Okajimas Folia Anat. Jpn., 70(1): 29-34, May, 1993

Ectopic in Front of the Right Common Iliac and Its Vascular Supply - a Case Report

By

Aiji OHTSUKA, Akio KIKUTA, Takehito TAGUCHI and Takuro MURAKAMI

Human Morphology Section, Department of Anatomy, Okayama University School of Medicine, Okayama 700, Japan

-Received for Publication, January 28, 1993-

Key Words: Ectopic kidney, Renal blood vessels, Human, Anomaly, Gross anatomy

Summary: A discoid-shaped ectopic kidney located in front of the right was observed in a 71-year-old Japanese man. The right kidney was normally positioned, but the left kidney was not observed in the normal position. The of the ectopic kidney descended laterally to the left ductus deferens. The ectopic kidney received three which arose from the anterior aspect of the abdominal . Two of the arteries supplied the left half of the kidney. The other supplied the right half and gave off two branches to the adipose tissue around the right kidney; these branches meant that this artery belonged to the right side. Venous drainage from the kidney was handled by two . One collected venous radicles from the right half of the kidney and flowed into the inferior vena cava; this belonged to the right side. The other served the left half and joined with the left lumbar vein, which finally drained into the left common ; this vein was attributed to the left side. The present ectopic kidney had a left-side ureter, and vascular supply on both the right and left sides. This disunity or dissociation of laterality in the vessels and the ureter seemed to be strongly related to the location of this ectopic kidney in the median region.

It is well known that the developing kidney, formed during the 1987 human gross anatomy course initially located in the pelvic region, later shifts to for medical students at Okayama University School a more cranial position in the : so-called of Medicine. He had neither a history of abdominal ascent of the kidney (Langman, 1981). The disturb- surgical procedures nor surgical scars on his abdomi- ance or arrest of this change results abnormal pos- nal skin. In addition to the renal ectopia mentioned itions of the kidneys, i.e., ectopic kidney (Thompson and Pace, 1937). Ectopic kidney has been found on radiographs Table 1. Abbreviations in Figures 1-4

(Hanley and Steel, 1947; Dretler et al., 1971), Al: 1st artery to the ectopic kidney* during surgery (Ransohoff, 1920) and in macro- A2: 2nd artery to the ectopic kidney* scopic dissections (Anitschkow, 1912; Wilhelmj, A3: 3rd artery to the ectopic kidney* 1920; Takeshige et al., 1967; Hanai and Fujii, 1984). AA: This paper reports a kidney misplaced in front of the Ad: adrenal gland right common iliac artery with details of its blood C: celiac trunk D: ductus deferens vascular supply, and discusses the relationship E: ectopic kidney between the abnormal renal position and laterality IVC: inferior vena cava attribution of the vessels and ureter. IM: inferior mesenteric artery L: lumbar artery and/or vein LCIV: left common iliac vein MS: Findings R: right kidney SM: superior mesenteric artery The positional anomaly of the kidney was found TAV: testicular artery and vein in a 71-year-old Japanese man who died of heart U: ureter Vi: 1st vein from the ectopic kidney* failure. His cadaver had been fixed routinely with V2: 2nd vein from the ectopic kidney* arterial perfusion of 20`)/0formalin, and subsequently dehydrated with 60% ethanol. Dissection was per- * See text .

* Part of this report was presented at the 96th Annual Meeting of the Japanese Association of Anatomists.

29 30 A. Ohtsuka et a!. below, some other variations were found: a bilobate celiaco-mesentericus) (Adachi, 1928). In the uro- right lung. a third head of the biceps brachii muscle , genital system, we observed no significant anomalies and common trunk formation of the celiac and other than this ectopic kidney. superior mesenteric arteries (so-called truncus

Fig. 1. A photograph of the present case, ventral view. The ectopic kidney (E) is located in front of the right common iliac artery. Note a vein (V2) from this kidncy joins the left (arrow). Sec Table 1 and text for abbreviations. Ectopic Kidney 31

