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.

Inferior vena cava (IVC) filter thrombosis in a renal transplant recipient.

We report a renal transplant patient with a functioning allograft who had an inferior vena cava (IVC) filter placed above the renal allograft vein. The patient occluded the IVC filter and developed extensive distal thrombosis. This included complete occlusion of the renal allograft vein (RAV). However, this complication did not lead to a loss of kidney transplant function. Alternate allograft venous drainage via capsular collaterals and subsequent recanalization of transplant vein were demonstrated.

Duplex ultrasound evaluation for dialysis access selection and maintenance: a practical guide.

Detailed case directed history and examination is the mainstay of dialysis access modality selection, ie site and type of access, as well as for maintenance of dialysis access for longevity. As a logical step following history and physical examination, duplex ultrasound evaluation (DUE) is the most cost effective and non-invasive screening tool for evaluation for access placement and for assessment of an established access. Pre-operative vascular mapping allows selection of the optimal dialysis access modality and site. In established accesses, duplex ultrasound testing will diagnose the majority of vascular access complications and direct proper surgical or interventional radiology management. This review outlines a practical decision-making algorithm using DUE for choosing and managing the dialysis access.

Understanding the dialysis access steal syndrome. A review of the etiologies, diagnosis, prevention and treatment strategies.

Distal hypoperfusion ischemic syndrome (DHIS), commonly referred to as hand ischemia or 'steal' after dialysis access placement, occurs in 5-10% of cases when the brachial artery is used, or 10 times that of wrist arteriovenous fistulas (AVFs) using the radial artery. It is typically seen in elderly women with diabetes, and may carry severe morbidity including tissue or limb loss if not recognized and treated. Three distinct etiologies include (1) blood flow restriction to the hand from arterial occlusive disease either proximal or distal to the AV access anastomosis, (2) excess blood flow through the AV fistula conduit (true steal), and (3) lack of vascular (arterial) adaptation or collateral flow reserve (ie atherosclerosis) to the increased flow demand from the AV conduit. These three causes of steal may occur alone or in concert. The diagnosis of steal is based on an accurate history and physical examination and confirmed with tests including an arteriogram, duplex Doppler ultrasound (DDU) evaluation with finger pressures and waveform analysis. Treatment of steal includes observation of developing symptoms in mild cases. Balloon angioplasty is the appropriate intervention for an arterial stenosis. At least three distinct surgical corrective procedures exist to counteract the pathophysiology of steal. The ultimate treatment strategy depends on severity of symptoms, the extent of patient co-morbidity, and the local dialysis access technical team support and skills available.

A patient centered decision making dialysis access algorithm.

Much controversy surrounds the establishment of proper planning, placement and management (the best practice pattern) of dialysis access. These include the dialysis type and modality selection, timing of access placement and who places the access. The lack of and the difficulty of performing randomized studies with multiple confounding factors, in an extremely heterogeneous and rapidly changing ESRD population demographics, only partly explains the dialysis access conundrum. Add to this the rapidly developing and competing technologies, the wide spectrum of the professional experience, bias and socio-economic forces to make the ESRD problems as multivariate and complex as life itself. This overview describes a dialysis access algorithm approach to the patient needing renal replacement therapy, considering long-term improved patient outcome as the ultimate objective.

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.

Preoperative radiological evaluation of the liver by computerized tomographic portography in patients with hepatic tumors.

The main objective of preoperative imaging studies is to define as accurately as possible the number, size, location, and relationship of tumor masses in the liver to pertinent portal and hepatic venous vasculature. Computerized tomographic portography images hepatic veins and segmental portal vein branches and identifies the anatomical location of tumor nodules with excellent sensitivity and a low false-positive rate. The intraoperative correlation of computerized tomographic portography on 30 patients in the last 20 months at this institution shows a sensitivity of 88 per cent with a low rate of false-positivity. The ability to detect metastatic lesions in the liver by computerized tomographic portography diminishes when the lesions are noted to be less than 1 cm. The authors conclude that the preoperative interpretation of the computerized tomographic portogram provides valuable information not previously available to the surgeon operating on the liver.

Formyl peptide chemotactic receptor. Evidence for an active proteolytic fragment.

