Post-transplant Renal Artery Stenosis Research Articles

Percutaneous Transluminar Angioplasty and Stenting of Post Transplant Renal Artery Stenosis(TRAS): Monocentric Experience.

Introduction We retrospectively evaluated the occurrence of post transplant renal artery stenosis (TRAS) in 808 recipients of a cadaveric renal transplantation performed in our unit between 1991 and 2013 and the outcome after a percutaneous revascularization. Materials TRAS was diagnosed when a Peak systolic Velocity(PSV) > 2.5 m/sec was found in the graft renal artery by Doppler ultrasound. Subsequently an angiography and eventually a percutaneus transluminal angioplasty (PTA) with stenting was performed. We compared renal function, blood hypertension, PSV and Resistive index (RI) at the time of the diagnosis of TRAS with the values collected at the last follow up visit. Results We found 74 (8.9%) TRAS of whom 18 due to a kinking of the artery or a non hemodinamic stenosis (defined as PSV between 2.0 and 2.5 m/sec) that didn't require angiography. 56 patients underwent an angiography. In 4 cases the stenosis was not confirmed, 51 were treated with PTA with stenting and one only with PTA without stenting. The median of the time between the diagnosis of TRAS and the renal transplantation was 70 days (range 2-3347 days). TRAS occurred near the anastomosis in 60% of the cases. We observed 1 hemorragic complication during the procedure (1.9%) that required an urgent nephrectomy. A restenosis was found in 8 cases (17%) treated again with a PTA in 4 patients, PTA and stenting in 2, and with medical therapy in 2. With a mean follow up of 5±4 years we confirmed the reduction of PSV, blood pressure and serum creatinine and an increase of RI and GFR as show in table 1.Table: No Caption available.Conclusions TRAS was found in 8.9% of our cohort of transplanted patients. The angiography is useful to confirm the diagnosis made by doppler examination and eventually treat the lesion

Obesity and urologic complications after renal transplantation

Although obesity has been associated with improved survival on dialysis, its short-and long-term effects on renal transplantation outcomes remain unclear. Herein, we evaluate the short-term and intermediate long-term effects of obesity on first-time renal transplant patients. A retrospective analysis was performed on 180 consecutive renal transplant recipients from living unrelated donors during 2006-2008 in a major transplantation center in Tehran, Iran. Among these, 34 (18%) patients were found to be obese (body mass index ≥30 kg/m 2 ). Obese patients were more likely to develop post-transplant renal artery stenosis (RAS) (17.6% vs. 2.8%, P <0.001), hematoma (47.9% vs. 17.6, P = 0.009), surgical wound complications (64.7% vs. 9.6%, P <0.001) and renal vein thrombosis (2% vs. 0%, P <0.001). However, the incidence of delayed graft function, lymphocele, urologic complications of ureterovesical junction stenosis or urinary leakage, surgical complications of excessive bleeding or renal artery thrombosis and duration of hospitalization were similar between the two groups. The two-year patient and graft survival were also statistically not different. Renal transplantation in obese recipients is associated with a higher incidence of post-transplant RAS, hematoma, surgical wound complications and renal vein thrombosis, but similar two-year patient and graft survival.

Angioplasty with stent is the preferred therapy for posttransplant renal artery stenosis

Angioplasty with stent is the preferred therapy for posttransplant renal artery stenosis

Post-transplant renal artery stenosis: The hemodynamic response to revascularization

