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Biomedical subjects

F M Ameli

Publications and source records attributed to F M Ameli.

At least 37 records · Page 2Linked to original sources
PubMed1990

Inflammatory abdominal aortic aneurysms and ureteric obstruction.

Inflammatory abdominal aortic aneurysms are rare, but when they occur the ureters may be involved in the perianeurysmal fibrosis. Treatment of this ureteric involvement is controversial. The authors present one such case, review the literature and describe what they believe is the appropriate method of diagnosis and treatment. This includes the use of computed tomography, retrograde pyelography, ureteral stenting, repair of the aneurysm and ureterolysis.

Aged↗
PubMed1990

Failure of bicycle exercise electrocardiograms to predict major post-operative cardiac complications in patients undergoing abdominal aortic surgery.

To determine if exercise electrocardiograms (EECGs) are justified in routine pre-operative screening for cardiac disease, we performed a prospective study on 77 consecutive patients scheduled for infrarenal aortic reconstructive surgery. All patients had EECGs performed 1-12 days prior to elective surgery. In addition to routine clinical assessment of cardiac disease, all patients were allocated a Goldman risk score. Four patients developed major post-operative cardiac complications of whom one patient died. EECG was not a significant predictor of outcome, as 48.6% of all EECGs were inadequate due to non-completion of the exercise protocol. Significant pre-operative predictors of outcome were a history of angina (p less than 0.01), myocardial infarction (p less than 0.001), congestive cardiac failure (p less than 0.0001), or a Goldman score of greater than 14 (p less than 0.05). By multivariate analysis of the pre-operative risk factors a history of congestive cardiac failure was found to be the most significant independent predictor of post-operative cardiac complications.

Adult↗
PubMed1989

Transient cerebral ischemia.

Stroke is a major cause of disability and death in North America. About 30% to 40% of patients with stroke have had transient ischemic attacks (TIAs). The recognition and treatment of TIAs and possibly of asymptomatic stenoses of the carotid arteries may be beneficial in preventing stroke. We review the epidemiologic features, natural history, pathogenetic features, clinical presentation, methods of investigation and management of patients with TIAs.

Aged↗
PubMed1989

A statistical assessment of the dependability of transcutaneous tissue oxygen tension measurements.

Transcutaneous oxygen tension measurements (PtcO2) were obtained for subjects in two groups: peripheral vascular patients (N = 15) and disease-free controls (N = 9). Readings were taken in each of three locations, arm, knee and foot, in supine and erect positions, at fixed and random times, on each of 3 consecutive days. The dependability (the proportion of true variance in total variance) of PtcO2 measurements was evaluated using a generalizability model. The preliminary generalizability study analysis indicated that day-to-day variation of PtcO2 level was larger than within-day variation. Therefore, in order to decrease the measurement error variance one would preferably increase the number of days for measurements (nd) rather than increase the number of measurements within each day (nt). A decision study analysis was also performed which resulted in estimates of error variance and two interdependent dependability measures: dependability coefficients (DCs) and signal to noise ratios (S/Ns). PtcO2 dependability values were generally different for the two groups. Cases had high DCs and S/Ns (DC greater than or equal to 0.9, S/N greater than or equal to 9) in all location-position combinations except for arm measurements. On the other hand, controls had low and unacceptable DCs and S/Ns (DC less than 0.8, S/N less than 4) in all location-position combinations. Cases and controls had generally lower dependability values when PtcO2 ratios were analyzed. The only two ratio-position categories for which dependability values were in the acceptable range (DC greater than or equal to 0.8, S/N greater than or equal to 4) were foot/arm erect and foot/arm supine for the cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

The effect of postoperative smoking on femoropopliteal bypass grafts.

Effect of smoking habits on limb loss rates and cumulative patency rates of 136 arterial reconstructions performed for lower limb ischemia were analyzed in a five year follow-up retrospective study. Of 121 patients, 103 (85%) smoked before the operation and 43 of the smokers (42%) discontinued smoking postoperatively. Patients who continued to smoke more than 15 cigarettes per day (34 patients) increased the probability of losing their limb approximately five times at two years and three times at five years postoperatively, compared with nonsmokers and smokers of up to 15 cigarettes per day (87 patients) (p = 0.013). Cumulative patency rates of nonsmokers and smokers of up to five cigarettes per day (Group A, 66 patients) were not significantly influenced (p = 0.518) by preoperative symptoms (claudication versus limb salvage). However, for smokers of more than five cigarettes per day (Group B, 55 patients), at five years claudicants had a cumulative patency rate of 62.9% compared to 38.3% for limb salvage patients (p = 0.015). In group A at five years, autologous saphenous vein grafts had a cumulative patency rate of 74.2%, compared to 24% for prosthetic grafts (P = 0.013). In group B the CPR differences between autologous saphenous vein and prosthetic grafts were not significantly different (p = 0.394). Multiple interactions between smoking and variables like age, preoperative symptoms, and graft material demonstrate the complexity of the effects of smoking on cumulative patency rate and the need for sub-grouping and removal of confounding factors. In view of the adverse affects of continued smoking on postrevascularization prognosis, patients should be strongly advised to discontinue smoking.

