Utility of 'back-up' arterio-venous fistulae in patients on peritoneal dialysis and use of haemodialysis catheters.

BACKGROUND: Patients undergoing peritoneal dialysis may require unanticipated transfer to haemodialysis. Back up fistula are often created in selected patients. These may help reduce the infective burden of haemodialysis (HD) catheter. AIM: To study the utility of back-up arterio-venous fistulae (AVF) in patients initiated on peritoneal dialysis (PD) and to determine the rates of HD catheter use in patients requiring conversion to HD. METHODS: Data on HD transfer and HD catheter usage were retrospectively analysed in all patients initiating PD between January 2010 and December 2014 at Royal Adelaide Hospital (RAH; universal back-up AVF creation at PD commencement) and Princess Alexandra Hospital (PAH; selective back-up AVF creation in 'high risk' patients). RESULTS: A total of 374 patients initiated PD during the study period: 142 in RAH group and 232 in PAH group. The groups were reasonably comparable, except that RAH patients were more likely to be older, Caucasian and diabetic. Transfer to HD occurred in 33 (23%) patients in RAH group and 99 (43%) in the PAH group with respective median times to HD transfer of 289 and 295 days. HD catheter usage was required at the time of HD transfer in 11 (33%) patients at RAH and 64 (65%) in patients at PAH (P < 0.001). AVF complications occurred in 13 (9%) patients in RAH group (fistuloplasty n = 8, transposition n = 2, ligation due to ischaemia n = 2 and construction of new AVF n = 1). CONCLUSION: Patients undergoing PD frequently require urgent unanticipated transfer to HD and back-up AVF can be successfully utilised in this setting in the majority of cases, which in turn can reduce the infective burden of HD catheter exposure.

Effects of Arteriovenous Fistula Ligation on Cardiac Structure and Function in Kidney Transplant Recipients.

BACKGROUND: Cardiovascular morbidity and mortality remain high in recipients of a kidney transplant. The persistence of a patent arteriovenous fistula (AVF) after transplantation may contribute to ongoing maladaptive cardiovascular remodeling. The ability to reverse this maladaptive remodeling by ligation of this AVF is unknown. We conducted the first randomized controlled trial to evaluate the effect of AVF ligation on cardiac structure and function in stable kidney transplant recipients. METHODS: In this randomized controlled trial, kidney transplant recipients (>12 months after transplantation with stable graft function) were randomized to AVF ligation or no intervention. All participants underwent cardiac magnetic resonance imaging at baseline and at 6 months. The primary outcome was the change in left ventricular (LV) mass. Secondary outcomes included changes in LV volumes, left and right atrial areas, LV ejection fraction, NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, cardiac output/index, brachial flows (ipsilateral to AVF), and pulmonary artery velocity. RESULTS: A total of 93 patients were screened, of whom 64 met the inclusion criteria and were randomized to the AVF ligation (n=33) or control (n=31) group. Fifty-four participants completed the study: 27 in the AVF ligation group and 27 in the control group. On the second cardiac magnetic resonance scan, a mean decrease of 22.1 g (95% CI, 15.0-29.1) was observed in LV mass in the AVF ligation group compared with a small increase of 1.2 g (95% CI, -4.8 to 7.2) in the control group ( P<0.001). Significant decreases in LV end-diastolic volumes, LV end-systolic volumes, cardiac output, cardiac index, atrial volumes, and NT-proBNP were also seen in the AVF closure group ( P<0.01). No significant changes were observed in LV ejection fraction ( P=0.93) and pulmonary artery velocity ( P=0.07). No significant complications were noted after AVF ligation. No changes in estimated glomerular filtration rate or systolic and diastolic blood pressures were observed between cardiac magnetic resonance scans. CONCLUSIONS: Elective ligation of patent AVF in adults with stable kidney transplant function resulted in clinically significant reduction of LV myocardial mass. CLINICAL TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry URL: https://www.anzctr.org.au . Unique Identifier: ACTRN12613001302741.

