Estenosis arterial del injerto renal: evaluación de la incidencia mediante ecografía doppler, factores de riesgo y análisis de las complicaciones que pueden afectar a la supervivencia del injerto / Transplant renal artery stenosis: Study of incidence using doppler ultrasound, risk factors and analysis is effect in graft outcomes

Introducción y objetivos La estenosis de la arteria del injerto renal (EAR) es una complicación vascular del trasplante renal cuya incidencia estimada es del 13%, la cual puede causar hipertensión arterial refractaria, disfunción renal y muerte prematura en los receptores. Métodos Se realizó un estudio retrospectivo que incluyó a todos los pacientes sometidos a trasplante renal entre 2014 y 2020. Los pacientes fueron evaluados mediante ecografía doppler renal sistemática tras el trasplante. Para identificar los factores de riesgo independientes de la estenosis de la arteria renal tras el trasplante, realizamos un análisis multivariante. Resultados Se incluyeron 724 trasplantes renales, el 12% eran de donante vivo y el 88% de donante fallecido. La edad media en los receptores era de 54,8 años y en los donantes era de 53. Se diagnosticó estenosis de la arteria del injerto renal en 70 (10%) receptores, la mayoría durante los primeros 6 meses después de la intervención. El 51% de los pacientes con estenosis de la arteria del injerto renal se manejaron de manera conservadora. El análisis multivariante mostró que la diabetes mellitus, el rechazo del injerto, la resutura arterial y el índice de masa corporal del donante eran factores de riesgo independientes de estenosis de la arteria renal después del trasplante. La supervivencia de los injertos con estenosis de la arteria del injerto renal fue del 98% a los 6 meses y del 95% a los 2 años. Conclusiones El uso sistemático de la ecografía doppler en el período inmediatamente posterior al trasplante permitió diagnosticar un 10% de estenosis de la arteria del injerto renal en nuestra cohorte. A pesar de los factores de riesgo mencionados anteriormente, un seguimiento y tratamiento adecuados podrían reducir el riesgo de pérdida del injerto en pacientes con estenosis de la arteria del injerto renal. (AU)

Introduction and objectives Transplant renal artery stenosis (TRAS) is a vascular complication after kidney transplantation which estimated incidence is 13%. It could cause refractory arterial hypertension, kidney dysfunction and premature death in transplant recipients. Methods We carried out a retrospective study including every patient who underwent renal transplantation between 2014 and 2020. They were evaluated with a systematic post-transplant renal Doppler ultrasound. To identify independent risk factors for transplant renal artery stenosis we performed a multivariate analysis. Results Seven hundred twenty-four kidney transplants were included, 12% were living donors and 88% were deceased donors. The mean age was 54.8 in recipients and 53 in donors. Transplant renal artery stenosis was diagnosed in 70 (10%) recipients, the majority in the first 6 months after surgery. The 51% of patients with transplant renal artery stenosis were managed conservatively. The multivariate analysis showed diabetes mellitus, graft rejection, arterial resuture and donor body mass index as independent risk factors for transplant renal artery stenosis. Survival of the grafts with transplant renal artery stenosis was 98% at 6 months and 95% at two years. Conclusions The systematic performance of Doppler ultrasound in the immediate post-transplant period diagnosed 10% of transplant renal artery stenosis in our cohort. Despite the above risk factors, an adequate monitoring and treatment could avoid the increased risk of graft loss in patients with transplant renal artery stenosis. (AU)

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.

Percutaneous transluminal angioplasty with stenting for transplant renal artery stenosis at the anastomosis site in a young female patient: A case report.

INTRODUCTION: Transplant renal artery stenosis (TRAS) is one of the major vascular complications and is mostly reported within six months following kidney transplant. CASE PRESENTATION: The present case was a 16-year-old female whose blood urea nitrogen (BUN) and creatinine rose seven days after a kidney transplant. Ultrasound investigation revealed well-prefusion with a 90-degree angle anastomosis, apparent narrowing, and peak systolic velocity of 300 cm/s. Fourteen days after the transplant, with pre-and post-intervention hemodialysis and well hydration, an angiography with diluted iodinated contrast was done for the patient, which revealed >80 % narrowing at the anastomosis site. Percutaneous transluminal angioplasty (PTAS) with stenting was carried out for the patient, resulting in normal levels of BUN, creatinine, and urinary output. CLINICAL DISCUSSION: While the patient did not have any risk factors for TRAS and was young, an early stenosis occurred in her left internal iliac artery one week after the kidney transplant. Due to the lower accuracy of CO2 angiography, diluted iodinated contrast angiography with well hydration and pre- and post-intervention dialysis was preferred. Endovascular treatment was preferred by the patient and attending physician due to possible adhesion and complications of open surgery and the possibility of arterial rupture. CONCLUSION: Performing PTAS two weeks after the renal transplantation at the anastomosis site can be a treatment in patients with early TRAS. However, due to the higher risk of rupture at the anastomosis site, it should be carried out carefully and with consideration of the need for open surgery.

