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Biomedical subjects

T K Scobie

Publications and source records attributed to T K Scobie.

At least 19 recordsLinked to original sources
PubMed1990

Factors affecting survival after rupture of abdominal aortic aneurysm: effect of size on management and outcome.

Between 1970 and 1985, 172 consecutive patients (146 men, 26 women) underwent repair of ruptured abdominal aortic aneurysms. The mean age was 69.8 years. The overall death rate was 49.4%. The most significant predictors of death were an intraoperative urine output under 100 ml, systolic blood pressure less than 90 mm Hg on admission or in the operating room, cardiac arrest and a history of collapse. Discriminant analysis correctly classified 90% of the survivors and 84% of the nonsurvivors. Aneurysm size was documented in 133 cases; the average diameter was 8.78 cm, and 13 (10%) of the aneurysms were smaller than 6.0 cm. A correct diagnosis was made preoperatively in 46% of these 13 cases compared with 77% overall (p less than 0.05), and the time from arrival to transfer to the operating room was 6.71 versus 2.37 hours (p less than 0.05). The death rate for patients who had the small aneurysms was 77% versus 45% for those with larger aneurysms (p less than 0.06). This study confirms the continuing poor results after repair of ruptured abdominal aortic aneurysms. A subset of patients having small aneurysms (less than 6.0 cm) require an aggressive approach to diagnosis and treatment.

Aged↗
PubMed1989

Smoking: a decision-making dilemma for the vascular patient.

This descriptive study examined the differences in beliefs and social influences between patients who decided to quit or to continue smoking following diagnosis of chronic peripheral vascular disease. A consecutive quota sample of 20 patients who had quit smoking (quitters) and 22 who had continued smoking (continuers) agreed to participate in the study. There were no statistically significant differences between quitters and continuers in demographic characteristics, clinical variables and perceived social influences. Statistically significant differences were found between groups in beliefs about and attitudes towards the risk of continued smoking. These findings underline the need to investigate more fully the factors which influence patients' decisions to quit or to continue smoking. Further investigation may also provide detailed information on the role of risk perception in influencing this decision-making process.

Amputation, Surgical↗
PubMed1989

Popliteal aneurysms: an index of generalized vascular disease.

A review of 59 popliteal aneurysms in 38 patients seen over 10 years revealed that 34 (58%) aneurysms were symptomatic. Symptoms included gangrene (15%), ischemia due to thrombosis (38%) and embolism (5%). Patients with unilateral aneurysms (45%) were a median of 7 years younger than those with bilateral lesions (55%). The latter group had more frequent manifestations of occlusive disease, which included previous myocardial infarction, coronary artery bypass grafting and stroke. They also had more concomitant aneurysms, those of the abdominal aorta and femoral and iliac arteries being the most common. Management consisted of bypass grafting in 34 limbs and immediate amputation in 9; 16 inoperable limbs remained viable. At last follow-up (median 32 months) or time of death, 30 of 34 grafts were patent. Four grafts occluded, one perioperatively and the others at 4, 5, and 32 months respectively, resulting in two amputations. The cumulative patency rate in the asymptomatic group was 94% compared with 81% in the symptomatic group. These data illustrate that patients with popliteal aneurysms may have associated vascular disease, the likelihood of which is increased when aneurysms are bilateral.

Aneurysm↗
PubMed1988

Multicenter prospective study of nonruptured abdominal aortic aneurysms. I. Population and operative management.

