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A unilateral pelvic kidney with variant vasculature: clinical significance

A unilateral pelvic kidney with variant vasculature: clinical significance The incidence of ectopic pelvic kidney accounts for ∼1 of 2500 live births. Although pelvic kidneys are most often asymp- tomatic, they may be associated with several pathologies including hypertension. As pelvic kidney results from a brief interference of the ascension of the developing kidney, it is frequently accompanied by an atypical and variable blood supply. The presence of multiple arteries and veins and their abnormal course and morphology are associated with surgical and radiological significance. Malrotation of the kidney with extrarenal calyces further predisposes the pelvic kidney to recurrent urinary tract infections. This report describes a rare case of a unilateral pelvic kidney with vascular and calyceal variations, and this case is reported to provide additional insight into this variation and its correlation to clinical practice. INTRODUCTION CASE REPORT The kidneys are retroperitoneal organs surrounded by adipose A unilateral pelvic kidney of abnormal morphology and vascular tissue and located between the 12th thoracic vertebra and third supply was discovered in a 65-year-old Caucasian male cadaver lumbar vertebra. Pelvic ectopia accounts for 1 of 2500 births and during dissection in the anatomy laboratory. The cause of death is surgically and radiologically significant. was Lewy body dementia. The intestines were removed, and Pelvic kidneys are often asymptomatic and incidentally the retroperitoneum was cleared of excess connective tissues. discovered. They are mostly supplied by the distal aorta, as is the The left and right ureters were traced from renal pelvis to the case here, which is the vessel first and most severely affected urinary bladder. The renal vasculature was dissected bilaterally, by atherosclerosis, predisposing to segmental ischemia and and kidney dimensions were noted. The right kidney was located hypertension [1]. However, the abnormal size of ectopic kidneys at L4–L5 vertebral level and was positioned anterior to the right makes detection of ischemic events more difficult. Furthermore, psoas major with an anterior facing hilum, while the left kidney because of the abnormal rotation, shape and vasculature, pelvic was located at T12–L3 vertebral level. The right kidney was kidneys predispose patients to complications such as urinary smaller than the left and had an irregular shape and uneven tract infections (UTIs), renal calculi, uretero-pelvic junction surface (Tables 1–2). The arterial supply consisted of five arteries obstructions, vesicoureteral reflux among many others. The branching from a stem arising from the descending aorta, four of abnormal kidney position also makes ectopic kidneys more which entered the superior pole of the kidney and one entered vulnerable to physical damage [1]. This report describes a case the posterior surface. The abdominal aorta showed calcification of a cadaveric unilateral pelvic kidney with multiple vascular suggestive of possible atherosclerosis. The pelvic kidney was variations, extrarenal calyces and malrotation. drained by five renal veins, two of them emerged anteriorly and Received: September 27, 2019. Accepted: October 11, 2019 Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2019. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com 1 Downloaded from https://academic.oup.com/jscr/article-abstract/2019/11/rjz333/5645656 by DeepDyve user on 03 December 2019 2 R. Gencheva et al. Table 1. Dimensions of both kidneys (cm) Dimensions Right kidney Left kidney Length 8.6 11.9 Lower width 5.2 5.0 Middle width 5.9 5.4 Upper width 3.3 5.7 Ureter 15.8 29.7 Gonadal vein 19 17.0 Table 2. Length of the pelvic renal vasculature (cm) Arteries Veins A1 5.3 V1 10.3 A2 2.5 V2 5.3 A3 1.8 V3 2.5 A4 1.5 V4 3.7 A5 2.9 V5 8.4 Figure 2: Schematic diagram of kidneys and vasculature. V1–V5—renal veins. DISCUSSION Kidney development proceeds between the sixth and eighth weeks of life with kidney ascent occurring during the ninth week. Renal ectopia occurs due to brief interference of kidney ascen- sion by the failure of degeneration of fetal renal blood supply or lack of factors responsible for ureteral growth and elongation [2, 3]. Multiple renal arteries are the most common variant among ectopic cases, with an incidence rate of 20–30%. Considering the increase of renal transplants and the use of laparoscopic tech- niques, detailed knowledge of ectopic kidneys is essential [4, 5]. Laparoscopic techniques employ a limited surgical window, thus making variant vasculature a potential obstacle to successful surgery especially if there is a lack of detailed knowledge of the variant vasculature. Presurgical computed tomography angiog- raphy is suggested as a way to circumnavigate difficult surgical Figure 1: Posterior abdominal wall and pelvis. 