Graft survival after percutaneous transluminal renal stenting for transplant renal artery stenosis (TRAS) is worse compared to matched cadaveric grafts without TRAS.

OBJECTIVES: Transplant renal artery stenosis (TRAS) is now recognized as a curable disease with a good prognosis if intervention occurs in the early stage. However, the mid-term outcomes of TRAS when treated by percutaneous transluminal angioplasty with stent placement have yet to be fully elucidated. The purpose of this study was to compare mid-term graft and patient survival of TRAS group with a control group. PATIENTS AND METHODS: Ninety-two patients were diagnosed of TRAS between January 2016 and January 2022 in our center. Fifty-six pairs of recipients with grafts from the same donor were selected as a study group with TRAS and a control group without TRAS, respectively. All donor kidneys were from deceased organ donation rather than living donors. The primary endpoints were graft and patient survival. The secondary outcomes were changes in renal graft function. RESULTS: The mean follow-up time for the TRAS group was 43.6 months, while the mean follow-up time for the control group was 45.3 months. In the TRAS group, the age of patients ranged from 11 to 62 years with 39 males and 17 females. In the control group, the age of patients ranged from 18 to 67 years with 40 males and 16 females. In the TRAS group, there were more patients with diabetic nephropathy as the primary renal disease compared to the control group (5/56 vs 0/56), and the incidence of acute rejection was higher in the TRAS group than in the control group (12/56 vs 3/56). Eight patients in the TRAS group and one patient in the control group experienced graft loss (p = .019). Four patients in the TRAS group and four patients in the control group died with functional renal allograft during the follow-up time (p = .989). The levels of eGFR did not differ significantly between the two groups in the first three years after kidney transplant (p > .05). Patients in the TRAS group had worse graft functionality (eGFR, 44.96 ± 18.9 vs 54.9 ± 19.6 mL/min) in the fourth year when compared with the control group (p = .01). CONCLUSIONS: The graft function deteriorated faster, and graft survival was lower in the TRAS group treated by stent placement when compared with a control group without TRAS over the mid-term.

Perfusion and oxygenation in allografts with transplant renal artery stenosis: Evaluation with functional magnetic resonance imaging.

BACKGROUND: Transplant renal artery stenosis (TRAS) has been shown to reduce kidney perfusion leading to post-operative hypertension. We aimed to measure the perfusion and oxygenation changes in TRAS with arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) imaging, respectively. METHODS: In this single-center prospective study, a total of seven patients with TRAS and seven age- and sex-matched normal kidney transplant recipients underwent both ASL and BOLD imaging. Moreover, measurements of ASL and BOLD were also performed in five patients after successful angioplasty for TRAS. RESULTS: Allograft cortical perfusion as measured by ASL in the TRAS group was significantly decreased as compared with normal control group (129.9 ± 46.6 ml/100 g vs. 202.4 ± 47.7 ml/100 g, P = .01). Interestingly, allograft oxygenation as indicated by R2* derived from BOLD in both the cortex (16.42 ± 1.90 Hz vs. 18.25 ± 4.34 Hz, P = .33) and the medulla (30.34 ± 2.35 Hz vs. 30.43 ± 6.85 Hz, P = .97) showed no statistical difference between the TRAS and normal control group. In addition, both cortical and medullary oxygenation remained unchanged despite significantly improved cortical perfusion in those undergone successful angioplasty. CONCLUSION: Cortical and medullary oxygenation were preserved in the presence of reduced allograft perfusion in clinically significant TRAS. Prospective larger studies are needed to conclusively establish perfusion and oxygenation changes in TRAS.

Endovascular Treatment of Transplant Renal Artery Stenosis: A Systematic Review and Meta-analysis.