This article describes the patient population and operative management of 666 patients with nonruptured aneurysms of the abdominal aorta. Statistical significance of variables was determined by the chi-square test and logistic regression analysis. There were no statistically significant differences (p greater than 0.05) in mortality rate for abdominal aortic aneurysm (AAA) on the basis of indication for surgery (asymptomatic, 3.9%; asymptomatic but with evidence of enlargement, 4.9%; and symptomatic, 7.2%) or the urgency of operation (elective operation, 4.5%; and urgent operation, 7.1%). Characteristics of the 72 participating surgeons did not influence the operative mortality rate. A family history of AAA was documented in 6.1% of cases and was more common if the patient was female (p = 0.03) and less than 65 years of age (p = 0.04). Patients without clinical evidence of coronary artery disease had a 0.8% mortality rate from cardiac disease compared with 6.2% if any stigmata of coronary disease were present. Prior aortocoronary bypass surgery did not reduce the incidence of postoperative cardiac events or operative mortality rate. Patients having "routine" angiography did not have a less complicated operative course, fewer thrombotic complications, or lower mortality rate than those not having it. Those patients with an inflammatory AAA (4.5%) did not have a significantly higher incidence of pain. Heparin administration (84.8%) did not reduce the complications of graft thrombosis, "trash," distal thrombosis, and/or amputation. The 6.8% of patients requiring suprarenal aortic cross-clamping had a higher incidence of postoperative renal dysfunction (p = 0.02) and intraoperative blood loss (p less than 0.001), but cardiac events were not more frequent. When the aortic cross-clamping time was prolonged (more than 70 minutes), the requirement for crystalloid fluid administration increased (p less than 0.001) and postoperative myocardial infarction was more common (p = 0.004). After ligation of the left renal vein in 7.9%, renal damage or dialysis was more frequent (p = 0.01). Patients having an intra-abdominal graft (tube, 38.5% and biiliac, 30.7%) had fewer wound infections (p = 0.02) and graft thromboses (p less than 0.001) than the patients with a femoral anastomosis. When the internal iliac artery flow was interrupted bilaterally (12%), diarrhea (p = 0.03) and ischemic colitis (p = 0.03) were more frequent complications. Reimplantation of the inferior mesenteric artery was carried out in 4.8%. After renal artery bypass in 2.1%, the mortality rate was not increased, but the incidence of transient renal dysfunction was increased (p = 0.03).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1988

The use of preoperative exercise testing to predict cardiac complications after arterial reconstruction.

To assess the value of exercise testing in the prediction of cardiac risk, 100 patients requiring arterial reconstructive surgery had either treadmill testing or arm ergometry before operation. Thirty-four patients then had abdominal aortic aneurysm repair, 48 had reconstructions for aortoiliac occlusive disease, and 18 had infrainguinal revascularization procedures. Cardiac complications included myocardial infarction in 10%, acute congestive failure in 5%, malignant ventricular arrhythmias in 7%, and cardiac death in 7%. Contingency table analysis showed that patients who achieved less than 85% of their predicted maximum heart rate (PMHR) during exercise testing had a complication rate of 24%, whereas patients who achieved more than 85% of PMHR had a 6% complication rate (p = 0.0396). The degree of ST segment depression during exercise testing was not a significant predictor of cardiac complications. However, patients who had a positive stress test (ST depression more than 1 mm) and achieved less than 85% of their PMHR had a complication rate of 33%, whereas patients with a positive stress test who achieved more than 85% of their PMHR had no complications (p = 0.048). Statistical analysis with a logistic regression model showed two factors to be significant. Patients who achieved a high maximum heart rate during exercise testing had a low probability of developing postoperative cardiac complications (p = 0.04), as did patients who achieved high cardiac work load maximal oxygen uptake (p = 0.03). We conclude that preoperative exercise testing is useful to predict cardiac complications after arterial reconstruction. Patients who are able to achieve more than 85% of their PMHR and a high maximal oxygen uptake represent a low-risk group.

Aorta, Abdominal↗
PubMed1987

Current status of transluminal angioplasty.

Although the published results of transluminal angioplasty have been satisfactory, its role in the practice of vascular surgery has not been well documented. Of 137 members of the Canadian Society for Vascular Surgery polled, 102 (74.5%) responded to a questionnaire drawn up to assess the current status of transluminal angioplasty in Canada. Of 1343 angioplasties reported, 64% were iliac, 21% femoral, 12% renal and 3% of other arteries. Claudication was the indication in 80%, limb salvage in 20%. In 15% angioplasty was used as an adjunct to subsequent arterial surgery. The lesion and results of treatment were assessed by clinical, noninvasive and pressure-gradient evaluation in most hospitals. Complications varied widely, reflecting the large number of physicians reporting. Most angioplasties were performed by vascular radiologists, and joint decision-making by radiologist and surgeon was the most common approach. The use of angioplasty increased in hospitals carrying out the most intensive evaluation, suggesting that it should have an expanded role.

