Monorail system for percutaneous repositioning of the Greenfield vena caval filter.

The authors describe a technique for removing or repositioning a malpositioned Greenfield inferior vena caval filter. A "monorail" system was used, in which a wire was passed from the femoral vein through the apical hole in the filter and out the internal jugular vein; the wire was held taut from above and below and thus facilitated repositioning or removal of the filter. The technique was used successfully in two cases.

Natural history of the false channel of type A aortic dissection after surgical repair: CT study.

To evaluate the false channel after surgical repair of a type A aortic dissection, postoperative computed tomographic (CT) scans were retrospectively reviewed in 33 patients. Initial CT demonstrated persistence of a double channel distal to the site of surgical repair in 26 patients (79%). In four of these patients serial CT demonstrated enlargement of the false channel, a finding that contributed to the decision to repeat surgery.

Safety of 125iodine and 192iridium implants to the canine carotid artery. Long-term results.

Thirty-nine healthy dogs underwent a simulated radical neck dissection followed by implantation of either 125Iodine (125I) or 192Iridium (192Ir) in various dose regimes randomized prospectively from 3,000 to 30,000 rad. Bilateral selective carotid angiography was performed immediately postoperatively and at 6, 12, 18, and 24 months. No significant effects occurred to the animals who received 15,000 rad 125I or 6,000 rad 192Ir.

Diagnostic challenges following cardiac transplantation.

It is now almost two decades since the first human cardiac transplantation was performed. Recipients will require close follow-up by their referring physicians outside of the main referral centers. This article is intended to assist the referring physician in choosing the most appropriate diagnostic studies throughout the posttransplant period.

Naturally corrected double-outlet right ventricle with biventricular outflow tract obstruction.

A 5-year-old girl had presyncopal episodes associated with exertion. Diagnostic evaluation revealed a combination of congenital abnormalities: double-outlet right ventricle with apparent "natural correction" of a large subaortic ventricular septal defect and severe biventricular outflow tract obstruction. Intraoperative and postoperative studies confirmed satisfactory relief of the biventricular outflow tract obstruction.

Aortic pseudoaneurysm complicating Takayasu disease: CT appearance.

The CT findings of a patient with Takayasu arteritis and an ascending aortic pseudoaneurysm are presented. Computed tomography demonstrated the nature, location, and extent of the aortic lesion and revealed the ominous finding of a related large hematoma indicating prior aortic rupture.

Digital subtraction angiography of coronary grafts: optimization of technique.

Forty patients who had undergone coronary artery bypass surgery were studied with digital subtraction angiography (DSA) to develop an outpatient screening technique for coronary artery bypass graft visualization. Of 103 grafts in 40 patients, 101 were seen: 95 were clearly patent and in six the stump of an occluded graft was seen. Of 32 grafts seen in 14 patients using intraarterial DSA, only 13 (41%) were demonstrated using intravenous DSA.

Evaluation of the portable chest roentgenogram for quantitating extravascular lung water in critically ill adults.

The diagnosis of pulmonary edema is frequently made from characteristic findings on the chest roentgenogram that suggest an increase in lung water. Optimal radiographic technique depends on a cooperative upright patient, which is not possible with most critically ill patients. These patients may also have multiple radiographic abnormalities that make interpretation of the chest roentgenogram difficult.

Flow determination using computed tomography: application to aortic dissection. Part II.

Dynamic CT is not only useful in imaging an aortic dissection but may provide additional information concerning the hemodynamic significance of differing flow patterns in the false channel compared with the true channel. Once validated, the computed tomographic (CT) method of flow determination (See Part I) was applied to an experimental animal model with a surgically created aortic dissection. Good correlation was obtained for the flow estimates of cardiac output derived for the true and false channel (r = .

Flow determination using computed tomography: application to aortic dissection. Part I.

The CT method of flow determination evaluated in this study was based on the application of contrast enhancement dynamics. In order to characterize flow, such parameters as mean transit time, rise time, peak CT value, curve width and variance, and others were derived from the venoarterial indicator dilution curves using a perfect mixers-in-series model of curve fitting analysis and a bolus injection of contrast medium. The technique was first validated in a steady state phantom model that simulated in vivo conditions of right-sided mixing closely by the introduction of a number of mixers.

Quantitative evaluation of left ventricular function using computed tomography.

Computed tomography (CT) provides a noninvasive technique with high resolution cross-sectional tomographic images which allow volume measurements of an object, independent of its geometric configuration. A phantom of known volume with controllable periodic motion was used to validate the CT method of volume determination. A good correlation (P less than 0.

Safety of 125iodine and 192iridium implants to the canine carotid artery: preliminary report.