Transplant renal artery stenosis: Study of incidence using doppler ultrasound, risk factors and analysis is effect in graft outcomes.

INTRODUCTION AND OBJECTIVES: Transplant renal artery stenosis (TRAS) is a vascular complication after kidney transplantation which estimated incidence is 13%. It could cause refractory arterial hypertension, kidney dysfunction and premature death in transplant recipients. METHODS: We carried out a retrospective study including every patient who underwent renal transplantation between 2014 and 2020. They were evaluated with a systematic post-transplant renal Doppler ultrasound. To identify independent risk factors for transplant renal artery stenosis we performed a multivariate analysis. RESULTS: Seven hundred twenty-four kidney transplants were included, 12% ​​were living donors and 88% were deceased donors. The mean age was 54.8 in recipients and 53 in donors. Transplant renal artery stenosis was diagnosed in 70 (10%) recipients, the majority in the first 6 months after surgery. 51% of patients with transplant renal artery stenosis were managed conservatively. The multivariate analysis showed diabetes mellitus, graft rejection, arterial resuture and donor body mass index as independent risk factors for transplant renal artery stenosis. Survival of the grafts with transplant renal artery stenosis was 98% at 6 months and 95% at two years. CONCLUSIONS: The systematic performance of Doppler ultrasound in the immediate post-transplant period diagnosed 10% of transplant renal artery stenosis in our cohort. Despite the above risk factors, an adequate monitoring and treatment could avoid the increased risk of graft loss in patients with transplant renal artery stenosis.

Life-Threatening Hematuria as Initial Presentation of a Complicated Transplant Renal Artery Pseudoaneurysm.

In this case report, we describe the clinical course of a complicated transplant renal artery (TRA) pseudoaneurysm, clinically featured by gross and massive hematuria one month after a kidney transplant was performed on a 50 year-old male patient. TRA pseudoaneurysm is a rare but potentially life-threatening complication that may result in bleeding, infection, graft dysfunction/loss, lower limb ischemia/loss, hemorrhagic shock, and death. TRA pseudoaneurysm treatment remains challenging as it needs to be tailored to the patient characteristics including hemodynamic stability, graft function, anatomy, presentation, and pseudoaneurysm features. This publication discusses the clinical scenario of massive gross hematuria that derived from a retroperitoneal hematoma which originated from an actively bleeding TRA pseudoaneurysm. This case highlights the combined approach of endovascular stent placement and subsequent transplant nephrectomy as a last resort in the management of intractable bleeding from a complicated TRA pseudoaneurysm. To the best of our knowledge, this is the first published case report of an actively bleeding TRA anastomotic pseudoaneurysm that caused a massive retroperitoneal bleed that in turn evacuated via the bladder after disrupting the ureter-to-bladder anastomosis. A temporizing hemostatic arterial stent placed percutaneously allowed for a safer and controlled emergency transplant nephrectomy.

Successful repair of transplant renal artery aneurysm (TRAA).

BACKGROUND: Transplant renal artery aneurysm (TRAA) is rare. TRAA that develops post transplantation consists of 0.10% of the vascular complications post renal transplant (Transplant Proc 41:1609-1614, 2009; Indian J Urol 29:42-47, 2013). CASE PRESENTATION: We report a case of TRAA in an asymptomatic young female. CT angiogram with detailed 3D reconstruction showed a 2.6 × 2.2 cm wide neck saccular TRAA arising from the anterior segmental branch of the graft renal artery (Figs. 2 and 3). A multidisciplinary team of interventional radiologists, vascular and urologist was involved for preoperative surgical planning and unique repair methods. Endovascular and percutaneous approaches were deemed not feasible, and an open in vivo approach with a saphenous vein graft was taken. CONCLUSION: TRAA, albeit rare, is a complication that can occur post renal transplant. In-vivo surgical repair of TRAA is feasible with a multidisciplinary approach and careful preoperative planning. Saphenous vein graft is still a versatile graft and can be used as a conduit successfully.

Aspergillus spp. renal arteritis after kidney transplantation: A reappraisal.