Do arteriovenous fistulas increase cardiac risk?

An effectively functioning arteriovenous fistula is the life line for patients on long-term hemodialysis, and for most an upper limb, native vessel fistula has significant short- and long-term advantages. There are, however, situations where a fistula has deleterious effects, including the relatively uncommon problem of severe heart failure exacerbated in particular by high-flow fistulas. There is also increasing evidence that a fistula can add to the already high burden of cardiovascular risk in patients with advanced kidney disease, including by promoting water and salt retention, and by inducing or worsening left ventricular hypertrophy. While cases periodically arise where a fistula needs to be ligated with some urgency, such as severe heart failure, an increasingly persuasive case can be made for electively ligating fistulas that are not being used. The most common example of this is in stable renal transplant recipients, where the risks of ligation are outweighed by the potential risks of maintaining an unused fistula. Surgically reducing the blood flow in large (usually upper arm) fistulas is also a legitimate maneuver in specific high-risk situations.

The Impact of Arteriovenous Fistulae for Hemodialysis on the Cardiovascular System.

An arteriovenous fistula (AVF) is critical for the provision of optimal chronic hemodialysis. Its creation causes significant hemodynamic alterations in cardiovascular parameters, and can result in progressive left and right heart failure. Despite successful kidney transplantation, many patients retain a functional AVF indefinitely, which may contribute to ongoing adverse cardiovascular outcomes. A similar high risk:benefit ratio may exist in peritoneal dialysis patients with "backup" AVF.

Nocardiosis presenting as a lung mass in a kidney transplant recipient.

Nocardiosis is a potentially life-threatening disease in renal transplant recipients. It is an uncommon infection with high lethality if left untreated. We report a case of a 67 year-old kidney transplant recipient who developed pulmonary nocardiosis and presented with pleural effusion along with an underlying lung mass, which was successfully treated with trimethoprim-sulphamethoxazole in conjunction with a reduction in immunosuppressive therapy. Five months later, graft function remains stable with complete regression of radiological abnormalities and absence of symptoms. Nocardiosis should be suspected in the presence of pulmonary symptoms in a transplant patient with unusual radiological presentation.

Angiotensin II type 1 receptor antibody precipitating acute vascular rejection in kidney transplantation.

Atypical non HLA antibodies are increasingly recognised as causes of immunological injury in allotransplantation. In this report we describe a non HLA sensitized male renal allograft recipient who developed acute vascular rejection on a "for cause" biopsy (Banff v2, g2, ptc 3) at day 4 post first renal allograft in the presence of elevated angiotensin II type 1 receptor antibodies (AT1R-Ab level 14.1). The acute rejection was treated with pulse corticosteroid therapy, anti-thymocyte globulin (ATG × 6), plasma exchange (1.5 plasma volume replacement x6) and oral candesartan. Serum creatinine improved and follow up biopsy confirmed resolution of rejection following treatment. AT1R-Ab should be considered when rejection is diagnosed in the absence of HLA antibodies.

Dramatic improvement in decompensated right heart failure due to severe tricuspid regurgitation following ligation of arteriovenous fistula in a renal transplant recipient.

Arteriovenous (AV) fistulas with high blood flow rate are necessary for adequate hemodialysis, but they can also cause significant hemodynamic changes, including raised cardiac output, left ventricular hypertrophy and occasionally overt cardiac failure (Basile et al., Nephrol Dial Transplant, 23, 2008, 282; Unger et al., Am J Transplant, 4, 2004, 2038). We now report a case of rapid and dramatic improvement in symptomatic right heart failure due to severe tricuspid regurgitation following ligation of an arteriovenous fistula. Cardiac magnetic resonance imaging (MRI) performed before and after the ligation of fistula showed striking improvement in both the tricuspid regurgitation and right ventricular dimensions, with minimal impact on left ventricular mass, size, and function.

Recurrent nephrolithiasis and loss of kidney function: a cohort study.

