Comparison of early and delayed scintigraphy with 99mTc-apcitide and correlation with contrast-enhanced venography in detection of acute deep vein thrombosis.

UNLABELLED: Preliminary studies with 99mTc-apcitide (99mTc-P280), a synthetic peptide that binds to glycoprotein IIb/IIIa receptors expressed on activated platelets, have shown promising results in the detection of acute deep vein thrombosis (ADVT). The purpose of this study was to compare the diagnostic value of early and delayed imaging with 99mTc-apcitide in patients with suspected ADVT, using contrast-enhanced venography as the gold standard. METHODS: Thirty-nine patients (17 women, 22 men; mean age 59 y) with signs or symptoms suggestive of ADVT (within 10 d of onset) and scheduled for contrast-enhanced venography were prospectively studied. The patients were injected with approximately 740 MBq (20 mCi) 99mTc-apcitide within 36 h of contrast-enhanced venography. Both anterior and posterior planar images (8-10 min/view) of the lower extremities using a dual-head gamma camera were obtained at 10, 60 and 120 min after the injection of 99mTc-apcitide. The three sets of images initially were interpreted randomly and separately by three experienced observers unaware of the clinical history, the site of ADVT and results of contrast-enhanced venography. All images from the three sets for a given patient were then analyzed together during a second session. Conventional contrast-enhanced venography was performed on 31 patients before 99mTc-apcitide scintigraphy and in the remaining 8 patients after 99mTc-apcitide scintigraphy. 99mTc-apcitide findings were considered positive forADVT when a focus of increased uptake was found to correspond to the location of a deep vein. Disagreements were resolved by consensus. RESULTS: Twenty-two patients had ADVT observed on contrast-enhanced venography, whereas 17 had normal findings. Six cases of ADVT were infrapopliteal. One patient did not complete the third set of images with 99mTc-apcitide. The sensitivity of 99mTc-apcitide in detecting ADVT was 63.6% (14/22), 68.2% (15/22), 76.2% (16/21) and 86.4% (19/22) for images obtained at 10, 60 and 120 min and for the three sets analyzed together, respectively. The specificity was 82.4% (14/17), 76.5% (13/17), 88.2% (15/17) and 88.2% (15/17) for images obtained at 10, 60 and 120 min and for the three sets of images together, respectively. CONCLUSION: Although the set of 99mTc-apcitide images obtained 120 min after injection showed good overall diagnostic accuracy, the combination of at least two sets of images provided the highest accuracy in detecting ADVT.

Preoperative embolization in the management of a mediastinal paraganglioma.

Parangliomas are rare and highly vascular tumors of neuroendocrine cell origin which are treated by complete surgical resection. Preoperative embolization to reduce perioperative bleeding complications, although described in paragangliomas of the neck and carotid body, has never before been described in the case of a mediastinal paraganglioma. The following is a presentation of such a case of mediastinal paraganglioma, in which embolization was used successfully before surgical resection.

Catheter-assisted totally thoracoscopic coronary artery bypass grafting: a feasibility study.

BACKGROUND: The purpose of this study is to examine the feasibility of performing totally thoracoscopic internal mammary-to-coronary artery bypass grafting with the assistance of radiologically guided catheter intervention. METHODS: Fourteen dogs were subjected to mobilization of the internal mammary artery and anastomosis of it to the left anterior descending coronary artery over an angiographic catheter inserted into the internal mammary artery under fluoroscopy. The anastomosis was completed over the catheter using sutures and the application of fibrin glue. Eight animals underwent the anastomosis after their sacrifice. The other 6 animals were put on closed chest cardiopulmonary bypass and had their anastomosis done after intraaortic balloon occlusion and cardioplegic arrest of the heart. All animals had an angiographic and pathologic examination at the completion of the anastomosis. RESULTS: Anastomosis was completed in all dogs. Three anastomoses leaked and two were noted to be stenosed at completion of the anastomosis. One leak was sealed by application of fibrin glue. Both stenotic anastomoses were caused by suturing of the back wall when a short angiographic catheter could not be positioned across the anastomosis. CONCLUSIONS: Minimally invasive totally thoracoscopic mammary-to-coronary artery bypass grafting with catheter assistance is feasible. Technical improvement and appropriate instrumentation are required to minimize anastomotic failure.