OBJECTIVE: Endovascular treatment through either percutaneous transluminal angioplasty (PTA) alone or stenting has been previously used as a treatment for transplant renal artery stenosis (TRAS). This review aimed to investigate the results of endovascular treatment for renal artery stenosis in transplanted kidneys as compared with the outcomes of interventions, medical management, and graft survival in non-TRAS patients. METHODS: A systematic review of PubMed, Google Scholar, Cochrane, and Scopus was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in which studies that reported outcomes of the treatment of TRAS via the endoluminal approach were identified, and their results were meta-analyzed. RESULTS: Fifty-four studies with a total of 1522 patients were included. A significant reduction of serum creatinine level was found, favoring the stenting group, with a mean difference of 0.68 mg/dL (95% confidence interval (CI), 0.17-1.19; Z=2.60, p=0.0009). Comparison of pre- and post-intervention values of any intervention revealed a significant decrease in overall serum creatinine level (0.65 mg/dL; 95% CI, 0.40-0.90; Z=5.09, p=0.00001), overall blood pressure, with a mean difference of 11.12 mmHg (95% CI, 7.29-14.95; Z=5.59, p=0.00001), mean difference in the use of medications (0.77; 95% CI, 0.29-1.24; p=0.002), and peak systolic velocity (190.05; 95% CI, 128.41-251.69; p<0.00001). The comparison of serum creatinine level between endovascular interventions and best medical therapy favored endovascular intervention, with a mean difference of 0.23 mg/dL (95% CI, 0.14-0.32; Z=5.07, p<0.00001). Graft survival was similar between the treated patients and those without TRAS (hazard ratio, 0.98; 95% CI, 0.75-1.28; p=0.091). The overall pooled success rate was 89%, and the overall complication rate was 10.4%, with the most prevalent complication being arterial dissection. CONCLUSION: The endovascular treatment of TRAS improves graft preservation and renal function and hemodynamic parameters. PTA + stenting appears to be a more effective option to PTA alone in the stabilization of renal function, with additional benefits from decreased restenosis rates. Further high-quality studies could expand on these findings.

Unusual Endovascular Treatment of Iliac Occlusive Disease With a Physician-Modified Endograft to Preserve a Transplant Renal Artery.

PURPOSE: We describe the feasibility and early results of iliac stenting using a physician-modified endograft (PMEG) to preserve a transplant renal artery in patient with iliac occlusive disease. CASE REPORT: A 70-year-old male patient, with sub-occlusive left common iliac artery stenosis at the level of the transplanted kidney arterial anastomosis, presented with left critical limb ischemia (CLI) and pseudo-transplant renal artery stenosis (pseudo-TRAS) symptoms. He was treated with a physician-modified fenestrated covered stent introduced percutaneously via ipsilateral femoral artery after failure of simple angioplasty (percutaneous transluminal angioplasty, PTA). The modified graft was created by performing a square fenestration graftotomy on a Medtronic iliac limb stent graft (Medtronic Cardiovascular, Santa Rosa, CA, USA). The procedure was technically successful with no intraoperative complications. Procedural time was 110 minutes, including 35 minutes for device modification. On short-term follow-up, the patient had early improvement of renal function and resolution of CLI. The iliac and transplant renal artery remained patent with no sign of stent migration or kinking on 6 months surveillance computed tomography angiography and 1 year color Doppler ultrasonography. CONCLUSION: Use of PMEG to preserve visceral branches in occlusive iliac disease is a feasible endovascular technique with encouraging technical success and satisfying early results.

Long-term clinical outcomes of patients with nonsignificant transplanted renal artery stenosis.

BACKGROUND: Transplant renal artery stenosis (TRAS) is the main vascular complication of kidney transplantation. For research and treatment purposes, several authors consider critical renal artery stenosis to be greater than 50%, and percutaneous intervention is indicated in this scenario. However, there are no reports in the current literature on the evolution of patients with less than 50% stenosis. METHOD: This retrospective study included data from all patients who underwent kidney transplantation and were suspected of having TRAS after transplantation with stenosis under 50% independent of age and were referred for angiography at a single centre between January 2007 and December 2014. RESULTS: During this period, 6,829 kidney transplants were performed at Hospital do Rim, 313 of whom had a clinical suspicion of TRAS, and 54 of whom presented no significant stenosis. The average age was 35.93 years old, the predominant sex was male, and most individuals (94.4%) underwent dialysis before transplantation. In most cases in this group, transplants occurred from a deceased donor (66.7%). The time between transplantation and angiography was less than one year in 79.6% of patients, and all presented nonsignificant TRAS. Creatinine levels, systolic blood pressure, diastolic blood pressure and glomerular filtration rate improved over the long term. The outcomes found were death and allograft loss. CONCLUSION: Age, sex and ethnic group of patients were factors that did not interfere with the frequency of renal artery stenosis. The outcomes showed that in the long term, most patients evolve well and have improved quality of life and kidney function, although there are cases of death and kidney loss.

