Percutaneous stent-graft management of renal artery aneurysms

A Qualitative Systematic Review of Endovascular Management of Renal Artery Aneurysms

PURPOSE

To perform a qualitative systematic review of endovascular management of renal artery aneurysms (RAAs).

MATERIALS AND METHODS

A comprehensive electronic search of PubMed, MEDLINE, Embase, Google Scholar, and Cochrane databases from 2000 to 2022 was performed using the search terms "renal artery," "aneurysm," and "endovascular." Means of outcome measures were calculated with a primary end point focused on RAA-related mortality and rupture. Secondary end points included reintervention rate and renal infarction.

RESULTS

Twenty-six, single-center, retrospective, observational studies were included. There were 454 RAAs treated in 427 patients using endovascular techniques. Mean age was 53.8 years, with a female predominance (62%). A variety of endovascular treatments of RAA were used with excellent technical success (96%), renal parenchymal preservation, and a low rate of moderate/severe adverse events (AEs). Primary coil embolization was the most commonly used technique (44.7%). There was an overall AE rate of 22.9%, of which 6.7% were moderate/severe and there was 0% periprocedural mortality. The most common AE was renal infarction (49 patients, 11.5%); however, renal function was preserved in 84% of patients. Nephrectomy rate was 0.4%. Computed tomography (CT) angiography was the most common imaging follow-up modality used in 72% of studies. Only 9 studies (34%) reported anticoagulant use. Although the risk of delayed aneurysm reperfusion warrants clinical and imaging surveillance, relatively few patients (3%) required reintervention in this cohort.

CONCLUSIONS

Endovascular management of RAA is a technically feasible treatment option with low rates of AEs and reintervention. The present study highlights the techniques available for interventional radiologists, a need for standardization of AE reporting, anticoagulation therapy, and follow-up imaging.

Contained rupture of a left renal artery aneurysm: Report of a case

Ruptured renal artery aneurysms are uncommon. Although the increased use of endovascular technologies, controversy persists over the management. Contained rupture may be more difficult to diagnose, hence delay the management. We report a case of contained rupture of renal artery aneurysm treated with selective embolization prior to nephrectomy.

An Anatomic Classification Scheme for Surgical Planning of Renal Artery Aneurysms

PURPOSE

Renal artery aneurysm (RAA) is a rare disease. This study proposed and evaluated a new classification for RAA to assist in surgical decision-making.

MATERIALS AND METHODS

Single-center data of 105 patients with RAAs from the vascular department of vascular surgery were collected retrospectively. A new classification scheme was proposed. Type I aneurysms arise from the main trunk, accessory branch, or first-order branches away from any bifurcation. Type II aneurysms arise from the first bifurcation with narrow necks (defined as dome-to-neck ratio >2) or from intralobular branches. Type III aneurysms with a wide neck arise from the first bifurcation and affect 2 or more branches that cannot be sacrificed without significant infarction of the kidney.

RESULTS

There was 50 (47.62%) type I, 33 (31.43%) type II, and 22 (20.95%) type III aneurysms. The classification assigned endovascular repair as first-line treatment (for type I or II), while open techniques were conducted if anatomically suitable (for type III). A kappa level of 0.752 was achieved by the classification compared with a level of 0.579 from the classic Rundback classification. Technical primary success was achieved in 100% and 96.05%, and symptoms were completely resolved in 100% and 84.85%, while hypertension was relieved in 84.21% and 72.92% of patients receiving open surgery or endovascular repair, respectively. No significant difference was observed for perioperative or long-term complications among the 3 classification types.

CONCLUSION

The new classification proved to be a convenient and effective method for facilitating choice of intervention for RAAs.

CLINICAL IMPACT

This study proposed and evaluated a new classification scheme for renal artery aneurysms, which proved to be a convenient and effective method for facilitating surgical decision-making. Coil embolization was the first-line treatment if suitable, while aneurysm resection and reconstruction with vein graft were conducted for some complex lesions. The safety and efficacy of both open and endovascular methods were validated.

Risks and benefits of renal artery stenting in fibromuscular dysplasia: Lessons from the ARCADIA-POL study

INTRODUCTION

Although renal stenting is the standard revascularization method for atherosclerotic renal artery stenosis (RAS) (FMD-RAS), stenting in fibromuscular dysplasia (FMD) RAS is usually limited to periprocedural complications of angioplasty and primary arterial dissection. The main aim of the study was to retrospectively analyze the immediate and long-term results of renal stenting versus angioplasty in patients with FMD.

METHODS

Of 343 patients in the ARCADIA-POL registry, 58 patients underwent percutaneous treatment due to FMD-RAS (in 70 arteries). Percutaneous transluminal renal angioplasty (PTRA) was performed as an initial treatment in 61 arteries (PTRA-group), whereas primary stenting was undertaken in nine arteries (stent-group). Stent-related complications were defined as: in-stent restenosis > 50% (ISR); stent fracture; under-expansion; or migration.

RESULTS

In the PTRA-group, the initial restenosis rate was 50.8%. A second procedure was then performed in 22 arteries: re-PTRA (12 arteries) or stenting (10 arteries). The incidence of recurrent restenosis after re-PTRA was 41.7%. Complications occurred in seven of 10 (70%) arteries secondarily treated by stenting: two with under-expansion and five with ISR. In the stent-group, stent under-expansion occurred in one case (11.1%) and ISR in three of nine stents (33.3%). In combined analysis of stented arteries, either primarily or secondarily, stent-related complications occurred in 11/19 stenting procedures (57.9%): three due to under-expansion and eight due to ISRs. Finally, despite several revascularization attempts, four of 19 (21%) stented arteries were totally occluded and one was significantly stenosed at follow-up imaging.

