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HORSESHOE KIDNEY WITH ACCESSORY RENAL ARTERY AND EXTRARENAL CALYCEAL
SYSTEM – A Case Report
ABSTRACT:
The congenital anomalies of kidney are important as they may cause renal failure in
middle age group. Horseshoe Kidney is the most common congenital fusion anomaly in which both
kidneys were fused at their lower poles by an isthmus in front of inferior vena cava and abdominal
aorta. We present a case report of horseshoe kidney with long hilum opened anteriorly with
extrarenal calyces in left kidney along with accessory renal artery arising from aorta, supplied to
lower pole of left kidney and there was a separate renal vein opening into inferior vena cava. The
knowledge of horseshoe kidney with accessory renal vessels and extrarenal calyceal system is
helpful for surgeons or urologists during operations.
KEY WORDS:
Horse shoe Kidney, accessory renal artery, extrarenal calices and renal hilum.
MeSH TERMS:
Kidney calices – A05.810.453.537.503
Renal artery – A07.231.114.745
Renal vein
– A07.231.908.752
INTRODUCTION:
Occurrence of horseshoe kidney is about 0.25% in general population [1] Allen et. al.
1951; and are seen in approximately 1 out of 300 pyelographies [2] Dees, 1941; [3] Lowsley, 1952;.
Horseshoe kidney is found in 1 out of 1000 necropsies and more common in men [4] Mann et. al.
1995;. Horseshoe kidney usually asymptomatic because there was normal development of calyceal
system. If urinary flow is obstructed, signs and symptoms of obstruction or infection may appear.
About 7% of persons with Turner’s syndrome have horseshoe kidney. However, horseshoe kidney
with extrarenal calyces and accessory renal artery on left side is a rare association and this has
prompted the authors to report the case.
CASE REPORT:
The present report describes a horseshoe kidney found in approximately 55 years old
male cadaver during routine dissection practice for undergraduate students. The horseshoe kidney
was located in front of the aorta and the inferior vena cava at the junction between L3 & L4
vertebrae. The isthmus connected the lower poles of both kidneys and was below the origin of
inferior mesenteric artery. Inferior mesenteric artery passed in front of the isthmus [fig no: 1]. The
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hilum of right kidney was opened medially and short. The hilum of left kidney was long & opened
anteriorly. Both ureters passed infront of the isthmus.
The arterial supply of right kidney was provided by the right renal artery that
originated from the lateral surface of the abdominal aorta. It was divided into anterior and
posterior branches and then into upper and lower branches. The left kidney was supplied by left
renal artery, which was a lateral branch of abdominal aorta and divided into anterior, posterior and
then into upper & lower branches. Here lower pole of left kidney was supplied separately by an
accessory renal artery, which was a branch of aorta. No separate blood supply to the isthmus.
Two renal veins, right & left, were draining the horseshoe kidney into inferior vena
cava. The lower pole of left kidney was drained by a separate vein into inferior vena cava.
The right hilum was small and directed medially. Major calyces joined to form pelvis,
which emptied into a single ureter. The left hilum was large, opened anteriorly. Small minor calyces
joined to form two major calyces which again joined to form pelvis of ureter. All these were present
outside the left kidney. Both ureters passed in front of the isthmus [fig no:2].
Table 1:
Dimensions of the Horseshoe Kidney and hilar structures
Length
Width
Thickness
Length of Hilum
Diameters:
Renal Artery
Renal Vein
Accessory Renal Artery
Accessory Renal Vein
Ureter
Length of Ureter
LEFT (mm)
123
55
33
102
RIGHT (mm)
115
54
50
46
4
6
3
2
4
195
5
10
ISTHMUS (mm)
30
12
3
5
220
DISCUSSION:
As the renal rudiments are ascending from the pelvic region to the loin, they normally
remain separate. However, they may come in contact and fused at the lower poles resulting in
horseshoe kidney [5] Decker and Plessis, 1996; with fibrous isthmus. More recently, it has been
proposed that the horseshoe kidney is the result of a teratogenic event that involves abnormal
migration of cells that form the isthmus, which is related to a parenchymal isthmus. In our report,
the specimen presents a fibrous isthmus.
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The position of the horseshoe kidney can be anywhere from the normal lumbar
location to the pelvis. In our report, it is present below the origin of inferior mesenteric artery. The
measurements of the kidneys considered individually had small variations, but were within expected
limits.