Adult↗
PubMed1989

Percutaneous transluminal angioplasty without anticoagulation.

This paper presents the results of a retrospective study of 110 percutaneous transluminal angioplasties done over a period of two years on 110 consecutive patients. Anticoagulation or antiplatelet drugs were not used during or after percutaneous transluminal angioplasty. Life-table analysis was used to calculate success rates at one and three months following the procedure. Success rates were determined using three criteria: clinical improvement, pre- and post-percutaneous transluminal angioplasty Doppler studies, and radiographic appearance. Claudication was present in 87 (79%) patients and severe ischemia in 23 (21%) patients. Sixty-eight (62%) PCTAs were done in the iliac arteries, 35 (32%) in the femoral arteries, and 7 (6%) in the popliteal artery. The majority of patients (61%) had 50%-75% arterial stenosis and only 18% had complete occlusion. Percutaneous transluminal angioplasty in the iliac arteries had the best results with cumulative success rates of 90% and 85% at one and three months, respectively. Success rates in the femoral arteries were 83% and 79% and in the popliteal artery 71% and 57% at one and three months, respectively. None of our patients required amputation. Ten patients (9.1%) suffered the following complications within 30 days of percutaneous transluminal angioplasty: death (2), thrombosis (2), perforation (3), minor hematoma (2), and false aneurysm (1). In conclusion, we have shown that percutaneous transluminal angioplasty can be performed safely and effectively without the use of anticoagulation and its associated risks.

Adult↗
PubMed1989

Comparison between transcutaneous oximetry and ankle-brachial pressure ratio in predicting runoff and outcome in patients who undergo aortobifemoral bypass.

In a prospective study, transcutaneous oxygen tension and ankle-brachial pressure index (ABI) were measured pre- and postoperatively in 105 symptomatic patients who underwent aortobifemoral bypass to compare the ability of these two measurements to reflect the runoff status, determined by angiography, and to predict the outcome of surgery. Postoperatively, ABI better reflected the runoff status. The difference in mean ABI for good versus poor runoff was 0.17 (p less than 0.05). The difference in mean transcutaneous oxygen tension below the knee for the two runoff categories was relatively small (6.3 mm Hg, p less than 0.05). Post-minus preoperative increases in ABI reflected the runoff status better than increases in transcutaneous oxygen tension. For good runoff, the mean ABI increase was 0.25 and for poor runoff it was only 0.14 (p less than 0.05). Runoff and transcutaneous oxygen tension were found to be the best predictors of symptomatic recurrence. Poor runoff was associated with a relative risk of 2.5 (p = 0.017) and transcutaneous oxygen pressure of less than 40 mm Hg implied a relative risk of 2.3 (p = 0.029) for symptomatic recurrence. The most important predictor of graft failure was preoperative ABI. Transcutaneous oxygen tension and the ankle-brachial pressure index appear to be valuable noninvasive techniques for vascular assessment, offering different insights and different predictions for management and prognosis of peripheral vascular disease.

Ankle↗
PubMed1988

Indications and role of axillofemoral bypass in high-risk patients.

The purpose of this study was to determine whether axillofemoral bypass was justified as an alternative revascularization procedure to direct reconstruction and to specifically define the indications for this extraanatomical bypass. Forty-one patients operated on between 1978 and 1985 were evaluated. The average age was 69 years. Indications were based upon limb salvage for aortoiliac occlusive disease in the following situations: infected aortobifemoral bypass graft (8 patients) and high risk with co-existing medical problems (33 patients). Patients were classified according to Goldman's Multifactorial Index of Cardiac Risk and Cooperman's Cardiovascular Risk Index. Twenty-four patients had axillobifemoral bypass and 17 had unilateral axillofemoral procedures. In 66 femoral anastomoses there were 13 extended profundaplasties, 25 profunda arterioplasties, 11 profunda patch angioplasties and 16 anastomoses to the common femoral artery. Postoperative mortality was 4.8% (2 patients). Cumulative survival at 60 months was 43% +/- 11% and primary patency rate of the axillofemoral bypass was 69 +/- 9.8%. We conclude that axillo-femoral bypass is indicated in the presence of infection, in patients who fall into Goldman's Class III-IV or in patients with risk greater than 10% as calculated by Cooperman's equation.

Aged↗
PubMed1988

Factors influencing results of femoropopliteal bypass operations for lower limb ischemia.

