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Biomedical subjects

K W Sniderman

Publications and source records attributed to K W Sniderman.

At least 37 records · Page 2Linked to original sources
PubMed1989

Hepatic venography in the surgical assessment of hepatic tumours.

Hepatic venography was performed on 80 patients with hepatic tumours for the pre-operative assessment of resectability. Sixty-six patients subsequently underwent laparotomy, 27 undergoing hepatic resection. Forty-two patients had metastases from colo-rectal primaries, 19 hepatocellular carcinoma and 19 a variety of other tumours. The type and frequency of the abnormalities shown on venography were noted for each tumour category and for their hepatic segmental distribution. The results of venography were compared with those of arteriography, computed tomography and ultrasound and with the findings at laparotomy. Displacement was the commonest abnormality seen while encasement or obstruction occurred less frequently and tumour invasion was rare. The sensitivity of venography in correctly identifying the segmental distribution of tumour deposits was 41%. Sensitivity was poorest with tumours in the left lobe (31%) and bilobar tumours (0%). Venography was most sensitive in detecting tumour involvement of the major segmental hepatic veins and inferior vena cava (100%). Peripheral colo-rectal metastases frequently produced no venographic abnormality. Hepatic venography provides no additional information to arteriography, computed tomography or ultrasound in patients with peripheral or bilobar tumour deposits. Some additional information may be obtained with central tumours and venography is the most accurate means of detecting tumour involvement of the major segmental hepatic veins.

Adult↗
PubMed1989

Low-dose fibrinolytic therapy for recent lower extremity thromboembolism.

Low-dose catheter-directed fibrinolytic therapy (LDCF) using streptokinase (35) and urokinase (7) was performed on 42 separate occasions in 36 patients for recent lower extremity thromboembolic occlusion. Twenty-seven grafts and 15 native arteries were treated. Causes of occlusion were known in 32 instances: native artery proximal or distal occlusive disease or both (18 vessels); bypass graft stenosis (6); aneurysm (2); embolus (4); and postangiography thrombosis (2). Twenty-nine infusions were technically successful, and patients were clinically improved by 26 of the treatments. Twelve patients had unsuccessful infusions and six underwent subsequent amputation. In all patients, infusions longer than 12 hours resulted in prolonged thrombin times and lowered plasma fibrinogen concentrations; one infusion was discontinued due to a low fibrinogen concentration. Complications occurred on 17 occasions and included hemorrhage (6), distal embolization (3), compartment syndrome (1), retrograde thrombosis during infusion (5), hypotension (1), and systemic fibrinogenolysis (1). The cumulative success rate was 44% +/- 9% at 24 months. Late rethrombosis (five instances) was more common in patients who had inflow or outflow structural lesions not corrected following successful fibrinolysis. LDCF is a useful alternative to other methods of treatment for recent onset lower extremity thromboembolic occlusion. Structural vascular lesions uncovered by successful infusion should be corrected immediately after infusion to ensure long-term patency.

Blood Vessel Prosthesis↗
PubMed1988

Intestinal angina: percutaneous transluminal angioplasty of the celiac and superior mesenteric arteries.

Percutaneous transluminal angioplasty (PTA) was performed in ten patients with chronic ischemia of the mesenteric arteries and stenoses of the celiac artery and/or the superior mesenteric artery (SMA). PTA was performed on 14 occasions, with attempted dilation of 19 arteries. PTA was technically unsuccessful in two patients. Seventeen of 19 arteries (90%) were successfully dilated in eight patients, resulting in relief of symptoms that lasted from 6 to 24 months. Symptoms recurred in five patients, and redilation in three of them relieved the symptoms. Three patients, one of them following redilation, remained asymptomatic 7-9 months following PTA. An asymptomatic intimal dissection of the SMA was the only complication attributable to the procedure. PTA of celiac and SMA stenoses is an alternative to surgical revascularization and can be repeated if symptoms recur.

Adult↗
PubMed1987

5-year results of a prospective study of percutaneous transluminal angioplasty.