Angioplasty, Balloon↗
PubMed1986

Transluminal angioplasty: indications and overview.

Reasons for the slow acceptance of percutaneous transluminal angioplasty over the past 20 years are multiple and include the lack of understanding of the changes in the arterial wall caused by angioplasty. Factors responsible for the present popularity of the technique include a better understanding of the pathophysiology of catheter dilatation of an artery, more efficient catheters and monitors, increasing experience and competence of angiographers, better drugs to decrease spasm and thrombosis, greater knowledge of the immediate and long-term results and social pressure to reduce both cost and time in treating patients. The indications for percutaneous transluminal angioplasty are being standardized, as were the indications for reconstructive arterial surgery, and now the role of angioplasty should be understood by all physicians treating patients with arterial disease. The best results of this procedure are obtained with segmental occlusive lesions of the iliac, superficial femoral, coronary and renal arteries.

Aged↗
PubMed1986

Cardiac mortality and morbidity after vascular surgery.

To determine the clinical, hemodynamic and pathological features that contribute to major cardiac complications after vascular surgery, six patients with early postoperative cardiogenic shock (group 1) were analysed retrospectively and compared to nine patients without complications (group 2) who were carefully analysed prospectively. Four group 1 patients had elective repair of an abdominal aortic aneurysm, one had repair of a false iliac artery aneurysm and one had a femoropopliteal graft inserted. Four group 2 patients had elective repair of an abdominal aortic aneurysm and five had aortobifemoral reconstruction. The Goldman multifactorial index was similar in both groups and indicated an expected death rate of 2% and a morbidity rate of 5%. In group 1, the earliest sign of cardiovascular compromise was an elevated pulmonary wedge pressure during operation. Postoperatively, electrocardiographic evidence of myocardial ischemia was present in all six patients and preceded cardiogenic shock. Autopsy of the four patients who died demonstrated triple-vessel disease in all but recent occlusion in only one patient. There was evidence of extensive subendocardial infarction in all four. Angiography of the two survivors in group 1 also demonstrated triple-vessel disease. The authors conclude that by using ordinary clinical methods it is difficult to identify patients likely to have major complications postoperatively. Elevated pulmonary wedge pressures or electrocardiographic evidence of myocardial ischemia may be early warning signs of impending cardiac catastrophe and should be treated aggressively. The underlying pathophysiology appears to be perioperative stress in a setting of severe triple-vessel coronary artery disease.

Aged↗
PubMed1985

Subclavian steal despite ipsilateral vertebral occlusion.

In the classic subclavian steal syndrome, vertebrobasilar insufficiency is caused by reverse flow in the vertebral artery ipsilateral to a subclavian stenosis or occlusion. We present two patients with vertebrobasilar insufficiency and ipsilateral vertebral and subclavian occlusive disease. The postulated mechanism of vertebrobasilar insufficiency is reverse flow in collateral neck vessels. In both patients, symptoms were relieved by carotid subclavian bypass. Thus, vertebral occlusion ipsilateral to a subclavian stenosis does not preclude subclavian steal syndrome.

Blood Vessel Prosthesis↗
PubMed1983

Management of acute thromboembolic limb ischemia.

Acute arterial occlusion affecting the extremities remains a significant cause of death and limb loss. Our approach to the management of these patients has been selective, and it is based upon a clinical distinction between embolism and thrombosis. Patients with acute embolic occlusion are treated with prompt embolectomy. Patients with thrombosis are given a course of heparin therapy, followed by elective arterial repair if necessary. Deterioration of the limb is an indication for emergency reconstruction, and nonviable limbs are amputated early. This approach to treatment was assessed in a 1-year prospective study, involving 29 patients with embolism and 50 patients with thrombosis. The initial diagnosis was found to be incorrect for seven patients (8.9%). Of the patients with embolism, four died (13.8%) and three required amputation (10.4%). There were six deaths (12%) among the patients with thrombosis, but eleven required amputation (22%), and in seven of these amputation was the definitive treatment. We have concluded that the selective use of surgery is an appropriate method of treatment for patients with acute thromboembolic limb ischemia.

