An unusual case of aortic graft infection: a case report and review of the literature

LH Moyes, B Majumder, DP Leiberman 

Department of Vascular Surgery, Glasgow Royal Infirmary, 84 Castle Street, Glasgow, G4 0SF   

Address for Correspondence: Miss LH Moyes Email: lisa_moyes@hotmail.com

SMJ 2007 52(4): 53

   

Abstract

Graft-appendiceal fistula is a rare variation of aorto-enteric fistula.  We report on the presentation and management of a 70-year-old lady who presented ten years after an aortobifemoral graft with a discharging sinus in her right groin.  Investigations suggested aortic graft infection and she was taken to theatre for a laparotomy.  An inflamed appendix with a necrotic tip was found in contact with the aortic graft.  The infected graft was excised and an appendicectomy was performed.  The distal organs were revascularised with an axillobifemoral graft.  We review similar case reports.

Key words : Aortic graft infection, appendicitis, fistula, iliac-appendiceal fistula

 

Introduction

The first case of aortoenteric fistula was described by Sir Astley Cooper in 1829.1  With an increasing number of aortic operations performed, the condition is now seen more often and the incidence of fistula formation after aortic surgery is quoted as 0.5% and 1.6%.2, 3, 4  The presentation of graft infection may be subtle when patients present with gastrointestinal bleeding or vague abdominal pain, or more obvious when groin sepsis or pseudoaneurysms are present.  In the majority of cases, the fistula involves the duodenum at the proximal anastomosis (70%) although fistulation with the jejunum, ileum and colon have been described.5  Graft appendiceal fistula is a rare variation of aorto-enteric fistula, the first case of eight being reported in 1969.6  We shall present a further case of a graft-appendiceal fistula with a review of the literature.

 

Case Report

A 70-year-old lady presented as an emergency with a three week history of a tender swelling in her right groin.  She had an extensive vascular history, initially presenting 14 years previously with bilateral claudication.  She underwent a left to right femoral-femoral crossover graft at that time but eventually the graft failed and she had an aortobifemoral graft four years later.  She made a good recovery and was symptom free for five years.  Unfortunately she complained of worsening claudication of the right leg and an angiogram showed a right interface stenosis.  A tube graft extension to the right profunda was carried out with good result. 

 

On admission to the vascular unit, she was found to have a discharging sinus in her right groin.  She was afebrile and her admission bloods revealed haemoglobin of 11.6 g/dL, white cell count of 8.7x109 and a CRP of 36.  A CT scan showed a cuff of inflammatory tissue around both limbs of the graft with fluid around the right limb.  This suggested the diagnosis of aortic graft infection and she was taken to theatre two days after admission for a laparotomy and exploration of the graft.    There was an inflammatory process around the right limb of the graft and the tip of the appendix had become involved with the fibrous tissues surrounding the aortic graft (Figure I).  An appendicectomy and excision of the bifurcation graft was carried out and an axillobifemoral graft inserted using a Dacron prosthesis to revascularise the distal limbs.  Pathology of the specimen confirmed acute inflammation of the appendix and peritonitis involving the distal appendix with perforation at its tip.  Microbiological swabs from the groin and graft grew Streptococcus milleri and Bacteroides.  The patient made a good recovery and was able to go home 14 days after her operation.  She is doing well at her six months from her surgery.

 

Review of the literature

Methods

The terms “aortic graft infection”, “acute appendicitis”, “aorto-enteric fistula” and review of relevant references yielded 8 case reports in the literature.  Our patient was included in the review.  Details of the cases are summarised in Table I.

 

Results

There were nine cases of graft-appendiceal fistula in the literature including our own case.  The male to female ratio was 8:1 with a median age of 59 years (range 51 to 75 years).  Four patients had initial aortic surgery for aneurysm and five patients underwent surgery for occlusive disease.  The median interval from initial operation to presentation with fistula was 7 years (range 13 months and 17 years).  Six patients presented with intermittent minor rectal bleeding before they became haemodynamically unstable with a significant bleed.  Two patients complained of vague abdominal pain and three patients had a pulsatile mass or evidence of groin sepsis.  Multiple investigations were executed before definitive surgery was carried out.  Five patients had an upper gastrointestinal endoscopy with two barium enemas, three computed tomography scans and three arteriograms performed.  This illustrates the lack of effectiveness of individual diagnostic modalities and demonstrates the need for a high index of clinical suspicion in a patient who presents with gastrointestinal bleeding or sepsis with history of aortic reconstruction.  At laparotomy there was a fistula between the appendix and the right limb of the graft, often near the iliac anastomosis in each case.  Microbiological cultures were variable in eight cases with 50% showing no growth and 50% infected with Escherichia coli, Enterococci or Staphylococcus epidermidis.  The management of the patients with graft appendiceal fistula was varied and is summarised in Table I.  Two patients died, one of whom did not have complete excision of the infected graft at initial operation.  Significant morbidity included myocardial infarction, deep venous thrombosis and below knee amputation.  Some patients were followed up for up to seven years, and of the nine patients in the literature, seven were well on review at clinic.