We have developed a radioiodinated photoaffinity label, N-formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys-N-6-(4'-azido-2'-nitrophenylamino) hexanoate (where Nle represents norleucine) (125I-PAL), which forms a covalent complex with the formyl peptide chemotactic receptor of living human neutrophils. Labeling was 12 to 16% efficient and did not alter cell viability. The receptor on live neutrophils and neutrophil membranes has an apparent molecular weight of 50,000 to 70,000 by sodium dodecyl sulfate-polyacrylamide electrophoresis. The receptor on intact cells possesses one predominant papain cleavage site, yielding a 35,000-Da fragment. This receptor fragment retains an affinity for N-formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys indistinguishable from the receptor on control cells (KD = 1.9 and 1.8 nM, respectively). The 35,000-Da papain fragment was biologically active as evidenced by an unchanged dose-response curve for peptide-stimulated beta-glucuronidase release and fluorescent peptide uptake. Papain treatment of 125I-PAL-labeled neutrophil membranes or of digitonin-soluble 125I-PAL-labeled receptors produced a predominant 28,000-Da fragment without evidence of the 35,000-Da fragment seen with whole cells. Pronase, which did not cleave the receptor on intact cells, produced multiple receptor fragments when used to treat 125I-PAL-labeled membranes.

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.

Combination "sandwich" therapy for extensive renal calculi in 100 consecutive patients: immediate, long-term and stratified results from a 10-year experience.

PURPOSE: We determined the immediate and long-term efficacy of combination "sandwich" therapy for management of large, extensively branched calculi in 100 consecutively treated patients. MATERIALS AND METHODS: We treated 61 women and 39 men for stones ranging from 2.2 to 66 cm2 (mean 20.8) with percutaneous debulking followed by shock wave lithotripsy and, when necessary, secondary nephroscopy via the mature tract. The primary debulking was performed via 1 to 3 tracts (total 106, mean 1.06 per patient), following which 1 to 3 shock wave treatments (total 127, mean 1.3 per patient) were administered. Subsequently, 62 patients underwent 71 secondary or tertiary percutaneous procedures (mean 1.1 per patient). RESULTS: Total hospital stay ranged from 3 to 44 nights (mean 12.2) and decreased with experience. In 34 patients 40 complications developed, the most frequent of which were bleeding requiring transfusion in 14 patients and fever or sepsis delaying a planned procedure or hospital discharge in 20 patients. For patients with struvite stones the transfusion rate and fever/sepsis rate was 20 and 33%, respectively, compared to only 10 and 12%, respectively, for those patients with noninfection related stones. Of 87 patients available for 1-month radiographic followup 55 (63%) were stone-free, while 32 (37%) had discrete residual gravel. With time and experience, the stone-free rate improved from 52 to 70%. Of 55 patients followed for a mean of 40.5 months ipsilateral stones recurred in 13 (22.8%). Of 39 patients with struvite calculi 11 (28%) had recurrent bacteriuria or infection. Renal function, defined by serum creatinine, ranged from 0.6 to 3.9 mg./dl. (mean 1.3) before treatment and from 0.5 to 6.4 mg./dl. (mean 1.4) 1 to 101 months (mean 31) after treatment. CONCLUSIONS: This combined sandwich approach offers immediate and long-term results comparable to other forms of management currently available for these challenging cases. Furthermore, this approach may be applied successfully to virtually any patient with large, extensively branched or otherwise complex stones.

Delayed onset of ascending paralysis after thoracic aortic stent graft deployment.

Delayed spinal cord ischemia after thoracic aortic aneurysm repair is an infrequent but devastating complication. The use of stent grafts to exclude aortic aneurysms is thought to decrease the incidence of the neurologic deficit because there is no period of significant aortic occlusion. We report a case of paraplegia that progressed to quadriplegia occurring 48 hours after the apparently successful deployment of a thoracic aortic stent graft.

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.

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.

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.

Transjugular core liver biopsy with a 19-gauge spring-loaded cutting needle.

One hundred and five sequential transjugular core liver biopsies (TJLBx) were performed in 101 patients with coagulopathy and/or ascites using the 19-gauge Quick-Core Biopsy (QCB) needle. Two-hundred and seventy-three cores were obtained in 295 passes (92. 5%). One-hundred and two of the 105 procedures (97.1%) led to a histopathologic diagnosis. One of the three nondiagnostic biopsies was done because of severe autolysis of the liver. There was one subcapsular hematoma, one hepatic arteriovenous fistula, and one liver capsular puncture. Two minor neck hematomas occurred. One death was reported (unrelated to the procedure). QCB needle TJLBx is an effective and relatively safe way to obtain core liver samples.