Endovascular stents covered with pre-expanded polytetrafluoroethylene for treatment of iliac artery aneurysms and fistulas.

PURPOSE: This report describes the early clinical experience with use of a transluminally placed endovascular graft (TPEG) covered with pre-expanded polytetrafluoroethylene (PTFE) to treat iliac artery aneurysms and fistulas. MATERIALS AND METHODS: Eight patients with iliac artery aneurysms (n = 7) and common iliac artery to common iliac vein fistula (n = 1) were treated with TPEGs. The iliac artery aneurysms were either common iliac (n = 6) or hypogastric (n = 1). All of the patients had significant comorbid diseases. The TPEG devices were made with pre-expanded PTFE sutured to Palmaz stents and delivered through 10- or 12-F sheaths. RESULTS: The aneurysms were successfully excluded in six of seven patients and the one iliac artery-to-vein fistula was successfully occluded. There were no immediate procedural complications related to the TPEG devices. Follow-up was limited (mean, 12 months), but no stenoses or occlusions of the TPEG devices were detected. The one failure was probably due to the marked tortuousity of the iliac artery, which prevented an adequate seal. CONCLUSION: In the authors' early clinical experience, the use of TPEG devices with pre-expanded PTFE successfully treated iliac artery aneurysms and an iliac artery-to-vein fistula. Although the results are encouraging, longer follow-up is necessary to better evaluate this type of treatment.

Malignant ureteral obstruction: treatment with metal stents--technique, results, and observations with percutaneous intraluminal US.

PURPOSE: To test the technical feasibility and results of placement of metal stents into ureters obstructed by extensive tumor. MATERIALS AND METHODS: Six consecutive patients (two men and four women, aged 35-66 years and with incurable malignancies) underwent insertion of metallic endoprostheses in nine obstructed ureters through percutaneous tracts. RESULTS: Metal stents were inserted without technical difficulty in all obstructed ureters. The stents functioned well in four patients. In two patients, the metal were not tolerated and plastic double-J stents were placed through the metal stents; this permitted effective functioning and withdrawal of the protective external catheter. Intraluminal ultrasonography depicted stent clogging and debris, dimensions of stent opening, and tumor level. CONCLUSION: Insertion of metal stents in the ureter is technically straightforward and was well tolerated by patients. However, the efficacy is variable, and a greater beneficial effect than is achieved with plastic stents is not established.

Ultrasound guided biopsy of nonpalpable and difficult to palpate thyroid masses.

We reviewed our experience with ultrasound-guided biopsies of masses of the thyroid gland that were either nonpalpable or difficult to localize by palpation to evaluate the technique and correlate the results. Thirty-two biopsies were performed upon 25 patients whose clinical presentations were palpable nodule (six patients), throat discomfort (two patients), postpartial thyroidectomy follow-up evaluation (two patients), incidental discovery of a mass--by ultrasound of the neck (two patients), roentgenogram of the chest (two patients), computed tomography of the chest (one patient) and during tracheostomy placement (one patient). Other presentations were eliminate infection (one patient), odynophagia (one patient), hoarseness (one patient), cold nodule on a nuclear medicine study (one patient), hyperparathyroidism (one patient), rule out metastasis from carcinoma of the colon (one patient), persistent cough (one patient), enlarged thyroid gland (one patient) or family history of carcinoma of the thyroid gland (one patient). Fifteen patients had nuclear medicine studies showing either a cold nodule (ten patients), multinodular goiter (one patient), normal examination (two patients), hot nodule (one patient) or no thyroid gland activity (one patient). The ultrasound examinations showed either a hypoechoic nodule (25 patients), inhomogeneous or mixed echogenic nodule (six patients) or a hyperechoic nodule with hypoechoic rim (one patient). The nodules ranged in size from 3 milliliters to 7 centimeters. Twenty-six lesions were less than 3 centimeters in diameter; of the other six, four were substernal goiters. Six patients had a previous nondiagnostic biopsy directed by palpation only. Biopsy was performed using real-time ultrasound guidance with various needles. One patient had a small hematoma, which was the only complication in the study. The results of the biopsies were diagnostic in 26 of 32 patients. The final diagnosis was benign follicular cells (ten patients), adenomatous nodule (seven patients), follicular neoplasm (three patients), colloid cyst (two patients), aspergillus (two patients), fibrosis (one patient) and papillary carcinoma (one patient). Six of the biopsies yielded unsatisfactory specimens. One of the patients with a diagnosis of benign follicular cells on biopsy had a follicular carcinoma after surgical pathologic factors were obtained; that was the only false-negative result. We conclude that ultrasound-guided biopsy of the thyroid is a safe and useful method of evaluating nonpalpable and difficult to palpate thyroid masses.