Percutaneous transluminal angioplasty in coronary-internal thoracic-subclavian steal syndrome.

Internal thoracic artery implants are widely used as conduits in coronary artery bypass surgery because of their resistance to the development of atherosclerosis. Two cases are reported of subclavian artery stenosis proximal to the internal mammary artery in patients who had undergone coronary bypass surgery. In both cases, an atypical pattern of postsurgical angina developed, with retrosternal chest pain occurring specifically with upper extremities exercise. Coronary and graft angiography revealed retrograde flow in the left internal thoracic artery during injection of the grafted coronary. Severe stenosis was identified in the subclavian artery. Treatment consisted of dilation of the subclavian artery stenosis with stent placement in one patient. Both patients had marked symptomatic improvement after the procedure.

[Percutaneous metallic biliary prosthesis]. / Prothèses biliaires métalliques percutanées.

Two types of metallic endoprostheses may be placed via a transhepatic approach: 1) self expandable stents which open by themselves as soon as they are released from the carrier system, 2) balloon expandable stents which need to be dilated by a balloon catheter at the time of deployment. Gianturco and Wallstent endoprostheses belong to the first group and are most often used. The fenestrated wall of metallic endoprostheses preserves the patency of bile ducts joining the stented segment, which is a major advantage for hilar and intra-hepatic stenosis. Their design allows the endoprostheses to be incorporated into the bile duct wall, minimising biliary encrustation and leaving a wider internal lumen as compared to plastic stents. On the other hand, tumor ingrowth in the stented segment is possible and parietal incorporation makes the stent nonretrievable after a few weeks. A favorable indication is therefore extrinsic compression, especially in hilar and intra-hepatic segments. Whatever the indications, metallic stenting has an advantage in the treatment of biliary stenosis, either benign or malignant, owing to less traumatic positioning while their patency rate remains high.

Experimental study of balloon-expandable metallic vena caval stents in rabbits.

PURPOSE: The reactivity and patency of balloon-expandable Strecker stents were determined in the superior vena cava (SVC) and inferior vena cava (IVC) of rabbits. MATERIALS AND METHODS: One stent was placed in each of 24 rabbits; 15 were placed in the SVC and nine in the IVC. The duration of stent placement varied between 3 days and 15 months. After the animals were killed, the segments in which the stent was placed were sectioned and analyzed under light microscopy for quantification of neointimal hyperplasia with metal struts in situ. RESULTS: Twenty-three stents remained patent throughout. Two SVC stents thrombosed at 1 week; one of these recanalized spontaneously after 4 weeks. Self-limiting neointimal hyperplasia reached a maximum thickness at 1 month and receded over 3-6 months. In five rabbits with long-term SVC stents, there was a radial shift of the stent to the perivascular layer of fat. Despite this shift, these stents remain patent. CONCLUSION: Strecker stents are well adapted to the venous system in terms of both patency and histocompatibility.

Infection with fatal outcome after endovascular metallic stent placement.

The authors describe a case in which infection developed in a patient after placement of a metallic endoprosthesis in the iliac artery. The patient died of respiratory failure secondary to sepsis. Imaging studies did not reveal an abscess, aneurysm, or stent occlusion. Stent cultures and hemocultures grew Staphylococcus aureus. As with any foreign body, infectious complications may occur after insertion of metallic stents and should be recognized as soon as possible to initiate appropriate therapy.

Soft-tissue venous malformations in adult patients: imaging and therapeutic issues.

Venous malformations are the most common vascular malformations. However, confusion with respect to terminology and imaging guidelines continues to result in improper diagnosis and treatment. An appropriate classification scheme for vascular anomalies is important to avoid the use of false generic terms. Adequate imaging in association with clinical findings is crucial to establishing the correct diagnosis. Doppler ultrasonography should be the initial imaging modality and demonstrates absence of flow or low-velocity venous flow. Computed tomography and magnetic resonance (MR) imaging are used primarily for pretreatment evaluation of lesion extension. These lesions are usually hypointense on T1-weighted MR images and markedly hyperintense on T2-weighted images with variable gadolinium enhancement. Direct phlebography helps confirm the diagnosis and exclude other soft-tissue tumors. Three distinct phlebographic patterns (cavitary, spongy, dysmorphic) have been identified. In most cases, conservative treatment is recommended. Sclerotherapy with or without surgery is useful in cases of functional impairment or significant aesthetic prejudice, even if recurrences are frequent. Direct phlebography is performed when a more detailed assessment of the vascular pattern is needed or as part of sclerotherapy. Use of the appropriate imaging technique is critical in establishing the diagnosis, evaluating extension, and planning appropriate treatment.

