George Larcos

Predicting Clinical Discordance of Bone Mineral Density

OBJECTIVE To identify clinical and lifestyle factors that may predict clinical discordance of bone mineral density (BMD) in otherwise healthy perimenopausal and postmenopausal women referred for bone densitometry. MATERIAL AND METHODS Data from 304 white women referred for bone densitometry were retrospectively reviewed in order to determine predictors of BMD status at the lumbar spine, femoral neck, and distal radius. In addition, a cross-validation study in a further independent sample of 50 patients was undertaken. Dual-energy x-ray absorptiometry of all three sites was performed, and T-scores were determined with use of standard criteria established by the World Health Organization. Covariables including age, postmenopausal status, years since menopause, use of alcohol and cigarettes, family history of osteoporosis, exercise, height, weight, and body mass index were analyzed by canonical discriminant functions. RESULTS Seventy-six patients (25%) had normal BMD at all three sites (group A); 55 patients (18%) had osteopenia or osteoporosis at all sites (group B); and 173 patients (57%) showed regional discordance of BMD (group C). Menopausal status, years since menopause, use of alcohol and cigarettes, exercise levels, and weight allowed distinct separation of these three groups by using the plot of one canonical discriminant function against the other. When tested, this method of assignment correctly predicted the regional BMD status in 38 of 50 women (76%) in the independent sample. CONCLUSION Thus, the combination of certain clinical and lifestyle factors may be helpful in predicting variations in the clinical classification of BMD in an ambulatory healthy perimenopausal or postmenopausal woman.

Mercaptoacetyltriglycine diuretic renography and output efficiency measurement in renal transplant patients.

Abstract Suspected urinary tract obstruction following renal transplantation presents a diagnostic dilemma. The purposes of this study were: (1) to establish a normal range of measurement of output efficiency (OE) in the renal transplant population, and (2) to assess prospectively the usefulness of OE in the setting of allograft obstruction. Twenty-two renal transplant patients with stable renal function and no evidence of hydronephrosis on serial ultrasound examination had a diuretic mercaptoacetyltriglycine scan with calculation of OE. Three renal transplant patients with confirmed graft obstruction were also studied. Standard qualitative and quantitative parameters as well as OE were calculated. The mean OE for the 22 normal renal transplant patients was 86.3%±3.7% (range: 77%–91%). OE values in the three obstructed patients were 59%, 68% and 75% respectively. It is concluded that OE should normally exceed 77% in renal graft recipients. OE is a promising means of diagnosing functional obstruction in these patients.

Bone metastases in hypernephroma. Frequency of scapular involvement

A consecutive series of 95 patients with hypernephroma was studied retrospectively after it was clinically suspected that there was a propensity for this tumor to metastasize to the scapula. Fifteen patients (15.8%) have developed scapular metastases which account for 36.6% of all bone metastases in this series, the majority of which required radiotherapy for pain relief. The scapula was a solitary site of bone metastasis in the majority of patients, and, even when associated with other bone lesions, was frequently an isolated site of pain. A comparative series of 40 consecutive patients with breast cancer metastatic to bone was retrospectively studied. Twenty‐five percent of these showed scapular metastases but these were all in association with multiple (>3) other bone metastases; none was symptomatic or required treatment. There was a suggestion that hypernephromas spread more often to the ipsilateral scapula, but the trend did not reach statistical significance. Scapular metastasis in hypernephroma is a common and clinically significant problem, sometimes giving a clue to the primary site. The cause for this predilection is not known.

