Aberrant renal arteries: General considerations
Bilbil Hoxha1, Artur Hafizi2
1 Service of Urology, University Hospital Cther Teresa”, Tiraenter “Mona, Albania;
2 Faculty of Medicine, University of Medicine, Tirana, Albania.
Corresponding author: Bilbil Hoxha, MD;
Address: Rr. “Dibres”, No. 371, Tirana, Albania
Telephone: +355674824720
Abstract
Aberrant renal arteries are also referred to as accessory arteries. These conditions pose serious concern to urologists due to the involvement of the affected vessels in the ethiology of hydronephrosis. The medical literature has well-documented and exhaustedly characterized many cases of aberrant or accessory arteries, where the renal vessels have been reported to enter the lower pole of the kidney and to lie in such a position as to appear to obstruct the outflow of urine at the pelviureteric junction.
According to the international literature, the incidence of aberrant or accessory renal arteries varies widely based also one the fact that there is no fixed criterion for aberrance. From this point of view, this term is many times employed interchangeably to an extra artery in the renal pedicle, or to an artery entering the kidney at either pole, whether derived from the main renal artery, from the aorta or from a branch of the aorta.
Since many decades ago, it has been suggested that the arteries which have a proximal origin at the hilum or in the pedicle may be most likely a consequence of a variation in the degeneration of the rete arteriosum, whilst the arteries which arise from the aorta may be persistent mesonephric arteries.
The issue of aberrant renal arteries is also of particular concern in the urology practice at the University Hospital Center “Mother Teresa” in Tirana, Albania. In all cases, it is recommended that the affected arteries should be named together with an indication of their origin and type and the words “aberrant” or “accessory” should be avoided, because these terms bear little anatomical, or explanatory value in the clinical practice.
Keywords: aberrant renal arteries, accessory arteries, renal vessels, urology.
Aberrant renal arteries
Aberrant renal arteries are also referred to as accessory arteries. These conditions pose serious concern to urologists due to the involvement of the affected vessels in the ethiology of hydronephrosis. The medical literature has well-documented and exhaustedly characterized many cases of aberrant or accessory arteries, where the renal vessels have been reported to enter the lower pole of the kidney and to lie in such a position as to appear to obstruct the outflow of urine at the pelviureteric junction (1-3).
According to the international literature, the incidence of aberrant or accessory renal arteries varies widely based also one the fact that there is no fixed criterion for aberrance. From this point of view, this term is many times employed interchangeably to an extra artery in the renal pedicle, or to an artery entering the kidney at either pole, whether derived from the main renal artery, from the aorta or from a branch of the aorta (1,4).
Since many decades ago, it has been suggested that the arteries which have a proximal origin at the hilum or in the pedicle may be most likely a consequence of a variation in the degeneration of the rete arteriosum, whilst the arteries which arise from the aorta may be persistent mesonephric arteries (1).
Links with hydronephrosis
Aberrant arteries may cause hydronephrosis. As a matter of fact, according to the scientific literature, Eustachius has reported the issue of aberrant arteries in one of his well-known plates which remained unprinted in the Papal Library until 1714 (1,4).
Gleason et al. have reported the presence of hydronephrosis in 15 of 58 cases with contralateral nonectopic kidneys. Of these 15 cases, 11 required surgeries mainly for the presence of vesicoureteral reflux disease (5).
On the other hand, Mustafa et al. have reported the aberrant renal vessel causing hydronephrotic changes, but it was associated with contralateral crossed ectopia without fusion (3).
In a more recent study, there was reported an aberrant vessel causing pelvi-ureteric junction obstruction in the normally placed left kidney associated with the contralateral crossed-fused right kidney (4). This is not a common finding which is reported in the medical literature. In this study, the obstructed drainage in the ectopic right kidney was due to malrotation and compression effect of the hydronephrotic left kidney (4).
Accessory renal arteries
In 2008, Mir et al. introduced the simplest definition of accessory renal artery (6). Based on this work, the “normal” renal arteries were described as entering the kidney through its hilum, whereas the accessory renal arteries might enter the renal artery through the hilum or through the surfaces of the kidney (6,7).
Nevertheless, it should be pointed out that, from the sixteenth century until the present days, the terminology related to accessory renal artery has been controversial and vague (7-9). Of note, the first description of accessory renal arteries was provided in the sixteenth century. Hence, in 1564, Eustachi described the accessory renal arteries as end-arteries, which are not supplemental or accessory not making anastomotic connections after entering the kidney (7,10).
