Testicular artery (previously known as internal spermatic artery or also known as gonadal artery) is an artery that branches from the anterolateral part of abdominal aorta at the level of the second lumbar vertebra and supplies the blood to the testes . It is a paired artery that passes down and laterally toward the deep inguinal ring and is vital for adequate gametogenesis and hormone production . It is accompanied by the corresponding vein, the spermatic cord and ilioinguinal nerve in the inguinal canal.
Anatomical variations of the origin, number, course and relationship with other anatomical structures have been frequently described in the literature . Unusual course of the testicular artery can lead to its damage during surgical procedures. There is a constant decrease in the number of anatomical studies on cadavers. This in turn is alarming, as anatomical studies are fundamental for a number of clinical disciplines, especially surgical. Surgeons should be aware of these variations to ensure that are not neglected due to the fact that decreased blood supply to the testes leads to its atrophy.
We present a rare case of origin of the right testicular artery as a common trunk of superior polar artery of the kidney, inferior phrenic artery and capsular artery combined with an unusual course of the left testicular artery. Both of these arteries had unusual course particularly risky during surgical procedures on abdominal and retroperitoneal organ and/or structures.
During the dissection of 77-year-old male cadaver we encountered several anatomical variations of testicular arteries. The left testicular artery originated from the left semi-circumference of the abdominal aorta below the level of the left renal artery and had a course on the renal surface then descending into the inner ring of the inguinal canal. The right testicular artery was one of the branches of a common trunk that originated from the right renal artery and branched into three separate arteries (Fig. 1).
Fig. 1: Variant of branching of the testicular arteries: 1 - right kidney; 2 - right testicular artery; 3 - artery of the fatty capsule and fascia of the kidney; 4 - right polar artery; 5 - common trunk, branching into the right polar and right testicular arteries; 6 - common trunk, branching into the right inferior phrenic and common trunk for the right upper polar and right testicular arteries; 7 - right inferior phrenic artery; 8 - superior mesenteric artery; 9 - right aortorenal ganglion; 10 - left renal artery; 11 - left polar artery; 12 - left renal vein; 13 - left kidney; 14 - left ureter; 15 - left testicular artery, originating from the left semicircle of the abdominal aorta; 16 - abdominal aorta; 17 - right renal artery; 18 - right renal vein; 19 - right ureter.
Fig. 2: Trajectory of the left testicular artery: 1 - inferior vena cava; 2 - abdominal aorta; 3 - left renal vein; 4 - left renal artery; 5 - adrenal vein; 6 - left polar artery; 7 - left adrenal gland; 8 - spleen; 9 - left testicular artery, originating from the left semicircle of the abdominal aorta; 10 - left kidney; 11 - left renal vein; 12 - left ureter; 13 - subcostal nerve; 14 - iliohypogastric nerve; 15 - lateral cutaneous nerve of the thigh; 16 - femoral nerve; 17
- genitofemolar nerve; 18 - ilioinguinal nerve.
Fig. 3: Trajectory of the right testicular artery: 1 - renal fascia; 2 - right kidney; 3 - fatty capsule of the kidney; 4 - artery of the fatty capsule and fascia of the kidney; 5 - right testicular artery; 6 right renal vein; 7 - inferior vena cava; 8 - right ureter; 9 - right iliohypogastric nerve; 10 - abdominal aorta; 11 - ilio-inguinal nerve; 12 - inferior mesenteric artery; 13 - right testicular vein; 14 - subcostal nerve.
The unusual location of the testicular arteries leads to changes in the relationship between the vessels themselves and neighboring organs. Therefore, the left testicular artery, having branched off from the left semicircle of the abdominal part of the aorta below the level of the origin of the left renal artery, was covered from above by the trunk of the left renal vein. Due to its origin it emerged between the trunks of the left renal artery and vein, lied on the anterior surface of the vein and descended between the ureter and the trunk of the left testicular vein, which later drained to the left renal vein. Slightly above the left iliac artery, above the beginning of the left iliac fossa, the ilioinguinal nerve joined the artery, and they descended to the inner ring of the inguinal canal (Fig. 2).
