The Effects of Tooth Brushing on Whole Salivary Flow Rate in Older Adults.

OBJECTIVES: (1) To determine whether manual (MTB), or electric, tooth brushing (ETB) modulates whole salivary flow rate in older adults who are free of systemic disease. (2) To determine the duration of the brushing-related modulation of salivary flow rate. (3) To compare salivary flow rate modulation associated with MTB and ETB. METHOD: Twenty-one adults aged 60 years and older participated in two experimental sessions during which they used a manual, or electric, toothbrush to brush their teeth, tongue, and palate. Whole salivary flow rates were determined using the draining method before, during, and after brushing. Differences in salivary flow rates across time periods, and between conditions, were examined using paired samples t-tests applying a Holm-Bonferroni sequential procedure (pcorr < 0.0045). The relationship between tooth brushing and age with respect to maximum salivary flow rate increase was examined using Pearson's correlation coefficient (p < 0.05). RESULTS/CONCLUSION: Whole salivary flow rates increased during, and for up to 5 minutes following, tooth brushing in adults aged 60 years and older who were free of systemic disease. The salivary effects of MTB and ETB were not significantly different. A moderate, positive correlation was observed between tooth-brushing-related maximum salivary flow rate increase and age.

Progression of retinal ganglion cell loss in multiple sclerosis is associated with new lesions in the optic radiations.

BACKGROUND AND PURPOSE: The mechanism of retinal ganglion cell and retinal nerve fiber layer loss in multiple sclerosis (MS) remains unknown. This study aimed to investigate the association between temporal retinal nerve fiber layer (tRNFL) thinning and disease activity in the brain determined by T2 lesions on magnetic resonance imaging (MRI). METHODS: Fifty-five consecutive patients with relapsing-remitting MS and 25 controls were enrolled. All patients underwent annual optical coherence tomography and high-resolution MRI scans for tRNFL thickness and brain lesion volume analysis, respectively. RESULTS: Significant tRNFL thickness reduction was observed over the 3-year follow-up period at a relatively constant rate (1.02 µm/year). Thinning of tRNFL fibers was more prominent in younger patients (P = 0.01). The tRNFL loss was associated with new MRI lesions in the optic radiations (ORs). There was significantly greater tRNFL thinning in patients with new lesional activity in the ORs compared with patients with new lesions outside the ORs (P = 0.009). CONCLUSIONS: This study supports the notion that retrograde transneuronal degeneration caused by OR lesions might play a role in progressive retinal nerve fiber layer loss. In addition, the results of the study also indicate that the disease-related neurodegenerative changes in the retina start much earlier than the clinical diagnosis of MS.

Relationship between chronic demyelination of the optic nerve and short term axonal loss.

BACKGROUND: Axonal loss is a major determinant of disability in multiple sclerosis (MS). While acute inflammatory demyelination is a principal cause of axonal transection and subsequent axonal degeneration in acute disease, the nature of chronic axonal loss is less well understood. In the current study, the relationship between degree of chronic demyelination and axonal degeneration was investigated using optic neuritis (ON) as a model. METHOD: 25 patients with a first episode of unilateral ON, good recovery of visual function and concurrent brain or spinal cord MRI lesions were enrolled. Axonal loss was assessed using change in retinal nerve fibre layer (RNFL) thickness between 1 and 3 years after ON. Optic nerve conduction was evaluated using latency of multifocal visual evoked potentials (mfVEP). The level of mfVEP latency delay at 12 and 36 months was considered indicative of the degree of permanent demyelination. Data from 25 age and gender matched normal controls were used for comparison. RESULTS: RNFL thickness was significantly reduced in ON eyes at 12 months compared with controls but remained unchanged in fellow eyes. Average RNFL thickness demonstrated a small but significant reduction between 12 and 36 months for both ON and fellow eyes. Change in RNFL thickness between 12 and 36 months, however, did not correlate with the degree of mfVEP latency delay. CONCLUSION: The results, therefore, show no association between the degree of permanent optic nerve demyelination (as measured by latency delay) and progressive axonal degeneration, at least in the early stages of the disease. The fact that fellow eyes demonstrated a similar degree of progressive axonal loss supports this suggestion.

