Endovascular vs open repair of renal artery aneurysms: outcomes of repair and long-term renal function

Title: Is Celiac Trunk Revascularization Necessary After High-Flow Pancreaticoduodenal Arterial Arcades Aneurysm Retrograde Embolization?

Background and Objective: High-flow pancreaticoduodenal artery (PDA) aneurysms secondary to celiac trunk occlusion or stenosis have a high risk of rupture. Embolization offers a less invasive alternative to surgery. We evaluated the effectiveness and safety of retrograde embolization via the superior mesenteric artery of high-flow PDA aneurysms without celiac trunk revascularization. Methods: This retrospective bicentric study included patients who underwent embolization of high-flow PDA aneurysms due to significant celiac trunk stenosis or occlusion. All patients underwent pre-interventional dynamic contrast-enhanced computed tomography. Retrograde embolization was performed using microcoils and/or liquid agents without celiac trunk revascularization. Follow up involved clinical and radiological assessment at one month. Technical and clinical success were evaluated, and complications were categorized as minor or major. Results: Twenty-three patients (mean age 65 ± 14 years; 52% male) were included. Emergency embolization was required in 12 patients (52%). The technical success rate was 100%. Patients were monitored for a median of 16 months. Clinical success was 87%. No hemorrhagic recurrences were observed. Minor complications occurred in two cases. One major complication involved splenic infarction due to glue migration, requiring splenectomy and intensive unit care admission. Conclusions: Retrograde embolization of high-flow PDA aneurysms is effective and safe without needing celiac trunk revascularization.

Giant renal artery aneurysm with severe compression of the right kidney

OBJECTIVES

Renal artery aneurysm (RAA) is a rare condition among visceral aneurysms, often asymptomatic and incidentally discovered through imaging. Surgical or interventional procedures are utilized for treatment, depending on the aneurysm's size, morphology, and the patient's physical condition, to prevent rupture.

METHODS

A patient was admitted with a giant asymptomatic RAA, measuring a maximum diameter of 11 cm on a serendipitous occasion.

RESULTS

We successfully accomplished a full embolization treatment for the aneurysm, exclusively utilizing inflow tract embolization techniques. Six months post-treatment, a follow-up abdominal ultrasound examination demonstrated a notable decrease in the aneurysm's diameter, signifying the positive outcome of our intervention.

CONCLUSIONS

This approach offers a feasible alternative in challenging cases, especially when traditional surgical methods are not feasible or carry significant risks.

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.

Management of renal artery aneurysms: A retrospective study

BACKGROUND

Although renal artery aneurysms (RAAs) are rare and often asymptomatic with slow growth, their natural progression and optimal management are not well understood. Treatment recommendations for RAAs do exist; however, they are supported by limited data.

METHODS

A retrospective cohort study was conducted to explore the management of patients diagnosed with an RAA at our institution from January 1st, 2013, to December 31st, 2020. Patients were identified through a search of our radiological database, followed by a comprehensive chart review for further assessment. Data collection encompassed patient and aneurysm characteristics, the rationale for initial imaging, treatment, surveillance, and all-cause mortality.

RESULTS

One hundred eighty-five patients were diagnosed with or treated for RAAs at our center during this timeframe, with most aneurysms having been discovered incidentally. Average aneurysm size was 1.40 cm (±0.05). Of those treated, the mean size was 2.38 cm (±0.24). Among aneurysms larger than 3 cm in size, comprising 3.24% of the total cases, 83.3% underwent treatment procedures. Only 20% of women of childbearing age received treatment for their aneurysms. There was one instance of aneurysm rupture, with no associated mortality or significant morbidity.

CONCLUSIONS

Our institution's management of RAAs over the period of the study generally aligned with guidelines. One potential area of improvement is more proactive intervention for women of childbearing age.

Visceral Aneurysms: Systematic Review and Meta-analysis of Endovascular Versus Open Repair

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID 348699.

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.

Blood pressure and renal outcomes after renal artery aneurysm intervention: Single-center experience and review of literature

Objective

To explore the results of hypertension improvement and renal function preservation after renal artery aneurysm (RAA) repair.

