Introduction:
Testicular (gonadal) arteries (TA) are paired branches of the abdominal aorta,
given off at the level of the second lumbar vertebra. In its usual course, it passes downward, laterally and
retroperitoneally on the posterior abdominal wall, accompanied by the corresponding testicular vein on its
lateral side towards the deep inguinal ring and supplies the testis.(1) The typical morphology of testicular
vessels is essential in the fundamental process of reproduction and the achievement of thermoregulation of
testis.
Many reports on the variant origin of TA are available in the scientific literature. Anatomical variation of the gonadal
arteries is reported to be more common in females than in males as well as higher prevalent on the right side than on the left.
(2) A case of variant right testicular vessels wherein, TA originating from the accessory renal artery and testicular vein
draining into the right accessory renal vein instead of inferior vena cava is reported by Royana et al.(3) Bilateral high
origin of TA superior to corresponding renal arteries have been reported by Jing et al.(4) Hence, the variant origin of the
testicular artery is considered to be a common vascular variation. However, looping or arching course of TA over neighboring
vessels, particularly on renal vein has great clinical importance, as it may be an additional possible cause of the renal
vein compression or such a course might lead to testicular artery compression resulting in testicular atrophy. Therefore,
cautious identification of arched or looped TA is necessary for the radiologists, urologists, and oncologists to provide an
accurate diagnosis during pre-operative studies.
Case Report
During routine posterior abdominal wall dissection for the first-year medical
students, an abnormal course of the left testicular artery and left renal artery was noticed. The left
testicular artery had a high origin from the anterior aspect of the abdominal aorta, about 2cm below the level
of origin of renal artery. From its point of origin, it took a recurrent course, upwards and laterally, lying
first between the left renal vein and the aorta and then between the left renal vein and the left renal artery.
On reaching the upper border of the left renal vein, it looped over it and descended in front of it. In its
subsequent course, it was accompanied by the left testicular vein on its medial side in contrary to the normal
relation and proceeded till the deep inguinal ring.
The left renal artery had normal origin from the abdominal aorta and had the normal course of its proximal half. However,
at its distal half, hereafter, it arched over the superior border of renal vein and appeared on its anterior surface to reach
the renal hilum. Because of this, the proximal half of the renal artery was posterior to renal vein, and the distal half was
anterior to it, causing a mild tortuous course in contrast to the usual straight course (Figure 1, Figure 2). These vascular
variations were unilateral and found in adult male cadaver aged about 60 years.
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Figure 1: Dissection of the abdomen showing the high origin and looped pattern of left testicular artery (LTA) accompanied by the arched left renal artery (LRA) on the left renal vein (LRV). AA: Abdominal aorta, LTV: Left testicular vein, LK: Left kidney. |
Figure 2: Schematic diagram showing the looped left testicular artery (LTA) and left renal artery (LRA) on the left renal vein (LRV). AA: Abdominal aorta, IVC: Inferior vena cava, LTV: Left testicular vein, RTA: Right testicular artery, LK: Left kidney, LU: Left ureter.
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Discussion
Variations in the anatomical relationship of the testicular (gonadal) arteries to the renal
vessels are frequently reported. However, reports on unusual course of testicular and renal arteries are scanty. An abnormal
course of TA often warrants clinical attention because of its importance in maintaining thermoregulation and proper
spermatogenesis of the testis.
A rare presence of double TA (superior and inferior), with the presentation of superior testicular artery being hooked by
left supra renal vein, has been reported by Jyothsna et al.(5) Mirapeix et al reported a peculiar course of right TA with
retrocaval course and passing through the bifid renal vein.(6) A case of bifid testicular artery has been reported by Aithal
et al.(7) High origin of left TA at the level of origin of the renal artery, associated with arching over the left renal vein
at been reported before.(8,9) A case of entrapment of arched left TA between the main renal vein and abnormally persistent
accessory left hilar renal veins was reported by Gabriel et al.(10) However, no arching of renal artery was reported in these
cases.
The prevalence of recurrent course of gonadal arteries with subsequent arching over the renal vein is reported to be 17.2%
on the left side and 22% on the right side.(11) While Machniki & Grzybiak (12) and Cicekcibasi et al., (2) proposed two
different categories of classification of TA on the basis of its origin or number, Notkovich (13) suggested three types of
TA based on its relation to renal vein as follows:
Type I- TA passing posterior or inferior to the renal vein, without making contact with it
Type 2- Higher origin of TA crossing in front of renal vein
Type 3- TA coursing superiorly and around the renal vein
The looping pattern of TA in the present case is categorized under Type 3 classification of Notkovich and model of origin
of TA in the present case falls under Type A classification of Machnicki & Grzybiak (i.e. TA originated from abdominal
aorta) and Type III of Cicekcibasi et al (i.e. high positional origin of TA from AA) classification.
