Evaluation of the renal arteries of 2,144 living kidney donors using computed tomography angiography and comparison with ıntraoperative findings

0

Evaluation of the Renal Arteries of 2,144
Living Kidney Donors Using Computed
Tomography Angiography and Comparison
with Intraoperative Findings
Mehmet Sariera

Mehmet Callioglub Yucel Yukselc

Enes Dumanb

Mestan Emekd Sibel Surmen Ustae
aDepartment of Urology, Istinye University Medical Faculty, Istanbul, Turkey; bDepartment of Radiology,
Medical Park Hospital, Antalya, Turkey; cDepartment of Transplantation, Medical Park Hospital, Antalya, Turkey; dDepartment of Public Health, Akdeniz University, Antalya, Turkey; eDepartment of Obstetrics and Gynecology,
Medical Park Hospital, Antalya, Turkey

Received: January 7, 2020
Accepted: April 2, 2020
Published online: May 14, 2020

Mehmet Sarier
Department of Urology, Medical Park Hospital
Tekelioglu Str. 7, Muratpaşa
TR–07160 Antalya (Turkey)
drsarier@gmail.com

karger@karger.com © 2020 S. Karger AG, Basel
www.karger.com/uin

DOI: 10.1159/000507796

Keywords
Renal transplantation · Donor candidates · Renal artery ·
Computed tomography angiography

Abstract
Objectives: A carefully chosen and suitably prepared kidney
donor is essential in living-donor kidney transplantation.
Computed tomography angiography (CTA) is an effective

imaging method for evaluating the renovascular morphol-
ogy of donor candidates. The aim of this study was to evalu-
ate renal artery variations in kidney donors using CTA and

compare the findings with the number of arteries detected
during laparoscopic donor nephrectomy. Materials and

Methods: The study included 2,144 living donors who un-
derwent pretransplant renovascular assessment using CTA

and laparoscopic donor nephrectomy in our center between
August 2012 and October 2018. The number of renal arteries
to the donor kidney detected on CTA was compared with the
number of arteries discovered intraoperatively. Results: The
mean age of the 2,144 living kidney donors included in the

study was 47.19 ± 13.3 (18–87) years. According to CTA find-
ings, 81.1% (n = 1,738) had a single renal artery, 17.2% (n =

369) had double renal arteries, 1.6% (n = 35) had triple renal
arteries, and 0.1% (n = 2) had quadruple renal arteries. The
same number of renal arteries were detected by CTA and in
laparoscopic donor nephrectomy in 97.9% (n = 2,099) of the
donors. In the other 2.1% (n = 45), fewer renal arteries were
detected intraoperatively compared to their CTA findings.

None of the donors included in the study had a greater num-
ber of renal arteries discovered during nephrectomy than by

CTA. Conclusion: CTA is a highly accurate method for the
evaluation of renovascular variations in donor candidates for
living-donor kidney transplantation. However, it must be
kept in mind that double or multiple renal artery variations
may be detected on CTA in 18.9% of donor candidates.
© 2020 S. Karger AG, Basel

Introduction
Based on outcome, kidney transplantation is the most

effective method for the treatment of end-stage renal dis-
ease [1]. Due to a shortage of cadaveric organs, living-
donor kidney transplantation is becoming more common

[2]. As the success of organ transplantation depends on

Downloaded by:
Univ. of California Santa Barbara
128.111.121.42 – 5/16/2020 4:42:39 AM

Sarier/Callioglu/Yuksel/Duman/Emek/
Usta

2 Urol Int

DOI: 10.1159/000507796

the quality of the graft organ, preoperative radiological

evaluation of living donors is critical. This requires accu-
rate visualization of the renal anatomy, collecting system,

and renovascular structures in the potential donor. Spiral
computed tomography angiography (CTA) is a rapid,
safe, minimally invasive, and widely accepted method for
preoperative assessment of the renal vasculature [3]. An

accurate and detailed demonstration of renal artery vari-
ations in the preoperative assessment is particularly im-
portant to avoid unwanted complications, such as venous

and/or ureteral injury during donor nephrectomy [4].
The aim of this retrospective study was to evaluate renal

artery variations according to pretransplant CTA in com-
parison with intraoperative findings in a large series of

living kidney donors.