PURPOSE: To evaluate whether symptomatic recurrent nephrolithiasis leads to loss of kidney function. METHODS: Adults who presented to the Emergency Department at least twice with symptomatic and radiologically confirmed nephrolithiasis were retrospectively recruited. Primary endpoint was the change in glomerular filtration rate (GFR) between baseline and at the time of data collection. Secondary endpoints include GFR slope defined as the mean rate of change in GFR from baseline to the end of the study period. RESULTS: 240 patients had recurrent symptomatic nephrolithiasis. Median follow-up was 5.4 years. The median age of first acute presentation was 51.6 years and the median baseline serum creatinine (bsCr) was 85.5 umol/l. 17.5% (n = 42) had worsening GFR, with the average change in GFR of - 8.64 ml/min/1.73 m2 per year. Four patients progressed to ESKD requiring haemodialysis. 14.5% (n = 35) had calcium oxalate stones. Univariate analysis showed older patients (p < 0.001), more symptomatic stone episodes (p < 0.001) and non-calcium-containing stones (p < 0.001) were strongly associated with deteriorating kidney function. Age (p = 0.002) and number of acute stone episodes (p = 0.011) were significant predictive factors when unadjusted to co-morbidities. Age (p = 0.018) was the only predictive factor of worsening GFR when adjusted for co-morbidities. Average mean GFR slope was - 2.83/min/1.73 m2 per year. CONCLUSIONS: Recurrent symptomatic nephrolithiasis is associated with loss of kidney function, in older patients, increased episodes of symptomatic nephrolithiasis and non-calcium-containing stones. Age is the only predictive factor for progression to chronic kidney disease in this subgroup.

Successful treatment of calcific uremic arteriolopathy with sodium thiosulfate in a renal transplant recipient.

Abstract Calcific uremic arteriolopathy (CUA) is a rare but life-threatening disorder of arteriolar calcification. It frequently leads to severe ischemia, intense pain, and tissue necrosis with non-healing skin ulcerations. CUA usually occurs in patients with chronic kidney disease (CKD), especially those on dialysis, and its occurrence is rare in kidney transplant recipients. The treatment of this disorder is not clearly defined, and no randomized prospective trials are available. Treatment has focused on optimizing dialysis treatment, control of bone mineral parameters, wound care, experimental anticalcification therapies-using bisphosphonates, cinacalcet, parathyroidectomy, and hyperbaric oxygen. Such treatments are based on the pathophysiological considerations and evidences from case reports or series. Recently, several cases have reported about the emerging benefits of intravenous sodium thiosulfate (STS) in the treatment of CUA. STS has resulted in rapid pain relief, wound healing, and prevention of death. We report a case of CUA in a 63-year-old Caucasian man with a functioning renal allograft. In this patient, intravenous STS was administered for 8 months, which was the principal therapy, which resulted in complete resolution of the CUA and skin healing.

Gadolinium-Induced Acute Graft Pancreatitis in a Simultaneous Pancreas-Kidney Transplant Recipient.

Gadolinium-induced acute pancreatitis is a rare phenomenon associated with the administration of gadolinium-based contrast agents. Only five cases of gadolinium-induced acute pancreatitis have been reported worldwide in patients with native pancreas and none with a pancreatic graft. We present a 32-year-old woman with prior history of simultaneous pancreas-kidney transplant who presented with generalized abdominal pain associated with systemic inflammatory response syndrome requiring admission to the intensive care unit. This occurred within 48 hours after having a magnetic resonance imaging (MRI) with gadolinium for investigation of subacute left optic atrophy. She was noted to have a marked rise in serum lipase, and the computed tomography findings were consistent with acute graft pancreatitis. Other causes of pancreatitis were ruled out, and she was managed conservatively with aggressive hydration, bowel rest, and analgesia with good recovery. This is the first reported case of gadolinium-induced acute graft pancreatitis occurring in a simultaneous pancreas-kidney transplant recipient. Clinicians should consider this rare differential diagnosis as a cause of graft pancreatitis in patients who have received gadolinium-based contrast agents.

