Management of failing prosthetic bypass grafts with metallic stent placement.

PURPOSE: To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts. METHODS: Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n = 3), rest pain (n = 9), and minor or major tissue loss (n = 3). Lesions were at the proximal anastomosis (n = 6), the distal anastomosis (n = 3), or within the graft (n = 6). RESULTS: Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up. CONCLUSION: Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.

Interventional procedures for congenital heart disease.

Interventional techniques available for use in treating congenital heart disease include balloon dilation of valves and vessels, stent placement and coil embolization of collaterals, patent ducts and other arterial fistulae. In addition, a variety of devices for closure of atrial and ventricular septal defects and patent ducts currently are under investigation. Radiofrequency ablation of arrhythmias also is applicable to the pediatric population.

Isolated peripheral pulmonary artery stenoses in the adult.

BACKGROUND: Isolated peripheral pulmonary artery stenosis (PPS) in the adult is rare and frequently unsuspected. We review in this article our experience with 12 adult patients with isolated PPS, half of whom had been previously diagnosed with chronic pulmonary thromboembolic disease. METHODS AND RESULTS: The presentation, evolution, and management of 12 adults with isolated PPS, 17 to 51 years of age (mean, 36.2 +/- 9.7 years), were evaluated. Presenting symptoms were dyspnea and fatigue. Three patients had New York Heart Association (NYHA) functional class III or greater. Lung perfusion scans revealed multiple segmental abnormalities in flow distribution in all patients. Oxygen desaturation at rest was present in 4 patients. At catheterization, right ventricular (RV) pressure was suprasystemic in 2 patients, systemic in 1, and more than half-systemic in 7. All had multiple bilateral non-uniform stenoses in segmental and subsegmental arteries. Balloon pulmonary angioplasty (BPA) to decrease RV hypertension and improve pulmonary flow distribution was performed in 11 patients. After BPA, vessel diameter increased > 50% in 10 patients, distal pulmonary artery pressure increased > or = 30% in 6, and RV pressure decreased > 30% in 5. One patient died shortly after BPA as a result of pulmonary hemorrhage. Immediate procedural success was achieved in 9 of 11 patients. At a mean follow-up period of 52 +/- 32 months, 7 patients had sustained symptomatic improvement (NYHA class I-II). CONCLUSIONS: We describe a severe syndrome of isolated PPS in the adult that mimics chronic pulmonary thromboembolic disease. Pulmonary hemodynamics and angiography are required for definitive diagnosis. BPA may offer these patients successful short-term reduction in RV hypertension and alleviation of symptomatology.

Right ventricular decompression and left ventricular function in pulmonary atresia with intact ventricular septum. The influence of less extensive coronary anomalies.

BACKGROUND: Right ventricular decompression (RVD) may cause myocardial ischemia in patients with pulmonary atresia with intact ventricular septum and associated coronary artery abnormalities. Although we have previously shown that mortality is very high when two or more coronary arteries are obstructed, the effects of lesser degrees of coronary abnormalities are unknown. We therefore evaluated the effect of RVD on left ventricular (LV) function in those with less extensive coronary artery abnormalities. METHODS AND RESULTS: Preoperative cineangiograms demonstrated fistulas with or without one coronary artery stenosis in 12 of 24 patients aged 2 days to 33 months at the time of RVD. Preoperative and postoperative two-dimensional echocardiograms were analyzed for global and regional LV function. One infant with fistulas involving two coronary arteries and stenosis of the right coronary artery died from severe global LV dysfunction after RVD. Despite this, mean LV end-diastolic volume (66 +/- 17 mL/m2) and mean LV ejection fraction (60 +/- 9%) were similar in patients with and without coronary artery abnormalities before and after RVD. Before RVD, regional LV dysfunction was seen in 8 of 132 (6%) regions in those with coronary artery abnormalities and in 3 of 132 (2%) in those without coronary artery abnormalities. After RVD, there were 16 of 132 (12%) abnormal regions in those with coronary artery abnormalities and 1 of 132 (< 1%) in those without coronary artery abnormalities. In regions with normal wall motion before RVD, the presence of coronary artery abnormalities was related to regional LV dysfunction after RVD (P < .001). CONCLUSIONS: Regional LV dysfunction was rare in patients without coronary artery abnormalities. In those with less extensive coronary artery abnormalities not involving obstruction to multiple coronary arteries, regional LV dysfunction was common before and increased after RVD, but severe global LV dysfunction was unusual.