Methods

After obtaining institutional review board approval (IRB ap-
proval No, 2019/004), we retrospectively evaluated records per-
taining to 2,165 living-donor kidney transplantations performed

between August 2012 and October 2018 in the Department of
Transplantation of the Medical Park Hospital of Antalya. Of these
transplantations, 2,144 living donors who underwent preoperative
renovascular assessment using CTA were included in the study.
For all donors, veri on age, sex, number of renal arteries detected
in CTA, and the planned nephrectomy side were recorded. The

number of renal arteries detected by CTA was compared with in-
traoperative findings during laparoscopic donor nephrectomy. No

oral contrast agent was used during imaging. Nonenhanced, arte-
rial phase, and 2-min delayed-phase thin-section imaging was per-
formed with 2-mm, axial, multiplanar reformation; maximum in-
tensity projection; and volume-rendered angiographic reconstruc-
tions. Images were acquired from both the abdomen and pelvis,

with nonenhanced imaging included to enable visualization of cal-
cifications in the aortoiliac system, which may be obscured in con-
trast-enhanced images. CTA was performed using a 16-row mul-
tidetector CT device (General Electric Company Healthcare, USA)

İlginizi Çekebilir;  Prevalence of sexually transmitted diseases in asymptomatic renal transplant recipients

after administration of a mean of 90 (60–100) mL of iohexol 350

(OmnipaqueTM, General Electric Company Healthcare, USA) in-
travenous contrast material. The contrast material was adminis-
tered via a 20-gauge intravenous catheter placed in an antecubital

vein at a rate of 4–5 mL/s using a pump injector unit (AngiomatTM,
Mallinckrodt, USA). The number of renal arteries entering the

kidney was determined based on the acquired images. After deter-
mining the appropriate side for donor nephrectomy, all living do-
nors underwent laparoscopic nephrectomy. Intraoperative reno-
vascular findings were noted.

Statistical analyses were performed using the OpenEpi® ver-
sion 3.01 (Atlanta, GA, USA) statistical program. Descriptive sta-
tistics were presented as frequency and percentage, and age was

expressed as mean ± SD (range). Sensitivity, specificity, positive

predictive value, negative predictive value, and diagnostic accu-
racy were calculated within a 95% confidence interval.

Results
The 2,144 living kidney donors included in the study
had a mean age of 47.19 ± 13.3 (18–87) years; 57.5% (n =

1,233) were female and 42.5% (n = 911) were male. Ne-
phrectomy was performed on the left side in 90.6% (n =

1,942) and on the right side in 9.4% (n = 202) of the donors.
According to CTA findings, 81.1% (n = 1,738) had a single
renal artery, 17.2% (n = 369) had double renal arteries,
1.6% (n = 35) had triple renal arteries, and 0.1% (n = 2) had
quadruple renal arteries (Table 1). The number of renal
arteries found during laparoscopic donor nephrectomy
was the same as detected by CTA in 97.9% (n = 2,099) of
the patients. In the other 2.1% (n = 45), fewer renal arteries

were detected intraoperatively compared to the CTA find-
ings. None of the donors included in the study had a great-
er number of renal arteries discovered during nephrecto-
my than were detected by CTA (Table 2).

Discussion
Living-donor surgeries completely contradict the first

rule of medicine, “primum non nocere.” In these proce-
dures, a healthy organ is surgically removed from a

Table 1. Distribution of donors according to the number or renal
arteries detected by CTA and intraoperatively
Arteries discovered intraoperatively
1 2 3 4
Arteries detected on CTA
1 1,738
2 32 337
3 2 10 23
4 1 1

Table 2. Comparison of CTA results with intraoperative findings
according to the number of renal arteries
Parameter Mean 95% CI
Sensitivity, % 100 98.95–100
Specificity, % 97.48 96.64–98.11
Positive predictive value, % 91.39 88.21–93.78
Negative predictive value, % 100 99.78–100
Diagnostic accuracy, % 97.9 97.2–98.43
CI, confidence interval.

