The long-term effects of the fenestration in patients with extracardiac Fontan circulation-a multicenter Korean cohort study based on national Fontan registry

Introduction

The long-term effects of fenestration in patients with Fontan circulation remain unclear. We aim to evaluate the fenestration impact on early and late outcomes in patients with extracardiac Fontan (ECF) using a propensity score matching analysis.

Methods

We performed an extensive retrospective multicenter clinical data review of the Korean Fontan registry and included 1,233 patients with surgical ECF (779 fenestrated, 454 non-fenestrated). Demographics, baseline, and follow-up data were collected and comprehensively analyzed. Patients were divided into two groups according to the baseline presence or absence of surgical fenestration. Subsequently, patients were sub-divided according to the fenestration status at the last follow-up. Propensity-score matching was performed to account for collected data between the 2 groups using a multistep approach. The primary outcomes were survival and freedom from Fontan failure (FFF). We also looked at postoperative hemodynamics, cardiopulmonary exercise test results, oxygen saturations, and functional status.

Results

After propensity-score matching (454 matched pairs), there was no difference in survival or FFF between the 2 groups. However, ECF patients with baseline fenestration had significantly lower oxygen saturation (p = 0.001) and lower functional status (p < 0.001). Patients with fenestration had significantly longer bypass times, higher postoperative central venous pressure, higher postoperative left atrial pressure, and less prolonged pleural effusion in the early postoperative period. The propensity score matching according to the fenestration status at the last follow-up (148 matched pairs) showed that patients with a persistent fenestration had significantly lower oxygen saturation levels (p < 0.001). However there were no intergroup differences in the functional status, survival and FFF.

Conclusions

Our results showed no long-term benefits of the Fenestration in terms of survival and FFF. Patients with persistent fenestration showed oxygen desaturation but no difference in exercise intolerance was shown between the 2 groups.

The compatibility of new blood pressure reference values for Korean children and adolescents with the US reference: the Korean Working Group of Pediatric Hypertension

Background

Childhood hypertension is associated with hypertension and metabolic syndrome in adulthood. Since the definition of childhood hypertension is based on the distribution of normative blood pressure (BP), a reference range is essential to create hypertension guidelines for children. We aimed to investigate the compatibility of the new Korean BP reference with the United States (US) BP reference based on the 2017 Clinical Practice Guideline.

Methods

We compared the new Korean reference BP values for children and adolescents aged 10 to 17 years with those in the 2017 Clinical Practice Guidelines. We also analyzed the differences in the prevalence of hypertension in Korean children and adolescents when reference value was applied. Considering Korean and US BP references together, linear trend lines were sought.

Results

Systolic BP (SBP) and diastolic BP (DBP) values in 95th percentiles showed no significant differences between the two BP references. Applying the two reference values, there was no significant difference in the prevalence of elevated BP and a combination of elevated BP and hypertension. Combining the Korean and US BP values and plotting them against age, approximate lines for the 90th and 95th SBP and DBP percentiles were observed.

Conclusions

The BP values of the new Korean BP reference were similar to those of the US BP reference; they were reliable and interchangeable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40885-022-00200-x.

Association between the Use of Diuretics and Size Reduction in Pediatric Atrial Septal Defect

The effect of diuretics on ASD size reduction remains unclear. In pediatric patients with a large secundum ASD (≥10 mm), diuretic administration seemed to be associated with changes in ASD size. There seemed to be a little possibility of ASD size reduction in case of rim deficiency other than the aortic rim. The patients receiving diuretics may have a lower possibility to undergo surgical closure. The diuretics administration may be associated with the use of smaller ASD devices.

Background and Objectives

While diuretics are sometimes used in atrial septal defect (ASD) treatment, their effect on ASD size reduction remains unclear. We aimed to evaluate the efficacy of diuretics in ASD size reduction in pediatric patients.

Methods

We retrospectively reviewed the medical records of patients with secundum ASD (size ≥10 mm), between 2005 and 2019. Patients were divided into two groups based on the diuretic administration.

Results

Of the 73 enrolled patients, 40 received diuretics. The initial age at ASD diagnosis (2.8±1.7 vs. 2.5±2.0 years, p=0.526) and follow-up duration (22.3±11.4 vs. 18.7±13.2 months, p=0.224) were not significantly different between the groups. The ASD diameter at the initial diagnosis (13.7±2.0 vs. 13.5±3.4 mm, p=0.761) and the indexed ASD diameter (25.5±5.9 vs. 26.9±10.3 mm/m², p=0.493) were also not significantly different between two groups. The ASD diameter significantly increased in the non-diuretic group during follow-up (0.0±2.9 vs. +2.6±2.0 mm, p<0.001). The indexed ASD diameter significantly decreased in the diuretic group during follow-up (−5.7±6.5 vs. +0.2±3.9 mm/m², p<0.001). In the linear mixed model analysis, diuretic use was associated with ASD diameter decrease (p<0.001) and indexed ASD diameter reduction (p<0.001) over time. Device closure was more frequently performed in the diuretic (75.0%) than in the non-diuretic group (39.4%).

Conclusions

Patients receiving diuretics are less likely to undergo surgery. The diuretics administration may be associated with the use of smaller ASD devices for transcatheter treatment through ASD size reduction.

The occurrence of coronary artery lesions in Kawasaki disease based on C-reactive protein levels: a retrospective cohort study

BACKGROUND

This study aimed to assess the occurrence of coronary artery lesions (CAL) in patients with Kawasaki disease (KD) according to serum C-reactive protein (CRP) levels.

METHODS

This retrospective analysis was based on the nationwide survey of KD conducted in the Republic of Korea between 2015 and 2017. We enrolled 9131 patients and defined low (< 3 mg/dL) and high (≥3 mg/dL) CRP groups. Demographic data, clinical characteristics, z-scores, and scores based on the Japanese criteria for CAL were compared between the two groups. Logistic regression analysis was used to identify CAL risk factors.

RESULTS

The low CRP group accounted for 23% of patients. The mean age at diagnosis was higher in high CRP group compared to the low CRP group (34.4 ± 24.9 vs 31.7 ± 24.8 months, p < 0.001). Fever duration before treatment was not significantly different between the two groups (5.1 ± 1.7 days vs. 5.2 ± 2.1 days; p = 0.206). A non-response to intravenous immunoglobulin treatment was found in 1377 patients (20.1%) and 225 patients (11.7%) in the high and low CRP groups, respectively (p < 0.001). CAL were found in 12.9 and 18.3% of the high and low CRP patients, respectively (p < 0.001), based on z-scores; and in 9.9 and 12.5%, respectively (p = 0.001), based on the Japanese criteria in the acute phase. The giant coronary artery aneurysm occurrence ratio was similar between groups (p = 1.0).

CONCLUSIONS

CAL occurred in patients with both high and low CRP. Therefore, patients with KD should be carefully monitored regardless of their CRP levels.

Early development of hepatic fibrosis after Fontan procedure: A non-invasive study of a subclinical liver disease

BACKGROUND

To evaluate subclinical liver fibrosis after Fontan procedure using a comprehensive method that reflects the overall liver status rather than the focal biopsy lesion.

METHOD

This cross-sectional study included 66 patients without symptoms of liver disease who had at least 5 years of elapsed time since the Fontan procedure (time since Fontan procedure 17.5 ± 7.3 years). Serum enhanced liver fibrosis (ELF) scores and 2D shear wave elastography (SWE), which are expected to detect liver fibrosis earlier than liver enzyme tests and ultrasonography, were evaluated along with general examinations.

RESULTS

Liver cirrhosis diagnosed by ultrasonography showed a marked increase 16 years after surgery (elapsed time: 6-15 years since Fontan, 43.8%; 16-25 years, 70.8%; 26-35 years, 90.0%). The age-adjusted ELF score and liver stiffness according to SWE were elevated during the early postoperative period (6-15 years since Fontan). In adulthood (elapsed time > 16 years), the adjusted ELF score was correlated with liver stiffness (r = 0.514, p = .009) and liver enzyme levels. There was no correlation between liver fibrosis and the Fontan palliation type. AST to platelet count ratio and FIB-4, which are non-invasive fibrosis markers, presumed absence of fibrosis in approximately 90% of patients.

CONCLUSIONS

In the evaluation of early liver fibrosis after the Fontan procedure, abnormal findings of 2D SWE and ELF scores were observed before abnormal ultrasound and liver enzyme results. Therefore, these indicators may be helpful for the diagnosis of early liver fibrosis, and further longitudinal study might be needed.

Blood Pressure Reference Values for Normal Weight Korean Children and Adolescents: Data from The Korea National Health and Nutrition Examination Survey 1998-2016: The Korean Working Group of Pediatric Hypertension

Background and Objectives

Hypertension is becoming one of the most common health conditions in children and adolescents due to increasing childhood obesity. We aimed to provide the auscultatory blood pressure (BP) normative reference values for Korean non-overweight children and adolescents.

