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Biomedical subjects

T S Riles

Publications and source records attributed to T S Riles.

At least 91 records · Page 5Linked to original sources
PubMed1983

Evaluation of aorto-iliac occlusive disease by intravenous digital subtraction angiography.

Intravenous digital subtraction angiography (DSA) was used to evaluate 22 patients with Leriche syndrome. The technique successfully demonstrated both the level of obstruction and the reconstitution of arterial flow to the lower extremities. In view of the relative safety of DSA, compared with the axillary approach in standard angiography, the authors believe that it should be the initial procedure for presurgical evaluation of Leriche syndrome.

Angiography↗
PubMed1983

Ocular pneumoplethysmography (OPG-Gee) in noninvasive evaluation of carotid artery stenosis.

Carotid artery stenosis can be evaluated noninvasively by ocular pneumoplethysmography (OPG-Gee). This simultaneously measures both ophthalmic artery pressures and is therefore capable of detecting pressure-reducing or hemodynamically significant carotid lesions. An OPG-angiography correlation was made for 200 carotid arteries in 110 patients. Sensitivity, specificity and overall accuracy were 91%, 89%, and 90% respectively, if calculated per artery. On a per patient basis these figures were 94%, 88%, and 91%. Applications of this rapid and simple technique in clinical practice include selection of patients for angiography and carotid endarterectomy, as well as early and late control of the operative results.

Angiography↗
PubMed1983

Percutaneous phenol sympathectomy in advanced vascular disease.

Percutaneous phenol sympathectomy has been performed under fluoroscopic or CT guidance in 37 patients with extremely advanced vascular disease of the lower extremities. The technique is simple and well tolerated by the patient with a remarkably low incidence of complications. Of the 37 patients, 14 (38%) showed objective improvement and none of the patients experienced worsening of their ischemia. Results to date suggest that this procedure provides a sympathetic blockade as effectively as surgical sympathectomy in these patients with advanced disease.

Fluoroscopy↗
PubMed1982

The totally occluded internal carotid artery. Preliminary observations using rapid sequential computerized tomographic scanning.

Cerebral angiography often cannot distinguish between complete thrombosis or fibrosis of the internal carotid artery (ICA) and nonvisualization due to a total occlusion of the common carotid or origin of the ICA. Whereas surgery may be beneficial if the distal carotid is patent (type 1), thromboendarterectomy may be contraindicated if thrombus or fibrosis extend to the intracranial branches (type 2). Rapid sequential computerized tomography (RSCT) was used to examine 15 patients whose ICAs appeared occluded by angiography. Of four ICAs classed as type 1 by RSCT, three were found to be patent during surgical exploration, and carotid reconstruction was successfully performed. Three other ICAs classed as type 2 by RSCT were also surgically explored, and complete thrombosis was confirmed. The RSCT technique provides an effective and nonoperative means of determining whether a nonvisualized ICA is reconstructible.

Arterial Occlusive Diseases↗
PubMed1982

Comparison of results of bilateral and unilateral carotid endarterectomy five years after surgery.

Consecutive patients who successfully underwent carotid endarterectomy (C) between 1970 and 1975 were followed during a 5-year period (mean follow-up 4.3 years). The patients were divided into three groups. Group I comprised 146 patients who had unilateral CE with a patent, nonstenotic contralateral carotid artery. Group II included 45 patients who underwent unilateral CE but whose contralateral internal carotid artery was found to be totally occluded. Group III consisted of 86 patients who underwent bilateral CE. There was no significant difference between the groups with respect to age, sex, neurologic status, or associated diseases, and all were maintained on antiplatelet medications for surgery. During the follow-up period a total of 22 of the 277 patients had a new hemispheric stroke; four others became comatose and died, presumably of stroke. Among the group I patients, 17 had new strokes, only six of which involved the hemisphere ipsilateral to the CE. Five later strokes occurred in group II, one ipsilateral to the CE. Four patients in group III had new strokes. The cumulative stroke rates at 5 years by the life-table method were 17.6% for group I, 16.4% for group II, and 5.6% for group III. The difference between group I and III was significant (P less than 0.05). The results suggest that patients undergoing unilateral CE should have close postoperative monitoring of the contralateral vessel.