CONCLUSION

Our study indicates that renal stenting in FMD-RAS may carry a high risk of late complications, including stent occlusion. Further observational data from large-scale registries are required.

Outcomes of endovascular, open surgical and autotransplantation techniques for renal artery aneurysm repair: a systematic review and meta-analysis

BACKGROUND

Renal artery aneurysms (RAA) can be repaired with endovascular exclusion (EVR), open repair (OR), or ex-vivo repair with renal autotransplantation (ERAT). This systematic review compares repair indications, aneurysm characteristics, and complications following these interventions.

METHODS

A systematic review of databases including MEDLINE, PUBMED, and EMBASE by two independent reviewers for studies from January 2000-November 2022. All studies evaluating repair indications, RAA morphology, morbidity and mortality following EVR, OR, and ERAT were included.

RESULTS

A total of 38 studies were included with 1540 EVR, 2377 OR and 109 ERAT subjects. Increasing aneurysm size, or diameters >20 mm, were the most common repair indications across EVR and OR (n = 537; 48%), and ERAT (n = 23; 52%). All ERAT repairs were at or distal to renal artery bifurcations (n = 46). Meta-analyses demonstrated significantly shorter length of stay (LOS) with EVR compared to OR (mean difference -4.06, 95% confidence interval (CI) -5.69 to -2.43, P < 0.001). No significant differences were found in mean aneurysm diameter (P = 0.23), total complications (P = 0.17), and mortality (P = 0.85). Major complications (Clavien-Dindo ≥III) across studies most commonly included acute renal failure (EVR 4.9% vs. OR 7.0%). Nephrectomy was the most common major complication in ERAT (5.5%).

CONCLUSIONS

Outcomes following EVR and OR of RAAs are comparable. EVR offers a shorter LOS, with no difference in morbidity or mortality. ERAT is currently only utilized for distal RAAs, however carries higher risk of infarction and nephrectomy necessitating specialized expertise or algorithms to assist appropriate selection of repair methods.

Ex vivo repair and autotransplantation for a complex renal artery aneurysm

Renal artery aneurysms (RAA) are rare, occurring with an incidence of <0.1%. Open repair remains the mainstay of treatment for anatomically complex aneurysms. Here, we present a case of a large hilar RAA managed with ex vivo reconstruction and heterotopic renal autotransplantation. In this case, the complex anatomy and location of the aneurysm precluded the use of an endovascular approach. In situ repair was deemed unfavorable because of the technical difficulty of the repair with the numerous arterial branches involved, risk of parenchymal injury from prolonged warm ischemic time, restricted surgical field and risk of aneurysm rupture. This case contributes to the literature on laparoscopic nephrectomy, ex vivo repair and autotransplantation as a safe and viable treatment strategy for patients with complex RAA.

Technical considerations of endovascular management of true visceral artery aneurysms

BACKGROUND

True visceral artery aneurysms are potentially complex to treat but with advances in technology and increasing interventional radiology expertise over the past decade are now increasingly the domain of the interventional radiologist. BODY: The interventional approach is based on localization of the aneurysm and identification of the anatomical determinants to treat these lesions to prevent aneurysm rupture. Several different endovascular techniques are available and should be selected carefully, dependent on the aneurysm morphology. Standard endovascular treatment options include stent-graft placement and trans-arterial embolisation. Different strategies are divided into parent artery preservation and parent artery sacrifice techniques. Endovascular device innovations now include multilayer flow-diverting stents, double-layer micromesh stents, double-lumen balloons and microvascular plugs and are also associated with high rates of technical success.

CONCLUSION

Complex techniques such as stent-assisted coiling and balloon-remodeling techniques are useful techniques and require advanced embolisation skills and are further described.

Eighteen cases of renal aneurysms: Clinical retrospective analysis and experience of endovascular interventional treatment

Background

Development of endovascular interventional techniques gradually replaced traditional open surgery and has become the preferred treatment for renal aneurysms. This study aimed to analyze the clinical characteristics of renal artery aneurysm (RAA) and the safety and efficacy of intravascular interventional treatment.

Materials and Methods

We retrospectively analyzed the clinical characteristics and imaging data of 23 aneurysms in 18 patients with RAA. The technical success rate, complication rate, mortality rate, reintervention rate, and use of embolization materials were evaluated.

Results

In 18 patients with RAA (age, 32-72 years, average age, 52.2 ± 11.2 years), a total of 23 aneurysms were found (diameter 0.5-5.5 cm, average diameter 2.2 ± 1.4 cm). Among them, 11 cases (61.1%) were discovered accidentally, and the remaining patients were diagnosed due to the following major complaints: four cases (22.2%) presented low back pain, two (11.1%) were due to high blood pressure, and one (5.5%) had low back pain with gross hematuria. A total of 14 aneurysms in 13 patients received endovascular interventional therapy. The technical success rate of 13 patients with renal aneurysms was 100%. Three of the 18 patients were lost to follow-up, and the remaining were followed up for 4-89 months. There was no recurrence of the aneurysm or displacement of the stent or coil.

Conclusion

Endovascular treatment for RAA has a high success rate, low complication rate, and low reintervention rate. It has the advantage of less trauma and is flexible and more targeted for different types of renal aneurysms.

Contrast-enhanced magnetic resonance angiography for monitoring an embolized renal artery aneurysm: A case report and literature review

This case report describes a 69-year-old male patient with a renal artery aneurysm that was followed up with contrast-enhanced magnetic resonance angiography at 8 months after coil embolization treatment. Due to the disappearance of residual lumen with few metal artifacts, the therapeutic effect was satisfactory. At present, the indications for the treatment of renal artery aneurysms are still controversial and there are very few reports of postembolization images of renal artery aneurysms, with no criteria for reintervention and few reports for monitoring the embolized aneurysms. Further reports and research are still needed for the treatment of this rare disease.