Multicentre, randomised, blinded, control trial of drug-eluting balloon vs Sham in recurrent native dialysis fistula stenoses

Background: Endovascular treatment of autogenous arteriovenous haemodialysis fistula stenosis has high reintervention rates. We investigate the effect of drug-eluting balloons in the treatment of recurrent haemodialysis fistula stenosis. Methods: This is a randomised, controlled, investigator-initiated and run, prospective, blinded, multicentre trial. Patients with recurrent autogenous arteriovenous haemodialysis fistula stenosis received standard endovascular treatment plus drug-eluting balloon or standard endovascular treatment plus uncoated balloon (Sham). Primary endpoint was late lumen loss in trial area on ultrasound at 6 weeks, 3, 6 and 12 months. Secondary endpoints were freedom from reintervention to the Index Trial Area and decline in fistula flow (Qa). Interim analysis was performed at 6 months (unblinded due to timeliness). Results: Patients with 132 recurrent stenoses (48% in bare Nitinol stents) were randomised with 70 receiving drug-eluting balloon and 62 Sham. At 6 months, decline in late lumen loss was 0.23 ± 0.03 mm/month for Sham and 0.045 ± 0.03 mm/month for drug-eluting balloon arm, a significant difference (0.18 mm, p = 0.0002). At 12 months, this difference persisted at 0.12 mm (p = 0.0003). At 6 months, significant difference in late lumen loss for instent restenoses (p = 0.0004) was observed, with non-significant difference for unstented restenoses (p = 0.065). Mean time for freedom from reintervention was 10.14 months for Sham versus 42.39 months for drug-eluting balloon (p = 0.001). The same was shown for instent (p = 0.014) and unstented (p = 0.029) restenoses. Qa decline rate at 6 months was 36.89 mL/min/month (Sham) and 0.41 mL/min (drug-eluting balloon). The difference was significant (36.48 mL/min; p = 0.02) and persisted to 12 months (p = 0.44). Conclusion: Paclitaxel drug-eluting balloon significantly delays restenosis after angioplasty for recurrent autogenous arteriovenous haemodialysis fistula stenosis, persisting to 12 months. Drug-eluting balloon significantly increases freedom from reintervention at 12 months with these effects true in stented and unstented fistulas.

Assessment of Pediatric Hydronephrosis Using Output Efficiency

UNLABELLED Diagnosing obstruction in pediatric patients with hydronephrosis, and renal impairment is often difficult. Renal output efficiency (OE) is a parameter that may improve diagnostic accuracy by allowing normalization of washout according to renal function. The aims of this study were to define a normal range for OE in infants and children and to evaluate its diagnostic accuracy in cases with hydronephrosis. METHODS Seventy-four children (91 hydronephrotic kidneys; median age, 4 mo; 22 girls and 52 boys) underwent 99mTc-labeled mercaptoacetyl-triglycine scintigraphy using intravenous volume expansion (15 ml/kg normal saline), furosemide diuresis and urethral catheterization, if vesicoureteric reflux was present. Images were interpreted by consensus of two or more experienced observers using visual assessment of the images, differential function and clearance half-time after furosemide (T(1/2)), as well as OE. The final diagnosis was based on surgical findings (n = 23 kidneys) or follow-up for >12 mo (n = 68). RESULTS Final diagnosis in 22 of the 91 hydronephrotic kidneys was obstruction at the pelviureteric (n = 21) or vesicoureteric (n = 1) junction and no obstruction in the remaining 69. The overall diagnostic accuracy of OE was 89%. Using exhaustive search multivariate logistic regression analysis, only reduced OE (p < 0.001) and decreased renal uptake by visual assessment (p = 0.058) were independently predictive of obstruction (R2 = 0.726). In dilated but unobstructed kidneys, mean OE was 93% +/- 7.1%. In the normal kidneys, mean OE was 96% +/- 3.1%. CONCLUSION OE improves the diagnostic accuracy of diuretic renography in children and neonates with hydronephrosis and suspected obstruction. Output efficiency should exceed 89% in normal kidneys and 79% in unobstructed, hydronephrotic kidneys.

Establishment and First Audit of a New Perioperative Echocardiography Service

Intraoperative echocardiography has become an integral service for cardiothoracic surgery. Establishing a service requires new ultrasound technologies and a dedicated team prepared to be trained in this new discipline. The establishment of a new perioperative service at Westmead Hospital, Australia is outlined. Early experience, current practice, teaching and research programs are presented and the first audit is reported.