Drug-eluting stent insertion in the treatment of in-stent renal artery restenosis in three renal transplant recipients

Urgent endovascular maneuvers to rescue a failing transplant kidney with a T-stent approach - A case report

Renal artery thrombosis (RAT) is a major cause of renal transplant loss and, for this reason, should be treated promptly. We present a case of a 48-year-old man with external iliac thrombosis associated with thrombosis of a transplant renal artery that led to worsening of renal function. Multiple mechanisms have been identified in the literature as risk factors for RAT. In our patient, a combination of anastomotic stenosis, hypercoagulability, and diabetic nephropathy had resulted in RAT, and an unconventional endovascular revascularization technique with a T-stent approach was needed to guarantee patency of the treated vessels. No 30-day perioperative complications occurred, and the postoperative follow-up examination showed patency of the treated vessels; thus, transplant loss was avoided.

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.

ACR Appropriateness Criteria® Renal Transplant Dysfunction

Renal transplantation is the treatment of choice in patients with end-stage renal disease because the 5-year survival rates range from 72% to 99%. Although graft survival has improved secondary to the introduction of newer immunosuppression drugs and the advancements in surgical technique, various complications still occur. Ultrasound is the first-line imaging modality for the evaluation of renal transplants in the immediate postoperative period and for long-term follow-up. In addition to depicting many of the potential complications of renal transplantation, ultrasound can also guide therapeutic interventions. Nuclear medicine studies, CT, and MRI are often helpful as complementary examinations for specific indications. Angiography remains the reference standard for vascular complications and is utilized to guide nonsurgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Transplant artery thrombosis and outcomes

Post-transplantation allograft arterial thrombosis is a well-recognized complication associated with solid organ transplantation. Much of the literature is centered on liver and kidney transplantation, which will therefore serve as the principle basis for this review, with a brief discussion on pancreas transplantation and associated arterial complications. The number of solid organ transplants has been steadily increasing over the past decade in parallel with growing demand for organs and expansion of the transplantation criteria for both donors and recipients. This increase has been accompanied by a number of innovative medical advances and surgical techniques, as well as improved imaging that has allowed for thoughtful exploration of vascular anatomic variants and the possibilities for transplant with which they are associated. It has also been accompanied by a growing field of behavioral research, as potential recipients must weigh the risk of accepting certain organs based on perceived outcomes that may differ according to the quality of the underlying organ. Improvements in imaging technology have brought greater sensitivity to detecting arterial complications in post-operative surveillance examinations and have allowed for further development of tailored endovascular and surgical interventions for transplant-associated vascular complications. This review will focus on post-transplantation solid organ allograft artery thrombosis, including discussion of risk factors, diagnostic imaging, natural history, and therapeutic options.

5 Years Experience With Drug Eluting and Bare Metal Stents as Primary Intervention in Transplant Renal Artery Stenosis

Background

Transplant renal artery stenosis (TRAS) is a common vascular complication after kidney transplantation and is associated with refractory hypertension, volume overload, and graft injury or loss. This article describes 5-year outcomes of endovascular intervention for TRAS with bare metal and drug eluting stents (DES).

Methods

We investigated, as a prospective cohort study, patient and graft outcomes after the targeted use of DES for vessel diameter less than 5 mm and bare metal stents (BMS) for vessel diameter greater than 5 mm as the primary management for TRAS.

Results

From March 2008 to November 2014, 57 patients were stented for hemodynamically significant TRAS; 29 received DES, 26 received BMS, and 2 patients received both stent types. They were followed up for a mean of 35.1 ± 22.8 months; a subset of these patients who all received DES were followed up for 61.7 ± 17.5 months. Mean serum creatinine declined from 2.87 ± 1.5 mg/dL at the time of intervention to 1.98 ± 0.76 mg/dL (P < 0.001) at one month follow-up and was 1.96 ±0.92 mg/dL (P < 0.001) at 35.1 ± 22.8 months. Mean systolic blood pressure declined from 159.05 ± 19.68 mm Hg at time of intervention to 135.65 ± 15.10 mm Hg (P < 0.001) at most recent visit. Clinically driven restenosis requiring repeat revascularization occurred in 15.7% of patients.

