Regression of perianeurysmal fibrosis and ureteral dilation following endovascular repair of inflammatory abdominal aortic aneurysm

An inflammatory component to abdominal aortic aneurysms (AAA) is thought to occur in approximately 5% of cases. Accompanying ureteral entrapment may be involved in 20% of these. Transabdominal repair of inflammatory AAA with ureterolysis may result in increased complications. Many authorities have recommended a retroperitoneal approach to decrease dissection. Similarly, an endovascular approach has been utilized. We report here the results of a patient with an inflammatory AAA with bilateral ureteral obstruction successfully treated with endovascular stent graft repair and bilateral ureteral stents with exclusion of the aneurysm and resolution of hydronephrosis.

Endovascular stent-graft in abdominal aortic aneurysms: the relationship between patent vessels that arise from the aneurysmal sac and early endoleak

PURPOSE

To determine the association of patent sac branch vessels (lumbar and inferior mesenteric arteries [IMAs]) with early endoleak rate after stent-graft repair of abdominal aortic aneurysm (AAA).

MATERIALS AND METHODS

Pre- and postoperative computed tomographic (CT) angiograms in 158 patients who underwent stent-graft AAA repair were retrospectively reviewed to determine the preoperative patency of IMAs and other sac branch vessels (feeders) and presence or absence of immediate postoperative endoleak. Relationships of early endoleak rate with total branch vessel, IMA, and lumbar artery patency and graft type were evaluated.

RESULTS

There was a significant association between patency of sac feeders and rate of early endoleak, especially type 2. As total patent feeders increased from zero to three to four to six, total endoleak rate increased from 6% (one of 17) to 35% (30 of 86); type 2 endoleak rate, from 0% to 25%. IMA patency was significantly associated with total early endoleak rate. Increasing lumbar artery patency also was associated with significantly higher total and type 2 endoleak rates: With zero to three lumbar arteries, the total endoleak rate was 17% and type 2 endoleak rate was 13%, as compared with 60% and 50%, respectively, with more than six patent lumbar arteries.

CONCLUSION

Sac branch vessel patency is associated with significantly higher early total and type 2 endoleak rates after stent-graft repair of AAAs; thus, patent sac branches play an important role in the pathogenesis of endoleaks.

Inferior vena caval filters: review of a 26-year single-center clinical experience

PURPOSE

To review a 26-year single-center clinical experience with inferior vena caval filters.

MATERIALS AND METHODS

During 1973-1998, 1,765 filters were implanted in 1,731 patients. Hospital files were reviewed, and data were collected about the indications, safety, effectiveness, numbers, and types of caval filters. Fatal post-filter pulmonary embolism (PE) was considered the primary outcome. Morbidity and mortality were determined as secondary outcomes. Survival and morbidity-free survival curves were calculated.

RESULTS

The prevalence of observed post-filter PE was 5.6%. It was fatal in 3.7% of patients. In most patients, fatal PE occurred soon after filter insertion (median, 4.0 days; 95% CI: 2.2, 5.8 days). Major complications occurred in 0.3% of procedures. The prevalence of observed post-filter caval thrombosis was 2.7%. The 30-day mortality rate was 17.0% overall, higher among patients with neoplasms (19.5%) as compared with those without neoplasms (14.3%; P =.004). Filter efficacy and associated morbidity were not different in 46 patients with suprarenal filters. The rate of filters placed for prophylaxis was 4.7% overall and increased to 16.4% in 1998. From 1980 to 1996, there was a fivefold increase in the number of caval filter implants. In recent years, more filters were implanted in younger patients.

CONCLUSION

Inferior vena caval filters provide protection from life-threatening PE, with minimal morbidity.

Utility and reliability of endovascular aortouniiliac with femorofemoral crossover graft for aortoiliac aneurysmal disease

OBJECTIVE

The purpose of this study was to determine the early efficacy of endovascular aortouniiliac stent grafts with femorofemoral bypass graft in the treatment of aortoiliac aneurysmal disease.

METHODS

We analyzed 51 consecutive patients from January 1997 to March 1999 with a mean follow-up of 15.8 months. Patients ranged in age from 44 to 93 years (mean, 75 years) with a mean aortic aneurysm diameter of 6.2 cm. Technical success was achieved in 50 patients; one patient required conversion to open repair intraoperatively. We placed 28 custom-made and 22 commercial devices. The mean operative time was 223 minutes. The endograft was extended to the external iliac artery in 42% of cases. The contralateral common iliac artery was occluded using either a closed covered stent or intraluminal coils.

RESULTS

The median hospital stay was 4 days with an average intensive care unit stay of 0.25 days. There were no operative mortalities. Two patients died during follow-up from unrelated conditions. Endoleaks occurred in 11 patients (22%); seven patients (14%) required intervention (four catheter based, three operative). Other complications occurred in 38% of patients but were largely remote or wound related. One femorofemoral bypass graft occluded immediately postoperatively as a result of an intraprocedural external iliac dissection yielding a 98% primary patency and 100% secondary patency. Clinical success was achieved in 88% of patients.