Methods

BP measurements in children and adolescents aged 10 to 18 years were performed in the Korean National Health and Nutrition Examination Survey (KNHANES) from 1998 to 2016. BP was measured using a mercury sphygmomanometer. Sex-, age- and height-specific systolic BP (SBP) and diastolic BP (DBP) percentiles were calculated in the non-overweight children (n=10,442). We used the General Additive Model for Location Scale and Shape method to calculate BP percentiles.

Results

The 50th, 90th, 95th, and 99th percentiles of SBP and DBP tables and graphs of non-overweight children and adolescents aged 10 to 18 years were presented by age and height percentiles. We found that the SBP and DBP at the 95th percentile were well correlated with height. The BP tables presented by height contained BP values from 124 cm to 190 cm for boys and from 120 cm to 178 cm for girls. Boys had higher SBP and DBP.

Conclusions

We provided the sex-, age- and height-specific auscultatory BP values using the KNHANES big data. These may be useful in diagnosis and treatment of hypertension in Korean children and adolescents.

Eisenmenger Syndrome in Adults: Treatment Pattern and Prognostic Factors in the Advanced Pulmonary Vasodilator Era

Patients with Eisenmenger syndrome (ES) have a higher mortality rate than patients with simple congenital heart disease (CHD). To determine factors associated with death in the era of advanced pulmonary vasodilator treatment, we analyzed the characteristics of adult ES patients depending on underlying CHD. Simple septal defects and patent ductus arteriosus were classified as simple CHD, and other conditions were classified as complex CHD. Sixty-seven adult ES patients (50.7% women) were reviewed retrospectively. CHD was diagnosed at a median of 10.0 years of age and ES was diagnosed at 18.6 years. Thirteen patients (19.4%) died; the median age was 38.6 years (IQR 32.2-47.8). In a multivariate analysis, patients with SpO₂ < 85% had a higher mortality rate than others [hazard ratio (HR) 9.7; 95% confidence interval (CI) 1.002-95.2, p = 0.05]. In simple CHD patients, those with a low platelet count (< 100 × 10⁹/L) or low SpO₂ (< 85%) were at a higher risk of death than those without (HR 16.32, 95% CI 1.25-2266.31, p = 0.032; and HR 38.91, 95% CI 3.44-5219.41, p = 0.001, respectively). Advanced pulmonary vasodilators were used more in survivors than in non-survivors (48.1% vs. 15.4%, p = 0.032). Low SpO₂ and platelet count were related to mortality in adult ES, especially in those with simple CHD. Therefore, careful attention should be paid to the care of adult ES patients with this tendency; active pulmonary vasodilator treatment should be considered.

Long-Term Prognosis for Patients with Kawasaki Disease Complicated by Large Coronary Aneurysm (diameter ≥6 mm)

Background and Objectives

Some patients with Kawasaki disease (KD) develop large coronary aneurysms and subsequent coronary stenosis or obstruction, leading to ischemic heart disease. This study examined the long-term outcomes of patients with KD complicated by large coronary aneurysms.

Subjects and Methods

The medical records of 71 patients (53 men and 18 women) diagnosed with large coronary aneurysms (diameter ≥6 mm) between December 1986 and December 2013 were retrospectively reviewed from our institutional database.

Results

The mean age at onset was 4.6±3.3 years, and the mean follow-up duration was 12.5±6.9 years. Maximum coronary artery internal diameter ranged from 6.1 to 25 mm. Giant coronary aneurysms occurred in 48 patients and coronary aneurysms 6-8 mm in diameter developed in 23 patients. Coronary stenosis and/or complete occlusion occurred in 30 patients (42.3%). Catheter and/or surgical interventions (mean: 1.5 interventions, range: 1-5 interventions) were performed in 20 patients (28.2%), 9 months to 18 years after KD onset, resulting in 33.7% cumulative coronary intervention rates at 20 years after onset. There were no differences in cumulative coronary intervention rates between two coronary aneurysm groups (6-8 mm vs. ≥8 mm). Myocardial infarction occurred in 7 patients with a giant aneurysm and there was one death.

Conclusions

Long-term survival of patients with KD complicated by large coronary aneurysm was good even though 28.2% of patients underwent multiple catheter or surgical interventions. Careful follow-up is also necessary in KD patients with coronary aneurysms 6-8 mm in diameter, such as those with giant aneurysms.

Appropriate Minimal Dose of Gadobutrol for 3D Time-Resolved MRA of the Supra-Aortic Arteries: Comparison with Conventional Single-Phase High-Resolution 3D Contrast-Enhanced MRA

BACKGROUND AND PURPOSE

The development of nephrogenic systemic fibrosis and neural tissue deposition is gadolinium dose-dependent. The purpose of this study was to determine the appropriate minimal dose of gadobutrol with time-resolved MRA to assess supra-aortic arterial stenosis with contrast-enhanced MRA as a reference standard.

MATERIALS AND METHODS

Four hundred sixty-two consecutive patients underwent both standard-dose contrast-enhanced MRA and low-dose time-resolved MRA and were classified into 3 groups; group A (a constant dose of 1 mL for time-resolved MRA), group B (2 mL), or group C (3 mL). All studies were independently evaluated by 2 radiologists for image quality by using a 5-point scale (from 0 = failure to 4 = excellent), grading of arterial stenosis (0 = normal, 1 = mild [<30%], 2 = moderate [30%-69%], 3 = severe to occlusion [≥70%]), and signal-to-noise ratio.

RESULTS

The image quality of time-resolved MRA was similar to that of contrast-enhanced MRA in groups B and C, but it was inferior to contrast-enhanced MRA in group A. For the grading of arterial stenosis, there was an excellent correlation between contrast-enhanced MRA and time-resolved MRA (R = 0.957 for group A, R = 0.988 for group B, R = 0.991 for group C). The SNR of time-resolved MRA tended to be lower than that of contrast-enhanced MRA in groups A and B. However, SNR was higher for time-resolved MRA compared with contrast-enhanced MRA in group C.

CONCLUSIONS

Low-dose time-resolved MRA is feasible in the evaluation of supra-aortic stenosis and could be used as an alternative to contrast-enhanced MRA for a diagnostic technique in high-risk populations.

Impaired Vascular Function of the Aorta in Adolescents with Turner Syndrome

To investigate intrinsic vascular abnormalities of the ascending aorta before adulthood in Turner syndrome patients (TS), we compared 25 adolescent TS patients (mean age 14.6 ± 3.4 years) and 16 healthy controls from a university hospital. Blood pressure and other vascular indices were evaluated using echocardiography such as aortic strain, stiffness index, distensibility, and pulse wave velocity. Aortic strain (0.1237 vs. 0.1865, respectively; P = 0.003) and aortic distensibility (0.0049 vs. 0.0081, P = 0.002) were significantly lower in the TS group than in the controls. The fractional area change on velocity vector imaging was also lower in TS patients (29.05 vs. 36.19, P = 0.002). These findings were still observed after adjustment for age, body mass index, and systolic blood pressure. The aortic stiffness index was greater in the TS patients than in the control group (6.79 vs. 3.34, P = 0.02). The pulse wave velocity and ascending aorta diameter did not significantly differ between the TS and control groups. Blood pressures were significantly higher in the TS patients than in the controls (systolic, 120.4 vs. 108.4 mmHg, P = 0.001; diastolic 71.5 vs. 61.7 mmHg, P < 0.001). Although the dimensional changes in the aorta were not clearly observed in adolescents with TS, the elastic properties of the aorta were significantly decreased in TS patients as compared to control subjects.

Complications of Cardiac Catheterization in Structural Heart Disease

Background and Objectives

Cardiac catheterization is used to diagnose structural heart disease (SHD) and perform transcatheter treatment. This study aimed to evaluate complications of cardiac catheterization and the associated risk factors in a tertiary center over 10 years.

Subjects and Methods

Total 2071 cardiac catheterizations performed at the Seoul National University Children's Hospital from January 2004 to December 2013 were included in this retrospective study.

Results

The overall complication, severe complication, and mortality rates were 16.2%, 1.15%, and 0.19%, respectively. The factors that significantly increased the risk of overall and severe complications were anticoagulant use before procedure (odds ratio [OR] 1.83, p=0.012 and OR 6.45, p<0.001, respectively), prothrombin time (OR 2.30, p<0.001 and OR 5.99, p<0.001, respectively), general anesthesia use during procedure (OR 1.84, p=0.014 and OR 5.31, p=0.015, respectively), and total procedure time (OR 1.01, p<0.001 and OR 1.02, p<0.001, respectively). Low body weight (OR 0.99, p=0.003), severe SHD (OR 1.37, p=0.012), repetitive procedures (OR 1.7, p=0.009), and total fluoroscopy time (OR 1.01, p=0.005) significantly increased the overall complication risk. High activated partial thromboplastin time (OR 1.04, p=0.001), intensive care unit admission state (OR 14.03, p<0.001), and concomitant electrophysiological study during procedure (OR 3.41, p=0.016) significantly increased severe complication risk.