Endovascular treatment of traumatic renal artery pseudoaneurysm with a Stanford type A intramural haematoma: A case report

BACKGROUND

Aortic intramural hematoma (IMH) associated with aortic branch tear and intramurally located pseudoaneurysm after blunt trauma has not been reported. Here, we report a case of progressive type A aortic IMH associated with a pseudoaneurysm arising from the injured proximal renal artery after blunt trauma.

CASE SUMMARY

During logging operations, a 66-year-old man experienced blunt force trauma after being injured by a fallen tree. He arrived at our trauma center with a left flank pain complaint. Computed tomography (CT) revealed a pseudoaneurysm arising from the proximal renal artery (localized within the aortic media) and Stanford type A IMH. A covered stent was deployed along the left main renal artery, bridging the pseudoaneurysm and covering the parent artery, successfully excluding the pseudoaneurysm as confirmed using aortography. However, although the degree of the pseudoaneurysm decreased, follow-up CT revealed remnant pseudoaneurysm, likely caused by an endoleak. Subsequently, a covered stent was additionally installed through the previously deployed covered stent. Successful exclusion of the pseudoaneurysm was confirmed using final aortography. In the 7-mo follow-up CT scan, the IMH and pseudoaneurysm completely disappeared with no evidence of stent-related complications.

CONCLUSION

Endovascular treatment such as stent-graft placement can be an effective and safe treatment for traumatic renal artery injury.

Endovascular interventions in main renal artery pathologies: an overview and update

Renal arteries are involved in a wide spectrum of pathologies including atherosclerosis, fibromuscular dysplasia, Takayasu arteritis, aneurysms, and aortic type B dissections extending into main renal arteries. They manifest as renovascular hypertension, renal ischemia, and cardiovascular dysfunction. The location of the renal arteries in relation to the abdominal aortic aneurysm is a critical determinant of interventional options and long-term prognosis. This article provides a comprehensive review of the role of interventional radiologists in transcatheter interventions in various pathologies involving the main renal arteries with analysis of epidemiology, pathophysiology, newer interventional techniques, and management options.

Endovascular Treatment of a Giant Renal Artery Aneurysm with High-Flow Renal Arteriovenous Malformation

Renal artery aneurysms (RAAs) are rare lesions with a prevalence of less than 1% in the general population. Renal arteriovenous malformations (AVMs) are rare lesions with an estimated incidence of less than 0.04%. The coexistence of these two clinical entities is extremely rare and narrows the available treatment options by endovascular or open surgery. We describe a case of a giant symptomatic RAA type III, which was combined with a high-flow renal AVM in the right kidney. Using two vascular plugs, the RAA was excluded successfully. The perfusion of the right kidney’s lower pole was preserved by implantation of two covered stents in the inferior segmental renal artery.

Multimodal repair of renal artery aneurysm-10-year single center experience

OBJECTIVES

Renal artery aneurysm (RAA) is a rare disease with various treatment options in indicated patients. In the current survey, the ten-year experience in treatment of RAAs using different endovascular and surgical treatments depending on RAA characteristics is discussed.

METHODS

All patients undergone RAA treatment via endovascular or surgical approaches at our center between January 2010 and December 2020 were enrolled. Patient demographics and peri-operative and late results were collected from a prospectively maintained database.

RESULTS

Eleven patients with RAA underwent treatment as follows: four patients received endovascular approach, four patients underwent in-situ RAA repair, and kidney autotransplantations were carried out in three patients. In all three treatment groups, the first therapeutic attempt was successful and none of the patients underwent secondary intervention due to RAA. Kidney autotransplantation was associated with a higher blood loss and a longer time of procedure compared to that of endovascular approach and in-situ repair. In-hospital postoperative complications were reported in five patients, including renal pole perfusion defect, renal artery thrombosis, and urinary tract infection. No acute kidney organ loss was seen, but one patient suffered from chronic kidney loss due to renal artery occlusion. In one patient undergoing autotransplantation, ureter anastomosis was reported, which led to acute renal failure, and a surgical treatment with resection and reanastomosis of the ureter was necessary. Hypertension was not resolved after RAA repair in any of the patients with preoperative hypertension.

CONCLUSIONS

RAA treatment selection depends on patient characteristics, anatomy, location, and arising branches of the aneurysm. In cases with complex anatomy, treatment strategy could not be just decided based on consensus guidelines, but a multidisciplinary team is required. Interventional therapies showed excellent results in non-complicated proximal aneurysms, especially regarding the length of hospital stay and postoperative morbidities. Open surgery is a complementary alternative in cases where minimally invasive therapy is not possible. Ex-situ repair with autotransplantation could be considered for anatomically complex distal aneurysms.

Endovascular management of a large renal artery aneurysm: a case report and review of the literature

Background

A renal artery aneurysm is a rare clinical presentation that can be found incidentally on imaging or during workup for refractory hypertension. Its presentation can be similar to that of a renal artery pseudoaneurysm, but the etiologies of the two vascular lesions differ. We present a patient who had an incidental finding of a large renal artery aneurysm that was managed with endovascular embolization. We also describe the literature surrounding the etiology, presentation and management of both renal artery aneurysms and renal artery pseudoaneurysms.

