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At least 1,459 records · Page 81Linked to original sources
PubMed1980

Swan-Ganz catheter: comparison of insertion techniques.

One hundred eighty-nine Swan-Ganz catheters were inserted in 165 critically ill patients with different techniques. Percutaneous catheterization through the subclavian, internal jugular, and antecubital veins and antecubital venous cutdown with or without fluoroscopy were compared. The antecubital approach, percutaneously or through a venous cutdown, was associated with most complications. We conclude that the method of choice is the percutaneous insertion of the balloon-tipped catheter through the subclavian or internal jugular veins and that fluoroscopy is unnecessary.

Catheterization↗
PubMed1998

Automated 3-dimensional computed tomographic and fluoroscopic image registration.

The registration of 3-dimensional (3-D) anatomical surfaces to sensor data such as intraoperative fluoroscopy is one of the basic problems in computer integrated surgery. The main objective is to find the relationship between 3-D preoperative computed tomographic images and a pair of intraoperative fluoroscopic images. Consequently, surgical navigation devices can use this relationship to provide improved surgical guidance. The proposed registration strategy presents a noninvasive anatomy-based (frameless) method for registration. In this article, we propose a cooperative approach between registration and contour segmentation on fluoroscopy. This approach is based on the duality between registration and segmentation in a model-based vision system. It associates a likelihood value to each pixel that corresponds to the probability that the pixel belongs to the contour of the object of interest. The registration is then achieved between backprojection lines stemming from likely contour pixels and the 3-D surface model of the object of interest. Then, in order to take into account the internal contour points extracted by the cooperative approach, we propose a new line to surface distance computation algorithm to be used during the data to model distance minimization step. Finally, we present the obtained results that demonstrate the validity of the proposed approach in carrying out accurate 3-D and 2-D registration.

Algorithms↗
PubMed1996

Advantage of Inoue balloon catheter in mitral balloon valvotomy: experience with 220 consecutive patients.

Percutaneous mitral balloon valvotomy (PMV) using the Inoue balloon catheter was attempted in 220 consecutive patients with severe symptomatic mitral stenosis. Their age range was 10-63 mean 30 +/- 10 years; 161 patients were females and 59 were males; 29 patients were in atrial fibrillation. Eleven patients were pregnant; 14 patients underwent previous surgical commissurotomy. The procedure was technically successfully performed in 215 (97.7%) patients. The mean fluoroscopy time was 15.5 +/- 6.4 min and mean procedure time was 109 +/- 79 min. Optimal results (group I) was achieved in 207 patients who have mitral score of 7 +/- 1. PMV resulted in decrease in left atrial pressure from 23 +/- 5 to 14 +/- 4 mm Hg (P < 0.001), the mean mitral valve gradient (MVG) decreased from 15 +/- 4 to 6 +/- 3 mm Hg (P < 0.001). The mitral valve area (MVA) by catheter increased from 0.7 +/- 0.2 to 1.7 +/- 0.5 cm2 (P < 0.001) and MVA as determined by echocardiography (2DE) increased from 0.8 +/- 0.1 to 1.9 +/- 0.3 cm2 (P < 0.001). The results were suboptimal in eight patients who have a mitral score of 10 +/- 1 (group II) MVA by catheter increased from 0.7 +/- 0.2 to 1 +/- 0.1 cm2 and Doppler MVA increased from 0.8 +/- 0.1 to 1.3 +/- 0.1 cm2. There were no deaths or thromboembolism. Two patients developed cardiac tamponade; mild mitral regurgitation (MR) developed in 24 patients (11%) and increased by one grade in another 22 patients (10%). Severe MR was encountered in three patients (1.4%). A small ASD (QP/QS < or = 1.3) was detected by oximetry in 5% of patients and by color-flow mapping in 26% of patients. One hundred fifty-eight patients from group I were followed up, for a mean of 32 +/- 12 months; MVA remained at 1.7 +/- 0.4 cm2. Seven patients developed mitral restenosis in group I, and 5 out of 8 patients developed restenosis in group II. We conclude that the hemodynamic results are good and comparable with those reported with double balloon technique. However, the Inoue balloon has several advantages over the double balloon technique: (1) low incidence of mitral regurgitation and ASDs; (2) shorter procedure and fluoroscopy time; and (3) low complication rates and the valve anatomy affects the immediate and late outcome of mitral balloon valvotomy.