Downloaded by:
Univ. of California Santa Barbara
128.111.121.42 – 5/16/2020 4:42:39 AM

Evaluating Renal Arteries of Donor
Candidates

Urol Int 3
DOI: 10.1159/000507796

healthy individual. While organs removed due to malig-
nancy or other pathological reasons are sent to pathology,

the organ removed in donor surgeries is used in another
individual. Therefore, it is crucially important that the
organ to be transplanted is removed with minimal harm
to the donor and the organ itself. Due to the shortage of
cadaveric donor kidneys in Turkey, living-donor kidney

transplantation is more common here than in the Euro-
pean Union or USA [5]. According to recent veri, living-
donor transplantations account for over 75% of all kidney

transplantations performed in Turkey [6], whereas this
percentage is only about 25% in the USA [7].

Both radiological and laboratory assessments are es-
sential components of the preoperative evaluation of po-
tential living donors. Intravenous pyelography and digi-
tal subtraction angiography have been successfully used

for many years to visualize the anatomy of candidate do-
nors’ kidneys. However, both imaging methods involve

exposing the donors to high levels of radiation and poten-
tially nephrotoxic intravenous iodinated contrast medi-
um. Moreover, digital subtraction angiography is a more

invasive method than CTA, and donor candidates had to
be hospitalized after the procedure. With technological
advances, CTA replaced these 2 imaging methods and has
been successfully used in the preoperative assessment of
living donors for 2 decades [8].
In recent years, magnetic resonance angiography
(MRA) has been introduced as an alternative imaging

modality to CTA for preoperative renovascular assess-
ment of living donors. Advantages of MRA over CTA in-
clude not exposing patients to radiation and avoiding the

side effects of contrast agents. The main advantage of
CT is that precontrast imaging enables the detection of
asymptomatic kidney stones. Donor kidney stones are

known to be a relative contraindication for transplanta-
tion [9]. Ultrasonography has a low sensitivity, especially

in the detection of kidney stones <5 mm, and noncontrast
CT is currently the gold standard for visualizing stones of
this size [10].
There are numerous known anatomical variations in
the renal vasculature. CTA is superior to MRA in imaging
the renal venous system, which includes the adrenal vein,

İlginizi Çekebilir;  Ergen terapisi / ergenlik ne değildir?

gonadal vein, and lumbar branches [11]. Another advan-
tage of CTA is that it is less expensive than MRA. How-
ever, there are many publications in the literature which

compare CTA and MRA in terms of the evaluation of re-
novascular structures in candidate donors. Some studies

showed that CT was superior, especially when its correla-
tion with intraoperative findings were analyzed [12, 13],

while others demonstrated equal effectiveness [14]. Some

researchers, however, emphasized that MRA should be
the only imaging method used for renal assessment of

candidate donors due to its high sensitivity and specific-
ity [15, 16], and recommended that CTA only be consid-
ered as an alternative imaging method in patients who are

ineligible for MRA. As a result, there is still no consensus
regarding the optimal evaluation method for potential
living donors.
In our study, renal artery imaging by CTA had 97.9%

diagnostic accuracy for the number of arteries when com-
pared with intraoperative findings. Similarly, Çıra et al.

[3] reported a 97% accuracy rate with CTA in their study

of 286 living donors. In this situation, false-negative re-
sults are of greater importance for the surgery than false-
positive results. It must be kept in mind that a vein or

veins not detected before donor nephrectomy may cause
unwanted complications during the operation. In our
study, more arteries were detected by CTA than during

surgery in only 2.1% of 2,144 patients, which can be con-
sidered false-positive results. None of the donors includ-
ed in the study actually had more renal arteries (discov-
ered during laparoscopic donor nephrectomy) than were

detected in CTA, which would be a false-negative result.
Our study, in which CTA was used to evaluate renal
arteries in over 2,000 kidney transplantations, is – to the
best of our knowledge – the largest series in the literature.
An important point in this series is that CTA revealed 2 or
more renal arteries in 18.9% of the donors. We believe that
this finding is especially valuable in terms of providing an
initial idea to the surgical team that will perform the donor
nephrectomy. The prevalence of accessory renal arteries
varies widely by region [17], and multiple renal arteries
are not a desirable factor in transplant surgery. In fact, the
number of renal arteries has a more significant negative
predictive value than renal vein length [8].
Laparoscopic donor nephrectomy has been performed
as a minimally invasive, standard method for living-donor

kidney transplantation for nearly 2 decades due to its ad-
vantages, which include shorter hospital stay, mild postop-
erative pain, low morbidity, and cosmetic superiority [18,

