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Intractable and recurrent ureteral stricture presents a continuous challenge to the urologist. We report on 5 patients with severe ureteral stricture who were successfully treated with self-expanding metallic stents. Ureteral stricture occurred at ureteroileal anastomotic sites after neoplasm resection in 2 cases, multiple upper ureteral strictures were related to multiple surgical procedures for correction of bladder exstrophy in 1 and a ureteral kink developed in 1. Treatment with transluminal balloon dilation provided poor results but self-expanding metallic stents were used successfully with no major complications. In the last patient the stent and the overlying ureter were removed due to recurrent reflux; the gross and histological ureteral changes are discussed in detail. The technical approach is described, alternative therapeutic options are considered and pertinent literature is reviewed.

OBJECTIVE Assessment of the relationship between changes in sequential coronary arteriograms and subsequent clinical coronary events. DESIGN The Program on the Surgical Control of the Hyperlipidemias, a randomized secondary atherosclerosis intervention trial, obtained coronary arteriograms at baseline, 3, 5, and 7 or 10 years of follow-up. Assessments of changes between pairs of coronary arteriograms were made by two-member panels blinded to the patients' assigned treatment and to the temporal sequence of the films. The relationship of changes between the baseline and the 3-year follow-up arteriograms and subsequent clinical coronary events was examined. SETTING Three university hospitals and one private primary care facility. PATIENTS A total of 838 patients, with 417 patients randomized to the control group and 421 to the intervention group. Of all patients, 695 had baseline and 3-year arteriograms. INTERVENTION The control group received American Heart Association Phase II diet instruction and the intervention group received identical dietary instruction plus a partial ileal bypass operation. MAIN OUTCOME MEASURE The use of arteriographic changes as a predictor of subsequent clinical coronary events. RESULTS Changes between the baseline and the 3-year coronary arteriographic overall disease assessment were significantly associated with subsequent overall and atherosclerotic coronary heart disease mortality (P less than .01). For the combined end point of atherosclerotic coronary heart disease mortality or confirmed nonfatal myocardial infarction, a significant relationship between the overall disease assessment and subsequent clinical events was found in the control group (P less than .0001) and in the surgery group (P = .04). For this combined end point, however, the control and the surgery groups were different with respect to clinical coronary events after 3 years, stratified by the baseline to 3-year overall disease assessment (P less than .001, unadjusted; P = .06, adjusted for 3-year clinical covariates). CONCLUSIONS Coronary arteriographic changes can be used in atherosclerosis intervention trials as a limited surrogate end point for certain clinical coronary events. This relationship is statistically compelling for overall mortality and atherosclerotic coronary heart disease mortality. For an individual patient, changes in the severity of coronary atherosclerosis seen on sequential coronary arteriograms can serve as prognostic indicators for subsequent overall or atherosclerotic coronary heart disease mortality.

Sixty-eight peripheral angioplasty procedures were augmented with direct argon laser energy in 63 non-consecutive patients. Technical success was achieved in 100% of femoropopliteal stenoses, 88% of femoropopliteal occlusions (mean length, 9 cm), and 71% of occluded iliac segments (mean length, 6 cm). In femoropopliteal arteries, the primary success rate was 83% (15 of 18) for occlusions longer than 7 cm and 92% (22 of 24) for occlusions 7 cm or shorter (P = .63). Complications included three thermal perforations and two emboli. The 1-year patency rate was 75% overall and 91% for femoropopliteal stenoses; iliac and femoropopliteal occlusions had patency rates of 79% and 60%, respectively. Disease severity was predictive of 1-year patency (85% for claudication vs 23% for limb-threatening ischemia; P = .0003), while distal run-off and femoropopliteal lesion length was not (P = .30 and .69, respectively). For patients with claudication who had femoropopliteal occlusions, a 1-year patency rate of 84% was obtained in short lesions versus 68% in long lesions (P = .36). For patients with limb-threatening ischemia, similar stratifications yielded patency rates of 21% and 33% (P = .38).