Intravascular ultrasound-supported percutaneous angioplasty of post-kidney transplant renal artery bifurcation stenosis.

BACKGROUND: Transplant renal artery stenosis (TRAS) is an uncommon complication following renal transplantation. Its usual clinical presentation includes worsening hypertension and/or renal function, without any evidence of graft rejection. Bifurcation renal artery stenosis of the transplanted renal artery is rarely encountered. METHODS: Percutaneous transluminal renal angioplasty (PTRA) with or without stenting is the procedure of choice to treat TRAS. We hereby describe a patient, who presented with impaired renal functions, four months following the renal transplantation. He underwent intravascular ultrasound-guided PTRA of the bifurcation lesion of TRAS.Results and conclusion: Superior renal artery had coronary drug-eluting stent implantation, while inferior renal artery and side branch of the superior renal artery had balloon angioplasty, alone. Post-intervention, the raised serum creatinine level decreased from 2.9 mg% to 1.7 mg%. The index case described the successful PTRA and stenting of the bifurcation lesion of TRAS, the technical results of which was optimized with the use of intravascular ultrasound.

Long-term outcome of percutaneous transluminal renal angioplasty (PTRA) versus PTRA with stenting (PTRAS) in transplant renal artery stenosis.

BACKGROUND: Endovascular treatment is standard of care for transplant renal artery stenosis (TRAS). No study has evaluated long-term outcomes compared between percutaneous transluminal renal angioplasty (PTRA) and PTRA with stenting (PTRAS). Accordingly, this study aimed to investigate the 1-year clinical success, and short- and long-term event-free survival between PTRA and PTRAS in patients diagnosed with TRAS at Thailand's largest national tertiary referral center. METHODS: This single-center retrospective study included kidney transplant patients treated for TRAS during January 2001 to June 2019. Clinical success was defined as (1) increase in estimated glomerular filtration rate (eGFR) > 15%, or (2) reduction in mean arterial pressure (MAP) > 15% with no decrease in antihypertensive medication, or no reduction in MAP or reduction in MAP < 15% with decrease in antihypertensive medication. Incidence of kidney transplant graft failure and transplant renal artery stenosis were also collected. RESULTS: Sixty-five cases of TRAS were identified from 1072 patients who underwent kidney transplantation. The majority (98.5%) had end-to-side anastomosis technique. Thirty-four patients had PTRA, while 31 patients had PTRAS. One-year clinical success according to renal outcome and BP reduction was 78.5% and 49.2%, respectively. Both renal outcome (79.4% vs. 77.4%, p = 0.845) and BP reduction (40.6% vs. 58.1%, p = 0.166) at 1 year were similar between the PTRA and PTRAS groups. Compared between PTRA and PTRAS, event-free survival for composite of kidney transplant graft failure or transplant renal artery restenosis was significantly higher for PTRAS at 1 year (82.4% vs. 100%, p = 0.025), but not significantly different at 10 years (73.5% vs. 71%, p = 0.818). CONCLUSIONS: We demonstrated the 1-year clinical success, and short- and long-term event-free survival between PTRA and PTRAS in TRAS patients. One-year clinical success was found to be similar between groups. Event-free survival for composite of kidney transplant graft failure or transplant renal artery restenosis was significantly higher in PTRAS at 1 year, but similar between groups at 10 years. Trial registration Thai Clinical Trials Registry, TCTR20200626002. Registered 26 June 2020-Retrospectively registered, http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trial search&smenu = fulltext&task = search&task2 = view1&id = 6441.

Simultaneous endovascular revascularization of external iliac artery dissection and transplant renal artery stenosis in a recent renal allograft recipient.

