Influence of respiratory cycle on proximal renal artery motion: an angiographic study in patients undergoing endovascular aneurysm repair.

BACKGROUND: The purpose of our study was to evaluate the influence of respiratory cycle on proximal renal artery (RA) motion in twenty consecutive patients with abdominal aneurysm and the potential impact on endograft deployment during endovascular aneurysm repair (EVAR). METHODS: Prior to the device introduction, a preoperative angiography to define the location of the RAs was performed by a calibrated pigtail catheter. A measuring tape on the table served as the reference point for all measurements. Images of RA levels were acquired during expiration (E) and inspiration (I) cycles. In order to have homogenous comparative values for each patient during inhalation, the anaesthesiologist maintained a controlled inspiration with a uniform pressure of 30 cm of water. Motion of the RAs was defined as the changes in distance between E and I measures, adjusted to the calibrated pigtail. RESULTS: The median right proximal RA motion was 3.0 mm (IQR 2.4 mm; range: 0 to 5.6 mm). The median left proximal RA motion was 3.1 mm (IQR 2.2 mm; range: 0.54 to 5.6 mm). The current results demonstrate the proximal RAs motion during breath with a median magnitude of 3 mm, without significant differences between both RA (P = .83). CONCLUSION: Our data confirm the RAs motion during respiratory cycle. More than the predictive absolute value of the RA motion between inspiratory and expiratory phases, it is the motion itself which is important. This unrecognized condition, even if it interests only a minority of patients, could potentially have clinical disastrous consequences : potential stenosis or covering of RAs.

Carotid endarterectomy with internal carotid artery segmental resection, temporary shunt and vein patch angioplasty: early and mid-term results.

AIM: The authors report an alternative procedure to carotid endarterectomy with internal carotid artery (ICA) segmental resection and end-to-end anastomosis associated with temporary shunt and venous patch angioplasty. DESIGN: prospective cohort study. METHODS: Between May 1995 and December 2004, 192 patients underwent 200 primary CEAs for significant ICA stenosis. There were 131 men and 61 women with a mean age of 72.4+/-8.4 years. The indications for CEA were asymptomatic lesions in 51.5%, transient ischemic attack in 27.5% and stroke in 21%. RESULTS: The combined early morbidity and mortality rate was 2%. Two patients died, one due to fatal intracerebral hemorrhage and the second patient died of acute mesenteric ischemia. Neurological complications occurred in 2 patients, including 1 TIA and 1 nondisabling cerebrovascular accident. Non-neurological complications occurred in 26 patients (13.5%). Seventeen patients (8.8%) developed hypertension, 3 neck hematomas (1.5%) required surgical evacuation, 1 patient had reversible supraventricular arrhythmia (0.5%) and 1 patient had pneumonia (0.5%). Furthermore, 1 asymptomatic carotid occlusion was identified (0.5%) and 3 patients suffered permanent cranial nerve injury (1.5%). Mean follow-up was 45.7 months and there were 41 late deaths (21.8%). Survival rates at 1 and 5 years were 96.7+/-1.2% and 73.58+/-4.2%, respectively. CONCLUSIONS: CEA with ICA shortening and reanastomosis is a safe and reliable procedure without any increase in morbidity or mortality.

Vitamin D insufficiency and the blunted PTH response in established osteoporosis: the role of magnesium deficiency.

INTRODUCTION: Vitamin D insufficiency is common, however within individuals, not all manifest the biochemical effects of PTH excess. This further extends to patients with established osteoporosis. The mechanism underlying the blunted PTH response is unclear but may be related to magnesium (Mg) deficiency. The aims of this study were to compare in patients with established osteoporosis and differing degrees of vitamin D and PTH status : (1) the presence of Mg deficiency using the standard Mg loading test (2) evaluate the effects of Mg loading on the calcium-PTH endocrine axis (3) determine the effects of oral, short term Mg supplementation on the calcium-PTH endocrine axis and bone turnover. METHODS: 30 patients (10 women in 3 groups) were evaluated prospectively measuring calcium, PTH, Mg retention (Mg loading test), dietary nutrient intake (calcium, vitamin D, Mg) and bone turnover markers (serum CTX & P1CP). Multivariate analysis controlling for potential confounding baseline variable was undertaken for the measured outcomes. RESULTS: All subjects, within the low vitamin D and low PTH group following the magnesium loading test had evidence of Mg depletion [mean(SD) retention 70.3%(12.5)] and showed an increase in calcium 0.06(0.01) mmol/l [95% CI 0.03, 0.09, p=0.007], together with a rise in PTH 13.3 ng/l (4.5) [95% CI 3.2, 23.4, p=0.016] compared to baseline. Following oral supplementation bone turnover increased: CTX 0.16 (0.06) mcg/l [95%CI 0.01, 0.32 p=0.047]; P1CP 13.1 (5.7) mcg/l [95% CI 0.29, 26.6 p=0.049]. In subjects with a low vitamin D and raised PTH mean retention was 55.9%(14.8) and in the vitamin replete group 36.1%(14.4), with little change in both acute markers of calcium homeostasis and bone turnover markers following both the loading test and oral supplementation. CONCLUSIONS: This study confirms that in patients with established osteoporosis, there is also a distinct group with a low vitamin D and a blunted PTH level and that Mg deficiency (as measured by the Mg loading test) is an important contributing factor.

