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Biomedical subjects

J B Chang

Publications and source records attributed to J B Chang.

30 records · Page 2Linked to original sources
PubMed1988

Intermittent claudication: predictors and outcome.

The authors reviewed 460 patients with intermittent claudication. With primarily conservative management, these patients were followed for an average of 4.1 years (one to ten years). The mean age was 71.7 years, ranging from thirty-six to eighty-four years; 55.9% were males. The subsequent follow-up study revealed that the status of 44.1% of the patients with underlying arterial insufficiency deteriorated. Eventually, they underwent vascular surgery for limb-threatening ischemia. From this study, the analysis of the parameters could predict the clinical outcome of intermittent claudication at the time of initial and follow-up evaluation. During initial evaluation, when the ankle brachial index (ABI) was higher than 0.7 or when follow-up evaluation did not show a decrease of ABI by 0.15, the chance of favorable outcome was increased by 2.4 and 1.6 times respectively. When the ABI was less than 0.5 at the initial evaluation and decreased 0.15 or more during follow-up studies, the risk of requiring vascular surgery for limb salvage increased by 3.8 and 1.9 times, respectively. The onset of major vascular events in other areas appeared to influence the time of significant deterioration in the lower limb arterial disease, indicating multifactorial and systemic contribution in the natural history of intermittent claudication. In this homogeneous patient population with arterial insufficiency referred to the vascular surgeon, conservative management with strong supervision for smoking cessation, exercise, diet control, body weight reduction, and medical regimen can modify the natural course of intermittent claudication and associated vascular problems.

Adult↗
PubMed1988

Surgonomics: the costs of ruptured abdominal aortic aneurysm.

Surgical care costs continue to rise at a rate greater than overall U.S. economic growth. Government and industry have vowed to slow the growth of health care spending. Prospective payment systems using the Diagnostic Related Group (DRG) mechanism are being phased in for payment of in-patient hospital care. One expected effect of the DRG payment scheme is a more careful financial analysis of the components of surgical care. The purposes of this study were to examine a vascular procedure, ruptured abdominal aortic aneurysm (RAAA), performed at a large teaching hospital during a ten-year period; to characterize patients by cost (hospital charges exclusive of physician fees) and outcome; and to test the hypothesis that an IDENTIFIER, here the presence or absence and duration of hypotension (less than 90 mm Hg systolic), could predict differences in cost and outcome. The results, in conjunction with historic data, were used to quantify aggregate hospital expenditures for this condition by survivor and the identifier. The results indicate: (1) mortality is higher for the hypotensive patient than for the normotensive patient (p less than 0.05) and is related to the duration of hypotension; (2) lowest mean charges per patient were in the hypotensive more than thirty minutes group ($5,587) followed by normotensive ($28,298), then hypotensive less than thirty minutes ($43,876); and (3) the mean charges for each survivor were $42,447 for normotensive patients versus $107,572 for hypotensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Lower extremity swelling: computerized tomography following negative venography.

In 21 patients who had lower extremity swelling and negative venography, radiographic evaluation was extended to include computerized tomography (CT) of the lower extremity, which we have termed venography-CT, or VCT. All patients were referred with the diagnosis of deep vein thrombosis (DVT) and no patient had a history of trauma. CT was effective in demonstrating two occult mechanisms of lower extremity swelling: knee joint effusion (three patients) and intramuscular hemorrhage (five patients). Selective utilization of CT in the evaluation of lower extremity swelling is effective in directing the clinical management of these patients.

Adult↗
PubMed1987

Disseminated intravascular coagulation as a result of supraceliac clamping: implications for thoracoabdominal aneurysm repair.

Massive coagulopathy and bleeding continues to play a major role in the operative mortality and perioperative multi-system failure of patients requiring elective thoracoabdominal aneurysm repair. It was the purpose of this study to determine the coagulation defect that occurs with supraceliac aortic clamping and the effects of increasing aortic cross-clamp time (AXCT) on the coagulation system and its recovery. Through a standard thoracoabdominal incision, 16 mongrel dogs had their aortas cross-clamped simultaneously just above the diaphragm and at the aortic bifurcation. Animals were divided into four groups of four animals each; sham operation, 30 minute AXCT, 60 minute AXCT, and 90 minute AXCT. Central venous blood was sampled prior to aortic cross clamping (AXC), during AXC and 1 hour, 2 hours, 5 hours, 7 hours, 12 hours, and 24 hours after the clamp was removed. All samples were assayed for platelets, fibrinogen, fibrin split products, prothrombin time (PT) and partial thromboplastin time (PTT). Platelets and fibrinogen decreased as PT and PTT increased with increasing AXCT consistent with disseminated intravascular coagulation (DIC) (P less than .001). Fibrin split products were positive in the 90 minute AXCT group only. The drop in platelets was greater for increasing AXCT and continued to fall in the 30, 60 and 90 minute AXCT groups at 24 hours (p less than .001). Fibrinogen dropped to the lowest levels between two and twelve hours after AXC and returned to normal at twenty-four hours in the 60 and 90 minute AXCT groups (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Superior mesenteric artery balloon occlusion. A nonoperative model of small bowel ischemia in dogs.

The purpose of this study was to develop a nonoperative animal model of small bowel ischemia that could be used for subsequent studies of intestinal ischemia. Ten mongrel dogs underwent balloon occlusion of their superior mesenteric artery after percutaneous insertion of a balloon tipped catheter through the femoral artery. Small bowel biopsies taken at various time intervals demonstrated mucosal congestion, hemorrhage, and sloughing consistent with classic small bowel ischemia. These changes consistently began 3 hours after occlusion with transmural necrosis and perforation occurring by 18 hours after occlusion. Fluoroscopy demonstrated little or no flow in the mesenteric circulation during balloon occlusion. This model provides a standard nonoperative approach for the induction of intestinal ischemia in dogs and could be a valuable tool in the study of intestinal ischemia.