An ideal way to assess the effectiveness of femoropopliteal bypass procedures is to standardize patient- and surgeon-related variables by randomization. Through statistical analysis of multiple factors influencing patency, limb loss, death rate and hospital stay, the authors reviewed retrospectively 136 bypass procedures performed over 5 years. Variables that contributed significantly to the results were: preoperative symptoms (p = 0.037), graft material used (p = 0.016), age of the patient (p = 0.007), adequacy of runoff (p = 0.041) and smoking postoperatively (p = 0.013). Autogenous vein grafts were superior to prosthetic grafts, the cumulative patency at 5 years being 67.5% and 38.2% respectively. The authors emphasize that all patients needing vascular surgery should be advised to stop smoking, since in this study postoperative smoking increased the probability of limb loss and adversely affected the cumulative patency rate by interaction with other variables such as preoperative symptoms, graft material and age.

Adult↗
PubMed1987

The role of intravenous digital subtraction angiography as an adjunct to computed tomography in the preoperative assessment of patients with abdominal aortic aneurysm.

The purpose of this article is to determine the role of intravenous digital subtraction angiography (IV-DSA) as an adjunct to computed tomography (CT) in the preoperative evaluation of patients with abdominal aortic aneurysm. Sixty-six patients underwent IV-DSA as well as CT during a 2-year period. Sixty-four of the 66 patients underwent abdominal aortic aneurysm repair. The results of the 66 patients were analyzed to assess what additional information was obtained by IV-DSA concerning aneurysm size, vascular anomalies, visceral arterial anatomy, associated aneurysmal disease, and iliofemoral and distal occlusive disease. On the basis of this study, it is suggested that IV-DSA has a limited role in the preoperative evaluation of patients with abdominal aortic aneurysm.

Aged↗
PubMed1987

Transcutaneous oxygen tension measurements in the detection of iliac and femoral arterial disease.

The sensitivity and specificity of the noninvasive measurement of transcutaneous oxygen tension (PtcO2) in detecting the site of vascular disease in either the iliac or superficial femoral arteries is reported herein. Patients presenting with intermittent claudication or ischemic pain at rest were studied to determine the presence or absence of iliac or femoral occlusive disease by assessing the level of PtcO2 measurements at sites above and below the knee. PtcO2 studies were assessed against changes in the arteriogram, the "gold standard" for judging peripheral arterial insufficiency. Using our criteria, PtcO2 measurements above the knee show a sensitivity rate of 86 per cent and a specificity rate of 20 per cent to detect iliac disease. PtcO2 measurements below the knee show a sensitivity rate of 91 per cent and a specificity rate of 33 per cent to detect femoral disease. The accuracy was 69 per cent and 76 per cent, respectively. The user of the test is mainly concerned with the "predictive values" which are functions of the sensitivity, specificity and prevalence of the disease. Transcutaneous oxygen measurements above and below the knee show a very good sensitivity for detecting iliac and femoral disease, indicating that they may well serve as a quick and convenient noninvasive diagnostic procedure.

Angiography↗
PubMed1987

Consequences of "conservative" conventional management of axillary vein thrombosis.

To evaluate the long-term effects of "conservative" management (heparin initially then Coumadin for 3 months) on patients with axillary vein thrombosis, the authors studied 20 patients (average age 44 years) who presented at the Wellesley Hospital in Toronto between 1975 and 1984. The diagnosis of axillary vein thrombosis was made from history, findings on physical examination and Doppler studies. In 12 patients, the diagnosis was confirmed by venography. Three patients subsequently underwent a first-rib resection for thoracic outlet syndrome. The average follow-up was 42 months. The cause of the thrombosis in 3 patients was an intravenous-line catheter, in 7 it was effort thrombosis and in 10 the cause was unknown. Two patients had had a previous deep venous thrombosis in the lower limb. Results of conservative treatment showed that only five patients had residual minimal swelling and two had minor discomfort. These symptoms did not interfere with either leisure or work activities in any of the patients. Fifteen patients were asymptomatic. One patient had nonfatal pulmonary embolism. The conservative management of axillary vein thrombosis is safe, effective, relatively inexpensive and gives excellent long-term results. The prognosis is good, irrespective of the cause of the thrombosis and, in view of this, a more aggressive approach, using either streptokinase therapy or thrombectomy, does not appear to be justified.

Adult↗
PubMed1987

Safety of cholecystectomy with abdominal aortic surgery.

Many surgeons are reluctant to remove asymptomatic gallstones during aortic reconstruction for fear of increasing the risk of graft infection. This is a review of 56 patients who underwent aortofemoral bypass or aortic aneurysm repair, with cholecystectomy, to determine if the morbidity or mortality was increased with the concomitant procedure. Follow-up averaged 25 months (range from 1 to 125 months). Three patients were lost to follow-up. Operative and postoperative hospital stay were not increased. One patient suffered a graft infection and a pseudoaneurysm; the infection was not related to the cholecystectomy since it occurred after a secondary procedure for repair of an infected false aneurysm. There were three superficial infections and three postoperative deaths, none of which specifically related to the cholecystectomy. The only related complications were three bile leaks, one liver injury due to a retractor and bleeding from the gallbladder bed in one patient who required reoperation. The authors conclude that concomitant cholecystectomy can be performed without increased risk to the patient but is advised only if the vascular procedure has been uncomplicated and the cholecystectomy appears straightforward.