Conclusions

Primary stenting with DES and BMS is both successful in the initial treatment of TRAS and also produced an immediate and long-term reduction in serum creatinine and systolic blood pressure.

Organ transplantation and drug eluting stents: Perioperative challenges

Patients listed for organ transplant frequently have severe coronary artery disease (CAD), which may be treated with drug eluting stents (DES). Everolimus and zotarolimus eluting stents are commonly used. Newer generation biolimus and novolimus eluting biodegradable stents are becoming increasingly popular. Patients undergoing transplant surgery soon after the placement of DES are at increased risk of stent thrombosis (ST) in the perioperative period. Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor such as clopidogrel, prasugrel and ticagrelor is instated post stenting to decrease the incident of ST. Cangrelor has recently been approved by Food and Drug Administration and can be used as a bridging antiplatelet drug. The risk of ischemia vs bleeding must be considered when discontinuing or continuing DAPT for surgery. Though living donor transplant surgery is an elective procedure and can be optimally timed, cadaveric organ availability is unpredictable, therefore, discontinuation of antiplatelet medication cannot be optimally timed. The type of stent and timing of transplant surgery can be of utmost importance. Many platelet function point of care tests such as Light Transmittance Aggregrometry, Thromboelastography Platelet Mapping, VerifyNow, Multiple Electrode Aggregrometry are used to assess bleeding risk and guide perioperative platelet transfusion. Response to allogenic platelet transfusion to control severe intraoperative bleeding may differ with the antiplatelet drug. In stent thrombosis is an emergency where management with either a drug eluting balloon or a DES has shown superior outcomes. Post-transplant complications often involved stenosis of an important vessel that may need revascularization. DES are now used for endovascular interventions for transplant orthotropic heart CAD, hepatic artery stenosis post liver transplantation, transplant renal artery stenosis following kidney transplantation, etc. Several antiproliferative drugs used in the DES are inhibitors of mammalian target of rapamycin. Thus they are used for post-transplant immunosuppression to prevent acute rejection in recipients with heart, liver, lung and kidney transplantation. This article describes in detail the various perioperative challenges encountered in organ transplantation surgery and patients with drug eluting stents.

Tailoring the endovascular management of transplant renal artery stenosis

In this study we analyze the different types of endovascular interventions (EVIs) in de novo transplant renal artery stenosis (TRAS) and its anatomical subtypes to examine any variation in recovery of allograft function, blood pressure control, EVI patency and allograft survival with respect to EVI type (DES: drug-eluting stent, BMS: bare-metal stent, PTA: percutaneous transluminal angioplasty). Forty-five patients underwent a total of 50 primary EVIs (DES: 18, BMS: 26, PTA: 6). Patients were stratified according to medical co-morbidities, graft characteristics, biopsy results, clinical presentation and TRAS anatomic subtypes (anastomotic: 26, postanastomotic: 17, bend-kink: 2). There was significant improvement in allograft function and mean arterial blood pressure (MAP) control across all interventions (pre-EVI-creatinine [CR]: 2.8 ± 1.4, post-EVI-Cr: 2.1 ± 0.7, p < 0.001; pre-EVI-MAP: 117 ± 16, post-EVI-MAP: 112 ± 17, p = 0.03) with no significant difference among EVI types. There was no significant difference in allograft survival with respect to EVI type. Patency was significantly higher in EVIs performed with DES and BMS compared to PTA (p = 0.001). In the postanastomotic TRAS subtype, patency rates were significantly higher in DES compared to BMS (p = 0.012) in vessels of comparable reference diameter (≤5 mm).