Actuarial Analysis↗
PubMed1981

Symptoms, stenosis, and bruit: interrelationships in carotid artery disease.

The relationship between focal neurologic symptoms, carotid artery stenosis, and cervical bruits was studied in 495 patients. Among the 990 carotid arteries, 562 (57%) were considered to be symptomatic and 505 (51%) were associated with bruit. There was a linear relationship between the degree of stenosis and symptoms. Of the highly stenotic vessels (80% to 99% narrowing), 253 of 350 (72%) were symptomatic; 85 of 104 (82%) occluded vessels were symptomatic. There was a linear relationship between the occurrence of cervical bruit and degree of stenosis, up to but not including total occlusion. The relationship between bruits and focal neurologic symptoms was less direct. Among 562 symptomatic arteries, 297 (53%) had a bruit and 265 (47%) did not. In symptomatic patients, the absence of a cervical bruit should not delay a workup for extracranial vascular disease.

Auscultation↗
PubMed1981

Limited success of lumbar sympathectomy in the prevention of ischemic limb loss in diabetic patients.

The results of 93 consecutive lumbar sympathectomies performed over a five year period upon 54 patients with diabetes and 39 without diabetes were compared in terms of subsequent amputation using life table analysis methods. Cumulative success rates for avoiding amputation were significantly lower in those with diabetes as compared with rates for those without diabetes at five years and at most shorter six month intervals. Although there are a number of possible explanations for this difference, an important contributing factor may be the prior spontaneous denervation of diabetic blood vessels. The results demonstrate that better predictive indexes for lumbar sympathectomy are needed.

Adult↗
PubMed1981

Effect of surgical lumbar sympathectomy on innervation of arterioles in the lower limb of patients with diabetes.

The innervation of lower limb epineurial arterioles, specimens of which were obtained from six patients in the sympathectomy and from six patients in the nonsympathectomy diabetic groups at amputation for ischemic peripheral vascular disease, was compared by quantitative ultrastructural methods. Results demonstrated no statistically significant difference in the number of vasomotor axons present, the average axon to smooth muscle cell distance or the axon distribution pattern in the adventitia between the two diabetic groups of patients. A previous investigation has established that innervation of these arterioles is significantly reduced in patients with diabetes having end-stage ischemia of the lower limb when compared with similar patients without diabetes. The present results demonstrate that surgical lumbar sympathectomy does not significantly further reduce the already severely diminished number of vasomotor nerves in some diabetic arterioles. This observation offers a possible explanation for the poorer success rate of those with diabetes compared with those without diabetes in avoiding amputation of the limb after lumbar sympathectomy.

Arteries↗
PubMed1981

Cervical vertebral angioplasty for brain stem ischemia.

Fifty-eight patients underwent unilateral vertebral arterial reconstructions over a 16-year period. Thirty-four underwent carotid operations as well. The first 18 patients underwent vertebral arterial reconstructions in conjunction with carotid endarterectomy as mandated in the Joint Study of Extracranial Arterial Occlusion as a Cause of Stoke. The next 40 underwent vertebral procedures for either brain stem symptoms alone, or for combined cerebral cortical and stem symptoms for specific indications after flow-obstructing carotid lesions had been corrected, but symptoms failed to subside. The surgical procedure consisted of subclavian-vertebral angioplasty except in one patient who underwent a subclavian distal-vertebral bypass graft to the level of the second cervical vertebral body. Syncopal episodes occurred as a major symptom in 16 and was controlled by either carotid and vertebral or vertebral artery operation alone except in four who also required cardiac pacemakers and one who needed correction of aortic stenosis. The long-term follow-up reveals that the stroke rate per average year for the first 14 years of follow-up was 1.2% per patient year with only five strokes having occurred in 410 patient years of follow-up and 70% of the patients having sustained no new neurologic episodes at the fourteenth year. Survival, however, was 45% at the fourteenth year with most deaths caused by myocardial infarction. The surgical procedure of vertebral angioplasty is indicated when bilateral vertebral arterial flow-obstructing lesions are found in patients with brain stem ischemia including drop attacks and syncopal episodes if flow-obstructing carotid lesions have been corrected and symptoms persist. The surgical procedure can be performed with a high degree of safety. The differential diagnosis of drop attacks and syncope in this age group should include, in addition to vertebrobasilar arterial insufficiency, transient cardiac arrhythmias, aortic stenosis, and convulsive disorders.

