Celiac Axis Stenosis: Incidence and Etiologies in Asymptomatic Individuals

Objective

To determine the incidence and etiologies of celiac axis stenosis in asymptomatic individuals.

Materials and Methods

This prospective study involved 400 consecutive patients (male: 319, female: 81) referred to us for celiac arteriography between April and July 1999. When celiac axis branches were opacified by collateral circulation during superior mesenteric arteriography, the presence of celiac axis stenosis was suspected; lateral projection celiac arteriography was performed and the pressure gradient was measured. The indicators used to determine whether or not celiac axis stenosis was significant were luminal narrowing of more than 50% and a resultant pressure gradient of at least 10 mmHg. Its etiology was determined on the basis of angiographic appearances and CT findings.

Results

Twenty-nine patients (7.3%) had celiac axis stenosis. The etiology of the condition was extrinsic compression due to the median arcuate ligament in 16 patients (55%) and atherosclerosis in three (10%), while in ten (35%) it was not determined. The incidence of celiac axis stenosis did not vary significantly according to sex, age and the presence of calcified aortic plaque representing atherosclerosis.

Conclusion

The incidence of hemodynamically significant celiac axis stenosis in this asymptomatic Korean population was 7.3% and the most important etiology was extrinsic compression by the median arcuate ligament of the diaphragm. Atherosclerosis was only a minor cause of the condition.     

Cryoplasty for Occlusive Disease of the Femoropopliteal Arteries: 1-Year Follow-Up

Atherosclerosis of femoropopliteal arteries is an important cause of morbidity and mortality. Percutaneous transluminal angioplasty (PTA) has only limited success in treating these arteries, mainly because of the high rate of recurrent stenosis. Cryoplasty has been proposed as a technique which might improve treatment outcome. This study reports our single-center experience with cryoplasty. Thirty-two claudicants, 33 arteries, in whom conservative therapy failed, were consecutively included. Duplex ultrasound (US), angiography, and ankle-brachial index (ABI) measurement were performed before the procedure; ABI and duplex US, 2 weeks and 3, 6, and 12 months after the procedure. Patients’ symptoms were categorized according to the Rutherford classification. Lesions were classified as TASC A, B, or C according to angiographic appearance. Differences in ABI before and after the procedure were defined as significant at p < 0.05 by paired t-test. Patency was evaluated using duplex US by determining the peak systolic velocity ratio. Sixteen TASC A lesions, 13 TASC B lesions, and 4 TASC C lesions were included. ABI improved significantly for TASC A lesions 2 weeks and 3 months postprocedure. Patency after 2 weeks, 6 months, and 12 months was 93%, 67%, and 64% for TASC A lesions, 83%, 31%, and 31% for TASC B lesions, and 100%, 50%, and 33% for TASC C lesions, respectively. In conclusion, cryoplasty has good immediate success rates and patency rates similar to the results of conventional PTA in the literature.     

Supplemental Transcatheter Arterial Chemoembolization Through a Collateral Omental Artery: Treatment for Hepatocellular Carcinoma

Purpose: To evaluate the therapeutic efficacy and safety of supplemental transcatheter arterial chemoembolization (TACE) through the extrahepatic collateral omental artery (OA) for the treatment of hepatocellular carcinoma (HCC). Methods: We studied 21 patients with extrahepatic collaterals of the OA, among 1,512 patients with HCC who had undergone angiography. HCCs supplied by collateral OAs were located at: segment IV in seven, segment V in five, segment III in three, segment VI in three and segment VIII in three patients (Couinaud classification of segments). On preoperative CT scans, every HCC was abutting the liver surface. Adjacent omental infiltration or engorgement was noted in 11 patients. Celiac and hepatic arteriograms showed hypertrophy of the feeding OA in all patients. TACE of the OA was performed in 19 patients with an emulsion of iodized oil and doxorubicin hydrochloride. Embolization with gelatin sponge particles was added in five patients. Results: Collaterals of the OA to the HCC were found on the first to seventeenth sessions of TACE. On follow-up CT scans, five patients showed complete uptake of iodized oil in the tumor. Partial uptake of iodized oil was noted in 13 patients and no uptake in one patient. There was no serious complication that related to the omental embolization, such as omental or bowel ischemia. The cumulative survival rates from the time of the TACE of the OA were 81% at 6 months and 68% at 12 months. Conclusion: TACE of the OA is safe and has a potential therapeutic effect in the treatment of HCC.     