Magnetisation transfer ratio in optic neuritis is associated with axonal loss, but not with demyelination.

BACKGROUND: Pathophysiological basis of Magnetisation Transfer Ratio (MTR) reduction in multiple sclerosis still remains a matter of controversy. Optic nerve represents an ideal model to study the consequences of axonal loss and demyelination on MTR since effects of disease on the optic nerve are clinically apparent and potentially quantifiable by objective means. By measuring the latency of multifocal visual evoked potentials (mfVEP) (measure of optic nerve conduction) and Retinal Nerve Fiber Layer (RNFL) thickness (measure of axonal damage) we investigated the effect of neurodegeneration and demyelination on MTR after an episode of optic neuritis (ON). METHODS: 23 patients with a single unilateral episode of ON and 10 healthy volunteers were enrolled. Orbital MRI including MTR protocol, Optical Coherence Tomography and Multifocal VEP were performed at post-acute stage of ON. RESULTS: Average MTR of affected eye was significantly reduced as compared to the fellow eye and normal controls. There was a highly significant correlation between MTR and measures of axonal loss (RNFL thickness and mfVEP amplitude), which was independent on the level of demyelination. While latency delay also correlated significantly with MTR, correlation became non-significant when adjusted for the degree of axonal loss. There was a significant reduction of MTR in a group of patients with extensive axonal damage, while MTR remained normal in a group of patients with extensive demyelination, but little or no axonal loss. CONCLUSION: Results of this study indicate that reduction of optic nerve MTR after an episode of ON has a strong association with the degree of axonal damage, but not with demyelination.

Fellow eye changes in optic neuritis correlate with the risk of multiple sclerosis.

BACKGROUND: Recent studies demonstrate early diffuse central nervous system (CNS) inflammation in patients with multiple sclerosis (MS). The clinically unaffected (fellow) eye of patients with unilateral optic neuritis (ON) may reflect the status of normal-appearing white matter in the CNS, which can be assessed electrophysiologically. OBJECTIVE: To study the relationship between electrophysiological parameters in the fellow eye of ON patients, and risk of conversion to MS. METHODS: Forty-eight consecutive patients with acute unilateral ON were examined 12 months after ON of which 14 had MS, 19 remained high risk (HR) for MS, and 15 had low risk (LR) for MS according to McDonald's criteria. Twenty-five age-matched controls were also tested. Amplitude and latency of multifocal visual evoked potential (mfVEP) in the fellow eyes of patients at 12 months were analyzed and compared with controls. RESULTS: Average mfVEP amplitude was 240 +/- 35, 232 +/- 36, 181 +/- 38, and 169 +/- 48 nV for controls, LR, HR, and MS groups respectively. Average mfVEP latency for controls, LR, HR, and MS patients was 139.7 +/- 5.5, 141.7 +/- 3.6, 145.9 +/- 8.9, and 152.0 +/- 9.9 ms respectively. CONCLUSIONS: The magnitude of latency prolongation and amplitude decline 12 months after the initial episode was proportional to the risk of MS. The prognostic significance of these changes as predictors of subsequent MS should be investigated longitudinally.

Not just vicariance: phylogeography of a Sonoran Desert euphorb indicates a major role of range expansion along the Baja peninsula.