Anterior mediastinal lesions: transsternal biopsy with CT guidance. Work in progress.

PURPOSE: To assess the technique, results, and patient tolerance of transsternal biopsy of anterior mediastinal lesions under computed tomographic (CT) guidance. MATERIALS AND METHODS: Seven patients (four women and three men) with anterior mediastinal lesions underwent eight transsternal biopsies. Patients were included in the study if there was a risk of injury to internal mammary vessels or a danger of tranversing the lung by the biopsy needle. Patients were specifically questioned about the pain caused by the transsternal needle. A pain scale was not used. Conscious sedation and local anesthesia requirements provided gross evaluation of the patients' tolerance to the procedure. CT scans were used to guide and confirm optimal alignment of the transsternal needle with the lesion. RESULTS: Patients experienced minimal discomfort when the sternum was traversed. No instances of pneumothorax, postprocedural pain, or infection were encountered. In six of the seven patients, biopsy specimens were diagnostic. CONCLUSION: The transsternal approach for biopsy of anterior mediastinal lesions appears safe and is well tolerated.

Occluded peripheral arteries and bypass grafts: lytic stagnation as an end point for pulse-spray pharmacomechanical thrombolysis.

Angiographic demonstration of luminal narrowing during pulse-spray pharmacomechanical thrombolysis (PSPMT) may reflect residual lysable clot, organized thrombus, platelet-rich clot, atherosclerosis, neointimal hyperplasia, or functional narrowing. The authors evaluated the efficacy and safety of lytic stagnation (initial rapid lysis followed by insubstantial further lysis with additional treatment) as an end point for PSPMT. Lytic stagnation was evaluated with serial angiography in 16 arterial and five bypass graft occlusions. Substantial lysis occurred after administration of mean doses of 512,000 units +/- 182,000 of urokinase or 5.3 mg +/- 2.0 of tissue-type plasminogen activator. Additional treatment with either of those agents produced minimal or no further change in the appearance of residual disease. Recanalization was successful in all patients after angioplasty. Distal emboli were noted in four cases, in three of which angioplasty of large intraluminal filling defects had been performed. The authors conclude that lytic stagnation is a reliable and safe end point for PSPMT in the absence of large intraluminal filling defects.

Complications of laparoscopic cholecystectomy: coordinated radiologic and surgical management in 21 patients.

The authors describe their experience in management of bile duct injuries (n = 11), bile leaks or abscesses (n = 11), and bleeding (n = 1) as complications of laparoscopic cholecystectomy in 21 patients. Clinical presentations included jaundice, sepsis, pain, abdominal distention, and persistent gallstones. Twelve patients underwent operative cholangiography, three underwent conversion to open cholecystectomy, and 12 reoperations were performed in nine patients before interventional radiologic procedures, which included diagnostic percutaneous transhepatic cholangiography (n = 13), percutaneous biliary drainage (PBD) (n = 13), percutaneous stricture dilation (n = 3), stent insertion (n = 1), percutaneous abscess or biloma drainage (n = 19), and gallstone removal (n = 1). Each procedure was technically successful. Clinical improvement occurred in 18 of 19 patients. PBD was used as an operative guide before reconstructive surgery in two patients. Reoperation was unnecessary in 10 of 21 patients (48%). One patient died of fungal sepsis and pulmonary complications. This radiologic-surgical approach provided rapid and safe management of these complications.

Treatment of pancreatic pseudocysts with percutaneous drainage and octreotide. Work in progress.

