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Biomedical subjects

G D Shanik

Publications and source records attributed to G D Shanik.

33 records · Page 2Linked to original sources
PubMed1990

"Haemorrhagic" carotid plaque does not contain haemorrhage.

The presence of haemorrhage in carotid bifurcation atheromatous plaques is widely believed to be associated with the production of ischaemic neurological events. This study set out to characterise plaque composition in symptomatic (SYM) and asymptomatic (ASYM) patients and to identify, if possible, the origin of intra-plaque haemorrhage. Fifty-nine plaques (50 SYM and 9 ASYM) were serially sectioned and examined for haemorrhage, haemosiderin, fibrin, cholesterol and collagen. Immunoperoxidase and electron microscopy studies were carried out on sections from five plaques in order to identify blood breakdown products. Intra-plaque haemorrhage was identified in 40 (68%) plaques and was similar in SYM and ASYM plaques. In only one did it constitute more than 15% of plaque content, and in the remainder it consisted of small collections of erythrocytes constituting greater than 1% of plaque content in only 21 (35%) plaques. The predominant non-fibrous component was a pink amorphous material mixed with cholesterol. Apart from traces of platelet breakdown products there was no evidence of haemorrhage in this pink material. Plaque roof rupture or ulceration was seen in 39 (66%) and in almost all cases overlay the amorphous/cholesterol material. Blood vessels were identified in 51 87%) plaques but were in close proximity to haemorrhage in only nine (15%).

Arteriosclerosis↗
PubMed1990

Microcomputer database and system of audit for the vascular surgeon.

We have set up a vascular database based upon an IBM personal computer in the vascular unit at Repatriation General Hospital, Concord, using 'Dataease'. This is commercially available software that allows the development of a database by users with little or no programming knowledge. The database is menu driven and designed to record details of admissions, indications for surgery, operations, complications and follow-up and has been set up as a prospective project from 1 January 1989 after a pilot study in 1988. Currently, interns, residents and registrars enter data directly onto the computer, providing an excellent teaching and review medium. Unit audit is easy as the program is completely menu driven and there are more than 100 customized reports written, ranging from providing simple complication details to complex reports deriving graft cumulative patency rates. This system also provides for 'instant' discharge letters which have markedly improved communication with the general practitioner.

Hospital Information Systems↗
PubMed1990

Home parenteral nutrition using a totally implanted subcutaneous venous access device.

Despite advances in the design and care of in-dwelling catheters, sepsis remains a significant problem in patients on long-term parenteral nutrition. In recent years there have been a number of reports concerning the successful use of totally implanted subcutaneous venous access devices in the management of patients requiring long-term intermittent intravenous administration of cytotoxic therapy and frequent blood sampling. The use of such a system for the administration of supplementary home parenteral nutrition in a patient with short-bowel syndrome is reported.

Catheters, Indwelling↗
PubMed1989

Diagnosis, complications and treatment of Takayasu's arteritis.

Takayasu's arteritis is a large vessel vasculitis involving the aorta and it's major branches. Clinical diagnosis in the early stage is important as the disease may then be treatable. We present the first two cases ever reported in the Irish literature.

Adrenal Cortex Hormones↗
PubMed1988

Assessment of arterial disease using digital systolic pressure measurement.

Digital systolic pressure measurements were made on 140 big toes using a photoplethysmographic technique before and after extrinsic heating of the foot. Most patients with apparent, critically ischemic feet demonstrated vasomotor activity, suggesting that much of the microcirculation of the foot was in fact intact. Significantly, nine of 21 feet which would have fallen into a critically ischemic category were recategorized after heating into a less severe group. These data confirm the value of toe pressure measurements in the assessment of severe ischemia but show that adequate foot vasodilation is essential to allow accurate conclusions to be drawn and to allow meaningful interpretation of results.

Adult↗
PubMed1988

Duplex ultrasonography and selection of patients for carotid endarterectomy: plaque morphology or luminal narrowing?

Percentage of carotid stenosis and plaque morphology as determined by duplex scanning were correlated with symptoms and CT evidence of infarction in 108 patients. Severity of carotid stenosis less than 49% or greater than 50% narrowing was not associated with an increased risk of ipsilateral symptoms or CT infarction. However, a heterogeneous plaque appearance, suggesting intraplaque hemorrhage, did correlate with ipsilateral cerebral symptoms. Heterogeneous plaque appearance may be a more reliable indication for carotid endarterectomy than a hemodynamically significant stenosis.

Aged↗
PubMed1987

Duplex scanning for noninvasive assessment of both carotid luminal diameter and atheromatous plaque morphology.