To examine the generality of population-level impacts of ancient vicariance identified for numerous arid-adapted animal taxa along the Baja peninsula, we tested phylogeographical hypotheses in a similarly distributed desert plant, Euphorbia lomelii (Euphorbiaceae). In light of fossil data indicating marked changes in the distributions of Baja floristic assemblages throughout the Holocene and earlier, we also examined evidence for range expansion over more recent temporal scales. Two classes of complementary analytical approaches - hypothesis-testing and hypothesis-generating - were used to exploit phylogeographical signal from chloroplast DNA sequence data and genotypic data from six codominant nuclear intron markers. Sequence data are consistent with a scenario of mid-peninsular vicariance originating c. 1 million years ago (Ma). Alternative vicariance scenarios representing earlier splitting events inferred for some animals (e.g. Isthmus of La Paz inundation, c. 3 Ma; Sea of Cortez formation, c. 5 Ma) were rejected. Nested clade phylogeographical analysis corroborated coalescent simulation-based inferences. Nuclear markers broadened the temporal spectrum over which phylogeographical scenarios could be addressed, and provided strong evidence for recent range expansions along the north-south axis of the Baja peninsula. In contrast to previous plant studies in this region, however, the expansions do not appear to have been in a strictly northward direction. These findings contribute to a growing appreciation of the complexity of organismal responses to past climatic and geological changes - even when taxa have evolved in the same landscape context.

Multifocal VEP and OCT in optic neuritis: a topographical study of the structure-function relationship.

PURPOSE: To investigate topographical relationship between amplitude of multifocal visual evoked potentials (mfVEP) and retinal nerve fibre layer (RNFL) thickness following acute optic neuritis (ON). PATIENTS AND METHODS: Fifty patients with a clinical diagnosis of acute unilateral ON between 6 and 36 months prior to the study and 25 age-matched controls underwent mfVEP testing (Accumap V 2.1, ObjectiVision Pty Ltd, Sydney, Australia) and OCT imaging (fast RNFL protocol, Stratus, software version 3.0, Carl Zeiss Meditec, Inc., Dublin, CA). RNFL thickness and mfVEP amplitude were measured for upper, temporal and lower retinal sectors and corresponding areas of the visual field in affected eyes of ON patients and control eyes. Inter-eye asymmetry coefficients for both RNFL thickness and mfVEP amplitude were calculated for each zone, and corresponding coefficients were correlated between each other. RESULTS: There was highly significant reduction of RNFL thickness and mean mfVEP amplitude in all three retinal sectors of the affected eye. Largest reduction of RNFL thickness was noticed in temporal sector and of mfVEP amplitude in corresponding central part of the visual field. RNFL thickness correlated highly with amplitude of the mfVEP derived from corresponding areas of the visual field in all three zones. CONCLUSIONS: We demonstrated strong topographical associations between structural and functional measures of optic nerve integrity in patients with ON.

Catchments catch all: long-term population history of a giant springtail from the southeast Australian highlands--a multigene approach.

Phylogeography can reveal evolutionary processes driving natural genetic-geographical patterns in biota, providing an empirical framework for optimizing conservation strategies. The long-term population history of a rotting-log-adapted giant springtail (Collembola) from montane southeast Australia was inferred via joint analysis of mitochondrial and multiple nuclear gene genealogies. Contemporary populations were identified using multilocus nuclear genotype clustering. Very fine-scale sampling combined with nested clade and coalescent-based analyses of sequences from mitochondrial cytochrome oxidase I and three unlinked nuclear loci uncovered marked population structure, deep molecular divergences, and abrupt phylogeographical breaks over distances on the order of tens of kilometres or less. Despite adaptations that confer low mobility, rare long-distance gene flow was implicated: novel computer simulations that jointly modelled stochasticity inherent in coalescent processes and that of DNA sequence evolution showed that incomplete lineage sorting alone was unable to explain the observed spatial-genetic patterns. Impacts of Pleistocene or earlier climatic cycles were detected on multiple timescales, and at least three putative moist forest refuges were identified. Water catchment divisions predict phylogeographical patterning and present-day population structure with high precision, and may serve as an excellent surrogate for biodiversity indication in sedentary arthropods from topographically heterogeneous montane temperate forests.

