.4 cm/s predicted 6MWD > or = 350 m and a lower 1-year readmission rate with good sensitivity and specificity.
The tricuspid FPV technique provides a simple method for predicting exercise tolerance, the severity of PAH, and readmission among patients with SLE.
Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 02/2009; 22(4):411-7. · 2.98 Impact Factor
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ABSTRACT: Percutaneous vertebroplasty (PV) is generally performed under fluoroscopic guidance. Technically, single fluoroscope is considered sufficient for effectively monitoring PV. However, single fluoroscopic technique might be time-consuming in rotating the C-arm of the fluoroscope for either antero-posterior (AP) or lateral radiographic view, and causing delay in detecting cement leakage that can occur if the correct sight is not given. The aim of the current investigation was to compare the efficacy and safety of performing PV using one or two sets of fluoroscope.
This retrospective study enrolled 43 patients with painful osteoporotic vertebral fractures and they were treated with one-level PV. A single orthopaedic surgeon operated on all these patients. The patients were divided into two groups on the basis of the method of fluoroscopic control. In Group 1 (15 patients), PV was performed under the assistance of one fluoroscope. In Group 2 (28 patients), PV was performed under the control of two fluoroscopes. The mean follow-up was 19 months (range, 12 to 30).
Neither symptomatic cement leakage nor postoperative infection was found in both groups. The mean operation time in Group 2 was shorter, 37.8 vs. 31.0 minutes for Groups 1 and 2, P = 0.03. The incidence of cement leakage for Groups 1 and 2 was 26.7% (4/15) vs. 14.3% (4/28), respectively, P = 0.19.
We found that the two-fluoroscopic technique can provide simultaneous, real-time AP and lateral radiographic views to monitor entry point and cement delivery for PV and therefore reduce the operation time. The two-fluoroscopic technique did not require a complex manpower organization and has been proved to be a safe and effective technique for PV.
BMC Musculoskeletal Disorders 02/2008; 9:67. · 1.58 Impact Factor
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ABSTRACT: Cervical interbody device subsidence can result in screw breakage, plate dislodgement, and/or kyphosis. Preoperative bone density measurement may be helpful in predicting the complications associated with anterior cervical surgery. This is especially important when a motion preserving device is implanted given the detrimental effect of subsidence on the postoperative segmental motion following disc replacement. To evaluate the structural properties of the cervical endplate and examine the correlation with CT measured trabecular bone density. Eight fresh human cadaver cervical spines (C2-T1) were CT scanned and the average trabecular bone densities of the vertebral bodies (C3-C7) were measured. Each endplate surface was biomechanically tested for regional yield load and stiffness using an indentation test method. Overall average density of the cervical vertebral body trabecular bone was 270 +/- 74 mg/cm3. There was no significant difference between levels. The yield load and stiffness from the indentation test of the endplate averaged 139 +/- 99 N and 156 +/- 52 N/mm across all cervical levels, endplate surfaces, and regional locations. The posterior aspect of the endplate had significantly higher yield load and stiffness in comparison to the anterior aspect and the lateral aspect had significantly higher yield load in comparison to the midline aspect. There was a significant correlation between the average yield load and stiffness of the cervical endplate and the trabecular bone density on regression analysis. Although there are significant regional variations in the endplate structural properties, the average of the endplate yield loads and stiffnesses correlated with the trabecular bone density. Given the morbidity associated with subsidence of interbody devices, a reliable and predictive method of measuring endplate strength in the cervical spine is required. Bone density measures may be used preoperatively to assist in the prediction of the strength of the vertebral endplate. A threshold density measure has yet to be established where the probability of endplate fracture outweighs the benefit of anterior cervical procedure.
European Spine Journal 01/2008; 16(12):2104-9. · 1.97 Impact Factor
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ABSTRACT: Abstract
Background
Percutaneous vertebroplasty (PV) is generally performed under fluoroscopic guidance. Technically, single fluoroscope is considered sufficient for effectively monitoring PV. However, single fluoroscopic technique might be time-consuming in rotating the C-arm of the fluoroscope for either antero-posterior (AP) or lateral radiographic view, and causing delay in detecting cement leakage that can occur if the correct sight is not given. The aim of the current investigation was to compare the efficacy and safety of performing PV using one or two sets of fluoroscope.