CONCLUSIONS

These data suggest that this strategy represents a reliable method of repair of aortoiliac aneurysmal disease and extends the capability of an endoluminal approach to patients with complex iliac anatomy.

Clinical outcome of internal iliac artery occlusions during endovascular treatment of aortoiliac aneurysmal diseases

PURPOSE

To determine the clinical outcome of hypogastric artery occlusion in patients who underwent endovascular treatment of aortoiliac aneurysmal disease.

MATERIAL AND METHODS

From January 1994 to March 1998, 94 patients underwent endovascular treatment of aneurysmal diseases involving the infra-abdominal aorta or iliac arteries. Preoperative and intraoperative radiologic data were reviewed. Discharge summaries, clinic visits, and phone calls formed the basis for clinical follow-up, with a mean follow-up period of 7.3 months (range, 1-24 months).

RESULTS

Because of the anatomy of the aneurysms, 28 patients required occlusion of one or more hypogastric arteries. One of the 28 patients died of unrelated causes before follow-up. Seven (26%) of the remaining 27 patients developed symptoms attributable to the hypogastric artery occlusions. Five patients developed new buttock or thigh claudication; of these five patients, three with initially mild symptoms noted complete or near complete resolution of symptoms upon follow-up. One patient with originally significant claudication at 2-year follow-up noted near resolution of symptoms. The other patient with severe pain did not improve significantly on final 1-year follow-up before his death (of unrelated causes). Other clinical complications were worsening sexual function in one patient and a nonhealing sacral decubitus ulcer that developed in a debilitated patient in the postoperative setting, which required surgery. No bowel ischemia was observed.

CONCLUSION

When treating aortoiliac aneurysmal disease through an endovascular approach, the occlusion of internal iliac artery is often necessary but carries with it a small but finite chance of morbidity.

Custom bifurcated stent-graft for abdominal aortic aneurysms: initial experience

PURPOSE

To describe a custom bifurcated stent-graft for possible treatment of abdominal aortic aneurysm (AAA).

MATERIALS AND METHODS

Five male patients (mean age, 76 +/- 6 years), who had AAA (mean diameter, 4.7 +/- 0.4 cm) and who were considered to be at high risk for conventional surgery, were treated with a custom modular bifurcated stent-graft constructed with bifurcated 24-mm x 12-mm (upper body diameter x iliac limb diameter) Cooley Veri-Soft Woven polyester grafts and Gianturco-Rösch Z stents. The stent-graft body was delivered through 20-22-F sheaths, and the contralateral iliac limb was delivered through a 16-F sheath by means of surgical exposure of the common femoral arteries. A flared distal limb extender (12 mm to 14 mm) was created for one patient to accommodate a large common iliac artery.

RESULTS

Stent-grafts were successfully deployed without complications in all five patients. There were no proximal or distal leaks. A lumbar-to-inferior mesenteric artery leak was seen in one patient at 24 hours. At 6-month follow-up, all devices were intact, with complete exclusion and shrinkage of the aneurysm in four of five patients. Aneurysm size remained stable in the one patient with a lumbar-to-inferior mesenteric artery leak.

CONCLUSION

A custom, bifurcated stent-graft was utilized for endovascular treatment of AAA. Long-term follow-up is necessary for the device.

Gadolinium-based contrast agents as an alternative at vena cavography in patients with renal insufficiency--early experience

The authors reviewed results of digital subtraction vena cavography with a gadolinium-based contrast agent in 14 patients with serum creatinine levels greater than or equal to 1.5 mg/dL (133 mumol/L). All cavograms were diagnostic. In 11 patients, there was no impairment of renal function. In three patients, a rise in serum creatinine level of greater than or equal to 0.5 mg/dL (44 mumol/L) was attributable to concurrent medical problems. Gadolinium-based contrast agents may be suitable for digital subtraction vena cavography in patients with renal insufficiency.

Cost comparison of radiologic versus surgical placement of long-term hemodialysis catheters

OBJECTIVE

The purpose of this study was to compare the cost of radiologic versus surgical placement of long-term hemodialysis catheters.

MATERIALS AND METHODS

Our cost analysis was based on 47 long-term hemodialysis catheters radiologically placed in 45 patients and 25 catheters surgically placed in 25 patients from October 1996 through March 1997. Variable and total costs were calculated using data from the hospital administrative computer system that records the actual costs incurred by the hospital in caring for patients.

RESULTS

The average total hospital cost was $926 for each radiologic placement and $1849 for each surgical placement of long-term hemodialysis catheters. The total cost saving for radiologic placement was $923 for each catheter.

CONCLUSION

Radiologic placement of long-term hemodialysis catheters resulted in substantial savings over surgical placement.

Gadopentetate dimeglumine: a possible alternative contrast agent for CT angiography of the aorta

We report the use of a gadolinium chelate for limited CT angiography of the aorta in a patient in whom iodinated contrast agent was contraindicated and who had undergone nondiagnostic MRI.

Initial experience with endovascular aneurysm repair: comparison of early results with outcome of conventional open repair

PURPOSE

To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA.

METHODS

Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months.

RESULTS

Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture.

CONCLUSIONS

Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk.