Various vascular complications following renal transplantation include renal artery and vein thrombosis, renal artery stenosis, pseudoaneurysm, and iliac artery dissection. Transplant renal artery stenosis (TRAS) is the most common, while iliac artery dissection is the rarest of these various vascular complications. We describe an elderly male, who had both external iliac artery dissection and TRAS at 2 months following renal transplantation. He underwent successful percutaneous endovascular intervention of both complications. The post-intervention course was uneventful, with improvement in graft renal functions and left lower limb perfusion.

As diversas complicações vasculares possíveis após um transplante renal incluem trombose da veia e artéria renais, estenose da artéria renal, pseudoaneurisma e dissecção da artéria ilíaca. Entre essas diversas complicações, a estenose da artéria renal transplantada é a mais comum, enquanto a dissecção da artéria ilíaca é a mais rara. Relatamos o caso de um homem idoso que desenvolveu tanto dissecção da artéria ilíaca quanto estenose da artéria renal transplantada 2 meses após transplante renal. As intervenções endovasculares percutâneas foram bem-sucedidas em ambas as complicações. O período pós-intervenção cursou sem complicações, com melhora na função renal do enxerto e na perfusão do membro inferior esquerdo.

Endovascular stenting with a drug-eluting stent of transplanted renal artery stenosis in a dual kidney transplanted patient.

Renal transplant remains the preferred therapy for end-stage renal disease (ESRD). Given the shortage of suitable donor kidneys, use of an expanded criteria donor (ECD) allows marginal kidneys to be transplanted; albeit at risk of increased graft failure due to lower nephron mass. To reduce the risk of graft failure, double kidney transplant (DKT) is advocated, with favorable outcomes. Transplant renal artery stenosis (TRAS) is one of the most common vascular complications following renal transplant. Unlike single kidney transplants, where TRAS usually presents with fluid overload, uncontrolled hypertension, and worsening kidney functions; it may be clinically silent in DKT patients since they have two functional transplanted kidneys. We hereby report a case of TRAS in a DKT patient who had 2 years of favorable clinical outcomes following successful endovascular stenting. He however recently died of COVID-19 associated pneumonitis.

O transplante renal continua sendo a terapia preferida para doenças renais em fase terminal. Dada a escassez de rins de doadores adequados, o doador com critérios expandidos permite que rins marginais sejam transplantados, embora haja um maior risco de falha do enxerto devido à diminuição da massa nefrótica. Para diminuir o risco de falha do enxerto, recomenda-se o transplante renal duplo (TRD), com resultados favoráveis. A estenose de artéria renal transplantada (EART) é uma das complicações vasculares mais comuns após o transplante renal. Ao contrário dos transplantes de rim simples, nos quais a EART geralmente se manifesta como sobrecarga de fluido, hipertensão descontrolada e piora das funções renais, ela pode ser clinicamente silenciosa em pacientes com TRD, pois eles têm dois rins funcionais transplantados. Relatamos aqui um caso de EART em um paciente com TRD que teve resultados clínicos favoráveis por dois anos após o sucesso do implante de stent endovascular. No entanto, ele morreu recentemente de pneumonite associada à covid-19.

Unexpected presentation and surgical salvage of transplant renal artery dissection caused by vascular clamping: a case report.

BACKGROUND: Transplant renal artery dissection is a rare and serious event that can cause allograft dysfunction and activation of the renin-mediated renovascular hypertension. Most cases are induced by percutaneous transluminal angioplasty, arteriosclerotic disease, or fibromuscular dysplasia. We observed a case of transplant renal artery dissection induced by unusual causes during kidney transplantation. CASE PRESENTATION: A 35-year-old woman, whose mother donated a kidney to her, underwent ABO-incompatible living kidney transplantation. The allograft had one renal artery and vein that were anastomosed to the internal iliac artery and external iliac vein, respectively. Although careful handling was performed in all procedures including vascular clamping, Doppler ultrasonography (US) immediately after reperfusion showed an increase in the systolic blood velocity and urine output was not observed. Arterial anastomotic stenosis was suspected, but upon exploration, a renal artery dissection was detected in the middle portion of the donor artery. The part of the transplant renal artery was resected, and cold reflux was started again. At the resected part of transplant renal artery, dissection was identified. After re-anastomosis, Doppler US revealed that the blood flow of the renal artery was adequate without an increase in the systolic blood velocity, and sufficient blood flow was observed throughout the allograft. Urine output was also observed as soon as blood flow returned, and serum creatinine level decreased to 0.95 mg/dL after surgery. The cause of injury might have been vascular clamping in order to drain the air and check bleeding at the anastomosis. CONCLUSIONS: Our case reaffirmed that careful handling is needed in all procedures, including donor nephrectomy, cannulation for transplant perfusion, vascular clamping, and anastomosis, even without any evidence of arteriosclerosis. Kidney transplant recipients commonly have atherosclerosis and hypertension, which are risk factors for arterial dissection. Early diagnosis and intervention can lead to the prevention of allograft dysfunction. Therefore, close monitoring of allograft blood flow by Doppler US during surgery should be considered.