Animals↗
PubMed1987

Adrenal cortical adenoma and adrenal medullary hyperplasia of the right adrenal gland--a case report.

The normal adrenal gland contains two types of tissue, the adrenal cortical tissue and the adrenal medullary tissue. The cortex is divided into three portions: the outermost "zona glomerulosa," the central "zona fasciculata," and the innermost "zona recticularis." The adrenal medulla is a developmentally separate organ, derived from neuroectoderm, and is the site of epinephrine and norepinephrine production. Adrenal cortical adenoma is commonly the result of a basophilic tumor of the anterior pituitary that secretes excessive amounts of ACTH. Adrenal medullary hyperplasia (or pheochromocytoma) are clinically hazardous tumors because of their excessive secretion of catecholamines. Combined adrenal cortical adenoma and adrenal medullary hyperplasia of the right adrenal gland has never been described previously.

Adenoma↗
PubMed1987

Intermittent claudication associated with cancer--case studies.

Cancer was diagnosed in 15 patients among 300 consecutive patients with intermittent claudication. The cancer-associated claudication is characterized by a more accelerated course of claudication, more often requires vascular surgery, and moreover, the lasting relief of claudication depends upon the efficiency of cancer therapy. It is the authors' impression that cancer-associated claudication is predetermined by atherosclerosis and aggravated by cancer through the chronic hypercoagulability state secondary to neoplasm. The clinical picture is characterized by rapid progression, with the frequent necessity of vascular surgery for limb salvage and a higher incidence of graft occlusion. Awareness of this possibility of hidden malignancy may be related to the clinical picture of hemodynamic deterioration of the underlying arterial insufficiency. A high index of suspicion leads to earlier diagnosis of neoplasm. Effective oncologic therapy will often bring the symptomatic relief of ischemic symptoms in the lower extremities. This report indicates that associated neoplasm has a more vicious course of the underlying arterial insufficiency and intermittent claudication.

Adenocarcinoma↗
PubMed1986

Antacid vs sucralfate in preventing acute gastrointestinal tract bleeding in abdominal aortic surgery. A randomized trial in 50 patients.

We carried out a randomized, controlled trial of sucralfate vs antacid as prophylaxis against upper gastrointestinal tract bleeding in 50 patients who had undergone abdominal aortic surgery. The groups were similar in age, sex, duration of prophylaxis, and number of risk factors per patient. No patient in the antacid group had upper gastrointestinal tract bleeding. One patient in the sucralfate group had frank bleeding from the nasogastric tube; however, she also had a coagulopathy and thrombocytopenia. The bleeding stopped when these conditions were corrected. No complications occurred in the sucralfate group; five patients in the antacid group had minor complications. Sucralfate was as effective as antacid in this trial, and it resulted in a considerable saving in nursing time.

Aged↗
PubMed1986

Current state of extraanatomic bypasses.

From my personal experience with a series of 227 extraanatomic bypasses, it is concluded that a high risk group of patients with multiple problems may have a reasonable alternative mode for limb salvage with extraanatomic bypass procedures. Axillo-bilateral femoral artery bypass grafts have a primary patency rate of 75 percent at the fifth year. With appropriate measures, net limb salvage can be accomplished in 84 percent of surviving patients at the fifth year. The result of a small group of patients with descending thoracic-aortofemoral artery bypass in this series was poor because of meager distal runoff and multiple previous operations. Axilloaxillary artery bypass grafts have shown an excellent long-term patency rate. A group of patients who underwent simultaneous axilloaxillary artery bypass and carotid endarterectomy have shown symptom-free long-term results with no subsequent stroke. This combined procedure showed no added neurologic morbidity. By proper application of extraanatomic bypass procedures, adequate palliation can be accomplished without major procedures in many patients who otherwise are high surgical risks.

Aged↗
PubMed1981

Surgical treatment of aorto-iliac artery disease.

In a period of 6 years, up to January, 1980, the author has treated 248 cases of aorto-iliac artery disease. There were 109 cases of abdominal aortic aneurysm, and the remainder was obstructive aorto-iliac artery disease. All but 20% of elective abdominal aortic aneurysms were asymptomatic. There were 100 cases of elective abdominal aortic aneurysm resection with operative mortality of 2%. There were 19 cases of ruptured aortic aneurysm with hospital mortality of 47%. There were 49 cases of aorto-femoral artery bypasses with 6th year cumulative patency rate of 89% in aorto-femoral bypass with Dacron graft, and 69% in aorto-iliac artery bypass with Dacron graft, and 2 year cumulative patency rate of 75% in descending thoracic aorto-femoral artery bypass with Poly Tetra Fluoro Ethylene graft. There were 32 cases of axillo-femoral artery bypasses and 48 cases of femoral-femoral artery bypasses. The 3 year cumulative patency rate of axillo-femoral artery bypass with PTFE graft was 89%, and that of femoral-femoral artery bypass with PTFE was 85%. However, axillo-femoral artery bypass with Dacron graft had 3-year patency rate of 67% and femoral-femoral artery bypass with Dacron graft was 62%. The 4 year cumulative patency rate of axillo-femoral artery bypass with Dacron graft was 39%. The 5 year cumulative patency rate of femoral-femoral artery bypass with Dacron graft was 62%

Aged↗