Case presentation

A 62-year-old man was referred to a urologic oncologist for workup of a newly found renal mass. Initial imaging with computed tomography showed a homogenous, well-circumscribed mass arising from the right kidney. Further evaluation with Doppler ultrasonography demonstrated pulsatile flow within the renal mass that was concerning for a renal artery pseudoaneurysm. The patient initially underwent a diagnostic angiogram by interventional radiology and was found to have a true renal artery aneurysm. Interventional radiology considered placement of a covered stent or angioembolization, but treatment was deferred due to concern for compromising the patient’s renal function. Patient was subsequently transferred to a neighboring hospital for management by vascular surgery. After considering both open surgical and endovascular approaches, the patient ultimately underwent angioembolization of the renal artery aneurysm. Short-term follow-up showed successful exclusion of the aneurysm with minimal adverse effects to the patient.

Conclusions

Our case report documents a unique case of an incidentally found large renal artery aneurysm that was successfully managed with endovascular embolization. Renal artery aneurysms and renal artery pseudoaneurysms, which can present similarly on imaging, are important diagnostic considerations in a patient presenting with a new renal mass. While open surgical approaches can be used to repair aneurysms, endovascular approaches using stenting or angioembolization are safe and effective options for treating renal aneurysms and renal pseudoaneurysms.

Contemporary Outcomes of in Situ Open Surgical Repair of Mid-Portion and Distal Renal Artery Aneurysms

INTRODUCTION

The best management of renal artery aneurysms (RAAs) remains controversial, especially when they are located from the mid to distal portions of the main renal artery. Our aim is to evaluate our 10-year experience with in situ open surgical repairs from a cohort of non-proximal RAAs at a single vascular surgery center.

METHODS

A retrospective review of a prospectively maintained database of all patients who underwent RAA in situ repairs located from the mid to distal portions of the renal artery at our Institution was performed between 2009 and 2020. Data on patient demographics, comorbidities, aneurysm location and morphology, type of in situ technique, and perioperative data were assessed. Postoperative biomarkers and renal function were collected, and mid-term follow-up results were analyzed.

RESULTS

A total of 15 RAA located at mid and distal portions of the renal artery repaired with in situ techniques were performed in 15 patients (nine men, mean age 62.4 ± 6.36 years). At diagnosis, 12 patients were asymptomatic; a history of abdominal pain was found in one patient, and two patients had drug-resistant hypertension. Two patients had already undergone previous unsuccessful attempts of endovascular treatment. All patients presented an aneurysm diameter >20 mm (mean diameter 2.75 ± 5 mm). At admission, mean serum creatinine and glomerular filtration rate were 1.10 ± 0.23 mg/dL and 69.8 ± 9.8 mL/min/1.73 m², respectively. Nine lesions were present in the distal portion of the renal artery, with 4 cases having ≥3 efferent branches and the other 5 with two efferent branches. The other six RAAs were in the mid-portion: in 4 cases, one efferent branch, and in 2 cases, two efferent branches were involved. All patients underwent in situ open repair: an end-to-end anastomosis was performed in 9 cases, aneurysm resection with primary closure in 3 cases, bypass with graft interposition in 2 cases (one iliac-renal reconstruction), and with vein interposition in 1 case. The mean renal ischemia time was 21.8 ± 9.4 min. A significant decrease on renal function was not observed (mean glomerular filtration rate at discharge: 64.8 ± 12.0 mL/min/1.73m²; P > 0.22). During recovery, one patient developed retroperitoneal hematoma treated conservatively. During follow-up (mean 46 months, range 2-135), one patient developed occlusion of a terminal renal artery branch without decreased kidney function.

CONCLUSION

In situ techniques for RAA from the mid to distal portions of the renal artery are technically complex; however, based on our results, these procedures were safe and effective, providing satisfactory early and mid-term outcomes.

Remodeling technique using T-stenting and coils to treat complex renal aneurysm

Renal artery aneurysm is a rare condition that is being diagnosed with increasing frequency because of wider use of angiotomography. We describe a case of complex type II renal artery aneurysm in a patient with systemic arterial hypertension and non-dialysis chronic kidney disease. The treatment performed was endovascular repair using the remodeling technique with T-stenting and coils to preserve the renal arterial branches, obtaining satisfactory arteriographic results and good clinical outcomes.

Endovascular interventions in management of renal artery aneurysm

Renal artery aneurysm (RAA) is a rare disease. With modern non-invasive imaging modalities, the disease is being increasingly diagnosed. It is a slow-growing aneurysm with high mortality in the event of rupture; especially in pregnant females for in which case patients were treated surgically. With advances in endovascular therapy, numerous techniques have been employed to manage complex RAA in artery bifurcation, branch and segmental arteries with excellent technical and clinical success. The various recent techniques include the use of flow diverter stents, remodelling with stent-assisted coil embolization (SACE), balloon-assisted coil embolization (BACE), selective embolization with coils-sac packing, inflow occlusion and coil trapping and selective embolization with liquid embolic agents-hystroacril and onyx. A combination of stent-graft with liquid embolization and liquid with microcoil embolization has been advocated with success. The most common complication encountered is renal infarction. This is mostly without impairment of renal function and secondary to embolization. Endovascular therapy has shorter operative time, less blood loss, shorter intensive care stay, done under conscious sedation and is associated with lesser postoperative morbidity compared to surgery. Reduction in hypertension, improvement of renal function and symptoms has been seen in most studies. Endovascular management of RAA has become the management of choice even with complex anatomy and technically challenging lesions.

Repair of renal artery aneurysm with stent angiography and coil embolization

Renal artery aneurysms (RAAs) are rare and are frequently discovered incidentally during the workup for other renal issues. Open surgery has been a popular approach to managing RAAs; however, endovascular techniques have recently emerged as a less invasive option. Endovascular therapy involves stent angiography and coil embolization of the aneurysm. RAA classification (type 1, 2, and 3) is determined by its anatomical location and shape, which has been demonstrated to affect whether an open or an endovascular method is most suitable. We report two patients with type 1 RAAs and a history of hypertension who were successfully repaired endovascularly using VBX stents.