Influence of right heart size on outcome in pulmonary atresia with intact ventricular septum.

BACKGROUND: Neonates with pulmonary atresia and intact ventricular septum (PA-IVS) are frequently born with hypoplastic right heart structures that must grow after right ventricular decompression (RVD) procedures for a complete two-ventricle physiology to be achieved. Previous authors have asserted that neonatal right heart size or morphology will predict right heart growth potential. Since 1983, our bias has favored early RVD regardless of initial right heart size. In 1986, we recognized a subset of patients with coronary artery abnormalities associated with poor outcome after RVD and have defined these patients as having a right ventricular-dependent coronary circulation (RVDCC). METHODS AND RESULTS: To assess the influence of right heart size on outcome independent of the presence of RVDCC, we measured echocardiographic right ventricular (RV) dimensions in 37 neonates with adequate studies presenting between 1983 and 1990. Coronary artery anatomy was adequately assessed by angiography in 36. RV volume and tricuspid valve (TV) diameter were significantly smaller in patients with RVDCC than in those without. However, there was no statistically significant association between RV volume or TV diameter and survival among patients with or without RVDCC: Among 29 patients without RVDCC, 23 of 24 (95.8%) who achieved RVD are alive compared with 1 of 5 (20%) who did not achieve RVD (P = .001). Twenty-one of the 23 survivors have a complete two-ventricle physiology with low right atrial pressure. Among 7 patients with RVDCC, 2 patients who underwent RVD died early of left ventricular failure, whereas 4 of 5 who did not undergo RVD have survived single ventricular palliation. CONCLUSIONS: Small right heart size is associated with RVDCC but is not associated with survival in PA-IVS. Patients without RVDCC have improved survival after RVD regardless of neonatal right heart size.

Reliability of Doppler color flow mapping in the identification and localization of multiple ventricular septal defects.

The purpose of this study was to compare Doppler color flow mapping with angiography and surgical observation for detection of multiple ventricular septal defects (VSDs). Only patients with elevated pulmonary ventricular pressure were included. Among 137 patients with VSDs, 38 multiple defects were identified in 25 patients echocardiographically, 34 multiple defects in 24 patients angiographically, and 21 multiple defects in 17 patients surgically. Using surgical observation as the reference standard, the sensitivity of echocardiography for identifying patients with multiple VSDs was 17 of 17 (100%) and for angiography 15 of 17 (88%). The sensitivity of echocardiography for identifying all multiple VSDs seen at operation was 19 of 21 (90%) and of angiography was also 19 of 21 (90%). In many patients, use of both techniques may no longer be necessary.

Enlarged bronchial arteries after early repair of transposition of the great arteries.

OBJECTIVES: This study was undertaken to define the incidence of enlarged bronchial arteries after early surgical repair of transposition of the great arteries by the arterial switch operation, and to report the results of catheter-directed therapy in five patients. BACKGROUND: Pathologic and angiographic studies have demonstrated enlarged bronchial arteries in patients with transposition of the great arteries. METHODS: A subjective 4-point scale was used to grade postoperative angiograms performed in 119 patients at our institution between January 1983 and December 1991. Grades 0 and 1 were designated if there was no opacification of the pulmonary arteries or veins, whereas grades 2 and 3 were assigned if there was such opacification. The median age at repair was 8 days (range 1 day to 13 months) and the median age at catheterization was 11.2 months (range 3.6 to 58.5). An intact ventricular septum was present in 84 (71%) of 119 patients. RESULTS: Significantly increased bronchial flow (grade 2 or 3) was present in 55 (46%) of 119 patients. Age at repair, age at catheterization and interval between repair and catheterization were not associated with significantly increased bronchial flow; however, an intact ventricular septum was weakly associated with increased flow (p = 0.04). Coil embolization was performed in five patients with complete occlusion of the vessels and no significant complications. CONCLUSIONS: Abnormally enlarged bronchial arteries are frequently identified at postoperative catheterization despite early repair and may explain continuous murmurs or persistent cardiomegaly in patients with otherwise normal noninvasive findings. When clinically indicated, catheter-directed therapy can be performed with good results.