The value of Duplex scanning in 50 consecutive patients with symptomatic carotid stenosis was evaluated. Compared with contrast arteriography, the sensitivity of Duplex scanning, for a greater than 50% internal carotid diameter reduction, was 90% (66/73) with a specificity of 96% (26/27). The overall agreement between Duplex and contrast arteriography as measured by the Kappa value was K = 0.561. One of the 13 arteries felt to be occluded on Duplex scanning was radiologically found to be patent. Excluding the six normal and 13 occluded arteries, 81 carotid plaques were defined as either heterogeneous, suggestive of intraplaque hemorrhage or as homogeneous. Twenty-four of the 32 asymptomatic cerebral hemispheres were associated with ipsilateral homogeneous plaques, while 30 of the 49 symptomatic hemispheres had heterogeneous plaques in the ipsilateral carotid, (p less than 0.001). This study confirms the accuracy of duplex scanning in detecting internal carotid stenosis as well as in identifying plaques which are morphologically heterogeneous and more likely to be associated with ipsilateral cerebral hemispheric symptoms.

Aged↗
PubMed1986

Angiographically-induced infection of the aorta.

We present three cases of infection of the native aorta following angiography. The infection was an incidental finding at operation in two patients, while a third presented with fulminant sepsis. All had debridement of the retroperitoneum and underwent successful extraanatomic bypass. We feel caution is warranted in placing a retroperitoneal graft even in suspected aortic sepsis. Prophylactic antibiotics may be advisable to protect against infection of atherosclerotic plaque during angiography.

Aged↗
PubMed1986

The influence of duplex scanning on early patency rates of in situ bypass to the tibial vessels.

Duplex scanning was used in the follow up of 49 in situ infrapopliteal bypasses per formed for limb salvage using the valve incision method. In 19 cases (39%) the peroneal artery was the best available vessel for distal insertion; the anterior tibial and dorsalis pedis were used in 17 cases (35%) and the posterior tibial artery and tibioperoneal trunk in 13 cases (26%). In the early postoperative period three AV fistulas presented with painful skin lesions. These were located using duplex scanning and following ligation rapid resolution followed. Primary patency at one month was 87% and was increased to 96% by successful correction of four out of six failed bypasses. A total of 11 stenoses were found in five bypasses between three and 15 months postoperatively. In four of these patients the ankle/arm index decreased by at least 0.15 between examinations. A comparison was made between the spectral analysis on duplex scanning and the findings on arteriography and at operation. Peak systolic frequencies greater than 6,000 Hz were associated with 50% or greater reduction in vein bypass diameter. The majority were corrected using vein patch angioplasty. Primary cumulative patency at two years was maintained at 68% while correction of two out of seven bypass failures raised this to 80%. Duplex scanning allows precise definition of vein bypass pathology, facilitates operative correction and increases long-term limb salvage.

Aged↗
PubMed1977

Surgical management of hyperhidrosis.

Sixty-five patients with severe disabling hyperhidrosis were subjected to operation. Eighty-nine sympathectomies and 42 axillary skin excisions were performed to abolish sweating. Almost 90% of these patients were extremely satisfied with the outcome of surgery which resulted in a change for the better in their social and working lives. When conservative therapy fails, we recommend these procedures, which often alleviate this most distressing symptom.

Adolescent↗
PubMed1976

Pedal vasomotor tone following aortofemoral reconstructions: a randomized study of concomitant lumbar sympathectomy.

A prospective randomized trial was undertaken to evaluate effects of lumbar sympathectomy as an adjunct to reconstructive surgery of the lower limb. The objective of this study was to assess the early postoperative effect of these procedures on pedal vasomotor tone. A pedal arterial resistance index (PARI) at rest was derived from the ratio of the ankle-digit systolic pressure gradient and pedal blood flow measured plethysmographically. Studies were performed on 32 normal individuals and pre- and postoperatively in 29 patients undergoing aortic reconstruction, 12 of whom were randomly chosen to have lumbar sympathectomy. The mean postoperative PARI in 17 patients who had reconstructions alone was 42+/-7 (S.E.M.) units which approximated the preoperative PARI (43+/-9 units) and normal control values (45+/-6 units). In contrast, 12 patients who had a concomitant lumbar sympathectomy had a significant reduction in the postoperative PARI (8+/-1 units, Pless than 0.005). These initial results indicate that the addition of lumbar sympathectomy to an aortic reconstruction may enhance blood flow to the foot by significantly reducing outflow resistance.

Adult↗
PubMed1976

An index of healing in below-knee amputation: leg blood pressure by Doppler ultrasound.

Preoperative Doppler ultrasonic assessment of below-knee (BK) arterial signals and systolic blood pressures was performed on 50 patients undergoing 53 BK amputations for advanced ischemia. No patient was excluded from initial BK amputation unless gangrene at that level or severe joint contracture was present. Failure of healing of the BK amputation occurred in all five limbs with an undetectable Doppler arterial signal (and thus pressure) below the knee. Failure of amputation occurred in four of 16 limbs with detectable arterial signals and BK pressures less than 70 mm. Hg. Healing occurred in all 32 limbs with BK pressures greater than 70 mm. Hg. The differences in healing between these three groups are highly significant (p less than 0.005). This study suggests that Doppler ultrasonic assessment of BK arterial signals and pressures may be a simple hemodynamic correlate of healing of a BK amputation. Absence of a detectable arterial signal below the knee may be an indication for initial above-knee (AK) amputation in advanced ischemia.

Amputation, Surgical↗