INTRODUCTIONRenovascular injury is a well-recognized complication of percu-

taneous renal procedures such as renal biopsies, percutaneous

nephrostomy (PCN) and percutaneous nephrolithotomy (PCNL).

Needle injury of a branch of the renal artery may result in the

formation of a pseudoaneurysm or an arteriovenous fistula

(AVF). The high-pressure leak from a lacerated artery is trans-

mitted through the tract into a lower resistance system of a vein or

a connective tissue space, such as is found around the pelvis or

calyces. A CT examination immediately following renal biopsies

has revealed haematomas in 90% of cases;1 whereas renal

angiography performed immediately after renal biopsies has

shown haematomas in 23%, arteriovenous fistulas in 8%, and

renal infarcts in 6% of patients.2 Most of these lesions close

spontaneously, but a few remain open and slowly increase in

size, leading to life-threatening haematuria that requires thera-

peutic intervention.

Iatrogenic lumbar arterial injuries related to percutaneous

renal procedures are very rare and may go undetected because

of a problem in the localization of the accompanying haemor-

rhage.3–5 A case of pseudoaneurysm of a lumbar artery

following vertebral biopsy has also been reported.6 We describe

here a case of lumbar artery pseudoaneurysm following PCNL,

which required intra-arterial embolization of the lumbar artery

using a metallic coil and gel foam particles.

CASE REPORTA 45-year-old man presented with significant haematuria of 10

days duration following left PCNL. Before the procedure his

blood pressure was 140/90 mmHg, and his bleeding and

coagulation parameters were normal; that is, prothrombin time

(PT) was 13.6 s (control 12.8 s), partial thromboplastin time

(PTT) was 30 s (control 27 s) and platelet count was 500 �

109/L. Six hours after an uneventful procedure, the patient

complained of pain in the lumbar region and started having

haematuria. Ultrasound examination revealed a left hydro-

nephrosis with residual calculi and hyperechoic medium level

echoes, which suggested clots in the collecting system. The

haematocrit dropped from 39 to 25%. Even after an infusion of

six units of blood and four packs of platelets, the patient

continued to have haematuria; hence, the patient was referred

for an angiographic evaluation.

A selective left renal angiogram obtained via a right

transfemoral artery route showed a main renal artery supplying

the upper and midpolar regions of the left kidney along with

incidental reflux of contrast into the first left lumbar artery. A

small pseudoaneurysm was seen overlapping the midpolar

region of the kidney (Fig. 1) and, on fluoroscopy, was seen not

to move with the kidney in different phases of respiration.

Selective injection of the left first lumbar artery revealed a small

pseudoaneurysm filling from it. No radiculomedullary artery

Case Report

Intra-arterial embolization of lumbar arterypseudoaneurysm following percutaneousnephrolithotomyR Jain, S Kumar, RV Phadke, SS Baijal and RB GujralDepartment of Radiodiagnosis, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

SUMMARY

The management of a patient with haematuria following percutaneous nephrolithotomy is described. The patientunderwent renal angiography to assess the cause of bleeding. A pseudoaneurysm arising from first left lumbar arterywas incidentally discovered, which was then successfully embolized using an indigenously fabricated metallic coil andgel foam particles in the same sitting.

Key words: Lumbar artery embolization; percutaneous nephrolithotomy; pseudoaneurysm.

R Jain MD; S Kumar MD; RV Phadke MD; SS Baijal MD; RB Gujral MD.

Correspondence: Dr Sunil Kumar, Additional Professor, Department of Radiodiagnosis, Sanjay Gandhi Post-Graduate Institute of Medical Sciences,

Rae Bareily Road, Lucknow, UP 226014, India. Email: sunilk@sgpgi.ac.in

Submitted 15 October 1999; resubmitted 22 February 2000; accepted 5 April 2000.

Australasian Radiology (2001) 45, 383–386

(artery of Adamkiewicz) was seen originating from the first left

lumbar artery. An accessory renal artery arising from the aorta

at L3–4 level was seen supplying the lower polar region of the

left kidney and no intrarenal vascular lesion could be detected.

This pseudoaneurysm was embolized first with an injection

of gel foam particles using a 5 F multipurpose catheter. A small,

indigenously fabricated metallic coil, measuring 2 mm in dia-

meter and 12 mm in length, was then placed in the lumbar

artery followed by a gel foam pledget to occlude the artery

completely. Post-embolization check aortogram revealed no

flow into the left first lumbar artery and no filling of the

pseudoaneurysm (Fig. 2). The patient had pain in the lumbar

region, which settled with analgesics, but had no neurological

deficit. The heamaturia decreased after embolization, but after

three days the patient again underwent angiographic evaluation

as the haematuria persisted. Repeat examination did not reveal

any vascular lesion and the haematuria settled completely after

four days.