Adolescent↗
PubMed1997

Beneficial impact of aorto-coronary graft markers on post-operative angiography.

OBJECTIVE: When coronary and graft angiography is required for patients with prior coronary artery bypass (CAB) graft surgery, it is often difficult to localize the proximal aorto-coronary graft anastamosis. Our goal was to quantify the potential benefit during subsequent angiography if the proximal anastamosis is marked by an aorto-coronary graft marker at the time of CAB. METHODS: Retrospective review of 414 angiograms that were performed for patients with prior CAB. Cohorts with an without graft markers were compared. RESULTS: In the group with aorto-coronary graft markers and > or = 2 aorto-coronary grafts, there were significant reductions in fluoroscopy time (30.5%, p < 0.0001), contrast volume (21.7%, p < 0.0001), and numbers of angiographic catheters used (17.0%, p = 0.0001). If only one aorto-coronary graft was placed and marked, a trend toward reduced fluoroscopy time was observed (23.8%, p = 0.07). CONCLUSIONS: This study demonstrates the objective benefit supporting routine placement of circumferential aorto-coronary graft markers during CAB, particularly if > 1 graft is required.

Anastomosis, Surgical↗
PubMed2000

Exposure to ionizing radiation in children undergoing Amplatzer device placement to close atrial septal defects.

To evaluate exposure to ionizing radiation during Amplatzer device occlusion, a prospective study was performed to measure surface entrance radiation dose by thermoluminescent dosimetry (TLD). Between June 1998 and April 1999, dosimetry was carried out on 12 patients with Amplatzer device occlusion of atrial septal defects (n = 10) or Fontan fenestration (n =) and 12 age-matched patients who underwent diagnostic catherization. TLD chips were placed at the posterior (PA) and right lateral (LA) chest wall as well as the thyroid (TH) and gonadal (GN) regions. The Amplatzer group had a median age of 6.4 yr (2.4-12.4 yr) and a median weight of 23.7 kg (15.6-28.9 kg), which were similar (p = NS) to those of the control group, who had a median age of 7.9 yr (3.3-16.2 yr) and a median weight of 29.9 kg (10.6-58.0 kg). Device placement was successful in 11 of 12 patients; one device was removed owing to partial obstruction of the right-upper pulmonary vein. Fluoroscopy times were also similar in the Amplatzer group (23.5 +/- 2.1 min) and the control group (16.4 +/- 3.1 min; P = NS). The measured surface entrance doses of the Amplatzer group was similar (p = NS) to those of the control group in all four regions: PA (4.96 +/- 1.88 vs. 6.07 +/- 2.16 cGy), LA (5.22 +/- 1.68 vs. 3.13 +/- 1.25 cGy), TH (0.92 +/- 0.14 vs. 0.69 +/- 0.09 cGy), and GN (0.20 +/- 0.00 vs. 0.22 +/- 0.01cGy). Fluoroscopy times and measured surface entrance doses of ionizing radiation in patients undergoing Amplatzer device occlusion are similar to those in patients undergoing routine diagnostic catheterization.

Cardiac Catheterization↗
PubMed2002

Initial and late results after catheter intervention for neonatal critical pulmonary valve stenosis and atresia with intact ventricular septum: a technique in continual evolution.

Critical pulmonary valve stenosis or atresia with intact ventricular septum is a rare congenital cardiac defect that can be technically difficult to alleviate in the catheterization laboratory. Over the past 10 years, several techniques and modifications with variable results have been advocated to facilitate the valvuloplasty procedure. This report describes a single operator's experience using various techniques in 28 neonates with critical pulmonary stenosis or atresia who were considered candidates for transcatheter intervention. The first two patients underwent a gradational balloon valvuloplasty approach that resulted in prolonged fluoroscopy exposure. Thereafter, a "snare assisted" umbilical artery approach was developed which facilitated the valvuloplasty procedure and resulted in significantly fewer balloons used and shorter fluoroscopy times. Early in our experience, stiff guidewire perforation of atretic pulmonary valves was used, whereas in our last two patients, a simplified perforation technique with a new 0.9-mm excimer laser catheter was used. Late echocardiographic and clinical follow-up evaluation in 27 patients demonstrates persistent gradient relief, resolution of tricuspid valve insufficiency, and elimination of right to left shunting at the atrial level. Balloon valvuloplasty is the treatment of choice for critical pulmonary valve stenosis or atresia with intact ventricular septum. When necessary, the use of umbilical artery "snare assistance" facilitates the valvuloplasty technique and shortens procedure time while laser perforation is currently preferable for perforation of the atretic pulmonary valve.