Methods

This study retrospectively analyzed the change in blood pressure (BP) and renal outcomes of 59 RAA patients throughout either open or endovascular operations and follow-up at a large center. Patients were grouped according to the difference in their BP at the last follow-up vs. their baseline value. Logistic regression was conducted to explore risk factors for perioperative BP relief and long-term hypertension reonset. Previous studies of RAA with records of BP, blood creatinine level, or GFR/eGFR results are reviewed.

Results

Hypertension was observed in 62.7% (37/59) of the patients included. Postoperative BP declined from 132.20 ± 16.46/79.92 ± 9.64 mmHg to 122.41 ± 11.17/71.10 ± 9.82 mmHg, while eGFR changed from 108.17 ± 24.73 to 98.92 ± 23.87 ml/min/1.73 m². The median follow-up was 854 [IQR: 1,405] days. Both open and endovascular techniques significantly relieved hypertension and did not impair renal function much. Lower preoperative systolic BP (SBP) was significantly associated with hypertension relief (OR = 0.83, 95% CI: 0.70-0.99). Among patients with normal BP after the operation, higher postoperative SBP was significantly associated with new-onset hypertension (OR = 1.14, 95% CI: 1.01-1.29). Literature review indicated that renal function usually remained normal at follow-up, whereas relief of hypertension varied.

Conclusion

Patients with lower preoperative SBP were likely to benefit more from the operation, while higher postoperative SBP indicated a higher chance of hypertension reonset. Creatinine level and eGFR generally remained stable regardless of operation type.

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.

Coil embolization of ruptured distal renal artery pseudoaneurysm with gross hematuria and hemorrhagic shock

Renal artery pseudoaneurysms have been infrequently reported in the literature. In the present report, we have described a case of a ruptured renal artery pseudoaneurysm requiring coil embolization. A 49-year-old man had presented to our institution with a hypertensive emergency. Computed tomography revealed a 3.4-cm right renal artery pseudoaneurysm. Nonemergent coil embolization was planned for the following day. However, he became hypotensive, exsanguinating frank blood from the urethra. An arteriogram showed extravasation of contrast into the pseudoaneurysm sac, renal pelvis, and ureter, consistent with intrarenal pseudoaneurysm rupture. We have demonstrated coil embolization as a method of repairing a ruptured renal artery pseudoaneurysm with gross hematuria.

Single Centre Experience in Open and Endovascular Treatment of Renal Artery Aneurysms

BACKGROUND

The true incidence and natural history of renal artery aneurysm (RAA) remain unclear and still exists controversy over indication for treatment. Several techniques of conventional surgical reconstructions are described in literature, and more recently endovascular therapies have been reported with satisfying results and lower complication rate. This paper aims to investigate the outcomes of both endovascular and open repair of RAA achieved in a single institution involving 3 medical teams (urology, vascular surgery and neuroradiology).

MATERIAL AND METHODS

We conducted a single-centre retrospective observational study about all patients surgically or endovascularly treated for RAA over a 15-year period. Pre-operative, procedural and post-operative data at the early, mid- and long-term follow-up were collected and analysed, focusing on operative technique used for repair and related outcomes.

RESULTS

A total of 27 patients (n = 17 (63%) women, mean age 58 ± 13.2, n = 26 saccular RAA) were included. Mean aneurysm was size was 18.8 ± 6.3 mm. Most diagnosis were accidental. Symptomatic RAA showed with macroscopic haematuria (n = 3, 25.9%), unstable hypertension (n = 2; 7%), chronic lumbar pain (n = 1, 3.7%) and renal infarct (n = 1, 3.7%). Conventional surgery (ex-vivo repair, aneurysmorraphy, aneurysm resection and end-to-end anastomosis) was performed in 14 (51.8%) cases and endovascular coiling embolization in 13 (48.2%). Mean hospital length of stay was 5.4 ± 3.6 days. Intensive Care Unit stay was needed only in the surgically treated patients (mean 1.1 ± 1.2 days). During the early follow-up, morbidity rate was 7/14 in surgically treated patients vs. 1/13 in endovascular group; it included bleeding, retroperitoneal hematoma, arterial thrombosis and bowel obstruction. The discharge imaging showed complete aneurysm exclusion and renal artery patency in all cases. At a mean follow-up of 39 ± 42 months, 3 patients (11%) were lost to follow up and 2 (7.4 %) died from unrelated cause. None of these patients required dialysis but a statistically significant (P = 0.09) decrease in GFR was noted between the preoperative period and last follow-up control. RAA repair neither showed blood pressure control improvement nor reduced the need for anti-hypertensive drug use.