Spontaneous recanalization of occluded transplant renal artery: a rare case report.

BACKGROUND: Transplant renal artery stenosis (TRAS) is a serious vascular complication that occurs after renal transplantation and can result in hypertension, renal functional impairment, and graft loss. Endovascular treatment has become the first-line treatment for TRAS because of its low invasiveness and high success rate. CASE PRESENTATION: A 23-year-old female with end-stage renal disease of unknown cause received a living-donor kidney transplantation 10 months ago. Seven months after the transplantation, her blood pressure gradually deteriorated. Magnetic resonance angiography revealed bending and stenosis of the transplant renal artery, and the patient received endovascular treatment. A digital subtraction angiography revealed significant stenosis of 95% in the proximal transplant renal artery. The guidewire could not pass through the stenotic segment of the transplant renal artery even with repeated attempts by the surgeons; as a result, the transplant renal artery became occluded, and vasodilators were ineffective. After the operation, renal function gradually worsened, so she began to receive regular dialysis. Twenty-five days later, the patient's urine volume was significantly higher than that before, and ultrasound showed that the proximal transplant renal artery was not completely occluded. A re-intervention was performed, and the stent was placed successfully in the stenotic segment. After the operation, renal function gradually recovered, and dialysis was no longer needed. CONCLUSION: Patients with iatrogenic transplant renal artery occlusion may have the possibility of spontaneous recanalization, which can help prevent the need for re-transplantation.

Intra-arterial computed tomography angiography with ultra-low volume of iodine contrast and stent implantation in transplant renal artery stenosis in terms of contrast-induced kidney injury - a preliminary report.

PURPOSE: Traditional digital subtraction angiography is still regarded as the gold standard in the diagnostics of transplant renal artery stenosis (TRAS). However, this procedure requires a high volume of iodine contrast medium for optimal visualisation of the renal artery. The aim of this study was to analyse both the usefulness and the safety of intra-arterial computed tomography angiography (IA-CTA) with ultra-low-volume iodine contrast administration in the diagnostic and therapeutic management of TRAS in patients with impaired renal transplant function. MATERIAL AND METHODS: Thirty-three patients with a suspicion of TRAS based on Doppler-ultrasound and clinical setting underwent IA-CTA with ultra-low iodine contrast volume. A special, author-elaborated CTA protocol was used. The volume of 8-18 ml of diluted iodine contrast medium was administered through a catheter with the tip placed 2 cm below the aortic bifurcation. RESULTS: In six patients the CTA examinations revealed TRAS in three configurations: in the anastomosis, in the trunk (critical and high-grade), or in both sections. Stenoses were treated with primary stenting obtaining favourable anatomical outcome. No intervention-related complications were observed. No contrast-induced acute kidney injury was diagnosed in this study. Mean serum creatinine concentration was 2.93 ± 0.89 mg/dl at the baseline and 2.89 ± 1.73 mg/dl and 2.17 ± 0.51 mg/dl after three and seven days from IA-CTA, respectively. CONCLUSIONS: Intra-arterial CTA with ultra-low volume of iodine contrast seems to be a safe and reliable diagnostic tool to detect and assess TRAS in the aspect of stent implantation. Application of this imaging modality eliminates the need for a high volume of iodine contrast and thus does not adversely influence renal transplant function.

Angioplasty vs stent in the treatment of transplant renal artery stenosis.