Catheterization↗
PubMed2001

Bioptome-assisted simultaneous delivery of multiple coils for occlusion of the large patent ductus arteriosus.

We describe a novel method that allows bioptome-assisted delivery of multiple Gianturco coils simultaneously for occlusion of the large patent ductus arteriosus (PDA). Two or more coils were intertwined at one end and held by a bioptome (5.2 Fr) and pulled into a short introducer. The coils were then deployed in the PDA via a long sheath (7-11 Fr) previously placed across the duct via the femoral vein. Twelve patients (6 months to 64 years; median, 10.5 years) with large PDAs (4.7 +/- 1.3 mm; range, 3.1-8.4 mm; PA mean pressure, 40 +/- 17 mm Hg; pulse pressure 63 +/- 18 mm Hg) underwent bioptome-assisted occlusion with multiple coils at our institutions. The procedure was uneventful in nine patients (fluoroscopy time, 6-23 min) and prolonged in three patients (fluoroscopy time, 26, 72, and 120 min) because of dislodgment of the coil mass and embolization of an additional coil. Successful coil deployment was feasible in all patients. Three patients required repeat coil deployment for flow elimination (hemolysis occurred in two). Flow elimination was demonstrated on the last follow-up evaluation in all except two patients. One infant has developed significant left pulmonary artery stenosis. Bioptome-assisted PDA occlusion using multiple coils delivered simultaneously may be a promising alternative to devices for transcatheter closure of large PDAs. Cathet Cardiovasc Intervent 2001;54:95-100.

Adolescent↗
PubMed1992

Balloon angioplasty of chronic total coronary artery occlusions: what does it cost in radiation exposure, time, and materials?

Coronary angioplasty of chronic total occlusions is known to have a lower success rate and higher frequency of restenosis than angioplasty of subtotal stenoses, but there are no data describing the additional time, resources, and radiation exposure associated with this procedure. The purpose of this study was to compare these features in 90 consecutive patients who underwent angioplasty of a total occlusion (group 1) to those of 100 consecutive patients who underwent angioplasty of a subtotal stenosis (group 2). Angioplasty was successful in 60% of group 1 and in 94% of group 2 patients. Procedures were longer in group 1 and significantly more guide catheters, angioplasty balloon catheters, and guide wires were required per patient compared to group 2. The volume of contrast media used in each group was similar. Estimates of radiation entry exposure, calculated from fluoroscopy exposure times and using data from phantom studies, were 53 R (roentgen) per patient in group 1 vs. 34 R in group 2. These procedures were performed using pulsed progressive fluoroscopy; radiation exposure would be considerably higher using conventional fluoroscopic systems. Cineangiographic radiation exposures were similar for each group and accounted for an average additional exposure of 14-22 R for each procedure. Total radiation exposure was reduced in both groups when the angioplasty procedure was combined with the diagnostic angiogram. These observations should be considered when dilation of a total occlusion is planned. Efforts to reduce the amount of radiation exposure should remain a priority in interventional catheterization laboratories.

Aged↗
PubMed2004

Interatrial defect sizing by intracardiac and transesophageal echocardiography compared with fluoroscopic measurements in patients undergoing percutaneous transcatheter closure.

