Percutaneous Management of Dialysis Access Steal Syndrome: Interventions and Outcomes from a Single Institution's 20-Year Experience

PURPOSE

To determine safety and effectiveness of percutaneous interventions performed by interventional radiologists at a single institution over 2 decades in patients with dialysis access steal syndrome (DASS).

MATERIALS AND METHODS

A retrospective review of fistulograms from 2001 to 2021 (N = 11,658) was performed. In total, 286 fistulograms in 212 patients with surgically created dialysis accesses met inclusion criterion of fistulography for suspected DASS. Chart review collected data regarding patient demographics, comorbidities, access characteristics, fistulography findings, intervention(s) performed, and outcomes. Procedures with and without DASS intervention were compared. Odds ratios (ORs), adjusted for age, sex, comorbidities, access characteristics, and multiple within-patient events, were calculated using logistic regression to determine associations between steal intervention status and outcome variables: (a) major adverse events, (b) access preservation, and (c) follow-up surgery. A percutaneously treatable cause of DASS was present in 128 cases (45%). Treatment of DASS lesions was performed in 118 cases. Fifteen embolizations were also performed in patients without DASS lesions.

RESULTS

Technical success of DASS interventions, defined by the Society of Interventional Radiology (SIR) reporting standards, was 94%; 54% of interventions resulted in DASS symptom improvement at a median follow-up of 15 days. Patients with steal intervention had 60% lower odds of follow-up surgery (OR, 0.4; P = .007). There was no difference in major adverse events (P = .98) or access preservation (P = .13) between groups.

CONCLUSIONS

In this retrospective cohort study, approximately half of DASS fistulograms revealed a percutaneously treatable cause of steal. Over half of DASS interventions resulted in symptomatic relief. Percutaneous intervention was associated with lower odds of follow-up surgery without compromising access preservation.

Transcatheter and Surgical Aortic Valve Replacement in Dialysis Patients: A Propensity-Matched Comparison

BACKGROUND

Transcatheter aortic valve replacement (TAVR) clinical trials in North America excluded patients on dialysis and, consequently, the outcomes of TAVR in dialysis-dependent patients remain unknown.

METHODS

All Medicare fee-for-service patients undergoing TAVR (n = 5,005) or surgical aortic valve replacement (SAVR) (n = 32,634) between January 1, 2011, and November 30, 2012, were identified using procedural codes collected by the Centers for Medicare & Medicaid Services. Dialysis status and comorbidities were identified using diagnosis codes present on arrival for TAVR hospitalization. Patients supported on dialysis who underwent TAVR (n = 224) were compared with non-dialysis patients who underwent TAVR as well as a propensity-matched group of contemporaneous dialysis patients who underwent SAVR (n = 194 pairs).

RESULTS

The TAVR patients on dialysis were younger than non-dialysis TAVR patients (79.2 years vs 84.1 years; p < 0.01) but had higher prevalence of comorbidities. Dialysis TAVR patients had increased mortality at 30 days (13% vs 6%, p < 0.01) and significantly worse survival by Kaplan-Meier analysis. Multivariable regression found dialysis to be independently associated with worse survival (hazard ratio, 1.73; 95% confidence interval, 1.33% to 2.25%, p < 0.01) in TAVR patients. Propensity-matched dialysis SAVR and dialysis TAVR patients had no significant differences in demographic or risk factors. Matched dialysis TAVR patients had shorter length of stay (6 interquartile range, 4 to 10] vs 10 [IQR 7 to 18] days; p < 0.01) and comparable survival.

CONCLUSIONS

TAVR in dialysis patients is associated with decreased survival compared with non-dialysis patients; however, it is comparable with SAVR in high risk dialysis patients based on a propensity-matched comparison.

Outcomes of percutaneous interventions in transposed hemodialysis fistulas compared with nontransposed fistulas and grafts

PURPOSE

To compare postpercutaneous intervention outcomes of autogenous venous-transposition arteriovenous fistulas (AVFs) versus those of autogenous nontransposed AVFs (nAVFs) and prosthetic arteriovenous grafts (AVGs).

MATERIALS AND METHODS

A total of 591 hemodialysis accesses (195 transposed AVFs [tAVFs], 205 nAVFs, 191 AVGs) in 522 patients (278 male; mean age, 57 y; range, 15–91 y) underwent percutaneous transluminal angioplasty (PTA) and/or mechanical thrombectomy (ie, declotting). Access characteristics, surgical history, percutaneous interventions, postinterventional primary and secondary access patency, and follow-up data were collected. Cox proportional-hazards regression analyses, Fisher exact tests, and χ2 tests were performed.