Devices for transcatheter closure of intracardiac defects.

Transcatheter closure of intracardiac defects is an investigational procedure that is in use at a number of centers in North America and Europe. A radiologist should be able to recognize these devices on a chest radiograph, understand their actual physical appearance, and be able to recognize their expected location. This essay summarizes the indications for, technical aspects of, and radiologic appearance of these devices.

Diagnosis and management of right ventricle-dependent coronary circulation in pulmonary atresia with intact ventricular septum.

BACKGROUND: Coronary artery anomalies including 1) right ventricle (RV)-to-coronary artery fistulas, 2) coronary artery stenoses, and 3) coronary occlusions occur in patients with pulmonary atresia with intact ventricular septum (PA-IVS). In some, a large part of the coronary blood supply may depend on the RV. This RV-dependent coronary circulation may determine survival after right ventricular decompression (RVD): RVD may cause RV "steal" in the presence of fistulas alone and ischemia, coronary isolation, or myocardial infarction in the presence of coronary stenoses. METHODS AND RESULTS: Eighty-two patients with PA-IVS who presented between January 1979 and January 1990 were reviewed; 26 (32%) had RV-to-coronary artery fistulas. Of these 26, 23 had adequate preoperative coronary angiograms for analysis. RVD was achieved in 16. Seven of 16 had fistulas only; each survived RVD. Six of 16 had stenosis of a single coronary artery [left anterior descending coronary artery (LAD), four; right coronary artery (RCA), two]; four of six survived RVD. Three of 16 had stenoses and/or occlusion of both the RCA and LAD; all three died shortly after RVD of acute left ventricular dysfunction. CONCLUSIONS: 1) Potential RV steal alone does not preclude successful RVD. 2) Fistulas with stenoses to a single coronary artery may not preclude successful RVD. 3) RVD appears to be contraindicated in the presence of stenoses and/or occlusion involving both the right and left coronary systems. Nonsurvival after RVD seems to depend on the amount of the left ventricular myocardium at risk, i.e., that which is distal to coronary artery stenoses, especially when involvement of both coronary arteries limits effective collateralization. Precise definition of coronary arterial anatomy is mandatory in neonates with PA-IVS.

Transcatheter umbrella closure of valvular and paravalvular leaks.

OBJECTIVES: Our aim was to adapt the technique of transcatheter umbrella closure of intracardiac defects for closure of valvular and paravalvular defects. BACKGROUND: The double-umbrella device developed by Rashkind and Cuaso has been safely and effectively delivered across a host of intracardiac defects, but transcatheter closure of valvular and paravalvular leaks has not been reported. METHODS: Between February 1987 and September 1990, eight patients who were believed to be poor operative candidates were taken to the catheterization laboratory for transcatheter double-umbrella closure of a valvular or a paravalvular leak. Four patients had a paravalvular leak around a prosthetic aortic valve. The other four patients had a valvular leak: one patient with a regurgitant native aortic valve after a Stansel procedure and three patients with a regurgitant porcine valve in a left ventricular apex to descending aorta conduit. RESULTS: Placement of a double-umbrella device was attempted in seven of the eight patients and was successful in all seven. Device placement was not attempted in one patient because of the crescentic shape of his defect. Two patients required two devices for each closure; the other five required only one device each. Angiography, performed on six patients after device closure, demonstrated that three patients had a completely occluded defect, two had trivial residual flow and one patient had mild residual flow through the device. All significant complications occurred in one patient who had hemolysis and oliguria that resolved when the initial umbrella was replaced by a larger device. In addition, two devices migrated to the patient's pulmonary arteries but were retrieved in the catheterization laboratory without difficulty. No other early or late complications occurred in 21 to 50 months of follow-up. Of the four patients with a paravalvular leak, the one who did not receive a device died at operation, one patient died at operation for an associated defect (in the operating room the umbrella was found securely in place across the paraaortic defect) and two patients are clinically well at home after 21 and 32 months, respectively. Of the four patients with closure of a valvular leak, one patient remains well at home 50 months later, one patient died at operation for associated defects and two patients had additional successful surgical treatment and remain well 29 months after device placement. CONCLUSIONS: Transcatheter umbrella closure appears to be a reasonable alternative for closure of a valvular or paravalvular leak in patients who are poor operative candidates.

