What we still do not know about adrenal vein sampling for primary aldosteronism.

During the last two decades, primary aldosteronism has emerged as the most common cause of secondary hypertension, and advances in the diagnosis and treatment of this condition have improved patient care substantially. A major stumbling block in the evaluation and management of these patients, which ultimately guides treatment and prognosis, is answering the question, "Which adrenal gland(s) produce aldosterone?" Adrenal vein sampling has emerged as the only reliable method to determine the answer to this question; however, the methodology and criteria for lateralization have been determined empirically with little prospective data. The major remaining controversies surrounding adrenal vein sampling include: who should perform and who should undergo the procedure; what criteria should be used to define a successful study and lateralization of aldosterone production; whether cosyntropin should be infused during the procedure and how; and what to do when results are ambiguous? This article reviews some of the advances in the execution of this procedure, the variations in procedure, the data that fuel the controversies, and the issues that need to be resolved in the future.

Single-lumen subcutaneous ports inserted by interventional radiologists in patients undergoing chemotherapy: incidence of infection and outcome of attempted catheter salvage.

BACKGROUND: Subcutaneous ports are commonly used for vascular access in patients with cancer undergoing chemotherapy. OBJECTIVES: To determine the incidence of catheter-related infection and to assess the efficacy of catheter salvage in subcutaneous ports. METHODS: We retrospectively reviewed 300 subcutaneous single-lumen chest ports inserted by interventional radiologists in 294 patients between December 1, 1995, and November 15, 1997, at the Cleveland Clinic Foundation, Cleveland, Ohio. The number of days that the catheter remained in situ, infection rate, treatment, and outcome of infection were determined. RESULTS: Two hundred ninety-four patients had a total of 79 748 catheter-days. Vascular access for chemotherapy was the indication for 95% of the subcutaneous ports placed. Seventeen catheters (5.7%) developed 20 episodes of noninfectious complications resulting in the removal of 6 ports. Seventeen patients (5.7%) developed catheter-related infections (2.1/10 000 catheter-days) including 10 episodes of catheter-related bacteremia (1.2/10 000 catheter-days). The most common organism isolated was Staphylococcus aureus. A total of 15 of the 17 infected catheters were removed. Salvage was attempted in 6 patients in whom 4 catheters were eventually removed due to recurrent bacteremia (2 patients) and persistent local infection (2 patients). One of the 10 patients with catheter-related bacteremia developed septic arthritis. There were no complications associated with attempted catheter salvage. CONCLUSIONS: Subcutaneous single-lumen ports inserted by interventional radiologists in patients undergoing chemotherapy have low complication rates but infections remain the leading cause of catheter loss. Antibiotic therapy without catheter removal is unlikely to eradicate catheter-related bacteremia.

Modifications on the heterocyclic base of acyclovir: syntheses and antiviral properties.

A group of compounds was prepared in which variations of the ring portion of the acyclovir (ACV) structure were made. These modifications included monocyclic (isocytosine, triazole, imidazole), bicyclic (8-azapurine, pyrrolo[2,3-d]pyrimidine, pyrazolo[3,4-d]pyrimidine) and tricyclic (linear benzoguanine) congeners. The derivatives were evaluated against herpes simplex virus type 1 (HSV-1) by the plaque-inhibition and plaque-reduction methods with only the 8-azapurine analogue 28 showing some activity. In a test measuring the ability of these compounds to inhibit the HSV-1 thymidine kinase, 28 and the tricyclic derivative 38 exhibited competition with ACV for binding to the enzyme. The inability of the group to exert significant antiherpetic action is attributed to their lack of phosphorylation to the requisite triphosphate stage.

Self-expandable metallic airway stent insertion employing flexible bronchoscopy: preliminary results.

We describe 37 patients in whom 52 self-expandable metallic stents were successfully placed using a flexible bronchoscope. Indications for stenting were tracheobronchomalacia (n=13), neoplasia (n=20), and tracheal stenosis (n=4). Airway patency was restored in all patients. Symptoms improved in all but one patient. The median follow-up for all patients and the group of 16 patients alive has been 21 and 69.5 weeks, respectively. Complications have included granulomas and bronchitis. Migration or mucus plugging was not encountered. We conclude that metallic stents can be inserted safely using a flexible bronchoscope. At least in the short term, major complications are uncommon.

Treatment of TIPS stenosis with ePTFE graft-covered stents.