Position of the kidneys 1, 3, 4). The first artery (Al) arose from the anterior The right kidney was normally located in front of aspect of the abdominal aorta and descended from the right lumbar part of the diaphragm, at a level the upper pole of the ectopic kidney on its anterior between the 12th thoracic and 3rd lumbar vertebrae surface, where the artery gave off branches to supply (Figs. 1, 3). the kidney. The second artery (A2) arose from the The left kidney could not be found in the normal right antero-lateral aspect of the aorta. and ran in position; instead, an ectopic kidney was located in front of the inferior vena cava along, the right upper front of the right common iliac artery (Figs 1, 3). margin of the kidney. There, this artery gave off The upper pole of this ectopic kidney was at the 3rd three branches: one ran to the ectopic kidney, and lumbar vertebra, and the lower pole was at the 5th the other two ran posterior to the right testicular lumbar vertebra. The ectopic kidney was discoid or artery and vein and to the right ureter. and supplied pancake-like in shape, its longitudinal diameter was the adipose tissue around the right kidney (Figs. 2, 75 mm, transverse diameter 65 mm, and thickness 3). The second artery coursed downward on the 25 mm. The hilus faced the anterior direction. Four right anterior surface of the ectopic kidney. where it renal calices originated in the central part of the elaborated branches to enter the kidney. The third anterior surface. These calices converged into the artery (A3) originated from the anterior aspect of renal , which in turn tapered to become the the aorta just below the Al artery, descended on the ureter. The ureter passed downward along the left posterior surface of the kidney, where gave off a side of the rectum on the left pelvic wall, ran laterally branch to the kidney, then turned to appear on the to the left ductus deferens, and opened at the left anterior surface, where it entered the kidney. lower portion of the . Venous drainage from the ectopic kidney gathered into two veins (Figs. 1, 3, 4). The first vein (V1) Blood vascular supply of the ectopic kidney originated as three venous radicles at the anterior Three arteries supplied the ectopic kidney (Figs. aspect of the right lower part of the kidney. This VI

Fig. 2. Right lateral view of the present case. Right side of this figure is cranial. Note an artery (A2) to this ectopic kidney (E) elves off two branches (arrowheads) to the adipose tissue around the right kidney. Sec Table 1 and text for abbreviations . 32 A. Ohtsuka et al.

Fig. 3. Schematic illustration of this case. See Table 1 and text for abbreviations. Ectopic Kidney 33

anastomosed each other at the anterior lower surface of the kidney.

Discussion

An ectopic kidney is one that owes its position to developmental failure: it has been arrested in renal ascent during embryonic life and usually has failed to rotate (Thompson and Pace, 1937). The ectopic kidney of the present case was located in a lower median position; the hilus faced anterior. These anatomical features resulted from arrested renal ascent and failed rotation. The ureter of the present ectopic kidney passed laterally to the left ductus deferens and opened at the left inferior region of the urinary bladder. There- fore, this ureter belonged to the left side. The A2 artery to the ectopic kidney gave off small branches to the adipose capsule of the right kidney, indicating that it belonged to the right side. The VI_vein from this ectopic kidney flowed into the inferior vena cava. The segment of the inferior vena cava between the iliac and renal veins develops from the right supracardinal vein (McClure and Butler, 1925). Thus, the V1 vein belonged to the right side. The V2 vein of this kidney joined with the left lumber veins and opened into the left common iliac veins. There- fore, this V2 vein belonged to the left side. Affili- ations of the blood vessels and the ureter to the right or left side were dissociated in the present ectopic kidney. This dissociation seemed to be strongly related to its median location. The horseshoe kidney, another well-known anomaly, is formed by fusion of the right and left kidneys (Fuyuta et al., 1977; Ohkubo et al., 1981). As discussed above, some of the vessels of the present ectopic kidney belonged to the right side, and others the left. This suggested that, in the present ectopic kidney, the renal tissue which was supplied by right-sided vessels originally attributed to the right, and those supplied by left-sided vessels to the left. It was considered that the present ectopic kidney

Fig. 4. Schematic illustration of the vascular system of was formed by fusion of the left kidney and part of this case. See Table 1 and text for abbreviations. the right kidney. It is not uncommon for an ectopic kidney to be supplied by multiple and aberrant blood vessels , vein ascended along the A2 artery, received a venous such as tributaries of the common or internal iliac tributary from the upper part of the kidney and artery/vein (Anitschkow, 1912; Takeshige et al., flowed into the anterior aspect of the inferior vena 1967). In the present case, the V2 vein joined with cava (Figs. 1, 3). The second one (V2) originated as the left lumbar vein and drained into the left common three venous radicles at the anterior aspect of the iliac vein. In normal development, as the kidneys left lower part. This V2 vein ran along the A3 artery, move out of the pelvis, they are supplied by vessels ascended across the left common iliac artery, joined at successively higher levels (Moore, 1977). In renal with the left lumbar veins and finally flowed into the ectopia due to the arrest of renal ascent, the tempor- left common iliac vein (Fig. 4). These two veins ary blood supply becomes permanent (Forbes , 1945). 34 A. Ohtsuka et al.

