Ectopic pelvic kidney and its renal artery from the common iliac artery

Sevda Lafci Fahrioglu; Musa Muhtaroglu; Selda Onderoglu; Sezgin Ilgi

doi:10.4103/JASI.JASI_210_19

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CASE REPORT

Year : 2020 | Volume : 69 | Issue : 4 | Page : 249-251

Ectopic pelvic kidney and its renal artery from the common iliac artery

Sevda Lafci Fahrioglu, Musa Muhtaroglu, Selda Onderoglu, Sezgin Ilgi
Department of Anatomy, Faculty of Medicine, Near East University, Nicosia, Cyprus

Date of Submission	03-Dec-2019
Date of Acceptance	22-May-2020
Date of Web Publication	29-Dec-2020

Correspondence Address:
Assoc. Prof. Sevda Lafci Fahrioglu
Department of Anatomy, Faculty of Medicine, Near East University, TRNC, Nicosia
Cyprus

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JASI.JASI_210_19

Abstract

The pelvic kidney is the most common type of renal ectopia. It is clinically asymptomatic in general but are more prone to the urinary infections. It has also been associated with an increased risk of nephrolithiasis. The 37-year-old man was admitted to the emergency room with complaints of left flank pain, nausea and vomiting. In addition to this flank pain, the patient had an intermittent pain in the lower abdomen and pelvic region for 6 years with no history of fever. The renal ultrasound demonstrating several shadowing echogenic areas consistent with nephrolithiasis in both kidneys. In addition, while the right kidney was in the normal size and location, the left kidney was located on the ectopic site, just above the bladder. Doppler examination revealed double renal arteries originating from the aorta on the right side. Our case indicates the importance of the ectopic pelvic kidney location when planning surgical procedures in patients with renal and pelvic pathology, kidney transplantation and nephrectomy.

Keywords: Ectopic kidney, double renal artery, renal anatomy

How to cite this article:
Fahrioglu SL, Muhtaroglu M, Onderoglu S, Ilgi S. Ectopic pelvic kidney and its renal artery from the common iliac artery. J Anat Soc India 2020;69:249-51

How to cite this URL:
Fahrioglu SL, Muhtaroglu M, Onderoglu S, Ilgi S. Ectopic pelvic kidney and its renal artery from the common iliac artery. J Anat Soc India [serial online] 2020 [cited 2023 Mar 24];69:249-51. Available from: https://www.jasi.org.in/text.asp?2020/69/4/249/305373

Introduction

During the normal fetal developmental stages, the kidney does not yet reach its adult anatomical location.^[1] If it continues to remain in the pelvic region after the fetal stages, it will be called pelvic kidney.^[2] The pelvic kidneys which reside in the pelvis minor are clinically asymptomatic in general but are more prone to urinary infections and stone formation.^[2],[3]

The congenital anomalies of the kidney and the urinary system are common congenital organ malformations, with an incidence of 0.03%–0.16%.^[3] The pelvic kidney is the most common type of renal ectopia. The ectopic kidney can rarely be found at the thorax.^[2],[3] The pelvic kidney can cause deep vein thrombosis due to its pressure on the iliac vein.^[4] Ectopic kidney has also been associated with an increased risk of nephrolithiasis.^[5] Furthermore, transitional cell carcinoma of a pelvic kidney is also observed, but it has a more rare occurrence.^[6],[7],[8]

Embryology

Initially, the kidneys are located near the tail of the embryo in the early stages of embryogenesis.^[1] The metanephric diverticulum and metanephric blastema, which are the main parts of the permanent kidney, develop from methanephrosis in the pelvis. The kidneys migrate to the lumbar region with the effect of the abdominal wall growth during the intra-uterine period. The kidneys also rotate medially during migration to renal fossa.^[2],[4] The vascular buds from the kidneys grow toward and invade the common iliac arteries. The genetic and teratogenic risk factors may affect the physiological development of the kidneys and lead to congenital disabilities. The congenital abnormalities of the kidney and urinary system are one of the common congenital organ malformations. It has two subgroups, which are the congenital malformations of the kidney and the anomalies of the lower urinary system.^[2],[3],[9] The most common type of renal ectopia is a pelvic kidney. During the fetal period in the normal developmental stages, the kidney does not reach the anatomic location, and if it remains in the pelvic region is called the pelvic kidney.^[5]