Prostatic urethroplasty with a balloon catheter is an easy procedure to perform, but certain guidelines must be followed to avoid complications. This procedure will reduce the overall treatment cost of benign prostatic hyperplasia significantly. Preliminary results range from 70% to 85% symptomatic improvement or resolution of the prostatism symptoms. Its recurrence rate is still not known, but a small one is expected. Nevertheless, because of the noninvasiveness, low cost, and simplicity of the procedure, it potentially could be repeated, if necessary. This procedure is one that when it is done in combination with another specialist, in this case a urologist, the patient will benefit by the use of the expertise of both the urologist's knowledge of the disease of the urinary system and the interventional radiologist's skills with catheters and guide wires.

The purpose of this study was to evaluate the use of intravascular sonography for the detection of arteriosclerosis and to determine the effects of vascular interventional procedures on the arterial wall. A catheter-based 20-MHz transducer was used. Forty patients were studied. Twelve had clinical evidence of peripheral vascular disease, 13 were healthy renal donors, and 15 underwent vascular interventional procedures. The aorta and the ipsilateral iliac artery were examined in real time under fluoroscopic guidance and the results were compared with angiography. Sonography in eight of the 13 renal donors showed arterial wall abnormalities in the absence of angiographic evidence of disease. Sonography of the 15 patients after angioplasty or atherectomy demonstrated plaque fractures, intramural dissections, or atherectomy grooves. Our experience suggests that intravascular sonography is of value in reducing the use of angiography to monitor progress or complications of vascular interventional procedures.

Prostatic urethroplasty with balloon catheter is a new interventional uroradiological procedure that appears promising in treating benign prostatic hyperplasia in selected patients. As with many of the interventional radiographic procedures, it reduces the cost of therapy, it is associated with very low morbidity in an outpatient setting, and it can be performed in almost any patient, regardless of their medical condition. The recovery period is minimal. The procedure is easy to perform, but certain guidelines have to be followed to avoid complications. The workup of these patients is relatively the same as a patient undergoing surgical intervention. The patient needs to be thoroughly assessed to exclude the possibility of prostatic malignancy.

Radiolabeling of Ivalon (polyvinyl alcohol sponge) particles permits localization of injected particles during embolization through the use of a portable gamma camera and provides a means to prevent potentially fatal complications such as pulmonary embolization. A more efficient technique of labeling Ivalon particles with technetium-99m sulfur colloid was developed. An increase in labeling efficiency allowed more accurate determination of the distribution of injected Ivalon particles. Scanning electron microscopy demonstrated the stability of the Ivalon particles during this new labeling process. Two patients with arteriovenous malformations underwent therapeutic embolization with radiolabeled Ivalon particles; gamma camera imaging of the lesion and chest was performed throughout the procedure.

Assessment of the relationship between changes in sequential coronary arteriograms and subsequent clinical coronary events.The Program on the Surgical Control of the Hyperlipidemias, a randomized secondary atherosclerosis intervention trial, obtained coronary arteriograms at baseline, 3, 5, and 7 or 10 years of follow-up. Assessments of changes between pairs of coronary arteriograms were made by two-member panels blinded to the patients' assigned treatment and to the temporal sequence of the films. The relationship of changes between the baseline and the 3-year follow-up arteriograms and subsequent clinical coronary events was examined.Three university hospitals and one private primary care facility.A total of 838 patients, with 417 patients randomized to the control group and 421 to the intervention group. Of all patients, 695 had baseline and 3-year arteriograms.The control group received American Heart Association Phase II diet instruction and the intervention group received identical dietary instruction plus a partial ileal bypass operation.The use of arteriographic changes as a predictor of subsequent clinical coronary events.Changes between the baseline and the 3-year coronary arteriographic overall disease assessment were significantly associated with subsequent overall and atherosclerotic coronary heart disease mortality (P less than .01). For the combined end point of atherosclerotic coronary heart disease mortality or confirmed nonfatal myocardial infarction, a significant relationship between the overall disease assessment and subsequent clinical events was found in the control group (P less than .0001) and in the surgery group (P = .04). For this combined end point, however, the control and the surgery groups were different with respect to clinical coronary events after 3 years, stratified by the baseline to 3-year overall disease assessment (P less than .001, unadjusted; P = .06, adjusted for 3-year clinical covariates).Coronary arteriographic changes can be used in atherosclerosis intervention trials as a limited surrogate end point for certain clinical coronary events. This relationship is statistically compelling for overall mortality and atherosclerotic coronary heart disease mortality. For an individual patient, changes in the severity of coronary atherosclerosis seen on sequential coronary arteriograms can serve as prognostic indicators for subsequent overall or atherosclerotic coronary heart disease mortality.