Bowstring Phenomenon in Renal Artery Aneurysm Exclusion Using a Viabahn Stent Graft

A 77-year-old man presented with an incidental finding of right renal artery aneurysm without symptoms. Computed tomography revealed a 22 mm saccular aneurysm with a wide neck at the main renal artery trunk. An 8 × 100 mm Viabahn stent graft (W. L. Gore, Flagstaff, AZ) was deployed by fully pulling back the guiding sheath. However, the deployment knob was not able to be pulled. We returned the guiding sheath to the original position and confirmed the cause was the bowstring phenomenon. Because avoidance of this phenomenon required straightening of the tortuous vessel, the stent graft was deployed by short pull-back of the guiding sheath. Computed tomography after a year revealed no opacification of the aneurysm and the patency of the stent graft.

Renal artery aneurysms in pregnancy-Management of an uncommon but serious vascular lesion

Renal artery aneurysm (RAA) is defined as a localized saccular or fusiform dilation of the renal vasculature that exceeds 50% of the adjacent artery diameter. RAAs are rare in the general population and account for <1% of all peripheral aneurysms. Incidental diagnosis of RAA has increased due to the widespread clinical application of visceral duplex ultrasound scanning and computed tomography imaging. While the diagnosis of RAA before or during pregnancy is rare, pregnancy increases the risk of rupture significantly during the third trimester, with associated high mortality rates for both mother and fetus. The rarity of pregnancy-related RAAs contributes to our limited knowledge of their natural history, morphologic features, criteria for intervention, and treatment options. This review compiles opinions of published articles to provide an updated overview of RAA in pregnancy and aid clinicians in the management of this rare but serious vascular condition. An RAA 1.5 cm in diameter requires open or endovascular treatment in a woman planning to become pregnant or who is pregnant.

In Situ Treatment of Branch Renal Artery Aneurysms With Pantaloon Vein Graft

Introduction:

The optimal method of operative management of complex renal artery aneurysms (RAAs) involving distal branches (BRAAs) remains unclear. When more than 1 artery is involved within the BRAA, endovascular techniques are not advisable and an ex vivo approach is often preferred. In this study, we introduce an alternative surgical in situ technique to treat BRAAs.

Methods and Surgical Technique:

Five aneurysms involving the main or second-order bifurcation of the renal artery (RA) were treated in 4 patients at our institute between November 2012 and January 2017. The treatment of the BRAAs was based on resection of the aneurysm wall and reconstruction with autologous Pantaloon vein graft (PVG): a “Y-shaped” bypass created on-bench with autogenous great saphenous vein. Sequential clamping/reperfusion of the kidney allows to reduce renal function impairment.

Results:

No perioperative mortality or morbidity was observed, including none nephrectomy. In all the cases, aneurysms were treated with an in situ technique as previously planned. All the grafts were patent at the follow-up time (mean 64.1 ± 11.7 months). Renal function was preserved in all the cases. Vascularization of the renal parenchyma was satisfactory both on arterial echo Doppler and contrast-medium ultrasound in all the cases. Average cross-clamping times of the main RA and of a single branch RA were 15.8 ± 1.7 and 17.7 ± 4.6 minutes, respectively. Mean total operating time was 266.3 ± 18.9 minutes.

Conclusion:

The PVG with sequential clamping applied in the surgical treatment of BRAAs permits to reduce the ischemic effects to the renal parenchyma. To our knowledge, these are the first cases described in which BRAAs are treated with a PVG and our experience suggests that it is a feasible technique, with good long-term results and without severe adverse events recorded.

Open and endovascular treatment by covered and multilayer stents in the therapy of renal artery aneurysms: mid and long term outcomes in a single center experience

AIM

The purpose of this paper is to evaluate the mid and long terms outcomes of open and endovascular surgical treatment, as well as multilayer stent, in patients affected by Renal Artery Aneurysm (RAA).

PATIENTS AND METHODS

Twenty five patients with RAA (24 monolateral and 1 bilateral aneurysm, 26 aneurysms) were observed between 2000 and 2015: 4 were not treated due to the small size of the aneurysm (< 2.5 cm); out of the remaining, 16 underwent endovascular treatment, 2 were treated by open surgery consisting in aneurysmectomy and graft reconstruction and 5 (in 1 patient bilateral) were treated by ex vivo repair and autotransplantation.

RESULTS

Out of the 22 patients treated for RAA, one patient operated upon open surgery presented an early thrombosis of a PTFE graft, followed by nephrectomy (4.7%); one patient underwent autotransplantation showed an ureteral kinking without functional consequences. In a follow-up ranging from 1 and 11 years (mean 5 years), no deaths were observed; all the renal arteries repaired were patents and 16 out of 21 patients had a significative reduction of systemic blood pressure.

DISCUSSION

The choice of the best treatment is based on aneurysm's morphology according to Rundback's classification. The type I, involving the main renal artery, is always treated by endovascular approach; type II, involving renal artery bifurcations may be treated by open surgery or multilayer stents; type III (hilar or intraparenchymal aneurysms) needs only an open surgical treatment as autotransplantation.

CONCLUSION

Based on our experience it seems that most of RAAs may be treated by endovascular technique. The ex vivo autotransplantation represents the first-line treatment in hilar and intraparenchymal aneurysms. Multilayer stents seem to have good outcome in the treatment of aneurysms involving arterial bifurcations. Mid and long term results, related to kidney preservation and to normalization of blood pressure, seems satisfying.