A Newly Designed Nitinol Stent: Early Clinical Experience in the Treatment of Iliac Artery Stenoses and Occlusions

Objective

To investigate the effectiveness of the newly designed Niti-S stent in the management of iliac arterial stenoses and occlusions.

Materials and Methods

Stenoses (n=25) or occlusions (n=5) in the iliac arteries of 25 patients (30 limbs) were treated. The site of the lesions was the common (n=15) or external (n=11) iliac artery, or both (n=4). Eight limbs were treated for diffuse disease, six for highly eccentric lesion, five for occlusive lesion, and 11 for failed angioplasty.

Results

In all patients, technical success was achieved without major complications. One death, not procedure-related, occurred within 30 days. Ankle-brachial indexes improved from 0.63±0.30 to 0.99±0.21, and ischemic symptoms showed improvement in 22 patients (88%). Fontaine classifications before stenting, namely IIa(n=3), IIb(n=16), III(n=2), and IV(n=4) improved to I(n=17), IIa(n=5), and IV(n=3). Follow-up over a 27 (mean, 19.8±8)-month period showed that cumulative patency rates were 95.8% at 1 year and 86.2% at 2 and 3 years. No significant decrease in the mean ankle-brachial index was observed.

Conclusion

The Niti-S stent appears to be a safe and effective device for the treatment of iliac stenoses and occlusions. These preliminary results require confirmation with a larger series.     

Stent Placement for Chronic Iliac Arterial Occlusive Disease: the Results of 10 Years Experience in a Single Institution

Objective

We wanted to retrospectively evaluate the long-term therapeutic results of iliac arterial stent placement that was done in a single institution for 10 years.

Materials and Methods

From May 1994 to April 2004, 206 patients who underwent iliac arterial stent placement (mean age; 64±8.8) were followed up for evaluating the long term stent patency. Combined or subsequent bypass surgery was performed in 72 patients. The follow up period ranged from one month to 120 months (mean; 31±25.2 months). The factors that were analyzed for their effect on the patency of stents were age, the stent type and diameter, the lesion site, lesion shape, lesion length, the Society of Cardiovascular and Interventinal Radiology criteria, the total run off scores, the Fontaine stage and the cardiovascular risk factors (diabetes mellitus, hypertension and smoking). Follow-up included angiography and/or CT angiography, color Doppler sonography and clinical evaluation with the ankle-brachial index.

Results

Two hundred and eighty-four stents were placed in 249 limbs of 203 patients. The technical success rate was 98% (203/206). The primary patency rates of the stents at 3, 5, 7 and 10 year were 87%, 83%, 61% and 49%, respectively. One hundred seventy-seven patients maintained the primary stent patency until the final follow up and 26 patients showed stenosis or obstruction during the follow up. Secondary intervention was performed in thirteen patients. Lesions in the external iliac artery (EIA) or lesions in both the common iliac artery (CIA) and EIA were a poor prognostic factor for stent patency. The run off score and stent diameter also showed statistically significant influence on stent patency. The overall complication rate was 6%.

Conclusion

Iliac arterial stent placement is a safe treatment with favorable long term patency. Lesions in the EIA or lesions in both the EIA and CIA, poor run off vessels and a stent having the same or a larger diameter than 10 mm were the poor prognostic factors for long term stent patency.     

Percutaneous implantation of a catheter with subcutaneous reservoir for intraarterial regional chemotherapy: Technique and preliminary results