 

Discussion

Aortoenteric fistulae present a challenge to the vascular surgeon.  The presentation is often subtle and cases should be managed on an individual basis.    It is thought that direct contact between the prosthesis and the gastrointestinal tract is the initiating event, ultimately leading to fistula formation and graft infection.  Patients can present with gastrointestinal bleeding, either intermittent rectal bleeding or if the infection involves an anastomosis, massive haemorrhage with shock.  An infected graft can then develop pseudoaneurysms at any anastomosis or give rise to evidence of sepsis either systemically or in the groin.7, 8  The literature suggests that gastrointestinal endoscopy is the most useful diagnostic tool in patients who present with gastrointestinal bleeding.  Endoscopy may reveal an erosion between the graft and the intestinal lumen, but can also exclude other causes of bleeding from the upper GI tract.  However CT, MRI and more recently nuclear medicine studies also have a role. Recent sensitivities and specificities for CT and nuclear positron emission tomography studies in the diagnosis of graft infection are 74%, 86%, 91% and 64% respectively. MRI produces similar results to CT.9  The general consensus in the literature was that treatment should be directed to removal of the appendix and complete graft excision with revascularisation through non-infected tissue planes.10, 11 

 

Conclusion

This case report demonstrates that graft-appendiceal fistula is an unusual cause of graft infection but it should be borne in mind when dealing with patients who present with possible graft infection.  The most important management strategy is early diagnosis and complete excision of the graft.

 

References 

  1. Cooper, Sir Astley.  Lectures on the principles and practice of surgery.  London, Westley, 1829.

  2. Sheil AG, Reeve TS, Little JM et al. Aorto-intestinal fistulas following operations on the abdominal aorta and iliac arteries.  British Journal of Surgery 1969; 56: 840-843. 

  3. Elliott JP, Smith RF, Szilagyi DE.  Aortoenteric and paraprosthetic enteric fistulas: Problems of diagnosis and management.  Arch Surg 1974; 108: 479.

  4. Alfrey EJ, Stanton C, Dunnington G et al.  Graft appendiceal fistulas.  J Vasc Surg 1988; 7: 814-817.

  5. Humphries AW, Young JR, de Wolfe VG et al.  Complications of abdominal aortic surgery.  Archives of Surgery 1963, 86:43

  6. Tyson RR, Maier WP, DiPietrantonio S.  Iliaco-appendiceal fistula following Dacron aortic graft.  Am Surg 1969; 35(4): 241-243.

  7. Dean RH, Allen TR, Foster JH et al.  Aortoduodenal fistula: An uncommon but correctable cause of upper gastrointestinal bleeding.  Am Surg 1978; 44(1): 37-43.

  8. Pipinos II, Carr JA, Haithcock BE et al.  Secondary aortoenteric fistula.  Annals of Vascular Surgery 2000; 14(6): 688-696.

  9. Fukuchi K, Ishida Y, Higashi M et al.  Detection of aortic graft infection by fluorodeoxyglucose positron emission tomography: comparison with computed tomographic findings.  J Vas Surg 2005; 42(5): 919-925.

  10. Kleinman LH, Towne JB, Bernhard VM.  A diagnostic and therapeutic approach to aortoenteric fistulas: Clinical experience with 20 patients.  Surgery 1979; 86: 868-880.

  11. Bunt TJ.  Synthetic vascular graft infections: Graft enteric erosions and graft enteric fistulas.  Surgery 1983; 94: 1-9.

  12. Risberg B, Kewenter J.  Arterio-appendiceal fistula after arterial reconstruction with synthetic graft.  Acta Chir Scand 1978; 144: 121-123.

  13. Krupski WC, Mitchell A, Gewertz B et al.  Appendicitis and aortofemoral graft infection.  Archives of Surgery 1979; 114(8): 969.

  14. Criado FJ, Classen JN, Wilson TH Jn.  Secondary aorto-enteric fistulas: prosthetic and paraprosthetic.  American Surgeon 1981; 47: 313-321.

  15. Kitzmiller JW, Robb HJ, Barkel D et al.  Iliac appendiceal fistula: Case presentation and review of management.  J Vasc Surg 1984; 1: 695-696.

  16. Moore-Gillon V, Jarrett PE.  Aorto-appendicular fistula presenting with intermittent gastrointestinal bleeding.  J R Coll Surg Edin 1985; 30: 201-202.

  17. Lauwers P, De Greef K, Van den Brande F et al.  Aortic graft infection from appendicitis. A case report.  Acta Chir Belg 2004; 104: 454-456.

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