Methods
This retrospective study enrolled 43 patients with painful osteoporotic vertebral fractures and they were treated with one-level PV. A single orthopaedic surgeon operated on all these patients. The patients were divided into two groups on the basis of the method of fluoroscopic control. In Group 1 (15 patients), PV was performed under the assistance of one fluoroscope. In Group 2 (28 patients), PV was performed under the control of two fluoroscopes. The mean follow-up was 19 months (range, 12 to 30).
Results
Neither symptomatic cement leakage nor postoperative infection was found in both groups. The mean operation time in Group 2 was shorter, 37.8 vs. 31.0 minutes for Groups 1 and 2, P = 0.03. The incidence of cement leakage for Groups 1 and 2 was 26.7% (4/15) vs. 14.3% (4/28), respectively, P = 0.19.
Conclusion
We found that the two-fluoroscopic technique can provide simultaneous, real-time AP and lateral radiographic views to monitor entry point and cement delivery for PV and therefore reduce the operation time. The two-fluoroscopic technique did not require a complex manpower organization and has been proved to be a safe and effective technique for PV.
BMC Musculoskeletal Disorders. 01/2008;
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ABSTRACT: Interleukin-6 (IL-6) protein has been recognized as a sensitive marker of surgical stress response. However, little is known about the clinical significance of IL-6 mRNA levels as a marker of surgical stress. This study aims to examine the role of IL-6 mRNA expression in comparing the tissue invasiveness of microendoscopic discectomy (MED) and open discectomy (OD).
Twenty-three consecutive patients were randomly selected to undergo either MED or OD. The total RNA was extracted from the peripheral whole blood of patients at pre-op and at 1, 2, 4, 8, 12 h post-op. The real-time reverse transcription polymerase chain reaction (RT-PCR) using the SYBR Green I fluorescence dye and the 2(-DeltaDeltaCt) method was adopted to measure the IL-6 gene expression.
The quantitative changes of IL-6 mRNA expression in MED and OD patients at different times post-op differed significantly, P = 0.04. Experimental results indicate that the changes in IL-6 mRNA expression in OD and MED groups varied significantly at 1 h, 12 h post-op, 10.26-fold versus 4.42-fold and 52.15-fold versus 26.78-fold increase, respectively. Although IL-6 mRNA expression demonstrated an earlier difference than protein levels at 1 h post-op, IL-6 mRNA levels were found to be significantly affected after surgical procedures. Furthermore, compared with our enzyme-linked immunosorbent assay data, no significant correlation existed between IL-6 mRNA and protein levels at any post-op time interval.
We conclude that IL-6 mRNA expression using RT-PCR to extract the total RNA from a patient's peripheral whole blood is more sensitive than protein levels but can be significantly affected by surgical procedures. The enzyme-linked immunosorbent assay data on IL-6 protein expression are more consistent and significant than IL-6 mRNA levels in comparing tissue invasiveness between MED and OD.
Journal of Surgical Research 10/2007; 142(1):53-8. · 2.25 Impact Factor
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ABSTRACT: In vitro biomechanical study.
This biomechanical study was designed to evaluate the loss of endplate integrity with incremental removal of the endplate.
The position of the anterior cervical motion preserving prosthesis is very important. Unlike interbody bone graft, where a certain amount of settling is tolerable and potentially advantageous with respect to the fusion rate, a settled total disc replacement will not function properly and may dislodge. Partial or aggressive endplate removal may be a factor resulting in subsidence of an interbody device. This study was designed to precisely examine the change of endplate strength following precise burring of the surface.
Eight human cadaver cervical spines (C3-C7) were dissected and 6 locations on the endplates from each vertebra were biomechanically tested using an indentation test protocol. Pairs of locations were randomly assigned to be burred to the depth of 0 mm (intact), 1 mm, or 2 mm before the testing using a flat 3-mm end mill. Strength of the endplate was statistically analyzed to examine the effect of the depth of the burr and any regional variations.
