Search PubMed⌕ Search

Biomedical subjects

J Bonn

Publications and source records attributed to J Bonn.

At least 19 recordsLinked to original sources
PubMed2001

Quantification of elastic recoil after balloon angioplasty in the iliac arteries.

PURPOSE: Elastic recoil of the arterial wall has been shown to be responsible for a significant loss of luminal area after balloon angioplasty in the coronary arteries, but it has not been well studied in the peripheral arteries. Because elastic recoil depends on the presence of elastin in the arterial wall, and the amount of elastin varies by artery and proximity to the aorta, the importance of this response to angioplasty may be different in peripheral arteries. The purpose of this study is to document the degree of elastic recoil in the iliac arteries, and analyze variables that might influence the results. MATERIALS AND METHODS: A series of 19 patients with 25 iliac artery stenoses underwent balloon angioplasty followed by placement of a Palmaz stent with the same-sized angioplasty balloon. The minimum luminal diameter of the lesion was measured before treatment, immediately after balloon angioplasty, and again after stent placement. The arterial diameter after stent placement was defined as the diameter of the inflated balloon. The degree of recoil was correlated with nine variables: patient age and sex, lesion location and length, lesion severity (as percent stenosis), the balloon:artery ratio, and three factors related to lesion morphology--complex versus simple, eccentric versus concentric, and calcified versus noncalcified. RESULTS: Elastic recoil averaged 36% +/- 11% and ranged from 19% to 54% in this series of patients. The only variable that significantly influenced the degree of elastic recoil was the balloon:artery ratio (P =.039), which was directly related. CONCLUSION: Elastic recoil is a significant limitation of balloon angioplasty in the iliac arteries. This study illustrates the importance of techniques that limit recoil, such as vascular stents, in angioplasty of the iliac arteries.

Angioplasty, Balloon↗
PubMed2001

A validation of the 10-meter incremental shuttle walk test as a measure of aerobic power in cardiac and rheumatoid arthritis patients.

OBJECTIVE: To validate a simple, clinically relevant, and inexpensive test of aerobic power-the 10-meter incremental shuttle walk test (SWT)--in 2 separate patient populations. DESIGN: Two-sample validity study. SETTING: Physiotherapy department of major hospital in the United Kingdom. PATIENTS: Convenience samples of rheumatoid arthritis (RA) patients (n = 10) and cardiac patients (n = 10). INTERVENTION: Subjects were attached to a portable respiratory gas analyzer to measure oxygen uptake. They walked around an oval 10-meter course, starting at 0.5m/s, with velocity gradually increased by .17m/s increments for as long as they could, for up to 12 minutes. MAIN OUTCOME MEASURES: A subject's maximal rate of oxygen uptake during exercise (V(O)(2)max) established with linear extrapolation was regressed against the number of shuttles completed (distance walked). An earlier study (n = 28) showed high levels of reliability and validity with linear extrapolation. RESULTS: No significant linear relationship was found between V(O)(2)max and the number of shuttles completed (R(2); RA subjects = 9.7%, cardiac subjects = .03%, p > .05). CONCLUSION: These results do not support use of the SWT as a representative measure of aerobic power. Despite this finding, the advantages of developing a clinically viable alternative to costly laboratory testing warrants further study of the SWT in patient groups.

Adult↗
PubMed1999

Accuracy and safety of carbon dioxide inferior vena cavography.

PURPOSE: The purpose of this study was to assess the accuracy of carbon dioxide compared to iodinated contrast material for determining inferior vena cava (IVC) diameter prior to filter placement, and to assess the safety of CO2 when used for this purpose. PATIENTS AND METHODS: Consecutive patients undergoing inferior vena cavography prior to filter placement were prospectively evaluated with use of both CO2 and iodinated contrast material. The diameter of the IVC was measured and compared in the same four locations in each patient for both agents. The diameter was corrected for magnification and pin-cushion distortion. The ability of CO2 to correctly classify IVC diameter as < or =28 mm or >28 mm, based on the IVC diameter with iodinated contrast material, was determined. A consensus panel assessed renal vein visualization with CO2 and iodinated contrast material. Blood pressure and arterial oxygen saturation were measured immediately before and after CO2 injection. RESULTS: Among 30 patients, there was no significant difference in the measured diameter of the IVC with CO2 versus iodinated contrast material after correction for magnification and pin-cushion distortion. One of 30 patients (3.3%) in this study was misclassified as having an IVC < or =28 mm with CO2 when, in fact, the IVC diameter was >28 mm based on iodinated contrast material. This could be clinically significant for certain IVC filters. Forty-seven percent of renal veins identified on contrast venography were identified by CO2 vena cavography. There was no significant difference in the blood pressure or oxygen saturation values measured before and after CO2 injection. However, one patient with pulmonary artery hypertension did experience transient, symptomatic hypotension after CO2 injection. CONCLUSIONS: In most patients, CO2 vena cavography accurately evaluated IVC diameter prior to filter placement. In 3.3% of patients, the discrepancy in measurements between CO2 and iodinated contrast material could be clinically significant, depending on the type of filter placed. CO2 was less accurate than iodinated contrast material in identifying renal veins. Although CO2 vena cavography is safe in the majority of patients, it should be used with caution in patients with pulmonary hypertension.