Evaluation of renal artery stenosis with dynamic gadolinium-enhanced MR angiography

OBJECTIVE

The purpose of this study was to compare dynamic gadolinium-enhanced three-dimensional spoiled gradient-recalled MR angiography with conventional arteriography in the evaluation of proximal renal artery stenosis (RAS).

MATERIALS AND METHODS

MR angiography and conventional arteriographic examinations of 30 patients evaluated for RAS were analyzed retrospectively. Three-dimensional MR angiography was performed with an RF spoiled gradient-recalled imaging sequence acquired during the dynamic i.v. injection of gadolinium (0.2-0.3 mmol/kg), MR data and conventional arteriograms were independently evaluated for the number and location of renal arteries and the degree and location of stenoses. The patients had a mean age of 70 years old and a mean serum creatinine level of 2.9 mg/dl, reflecting a population in whom atherosclerotic RAS was the primary concern.

RESULTS

Gadolinium-enhanced MR angiography revealed 100% of main renal arteries. For RAS of 50% or greater occlusion, the technique was 100% sensitive and 71% specific; the negative predictive value was 100%. The technique was 100% sensitive and 71% specific for RAS of 75% or greater occlusion.

CONCLUSION

Dynamic gadolinium-enhanced three-dimensional spoiled gradient-recalled MR angiography has a high sensitivity for revealing proximal RAS and is a quick and reliable technique for obtaining helpful anatomic information.

Migration of central venous catheters: implications for initial catheter tip positioning

PURPOSE

To evaluate the change in position of chest wall central venous access catheters (CVACs) after placement. Complication rates associated with catheter tip position were reviewed.

PATIENTS AND METHODS

Fifty patients (36 women, 14 men) with chest wall CVACs placed in the angiography suite were studied. Catheter migration was calculated as the difference between the carina-catheter tip measurements on immediate supine and upright postprocedure (within 24 hours) chest radiographs. Catheter-related complication data were gathered via telephone interview and review of the medical records.

RESULTS

Peripheral catheter migration occurred in 49 of 50 patients (average, 3.2 cm +/- 1.8); central catheter migration occurred in one of 50 patients (3.9 cm). Catheter type was the only significant factor that affected the amount of migration; side of insertion or the patient's gender were not significant. Catheter malfunction and symptomatic upper extremity venous thrombosis rates tended to be lower in patients with right atrial versus superior vena cava catheters (18% vs 34%), but differences were not significant (P = .202).

CONCLUSION

Catheter migration after chest wall CVAC placement is a common event. The catheter tip should be initially positioned approximately 3-4 cm more centrally than the desired final position. Further study is necessary of catheter-related complication rates relative to the final position of the catheter tip.

Long-term outcomes of radiologically placed arm ports

PURPOSE

To evaluate long-term outcomes of an initial experience with radiologic placement of arm ports.

MATERIALS AND METHODS

The follow-up of 46 consecutive arm port placements (44 patients) was reviewed by means of chart review (hospital, office, and clinic) in 41 patients, telephone interview in 20, physical, examination in 15, and venous ultrasound in 14. Data on port complications and function were recorded. Statistical methods were the Fisher Exact Test and Cochran-Mantel-Haenszel Test.

RESULTS

Technical success for placement was 100%. Follow-up was obtained in 41 (93%) of the 44 patients (43 ports); mean days of catheter use was 344 days (total, 14,797 days; range, 10-1,104 days; median, 278 days). Rate (per 100 catheter days) of symptomatic central venous thrombosis was 0.054; arm phlebitis, 0.007; confirmed infection, 0.034; and catheter dysfunction, 0.095. Prophylactic anti-coagulants did not affect symptomatic central venous thrombosis (P > .05, Fisher Exact Test). Catheter tip high in the right atrium was marginally associated with better catheter function (P = .041, Fischer Exact Test).

CONCLUSION

Good long-term results can be anticipated with radiologic placement of arm ports.

Embolization of pulmonary catheter-induced pulmonary artery pseudoaneurysms

STUDY OBJECTIVES

To determine the outcome of patients with pulmonary catheter-induced pulmonary artery pseudoansurysms (PSAs) treated with embolization.

DESIGN

Retrospective outcomes review.

SETTING

Large urban tertiary-care hospital.

PATIENTS

All patients who presented to diagnostic angiography for ruptured pulmonary artery PSA caused by pulmonary artery catheters (PACs) from November 1990 to September 1995. A total of six patients were examined.

INTERVENTIONS

Transcatheter embolotherapy with coils, absorbable gelatin sponges (Gelfoam), and suture material.

RESULTS

These procedures were technically successful in all patients, and none had recurrent hemoptysis. Four of the six patients were discharged from the hospital.

CONCLUSION

Embolotherapy is a useful alternative to surgery for some patients with PAC-induced pulmonary PSA.

MR angiography of tibial runoff vessels: imaging with the head coil compared with conventional arteriography

OBJECTIVE

We compared peripheral vascular MR angiography done with a standard transmit-receive head coil with conventional arteriography for identifying and evaluating runoff vessels below the knee.