Significant differences (P < 0.0001) in endplate strength was noted between the intact endplate (106 +/- 86 N) and burred endplates (1 mm depth, 59 +/- 49 N; 2 mm depth, 51 +/- 46 N). No significant differences existed between the burr depths of 1 and 2 mm (P = 0.21). The posterior endplate was significantly stronger than the anterior endplate irrespective of depth of burr.
There is a significant loss of endplate integrity when 1 mm of endplate (44% loss) or 2 mm of endplate (52% loss) is removed. Although the implant interface plays an important role in the magnitude of the subsidence of a device, this study in general shows that the endplate is important in terms of maximizing the strength of a construct.
Spine 09/2007; 32(17):1852-5. · 2.08 Impact Factor
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ABSTRACT: One C-arm fluoroscope is widely considered to be sufficient for effectively monitoring minimally invasive vertebroplasty. However, rotating the C-arm fluoroscope for different radiographic views of the spine can be time-consuming, causing delay in detecting cement leakage. We retrospectively reviewed the results of minimally invasive vertebroplasty utilizing two C-arm fluoroscopes in the treatment of osteoporotic vertebral fractures. Forty-two patients (50 vertebrae) were treated with minimally invasive vertebroplasty under the guidance of two C-arm fluoroscopes. The mean operation time, patient satisfaction rate and the incidences of cement leakage or infection were used to evaluate the feasibility and efficacy of the two C-arm fluoroscopic technique in performing minimally invasive vertebroplasty. The mean follow-up duration was 17.4 months (range 6 approximately 36). The mean operation time was 37+/-14 minutes. Thirty patients (71%) were very satisfied or satisfied with the procedure. Cement leakages were identified in nine patients (nine vertebrae, 18%). Only one vertebra had a posterior leakage into spinal canal, which did not cause neurologic deficits. No wound infection was observed. This study indicates that the two C-arm fluoroscopic technique provides simultaneous antero-posterior and lateral radiographic views, and therefore may reduce the operation time. No symptomatic cement leakage or wound infection was noted in this investigation. Moreover, no additional staff is needed to rotate the C-arm for fluoroscopy. The proposed technique has been shown to be effective and useful for performing minimally invasive vertebroplasty.
Minimally Invasive Therapy & Allied Technologies 02/2007; 16(6):350-4. · 0.94 Impact Factor
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ABSTRACT: A retrospective study was conducted.
This study aims to analyze the feasibility and efficacy of using minimal access spinal surgery (MASS) for managing thoracic spine metastasis.
Literature regarding minimally invasive surgical treatment for thoracic spine metastasis is sparse. In the past decade, the role of minimally invasive or endoscopic technique in managing metastatic thoracic disease has evolved.
From February 1997 to March 2003, 46 patients with spine metastases, from T3-T12, were enrolled in this study. There were 29 patients undergoing MASS. Seventeen patients received standard thoracotomy (ST) in the early study period served as the control group. The indications for MASS include intractable back pain and/or neurologic deficits or neurologic deterioration during or after radiotherapy. Inclusion criteria for this study included tumor limited to one or two vertebral segments.
In the MASS and ST groups, no patient died as a result of an immediate intraoperative event. The mean operative blood loss was 1,110 versus 1,162 mL (P = 0.63), and the mean operative length was 179 versus 180 minutes (P = 0.54). Complication rates and 1-year, 2-year, and overall survival rates were comparable and the mean grade of neurologic recovery was 1.2 on the Frankel scale in both groups. Only 6.9% of MASS patients required a 2-day postoperative ICU stay compared with 88% of ST patients (P < 0.0001).
The MASS technique is safe and effective and has proved to be an excellent alternative in managing thoracic spine metastasis. Surgeons may use progressively smaller incisions (5-6 cm in length) for the procedure. The learning curve for performing MASS procedures was not steep.
Spine 07/2006; 31(16):1860-3. · 2.08 Impact Factor