Adult↗
PubMed1999

Feasibility of three-dimensional intravascular ultrasonography: preliminary clinical studies.

The aim of this study was to demonstrate the clinical utility of reconstructed three-dimensional intravascular ultrasonography using a voxel-based volume rendering technique. Three-dimensional reconstruction of intravascular ultrasonographic data was performed in 12 patients with various vascular abnormalities during interventional radiology procedures. A stepping motor device was used to pull either a 12.5 or a 20 MHz catheter-based transducer through the lumen of a variety of vessels at a rate of 1.5 mm/s. Images were downloaded to a Life Imaging System for three-dimensional reconstruction. The value of three-dimensional ultrasonographic imaging was evaluated in comparison to conventional intravascular ultrasonography. A variety of abnormalities were demonstrated in reconstructed three-dimensional ultrasound imaging, including arterial atheroma and plaque, aneurysm and pseudoaneurysm, aortic dissection and stenosis (May-Thurner syndrome). The vascular branches and accessory vessels, as well as their relationships to each other, were easily demonstrated on three-dimensional imaging by selecting an appropriate angle, plane, and section of the image. The dimensions and shapes of the vascular lumen were determined in the longitudinal view. Three-dimensional information proved useful for determining the distribution and type of plaque in vessels. Reconstructed three-dimensional imaging allows for global evaluation of the dissection entry site, extent of the flap, and the false lumen of a pseudoaneurysm. Intravascular three-dimensional ultrasonography provides information complementary to that obtained with two-dimensional imaging. It supplies information about spatial relationships of anatomic structures that cannot be evaluated using conventional imaging methods.

Adult↗
PubMed1998

Carbon dioxide as a contrast agent to guide vascular interventional procedures.

OBJECTIVE: The purpose of this study was to assess the value and limitations of carbon dioxide (CO2) as a contrast agent to guide vascular interventional procedures. SUBJECTS AND METHODS: Twenty-two adults underwent 26 vascular interventional procedures (21 arterial, five venous). We aimed to use only CO2 if possible because these patients had renal insufficiency (n = 21; mean creatinine level, 2.8 mg/dl) or were allergic to contrast material (n = 1). Arterial procedures performed included renal angioplasty or stent (n = 6), iliac angioplasty or stent (n = 5), infrainguinal angioplasty (n = 5), arterial bypass graft angioplasty (n = 3), and thrombolysis (n = 2). Venous procedures included transjugular intrahepatic portosystemic shunt recanalization (n = 3), angioplasty of the venous anastomosis of a thigh dialysis graft (n = 1), and angioplasty of the inferior vena cava (n = 1). RESULTS: Twenty-five of the 26 procedures were successfully performed. Of the 26 procedures, eight required no iodinated contrast material and 11 required less than or equal to 20 ml of contrast material. CO2 proved to be inadequate for the remaining seven procedures. Iliac artery angioplasty or stent placement required an average of 9 ml of iodinated contrast material; infrainguinal angioplasty required an average of 22 ml of iodinated contrast material. CONCLUSION: CO2 can be successfully used as a contrast agent in a variety of vascular interventional procedures. Such procedures can usually be performed in the iliac and infrainguinal arteries using minimal supplemental iodinated contrast material. However, CO2 failed to provide satisfactory guidance in half of the intraabdominal procedures in our study.

Adult↗
PubMed1997

Biliary-pleural fistulas without biliary obstruction: percutaneous catheter management.

OBJECTIVE: Our purpose was to report the use of percutaneous catheter drainage as a therapeutic option in the management of three patients with biliary-pleural fistulas without biliary obstructions. CONCLUSION: In the proper clinical setting, the CT findings of liver dome laceration or abscess, diaphragm disruption, and pleural effusion should suggest biliary-pleural fistula. Percutaneous catheter management can be curative or serve a temporizing function before surgery.

Adult↗
PubMed1996

Malignant biliary duct obstruction: long-term experience with Gianturco stents and combined-modality radiation therapy.