Midshunt stenosis and recurrent variceal bleeding occurred in 2 patients after transjugular intrahepatic portosystemic shunts (TIPS). Repeat angioplasty was performed in both cases but recurrent stenosis again led to hemorrhage. Expanded polytetrafluoroethylene (ePTFE) graft-covered stents were expanded in each of the TIPS at the midshunt, reducing the portosystemic gradient for both patients. Variceal bleeding ceased, and follow-up studies showed no evidence of recurrent stenosis in either case.

Directional atherectomy treatment for hemodialysis access: early results.

The Simpson atherectomy device was used to treat 12 intragraft stenoses, six complete subclavian vein occlusions, and 14 venous outflow stenoses in 24 patients undergoing hemodialysis. Patients were followed up clinically and by means of venography at approximately 1, 3, 6, 9, and 12 months after treatment. Twenty-eight atherectomy specimens were examined histologically. Twenty-six (81%) of 32 lesions were treated with initial technical success. Including technical failures, seven (58%) of 12 intragraft stenoses are angiographically patent at a mean of 5.0 months and five (50%) of 10 are clinically patent at 6 months. Three (50%) of six subclavian veins are angiographically patent at a mean of 5.6 months, and four (67%) of six are clinically patent at 6 months. Three (21%) of 14 venous outflow stenoses are angiographically patent at a mean of 5.0 months and five (38%) of 13 are clinically patent at 6 months. Histologic examination showed neointimal fibromuscular hyperplasia in 26 of 28 lesions. When 30% or less angiographic residual stenosis is used as the criterion for initial technical success, directional atherectomy appears to be effective therapy for intragraft stenoses and, with balloon angioplasty, for some catheter insertion-related subclavian occlusions. Directional atherectomy appears to have a recurrence rate for venous outflow stenoses similar to that for balloon angioplasty when the same criterion is used.

The cause of superior vena cava syndrome: diagnosis with percutaneous atherectomy.

The cause of superior vena cava syndrome (SVCS) in two patients was identified by means of endovascular biopsy of the superior vena cava (SVC) performed with a percutaneous atherectomy catheter. In both cases, the extracted tissues were neoplastic, therefore obviating additional invasive procedures. After a specific diagnosis was established, external-beam radiation therapy was used to treat the SVCS. The atherectomy catheter was used in conjunction with other percutaneous techniques, including balloon angioplasty and endovascular stenting of the SVC.

AIDS-related cholangitis: radiographic findings in nine patients.

Acalculous inflammation of the biliary tract is a recently reported complication of the acquired immunodeficiency syndrome (AIDS). In a 33-month period, nine men with AIDS were evaluated because of right upper quadrant and/or epigastric pain, jaundice, or abnormal liver function test results. Each patient underwent ultrasonography and endoscopic retrograde cholangiopancreatography; seven also underwent computed tomography. In eight of nine patients the imaging studies disclosed intrahepatic and extrahepatic bile duct changes identical to those seen in sclerosing cholangitis (strictures, focal dilatation, thickened duct walls). Isolated papillary stenosis and ductal dilatation were present in one patient, while eight patients had some stricturing of the distal common duct. The combination of papillary stenosis and intrahepatic ductal strictures appears unique to AIDS-related cholangitis. Endoscopic papillotomy provided variable relief to symptoms and biochemical abnormalities. Cholangitis caused by cytomegalovirus and/or Cryptosporidium infection is the proposed pathophysiologic mechanism.

Combined retrograde-antegrade ureteral stent passage: salvage procedure for a ureteral leak.

The authors describe a stent placement procedure for treatment of an infected ureteral leak after failure of traditional antegrade and retrograde approaches. In this procedure, a guide wire was placed across the distal ureteral segment into a urinoma with use of cystoscopic guidance. Thereafter, an antegrade approach was used to pass a wire loop snare, capture the guide wire, and withdraw it through the proximal ureter for subsequent stent passage. This approach allowed percutaneous stabilization of a ureteral leak in a patient who would have otherwise required immediate surgical repair.

Treatment of type II endoleaks with Onyx.

Endoleaks are defined as persistent perfusion of an abdominal aortic aneurysm (AAA) after endovascular stent-graft deployment. The authors describe their experience treating six endoleaks with the liquid embolic agent Onyx (ethylene-vinyl-alcohol copolymer). Complete endoleak occlusion was achieved in five of six cases. Follow-up imaging has demonstrated decreased aneurysm diameter in all patients 7-29 weeks (mean = 19.2 weeks) after treatment.

Patency and tissue response related to two types of polytetrafluoroethylene-covered stents in the dog.