The relationship between vitamin D and parathyroid hormone: calcium homeostasis, bone turnover, and bone mineral density in postmenopausal women with established osteoporosis.

It is evident from several studies that not all patients with hypovitaminosis D develop secondary hyperparathyroidism. What this means for bone biochemistry and bone mineral density (BMD) remains unclear. The aim of this study was to investigate the effects of hypovitaminosis D (defined as a 25OHD < or = 30 nmol/l) and patients with a blunted PTH response (defined arbitrarily as a PTH within the standard laboratory reference range in the presence of a 25OHD < or = 30 nmol/l) in comparison to patients with hypovitaminosis D and secondary hyperparathyroidism (defined arbitrarily as a PTH above the standard laboratory reference range in the presence of a 25OHD < or = 30 nmol/l) and vitamin D-replete subjects (25OHD > 30 nmol/l). Four hundred twenty-one postmenopausal women (mean age: 71.2 years) with established vertebral osteoporosis were evaluated by assessing mean serum calcium, 25OHD, 1,25(OH)2D, bone turnover markers, and BMD. The prevalence of hypovitaminosis D was 39%. Secondary hyperparathyroidism was found in only one-third of these patients who maintained calcium homeostasis at the expense of increased bone turnover relative to the vitamin D-replete subjects (bone ALP mean difference: 43.9 IU/l [95% CI: 24.8, 59.1], osteocalcin: 1.3 ng/ml [95% CI: 1.1, 2.5], free deoxypyridinoline mean difference: 2.6 nmol/nmol creatinine [95% CI: 2.5, 4.8]) and bone loss (total hip BMD mean difference: 0.11 g/cm2 [95% CI: 0.09, 0.12]). Patients with hypovitaminosis D and a blunted PTH response were characterized by a lower serum calcium (mean difference: 0.07 mmol/l [95% CI: 0.08, 0.2]), a reduction in bone turnover (bone ALP mean difference: 42.4 IU/l [95% CI: 27.8, 61.9], osteocalcin: 1.6 ng/ml [95% CI: 0.3, 3.1], free-deoxypyridinoline mean difference: 3.0 nmol/nmol creatinine [95% CI: 1.9, 5.9]), but protection in bone density (total hip BMD mean difference: 0.10 g/cm2, [95% CI: 0.08, 0.11]) as compared to those with hypovitaminosis D and secondary hyperparathyroidism. This study identifies a distinct group of patients with hypovitaminosis D and a blunted PTH response who show a disruption in calcium homeostasis but protected against PTH-mediated bone loss. This has clinical implications with respect to disease definition and may be important in deciding the optimal replacement therapy in patients with hypovitaminosis D but a blunted PTH response.

Recovery of pregnancy mediated bone loss during lactation.

It is uncertain whether bone is routinely mobilised during pregnancy to provide calcium for the fetus and whether this is of a magnitude to cause osteoporosis. We have made sequential measurements of lumbar spine and hip bone mineral density (BMD) in 60 normal women before conception and then during the subsequent pregnancy out to one year after delivery. During pregnancy there was a significant fall in the BMD at the spine (1.53%), total hip (1.15%), and trochanter (3.90%) but not at the femoral neck. After delivery the women who breast-fed (n=34) showed a significant fall in BMD at all measurement sites (P<0.001) with the greatest change at the spine (4.7 +/- 3.1%) with 38% of women showing a change >5%. The women who bottle fed (n=10) increased or maintained BMD at all sites with the mixed feeders (n=16) showing an intermediate response. There was no consistent relationship between the change during pregnancy and lactation but 47% of the breast-feeders lost >5% at either the lumbar spine or trochanter. There was a good correlation between the change in BMD at these two sites (r=0.48, P<0.001). At 1 year after delivery all but 7 women had returned to within 5% of the preconceptual value at the spine and trochanter but the recovery at the total hip was less complete. Several women became transiently osteoporotic (T score below -2.5) at either spine or hip during reproduction of whom three started pregnancy with a normal BMD.

