Endovascular treatment of transplanted renal artery stenosis with PTA/stenting

Value and limitations of sonography in kidney transplant recipients with special attention to the resistive index - An update

Kidney transplantation has become the standard treatment for end-stage renal disease. Even though the success rates are high, early and late post-transplant complications remain a major clinical problem due to the risk of graft failure. Therefore, it is of highest interest to early diagnose post-transplant complications. Ultrasound with color coded Duplex analysis plays a crucial role in imaging mechanical and vascular complications. In this article, we give an update of the visualizable complications in kidney transplant recipients and discuss the value of resistive index (RI) measurement with its limitations in allograft rejection.

Assessment and management of transplant renal artery stenosis. A literature review

BACKGROUND

transplant renal artery stenosis (TRAS) following kidney transplantation is a possible cause of graft failure. This review aimed to summarize the evidence about physiopathology, diagnosis and early and late effectiveness of the endovascular treatment (EVT), including angioplasty and stenting procedures.

METHODS

a literature research was performed using Pubmed, Scopus and the Cochrane Library databases (January 2000 to September 2020) according to PRISMA guidelines. Studies were included if they describe EVT, percutaneous transluminal angioplasty or stent placement of TRAS, published in English and with a minimum of ten patients.

RESULTS

56 studies were included. TRAS incidence ranges from 1% up to 12% in transplanted kidneys. The TRAS risk factors were: elderly donor and recipient, cytomegalovirus match status, Class II Donor Specific Antibodies (DSA), expanded donor criteria, delayed graft functioning and other anatomical and technical factors. The highest frequency of TRAS presentation is after 3-6 months after kidney transplantation. The most frequent localization of stenosis was para-anastomotic (ranging from 25% to 78%). In 9 studies, all patients were treated by percutaneous transluminal angioplasty (PTA), in 16 studies all patients received percutaneous transluminal stenting (PTS) and in 21 series patients received either PTA or PTS. The Twelve months patency rates after EVT ranged from 72% to 94%. The overall complication rate was 9%, with pseudoaneurysms and hematomas as most frequent complications.

CONCLUSION

TRAS can be successfully and safely treated through an endovascular approach. Stent delivery seems to guarantee a higher patency rate compared to simple angioplasty, however further studies are needed to confirm these results.

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.

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

Endovascular management of transplant renal artery stenosis: A single-center retrospective study

OBJECTIVES

The aim is to evaluate the efficacy and complications of percutaneous transluminal angioplasty (PTA)/stenting in the treatment of transplant renal artery stenosis (TRAS).

BACKGROUND

TRAS is a relatively rare condition, and currently, there is not enough study about interventional therapy for TRAS.

METHODS

Between April 2011 and July 2018, 33 patients with TRAS underwent interventional therapy. Analysis of parameters was as follows: technical success, pretreatment and posttreatment serum creatinine, and blood pressure, and vessel patency via ultrasound at 1, 6, and 12 months posttreatment and once a year thereafter.

RESULTS

One procedure failed. The success rate of PTA/stenting placement was 97.0%. Fourteen PTAs with 16 stents were primary interventions, with 2 stent procedures performed subsequently due to restenosis; the restenosis rate was 6.3%. During the follow-up period, two patients progressed to graft renal failure and three patients were lost to follow-up. The rest of the patients still had stable graft function and blood pressure. Compared with preoperative conditions, blood pressure and serum creatinine significantly decreased (p < .05). No treatment-related deaths or serious complications occurred.

CONCLUSIONS

PTA/stenting is a safe and effective treatment for TRAS. For selected TRAS patients, PTA or PTA with stent may achieve good therapeutic outcomes. Selecting appropriate puncture pathways may help improve the success rate and affect the operation results, and open surgery may be avoided.

Percutaneous transluminal angioplasty alone versus stent placement for the treatment of transplant renal artery stenosis

PURPOSE

The purposes of this retrospective study were to assess the efficacy of endovascular techniques for the treatment of transplant renal artery stenosis (TRAS) by analyzing technical and clinical success and to compare the results of percutaneous transluminal angioplasty (PTA) alone to those of stenting.

MATERIALS AND METHODS

A retrospective analysis was conducted on 31 patients who underwent endovascular treatment for TRAS between January 2012 and December 2017. There were 23 men and 8 women with a mean age of 60.5±14 (SD) years (range: 24-81 years). Ten patients (10/31; 32%; 8 men, 2 women; median age, 63 years) were treated with PTA alone and 21/31 (68%; 15 men, 6 women; median age, 65 years) with metallic stent placement. Several variables including serum creatinine level, glomerular filtration rate, arterial blood pressure value, antihypertensive medication obtained before and after treatment were compared. Technical success was assessed for each procedure. Clinical success was defined as a 15% drop in serum creatinine level, a decrease greater than 15% in mean blood pressure values or a decrease greater than 10% in mean blood pressure values with a reduction in the number of antihypertensive drugs needed for hypertension control.

RESULTS

Technical success was obtained in all patients [31/31; 100%; 95% confidence interval (CI): 89-100%] and clinical success in 27/31 patients (87%; 95%CI: 71-95%). Four patients (4/31; 13%; 95%CI: 5-29%) underwent repeat endovascular intervention. Mean serum creatinine level and mean arterial blood pressure values were significantly lower after treatment (177.4 and 93.8μmol/l, respectively) compared to before treatment (319.4 and 106.7μmol/l, respectively) in the stent group but not in the group treated with PTA alone (P=0.0012 and P=0.002, respectively).

CONCLUSION

The endovascular approach is safe and effective in the management of TRAS and stenting, depending on the morphology of the stenosis, should be the treatment of choice when possible.