PURPOSE: To evaluate the effect of combined-modality therapy including intraluminal iridium-192 on stent patency and survival in patients with malignant biliary obstruction treated with Gianturco stents. MATERIALS AND METHODS: Twenty-two patients with unresectable biliary obstruction caused by cholangiocarcinoma (n = 11) or by secondary extrahepatic bile duct malignant tumors (n = 11) were treated with percutaneous biliary drainage followed by intraluminal Ir-192 wire placement (mean dose, 25 Gy) before insertion of Gianturco metal stents. Eleven patients also received external-beam radiation therapy, and 13 patients received chemotherapy. Patency was defined as absence of jaundice or cholangitis that necessitated hospitalization, or as seen on hepatobiliary scans. Survival was determined from the time of stent insertion after brachytherapy. RESULTS: Patients with cholangiocarcinoma had extended mean stent patency of 19.5 months (range, 2-46 months) and mean survival of 22.6 months (range, 2-72 months). Patients with secondary malignant tumors had a mean patency of 4.8 months (range, 1.5-8 months) and a mean survival of 5.3 months (range, 2-9 months). CONCLUSION: Radiation therapy including intraluminal Ir-192 appears to extend stent patency and survival in patients with inoperable cholangiocarcinoma treated with Gianturco metal stents compared with patients with other extrahepatic bile duct malignant diseases and patients treated without combined-modality therapy in other studies.

Aged↗
PubMed1995

Participation by radiologists and other specialists in percutaneous vascular and nonvascular interventions: findings from a seven-state database.

PURPOSE: To determine the relative degree of participation by radiologists and other specialists in percutaneous interventional procedures. MATERIALS AND METHODS: By using 1992 Medicare Part B claims data that covered seven states, the specialty of the physician provider was determined for all services performed within various percutaneous vascular and nonvascular interventional procedure codes. RESULTS: Radiologists' performance of interventional procedures in descending percentage of participation was as follows: renal cyst aspiration (92.7%), biliary decompression (90.5%), abdominal or retroperitoneal mass biopsy (87.7%), lung or mediastinal biopsy (84.2%), noncardiac angioplasty (76.8%), pancreatic biopsy (75.2%), upper urinary tract decompression (73.7%), liver biopsy (43.7%), renal biopsy (38.4%), certain types of abscess drainages (38.2%), and thoracentesis with tube insertion (29.4%). They had only small roles in thoracentesis for aspiration (4.7%) and tube thoracostomy (1.7%). CONCLUSION: Despite controversy between radiologists and other specialists over who should perform percutaneous interventions, radiologists have maintained strong predominance in many types of these procedures. In others, they have a shared, but still major, role.

Angioplasty, Balloon↗
PubMed1994

Fallopian tube recanalization in an unrestricted patient population.

PURPOSE: To review the effectiveness of fallopian tube recanalization (FTR) when performed without restriction based on history or tubal condition. MATERIALS AND METHODS: From October 1989 to July 1992 in 37 consecutive women, aged 22-44 years (mean, 35 years), 42 FTRs were performed (five patients each underwent two FTRs). Water-soluble contrast material and selective ostial salpingography and/or microcatheter technique were used exclusively. Eighty tubes were evaluated, since four patients had previously undergone unilateral salpingectomy. Sixty-three tubes (79%) were occluded at the outset of the procedure. RESULTS: Complete recanalization was achieved in 45 of 63 (71%) occlusions. Adhesions were present in 25 of 80 (31%) tubes, salpingitis isthmica nodosa in 12 (15%), and hydrosalpinx in nine (11%). The 42 procedures resulted in 14 (33%) conceptions, nine (64%) of which involved pathologic tubes. Eleven intrauterine pregnancies resulted in five spontaneous first-trimester abortions, five full-term deliveries, and one continuing pregnancy. CONCLUSION: Favorable conception and live birth rates can be achieved with FTR, despite a high prevalence of tubal disease.

Adult↗
PubMed1994

Transrectal sonographically guided drainage of deep pelvic abscesses.

OBJECTIVE: As an alternative to traditional surgical transrectal and transgluteal drainage, we have examined the efficacy of transrectal sonographically guided drainage for deep pelvic abscesses not accessible by percutaneous transabdominal or transvaginal routes. SUBJECTS AND METHODS: In nine patients (five males and four females) 5-51 years old, sonography or CT showed pelvic abscesses that were deemed unapproachable by percutaneous transabdominal or transvaginal routes because of interposed bowel (five patients), presacral location (two patients), or inability of the pediatric vagina to accommodate a transvaginal probe (one patient). One patient refused both transvaginal and transgluteal routes in preference to transrectal drainage. IV sedation (adults) or general anesthesia (children) was used for all drainages. A 7.5-MHz end-fire transrectal sonographic probe fitted with a biopsy guide was inserted into the rectum, and the collection was localized. With sonographic guidance, an 18-gauge needle and then a guidewire were advanced into the collection. Then with fluoroscopic guidance, a self-retaining drainage catheter was placed by using the Seldinger technique. RESULTS: All nine collections were successfully accessed and effectively drained without complication. Catheters were removed after 1-24 days (mean, 7 days; median, 5 days) without recurrent abscesses. CONCLUSION: Transrectal sonographically guided drainage of deep pelvic abscesses is a safe, well-tolerated, effective alternative to the more traditional surgical transrectal drainage or transgluteal approach, especially in pelvic abscesses that cannot be safely drained via a percutaneous transabdominal or transvaginal route.