The Simpson atherectomy catheter has been used successfully to recanalise eleven complete occlusions of the iliac and femoropopliteal arteries. Atherectomy and angioplasty were used in combination in 8 cases. Following atherectomy, all patients showed clinical improvement. Distal pulses returned in 7; rest pain and/or claudication disappeared in the other 4. Ischaemic ulcers healed in the 2 affected patients. Overall, ankle-arm indices (AAI) improved by an average of 0.43, with the improvement being greatest (0.55) in patients in whom the lumen was recanalised to within 91-100% of the native luminal diameter. Seven patients have remained with stable AAI values and without change in their clinical status at 18 months follow-up.

The Program on the Surgical Control of the Hyperlipidemias (POSCH), a randomized clinical trial, was designed to test whether cholesterol lowering induced by the partial ileal bypass operation would favorably affect overall mortality or mortality due to coronary heart disease. The study population consisted of 838 patients (417 in the control group and 421 in the surgery group), both men (90.7 percent) and women, with an average age of 51 years, who had survived a first myocardial infarction. The mean follow-up period was 9.7 years.When compared with the control group at five years, the surgery group had a total plasma cholesterol level 23.3 percent lower (4.71 +/- 0.91 vs. 6.14 +/- 0.89 mmol per liter [mean +/- SD]; P less than 0.0001), a low-density lipoprotein cholesterol level 37.7 percent lower (2.68 +/- 0.78 vs. 4.30 +/- 0.89 mmol per liter; P less than 0.0001), and a high-density lipoprotein cholesterol level 4.3 percent higher (1.08 +/- 0.26 vs. 1.04 +/- 0.25 mmol per liter; P = 0.02). Overall mortality and mortality due to coronary heart disease were reduced, but not significantly so (deaths overall [control vs. surgery], 62 vs. 49, P = 0.164; deaths due to coronary disease, 44 vs. 32, P = 0.113). The overall mortality in the surgery subgroup with an ejection fraction greater than or equal to 50 percent was 36 percent lower (control vs. surgery, 39 vs. 24; P = 0.021). The value for two end points combined--death due to coronary heart disease and confirmed nonfatal myocardial infarction--was 35 percent lower in the surgery group (125 vs. 82 events; P less than 0.001). During follow-up, 137 control-group and 52 surgery-group patients underwent coronary-artery bypass grafting (P less than 0.0001). A comparison of base-line coronary arteriograms with those obtained at 3, 5, 7, and 10 years consistently showed less disease progression in the surgery group (P less than 0.001). The most common side effect of partial ileal bypass was diarrhea; others included occasional kidney stones, gallstones, and intestinal obstruction.Partial ileal bypass produces sustained improvement in the blood lipid patterns of patients who have had a myocardial infarction and reduces their subsequent morbidity due to coronary heart disease. The role of this procedure in the management of hypercholesterolemia remains to be determined. These results provide strong evidence supporting the beneficial effects of lipid modification in the reduction of atherosclerosis progression.

