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Biomedical subjects

N Sacharias

Publications and source records attributed to N Sacharias.

18 recordsLinked to original sources
PubMed2004

Embolization for major lower gastrointestinal haemorrhage: five-year experience.

The management of major lower gastrointestinal haemorrhage has changed dramatically in the last 15 years. Innovations in coaxial catheter technology have allowed the interventional radiologist to reach the small peripheral mesenteric arteries and perform superselective embolization with a variety of agents. The present large series represents the 5-year experience of this technique at the Alfred Hospital, Melbourne, in a patient cohort with a high number of comorbidities. Technical success was achieved in 96% of cases. The clinical symptoms of mesenteric ischaemia developed in four patients after embolization and were managed conservatively in two. The procedure-related mortality was low when compared with the published complication rates for emergency surgery, in this clinical setting.

Adult↗
PubMed1997

Preoperative screening for common bile duct stones with infusion cholangiography: review of 1000 patients.

OBJECTIVE: The authors aimed to study the safety and accuracy of infusion cholangiography in patients undergoing laparoscopic cholecystectomy. SUMMARY BACKGROUND DATA: Intravenous cholangiography is a theoretically attractive method of screening the common bile duct for stones. However, there still remain serious reservations regarding its safety and accuracy, despite some reports in the literature to the contrary. METHODS: A personal series of 1000 patients undergoing routine preoperative infusion cholangiography was reviewed. RESULTS: The cholangiograms detected bile duct stones with a sensitivity of 93.3% and a specificity of 99.3%. There were no serious contrast reactions, and the minor contrast reaction rate was 0.7%. CONCLUSIONS: The authors conclude that infusion cholangiography is indeed safe and accurate and should play a substantial role in preoperative screening for incidental common bile duct stones.

Cholangiography↗
PubMed1993

Perimesencephalic subarachnoid haemorrhage: negative angiography and favourable prognosis.

The computed tomography (CT) scans of 110 consecutive patients who presented, over a 4.5-year period, following spontaneous subarachnoid haemorrhage (SAH), were reviewed. All 110 patients also had one or more 4-vessel digital subtraction cerebral angiograms. The CT scans were reviewed in each case without knowledge of the angiographic result. In nine patients (8%), SAH was confined to the perimesencephalic area, interpeduncular cistern and/or prepontine region at CT. All nine patients had at least two, and some as many as four, negative cerebral angiograms. Eighteen of the 110 patients (16%) ultimately had negative angiography. Hence, the patients with isolated perimesencephalic haemorrhage (PMH) accounted for 50% of the negative angiograms. There was a significant association between isolated PMH and negative angiography (chi 2 = 50.1, P < 0.005). The specificity of PMH for negative angiography was 100% (95% confidence interval (CI) = 97-100%) and the sensitivity of PMH for a negative study was 50% (95% CI = 16-84%). Six of the 110 patients had basilar artery aneurysms demonstrated angiographically as the cause of their SAH but none of these six had isolated PMH at CT. All patients with isolated PMH were alive and well at follow up and none had suffered repeat SAH or vasospasm-related ischaemic cerebral injury. Perimesencephalic haemorrhage should be distinguished from SAH in general, because of the good prognosis associated with it and the doubtful need for repeat cerebral angiography after an initial negative study.

Adolescent↗
PubMed1992

Traumatic rupture of the aorta.

In a series of 28 patients with suspected ruptured thoracic aorta, only three were shown to have sustained such an injury. To minimise the number of negative examination, the importance of optimising the initial radiological examination of the chest is discussed along with the importance of visualisation of the descending aorta. The signs that lead to the suspicion of rupture of the aorta are numerous and non specific and indicate some change in the mediastinum which could be significant in the given clinical context. This paper wishes to emphasise a negative sign, namely visibility of the descending aorta.

Aorta, Thoracic↗
PubMed1992

Arteriographic complications in the DSA era.