BACKGROUND: Aspergillus spp. is an uncommon and life-threatening cause of transplantrenal artery pseudoaneurysm after kidney transplantation. CASE: We report the case of a 62-year-old woman who underwent kidney transplantation 10 months before and presented a 7-cm asymptomatic transplant renal artery pseudoaneurysm. Transplanted kidney and pseudoaneurysm were surgically removed in emergency. Renal graft, urine, and pseudoaneurysm cultures grew Aspergillus flavus. She recovered after 12 months of antifungal therapy. LITERATURE REVIEW: To date 14 cases of Aspergillus spp. renal arteritis after kidney transplantation have been published, including 50% Aspergillus flavus arteritis. Vast majority were diagnosed within 90 days after transplantation (73%). Despite allograft nephrectomy and antifungal therapy, mortality rate was high (33%).

Predicting older-donor kidneys' post-transplant renal function using pre-transplant data.

This paper provides a methodology for predicting post-transplant kidney function, that is, the 1-year post-transplant estimated Glomerular Filtration Rate (eGFR-1) for each donor-candidate pair. We apply customized machine-learning algorithms to pre-transplant donor and recipient data to determine the probability of achieving an eGFR-1 of at least 30 ml/min. This threshold was chosen because there is insufficient survival benefit if the kidney fails to generate an eGFR-1 ≥ 30 ml/min. For some donor-candidate pairs, the developed algorithm provides highly accurate predictions. For others, limitations of previous transplants' data results in noisier predictions. However, because the same kidney is offered to many candidates, we identify those pairs for whom the predictions are highly accurate. Out of 6977 discarded older-donor kidneys that were a match with at least one transplanted kidney, 5282 had one or more identified candidate, who were offered that kidney, did not accept any other offer, and would have had ≥80% chance of achieving eGFR-1 ≥ 30 ml/min, had the kidney been transplanted. We also show that transplants with ≥80% chance of achieving eGFR-1 ≥ 30 ml/min and that survive 1 year have higher 10-year death-censored graft survival probabilities than all older-donor transplants that survive 1 year (73.61% vs. 70.48%, respectively).

Transplant renal artery stenosis: utilization of machine learning to identify ancillary sonographic and doppler parameters to predict stenosis in patients with graft dysfunction.

PURPOSE: To determine if ancillary sonographic and Doppler parameters can be used to predict transplant renal artery stenosis in patients with renal graft dysfunction. MATERIALS AND METHODS: IRB-approved, HIPAA-compliant retrospective study included 80 renal transplant patients who had renal US followed by renal angiogram between January 2018 and December 2019. A consensus read of two radiologists recorded these parameters: peak systolic velocity, persistence of elevated velocity, grayscale narrowing, parvus tardus, delayed systolic upstroke, angle of the systolic peak (SP angle), and aliasing. Univariate analysis using t-test or chi-square was performed to determine differences between patients with and without stenosis. P values under 0.05 were deemed statistically significant. We used machine learning algorithms to determine parameters that could better predict the presence of stenosis. The algorithms included logistic regression, random forest, imbalanced random forest, boosting, and CART. All 80 cases were split between training and testing using stratified sampling using a 75:25 split. RESULTS: We found a statistically significant difference in grayscale narrowing (p = 0.0010), delayed systolic upstroke (p = 0.0002), SP angle (p = 0.0005), and aliasing (p = 0.0024) between the two groups. No significant difference was found for an elevated peak systolic velocity (p = 0.1684). The imbalanced random forest (IRF) model was selected for improved accuracy, sensitivity, and specificity. Specificity, sensitivity, AUC, and normalized Brier score for the IRF model using all parameters were 73%, 81%, 0.82, and 69 in the training set, and 78%, 58%, 0.78, and 80 in the testing set. VIMP assessment showed that the combination of variables that resulted in the most significant change of the training set performance was that of grayscale narrowing and SP angle. CONCLUSION: Elevated peak systolic velocity did not discriminate between patients with and without TRAS. Adding ancillary parameters into the machine learning algorithm improved specificity and sensitivity similarly in the training and testing sets. The algorithm identified the combination of lumen narrowing coupled with the angle of the systolic peak as better predictor of TRAS. This model may improve the accuracy of ultrasound for transplant renal artery stenosis.

Case report: Application of nonsurgical method in saving transplant renal vein thrombosis caused by acute diarrhea.