Morphological variations of testicular arteries are accredited to its embryological perspectives because of its origin from
lateral splanchnic arteries of the aorta. Due to subsequent development of new splanchnic arteries because of descent of
gonads, the higher branches undergo atrophy.(14) Abnormal persistence of higher branches or erroneous atrophy of lower
branches tend to form the arched type of TA over the renal veins.
In addition to looping of TA with the renal vein, the present case also witnessed the peculiar course of the left renal
artery in which its distal half arched the renal vein before its entry into the renal hilum. This appearance gave a mild
touristy to the left renal artery.
This arching of testicular artery and renal artery over the left renal vein might compress the renal vein resulting in
renal vein hypertension. Clinically, persistent left renal vein hypertension can cause the development of collateral veins,
varicocele, orthostatic proteinuria and hematuria. (15) Thus, surgeons need to pay attention to the possible presence of
arching testicular and renal arteries during surgical operation on the kidney to prevent acute hemorrhage resulting from their
injury in renal hilar dissections and retroperitoneal surgical investigations.
Conclusion
The entrapment of the left TA between renal vein and abdominal aorta after that between renal vessels is clinically and
surgically significant as these structures could compress the testicular artery causing testicular and pelvic varicocele.
Additionally, higher origin of testicular artery and its arched pattern along with arched renal artery might lead to
complications during nephrectomy procedures.
Acknowledgements
We acknowledge Mr. Ganesh N Prasad, Artist, Department of Pathology, Kasturba Medical College, Manipal, for the schematic
diagram.
References
- Standring S, Borley NR, Collins P, Crossman AR, Gatzoulis MA, Healy JC, et al. 40th ed. Vol. 1198. London: Elsevier, Churchill Livingstone; 2008. Gray's Anatomy: The Anatomical Basis of Clinical Practice; pp. 207–208
- Cicekcibasi AE, Salbacak A, Seker M, Ziylan T, Büyükmumcu M, Uysal II: The origin of gonadal arteries in human fetuses: anatomical variations. Ann Anat. 2002;84:275-279.
- Singh R, Jaiswal A, Shamal SN, Singh SP. Variation in the origin of the testicular arteries and drainage of the right testicular vein. Int. J. Morphol. 2011;29(2):614-616.
- Jing Li, Zhen Li, Zhen Feng R, Tao Sun. A Bilateral high origins of testicular arteries: a rare variant. Rom J Morphol Embryol. 2012;53(2):427–429
- Jyothsna P, Mohandas Rao KG, Somayaji SN, Ashwini LS. Multiple Vascular Anomalies Involving Testicular, Suprarenal Arteries, and Lumbar Veins. N Am J Med Sci. 2012;4(3):154–156.
- Mirapeix RM, Sañudo JR, Ferreira B, Domenech-Mateu JM, A retrocaval right testicular artery passing through a hiatus in a bifid right renal vein. J Anat. 1996;189(Pt 3):689–690.
- Aithal AP, Kumar N, Ravindra SS, Patil J. A unique case of bifid left testicular artery having its anomalous high origin from renal artery. J Med Sci. 2016;36:75-77.
- Kumar N, Aithal AP, Swamy RS, Patil J, Nayak SB, Shetty SD. High origin of left testicular artery associated with its peculiar arched course- A rare anatomical variation. Int J Clin Surg Adv. 2014;2(2):89-93.
- Ranade AV, Rai R, Prabhu LV, Mangala K, Nayak SR. Arched left gonadal artery over the left renal vein associated with double left renal artery. Singapore Med J. 2007;48(12):e332-4.
- Gabriel JM, Masumbuko Y M, Flora MF, Ainory PG. Looped left testicular artery in relation to a variant left renal vein: a case report. IJAV. 2014;7:57–59.
- Grine FE, Kramer B, Arched gonadal arteries in the South African negro. J Anat. 1981;132(Pt 3):387–390.
- Machnicki A, Grzybiak M. Variations in testicular arteries in fetuses and adults. Folia Morphol (Warsz). 1997;56:277–285.
- Notkovich H. Variations of the testicular and ovarian arteries in relation to the renal pedicle. Surg Gynecol Obstet. 1956;103:487–495.
- Moore KL, Persaud TVN. The urogenital system. In: Moore KL, Persaud TVN. (Eds). The Developing Human. 5th edn. Philadelphia, WB Saunders, 1993. pp.265-303.
- Naito M, Terayama H, Nakamura Y, Hayashi S, Miyaki T, Itoh M. Left testicular artery arching over the ipsilateral renal vein. Asian J Androl. 2006;8(1):107–110.
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