Prospective data were collected on complications associated with intraarterial digital subtraction angiography in 2,475 consecutive patients at a 650-bed Melbourne teaching hospital. Carotid or cerebral studies were performed in 939 patients, and the prevalence of stroke (ie, permanent neurologic deficit) was 0.3%. The overall prevalence of systemic complications was 1.8%, with no patients requiring hemodialysis because of renal failure. Comparison was made with previously reported complication rates for conventional film angiography.

Angiography, Digital Subtraction↗
PubMed1992

Thrombolytic therapy in vertebrobasilar occlusion.

Since 1983 at the Alfred Hospital 4 patients with thrombotic or embolic vertebrobasilar occlusions have been treated with intra-arterial streptokinase (SK) infusions for the effects of persisting brainstem ischaemia despite anticoagulation with heparin. In 3 cases there was immediate and dramatic neurological improvement, in all cases associated with arteriographically demonstrated reperfusion of a blocked vessel. Two of these patients suffered further thromboembolic vertebral or basilar artery occlusions (3 days and 2 years later) but recovered fully without further thrombolytic therapy. The other patient was given intra-arterial SK 12 days after an apparently completed brainstem stroke: the therapy failed to cause reperfusion of a vertebral occlusion or produce any clinical improvement. Complications from the therapy were nausea requiring the termination of the SK infusion in one case, easily controlled bleeding from a recent surgical wound, and a clinically insignificant haemorrhagic transformation of cerebellar infarction in a third. The benefits of thrombolytic therapy in vertebrobasilar ischaemia and the dose of streptokinase required are discussed.

Cerebral Angiography↗
PubMed1989

Outpatient myelography with iohexol and iopamidol; pilot study and contrast trial.

50 patients underwent myelography on an outpatient basis; the incidence and severity of side effects were compared, in a prospective study, with 180 inpatient examinations over the same period. In addition, in the initial 200 myelograms (36 outpatients and 164 inpatient) iohexol and iopamidol were compared in a double blind trial. Headache was the most common side effect in both patient groups, recorded in 50% of outpatients and 25% of inpatients. Other side effects were of comparable incidence. 84% of outpatients undergoing myelography found it "acceptable", and did not consider a night in hospital necessary after the procedure. No difference in side effects was demonstrated between the two contrast media. This pilot study suggests that outpatient myelography is practical and safe, with considerable cost saving implications.

Adolescent↗
PubMed1989

Cerebral venous malformations.

Cerebral venous malformations (CVM) are increasingly being recognised with the widespread use of CT scanning. Five cases are presented which demonstrate typical angiographic features and CT findings. These lesions when located in the cerebral hemispheres are benign and have been distinguished from the better known arteriovenous malformations on the basis of their characteristic angiographic features. CT findings have been considered nonspecific but our early post contrast CT scans demonstrate characteristic features suggesting that in many cases the diagnosis of cerebral venous malformations may be made on the CT scan alone.

Adolescent↗
PubMed1988

The risks of suboptimal mammography.

This report emphasizes the importance of obtaining high-quality mammograms in patients with breast symptoms. An initial negative report in a 40-year-old woman with no palpable breast lump unfortunately was based upon inadequate films which, had they not been reviewed and repeat mammography been arranged, would have led to the patient being reassured mistakenly that no significant breast disease was present.

Adult↗
PubMed1986

The use of regional, low dose streptokinase in recently thrombosed arterial grafts.

Between August 1983 and January 1985, 20 patients aged 33-77 years, with occluded lower limb bypass grafts, were on 23 occasions treated with streptokinase via intra-arterial infusion. Streptokinase (5000 units/h) was effective in clearing occluded grafts in 15 patients on 16 occasions. The median duration of occlusion in these patients was 5 days and the median duration of streptokinase infusions was 24 h. Completion angiography following streptokinase thrombolysis revealed five graft stenoses and 12 outflow stenoses or occlusions. In two grafts no cause for graft failure could be identified. These results permitted the surgeon to make an accurate pre-operative assessment of the definitive therapy required to ensure graft patency.