MATERIALS AND METHODS

We examined 55 legs in 31 symptomatic patients with both conventional contrast angiography and gradient-echo two-dimensional time-of-flight MR angiography. Both legs of patients were placed in a standard transmit-receive head coil for MR angiography and were imaged simultaneously. For evaluation of stenoses, images of vessels were divided into 10 segments, and each segment was graded on a four-point scale.

RESULTS

In the 393 native vascular segments evaluated, the sensitivity of MR angiography in identifying normal vessels was 95% and the specificity was 98%. In detecting segmental occlusion, MR angiography was 98% sensitive and 97% specific. Sensitivity and specificity for stenoses greater than 75% were 98% and 96%, respectively, and for stenoses greater than 50%, they were 98% and 95%, respectively. Interpretative discrepancies were found in 35 vessel segments in 18 legs; none was of clinical relevance. Of all vessel segments shown as occluded by conventional angiography, 1% appeared patent on MR angiograms. No vessel segments shown as normal on MR angiograms were found to be occluded on conventional angiograms.

CONCLUSION

When performed simultaneously on both legs of symptomatic patients, 2D time-of-flight MR angiography with a standard transmit-receive head coil provides a time-efficient and highly sensitive and specific means of evaluating below-knee runoff.

Mesenteric venous thrombosis treated with urokinase via the superior mesenteric artery

A 77-year-old man with a history of multiple surgically treated malignancies presented with increasing abdominal pain after eating. Computerized tomographic scan showed superior mesenteric vein and portal vein thrombosis. The patient was treated with selective superior mesenteric artery infusion of urokinase resulting in clinical improvement and near complete resolution of the mesenteric venous thrombosis. An underlying gastric malignancy was found and is believed to be the cause of the patient's hypercoagulable state. Direct infusion of urokinase into the superior mesenteric artery for treatment of mesenteric venous thrombosis is an alternative to surgery in selected patients and an alternative to the much more complicated delivery systems presently used.

Renal insufficiency: gadopentetate dimeglumine as a radiographic contrast agent during peripheral vascular interventional procedures

Gadopentetate dimeglumine diluted 1:1 with 0.9% normal saline was used as the radiographic contrast agent in two patients with azotemia who underwent peripheral vascular interventional procedures. The patients had no evidence of contrast material-induced renal failure after the procedures. The radiographic attenuation of the diluted gadopentetate dimeglumine was equivalent to diatrizoate meglumine diluted to 40 mg iodine per milliliter. Gadopentetate dimeglumine is an alternative radiographic contrast material for azotemic patients.

Guide-wire entrapment by inferior vena caval filters: in vitro evaluation

PURPOSE

To study guide-wire engagement and entrapment by inferior vena caval (IVC) filters.

MATERIALS AND METHODS

Patterns of engagement were determined in six IVC filters with four commonly used guide wires in a simulated IVC. Force required to disengage guide wires from filters was measured.

RESULTS

Eleven engagement patterns were identified with J-tipped guide wires; straight guide wires never engaged. The Simon-Nitinol filter engaged guide wires with the highest frequency (P < .05). The 15-J wire was engaged most frequently overall (P < .0005) but disengaged with forces not significantly different (P > .05) from those required to open the J. Entrapment occurred with only the Vena-Tech (VT) and 12-F stainless steel Greenfield (12SSG) filters and the 1.5-J and 3-J guide wires. The former guide wire became entrapped regardless of engagement pattern; the latter became entrapped only when engaged in the hole in the apex of the 12SSG and VT filters.

CONCLUSION

Guide wires with a J tip 3 mm or less in radius are at risk for entrapment by the 12SSG and VT filters.

Operator errors during percutaneous placement of vena cava filters

Operator errors during percutaneous insertion of inferior vena cava (IVC) filters are procedural complications specific to filter placement that cannot be attributed to defects in the device itself. These errors can occur during preplacement imaging of the IVC, selection of the filter, or deployment of the filter. Although technical problems are reported to occur in 5-20% [1] of filter insertions, the precise frequency of operator errors is not known. This pictorial essay reviews the different types of operator errors that can occur during percutaneous insertion of IVC filters.

Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms

PURPOSE

Contrast arteriography (CA) is a useful but invasive technique for the preoperative evaluation of patients with abdominal aortic aneurysms (AAA). To evaluate the use of magnetic resonance arteriography (MRA) as a preoperative study we prospectively studied 38 patients undergoing AAA repair.

METHODS

All patients underwent biplane CA and MRA with use of a gadolinium-enhanced technique. Radiographic studies were then independently evaluated by blinded radiologists for anatomic findings with CA used as the standard. Studies were then independently evaluated by blinded vascular surgeons, and a surgical plan was made.