19]. The main difference between donor nephrectomy and
other nephrectomies is that the removed organ will be used

in another patient. Before laparoscopic donor nephrecto-
my, the renovascular anatomy and collecting system must

be carefully and accurately assessed. Loss of tactile sensation
and/or limited field of view in the laparoscopic approach
might cause an important limitation compared to classical

open surgery [20]. Complex renovascular structures in par-
ticular may have consequences that can directly impact the

surgical outcome [4]. Although small accessory arteries do

Downloaded by:
Univ. of California Santa Barbara
128.111.121.42 – 5/16/2020 4:42:39 AM

Sarier/Callioglu/Yuksel/Duman/Emek/
Usta

4 Urol Int

DOI: 10.1159/000507796

not affect graft function, lower pole renal arteries are criti-
cally important as they may also have a role in supplying

both the renal pelvis and upper portion of the ureter [21].
The surgical team must be prepared for such variations. The
other key point is to protect the donor from postoperative
morbidity and mortality.
A limitation of this study is that only the number of

renal arteries in the donor kidney was evaluated. The ve-
nous structures and other renovascular variations in the

donor kidney were not included in the study.

Conclusion
CTA is highly accurate compared to intraoperative
findings, and it is an effective method for assessing donor
candidates for living-donor kidney transplantation and
identifying renovascular variations. However, it must be

kept in mind that 2 or more renal arteries may be detect-
ed in 18.9% of candidate donors in CTA assessment.

Statement of Ethics

The study was approved by the local ethics committee (approv-
al No. 2019/004), and written informed consent was obtained from

İlginizi Çekebilir;  Teknoloji bağımlılığı ve ruhsal sıhhat:

all participants. The study protocol conformed to the ethical
guidelines of the 1975 Declaration of Helsinki.

Disclosure Statement
The authors declare to have no conflict of interest.

Funding Sources
No funding was received for this work.

Author Contributions
M.S.: writing and concept, M.C.: veri collection, Y.Y.: literature
Search, E.D.: critical review, and M.E.: analysis.

References
1 Sarier M, Sepin İtina N, Guler H, Duman I,

Yüksel Y, Tekin S, et al. Prevalence of Sexu-
ally Transmitted Diseases in Asymptomatic

Renal Transplant Recipients. Exp Clin Trans-
plant. 2018, DOI: 10.6002/ect.2017.0232.

2 Chkhotua AB, Klein T, Shabtai E, Yussim A,
Bar-Nathan N, Shaharabani E, et al. Kidney

transplantation from living-unrelated do-
nors: comparison of outcome with living-re-
lated and cadaveric transplants under current

immunosuppressive protocols. Urology. 2003
Dec;62(6):1002–6.
3 Çıra K, Demirtaş H, Durmaz MS, Çeken K.

Evaluation of renal arteries of 286 living do-
nors by multidetector computed tomography

angiography: A single-center study. Exp Clin
Transplant. 2015 Dec;13(6):581–7.

4 Carter JT, Freise CE, McTaggart RA, Mahan-
ty HD, Kang SM, Chan SH, et al. Laparoscop-
ic procurement of kidneys with multiple renal

arteries is associated with increased ureteral

complications in the recipient. Am J Trans-
plant. 2005 Jun;5(6):1312–8.

5 Yuksel Y. Comparison of experienced and in-
experienced centers in cadaveric organ prepa-
ration for transplantation. Ann Med Res.

2019;26(3):432–9.
6 Diniz G, Tugmen C, Sert İ. Türkiye ve
dünyada organ transplantasyonu. Tepecik
Eğit ve Araşt Hast Mecmuası. 2019;29(1):1–10.
7 Black CK, Termanini KM, Aguirre O,

Hawksworth JS, Sosin M. Solid organ trans-
plantation in the 21st century. Ann Transl

Med. 2018 Oct;6(20):409–409.