Imaging of renovascular hypertension: respective values of renal scintigraphy, renal Doppler US, and MR angiography.

Renovascular hypertension affects 15%-30% of patients who have clinical criteria suggestive of renovascular disease. Noninvasive screening is crucial for patient selection prior to conventional angiography and renal revascularization. Renal scintigraphy has been reported to be sensitive for detection of renovascular hypertension, but some of its limitations (eg, in the setting of bilateral renal artery stenosis and renal failure) should be considered. Doppler ultrasonography (US) allows direct evaluation of the renal arteries as well as transrenal Doppler waveform analysis, but it remains operator dependent. Gadolinium-enhanced magnetic resonance (MR) angiography is becoming an excellent alternative to conventional angiography. The main limiting factors of this technique are inadequate visualization of segmental and accessory renal arteries as well as a tendency toward overestimation of stenoses. Given the high cost and low availability of MR angiography, scintigraphy and Doppler US should be considered the primary studies in screening for renovascular hypertension. MR angiography could be reserved for patients with inconclusive scintigraphic and Doppler US results, patients with high clinical suspicion of renovascular hypertension, and patients with a contraindication to conventional angiography.

The value of internal carotid systolic velocity ratio for assessing carotid artery stenosis with Doppler sonography.

OBJECTIVE: The purpose of this study was to assess the value of the ratio between the internal carotid systolic velocity (ICSV) at the carotid bulb and the distal internal carotid systolic velocity (DICSV) for the detection of carotid artery stenosis. SUBJECTS AND METHODS: Two hundred eleven patients were enrolled in a prospective study comparing several Doppler measurements with carotid angiography. The following spectral measurements were obtained with Doppler sonography: ICSV/DICSV ratio, ICSV, ICSV/common carotid systolic velocity (CCSV) ratio, and internal carotid (end) diastolic velocity (ICDV). Receiver operating characteristic curves were generated for two groups: the first group being 365 carotid arteries for which all Doppler measurements were successfully obtained and the second being a subgroup of 258 carotid arteries for which an ICSV of 100 cm/sec or greater was present. RESULTS: In the group of 365 carotid arteries, the ICSV/DICSV ratio improved the detection of stenosis of 60% or greater as compared with the ICDV (p = .03). In 258 carotid arteries with an ICSV of 100 cm/sec or greater, the ICSV/DICSV ratio allowed for a better angiographic correlation for identifying stenoses of 60% or greater and 70% or greater as compared with ICSV (p = .006 and .023, respectively), ICSV/CCSV (p = .0013 and .003, respectively), and ICDV (p = .0015 and .020, respectively). CONCLUSION: Using the ICSV/DICSV ratio for the Doppler detection of carotid artery stenosis is advantageous when the ICSV is 100 cm/sec or greater.

Portal vein embolization: utility for inducing left hepatic lobe hypertrophy before surgery.

Right portal vein embolization (PVE) was performed in patients in need of wide hepatectomy to induce preoperative hypertrophy of the future remnant liver (FRL), which would have been insufficient for safe resection. PVE was achieved with cyanoacrylate or gelatin sponges by using a percutaneous subxiphoid approach in 10 patients with tumors in noncirrhotic liver. Surgery was performed in nine patients 17-48 days (mean, 34 days) after PVE. Computed tomographic liver volumetric studies were performed before embolization and before surgery. Clinical and biologic tolerance of PVE was excellent except in one case. Histopathologic studies showed occlusion of portal veins with minimal parenchymal ischemia in eight of nine patients. The FRL volume increased by 64%, which represented 31% of the preresection volume of the liver. Better hypertrophy was seen after cyanoacrylate embolization. The authors conclude that PVE is safe and well tolerated and induces marked hypertrophy of the unembolized parenchyma in noncirrhotic patients. This hypertrophy allows hepatectomy to be performed under safe conditions when the FRL volume is initially insufficient.