Endovascular treatment of true renal artery aneurysms: a single center experience

PURPOSE

We aimed to report a single center's experience on endovascular treatment of true renal artery aneurysms (TRAAs), including treatment techniques and outcomes.

METHODS

This retrospective study was designed to evaluate the treatment and follow-up of TRAAs treated by a variety of endovascular interventional techniques over a period of 6 years. Six patients with nine TRAAs were identified; seven of the TRAAs were treated using different combinations of coil embolization and flow diverter stents. The clinical findings, aneurysm characteristics, endovascular methods and treatment outcomes were reported.

RESULTS

Seven TRAAs of six patients were treated, with a median aneurysm size of 20 mm. Three TRAAs were treated with primary sac occlusion (one with primary coil embolization, one with balloon and stent assisted coil and glue embolization, and one with amplatzer vascular occlusion device and coil embolization). The remaining four TRAAs of three patients were treated with flow diverter stents (Cardiatis, Silk, Pipeline, and Surpass). Immediate clinical success was achieved in patients treated with primary sac embolization (95% CI, 29.2%-100%). Among patients treated with flow diverter stents, one patient required an additional flow diverter at 6-month follow-up. The occlusion time in flow diverters ranged from 1 month to 12 months (median, 3.5 months) taking the repeat procedure into account. In patients treated with flow diverters, the clinical success rate was 100% (95% CI, 29.2%-100%) at one-year follow-up. Long-term follow-up ranged from 3 to 52 months. One intraprocedural complication was encountered with a flow diverter during deployment, which required additional stenting and tirofiban infusion. No other major complication was seen.

CONCLUSION

Endovascular treatment is an effective and safe method offering high success rates and low morbidity in the treatment of TRAAs and may supplant surgery as the primary therapy. Current experience in the use of flow diverter stents in TRAAs is limited to individual case reports with one brand of flow diverter device. Our small numbered series of four TRAAs shows our experience regarding endovascular treatment with different flow diverter brands.

Endovascular Stent-graft Repair of Combined Renal Artery Aneurysm and Arteriovenous Fistula

Renal artery aneurysm with concomitant presence of arteriovenous fistula is an extremely rare entity. Few reports have been described in the literature. Nowadays, endovascular repair with covered stents or transarterial embolization with coils or glue has become the first line of treatment. We present the successful repair of a distal renal artery aneurysm combined with arteriovenous fistula with stent graft.

Spontaneous Accessory Renal Artery Aneurysm Rupture in a Patient With Neurofibromatosis Type 1: A Case Report

True renal artery aneurysms are rare. Ruptured aneurysms are even rarer but can have devastating consequences. Renal artery aneurysms most commonly occur in patients with hypertension, atherosclerosis, or fibromuscular dysplasia. Treatment options can range from embolization to nephrectomy. We describe an interesting case of spontaneous accessory renal artery aneurysm rupture in a 44-year-old female with neurofibromatosis type 1 (NF1) who otherwise had no medical problems. She was successfully treated with selective coil embolization, recovered without complications, and maintained preoperative renal function.

Hilar Renal Artery Aneurysm Repair Using Coil Embolization and Covered Stent

INTRODUCTION:

Little has been reported regarding endovascular therapy with stent of renal artery hilar aneurysms. To that end, we herein report the outcomes of 3 hilar renal artery aneurysms (RAA) treated with an endovascular technique that makes use of a covered stent and coil embolization in the repair of hilar RAA and deem using this technique is better than traditional open approach with back-table repair and autotransplatation.

METHODS:

Since November 2014, 3 consecutive patients have been referred to the vascular surgery service for evaluation of a right RAA; these patients' aneurysms were diagnosed with a CT arteriogram prior to evaluation. These patients, typically treated with open surgery, were deemed to be candidates for endovascular repair and were treated as follows: (1) cannulation of the right Common Femoral Artery with a selective arteriogram of the right renal artery, (2) covered stent to dominant hilar artery branch, and (3) coil embolization of the remaining branches/tributaries. Perioperative outcomes and quality measures were analyzed and compared.

RESULTS:

The aneurysms were successfully covered and excluded as confirmed by a completion arteriogram. There were no perioperative morbidities (ie, acute kidney injury, endoleak, etc), and all 3 patients were discharged home the same days of their interventions. At their follow-up visits, the patients were free of symptoms and had normal renal functions as well as Computed tomography angiography (CTA) confirming successfully excluded aneurysms and no endoleaks.

CONCLUSION:

The technique we used demonstrated excellent outcomes with minimal comorbidities and preservation of renal function. As with many endovascular interventions, our technique compared favorably to traditional open technique in terms of technical feasibility, decreased length of stay, faster recovery, maintaining renal function, and reduced complication rates.

Case - Ex-vivo aneurysm resection, autotransplantation, and aorto-renal bypass in a solitary kidney with fibromuscular dysplasia

N/A

Coil embolization of renal artery bifurcation and branch aneurysms with flow preservation

OBJECTIVE

Coil embolization is one of the most common endovascular approaches to treatment of renal artery aneurysms (RAAs). The purpose of this retrospective study was to compare complications, mortality, and morbidity associated with sac packing, coil trapping, and inflow occlusion.

METHODS

The records of all patients with RAAs treated with coil embolization at our center from June 2003 to May 2017 were retrospectively reviewed. Demographics of the patients, aneurysm characteristics, management strategies, perioperative and long-term outcomes, and complications were analyzed.