A comparison of the longitudinal changes in quantitative ultrasound with dual-energy X-ray absorptiometry: the four-year effects of hormone replacement therapy.

Quantitative ultrasound (QUS) has been proposed as a tool which can measure both the quantitative and qualitative aspects of bone tissue and can predict the future risk of osteoporotic fractures. However, the usefulness of QUS in long-term monitoring has yet to be defined. We studied a group of early postmenopausal women over a 4-year period. Thirty subjects were allocated to hormone replacement therapy and 30 selected as controls matched for age, years past the menopause (YPM) and bone mineral density (BMD) at the anteroposterior spine (AP spine). The mean age of the subjects was 52.4 years (SD 3.9 years), mean YPM 4.0 years (SD 3.2) and all subjects had a BMD T-score above -2.5 SD (number of standard units related to the young normal mean population). BMD was measured at baseline and annually by dual-energy X-ray absorptiometry (DXA) at the AP spine and total hip, and QUS carried out at the calcaneus, measuring broadband ultrasound attenuation (BUA), speed of sound (SOS) and Stiffness. Mean percentage changes from baseline were assessed at 2 and 4 years. The overall treatment effect (defined as the difference in percentage change between the two groups) was: AP spine BMD, 11.4%; total hip BMD, 7.4%; BUA, 6.4%; SOS, 1.1%; and Stiffness, 10.4% (p<0.01). To compare the long-term precision of the two techniques we calculated the Standardized Precision, which for QUS was approximately 2-3 times that of DXA, for a given rate of change. The ability of each site to monitor response to treatment was assessed by calculating the Treatment Response Index (Treatment Effect/Standardized Precision), which was: AP spine BMD, 10.4; total hip BMD, 3.9; BUA, 3.1; SOS, 0.3; and Stiffness, 4.2. This was then normalized for AP spine BMD (to compare the role of QUS against the current standard, AP Spine BMD), which was: total hip BMD, 0.38; BUA, 0.30; Stiffness, 0.40 (p<0.01); and SOS, 0.03 (NS). In summary, QUS parameters in the early menopause showed a similar rate of decline as AP spine BMD and total hip BMD measured by DXA. Hormone replacement therapy results in bone gain at the AP spine and total hip, and prevents loss in BUA and SOS measured by QUS at the calcaneus. QUS has a potential role in long-term monitoring, although presently the time period to follow individual subjects remains 2-3 times that for DXA, for a given rate of change. Anteroposterior spine remains the current optimal DXA monitoring site due to its greater rate of change and better long-term precision.

A comparison of continuous alendronate, cyclical alendronate and cyclical etidronate with calcitriol in the treatment of postmenopausal vertebral osteoporosis: a randomized controlled trial.

A number of drugs are now available for the treatment of established osteoporosis and have been shown to significantly increase bone mineral density (BMD). There are, however, few comparative treatment studies and, furthermore, adverse events remain a problem with some of the newer agents, particularly in the elderly, in everyday clinical practice. We report a 12 month, open labeled, randomized controlled, prospective treatment study in 140 postmenopausal women with established vertebral osteoporosis, comparing the effect of continuous alendronate, cyclical alendronate and cyclical etidronate with calcitriol in terms of gain in BMD, reduction in bone turnover markers and adverse event profile. The mean percentage increases in BMD at 12 months, at the spine and hip respectively, were: continuous alendronate 5.7%, 2.6%; cyclical alendronate 4.1%, 1.6%; cyclical etidronate 4.9%, 2.0% (p<0.0 1) and calcitriol 2.0%, 0.4% (NS). In comparison with calcitriol, the mean changes in BMD at the spine and hip respectively were greater in the other groups; continuous alendronate: 3.7% (95% CI 1.4 to 8.3), 2.2% (95% CI 0.7 to 4.0); cyclical alendronate: 2.1% (95% CI 1.2 to 6.4), 1.2% (95% CI -0.3 to 3.0); cyclical etidronate: 2.9% (95% CI 1.9 to 6.5), 1.6% (95% CI 0.9 to 3.1)). The reduction in bone turnover markers was between 26% and 32% in the alendronate and etidronate groups (p<0.01), with a trend toward greater reduction in the continuous alendronate group. Eight patients discontinued the study: 6 in the continuous alendronate group, 1 in the cyclical alendronate group and 1 in the calcitriol group. Two patients in the cyclical etidronate group were unable to tolerate the Cacit component, but continued on substituting Cacit with Calcichew. In summary, 12 months of treatment with continuous alendronate, cyclical alendronate and cyclical etidronate are effective in terms of the gain in BMD at the anteroposterior spine and total hip in a comparable treatment population. These treatments are more effective than calcitriol and were generally well tolerated. Continuous alendronate showed a trend toward a larger gain in BMD and greater suppression of bone turnover markers than the other treatment groups, but had a higher incidence of adverse events, particularly within the older subgroup. Cyclical alendronate offers a lower adverse event profile and appears to be effective in comparison with continuous treatment, and may possibly be an alternative in the elderly. However, further studies are necessary, but more importantly with fracture end-points.

