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The indications for endovascular aneurysm repairhave been extended since first described byParodi and colleagues.1 Although initiallydesigned for simple infrarenal aortic aneurysm

repair, the development of bifurcated, modular, and cus-tom-made grafts has extended the use of this technologyto allow inclusion of different and challenging aorticanatomies and pathologies, including aortoiliacaneurysms, internal iliac aneurysms, as well as emergentruptured aneurysms and aortoenteric fistulas.2-5

Aortic pseudoaneurysm resulting from infiltratingmetastatic choriocarcinoma is a relatively rare entity,with a reported incidence of three cases in the literaturein which these patients were mainlymanaged surgically.6-8

We report an unusual case of apatient with aortic pseudoaneurysmsecondary to metastatic choriocarci-noma, in which the aortic defect wasmanaged with a custom-made aorticgraft.

CA SE REPORTA 25-year-old man presented to

the emergency department with 4weeks of lower right back pain. Onsuspicion of ureteric colic, a comput-ed tomography (CT) scan was per-

formed and showed large enhancing necrotic masslesions in the retroperitoneum with compression of theinferior vena cava and right-sided hydronephrosis. A tes-ticular lump was palpated. Scrotal ultrasound showed acomplex cystic mass measuring 6 mm in diameter withinthe right testicle and bilateral testicular microlithiasis. CT-guided lymph node biopsy of the retroperitoneal mass inthe right iliac fossa was performed where histopathologi-cal examination showed choriocarcinoma, with nodemonstration in the sample of other germ cell types.Before establishing chemotherapy, the patient was takento the endovascular suite where a ureteric JJ stent(Boston Scientific Corporation, Natick, MA) was placed

Managing AorticPseudoaneurysm

Caused by MetastaticChoriocarcinoma

A case in which a custom-made graft is used to successfully treat an unusual aortic defect.

BY BIBOMBE P. MWIPATAYI, MMED (SURG), FCS (SA), CERT VASC SURG (SA), FRACS;

SHANNON THOMAS, BMEDSC (HONS), MBBS (HONS); SARAH NORTON, MBBS;

AND VIKRAM VIJAYAN, MBCHB, MRCS, FRCS

Figure 1. Axial slice (A) and sagittal slice (B) of a preoperative CT angiogram taken

of the patient with aortic pseudoaneurysm secondary to choriocarcinoma.

Contrast extravasation into the tumor mass from the aorta is demonstrated on

arterial phase imaging.

A B

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in the obstructed ureter. Chemotherapy(cisplatin and etoposide) was started,and the patient was found to be severelyneutropenic. Because serial CT scan andultrasound determined that the lesionwas stable, he was kept in the ward untilthere was an improvement in his bloodcells. However, the patient’s course wascomplicated by respiratory failure withchest and abdominal pain.

This prompted a CT scan and ultra-sound examination of the chest andabdomen. Cannonball metastases to thelungs were evident. The large retroperi-toneal necrotic mass (5.9 X 8.9 cm) inthe abdomen was stable in size, but ananterior aortic defect was demonstratedwith contrast extravasation into theretroperitoneal tumor mass. The com-munication measured 6 to 8 mm indiameter and was situated approximate-ly 30 mm below the renal arteries. Theinferior mesenteric artery originated 18mm distal to the communication. Thedistal aorta and common iliac arteries appeared smoothwalled and free from tortuosity. The proximal landingzone aortic diameter was 15.2 mm, and the distal landingzone diameter was 15.6 mm. The external iliac arteriesappeared smooth walled, free from any tortuosity, andmeasured 7 to 8 mm in diameter (Figure 1). An ultra-sound performed at the time demonstrated a pseudo-aneurysm with a wide neck.