CONCLUSION

Open or endovascular techniques are both safe and efficient to treat RAA. Even though, surgical management is burdened with higher morbidity rate, the operative technique should be selected according to anatomical features, diameters and location of RRA; and the number of renal branches involved. Further larger studies are needed to define the feasibility and safety for a wider application of the endovascular approach.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

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.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

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.

Packing Technique with or without Remodeling for Endovascular Coil Embolization of Renal Artery Aneurysms: Safety, Efficacy and Mid-Term Outcomes

The endovascular treatment of renal artery aneurysms (RAAs) has lower morbidity and shorter stay lengths compared to surgical repair. Here, we describe coil packing with or without remodeling and assess outcomes and complications. We retrospectively identified the 19 consecutive preventive endovascular RAA coil embolizations done in 18 patients at our center in 2010-2020. Patient and aneurysm characteristics, technical success rate, complications, and recurrences were recorded. Mean patient age was 63 ± 13 years. The RAA was >1.5 cm in 11 cases, and in four cases, the aneurysm-to-parent artery size ratio was >2. Simple coiling was performed for 11 (57.9%) aneurysms, stent-assisted coiling for seven (36.8%) aneurysms, and balloon-assisted coiling for one (5.3%) aneurysm. Technical success rate was 100%. Complete definitive RAA exclusion was achieved with a single procedure for 17 (89.5%) aneurysms, whereas two (10.5%) aneurysms required a repeat procedure. Four minor complications occurred but resolved with no long-term consequences. No major complications occurred during the mean follow-up of 41.1 ± 29.7 months. Coil embolization by sac packing or remodeling proved very safe and effective. Together with the known lower morbidity and shorter stay length compared to open surgery, these data indicate that this endovascular procedure should become the preventive treatment of choice for RAAs.

Mid-term Results of Coil Embolization Alone and Stent-assisted Coil Embolization for Renal Artery Aneurysms

BACKGROUND

Coil embolization (CE) alone and stent-assisted coil embolization (SCE) are two major endovascular techniques to treat renal artery aneurysms (RAAs). This study aimed at providing safety and efficacy data of CE and SCE for RAAs.

METHODS

Between August 2015 and June 2019, 40 RAA patients treated with CE or SCE were included in the retrospective study. Patients' demographics, clinical manifestations, aneurysm characteristics, treatment strategies, and follow-up results were collected and analyzed.

RESULTS

There were 26 and 14 patients in the CE and SCE group, respectively. The mean aneurysm diameter was 2.5 ± 1.5 cm and 2.2 ± 0.8 cm (CE versus SCE, P = 0.52). The neck width of the aneurysm was 0.63 ± 0.37 cm and 1.07 ± 0.42 cm (CE versus SCE, P = 0.021). Technical success was achieved in 97.5% patients. No death or aneurysm rupture occurred. During the perioperative period, 12% and 7.1% patients suffered partial renal infarction (CE versus SCE, P = 0.45). The mean duration of follow-up was 8.8 ± 9.4 months and 16.1 ± 16.3 months (CE versus SCE, P = 0.158) by imaging and 20.8 ± 11.3 and 22.7 ± 16.5 months by visit/telephone (CE versus SCE, P = 0.703). During the follow-up, 17.4% patients in the CE group and 30.8% patients in the SCE group suffered partial renal infarction, while their overall renal function remained normal. In addition, there was no aneurysm recurrence, sac enlargement, or death in both groups.