Conclusion

Currently, the use of cardiac catheterization in SHD is increasing and becoming more complex; this could cause complications despite the preventive efforts. Careful patient selection for therapeutic catheterization and improved technique and management during the peri-procedural period are required to reduce complications.

Long-Term Outcomes of Pulmonary Hypertension in Preterm Infants with Bronchopulmonary Dysplasia

BACKGROUND

The long-term cardiovascular outcomes of pulmonary hypertension (PH) in preterm infants with bronchopulmonary dysplasia (BPD) are uncertain.

OBJECTIVES

The purpose of this study was to assess outcomes of PH in prematurely born children diagnosed with moderate to severe BPD.

METHODS

We retrospectively reviewed the medical records of patients born before 32 weeks of gestation and diagnosed with moderate to severe BPD from June 2004 to April 2008. Patients were recruited for a cross-sectional study from August to October 2014 and underwent echocardiography.

RESULTS

Forty-two children were enrolled. Their mean gestational age and birth weight were 26.2 ± 1.7 weeks and 753.1 ± 172.5 g, respectively. Sixteen patients (38%) were diagnosed with PH at a mean age of 3.3 ± 1.6 months, and the PH improved after a median of 12.3 months (range 0.7-46.6). Cardiovascular function was reassessed at a mean age of 7.7 ± 0.9 years, at which time 1 patient was taking a medication for recurrent PH, and 12 (28.6%) patients exhibited elevated blood pressure. Conventional 2-dimensional and Doppler echocardiography indicated normal ventricular function in all children. However, right ventricular longitudinal strains were decreased in children with previous PH.

CONCLUSIONS

Subclinical ventricular dysfunction was detectable using sensitive echocardiographic techniques in children with previous BPD-associated PH. Long-term follow-up and meticulous cardiovascular function assessment are required in this population.

Comparison of genetic diversity between wild-caught broodstock and hatchery-produced offspring populations of the vulnerable Korean kelp grouper (Epinephelus bruneus) by microsatellites

The kelp grouper Epinephelus bruneus (Perciformes: Haemulidae), is one of the most economically important fishery resources in Korea. This fish is regarded as a target for prospective aquaculture diversification; therefore, maintenance of stock quality is important. To investigate the effects of current artificial reproduction in a hatchery facility, genetic variation in wild-caught broodstock and hatchery-produced offspring of kelp grouper was analyzed using eight polymorphic nuclear microsatellite DNA loci; 77 alleles were identified. Allelic variability ranged from 2 to 22 in the broodstock and from 1 to 10 in the offspring. The average observed and expected heterozygosities were 0.620 and 0.623 in the broodstock and 0.600 and 0.513 in the offspring, respectively. The possibility of a recent genetic bottleneck was suggested in both populations of E. bruneus. The minor, but significant, genetic differentiation (FST = 0.047, P < 0.05) observed was mainly due to statistically significant reductions in the number of alleles in the offspring compared with the broodstock, suggesting that these genetic changes could be related to genetic drift. Our results demonstrate the usefulness of microsatellite markers to monitor genetic variation and raise concerns about potential harmful genetic effects of inappropriate hatchery procedures. Therefore, genetic variation between broodstock and offspring in a hatchery should be monitored in both breeding and release programs as a routine hatchery operation, and inbreeding should ideally be controlled to improve kelp grouper hatchery management. Our data provide a useful genetic basis for future planning of sustainable culture and management of E. bruneus in fisheries.

Genetic differences between the wild and hatchery-produced populations of Korean short barbeled grunter (Hapalogenys nitens) determined with microsatellite markers

Short barbeled grunter, Hapalogenys nitens, is an economically important fishery resource. In Korea, this fish is in the early stage of domestication, and it has been regarded as the candidate marine fish species for prospective aquaculture diversification. This study presents a preliminary investigation of the future viability of sustainable fry production from short barbeled grunter. We used 12 polymorphic nuclear microsatellite DNA loci to analyze the possible genetic variability between the wild and hatchery-produced populations of short barbeled grunter from Korea and identified 91 alleles. Compared to the wild population, significant genetic changes including reduced genetic diversity (average allele number: 7.42 vs 3.75; average expected heterozygosity: 0.713 vs 0.598, Wilcoxon signed-rank test; P < 0.05) and differentiation [overall fixation index (FST) = 0.088, P < 0.01] occurred in the hatchery-produced population, as indicated by the observation of allele richness, unique allele, heterozygosity, FST, and results of molecular analysis of variance. These findings indicate that genetic drift may have promoted the differentiation between these 2 populations, which may have negative effects on sustainable fry production. Therefore, genetic variations of the wild and hatchery-produced populations should be monitored and subjected to control inbreeding through a commercial breeding program. The information presented by this paper would provide a useful genetic basis for future sustainable culturing planning and management of H. nitens.

New polymorphic microsatellite markers for the Korean manila clam (Ruditapes philippinarum) and their application to wild populations

Manila clam (Ruditapes philippinarum) is a valuable and intensively exploited shellfish species in Korea. Despite its importance, information on its genetic background is scarce. For the genetic characterization of R. philippinarum, expressed sequence tag-derived microsatellite markers were developed using next-generation sequencing. A total of 5879 tandem repeats containing di- to hexanucleotide repeat motifs were obtained from 236,746 reads (mean = 413 bp). Of the 62 loci screened, 24 (38.7%) were successfully amplified, and 10 were polymorphic in 144 individuals from 2 manila clam populations (Incheon and Geoje, Korea). The number of alleles ranged from 2 to 17 in the Incheon population and from 3 to 13 in the Geoje population (overall AR = 7.21). The mean observed and expected heterozygosities were estimated to be 0.402 and 0.555, respectively. Hence, there is less genetic variability in the Geoje population than in the Incheon population, although no significant reductions of genetic diversity were found between the populations (P > 0.05). However, significant genetic differentiation was detected between the populations (FST = 0.064, P < 0.001). Significant deviations from Hardy-Weinberg equilibrium and high inbreeding coefficients (mean FIS = 0.22-0.26) were detected in both populations. The 10 novel polymorphic microsatellite loci used in this study will be useful for future genetic mapping studies and for characterizing population structures, monitoring genetic diversity for successful aquaculture management, and developing conservation strategies for manila clam populations in Korea.

Genetic characterization of hatchery populations of Korean spotted sea bass (Lateolabrax maculatus) using multiplex polymerase chain reaction assays

The spotted sea bass, Lateolabrax maculatus, is an important commercial and recreational fishery resource in Korea. Aquacultural production of this species has increased because of recent resource declines, growing consumption, and ongoing government-operated stock release programs. Therefore, the genetic characterization of hatchery populations is necessary to maintain the genetic diversity of this species and to develop more effective aquaculture practices. In this study, the genetic diversity and structure of three cultured populations in Korea were assessed using multiplex assays with 12 highly polymorphic microsatellite loci; 144 alleles were identified. The number of alleles per locus ranged from 6 to 28, with an average of 13.1. The mean observed and expected heterozygosities were 0.724 and 0.753, respectively. Low levels of inbreeding were detected according to the inbreeding coefficient (mean FIS = 0.003-0.073). All hatchery populations were significantly differentiated from each other (overall fixation index (FST) = 0.027, P < 0.01), and no population formed a separate cluster. Pairwise multilocus FST tests, estimates of genetic distance, mantel test, and principal component analyses did not show a consistent relationship between geographic and genetic distances. These results could reflect the exchange of breeds and eggs between hatcheries and/or genetic drift due to intensive breeding practices. For optimal resource management, the genetic variation of hatchery stocks should be monitored and inbreeding controlled within the spotted sea bass stocks that are being released every year. This genetic information will be useful for the management of both L. maculatus fisheries and the aquaculture industry.

Mitochondrial and microsatellite DNA analyses showed comparative genetic diversity between parent and offspring populations of Korean black rockfish in a hatchery facility

The black rockfish, Sebastes inermis (Sebastidae), is an important commercial fishery resource in Korea. As a preliminary investigation into the effect of artificial reproduction in a hatchery facility, the genetic divergence between parent and offspring populations of black rockfish was accessed using 10 polymorphic nuclear microsatellite DNA loci and a mitochondrial (mt) control gene. All loci that were screened showed marked polymorphisms. mtDNA control region sequences were also highly variable. Of approximately 350 base pairs (bp) sequenced, 52 variable sites, comprising 56 base substitutions, were found among 233 individuals. Offspring populations showed less genetic variability than the parent population in terms of numbers of microsatellite alleles and mtDNA haplotypes, as well as mtDNA haplotype diversity. Statistical analysis of the fixation index (ΦST and F(ST)) and analysis of molecular variance using both DNA markers showed significant genetic differences between the parent and offspring populations. These results suggest that random genetic drift and/or inbreeding events, as well as artificial selection and founder effects, occurred when the offspring strain was reproduced in a hatchery facility despite thousands of males and females from different hatcheries being maintained for artificial reproduction. Therefore, it is necessary to improve current hatchery programs by monitoring genetic variation in both the broodstock and progeny and controlling inbreeding within stocks in commercial breeding facilities to maintain the production of high-quality black rockfish. This information will be useful for determining suitable guidelines for establishing and maintaining cultured stocks and the aquaculture industry of S. inermis.