In an attempt to decrease catheter drainage of pancreatic pseudocysts, a combined regimen of percutaneous drainage and administration of octreotide acetate was used in eight symptomatic patients. Indications for the combined therapy were pseudocyst recurrence (four patients), pancreatic fistula from percutaneous drainage (two patients), or elective treatment to restrict pancreatic drainage. Octreotide acetate was administered subcutaneously in doses of 50-1,000 micrograms three times a day. The drug was well tolerated and produced only limited adverse effects in four patients: pain at the injection site, hypoglycemia, diarrhea, headaches, and lower-extremity edema (more than one adverse effect was experienced by each patient). The combined use of percutaneous drainage and administration of octreotide was effective in seven patients and failed in one patient who had distal pancreatic duct occlusion. In five patients, catheter drainage decreased to no measurable amount by a mean of 13.8 days. These results suggest octreotide is effective in decreasing the output from pancreatic pseudocysts drained percutaneously.

Influence of the stopcock on the efficiency of percutaneous drainage catheters: laboratory evaluation.

The effects of stopcocks on percutaneous fluid drainage were tested in a laboratory model by using a standard stopcock (6-French inner diameter) and a prototype stopcock (9-French inner diameter) connected to 8-, 10-, 12-, 14-, and 16-French catheters. Catheters were immersed in water alone or in viscous fluid with particulate matter, and the system was connected to low wall suction or gravity drainage. The average volume of fluid aspirated in a given period with and without a stopcock was compared for each catheter. The standard stopcock decreased drainage efficiency for these catheters by 13-42%. This decreased drainage efficiency was worse with the larger catheters. Particulate fluid blocked the stopcock connection for all catheters. With the prototype stopcock, drainage of water alone was reduced by 0-9% for the catheters of different sizes. Particulate fluid did not obstruct the prototype stopcock with any size catheter. With gravity drainage, the volume of water aspirated was reduced by 12-42% with the standard stopcock and by 3-6% with the prototype stopcock. These data suggest that stopcock connections greatly influence the efficiency of the percutaneous drainage systems. Stopcocks with larger inner diameters may improve drainage over that achievable with the stopcocks that are currently available.

CT guidance for percutaneous gastrostomy and gastroenterostomy.

The authors describe the value of computed tomographic (CT) guidance for percutaneous gastrostomy (PG) or gastroenterostomy (PGE) in 22 patients with anatomic or pathologic difficulties precluding fluoroscopic guidance. Indications for PG or PGE were decompression for gastrointestinal obstruction (n = 15) or for feeding (n = 7). Thirteen patients previously underwent an unsuccessful attempt at or had been rejected as unsuitable for percutaneous endoscopic gastrostomy. CT guidance was selected because of inability to pass a nasogastric tube due to esophageal obstruction (n = 4), inability to tolerate gastric distention (n = 1), abnormal morphology in or around the stomach (n = 16), or simultaneous performance of a PG in one patient who was undergoing emergency CT-guided abscess drainage. Catheters were placed successfully in all 22 patients. No major complications occurred. CT is valuable for PG or PGE when anatomic or pathologic problems make fluoroscopic or endoscopic puncture unsafe or impossible.

Percutaneous gallbladder puncture and cholecystostomy: results, complications, and caveats for safety.

The authors describe the technical results in 127 patients who underwent diagnostic gallbladder puncture and percutaneous cholecystostomy. The procedures were performed for a variety of indications including treatment of acute calculous or acalculous cholecystitis, drainage of obstructive jaundice or gallbladder perforation, percutaneous removal or dissolution of gallstones, diagnostic cholecystocholangiography, and gallbladder biopsy. Successful completion of the intended procedure was achieved in 125 of 127 patients (98.4%). Major complications occurred in 11 patients (8.7%); these included bile peritonitis, bleeding, vagal reactions, hypotension, catheter dislodgement, and acute respiratory distress. Minor complications were noted in five patients (3.9%). The 30-day mortality rate was 3.1% (four patients); the deaths were due to the underlying diseases. The data help support percutaneous cholecystostomy as a primary interventional radiologic procedure that has an extremely high likelihood of technical success. Recommendations to minimize or avoid complications are presented.

A simple method to lock large mushroom-tip catheters.

Dislodgment is a major drawback with large-bore Malecot catheters. A locking mechanism with a suture affixed to the distal portion of the mushroom tip is described. In a 32-month period, 17 Malecot catheters with locking mechanisms were placed in 15 patients. One catheter dislodged as a result of suture failure. A variation in design prevented subsequent failure of sutures. This simple locking mechanism prevents collapse of the catheter wings and thereby maintains catheter placement.