CONCLUSIONS

Both CE and SCE were safe and effective to treat RAAs. In addition, SCE may prevent coil migration in the wide neck aneurysm in selected patients.

Results of Surgical Repair of Hilar Renal Artery Aneurysm to Preserve Renal Blood Flow

Objective: Surgical indications and procedures for hilar renal artery aneurysm (HRAA) are controversial in terms of invasiveness and feasibility. Catheter treatment is minimally invasive but leads to renal dysfunction due to renal infarction. This study aims to investigate the results of surgical repair of HRAA.

Method: Fourteen patients (58.7±11.6 years old, 7 male) who underwent surgical repair of HRAA were retrospectively reviewed. Nine patients (64%) developed HRAA in the right renal artery, and the mean maximum aneurysmal diameter was 25.9±10.3 mm. HRAA was exposed via the extraperitoneal approach. HRAA was resected completely, and reconstruction of renal arteries was performed by direct closure in two, direct anastomosis in nine, and interposition of saphenous vein graft in three patients.

Results: The average operation and renal ischemic times were 186±49 and 35±16 min, respectively. No operative death occurred, and postoperative renal function at the time of discharge had not deteriorated (creatinine, 0.74±0.15 mg/dl). During the follow-up periods (4.7±5.1 years), there was no death, no new introduction of hemodialysis, and no recurrence of renal artery aneurysm.

Conclusion: Surgical repair of HRAA remains a valid option because of its operative safety, preservation of renal function, and long-term feasibility and patency.

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.

Ex vivo repair and renal auto-transplantation for treatment of a renal artery aneurysm after endovascular failure

Renal artery aneurysms are rare and typically found incidentally. Risk of rupture drives the incentive for repair, which can be achieved by both open and endovascular techniques. Ex vivo repair with renal auto-transplantation is recommended for complex aneurysms involving distal or multiple arteries. Here we describe a successful treatment of a renal artery aneurysm after previous endovascular treatment failure. A multi-layered stent was left misplaced inside of the aneurysm. Ex vivo repair with renal auto-transplantation allowed for complete aneurysm exclusion. With increasing use of endovascular techniques, failure of endovascular treatment might become a common indication for ex vivo repair in renal artery aneurysms.

Think twice before stent insertion for renal artery aneurysm with elusive etiology: a case report

BACKGROUND

Endovascular treatment has been recognized as the first line therapy for renal artery aneurysm (RAA). However, RAA related with malignancies had been sporadically reported in the literature. Stent insertion should be contraindicated for RAAs with malignant etiology, whereas surgery be optimal.

CASE PRESENTATION

A 40-year-old female underwent covered stent insertion to exclude the left RAA for suspected Takayasu arteritis in a reginal hospital. Three months later the RAA recurred with sign of threatened rupture, and the patient was transferred for salvage embolization with coils and thrombin injection. However, 20 days after the embolization procedure, multiple painful subcutaneous nodules developed in her flanks. Undifferentiated sarcoma was revealed by the pathological biopsy of the nodules. The RAA in this case was most likely related with the malignancy.

CONCLUSION

Malignancy was the most likely etiology behind recurrent aneurysm in this case. Definite diagnosis is mandatory for interventional radiologists before stent insertion for treatment of RAA.

Ex vivo revascularization of renal artery aneurysms in a patient with solitary kidney: A case report

BACKGROUND

Multiple renal artery aneurysms (RAAs) involving multiple branches in a solitary kidney are rare and present a major challenge to surgeons. Ex vivo or in situ repair combined with renal artery revascularization is the classical procedure for these complicated cases, which are not suitable for endovascular repair. The choice of bypass graft remains controversial because of the risk of aneurysmal degeneration for autologous graft.

CASE SUMMARY

A 39-year-old female patient presented with left lumbar pain for more than 3 mo. Computed tomography angiography showed congenital absence of the right kidney and three left RAAs involving multiple distal branches. This patient met the criteria for surgical repair due to symptoms of threatened rupture. According to the anatomy and location of multiple RAAs, ex vivo revascularization with saphenous vein graft (SVG) was performed. At the 3-year follow-up, computed tomography angiography demonstrated the aneurysmal degeneration of the Y-shaped SVG. The patient remained asymptomatic and follow-up ultrasound showed no continuous growth of SVG aneurysm.