Noteworthy is that, in the present case, the V2 6) Fuyuta, M., Ukeshima, A. and Miyayama, Y.: An autopsy vein drained into the lumbar vein system. Such veins case of horseshoe kidney. Okajimas Folia Anat. Jpn., 53: sometimes occur in normally positioned kidneys, as 323-336, 1977. 7) Hanai, H. and Fujii, H.: A case of the pelvic kidney with a they arise behind the renal pelvis and join with few vascular anomalies. (in Japanese with English abstract) the lumbar vein system (Anson and Riba, 1939; Bull. Josai. Dent. Univ., 13: 264-270, 1984. Okamoto, 1990). These veins have been expected to 8) Hanley, H. G. and Steel, W. A.: The solitary ectopic pelvic appear more frequently during developmental stages kidney with reports of two further cases. Br. J. Surg., 34: before renal ascent has come to its end (Okamoto, 402-407, 1947. 9) Langman, J.: Urogenital system. In: Medical Embryology 1990). The V2 vein of the present case is considered 4th ed., pp. 234-267, Williams & Wilkins, Baltimore/ to be part of a renal venous system under the devel- London, 1981. opmental stage and may support this expectation. 10) McClure, C. F. W. and Butler, E. G.: The development of Furthermore, the course of this vein running behind the vena cava inferior in man. Am. J. Anat., 35: 331-383, the left common iliac artery to connect with the left 1925. 11) Moore, K. L.: The urogenital system: the urinary and common iliac vein corresponds to a part of the left genital systems. In: The Developing Human, 2nd ed., supracardinal vein at the embryonic stage (McClure pp. 220-258, W.B. Saunders, Philadelphia/London/ and Butler, 1925). Toronto, 1977. 12) Ohkubo, M., Ichikawa, S., Odajima, G. and Uchino, S.: An autopsy case of horseshoe kidney. Okajimas Folia Anat. References Jpn., 57: 337-346, 1981. 13) Okamoto, K.: The posterior (new definition), 1) Adachi, B.: Das Artreiensystemder Japaner. Band II. together with its morphological significance. Okajimas Folia Kenkyusha,Kyoto, 1928. Anat. Jpn., 67: 203-218, 1990. 2) Anitschkow,N. N.: Studienfiber Nierengefa3e bei ange- 14) Ransohoff, J. I..: Gangrene of ectopic kidney from twisted borener Nierendystopie.Virchows Arch. Pathol. Anat. pedicle. Surg. Gynecol. Obstet., 30: 356-357, 1920. Physiol.Kiln. Med., 207: 213-235, 1912. 15) Takeshige, Y., Kanaya, S., Takase, A., Hara, M. and Inoue, 3) Anson,B. J. andRiba, L. W.: The Anatomical and surgical T.: Ober einen Fall der einseitigen gelappten Beckenniere features of ectopickidney. Surg. Gynecol.Obstet., 68: mit der abnormen A. renalis. (in Japanese with German 37-44, 1939. abstract) J. Kurume Med. Assoc., 30: 354-362, 1967. 4) Dretler, S. P., Olsson,C. andPfister, R. C.: The anatomic, 16) Thompson, G. J. and Pace, J. M.: Ectopic kidney. A review radiologicand clinicalcharacteristics of the pelvic kidney: of 97 cases. Surg. Gynecol. Obstet., 64: 935-943, 1937. an analysisof 86 cases. J. Urol., 105: 623-627, 1971. 17) Wilhelmj, C. M.: A case of crossed displacement of the left 5) Forbes,G.: Pelvic ectopic kidney. Br. J. Surg.,33: 139-142, kidney with fusion. Anat. Rec., 18: 167-177, 1920. 1945.