Surg Today Jpn J Surg (1997) 27:376-378

~ © Springer-Verlag 1997

S U R G E R Y T O D A Y

False Aneurysm of the Axillary Artery Caused by Graft Infection: Report of a Case

KAZUO YAMAMOTO, TAKAO YOSHIMURA, and SHIN-ICHI OHTANI

Department of Cardiothoracic Surgery, Mito Saiseikai Hospital, 3-3-10 Futabacho, Mito City, Ibaraki 311-41, Japan

Abstract: A 77-year-old man presented to our hospital follow- ing the sudden onset of left subclavicular swelling, 8 years after undergoing subtotal removal of an axillofemoral bypass. Computed tomography revealed a rupture of the left axillary artery with the formation of a false aneurysm. Emergency surgery was performed in the form of an extraanatomic, axillo-axillary bypass with resection of the false aneurysm. Prior to removal of the false aneurysm, the subclavian artery was ligated via a left thoracotomy to minimize blood loss. The pathogen was identified as Proteus mirabilis, which is a rare causative organism for prosthetic graft infection. This case report demonstrates that total removal of the graft with revascnlarization should be performed for graft infections.

Key Words: prosthetic graft infection, false aneurysm, anasto- motic aneurysm, extra-anatomic bypass, axillofemoral bypass

Introduct ion

Despite advances in graft materials and vascular surgi- cal techniques, prosthetic graft infections remain a seri- ous problem. As most graft infections occur in the groin region, 1,2 graft infections requiring revascularization of the upper extremity are rare. We report herein a case of an infected false aneurysm of the axillary artery caused by rupture at the anastomotic site.

Case R e p o r t

A 77-year-old man was admitted to the emergency de- partment of our hospital with pain and swelling in the

Reprint requests to: K. Yamamoto, Department of Thoracic and Cardiovascular Surgery, Niigata University School of Medicine, 1 Asahimachi-dori, Niigata 951, Japan (Received for publication on Feb. 1, 1996; accepted on July 4, 1996)

left subclavicular region. At the age of 66 years, he had undergone a left axillofemoral (Ax-F) bypass for arteriosclerotic occlusive disease at another hospital, but due to poor runoff, it had occluded, and a left above-knee amputation had been performed the fol- lowing month. At the age of 69 years, the occluded Ax-F graft had been removed as a result of graft infec- tion, except for some small remnants at the anastomotic sites. The right leg had then also been amputated at the age of 76 years due to the progression of atherosclerotic disease. On admission, the patient's blood pressure was 160/80mmHg; pulse rate, 120 beats/rain; and tem- perature, 37.8°C. There was a warm, erythematous pul- sating mass, 7.5 × 6 cm in size, in the left subclavicular region. Laboratory data revealed leukocytosis, with a white blood cell count of 12900/gl, and an elevated C-reactive protein level of 18.3mg/dl. Computed tomography (CT) revealed a rupture of the left axillary artery with the formation of a false aneurysm (Fig. 1). The abdominal aorta was totally occluded below the renal arteries.

Following rehydration, an emergency operation was performed under the diagnosis of false aneurysm of the axillary artery caused by infection of the remnant Ax-F graft. An extraanatomic, right axillo--left axillary by- pass using a woven Dacron graft (Hemashield 8ram, Meadox Medicals,Oakland, NJ, USA) was performed with the patient in the supine position. First, a left thoracotomy was performed and the left subclavian ar- tery was ligated just distal to the origin of the vertebral artery and the internal thoracic artery to interrupt the antegrade blood flow to the rupture site. The patient was then placed in the supine position, and a left subcla- vian incision was made. Following removal of a small amount of purulent fluid and thrombus, the remnant Dacron graft was noted to be detached hemicircularly. The remnant graft was removed, and the opening of the axillary artery was sutured with a 4-0 polypropylene suture both proximally and distally. The pathogen was

K. Yamamoto et al.: False Aneurysm of the Axillary Artery 377

Fig. 1. Enhanced computed tomogram demonstrating rup- ture of the axillary artery and formation of a false aneurysm

Fig. 2. Postoperative intravenous digital subtraction angi- ography showing a patent extra-anatomic bypass (arrows)

identified as Proteus mirabilis in both the purulent fluid and the remnant graft.