There is a wide variation in kidney vascular supply, renal arteries can originate from
the aorta, the iliac arteries and the inferior mesenteric arteries [6] Rossi et. al. 2006; [7] Satyapal et.
al. 2006;. In the present case, a renal artery from each kidney was found that originated as lateral
branches of the abdominal aorta and an accessory renal artery to the lower pole of left kidney,
arising from aorta distal to inferior mesenteric artery. In the case reported by [8] Vaniya V.H, 2004;
multiple renal arteries arising from the abdominal aorta at different levels were observed. Four
arteries entered the right kidney, three entered the left kidney and the isthmus was supplied by an
independent special branch originated from distal aorta at the site of its bifurcation. In the case
reported by [9] Tijerina, G.O; et. al. 2009; isthmus was supplied by two renal arteries which
originated from the aorta below the inferior mesenteric artery. In the case reported by [10]
Mohanty.C; et al; 2002; a single accessory renal artery originated from the right side of aorta and
branched to supply the right & left middle segments and also the isthmus.
In the case reported by [11] Oktem; et al, 2008; only one renal artery for the isthmus
was found that originated above the inferior mesenteric artery. Venous drainage occurred through
three renal veins that emptied in the inferior vena cava independently, as reported by [12]
Yoshinaga et. al. 2002;.
In the present report, hilum of left kidney opened anteriorly with extrarenal calycal
system and that of right kidney opened medially. Both ureters crossed in front of the isthmus of
horseshoe kidney and drained independently in to the bladder. In the case reported by [10]
Mohanty, c; et al 2002; all the major and minor calyces were extrarenal on both sides. In the case
presented by [8] Vaniya V.H. 2004; all the major calyces on both sides and few minor calyces on the
left side were found extrarenal in position. Some cases of variations with the existence of
interconnected renal pelvices and a single ureter have been reported [13] Yesilli et al; 2003,
although they are rare. The knowledge of horseshoe kidney with variable vascular pattern and
extrarenal calyceal system is helpful for surgeons or urologists during operations and to treat
medical conditions of kidney.
ACKNOWLEDGEMENT:
We extend our thanks to Ms. R.V.S. Bhaskar, Office Superintend, Department of
Anatomy, NRIIMS, Sangivalasa, Visakhapatnam, A.P [India].
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REFERENCES:
1. Allen, A.C. the kidney: Medical and Surgical Diseases, Grune&Stratton, Inc., New York:
1951; P. 94.
2. Dees, J.E : Clinical importance of congenial anomalies of upper urinary tract. Journal of
Urology, 1941; 46: 659-666.
3. Lowsley O.S. : Surgery of horseshoe kidney. Journal of Urology, 1952; 67. 565-578.
4. Mann, Russell & Williams: Baily & Loves Short practice of surgery, 22 nd Edn.Chapter57,
p.916, ELBS with Chapman & Hall, London 1995; p 916.
5. Decker GAG & Plessis DJ du: Lee Mc Gregor’s synopsis of surgical anatomy, 12 th Edn.
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6. Rossi, U.G ; Romano, M. & Ferro, C. Seven renal arteries. Clin. Anat., 19(7):632-3, 2006.
7. Satyapal, K. S.; Haffejee, A. A.; Naidoo, M. L.; Rabbs, J. V.; Akojee, S. & Ramsaroop, L. Rare
additional renal artery in live-related transplantation. Clin. Anat., 19(4):363-4, 2006.
8. Vaniya V.H. Horseshoe Kidney with multiple Renal Arteries and Extrarenal Calyces – A
Case Report. J. Anat. Soc. India 53 (2) 52-54 (2004).
9. TIJERINA; G.O.; URESTI, J.; URRUTIA, V.E.; ELIZONDO-OMANA, R.E. & GUZMAN-LOPEZ, S.
Anatomical study of the horseshoe kidney. Int. J. Morphol., 27(2):491-494, 2009.
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13. Yesilli, C.; Erdem, O.; Akduman, B.; Erdem, Z.; Gundogdu, S. & Mungan, N. A. Horseshoe
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Fig 1: Showing horseshoe kidney;
1. Inferior mesenteric vessels, 2. Isthmus, 3. Ureter.
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Fig 2: Showing horseshoe kidney with renal vessels, extrarenal calyceal system;
1. Renal vein, 2. Renal artery, 3. Extrarenal calices, 4. Accessory renal artery, 5. Isthmus, 6. Ureter.