Brain Stem↗
PubMed1981

Long-term results in superficial femoral artery endarterectomy.

Semiclosed femoral popliteal endarterectomy, herein described as extending from groin to knee and performed with an arterial stripper, has proved to be a satisfactory alternative to revascularization of comparable occluded segments of thigh arteries employing autologous saphenous vein. Cumulative patency of 95.7% in all groups initially decreases to 59.6% in claudicators at 5 years and 30.6% in those who had surgery for limb salvage, whereas the limb salvage rate exceeds patency rate, being 62.9% at 5 years.

Endarterectomy↗
PubMed1979

Dilation of synthetic grafts and junctional aneurysms.

Dilation of prosthetic graft has been noted by authors in association with junctional aneurysm between the synthetic graft and host arteries. Dilation of graft materials was suspected as one of the etiologic factors of the junctional aneurysm. Increase in transverse diameter was observed as early as a few minutes to five years postimplantation in clinical cases. The phenomenon of dilation was studied experimentally. Nine different types of graft materials were tested using intraluminal pulse pressure of 100/60 mm Hg, and the transverse diameters were measured at various time intervals. Knitted grafts showed the more pronounced changes compared with the woven. Degree of dilation differed considerably among the different types of knitted grafts.

Aged↗
PubMed1979

Management of acute aortic occlusion.

Acute aortic occlusion is most often seen in elderly patients with advanced cardiac disease. The management of these patients has been facilitated by the use of extraanatomic bypass. Over the past 2 years, six patients aged 55 to 87 years presented to our medical center with acute aortic occlusion, three after major operative procedures. One patient had a thrombosed abdominal aortic aneurysm; in the other five patients differentiation between saddle embolus and thrombosis of the distal aorta was impossible. There was one operative death. Four of the other five patients underwent axillobifemoral bypass and one underwent aortofemoral thrombectomy. All survived, and none required amputation. Two of the three patients who underwent preoperative aortography developed transient renal failure postoperatively. Aortography is of little value in diagnosis and is probably contraindicated in acute aortic occlusion. Our recommendation for operative management includes (1) preparation of the patient for possible axillobifemoral bypass, (2) angiography of distal runoff via both femoral arteries, (3) attempt at bilateral aortofemoral embolectomy with Fogarty catheters, and (4) axillobifemoral bypass if embolectomy fails to restore normal pulsatile flow.

Acute Disease↗
PubMed1979

Myocardial infarction following carotid endarterectomy: a review of 683 operations.

In a series of 683 consecutive carotid endarterectomies, there were 16 postoperative myocardial infarctions which resulted in five deaths. Of 399 operations on patients with no previous history of heart disease, there were only two myocardial infarctions (0.5%). Two hundred and eighty-four operations were performed on patients with heart disease, and vasopressors were administered in 135 of these procedures. For these patients the risk of myocardial infarction increased from 2.0% to 8.1% with the use of vasopressors (P less than 0.001). The management of the patient with stable heart disease undergoing carotid endarterectomy is discussed.

Carotid Artery Diseases↗
PubMed1977

Low dose heparin: bleeding and wound complications in the surgical patient. A prospective randomized study.

A randomized prospective study of low dose heparin was performed in 175 surgical patients to determine the frequency of bleeding and wound complications. The patients were divided into three groups: (1) low dose heparin (5000 units two hours before operation and 5000 units every 12 hours following operation for five days); (2) low dose heparin postoperatively only; and (3) a control group. The frequency of bleeding and wound complications was 27% in group I, 7.5% in group II, and 1.4% in group III. The difference between the control patients and those heparinized pre- and postoperatively is statistically significant (p less than 0.005). None of the patients in any of the three groups had a pulmonary embolus, but the number of patients involved is too small to assess the significance of this finding. However, a bleeding and wound complication rate of 27% is significant. These findings indicate that perhaps the routine use of low dose heparin should be reserved for those patients with preoperative factors indicating an increased risk from thromboembolism.

Hematoma↗
PubMed1977

Heparin.

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Heparin↗