Cas clinique

DOI of or

DepartmenJapon.

CorrespondTokyo Medica160-0023, Jap

Ann Vasc Surhttp://dx.doi.or� Annals of V�Edit�e par ELS

�Evaluation perop�eratoire de la perfusionsanguine par angiographie au vertd’indocyanine assist�ee par laser apr�esreconstruction vasculaire ex vivo d’unan�evrysme intra-hilaire de l’art�ere r�enale

Toru Iwahashi, Yukio Obitsu, Nobusato Koizumi, Naozumi Saiki, Satoshi Takahashi,

Hiroshi Shigematsu, Tokyo, Japon

La reconstruction chirurgicale des an�evrysmes intra-hilaires de l’art�ere r�enale (RAAs) est unechirurgie difficile en raison de l’anatomie complexe. Nous pr�esentons un cas de RAA intra-hilairedroit diagnostiqu�e chez un homme de 67 ans. Nous avons fait une reconstruction ex vivo enutilisant une solution de conservation d’organe pour empecher l’insuffisance r�enale post-op�eratoire. Nous avons �evalu�e la perm�eabilit�e de la revascularisation et la perfusion sanguinepar angiographie laser-assist�ee au vert d’indocyanine avec le syst�eme SPY apr�es auto-transplantation. On n’a pas observ�e d’insuffisance r�enale postop�eratoire. Les r�esultatsd�emontrent que la reconstruction ex vivo des RAA intra-hilaires utilisant une solution de con-servation d’organe, et que l’�evaluation de la perm�eabilit�e et de la perfusion sanguine par lesyst�eme SPY sont des m�ethodes efficaces pour pr�eserver la fonction r�enale.

The incidence of renal artery aneurysms (RAAs) is

very rare, occurring at approximately 0.01-0.09%

as reported in an autopsy study1 and at 0.1-0.3%

as described in an angiography study.2 Moreover,

the risk of RAA rupture has been reported to be

2.8-5.6%,3 with a reported mortality rate of 80%

from ruptured RAAs.4 Progress of the endovascular

technique has enabled the treatment of RAAs

located in the main renal artery, but not of those

found in the renal hilum. The surgical arterial

reconstruction of intrahilar RAAs involves many

iginal article: 10.1016/j.avsg.2011.02.019.

t of Vascular Surgery, Tokyo Medical University, Tokyo,

ance : Toru Iwahashi, Department of Vascular Surgery,l University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyoon, E-mail: tnr9634@me.com

g 2011; 25: 838.e5-838.e8g/10.1016/j.acvfr.2012.07.022ascular Surgery Inc.EVIER MASSON SAS

risks, including difficulty in securing a surgical view,

difficult surgery due to complex anatomy in the

renal hilum, possible ischemia-reperfusion injury of

the kidney, and postoperative renal failure. We

report a case demonstrating that the ex vivo arterial

reconstruction of intrahilar RAA using an organ

preservation solution, and graft patency and organ

blood perfusion evaluation using the SPY� intrao-

perative imaging system (Novadaq Technologies,

Toronto, Canada) are useful methods for preserving

renal function.

CASE REPORT

We describe the case of a 67-year-old man who presented

with fecal occult blood. To determine the cause of the occult

blood, we performed abdominal computed tomography

(CT) during the medical checkup. CT showed a saccular

aneurysm of 25 mmmaximal dimension in the right renal

artery, and specifically located in the right renal hilum. The

patient had been healthy without any evidence of cardio-

vascular risk factors, such as hypertension, hyperlipidemia,

894.e5

Fig. 1. (A) Computed tomography angiography with three-dimensional reconstruction demonstrated a right renal artery

aneurysm in the renal hilum. (B) Digital subtraction angiography revealed a right renal artery aneurysm in the renal hilum.

Fig. 2. Right renal artery reconstructed with saphenous

vein graft (RA, renal artery; RV, renal vein).