PURPOSE: A canine model was used to determine tissue response related to placement of two different designs of polytetrafluoroethylene (PTFE) covered stents in the peripheral vascular system. MATERIALS AND METHODS: Two types of PTFE covered stents were implanted in the iliac arteries of 15 mongrel dogs. The tissue response within and beneath these endoprostheses was studied and compared to that for control Palmaz stents with angiographic and histologic examination at 1, 3, and 6 months. RESULTS: The bare Palmaz stent endothelialized faster and with a thinner neointima than either covered stent design. Neointima formation proceeds from the ends toward the center of PTFE-covered stents regardless of design, with minimal transgraft tissue penetration. However, the pattern of neointimal response differed for the two designs and suggests that early thrombus formation at the stent-graft interface promotes neointimal development. CONCLUSION: The bare Palmaz stent showed the least amount of luminal encroachment at all time points compared with either covered stent. Regarding the covered stents, the different patterns of tissue response with the covered stents may provide insight into the design of stent-grafts for human use.

Ergonomic vascular access needle with blood-containment capability: clinical evaluation during arterial access procedures.

PURPOSE: To evaluate the performance of the ergonomic vascular access needle (EVAN), which is designed to contain blood while allowing for observation of pulsations before passage of a guide wire, in arterial catheterization. MATERIALS AND METHODS: EVANs were used for initial puncture in 118 arterial access procedures. Visualization of pulsatile blood motion and containment of blood were prospectively evaluated. Results from 82 separate procedures performed with standard access needles were used as a control. Success or failure of guide-wire passage through the needle, number of attempts, guide-wire type, findings on the access vessel arteriogram, and complications were recorded for both groups. RESULTS: In the EVAN group, 92% of procedures were successfully completed, usually within two attempts (82%). Success was independent of guide-wire type (P = .4) and was not significantly different from that of the control group (96%) (P = .37). In 89% of the EVAN procedures, contained pulsatile blood motion was observed before attempted guide-wire passage. Uncontrolled spraying of pulsatile blood did not occur unless the hemostasis valve was removed. In 16%, slow oozing of blood occurred through the needle hub, mainly during guide-wire passage. Oozing was common with floppy-tipped guide wires (46%) but was uncommon with stiffer-tipped wires (6%). There were no needle-related complications. CONCLUSION: The EVAN provides protection from blood spray while allowing for successful guide-wire passage into the arterial system as often as standard access needles. However, slow periwire leakage occurs frequently with floppy-tipped guide wires.

Efficacy of percutaneous fibrin sheath stripping in restoring patency of tunneled hemodialysis catheters.

OBJECTIVE: Our objective was to determine the effectiveness of percutaneous fibrin sheath stripping as a method of restoring function to failing tunneled hemodialysis catheters. SUBJECTS AND METHODS: A total of 131 percutaneous fibrin sheath stripping procedures were performed on 100 failing tunneled hemodialysis catheters in 91 patients. Only the initial stripping procedure of the first catheter inserted in each patient was included for analysis. Patients were excluded if an additional cause of catheter failure was noted at the time of percutaneous fibrin stripping. Failure of the hemodialysis catheter was defined as inability to sustain an average blood flow rate of 250 ml/min or more in a hemodialysis session. Patients were followed up until the time of catheter failure, catheter removal, or a second stripping. Poststripping primary patency and complication rates were determined. RESULTS: The technical success of the procedure was 95.6%. Median follow-up was 16 weeks (range, 0-128 weeks). The overall median duration of primary patency after the first stripping was 89 days (3 months). No statistically significant difference in primary patency rates was seen between patients who underwent fibrin sheath demonstration by contrast injection and those who did not (p = .71). Female patients were statistically more likely to have catheter failure after catheter stripping than were male patients (p = .02). The route of catheter insertion did not significantly influence poststripping patency rates. No complications were associated with the procedure. CONCLUSION: Percutaneous fibrin sheath stripping is a safe, effective method of restoring patency to failing hemodialysis catheters when the failure is due to fibrin sheath formation and other causes are excluded.

Use of ethylene vinyl alcohol copolymer for tubal sterilization by selective catheterization in rabbits.