Abscess↗
PubMed1994

Arterial abnormalities following orthotopic liver transplantation: arteriographic findings and correlation with Doppler sonographic findings.

OBJECTIVE: We studied the findings on conventional arteriography in patients who had suspected graft ischemia after orthotopic liver transplantation to determine the value of a single Doppler signal in predicting these lesions. MATERIALS AND METHODS: We retrospectively reviewed selective visceral arteriograms with abnormal findings from 20 adults who had suspected graft ischemia after orthotopic liver transplantation and a single Doppler signal from the hepatic artery at the porta hepatis on sonograms obtained before arteriography. Arteriographic abnormalities were categorized according to morphology and location as follows: stenosis of recipient's hepatic artery, occlusion or stenosis of the transplanted extrahepatic artery, and occlusion or stenosis of the transplanted intrahepatic artery. RESULTS: Twenty-three arteriographic abnormalities were detected: four recipient celiac axis stenoses, seven extrahepatic occlusions, nine extrahepatic stenoses, and two occlusions and one stenosis of the transplanted intrahepatic artery. Six of the extrahepatic occlusions, two of the extrahepatic stenoses, and none of the recipient artery stenoses or the intrahepatic occlusions or stenoses were correctly diagnosed on the basis of Doppler findings. One patient with both an extrahepatic stenosis and an extrahepatic occlusion was thought to have an intrahepatic occlusion, and two patients with mild (< 50%) extrahepatic stenoses and one with an intrahepatic occlusion were thought to have an extrahepatic occlusion. CONCLUSION: A wide spectrum of abnormalities in the recipient's celiac axis or the transplanted arteries that may be associated with graft ischemia after orthotopic liver transplantation are often not detected or findings are misinterpreted on routine Doppler examination. In patients with suspected graft ischemia, visceral arteriography should be performed promptly to confirm the diagnosis and to allow early intervention.

Adult↗
PubMed1993

Hemodynamics of failing dialysis grafts.

Pressures were measured in the graft and the central vein during 104 consecutive angiographic examinations of failing hemodialysis grafts. Stenosis severity greater than 40% led to a statistically significant rise in graft pressure. In grafts in which all stenoses were of 40% or less severity, the systolic pressures in the venous and arterial limbs of the grafts were 31% +/- 16 and 45% +/- 17, respectively, of systemic systolic pressure. In grafts in which the highest grade of stenosis was greater than 40%, pressures in the venous and arterial limbs of the grafts were 53% +/- 25 and 75% +/- 24, respectively, of systemic systolic pressure. Graft thrombosis tended to occur at a higher degree of lumen reduction (but at similar pressures) with central vein stenoses compared with venous anastomotic stenoses. Dialysis graft pressures can help determine the hemodynamic importance of stenoses and the need for intervention. Percutaneous intervention should achieve arterial and venous limb pressures of less than 50% and 33% of systemic pressure, respectively.

Angiography, Digital Subtraction↗
PubMed1993

Water quality, waterborne disease and enteric disease in Israel, 1976-92.

Israel experienced a large number of waterborne disease outbreaks between 1975 and 1985, followed by a steep decline in the period 1986-92. Large-scale community waterborne disease outbreaks occurred primarily in the late 1970s, and in 1985 (the Krayot, four small towns neighboring Haifa), but substantial outbreaks occurred as late as 1989, with 4 during 1986-90, and 1 during 1991-92. New water standards, including mandatory chlorination of all community water supplies, came into effect in late 1988. Water quality, as monitored by the Ministry of Health, showed a marked improvement even when measured by the more stringent standards of the 1988 regulations. Long-term trends in the total of reported enteric infectious diseases from all sources, including typhoid, hepatitis, Shigella and Salmonella in Israel are examined. Typhoid, which has been declining since the 1960s, peaked in 1985 with the large waterborne disease episode of the Krayot. Shigella and total hepatitis incidence increased slowly up to the mid-1970s, followed by large increases during the 1975-85 period, then by a rapid decline up to 1991. Shigella, from childhood contacts in kindergartens, increased in 1992. Salmonella incidence continues to increase steadily. Mandatory chlorination and more stringent water standards have had an important impact on water quality and on waterborne disease outbreaks in Israel. Empiric evidence suggests that improving water quality may also be a factor in the changing patterns of some enteric diseases and the total burden of enteric disease in Israel.

Chlorine↗