Case Report

In September 2018, the 37-year-old male was admitted to the emergency room with complaints of left flank pain, nausea, and vomiting. In addition to this flank pain, the patient had intermittent pain in the lower abdomen and pelvic region for 6 years with no history of fever. On careful investigation of the patient's medical history, it was discovered that he was admitted to the emergency department with the same flank pain complaint after seeing several physicians in different hospitals over many years. The patient was thin and tall. A kidney stone was suspected, and the renal ultrasound demonstrated several echogenic areas consistent with nephrolithiasis in both kidneys. In addition, while the right kidney was in the normal size and location, the left kidney was located on the ectopic site, just above the bladder. The left ectopic kidney was slightly malrotated with its pelvis oriented posteriorly. The size of the left kidney was 94 mm × 61 mm × 52 mm, and the renal pelvis was in the right and posterior position [Figure 1]. The size of the right kidney was 129 mm × 51 mm × 45 mm [Figure 2]. The thickness of the parenchyma of the right and the left kidneys were 11–12 mm and 12–13 mm, respectively. The cortical and medullary echogenicity of both kidneys were normal, and a parenchymal band was present in the middle, but there was no double collecting system. In addition, 8–10 stones were found in the calyces of both kidneys, ranging in size from 3 to 11 mm.

Figure 1: Renal ultrasonography demonstrating of the left kidney

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Figure 2: Renal ultrasonography demonstrating of the right kidney

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The computed tomography (CT) scan performed after ultrasound demonstrated multiple renal stones, but no double collecting systems in both kidneys [Figure 3] and [Figure 4].

Figure 3: Computed tomography urogram demonstrating the right kidney, the left kidney, and the pelvic part of the right ureter

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Figure 4: The sagittal section of the computed tomography urogram demonstrating the left kidney, which is located at the top of the bladder. *: Urinary bladder

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Doppler examination revealed double renal arteries originating from the aorta on the right side. The diameter of the right renal arteries was 4 mm and 3.5 mm. The diameter of the left renal artery was 5 mm, and it originated from the left common iliac artery immediately after the aortic bifurcation. The vascularization of both kidneys was symmetrical and normal. Segmental and interlobar arteries were normal, and resistivity indices up to arcuate arteries were normal. There was no renal artery stenosis in both kidneys.

Discussion

The kidneys that develop in the pelvis move to a more proximal site and merge with the adrenal gland. The growth of the lumbar and sacral regions of the embryo in length causes the kidneys to “ascend” to their final position in the upper lumbar region at the 9^th week of gestation.^[4] During this migration, as the kidneys rise, they continue to have new blood vessels at their new level and leave behind their old blood vessels to regress. As the kidneys migrate upward, the renal hilum turns 90° medially, and thereby, the renal hilum is finally located at the medial side of the kidney.^[1] Absence of the kidney in the renal fossa (also called “Empty renal fossa”) indicates renal agenesis; ectopic kidney is kidney located in an abnormal ectopic position which arises due to the failure of ascent or arrest of the ascent of the kidney.^[3] The pelvic ectopia is a type of renal ectopia, which is caused by faulty migration from the pelvis during the embryological process. Although the ectopic kidney can be found in the lower lumbar, abdominal, and thoracic locations, the left pelvic region is the most common site for the ectopic kidney. In addition, contralateral and crossed ectopic kidneys can also occur.^[5]

Urinary system anomalies can be detected in about 10% of the population. The presence of pelvic kidneys may not be noticed early in life unless it is detected by kidney ultrasound or abdominal tomography for different reasons. The pelvic kidney, which is the most common type of renal ectopia, can be seen in adults at the rate of 1/1000.^[6] The incidence of a normal and a pelvic kidney ranges from 1:800 to 1:3000.^[9] The pelvic kidneys are mostly asymptomatic. In the presence of an ectopic kidney, genital system abnormalities such as undescended testicles, urethral duplication, and hypospadias may also be defined. The malrotated ectopic kidney is one of the risks of stones formation, which may present as renal colic and hematuria, like in our case.

Since the renal vessels are shaped according to the normal anatomical position of the kidney, the position of the ectopic kidney also affects the origin of the kidney vessels. As we found in our patient, the artery of a distally located ectopic kidney may originate from a common iliac artery close to the aortic bifurcation, as well as from the inferior mesenteric artery, distal aorta, or external iliac artery.^[9]

Although the ectopic kidney is asymptomatic, the patients should be monitored with ultrasound at regular intervals since these patients have a higher risk of developing nephrolithiasis. They should be alerted against complications such as secondary infection and hydronephrosis.^{[10],[11],[12]} The treatment of hydronephrotic pelvic kidney involves various difficulties, as the kidney can be found in front of the sacrum, behind the lower gastrointestinal system and internal genital organs. Although the prevalence of renal cancer in the pelvic kidneys is exceedingly rare, it should also be kept in mind.^{[6],[7],[8],[11]}

Surgical removal of the pelvic kidney may be complicated because of its neighboring anatomical structures or the presence of a tortuous ureter in the presence of abnormal neurovascular structures.^[10],[12] For this reason, it is important to have information about the anatomical locations of the pelvic kidney. Our case indicates the importance of the ectopic kidney location when planning surgical procedures in patients with renal and pelvic pathology, kidney transplantation, and nephrectomy.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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