Long-term outcome of single institutional experience with conservative and surgical management for renal artery aneurysm

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.

Rare giant renal artery aneurysm in neurofibromatosis type 1 patient: a case report

Introduction and importance

Neurofibromatosis type 1 (NF1) is a genetic disorder characterised by multiple neurofibromas, café-au-lait spots, and iris hamartomas. The variety of vasculopathies that can occur in NF1 make it difficult for clinicians to accurately follow-up patients. Most cases of vasculopathies are stenotic, and, in few cases, aneurysms may form.

Case presentation

A 35-year-old male presented with extreme left flank pain for the past 2 days. His physical examination revealed whole-body several café-au-lait skin macules, a subcutaneous lesion, and a palpable abdominal mass in the left flank. His laboratory workup was within normal ranges. A multi-slice computed tomography and computed tomography angiogram with contrast outlined a giant left renal artery aneurysm (RAA). A kidney salvage surgery was planned. However, due to ectatic dilatation and large extension of the aneurysm, the affected renal artery branches and renal vein were found unfit for auto-transplantation during the surgical procedure and a total nephrectomy was necessary. Symptoms improved significantly postoperatively and no complications developed.

Clinical discussion

RAA is an uncommon finding in NF1 patients. Diagnosis is often dependent on computed tomography angiogram. Management techniques are conservative, endovascular, or surgical. In few surgical cases, a total nephrectomy may be necessary if auto-transplantation is not feasible.

Conclusion

Despite its rarity, the diagnosis of RAA should be considered in patients with NF1 presenting with flank pain. Moreover, early screening for renal vasculopathies can evade critical surgical outcomes including a total nephrectomy. Hence, the authors recommend a total vascular workup for these patients, consisting of doppler ultrasound and, if necessary, a multi-slice computed tomography with contrast.

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.

Natural history of renal artery aneurysms

OBJECTIVE

The existing renal artery aneurysm (RAA) literature is largely composed of reports of patients who underwent intervention. The objective of this study was to review the natural history of RAA.

METHODS

This single-institution retrospective analysis studied all patients with RAA diagnosed by computed tomography imaging between 2015 and 2019, identified by our institutional radiology database. Imaging, demographic, and clinical data were obtained via the electronic medical record. He growth rate was calculated for all patients with radiological follow-up.

RESULTS

The cohort consists of 331 patients with 338 RAAs. Most patients were female (61.3%), with 11 (3.3%) of childbearing age. The mean age at diagnosis was 71.5 years (range, 24-99 years). Medical comorbidities included hypertension (73.7%), prior smoking (34.4%), and connective tissue disease (3.9%). Imaging indications included abdominal pain (33.5%), unrelated follow-up (29.6%), and follow-up of an RAA initially diagnosed before the study period (10.7%). Right RAA (61.9%) was more common than left (35.1%); 3% of patients had bilateral RAA. The mean diameter at diagnosis was 12.9 ± 5.9 mm. Size distribution included lesions measuring less than <15 mm (69.9%), 15 to 25 mm (27.1%), and more than 25 mm (3.0%). Anatomic locations included the distal RA (26.7%), renal hilum (42.4%), and mid-RA (13.1%). The majority were true aneurysms (98%); of these, 72.3% were fusiform and 27.7% were saccular. Additional characteristics included calcification (82.2%), thrombus (15.9%), and dissection (0.9%). Associated findings included aortic atherosclerosis (65.6%), additional visceral aneurysms (7.3%), and abdominal aortic aneurysm (5.7%). The mean clinical follow-up among 281 patients was 41.0 ± 24.0 months. The mean radiological follow-up among 137 patients was 26.0 ± 21.4 months. Of these, 43 patients (31.4%) experienced growth, with mean growth rate of 0.23 ± 4.7 mm/year; the remainder remained stable in size. Eight patients eventually underwent intervention (5 endovascular), with the most common indications including size criteria (4/8) and symptom development (3/8). No patient developed rupture. On multivariate analysis, obesity (P = .04) was significantly associated with growth. An initial diameter of more than 25 mm was significantly associated with subsequent intervention (P = .006), but was not significantly associated with growth. Four of five RAAs with an initial diameter 30 mm or greater did not undergo intervention. The mean clinical follow-up for these patients was 24 months; none developed rupture and two remained stable in size.

CONCLUSIONS

This large institutional cohort found that the majority of RAAs remained stable in size, with few patients meeting indications for repair based on societal guidelines. Current guidelines recommending intervention for asymptomatic aneurysms more than 30 mm seem to be appropriate given their slow progression.

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.

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.

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.

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.

Laparoscopic-assisted Ex Vivo Reconstruction of Renal Artery Aneurysm with Internal Iliac Artery and Auto-transplantation

Renal artery aneurysms (RAA) represent a complex and an often incidentally found disease commonly treated with endovascular approaches. In cases where in situ approaches are unsuitable, laparoscopic-assisted ex vivo repairs offer significant advantages during and post-surgery. We present a case of a female patient who presented with a long-standing right-sided flank pain. She was diagnosed with bilateral asymptomatic RAAs positioned well into the hilum, therefore making in situ repair infeasible. A laparoscopic-assisted ex vivo repair of the renal artery was performed using a graft from the internal iliac artery, which is a novel approach.