Fluoroscopic placement of jejunal feeding tubes.

Over a two-and-one-half year period, 50 children underwent placements of jejunal tubes through a nasal route (NJ, n = 47) or through an existing gastrostomy site (GJ, n = 119). There were four attempted placements (98% success rate). The NJ tubes remained in place an average of 13 days, and the GJ tubes remained in place an average of 37 days. Fluoroscopic time for placement of an NJ tube averaged 6 min (29 cases), and for a GJ tube 8 minutes (91 cases). In spite of the limited retention time, fluoroscopic time, and availability of alternative methods, fluoroscopically placed jejunal feeding tubes are still playing an active role in this institution.

Chronic posttraumatic aortic pseudoaneurysm. Recognition before rupture.

Few patients survive transection of the aorta caused by blunt trauma. However, among those who do are a small number who go on to live with an unrecognized pseudoaneurysm that may rupture at any time. Because these aneurysms may be mistaken for more common disease processes, such as hilar adenopathy, atherosclerotic aneurysm, or neoplasia, the authors describe radiographic findings that suggest the correct diagnosis.

The "laid-back" aortogram: an improved angiographic view for demonstration of coronary arteries in transposition of the great arteries.

Preoperative demonstration of coronary arterial anatomy may be important for babies undergoing the arterial switch operation. Echocardiography is clearly useful, but may not unequivocally show all coronary branches. Standard angiographic views can be confusing. An improved angiographic projection in which the frontal x-ray tube is caudally angled, resulting in a "laid-back" position of the image intensifier and cine camera, provides superior visualization of the coronary arteries and their relation to the aorta and the pulmonary artery. The balloon occlusion technique is used for opacification of the aortic root from the transvenous approach. Injection of 1 ml/kg of contrast delivered in 1/2 to 1 second provides the best images. The caudal aortogram is easier to interpret than standard views and facilitates description and recognition of various coronary patterns. The relation between the pulmonary artery and the aorta, the origins of the coronary arteries from the facing sinuses and their proximity to the intercoronary commissures, and the myocardial distribution of each coronary vessel are shown clearly. The caudal view therefore offers significant advantages over conventional projections for demonstration of coronary arterial anatomy in infants with transposition of the great arteries or double-outlet right ventricle.

Interventional cardiac procedures in neonates and infants: state of the art.

The currently available interventional cardiac procedures in neonates and infants are at various stages of development. We currently dilate neonates and infants with critical valvular pulmonary and aortic stenosis and postoperative aortic obstruction. We do not routinely dilate native coarctation of the aorta because of the possibility of aneurysm formation, unless the neonate is very sick and acidotic and an operative approach is considered to be high risk. Balloon and blade atrial septostomy are done routinely whenever indicated with a low incidence of morbidity. Coil embolization, endomyocardial biopsy, foreign body retrieval and percutaneous pericardial drainage are relatively safe, and with the currently available instruments these techniques can be performed safely in neonates and infants with the same indications as for older patients. We currently consider stenotic pulmonary veins to be an undilatable lesion and an optimal therapy remains to be defined. Transcatheter closure of PDA and intracardiac shunts is presently limited to older patients, due to the large size of the delivery system devices and cannot currently be used in neonates. Dilation of the pulmonary valve in cyanotic congenital heart disease appears useful, but further experience is needed.