Objective. —Assessment of the relationship between changes in sequential coronary arteriograms and subsequent clinical coronary events. Design. —The Program on the Surgical Control of the Hyperlipidemias, a randomized secondary atherosclerosis intervention trial, obtained coronary arteriograms at baseline, 3, 5, and 7 or 10 years of follow-up. Assessments of changes between pairs of coronary arteriograms were made by two-member panels blinded to the patients' assigned treatment and to the temporal sequence of the films. The relationship of changes between the baseline and the 3-year follow-up arteriograms and subsequent clinical coronary events was examined. Setting. —Three university hospitals and one private primary care facility. Patients. —A total of 838 patients, with 417 patients randomized to the control group and 421 to the intervention group. Of all patients, 695 had baseline and 3-year arteriograms. Intervention. —The control group received American Heart Association Phase II diet instruction and the intervention group received identical dietary instruction plus a partial ileal bypass operation. Main Outcome Measure. —The use of arteriographic changes as a predictor of subsequent clinical coronary events. Results. —Changes between the baseline and the 3-year coronary arteriographic overall disease assessment were significantly associated with subsequent overall and atherosclerotic coronary heart disease mortality ( P P P =.04). For this combined end point, however, the control and the surgery groups were different with respect to clinical coronary events after 3 years, stratified by the baseline to 3-year overall disease assessment ( P P =.06, adjusted for 3-year clinical covariates). Conclusions. —Coronary arteriographic changes can be used in atherosclerosis intervention trials as a limited surrogate end point for certain clinical coronary events. This relationship is statistically compelling for overall mortality and atherosclerotic coronary heart disease mortality. For an individual patient, changes in the severity of coronary atherosclerosis seen on sequential coronary arteriograms can serve as prognostic indicators for subsequent overall or atherosclerotic coronary heart disease mortality. ( JAMA . 1992;268:1429-1433)

Four patients with primary subclavian-axillary vein thrombosis are described. Each patient received local thrombolytic therapy, resulting in reestablishment of antegrade flow via the axillary and subclavian veins. An intrinsic venous abnormality (perimural fibrosis and/or intimal dissection) identified at the first rib-clavicle junction (subclavian-axillary vein junction) was thought to be responsible for the thrombosis. One of the four patients subsequently underwent a surgical venous bypass of the abnormal segment, and a second underwent percutaneous transluminal angioplasty.

Regional segmental wall motion analysis assumes a linear or radial grid system. In this study, motion patterns of points on the canine endocardium were evaluated. Radiopaque endocardial and epicardial markers were inserted along the anterior and posterior descending coronary arteries. Postoperative cine radiography showed that the endocardial markers did not move along either linear or radial grids. The endocardial and epicardial markers were shown to have different patterns of movement.

Direct laser light, in combination with percutaneous transluminal angioplasty (PTA), was used to recanalize atherosclerotic peripheral arteries. Argon laser energy was controlled with an optical assembly and aligned with a special centering/dilation balloon so that plaque tissue absorbed laser energy directly and was vaporized. A channel was thereby created with multiple 10-W laser exposures (2-10 seconds), and conventional angioplasty was then performed. Recanalization was achieved in 33 of 36 procedures (92%), in 23 femoropopliteal (mean length, 9 cm) and three iliac total occlusions and ten femoropopliteal high-grade stenoses, with the three failures occurring in the first group. Complications included two emboli, six moderate groin hematomas, and one laser perforation. While these results are preliminary (mean follow-up, 3 months), direct laser angioplasty appears to be a useful adjunct to PTA for treating atherosclerotic arteries.

Of 356 patients in whom percutaneous nephrostomy was performed at this institution 59 had ureteral stones. In our experience with the first 36 patients antegrade techniques for ureteral stone extraction had many assets but sometimes they were difficult. Recently, we incorporated a retrograde flushing technique, using carbon dioxide and diluted radiopaque dye, into our percutaneous approach to ureteral stones. Based on our experience with this technique in the next 23 consecutive patients, we believe that percutaneous nephrostolithotomy and retrograde flushing should be added to the armamentarium of urologists committed to the percutaneous endourological approach to ureteral stones.

For surgical treatment of patients with FMD of the renal arteries an optimal angiographic study is necessary. Preferably aortography as well as selective magnification renal angiography should be carried out. Oblique views may be necessary to demonstrate the peripheral extension into segmental branches, collateral circulation, the presence of aneurysms, and/or associated complications as AV fistulas, infarctions, intramural hematomas and pseudoaneurysms.

The treatment of renal and ureteral stones has undergone rapid and major changes over the past ten years. Extracorporeal Shockwave lithotripsy has become the most commonly used modality for the treatment of renal and upper ureteral stones. Lower ureteral stones are more commonly being approached by retrograde techniques. Percutaneous nephrolithotomy, medical therapy, and open surgical nephrolithotomy offer viable alternatives in given situations. Presented here is the current application of each of these techniques, both alone and in combination, for the treatment of urinary stones.