RESULTS

Mean follow-up period was 32 months. Mean access ages at initial percutaneous intervention were 260 days (tAVF), 206 days (nAVF), and 176 days (AVG; P < .01). One-year postinterventional primary patency (PIPP) rates were 25% (tAVF), 24% (nAVF), and 14% (AVG). One-year postinterventional secondary patency (PISP) rates were 77% (tAVF), 61% (nAVF), and 63% (AVG). Median PIPP durations were 138 days (tAVF), 121 days (nAVF), and 79 days (AVG; P = .0001). Median PISP durations were 1,076 days (tAVF), 783 days (nAVF), and 750 days (AVG; P = .019). Total interventions needed to maintain PISP were 2.4 (tAVF), 1.3 (nAVF), and 3.2 (AVG) per patient-year (P < .001), which included 1.9, 1.2, and 1.4 PTAs (P < .01) and 0.45, 0.15, and 1.8 declotting procedures, respectively (P < .001).

CONCLUSIONS

Based on the number of percutaneous interventions needed to maintain PISP, these results confirm the current Dialysis Outcomes Quality Initiative access preference of nAVFs before tAVFs before AVGs. tAVFs offered superior postinterventional outcomes than AVGs. With additional interventions, tAVFs could even outperform nAVFs in terms of PISP.

Endocarditis Is a Common Stroke Mechanism in Hemodialysis Patients

Background and Purpose—

Hemodialysis patients are at high risk for ischemic stroke, and previous studies have noted a high rate of cardioembolism in this population. The aim of this study was to determine ischemic stroke causes among hemodialysis patients and elucidate specific cardioembolic stroke mechanisms.

Methods—

This study is a retrospective cross-sectional study of hemodialysis patients admitted with acute stroke to the University of Pennsylvania Health System between 2003 and 2010. Strokes were classified using modified Trial of Org 10 172 in Acute Stroke Treatment (TOAST) criteria as large vessel, cardioembolism, small vessel, atypical, multiple causes, or cryptogenic. Cardioembolic strokes were further characterized for specific mechanism.

Results—

We identified 52 patients hospitalized with acute stroke while receiving hemodialysis. Mean age was 64±13 years, 56% were female, and 67% were black. Stroke subtypes included 3 (6%) large vessel, 20 (38%) cardioembolism, 6 (11%) small vessel, 3 (6%) other, 4 (8%) with multiple causes, and 16 (31%) were unknown. Among patients who had an echocardiogram performed, 5 of 52 (10%; 95% confidence interval, 1%–18%) had a patent foramen ovale. Cardioembolic stroke mechanisms included 6 with infective endocarditis (accounting for 12% of all strokes).

Conclusions—

Cardioembolism and cryptogenic stroke are the predominant stroke mechanisms among hemodialysis patients. Infective endocarditis was identified frequently relative to other stroke cohorts, and a raised index of suspicion is warranted in the hemodialysis population.

Extracorporeal treatment of cast nephropathy

Acute kidney injury (AKI) is common in patients with multiple myeloma (MM), most commonly caused by cast nephropathy resulting from precipitation of free light chains (FLC) in renal tubules. AKI may be irreversible and require dialysis and predicts a poor prognosis. Reduction in serum FLC concentration is thought to be associated with improved likelihood of kidney function recovery in MM patients with AKI. Plasma exchange (PE), by removing circulating FLC, has been used as a treatment modality to improve kidney function in MM, although its efficacy remains uncertain. Extracorporeal treatment with extended high cutoff hemodialysis (HCO-HD) has also recently been studied as a potentially more effective means of FLC removal. Both PE and HCO-HD may be beneficial in some patients, but only when used as adjuncts to successful chemotherapy. Further research is necessary to establish the specific efficacy of each of these extracorporeal methods in the treatment of cast nephropathy.

Salvage of nonmaturing native fistulas by using angioplasty

PURPOSE

To retrospectively review outcomes following angioplasty of nonmaturing autogenous hemodialysis fistulas.

MATERIALS AND METHODS

Institutional review board exemption was received for this HIPAA-compliant retrospective study; informed consent was waived. During 48 months, 101 patients underwent fistulography for percutaneous salvage of nonmaturing native fistulas. Clinical and technical success, need for secondary interventions, and complications were recorded according to consensus definitions. Patency following angioplasty was estimated with the Kaplan-Meier technique. Patient age, sex, ethnicity, fistula age, fistula type, number of stenoses, maximal angioplastic balloon diameter used, and presence of palpable thrill following angioplasty were examined as predictors of primary patency of the fistula following intervention by using Cox proportional hazards model.