894.e6 Cas cliniques Annales de chirurgie vasculaire

diabetes mellitus, or a history of smoking. On physical

examination, the patient showed no symptoms related to

the renal aneurysm. Laboratory data were unremarkable,

including a blood urea nitrogen level of 12.3 mg/dL and a

creatinine level of 0.65 mg/dL. CT angiography with

3-dimensional reconstruction (3DCT) and digital subtrac-

tion angiography revealed each polar branch arising from

the aneurysm in the renal hilum (Fig. 1). Because the

location of the aneurysm contraindicated endovascular

repair, an ex vivo arterial reconstruction and auto-

transplantion was performed. As the duration of renal

ischemia was expected to be longer than 2 hours, we deci-

ded to use an organ preservation solution to protect the

kidney. For the operative procedure, the patientwas placed

ina supineposition.Aftermedian laparotomy, right visceral

mobilization was performed which facilitated entry to the

retroperitoneal space anterior to Gerota’s fascia. The right

renal artery, renal vein, and ureter were then exposed. The

RAAwas located in the renal hilum, as also shown by 3DCT

and digital subtraction angiography. Concomitantly, a

saphenous vein graft (SVG) was harvested from the

proximal right thigh. After systemic heparinization, the

proximal right renal artery was clamped and divided. The

renal vein was clamped at its juncture with the vena cava

and excised. The ureter was left intact. The kidney was

placed on ice slush and flushed with 400 mL of ice-cold

(4�C) Ringer solution containing heparin (2,000 IU/L),

prednisolone (20 mg/L), and 7% sodium bicarbonate

(20mL/L). Additionally, 200mL of University ofWisconsin

solution (Viaspan�, Astellas Pharmaceutical, Tokyo, Japan)

containing dexamethasone (16 mg/L), penicillin G (20 �104 IU/L), and human insulin (40 IU/L) was perfused from

the renal artery to prevent renal insufficiency. Following

these procedures, the aneurysm was resected. The upper

and lower polar branches were reconstructed together to

the SVG with end-to-end suture, and vein graft interposi-

tion was required for the middle polar branch reconstruc-

tion (Fig. 2). Followingarterial reconstruction,Universityof

Wisconsin solutionwaswashed outwith 400mLof ice-cold

Ringer solution. Then, the kidney was placed in an

orthotopic position and anastomosis from the SVG to the

proximal right renal artery was performed. Finally, the

renal vein was sutured to the vena cava. The total ischemic

time was 138 minutes. To assess renal blood perfusion and

the anastomosis, the SPY intraoperative imaging system

(Novadaq Technologies) was used. We injected 25 mg of

indocyanine green (ICG) dissolved in 20 mL of normal

saline into the abdominal aorta. Laser-assisted ICG angio-

graphy demonstrated adequate arterial reconstruction and

reperfusion (Fig. 3). For renal flow assessment, we used an

ultrasonic transit-timeflowmeterwhich showedaflowrate

of267mL/min in themain renal artery. Postoperativeblood

urea nitrogen and creatinine levels werewithin the normal

range. Renogram with technetium-99m-labeled dimer-

captosuccinic acid (99mTc-DMSA) demonstrated mild

renal dysfunction in the right kidney (53 mL/min), and

3DCT showed segmental renal infarction in one part of the

upper pole. The patient was discharged 11 days after the

surgery.

Fig. 3. Intraoperative fluorescent angiography after renal vascular reconstruction; 5 and 12 seconds after the injection of

indocyanine green, the renal parenchyma turned bright gradually (RA, renal artery; IVC, inferior vena cava; Ao, aorta).

Vol. 25, No. 6, 2011 Cas cliniques 894.e7

DISCUSSION

The surgical indication for asymptomatic RAAs is cur-

rently not established. However, rupture of small-

diameter RAAs has been reported.5 For most cases,

nephrectomy may be required if the RAAs rupture.

Therefore, experts have suggested the following

indications for the surgical intervention of asympto-

matic RAAs: aneurysmal diameter >20 mm, RAAs

with calcification, enlarging RAAs, and RAAs in

pregnant women.6

Recently, advances in endovascular techniques

have allowed the successful treatment of RAAs.

