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Ureteroscopy is an important technique in the management of calculous disease and ureteral lesions but it appears to have a greater potential for injury than percutaneous nephroscopy. In 2 years 4 patients with severe ureteroscopic injuries were treated. In 3 patients complete obstruction of the ureter occurred, and 1 had a major ureteral tear, prolonged urinary extravasation and infection. Even in the presence of total ureteral occlusion patients with short strictures were managed successfully percutaneously but the 2 patients with longer strictures were not. Previous surgery on the ureter or pelvic surgery and radiation therapy appear to be negative factors that affect adversely the ureteral blood supply, and potentiate poor healing and scarring. Nephrostomy tube drainage and ureteral stenting after ureteral dilation appear to be important steps in the percutaneous management of these patients.

A variety of imaging procedures were performed in 28 patients with ectopic adrenocorticotropic hormone (ACTH) syndrome in an attempt to localize the ACTH-producing tumor. Diagnosis was made on the basis of removal of an ACTH-producing tumor or biopsy of metastases in the 19 patients with a proved source and the absence of ACTH gradients in bilateral samples of the inferior petrosal sinuses in the nine patients in whom an ACTH-secreting tumor had not been localized. Eleven bronchial carcinoids, two thymic carcinoids, three pheochromocytomas, and three islet-cell tumors constituted the proved sources. The condition has been cured in eight patients, six are alive with residual tumor, and five have died. Of the nine patients with undetected sites of ACTH production, one has died of pneumocystis pneumonia and eight are being treated medically or with bilateral adrenalectomy. Computed tomography (CT) of the chest and abdomen was the most helpful study in the detection of these tumors. Selective arteriography (bronchial and visceral), systemic and portal venous sampling, and iodine-131 meta-iodobenzylguanidine scintigraphy failed to demonstrate tumors when findings at CT were negative. Bronchial carcinoids constituted most of the ACTH-secreting tumors in this study (58%) and in a review of four large series (47%). To assure early detection of these potentially malignant tumors, pulmonary CT should be performed every 6 months, even after hypercortisolism has been medically or surgically controlled.

A prospective comparison of superselective arterial digital subtraction angiography (DSA) and superselective conventional angiography (CA) was performed in a consecutive series of 26 patients with hyperparathyroidism, previous unsuccessful surgery, and single gland involvement. All patients had negative or inconclusive findings from noninvasive localization studies. Superselective studies included injection of both thyrocervical trunks, both internal mammary arteries, and both common carotid arteries in all patients in whom this was technically possible. DSA findings were true positive in 16 patients (62%); CA findings were true positive in ten patients (38%) and equivocal in four (15%) (P less than .046). There were no false-positive angiograms. DSA findings were positive in all patients in whom CA findings were positive or equivocal. Superselective DSA appears to be as sensitive as CA for preoperative parathyroid localization and may be more sensitive for the localization of mediastinal glands.

Seventeen patients experienced severe hemobilia following percutaneous (nine patients) or surgical (eight patients) placement of biliary drainage catheters. Fourteen patients bled early after catheter placement (0.5-32 weeks; mean, 5.4 weeks) and three bled late during long-term biliary drainage (1.1-3.6 years; mean, 2 years). Hepatic angiography demonstrated the source of bleeding in 15 (88%) patients (hepatic artery pseudoaneurysm in ten, hepatic artery-portal vein fistula in four, varix along the tube tract in one) but showed no source of bleeding in two. Thirteen patients with hemobilia were treated with embolotherapy, using detachable balloons in 12. The advantages of this technique included the ability to flow-direct the balloon without selective catheterization; the ability to test-inflate the balloon at the site of the aneurysm or fistula during angiographic study and adjust its position before detachment; and preservation of the hepatic artery proximal and distal to the inflated balloon, thus preserving hepatic function following embolization.