RESULTS

Mean patient age was 58 years; 35% were women. Median time from fistula creation to fistulography was 2.5 months. Hemodynamically significant (>50%) stenoses were identified in 88% (89 of 101) of patients; angioplasty was attempted in 96% (85 of 89). Technical success was achieved in 92% (78 of 85) of fistulas following angioplasty; clinical success of normal hemodialysis with total access blood flow of more than 500 mL/min occurred following 88% (75 of 85) of angioplastic interventions. No major and two minor complications occurred. Mean primary unassisted patency at 3, 6, and 12 months was 60%+/-6% (95% confidence interval), 45%+/-6%, and 34%+/-6%, respectively. Additional angioplasty (n=12), stent placement (n=1), or thrombectomy (n=1) during subsequent interventions resulted in mean secondary patency at 3, 6, and 12 months of 82%+/-4%, 79%+/-5%, and 75%+/-6%, respectively. Patients without thrill following angioplasty were more than twice as likely to lose patency as patients with thrill (P=.035). No relationship was seen between primary patency and other predictors examined.

CONCLUSION

Early fistulography enables identification of underlying areas of stenosis in nonmaturing fistulas, which can be safely and effectively treated with angioplasty. With continued surveillance and repeat interventions, functional patency can be sustained in the majority of fistulas.

Single-center experience with the Arrow-Trerotola Percutaneous Thrombectomy Device in the management of thrombosed native dialysis fistulas

PURPOSE

The present study sought to evaluate the performance of the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) in the treatment of native fistula thrombosis in a U. S. hemodialysis population. Specifically, the technical success, clinical success, complication rate and type, primary and secondary patency rates, effect of adjunctive thrombolytic therapy, and any variables that affected outcomes of procedures in which this device was used were analyzed.

MATERIALS AND METHODS

Forty-two patients with 44 thrombosed native fistulas (17 radiocephalic, 10 brachiocephalic, 10 transposed or superficialized, five graft/fistula hybrids, and two leg fistulas) were treated with 62 mechanical thrombolysis procedures with use of the PTD. All patients had large clot burden. The device type was recorded in 43 procedures: standard (n = 21), over-the-wire (OTW; n = 19), or both (n = 3). No device was used in two cases because of inability to cross the anastomosis. Adjunctive therapies (n = 18) included the use of tissue plasminogen activator (tPA; n = 16) and deployment of the AngioJet device with (n = 1) or without tPA (n = 1). Stents were inserted in four procedures. Outcome variables included technical and clinical success, complications, and primary and secondary patency. Cox proportional-hazards regression and Kaplan-Meier analyses were performed.

RESULTS

The technical success rate was 87% (54 of 62) and the clinical success rate was 79% (49 of 62). Percutaneous transluminal angioplasty was performed in all but two procedures. Complications occurred in 13% of procedures (n = 8); three resulted in technical failure. The primary patency rates were 38% at 6 months and 18% at 12 months; secondary patency rates were 74% and 69%, respectively. Outcomes were not affected by adjunctive techniques, fistula type, age of fistula, device type (ie, OTW vs standard), or patient sex. Secondary patency was superior when no residual clot or stenosis was present (P = .003).

CONCLUSIONS

The PTD is effective for percutaneous treatment of thrombosed hemodialysis fistulas, with good short- and long-term outcomes in a U.S. population. Within the limitations of a retrospective study with a small sample size, use of an adjunctive thrombolytic agent did not appear to improve results compared with the use of the device alone.

Asaia bogorensis peritonitis identified by 16S ribosomal RNA sequence analysis in a patient receiving peritoneal dialysis

Here the authors report a case of refractory peritonitis leading to multiple hospitalizations and the loss of peritoneal dialysis access in a patient on automated peritoneal dialysis, caused by Asaia bogorensis, a bacterium not previously described as a human pathogen. This organism was identified by sequence analysis of the 16S ribosomal RNA gene. Unusual microbial agents may cause peritonitis, and molecular microbiological techniques are important tools for identifying these agents.

Hemodialysis-related venous stenosis: treatment with ultrahigh-pressure angioplasty balloons

The authors retrospectively reviewed the use of ultrahigh-pressure angioplasty balloons at atmospheric pressures at or above the manufacturer recommended burst pressure (30 atm) for the treatment of resistant hemodialysis-related venous stenosis at their institution. In seven of 87 procedures, high-pressure angioplasty (up to 27 atm) was unsuccessful. By coupling new balloon technology with aggressive inflation pressures, 100% technical success was achieved in the treatment of stenoses that were resistant to high-pressure angioplasty in these seven procedures. This approach could potentially offer cost savings compared with the costs of other previously described treatment methods for resistant lesions, such as atherectomy devices and cutting balloons.

