Prolonged Catheter Dependency Research Articles

Arteriovenous Grafts: Much Maligned But in Need of Reconsideration?

There are substantial variations in arteriovenous fistula (AVF) use among hemodialysis patients in different countries, in different regions of the U.S., and even in different hemodialysis units within a single metropolitan area. These variations persist after adjustment for patient demographics and comorbidities, suggesting that practice patterns play a major role in determining the frequency of AVF use. These observations led to vascular access guidelines urging nephrologists and surgeons to increase AVF creation in patients with chronic kidney disease. Over the past 20 years, as clinicians have adopted these guidelines, the prevalence of AVF use in hemodialysis patients has increased substantially. At the same time, clinicians have recognized important limitations of an unwavering "Fistula First" approach. First, a substantial proportion of AVFs fail to mature even when routine preoperative vascular mapping is used, leading to prolonged catheter dependence. Second, certain patient subgroups are at high risk for AVF nonmaturation. Third, nonmaturing AVFs frequently require interventions to promote their maturation. Fourth, AVFs that require such interventions have shortened cumulative patency. Fifth, arteriovenous grafts (AVG) have several advantages over AVFs, including lower primary failure rates, fewer interventions prior to successful cannulation, and shorter duration of catheter dependence with its associated risk of bacteremia. All these observations have led nephrologists to propose an individualized approach to vascular access, with AVG being preferred in patients who initiate hemodialysis with a catheter, particularly if they are at high risk for AVF nonmaturation and have a relatively short life expectancy.

The Venous Window Needle Guide, a hemodialysis cannulation device for salvage of uncannulatable arteriovenous fistulas

Arteriovenous fistulas (AVFs) are recommended for hemodialysis access when possible. A noncannulatable but otherwise well functioning AVF leads to prolonged catheter dependency and frustration for the patient and the renal health care provider team. Difficult cannulation patients include obese individuals in whom cannulation sites are too deep, and others with vein segments that are short, tortuous, or otherwise difficult to palpate. The Venous Window Needle Guide for Salvage of AV Fistulae (SAVE) trial was designed to evaluate the efficacy and safety of the Venous Window Needle Guide (VWING; Vital Access Corp, Salt Lake City, Utah) device for salvage of such noncannulatable AVFs that are otherwise functional. The SAVE study included patients with an established and otherwise mature AVF, in whom an additional procedure would otherwise be necessary to establish reliable cannulation. The VWING is a single-piece titanium device that allows repeated access of an AVF through a single puncture site (buttonhole technique). Inclusion criteria included mature AVFs 6.0 to 15.0mm in depth with multiple failed attempts at cannulation or where the access could not be palpated. The devices were implanted subcutaneously and sutured to the anterior wall of the mature fistula. Study end points were reliable and successful cannulation and avoidance of adverse events during the 6-month follow-up, implant technical success, and clinical cannulation success. Enrollment included 54 patients at 11 trial sites with implantation of 82 VWING devices. Body mass index was 26 to 50 (median, 36), 40 (74%) patients were female, and age was 17 to 84 (median, 59) years. Forty (74%) individuals were diabetic. Thirty-three (61%) patients were white, 16 (30%) black, and 10 (18%) patients were Hispanic, Pacific Islander, or Native American. Three patients were excluded from data analysis for reasons unrelated to the device. Successful AVF access was achieved using the VWING in 49 (96%) of the 51 patients evaluated. The rate of device-related serious adverse events was 0.31 per patient-year; each event was resolved leaving the AVF functional. The rates of sepsis and study-related interventions were 0.04 and 0.65 per patient-year, respectively. There were no study-related deaths. One device was removed because of infection. The AVF survival rate at 6months was 100%. The total number of study days was 9497 and the estimated number of device cannulations was4238. The VWING was safe and effective in facilitating AVF cannulation for patients with an otherwise mature but noncannulatable fistula. Successful AVF access was achieved using the VWING in 49 (96%) of the 51 patients evaluated. The AVF survival rate at 6months was 100%.