Angiographic ablation of parathyroid adenomas with ionic contrast material was performed in 24 patients with persistent hyperparathyroidism who had undergone at least one prior unsuccessful surgical resection; 23 had mediastinal adenomas. The success rate was 83% at 1 month after ablation and 71% at both 5 and 9 years. Ablation was successful in 85% of the patients in whom the catheter could be wedged into the artery feeding the adenoma. Long-term success was achieved in 89% of the patients in whom contrast enhancement persisted in the adenoma on computed tomographic scans obtained 24 hours later. Acute complications were seen only in patients with glands supplied by the inferior or superior thyroid arteries. Long-term complications were limited to permanent hypocalcemia, present in 8% of patients. Even if unsuccessful for ablation, the procedure may provide localization and does not preclude surgical resection. It is recommended for most patients with persistent hyperparathyroidism and mediastinal adenomas, especially adenomas supplied by the internal thoracic artery.

A prospective, blinded comparison of three methods of hepatic contrast enhancement in computed tomography (CT) was conducted in 15 patients with colorectal carcinoma metastatic to the liver. Arterial portography (AP-CT) was performed with injection of contrast material into the superior mesenteric artery during CT. Delayed scanning (DS-CT) was performed 4 hours after intravascular administration of contrast material (mean dose, 280 mL). CT with an ethiodized oil emulsion (EOE-CT) was performed 1 hour after slow intravenous infusion of the emulsion. All patients underwent laparotomy following imaging studies. A lesion-by-lesion analysis of 56 metastases showed no significant differences in sensitivity (AP-CT, 77%; DS-CT, 83%; EOE-CT, 82%), but the false-positive rate for AP-CT was significantly higher than that for DS-CT (P less than .001) or EOE-CT (P less than .01). False-positive rates for EOE-CT and DS-CT were not significantly different. The predictive value of a positive test was 63% for AP-CT, 90% for DS-CT, and 81% for EOE-CT. AP-CT does not appear to be clinically useful for detection of hepatic metastases because of the high false-positive rate. No difference could be demonstrated between DS-CT and EOE-CT. DS-CT is a valuable method for hepatic contrast enhancement.

The synchronicity is a strong restriction that in some cases of wide applications can be difficult to obtain. This paper studies the methodology of using a non synchronized camera network. We consider the cases where the frequency of acquisition of each element of the network can be different. The following work introduces a new approach to retrieve the temporal synchronization from the multiple unsynchronized frames of a scene. The mathematical characterization of the 3D structure of scenes, is used as a tool to estimate synchronization value, combined with a statistical stratum. This paper presents experimental results on real data for each step of synchronization retrieval.

A simple method of measuring vessel diameters using intraarterial digital subtraction angiography has been designed. With a catheter in place within the vessel of interest, a segmented guide wire with known dimensions is advanced into the catheter in the area to be measured. We have used the method successfully for balloon angioplasty as well as balloon embolization.

Ventricular outflow obstruction in the infant remains a surgical challenge with high operative mortality despite a variety of approaches. An apical to aortic conduit would be a direct approach but usually required cardiopulmonary bypass and removal or fixation of perhaps a critical amount of apical myocardium. Therefore, we developed a two component apical prosthesis consisting of a grommet, fixed internally by a flange, that can be placed via the atrium without bypass and an external female adapter. This transatrial ventricular access device (TAVAD) does not require removal of myocardial tissue or sutures. The TAVAD concept was acutely tested in 8 anesthesized dogs (mean wt. = 15 kg). Initially the TAVAD device was capped and acute stability in the myocardium was demonstrated in 5 dogs. Subsequently, in 3 dogs, the TAVAD method was used to achieve communication with a valved conduit to the thoracic aorta. Acute grommet stability in the myocardium was evident even with the conduit attached and ventricular pressures up to 250 mmHg. The ability to carry cardiac output was demonstrated by ascending aortic occlusion. Chronic implantation off bypass in 3 lambs (mean wt, = 8.5 kg) has shown continued myocardial fixation and conduit function. Angiography demonstrated unobstructed apical to aortic flow and normal ventricular wall motion. Since the lamb myocardium is similar in thickness to the human infant, we conclude that the TAVAD device and method may be useful in relieving ventricular outflow obstuction in infants while preserving myocardial tissue and function.