Willingness of dialysis patients to participate in a randomized controlled trial of daily dialysis

BACKGROUND

The National Institutes of Health (NIH) has proposed conducting randomized controlled trials comparing short, daily, in-center hemodialysis with conventional hemodialysis. However, there is concern that difficulties recruiting patients may prevent the successful completion of such trials if patients believe the inconveniences of daily dialysis outweigh any potential health benefits.

METHODS

To gauge willingness to participate in a daily dialysis trial, we described a hypothetical, randomized controlled trial comparing conventional to daily hemodialysis to 209 chronic hemodialysis patients, and assessed their motivations for and concerns about participating.

RESULTS

We found that 85 patients (41%) of 209 patients who agreed to be interviewed expressed some willingness to participate in the hypothetical trial. Patients who expressed greater willingness to participate were younger (OR for participating = 0.96 per year, 95% CI = 0.94 to 0.98, P= 0.001), less likely to smoke (OR = 0.38, 95% CI = 0.17 to 0.84, P= 0.017), more likely to have been hospitalized during the last 12 months (OR = 2.8, 95% CI = 1.5 to 5.5, P= 0.002), less likely to have reactive airway disease (OR = 0.21, 95% CI = 0.06 to 0.69, P= 0.01) or coronary artery disease (OR = 0.20, 95% CI = 0.08 to 0.53, P= 0.001), and less likely to be on the waiting list for a kidney transplant (OR = 0.23, 95% CI = 0.10 to 0.50, P < 0.0001).

CONCLUSION

The study suggests that less than half of eligible patients would be willing to participate in the randomized controlled trial. Differing willingness to participate across patient subgroups suggests that certain subgroups (i.e., older patients and those with coronary artery disease) will need to be targeted to ensure that results are generalizable to most hemodialysis patients.

Preliminary observations of sildenafil treatment for erectile dysfunction in dialysis patients

Erectile dysfunction is common in dialysis patients. We report our experience with sildenafil citrate in patients undergoing dialysis therapy. Male subjects attending the Outpatient Dialysis Unit at the University of Pennsylvania (Philadelphia, PA) who were prescribed sildenafil by their primary physician or nephrologist were asked to complete the International Index of Erectile Function before their first dose of sildenafil and after at least 4 weeks of therapy. Subjects' mean age was 50.3 +/- 14.63 (SD) years. Ninety-three percent of the subjects were black. Based on a global efficacy question, 66.7% of the subjects believed that treatment had improved their erections. Subjects reported no increase in the sexual desire domain despite experiencing a significant increase in erectile function, orgasmic function, and satisfaction with intercourse. Sildenafil was well tolerated in a selected group of patients who reported improved sexual function with no major adverse effects.

Dramatic recovery of renal function after 6 months of dialysis dependence following surgical correction of total renal artery occlusion in a solitary functioning kidney

Revascularization of renal artery stenosis for the treatment of hypertension is an established procedure. In selected clinical scenarios, successful revascularization procedures may preserve or restore renal function. We present a 31-year-old man who underwent successful renal revascularization of a solitary functioning kidney after being dialysis dependent for approximately 190 days. He had dramatic improvement of renal function and has remained off dialysis since his surgery 18 months ago. He continues to have severe but controllable hypertension.

Predictive performance study of two digoxin assays in subjects with various degrees of renal function