The purpose of this study was to evaluate prospectively the feasibility and accuracy of using echocardiographic measurements by transesophageal and intracardiac echocardiography (TEE and ICE, respectively) for interatrial septal defect sizing during percutaneous transcatheter closure. Forty-two patients underwent balloon sizing of interatrial septal defects using TEE in 21 of them and ICE in the other half. These measurements were correlated with quantitative fluoroscopic analysis and evaluated for bias and agreement between methods using a Bland-Altman analysis. Echocardiographic measurements were obtained by ICE and TEE in all patients. An excellent correlation was found between TEE and quantitative fluoroscopy (r = 0.898; P < 0.001) and between ICE and quantitative fluoroscopy (r = 0.876; P < 0.001), with a significant agreement (P < 0.001) and minimal positive bias toward the echocardiographic measurements. Both TEE and ICE are excellent methods of interatrial defect sizing when compared with quantitative fluoroscopic measurements.

Angioplasty, Balloon, Coronary↗
PubMed2005

Fluoroscopic localization of the femoral head as a landmark for common femoral artery cannulation.

We sought to determine the reliability of frequently used landmarks for femoral arterial access in patients undergoing cardiac catheterization. The common femoral artery (CFA) is the most frequently used arterial access in cardiac catheterization. Arterial sheath placement into the CFA has been shown to decrease vascular complications. Some authors recommend locating the inferior border of the femoral head using fluoroscopy due to the relationship of the femoral head and the bifurcation of the CFA. We performed a descriptive study in a prospective design of 158 patients undergoing catheterization from the femoral approach. A femoral angiogram was performed, and the CFA bifurcation location was recorded in relation to the inguinal ligament, middle and inferior border of the femoral head, and the inguinal skin crease. The CFA bifurcation was distal to the inguinal ligament, middle femoral head, and inferior femoral head in most patients with mean distances (cm +/- SD) of 7.5 +/- 1.7, 2.9 +/- 1.5, and 0.8 +/- 1.2, respectively. The inguinal skin crease was below the bifurcation in 78% of patients (-1.8 +/- 1.6 cm). The CFA overlies the femoral head in 92% of cases. The femoral head has a consistent relationship to the CFA, and localization using fluoroscopy is a useful landmark.

Catheterization↗
PubMed1988

Association of coronary calcification with obstructive disease in coronary arteries in Indian patients.

A total of 1150 consecutive patients (1052 males and 98 females; age 51.2 +/- 10.1 years) with suspected coronary artery disease (Group I) were subjected to fluoroscopy for detection of coronary artery calcification (CAC) and coronary angiography. Another group (Group II) of 120 patients (95 males and 25 females; age 51.4 +/- 9.4 years) catheterized for cardiac diseases other than coronary artery disease (CAD) were subjected to the same protocol of fluoroscopy and coronary angiography to exclude incidental CAD in view of their age. CAC was present in 240 patients (20.0%) in Group I. Of these, 200 (83.4%) had triple-vessel disease (TVD); 20 (8.3%) had double-vessel disease (DVD); 19 (7.9%) had single-vessel disease (SVD); and 37 (15.4%) patients had left main coronary disease (LMCAD). Only one of these patients had insignificant CAD considered as "normal" coronary arteries (NC). Incidence of LMCAD, TVD, DVD, SVD, and NC in patients without CAC was 4.4%, 56.3%, 18.2%, 14.0%, and 11.5%, respectively. Incidence of CAC in patients with LMCAD, TVD, DVD, SVD, and NC was 48.1%, 28.1%, 10.8%, 13.0%, and 1.0% respectively. In Group II (n = 120), 24 patients (20%) had CAD, CAC was present in 5 patients with CAD (20.9%), and in two patients without CAD (2%). CAC is relatively uncommon in Indian CAD patients. Its presence, however, indicates severe multivessel disease.

Adult↗
PubMed2005

Development of new injectable bulking agents: biocompatibility of radiopaque polymeric microspheres studied in a mouse model.