Acute Disease↗
PubMed1983

A prospective study of lower limb amputations.

Most leg amputations are performed for vascular disease. A mortality of 30% was associated with above-knee amputations in this study. Healing by primary intention took place in 59% of patients, 31% had delayed healing and 10% required a revision. Only 10% of above-knee amputees used a prosthesis and 48% required total bed care. Below-knee amputations in which a rigid dressing was used had slightly better healing than when soft dressings were used but the difference was not significant. The overall reamputation rate was 15%, the mortality was 7.2% and 57% were fully ambulatory with a prosthesis. Amputation at either the transmetatarsal or digital level was carried out in 25% and 80% healed. The mortality was 11%. Clinical observation is still the best determinant of the level of amputation; below-knee amputation should be strived for in every patient who is a candidate for rehabilitation. Use of a rigid dressing is recommended.

Aged↗
PubMed1982

Venous ulcers.

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Adult↗
PubMed1980

Abdominal aortic aneurysms: how can we improve their treatment?

Arteriosclerotic abdominal aortic aneurysms are present in a least 2% of the elderly population of the Western world and their number is increasing. Without treatment 30% of patients with asymptomatic aneurysms live for 5 years, although the risk of rupture becomes greater as the size of the aneurysm increases. Of those with untreated symptomatic aneurysms 80% are dead within a year. Elective repair of aneurysms has a low mortality, and 50% of the patients live for at least 5 years. Symptomatic aneurysms all cause pain and may produce other symptoms from pressure on adjacent structures, distal embolism, acute thrombosis or rupture. In 88% of cases an aneurysm can be diagnosed by physical examination alone; confirmatory tests include soft-tissue roentgenography of the abdomen, ultrasonography, computer-assisted tomography and aortography. Repair is indicated for symptomatic or ruptured aortic aneurysms and for asymptomatic aneurysms over 5 cm in diameter. Early diagnosis and referral for repair is essential for optimum treatment of this common condition.

Aged↗
PubMed1980

Hemodynamic assessment of the aortoiliac segment: a prospective study.

A test for assessing stenosis in the aortoiliac segment is described in which femoral pressure is measured directly by continuous monitoring and an intra-arterial injection of papaverine is used to augment blood flow. This test has been described previously but is not widely used. A prospective study of this test was carried out on 64 patients and the results were compared with those obtained by aortography. The test helped to determine whether an operation on the aortoiliac segment was indicated. Clinical results were assessed. Thirty-two of the 64 patients were found to have significant inflow disease (more than 50% stenosis). They underwent aortic reconstruction with total relief or improvement of symptoms in all cases. Aortography demonstrated an essentially normal aortoiliac segment in 3 of the 32 patients and 16 had only irregular segments with no definite stenosis. The authors conclude that any patient presenting with sufficient indication to warrant reconstructive surgery who has a normal or equivocal angiogram should undergo the papaverine pressure test.

Aorta, Abdominal↗
PubMed1976

Perforation of the gallbladder: analysis of 19 cases.

Perforation of the gallbladder occurred in 19 (3.8%) of 496 patients with acute cholecystitis treated at one hospital in an 8-year period. The average age of the 19 patients was 69 years and the female:male ratio was 3:2. Most had a history suggestive of gallbladder disease and most had coexisting cardiac, pulmonary, renal, nutritional or metabolic disease. The duration of the present illness was short, perforation occurring within 72 hours of the onset of symptoms in half the patients; the diagnosis was not suspected preoperatively in any. In the elderly patient with acute cholecystitis who has a long history of gallbladder disease, cholecystectomy should be performed early, before gangrene and perforation of the gallbladder can occur.

Adult↗
PubMed1975

Cystic adventitial disease of the popliteal artery.

The first case of cystic adventitial disease of the popliteal artery recorded in Canada is reported and discussed in conjunction with a review of the world literature of 45 reported cases. This rare cause of arterial insufficiency occurs usually in young men and should be considered in the differential diagnosis of claudication. Angiographic findings are diagnostic and surgery is usually corrective. The theories of etiology and pathogenesis are discussed and the gross and microscopic pathology is demonstrated.

Adolescent↗