This prospective study was conducted to compare the predictive performance of fluorescence polarization immunoassay (FPIA, Abbott TDx Digoxin II) and radioimmunoassay (RIA, Kallestad Labs) with combined low-pressure liquid chromatography/RIA (LPLC/RIA) digoxin assay in measuring 15-17 serum digoxin concentrations (SDC) obtained after a single 10 microg/kg intravenous digoxin dose in patients with various degrees of renal function and at different SDC ranges. Eighteen men and women were stratified into 3 age- and gender-matched groups based upon renal function [N = 6 in each, group I (Cl(cr) < 10 mL/min), group II (Cl(cr) = 10-50 mL/min), and group III (Cl(cr) > 50 mL/min)]. Serum digoxin concentrations were measured at time zero; at 0.25, 0.5, 0.75, 1, 2, 3, 4, 6, 8, and 12 hours; and at 2, 3, 4, and 5-7 days after the digoxin dose, using the three different digoxin assays. TDx Digoxin II was unbiased [mean error -0.09 (95% CI -0.19, 0.01)] and RIA biased [mean error -0.29 (95% CI -0.36, -0.21)] to over-predict SDC by 14.2%. In group I patients, the analysis revealed a bias to over-predict SDC by 6.0% for TDx Digoxin II [mean error -0.16 (95% CI -0.29, -0.07)] and an unbiased performance by RIA. In groups II and III, both TDx Digoxin II and RIA showed biased performance, the mean magnitude of bias was low (< 20%). For intermediate SDC range (> 0.5 ng/mL and < or = 3.0 ng/mL), TDx Digoxin II was unbiased in predicting SDC, whereas RIA was biased to under-predict SDC [mean error 0.13 (95% CI 0.10, 0.16)] by 9.9%. The magnitude of bias observed in all cases was less than 20%. Both assays, TDx Digoxin II and RIA, imprecisely measured SDC for all samples combined, different groups and SDC ranges. In all time-paired samples, TDx Digoxin II (FPIA) performed better than the RIA. In conclusion, the magnitude of bias observed with either assay at different groups and SDC ranges was not likely to be clinically relevant. Therefore, either assay may be used to measure SDC in clinical practice.

Outbreak of sterile peritonitis among continuous cycling peritoneal dialysis patients

BACKGROUND

Approximately 30,000 patients receive peritoneal dialysis in the United States. In August 1996, several dialysis centers from different states reported sterile peritonitis among CCPD patients using sterile peritoneal dialysis solution (PDS) from a single manufacturer. The manufacturer recalled 53 lots of PDS that had passed established industry guidelines and Food and Drug Administration (FDA) approved quality control tests [including endotoxin levels <0.5 endotoxin units (EU)/ml], but had pre-sterilization bacterial colony counts >1 cfu/ml.

METHODS

At one outpatient dialysis center, Hospital of the University of Pennsylvania (HUP), we conducted a retrospective cohort study of all CCPD patients treated during July 15 to August 30, 1996. A case-patient was defined as any HUP patient with culture-negative peritoneal fluid with a white blood cell count >100/mm3, cloudy peritoneal fluid, and/or abdominal pain. PDS and tubing were cultured for bacteria and assayed for endotoxin.

RESULTS

Overall, 14 of 28 patients had sterile peritonitis. The only risk factor identified was exposure to > or =1 lot of recalled PDS (14 of 22 vs. 0/6, P = 0.02); the more recalled lots received, the higher the attack rate (P = 0.0001). Five of 47 PDS bags had detectable endotoxin; recalled lots were more likely to have measurable endotoxin than nonrecalled lots (5/19 vs. 0/17, P = 0.05). When case-patients resumed CCPD using PDS from non-recalled lots, no further cases were reported.

CONCLUSIONS

Our results suggest that this outbreak was caused by intrinsic PDS contamination with endotoxin. Pre-sterilization colony counts may be an important quality control indicator for CCPD fluids in conjunction with endotoxin levels.

Engagement of African American families in research on chronic illness: a multisystem recruitment approach

Our multisystem approach addressed the recruitment of African American families with a chronically, physically ill member. The approach focused on the social transactions between the family, the healthcare team, and the research staff, and the influence of these transactions on family recruitment. This multisystem approach included three core strategies: defining the membership of families in a culturally appropriate fashion and engaging those members; engaging the healthcare team; and building and maintaining the skills and morale of the research staff. A description of a longitudinal family health study and potential sources of recruitment biases is provided. Descriptive and bivariate analyses examined the effectiveness of the recruitment approach. A focus groups explored the reciprocal process of family protectiveness that both facilitated and hindered family recruitment and the research staff's alliance with families and the dialysis staff. Discussion focuses on the family health study's recruitment rate, sampling biases, and methods for improving the effectiveness of the multisystem recruitment approach.

Is the volume of distribution of digoxin reduced in patients with renal dysfunction? Determining digoxin pharmacokinetics by fluorescence polarization immunoassay

STUDY OBJECTIVE

To determine digoxin pharmacokinetics in subjects with different degrees of renal function using fluorescence polarization immunoassay (FPIA), which is associated with less interference from digoxin-like immunoreactive substances (DLIS) than radioimmunoassay.

SETTING

University hospital clinical research center.

PARTICIPANTS

Eighteen subjects (mean age 44 yrs) with different degrees of renal function: group 1, creatinine clearance (Clcr) below 10 ml/minute; group 2, Clcr 10-50 ml/minute; and group 3, Clcr greater than 50 ml/minute (6 patients in each group).