PURPOSE: To assess the efficacy of ethylene vinyl alcohol copolymer (Uryx) in nonsurgically occluding the fallopian tube and achieving tubal sterilization in the rabbit model. MATERIALS AND METHODS: Ten mature virgin female New England rabbits underwent transvaginal selective bilateral fallopian tube cannulation with use of a coaxial catheter system under general anesthesia. Selective salpingography was performed bilaterally to assess patency of the fallopian tubes. Ethylene vinyl alcohol copolymer was injected unilaterally through a microcatheter to completely fill the middle portion of the tube. Three to seven days after injection, each animal was bred. Conception was determined by ultrasonography (US) 7-19 days after effective breeding. If pregnant, the rabbit was killed. Otherwise, it was permitted to rebreed until pregnancy was achieved. Histologic specimens of the fallopian tubes were prepared and analyzed. RESULTS: Patency of the fallopian tubes was demonstrated bilaterally in all animals by the free spillage of contrast material into the peritoneum. The delivery of ethylene vinyl alcohol copolymer into the fallopian tubes was successful in all animals but one, in which most of the plug almost immediately extruded into the uterus. Pregnancy was detected by US in the untreated fallopian tube in the nine rabbits that were receptive to breeding. No pregnancies were detected in the injected side. Histologic analysis demonstrated variable degrees of occlusion, fibrosis, and inflammation, with the majority of specimens demonstrating mild to moderate inflammation and moderate to marked fibrosis. CONCLUSION: Ethylene vinyl alcohol copolymer can reliably be placed nonsurgically via the transvaginal approach into the fallopian tubes with use of a coaxial catheter system. Ethylene vinyl alcohol copolymer appears to result in less fibrosis than previously investigated agents and demonstrates a 100% early sterilization rate in the rabbit model.

Treatment of anastomotic bypass graft stenosis with directional atherectomy: short-term and intermediate-term results.

PURPOSE: Areas of anastomotic stenosis in lower-extremity bypass grafts (BPGs) were treated by means of directional atherectomy (DA) in hopes of achieving better patency rates than have been reported with percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: During a 4-year period, 17 patients (11 men and six women) with 23 areas of anastomotic stenosis in 18 lower-extremity BPGs were selected for treatment with DA. Urokinase thrombolysis was initially performed in eight BPGs that were thrombosed at the time of presentation. Adjunctive preatherectomy PTA was performed in six lesions, and postatherectomy PTA was performed in three lesions. RESULTS: The technical success rate for DA was 92% (23 of 25 sites). There was less than 50% restenosis at 74% of the areas of stenosis (14 of 19 sites), with a mean follow-up time for the sites of 13 months. The graft patency rate was 88% (14 of 16 grafts), with a mean follow-up time for the grafts of 14 months. Areas of stenosis treated with DA alone had the same patency rates as those treated with DA and PTA. CONCLUSIONS: DA is an effective treatment method for anastomotic peripheral arterial BPG stenosis. The intermediate-term patency rates following DA are superior to those reported for PTA and similar to those reported for surgical revision.

Percutaneous hepatic venous reanastomosis in a patient with Budd-Chiari syndrome.

A 33-year-old woman with Budd-Chiari syndrome for 9 years presented with worsening right upper quadrant pain and progressive liver dysfunction. Hepatic venography demonstrated hepatic vein occlusions, without significant IVC obstruction. Attempts at stenting a stenotic middle hepatic vein were unsuccessful. Transjugular access, however, allowed puncture from the stump of the right hepatic vein into the engorged right intrahepatic vein that had been demonstrated by retrograde hepatic venography. Two Palmaz stents were used to form the veno-venous reanastomosis. Initial success was documented angiographically and by pressure measurements before and after shunting. Followup at 7 and 16 months confirmed patency of the anastomosis without intimal hyperplasia. The patient noted near-complete resolution of her pain, and her liver function stabilized.

Synthetic dialysis shunts: thrombolysis with the Cragg thrombolytic brush catheter.

PURPOSE: To evaluate the effectiveness of the Cragg thrombolytic brush catheter for declotting of synthetic arteriovenous dialysis shunts. MATERIALS AND METHODS: In this randomized controlled trial, 77 patients with synthetic forearm loop shunts that were thrombosed were randomly assigned to undergo pharmacomechanical thrombolysis with a pulsed spray (n = 34) or a thrombolytic brush catheter (n = 43). The following findings were evaluated: declotting time, urokinase dose, procedure time, complications, and shunt patency at the first dialysis session and at 3 months. All data were collected prospectively in an unblinded manner. RESULTS: The total amount of urokinase used, including secondary interventions, was 243,657 IU with the catheter versus 476,563 IU with the pulsed spray (P = .001). At 15 minutes, clot lysis was successful in 66% of the patients with the catheter versus in 19% with the pulsed spray (P = .001). At 30 minutes, clot lysis was successful in 98% with the catheter versus 47% with the pulsed spray (P = .001). Procedure complication rates and patency at 3 months were similar for the catheter and the pulsed-spray groups. CONCLUSION: Use of the Cragg catheter with urokinase offered faster and more complete clot lysis than did use of the pulsed spray with urokinase. The amount of urokinase used with the catheter was half that used with the pulsed spray. Shunt patency at 3 months was similar for the two treatment methods.