Percutaneous stent placement for treatment of stenosis of a portacaval H-graft shunt.

Surgical treatment of an occluded or stenotic portacaval shunt carries a high risk of mortality, but the rate of restenosis after transluminal angioplasty is also high. The authors report high-grade stricture of a portacaval H-graft shunt in a 51-year-old man, who presented with hematemesis and melena. The patient was treated with concomitant balloon angioplasty and placement of a metallic stent through a percutaneous venous approach. The procedure was tolerated well by the patient, and stenosis had not recurred at follow-up 1 year later.

Arterial embolotherapy for upper gastrointestinal hemorrhage: outcome assessment.

PURPOSE: To identify predictors of clinical outcome after arterial embolotherapy for upper gastrointestinal (UGI) hemorrhage. MATERIALS AND METHODS: Seventy-five consecutive patients (mean age, 62.5 y) underwent arterial embolization for acute UGI hemorrhage. Bleeding was detected at endoscopy and angiography in 22 patients, at endoscopy alone in 29 patients, and at angiography alone in 24 patients. As such, embolization was directed by angiography in 46 patients (61.3%) and by endoscopy (referred to as "blind" embolization) in 29 patients (38.7%). The embolic agents used were metallic coils, polyvinyl alcohol particles (size range, 355-710 microm), gelatin sponge, and tissue adhesive. Predictors of bleeding recurrence and mortality were analyzed with logistic regression and Cox models, respectively. RESULTS: The technical success rate of embolization was 98.7%. Primary clinical success was achieved in 57 patients (76%). Secondary clinical success occurred in five additional patients (82.5%) after repeat embolization. There were four (5.3%) complications: two cases of self-resolving duodenal ischemia, one hepatic infarct, and one inguinal hematoma. The periprocedural mortality rate was 34.6% (26 of 75), mostly related to underlying illness. Early recurrence of bleeding (within 30 days of embolization) was associated with coagulation disorders (international normalized ratio >1.5, partial thromboplastin time >45 seconds, or platelet count <80,000/microL; odds ratio, 19.46; P = .001) and with the use of coils as the only embolic agent (odds ratio, 7.73; P = .01). Cirrhosis and cancer shortened the overall survival of patients after embolic therapy. The mean patient follow-up time was 34.5 months. CONCLUSION: Arterial embolotherapy for UGI hemorrhage is safe, effective, and durable. Coagulopathy and the use of coils as the only embolic agent were associated with a higher risk of early bleeding recurrence.

Percutaneous biliary drainage: clinical trial of analgesia with interpleural block.

PURPOSE: To determine the analgesic efficacy and safety of interpleural block for percutaneous biliary drainage. MATERIALS AND METHODS: In this double-blind study, 34 age- and sex-matched patients who were to undergo percutaneous biliary drainage because of malignant biliary obstruction were randomly assigned to the true-block group (30 mL 0.5% bupivacaine block) or placebo-block group; all had access to a patient-controlled analgesia (fentanyl) pump. Self medication, pain reports, blood pressure, heart rate, and oxygen saturation were monitored during and until 8 hours after drainage. The McGill Pain Questionnaire was administered 1 hour after biliary drainage. RESULTS: Patients in the placebo group self administered statistically significantly more fentanyl than did patients in the true-block group (P = .008). Peak pain scores (10-point scale) and McGill Pain Questionnaire scores were statistically significantly higher for the placebo group patients (P = .017 and P = .001, respectively). There were no differences between groups in terms of blood pressure, heart rate, and oxygen saturation. Two patients had pneumothorax caused by the interpleural block. CONCLUSION: Interpleural block was effective in decreasing pain and opioid requirements during and after percutaneous biliary drainage and did not compromise the cardiopulmonary status of the patient. However, the rate of pneumothorax was higher than previously reported.

Lower extremity: nonstepping digital angiography with photostimulable imaging plates versus conventional angiography.

