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Biomedical subjects

W D Routh

Publications and source records attributed to W D Routh.

At least 19 recordsLinked to original sources
PubMed2001

Role of angiography in the detection of aortic branch vessel injury after blunt thoracic trauma.

PURPOSE: The occurrence of aortic arch branch vessel injury as an isolated occurrence or in association with aortic injury after blunt chest trauma has not been emphasized in the literature. The imaging evaluation is also controversial. METHODS: We reviewed thoracic aortograms of 166 patients examined at our institution from May 1995 to May 1999 performed after blunt thoracic trauma. We evaluated the aortograms for aortic and arch branch vessel injuries. Twenty-four injuries were detected and all patients had either a wide mediastinum demonstrated on plain radiographs (22 patients) or mechanism of injury conducive to aortic injury. RESULTS: Of the 166 patients, 24 (14%; 16 men, 8 women; mean age, 50 years) had aortic or arch branch vessel injuries. Isolated aortic injury occurred in 15 (9%) of 166 patients. Branch vessel injury occurred in 9 (5%) of 166 patients; seven patients (10 branch vessels) had isolated branch vessel injury and two patients (three branch vessels) had branch vessel injury associated with aortic injury. The injured branch vessels were brachiocephalic artery (four), left common carotid artery (four), left subclavian artery (three), right internal mammary artery (one), and left vertebral artery (one). The types of branch vessel injuries included intimal tears (nine vessels; 69%), and transection causing a pseudoaneurysm (four vessels; 31%). Revised Trauma Scores in patients with branch vessel injuries were 12 in seven patients and 11 and 4 in one each. CONCLUSION: We emphasize the angiographic findings in these patients that can at times be quite subtle. Awareness of the incidence of such injuries either in isolation or associated with aortic injury has implications regarding evaluation of this patient population with less invasive techniques such as CT or transesophageal echocardiography.

Adolescent↗
PubMed2000

Experimental and computational flow evaluation of coronary stents.

Local flow alterations created by a metallic stent in a simulated coronary artery were studied to compare the hemodynamic effects of two different stent geometries. Dye injection flow visualization and computational fluid dynamics were used. Resting and exercise conditions were studied. Flow visualization using the dye injection method provided a qualitative picture of stent hemodynamics while the computational approach provided detailed quantitative information on the flow next to the vessel wall near the intersections of stent wires. Dye injection visualization revealed that more dye became entrapped between the wires where the wire spacing was smallest. The dye washout times were shorter under exercise conditions for both wire spacings tested. The computational results showed that stagnation zones were continuous from one wire to the next when the wire spacing was small. Results from greater wire spacing (more than six wire diameters) showed that the stagnation zones were separate for at least part of the cardiac cycle. The sizes of the stagnation zones were larger under exercise conditions, and the largest stagnation zones were observed distal to the stent. These studies demonstrate that stent geometry has a significant effect on local hemodynamics. The observation that fluid stagnation is continuous in stents with wire spacings of less than six wire diameters may provide a criterion for future stent design.

Biomechanical Phenomena↗
PubMed1993

Percutaneous nephrostomy for treatment of intractable hemorrhagic cystitis.

Six patients with severe hemorrhagic cystitis unresponsive to traditional localized therapy were treated with percutaneous nephrostomy for diversion of urine. Bladder hemorrhage ceased in 3 patients, decreased in 2 and was unchanged in 1. In 1 patient with profound thrombocytopenia perirenal hematoma developed as a result of the nephrostomy placement but this complication was self-limited and did not require surgery. Our experience with these 6 patients indicates that nephrostomy diversion is safe and effective in most cases of hemorrhagic cystitis refractory to traditional, nonoperative therapy. Percutaneous urine diversion may obviate the need for surgical urinary diversion in patients who have intractable hemorrhagic cystitis.

Cystitis↗
PubMed1993

Comparison of penile duplex ultrasonography to pudendal arteriography. Variant penile arterial anatomy affects interpretation of duplex ultrasonography.