Radiopaque polymeric microspheres have a potential as new bulking agents for treatment of stress urinary incontinence (SUI). The advantage over existing bulking agents lies in their X-ray visibility in situ; other polymeric bulking agents (e.g., PTFE or silicone rubbers) are practically radiolucent (i.e., incapable of absorbing X-radiation). Radiopacity is useful in practice because of the high spatial accuracy of X-ray imaging. For instance, X-ray fluoroscopy can be used to assess possible migration of the bulking agent over time or to provide guidance in cases in which a second injection of a bulking agent is necessary (repeated treatment of SUI). Biocompatibility of injected radiopaque microspheres was investigated in vivo by using the mouse as a model. Microspheres were injected subcutaneously (9 animals) or intramuscularly (9 animals), and follow-up was 8 days or 3 months. X-ray fluoroscopy gave clear images of the microspheres as an ensemble, and it was found that no migration occurred during 3 months. Histopathology confirmed that all microspheres stayed close to the site of the injection. The microspheres appeared to be well tolerated; only a few giant cells, manifesting a mild inflammatory reaction, were encountered. At 3 months, capillary blood vessels were observed throughout the microsphere beds, and macrophages and fibroblast cells were seen in between the microspheres. This is encouraging with respect to the intended application, although it must be acknowledged that the data refer merely to a mouse model. Further experiments with larger, more representative models (rabbit and goat) are in progress.

Animals↗
PubMed1992

Formulation of radiographically detectable gastrointestinal contrast agents for magnetic resonance imaging: effects of a barium sulfate additive on MR contrast agent effectiveness.

Complete and homogeneous distribution of gastrointestinal (GI) contrast media are important factors for their effective use in computed tomography as well as in magnetic resonance (MR) imaging. A radiographic method (using fluoroscopy or spot films) could be effective for monitoring intestinal filling with GI contrast agents for MR imaging (GICMR), but it would require the addition of a radiopaque agent to most GICMR. This study was conducted to determine the minimum amount of barium additive necessary to be radiographically visible and to evaluate whether this additive influences the signal characteristics of the GICMR. A variety of barium sulfate preparations (3-12% wt/vol) were tested in dogs to determine the minimum quantity needed to make the administered agent visible during fluoroscopy and on abdominal radiographs. Solutions of 10 different potential GI contrast agents (Gd-DTPA, ferric ammonium citrate, Mn-DPDP, chromium-EDTA, gadolinium-oxalate, ferrite particles, water, mineral oil, lipid emulsion, and methylcellulose) were prepared without ("nondoped") and with ("doped") the barium sulfate additive. MR images of the solutions in tubes were obtained at 0.38 T using 10 different spin-echo pulse sequences. Region of interest (ROI) measurements of contrast agent signal intensity (SI) were made. In addition, for the paramagnetic contrast media, the longitudinal and transverse relaxivity (R1 and R2) were measured. A 6% wt/vol suspension of barium was the smallest concentration yielding adequate radiopacity in the GI tract. Except for gadolinium-oxalate, there was no statistically significant difference in SI for doped and non-doped solutions with most pulse sequences used. In addition, the doped and nondoped solutions yielded R1 and R2 values which were comparable. We conclude that barium sulfate 6% wt/vol added to MR contrast agents produces a suspension with sufficient radiodensity to be viewed radiographically, and it does not cause significant alteration in the MR signal appearance of most GICMR. These formulations can be useful for achieving optimal filling of the gastrointestinal tract prior to MRI.

Animals↗
PubMed2005

C-arm calibration--is it really necessary?

C-arm fluoroscopy is modelled as a perspective projection, the parameters of which are estimated through a calibration procedure. It has been universally accepted that precise intra-procedural calibration is a prerequisite for accurate quantitative C-arm fluoroscopy guidance. Calibration, however, significantly adds to system complexity, which is a major impediment to clinical practice. We challenge the status quo by questioning the assumption that precise intra-procedural calibration is really necessary. We derived theoretical bounds for the sensitivity of 3D measurements to mis-calibration. Experimental results corroborated the theory in that mis-calibration in the focal spot by as much as 50 mm still allows for tracking with an accuracy of 0.5 mm in translation and 0.65 degrees in rotation, and such mis-calibration does not impose any additional error on the reconstruction of small objects.

Algorithms↗
PubMed1981

Exposure to X-rays during small bowel biopsies in children.