Abnormal systemic-to-pulmonary-artery anastomoses can exist in many pathological conditions and result in a left-to-right shunt. Three such conditions are (a) congenital abnormalities, e.g., pulmonary vein atresia, (b) acquired states, e.g., chronic bronchiectasis, and (c) post-surgical states, e.g., a Mustard procedure for complete transposition. Regardless of the etiology, the anastomosis and resulting shunt produce increased oxygen saturation in the ipsilateral pulmonary artery. Four cases are presented, with emphasis on the angiographic and hemodynamic findings.

Ablation of the kidney was attempted in 12 dogs by injecting 10-30 ml of heated (100 degrees C) contrast medium (Hypaque-60, diatrizoate meglumine) into the renal artery. Complete renal ablation without collateralization was demonstrated. Hot contrast medium is an effective embolic agent, and its use is associated with few of the drawbacks of presently used techniques.

Doming of the pulmonary valve is considered an important angiographic sign for valvar stenosis. But, this sign cannot be used with similar specificity following valvotomy because at the time of surgery a bicuspid valve is created. Pre- and postoperative hemodynamic data and right ventriculograms are reviewed in 22 patients with simple pulmonary valvar stenosis. There was no correlation between the transvalvar gradient and appearance of the pulmonary valve after surgery.

Various embolization cases are described, and these require certain embolization materials. In our experience Gelfoam particles are very well suited for gastrointestinal tract lesions. Ivalon shavings gave excellent results in congenital arteriovenous malformations with permanent occlusions. Bristle brushes are a new device for larger artery occlusion. Stainless steel coils in combination with silk tufts proved thrombosis of large AV fistuals or of aneurysms particularly of the splenic artery.

The images produced in rotational scanography, currently under investigation at several institutions, may contain several kinds of artifacts. The sources of such artifacts are: 1. vertical and horizontal misalignment of the focal spot with the axis of rotation; 2 misalignment of the primary and secondary slits; 3 a density gradient due to slit cut-off; 4 vibration of the x-ray tube during rotation; 5. A density gradient due to variation in motor speed; 6. radiographic striations due to ripple of the tube output. Striations are present even if a 12-pulse generator is used, but they disappear if a constant potential generator is employed.

Traditionally it has been said that transluminal angioplasty increases lumen diameter by compression and remodeling of atheromatous material. Recently, a new concept explaining the mechanics of angioplasty was described which challenges the classic concept of Dotter. It was argued that arterial balloon dilatation is achieved by intimal disruption and overstretching of the arterial wall, not by remodeling of atheromatous material.

The conventional approach to the removal of secondary radiation in chest radiography is by using an air gap or a radiographic grid. However, grids become ineffective at high kVp levels. This study evaluated efficient scatter removal by radiographic scanography versus the conventional technique. Nylon spheres simulating lung nodules were attached to a standard radiographic thorax phantom and to a special chest phantom of our own design. Conventional and scanographic films were made of the phantoms using the same conditions. The films were read in a double-blind fashion. The results indicated that scanograms permitted appreciation of the simulated nodules over the lungs better than did the conventional films, particularly at higher kVp levels. However, the marked increase of contrast resulted in an underpenetration of the mediastinum. If properly penetrated, the lung fields were overexposed, which resulted in a decrease of the detectability of lesions in spite of a higher normalized contrast. Scanography is a promising technique for improving the detection rate of lung nodules on chest films, provided that means can be found to penetrate the mediastinum without overexposing the lungs.

Nine recent endourologic cases are presented that evidence percutaneous electrolysis and electrocautery as new and safe techniques for incising the urothelium. Electrolysis with balloon dilation was employed to remove stones sequestered behind infundibular and/or diverticular neck stenoses, to correct uretero-pelvic junction (UPJ) stenoses and strictures, and to recanalize a totally obstructed fibrotic UPJ.

Four patients with atherosclerotic disease were found to have a recanalized coronary arterial thrombus on angiography. The functional significance of this finding varied. In 2 cases, flow (judged by collaterals) was insignificant in spite of the recanalization. In the other 2, collateral supply had been shown to be absent during the initial stage of thrombosis. In one case, recanalization was confirmed pathologically.