The patient was initially assessed for open surgicalrepair. He was noted to have responded well to resuscita-tive measures and was hemodynamically stable. He con-currently had a pancytopenia with profound neutropeniaon blood laboratory examination secondary to hischemotherapy. Despite widespread metastases, thepatient was given a good prognosis by the oncologicalmedical team. It was therefore believed that the patientshould be managed expectantly, and an endovasculargraft was planned to manage the aortic injury when thepatient was medically fit for intervention.

PROCEDUR AL DETAIL SA custom-made graft was developed in conjunction

with Cook Medical (Brisbane, Australia) based on thebasic Zenith Flex system. This consisted of a stainless steelstent tube graft with fabric made from woven Dacron.The graft was sized to seal in the infrarenal aorta proxi-mally and above the aortic bifurcation distally. Nosuprarenal fixation or barbs were employed in the device,

with the graft to be delivered via an 18-F introducer system that has an outerdiameter (OD) of 7.1 mm (21.5 F)(Figure 2).

Although an open approach was con-sidered, due to the availability of ahybrid endovascular suite and thepatient’s preference, the procedure wasperformed via percutaneous access withcomplete exclusion of the falseaneurysm (Figure 3). Unfortunately, theright common femoral artery wasoccluded on the final angiogram, and itwas believed that the vessel had dissect-ed due to the size of the delivery device.Given the patient’s young age, the deci-sion was made to repair this dissectionvia open vein patch angioplasty, wherevein was harvested from the left arm.

Postoperatively, the patient recoveredwell with no complications. He recom-menced chemotherapy 1 week postop-eratively and was later dischargedhome. At 4-month follow-up, a CT scan

showed that there was no evidence of contrast extrava-sations and that the stent graft was in satisfactory posi-tion. The tumor had decreased in size and vascularity(Figure 4).

DISCUSSIONChoriocarcinoma of testicular origin is one of many

subtypes of germ cell tumors that, although being rare(occurring in 1% to 2% of all malignancies affectingmales), are the most common malignancy affectingmales aged 15 to 35.9

Pure choriocarcinoma is the rarest form of testiculartumor, with (in order of frequency) seminoma, embryon-ic tumor, teratocarcinoma, and teratoma being morecommon. Choriocarcinoma metastasizes early viahematogenous routes to the brain, lungs, and liver andusually presents via clinical manifestations of metastaticdisease. The testicular primary tumor in such cases maybe small and “burned-out.” Most germ cell tumorsrespond well to radiotherapy and cisplatin-basedchemotherapy. Surgery for pure choriocarcinoma is limit-ed to radical orchiectomy for tissue diagnosis.10

Degenerative changes of the vessel wall or secondary ero-sion by the adjacent tumor into the aorta are believed torepresent the mechanism of pseudoaneurysmformation.11

The literature generally reports that malignant tumorscause life-threatening bleeding that may occur via aor-

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30 I ENDOVASCULAR TODAY I APRIL 2010

Figure 2. A custom-made tube

graft (Cook Medical).This is an

18-mm-diameter tube graft with

a length of 74 mm, planned to

land immediately below the

renal arteries with vessel cover-

age to the distal aorta.

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toenteric fistula formation.6 Pseudoaneurysm formationis a rare presentation of neoplastic invasion of the aorta12

in relation to aortic injury. Hansen and colleagues describe endovascular repair of

an aortoenteric fistula caused by choriocarcinoma pre-senting with life-threatening hemorrhage. Although ini-tially technically successful, the patient later died fromaortic bleeding secondary to further necrosis and deteri-oration of the aortic wall.6 Open surgical approachesdescribed for aortic invasion include en bloc resection ofthe aorta with replacement with Dacron graft.13

Treatment options for the aortic defect in our patientincluded conservative management, open surgery, andendovascular surgery. Conservative management was ini-tially chosen to allow forimprovement in the patient’sgeneral medical condition,where it was believed therisk associated with an inter-vention in a patient withpancytopenia would haveoutweighed the benefits ofaneurysm exclusion. Opensurgery was considered forthe patient; however, theretroperitoneal tumor wasbelieved to be too extensivewith disease noted deep inthe pelvis, as well as encasingthe pancreas, superior

mesenteric artery, and inferior vena cava. Complete mar-gin-free tumor resection would not have been possible,and dissection of the tumor off the aorta would havebeen difficult and not without risk.