Transplant renal vein thrombosis is a rare complication after kidney transplantation, which can seriously threaten graft survival. Though the measures like thrombolytic therapy or operative intervention could be taken to deal with this complication, allograft loss is the most common outcome. Thus, early finding as well as decisive intervention is crucial to saving the graft. Here we present a 46-year-old male patient who underwent kidney transplantation from a cadaveric donor who developed a transplant renal venous thrombosis induced by acute diarrhea more than 1 year after renal transplantation with an initial symptom of sudden anuria and pain in the graft area. Subsequently, serum creatinine levels increased to 810.0 µmol/L. Pelvic CT showed increased vascular density of the transplanted kidney, and contrast-enhanced ultrasound confirmed venous thrombosis. The patient was treated with heparin sodium alone and diuresis gradually resumed. After more than 1 year of follow-up, serum creatinine returned to the baseline level prior to thrombosis. Our case indicates that quick ancillary examination and treatment without hesitation would be indispensable in rescuing allografts with renal vein thrombus. Unfractionated heparin can be recommended as an effective treatment for mid-long-term renal transplantation patients with renal vein thrombosis.

Risk factors of transplant renal artery stenosis in kidney transplant recipients.

BACKGROUND: Transplant Renal Artery Stenosis (TRAS) is a recognized vascular complication after kidney transplantation. The overall risk predictors of TRAS are poorly understood. METHODS: Retrospective analysis of patients with suspected TRAS (Doppler ultrasound PSV > 200 cm/s) who underwent angiographic study in a single center between 2007 and 2014. All patients with stenosis > 50% were considered with TRAS. Stenosis restricted in the body of the artery was also analyzed in a subgroup. RESULTS: 274 patients were submitted to a renal angiography and 166 confirmed TRAS. TRAS group featured an older population (46.3 ± 11.0 vs. 40.9 ±14.2 years; p = 0.001), more frequent hypertensive nephropathy (30.1% vs. 15.7%; p = 0.01), higher incidence of Delayed Graft Function (DGF) (52.0% vs. 25.6%; p < 0.001) and longer Cold Ischemia Time (CIT) (21.5 ± 10.6 vs. 15.7 ± 12.9h; p < 0.001). In multivariable analyses, DGF (OR = 3.31; 95% CI 1.78‒6.30; p < 0.0001) was independent risk factors for TRAS. DM and CIT showed a tendency towards TRAS. The compound discriminatory capacity of the multivariable model (AUC = 0.775; 95% CI 0.718‒0.831) is significantly higher than systolic blood pressure and creatinine alone (AUC = 0.62; 95% CI 0.558-0.661). In body artery stenosis subgroup, DGF (OR = 1.86; 95% CI 1.04‒3.36; p = 0.03) and Diabetes Mellitus (DM) (OR = 2.44; 95% CI 1.31‒4.60; p = 0.005) were independent risk factors for TRAS. CONCLUSION: In our transplant population, DGF increased more than 3-fold the risk of TRAS. In the subgroup analysis, both DGF and DM increases the risk of body artery stenosis. The addition of other factors to hypertension and renal dysfunction may increase diagnostic accuracy. TRAS TRIAL REGISTRED: clinicaltrials.gov (n° NCT04225338).

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.

Various Techniques and Outcomes of Arterial Anastomosis in Live Renal Transplant: An Institutional Experience.

Introduction Renal transplantation with multiple arteries is associated with a major index of surgical complications. Relevant papers and meta-analyses have shown relatively more vascular and urological complications in transplant of donor kidneys with multiple arteries. In live donor grafts due to the unavailability of a carrel patch, several techniques for bench and in situ reconstruction have been described in order to reduce the incidence of these vascular complications. In this study, the short and long-term results of living donor kidney transplants with multiple renal arteries (MRAs) versus single renal artery (SRA) were compared retrospectively. Methods This is a retrospective study done on patients who received a living donor kidney between January 2012 and January 2018 at the Institute of Urology, Madras Medical College, Chennai. We have excluded deceased donor kidney transplants and ABO-incompatible cases done in the same time period. The study was approved by the Institutional Ethics Committee (Approval No: IES-MMC-008) and performed in accordance with the guidelines of the Declaration of Helsinki. Open live donor nephrectomy was performed through an extra-peritoneal flank incision in all cases. In the SRA group, the renal artery was anastomosed end to end to the Internal iliac artery, while the renal vein was anastomosed to the external iliac vein in the end to side fashion. Urinary tract reconstruction was accomplished by the Gregoir technique in both groups. We looked at recipient complications, baseline and postoperative serum creatinine, total ischemia time, mean operating time, and short- and long-term graft and patient survival as postoperative outcomes. Results In a six-year period (2012-2018) at our institute, 256 living donor transplantations were performed; 36 (14%) kidneys had two or more renal arteries which were anastomosed using various techniques. Cold ischemia time was relatively longer in the MRA group (45 mins vs 28 mins in the SRA group) (p-value <0.05). while warm ischemia time was comparable in both groups (2.5 vs 2.9 mins) serum creatinine was comparable in both groups at the 30th postoperative day (1.4 in SRA group vs 1.2 in MRA group) (p-value >0.05). Incidence of surgical complications in SRA and MRA groups was: vascular - 3.6% and 2.7%; urological - 3.2% and 2.7%; the incidence of lymphocele was 4.5% and 5.5% and delayed graft function 4.5% and 5.5% respectively. Conclusion Multiple renal arteries are no longer a relative contraindication with advanced surgical techniques. in renal grafts with multiple arteries, all techniques of vessel anastomosis are comparable in terms of post-surgical complications.