RESULTS

With CA and intraoperative findings as the standards, MRA proved highly accurate in the determination of multiple key anatomic elements. The proximal extent of aneurysmal disease was correctly predicted in 87% (33/38) patients. Significant iliofemoral occlusive disease was identified with a sensitivity of 83% (5/6). Iliac or femoral aneurysms were detected with a sensitivity of 79% (22/28) and specificity of 86% (41/48). Significant renal artery stenosis was detected with a sensitivity of 71% (12/17) and a specificity of 99% (72/73). Accessory renal arteries were correctly identified in 71% (12/17). Surgeon evaluators correctly predicted the proximal cross-clamp site in 87% (33/38) of patients with use of MRA as compared with the actual operative conduct. Proximal anastomotic sites were correctly predicted in 95% (36/38) with MRA and 97% (37/38) with CA. Renal revascularization was predicted by MRA with a sensitivity of 91% (10/11) and specificity of 100% (65/65). The use of bifurcated aortic prostheses was correctly predicted by MRA in 75% (12/16), which was similar to that predicted by CA (81%, 13/16).

CONCLUSIONS

MRA can provide preoperative anatomic information that is equivalent to CA for surgical planning. Because of favorable cost and patient safety considerations MRA will assume increasing importance in the preoperative evaluation of AAA.

MR imaging (including MR angiography) of abdominal aortic aneurysms: comparison with conventional angiography

OBJECTIVE

The purpose of this report is to compare the results of MR imaging, including MR angiography, with the results of conventional angiography in the imaging of abdominal aortic aneurysms (AAA).

SUBJECTS AND METHODS

Twenty seven nonconsecutive patients with known AAA underwent both MR imaging (including MR angiography) and conventional angiography preoperatively. MR imaging was done before angiography according to the following protocol in all patients: sagittal and coronal T1-weighted images of the abdomen, followed by axial MR angiograms obtained with a multiple overlapping thin-slab acquisition (MOTSA) three-dimensional time-of-flight (3D TOF) volume centered on the renal arteries. Last, coronal MR angiograms were obtained with a dynamic contrast-enhanced 3D TOF volume centered on the aorta. Conventional angiography was subsequently performed in all patients. Data from each study were collected prospectively and analyzed in a blinded manner. For the MR studies, all sequences were used to determine the extent of the AAA and the presence of iliac aneurysms; stenotic disease of the celiac, superior mesenteric, renal, and iliac arteries and the number and location of renal arteries were determined from the MR angiograms. For evaluation of the extent of the aneurysm, results from both techniques were compared with surgical results; otherwise MR angiography was compared with conventional angiography. Confidence intervals for sensitivity and specificity were calculated at the 95% level. The McNemar test was used for comparison of proportions.

RESULTS

MR angiography had a sensitivity of 100% (4/4) and a specificity of 91% (21/23) for the four stenoses of the celiac artery that were greater than 50%. For detection of renal artery stenoses of greater than 50%, present in nine arteries, the sensitivity was 89% (8/9) and specificity was 98% (49/50). MR angiography showed 100% (54/54) of all main renal arteries and 78% (7/9) of all accessory renal arteries seen on conventional angiograms. The proximal extent of the aneurysm was correctly predicted on the basis of MR findings in 100% (26/26) of patients with surgical correlation, compared with 92% (24/26) when conventional angiograms were used. This difference was not statistically significant (p > .1). MR imaging had a sensitivity of 100% (19/19) for detection of isolated aneurysms of the common iliac artery, and MR angiography had a 100% sensitivity (5/5) and specificity (103/103) for detection of stenosis greater than 50% in the common and external iliac arteries. One circumaortic left renal vein was visualized on MR images.

CONCLUSION

These results suggest that MR angiography may be a useful noninvasive method for determining the presence of coexistent celiac, superior mesenteric, renal, and iliac atherosclerotic disease in patients with AAA.

MR angiography in the preoperative evaluation of abdominal aortic aneurysms: a preliminary study

PURPOSE

The ability of magnetic resonance (MR) angiography to depict visceral and renal vessels was evaluated in patients with abdominal aortic aneurysms (AAAs).

PATIENTS AND METHODS

MR sequences (sagittal T1-weighted, two-dimensional coronal, and three-dimensional axial time-of-flight) were compared in a prospective blinded fashion with conventional angiograms obtained preoperatively in 23 patients with AAAs. Results were correlated with surgical findings when available.

RESULTS

Operative aortic clamp site was correctly predicted with conventional angiography in 95% of patients and with MR angiography in 86% (P > .1). Aneurysm neck measurements obtained with the two modalities were within 1 cm in 91% of cases. With conventional angiography as the standard of reference, 96% of all renal arteries were identified on MR angiograms but 36% of accessory arteries were missed. MR angiography enabled identification of patients who had at least one renal artery stenosis greater than 50% with a sensitivity of 100% and specificity of 89%. For identifying individual renal artery, celiac artery, and superior mesenteric artery stenoses of similar severity, the sensitivity and specificity were 67% and in excess of 96%, respectively. The celiac artery could not be evaluated in one case.

CONCLUSION

The results of this small study suggest that the role of MR angiography in the preoperative evaluation of AAA warrants further investigation.