Endovascular interventions for managing vascular complication of renal transplantation

Renal transplantation is a well-established treatment for patients with end-stage renal disease. Although the procedure is commonly undertaken with a high rate of initial technical success, a low but significant risk of vascular complications can develop and ultimately threaten the transplanted kidney. Complications include transplant renal artery stenosis, extraparenchymal and intraparenchymal pseudoaneurysm and arteriovenous fistula formation, and stenosis of native iliac arteries due to aortoiliac occlusive disease. Historically, open surgical correction of these complications has been associated with high morbidity and the risk of graft loss. Endovascular approaches are better tolerated by renal transplantation patients and are used increasingly for management of vascular complications associated with kidney transplantation. We review the contemporary diagnosis and treatment of these complications using endovascular techniques.

Transplant renal artery stenosis secondary to mechanical compression from polycystic kidney disease: A case report

Transplant renal artery stenosis (TRAS) is a potentially treatable cause of allograft dysfunction, hypertension and graft loss. The mainstay of treatment includes angioplasty and endovascular stenting, although observation and surgery are at times indicated. We present an unusual case of TRAS secondary to mechanical compression from a patient's enlarged native polycystic kidneys. This was treated with bilateral native nephrectomy and evidence of TRAS improved both clinically and radiographically. Recognition and treatment are important in preventing irreversible complications of TRAS.

The use of drug-eluting stents in the management of transplant renal artery stenosis

Transplant renal artery stenosis (TRAS) is a common occurrence following kidney transplantation with an incidence rate ranging from 6% to 23%. A single-center retrospective study was conducted to examine the use of drug-eluting stents (DES) in eligible patients with hemodynamically significant TRAS. Between March 2008 and January 2011, 12 patients were diagnosed with TRAS with reference vessel diameter measuring <5 mm and underwent endovascular intervention (EVI) with DES placement. TRAS was detected within the first year posttransplantation in a majority of these patients (83%) and manifested as hypertension (100%), allograft dysfunction (100%) and edema (58%). Procedural success rate was 100%. Patients were followed for a mean period of 16 ± 10 months. Blood pressure improved from a mean of 156/82 to 138/73 mmHg at the end of the follow-up period. In 11/12 patients, serum creatinine improved from 3.1 ± 1.3 mg/dL to 2.3 ± 0.5 mg/dL at the end of the follow-up period. TRAS of early onset is readily amenable to EVI with stent placement resulting in improvement in blood pressure control and allograft function.

Analysis of vascular complications after renal transplantation

PURPOSE

Despite medical and surgical advances, vascular complications remain common after renal transplant, occurring among 3%-15% of patients. These complications may compromise graft function. This study sought to evaluate the frequency and management of vascular complications after renal transplant.

MATERIALS AND METHODS

We retrospectively analyzed the 1843 transplantations performed at 2 centers by our team since November 1975. The 1349 male and 494 female patients had an overall mean age of 31.5±11.2 years; (range, 3-66). Grafts were obtained from a living-related donor in 1406 (76.29%) or a deceased donor in the remaining 437 (23.71%). The mean donor age was 40.7±13.7 years (range, 2-76). Of 1843 transplants, multiple vascular anastomoses were performed in 155 cases (8.4%), including 130 involving renal arteries and 25 renal veins.

RESULTS

Forty-seven vascular complications (2.55%) were observed in 43 procedures (2.33%), most frequently renal artery stenosis (n=14). It was followed by allograft renal artery kinking (n=7), renal vein kinking (n=7), renal artery thrombosis (n=5), renal vein laceration (n=4), renal artery laceration (n=3), renal vein thrombosis (n=2), renal artery disruption (n=2), renal and iliac vein obstructions owing to pressure from a lymphocele (n=1), renal artery and vein obstruction owing to pressure from a hematoma (n=1), or an arteriovenous fistula after percutaneous graft biopsy (n=1). Fifteen of these 47 complications were treated by interventional radiologic procedures.

CONCLUSION

The vascular complication rates in our patients were somewhat lower than those reported in the literature. A thorough understanding of how complications impair allograft function and survival is essential for adequate treatment. Interventional radiology is invaluable in the postoperative management of transplant-related complications.