On the right side, the testicular artery branched as one of the several branches of the right renal artery. The right renal artery branched off from the right semicircle of the abdominal aorta at the same level as the superior mesenteric artery. A common trunk branched off and divided into the right inferior phrenic and common trunk for the right upper polar and right testicular arteries at a distance of 2 cm from the aorta from the upper semicircle of the right renal artery. All of these branches were covered by the trunk of the inferior vena cava (Fig. 3). The right testicular artery emerged from under the right edge of the inferior vena cava, from which the common trunk branched off, giving rise to the artery for the fatty capsule and fascia of the kidney. Below, the right testicular artery crossed in front of the renal vessels and hilum of the kidney and descended parallel with the right ureter to the pelvic cavity.
The right testicular vein emerged from the deep inguinal ring in two vessels that join immediately and form the trunk of the right testicular vein. The vein rised up the anterior surface of the inferior vena cava parallel to the trunk of the ilioinguinal nerve and drained into it. The ilioinguinal nerve emerges between the trunks of the abdominal aorta and the inferior vena cava, crossed the right testicular vein in the upper section, and descended along the anterior surface of the trunk of the inferior vena cava to the deep ring of the inguinal canal.
Anatomical variations and anomalies of the excretory system are common . Vascular variations are frequently encountered during surgical procedures and may lead to iatrogenic injury. Developmental variations of the arteries are usually more common that veins [5,6]. However, arterial variations typically receive more attention that venous . Variations of gonadal arteries include high origin of the vessel, bifurcation, origin by several trunks, origin from other vessels besides the aorta and others. Most of these variations can cause alteration in the course of the vessel, which should be taken into account during invasive procedures on the retroperitoneal organs and organs of the abdomen and pelvis.
Anatomical variations of testicular artery occur due to changes during embryology. In utero, nine lateral mesonephric arteries develop and are divided into the cranial, middle and caudal groups. Usually, caudal arteries develop into gonadal artery and others undergo atrophy . Changes in the development or atrophy of mesonephric arteries lead to anatomical variations.
Variation of the gonadal arteries is reported to be more common in females than in males and its prevalence in high on the right side than on the left side . They are seen in 8.8-20% of cases [1, 9]. A classification and prevalence testicular artery variations is present in Table 1.
Table 1: Classification and prevalence of developmental variations of testicular arteries
Originating from the suprarenal artery
Originating from the renal
High-positional origin from the abdominal aorta close to the renal artery levels
Duplication of the testicular arteries
Subtype A: Two right testicular arteries originating from the right side of the aorta
Subtype B: Two right testicular arteries originated from different vessels
The current case is similar to type II variation . However, the original study described this type as testicular artery originating from the renal artery, and in several cases the artery originated from the inferior polar artery . This case is different as the right testicular artery originated as a common trunk with the superior polar, inferior phrenic and capsular arteries, then had a descending course covering the kidney. The left testicular artery had a high origin and a similar trajectory along the kidney. A schematic representation of these variations is present in figure 4.
Fig. 4. Schematic representation of the variations of testicular arteries in the presented case. CA - capsular artery, RK - right kidney, LK - left kidney, AA - abdominal aorta, RU - right ureter, LU - left ureter, KCF - kidney capsule and fat, RRA - right renal artery, LRA - left renal artery, RPA - right polar artery, RIPA - right inferior phrenic artery, CA - capsular artery, RTA - right testicular artery, LTA - left testicular artery.
It is believed that origin from the superior polar artery is a rare occurrence and there have been only a few case reports in the literature . The present case is unique as the right testicular artery branched together with several other arteries, which to our knowledge hasn't been reported previously.