Purpose: We present the technique and the preliminary results of percutaneous implantation of intraarterial catheters connected to a subcutaneous infusion reservoir for prolonged regional chemotherapy of hepatic and extrahepatic tumors. Methods: Two hundred patients with primary or secondary hepatic neoplasms, pelvic, pancreatic, renal, lingual, and breast cancer underwent the procedure. The access was the left axillary artery (188 patients) and the femoral artery (12 patients). The catheter tip was placed in the hepatic (170 patients), hypogastric (18), splenic (4), internal thoracic (2), gastroduodenal (3), renal (2) or the external carotid artery (1). The catheter was connected to a subcutaneous reservoir and filled with heparin; chemotherapeutic infusion was subsequently started. Results: One hundred percent immediate technical success was obtained. Forty-three of 200 (21.5%) patients had a complication: 29 patients had a catheter dislodgment, nine had arterial thrombosis, three had a pseudoaneurysm of the left axillary artery and two had a port pocket hematoma. Most complications (37/43, 86%) were treated percutaneously without interruption of chemotherapy. In only six cases (3% of the total population) was chemotherapy discontinued due to the complication itself. The mean duration of catheter patency was 7.2 months. Conclusion: Percutaneous placement of an intraarterial catheter is feasible and causes less discomfort to the patient than the surgical approach. The technique has an acceptable complication rate (21.5%), similar to that for surgical implantation (17.8%), with the advantage that in most cases the complications can be resolved percutaneously. This technique represents an alternative to surgical implantation in the treatment of liver metastases from colorectal cancer and opens new therapeutic possibilities for the local prolonged treatment of other kinds of tumor, though its clinical efficacy must be assessed in selected trials.     

Effect of contrast dilution on contrast-enhanced MR angiography of the aorta and renal arteries

The aim of this study was to investigate the effect of gadolinium chelate dilution on vascular enhancement in contrast-enhanced two-dimensional (2D) MR subtraction angiography of aorta and renal arteries. Twenty patients were prospectively included. 2D subtraction MR angiography consisted of successive multisection breathhold GRE acquisitions of 16 s (2D FLASH, TR/TE 72/4, flip angle 60 degrees) obtained in the coronal plane before and after intravenous bolus administration of 0.1 mmol/kg BW gadolinium chelate. Patients underwent both diluted and undiluted gadolinium chelate administration in a random order. The data were studied both qualitatively and quantitatively on source and maximum intensity projection images. The length of renal arteries opacified was found not to differ significantly according to contrast dilution. The contrast enhancement percentage was not significantly modified according to the dilution used, but the time to peak enhancement was observed to be longer with the diluted contrast. Qualitatively, the best MR images were those obtained when undiluted contrast was injected first (chi2, P = 0.01). At a dosage of gadolinium chelate 0.1 mmol/kg BW, undiluted contrast 2D MR subtraction angiography seems to be more appropriate for studying diseases of the aorta and renal arteries than a similar diluted dose.     

Prospective evaluation of peripheral arterial occlusive disease by 2D MR subtraction angiography

The purpose of this study was to assess the diagnostic value of two-dimensional (2D) MR subtraction angiography of lower extremities in patients with symptomatic peripheral arterial occlusive disease with conventional angiography as the standard of reference. Twenty patients were prospectively included. 2D subtraction MR angiography (MRA) consisted of multisection gradient-recalled echo (GRE) acquisitions with the shortest TE available on our machine (4 msec), obtained in the coronal plane before and after intravenous bolus administration of gadolinium chelate. MR images were reconstructed after subtraction with a maximum-pixel-intensity-projection (MIP) algorithm. MRA was performed in all cases 1–4 days before diagnostic angiography. In a prospective blinded analysis, the number and location of significant (ie, >50%) stenoses and occlusions were evaluated for each vascular segment. Sensitivity and specificity were used to evaluate MRA data. Significant stenoses (38 of 46, 83%) and occlusions (66 of 67, 99%) seen at conventional angiography were identified with MRA. The sensitivity and specificity of MRA for determination of stenoses >50% or occlusions was 100% and 97%, respectively. The location and extent of stenoses and/or occlusions on MRA and angiograms were well correlated (kappa values, r = .73, P < .05). Contrast 2D MR subtraction angiography, by providing comparable information to that of conventional angiography, is well suited to evaluate the presence and severity of atherosclerotic lesions of the lower limbs.     

A new method using J-type long sheath for implantation of indwelling catheters for trans-femoral hepatic arterial infusion

Purpose For implantation of a catheter-port system for hepatic arterial infusion chemotherapy, catheterization via the femoral artery is occasionally difficult. The purpose of this study was to determine the usefulness of a J-type long sheath, which facilitates difficult trans-femoral catheterization. Materials and Methods We applied this technique to 15 patients for difficult trans-femoral catheterization for catheter-port system placement. Results We successfully implanted a catheter-port system in all patients using this technique without significant complications. Conclusion We emphasize that our new technique using a J-type long sheath seems to be a reasonable option when trans-femoral catheterization is difficult. This paper was not presented at a JRS meeting.     

