Ex Vivo Open Reconstruction of Hilar Renal Artery Aneurysms: A Single-Center Experience

Abstract

The renal artery aneurysms (RAAs) represent 3% of all visceral aneurysms. Their incidence rate is about 0.1% in the general population [1], even if angiographic findings report a little higher incidence (0.3-2.5%) [2] with a modest prevalence in female patients. RAAS are mainly detected in the sixthseventh decade, and female patients are associated with an earlier incidence [3]. True RAAs are extra-parenchymal in 90% of cases, while intraparenchymal RAAs represent 10% of cases, and they are often multiple and congenital. RAAs can be saccular in 75% of cases or fusiform. Saccular RAAs usually affect the main renal artery bifurcation, while fusiform aneurysms often involve the main arterial trunk [4]. RAAs can be bilateral (10-20%) or associated with a multiple location. High calcifications are detected in 18-68% of cases [1]. HRAAs represent a rare subgroup of RAAs, located in the distal part of the renal artery, very close to the renal hilum even though they are considered extra-parenchymal (Fig. 12.1). In addition to "true aneurysms," the main renal arteries and their collaterals can be affected by:

Endovascular therapy for distal hilar renal artery aneurysm: a case report and literature review

“…Although the natural course of HRAAs is undetermined, the surgical indications for the treatment of HRAA are an enlarged renal arterial diameter of >2 cm, female sex and childbearing age, and symptoms such as flank pain, hematuria, refractory hypertension, thromboembolism, dissection, and rupture. 1 , 3 , 8 In the present case, the patient was cured by endovascular therapy.…”

“…Among the reported cases, four patients had a solitary kidney, two patients were pregnant, and two repaired kidneys were successfully transplanted to two men, respectively, which provided benefits to both donors and recipients. 5 , 8 , 10 , 11 , 13 – 19 After analysis of the therapeutic strategies, we found that 47% ( N = 26) of HRAAs were treated by ex vivo reconstruction (EVR), 44% ( N = 24) were treated by in situ reconstruction (ISR), 5% ( N = 3) were treated by endovascular therapy, and 4% ( N = 2) were treated with nephrectomy. Laparoscopy was used to reduce surgical trauma owing to its lower invasiveness, and 17% ( N = 9) of the operations were performed with the aid of laparoscopy.…”

“…Therefore, in one study, the kidney surface was cooled to minimize warm ischemic damage during preservation to prolong the preservation time to 3 hours. 8 Autologous grafting or prosthetic bypass was used for the replacement of the aneurysmal tract if a primary closure was not available. The great saphenous vein (GSV) was the most frequently used graft.…”

Laparoscopic nephrectomy with ex vivo repair of aneurysm and autotransplantation

“…One potential mechanism is due to turbulent flow in the renal artery and increased renin production; other theories include concomitant renal artery stenosis, kinking of the renal artery, and distal embolization to the renal parenchyma. 2 Although the mechanism is unclear, it has been noted that some patients have had improved hypertension after treatment, but despite this, it is not considered to be a treatment indication. 3,4 Symptoms related to RAA can depend on the type of aneurysm and its location.…”

“…5,6 A small portion of the extraparenchymal aneurysms include hilar RAAs, which occur at the distal portion of the renal artery. 2 Although these aneurysms are considered extraparenchymal, they are often close to the hilum and require more complex interventions.…”