Imaging of the percutaneous cholecystostomy tract: observations and utility.

The technique and observations in 28 patients who underwent imaging of the percutaneous cholecystostomy (PC) tract are described. Imaging of the tracts was performed by injecting contrast material through an end-hole dilator during catheter removal (n = 13) or through an end-hole dilator with a side adapter over a thin guide wire (n = 15); the latter method permitted simple catheter reinsertion if the tract was poorly formed. Catheters were removed between 9 and 158 days (mean, 36.6 days; median, 29.5 days) after PC. Twenty-three patients had well-formed tracts and five patients did not. Among the five patients with a poorly formed tract, two experienced no sequela as a result of catheter withdrawal, two underwent immediate catheter reinsertion, and one developed bile peritonitis; this last patient was treated with repeated PC and antibiotics. All patients in whom a catheter was placed for at least 20 days had a well-formed, intact tract. Imaging of the PC tract is helpful to identify patients who have an immature tract. In a patient with a poorly formed tract, catheter reinsertion may be advisable to prevent bile leakage and peritonitis.

US-guided transvaginal drainage of pelvic abscesses and fluid collections.

Ultrasound (US)-guided transvaginal needle or catheter drainage was performed in 14 women for a variety of pelvic abscesses and fluid collections; tubo-ovarian abscesses and postoperative collections were most common. Diagnosis was achieved in all 14 patients (100%), including one patient with suspected ovarian carcinoma who underwent only diagnostic needle aspiration and no therapeutic drainage. Abscesses or fluid collections were evacuated in 13 of 13 patients (100%) with either needle (n = 7) or catheter (n = 6) drainage (with appropriate antibiotics). Twelve of the 14 patients (86%) were spared an operation; surgery was undertaken in two patients for a persistent tubo-ovarian phlegmon. No major complications were associated with drainage. Catheters were removed an average of 6.7 days after insertion. The success, safety, and advantages of US-guided transvaginal drainage in our early experience suggest its use as an alternative to standard percutaneous catheter procedures to diagnose and drain certain pelvic abscesses and fluid collections.

Percutaneous dissolution of gallstones.

Contact dissolution with MTBE is an effective and safe method to treat symptomatic patients with cholesterol gallstones. Personnel, time, and safety factors have limited widespread use of the procedure. With current competing methods to treat gallstones, it is likely that MTBE use will be reserved for those patients who elect percutaneous therapy due to fear of surgery or anesthesia and in those elderly patients who are compromised by underlying medical conditions.

Musculoskeletal neoplasms after intraarterial chemotherapy: correlation of MR images with pathologic specimens.

The most accurate prognostic indicator in patients with musculoskeletal sarcomas is the percentage of tumor necrosis after intraarterial chemotherapy. Magnetic resonance (MR) imaging was evaluated to determine its ability to indicate the percentage of necrosis in musculoskeletal neoplasms after treatment. Fourteen patients with musculoskeletal neoplasms underwent treatment protocols including intraarterial chemotherapy (n = 14), radiation therapy (n = 6), and systemic chemotherapy (n = 14). All patients underwent MR imaging before and after treatment, and all underwent either limb salvage surgery (n = 8) or amputation (n = 6) within 1 week of the last MR examination. Standard unehanced spin-echo T1-, spin-density-, and T2-weighted MR sequences were used. The MR images were compared with the pathologic specimens. On T2-weighted images, the signal intensities of viable tumor, tumor necrosis, edema, hemorrhage, and necrosis overlapped. With the unenhanced spin-echo technique, MR imaging cannot be used to predict the percentage of tumor necrosis in musculoskeletal neoplasms after intraarterial chemotherapy.

MRI of inflammatory synovial processes.

MRI was used to evaluate inflammatory synovial processes in 53 patients over a 4-year period. Multiple disease processes were imaged, including: rheumatoid arthritis [n = 12], osteochondromatosis [n = 6], bursal abnormalities [n = 17], ganglion cyst [n = 1], meniscal cyst [n = 5], hemophilia [n = 1], and septic arthritis [n = 11]. The soft tissue contrast resolution of MRI and its multiplanar capability makes it particularly suitable for evaluating masslike or fluid inflammatory processes for diagnostic purposes, to determine extent of disease, and in some cases, to determine the composition of the inflammatory processes.