Natural history and management of renal artery aneurysms in a single tertiary referral center

OBJECTIVE

Although renal artery aneurysms (RAAs) are uncommon, several large reports have been published indicating their benign natural history. The objective of our study was to review our single-center experience managing this disease entity.

METHODS

A retrospective review of the Yale radiologic database from January 1999 to December 2016 was performed. Only patients with RAA and a computed tomography scan of the abdomen were selected for review. Demographics of the patients, aneurysm characteristics, management, postoperative complications, and follow-up data were collected.

RESULTS

There were 241 patients with 259 RAAs identified, with a mean age of 69 years (range, 35-100 years); 147 were female (61%). On computed tomography, aneurysms were solitary and right sided in 224 (86%) and 159 (61%), respectively; 64 (27%) patients had aneurysms elsewhere. The breakdown of RAAs by location was as follows: renal bifurcation in 84 (32%), renal pelvis in 77 (30%), distal renal artery in 58 (22%), mid renal artery in 34 (13%), and proximal renal artery in 6 (2%). Five patients had symptoms that were attributed to the RAA and underwent operative repair; all others were observed without an operation. Symptoms in the operative repair group included flank pain in four and uncontrolled hypertension in one. The mean overall diameter of the RAAs was 1.22 ± 0.49 cm. The diameter of operatively repaired and observed RAAs was 1.84 ± 0.55 cm and 1.21 ± 0.48 cm, respectively (P = .002). Operative repair included four coil embolizations and one open resection. There were no renal function changes in any of these patients after operation and no other complications. Mean follow-up was 41 ± 35 months for patients in the group that was observed; 18 of these RAAs were >2 cm, and none ruptured. On multivariable regression analysis, female sex (P = .0001), smoking history (P = .00007), left-sided RAA (P = .03), and main renal artery location (P = .03) were inversely related to growth, whereas a history of hypertension was directly related to growth rate (P = .01). The mean growth rate for RAAs was 0.017 ± 0.052 cm/y.

CONCLUSIONS

RAAs tend to have a benign natural history. Although previous reports have not identified any factors that contribute to RAA growth, we observed that RAA location, sex, smoking history, and hypertension may have an impact on growth rates. No ruptures were observed. Operative repair at our institution was rare, with no morbidity or mortality. Observation of RAAs over time seems feasible in the asymptomatic patient with a small RAA.

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.

Visceral artery aneurysms: Incidence, management, and outcome analysis in a tertiary care center over one decade

Objectives

To evaluate the incidence, management, and outcome of visceral artery aneurysms (VAA) over one decade.

Methods

233 patients with 253 VAA were analyzed according to location, diameter, aneurysm type, aetiology, rupture, management, and outcome.

Results

VAA were localized at the splenic artery, coeliac trunk, renal artery, hepatic artery, superior mesenteric artery, and other locations. The aetiology was degenerative, iatrogenic after medical procedures, connective tissue disease, and others. The rate of rupture was much higher in pseudoaneurysms than true aneurysms (76.3 % vs.3.1 %). Fifty-nine VAA were treated by intervention (n = 45) or surgery (n = 14). Interventions included embolization with coils or glue, covered stents, or combinations of these. Thirty-five cases with ruptured VAA were treated on an emergency basis. There was no difference in size between ruptured and non-ruptured VAA. After interventional treatment, the 30-day mortality was 6.7 % in ruptured VAA compared to no mortality in non-ruptured cases. Follow-up included CT and/or MRI after a mean period of 18.0 ± 26.8 months. The current status of the patient was obtained by a structured telephone survey.

Conclusions

Pseudoaneurysms of visceral arteries have a high risk for rupture. Aneurysm size seems to be no reliable predictor for rupture. Interventional treatment is safe and effective for management of VAA.

Key Points

• Diagnosis of visceral artery aneurysms is increasing due to CT and MRI.

• Diameter of visceral arterial aneurysms is no reliable predictor for rupture.

• False aneurysms/pseudoaneurysms and symptomatic cases need emergency treatment.

• Interventional treatment is safe and effective.

Renal artery embolization-indications, technical approaches and outcomes

Owing to improvements in catheters and embolic agents, renal artery embolization (RAE) is increasingly used to treat nephrological and urological disease. RAE has become a useful adjunct to medical resuscitation in severe penetrating, iatrogenic or blunt renal traumatisms with active bleeding, and might avoid surgical intervention, particularly among patients that are haemodynamically stable. The role of RAE in pre-operative or palliative management of advanced malignant renal tumours remains debated; however, RAE is recommended as a first-line therapy for bleeding angiomyolipomas and can be used as a preventative treatment for angiomyolipomas at risk of bleeding. RAE represents an alternative to nephrectomy in various medical conditions, including severe uncontrolled hypertension among patients with end-stage renal disease, renal graft intolerance syndrome or autosomal dominant polycystic kidney disease. RAE is increasingly used to treat renal artery aneurysms or symptomatic renal arteriovenous malformations, with a low complication rate as compared with surgical alternatives. This Review highlights the potential use of RAE as an adjunct in the management of renal disease. We first compare and contrast the technical approaches of RAE associated with the various available embolization agents and then discuss the complications associated with RAE and alternative procedures.