Tissue response to covered Wallstents.

PURPOSE: To evaluate and compare the healing response related to two types of graft-covered Wallstents (WSs) and an uncovered WS in the canine iliac artery. MATERIALS AND METHODS: Eight bare mesh WSs, 10 polyethylene terephthalate interbraided WSs (PET-WSs), and six polytetrafluoroethylene covered WSs (ePTFE-WSs) were placed in the iliac arteries of 12 dogs. Arteriograms were obtained before and after implantation and at explantation. Devices were explanted at 1 month (n = 8), 3 months (n = 6), and 6 months (n = 10) and sent for histologic study. RESULTS: One ePTFE-covered stent-graft was found to be thrombosed at 3 months; the remaining 23 of 24 implants remained patent to the time of explantation. The WS and ePTFE-WS both generated a uniform myointimal cell response without inflammation. The PET-WS induced a fibrous luminal response with substantial foreign body-type inflammatory reaction around the PET fibers. Although neointima associated with the PET-WS appeared thicker than that associated with either the ePTFE-WS or the bare WS, none of the patent implants developed greater than 50% angiographic narrowing. CONCLUSION: The PET-WS induced chronic inflammation, a response not seen with either the WS or ePTFE-WS. This may explain the occurrence of pain and/or fever in human studies of arterial PET endoluminal stent-grafts. Patency for all three implants was excellent in this model.

Acute upper extremity deep venous thrombosis: safety and effectiveness of superior vena caval filters.

PURPOSE: To evaluate the safety and effectiveness of percutaneous filter placement in the superior vena cava for prevention of pulmonary embolism (PE) due to acute upper extremity deep venous thrombosis (DVT) in patients with contraindications to or unsuccessful anticoagulation. MATERIALS AND METHODS: Forty-one patients with acute upper extremity DVT and contraindications to or unsuccessful anticoagulation underwent percutaneous placement of a superior vena caval filter for prevention of PE. Four types of filters were used. Follow-up chest radiographs were used to detect filter migration, dislodgment, and fracture. Placements of central venous and Swan-Ganz catheters after filter insertion were recorded. Patients were followed up clinically for evidence of superior vena cava syndrome and PE. Kaplan-Meier survival rates were determined. Follow-up was 1 day to 221 weeks. RESULTS: No complications such as filter migration, dislodgment, or fracture occurred (median follow-up, 12 weeks). No patients developed clinical evidence of PE due to upper extremity thrombosis or superior vena cava syndrome (median follow-up, 15 weeks). Catheters were placed subsequent to filter placement in 23 patients (56%) without complication. CONCLUSION: Percutaneous filter placement in the superior vena cava is a safe and effective method for preventing symptomatic PE due to acute upper extremity DVT in patients in whom therapeutic anticoagulation has failed or is contraindicated.

Phase I results of pullback atherectomy for hemodialysis access.

PURPOSE: Balloon angioplasty and directional atherectomy frequently have short-lived results for stenoses associated with hemodialysis. Results are reported for a phase I trial of the pullback atherectomy catheter (PAC) for treatment of hemodialysis access-related stenoses. PATIENTS AND METHODS: Six intragraft and six venous stenoses in nine patients were treated with the PAC. Two lesions were treated with adjunctive balloon angioplasty, and two were treated with adjunctive directional atherectomy. Clinical and angiographic follow-up were obtained for all patients. All specimens were examined histologically. RESULTS: Initial procedural success was achieved in 83% of stenoses (10 of 12). For intragraft stenoses, the 6-month primary patency was 60% (three of five) and the 6-month secondary patency was 80% (four of five). All six venous stenoses restenosed or thrombosed within 3 months. All specimens contained fibrous plaque or intimal hyperplasia. In addition, all six venous stenosis specimens contained media and two contained adventitia. Significant complications during treatment of venous stenoses included severe venous spasm in three and venous pseudoaneurysms in two. One PAC tip fracture occurred during treatment of an intragraft stenosis. CONCLUSION: Pullback atherectomy is potentially safe and effective for intragraft stenoses; however, it is not safe or effective for venous stenoses.