Fistula Eligibility: A Work in Progress

Effective hemodialysis requires a reliable vascular access. Clinical practice guidelines strongly recommend the fistula as the preferred option followed by arteriovenous (AV) grafts, with central venous catheters being least preferred. Recently, there has been a growing awareness of the limitations of the fistula, its high rate of primary failure and that a fistula may not be appropriate for all patients initiating or on hemodialysis. However, determinates for fistula eligibility have not been clearly defined. The creation and use of a fistula requires the complex integration of patient, biological, and surgical factors, none of which can be easily predicted or planned. There have been several successful initiatives over the last decade addressing patient suitability for AV access, but none have validated defined criteria for fistula eligibility. We discuss these initiatives by addressing: 1) process of care, 2) radiological and nonradiological tests and procedures, and 3) alternative surgical approaches. Careful clinical judgment, appropriate vascular access assessment and placement, and an individualized approach to the risks and benefits will optimize patient health outcomes while minimizing prolonged catheter dependence among hemodialysis patients.

When Should a Patient Receive an Arteriovenous Graft Rather Than a Fistula?

There has been a dramatic increase in the placement and use of arteriovenous fistulas (AVF) in US patients with chronic kidney disease over the past few years, in accordance with strong recommendations by Fistula First Initiative and KDOQI guidelines. However, AVF nonmaturation remains a substantial obstacle to achieving functional AVFs in a subset of patients, despite the widespread use of preoperative vascular mapping to assist surgeons in planning access surgery, and the growing use of interventions to salvage nonmaturing AVFs. In the right patient, aggressive efforts result in a functioning AVF, which provides adequate dialysis with relatively few interventions required to maintain its long-term patency for dialysis. In the wrong patient, aggressive efforts to achieve a mature AVF may result in numerous failed surgical and percutaneous procedures and prolonged catheter dependence, with all its associated complications. Thus, strict recommendations to place an AVF in all dialysis patients might not benefit every patient, and may actually harm some patients. There are no randomized clinical trials to address which patients are more suitable for placement of an arteriovenous graft (AVG), rather than an AVF. However, there is a wealth of observational studies, which taken cumulatively, may assist clinicians in identifying those patients who should receive an AVG. In this article, we review the relevant published literature regarding this topic and provide suggestions for stratifying patients who should receive each type of vascular access.

Arteriovenous Graft Placement in Predialysis Patients: A Potential Catheter-Sparing Strategy

When predialysis patients are deemed unsuitable candidates for an arteriovenous fistula, current guidelines recommend waiting until just before or after initiation of dialysis therapy before placing a graft. This strategy may increase catheter use when these patients start dialysis therapy. We compared the outcomes of patients whose grafts were placed before and after dialysis therapy initiation. Retrospective analysis of a prospective computerized vascular access database. Patients with chronic kidney disease receiving their first arteriovenous graft (n = 248) at a large medical center. Timing of graft placement (before or after initiation of dialysis therapy). Primary graft failure, cumulative graft survival, catheter dependence, and catheter-related bacteremia. The first graft was placed predialysis in 62 patients and postdialysis in 186 patients. Primary graft failure was similar for pre- and postdialysis grafts (20% vs 24%; P = 0.5). Median cumulative graft survival was similar for pre- and postdialysis grafts (365 vs 414 days; HR, 1.22; 95% CI, 0.81-1.98; P = 0.3). Median duration of catheter dependence after graft placement in the postdialysis group was 48 days and was associated with 0.63 (95% CI, 0.48-0.79) episodes of catheter-related bacteremia per patient. Retrospective analysis, single medical center. Grafts placed predialysis have primary failure rates and cumulative survival similar to those placed after starting dialysis therapy. However, postdialysis graft placement is associated with prolonged catheter dependence and frequent bacteremia. Predialysis graft placement may decrease catheter dependence and bacteremia in selected patients.

Dialysis Fistula or Graft

The Fistula First Initiative has strongly encouraged nephrologists, vascular access surgeons, and dialysis units in the United States to make valiant efforts to increase fistula use in the hemodialysis population. Unfortunately, the rigid "fistula first" recommendations are not based on solid, current, evidence-based data and may be harmful to some hemodialysis patients by subjecting them to prolonged catheter dependence with its attendant risks of bacteremia and central vein stenosis. Once they are successfully cannulated for dialysis, fistulas last longer than grafts and require fewer interventions to maintain long-term patency for dialysis. However, fistulas have a much higher primary failure rate than grafts, require more interventions to achieve maturation, and entail longer catheter dependence, thereby leading to more catheter-related complications. Given the tradeoffs between fistulas and grafts, there is equipoise about their relative merits in patients with moderate to high risk of fistula nonmaturation. The time is right for definitive, large, multicenter randomized clinical trials to compare fistulas and grafts in various subsets of chronic kidney disease patients. Until the results of such clinical trials are known, the optimal vascular access for a given patients should be determined by the nephrologist and access surgeon by taking into account (1) whether dialysis has been initiated, (2) the patient's life expectancy, (3) whether the patient has had a previous failed vascular access, and (4) the likelihood of fistula nonmaturation. Careful clinical judgment should optimize vascular access outcomes and minimize prolonged catheter dependence among hemodialysis patients.