The patients' postoperative course was uneventful. A postoperative intravenous digital subtraction anglo- gram revealed sufficient flow to the left axillary artery through the extra-anatomic bypass (Fig. 2).

D i s c u s s i o n

Although there have been some reports on disruption of an axillary anastomosis, 3 the occurrence of false an- eurysms of the axillary artery due to graft infection requiring revascularization of the upper extremity has rarely been documented in the literature. Gaylis re-

ported 36 prosthetic-related anastomotic aneurysms, 4 among which there was no case of a subclavian-axillary aneurysm. Yeager et al., in a report on 14 aortic and 11 peripheral graft infections, most of which occurred in the groin region, 2 stated that the mean interval between the bypass operation and the onset of graft infection was 35 weeks, and the mortality rate was 36 percent? In our patient, the time span from the first operation to subtotal graft removal due to infection was 3 years, and the disruption of the remnant graft occurred 8 years following the subtotal excision. When graft infec- tion occurs, a subtotal, rather than a total, graft excision might be performed more safely in the critically ill patient. However, Yeager et al. reported that perform- ing partial graft removal in three patients with periph- eral graft infection yielded unsuccessful results. 2 Therefore, complete graft removal should be per- formed, whenever possible, for the prevention of recur- rent infection.

Staphylococci and Streptococci are the most common causative microorganisms of graft infection, 5 whereas gram-negative rods such as the Proteus mirabilis as seen in our patient are relatively rare. Although Proteus mirabilis is one of the Enterobacteriaceae, it sometimes causes extraintestinal infections. 6 The source of the organism in this patient was unknown; however, his advanced age, the fact that a right leg amputation had been performed the year before, and poor nutrition were all considered to be contributory factors.

The treatment of graft infection involves removal of the graft and revascularization. It is important that re- moval of the graft without construction of an alternative bypass be avoided because it is associated with a greater incidence of limb loss and a high mortality rate. With respect to the surgical procedure, it may be preferable to ligate the subclavian artery first through a left thoracotomy, then construct an extra-anatomic bypass and excise the false aneurysm, to shorten the operative time. However, in our patient we performed the extraanatomic bypass initially to preserve a sterile op- erative field.

R e f e r e n c e s

1. Goldstone J (1989) Infected prosthetic grafts. In: Haimovici H (ed) Vascular surgery, 3rd edn. Appleton and Lange, Norwalk, pp 564- 574

2. Yeager RA, McConnell DB, Sasaki TM, Vetto RM (1985) Aortic and peripheral prosthetic graft infection: Differential management and causes of mortality. Am J Surg 150:36-43

3. Taylor LM, Park TC, Edwards JM, Yeager RA, McConnel DC, Moneta GA, Porter JM (1994) Acute disruption of polytetrafluoroethylene grafts adjacent to axiHary anastomoses: A complication of axillofemoral grafting. J Vasc Surg 20:520- 528

378 K. Yamamoto et al.: False Aneurysm of the Axillary Ar te ry

4. Gaylis H (1981) Pathogenesis of anastomotic aneurysms. Surgery 90:509-515

5. Goldstone J, Bowersox JC (1996) Infected prosthetic arterial grafts. In: Haimovici H (eds) Vascular surgery, 4th edn. Blackwell Science, Cambridge, pp 725-739

6. Farmer JJ, Kelly MT (1991) Enterobacteriaceae. In: Balows AB, Hausler WJ, Herrmann KL, Isenberg HD, Shadoney HJ (eds) Manual of clinical microbiology, 5th edn. American Science for Microbiology, Washington, pp 360-383