Dynamic gadolinium-enhanced three-dimensional abdominal MR arteriography

The abdominal aorta and renal, visceral, and iliac arteries were evaluated in 16 patients with three-dimensional Fourier transform imaging enhanced with gadopentetate dimeglumine. By imaging dynamically during the arterial phase of a 5-minute injection (0.2 mmol/kg), highly significant (P < .0001) preferential arterial enhancement (signal-to-noise ratio +/- standard deviation, 10 +/- 0.9), with minimal enhancement of the inferior vena cava (5.1 +/- 1.4) or background tissues (fat, 4.3 +/- 0.7; muscle, 2.4 +/- 0.5), was achieved in every patient. In six patients with angiographic and/or surgical correlation, 10 of 10 stenoses and two of two occlusions were correctly identified. No in-plane saturation or pulsatility artifact was identified in any of the 16 patients. In conclusion, dynamic imaging during the injection of gadopentetate dimeglumine is a promising technique for evaluation of the abdominal aorta and branch vessels.

Atherosclerotic occlusive disease of the lower extremity: prospective evaluation with two-dimensional time-of-flight MR angiography

A prospective, blinded comparison of two-dimensional time-of-flight (TOF) magnetic resonance (MR) angiography and conventional arteriography was performed in 25 patients who underwent routine arteriography for symptomatic atherosclerotic occlusive disease of the lower extremity. MR angiography was performed from the distal abdominal aorta through the popliteal trifurcation. The native arterial tree was divided into nine segments; each segment was assessed for patency (defined as stenosis < 50% of arterial diameter), moderate stenosis (50%-69%), severe stenosis (70%-99%), or occlusion (100%). In all 206 segments examined, the sensitivity of MR angiography in diagnosis of occlusion was 100%; the specificity, 98%. All long occlusions were correctly classified. In specific categories of occlusive disease, the sensitivity and specificity were as follows: in all segments with 70% or greater stenosis, including occlusions, 90% and 97%; in all segments with 50% or greater stenosis, including occlusions, 92% and 88%; in femoropopliteal segments with 50% or greater stenosis, 92% and 93%; and in iliac segments, 93% and 83%. Long occlusions were distinguished from short occlusions and stenoses; hence, MR angiography enabled identification of patients with lesions suitable for angioplasty.

Access-site thrombosis after placement of inferior vena cava filters with 12-14-F delivery sheaths

Inferior vena cava filters were placed in 60 patients. Ultrasound (US) of the venous access site was performed before and 3-5 days after filter placement to determine the prevalence of occlusive and nonocclusive access-site thrombosis (AST). Prevalence of symptoms attributable to AST was also evaluated at 1-month clinical follow-up in 58 of the 60 patients. All filters were placed with delivery sheaths with outer diameters of 12-14 F. US depicted development of occlusive AST in six of the 60 patients (10%). Nonocclusive AST developed in 15 (25%). Symptoms related to AST occurred in two of 58 patients (3%). There was a substantially increased prevalence of occlusive thrombus in patients in whom partially occluding thrombus or extrinsic compression in the inferior vena cava or ipsilateral iliofemoral veins was demonstrated on vena cavograms obtained before filter placement. The prevalence of both symptoms attributable to AST and US-detected occlusive thrombus in this series with smaller delivery systems is lower than that reported after percutaneous placement of stainless steel Greenfield filters via 29.5-F (outer diameter) sheaths.

Transfemoral venous catheterization through inferior vena caval filters: results in seven cases

Use of the transfemoral route for venous catheterization has been considered contraindicated in patients with inferior vena caval (IVC) filters. The transjugular route has been used instead in such patients when subsequent diagnostic or therapeutic procedures are required. Many radiologists, however, are more accustomed to the transfemoral approach, and may not find the transjugular route a desirable alternative. We describe seven patients with previously placed IVC filters in whom the transfemoral route was used to perform pulmonary arteriography (five patients) or to place additional IVC filters (two patients). After venographic confirmation of caval patency, filters were catheterized under fluoroscopic control and the procedures were performed. All procedures were technically successful; no complications occurred. We believe the transfemoral route to be a safe and feasible approach for performing venous procedures in selected patients with IVC filters, obviating the less familiar and potentially more hazardous transjugular approach.

Carotid surgery without arteriography: noninvasive selection of patients

All carotid noninvasive studies at our institution comprised of duplex scanning, spectral frequency analysis, and ocular-pneumoplethysmography-Gee supraorbital Doppler assessments from 1985-1987 were reviewed. Forty symptomatic and 104 asymptomatic internal carotid arteries, concomitantly studied noninvasively and arteriographically, were identified. All studies were rereviewed prospectively and in blinded fashion. Utilizing peak frequency--internal carotid artery greater than 10 mHz and carotid index (Pf-ICA)/PF-common carotid) greater than 5 as criteria for surgery, 39/40 symptomatic internal carotid arteries were considered appropriate for carotid endarterectomy by noninvasive study. All of these internal carotid arteries had arteriographic confirmation of greater than 50% internal carotid artery stenosis; 22 of them met noninvasive criteria for surgery of peak systolic frequency-internal carotid artery greater than 14 mHz, carotid index greater than 7 and abnormal ocular-pneumoplethysmography-Gee/supraorbital Doppler. All of these had arteriographic confirmation of greater than 80% internal carotid artery stenosis. Eleven asymptomatic internal carotid arteries met spectral frequency criteria for carotid endarterectomy but had normal ocular-pneumoplethysmography-Gee/supraorbital Doppler. Eight in this group had less than 80% stenosis on arteriographic exam. Carotid endarterectomy may be performed without prior arteriography, provided objective criteria are established in a reliable noninvasive lab and met by individual patients.