Site-specific variation in the classification of osteoporosis, and the diagnostic reclassification using the lowest individual lumbar vertebra T-score compared with the L1-L4 mean, in early postmenopausal women.

In this study we report first the concordance and variation in diagnostic osteoporosis classification using multiple skeletal site measurements compared with the lumbar spine only; and secondly, at the lumbar spine, the variation and diagnostic osteoporosis reclassification using the lowest individual vertebra T-score compared with the L1-L4 mean T-score. One hundred and fifty early postmenopausal women were evaluated as part of the recruitment for a multicenter osteoporosis prevention study. Bone mineral density (BMD) was restricted such that no more than 10% of the subjects had a lumbar spine BMD below 0.8 g/cm2. Forty-seven per cent of the subjects were classified as having low bone mass (T-score < or = -1.0) at the lumbar spine, 63% at the mid-forearm, 39% at the distal forearm and 50% at the hip (p < 0.05). The greatest proportion of subjects were categorized as osteoporotic at the lumbar spine, followed by the forearm and then the hip. Correlation between sites ranged from 0.57 to 0.60 (p < 0.01). Eighty-one percent of the subjects had a significant difference between their highest and lowest individual lumbar vertebra T-score (defined as a difference outside the 90% confidence interval coefficient of variation T-score value). Using the lowest individual lumbar T-score, recategorized 33% of the subjects classified as osteopenic (based on the mean L1-L4 T-score) as osteoporotic, and 23% of those classified as normal as osteopenic (p < 0.05). Of all four vertebrae, L2 had the highest T-score in 37.7% of the subjects (mean -0.3) and L4 the lowest in 61% (mean -1.5) (mean difference 1.2 units, 95% CI 0.7 to 1.7). The classification of osteoporosis varies according to skeletal site, with pronounced differences in the early menopausal population. T-scores are useful for characterizing subjects with the highest risk of osteoporosis but BMD and fracture risk must be recognized in a continuum. Individual T-scores of the lumbar vertebrae show wide variation in the absence of degenerative spinal disease or vertebral collapse and the use of the lowest, significantly different, individual lumbar vertebra T-score reclassified over half of the subjects in this study. This poses a great therapeutic dilemma in clinical practice, particularly if these fractures are at higher risk of future collapse.

Vitamin D insufficiency increases bone turnover markers and enhances bone loss at the hip in patients with established vertebral osteoporosis.

AIM: The aim of this study was to determine whether the presence of vitamin D insufficiency increases bone turnover and enhances bone loss by examining the relationship between bone turnover markers and Bone mineral density (BMD) in vitamin D insufficient and vitamin D sufficient patients, with established vertebral osteoporosis. SUBJECTS: 119 consecutive, active, community dwelling, elderly women were assessed over a 7-month period between the months of March to October. RESULTS: There was a significant correlation between parathyroid hormone (PTH) and 25 hydroxyvitamin D (25(OH)D), r = - 0. 42 (P < 0.01). The prevalence of vitamin D insufficiency was 26.9% (defined by a 25(OH)D >/= 6.1 microg/l and

Intraoperative hemodynamic assessment of gastroepiploic artery and saphenous vein bypass grafts: a comparative study.