Peroral small bowel biopsy is a decisive step in the diagnosis of coeliac disease and is performed frequently. The patient's exposure to ionizing radiation during fluoroscopic control therefore deserves consideration. Compared to data in the literature, the biopsy method employed at the University Children's Hospital in Vienna achieves a markedly shorter duration of fluoroscopy. These values were registered during 1039 biopsies. In 439 examinations the exposure area products were also documented In 10 consecutive biopsies additional measurements were carried out by lithium fluoride thermoluminescence dosimeters attached to the patient. Expert biopsy-technique with precise and thoughtful use of modern fluoroscopes on the one hand, and critical self-control by routine documentation of the exposure area product and duration of fluoroscopy on the other can markedly reduce the patient's exposure to X-rays.

Biopsy↗
PubMed1999

Digital fluoroscopic assessment of the scapulohumeral rhythm.

Previous studies have shown that abnormal rotation of the scapula is associated with shoulder pathology. Among the methods which have been proposed, planar x-ray measurements are probably the only methods, which enable clinicians to assess accurately and objectively the scapulohumeral function in vivo. The aim of this study was to develop a method for the assessment of scapulohumeral kinematics using digital fluoroscopy. Anteroposterior images of the right glenohumeral joint were taken, in thirty-four healthy males, with the arm at rest, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees and maximum abduction, in the scapular plane. High inter- and intra-examiner reliability was observed regarding the arm and scapular angle measurements (ICC = 0.92-0.99). The positioning of the arm at the proposed angles was also highly accurate (< 2.3 degrees misplacement) and reproducible (CV% < 5.3%). The mean radiation dose was 0.075 mSv (+/- 0.027 mSv). At the resting position the scapula was in slight downward rotation (-2.4 degrees +/- 4.3 degrees) and the arm in slight abduction (1.5 degrees +/- 6.6 degrees). The mean maximum scapular rotation and the mean maximum arm abduction was 61.4 degrees (+/- 5.2 degrees) and 162.4 degrees (+/- 6.6 degrees) respectively. A curvilinear relationship was found between the arm angle (AA) and the scapular angle (SA) (p < 0.0001). The AA:SA ratio for the entire range of abduction was 2.5:1. The greatest contribution of the scapula (1.7:1) achieved at 30 degrees-60 degrees of arm. The high accuracy and reliability of our method and the low radiation recordings suggests that digital fluoroscopy may be considered for further investigation of the scapulohumeral kinematics in both healthy and pathological shoulders.

Adolescent↗
PubMed1978

Radiation exposure in patients undergoing endoscopic retrograde cholangiopancreatography and endoscopic papillotomy.

Radiation exposure was studied in 327 patients undergoing endoscopic retrograde cholangiopancreatography, or endoscopic papillotomy taking into account fluoroscopy time and incident area exposure. The mean fluoroscopy time was 238 +/- 152 seconds and the incident area exposure 3,730 +/- 2,790 R X cm2. These results were compared with standard exposures in upper GI series and colon examinations as found in the literature.

Adult↗
PubMed1982

The "free" routine postcatheterization urogram: a cost/benefit analysis.

Postangiography urography has become routine procedure in most centers performing cardiac catheterization in children. We analyzed the x-radiation dosage and clinical yield of this procedure. Using lithium fluoride thermoluminescent dosimeters, radiation exposure to the abdomen and gonads was measured in 35 children during postangiography urography. Results of 334 consecutive routine postangiography cine-urograms were evaluated based on clinical significance and compared to previous reports on this subject. Average absorbed abdominal radiation dosage was 241 mR +/- 240 from cine-urography, 16 mR +/- 13 from fluoroscopy, and 107 mR +/- 111 from a single abdominal roentgenogram. Gonadal dosage averaged 8 mR and was uniformly less than 27 mR. Of 334 routine postangiography cineurograms, 282 (84%) were normal, 30 (9%) were technically inadequate, 12 (3%) had abnormalities that were clinically insignificant or were falsely "positive" and in 10 (3%), clinically significant urologic conditions were confirmed. Because of the low yield of clinically significant anomalies and the added radiation exposure, we no longer perform routine postangiography cine-urography in children. Following cardiac angiography, the upper renal collecting systems are examined fluoroscopically. If abnormalities are suspected or fluoroscopy is equivocal, a single abdominal roentgenogram is performed. Using this procedure, mean average absorbed abdominal radiation dose can be reduced from 241 mR to 30.5 mR.

Cardiac Catheterization↗