1. Right (Pelvic) kidney, 2. inferior vena cava, 3. thoracic aorta, 4. left kidney, 5. ureter, 6. liver, 7. urinary bladder, 8. cases [5]. Furthermore, multiple renal arteries have been linked renal vein, 9. renal artery, 10. gonadal vein, 11. common iliac artery, 12. common to elevated plasma renin levels and an increased likelihood of iliac vein, 13. external iliac artery, 14. psoas major, 15. iliacus, 16. rectum, 17. gall hypertension [6]. The calcified aorta noted here substantiates bladder. the correlation between an increased likelihood of hyperten- sion in patients with renal ectopia. Furthermore, due to the size difference between both kidneys in this donor, the pelvic the rest emerged from the posterior aspect of the kidney. Four kidney may have decreased functional capacity if any at all. veins drained into the inferior vena cava, one of them drained This case has a unique vasculature which has not been reported into the left common iliac vein (Figs 1–4). All vasculature pierced before, with multiple arteries entering the kidney, a prehilar through the capsule of the kidney instead of the hilum. Five branching pattern, which is clinically significant and can easily major calyces emerged out of the hilum of the right kidney to be identified in 3D imaging [1, 5]. The vasculature of the pelvic converge into a single ureter. A sagittal cross-section of the pelvic kidney has been reported as complicated and highly variable, kidney revealed malformed and abnormally located pyramids. due to retention of its fetal blood supply. The arterial supply The left kidney had normal morphology, and there were no can arise from several sources including the aorta, common iliac major anatomical variations noted in the cardiac, respiratory, artery, external iliac artery and internal iliac artery. Knowledge of gastrointestinal and skeletal systems. these anatomical variations is beneficial for patients undergoing Downloaded from https://academic.oup.com/jscr/article-abstract/2019/11/rjz333/5645656 by DeepDyve user on 03 December 2019 A unilateral pelvic kidney with variant vasculature 3 ectopic kidneys, with an incidence rate of 15–30%, similar to that of arterial variance [5]. In this case, there is a renal vein which crossed the midline which presents an increased risk of injury to vessels or the kidney itself during abdominopelvic surgical procedures. Another variation seen in this case is the extrarenal calyces. This type of abnormality is one of the rarest occurrences asso- ciated with renal ectopia, with only 20 cases reported this far. Although the cause of extrarenal calyces has not yet been deter- mined, it has been speculated to occur because of difference in the speed of development between the metanephric mass and ureteric bud [8]. Extrarenal calyces predispose patients to recurrent UTIs or obstructions, both of which may cause long- term renal damage and must be monitored for in patients with known anomalies similar to this case [3]. Although pelvic ectopic kidneys are often found incidentally, they can be associated with complications such as urolithiasis, hydronephrosis, renal calyces, ureteropelvic junction obstruc- tion, hypertension and renal carcinoma [1, 3, 7, 8].One in ten thousand individuals who have renal abnormalities also present with vertebral, cardiac and limb defects, anal atresia and trachea-esophageal fistulas, none of which were discovered in this case [9]. The clinicians should be aware of the possible surgical complications and clinical presentations in patients with pelvic kidney and exercise caution to avoid inadvertent damage to the variant vasculature during surgery. CONFLICT OF INTEREST STATEMENT The authors declare there are no potential conflicts of interest. Figure 3: Posterior aspect of the pelvic kidney showing its arterial supply. A1– A5—renal arteries. FUNDING This work was supported by Marian University College of Osteo- pathic Medicine. ETHICAL APPROVAL The research was conducted on a cadaver, and the materials do not contain personal identifiers. The Institutional Review Board of Marian University reviewed the protocol and determined the study as appropriate for exemption under federal regulations. CONSENT. Not applicable. GUARANTOR Guarantor for the article is ‘Sumathilatha Sakthi Velavan’. Figure 4: Posterior aspect of the pelvic kidney showing its venous drainage. V1– ACKNOWLEDGEMENTS V5—renal veins. The authors are grateful to the donor who donated his body to the medical school involved in this research and to his family abdominal surgery with pelvic kidneys [7]. Any anomaly in the and friends. We would like to thank Marian University College renal arteries’ origins can stop the ascension and cause ectopia of Osteopathic Medicine, Division of Biomedical Sciences for or rotation anomalies, and this could explain malrotation in allowing us to collect data from the cadaver and supporting this this case [4]. Multiple renal veins are also seen in patients with research. Downloaded from https://academic.oup.com/jscr/article-abstract/2019/11/rjz333/5645656 by DeepDyve user on 03 December 2019 4 R. Gencheva et al. 5. Urban BA, Ratner LE, Fishman EK. Three-dimensional REFERENCES volume-rendered CT angiography of the renal arteries and 1. Gulsun M, Balkanci F, Cekirge S, Deger A. Pelvic kidney with veins: normal anatomy, variants, and clinical applications. an unusual blood supply; angiographic findings. Surg Radiol Radiographics 2001;21:373–86. doi: 10.1148/radiographics. Anat 2000;22:59–61. doi: 10.1007/s00276-000-0059-6. 21.2.g01mr19373. 2. Bush KT, Vaughn DA, Xue L, Rosenfeld MG, Rose DW, Mendoza 6. Gokalp G, Hakyemez B, Erdogan C. Vascular anomaly in SA, et al. Development and differentiation of the ureteric bud bilateral ectopic kidney: a case report. Cases J 2010;3:5. doi: into the ureter in the absence of a kidney collecting system. 10.1186/1757-1626-3-5. Dev Biol 2006;298:571–84. doi: 10.1016/j.ydbio.2006.07.006. 3. Rui M, Rong-de W, Wei L, Gang W, Tao W, Zhuo-dong X, 7. Eid S, Iwanaga J, Loukas M, Oskouian RJ, Tubbs RS. Pelvic kidney: a review of the literature. Cureus 2018;10:e2775. doi: et al. A new classification of duplex kidney based on kidney 10.7759/cureus.2775. morphology and management. Chin Med J 2013;126:615–9. doi: 10.3760/cma.j.issn.0366-6999.20121259. 8. Gupta T, Goyal SK, Aggarwal A, Sahni D, Mandal AK. 4. Zahoi DE, Miclaus G, Alexa A, Sztika D, Puszati AM, Farca Extrarenal calyces: a rare renal congenital anomaly. Surg Radiol Anat 2015;37:407–10. doi: 10.1007/s00276-014-1349-8. Ureche M. Ectopic kidney with malrotation and bilateral mul- tiple arteries diagnosed using CT angiography. Rom J Morphol 9. Solomon BD. VACTERL/VATER association. Orphanet J Rare Dis Embryol 2010;51:589–92. 2011;6:56. doi: 10.1186/1750-1172-6-56. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Surgical Case Reports Oxford University Press

A unilateral pelvic kidney with variant vasculature: clinical significance

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Oxford University Press
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Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2019.
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Abstract

The incidence of ectopic pelvic kidney accounts for ∼1 of 2500 live births. Although pelvic kidneys are most often asymp- tomatic, they may be associated with several pathologies including hypertension. As pelvic kidney results from a brief interference of the ascension of the developing kidney, it is frequently accompanied by an atypical and variable blood supply. The presence of multiple arteries and veins and their abnormal course and morphology are associated with surgical and radiological significance. Malrotation of the kidney with extrarenal calyces further predisposes the pelvic kidney to recurrent urinary tract infections. This report describes a rare case of a unilateral pelvic kidney with vascular and calyceal variations, and this case is reported to provide additional insight into this variation and its correlation to clinical practice. INTRODUCTION CASE REPORT The kidneys are retroperitoneal organs surrounded by adipose A unilateral pelvic kidney of abnormal morphology and vascular tissue and located between the 12th thoracic vertebra and third supply was discovered in a 65-year-old Caucasian male cadaver lumbar vertebra. Pelvic ectopia accounts for 1 of 2500 births and during dissection in the anatomy laboratory. The cause of death is surgically and radiologically significant. was Lewy body dementia. The intestines were removed, and Pelvic kidneys are often asymptomatic and incidentally the retroperitoneum was cleared of excess connective tissues. discovered. They are mostly supplied by the distal aorta, as is the The left and right ureters were traced from renal pelvis to the case here, which is the vessel first and most severely affected urinary bladder. The renal vasculature was dissected bilaterally, by atherosclerosis, predisposing to segmental ischemia and and kidney dimensions were noted. The right kidney was located hypertension [1]. However, the abnormal size of ectopic kidneys at L4–L5 vertebral level and was positioned anterior to the right makes detection of ischemic events more difficult. Furthermore, psoas major with an anterior facing hilum, while the left kidney because of the abnormal