INTERVENTION

Over 5-7 days, 15 serum samples were collected after a single intravenous dose of digoxin 7 or 10 micrograms/kg actual body weight (WT) for serum concentration measurements by FPIA. Two-compartment pharmacokinetic parameters (zero-time intercept of the concentration-time curve of the initial distribution phase [A], zero-time intercept of the concentration-time curve of the terminal elimination phase [B], initial distribution phase constant [alpha], terminal elimination rate constant [beta], volume of distribution in the central compartment [Vc] and at steady state [Vss], total body clearance [Cl], mean residence time [MRT], area under the concentration-time curve [AUC]) were determined using a nonlinear least squares regression program.

MEASUREMENTS AND MAIN RESULTS

No significant differences were found among groups for A, B, alpha, beta, beta-half-life Vc/WT, MRT, AUC, and Cl/WT. Significant differences were observed in Vss/WT (4.8 +/- 1.0, 6.6 +/- 0.5, 6.4 +/- 0.7 L/kg) between group 1 versus group 2 and group 1 versus group 3 (p < 0.01). Measured Clcr was correlated with Cl (r2 = 0.40, p < 0.01), Cl/WT (r2 = 0.29, p < 0.05), Vss (r2 = 0.35, p = 0.01), and Vss/WT (r2 = 0.24, p < 0.05).

CONCLUSION

This study confirmed that Vss is smaller in patients with chronic renal failure (Clcr < 10 ml/min) than those without chronic renal failure. Therefore, previous recommendations that lower digoxin loading doses should be administered in patients with renal failure are applicable to digoxin serum concentration monitoring using FPIA.

Staff security and work pressure: contrasting patterns of stability and change across five dialysis units

Differences among clinical care units in social dynamics and social organization are associated with differences in the clinical course of patients with a range of chronic illness. These differences are also associated with well-being of staff members. Recent attention has focused on understanding these differences among units with an eye towards correcting deficiencies and enhancing strengths of clinical care units. The current study sought to delineate the effect of social and organizational dynamics unique to each unit on staff perceptions of the security of their relationships with other staff and their perceived work pressure. The unit as a major source of differences among staff subjects was compared with the impact of ethnic identity, of work in the morning shift vs other shifts, and of professional role. Results confirmed that unit membership was, by far, the most important correlate of staff perceptions of the unit, particularly those concerning security of relationships with others and perceived work pressure. Moreover, the results suggested that unit differences in perceived security were due to differences among units in long standing turmoil within the unit or long standing problematic ties between the unit and the larger institution which controls it. However, perceived work pressure seems more transient and may reflect the challenge of shorter-term fluctuations in the demands of patient care.

Hemodialysis vascular access morbidity

Complications associated with hemodialysis vascular access represent one of the most important sources of morbidity among ESRD patients in the United States today. In this study, new data on the magnitude and growth of vascular access-related hospitalization in the United States is presented, demonstrating that the costs of this morbidity will soon exceed $1 billion per yr. This study also reviews published literature on the morbidity associated specifically with native arteriovenous fistulae, polytetrafluoroethylene bridge grafts, and permanent central venous catheters. Next, new information on the changing patterns of vascular access type in the United States is presented, demonstrating the continuing evolution of medical practice away from the use of arteriovenous fistulae in favor of more reliance on synthetic bridge grafts. Based on these data, a discussion is provided of the tradeoffs among the most commonly available modalities of vascular access today. Although radial arteriovenous fistulae continue to represent the optimal access modality, the appropriate roles for brachial arteriovenous fistulae, synthetic bridge grafts, and central venous catheters are less certain because of inadequate data on the long-term function of the first and the high rates of complications associated with the latter two. To reduce vascular access-related morbidity, strategies must be developed not only to prevent and detect appropriately early synthetic vascular access dysfunction, but to better identify the patients in a whom radial arteriovenous fistula is a viable clinical option.

The effect of renal function on serum levels of CA 125

OBJECTIVE

Serum assays for CA 125 are used to monitor disease status in patients undergoing treatment for epithelial ovarian cancer. While a number of benign gynecologic as well as benign and malignant nongynecologic conditions are associated with CA 125 elevations, the established "normal" range describes a healthy population of women. The metabolism and clearance of CA 125 is not well understood. Because mild degrees of renal impairment frequently occur in ovarian cancer patients, we investigated the effect of impaired renal function on basal CA 125 in a population of female dialysis patients.