Laser Doppler flowmetry detection of endothelial dysfunction in end-stage renal disease patients: correlation with cardiovascular risk.

Prediction of cardiovascular (CV) complications represents the Achilles' heel of end-stage renal disease. Surrogate markers of endothelial dysfunction have been advocated as predictors of CV risk in this cohort of patients. We have recently adapted a noninvasive laser Doppler flowmetry (LDF) functional testing of endothelium-dependent microvascular reactivity and demonstrated that end-stage renal disease patients are characterized by profound alterations in thermal hyperemic responsiveness. We hypothesized that such functional assessment of the cutaneous microcirculation may offer a valid, noninvasive test of the severity of endothelial dysfunction and CV risk. To test this hypothesis, we performed a cross-sectional study, in which we compared LDF measurements to conventional risk factors, and performed a pilot longitudinal study. LDF studies were performed in 70 patients and 33 controls. Framingham and Cardiorisk scores were near equivalent for low-risk patients, but more divergent as risk increased. C reactive protein (CRP) levels and LDF parameters (amplitude of thermal hyperemia (TH), area under the curve of TH) showed significant abnormality in high-risk vs low-risk patients calculated using either Framingham or Cardiorisk scores. Patients who had abnormal LDF parameters showed increased CV mortality, however, had similar risk assessments (Framingham, Cardiorisk, CRP, and homocysteine) to those with unimpaired LDF tracings. In conclusion, LDF parameters of microvascular reactivity offer a sensitive characterization of endothelial dysfunction, which may improve CV risk assessment through incorporation into the Framingham or Cardiorisk algorithm.

Phylogeography recapitulates topography: very fine-scale local endemism of a saproxylic 'giant' springtail at Tallaganda in the Great Dividing Range of south-east Australia.

Comparative phylogeography can reveal processes and historical events that shape the biodiversity of species and communities. As part of a comparative research program, the phylogeography of a new, endemic Australian genus and species of log-dependent (saproxylic) collembola was investigated using mitochondrial sequences, allozymes and anonymous single-copy nuclear markers. We found the genetic structure of the species corresponds with five a priori microbiogeographical regions, with population subdivision at various depths owing to palaeoclimatic influences. Closely related mtDNA haplotypes are codistributed within a single region or occur in adjacent regions, nuclear allele frequencies are more similar among more proximate populations, and interpopulation migration is rare. Based on mtDNA divergence, a late Miocene-late Pliocene coalescence is likely. The present-day distribution of genetic diversity seems to have been impacted by three major climatic events: Pliocene cooling and drying (2.5-7 million years before present, Mybp), early Pleistocene wet-dry oscillations (c. 1.2 Mybp) and the more recent glacial-interglacial cycles that have characterized the latter part of the Quaternary (<0.4 Mybp).

Holmium laser enucleation of the prostate: morbidity in a series of 206 patients.

OBJECTIVES: To review the complications associated with 206 holmium laser enucleation of the prostate (HoLEP) procedures. HoLEP is a minimally invasive surgical treatment for benign prostatic hyperplasia. METHODS: A retrospective review was conducted of HoLEPs performed from April 1, 1999 to October 1, 2001. Patients with previous diagnoses of prostate carcinoma or who had undergone HoLEP after admission for unrelated problems were excluded. Demographic, intraoperative, and immediate postoperative data were recorded to determine the incidence of complications. Patients were also contacted by telephone or mailed surveys for documentation of longer term complications. RESULTS: The mean age and procedure time was 70.5 years (range 45 to 91) and 133.6 minutes (range 25 to 473), respectively. The mean specimen weight was 68.2 g (range 3 to 376), with 20 (9.7%) of 206 patients diagnosed with adenocarcinoma. The mean hospital stay was 1.1 days, with 86.9% of patients discharged after an overnight stay without a catheter. Two patients required postoperative transfusions (1.0%). No deaths, major complications (myocardial infarction or pulmonary embolism), or transurethral resection syndrome episodes occurred. Intraoperative complications consisted of three capsular perforations (1.5%), one bladder neck false passage (0.5%), four incomplete morcellations (1.9%), and four minor bladder mucosal morcellation injuries (1.9%). Of 206 patients, 173 (84.0%) provided follow-up data (mean 19.0 +/- 8.4 months), allowing documentation of longer term complications, including five clot retention episodes (2.4%), five urethral strictures (2.4%), eight bladder neck contractures (3.9%), and 16 patients requiring re-catheterization (7.8%). CONCLUSIONS: HoLEP can be performed with minimal complication risks and blood loss. Patients can expect an overnight hospital stay and discharge without an indwelling catheter.

