CASE REPORTS

Transcatheter embolization facilitating surgical management of a giant inferior gluteal artery pseudoaneurysm Steven C. Herber, MD, George M. Ajalat, MD , Douglas C. Smith, MD , David B. Hinshaw, Jr., M D , and J. David Killeen, Jr., M D , Loma Linda, Calif.

This article is a report on a case of a giant pseudoaneurysm of the inferior gluteal artery where important features of the diagnosis, with special mention of magnetic resonance imaging and arteriography, are discussed. Surgical therapy is the treatment of choice for these lesions. Historically, proximal arterial control has been the main dilemma in the management of gluteal artery pseudoaneurysm. We found transcatheter embolization to provide optimal control and eliminate the need for preperitoneal or intraabdominal dis- section. Surgical repair can then be carried out without risk ofintraoperative hemorrhage. (J VAsc SuRG 1988;8:716-20.)

Gluteal artery pseudoaneurysms are uncommon, with approximately 100 cases reported in the liter- ature. These pseudoaneurysms are usually posttrau- matic and can involve the superior or inferior gluteal artery. The fact that they may become clinically ev- ident many years after the injury may cause diagnostic confusion. The presence o f a firm buttock mass with a history o f trauma should alert the clinician to the correct diagnosis and avoid the potentially disaster- ous consequences o f an initial misdiagnosis. Herein we report a case o f large inferior gluteal artery pseu- doaneurysm. It illustrates the important features in diagnosis and the usefulness o f transcatheter embo- lization as an adjunct in the surgical management o f these cases.

CASE R E P O R T A 57-year-old man consulted his physician because of

a mass in his left buttock. He was treated conservatively with analgesics and heat. Progressive enlargement of the mass occurred over a period of 6 months, with the devel- opment of pain and paresthesia that radiated down the thigh. During an examination of the patient at Loma Linda University Medical Center, a 16 cm firm, tender mass was found, causing gross enlargement of the left buttock. The mass was noted to be pulsatile although no bruit or thrill was present. Medical history was remarkable for a gunshot

From the Departments of Surgery (Drs. Herber, Ajalat, and Kil- leen) and Radiology (Drs. Smith and Hinshaw), Loma Linda University Medical Center.

Reprint requests: George M. Ajalat, MD, Department of Surgery, Loma Linda University Medical Center, 11234 Anderson St., Loma Linda, CA 92354.

wound to the left leg and buttock 7 years previously. At that time he was treated for his orthopedic injuries of the lower leg, but no significant buttock hematoma was no- riced at that time. The small buttock wound was allowed to close by secondary intention.

Plain radiographs of the pelvis were unremarkable ex- cept for two bullets seen superimposed over the left is- chium. Magnetic resonance imaging (MRI) revealed an 8 x 16 cm mass in the left buttock. It consisted of a pe- ripheral zone of mixed high-signal-intensity material on T-1 and spin density images showing paramagnetic char- acteristics typical of resolving hemorrhagic components and a central zone of low signal with externally phase- shifted information typical for flow. These MRI findings are highly consistent with pseudoaneurysm (Fig. 1). Aortic flush angiography did not demonstrate the aneurysm. The left inferior gluteal artery was noted, however, to be asym- metrically enlarged (8 mm diameter). Because of this find- ing and because the MR/findings were so specific, a se- lective inferior gluteal arteriogram was obtained demon- strating the 8 cm diameter central portion of the aneurysm (Fig. 2). The aneurysm probably did not opacify on the initial aottogram because of the markedly slow flow within the left inferior gluteal artery. However, with selective cath- eterization of this vessel, opacification of the aneurysm was readily achieved. Transcatheter occlusion was accom- plished by use of five 8 mm diameter Gianturco (Cook Inc, Bloomington, Ind.) steel coils (Figs. 3 and 4).

Immediately after embolizaton the patient was taken to the operating room where a large, nonpulsatile pseu- doaneurysm was exposed through a muscle-splitting inci- sion in the gluteus maximus muscle. Incision into the pseu- doaneurysm was made posteriorly avoiding the sciatic nerve, which was displaced laterally. There was complete thrombosis of the embolized vessel and minimal backflow of blood from the distal portion of the inferior gluteal

Volume 8 Number 6 December 1988 Gluteal artery pseudoaneu~sm 717

Fig. 1. Spin density, weighted (TR = 2000 msec, TE = 35 msec), transverse MRI image through the buttocks. The 16 cm mass (large arrows) consists of a central low signal region (small arrows) having vertically phase shifted information (arrowheads) typical for flow and an irregular peripheral zone typical for thrombus and hemorrhagic products (other non-illustrated pulse sequence information is useful in completely establishing the presence of hemorrhagic material).