Genetic relationships of Pacific abalone (Haliotidae) species determined using universal rice primer-polymerase chain reaction fingerprinting

Random amplified polymorphic DNA (RAPD) with universal rice primers (URP) was used to identify species and to determine phylogenetic relationships for the 6 economically important Korean Pacific abalone species: Haliotis discus hannai, H. discus discus, H. madaka, H. gigantea, H. diversicolor supertexta, and H. diversicolor diversicolor, whose morphological differentiation is difficult. Of the 12 URPs used in this study, 7 were effective in producing reproducible RAPD markers for these 6 species. Amplifications with the 7 URP primers yielded 129 reproducible amplified fragments ranging between 100 and 6000 bp in length. The dendrogram generated by the unweighted pair-group method using arithmetic averages showed that the 6 species were divided into 4 groups at 0.44 similarity level, indicating that they were genetically distant from each other and had little internal phylogenetic resolution. One group included H. discus hannai, H. discus discus, H. madaka, and H. gigantea, which were divided into 2 groups at 0.52 similarity level: one group of H. discus hannai, H. discus discus, and H. madaka, and the other of H. gigantea. H. diversicolor supertexta and H. diversicolor diversicolor belonged to the other group. Furthermore, the reproducible pattern of amplified DNA bands by URP primers indicated the possibility of using these as molecular markers for the discrimination of the 6 Pacific abalone species. These results suggest that the URP-PCR approach will be a useful tool for obtaining accurate taxonomic identification and genetic relationship of Korean Pacific abalones, which is one of the first prerequisites in effective conservation programs.

Comparative genetic variability between broodstock and offspring populations of Korean starry flounder used for stock enhancement in a hatchery by using microsatellite DNA analyses

Korean starry flounder, Platichthys stellatus (Pleuronectidae), is one of the most economically important fishery resources in Korea. We investigated the effect of current artificial reproduction in a hatchery facility, genetic divergence between the broodstock and their offspring populations of starry flounder in a hatchery strain to be stocked into natural sea areas was accessed using 9 polymorphic nuclear microsatellite DNA loci. High levels of polymorphism were observed between the 2 populations. A total of 96 alleles were detected at the loci, with some alleles being unique in the broodstock. Allelic variability ranged from 8 to 17 in the broodstock and from 7 to 12 in the offspring population. Average observed and expected heterozygosities were estimated at 0.565 and 0.741 in the broodstock samples and 0.629 and 0.698 in the offspring population, respectively. Although no statistically significant reductions were found in heterozygosity or allelic diversity in the offspring population, a considerable loss of rare alleles was observed in the offspring population compared with that in the broodstock. Significant genetic difference was detected between the broodstock and offspring populations (FST = 0.021, P < 0.05). These results suggest that more intensive breeding practices for stock enhancement might have resulted in a further decrease of genetic diversity. Thus, genetic variations of broodstock and progeny should ideally be monitored in both breeding and release programs as a routine hatchery operation in order to improve the starry flounder hatchery management. This information might be useful for fishery management and aquaculture industry of P. stellatus.

Fibroblast growth factor control of cartilage homeostasis

Osteoarthritis (OA) and degenerative disc disease (DDD) are similar diseases involving the breakdown of cartilage tissue, and a better understanding of the underlying biochemical processes involved in cartilage degeneration may allow for the development of novel biologic therapies aimed at slowing the disease process. Three members of the fibroblast growth factor (FGF) family, FGF-2, FGF-18, and FGF-8, have been implicated as contributing factors in cartilage homeostasis. The role of FGF-2 is controversial in both articular and intervertebral disc (IVD) cartilage as it has been associated with species- and age-dependent anabolic or catabolic events. Recent evidence suggests that FGF-2 selectively activates FGF receptor 1 (FGFR1) to exert catabolic effects in human articular chondrocytes and IVD tissue via upregulation of matrix-degrading enzyme production, inhibition of extracellular matrix (ECM) accumulation and proteoglycan synthesis, and clustering of cells characteristic of arthritic states. FGF-18, on the other hand, most likely exerts anabolic effects in human articular chondrocytes by activating the FGFR3 pathway, inducing ECM formation and chondrogenic cell differentiation, and inhibiting cell proliferation. These changes result in dispersed chondrocytes or disc cells surrounded by abundant matrix. The role of FGF-8 has recently been identified as a catabolic mediator in rat and rabbit articular cartilage, but its precise biological impact on human adult articular cartilage or IVD tissue remains unknown. The available evidence reveals the promise of FGF-2/FGFR1 antagonists, FGF-18/FGFR3 agonists, and FGF-8 antagonists (i.e., anti-FGF-8 antibody) as potential therapies to prevent cartilage degeneration and/or promote cartilage regeneration and repair in the future.

Focal nodular hyperplasia: characterisation at gadoxetic acid-enhanced MRI and diffusion-weighted MRI

PURPOSE

The aim of this study was to assess the enhancement patterns of hepatic focal nodular hyperplasia (FNH) on gadoxetic acid-enhanced MRI and diffusion-weighted (DW) MRI.

METHODS

This retrospective study had institutional review board approval. Gadoxetic acid-enhanced and DW MR images were evaluated in 23 patients with 30 FNHs (26 histologically proven and 4 radiologically diagnosed). The lesion enhancement patterns of the hepatobiliary phase images were classified as heterogeneous or homogeneous signal intensity (SI), and as dominantly high/iso or low SI compared with those of adjacent liver parenchyma. Heterogeneous (any) SI lesions and homogeneous low SI lesions were categorised into the fibrosis group, whereas homogeneous high/iso SI lesions were categorised into the non-fibrosis group. Additionally, lesion SI on T2 weighted images, DW images and apparent diffusion coefficient (ADC) values were compared between the two groups.

RESULTS

The lesions showed heterogeneous high/iso SI (n=16), heterogeneous low SI (n=5), homogeneous high/iso SI (n=7) or homogeneous low SI (n=2) at the hepatobiliary phase MR images. The fibrosis group lesions were more likely to show high SI on DW images and T2 weighted images compared with those in the non-fibrosis group (p<0.05). ADC values tended to be lower in the fibrosis group than those in the non-fibrosis group without significance.

CONCLUSION

FNH showed variable enhancement patterns on hepatobiliary phase images during gadoxetic acid-enhanced MRI. SI on DW and T2 weighted images differed according to the fibrosis component contained in the lesion.

ADVANCES IN KNOWLEDGE

FNH shows a wide spectrum of imaging findings on gadoxetic acid-enhanced MRI and DW MRI.

New polymorphic microsatellite loci of threadsail filefish, Stephanolepis cirrhifer (Teleostei, Monacanthidae), from Korean waters

The threadsail filefish, Stephanolepis cirrhifer (Monacanthidae), is found mainly in the western Pacific. It is intensively caught in Korea and is a highly appreciated seafood delicacy. Consequently, the natural population of this species has drastically decreased, despite introductions from hatcheries. To provide information necessary for its conservation and management, we developed 24 polymorphic microsatellite markers using a combination of a total enriched genomic library and a small-scale 454 pyrosequencing. A total of 90,847 raw reads were obtained, and 75,128 unique sequences were generated, with an average length of 477 bp; 5350 (7.12%) sequences contained a minimum of 5 di- to tetranucleotide repeat motifs. Seventy-four sequences were used for microsatellite primer design. They all amplified successfully; 24 were polymorphic, with 8 containing trinucleotide repeats and 3 containing tetranucleotide repeats. The genetic variations based on 15 primer sets were investigated using 45 wild individuals from the coastal waters of Geomun Island. The number of alleles per locus varied from 4 to 15, with an average of 7.47. The observed and expected heterozygosities ranged from 0.333 to 0.956 and from 0.316 to 0.870, with averages of 0.692 and 0.701, respectively. No linkage disequilibrium was found between any pair of loci, indicating their independence. One locus significantly deviated from Hardy-Weinberg equilibrium after Bonferroni's correction; this may be due to the existence of a null allele. Cross-amplification was also tested for all 24 polymorphic loci in another monacanthid species, Thamnaconus modestus; 7 loci were effectively amplified. The high degree of polymorphism that was exhibited by the 15 newly developed microsatellites will be useful for assessing genetic variation and for conservation genetic studies of these 2 monacanthid species.