rotation, shape and vasculature, pelvic was located at T12–L3 vertebral level. The right kidney was kidneys predispose patients to complications such as urinary smaller than the left and had an irregular shape and uneven tract infections (UTIs), renal calculi, uretero-pelvic junction surface (Tables 1–2). The arterial supply consisted of five arteries obstructions, vesicoureteral reflux among many others. The branching from a stem arising from the descending aorta, four of abnormal kidney position also makes ectopic kidneys more which entered the superior pole of the kidney and one entered vulnerable to physical damage [1]. This report describes a case the posterior surface. The abdominal aorta showed calcification of a cadaveric unilateral pelvic kidney with multiple vascular suggestive of possible atherosclerosis. The pelvic kidney was variations, extrarenal calyces and malrotation. drained by five renal veins, two of them emerged anteriorly and Received: September 27, 2019. Accepted: October 11, 2019 Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2019. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com 1 Downloaded from https://academic.oup.com/jscr/article-abstract/2019/11/rjz333/5645656 by DeepDyve user on 03 December 2019 2 R. Gencheva et al. Table 1. Dimensions of both kidneys (cm) Dimensions Right kidney Left kidney Length 8.6 11.9 Lower width 5.2 5.0 Middle width 5.9 5.4 Upper width 3.3 5.7 Ureter 15.8 29.7 Gonadal vein 19 17.0 Table 2. Length of the pelvic renal vasculature (cm) Arteries Veins A1 5.3 V1 10.3 A2 2.5 V2 5.3 A3 1.8 V3 2.5 A4 1.5 V4 3.7 A5 2.9 V5 8.4 Figure 2: Schematic diagram of kidneys and vasculature. V1–V5—renal veins. DISCUSSION Kidney development proceeds between the sixth and eighth weeks of life with kidney ascent occurring during the ninth week. Renal ectopia occurs due to brief interference of kidney ascen- sion by the failure of degeneration of fetal renal blood supply or lack of factors responsible for ureteral growth and elongation [2, 3]. Multiple renal arteries are the most common variant among ectopic cases, with an incidence rate of 20–30%. Considering the increase of renal transplants and the use of laparoscopic tech- niques, detailed knowledge of ectopic kidneys is essential [4, 5]. Laparoscopic techniques employ a limited surgical window, thus making variant vasculature a potential obstacle to successful surgery especially if there is a lack of detailed knowledge of the variant vasculature. Presurgical computed tomography angiog- raphy is suggested as a way to circumnavigate difficult surgical Figure 1: Posterior abdominal wall and pelvis. 1. Right (Pelvic) kidney, 2. inferior vena cava, 3. thoracic aorta, 4. left kidney, 5. ureter, 6. liver, 7. urinary bladder, 8. cases [5]. Furthermore, multiple renal arteries have been linked renal vein, 9. renal artery, 10. gonadal vein, 11. common iliac artery, 12. common to elevated plasma renin levels and an increased likelihood of iliac vein, 13. external iliac artery, 14. psoas major, 15. iliacus, 16. rectum, 17. gall hypertension [6]. The calcified aorta noted here substantiates bladder. the correlation between an increased likelihood of hyperten- sion in patients with renal ectopia. Furthermore, due to the size difference between both kidneys in this donor, the pelvic the rest emerged from the posterior aspect of the kidney. Four kidney may have decreased functional capacity if any at all. veins drained into the inferior vena cava, one of them drained This case has a unique vasculature which has not been reported into the left common iliac vein (Figs 1–4). All vasculature pierced before, with multiple arteries entering the kidney, a prehilar through the capsule of the kidney instead of the hilum. Five branching pattern, which is clinically significant and can easily major calyces emerged out of the hilum of the right kidney to be identified in 3D imaging [1, 5]. The vasculature of the pelvic converge into a single ureter. A sagittal cross-section of the pelvic kidney has been reported as complicated and highly variable, kidney revealed malformed and abnormally located pyramids. due to retention of its fetal blood supply. The arterial supply The left kidney had normal morphology, and there were no can arise from several sources including the aorta, common iliac major anatomical variations noted in the cardiac, respiratory, artery, external iliac artery and internal iliac artery. Knowledge of gastrointestinal and skeletal systems. these anatomical variations is beneficial for patients undergoing Downloaded from https://academic.oup.com/jscr/article-abstract/2019/11/rjz333/5645656 by DeepDyve user on 03 December 2019 A unilateral pelvic kidney with variant vasculature 3 ectopic kidneys, with an incidence