Fig. 2. Subtraction film of left inferior gluteal arteriogram demonstrates lumen (stra~qbt arrows) of pseudoaneurysm. The huge size of pseudoaneurysm is suggested by displaced proximal branches (arrowheads). Inferior gluteal artery (curved arrow) is markedly enlarged (8 mm diameter).

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Fig, 3. Plain radiograph immediately following embolization reveals five Gianturco steel coils (arrowhead) within inferior gluteal artery, proximal to pseudoaneurysm.

artery. Both ends of the vessel were ligated with suture inside the aneurysm sac, and a portion of the sac was ex- cised. Plication of the remaining sac was performed to eliminate the dead space. The procedure was accomplished with approximately 100 ml blood loss. The patient did well postoperatively and experienced complete relief of his pain and paresthesia at 2-month follow-up.

D I S C U S S I O N

Pseudoaneurysms of the gluteal arteries are rare. Whereas polyarteritis nodosa and bacterial infection have been implicated as causes, currently virtually all gluteal artery pseudoaneurysms are due to blunt or penetrating trauma. 1-s The superior gluteal artery is the largest branch of the internal iliac artery. As it exits the pelvis via the sciatic notch above the piri- formis muscle, it is most vulnerable to blunt trauma injury. The inferior gluteal artery is also vulnerable to blunt injury as it traverses the lower part of the sciatic notch. Penetrating trauma, on the other hand, may injure either artery anywhere along its course. 6

The diagnosis may be difficult because of the sub- tlety of presentation. A firm mass is present that may or may not be pulsatile. A history of trauma to the

area must increase the clinician's index of suspicion, even if the injury occurred several years previously.7 Gluteal pseudoaneurysms have been mistaken for ab- scess, sarcoma, lipoma, sciatic hernia, and ecchino- coccal cyst. 8,9 A misdiagnosis may have disastrous consequence for the surgeon who on exploration en- counters life-threatening hemorrhage. I°~2

Computed tomography may be helpful in the def- inition of the lesion. However, MKI is specific since it can demonstrate not only the flow characteristics within the aneurysm but also the typical paramag- netic effects of hemoglobin denaturation products within the layers of thrombus associated with the periphery of these lesions. A flush aortogram may not demonstrate the slow filling pseudoaneurysm; however, the feeding vessel may be dilated. Selective arteriography of this vessel will clearly outline the anatomy and provide the definitive diagnosis.

Therapy for this lesion is appropriately planned surgical intervention. ~s Historically, pseudoaneu- rysm of the gluteal artery has been a problem leading to great morbidity. This is primarily due to compli- cations resulting from attempted repair without ad-

Volume 8 Number 6 December 1988 Gluteal artery pseudoaneu~sm 719

Fig. 4. Internal iliac arteriogram immediately following embolization reveals abrupt occlusion of inferior gluteal artery adjacent to proximal coil (arrow). Pseudoaneu~sm no longer opacities.

equate preparation and control of arterial inflow. Since 1898 the concept of proximal control by li- gation or occlusion of the internal iliac artery via extraperitoneal or abdominal approach has remained unchanged. However, adequate proximal control is difficult to achieve by ligation of the internal iliac artery because of the extensive collateral circulation. Bttrchell 1~ found only a 48% decrease in the rate of flow in the internal iliac artery after proximal ligation of that artery. Transcatheter distal embolization, on the other hand, markedly decreases the potential for collateral flow into the involved artery. This provides for much more effective control than would be pro- vided by proximal ligation and eliminates the need for preperitoneal or intraabdominal dissection. Steel coils or inflatable balloons are the embolic agents of choice in vessels as large as this inferior gluteal artery (8 mm diameter). It should be noted that, even with excellent proximal control, distal backflow of blood via collateral can still occur. This is easily controllable by digital compression or insertion of a Fogarty bal- loon catheter if necessary.

With prompt recognition, use of correct diag-

nostic modalities, and appropriate transcatheter and surgical intervention, pseudoaneurysms of the gluteal artery can be easily deak with, keeping morbidity at a minimum and averting undesirable sequelae.