This paper presents the results of a prospective study of percutaneous transluminal angioplasty (PTA) for the treatment of patients with peripheral arterial occlusive disease and identifies the variables that are predictive of long-term success. The variables believed to be important prognostically were recorded for 984 consecutive PTAs performed between July 1978 and July 1986. Success or failure was defined using a combination of clinical and objective vascular laboratory criteria. The overall long-term success was estimated by the Kaplan-Meier method and differences between curves of success rate versus time for each variable were determined by the Wilcoxon and log-rank statistics. The combination of variables associated with success were determined by the Cox proportional hazards regression model. For all cases, the initial success rate was 88.6 +/- 1.0% and at 5 years was 48.2 +/- 2.3%. The following variables, when considered individually, were associated with success (p less than 0.05): indication for PTA, site of PTA, severity of lesion, runoff, number of sites dilated, diabetes, and the occurrence of a complication. From the Cox model, by using a stepwise multiple regression procedure, the following combination of variables were found to be predictive of success (p less than 0.05): (1) indication (claudication vs. salvage), (2) site (common iliac vs. other), (3) severity of lesion (stenosis vs. occlusion), and (4) runoff (good vs. poor). For all combinations of these four significant variables, curves of the success rate versus time were calculated. In conclusion, this study has identified the combination of four variables that together predict if PTA is likely to be successful in the management of a patient with peripheral arterial occlusive disease.

Angioplasty, Balloon↗
PubMed1986

Transluminal angioplasty of the hypogastric artery for treatment of buttock claudication.

Two patients with incapacitating isolated buttock claudication and bilateral hypogastric artery occlusive disease were treated by balloon dilatation of a single hypogastric artery. Symptoms were eliminated in 1 patient and reduced in the other. Percutaneous transluminal angioplasty represents an effective therapeutic approach in this relatively uncommon situation.

Aged↗
PubMed1986

Indium-111 platelet scintigraphy for the diagnosis of acute venous thrombosis.

Platelets labeled with indium-111 have been used successfully as a marker of active thrombosis in man. To establish the diagnostic accuracy of platelet scintigraphy in comparison to contrast venography in the diagnosis of acute lower limb venous thrombosis, we evaluated 103 consecutive patients divided into two groups. Platelets were labeled by the indium-111 oxine method. Patients from group I (n = 73, 56 had venograms) were asymptomatic and underwent platelet scintigraphy 1.1 +/- 0.6 days (mean +/- 1 SD) after a major orthopedic procedure. Patients from group II (n = 30, all had venograms) were symptomatic and underwent platelet scintigraphy 1.2 +/- 1.7 days after venography. In group II, 15 patients with positive findings on contrast venography were treated with intravenous heparin; five others with positive venograms did not receive heparin until platelet scintigraphy was completed. Both platelet scintigraphy and contrast venography were evaluated by two blinded observers. Only studies with blinded agreement of both platelet scintigraphy and contrast venography were included in the analysis. Sensitivity and specificity of platelet scintigraphy for the whole limb were 93% and 97% in group I and 42% and 67% in group II. The lower sensitivity in group II was most likely attributable to therapy with heparin. These results demonstrate that platelet scintigraphy, a test that permits imaging for up to five days after a single injection, correlates favorably with contrast venography in patients who have not received heparin and may be used as a surveillance test in high-risk patients. The role of platelet scintigraphy in acutely symptomatic patients requires further evaluation.

Aged↗
PubMed1986

Aortic dissection: a statistical analysis of the usefulness of plain chest radiographic findings.

Findings on plain chest radiographs of patients with aortic dissection are variable and often overlap those of patients without dissection. To determine which findings were most useful in predicting aortic dissection, plain chest radiographs from 36 patients with aortographically proven aortic dissection and 36 patients from a control population were randomized and analyzed independently by five radiologists for the presence of various radiographic features associated with this condition. A widened aortic knob, widened descending aorta, and widened mediastinum showed the greatest interobserver agreement (p less than .001) although the overall interobserver agreement was poor. The final conclusion of the radiologists was a better predictor of dissection than any of the individual radiographic features alone. Widening of the mediastinum (p less than .001) and widening of the aortic knob (p less than .012) were the only two radiographic features of significance in predicting dissection. In a stepwise multiple logistic regression model, the radiologists achieved an overall accuracy of 85%, a sensitivity of 81%, and a specificity of 89%. Although this illustrates the usefulness of plain chest radiographs in diagnosing aortic dissection, poor interobserver agreement dictates that further definitive investigation be undertaken.

Adolescent↗
PubMed1986

Comparison of intra-arterial digital subtraction angiography and conventional filming in peripheral vascular disease.