However, the indications of catheter intervention

remain limited because of the anatomical location,

complexity, and size of aneurysms. In particular,

intrahilar RAAs are difficult to treat by endovascular

therapy.

In situ or ex vivo repair is usually used for the

reconstructionof intrahilarRAAs. If RAAshavemul-

tiple branchvessels, it is expected that reconstruction

may take time. Crutchley et al suggested the use of

hypothermic perfusion when >30-40 minutes of

warm ischemia is anticipated.7 Levy reported that

hypothermic perfusion preserved kidney function

for 120 minutes in dogs.8 Moreover, ex vivo surgery

followed by hypothermic perfusion or perfusion

withorganpreservation solutions, suchasUniversity

of Wisconsin solution, Bretschneider’s Histidine-

Tryptophan-Ketoglutarate (HTK) solution, and

Euro-Collins solution, has been shown to prevent

renal dysfunction caused by ischemia-reperfusion

injury after renal artery reconstruction.7,9 By using

ex vivo vascular reconstruction and an organ pre-

servation solution, we were able to perform arterial

reconstruction with a good operative field without

the constraints of time limitation. By contrast, the

disadvantage of ex vivo repair is the elimination of

collateral blood flow.We speculate that this is one of

the reasons underlying the postoperative segmental

renal infarction at the upper pole.

In addition, we used laser-assisted ICG angio-

graphy to confirm the status of the reconstructed

vessels and the SPY system to verify substantial

renal perfusion. This laser-assisted ICG angiography

system enables fluorescent angiography through

ICG fluorescence (830 nm) by photoradiation laser

at 806 nm.10 The target vessels have been determi-

ned at a resolution of 570 � 485 TV line. Moreover,

this system can observe an area of 75 � 75 mL.

Recently, this system has been used to assess coro-

nary bypass grafts intraoperatively11,12 as well as

vascular reconstruction for parenchymal organ

transplantation.10,13 This technique can also assess

the quality of bypass graft similarly to standard

contrast angiography.14 As compared with contrast

angiography, the advantages of laser-assisted ICG

angiography lie in its ease of setting and avoidance

of nephrotoxicity. The laser-assisted ICG angio-

graphy system can be set up very easily, which

allows extra time to be used for the assessment of

graft patency for about 10 minutes, and there is no

need for any protective clothing. Duplex scanning is

another option for studying anastomosis in patients

with renal insufficiency. This procedure can eva-

luate the main renal artery, but it may become dif-

ficult to evaluate branches to the polar artery.

Moreover, there is a significant training and learn-

ing curve for individuals using duplex scanning,

which is not needed in ICG angiography. However,

laser-assisted ICG angiography also has some limi-

tations. The fluorescence signal is scattered by fat or

muscular tissue and false-positive defects may be

produced. Thus, target vessels should be skeletoni-

zed. Also, it can only visually assess quality of blood

flow. We believe that the combination of laser-

assisted ICG angiography and duplex scanning or

the use of an ultrasonic transit-time flow meter will

894.e8 Cas cliniques Annales de chirurgie vasculaire

complement the limitations of each technique and

enable the evaluation of the morphologic and

functional quality of the reconstruction.

Taken together, laser-assisted ICG angiography is

less invasive for preserving renal function, and

easier to use than angiography with iodine contrast

media. We consider that this technique might be

useful for the intraoperative evaluation of blood

perfusion without impairing renal function.

CONCLUSION

Ex vivo arterial reconstruction of intrahilar RAAs

using anorganpreservation solution is a safemethod

for preserving renal function. In addition, laser-

assisted ICG angiography is useful for the intraope-

rative evaluation of graft anastomosis and organ

blood perfusion without impairing renal function.

The authors are grateful to Assistant Professor Edward F.

Barroga and Professor J. Patrick Barron of the Department of

International Medical Communications of Tokyo Medical

University for reviewing the manuscript.

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