Sudden cardiac arrest during anesthesia in a 30-month-old boy with syndactyly: a case of genetically proven Timothy syndrome

Timothy syndrome, long QT syndrome type 8, is highly malignant with ventricular tachyarrhythmia. A 30-month-old boy had sudden cardiac arrest during anesthesia induction before plastic surgery for bilateral cutaneous syndactyly. After successful resuscitation, prolonged QT interval (QTc, 0.58-0.60 sec) and T-wave alternans were found in his electrocardiogram. Starting β-blocker to prevent further tachycardia and collapse event, then there were no more arrhythmic events. The genes KCNQ1, KCNH2, KCNE1 and 2, and SCN5A were negative for long QT syndrome. The mutation p.Gly406Arg was confirmed in CACNA1C, which maintains L-type calcium channel depolarization in the heart and other systems.

Population genetics of the Pacific abalone (Haliotis discus hannai) in Korea inferred from microsatellite marker analysis

Populations of the Pacific abalone, Haliotis discus hannai, have been severely overexploited over the past few decades in Korea. Information regarding the levels of genetic variability and structure within populations is insufficient for the development of effective strategies for conservation of genetic diversity of this species. To assess the genetic status of this species, we examined variation at six microsatellite loci in 842 individuals of Pacific abalone collected from three hatchery stocks of the main aquaculture areas and eight wild populations, which were two from the East Sea, two from the West Sea and three from the South Sea. High levels of polymorphism at these microsatellite loci were found in both the wild and hatchery populations. The genetic variation in the hatchery stocks [overall number of alleles (N(A)) = 24.00; allelic richness (A(R)) = 19.71; observed heterozygosity (H(O)) = 0.733] was similar to that of the wild (overall N(A) = 28.13; A(R) = 22.62; H(O) = 0.775) populations. Low levels of inbreeding and significant Hardy-Weinberg equilibrium deviations were detected in both the wild and hatchery populations. Significant F(ST) values were observed for the hatchery stocks and in most cases between the wild and hatchery populations (overall F(ST) = 0.017, P < 0.01); however, only a minor portion of the genetic diversity was distributed between the wild and hatchery populations. These results reflect intensive seedling and stocking practices. This preliminary study showed genetic separation between the eastern and pooled western and southern wild populations in Korea, which was based on the F(ST) value, phylogenetic tree clustering, PCA and MDS analyses, structure analysis, and AMOVA. This strong biogeographic structure of H. d. hannai in Korea may be considered to be independent management units. This study demonstrates the feasibility of microsatellite analyses for the monitoring of genetic diversity and for revealing the population structure of the wild Pacific abalone. This information will be useful for the proper management and conservation of H. d. hannai in Korea.

Population genetic structure of wild and hatchery black rockfish Sebastes inermis in Korea, assessed using cross-species microsatellite markers

The population structure of the black rockfish, Sebastes inermis (Sebastidae), was estimated using 10 microsatellite loci developed for S. schlegeli on samples of 174 individuals collected from three wild and three hatchery populations in Korea. Reduced genetic variation was detected in hatchery strains [overall number of alleles (N(A)) = 8.07; allelic richness (A(R)) = 7.37; observed heterozygosity (H(O)) = 0.641] compared with the wild samples (overall N(A) = 8.43; A(R) = 7.83; H(O) = 0.670), but the difference was not significant. Genetic differentiation among the populations was significant (overall F(ST) = 0.0237, P < 0.05). Pairwise F(ST) tests, neighbor-joining tree, and principal component analyses showed significant genetic heterogeneity among the hatchery strains and between wild and hatchery strains, but not among the wild populations, indicating high levels of gene flow along the southern coast of Korea, even though the black rockfish is a benthic, non-migratory marine species. Genetic differentiation among the hatchery strains could reflect genetic drift due to intensive breeding practices. Thus, in the interests of optimal resource management, genetic variation should be monitored and inbreeding controlled within stocks in commercial breeding programs. Information on genetic population structure based on cross-species microsatellite markers can aid in the proper management of S. inermis populations.

Pulmonary hypertension in preterm infants with bronchopulmonary dysplasia

Background and Objectives

With the increasing survival of preterm infants, pulmonary hypertension (PH) related to bronchopulmonary dysplasia (BPD) has become an important complication. The aim of this study was to investigate the characteristics and outcome of PH in preterm infants with BPD and to identify the risk factors for PH.

Subjects and Methods

We reviewed the records of 116 preterm infants with BPD cared for at a single tertiary center between 2004 and 2008.

Results

Twenty-nine (25%) infants had PH >2 months after birth. PH occurred initially at a median age of 65 days (range, 7-232 days). Severe BPD, a birth weight <800 g, long-term ventilator care and oxygen supplementation, a high ventilator setting, infection, and a patent ductus arteriosus (PDA) were related to PH based on univariate analysis (p<0.05). The infants who had longer oxygen supplementation were significantly more likely to have PH (odds ratio, 18.5; 95% confidence interval, 4.1-84.6; p<0.001). PH was improved in 76% of infants after a median of 85 days (range, 20-765 days). Four infants (14%) died. The death of 3 infants was attributed to PH.

Conclusion

BPD was frequently complicated by PH. Although PH resolved in the majority of infants, PH in preterm infants with BPD can be fatal. Regular screening for PH and adequate management are required.

A case of pulmonary thromboembolism associated with hypereosinophilia in a child

Pulmonary thromboembolism is a very rare event in children, but the mortality rate is reported to be approximately 10%. The majority of children with thromboemboli have multiple risk factors, such as a catheter-related thrombosis, an infection, and a congenital prothrombotic disorder. Hypereosinophilia is very rarely associated with pulmonary emboli in adults; however, this condition has not been reported in children. We present a 12-year-old boy who had a pulmonary thromboembolism and deep vein thrombosis associated with hypereosinophilia and thrombocytopenia. The thromboembolism was managed with anticoagulant therapy and the hypereosinophilia resolved spontaneously.

Relationship between disc injury and manual lifting: a poroelastic finite element model study

Understanding how failure originates in a lumbar motion segment subjected to loading conditions that are representative of manual lifting is important because it will pave the way for a better formulation of the exposure-injury relationship. The aim of the current investigation was to use a poroelastic finite element model of a human lumbar disc to determine its biomechanical characteristics under loading conditions that corresponded to three different, commonly occurring lifting activities and to identify the most hazardous type of loading with regard to damage to the disc. The current study showed that asymmetric lifting may increase the risk of back injury and pain. Lifting that involved lateral bending (asymmetric lifting) of the trunk was found to produce stresses at a localized area in the annulus, annuluar fibres, end plates, and facet joints that were higher than their respective tissue failure strength. Thus asymmetric lifting, if performed over a large number of cycles, might help to propagate this localized failure of the disc tissue to a larger area, owing to fatigue. The analyses also showed that largest fluid exchange between the nucleus and the end plates occurred during asymmetric lifting. If the fluid exchange is restricted owing to end plate calcification or sclerosis of the subchondral bone, high intradiscal pressure might develop, leading to higher disc bulge causing back pain.

In vivo segmental motion of the cervical spine in rheumatoid arthritis patients with atlantoaxial subluxation

OBJECTIVE

The dynamic mechanism underlying cervical spine involvement in rheumatoid arthritis (RA) remains unidentified. The purpose of the current study was to determine the in vivo cervical segmental motion in RA patients with atlantoaxial subluxation (AAS) using a patient-based three-dimensional magnetic resonance imaging (MRI) computer model.

METHODS

Healthy volunteers and RA patients with AAS (all females, n=10) underwent MRI examination of the cervical spine. Each vertebral body from the occipital bone (Oc) to the first thoracic vertebra (T1) was reconstructed from slices of T2-weighted sagittal MR images in the neutral, flexion, and extension positions. Using volume merge methods, each reconstructed vertebral body was virtually rotated and translated. Rotational segmental and translational segmental motions were obtained in three major planes.

RESULTS

Overall, the axial translational motions in the RA group were lower than those in the healthy volunteers; however the axial translational motion at only C1-C2 during flexion was at the same level as that in the healthy volunteers and was greater on the bottom side than that at other intervertebral levels. The frontal rotational motions at C1-C2 during extension were greater in the RA patients than those in the healthy volunteers (p<0.05).

CONCLUSION

The atlantoaxial joints in the RA patients with AAS showed great frontal rotational motion during extension and great axial translation on the bottom side during flexion. The current noninvasive MRI-based method could be useful in evaluating the 3-D dynamic mechanism underlying cervical involvement in RA in vivo.

Platelet-rich plasma stimulates porcine articular chondrocyte proliferation and matrix biosynthesis

OBJECTIVE

Platelet-rich plasma (PRP) is a fraction of plasma that contains high levels of multiple growth factors. The purpose of this study was to examine the effects of PRP on cell proliferation and matrix synthesis by porcine chondrocytes cultured in alginate beads, conditions that promote the retention of the chondrocytic phenotype, in order to determine the plausibility of using this plasma-derived material for engineering cartilage.