We studied a series of 114 patients with ischemic peripheral vascular disease angiographically by conventional film-screen (CF) and by intra-arterial digital subtraction (DSA) techniques. The quality of films and images was evaluated at four anatomic levels. We reached the following conclusions: a) in most patients a DSA study will suffice for diagnosis; b) an ability to see arteries was related to the film or image quality; c) in the pelvis, although most studies were of excellent quality, more CF than DSA were of excellent quality; d) in the thigh, both CF and DSA studies were mostly of excellent quality; e) in the leg and foot, more DSA than CF studies were of excellent quality; f) patients preferred DSA to CF studies; g) physician acceptance of DSA was mixed; and h) good patient hydration can reduce the potential renal complications of the larger contrast loads used in CF studies.

Angiography↗
PubMed1985

Postbiopsy renal allograft arteriovenous fistula: therapeutic embolization.

Two patients with large, postbiopsy renal allograft arteriovenous fistulae are presented. One patient also had a renal artery anastomotic stenosis. Prominent clinical features in these cases were deterioration of allograft function and severe hypertension. Following therapeutic embolization, combined with balloon angioplasty in the second patient, there was marked improvement in allograft function and a return to normal blood pressure.

Adult↗
PubMed1985

Pseudoaneurysm: a complication of faulty technique in femoral arterial puncture.

Pseudoaneurysm is a well-documented but rare complication of retrograde femoral arterial puncture. We present six patients in whom pseudoaneurysm complicated this procedure. The pseudoaneurysm arose from the superficial femoral artery in five patients and from the profunda femoris artery in one. An arteriovenous fistula also arose from the superficial femoral artery in one patient. In no patient did the pseudoaneurysm arise from the common femoral artery. Two mechanisms are postulated as to why pseudoaneurysms rarely complicate puncture of the common femoral artery.

Aneurysm↗
PubMed1985

Hepatoma, arterioportal shunting, and hyperkinetic portal hypertension: therapeutic embolization.

Four patients with hepatocellular carcinoma, shunting of blood from the hepatic artery to the portal vein, and hyperkinetic portal hypertension were treated by transcatheter embolization of the hepatic artery. In three acutely bleeding patients variceal hemorrhage was controlled by the embolization. Following embolization hepatofugal portal venous flow became hepatopetal in all four patients. No serious complications were encountered. When hepatoma is complicated by arterioportal shunting and hyperkinetic portal hypertension, occlusion of the fistula by transcatheter embolotherapy can reduce the portal pressure.

Aged↗
PubMed1984

Two cases of spontaneous lysis of arterial thrombi.

Two cases of spontaneous lysis of arterial thrombi are described. The occurrence of spontaneous thrombolysis and the relative ease of performing Fogarty embolectomy (thrombectomy) in peripheral arteries should be considered along with the clinical status of a patient who is viewed as a possible candidate for thrombolytic therapy, a procedure which has a potential for severe hemorrhagic complications.

Adolescent↗
PubMed1984

Percutaneous embolectomy by transcatheter aspiration. Work in progress.

Distal embolization occurred in 14 of 339 (4%) attempted percutaneous transluminal angioplasty (PTA) procedures, including five of 225 stenoses (2.2%) and nine of the 81 occlusions (11%) that were crossed successfully in 114 attempts (8%). Transcatheter embolectomy by aspiration through a nontapered large-bore catheter was technically successful in five of six attempts (83%), and was combined with successful PTA in three of five patients. In two patients in whom the clinical result of PTA was considered unsatisfactory, successful transcatheter embolectomy permitted an uncomplicated surgical by-pass procedure to be performed. If clinically significant embolization occurs during PTA, this procedure can be attempted prior to surgical embolectomy as an alternative to local fibrinolytic therapy.

Aged↗
PubMed1984

Optimal injection technique for intravenous digital subtraction angiography. Animal and clinical studies of right atrial injection using small volumes (25 ml) at a high rate (35 ml/sec).

Small-volume right atrial injections of contrast material (25 ml) delivered at a high rate (30-35 ml) were routinely performed for digital subtraction angiography in 232 studies (698 injections). Excellent opacification of the aorta and peripheral arteries was consistently obtained. Superior opacification following right atrial injections compared with peripheral or superior vena cava boluses was confirmed in animal experiments.

Angiography↗