8 Kaynan AM, Rozenblit AM, Figueroa KI, Hoff-
man SD, Cynamon J, Karwa GL, et al. Use of

spiral computerized tomography in lieu of an-
giography for preoperative assessment of living

renal donors. J Urol. 1999 Jun;161(6):1769–75.
9 Sarier M, Duman I, Yuksel Y, Tekin S, Ozer
M, Yucetin L, et al. Ex vivo stone surgery in
donor kidneys at renal transplantation. Int J
Urol. 2018 Oct;25(10):844–7.
10 Sarier M, Duman I, Callioglu M, Soylu A, Tekin
S, Turan E, et al. Outcomes of Conservative
Management of Asymptomatic Live Donor
Kidney Stones. Urology. 2018 Aug;118:43–6.
11 Schlunt LB, Harper JD, Broome DR, Baron

PW, Watkins GE, Ojogho ON, et al. Multide-
tector computerized tomography angiogra-
phy to predict lumbar venous anatomy before

donor nephrectomy. J Urol. 2006 Dec;176(6
Pt 1):2576–81.
12 Liefeldt L, Klüner C, Glander P, Giessing M,
Budde K, Taupitz M, et al. Non-invasive imaging

of living kidney donors: intraindividual compar-
ison of multislice computed tomography angi-
ography with magnetic resonance angiography.

Clin Transplant. 2012 Jul-Aug;26(4):E412–7.
13 Bhatti AA, Chugtai A, Haslam P, Talbot D, Rix
DA, Soomro NA. Prospective study comparing
three-dimensional computed tomography and
magnetic resonance imaging for evaluating the
renal vascular anatomy in potential living renal
donors. BJU Int. 2005 Nov;96(7):1105–8.
14 Gluecker TM, Mayr M, Schwarz J, Bilecen D,
Voegele T, Steiger J, et al. Comparison of CT

angiography with MR angiography in the pre-
operative assessment of living kidney donors.

Transplantation. 2008 Nov;86(9):1249–56.
15 Fleury N, Vallée JP, Hadaya K, Bühler L, Martin
PY, Iselin CE. Magnetic resonance imaging as

the sole radiological assessment for living do-
nor nephrectomy. Urol Int. 2010;84(1):56–60.

16 El-Diasty TA, El-Ghar ME, Shokeir AA, Gad
HM, Wafa EW, El-Azab ME, et al. Magnetic
resonance imaging as a sole method for the
morphological and functional evaluation of live
kidney donors. BJU Int. 2005 Jul;96(1):111–6.
17 Cenal U, Erturk T, Karayagiz AH, Ozdemir E,

Polatkan SV, Cakir U, et al. Geographic Dis-
tribution of Multiple Arteries and Veins of

878 Kidney Donors From a Transplant Cen-
ter in Turkey. Transplant Proc. 2019 May;

51(4):1086–8.

18 Simforoosh N, Basiri A, Tabibi A, Shakhssa-
lim N, Hosseini Moghaddam SM. Compari-
son of laparoscopic and open donor nephrec-
tomy: a randomized controlled trial. BJU Int.

2005 Apr;95(6):851–5.

19 Wolf JS Jr, Merion RM, Leichtman AB, Camp-
bell DA Jr, Magee JC, Punch JD, et al. Random-
ized controlled trial of hand-assisted laparo-
scopic versus open surgical live donor nephrec-
tomy. Transplantation. 2001 Jul;72(2):284–90.

20 Kok NF, Dols LF, Hunink MG, Alwayn IP,
Tran KT, Weimar W, et al. Complex vascular
anatomy in live kidney donation: imaging and

consequences for clinical outcome. Trans-
plantation. 2008 Jun;85(12):1760–5.

21 Taban MA, Dadkhah F, Ghadian AR, Razza-
ghi MR, Noorbala MH, Amini E. Evaluation

of the vascular anatomy in potential living
kidney donors with gadolinium-enhanced

magnetic resonance angiography: compari-
son with digital subtraction angiography and

intraoperative findings. Clin Transplant.
2011 May-Jun;25(3):481–5.

Cevap bırakın

E-posta hesabınız yayımlanmayacak.