Long-Term Impact of Arteriovenous Fistula Ligation on Cardiac Structure and Function in Kidney Transplant Recipients: A 5-Year Follow-Up Observational Cohort Study.

Background: The long-term effects of arteriovenous fistula (AVF) ligation on cardiovascular structure following kidney transplantation remain uncertain. A prospective randomized, controlled trial (RCT) examined the effect of AVF ligation at 6 months on cardiovascular magnetic resonance imaging (CMR)-derived parameters in 27 kidney transplant recipients compared with 27 controls. A mean decrease in left ventricular mass (LVM) of 22.1 g (95% CI, 15.0 to 29.1) was observed compared with an increase of 1.2 g (95% CI, -4.8 to 7.2) in the control group (P<0.001). We conducted a long-term follow-up observational cohort study in the treated cohort to determine the evolution of CMR-derived parameters compared with those documented at 6 months post-AVF ligation. Methods: We performed CMR at long-term follow-up in the AVF ligation observational cohort from our original RCT published in 2019. Results were compared with CMR at 6 months postintervention. The coprimary end point was the change in CMR-derived LVM and LVM index at long-term follow-up from imaging at 6 months postindex procedure. Results: At a median of 5.1 years (interquartile range, 4.7-5.5 years), 17 patients in the AVF ligation group were studied with repeat CMR with a median duration to follow-up imaging of 5.1 years (IQR, 4.7-5.5 years). Statistically significant further reductions in LVM (-17.6±23.0 g, P=0.006) and LVM index (-10.0±13.0 g/m2, P=0.006) were documented. Conclusions: The benefit of AVF ligation on LVM and LVM index regression appears to persist long term. This has the potential to lead to a significant reduction in cardiovascular mortality.

Successful pregnancy in a recipient of an ABO-incompatible renal allograft.

Kidney transplantation restores fertility in patients with end-stage renal disease, with many successful pregnancies after kidney transplantation being reported. However, there are little data regarding pregnancy in women transplanted under modern-era desensitisation protocols that utilise rituximab, plasma exchange and intravenous immunoglobulin, including ABO-incompatible transplants. Pregnancies in ABO-incompatible recipients can pose new challenges from an immunological perspective. Here, we report a case of successful pregnancy using in vitro fertilisation, in a renal transplant recipient who underwent desensitisation two years prior, that included use of rituximab and plasma exchange to receive an ABO-incompatible transplant from her husband and subsequent father of the baby. We believe this was the first case of successful pregnancy after ABO-incompatible kidney transplantation in Australia and New Zealand. This case also highlights the difficulties faced in conception following transplantation and demonstrates that in vitro fertilisation utilising ovulation induction can be successfully utilised for conception in this cohort. This recipient also had gestational diabetes, worsening renal function and preterm delivery which are important complications often seen in pregnancies of solid organ transplant recipients.

Cardiovascular Disease After Kidney Transplant.

Renal transplantation is the preferred treatment for patients with end-stage kidney disease. However, despite successful kidney transplantation, cardiovascular disease (CVD) remains one of the major causes of patient death and hence graft loss. The antecedents of this increased risk reside within the development of end-stage kidney disease and dialysis. Risk factors for the development of CVD include diabetes, hypertension, and dyslipidemia. Other transplant-specific factors include the presence of a patent arteriovenous fistula and immunosuppressive therapy. Efforts to modify these factors should be strongly encouraged to improve long-term outcomes of transplant patients and reduce death from CVD in this at-risk patient population.

Renal-limited thrombotic microangiopathy and acute interstitial nephritis with a single dose of quinine.

Quinine has been reported to cause acute kidney injury by various mechanisms. The response to quinine can result in a spectrum of problems ranging from isolated thrombocytopenia to thrombotic microangiopathy (TMA) to disseminated intravascular coagulation. Quinine has also been reported to cause acute interstitial nephritis (AIN). We report an unusual presentation where both of these entities of renal-limited TMA and AIN were precipitated by a single dose of quinine.