Between May 1983 and October 1984, 51 patients who had 68 ureteral stones underwent treatment at the University of Minnesota. All 68 stones were removed successfully using percutaneous techniques. The 100% success rate is a great improvement over previous results at our institution. The primary factors appear to be the development of the retrograde-flush technique, familiarity with and access to a wider range of methods, and the increasing use of the retrograde ureterorenoscope to see stones in the lower ureter. The average patient was a 45-year-old man who had no other medical problems. The average hospital stay was 6.8 days. Experimental studies with dogs indicate that injection rates of up to 30 ml/sec of contrast material through a retrograde catheter in the ureter are safe if a vent is present in the upper collecting system.

With increasing use of indwelling venous catheters, embolization of intravascular catheter fragments has become a well-known complication. Because of the high risk and serious complications, embolized fragments should be retrieved whenever possible. Four cases of successful nonsurgical percutaneous catheter retrieval (two adults and two children) are described using a wire loop and a hook-shaped catheter technique. The method described allow a safe and rapid retrieval and should always precede surgical exploration.

Vier Ballonkatheterfabrikate mit unterschiedlichen Konstruktionsmerkmalen und aus verschiedenen Materialien, mit Ballons von 4, 6 und 8 mm Durchmesser, wurden mittels einer automatischen Druckpumpe in Hundegefasen getestet. Die Ballons waren 0 %, 30 % und 80-100 % groser als das jeweilige arterielle Gefaslumen. Injizierte Volumina und Ballondrucke wurden wahrend der Dilatation simultan aufgezeichnet. Ballon- und Katheterverformungen sowie Berstungsmuster wurden radiographisch festgehalten und die traumatischen Veranderungen am Gefas histologisch untersucht. Wir konnten feststellen, das Dilatationsballonkatheter in vivo ein anderes Verhalten als in vitro zeigen; das durch eine Gefasscheide die Ballons eine hohere Druckbelastbarkeit erhalten; das formstabile Katheter starkere Gefaswandschaden verursachen als solche mit Deformierungstendenz; und das uberdimensionierte Ballons ihren geforderten Durchmesser erst bei hohen Drucken oder nach Ruptur der Gefase erreichen. In an experimental angioplasty study in dogs, we evaluated the characteristics of dilatation and deformation, as well as the pressure requirements, bursting points, and types of bursting of four different balloon dilatation catheters. The balloons, which were selected 0 %, 30 %, and 80-100 % larger than the arterial lumen, measured 4, 6, and 8 mm in diameter and were inflated with an automated pump which simultaneously recorded balloon pressure and volume. Changes to the vessel wall were assessed radiographically and by histology. In vivo, balloon dilatation catheters demonstrated a markedly different behaviour than in vitro. Significantly higher pressures were tolerated due to the support of the arterial sleeve. Non-compliant oversized balloons caused more damage to the arterial wall than compliant ones. Oversized balloons attained their required diameters only with high inflation pressures of 10 to 12 atm or after rupture of the artery.

Histological changes which developed after percutaneous transluminal angioplasty in normal and atherosclerotic rabbit aortas were correlated with balloon size and inflation time. In normal rabbits, progressive changes were observed in the intima and media with increasing balloon size and inflation time. The atherosclerotic aortas exhibited unpredictable fragility, with limited correlation between histological changes, balloon size, and inflation time, attributable mainly to the distribution and thickness of plaques. In atherosclerotic vessels, the mechanism of angioplasty consisted of plaque dehiscence and fracture, followed by overstretching of the plaque-free wall segments. No plaque compression was observed.

A model was developed which allows the dilatation of iliac cadaver arteries under normal blood pressure conditions (mean pressure 100 mmHg). Segments of the iliac artery were put under pressure and dilated with balloons under similar conditions as in clinical practice. Purposely oversized balloons were used because most of the arteries did not contain severely stenotic plaques and consequently the commercially available balloons had no effect because of their comparatively small diameter. In spite of the use of oversized balloons, the cadaver arteries could not be significant dilated. Rupture of the intima and media was almost invariably present. Leakage of distending fluid through the adventitia occurred commonly. The "therapeutic range" between minimal dilation and partial or total rupture in postmortem studies is small.