DESIGN

PRP and platelet-poor plasma (PPP) were prepared from adult porcine blood. Adult porcine chondrocytes were cultured in the presence of 10% PRP, 10% PPP or 10% fetal bovine serum (FBS) for 3 days. Cell proliferation, proteoglycan (PG) and collagen synthesis were quantified, and the structure of newly synthesized PG and collagen was characterized.

RESULTS

Treatment with 10% PRP resulted in a small but significant increase in DNA content (+11%, vs FBS; P<0.01; vs PPP; P<0.001). PG and collagen syntheses by the PRP-treated chondrocytes were markedly higher than those by chondrocytes treated by FBS or PPP (PG; PRP: +115% vs FBS; +151% vs PPP, both P<0.0001, collagen; PRP: +163% vs FBS; +163% vs PPP, both P<0.0001). Biochemical analyses revealed that treatment with PRP growth factors did not markedly affect the types of PGs and collagens produced by porcine chondrocytes, suggesting that the cells remained phenotypically stable in the presence of PRP.

CONCLUSION

PRP isolated from autologous blood may be useful as a source of anabolic growth factors for stimulating chondrocytes to engineer cartilage tissue.

Apoptosis induction by 4beta-acetoxyscirpendiol from Paecilomyces tenuipes in human leukaemia cell lines

The carpophores of Paecilomyces tenuipes are known in the Orient for their strong antitumor activity. In continuation of our study on acetoxyscirpendiol (ASD, 4beta-acetoxyscirpene-3alpha,15-diol) as a cytotoxic component from this fungus, we report particularly on the mode of action of ASD in inducing apoptosis in human MOLT-4, THP-1 and Jurkat T cell leukaemia in vitro. The antiproliferative effects of ASD seem attributable to its induction of apoptosis in the cells, as it blocked the cell cycle, induced hypodiploidity and bound annexin V and also cleaved poly-(ADP-ribose) polymerase (PARP) in these cell lines. The 50% inhibitory concentrations (IC50) of ASD on MOLT-4, THP-1 and Jurkat T cells were found to be 60, 85 and 60 ng/ml, respectively. ASD arrested the cell cycle at the G1/S transition and showed hypodiploidity due to the accumulation of sub-G0 population. Annexin V binding was increased in the presence of ASD in the MOLT-4 cell line in a time-dependent manner. ASD and three of its derivatives also induced cleavage of PARP in both MOLT-4 and Jurkat T cell lines. From these data, it is suggested that ASD exerts its cytotoxic activity by inducing apoptosis in leukaemia cell lines in vitro.

Biomechanical evaluation of diagonal fixation in pedicle screw instrumentation

STUDY DESIGN

Flexibility tests and finite element analyses were performed for the biomechanical evaluation of diagonal transfixation in pedicle screw instrumentation.

OBJECTIVE

To assess the biomechanical advantages of diagonal transfixation compared with conventional horizontal transfixation.

SUMMARY AND BACKGROUND DATA

A few pedicle screw instrumentation systems allow the use of cross-links in the diagonal direction. Such a diagonal transfixation is anticipated to improve the surgical construct stability, but its biomechanical qualities have not been completely evaluated.

METHODS

Flexibility tests were performed on 10 calf lumbar spines (L2-L5). Specimens were subjected to pure moments up to 8.2 Nm in flexion, extension, lateral bending, and extension while the resulting movements of L3 and L4 were measured by a three-dimensional motion analysis system. The tested cases included (1) intact, (2) pedicle screw fixation without transfixation after total removal of the L3-L4 disc, (3) pedicle screw fixation with diagonal transfixation, and (4) pedicle screw fixation with horizontal transfixation. Three-dimensional finite element models of the tested surgical constructs were also developed by use of three-dimensional beam elements to investigate the effect of diagonal transfixation and horizontal transfixation on the construct stability and the corresponding stress changes in the screws.

RESULTS

When compared with no transfixation, horizontal transfixation significantly improved the lateral bending and axial rotation stability by 15.7% and 13.9%, respectively, but there was no improvement of stability in flexion and extension. By contrast, diagonal transfixation significantly improved the flexion and extension stability by 12% and 10.7%, respectively, but not the lateral bending and axial rotation stability in comparison with no transfixation. Comparison between horizontal transfixation and diagonal transfixation showed that the stabilizing effect of diagonal transfixation was greater in flexion and extension (13% and 11%, P < 0.01) than that of horizontal transfixation but smaller in lateral bending (11%, P < 0.05) and axial rotation (6.6%, P > 0.1). Finite element model predictions of the motion changes were similar to the changes observed in flexibility tests. In horizontal transfixation, the load changes, compared with no transfixion, were a 0.02% increase in flexion-extension, a 27.5% increase in lateral bending, and a 58% decrease in axial rotation, and the magnitudes of the moments applied on both the right and left pedicle screws were identical. However, when diagonal transfixation was achieved by connecting the left superior screw and the right inferior screw, the loads in the left screw were increased by 11.5% in flexion-extension, 43.6% in lateral bending, and 7.9% in axial rotation, whereas the loads in the right screw were decreased by 10.9% in flexion-extension, increased by 0.06% in lateral bending, and decreased by 18.1% in axial rotation.

CONCLUSIONS

The results of this study showed that diagonal transfixation provides more rigid fixation in flexion and extension but less in lateral bending and axial rotation in comparison with horizontal transfixation. Furthermore, greater stresses in the pedicle screws were predicted in the diagonal transfixation model. These limitations of diagonal transfixation should be considered carefully for clinical application.

Dorsal root ganglia morphologic features in patients with herniation of the nucleus pulposus: assessment using magnetic resonance myelography and clinical correlation

STUDY DESIGN

Morphologic features of the dorsal root ganglia were investigated in patients with herniation of the nucleus pulposus by means of magnetic resonance myelography.

OBJECTIVES

This study was undertaken to assess morphologic changes of the dorsal root ganglia in patients with herniation of the nucleus pulposus and to determine the relations between the morphologic features of the dorsal root ganglia and clinical features.

SUMMARY OF BACKGROUND DATA

It has recently been reported that application of the nucleus pulposus to a nerve root induces edema in the rat dorsal root ganglion. Edema in the human dorsal root ganglion resulting from lumbar disc herniation has not been discussed in the literature, to the authors' knowledge.

METHODS

Eighty-three consecutive patients (average age 42.1 years; range 17 to 77 years) with monoradicular symptoms were examined. Dorsal root ganglion morphologic features, i.e., indentations and swelling, were evaluated by magnetic resonance myelography. The dorsal root ganglion swelling at each level was quantitatively expressed as a ratio of the dorsal root ganglion width on the involved side to that of the contralateral side and was termed dorsal root ganglion ratio. Eighty-three uninvolved levels were chosen as controls in a randomized manner. Factors possibly contributing to the morphologic changes in the dorsal root ganglion were investigated. Neurologic symptoms, evaluated by the Japan Orthopaedic Association scoring system, were correlated to the morphologic changes. The morphologic features were followed up for 1 year after treatment in a small group of patients.

RESULTS

Dorsal root ganglion indentations were always found in the narrowed intervertebral foramens. The incidence of indentations was significantly higher at the involved nerve roots (10.8%) than at the uninvolved nerve roots (4.0%) (P = 0.026). Patients with dorsal root ganglion indentations were significantly older (P = 0.0008). Leg pain scores in patients with indentations were significantly poor (P = 0.007). The dorsal root ganglion ratios were significantly higher at the involved levels than at the uninvolved levels (P = 0.001); the means +/- SD were 1.19 +/- 0.25 and 1.08 +/- 0.13, respectively. Patients with lateral herniated nucleus pulposus had significantly higher dorsal root ganglion ratios than those with central herniated nucleus pulposus (P = 0.0001); the mean ratios +/- SD were 1.48 +/- 0.32 and 1.10 +/- 0.12, respectively. A moderate positive correlation was found between dorsal root ganglion ratio and age (Pearson's correlation coefficient = 0.313). There was moderate negative correlation between the dorsal root ganglion ratio and leg pain, gait, motor, and total Japan Orthopaedic Association score (correlation coefficients were = -0.385, -0.350, -0.422, and -0.358, respectively). The dorsal root ganglion ratios were significantly diminished at 1-year follow-up (P = 0.001); the means +/- SD were 1.22 +/- 0.22 and 1.09 +/- 0.07, respectively. Indentations observed before treatment disappeared after treatment.

CONCLUSIONS

Swelling and impingement in the involved dorsal root ganglion were clearly visualized by magnetic resonance myelography. The swelling and indentations were well correlated with severity of leg pain. These findings have important value in understanding the pathophysiology of the nerve roots in herniated nucleus pulposus.

