Role of intravascular ultrasound imaging during endovascular interventions of failing hemodialysis access grafts.

BACKGROUND: Arteriovenous (AV) access graft complications represent a serious complication in patients undergoing hemodialysis. Angiography is one method of visualizing them. However, angiography is not always an effective means of detecting lesions that occur in this context. Intravascular ultrasound (IVUS) is an adjunct modality used to identify stenoses responsible for failing access by identifying multiple stenoses, including those that are most severe. The purpose of this study was to define the value of IVUS in patients with failing AV access grafts by comparing digital subtraction angiography (DSA) alone with DSA followed by IVUS. METHODS: This was a single-center randomized study comparing IVUS with DSA in patients with failing hemodialysis access grafts. It consisted of 100 randomized hemodialysis patients presenting with failing AV access who were being considered for endovascular intervention. Interventions in the control group were guided by DSA alone, whereas interventions in the test group were guided by DSA followed by IVUS. Patients were observed for 6 months after intervention. The primary end point was the time in days to AV access graft failure after the index intervention, expressed as median and interquartile range. Secondary analyses included influence of DSA and IVUS on index procedure decision-making and percentage of patients with AV access graft reinterventions or discontinuation through 3 and 6 months. RESULTS: Median time to first AV graft reintervention or discontinuation was 61 days in the test group and 30 days in the control group (P = .16), with analysis limited to patients who experienced reintervention or discontinuation (n = 59). IVUS resulted in a change in treatment plan in 76% (44/58) of patients, with no treatment change after IVUS in 24% (14/58) of patients. At 6 months, approximately 35% of patients in both the control and test groups remained free from reinterventions (P = .88). At 6 months, approximately 75% of patients in the control group and 80% of patients in the test group remained free from AV graft discontinuation or abandonment (P = .45). CONCLUSIONS: This pilot study suggests that addition of IVUS to standard angiography during endovascular interventions of failing hemodialysis access grafts holds potential to extend the time to the first reintervention. The data support the design and execution of an adequately powered randomized trial with longer follow-up to reliably discern the clinical benefit of IVUS as an addition to standard angiography in the setting of failing AV access grafts.

Training and certification in dialysis access.

Decreasing and eliminating the gaps in knowledge, skills, and effective communication are the mainstays for a successful dialysis access training program curriculum and at the core of the human factors training philosophy. Many of these skills can be learned in the simulation environment. Education and training will reduce gaps in knowledge and technical skills, before exposing patients to procedure-related risk. For dialysis access, a reliable workplace environment depends upon a culture where safety and accountability are balanced to recognize the human contribution to success or failure in the complex care of patients with end-stage renal disease. Rigorous testing and certification adds value to the participants and validates the training program.

Monthly screening for polyoma virus eliminates BK nephropathy and preserves renal function.

BACKGROUND: Polyoma BK virus nephropathy is a serious complication after renal transplantation and is associated with a high rate of allograft failure. Progressive infection with BK virus in immunocompromised renal transplant recipients occurs in detectable stages: Viruria, viremia, then nephropathy. METHODS: In January, 2006, we initiated a plasma screening policy for all new transplant recipients, with monthly blood testing for BK virus by polymerase chain reaction (PCR). Between January 1, 2006, and February 28, 2007, 66 renal transplants were performed at our center. The 11 patients with a positive plasma BK PCR test underwent prompt reduction in baseline immunotherapy consisting of a 50% daily dose reduction (n = 6) or complete discontinuation of therapy with mycophenolate mofetil (n = 5). RESULTS: After reduction or discontinuation of mycophenolate mofetil, 10 patients became negative for BK virus in the plasma within 6 months. Progression to BK nephropathy has not occurred, and renal transplant dysfunction secondary to acute cellular rejection developed in only 1 patient (9%). One year post-transplant, the mean serum creatinine values for these 11 patients remained stable at 1.5 mg/dL. CONCLUSION: Monthly plasma screening for BK virus by PCR together with immunosuppressive regimen reduction prevents BK nephropathy. In addition, this intensive screening protocol is associated with a low rate of acute rejection and excellent preservation of renal function.

Sirolimus-based, calcineurin-inhibitor sparing immunotherapy, long-term (6-year) results.

At the Albany Medical Center, we have a long-term experience, mean follow-up of 75 months, in 50 renal transplant recipients treated with maintenance sirolimus, prednisone and a calcineurin-inhibitor sparing immunosuppressive regimen. One-year patient and graft survival was 98% and six-year patient and graft survival was 82% and 72% respectively. The rate of early acute rejection (<3 months) was only 10%. Furthermore, no late (>3 months) acute rejection episodes developed despite calcineurin-inhibitor dose minimization. In addition, recipient mean serum creatinine remained stable at 1.6 mg/dl throughout the 6-year follow-up period. Sirolimus is an effective maintenance immunosuppressive agent that safely allows for a reduction in calcineurin-inhibitor dosing.

Early steroid withdrawal therapy in renal transplant recipients: a steroid-free sirolimus and CellCept-based calcineurin inhibitor-minimization protocol.