Aorta↗
PubMed1987

Current indications for axillounifemoral and axillobifemoral bypass grafts.

Revascularization of the lower extremities may require an axillofemoral bypass when an aortobifemoral bypass is contraindicated. Thirty-one patients underwent axillounifemoral and 59 had an axillobifemoral bypass, with a mortality rate of 9%. The indication for operation was limb salvage in 67%, intra-abdominal sepsis in 21%, and disabling claudication in 12%. Cumulative survival, patency, and limb salvage rates were determined by life-table analysis. The cumulative patency and limb salvage rates (with standard errors) at 3 years were 68% +/- 8% and 78% +/- 9%, respectively. When stratified for type of operation, axillobifemoral bypass had a superior patency rate compared with axillounifemoral bypass (log rank = 3.882, p less than 0.05). There was no significant difference when patients were stratified for diabetes (log rank = 2.213, p = no significance [NS]), operative indication (disabling claudication vs. limb salvage) (log rank = 0.0005, p = NS), or outflow (no profundaplasty vs. profundaplasty) (log rank = 2.011, p = NS). We conclude that axillofemoral bypass is a reasonable alternative for revascularization in high-risk patients or in those patients in whom a transabdominal approach is contraindicated. We recommend aggressive use of the profunda femoris artery when the superficial femoral artery is occluded to achieve optimal results.

Actuarial Analysis↗
PubMed1987

The predictability of the success of arterial reconstruction by means of transcutaneous oxygen tension measurements.

The cases of 100 patients with severe peripheral vascular disease were reviewed to determine whether the success or feasibility of arterial reconstruction could be correlated with the increase in transcutaneous tissue oxygen tension (tcPO2) that occurs in all persons when assuming an erect posture from the supine position. Resting supine tcPO2 levels of 20 mm Hg or less at the foot were noted in all patients in this study (normal values 60.10 +/- 6.82 mm Hg). Group I patients were defined by an increase of less than 15 mm Hg on standing, whereas group II patients showed an increase of 15 mm Hg or more. Group I patients had a supine tcPO2 value of 4.24 +/- 5.31 mm Hg, with an increase of 3.91 +/- 4.59 mm Hg on standing. The group II subjects also had a low supine tcPO2 level, 5.73 +/- 4.98 mm Hg, but the increase on standing, 36.14 +/- 11.41 mm Hg, was significantly higher (p less than 0.001). When these levels increased by less than 15 mm Hg on standing in group I (31 patients), only 29% of limbs (10 of 34) were saved or had patent grafts at 3 months and 55% of attempted vascular reconstructions (11 of 20) failed. Amputations were performed in 50% of the limbs (17 of 34). This contrasted in group II (69 patients) with a significantly higher limb salvage and graft patency rate (81%, 57 of 70 limbs), success of reconstruction (79%, 37 of 47 procedures), and a significantly lower rate of amputation (11%, 8 of 70 limbs) (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Abdominal aortic aneurysm resection in patients more than 80 years old.

Improvement in anesthetic and surgical techniques has prompted a more aggressive approach to repair of abdominal aortic aneurysms in patients more than 80 years old. In order to determine if surgical treatment is justified, all of the patients who were more than 80 years old admitted to the hospital during the ten year period from 1974 to 1983 with the diagnosis of abdominal aortic aneurysm were reviewed. A total of 90 patients were available for analysis. The mortality of the 18 patients treated conservatively for ruptured aortic aneurysms was 100 per cent. Ten of the 27 patients operated upon for a ruptured aneurysm died yielding a mortality of 37 per cent. Eleven patients with symptomatic aneurysms had urgent repair with a mortality of 27 per cent. Only one of the 34 patients undergoing elective aneurysm repair died. There was no difference in the size of aneurysms among the groups. Although the ruptured aneurysms required more blood (10.2 +/- 3.7 units), there was no difference between the other two groups (symptomatic 4.5 +/- 3.1 units, elective 4.6 +/- 2.8 units). There was significantly fewer myocardial and renal complications in the elective group, although the sole death in this group was from myocardial infarction. Based upon these observations, we recommend aggressive elective therapy for selected patients who are more than 80 years of age with asymptomatic abdominal aortic aneurysms. Although the mortality is higher in those patients with symptomatic or ruptured aneurysms, it is not formidable, and therefore, repair should not be ruled out on the basis of age alone.

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