A multicenter, prospective, randomized trial evaluating a new hemostatic agent for spinal surgery

STUDY DESIGN

A prospective, randomized trial comparing Proceed, a gelatin-based hemostatic sealant (treatment), with Gelfoam-thrombin (control) in stopping intraoperative bleeding during spinal surgery.

OBJECTIVES

To determine the effectiveness and safety of Proceed.

SUMMARY OF BACKGROUND DATA

Proceed has been tested in animal models to determine its safety and effectiveness as a hemostatic agent. The current study was conducted under a Food and Drug Administration-approved Investigational Device Exemption to evaluate the effectiveness and safety of Proceed in humans.

METHODS

For this study, 127 patients undergoing spinal surgery were randomized into either the treatment or control group after standard surgical means to control bleeding had failed. The bleeding site was evaluated at 1, 2, 3, 6, and 10 minutes after the hemostatic agent was applied. The application was considered successful if the bleeding stopped within 10 minutes. Follow-up evaluation was performed at 12 to 36 hours, then at 6 to 8 weeks after surgery.

RESULTS

Proceed stopped bleeding in 98% of the patients (first bleeding site only) within 10 minutes, as compared with 90% of the control patients (P = 0.001). At 3 minutes, successful hemostasis had been achieved in 97% of the Proceed group, as compared with 71% of the control group (P = 0.0001). There was no difference in the adverse event profile between the two groups.

CONCLUSIONS

A significantly larger number of bleeding sites had achieved hemostasis with Proceed than with Gelfoam-thrombin at 1, 2, and 3 minutes after application. Proceed was as safe as Gelfoam-thrombin when used for hemostasis during spinal surgery procedures.

Morphologic changes in the lumbar intervertebral foramen due to flexion-extension, lateral bending, and axial rotation: an in vitro anatomic and biomechanical study

STUDY DESIGN

A biomechanical and anatomic study with human cadaveric lumbar spine.

OBJECTIVES

The purpose of this study is to examine the morphologic changes in the intervertebral foramen during flexion, extension, lateral bending, and axial rotation of the lumbar spine and to correlate these changes with the flexibility of the spinal motion segments.

SUMMARY OF BACKGROUND DATA

Previous studies showed morphologic changes in the intervertebral foramen during flexion and extension; however, those changes during lateral bending and axial rotation were not well known.

METHODS

There were 81 motion segments obtained from 39 human cadaveric lumbar spines (mean age 69 years). The motion segments were imaged with CT scanner with 1-mm thick consecutive sections. For biomechanical testing each motion segment was applied with incremental pure moments of flexion, extension, lateral bending, and axial rotation. Rotational movements of the motion segment were measured using VICON cameras. After application of the last load, the specimens were frozen under load, and then CT was performed with the same technique described above. Six parameters of the intervertebral foramen were measured, including foraminal width (maximum and minimum), foraminal height, disc bulging, thickness of ligamentum flavum, and cross-sectional area of the foramen.

RESULTS

Flexion increased the foraminal width (maximum and minimum), height, and area significantly while significantly decreasing the disc bulging and thickness of ligamentum flavum (P < 0.05). However, extension decreased the foraminal width (maximum and minimum), height, and area significantly. Lateral bending significantly decreased the foraminal width (maximum and minimum), height, and area at the bending side, whereas lateral bending significantly increased the foraminal width (minimum), height, and area at the opposite side of bending. Likewise, axial rotation decreased the foraminal width (minimum) and area at the rotation side significantly while significantly increasing the foraminal height and foraminal area at the opposite side. The percent change in the foraminal area was found significantly correlated with the amount of segmental spinal motion except for the extension motion.

CONCLUSIONS

This study showed that the intervertebral foramen of the lumbar spine changed significantly not only on flexion-extension but also on lateral bending and axial rotation. The percent change in cross-sectional foraminal area was correlated with the amount of segmental motion except for extension motions. Further studies are needed to assess the morphologic changes in the intervertebral foramen in vivo and to correlate clinically.

Effect of endplate conditions and bone mineral density on the compressive strength of the graft-endplate interface in anterior cervical spine fusion

STUDY DESIGN

Destructive compression tests and finite element analyses were conducted to investigate the biomechanical strength at the graft-endplate interface in anterior cervical fusion.

OBJECTIVES

To investigate the effect of endplate thickness, endplate holes, and bone mineral density of the vertebral body on the biomechanical strength of the endplate-graft interface in an anterior interbody fusion of the cervical spine.

SUMMARY OF BACKGROUND

Subsidence of the graft into the vertebral body is a well-known complication in anterior cervical fusion. However, there is no information in the literature regarding the compressive strength of the graft-endplate interface in relation to the endplate thickness, holes in the endplate, and bone mineral density of the vertebral body.

METHODS

Biomechanical destructive compression tests and finite element analyses were performed in this study. Cervical vertebral bodies (C3-C7) isolated from seven cadaveric cervical spines (age at death 69-86 years, mean 79 years) were used for compression tests. Bone mineral density of each vertebral body was measured using a dual energy radiograph absorptiometry unit. Endplate thickness was measured using three coronal computed tomography images of the middle portion of the vertebral body obtained using a computer-assisted imaging analysis. Then each vertebral body was cut into halves through the horizontal plane. A total of 54 specimens, consisting of one endplate and half of the vertebral body, were obtained after excluding eight vertebrae with gross pathology on plain radiograph. Specimens were assigned to one of three groups with different endplate conditions (Group I, intact; Group II, partial removal; and Group III, complete removal) so that group mean bone mineral density became similar. Each endplate was slowly compressed until failure using an 8-mm-diameter metal indenter, and the load to failure was determined as a maximum force on a recorded force-displacement curve. The effect on the strength of the graft-endplate interface of various hole patterns in the endplate was studied using a finite element technique. The simulatedhole patterns included the following: one large central hole, two lateral holes, two holes in the anterior and posterior portion of the endplate, and four holes evenly distributed from the center of the endplate. Stress distribution in the endplate was predicted in response to an axial compressive force of 110 N, and the elements with von Mises stress greater than 4.0 MPa were determined as failed.

RESULTS

The endplate thickness and bone mineral density were similar at all cervical levels, and the superior and inferior endplates had similar thickness at all cervical levels. There was no significant association between bone mineral density and endplate thickness. Load to failure was found to have a significant association with bone mineral density but not with endplate thickness. However, load to failure tends to decrease with incremental removal of the endplate, and load to failure of the specimens with an intact endplate was significantly greater than that of the specimens with no endplate. Finite element model predictions showed significant influence of the hole pattern on the fraction of the upper endplate exposed to fracture stress. A large hole was predicted to be more effective than the other patterns at distributing a compressive load across the remaining area and thus minimizing the potential fracture area.

CONCLUSION

Results of this study suggest that it is important to preserve the endplate as much as possible to prevent graft subsidence into the vertebral body, particularly in patients with poor bone quality. It is preferable to make one central hole rather than multiple smaller holes in the endplate for vascularity of the bone graft because it reduces the surface area exposed to fracture stresses.

Orientation and osteoarthritis of the lumbar facet joint

Several studies have shown an association between sagittal orientation of the facet joint and degenerative spondylolisthesis. There is currently no information available on the association between orientation of the facet joint and osteoarthritis. This study examined the association between orientation and osteoarthritis of the lumbar facet joints. One hundred eleven consecutive patients underwent plain radiography and magnetic resonance imaging. These patients were divided into two groups: No Degenerative Spondylolisthesis Group (98 patients) and Degenerative Spondylolisthesis Group (13 patients). In the No Degenerative Spondylolisthesis Group, segments with higher grades of osteoarthritis showed more sagittal orientation of the facetjoints at the L3-L4 and L4-L5 levels. The facet joint was oriented significantly more sagittally in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L4-L5 and L5-S1 levels. The severity of facet joint osteoarthritis was significantly higher in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L3-L4, L4-L5, and L5-S1 levels. A significant association was found between sagittal orientation and osteoarthritis of the lumbar facet joints, even in patients without degenerative spondylolisthesis. Facet joint osteoarthritis, rather than spondylolisthesis, is the pathoanatomic feature that is associated with sagittal orientation of the facet joints in patients with degenerative spondylolisthesis.

Foraminal stenosis of the lumbar spine: a review of 65 surgical cases

This study provides clinical and radiographic information and characteristics that may best define the presence of significant lumbar foraminal stenosis and reports on the outcome of surgical intervention. Although anatomy of the lumbar intervertebral foramen (including static and dynamic pathologic compression of the exiting nerve root) has been described, few studies have focused on the clinical and radiographic features of foraminal stenosis requiring surgical intervention. We retrospectively studied 65 patients with lumbar foraminal stenosis for presenting clinical and radiographic features and intraoperative findings. Symptoms included leg and back pain (100%), paresthesias (45%), and subjective weakness (31%). Examination revealed lumbar tenderness (71%), limited lumbar extension (57%), focal motor weakness (48%), and positive tension signs (42%). The L5 nerve root was most often involved (75%). Almost 50% of patients had already undergone spinal decompression surgery. Surgical procedures included laminectomy and foraminotomy (52 patients) and laminotomy and foraminotomy (23 patients). A concomitant arthrodesis was performed in 63 patients. There were 29 excellent, 25 good, 6 fair, and 5 poor results based on a modified outcome scale at 32.5-month follow-up. Findings suggest that foraminal stenosis is a frequent cause of persistent symptoms after surgery, is most common at the lumbosacral junction, is best identified on parasagittal magnetic resonance images or on images reconstructed with computed tomography, and may be static or dynamic in etiology.