OBJECTIVE: Blood flow characteristics of right gastroepiploic artery and saphenous vein conduits were compared during bypass surgery. METHODS: This study is based on a consecutive series of 97 patients undergoing a bypass graft to the right coronary artery, posterior descending artery, or posterolateral branch using either a pediculated right gastroepiploic artery (n = 52) or a saphenous vein (n = 45) bypass graft. Flows and velocity profiles were measured with an 8-MHz pulsed-wave Doppler ultrasound flowmeter. Thorough flow measurements were made (1) after cessation of cardiopulmonary bypass and (2) before chest closure. RESULTS: At the end of cardiopulmonary bypass, flow in the right gastroepiploic artery (59. 0 +/- 6.7 mL/min) did not differ (P =.08) from flow in the saphenous vein (46.1 +/- 2.7 mL/min). Mean trace velocity was 11.9 +/- 0.7 cm/s in the right gastroepiploic artery and 11.6 +/- 0.8 cm/s in the saphenous vein (P =.80), but peak systolic velocity was 29.4 +/- 1.2 cm/s for the right gastroepiploic artery and 23.1 +/- 1.3 cm/s for the saphenous vein (P <.001). Likewise, before chest closure, flow was 57.1 +/- 4.7 mL/min in the right gastroepiploic artery and 46.5 +/- 4.0 mL/min in the saphenous vein (P =.10), mean velocity was 12. 9 +/- 0.7 and 11.6 +/- 0.8 cm/s, respectively (P = .22), and systolic peak velocity was 30.0 +/- 1.2 and 22.3 +/- 1.2 cm/s, respectively (P < .001). CONCLUSIONS: There were no flow differences between right gastroepiploic artery and saphenous vein grafts implanted into the same coronary bed in comparable groups of patients. Waveform shape of the right gastroepiploic artery grafts was characterized by a wider spectral dispersion resulting in a higher maximal frequency.

Access and payment for health care: the poor of Northern Vietnam.

In common with many developing countries, Vietnam has begun to introduce user fees at community and district level. This is part response to the transformation of the economy, economic recession, and the growing acceptability of alternative forms of health finance. This article examines the impact of these charges on the rural poor. Results from a 1995 survey in North Vietnam suggest that the poor generally delay treatment, make less use of government health facilities, and pay more for each episode of illness than the rich. There is evidence that the poor are forced to reduce consumption of essential goods or to borrow to meet these charges. A significant minority are deterred from using facilities. The current system of exemptions fails to provide adequate protection to the poor and a completely new system is required. The results suggest that it is the poor in poorer communes that are most affected by high user fees and it is to these areas that any assistance from government or donors should be targeted.

Early childhood survivorship in Vietnam.

The effects on early childhood mortality of birth order, age of the mother at the time of the child's birth, mother's education, as well as infant mortality risk in the province, urban/rural residence, the presence of schools and other facilities and health care services, were examined using data from the 1988 Vietnam Demographic and Health Survey and the 1990 Study of Accessibility of Contraceptives in Vietnam. A total of 4137 urban and rural children born between 1983 and 1988 to the 4172 women interviewed in the Demographic and Health Survey were included in the hazard model analysis of maternal and child characteristics. However, since the Accessibility of Contraceptives Study included only rural respondents, the hazard model analysis of community development characteristics and health services effects on early childhood mortality was based on a subsample of 3314 rural children. Rural children in birth orders five and higher had the greatest risk of early childhood death, birth order one an intermediate risk and orders 2-4 the lowest risk of early childhood death. Rural children residing in communes with fewer than 10,000 inhabitants were at significantly greater risk of early childhood death than children from larger communes. Neither age nor education of the mother nor gender of the child, had a significant impact on early childhood survivorship independent of other variables. Risk of infant mortality in the child's province was of borderline significance.

PIP: The authors examined the effects of the following factors upon early childhood mortality: birth order, mother's age at the time of the child's birth, mother's education, infant mortality risk in the province, urban/rural residence, and the presence of schools and other facilities and health care services. Data were used in a hazard model analysis of maternal and child characteristics for 4137 urban and rural children born between 1983 and 1988 whose 4172 mothers were interviewed in the 1988 Vietnam Demographic and Health Survey. Data were also used for a subsample of 3314 rural children from the 1990 Study of Accessibility of Contraceptives in Vietnam. Analysis found that rural children of birth orders five and higher had the greatest risk of early childhood death. Birth order one held an intermediate risk, while orders 2-4 held the lowest risk. Rural children residing in communes with less than 10,000 inhabitants were at significantly greater risk of early childhood death than children from larger communes. Neither mother's age nor education, nor gender of the child, had a significant impact upon early childhood survivorship independent of other variables. The risk of infant mortality in the child's province was of marginal significance.