OBJECTIVE: To compare outcomes between percutaneous transluminal angioplasty and stent placement in the treatment of transplant renal artery stenosis (TRAS). METHODS: We retrospectively studied patients who underwent angiography for TRAS between 1/1/2008 and 9/20/2016 at 1 center. We compared the rates of restenosis in patients who were treated with angioplasty alone vs those who were treated with stenting. Secondary outcomes included serum creatinine and blood pressure after intervention and graft and patient survival. RESULTS: A total of 82 patients were identified as having TRAS after angiography. Restenosis occurred in 28% (16 of 58) of the angioplasty patients compared with 8% (2 of 24) of the stented patients (P = .04). Repeat angiography occurred in 14% (8 of 58) of angioplasty patients vs 13% (3 of 24) of stented patients (P = .9). The stented group had significantly higher pre-intervention stenosis (71% vs 64%, P = .01) and lower postintervention stenosis (4% vs 30%, P < .001). Serum creatinine and blood pressures were not significantly different between the 2 groups at 30, 90, or 360 days postintervention. There was no statistically significant difference in graft or patient survival between groups (P = .37). CONCLUSIONS: Stent placement resulted in fewer cases of restenosis compared with angioplasty alone, although no benefit in terms of serum creatinine, blood pressure, or patient and graft survival was shown.

Endovascular treatment of transplant renal artery stenosis based on hemodynamic assessment using a pressure wire: a case report.

BACKGROUND: Transplant renal artery stenosis (TRAS) is a serious complication after renal transplantation, leading to hypertension, deterioration in renal function, and/or graft loss. The incidence of TRAS reportedly varies from 1 to 23%, depending on its definition or diagnostic tools. The hemodynamic definition or therapeutic indication of TRAS is unclear. CASE PRESENTATION: A 66-year-old man with a history of diabetes, chronic kidney disease, and angina presented with a 2-week history of dyspnea and leg edema. He had undergone living-donor kidney transplantation for end-stage renal disease secondary to diabetic nephropathy 7 years earlier. He developed acute deterioration in renal function after the administration of an angiotensin II receptor blocker and required emergency hospitalization owing to acute congestive heart failure with pulmonary edema. A vasodilator and loop diuretics were administered following his admission, and the patient's symptoms resolved quickly. Further investigation, including magnetic resonance angiography and ultrasonography, revealed severe stenosis of the transplant renal artery. Renal arteriography and pressure gradient measurement using a 0.014-inch pressure wire were performed. The systolic pressure gradient was 40 mmHg, and the resting Pd/Pa ratio (ratio of mean distal to lesion and mean proximal pressures) was 0.90 without hyperemia. Hemodynamically significant stenosis was suspected. Intravascular ultrasonography revealed vessel shrinkage in the stenotic area, suggestive of the end-to-end anastomosis site. Pre-dilation using a 4-mm balloon, implantation of a 6-mm self-expandable stent, and post-dilatation using a 5-mm balloon were performed. Although the moderate stenosis persisted angiographically, the systolic pressure gradient dropped to 20 mmHg with the mean systolic pressure ratio increased to 0.95, which was considered an acceptable result. One month after the procedure, the patient's renal function and blood pressure control had significantly improved. CONCLUSIONS: Hemodynamic assessment using a pressure wire is useful in determining the appropriate therapeutic indication and endpoint of endovascular treatment of TRAS.

Transplant renal artery stenosis caused by the stretch of an artey branch: a case report and literature review.