RATIONALE AND OBJECTIVES: Duplex ultrasonography is currently used as a noninvasive imaging modality for the functional evaluation of penile blood flow in impotent men. However, the accuracy of this test is controversial. The objective of this study was to determine the sensitivity and specificity of duplex ultrasonography, to assess the ultrasonographic parameters most predictive of arterial disease, and to evaluate the causes of misinterpretation of duplex ultrasound studies. METHODS: Duplex ultrasonography and pudendal arteriography were performed on 42 impotent men during a 4-year prospective study. The predictive power of the following ultrasonographic parameters were analyzed: cavernosal arterial diameter, peak blood flow velocity, and pulsations on real-time ultrasonography. RESULTS: The results of both studies were concordant in 81% of the patients with a 77% sensitivity and 85% specificity for ultrasonography when using arteriography as the gold standard. Arterial pulsations and peak blood flow velocity were most predictive, whereas dilation was not helpful. Variant penile arterial anatomy was present in 83% of the patients and was the most frequent cause of misinterpretation of duplex ultrasonography. CONCLUSION: Duplex ultrasonography is a fairly reliable screening test for arterial disease in impotent men. Visualization of arterial pulsations and measurement of peak blood flow velocity are the best predictors of arterial function. Awareness of the potential arterial anomalies may help reduce misinterpretation of ultrasonography. Arteriography is necessary in any patient being considered for penile arterial surgery because of the high frequency of anatomic variations.

Adult↗
PubMed1992

Transcatheter embolization of a high-flow congenital intrahepatic arterial-portal venous malformation in an infant.

An intrahepatic arterial-portal venous malformation (APVM) was diagnosed in a 4 1/2-month-old infant with portal hypertension. Visceral angiography showed a large saccular vascular space in the left hepatic lobe with a multiplicity of feeding arteries and drainage into the left portal vein. The lesion was successfully treated by transcatheter embolization following two unsuccessful surgical procedures. Two years later portal vein thrombosis with cavernous transformation was diagnosed, possibly a consequence of the high-flow arterial-portal shunt and its subsequent occlusion. Knowledge of the anatomic differences between this rare congenital APVM and the more commonly occurring arterial-portal fistula is crucial in planning effective transcatheter embolotherapy or surgery for these lesions.

Arteriovenous Fistula↗
PubMed1991

Urokinase infusion: feasibility of monitoring for complications in a non-intensive care setting.

In an effort to more effectively use critical care facilities and to reduce costs, during a 2 1/2-year period, the condition of 32 patients who received 37 local intraarterial urokinase (UK) infusions was monitored in a non-intensive care unit (ICU) setting. Techniques of infusion, mean total dose of lytic agent used (1.7 million IU), and mean duration of infusion (22 hours) were similar to those reported previously in series of patients monitored in the ICU. Complete lysis (no angiographically detectable residual clot within the treated segment) was achieved in 28 of 37 infusions (76%). Major complications occurred during two infusions (5.4%). In 33 of the 37 cases, systemic heparin was administered during UK infusion. No cases of pericatheter thrombosis were encountered. At the authors' institution, patients can be safely monitored during local UK infusion in a non-ICU setting without compromising effectiveness of therapy. This approach has resulted in enhanced cost-effectiveness of thrombolytic therapy and more effective use of critical care facilities.

Cost-Benefit Analysis↗
PubMed1991

Peripheral arterial occlusive disease: prospective comparison of MR angiography and color duplex US with conventional angiography.

Conventional angiography, two-dimensional inflow magnetic resonance (MR) angiography, and color duplex ultrasound (US) were performed on 12 patients in a blinded, prospective study. The ability to grade arterial lesions and plan revascularization interventions were compared. Arterial lesions were categorized as nonsignificant (0%-49% diameter reduction) or significant (50%-100% diameter reduction). Determination of nonsignificant and significant lesions with MR angiography was in agreement with that at conventional angiography in 100 of 140 lesions (71%). Agreement between results of conventional angiography and color duplex US occurred with 114 of 123 infrainguinal lesions (93%). Twenty-one vascular interventions were planned by using conventional angiography; there was agreement with color duplex US in 11 cases and MR angiography in five. Color duplex US performed well in the assessment of infrainguinal disease but was limited in the evaluation of iliac segments because of nonvisualization. The iliac region was visualized in more patients with MR angiography than with color duplex US, but image quality with MR angiography was inconsistent. Strategies to improve MR angiography of the peripheral vasculature merit further study.