Percutaneous transluminal angioplasty and stenting are relatively noninvasive approaches to treat post-transplant renal artery stenosis. However, the real impact of this procedure on renal function recovery has never been quantitated precisely to date. In eight consecutive renal transplant patients with renal graft artery stenosis, blood pressure, body weight, and anatomical, functional, and Doppler ultrasound parameters were evaluated before and one month after renal artery transluminal angioplasty and stenting. On both occasions, glomerular filtration rate and renal plasma flow were evaluated by inulin and paraaminohippuric acid renal clearances, and glomerular size-selective function was evaluated by the fractional clearances of neutral dextran macromolecules. The correction of renal artery stenosis, by normalizing renal vascular resistances, fully restored kidney perfusion and decreased arterial blood pressure, relieved water and sodium retention, restored an almost laminar arterial blood flow, and normalized vascular shear stress without appreciable effects on glomerular barrier size-selective function and proteinuria. Preangioplasty and postangioplasty renal resistive indices and peak systolic blood velocity estimated by Doppler ultrasounds were significantly correlated with the effective renal plasma flow and the blood velocity calculated at the site of stenosis. All patients were discharged without sequelae one or two days after angioplasty. Percutaneous transluminal angioplasty and stenting are safe and effective procedures to normalize the functional changes sustained by hemodynamically significant artery stenosis after renal transplantation. Doppler ultrasound scanning is a reliable and reproducible technique to monitor the renal functional response to vascular reperfusion.

Breath-hold 3D gadolinium-enhanced subtraction MRA in the detection of transplant renal artery stenosis

AIMS: The purpose of this study was to assess the value of breath-hold 3D gadolinium-enhanced subtraction magnetic resonance angiography (GD-MRA) in the detection of transplant renal artery stenosis (TRAS). PATIENTS AND METHODS: Seven patients with suspected post-transplant renal artery stenosis were studied. GD-MRA was performed at 1.5 T with a 3D fast spoiled gradient recalled echo (FSPGR) pulse sequence. Before injection of contrast medium, the 3D pulse sequence was performed to obtain a set of non-contrast images for subtraction purposes. Dynamic 3D imaging was performed simultaneously with the bolus injection of 40 ml of gadopentetate dimeglumine. Angiographic images were reconstructed using the Advantage Window workstation (version 2.0 GE Medical Systems) and subtraction was made with the pre-contrast image data. Any signal intensity cut-off or narrowing of more than 50% was regarded as significant stenosis. Ultrasound Doppler (USD) study was performed with both colour and spectral studies. Peak systolic velocity (PSV) of greater than 2.0 m/s and acceleration time (AT) greater than 120 ms was regarded as positive for TRAS. These were then compared with the digital subtraction angiography (DSA) as the gold standard. RESULTS: A total of nine examinations performed in seven patients were included in the analysis. MRA correlated with the DSA findings in eight examinations, with one false negative. USG correlated with DSA in six examinations, with two false negative and one false positive case. CONCLUSION: In our opinion, GD-MRA is a promising and non-invasive technique in the detection of TRAS.

ENDOLUMINAL STENT PLACEMENT AFTER PERCUTANEOUS TRANSLUMINAL ANGIOPLASTY IN THE TREATMENT OF POST-TRANSPLANT RENAL ARTERY STENOSIS

Purpose We report our experience with endoluminal stent placement after percutaneous transluminal angioplasty for the treatment of post-transplant renal artery stenosis. Materials and Methods From October 1992 to September 1996, 8 stents were successfully implanted in 7 patients affected by resistant transplant renal artery stenosis. All transplanted kidneys were procured from cadaver donors. The patients were routinely evaluated with duplex sonography and the median interval between transplantation and stenosis detection was 7.4 months (range 0.5 to 17). When serious renal stenosis was diagnosed (greater than 50%), selected angiography and percutaneous transluminal angioplasty were performed. In 8 cases (7 patients) an endoluminal metallic Palmaz stent was placed in the site of the restenosis. One patient received 2 stents repeatedly positioned in different stenosis sites. Results No major complications occurred. Clinical outcome was positive in 5 patients (71.4%) and Stenosis recurred in 2 (28.5%) (less than 50% and less than 35%, respectively). Median followup after stent placement was 14.8 months (range 1 to 37). Conclusions Percutaneous endoluminal stent procedures after resistant transplant renal artery stenosis or for ex novo treatment for severe anastomotic stenoses appears to be promising. Longer followup periods are necessary for true evaluation of this procedure.