Postmortem and intraoperative balloon valvuloplasty of calcific aortic stenosis in elderly patients: mechanisms of successful dilation.

Percutaneous balloon dilation of the aortic valve has recently been proposed as a palliative procedure for treating nonsurgical candidates with calcific aortic stenosis. To assess the safety, efficacy and mechanisms of successful balloon valvuloplasty, postmortem (n = 33) and intraoperative (n = 6) balloon aortic valvuloplasty was performed in the hearts of 39 elderly patients with calcific aortic stenosis. The cause of aortic stenosis was degenerative nodular calcification in 28 cases, calcific bicuspid aortic stenosis in 8 cases and rheumatic heart disease in 3 cases. Balloon dilation was performed with 15 to 25 mm balloons in the postmortem specimens, and with 18 to 20 mm balloons in the operating room immediately before aortic valve replacement. After balloon dilation, valve orifice dimensions and leaflet mobility increased in all patients. The mechanisms of successful dilation included fracture of calcified nodules in 16 aortic valves, separation of fused commissures in 5 valves, both in 6 valves and grossly inapparent microfractures in 12 valves. Valve leaflet avulsion occurred in one heart after inflation with a clearly oversized balloon. Liberation of calcific debris, valve ring disruption or midleaflet tears did not occur in any heart. In conclusion, there are at least three mechanisms of successful aortic valvuloplasty, depending on the origin of valvular stenosis. Embolic phenomena and acute valvular regurgitation do not appear to be likely events associated with this procedure.

Balloon dilatation of calcific aortic stenosis in elderly patients: postmortem, intraoperative, and percutaneous valvuloplasty studies.

To assess the safety and efficacy of percutaneous balloon valvuloplasty in calcific aortic stenosis, balloon dilatation of critically stenosed, calcified aortic valves was performed in five postmortem hearts, in five patients intraoperatively before aortic valve replacement, and in two elderly patients percutaneously at the time of diagnostic catheterization. The etiology of aortic stenosis in the 12 cases was rheumatic in two, congenital bicuspid calcific stenosis in one, and senile calcific degenerative stenosis in the remaining nine. Prevalvuloplasty examination in the 10 postmortem and intraoperative cases revealed rigid valve leaflets with commissural fusion in three valves and extensive nodular calcification in seven. Subsequent balloon dilatation with 15 to 18 mm valvuloplasty balloons resulted in decreased cusp rigidity and increased mobility of valve leaflets in all cases, without evidence of tearing of valve leaflets, disruption of the valvular ring, or liberation of calcific or valvular debris. In the three valve specimens with commissural fusion, balloon dilatation resulted in partial or complete separation of leaflets along fused commissures. In two cases with extensive nodular calcification, balloon dilatation resulted in a fracture of a calcified leaflet that was evident on both gross and radiologic examination. After postmortem and intraoperative studies, percutaneous catheter valvuloplasty was performed at the time of diagnostic catheterization in two elderly patients (93- and 85-year-old women) with long-standing calcific aortic stenosis. Balloon dilatation with 12 to 18 mm balloons resulted in significant decreases in aortic gradients and significant increases in cardiac index and aortic valve area in both patients. Percutaneous valvuloplasty in both patients resulted in a mild increase in aortic insufficiency and no evidence of embolic phenomena.

Pediatric urologic radiology. Intervention and endourology.

Over the past 10 years new imaging and interventional techniques have drastically changed the ease and scope of urologic diagnosis and treatment. It is both rewarding and exciting to approach each clinical problem with a broad armamentarium of available studies, always seeking the most efficient and direct route to diagnosis. Similarly, radiologic interventional techniques are potentially applicable to a multitude of problems and should be innovatively considered in the urologic patient including patients in the pediatric age group.