However, there have been several attempts to classify variations of testicular arteries over the years and most of these classifications cannot fully describe the spectre of variations . Kayalvizhi and co-workers (2017) have reviewed the available classifications and proposed their own which includes a broader analysis of the possible sights of origin and variations of testicular artery . Their analysis revealed that the testicular artery originates from polar of capsular arteries in 12 out of 162 reported cases (most of which are from the inferior polar artery) .
Vascular variations are clinically silent and remain unnoticed until discovered during imaging, surgery or autopsy . In some instances, these variations may lead to clinical manifestations such as varicocele and/or gonadal atrophy . The knowledge of anatomical variations of gonadal vessels are important because of its implications in renal transplantation, renal surgery, vascular surgery, oncological surgery and other disciplines . Anomalous course of testicular artery is a risk factor for iatrogenic injury, can restricts the availability for mobilization procedures, may lead to compression by other anatomical structures [11,12]. The current variation is important primarily from a surgical standpoint, but also from a physiological prospective [2,11].
Anatomical variations of the testicular vessels are not frequently reported in the literature. The available data demonstrates that there is an overall decrease in the number of studies published on cadaver material. The current case demonstrates a unique variation where the right testicular artery began as a common trunk with superior polar and inferior phrenic arteries and then had an unusual course covering the surface of the kidney. The left testicular artery, had a high origin from the aorta and also descended in an oblique course, covering the kidney. These variations are important to consider during various invasive procedures to avoid iatrogenic injury.
- Ciçekcibasi AE, Salbacak A, Seker M, Ziylan T, Büyükmumcu M, Uysal, II. The origin of gonadal arteries in human fetuses: anatomical variations. Annals of Anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft. 2002;184(3):275-9.
- Braedel HU, Steffens J, Ziegler M, Polsky MS, Platt ML. A possible ontogenic etiology for idiopathic left varicocele. The Journal of Urology. 1994;151(1):62-6.
- Kayalvizhi I, Narayan RK, Kumar P. Anatomical variations of testicular artery: a review. Folia Morphologica. 2017;76(4):541-50.
- Rompsaithong U, Amarttayakong P, Kanpittaya J, Chaiyamoon A, Sangkhano S. Retroaortic left renal vein and its new Variations: Triple retroaortic and circumiliac left renal veins. Asia-Pacific Journal of Science and Technology. 2022;27(05):APST-27-05-16.
- Covantev S, Mazuruc N, Belic O. Renal Arteries: A Morphological and Angiographic Assessment. Online J Health Allied Scs. 2018;17(2):9. Available at URL: https://www.ojhas.org/issue66/2018-2-9.html.
- Covantev S, Mazuruc N, Belic O. Renal Veins: Developmental Variations and Clinical Significance. Online J Health Allied Scs. 2017;16(4):12. Available at URL: https://www.ojhas.org/issue64/2017-4-12.html.
- Asala S, Chaudhary SC, Masumbuko-Kahamba N, Bidmos M. Anatomical variations in the human testicular blood vessels. Annals of Anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft. 2001;183(6):545-9.
- Notkovich H. Variations of the testicular and ovarian arteries in relation to the renal pedicle. Surgery, Gynecology & Obstetrics. 1956;103(4):487-95.
- H M, D'Souza AS, P V, Ray B, Suhani, Pallavi. A Cadaveric Study about the Anomolous Origin of Testicular Arteries Arising from the Accessory Renal Arteries. The Indian Journal of Surgery. 2015;77(2):111-6.
- Rai R, Ranade AV, Prabhu LV, Rai AR. Variant left testicular artery from the superior polar artery and triple right renal arteries: a case report. Eur J Anat. 2013;17:262-4.
- Padur AA, Kumar N. Unique variation of the left testicular artery passing through a vascular hiatus in renal vein. Anatomy & Cell Biology. 2019;52(1):105-7.
- Cussenot O, Desgrandchamps F, Bassi S, Teillac P, Lassau JP, Le Duc A. Anatomic basis of laparoscopic surgery in the male pelvis. Surgical and Radiologic Anatomy : SRA. 1993;15(4):265-9.