Non-pulmonary complications after lung transplantation: Part I.

Lung transplantation (LT) is a viable therapeutic option in the treatment of advanced lung disease. With improvements in post-transplant survival, complications involving different organ systems after LT are increasingly seen. While non-infectious, extrapulmonary complications after LT are not frequently responsible for early post-transplant mortality, they significantly impact the quality of life and long-term survival. These complications are, therefore, becoming increasingly relevant as patients with LT are living longer. These complications encompass almost all organ systems and are driven by a combination of the preexisting comorbidities, events, and complications around the operative procedure and recovery, and perhaps most importantly, medication side effects of the post-LT regimen. We will discuss the wide array of non-infectious extrapulmonary complications after LT in a two-part series of review articles. While we intend to discuss the relevant literature around these complications, there is little in terms of consensus documents to guide the management approach of these complications. We will, therefore, share our experience and learnings that have shaped the management protocols we have in place in an effort to prevent and treat such complications. The goal of the first part of this two-part review is to provide an overview of the most pertinent non-infectious extrapulmonary complications pertaining to cardiovascular, renal, neuropsychiatric and ophthalmologic organ systems.

Percutaneous transluminal interventions of transplant renal artery stenosis: A case series study.

Introduction: and importance: Transplant renal artery stenosis (TRAS) is a well-recognized vascular complication after kidney transplant that can lead to graft loss, when it is diagnosed early and treated appropriately it may prevent kidney damage and related systemic squeals. Case presentation: This case-series represents our center experience in managing TRAS using percutaneous transluminal angioplasty [either balloon angioplasty (PTA) or stent placement (PTAS)] in 11 patients. Clinical discussion: All treated patients experienced immediate total recovery of renal function and normalization of arterial blood pressure without any drug or reducing the number of drugs used; no complications related to the intervention were reported. Conclusion: PTA or PTAS of TRAS can be considered safe and effective when it diagnosed and treated early.

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.

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.

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.

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.

Risk factors of transplant renal artery stenosis in kidney transplant recipients

Abstract Background: Transplant Renal Artery Stenosis (TRAS) is a recognized vascular complication after kidney transplantation. The overall risk predictors of TRAS are poorly understood. Methods: Retrospective analysis of patients with suspected TRAS (Doppler ultrasound PSV > 200 cm/s) who underwent angiographic study in a single center between 2007 and 2014. All patients with stenosis > 50% were considered with TRAS. Stenosis restricted in the body of the artery was also analyzed in a subgroup. Results: 274 patients were submitted to a renal angiography and 166 confirmed TRAS. TRAS group featured an older population (46.3 ± 11.0 vs. 40.9 ±14.2 years; p = 0.001), more frequent hypertensive nephropathy (30.1% vs. 15.7%; p = 0.01), higher incidence of Delayed Graft Function (DGF) (52.0% vs. 25.6%; p < 0.001) and longer Cold Ischemia Time (CIT) (21.5 ± 10.6 vs. 15.7 ± 12.9h; p < 0.001). In multivariable analyses, DGF (OR = 3.31; 95% CI 1.78-6.30; p < 0.0001) was independent risk factors for TRAS. DM and CIT showed a tendency towards TRAS. The compound discriminatory capacity of the multivariable model (AUC = 0.775; 95% CI 0.718-0.831) is significantly higher than systolic blood pressure and creatinine alone (AUC = 0.62; 95% CI 0.558-0.661). In body artery stenosis subgroup, DGF (OR = 1.86; 95% CI 1.04-3.36; p = 0.03) and Diabetes Mellitus (DM) (OR = 2.44; 95% CI 1.31-4.60; p = 0.005) were independent risk factors for TRAS. Conclusion: In our transplant population, DGF increased more than 3-fold the risk of TRAS. In the subgroup analysis, both DGF and DM increases the risk of body artery stenosis. The addition of other factors to hypertension and renal dysfunction may increase diagnostic accuracy.