To investigate the acute and long-term effects on the vasa vasorum after massive overdilation, canine aortic segments were dilated with Gruentzig balloon catheters to more than 100% over normal size. In the acute study, the significant lumen increase was the result of intimal and medial rupture with stretching and thinning of the adventitia. In these areas, the vasa vasorum were stretched and severed, causing adventitial hemorrhage. In the chronic study, areas of previous subtotal wall rupture with adventitial thinning were repaired by scar tissue. This repair included formation of a neomedia, hyperplasia of the adventitia, and proliferation of the vasa vasorum. No progression of luminal dilatation was seen. This study showed that in subtotal aortic wall rupture, even a severely damaged adventitia is capable of preserving the lumen from further dilatation and rupture until healing. Blood flow to the damaged vessel wall was reestablished by revascularization via capillary budding in the aortic wall.

To gain more understanding about the changes that follow balloon angioplasty, an electron and light microscopic study was carried out in normal canine arteries. Thirty-five arterial segments were dilated with balloon catheters. Early changes consisted of denudation of the intima with widespread necrosis of myocytes and dehiscence of collagen fibers. After three days, myocytes had disappeared leaving empty spaces and edematous ground substance. After two weeks, reendothelization occurred and there was evidence of intimal hyperplasia persisting up to two months. Repair of the dilated arterial segments occurred by proliferation of myocytes, formation of intima, and proliferation of collagen. In two to three months, repair of the intima and media was completed. After six months, dilated segments were characterized by persistent intimal hyperplasia and increased collagen content in the media.

During angioplasty of artificial stenoses, atherosclerotic human cadaver arteries, and normal canine arteries, pressure and volume of the dilatation balloons were continuously recorded. We found that a sudden yield of a lesion corresponded to a sudden drop in the pressure curve and an increase of the balloon volume. Volume monitoring was insensitive, but pressure recording was very precise. Continuous pressure recording, using a non-compliant inflation system, correctly demonstrated small breaks and ruptures of atherosclerotic vessels, changes not seen on fluoroscopy.

For surgical treatment of patients with tracheoesophageal fistulas the localization of the aortic arch is great practical importance. Aortography and CT scanning have been advocated as the radiographic techniques of choice. The location of the aortic arch can be diagnosed on a chest x-ray by the deviation of the trachea alone. A barium swallow is not required. The optimal radiographic technique for this purpose was investigated in phantom studies and tested in animals and newborns. It is proposed that in addition to the standard chest x-ray a high kvp film with hardened beam (1 mm copper -- 1 mm aluminum) be added in order to demonstrate the tracheal deviation. The additional x-ray exposure to the infant is negligible; and the technique is simple, reliable, and noninvasive.

The treatment of renal and ureteral stones has undergone rapid and major changes over the past ten years. Extracorporeal shockwave lithotripsy has become the most commonly used modality for the treatment of renal and upper ureteral stones. Lower ureteral stones are more commonly being approached by retrograde techniques. Percutaneous nephrolithotomy, medical therapy, and open surgical nephrolithotomy offer viable alternatives in given situations. Presented here is the current application of each of these techniques, both alone and in combination, for the treatment of urinary stones.

Left atrial-coronary sinus fenestration is a rare cause of a left-to-right or right-to-left shunt which occurs most commonly with a persistent left superior vena cava. These fenestrations may represent the only pathway for an obligatory right-to-left or left-to-right shunt in atrioventricular valve atresia. Four cases are presented.

Vascular complications after hepatic transplantation can compromise graft and patient survival. Angiography defines the need for revascularization or retransplantation, but the value of noninvasive imaging in this setting is not clear. To assess the relative merit of noninvasive imaging techniques (sonography, scintigraphy, CT, and MR), we retrospectively reviewed 19 major vascular complications that occurred in 15 of 98 hepatic recipients over a 3 1/2-year period. Portal venous thrombosis was seen in seven patients, donor aortic or hepatic arterial thrombosis in seven, and inferior vena caval thrombosis in five. Sonography provided the initial diagnosis of portal venous thrombosis in three, arterial compromise in five, and caval obstruction in four. CT was the first diagnostic examination to identify portal occlusion in two, donor aortic thrombosis in one, and inferior vena caval thrombosis in one. Scintigraphy and MR imaging provided complementary data. Both sonography and CT are useful in the evaluation of vascular complications that occur after hepatic transplantation; however, neither is sufficiently sensitive to obviate angiographic assessment.