Isolated calf venous thrombosis: diagnosis with compression US

Compression ultrasound (US) is an excellent means of evaluating the femoral and popliteal veins but is generally regarded as inadequate for the diagnosis of calf vein thrombosis. This prospective study evaluated compression sonography of the calf veins in 45 symptomatic patients with normal femoral and popliteal veins. All patients underwent correlative venography. Compression US enabled identification of 15 of 17 patients with calf vein thrombosis (sensitivity, 88%). The two false-negative results were in patients with small isolated thrombi. Compression US results were true-negative in 26 of 27 patients with normal venograms (specificity, 96%). If these results can be duplicated by other investigators in larger series of patients, compression US will be an adequate screening modality for calf vein thrombosis.

Aortocaval and iliac arteriovenous fistulas: recognition and treatment

Despite the well characterized physiologic effects of aortocaval or iliac arteriovenous fistulas, patients with such uncommon lesions may manifest a diverse array of symptoms, and diagnosis is often delayed or overlooked. To examine clinical features that facilitate recognition and allow successful repair, a 30-year experience with 20 such fistulas was reviewed. Fourteen fistulas were caused by aneurysm erosion, four followed iatrogenic injury during lumbar disk surgery, and two developed from abdominal gunshot wounds. The interval from presumed occurrence to diagnosis ranged from 3 hours to 8 years. The diagnosis was not recognized before surgery in five (25%) patients. Back pain (70%) was the most common symptom. The presence of a typical abdominal bruit (80%) was the most reliable physical finding, but its significance was occasionally overlooked or misinterpreted. Congestive heart failure was prominent in only seven (35%) patients. Severe lower extremity edema and mottling was the primary manifestation in eight cases, often causing initial confusion with venous thrombosis. Hematuria (5 patients) and oliguric renal failure (4 patients), both fully reversible after fistula repair, also caused diagnostic uncertainty. The mean preoperative cardiac output was 12.2 L/min, falling to 5.4 L/min with fistula repair. Mean blood loss was 5960 ml, supporting use of intraoperative autotransfusion. Two operative deaths (10%) occurred, both in patients not correctly diagnosed before surgery. Despite varied modes of presentation, prompt recognition and use of appropriate operative techniques should achieve successful repair.

Penetrating aortic ulcers: diagnosis with MR imaging

The authors studied seven patients with penetrating aortic ulcers with use of magnetic resonance (MR) imaging. All patients were evaluated for acute chest symptoms, and the presence of aortic ulcers was confirmed by means of angiography in all seven patients. Five patients also underwent computed tomography (CT). Three patients underwent surgical repair of the thoracic aorta. MR findings included intramural hematoma and focal aortic wall ulceration in four patients, focal ulceration in one, focal intramural hematoma in one, and focal intramural hematoma with rupture in one. The diagnosis of intramural hematoma was made by the detection of increased signal intensity on T1- and T2-weighted MR images. MR imaging was superior to angiography in depicting the extent of intramural thrombus, although one ulceration diagnosed at angiography was missed at MR imaging. MR imaging was superior to CT in differentiating acute intramural hematoma from atherosclerotic plaque and chronic intraluminal thrombus, although it did not depict displaced intimal calcification in one patient with extensive intramural hematoma.

Testicular seminoma: clinical and pathological features that may predict para-aortic lymph node metastases

Patients with clinical stage I testicular seminoma usually receive elective para-aortic lymph node radiation after orchiectomy, which is effective in controlling subclinical microscopic disease. However, the majority of patients with clinical stage I seminoma do not harbor occult metastases and, therefore, do not require elective nodal treatment. Vascular space invasion by the primary testis tumor recently has been shown to be an important predictor of metastases in nonseminomatous tumors but no such information exists to date in pure seminoma. Therefore, patients with clinical stage I testicular seminoma were compared to clinical stage II to IV cancer patients with respect to the presence of several features of the primary tumor. Vascular space invasion was identified significantly less frequently in stage I cancer patients (17%, 5 of 29) than in those with stage II or greater disease (39%, 11 of 28, p equals 0.03, 1-tailed t test). Microscopic invasion of the tunica and rete testis, and necrosis also were identified slightly more frequently in the higher stage cancer patients. Of the 12 patients with a maximum tumor dimension of more than 6 cm. 9 (75%) were in the stage II or higher group. Patient age, symptom duration and presenting complaint were similar in the 2 groups. Many higher stage cancer patients did not exhibit aggressive histological characteristics and, therefore, the absence of these features cannot be used to select patients for surveillance. On the other hand, patients with clinical stage I tumors that exhibit vascular space invasion may have an increased rate of occult para-aortic lymph node metastases. Therefore, the presence of vascular space invasion may be a useful criterion for exclusion of patients from surveillance protocols. Confirmatory data are needed before a final recommendation can be made.