Dissecting pseudoaneurysm of the hepatic artery: A delayed complication of angioplasty in a liver transplant

We report a 59-year-old female with a dissecting pseudoaneurysm of the allograft hepatic artery, as a delayed complication of percutaneous transluminal angioplasty (PTA). PTA of a severe anastomotic stenosis was successful, but complicated by a dissection involving the allograft hepatic artery. A large dissecting pseiidoaneurysm developed and was incidentally detected during routine sonographic evaluation 14 months after PTA. Because of the extent of the pseudoaneurysm, percutaneous repair or surgical reconstruction was considered impossible. The patient underwent successful retransplantation 1 week after diagnosis. Key words: Liver, transplantation-Hepatic arteries, stenosis or obstruction-Transluminal angioplasty-Aneurysm, hepatic     

Comprehensive MR angiography of the lower limbs: a hybrid dual-bolus approach including the pedal arteries

The purpose of this study was to include the pedal vasculature into the coverage of peripheral multistation magnetic resonance angiography (3DceMRA). A total of 216 patients suffering from peripheral vascular disease were examined with a modified hybrid dual-bolus technique. The cruropedal arteries were acquired first with two sagittal slabs and time-resolved 3D sequences. Then the aortofemoral vessels were visualized using the bolus-chase technique and a second contrast injection. Interventional procedures were performed in 104 patients, and in 69 of those, the cruropedal vessels were also examined with digital subtraction angiography (iaDSA). Using 3DceMRA, the cruropedal arteries were displayed with both excellent and good quality in 95% (205/216 cases), and without any venous overlay in 94% (203/216 cases). The aortofemoral vessels were not jeopardized by the first contrast injection. With iaDSA as the standard of reference, observed sensitivity of 3DceMRA was found in ranges from 80% (29%, 99%) to 100% (86%, 100%) for assessing significant stenoses, and observed specificity ranged between 93% [80%, 98%] and 100% (82%, 100%). In conclusion, hybrid dual-bolus 3DceMRA significantly reduces the limitations of standard single-bolus 3DceMRA in anatomic coverage and temporal resolution of the cruropedal arteries, thus providing high-quality images of the entire peripheral vasculature.     

Breath-Hold Projection Magnetic Resonance-Cholangio-Pancreaticography (MRCP): a New Method for the Examination of the Bile and Pancreatic Ducts

Breath-hold MR cholangio-pancreaticography using the RARE method was evaluated as a noninvasive alternative to direct cholangio-pancreaticography in 30 healthy volunteers and in 30 patients with various diseases of the respective duct systems. In contrast to 3D MR cholangiography, RARE MRCP generates projection images requiring a 4-s acquisition time and no postprocessing. Diagnostic information gained from the cholangio-pancreaticograms was fully equivalent to that of conventional x-ray imaging by invasive procedures. Additional information was gained whenever endoscopic access was impossible and/or cystic malformations were present.     

A new catheter configuration for selective antegrade catheterization of the superficial femoral artery: Technical note

A new 5 F catheter configuration is presented with a very short, 90 degrees angled tip that allows safe catheter tip rotation near the puncture site. This facilitates catheterization of the superficial femoral artery and permits easy conversion of a retrograde into an antegrade guidewire placement after puncture of the common femoral artery.     

Primary Stenting of Focal Atherosclerotic Infrarenal Aortic Stenoses: Long-Term Results in 13 Patients and a Literature Review

We conducted this study to investigate the value of primary stent implantation for the endovascular treatment of focal atherosclerotic stenoses of the infrarenal abdominal aorta. The data of 13 patients with a localized complex infrarenal aortic stenosis who underwent primary stenting was retrospectively evaluated. The patients (6 females, 7 males) had a mean age of 57.3 ± 9.1 years (mean ± SD). In all patients, the aortic diameter was measured on CT sections, and a self-expanding endoprosthesis was primarily implanted followed by dilatation with single or double balloons. In 3 patients, additional distal stenoses were also endovascularly treated. The procedure was technically successful in all patients. No complications occurred except for 2 minor groin hematomas. During the 43 ± 23 months (mean ± SD) follow-up (range: 12–96 months), all stented aortic segments remained patent. Clinical patency was lost in 4 patients, which was due to atherosclerosis or restenosis distal to the aorta. In view of the excellent early and long-term results, we believe that primary stenting should be considered the first line treatment in properly selected patients with focal atherosclerotic infrarenal stenoses of the abdominal aorta.     