CONCLUSION

SVG aneurysm in RAA revascularization causes us to reflect on the choice of graft, especially for solitary kidney patients.

Renal artery reconstruction and kidney autotransplantation for Takayasu arteritis-induced renal artery stenosis

A young woman with Takayasu arteritis and complex renal artery stenosis in a solitary functional kidney underwent an ex vivo revascularization with autologous saphenous vein graft and renal autotransplantation. Before surgery, she had resistant hypertension and recurrent episodes of acute kidney injury. Two years later, her blood pressure is 123/77 mm Hg, and there have been no acute kidney injury episodes. Computed tomography scan demonstrates no abnormal thickening of the graft despite proximal progression of disease to involve the superior mesenteric artery. As Takayasu arteritis is a progressive disease, use of autologous vein graft, which is unlikely to become involved, is of paramount importance.

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 Treatment of Ruptured Renal Artery Aneurysm: A Case-Based Literature Review

Renal artery aneurysms are extremely uncommon with a reported incidence of less than one percent in general population. They are being more frequently detected due to increasing availability and use of abdominal imaging. Renal artery aneurysm rupture is an extremely unusual cause of acute flank pain with hemodynamic instability. Given the rarity of diagnoses, clinicians may not consider and address this ruptured renal artery aneurysm early which can potentially lead to adverse clinical outcomes. We report the case of a 55-year-old male who presented with retroperitoneal bleeding from a ruptured aneurysm of the interlobular branch of renal artery. He was endovascularly treated with coil embolization. We have also reviewed the inherent literature.

Endovascular Therapy of a Giant Renal Artery Aneurysm Combined With High-Flow Renal Arteriovenous Fistula Using a Patent Ductus Arteriosus Occluder

Renal artery aneurysm (RAA) concomitant with a renal arteriovenous fistula (RAVF) is extremely rare. A 32-year-old man suffered from a giant RAA combined with high-flow RAVF. The computer tomographic angiography (CTA) demonstrated a RAA, which is 6.3 cm in length and 2.1 cm in diameter, combined with an arteriovenous fistula between the right renal artery and right renal vein (fistula area:1.05 cm × 1.0 cm). After a comprehensive preoperative assessment, a patent ductus arteriosus occluder (PDAO) was implanted. At a 1-year follow-up, the CTA study showed that the PDAO was in situ and there was no recanalization of the lesion. At a third-year follow-up, ultrasound examination showed an image of right renal atrophy. The results of long-term follow-up demonstrate that PDAO is safe and effective for the management of RAAs combined with high-flow RAVF.

In situ revascularization of bilateral complicated giant renal artery aneurysms: Case report

RATIONALE

Renal artery aneurysm (RAA) is a rare entity, bilateral multiple RAAs near hilum with a maximum diameter of 7 cm are even rare and bring a great challenge to surgeons. As the technique of vessel reconstruction is quite difficult for the RAAs near hilum, some surgeons choose to resect the involved kidney. We reported a young female patient with the threatened rupture symptoms for further treatment. The details of revascularization methods and procedure design were discussed in the report.

PATIENT CONCERNS

A young female patient complained with lumbar and abdominal pain for 1 month. Computed tomography angiography showed bilateral RAAs with the maximum diameter of 6 and 7 cm on the left and right side separately. For the right RAA, apart from a giant aneurysm, there was another small aneurysm with a diameter of 3 cm located on the inferior polar right renal artery. There was a mild tenderness on the left lumbar and lower abdomen, no rebound tenderness was detected.

DIAGNOSIS

According to the image feature and symptoms, the diagnosis for this patient was bilateral giant RAAs with threatened ruptured.

INTERVENTIONS

Dissection of the bilateral giant RAA and in situ revascularization of renal arteries with prosthetic graft was performed.