METHODS

Twenty-five women on hemodialysis were selected at random. Patients ranged in age from 29 to 87 years. Renal disease was secondary in most cases to diabetes mellitus or hypertension. The creatinine clearance was less than 10 cc/min for all patients. The duration of dialysis ranged from 3 months to 14 years. Serum levels of CA 125 were measured using monoclonal antibodies in an immunoradiometric assay.

RESULTS

The mean of duplicate determinations for 23 of 25 (92%) patients fell within the normal range for otherwise healthy women (< 35 U/ml). There was no apparent correlation between CA 125 level and age, menopausal status, BUN, serum creatinine, adequacy of dialysis, or primary underlying diagnosis. Of the 2 patients (8%) with CA 125 levels above the normal range, 1 was premenopausal and the other was postmenopausal; their CA 125 elevations were marginal (49.81 and 50.51).

CONCLUSIONS

The results of this study demonstrate that even marked renal insufficiency is not itself associated with significant elevations of CA 125 above the normal range selected for otherwise healthy women. The development of renal insufficiency during treatment for ovarian cancer should not alter the interpretation of serum levels of CA 125.

The effects of computer-tailored smoking cessation messages in family practice settings

BACKGROUND

Many conventional health education materials, such as pamphlets and booklets, are designed to reach as wide an audience as possible; they are therefore often lengthy and contain information irrelevant to many consumers. Computer technologies allow sophisticated tailoring of messages targeted to individual patients and free of irrelevant information.

METHODS

In two studies in North Carolina (study 1, N = 51; study 2, N = 197), adult cigarette smokers were identified from a cohort of family practice patients. Cigarette consumption, interest in quitting smoking, perceived benefits and barriers to quitting, and other characteristics relevant to smoking cessation were collected. Based on this information, smoking cessation letters were tailored by computer to individuals. Smokers were randomly assigned to experimental (tailored health letters) or comparison groups (generic health letter in study 1, no health letter in study 2). Smoking status was assessed again at 4 months (study 1) or 6 months (study 2).

RESULTS

Both studies found statistically significant positive effects of tailored health letters among moderate to light smokers. In study 1, 30.7% reported quitting after 6 months vs 7.1% in the control group (P < .05); in study 2, 19.1% vs 7.3% (P < .05).

CONCLUSIONS

Results from both studies indicate positive effects of computer-tailored smoking messages among moderate to light smokers. These findings are consistent with the focus of our computer-tailored program on psychological and behavioral factors related to smoking cessation. Smoking cessation outcomes may be enhanced by combining tailored messages with nicotine replacement therapies to treat physical dependency. Methods of tailoring health messages and incorporating the results into family practice are described.

A controlled clinical trial of angiotensin-converting enzyme inhibition in type I diabetic nephropathy: study design and patient characteristics. The Collaborative Study Group

A placebo-controlled, double-blind clinical trial has been initiated to determine whether angiotensin-converting enzyme inhibitor (ACEI) therapy with captopril (25 mg three times daily) slows the progressive loss of renal function in patients with type 1 diabetes mellitus. Entry criteria include; (1) ages 18 to 50 yr; (2) onset of insulin-dependent diabetes before the age of 30 yr, insulin dependent for at least 7 yr; (3) 24-h urine protein excretion > 500 mg, plus: (a) diabetic retinopathy or (b) if no retinopathy, a renal biopsy diagnosis of diabetic nephropathy; (4) serum creatinine (SCr) < 2.5 mg/dL; (5) informed consent. Patients follow strict medical management protocols. Systemic blood pressure is controlled to predefined goals (< 140-90 mm Hg). The primary outcome of the Study is a doubling of the patients' entry SCr to at least 2 mg/dL confirmed by a > 50% decrease in GFR by radioactive iothalamate clearance technique. Baseline characteristics of the cohort at entry into the Study are (mean +/- SD): male/female, 52%/48%; age, 35 +/- 8 yr; duration of diabetes, 21 +/- 7 yr; duration of proteinuria, 2.8 +/- 3.3 yr; duration of retinopathy, 4.5 +/- 4.1 yr; 50% of cohort presented with hypertension, duration, 4 +/- 4.7 yr; blood pressure, 139/86 +/- 19/12; SCr, 1.35 +/- 0.44 mg/dL; GFR 78 +/- 32 mL/min; BUN, 24 +/- 11 mg/dL; proteinuria, 3.1 +/- 3.3 g/day; cholesterol, 236 +/- 50 mg/dL; total glycosylated hemoglobin, 11.1 +/- 2.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic lupus erythematosus and the syndrome of inappropriate secretion of antidiuretic hormone

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) has been reported rarely in systemic lupus erythematosus (SLE) with central nervous system disease. Previous case reports linking SIADH with lupus have either not documented clearly that SLE was the sole cause of the problem, or have not demonstrated a correlation between indicators of lupus activity and the onset and resolution of antidiuretic hormone secretion. We describe a case in which SLE was the sole contributor to the initiation of SIADH and where other evidence of lupus activity correlated temporally with inappropriate antidiuretic hormone secretion.