Thirty-nine healthy dogs underwent a simulated radical neck dissection followed by implantation of either 125Iodine (125I) or 192Iridium (192Ir) in various dose regimes randomized prospectively from 3,000 to 30,000 rad. Bilateral selective carotid angiography was performed immediately postoperatively and at six months and one year. No significant effects occurred to the animals who received 15,000 rad 125I or 6,000 rad 192Ir.

Heart-lung transplantation: the postoperative chest radiograph.

The postoperative chest radiographs of 10 patients who had undergone heart-lung transplantation at Stanford University Medical Center were evaluated and compared with those of 10 consecutive cardiac transplantation patients and 10 consecutive coronary artery bypass graft patients. In the second week after surgery, we observed an interstitial radiographic pattern in the heart-lung transplantation patients but not in the other two patient populations. This pattern, which did not correspond with any clinical evidence of infection, rejection, fluid overload, or oxygen toxicity, may represent the reimplantation response described in dogs and primates following transplantation of a single lung.

Comparative recognition of left ventricular thrombi by echocardiography and cineangiography.

Studies performed in 47 patients, 11 of whom underwent surgery for aneurysmectomy and 36 of whom underwent cardiac transplantation, were reviewed to assess the diagnostic accuracies of cross sectional echocardiography and cineangiography in detecting left ventricular mural thrombi and the effect of anticoagulation treatment on the incidence of such thrombi. Cross sectional echocardiography in 37 patients and cineangiography in 26 (16 patients were examined by both methods) were analysed independently by sets of two observers experienced in the respective methods. All four observers were blinded to the pathological or surgical findings regarding mural thrombus.

A high frame-rate digital subtraction angiography imaging technique for evaluation of aortofemoral runoff.

Intravenous digital subtraction angiography was used to obtain a complete aortofemoral runoff examination of high diagnostic quality in a single patient session in eight patients. Using a 9-inch (22.9-cm) image intensifier, oblique and posteroanterior projections were obtained from the level of the aortic bifurcation to the tibial artery trifurcation.

Validation of a CT method for flow determination. Work in progress.

The dynamic computed tomographic (DCT) method of flow determination is based on the application of venoarterial indicator dilution curves as they reflect flow. Using a simple model consisting of a tube and a single mixing chamber, experimental parameters were optimized in a controlled manner to achieve ideal mixing for flow determination. Under these ideal conditions, and using 16 consecutive 3-second scans of an 8-mm thick section, tube diameters of 8 mm and 20 mm, and flow range of 0.

Aortic dissection: CT and angiographic comparisons.

Computed tomography and aortography were compared in a retrospective study of 35 patients with aortic dissection of type A (n = 17) and type B (n = 18). Based on classical diagnostic criteria such as evidence of two channels, intimal flaps and displaced intimal calcification, computed tomography was able to confirm the presence and type of aortic dissection in 32 patients. Dynamic computed tomography was used in 20 cases.

Combined azygous vein and subclavian artery injury in blunt chest trauma.

Blunt chest trauma resulting in azygous vein injury with associated mediastinal widening is described. Emergency operative intervention was required, and subsequent arteriography revealed initial transection of the subclavian artery requiring repair. The potential significance of mediastinal venous bleeding and the importance of arteriography in diagnosing occult arterial injury in this setting are emphasized.

Salvage of an ischemic limb by laser angioplasty: description of a new technique.

A 62-year-old male with severe claudication and rest pain of the left leg resulting from a totally occluded superficial femoral artery and a 95% stenosis of the deep femoral artery was treated with laser angioplasty after attempts at surgical revascularization were unsuccessful. A 200 mu silica fiber was inserted through a catheter and advanced into the lesion using 2 watts of delivered energy from an argon laser source. The fiber was then withdrawn from the lesion using 7 watts of energy to enlarge the lumen.

Lymphoma of the heart.

A case of malignant lymphoma involving the heart is reported. The patient presented with symptoms of cardiac decompensation. The echocardiographic findings of an echogenic mass arising from the pulmonary valve as well as demonstration of soft tissue density diffusely infiltrating the heart and mediastinum was confirmed by computer tomography and angiography.

Revascularization of tracheal anastomosis following heart-lung transplantation.

The mechanism by which tracheobronchial arterial supply is reconstituted following heart-lung transplantation was investigated in seven monkeys (3 allografts, 2 autografts, and 2 nontransplanted control monkeys) and three patients. Descending tracheal branches of the thyrocervical arteries provided the major tracheal vascular supply. A collateral branch arising from atrial branches of the left coronary artery supplied tracheobronchial branches in the region of the carina in one allograft.