REFERENCES

1. Williams W Jr, Jackson GF Jr, Greene C. Superior gluteal artery aneurysm. J Trauma 1977;17:477-9.

2. Gostigian J, Schlitt RJ. Aneurysm of the gluteal artery sec- ondary to polyarteritis nodosa. Am J Surg 1963;105: 267-8.

3. CuUiford AT, Cukingham RA, Worth MH. Aneurysms of the gluteal vessels: their etiology and management. J Trauma 1974;14:77-81.

4. Willett E. Embolic aneu~sm of gluteal artery. Lancet 1890;1:403-4.

5. Benjamin j'E, Lachman GS. A case of mycotic aneuusm of the gluteal artery. JAMA 1924;82:1861-2.

6. Smith K, Ben-Menachem Y, Duke JH, Hill GL. The superior gluteah an artery at risk in blunt pelvic trauma. J Trauma 1976;16:273-9.

7. Htdtborn KA, Kjellman T. Gluteal aneurysm report of 3 cases and review of the literature. Acta Chir Scand 1963; 125:318- 28.

8. Smyth NPD, Rizzoli HV, Ordman CW, Khoury JN, Chiocca JC. Gluteal aneurysm. Arch Surg 1965;91:1014-20.

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9. Proschek R, Fowles JV, Bruneau L. A case of posttraumatic false aneurysm of a superior gluteal artery with compression of sciatic nerve. Can J Surg 1983;26:554-5.

10. Deitch HI, Lond MS. Gluteal aneurysm. Lancet 1937; 1:1516.

11. Frost HM. Ligature of the left hypogastric artery for trau- matic gluteal aneurysm. Lancet 1916;2:942-3.

12. Smith RB. Spontaneous rupture of a superior gluteal artery aneurysm. Injury 1981;12:343-5.

13. Meek GN, Hill RL. Surgical treatment of gluteal artery an- eurysms. Am J Surg 1968;116:731-4.

14. Burchdl RC. Physiology of internal iliac artery ligation. J Obstet Gynaecol Br Commonw 1968;75:642-51.

T H E E. J. WYLIE T R A V E L I N G F E L L O W S H I P OF T H E E D U C A T I O N A L FOUNDATION OF THE SOCIETY FOR VASCULAR SURGERY

The Educational Foundation of the Society for Vascular Surgery (with financial assistance from W. L. Gore & Associates, Inc.) has established an E. J. Wylie Traveling Fellowship.

The purpose o f the Fellowship is to enable young surgeons to visit centers o f excellence in vascular surgery in the United States and abroad. The benefits of educational travel for the maintenance and enhancement of excellence in the practice of vascular surgery are obvious.

To be considered for selection a candidate must: 1. Be younger than 40 years of age at the time the traveling fellowship is awarded 2. Have completed a postgraduate vascular training program or have considerable experience

in vascular surgery supplemental to general surgical training 3. Be committed to an academic career in vascular surgery and have obtained an academic

appointment in a medical school or freestanding clinic devoted to excellence in medical education

4. Have a demonstrated record of success in pursuing clinical or basic science research sufficient to achieve academic excellence in his or her pursuit of a career in vascular surgery

Selection will be made without regard to the candidate's geographic location. A candidate submitting documentation for consideration for selection must fumish an up-

to-date curriculum vitae and a list of publications, research projects, current research support, and a list of the centers that hc or she wishes to visit. Three letters of recommendation are required, including one from the Division Head and another from the Chairman of the De- partment o f Surgery of the institution in which the candidate holds a faculty appointment. A 500-word essay describing the objectives of the candidate's travel plans and linking these to his or her career goals must be appended.

The first Selection Committee has been appointed and consists of John Bergan, Chairman, and members Henry Bahnson, Ben Eiseman, Robert Hobson, Ronald Stoney, and James Yao. The incumbent Recorder o f the Society for Vascular Surgery will serve as an ex officio member of the Committee. The length of service of each of the members of the Committee and future members of the Committee will be determined by members of the Council of the Society for Vascular Surgery.

The Travel Fellowship Award is $10,000, granted to one person for use during a time limit and for an itinerary to be arranged by agreement between the awardee and the Committee.

Application for the Fellowship award shall be made in a letter containing the information and documents as detailed. The deadline for receiving applications is March 1, 1989. Letter of nomination or intent should be directed to:

Ronald J. Stoney, M.D., F.A.C.S. Chairman, E. J. Wylie Traveling Fellowship Committee Division of Vascular Surgery University o f California Medical Center 505 Parnassus Ave., M-488 Chicago, IL 60611