Aged↗
PubMed1990

Meckel's diverticula: angiographic diagnosis in patients with non-acute hemorrhage and negative scintigraphy.

Meckel's diverticula were detected by mesenteric angiography in 2 patients with unexplained gastrointestinal bleeding following negative barium, endoscopic, and scintigraphic evaluation. Abnormal, irregular, arterial branches supplied by an elongated, nonbranching ileal artery and an associated capillary stain were present in each case. Since neither diverticulum was bleeding at the time of angiography, focal contrast extravasation was not present. Superselective magnification angiography, evacuation of contrast from the urinary bladder, and careful patient positioning significantly improved the visibility of these lesions. Visceral angiography performed with meticulous attention to technical detail can be diagnostic of Meckel's diverticulum, even in the absence of acute hemorrhage.

Adolescent↗
PubMed1990

Anomalous origin of bronchial arteries: potential pitfall of embolotherapy for hemoptysis.

Bronchial artery embolization was performed in two patients with anomalous origins of the bronchial artery. In one patient, the anomalous bronchial artery originated from the convex surface of the aortic arch between the origins of the brachiocephalic and left carotid arteries, while in the other, it originated from the internal mammary artery. Anomalous bronchial arteries represent a potential pitfall during bronchial artery embolization. Radiologists involved in embolotherapy for hemoptysis should therefore be alerted to the possible presence of anomalous bronchial arteries, especially when significant bronchial artery supply to areas of abnormal pulmonary parenchyma is not demonstrated at a catheter search or aortography of the descending aorta. In these instances, arch aortography should be performed to identify anomalous origins of the bronchial arteries or other nonbronchial systemic collateral vessels.

Adult↗
PubMed1990

Renal artery stenosis: prospective evaluation of diagnosis with color duplex US compared with angiography. Work in progress.

A prospective, double-blind comparison of color duplex sonography with angiography was performed for diagnosing renal artery stenosis in 50 kidneys in 26 patients. The major criterion for diagnosing a diameter narrowing of more than 50% was a velocity of greater than 100 cm/sec. Angiography demonstrated 10 stenoses and one occlusion in main or accessory renal arteries in seven patients. Twenty-two percent of kidneys had accessory renal arteries. Color duplex scanning helped identify 58% of the main arteries and no accessory vessels. None of the stenotic vessels were identified with duplex scanning, but the single occluded vessel was correctly diagnosed. Nine of the 29 vessels identified with duplex scanning were incorrectly diagnosed as stenotic, findings yielding a specificity of 37%. The authors conclude that the published velocity threshold of 100 cm/sec is too low. Duplex scanning with current technology is unlikely to prove satisfactory for screening patients with hypertension for renal artery stenosis.

Adult↗
PubMed1990

Tube tamponade: potential pitfall in angiography of arterial hemorrhage associated with percutaneous drainage catheters.

Diagnostic angiography performed to search for a source of hemorrhage in three patients with percutaneous transhepatic biliary catheters and one patient with a percutaneous nephrostomy catheter was initially unrewarding when performed with the drainage catheter in place. In each patient, removal of the drainage catheter resulted in severe pulsatile hemorrhage from the parenchymal tract and allowed angiographic localization of the bleeding site. Temporary control of the hemorrhage was then obtained by inflating an angioplasty balloon within the tract. Transcatheter embolotherapy provided definitive control of bleeding in three patients. When initial angiographic evaluation for bleeding in patients with percutaneous biliary and nephrostomy catheters fails to depict a source, the study should be repeated immediately after removal of the drainage catheter. Because hemorrhage can be severe once tamponade is relieved, the drainage catheter should be withdrawn over a guide wire so that a tamponading catheter can be rapidly reinserted to control hemorrhage until more definitive therapy is undertaken.

Aged↗
PubMed1990

Transcatheter thrombosis of a leaking saccular aneurysm of the main renal artery with preservation of renal blood flow.

Percutaneous techniques have been used in the treatment of aneurysms and pseudoaneurysms in a variety of anatomic locations, including the kidney. An elderly patient with a leaking saccular aneurysm of the main left renal artery was considered a poor operative risk. We were able to embolize and thrombose the aneurysm selectively by using a combination of coil springs, guidewire, thrombin, and bucrylate without occluding the renal artery.

Aged↗