Con

Con

A Challenge for Nephrologists—Increasing Fistula Maturation Rates, Reducing Fistula Maturation Time, and Decreasing Dialysis Catheter Prevalence in the United States

Tunneled dialysis catheters are simultaneously a benefit and burden for hemodialysis patients. The infectious and vascular complications of catheters are well documented. Despite this, prevalence of catheter use in the US hemodialysis population remains high and could be due in part to increased efforts to create arteriovenous (AV) fistulas in most new end-stage renal disease patients. The editorial argues that creating fistulas instead of prosthetic grafts is the correct approach and that inadequately diagnosed and treated primary fistula failure is a major cause of excessive and prolonged catheter dependency. An understanding of AV fistula physiology and the treatable causes of primary fistula failure are key to maximizing the percentage of created fistulas that are successfully used for dialysis. Diagnosis of fistula malfunction based on history, physical examination, and hemodynamic and angiographic evaluation is discussed, and treatment strategies presented. A major emphasis is placed on early primary fistula failure recognition and intervention. It is the author's contention if adequate vein and artery are selected for initial fistula construction nearly all fistulas should eventually function adequately to support dialysis and sooner than previously appreciated by utilizing an array of percutaneous and surgical therapies. Fistula malfunction is a unique problem within the spectrum of vascular disease and therefore demands that patients are treated by physicians with demonstrated expertise and experience.

Severity categories of the International Prostate Symptom Score before, and urinary morbidity after, permanent prostate brachytherapy

To determine if the International Prostate Symptom Score (IPSS) before seed implantation, stratified into mild (0-7), moderate (8-19) and severe (>20) categories, predicts brachytherapy-related morbidity in terms of IPSS resolution, catheter dependency and the need for surgical intervention after brachytherapy. From January 1998 to September 2003, 1034 consecutive patients had permanent interstitial brachytherapy for clinical stage T1b-T3a NXM0 (2002 system) prostate cancer. Of the 1034 patients, 739 (71.5%) presented with an IPSS of 0-7, 287 (27.7%) of 8-19, and eight (0.8%) of > or = 20. The IPSS 8-19 cohort was further stratified into 8-14 (237 men) and 15-19 (50 men) subgroups. The median follow-up was 38.2 months. In all patients, an alpha-blocker was initiated before brachytherapy and continued at least until the IPSS normalized, the latter defined as a return to within 1 point of that before implantation. A median of 21 IPSS questionnaires were obtained per patient. Several clinical, treatment and dosimetric variables were evaluated as predictors of urinary morbidity. For the entire cohort, the IPSS peaked at a mean of 0.5 months after implantation and resolved at a mean of 1.7 months. At 5 years after brachytherapy, 90.1% of patients at risk (88.8%, 95.5%, and four of eight patients with a pre-implant IPSS of 0-7, 8-19 and > or = 20, respectively) were within the IPSS 0-7 category. Compared to the pre-implant IPSS, 13 patients (8%) were assigned to a higher IPSS severity category. Neither prolonged urinary catheter dependency (>5 days; 16 patients, 1.5%) or transurethral resection of the prostate (TURP, 17 patients, 1.6%) depended on the pre-implant IPSS subgroup. In Cox regression analysis, IPSS resolution was best predicted by pre-implant IPSS, prolonged catheter dependency by patient age, and TURP by any catheter dependency, the maximum IPSS increase and the maximum urethral dose. The IPSS before implantation predicted the resolution of IPSS after brachytherapy, but did not correlate with substantial urinary morbidity, including catheter dependency or the need for TURP. At 5 years after brachytherapy, 90.1% of patients at risk were assigned to the IPSS 0-7 category.