Chemistry and hypoglycemic activity of N-[[(Dialkylamino)alkoxy]phenyl]benzamidines

A series of N-[[(dialkylamino)alkoxyl]phenyl]benzamidines was synthesized and evaluated for hypoglycemic activity in the glucose-primed rat. Structure-activity relationship indicated that N'-phenyl-N-[4-[2(diisopropylamino)-ethoxy]phenyl]benzamidine dihydrobromide (7), N'-(4-chlorophenyl)-N-[4-[2-(diisopropylamino)ethoxy]phenyl]-benzamidine dihydrochloride (31), and N'-phenyl-N-[4-[(diisopropylamino)propoxy]phenyl]benzamidine dihydrobromide (11) are some of the more interesting compounds. A comparison of these hypoglycemic agents with classical standards (tolazamide, phenformin, and buformin) in several experimental models showed that the benzamidines seem to combine in one molecule some of the biological activities of the beta-cytotrophic sulfonylureas and some of the activities of the biguanides.

Chemistry and hypoglycemic activity of benzimidoylpyrazoles

A series of benzimidoylpyrazoles was synthesized and evaluated as hypoglycemic agents. Methyl 1-(N-cyclohexylbenzimidoyl)-5-methyl-3-pyrazolecarboxylate (13) and methyl 1-[N-(4-methoxyphenyl)benzimidoyl]-5-methyl-3-pyrazolecarboxylate (33) are two of the more interesting compounds. A comparison of these benzimidoylpyrazoles with classical standards (tolazamide, phenformin, and buformin) in several experimental models show that these compounds seem to combine in one molecule some of the biological activities of the beta-cytotrophic sulfonylureas and some of the activities of the biguanides. A synthetic scheme for the preparation of the benzimidolypyrazoles and a preliminary structure-activity relationship are presented.

Renal transplantation at the University of Pennsylvania Medical Center: an update of results in the cyclosporine era

This chapter presents a summary of living-related, living-unrelated, and cadaver renal transplantation performed at the University of Pennsylvania Medical Center between January 1984 and October 1992. Over the past 9 years, 895 patients (557 males, 338 females, mean age 42 yrs) received 942 renal transplants; 599 patients received kidneys from cadaver donors (n = 627) and 296 patients received kidneys (n = 315) from living donors of all types. During this period, 151 patients were retransplanted, sometimes more than once (159 total retransplants, 124 secondary grafts, and 35 third or more transplants). An analysis of patient ant graft survival rates (calculated by actuarial methods) for different categories of transplant recipients was performed. Black recipients, as a racial subcategory, had the poorest graft outcome, especially when followed over the long term. Graft survival rates for Black recipients who were retransplanted with cadaver grafts were even worse and were noted to be similar to the diabetic population that received cadaver retransplants (66% vs 62% at 1 yr and 32% vs 25% at 5 yrs). Diabetic recipients of living-donor transplants had excellent graft survival results, similar to nondiabetic, living-donor recipients (patient survival rates 98% and 92% vs 97% and 92% at 1 and 5 yrs; graft survival rates 92% and 82% vs 92% and 82% at 1 and 5 yrs). HLA-identical recipients of first cadaver grafts demonstrated the best outcome in the entire cadaver series (graft survival rates 91% and 83% at 1 and 5 yrs, respectively). HLA-identical recipients of second or more cadaver grafts had poorer results than expected (50% graft survival at 1 yr) despite a 100% patient survival rate. HLA-identical recipients of living-related grafts had the best graft survival rates (96% at 1 yr and 94% at 5 yrs) and superior graft survival rates for retransplanted grafts as well (100% at 1 and 5 yrs). We conclude that in the last decade, patient and graft survival rates for cadaveric and living-donor renal transplants have improved dramatically relative to the results obtained in the pre-CsA era. Long-term graft survival in Black recipients remains lower than in other races, suggesting the need to analyze other factors to explain poorer graft survival in this recipient population. Results in diabetic recipients continue to be excellent at our center, encouraging the continuation of our aggressive approach to try to transplant diabetics as early as possible, particularly when a living donor is available.