Current use of low-osmolality contrast agents: results of a survey

Members of the Society of Cardiovascular and Interventional Radiology and the Society of Uroradiology were surveyed to assess both current practice and determinants of use of low-osmolality contrast agents (LOCA). Of 715 questionnaires mailed, 229 were returned (32%). Many indicated that the responses referred to the practice of a group, rather than to an individual. Two thirds of the responses indicated that the choice of agent was made by the radiologist alone; one third shared the decision with administrators. Approximately 40% of respondents use written guidelines, but this percentage was higher when administrators were involved in the decision. Almost all (99%) obtained written informed consent--one third for all procedures that use contrast material and two thirds for angiographic studies only. Four percent noted the availability of LOCA in obtaining consent. Overall, LOCA were used for most angiographic procedures by 38% and for most IV studies by only 9% of respondents. All used them for at least some angiographic studies, and all but 2% used them for some IV studies. The major indications for use in both angiographic and IV studies were a prior major (but not minor) reaction and renal dysfunction. Anticipated patient discomfort also was important for intraarterial use. LOCA were used most often for peripheral and pulmonary arteriography. When LOCA were used, nonionic agents were preferred to low-osmolality ionic dimeric contrast agents for coronary angiography and venography, but this preference was essentially reversed for peripheral arteriography. This survey suggests that IV use of LOCA is much less frequent than intraarterial use and that use is individualized to certain risk factors and certain examinations. Guidelines for use are often in place, but this is clearly not universal. The importance of informed consent for use of contrast agents and of the appropriate role for LOCA remains unsettled.

Long-term results of combined iliac balloon angioplasty and distal surgical revascularization

Long-term results of combined use of iliac artery percutaneous transluminal angioplasty (PTA) and distal surgical revascularization for the management of multilevel occlusive disease were evaluated over a 12-year period. A total of 79 combined procedures were performed in 75 patients. All patients had tandem occlusive disease, with the inflow lesion felt to preclude a distal revascularization procedure alone. Revascularization was performed for incapacitating claudication in 17 (22%) and limb salvage indications in 62 (78%) cases. A mean resting iliac artery pressure gradient of 29 +/- 11 mmHg pre-PTA was reduced to 0.9 +/- 0.4 post-PTA. Major complications of PTA occurred in five (6%) cases, but four were successfully corrected at the time of the distal surgical procedure without alteration of the operative plan. Infrainguinal operations included 55 femoropopliteal or tibial bypass grafts, 18 femorofemoral grafts, and 6 profundaplasties. Mean follow-up was 43 months. By life table analysis, the 5-year primary patency rate of the distal surgical procedures was 76%; a secondary patency of 88% at 5 years was achieved by various means of reintervention. Mean pretreatment ankle/brachial index of 0.31 +/- 0.14 increased to 0.80 +/- 0.16 after operation (p less than 0.0001). The 5-year limb salvage rate was 90%. There were no operative deaths. We conclude that in carefully selected patients, combined use of iliac PTA and distal surgical reconstruction is effective and durable, safely reducing the extent of surgical intervention while reliably increasing the comprehensiveness of revascularization.

Regional infusion of urokinase into occluded lower-extremity bypass grafts: long-term clinical results

The initial outcome, long-term patency rate, and rate of limb salvage were studied in patients after regional urokinase infusion for treatment of thrombosed lower-extremity grafts. Seventy-one infusions were performed in 53 patients. Complete clot lysis occurred in 75% of grafts, with establishment of antegrade blood flow in 66%. Variables that favorably influenced clot lysis and the reestablishment of antegrade blood flow through the graft were a short duration of occlusion and a suprainguinal graft position. The median duration of patency after infusion and adjunctive therapy was 162 days, with 75% limb salvage at 301 days. No statistically significant variables that influenced the length of patency were identified. These long-term patency results are inferior to the reported results in suprainguinal grafts after reoperation. They appear similar to reported results for occluded infrainguinal grafts treated with thrombectomy and patch grafting.

Donor renal angiography: its influence on the decision to use the right or left kidney

The left kidney from a living, related donor is preferred for kidney transplantation because it has a longer renal vein and thus is easier to implant in the recipient. However, anatomic variations in the renal arteries occasionally dictate the choice of the right kidney instead. To determine the influence of angiographic findings on the decision to use the right or the left kidney for transplantation, we assessed the role of preoperative angiography in the evaluation of living, related kidney donors. The records of 81 potential renal donors who underwent arteriography were reviewed. Three patients did not undergo donor nephrectomy, for reasons unrelated to the results of arteriography. Of the remaining 78 patients, two-thirds (52) underwent left nephrectomy as planned. A right nephrectomy was performed in the other 26 donors. In 19 of these 26 patients (24% of the 78 who underwent nephrectomy), the right kidney was chosen because of anatomic variations in the renal arteries seen on arteriography. Right donor nephrectomy was performed in the remaining seven of the 26 patients because of venous or collecting-system variants in the left kidney in three and because of better anatomic compatibility with the recipient in the other four. We conclude that donor angiography will dictate the choice of kidney in approximately one-fourth of prospective renal donors.