The most typical kind of renal vascularization contains accessory renal arteries, which are classified according to their origin, given by Merklin and Michels in 1958 as follows (11):
• accessory renal arteries originating from the aorta;
• accessory renal arteries originating from the main renal artery;
• accessory renal arteries originating from other sources.
In 1982, Stephens (12) held the position that as the vessels are not redundant or unnecessary but, on the contrary, they are essential non-anastomotic arteries corresponding to the segmental branch of a single renal artery. From this viewpoint, the terms accessory, supernumerary or aberrant were not appropriate in these cases (12).
In 1992, Sampaio and Passos (13) introduced the terms hilar for the aortic branch penetrating the hilum; the term extrahilar for the branch of the renal artery with an extra-hilar penetration; the term superior polar for the aortic branch penetrating the superior pole; and the term inferior polar for the aortic or common iliac artery penetrating the inferior pole of the kidney (13). Furthermore, these authors retained that these vessels should be referred to as “multiple arteries”, because they are segmental end-arteries.
More recently, in 2010, Daescu et al. (14) have suggested a new classification: the renal arteries can be hilar and polar (superior/ inferior). The polar arteries are classified in four groups: (i) solitary; (ii) pedicular, if the second artery is accompanied by a polar vein and a nerve plexus; (iii) false supernumerary, if it replaces the segmental artery, and; (iv) true supernumerary artery, if the respective segmental artery emerges from the renal artery (7,14).
Conclusion
The issue of aberrant renal arteries is also of particular concern in the urology practice at the University Hospital Center “Mother Teresa” in Tirana, Albania. In all cases, it is recommended that the affected arteries should be named together with an indication of their origin and type and the words “aberrant” or “accessory” should be avoided, because these terms bear little anatomical, or explanatory value in the clinical practice.
Conflicts of interest: None declared.
References
1. Graves FT. Aberrant renal artery. J Anat 1956;90:553-8.
2. Ritchey M, Susan J. Anomalies of the kidney. In: Kelalis PP, King LR, Belman AB (eds) Clinical pediatric urology, 3rd edn. WB Saunders, Philadelphia; 2007.
3. Mustafa M, Alkan E. Aberrant vessels in ipsilateral malrotated kidney associated with contralateral cross ectopia without fusion. Int Urol Nephrol 2005;37:39-41.
4. Hasan Z, Kumar B, Thakur A, Kumar P, Kumar S. Aberrant renal vessel causing hydronephrosis in crossed-fused ipsilateral ectopic kidney: a rare case report. Indian J Surg 2013;75(Suppl 1):201-3.
5. Gleason PE, Kelalis PP, Husmann DA, Kramer SA. Hydronephrosis in renal ectopia: incidence, etiology and significance. J Urol 1994;151:1660-1.
6. Mir NS, ul Ashfag H, Ryiaz R, et al. Bilateral duplication of renal vessels: anatomical, medical and surgical perspective. Int J Health Sci (Qassim) 2008;2:179-85.
7. Gulas E, Wysiadecki G, Szymański J, Majos A, Stefańczyk L, Topol M, Polguj M. Morphological and clinical aspects ofthe occurrence of accessory (multiple) renal arteries. Arch Med Sci 2018;14:442-53.
8. Satyapal KS, Haffejee AA, Singh B, Ramsaroop L, Robbs JV, Kalideen JM. Additional renal arteries: incidence and morphometry. Surg Radiol Anat 2001;23:33-8.
9. Singh D, Finelli A, Rubinstein M, Desai MM, Kaouk J, Gill IS. Laparoscopic partial nephrectomy in the presence of multiple renal arteries. Urology 2007;69:444-7.
10. Eustachi Opuscula anatomia, Venice; 1564.
11. Merklin RJ, Michels NA. The variant renal and suprarenal blood supply with data on the inferior phrenic, ureteral and gonadal arteries: a statistical analysis based on 185 dissections and reviews of the literature. J Int Coll Surg 1958;29:41-76.
12. Stephens FD. Uterovascular hydronephrosis and the “aberrant” renal vessels. J Urol 1982; 128: 984-7.
13. Sampaio FJ, Passos MA. Renal arteries: anatomic study for surgical and radiological practice. Surg Radiol Anat 1992; 14: 113-7.
14. Daescu E, Jianu AM, Motoc A, Niculescu MC, Rusu MC. The renal polar arteries – anatomical considerations. Med Evolut 2010;16:11-5.