The use of a balloon-expandable stent was also consid-ered, but the angiographic impression that the balloongives as it inflates with the proximal and distal ends,known as the “dog bone effect,”14 was considered a prob-lem in this patient, because the uncovered expandingballoon could damage the already friable aorta and cre-ate further problems. This could lead to further disrup-tion of the aortic wall and/or a possible complete aorticrupture. Endovascular treatment was deemed challeng-ing.

In making our decision regarding therapy, we notedcase reports by Hansen et al6 and Yang et al,15 whichdemonstrated that a malignant process causing a defectin the aortic wall may not only cause wall degenerationat the site of pseudoaneurysm or aortoenteric fistula butthat a larger surrounding segment of the aortic wall maybe affected by the degenerative/invasive process. For thisreason, simple coiling and injection of the defect was notfelt to be a viable methodology to give the patient long-term protection from further aortic degeneration (par-ticularly in light of ongoing chemotherapy and expectedtumor necrosis). Although a balloon-expandable stentwould also allow coverage of a large area of aorta, it wasfelt that the risk of dog-boning the presumed friableaorta was too great; although the aortic diameter didlook normal, it was considered that it was weakened bythe tumor. It was important that ballooning should bestrictly inside the stent to avoid further damage of theaortic wall. The stent used was depleted of any hooks toavoid any catastrophic complication. Because of thedimensions of the nonaneurysmal aorta, an “off-the-shelf” graft would have been difficult to deploy. Also, it

Figure 3. Completion angiogram demonstrating in situ endo-

luminal graft with no endoleak or contrast extravasation out-

side the graft in the infrarenal aorta.

Figure 4. Axial slice (A) and coronal slice (B) of a postoperative CT angiogram.There is com-

plete exclusion of the false aneurysm and satisfactory position of the stent graft with reduc-

tion in size and vascularity of the surrounding tumor.

A B

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was believed that suprarenal fixation was not necessaryand that barbs may have caused further injury to thealready friable aorta. For these reasons, a custom-madegraft was designed that was essentially a simple Dacrontube stent graft without barbs or suprarenal fixation.

The dissection of the common femoral artery was feltto occur due to the large size of the delivery device andrelatively small artery, despite appearing as an acceptablediameter on initial imaging. This problem would havebeen overcome via design of a smaller delivery device;however, such design may be limited by the use of stain-less steel stents.

Finally, completion angiography revealed completeexclusion of the pseudoaneurysm from the circulationwith no evidence of endoleak. As per our protocol formonitoring patients after endoluminal repair of abdomi-nal aortic aneurysm, the patient will have clinical andradiological review (CT scan or duplex ultrasound) on anannual basis to look for the presence of endoleak, as wellas the development of a new pseudoaneurysm. This willbe particularly important because the tumor necroseswith chemotherapeutic treatment.

CONCLUSIONMalignancy resulting in aortic pseudoaneurysm is rare

and presents a difficult management problem for the sur-geon. We have presented a case of successful endolumi-nal management of an aortic defect resulting from malig-nant invasion and degeneration of the aortic wall. Theuse of a custom-made graft allowed for exclusion of thediseased aorta and preservation of distal blood supplywith minimal morbidity to the patient. n

Bibombe P. Mwipatayi, MMed (Surg), FCS (SA), Cert VascSurg (SA), FRACS, is an endovascular surgeon with theDepartment of Vascular Surgery at Royal Perth Hospital,Professor of Surgery at the School of Surgery, and Faculty ofMedicine, Dentistry, and Health Sciences at the Universityof Western Australia in Perth, Australia. He has disclosedthat he holds no financial interest in any product or manu-facturer mentioned herein. Dr. Mwipatayi may be reachedat +61-8-9224 0228; bibombe@iinet.net.au.