BACKGROUND: Renal transplant is the preferred treatment option for these patients with end-stage renal disease. Transplant renal artery stenosis (TRAS) is one of the most common and serious vascular complications after renal transplantation, and most of the TRAS occurred in the anastomosis. The complication must be diagnosed and treated timely, otherwise the function of transplanted kidney may be losed. CASE PRESENTATION: A 46-year-old male with end-stage renal disease of unknown cause received a cadaveric renal transplant one year ago. Although three antihypertensive medications were administrated, his blood pressure gradually increased to 190/120 mmHg 3 weeks posttransplantation. Also the level of creatinine increased to 194 µmol/L.Color Doppler ultrasonography indicated a decreased resistance index (RI) in intrarenal arteries and increased blood flow of the transplant renal artery, therefore, a vascular complication of TRAS was suspected. Arteriography was performed and demonstrated TRAS caused by stretch of an artery branch, and the TRAS occurred in the distal site of the anastomosis instead of the anastomosis. Percutaneous transluminal bare stent implantation treatment was successfully performed. Satisfactory clinical efficacy with improvement in transplant renal function and renovascular hypertension was achieved after the interventional treatment. CONCLUSION: To our knowledge this is the first reported case of TRAS caused by stretch of an artery branch. When refractory hypertension and allograft dysfunction are presented posttransplantation, TRAS should be suspected. Color Doppler ultrasonography as a non-invasive examination may provide some valuable information, three-dimention CT can be useful for further diagnosis, but is seldom necessary. Arteriography provides the definitive diagnosis of TRAS. Percutaneous transluminal stent implantation treatment of TRAS has high success rate with minimal invasion and complications. When an artery branch situated on the stenosis, a bare stent rather than covered stent is the preferred choice.

Transplant renal artery stenosis: The impact of endovascular management and their outcomes.

INTRODUCTION: Transplant renal artery stenosis (TRAS) is a well-known vascular complication of renal transplantation. The aim of this analysis was to assess the short and midterm outcomes of endovascular therapy to salvage transplant kidney. METHODS: We retrospectively analyzed our transplant database from 2000 to 2015. Percutaneous transluminal angioplasty/stenting was done in 24 patients (22 men and two women) with significant TRAS. The mean age was 59 ± 12 years. The parameters analyzed were: Technical success, pre- and post-treatment serum creatinine and number of antihypertensive drugs before and after treatment and vessel patency on Doppler ultrasonography at 3 and 6 months. RESULTS: Overall incidence of TRAS in this study was 5.06%. Incidence of TRAS following live donor transplantation was 4.68% while that in deceased donors was 11.5%. Technical success was 100%. There were no periprocedural deaths. Renal function was improved from 2.32 ± 0.5 mg/dL to 1.72 ± 0.3 mg/dL (P < 0.001) and number of antihypertensive medications after the procedure was reduced from 2.9 ± 0.7 to 2 ± 0.6 (P < 0.001) at 6 months follow-up. One patient developed restenosis within 5 months (4.2%). Clinical success at 6 months follow-up was 79.2%. CONCLUSIONS: Endovascular treatment of TRAS has high technical success with minimal complications. It also provides satisfactory clinical success with improvement in overall transplant renal function and renovascular hypertension in early follow-up.

Long-term outcomes of transplant recipients referred for angiography for suspected transplant renal artery stenosis.

Our aim was to study the long-term outcomes of all transplant recipients who underwent angiography for suspected TRAS at our institution. The patients were divided into TRAS+ve and TRAS-ve groups based upon angiographically confirmed results. TRAS was confirmed in 58.1% of 74 patients with median time of 8.9 months. Primary angioplasty alone was performed in 56% of patients with TRAS, while the remaining had PTA with stent (PTAS). There was reduction in systolic and diastolic BP (165 ± 19-136 ± 15 mmHg and 82 ± 14 mmHg to 68 ± 12 mmHg; p < 0.05) and number of antihypertensive drugs (3.5 ± 0.9-2.7 ± 1.0; p < 0.05). Overall, graft survival and patient survival from time of transplant were similar in both groups. Graft function was similar for the patients with treated TRAS+ve as compared to TRAS-ve over time. Graft survival and patient survival when compared to an age- and year of transplant-matched cohort control group were also similar. In conclusion, angiography for suspected TRAS is more likely to yield a confirmatory result early in the transplant course as compared to late. Treatment of TRAS in these patients had sustained long-term graft function. Alternative etiologies of HTN and graft dysfunction should be sought for recipients further out from transplant.

Minimally invasive salvage therapy for transplanted renal allografts.