RESULTS

A total of 52 patient records were reviewed; 28 patients received sac packing and 24 patients underwent coil trapping/inflow occlusion. There was no significant difference in patients' demographics or RAA characteristics between the groups. The mean aneurysm diameter was 25.6 ± 8.4 mm in the sac packing group and 31.1 ± 16.8 mm in the coil trapping/inflow occlusion group (P = .130). Most aneurysms in the sac packing group originated from the main renal artery bifurcation (67.9%), whereas in the coil trapping/inflow occlusion group, most aneurysms originated from the renal segmental branch arteries (54.2%). The immediate technical success rate was 100%, and the in-hospital mortality rate was 0% in both groups. Sac packing was more likely to be associated with endoleak immediately after the procedure (28.6% vs 8.3%; P = .065). The overall perioperative complication rate was not statistically different between the groups (7.1% vs 16.7%; P = .284). The mean duration of follow-up was 37.67 ± 29.84 months and 49.35 ± 28.11 months in the sac packing and coil trapping/inflow occlusion groups, respectively (P = .192). No deaths related to RAAs or aneurysm rupture occurred in either group. The overall morbidity rate was similar between groups (12.5% vs 25%; P = .284). Partial renal infarction occurred in two and five patients in the sac packing and coil trapping/inflow occlusion groups, respectively (8.3% vs 25%; P = .132). Impaired renal function was more frequent after coil trapping/inflow occlusion (0% vs 15%; P = .049). A single patient in the sac packing group required further intervention for reperfusion of the aneurysmal sac at 4 months (4.2% vs 0%; P = .356).

CONCLUSIONS

Sac packing might be a safe and effective way to treat RAAs located at the main bifurcation or in branch arteries and may be preferable to coil trapping/inflow occlusion, considering the potential loss of functional renal mass.

Endovascular Treatment of Visceral Artery Aneurysms and Pseudoaneurysms in 100 Patients: Covered Stenting vs Transcatheter Embolization

Purpose: To retrospectively report a large single-center experience of visceral artery aneurysms (VAAs) and pseudoaneurysms (VAPAs) treated with covered stenting (CS) as the first therapeutic option vs transcatheter embolization (TE). Methods: One hundred patients (mean age 59±14 years; 58 men) underwent 59 elective and 41 emergent endovascular procedures to treat 51 VAAs and 49 VAPAs. Seventy patients had TE and 30 received CS (27 Viabahn and 3 coronary stent grafts). Both TE and CS were performed in 10 cases. Results: Technical success was 96% (97% CS, 96% TE), and 30-day clinical success was 83% (87% CS, 81.4% TE). Four major complications occurred; 30-day mortality was 7%, mainly due to septic shock following pancreatic surgery. The midterm follow-up was 20.8 months in the total population and 32.8 months in the CS group. More than 6 months after CS all aneurysms remained excluded; stent patency was achieved in 88%. Twelve CS patients with >3 years’ follow-up had maintained stent patency. Conclusion: In endovascular treatment of visceral aneurysms, covered stenting was feasible in 30%. CS showed a slightly better efficacy than TE and good midterm patency. The Viabahn covered stent seems to be suitable for endovascular repair of tortuous visceral arteries affected by true or false aneurysms.

Treatment of Complex, Combined Renal Artery Aneurysm and Renal Arteriovenous Fistula with Nephrectomy

Renal artery aneurysms (RAAs) and renal arteriovenous fistulas (RAVFs) are rare lesions occurring in less than 1% of the population. Understanding treatment options is important in the care of these patients. Depending on the type of disease process, endovascular techniques, vascular bypass, renal autotransplantation, or nephrectomy may be indicated. The case reported describes a combined RRA and RAVF treated with nephrectomy.

Embolization of Renal Artery Aneurysm and Arteriovenous Fistula

A renal artery aneurysm with an associated arteriovenous fistula in a native kidney has been reported infrequently in the literature. Management depends on size, location, and the patient's physiological condition. We describe a case in which endovascular therapy was used to successfully exclude both aneurysm and fistula. This report describes a 13-centimeter renal artery aneurysm with arteriovenous fistula originating from an isolated branch of the renal artery. Coil-embolization resulted in thrombosis of the aneurysm and fistula while preserving parenchymal perfusion. Coil embolization is an alternative to surgery for coexistent renal artery aneurysm and arteriovenous fistula arising from a branch of adequate length for placement of embolic coils. Successful treatment is not limited by aneurysm size or presence of arteriovenous connection.

Endovascular management of renal artery aneurysms using the multilayer flow modulator

OBJECTIVE

Our aim was to describe our experience of the Multilayer Flow Modulator (MFM, Cardiatis, Isnes, Belgium) used in the treatment of type III renal artery aneurysms (RAA).

METHODS

This is a single-centre study. 3 patients (2 men and 1 woman; mean age 59 years; range 41-77 years) underwent treatment of a type III renal artery aneurysm using the MFM. The indications were a 23.9 mm type III RAA at the bifurcation of the upper and lower pole vessels, with 4 side branches; a 42.4 mm type III saccular RAA at the renal hilum; and a 23 mm type III RAA at the origin of the artery, supplying the upper pole.

RESULTS

Patients had a mean follow-up of 27 months, and were assessed by perioperative renal function tests, and repeat postoperative CT scan. There were no immediate postoperative complications or mortality. The first patient's aneurysm shrank by 8.6 mm, from 23.9 to 15.3 mm over 19 months, with all 4 side branches remaining patent. The largest aneurysm at 42.4 mm completely thrombosed, while the renal artery remained patent to the kidney. The final patient refused to have any follow-up scans but had no deterioration in renal function below 30 mL/min, and no further symptoms reported.