Shannon Thomas, BMedSc (Hons), MBBS (Hons), is avascular fellow with the Department of Vascular Surgery atRoyal Perth Hospital in Perth, Australia. Dr. Thomas hasdisclosed that he holds no financial interest in any productor manufacturer mentioned herein.

Sarah Norton, MBBS, is a resident with the Departmentof Vascular Surgery at Royal Perth Hospital in Perth,Australia. Dr. Norton has disclosed that she holds no finan-cial interest in any product or manufacturer mentionedherein.

Vikram Vijayan, MBChB, MRCS, FRCS, is a senior vascu-lar fellow with the Department of Vascular Surgery at RoyalPerth Hospital in Perth, Australia. Dr. Vijayan has disclosedthat he holds no financial interest in any product or manu-facturer mentioned herein.

1. Parodi JC, Palmaz JC, Barone HD. Transfemoral intraluminal graft implantation forabdominal aortic aneurysms. Ann Vasc Surg. 1991;5:491-499.2. Greenberg RK, West K, Pfaff K, et al. Beyond the aortic bifurcation: branched endovasculargrafts for thoracoabdominal and aortoiliac aneurysms. J Vasc Surg. 2006;43:879-886; dis-cussion 886-887.3. Tielliu IF, Bos WT, Zeebregts CJ, et al. The role of branched endografts in preserving inter-nal iliac arteries. J Cardiovasc Surg (Torino). 2009;50:213-218.4. Verhoeven EL, Tielliu IF, Bos WT, et al. Present and future of branched stent grafts in tho-raco-abdominal aortic aneurysm repair: a single-centre experience. Eur J Vasc EndovascSurg. 2009;38:155-161.5. Veith FJ, Lachat M, Mayer D, et al. Collected world and single center experience withendovascular treatment of ruptured abdominal aortic aneurysms. Ann Surg. 2009;250:818-824.6. Hansen KS, Sheley RC. Aortoenteric fistula in advanced germ cell tumor: a rare lethalcomplication. J Urol. 2002;167:2131.7. Kelly R, Skinner D, Yellin AE, et al. En bloc aortic resection for bulky metastatic germ celltumors. J Urol. 1995;153:1849-1851.8. Napolitano L, D’Aulerio A, Gargano E, et al. Clinical study of aortic co-involvement inlumbo-aortic lymph node metastasis of testicular carcinoma. G Chir. 2003;24:231-234.9. Mostofi FK, Sesterhenn IA. Anatomy and pathology of testis cancer. In: Vogelzang N, ed.Comprehensive Textbook of Genitourinary Oncology. Baltimore, MD: Williams and Wilkins;1996: 956-958.10. Ramón y Cajal S, Piñango L, Barat A, et al. Metastatic pure choriocarcinoma of the testisin an elderly man. J Urol. 1987;137:516-519.11. Smith BL, Munschauer CE, Diamond N, et al. Ruptured internal carotid aneurysm result-ing from neurofibromatosis: treatment with intraluminal stent graft. J Vasc Surg.2000;32:824-828.12. Sueyoshi E, Sakamoto I, Nakashima K, et al. Visceral and peripheral arterial pseudoa-neurysms. AJR Am J Roentgenol. 2005;185:741-749.13. Kelly R, Skinner D, Yellin AE, et al. En bloc aortic resection for bulky metastatic germ celltumors. J Urol. 1995;153:1849-1851.14. Hehrlein C, Devries J, Arab A, et al. Role of the "Dogbone" effect of balloon-expandablestents: quantitative coronary analysis of DUET and NIR stent implantation introducing a novelindexing system. J Invas Cardiol. 2002;14: 59-65 15. Yang DM, Yoon MH, Kim HS, et al. Interrenal pseudoaneurysms complicating renalchoriocarcinoma metastases: treatment with coil embolization. Clin Imaging. 2000;24:217-220.

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