PURPOSE: To compare nonstepping digital subtraction angiography (DSA) (ie, storage phosphor radiography adapted to a stationary imaging plate changer) with conventional screen-film angiography in the evaluation of the lower extremities. MATERIALS AND METHODS: Fifty-one patients with peripheral vascular disease underwent both nonstepping DSA and screen-film angiography. The angiographic and radiologic techniques of both systems were kept identical for each patient. Three radiologists independently rated the overall quality of each angiogram. In their evaluations for each of 12 arterial segments on all 102 angiograms, they also rated the degree of opacification, the diameter reduction of the most severe stenosis, and their level of confidence. RESULTS: Mean overall quality scores and levels of confidence were better for nonstepping DSA than for screen-film angiography (P < .001). Full opacification was reported in 95.6% and 89.2% of all 1,836 segments with nonstepping DSA and screen-film angiography, respectively (P < .0001). The difference between the mean stenosis grades obtained with screen-film angiography and nonstepping DSA was not statistically significant. Intertechnique agreements were good (kappa = 0.77, 0.81, and 0.81), whereas interobserver agreements were influenced by the observer's experience with the imaging techniques. CONCLUSION: Nonstepping DSA images of the lower extremity were of better diagnostic quality than were screen-film angiograms. The development of dedicated nonstepping DSA equipment is warranted.

Treatment of renal angioplasty failure by percutaneous renal artery stenting with Palmaz stents: midterm technical and clinical results.

OBJECTIVE: Renal artery stenting has recently been used to treat failures or complications of renal angioplasty. Although technical results and complication rates have been reported, clinical follow-up and long-term data are limited. The purpose of this study was to evaluate the midterm clinical efficacy and safety of Palmaz stents in rescuing renal artery angioplasty failures. MATERIALS AND METHODS: Palmaz stents were placed in 35 renal arteries of 33 patients (14 men and 19 women; 37-77 years old; mean age, 62.6 years old) for immediate angioplasty failure (29 arteries) or for recurrent stenosis after previous angioplasty (six arteries). Indications for treatment were hypertension alone (16 patients) or hypertension associated with renal failure (17 patients). Blood pressure, medication, and serum creatinine level were followed after stenting. RESULTS: No residual stenosis was found immediately after stenting. Mean clinical follow-up was 13.4 months (range, 1-34 months). Of the 33 patients, two (6%) were cured of their hypertension, 20 (61%) were improved, and 11 (33%) did not respond to renal artery stenting. Of the 17 patients whose serum creatinine level was greater than 132 mumol/dl (1.5 mg/dl), seven (41%) were improved by renal artery stenting, six (35%) were stabilized, and renal function deteriorated in four (24%). Of the 33 patients, seven developed complications including one renal artery thrombosis, four renal artery emboli, one cholesterol embolization to the lower limbs, and one femoral hematoma that required surgery. CONCLUSION: Midterm results of renal artery stenting with the Palmaz stent to treat immediate or late angioplasty failures reveal improvements in blood pressure and renal function similar to those of successful primary balloon angioplasty.

Digital subtraction angiography of the abdominal aorta and lower extremities: carbon dioxide versus iodinated contrast material.

PURPOSE: To compare the diagnostic value of carbon dioxide to that of iodinated contrast material for digital subtraction angiography of the abdominal aorta and lower extremities. MATERIALS AND METHODS: Thirty-five patients underwent comparative CO2 and iodinated contrast material arteriography of the abdominal aorta and lower extremities. For each contrast study, three independent observers evaluated the degree of opacification and percentage of stenosis of each vessel, the degree of certainty of their observations, and the overall quality of the study. Data of CO2 and iodinated studies were compared using analysis of variance for repeated measures. Interobserver and intertechnique agreements were estimated with Cohen's kappa and intraclass correlation coefficient. RESULTS: Iodine-based vascular opacification was superior to that with CO2 in the central and distal arteries (P = .02). The degree of certainty and overall quality score were higher for iodine than for CO2-based contrast studies (P = .00001). The interobserver agreement for categorizing stenoses was higher for iodine as compared to CO2-based angiography. No significant difference was observed between the mean stenosis values obtained with CO2 and iodine-based angiography in any segment. Intraclass correlation coefficient demonstrated a high degree of convergence of the two techniques for assessing the percentage of stenosis. CONCLUSION: CO2 can be used as an alternative to iodinated contrast material for obtaining arteriograms of the abdominal aorta and lower extremities for investigating atherosclerotic disease.