BACKGROUND: Maintenance steroid therapy is associated with significant morbidity and mortality in renal transplant recipients. Elimination of the many long-term side effects of corticosteroids, including those that impinge on cardiovascular risk, remains a laudable goal in designing immunosuppressive protocols. However, concern persists that prednisone-free maintenance immunotherapy in kidney transplant recipients will result in an increase incidence of acute rejections, renal dysfunction and ultimate graft loss. METHODS: From 24 March 2003 to 1 December 2004, 84 kidney transplant recipients (61 deceased donor, 23 living donors) discontinued prednisone on post-operative day 6. Immunotherapy consisted of polyclonal antibody induction (thymoglobulin) for five d and prednisone intraoperatively with a rapid taper over the next six d. Maintenance therapy consisted of a sirolimus and CellCept-based calcineurin inhibitor-minimization protocol. Tacrolimus and mycophenolate mofetil (CellCept) were initiated on day 0. Sirolimus immunotherpay was started on post-operative day 6 concomitant with the cessation of steroids. We compared outcomes with that of our historical controls, treated with sirolimus and tacrolimus, who did not discontinue steroids. In addition, we analyzed outcomes independently for recipients of living and deceased donors in the steroid-free protocol. RESULTS: The recipients on prednisone-free maintenance immunosuppression had excellent 2.5-yr actuarial patient survival (97%), graft survival (93%), and acceptable acute rejection-free graft survival (89%). The mean serum creatinine level (+/-SD) at one yr was 1.5 +/- 0.6 mg/dL and at two yr was 1.5 +/- 0.6 mg/dL. We noted that 5% of recipients developed cytomegalovirus (CMV) syndrome; 1%, polyoma nephropathy; 1%, post-transplant lymphoproliferative disorder (PTLD), and 5% developed post-transplant diabetes mellitus (PTDM). In all, 91% of kidney recipients with functioning grafts remain steroid-free as of 31 December 2005. When compared with historical controls, the recipients on the early steroid-withdrawal (ESW) protocol had comparable graft survival, acute rejection-free survival, graft function, but significantly better patient actuarial survival (p = 0.048). In addition, recipients on the steroid-free protocol had decreased prevalence of four risk factors for cardiovascular disease when compared with historical controls: hypertension (p = 0.008), hyperlipidemia (p = 0.003), weight gain (p = 0.024), and incidence of PTDM (p = 0.015). CONCLUSION: Early steroid-withdrawal in renal transplant recipients with a sirolimus and CellCept-based calcineurin inhibitor-minimimization protocol can effectively reduce many of the steroid-related side effects, decrease risk factors for cardiovascular disease, and is associated with improved recipient survival without compromising graft function.

A multicenter pilot study of early (4-day) steroid cessation in renal transplant recipients under simulect, tacrolimus and sirolimus.

This study presents the first prospective multicenter study assessing sirolimus-based immunosuppression with early (4-day) corticosteroid withdrawal (CSWD) in renal transplantation. Immunosuppression included: anti-IL-2 receptor antibody and tacrolimus/sirolimus. Inclusion criteria included adult primary recipients. Exclusion criteria included: (i) African Americans, (ii) current PRA >50%, (iii) multiple organ transplants, (iv) WBC < 3000 cells/microL and (v) fasting hypercholesterolemia/hypertriglyceridemia. The primary endpoints were acute rejection and the proportion of patients off corticosteroids. Seventy-seven patients were enrolled: mean age of 49.7 +/- 12 years. Transplants included: cadaveric (26%) and living donor (74%). Patient and graft survival were 100%. Biopsy proven acute rejection occurred in 13%; presumptive rejection in 10.5%. Banff grades included: IA (seven patients), IB (one patient), IIA (one patient) and IIB (one patient). Renal function at 1 year: serum creatinine (1.18 +/- 0.06 mg/dL). Mean weight gain was minimal at 1 year: 3 +/- 2 kg/patient. Mild increases in total, LDL and HDL cholesterol were observed and new antilipid agent use occurred in 26 patients. In conclusion, early CSWD under tacrolimus/sirolimus-based immunosuppression in selected, low-risk renal transplant recipients provides: (i) excellent patient and graft survival, (ii) good renal function, (iii) reduced hyperlipidemia and antilipid agent use and (iv) low acute rejection rates.

Hemodialysis arteriovenous fistula maturity: US evaluation.

PURPOSE: To compare various objective ultrasonographic (US) criteria for native arteriovenous fistula (AVF) maturation with subsequent fistula outcomes and clinical evaluation by experienced dialysis nurses. MATERIALS AND METHODS: US fistula evaluation results were analyzed retrospectively in 69 patients within 4 months after AVF placement; adequacy for dialysis was known in 54. Measurements included minimum venous diameter and blood flow rate. Experienced dialysis nurses examined 30 fistulas clinically. Predictors of fistula adequacy were analyzed with univariate and multivariate logistic regression. Mean fistula diameters and blood flow rates were compared by using analysis of variance or unpaired Student t tests. RESULTS: Fistula adequacy for dialysis doubled if the minimum venous diameter was 0.4 cm or greater (89% [24 of 27]) versus less than 0.4 cm (44% [12 of 27]; P <.001). Fistula adequacy for dialysis was nearly doubled if flow volume was 500 mL/min or greater (84% [26 of 31]) versus less than 500 mL/min (43% [nine of 21]; P =.002). Combining venous diameter and flow volume increased fistula adequacy predictive value: minimum venous diameter of 0.4 cm or greater and flow volume of 500 mL/min or greater (95% [19 of 20]) versus neither criterion met (33% [five of 15]; P =.002). Women were less likely to have an adequate fistula diameter of 0.4 cm or greater: 40% (12 of 30) of women versus 69% (27 of 39; P =.015) of men. No significant differences in blood flow or minimum venous diameter were found during 2-4 postoperative months. Experienced dialysis nurses' accuracy in predicting eventual fistula maturity was 80% (24 of 30). CONCLUSION: US measurements of AVF at 2-4 months in patients undergoing hemodialysis are highly predictive of fistula maturation and adequacy for dialysis.