rate of 15–30%, similar to that of arterial variance [5]. In this case, there is a renal vein which crossed the midline which presents an increased risk of injury to vessels or the kidney itself during abdominopelvic surgical procedures. Another variation seen in this case is the extrarenal calyces. This type of abnormality is one of the rarest occurrences asso- ciated with renal ectopia, with only 20 cases reported this far. Although the cause of extrarenal calyces has not yet been deter- mined, it has been speculated to occur because of difference in the speed of development between the metanephric mass and ureteric bud [8]. Extrarenal calyces predispose patients to recurrent UTIs or obstructions, both of which may cause long- term renal damage and must be monitored for in patients with known anomalies similar to this case [3]. Although pelvic ectopic kidneys are often found incidentally, they can be associated with complications such as urolithiasis, hydronephrosis, renal calyces, ureteropelvic junction obstruc- tion, hypertension and renal carcinoma [1, 3, 7, 8].One in ten thousand individuals who have renal abnormalities also present with vertebral, cardiac and limb defects, anal atresia and trachea-esophageal fistulas, none of which were discovered in this case [9]. The clinicians should be aware of the possible surgical complications and clinical presentations in patients with pelvic kidney and exercise caution to avoid inadvertent damage to the variant vasculature during surgery. CONFLICT OF INTEREST STATEMENT The authors declare there are no potential conflicts of interest. Figure 3: Posterior aspect of the pelvic kidney showing its arterial supply. A1– A5—renal arteries. FUNDING This work was supported by Marian University College of Osteo- pathic Medicine. ETHICAL APPROVAL The research was conducted on a cadaver, and the materials do not contain personal identifiers. The Institutional Review Board of Marian University reviewed the protocol and determined the study as appropriate for exemption under federal regulations. CONSENT. Not applicable. GUARANTOR Guarantor for the article is ‘Sumathilatha Sakthi Velavan’. Figure 4: Posterior aspect of the pelvic kidney showing its venous drainage. V1– ACKNOWLEDGEMENTS V5—renal veins. The authors are grateful to the donor who donated his body to the medical school involved in this research and to his family abdominal surgery with pelvic kidneys [7]. Any anomaly in the and friends. We would like to thank Marian University College renal arteries’ origins can stop the ascension and cause ectopia of Osteopathic Medicine, Division of Biomedical Sciences for or rotation anomalies, and this could explain malrotation in allowing us to collect data from the cadaver and supporting this this case [4]. Multiple renal veins are also seen in patients with research. Downloaded from https://academic.oup.com/jscr/article-abstract/2019/11/rjz333/5645656 by DeepDyve user on 03 December 2019 4 R. Gencheva et al. 5. Urban BA, Ratner LE, Fishman EK. Three-dimensional REFERENCES volume-rendered CT angiography of the renal arteries and 1. Gulsun M, Balkanci F, Cekirge S, Deger A. Pelvic kidney with veins: normal anatomy, variants, and clinical applications. an unusual blood supply; angiographic findings. Surg Radiol Radiographics 2001;21:373–86. doi: 10.1148/radiographics. Anat 2000;22:59–61. doi: 10.1007/s00276-000-0059-6. 21.2.g01mr19373. 2. Bush KT, Vaughn DA, Xue L, Rosenfeld MG, Rose DW, Mendoza 6. Gokalp G, Hakyemez B, Erdogan C. Vascular anomaly in SA, et al. Development and differentiation of the ureteric bud bilateral ectopic kidney: a case report. Cases J 2010;3:5. doi: into the ureter in the absence of a kidney collecting system. 10.1186/1757-1626-3-5. Dev Biol 2006;298:571–84. doi: 10.1016/j.ydbio.2006.07.006. 3. Rui M, Rong-de W, Wei L, Gang W, Tao W, Zhuo-dong X, 7. Eid S, Iwanaga J, Loukas M, Oskouian RJ, Tubbs RS. Pelvic kidney: a review of the literature. Cureus 2018;10:e2775. doi: et al. A new classification of duplex kidney based on kidney 10.7759/cureus.2775. morphology and management. Chin Med J 2013;126:615–9. doi: 10.3760/cma.j.issn.0366-6999.20121259. 8. Gupta T, Goyal SK, Aggarwal A, Sahni D, Mandal AK. 4. Zahoi DE, Miclaus G, Alexa A, Sztika D, Puszati AM, Farca Extrarenal calyces: a rare renal congenital anomaly. Surg Radiol Anat 2015;37:407–10. doi: 10.1007/s00276-014-1349-8. Ureche M. Ectopic kidney with malrotation and bilateral mul- tiple arteries diagnosed using CT angiography. Rom J Morphol 9. Solomon BD. VACTERL/VATER association. Orphanet J Rare Dis Embryol 2010;51:589–92. 2011;6:56. doi: 10.1186/1750-1172-6-56.

Journal

Journal of Surgical Case Reports – Oxford University Press

Published: Nov 1, 2019

There are no references for this article.