Comparison of biomechanical response to surgical procedures used for cervical radiculopathy: posterior keyhole foraminotomy versus anterior foraminotomy and discectomy versus anterior discectomy with fusion

The objective of this study was to compare the change in flexibility of C5-C6 caused by three procedures using a three-dimensional nonlinear finite element model: posterior foraminotomy (keyhole procedure), anterior foraminotomy with discectomy, and anterior discectomy with fusion. The keyhole procedure produced a minor increase in motion. The anterior foraminotomy and discectomy produced one to two times greater motion. Anterior discectomy with fusion produced 50% to 100% reduction in motion. The posterior keyhole foraminotomy has a much lesser effect on the stability of the cervical spine segment than does an anterior procedure, and fusion is a requisite part of the anterior decompression procedure.

A biomechanical comparison of modern anterior and posterior plate fixation of the cervical spine

STUDY DESIGN

A biomechanical study was designed to assess relative rigidity provided by anterior, posterior, or combined cervical fixation using cadaveric cervical spine models for flexion-distraction injury and burst fracture.

OBJECTIVES

To compare the construct stability provided by anterior plating with locked fixation screws, posterior plating with lateral mass screws, and combined anterior-posterior fixation in clinically simulated 3-column injury or corpectomy models.

SUMMARY OF BACKGROUND DATA

Anterior plating with locked fixation screws is the most recent design and is found to provide better stability than the conventional unlocked anterior plating. However, there are few data on the direct comparison of biomechanical stability provided by anterior plating with locked fixation screws versus posterior plating with lateral mass screws. Biomechanical advantages of using combined anterior-posterior fixation compared with that of using either anterior or posterior fixation alone also have not been well investigated yet.

METHODS

Biomechanical flexibility tests were performed using cervical spines (C2-T1) obtained from 10 fresh human cadavers. In group I (5 specimens), one-level, 3-column injury was created at C4-C5 by removing the ligamentum flavum and bilateral facet capsules, the posterior longitudinal ligament, and the posterior half of the intervertebral disc. In group II (5 specimens), complete corpectomy of C5 was performed to simulate burst injury. In each specimen, the intact spine underwent flexibility tests, and the following constructs were tested: (1) posterior lateral mass screw fixation (Axis plate) after injury; (2) polymethylmethacrylate anterior fusion block plus posterior fixation; (3) polymethylmethacrylate block plus anterior (Orion plate) and posterior plate fixation; and (4) polymethylmethacrylate block plus anterior fixation. Rotational angles of the C4-C5 (or C4-C6) segment were measured and normalized by the corresponding angles of the intact specimen to study the overall stabilizing effects.

RESULTS

Posterior plating with an interbody graft showed effective stabilization of the unstable cervical segments in all loading modes in all cases. There was no significant stability improvement by the use of combined fixation compared with the posterior fixation with interbody grafting, although combined anterior-posterior fixation tended to provide greater stability than both anterior and posterior fixation alone. Anterior fixation alone was found to fail in stabilizing the cervical spine, particularly in the flexion-distraction injury model in which no contribution of posterior ligaments is available. Anterior plating fixation provided much greater fixation in the corpectomy model than in the flexion-distraction injury model. This finding suggests that preservation of the posterior ligaments may be an important factor in anterior plating fixation.

CONCLUSIONS

This study showed that the posterior plating with interbody grafting is biomechanically superior to anterior plating with locked fixation screws for stabilizing the one-level flexion-distraction injury or burst injury. More rigid postoperative external orthoses should be considered if the anterior plating is used alone for the treatment of unstable cervical injuries. It was also found that combined anterior and posterior fixation may not improve the stability significantly as compared with posterior grafting with lateral mass screws and interbody grafting.

The relationship between disc degeneration and flexibility of the lumbar spine

BACKGROUND CONTEXT

A relationship between degenerative changes of the intervertebral disc and biomechanical functions of the lumbar spine has been suggested. However, the exact relationship between the grade of disc degeneration and the flexibility of the motion segment is not known.

PURPOSE

To investigate the relationship between degenerative grades of the intervertebral disc and three-dimensional (3-D) biomechanical characteristics of the motion segment under multidirectional loading conditions.

STUDY DESIGN/SETTING

A biomechanical and imaging study of human cadaveric spinal motion segments.

METHODS

One hundred fourteen lumbar motion segments from T12-L1 to L5-S1 taken from 47 fresh cadaver spines (average age at death, 68 years; range, 39 to 87 years) were used in this study. The severity of degeneration (grades I to V according to Thomson's system) was determined using magnetic resonance (MR) images and cryomicrotome sections. Pure unconstrained moments with dead weights were applied to the motion segments in six load steps. The directions of loading included flexion, extension, right and left axial rotation, and right and left lateral bending.

RESULTS

When the MR images were graded, 2 segments had grade I disc degeneration; 45, grade II; 20, grade III; 26, grade IV; and 21, grade V. When the cryomicrotome sections were graded, 14 segments had grade I disc degeneration; 31, grade II; 22, grade III; 26, grade IV; and 21, grade V. Segments from the upper lumbar levels (T12-L1 to L3-4) tended to have greater rotational movement in flexion, extension, and axial rotation with disc degeneration up to grade IV, whereas the motion decreased when the disc degenerated to grade V. In the lower lumbar spine at L4-5 and L5-S1, motion in axial rotation and lateral bending was increased in grade III.

CONCLUSIONS

These results suggest that kinematic properties of the lumbar spine are related to disc degeneration. Greater motion generally was found with disc degeneration, particularly in grades III and IV, in which radial tears of the annulus fibrosus are found. Disc space collapse and osteophyte formation as found in grade V resulted in stabilization of the motion segments.

The effect of disc degeneration and facet joint osteoarthritis on the segmental flexibility of the lumbar spine

STUDY DESIGN

A biomechanical and imaging study of human cadaveric spinal motion segments.

OBJECTIVE

To investigate the effect of both disc degeneration and facet joint osteoarthritis on lumbar segmental motion.

SUMMARY OF BACKGROUND DATA

Spinal degeneration includes the osteoarthritic changes of the facet joint as well as disc degeneration. Disc degeneration has been reported to be associated with spinal motion. The association of facet joint osteoarthritis with lumbar segmental motion characteristics and the combined influence of disc degeneration and facet osteoarthritis has not yet been investigated.

METHODS

A total of 110 lumbar motion segments (52 female, 58 male) from 44 human lumbar spines were studied (mean age = 69 years). Magnetic resonance images were used to assess the disc degeneration from Grade I (normal) to Grade V (advanced) and the osteoarthritic changes in the facet joints in terms of cartilage degeneration, subchondral sclerosis, and osteophytes. Disc height, endplate size, and facet joint orientation and width also were measured from the computed tomographic images. Rotational movements of the motion segment in response to the flexion, extension, lateral bending, and axial rotational moments were measured using a three-dimensional motion analysis system.

RESULTS

Female motion segments showed significantly greater motion (lateral bending: P < 0. 001, flexion: P < 0.01, extension: P < 0.05) and smaller endplate size (P < 0.001) than male ones. The segmental motion increased with increasing severity of disc degeneration up to Grade IV, but decreased in both genders when the disc degeneration advanced to Grade V. In male segments, the disc degeneration-related motion changes were significant in axial rotation (P < 0.001), lateral bending (P < 0.05), and flexion (P < 0.05), whereas female segments showed significant changes only in axial rotation (P < 0.001). With cartilage degeneration of the facet joints, the axial rotational motion increased, whereas the lateral bending and flexion motion decreased in female segments. In male segments, however, motion in all directions increased with Grade 3 cartilage degeneration and decreased with Grade 4 cartilage degeneration. Subchondral sclerosis significantly decreased the motion (female: axial rotation, P < 0. 05; extension, P < 0.05 vs.- male:flexion,P < 0.05). Severity of osteophytes had no significant association with the segmental motion.

CONCLUSION

Axial rotational motion was most affected by disc degeneration, and the effects of disc degeneration on the motion were similar between genders. Facet joint osteoarthritis also affected segmental motion, and the influence differed for male and female spines. Further studies are needed to clarify whether the degenerative process of facet joint osteoarthritis differs between genders and how facet joint osteoarthritis affects the stability of the spinal motion segment.