Holmium laser enucleation of prostate (HoLEP): the Methodist Hospital experience with greater than 75 gram enucleations.

PURPOSE: Holmium laser enucleation of the prostate (HoLEP) effectively removes obstructive prostate tissue in minimally invasive fashion. We present our large enucleation outcomes (greater than 75 gm retrieved). We examined post-procedural prostate specific antigen (PSA) and transrectal ultrasound (TRUS) volume changes to assess tissue removal completeness. MATERIALS AND METHODS: We retrospectively reviewed HoLEPs performed from April 1, 1999 through September 30, 2002 to identify all enucleations greater than 75 gm. Demographic, laboratory, operative and pathological data were obtained. Patients were surveyed to document longer term complications. RESULTS: The cohort of 108 patients had a mean age and specimen weight of 71.5 years (range 53 to 90) and 120.6 gm (range 75.3 to 376), respectively. Average procedural time and hospital stay were 166.8 minutes (range 75 to 473) and 1.2 days (range 0 to 4), respectively. No deaths or episodes of transurethral resection syndrome occurred. Postoperative complications included transfusion in 2 cases, a clot retention episode in 3, capsular perforation in 2, morcellator blade malfunction in 4, minor bladder mucosal injury in 1 and bladder neck contracture in 1. American Urological Association symptom scores reassessed in 53 patients without chronic retention an average +/- SD of 10.6 +/- 7.1 months postoperatively showed a mean decrease from 20.3 +/- 6.4 to 4.7 +/- 3.8. PSA in 48 patients a mean of 5.0 +/- 4.1 months postoperatively had decreased an average of 91.7%. In 10 patients TRUS data revealed a mean post-procedural volume decrease of 85.9%. CONCLUSIONS: HoLEP can be performed on extremely large prostates with minimal risk or need for secondary interventions. Most patients are discharged home after an overnight stay. Postoperative decreases in PSA and TRUS volumes support the completeness of enucleation that can be achieved.

The Indiana experience with artificial urinary sphincters in children and young adults.