CONCLUSIONS

The MFM is safe and effective in the management of patients with complex renal artery aneurysms. The MFM can be used to treat branched or distal renal artery aneurysms with exclusion of the aneurysm from the circulation, while successfully preserving the flow to the side branches and kidney. Initial results are promising, however, longer follow-up and a larger cohort are required to prove the effectiveness of this emerging technology.

Fibromuscular Dysplasia in a Normotensive Patient Presented With Renal Infarct: Case Report and Endovascular Technique

Fibromuscular dysplasia (FMD) is a well-known disease, but its diagnosis can be challenging. Typically, the symptomatic FMD are reported by young and middle aged people with high blood pressure refractory to medical treatment. We present a rare case of a young, healthy, and normotensive patient who presented with pain secondary to renal infarction, without any prior signs or symptoms or history of hypertension. This presentation of FMD has not been previously described. The typical but subtle angiographic findings of the macro-aneurysmal FMD as well as the successful endovascular treatment are discussed herein. The macro-aneurysmal form of FMD should be considered in the differential diagnosis of acute renal infarction in young and middle aged patients even if they do not have a history of hypertension.

Surgical repair of renal artery aneurysms

The pathogenesis of renal artery aneurysms (RAAs) is degenerative, which eventually leads to weakening of the vessel wall and, in extreme cases, rupture. RAAs are a rare occurrence. Patients generally are asymptomatic, with a small number presenting with uncontrollable hypertension or hematuria. Most RAAs are discovered incidentally on imaging and do not pose an immediate health threat. However, the risk of rupture is an indication for prophylactic repair in certain patients. Interest in interventional radiologic procedures in the management of RAAs has recently increased; however, open repair should still be considered in select instances. In this case series, we present three patients for whom an open approach was indicated and performed.

Operative Management of Hilar Renal Artery Aneurysm in a Pregnant Patient

Complications of renal artery aneurysms (RAAs) can be life threatening and include the spontaneous rupture which may lead to severe retroperitoneal hemorrhage, loss of the kidney, or death. As the incidence and diagnosis of RAAs is expected to rise, it is becoming increasingly important to enhance our awareness and knowledge of this rare clinical entity. Here, we present the case of a hilar right RAA and the surgical approach for primary repair during the postpartum period. Additionally, we discuss current pathophysiologic mechanisms, associated symptoms as well as current treatment modalities for RAAs.

Endovascular Management of True Renal Arterial Aneurysms: Results from a Single Centre

PURPOSE

To report a single centre's experience of the endovascular treatment of renal arterial aneurysms, including techniques and outcomes.

MATERIALS AND METHODS

This is a retrospective analysis of true renal arterial aneurysms (TRAAs) treated using endovascular techniques over a period of 12 years and 10 months. The clinical presentations, aneurysm characteristics, endovascular techniques and outcomes are reported.

RESULTS

There were nine TRAA cases with a mean aneurysm size of 21.0 mm, located at the main renal arterial bifurcation in all cases. Onyx(®) was used as the embolic agent of choice (88.9 % cases), with concurrent balloon remodelling. The overall primary technical success rate was 100 %. Repeat intervention was carried out in 1 case, secondary to reperfusion >8 years post-initial treatment. Long-term clinical follow-up was available in 55.6 % of cases (mean 29.8 months; range 3.3-90.1 months). Early post-procedural renal function, as measured by serum creatinine, remained within the normal reference range. Renal parenchymal loss post-embolisation was ≤20 % in 77.8 % of cases, as estimated on imaging. Minor complications included non-target embolization of Onyx(®) with no clinical sequelae (n = 1), transient pain requiring only oral analgesia with no prolongation of hospital stay (n = 2). No major complications occurred as a consequence of embolisation.

CONCLUSION

Endovascular therapy is an effective and safe primary therapy for TRAA with high success rate and low morbidity, supplanting surgery as primary therapy. Current experience in the use of Onyx(®) in TRAA is primarily limited to individual case reports, and this represents the largest case series of Onyx(®)-treated TRAAs to date.

Renal artery aneurysms

A renal artery aneurysm is defined as a dilated segment of renal artery that exceeds twice the diameter of a normal renal artery. Although rare, the diagnosis and incidence of this entity have been steadily increasing due to the routine use of cross-sectional imaging. In certain cases, renal artery aneurysms may be clinically important and potentially lethal. However, knowledge of their occurrence, their natural history, and their prognosis with or without treatment is still limited. This article aims to review the recent literature concerning renal artery aneurysms, with special consideration given to physiopathology, indications for treatment, different technical options, post-procedure complications and treatment outcomes.

Surgical treatment of ruptured renal artery aneurysm: a report of 2 cases

The rupture of a renal artery aneurysm is a rare disease that is difficult to diagnose. Although we usually consider the appropriate treatment to be open laparotomy with aortic aneurysm surgery or stenting with graft insertion through intravascular intervention, thus far, there is no general consensus on the treatment protocol for renal artery aneurysm. Notably, ruptured renal artery aneurysm is a true critical emergency that may result in a fatal outcome. We are reporting two renal artery aneurysm patients who had ruptured and underwent emergency laparotomy.

Surgical treatment of an aneurysm of a distal branch of the renal artery

Aneurysms of the renal artery and its branches are rare, but are associated with significant morbimortality due to the absence of clinical symptoms and hemorrhagic risk in the event of rupture. We report the case of a patient with an aneurysm of a distal branch of the right renal artery that measured 25 mm in diameter. The diagnosis and localization were obtained using selective arteriography. Treatment consisted of resection of the aneurysmal sac associated with closure with a saphenous vein patch rather than an endovascular treatment in order to preserve the nephronic capital. Right renal parenchymatous vascularization was satisfactory on arterial echo-Doppler and angioscanner assessment at 1 year.