DISCUSSIONThe first four lumbar arteries are usually paired arteries and

arise from the posterior aspect of the aorta. The fifth lumbar

artery is usually small in size and may originate from the median

sacral artery. Immediately after arising from the aorta, the

lumbar arteries curve around the bodies of the lumbar

vertebrae and give rise to small retroperitoneal branches to the

psoas muscle and to the spinal artery before dividing into

anterior and posterior branches.

The anterior branch gives branches to the quadratus

lumborum and sacrospinalis muscle as it runs between them,

and then branches to the muscles and skin of the flank. The

posterior branch supplies branches to the sacrospinalis muscle

and skin of the back. These muscular branches running dorsal

to the kidney are susceptible to injury during percutaneous

renal procedures as well as during percutaneous vertebral

biopsy. Accumulation of blood in the posterior pararenal space

should suggest lumbar artery injury because of its close

proximity to the lumbar arteries.

The reported incidence of renal pseudoaneurysm is 0.6–

1.0% following PCNL,7,8 and 2.0–3.4% following percutaneous

needle biopsy of a renal allograft.7–9 Deaths secondary to

bleeding have occurred in 0.07–0.17% of cases.10 However,

there are only three reported cases of lumbar artery injury

following renal biopsies and none following PCN or PCNL. In the

384 R JAIN ET AL.

Fig. 1. (a) Selective left renal arteriogram shows a small pseudoaneurysm (arrow) overlapping the midpolar region along with reflux of contrast into

the first left lumbar artery. (b) Nephrographic phase shows filling of the first left lumbar artery and the pseudoaneurysm.

385LUMBAR ARTERY PSEUDOAENURYSM

first reported case, the exact site of haemorrhage was difficult to

localize even at surgical exploration.3 In the second case report,

there were two sites of haemorrhage: (i) from a branch of the left

renal artery, which was successfully controlled by embolization;

and (ii) from the left fourth lumbar artery, which was identified

two days after initial embolization. Even after successful

embolization of the lumbar artery bleeding with gel foam

pledgets, the patient developed fatal complications from

prolonged hypotension.5 In the third case, initial abdominal

aortograms did not reveal any vascular lesion, while a repeat

oblique aortogram demonstrated contrast extravasation from

the first left lumbar artery, which was embolized using two

straight microcoils.4 In the present case, a lumbar artery

pseudoaneurysm was detected incidently because of reflux of

contrast material into the lumbar artery while obtaining a renal

arteriogram to look for some renal vasculature abnormality. All

these cases demonstrate that lumbar arterial injury following

percutaneous renal procedures is difficult to detect. Hence,

clinical suspicion of lumbar arterial injury should be high, and

angiograpy considered in appropriate cases.

Intra-arterial embolization for traumatic arterial bleeding may

be considered if the injured vessel is expendable or if the vessel is

surgically inaccessible or difficult. Lumbar arterial injury meets

both of these characteristics in most situations. Operative control

of lumbar arterial bleeding is often difficult because the site

of origin may not be readily isolated. Although embolization

appears to be a relatively safe and successful method of obtain-

ing haemostasis, it is not without complications. Spinal cord and

peripheral nerve infarction are the major complications. The

lumbar artery should be scrutinized carefully for major spinal

branches, such as the great anterior radicular artery (artery of

Adamkiewicz). It may arise anywhere from sixth intercostal to the

second lumbar artery and has the characteristic angiographic

configuration of a hair pin.However, it may be difficult to depict the

great radicular artery angiographically, even on selective lumbar

injections. Digital subtraction techniques, however, can greatly

enhance its delineation. Spinal cord injury can occur even during

diagnostic angiography. Thus, forceful injection of too much

contrast medium, particularly through a catheter wedged in the

lumbar artery giving rise to a radiculomedullary artery, should be

avoided. Placing the tip of the catheter distal to the spinal

branches of the lumbar artery before embolization may decrease

the risk of spinal cord or nerve root infarction. Embolic particle

size also should be large enough to preclude embolization of the

small radicular branches that supply the cord and the roots.Small

vessel occlusives such as cyanoacrylate or alcohol should not

be used because they defeat the purpose of vascular occlusion

in traumatic bleeding; that is, to facilitate haemostasis without

unnecessarily infarcting otherwise healthy tissue.11 Acute para-

spinal muscle infarction following lumbar artery embolization

has also been reported.12 Metallic wire coils of 12 mm in

length and 2 mm in diameter are compatible with the diameter

of the typical lumbar artery and can be used, as was done

successfully in the present case, along with gel foam particles

and pledgets.

In summary, lumbar artery injury following percutaneous

renal procedures is a rare occurrence and should be con-

sidered while doing angiography, especially if no intrarenal

vascular injury is seen. Once detected it can be embolized in the

same sitting after identifying and avoiding the radiculomedullary

feeders, if any.

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Fig. 2. Post-embolization aortogram shows non-filling of the first left

lumbar artery and the pseudoaneurysm with metallic coil (arrow) at

L1 level.

386 R JAIN ET AL.

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