PURPOSE: We reviewed a 22-year single institutional experience with the artificial urinary sphincter in children and adolescents. To our knowledge this report represents the largest series in the world in children. MATERIALS AND METHODS: Between 1980 and 2002, 142 patients underwent implantation of an artificial urinary sphincter, of whom 93 males and 41 females with a median age of 10 years (range 3 to 39) were available for analysis. A total of 59 patients initially received an AMS 742/792 (American Medical Systems, Inc., Minnetonka, Minnesota) artificial urinary sphincter, of whom 33 were subsequently changed to an AMS 800, while 75 initially received an AMS 800 model. Sphincter followup was terminated at device removal or at the last documented contact. The etiology of incontinence was neuropathic bladder in 107 cases (80%), the exstrophy/epispadias complex in 21 (16%) and other in 6 (4%). Outcome measures included continence, mechanical complications (leakage, tube kink and pump malfunction), functioning sphincter revisions (change in cuff size, pump repositioning and bulbar cuff placement), surgical complications (erosion, infection and misplacement) and associated surgical procedures. Mean followup of the pre-800 and 800 models was 6.9 (range 0.2 to 21.5) and 7.5 years (range 0.1 to 17.1), respectively. Fisher's exact test, Kaplan-Meier life analysis and the chi-square test were used for statistical analysis. RESULTS: After artificial urinary sphincter placement in the 134 patients continence was achieved in 86%, improved in 4% and not achieved in 10%. Of those with a sphincter in place 92% were continent. In terms of bladder emptying after artificial urinary sphincter insertion 22% of patients voided, 11% voided combined with clean intermittent catheterization, 48% performed clean intermittent catheterization only via the urethra, 16% performed it via a catherizable channel and 3% used urinary diversion. A mechanical complication developed in 38 of the 59 patients (64%) with pre-800 model compared with 33 of the 109 (30%) with the 800 model (p <0.0001). A mechanical complication occurred every 7.6 versus 16 patient-years for the pre-800 versus 800 models (p = 0.0001). Revision was required in 15 of the 59 patients (25%) with a pre-800 model versus 17 of the 109 (16%) with the 800 model (p = 0.103). Revision was performed every 22.7 versus 44.3 patient-years for the pre-800 versus the 800 model (p = 0.023). The artificial urinary sphincter eroded in 11 of the 59 patients (19%) with the pre-800 versus 17 of the 109 (16%) with the 800 model (p = 0.52). Ten patients experienced a total of 12 perforations of the augmented bladder after artificial urinary sphincter implantation. A total of 164 secondary surgical procedures were performed, including 38 of 134 bladder augmentations (28%). A total of 30 sphincters were permanently removed. CONCLUSIONS: The artificial urinary sphincter is the only bladder neck procedure that allows spontaneous voiding in the neuropathic population, obviates the need for clean intermittent catheterization and yet is compatible with it when necessary. It is also equally versatile in the 2 genders. Mechanical complications occur but they were dramatically decreased by the modifications of the AMS 800 model. In addition, secondary bladder augmentation was required in 28% of our patients. Lifelong followup is mandatory in all patients with an artificial urinary sphincter.

Salvage procedure for infected noneroded artificial urinary sphincters.

PURPOSE: We report our experience with removal, antiseptic irrigation and immediate reimplantation of infected noneroded artificial urinary sphincters. MATERIALS AND METHODS: From April 1996 to October 2000, 8 patients with an infected artificial urinary sphincter underwent a total of 9 salvage operations. All patients underwent cystoscopy before salvage to ensure nonerosion of the sphincter cuff. All previously implanted material was removed, the wounds were copiously irrigated according to a 7 solution protocol and an identical new system was implanted. All patients were discharged home the following morning on oral antibiotics. RESULTS: Followup was 5 to 66 months (mean 33). The predominant organisms cultured at salvage were gram-positive cocci. Time from implantation to salvage was from 2 weeks to 64 months (mean 13.7 months). Prostatectomy was the etiology of incontinence in all except 1 case. In 5 of the 8 men a double cuff system was placed and 3 underwent concurrent 3-piece inflatable penile prosthesis salvage. The salvage procedure was done twice in 1 patient 5 months apart. The system was removed 16 months later secondary to urethral erosion. At the most recent followup the other 7 patients were free of infection with a functioning artificial urinary sphincter. CONCLUSIONS: Salvage and immediate reimplantation of an infected, noneroded single or double cuff artificial urinary sphincter appears to be a valid option. Our overall success rate was 87%. The usual offending organisms are gram-positive skin flora. An associated inflatable penile prosthesis does not prohibit simultaneous salvage of the 2 devices.

Isolation and culture of capillary endothelial cells from the eel, Anguilla rostrata.