Splenic-artery aneurysms are commonly found incidentally during abdominal angiography. Because approximately 10% of these aneurysms may rupture and lead to fatal hemorrhage, surgical treatment is indicated. A new, nonsurgical approach is described in which the splenic-artery aneurysm is packed with foreign matter introduced through a catheter to induce thrombosis. The procedure can be carried out under local anesthesia and is the preferred technique in high-risk patients. As more experience is gained with this procedure, it can be performed on an elective basis under local anesthesia and the patients can be spared the disadvantages of laparotomy.

Angioplasty produces a persistent 20-fold increase in blood flow through mural vasa vasorum. To assess the role of prostaglandins in this phenomenon, vessel wall blood flow in experimentally dilated carotid arteries of aspirin treated dogs was measured. Aspirin (10 mg/kg, intravenously) significantly attenuated the increase in blood flow produced by dilation (+283 +/- 91% SE, n = 6) when compared to non-aspirin-treated controls (+2356 +/- 885% SE, n = 10). This suggests that aspirin, by interfering with arachidonate metabolism, may decrease local vasodilation after angioplasty. The effect of aspirin therapy on the long-term success of angioplasty requires further study.

A total of 31 patients with 45 episodes of failing arteriovenous dialysis fistulas was studied. Fistula failure was usually due to venous and/or anastomotic stenosis, often in conjunction with thrombosis. Abnormalities were treated by percutaneous dilation and occasionally streptokinase infusion. Most complications and failures occurred either in patients with recently created fistulas or in those with multiple or long segment stenosis associated with thrombosis. Patients with a single nonobstructing stenosis were very successfully treated with percutaneous techniques, which are the treatment of choice for this condition.

Variations of the scimitar syndrome have been reported previously, the most common being the absence of systemic arterial supply to the right lung and varying degrees of lung hypoplasia. Anomalous scimitar-like veins draining the entire right lung and connecting normally to the left atrium have been reported. The case presented is unique in that there is marked hypoplasia of the right bronchial tree and a large bronchogenic pulmonary cyst without dextroposition of the heart and anomalous systemic arterial supply to the right lung.

Diatrizoate (76%) contrast agent heated to 100 degrees C was injected into the veins of dogs and one human volunteer for the nonsurgical occlusion of the vessels. Follow-up venograms and histologic examinations, at intervals varying from one day to four weeks later, revealed thrombosis of the injected veins in all animals. Thrombosis occurred one to five days after injection of contrast agent. The authors conclude that hot contrast medium is a safe and convenient agent for inducing thrombosis. It is much easier to use than mechanical devices, tissue glues, and plastics, which involve complex procedures and specialized equipment. In contrast to other sclerosing agents, hot contrast agent is rapidly converted into a nonsclerosing agent by cooling. The new technique allows a more controlled thermal injury to the vascular wall and is under fluoroscopic control.

Benign prostatic hypertrophy (BPH) produces symptoms that currently can only be treated surgically either by open or endoscopic prostatectomy. We have undertaken animal (1) and human studies to determine if invasive radiologic techniques utilizing balloon catheters could be applied to the treatment of this common ailment. We report a series of twelve patients treated by retrograde transurethral balloon catheter prostatic dilatation. The procedure is performed using topical anesthesia with a specially designed balloon catheter (Medi-Tech, Inc.). The procedure is done on an outpatient basis and is completed within approximately 15 minutes. Relatively long-term results have resulted in persistent relief of symptoms. No complications have been encountered. We anticipate that balloon dilatation of the prostatic urethra will have a major impact on the treatment of BPH based on the promising preliminary results. Transurethral resection of the prostate (TURP) is associated with moderate morbidity and significant cost which can be reduced by the proposed procedure.