Adult↗
PubMed1984

Measurement of total and organ-specific norepinephrine kinetics in humans.

A variety of biochemical tests, most notably measurement of the plasma concentration of norepinephrine, have been used to quantify overall sympathetic nervous system activity in humans. Plasma norepinephrine values provide a fallible index of sympathetic activity in that they are dependent in part on the rate of removal of norepinephrine from plasma. Measurement of the rate of release of norepinephrine to plasma is a better guide to overall sympathetic nervous tone because it avoids this confounding influence of norepinephrine plasma clearance. The overall norepinephrine spillover measurement, however, suffers from one major limitation: the sources of the released norepinephrine are not identified. Recently developed radiotracer techniques allow the estimation of regional sympathetic nervous activity from measurements of the organ-specific norepinephrine spillover rate. We find that the lungs are the main source of norepinephrine release to plasma, with mean pulmonary norepinephrine spillover of 159 ng/min constituting 40% of total norepinephrine release. Pulmonary norepinephrine release exceeded the combined norepinephrine spillover from the heart (3%), kidneys (17%), and hepatomesenteric circulation (8%).

Humans↗
PubMed1984

Contribution of individual organs to total noradrenaline release in humans.

Plasma noradrenaline measurements are a fallible guide to sympathetic nervous tone, being dependent on noradrenaline plasma clearance. We have developed radiotracer techniques, based on measurement of the rate of spillover of noradrenaline to plasma, to simultaneously estimate total, and organ-specific, sympathetic nervous activity in humans. In 27 unmedicated subjects without renal or liver disease, or cardiac failure, regional noradrenaline spillover rates were as follows: lungs 138 +/- 36 ng/min (mean +/- SE) (33% of total noradrenaline spillover), kidneys 77 +/- 10 ng/min (22% of total), skeletal muscle 64 +/- 11 ng/min (20%), hepatomesenteric 29 +/- 9 ng/min (9%), skin 18 +/- 4 ng/min (5%), and heart 11 +/- 4 ng/min (3%). Organ-specific noradrenaline spillover measurements are well suited to the elucidation of sympathetic nervous system pathophysiology in human diseases. Since the sympathetic nervous system outflow to individual organs is not activated or suppressed uniformly in different disease states, biochemical measures of "overall sympathetic nervous activity" are insufficiently specific for this purpose.

Humans↗
PubMed1976

Diazoxide-induced stimulation of renin release in renal vein renin sampling.

1. The acute effect of diazoxide (150-300 mg, intravenously) on renal venous renin has been evaluated in forty-four patients with suspected renal hypertension. 2. In twenty-seven studies which showed no lateralization, diazoxide raised the mean peripheral renin to 175% of control (P less than 0-05) but the renal vein renin ratio showed an insignificant change (1-15 to 1-21). 3. In seventeen studies which showed lateralization the increase in peripheral renin was similar, but mean renal vein renin ratio increased from 1-90 to 3-52 (P less than 0-005), and the mean ratio of contralateral renal vein to peripheral renin showed no change (1-05 to 1-07), indicating persistence of contralateral suppression. 4. Diazoxide accentuates the distinction between lateralizing and non-lateralizing renal vein renin studies.

Adult↗
PubMed1976

Segmental renin sampling and partial nephrectomy in renal hypertension.

Selective renin sampling from renal vein tributaries identified a high-renin source in the lower pole of the left kidney in a 16-year-old boy who had gradually developed hypertension after blunt left renal trauma. Localized renin secretion from the ischemic pole was associated with suppression of renin secretion from both the contralateral kidney and the normal part of the affected kidney. Removal of ischemic tissue by partial nephrectomy produced sustained correction of hypertension. The findings indicate that segmental renin sampling can define indications for partial nephrectomy in renal hypertension.

Adolescent↗