There has been little development of endothelial cell cultures from vertebrates other than mammals. In this report the isolation of capillary endothelial cells from the rete mirabile of the eel, Anguilla rostrata, is described. The cells are isolated with collagenase H and dispase II. The cells are plated into fibronectin-hyaluronic acid coated flasks. The culture medium is M199 with Earle's salts supplemented with NaCl, HEPES, NaHCO(3), glutamine, pyruvate, heparin, antibiotics, endothelial cell growth supplement, and 20% serum. Cultures are incubated at 25 degrees C in humidified air. The rete mirabile contains pericytes in addition to endothelial cells. Variations in plating time, serum concentrations, and growth matrices were tried to separate the two cell types. The total number of endothelial cells and the ratio of endothelial cells to pericytes are the most important factors in obtaining pure cultures of capillary endothelial cells. Endothelial cells are isolated also from the endocardium, bulbus arteriosus, and large vessels. The initial isolates usually take 3-6 weeks to grow to confluence with subcultures taking about 2 weeks to confluence.

A case of thyrotoxicosis with chorea: association with anti-phospholipid antibody.

We report a case of thyrotoxicosis associated with chorea and detectable anti-phospholipid antibodies in which a structural abnormality could not be detected on routine imaging but cerebral perfusion single photon emission computed tomography scans suggested a reversible alteration of basal ganglia perfusion. The pathophysiological mechanisms of phospholipid antibody causing chorea in thyrotoxicosis are discussed.

Malignant transformation of craniopharyngioma.

Craniopharyngioma is a well recognised intracranial tumour; malignant transformation has been rarely described. In that case, malignant change occurred following irradiation for local recurrence and information is not provided on the biological behaviour of the tumour or the response to management. We report a further case of malignant transformation in recurrent craniopharyngioma following radiotherapy. The biological behaviour of malignant change in craniopharyngioma is uncertain so the treatment modalities require consideration of toxicity and other adverse sequelae balanced against anticipated outcome and comorbidities from previous treatments. The pathophysiology and therapeutic strategies are discussed. We review the possible pathogenic link between radiation therapy and malignant transformation.

Renal artery stent placement for the management of ischemic nephropathy.

PURPOSE: To evaluate the angiographic and clinical results of percutaneously implanted renal artery endoprostheses (stents) for the treatment of patients with ischemic nephropathy. MATERIALS AND METHODS: During a 52-month period, 45 patients with azotemia (serum creatinine > or = 1.5 mg/dL) and atheromatous renal artery stenosis untreatable by, or recurrent after, balloon angioplasty were treated by percutaneous placement of Palmaz stents. Stent implantation was unilateral in 32 cases and bilateral in 11 cases. Clinical results were determined by measurements of serum creatinine and follow-up angiography. Clinical benefit was defined as stabilization or improvement in serum creatinine level. Angiographic patency was defined as less than 50% diameter recurrent arterial stenosis. RESULTS: Stent placement was technically successful in 51 of 54 (94%) renal arteries. Technical failures were stent misdeployment requiring percutaneous stent retrieval (n = 2) and inadvertent placement distal to the desired position (n = 1). Complications included acute stent thrombosis (n = 1) and early initiation of hemodialysis (within 30 days; n = 1). There were two periprocedural deaths. With use of life-table analysis, clinical benefit was seen in 78% of patients at 6 months (n = 36), 72% at 1 year (n = 24), 62% at 2 years (n = 12), and 54% at 3 years (n = 3). In patients with clinical benefit, average creatinine level was reduced from 2.21 mg/dL +/- 0.91 before treatment to 2.05 mg/dL +/- 1.05 after treatment (P = .018). Lower initial serum creatinine level was associated with a better chance of clinical benefit (P = .05). No other variables affected outcome, including patient age, sex, diabetes, implanted stent diameter, unilateral versus bilateral stent placement, or ostial versus nonostial stent positioning. Conventional catheter angiography or spiral computed tomographic (CT) angiography performed in 19 patients (28 stents) at a mean interval of 12.5 months demonstrated primary patency in 75%. Maintained stent patency appeared to correlate with renal functional benefit. CONCLUSIONS: Percutaneous renal artery stent placement for angioplasty failures or restenoses provides clinical benefit in most patients with ischemic nephropathy.