The influence of isotope and prostate volume on urinary morbidity after prostate brachytherapy

To evaluate the influence of isotope and prostate size on International Prostate Symptom Score (IPSS) normalization, catheter dependency, and the need for surgical intervention secondary to bladder outlet obstruction after prostate brachytherapy. Between January 1998 and June 2003, 976 consecutive patients underwent brachytherapy for clinical stage T1b-T3a (2002 American Joint Committee on Cancer) prostate cancer. Seven hundred eighty-nine (80.8%) were implanted with 103Pd and 187 (19.2%) with 125I. The median follow-up was 41.2 months. Patients were stratified into size cohorts < or = 25 cm3, 25.1-35 cm3, 35.1-45 cm3, and >45 cm3. Four hundred eighteen patients (42.8%) received androgen deprivation therapy (ADT). Four hundred eighty-six patients (49.7%) received supplemental external-beam radiation therapy (XRT). In all patients, an alpha blocker was initiated before implantation and continued at least until the IPSS returned to baseline. IPSS resolution was defined as a return to within one point of baseline. The median number of IPSS determinations per patient was 21. Clinical, treatment, and dosimetric parameters evaluated included patient age, pretreatment PSA, Gleason score, clinical T stage, percent positive biopsies, preimplant IPSS, ultrasound volume, planning volume, isotope, V(100/150/200), D(90), urethral dose (average and maximum), supplemental XRT, ADT, and the duration of ADT (< or = 6 months vs. >6 months). Catheter dependency and the need for postsurgical intervention were also evaluated. For both isotopes and all prostate size cohorts, IPSS peaked 1 month after implantation and returned to baseline at a mean of 1.9 months. Stratification of prostate size cohorts by isotope demonstrated no significant differences in prolonged catheter dependency (> or = 5 days), IPSS resolution, or postimplant surgical intervention. In Cox regression analysis, IPSS normalization was best predicted by preimplant IPSS, XRT, and any need for a catheter after brachytherapy. Catheter dependency correlated with prostate size and ADT, whereas the need for surgical intervention was most closely related to any catheter dependency, maximum urethral dose, ADT, and maximum IPSS increase. Regardless of prostate size, isotope did not impact IPSS resolution, catheter dependency, or the need for postbrachytherapy surgical intervention. Although prostate size did predict for short-term (<5 days) catheter dependency, it did not influence IPSS resolution or the need for surgical intervention.

SU‐FF‐T‐51: Relationship Between Isotope, Prostate Volume and Urinary Morbidity Following Prostate Brachytherapy

Purpose: To evaluate the influence of isotope and prostate size on International Prostate Symptom Score (IPSS) normalization, catheter dependency and the need for surgical intervention following permanent prostate brachytherapy. Method and Materials: 976 consecutive patients underwent permanent brachytherapy for clinical stage T1b‐T3a prostate cancer. Of these, 789 were implanted with Pd‐103 and 187 with I‐125. Patients were stratified into size cohorts ⩽ 25.0 cm3, 25–35 cm3, 35–45 cm3, and &gt; 45.0 cm3. 418 received androgen deprivation therapy (ADT). 486 received supplemental external beam radiation therapy (XRT). In all patients, an α‐blocker was initiated prior to implantation and continued until the IPSS returned to baseline. The median number of IPSS determinations per patient was 21. Clinical, treatment and dosimetric parameters evaluated included patient age, pretreatment PSA, Gleason score, clinical T‐stage, percent positive biopsies, preimplant IPSS, ultrasound volume, planning volume, isotope, V100/150/200, D90, urethral dose, supplemental XRT, ADT, and the duration of ADT (⩽ 6 months versus &gt; 6 months). Results: For both isotopes and all size cohorts, IPSS peaked 1 month following implantation and returned to baseline at a mean of 1.9 months. Stratification of prostate size cohorts by isotope resulted in no significant differences in prolonged catheter dependency, IPSS resolution or postimplant surgical intervention. In Cox regression analysis, IPSS normalization was best predicted by preimplant IPSS, XRT and any need for a catheter following brachytherapy. Catheter dependency correlated with prostate volume, while the need for surgical intervention was related to catheter dependency, maximum urethral dose, ADT and maximum IPSS increase. Conclusion: When stratified by prostate size, the choice of isotope did not impact IPSS resolution, catheter dependency or the need for postbrachytherapy surgical intervention. While prostate size did predict for short‐term (&lt; 5 day) catheter dependency, it did not influence IPSS resolution or the need for surgical intervention.