OUTCOMES

The follow-up results showed the satisfactory patency of prosthetic graft and obvious improvement of renal function.

LESSONS

This complicated bilateral giant RAAs was successfully revascularized through in situ renal artery repair with a very difficult procedure process. For the RAA near hilum, vessel reconstruction no matter through in situ or ex vivo are both difficult for surgeons. This extremely rare and difficult case could bring more confidence to surgeons who meet such complicated bilateral RAAs for choosing the vessel reconstruction rather than kidney resection.

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.

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.

Coil Embolization of a Renal Aneurysm Using a Minimally Invasive Endovascular Robotic System

We present a case demonstrating the use of an endovascular robotic system in the treatment of a saccular renal artery aneurysm located at the renal hilum in a young patient.

Natural History and Chronological Growth Rate of Renal Artery Aneurysms

Objective: Renal artery aneurysm (RAA) is an uncommon disease, the natural course of which is still not well known. The objective of this study is to define factors that affect the growth rate of RAAs.

Materials and Methods: We retrospectively reviewed 32 aneurysms in 26 patients at our institute between January 2010 and March 2016. Basal demographics, comorbidities, reason for diagnosis, and details of the aneurysms and interventions were recorded. The chronological changes in the diameter of the RAA using multiplanar reconstructions of computed tomography images were measured and analyzed.

Results: The baseline mean diameter was 20.1±8.4 mm (range: 9.9–41). The mean follow-up period was 3.13±2.1 y (range: 0.5–7.1). The median growth rate was 0.35 mm/y (interquartile range: 0.05, 0.62). The growth rate was slower when the initial diameter was <20 mm than when it was >20 mm (p=0.036). Also, whole-completed calcification was a significant factor for slower growth (p=0.016). We performed ex-vivo surgery in two cases and coil packing with stenting in one. No ruptures occurred during the study period.

Conclusion: Our results suggest that cases with an RAA diameter <20 mm do not require intervention. The interval period can be longer in whole-completed calcification types.

Complete robotic repair of a renal artery aneurysm

Although the majority of renal artery aneurysms require only observation, those that require treatment have been addressed primarily surgically or endovascularly. We report a case of surgical resection of a large, symptomatic renal artery aneurysm from an entirely robotic approach.

The diagnosis and endovascular therapy of renal artery aneurysm: A 32-patient case report

RATIONALE

Renal aneurysm is a rare disease with the atypical symptoms and mostly diagnosed by imaging modalities. Endovascular therapy is a one of treatment methods.

PATIENT CONCERNS

A retrospective analysis of 32 patients with renal artery aneurysm, from June 2010 to May 2016 in our hospital, was made in our study. All of them underwent therapy, and the effects and perioperative characteristics of it were analyzed.

DIAGNOSIS

32 patients were taken contrast-enhanced CT and diuretic renal dynamic imaging to evaluate the state of illness.

INTERVENTIONS

The preoperative blood creatinine, perioperative hemoglobin and relief of hypertension were performed.

OUTCOMES

The preoperative blood creatinine was slightly increasing, while the perioperative hemoglobin was slightly decreasing. The relieving hypertension was performed in 9 of patients.

LESSONS

Endovascular therapy is a mature and feasible treatment method. There is little effect on hemoglobin and renal function in postoperation, while it can also decrease the blood pressure.

Stent-assisted detachable coil embolization of wide-necked renal artery aneurysms

Renal artery aneurysms (RAAs) are rare with an estimated incidence of 0.1% in the general population, and they represent approximately 25% of all visceral aneurysms. The gold standard of treatment is open surgery, but it is associated with a high risk of nephrectomy, mortality, and morbidity. Less invasive endovascular therapies are becoming increasingly common for the treatment of RAAs. Here, we aimed to report three cases of wide-necked complex renal artery aneurysms treated endovascularly using stent-assisted coil embolization with self-expandable stent nitinol Solitaire AB and Concerto Axium coils. In addition, we describe the use of the waffle-cone technique in a case of wide-necked saccular RAA involving the renal artery bifurcation. Technical success was achieved in all three cases with no early or late complications and no recurrences.