Doppler ultrasound evaluation of post-transplant renal artery stenosis

Doppler ultrasound evaluation of post-transplant renal artery stenosis

Post-Transplant Renal Artery Stenosis

Post-Transplant Renal Artery Stenosis

Post-Transplant Renal Artery Stenosis: Impact of Therapy on Long-Term Kidney Function and Blood Pressure Control

Purpose We assessed the long-term outcome of different treatment methods for transplant renal artery stenosis. Materials and Methods Outcome data for 23 patients with transplant renal artery stenosis treated during a 16-year period were reviewed and analyzed. Results There was a higher incidence of renal artery stenosis in cadaveric donor kidneys compared to living donor kidneys (2 percent versus 0.3 percent, p less than 2), and in cadaveric kidneys from pediatric donors less than 5 years old compared to those from adults (13.2 percent versus 1.3 percent, p less than 0.01). Six patients underwent primary medical treatment for renal artery stenosis, with a successful outcome in 4 (mean followup plus or minus standard error 57 plus/minus 22 months) and failure in 2. Of the patients 16 were treated with percutaneous transluminal angioplasty, including 12 who were cured or improved with respect to hypertension (followup 44.7 plus/minus 7.6 months). Five patients underwent surgical revascularization for renal artery stenosis with postoperative improvement of hypertension (followup 18.8 plus/minus 11.6 months). Overall, 21 of 23 patients (91 percent) were treated successfully for transplant renal artery stenosis with cure or improvement of associated hypertension. Posttreatment renal function was stable or improved in 18 patients, while renal function deteriorated due to parenchymal disease in 3. Conclusions Most patients with transplant renal artery stenosis can be treated successfully. Percutaneous transluminal angioplasty is the initial interventive treatment of choice for high grade renal artery stenosis. Surgical revascularization is indicated if percutaneous transluminal angioplasty cannot be done or is unsuccessful.

2. Captopril renography in post-transplant renal artery stenosis

Nally, J. V.; Sankari, B. R.; Stowe, N. T.; Bedoya, L. A.; Gavin, J. P.; Inman, S. R.; Remzi, F. H.; Novick, A. C. Author Information

Post-Transplant Renal Artery Stenosis: A Possible Immunological Phenomenon

A retrospective review of 110 consecutive kidney transplants performed during 4 years revealed the development of renal artery stenosis in 9 patients (8.18%). A comparison of this group with a control group similar in patient age and interval elapsed since transplantation revealed no significant differences in donor and recipient ages, degree of HLA compatibility or serum creatinine levels. However, there was a significant difference in the number of acute rejection episodes. In our series only male patients were affected. A sizable proportion of the patients (50%) had no detectable murmur over the graft area despite high blood pressure and increased creatinine levels. The absence of surgical injury during extraction and implantation of the grafts, together with the anatomical site of the stenosis and correlation with the degree of immunological intolerance suggest an immunological factor as the underlying cause in post-transplant renal artery stenosis.

Post-transplant Renal Artery Stenosis: A Cause of Anuria. Report of 2 Cases Corrected by Revascularization

We report 2 cases of severe hypertension and acute onset of anuria after renal transplantation in which angiography revealed renal artery stenosis. After renal artery reconstructive surgery renal function returned to normal and the hypertension improved, A high index of suspicion is needed to make the diagnosis. Only by heightened awareness of this important entity will patients with posttransplantation anuria secondary to renal artery stenosis be identified. Such patients may benefit from renal artery revascularization to reverse this type of renal failure.

Posttransplant renal artery stenosis: angiographic study in 32 children.

Renal artery stenosis was identified in 32 children who either developed or had an exacerbation of hypertension after renal transplantation. One child developed renal artery stenosis in two sequential transplants. Renal artery stenosis occurred only in those patients who received transplants from cadavers. In 14 of the 15 patients with end-to-end renal artery anastomoses, the stenosis was at the anastomosis. In 14 of the 18 patients with end-to-side anastomoses, the stenosis was distal to the anastomosis.

Percutaneous Transluminal Dilatation of Posttransplant Renal Artery Stenosis: Beneficial Effects in Two Cases at High Surgical Risk

Two clinical cases are described in which percutaneous transluminal dilatation (PTD) determined the correction of hypertension and renal hypoperfusion due to renal artery stenosis of the transplanted kidney.