Gadolinium-enhanced 3D MR angiography of renal artery stenosis: a pilot comparison of maximum intensity projection, multiplanar reformatting, and 3D volume-rendering postprocessing algorithms

RATIONALE AND OBJECTIVES: The authors compared diagnostic accuracy of maximum intensity projection (MIP), multiplanar reformatting (MPR), and three-dimensional (3D) volume rendering (VR) in the evaluation of gadolinium-enhanced 3D magnetic resonance (MR) angiography of the renal arteries. They hypothesized that VR is as accurate as or more accurate than MIP and MPR at depicting renal artery stenosis. MATERIALS AND METHODS: The study group comprised 28 consecutive patients who underwent gadolinium-enhanced 3D MR angiography of the renal arteries. Studies were postprocessed to display images in MIP, MPR, and VR formats. Digital subtraction angiography (DSA), when performed (nine of 28 patients), was the standard for comparison. For each main renal artery, an estimate of percentage stenosis was made for any stenoses detected by three independent radiologists. For calculation of sensitivity, specificity, and accuracy, MR angiographic stenosis estimates were categorized as mild (0%-39%), moderate (40%-69%), or severe (> or = 70%). DSA stenosis estimates of 70% or greater were considered hemodynamically significant. RESULTS: Analysis of variance demonstrated MIP estimates of stenosis were statistically greater than VR estimates in two readers and greater than MPR estimates in all readers for all patients. MIP images also showed the largest mean difference from DSA stenosis estimates for all three readers. For both VR and MPR, mean differences between MR angiographic stenoses estimates and DSA estimates reached significance for only one reader, whereas, for MIP versus DSA, mean differences reached significance for all three readers. Although not statistically significant compared with DSA, accuracies of VR (87%) and MPR (89%) were greater than that of MIP (81%). CONCLUSION: In this pilot study, MIP was the least accurate of the three image display algorithms tested. VR and MPR yielded similar values for each method of comparison.     

CO<Subscript>2</Subscript> Demonstration of Multiple Extravasations into a Subcapsular Hematoma of the Liver

In a case of esophageal cancer with liver metastases, rupture of a liver metastasis resulted in subcapsular hematoma of the liver. Digital subtraction angiography with carbon dioxide showed multiple extravasations at the surface of the liver suggesting multiple ruptures of the penetrating hepatic capsular arteries. It was suggested that these findings are not rare in cases of subcapsular hematoma; however, they have received little attention.     

Intraarterial Infusion Therapy via a Subcutaneous Port for Limb-Threatening Ischemia: A Pilot Study

Purpose: To present the initial results of a new percutaneously implantable catheter port system (PIPS) used for long-term intraarterial infusion therapy in patients with severe ischemic limb disease. Methods: Ten patients with deep, extended ischemic ulcerations (all 10) and osteomyelitis (6/10) of the foot received intraarterial infusions of prostaglandine E₁ and antibiotics, if indicated, via a new port catheter system with the port placed subcutaneously above the groin after percutaneous introduction and the catheter tip placed into the superficial or deep femoral artery. Results: Port implantation and repeated port access were uncomplicated. During the follow-up period (mean 11 months, range 1 week–50 months), port migration, leakage, or infection was not observed. Three catheters thrombosed and were opened by fibrinolysis with recombinant tissue plasminogen activator instilled via the port. Treatment success was achieved in 8 patients: relief from rest pain (8 patients), reduction of ulcer size (4/8), and complete healing (4/8). Limb savage rate was 80%. In 2 patients amputation could not be avoided. Conclusion: Selective long-term arterial infusion therapy presents a valuable therapeutic regimen for limb salvage. With the new catheter port system, repeated local intraarterial infusion is safe and simple.     