Androgen deprivation–induced changes in prostate anatomy predict urinary morbidity after permanent interstitial brachytherapy

Purpose To evaluate the cytoreductive consequences of neoadjuvant androgen deprivation therapy on International Prostate Symptom Score (IPSS) normalization, catheter dependency, and the need for surgical intervention secondary to bladder outlet obstruction after permanent interstitial brachytherapy. Methods and materials A total of 116 patients (median follow-up, 30 months) with preandrogen and postandrogen deprivation therapy ultrasound studies and no history of preimplant transurethral resection of the prostate were evaluated. Androgen deprivation–induced changes in prostate volume, transition zone (TZ) volume, and urethral location were correlated with IPSS resolution, catheter dependency, and the need for postimplant surgical intervention. Prostate gland and TZ dimensions and volumes were measured by prolate ellipsoid calculation from the static ultrasound images. The urethral location was determined by identification of a urinary catheter. Additional clinical, treatment, and dosimetric parameters evaluated included patient age, pretreatment prostate-specific antigen, Gleason score, clinical T stage, preimplant IPSS, pre- and postandrogen deprivation ultrasound studies, treatment planning volume, supplemental external beam RT, isotope, total implant activity, Day 0 maximal dose received by 90% of the prostate gland, Day 0 percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed minimal peripheral dose, and urethral dose. Results For hormonally manipulated patients, the prostate volume at implantation did not have a statistical influence on the percentage of patients returning to IPSS baseline, the time for IPSS normalization, the incidence of catheter dependency, the catheter-dependency time, or the need for postimplant surgical intervention. However, when compared with the hormone-naive cohort, hormonally manipulated patients were more likely to undergo postimplant surgical intervention (5.2% vs. 0.3%, p = 0.001). Greater androgen deprivation–induced reductions in prostate and TZ volumes, along with movement of the urethra closer to the posterior border of the prostate gland, resulted in a decreased incidence of postimplant urinary morbidity. Using Cox regression analysis, the time to IPSS resolution was best predicted by the percentage of TZ volume reduction. Stepwise linear regression analysis demonstrated that the catheter-dependency time was best predicted by the prehormonal therapy prostate volume, posthormonal therapy TZ volume, and the change in the urethral position; prolonged catheter dependency by the percentage of TZ volume reduction, prehormonal therapy TZ index, and the change in the urethral position; and the need for postimplant surgical intervention by the posthormonal therapy TZ index and the change in the urethral location. Conclusion After neoadjuvant androgen deprivation therapy for volume reduction, some brachytherapy-related urinary morbidity parameters are highly related to the preandrogen deprivation prostate volume, variants in the TZ volume, and changes in the urethral location.

The impact of prostate volume and neoadjuvant androgen-deprivation therapy on urinary function following prostate brachytherapy.

The purpose of this article is to evaluate the impact of prostate size and the magnitude of cytoreduction after neoadjuvant androgen-deprivation therapy (ADT) on catheter dependency, urinary symptomatology, and need for postbrachytherapy surgical intervention. From February 1998 to August 2002, 186 consecutive patients under went monotherapeutic brachytherapy (no supplemental external-beam radiotherapy or ADT), and 101 consecutive patients received < or = 6 months of ADT (a luteinizing hormone-releasing hormone agonist and an anti-androgen) in conjunction with brachytherapy without supplemental external-beam radiotherapy for clinical Tlc-T2b (2002 American Joint Committee on Cancer) prostate cancer. ADT was initiated approximately 3 months before brachytherapy. The median follow-up was 38.6 months. An alpha-blocker was initiated before implantation and continued at least until the International Prostate Symptom Score (IPSS) returned to baseline levels. Evaluated parameters included patient age, pretreatment prostate-specific antigen, Gleason score, clinical T stage, preimplantation IPSS, ultrasound volume, hormonal status, isotope, D(90), V(100/150/200), and urethral dose (average and maximum). Patients receiving neoadjuvant ADT were statistically older, presented with higher preimplantation IPSS scores, and larger prostate volumes. Patients receiving ADT were likelier to require a urinary catheter for the first 3 days after implantation; however, by day 4, no statistical difference in catheter dependency could be discerned between the two cohorts. Hormonal status did not predict for postbrachytherapy surgical intervention. IPSS returned to baseline at a mean of 1.8 and 1.7 months in hormone-naive and ADT patients, respectively. In multivariate Cox regression analysis, the preimplantation IPSS and the maximum postimplantation IPSS predicted for IPSS normalization overall and in both cohorts. Ultrasound prostate volume did not predict for IPSS normalization, catheter dependency, or need for postimplantation surgical intervention. Although patients receiving ADT were likelier to require a urinary catheter for the first three days after implantation, hormonal manipulation did not affect IPSS normalization, prolonged catheter dependency, or need for postbrachytherapy surgical intervention in these patients treated with brachytherapy without supplemental external-beam radiotherapy.