PURPOSE: To evaluate the effectiveness of interventional therapy for complications of transplanted renal allografts. MATERIALS AND METHODS: Between January 2009 and March 2014, 14 patients underwent interventional therapy for complications of renal allografts. Complications included transplant renal artery stenosis (TRAS), TRAS combined with pseudoaneurysms, transplant renal venous kinking and ureteral obstruction (UO). Serum creatinine (S.Cr) levels were evaluated before and after procedure. The characteristics and procedure outcomes of these patients with vascular and nonvascular complications were also analyzed. RESULTS: All primary procedures were successfully performed, which included percutaneous transluminal angioplasty (PTA) for TRAS (n = 4), stenting and coil embolization for TRAS combined with pseudoaneurysms (n = 1), stenting for renal vein kinking (n = 2), and percutaneous nephrostomy (PCN) for UO (n = 7) and secondary antegrade stent placement in six UO patients after 1 week of PCN. No major procedure related complications occurred. S.Cr level subsequently improved from 6.0 ± 3.6 to 2.6 ± 2.1 mg/dL (p < 0.001), as well as patients' clinical features within 1 week after procedure. In our study, the onset time of vascular complications was earlier (<6 months) than nonvascular complications with significant difference (p < 0.001). During follow-up, the patient with TRAS and pseudoaneurysms suffered acute rejection 1 month after treatment and received transplant renal artery embolization. One patient with TRAS showed restenosis 4 months after procedure, and was retreated successfully with stenting. Thirteen cases reserved their transplanted renal allografts. CONCLUSION: Interventional therapy could be prior considered for transplanted renal allograft complications as its effectiveness and minimal invasiveness in saving the transplanted renal grafts.

Postanastomotic transplant renal artery stenosis: association with de novo class II donor-specific antibodies.

In this study, we analyze the outcomes of transplant renal artery stenosis (TRAS), determine the different anatomical positions of TRAS, and establish cardiovascular and immunological risk factors associated with its development. One hundred thirty-seven of 999 (13.7%) patients had TRAS diagnosed by angiography; 119/137 (86.9%) were treated with angioplasty, of which 113/137 (82.5%) were stented. Allograft survival in the TRAS+ intervention, TRAS+ nonintervention and TRAS- groups was 80.4%, 71.3% and 83.1%, respectively. There was no difference in allograft survival between the TRAS+ intervention and TRAS- groups, p = 0.12; there was a difference in allograft survival between the TRAS- and TRAS+ nonintervention groups, p < 0.001, and between the TRAS+ intervention and TRAS+ nonintervention groups, p = 0.037. TRAS developed at the anastomosis, within a bend/kink or distally. Anastomotic TRAS developed in living donor recipients; postanastomotic TRAS (TRAS-P) developed in diabetic and older patients who received grafts from deceased, older donors. Compared with the TRAS- group, patients with TRAS-P were more likely to have had rejection with arteritis, odds ratio (OR): 4.83 (1.47-15.87), p = 0.0095, and capillaritis, OR: 3.03 (1.10-8.36), p = 0.033. Patients with TRAS-P were more likely to have developed de novo class II DSA compared with TRAS- patients hazard ratio: 4.41 (2.0-9.73), p < 0.001. TRAS is a heterogeneous condition with TRAS-P having both alloimmune and traditional cardiovascular risk factors.

Case report: Endovascular treatment of transplant renal artery stenosis in patient with normal color duplex ultrasound of the renal artery.

Key Clinical Message: Proper diagnosis and treatment of vascular stenosis which is a possible complication of renal transplant is important in improving patients' quality of life and prognosis. Abstract: One known consequence among recipients of renal transplants is graft renal artery stenosis. Early identification and therapy are crucial to avoid graft malfunction and the serious consequences that might arise due to elevated hypertension in several organs. We report a rare case of transplant renal artery stenosis in a mid-aged woman who presented with edema, hypertension, and increased creatinine 2 months after kidney transplant. The patient had normal renal arterial resistive index (RI) and perfusion index (PI), and there was only a modest decrease in perfusion on duplex ultrasound. Following the patient's renal stenting treatment, angiographic resolution was observed. After 14 days of regulated blood pressure following renal artery stenting, she was discharged from the hospital with her edema resolved. Considering complications in patients with clinical manifestations such as hypertension resistant to treatment and graft dysfunction, vascular stenosis is a notable issue to consider even in the context of normal renal arterial RI, PI, and duplex ultrasound. Proper diagnosis and treatment are of importance to improve patients' quality of life and prognosis.