CO2-enhanced CT imaging for the detection of pulmonary emboli: feasibility study in a porcine model

RATIONALE AND OBJECTIVES: The authors investigated the feasibility of using computed tomography (CT) with CO2 gas as a negative contrast agent for detecting pulmonary emboli in a porcine model. MATERIALS AND METHODS: Seven pigs with or without pulmonary emboli underwent thoracic imaging with multi-detector row spiral CT. To identify optimal injection and scanning protocols, the first four pigs were scanned repeatedly in the supine and prone positions with different scan delays (10, 15, and 20 seconds) and different volumes of CO2 (60, 120, 180, and 240 mL), which were hand infused (each infusion took 10-15 seconds). The last five pigs with emboli were scanned with iodinated contrast medium and then rescanned with 120 or 180 mL of CO2. The CO2 volumes and scan delays were qualitatively assessed. The supine and prone CT scans and the number and location of thrombi depicted in the CO2- and contrast material-enhanced CT scans were compared. RESULTS: Because the pulmonary artery in pigs is in the posterior anatomy, the prone position was more effective than the supine position with CO2 enhancement. An infusion of 120 mL of CO2 was sufficient to enhance the entire pulmonary artery, and scanning timed to coincide with the completion of infusion was the most effective. Both the CO2- and contrast-enhanced CT scans demonstrated all thrombi. Thrombi were more apparent on the CO2-enhanced CT scans than on the contrast-enhanced scans because of the high contrast interface between soft tissue and gas. However, two of the seven pigs with thrombi experienced abrupt cardiac arrest after CO2-enhanced scanning and could not be resuscitated. The cause of these events was not determined in the current study. CONCLUSION: The CT depiction of pulmonary emboli is feasible with CO2 gas as a negative contrast agent and may even be superior to that with iodinated contrast media. Further studies are required to evaluate the safety of this method and to develop an improved delivery of CO2 gas for this application.     

Hepatic artery stenosis following liver transplantation: significance of the tardus parvus waveform and the role of microbubble contrast media in the detection of a focal stenosis

PURPOSE: To evaluate the role of microbubble ultrasound contrast media in detecting stenosis of the post-liver transplant extrahepatic hepatic artery (HA) in the presence of the tardus parvus spectral Doppler waveform of the intrahepatic HA. MATERIALS AND METHODS: All post-liver transplant patients with a prolonged systolic acceleration time (SAT>0.08s) and/or a reduced resistant index (RI<0.50) of the HA (the tardus parvus waveform) on colour Doppler ultrasound (CDUS), were assessed with microbubble contrast medium for a focal arterial stenosis. Following microbubble contrast-enhanced CDUS, patients underwent arteriography or follow-up CDUS. RESULTS: A total of 2038 examinations were performed in 529 liver transplant recipients; 16 (3.02%) tardus parvus waveforms were identified. The median SAT of the intrahepatic HA was 0.18s (range 0.11-0.38s) and the RI 0.47 (range 0.22-0.58). No extrahepatic elevated peak systolic velocity (PSV), defined as above 1.00m/s, was detected on the baseline examinations. Following the administration of microbubble contrast, medium, PSV in the extrahepatic HA was elevated in 14 of 16 patients, (median=2.15m/s, range=1.44-3.10m/s); flow was not identified in two patients. Arteriography was performed in 10 patients and confirmed stenosis in eight (median grade of stenosis 93%, range 60-99%) and occlusion in two. The measured median PSV at contrast-enhanced CDUS in the stenosis group was 2.03m/sec (range 1.44-2.71m/sec). Repeat CDUS in six patients not undergoing arteriography showed resolution in four; one underwent re-transplantation before arteriography and one patient maintains a tardus parvus waveform. In transplant recipients undergoing arteriography during the study period (n=55), no hepatic artery stenosis without a tardus parvus waveform was seen. CONCLUSION: The tardus parvus waveform pattern is an excellent screening test for the presence of post-liver transplantation hepatic artery stenosis. There is only a limited role for microbubble ultrasound contrast agent in the presence of a tardus parvus waveform. It could be used following equivocal colour Doppler ultrasound, but arteriography will still be necessary.