Aneurysmal Degeneration of a Miller Vein Cuff
Article Outline
False aneurysms at anastomoses between synthetic grafts and native arteries are not uncommon. We report a case of true aneurysmal degeneration of a Miller vein cuff.
Keywords: Miller vein cuff, Aneurysm
Case Study
A 51yr male ex smoker presented to the Emergency department with acute ischaemia due to thrombosis of a 5.5
cm right common femoral artery aneurysm. The aneurysm had been detected 3 months previously during investigation of right sided varicose veins. Emergency ipislateral right external iliac to right common femoral artery bypass (EIA-CFA) and above knee femoro-popliteal (fem-pop) PTFE grafting was performed. The patient was anticoagulated with warfarin.
Over the next 8 years he required multiple intervention including thrombolysis, thrombectomy, patch angioplasty, extension of the fem-pop graft to below knee with later revision and left to right femoro-femoral cross over graft secondary to occlusion of the ipsilateral right EIA-CFA graft.
Subsequently his claudication distance fell to 10m and he was unable to work. Angiography revealed occlusion of the fem-fem cross over and right fem-pop grafts. This was treated by simultaneous left EIA to right profunda femoris artery (PFA) cross over and a right femoro-distal popliteal reverse long saphenous vein graft using the right long saphenous vein. In view of the previous right groin surgery and the need for a distal bypass, the cross over graft was anastomosed to a small patent PFA distal to the first bifurcation. The use of the Miller vein cuff made for an easier anastomosis and improved the configuration of the proximal fem-pop graft anastomosis. One year later he developed a stenosis in the mid section of the fem-pop vein graft that was treated by Dacron patch angioplasty and 3 years after this when the same area became aneurysmal a covered stent graft was inserted.
In 2004, six years following fem-pop vein graft, routine ultrasound graft surveillance revealed an aneurysm of the Miller vein cuff at the anastomosis to the right PFA and a 6cm infra renal AAA. A magnetic resonance angiogram confirmed these findings. Fig. 1. shows the image obtained of the right groin.
Fig 1.
Angiogram of right groin.
He underwent a conventional tube graft repair for the AAA, and following an uneventful recovery was readmitted 3 months later for elective repair of the Miller vein cuff aneurysm. Peroperatively the Miller vein cuff enlargement was noted to be concentric. Despite the grafts being patent on preoperative duplex, there was evidence of fresh thrombus extending into both left EIA-right PFA cross over and fem-pop LSV grafts. Thrombectomies were performed on both grafts, and they were then clamped before applying a curved vascular clamp to the base of the Miller vein cuff. The cuff was excised revealing intact suture lines and no evidence of false aneurysm. Occlusion catheters were inserted to control both proximal and outflow vessels before replacing the cuff with the flared distal end of a distaflow ® 6mm PTFE graft (BARD Ltd, West Sussex, England), (Fig. 2). The patient made another uneventful recovery.
Fig 2.
Right groin with distaflow PTFE graft replacing aneurysmal Miller vein cuff. (Proximal aspect of wound at top of picture).
Discussion
Our patient developed 4 aneurysms at different sites over a 15 year period. Two of these aneurysms occurred in native arteries (abdominal aorta and right common femoral artery) the others occurred in the autologous LSV graft.
The Miller vein cuff aneurysm in our patient was diagnosed 6 years after the initial operation. It grew rapidly increasing from 15mm to 24mm over 6 months suggesting a high risk of rupture. Other reports of aneurysms in vein grafts report similar time to onset and growth characteristics,1 however there has been little published on aneurysms of vein cuffs per se. One case of progressive enlargement of a vein cuff was reported in a letter to the Journal of Vascular Surgery in 1996.2
Many factors can contribute to the development of aneurysms in arterialised veins. Post stenotic dilatation, low grade infection, and excessive tobacco consumption are all implicated along with the established associations with genetic factors, Matrix Metalloprotease expression and atherosclerotic change.1, 3, 4
Fem-pop grafts inserted for popliteal aneurysms have been found to have a higher rate of aneurysmal degeneration4 and more chance of developing multifocal changes throughout the graft than fem-pop grafts for atherosclerotic disease only. That aneurysmal degeneration is a part of a systemic disease is supported by findings of a reduced elastin/collagen ratio throughout the vascular tree and elevated MMP-2 levels in venous samples from patients with AAA.3
Macroscopic histology reported ‘aneurysmal Miller vein cuff’. Microscopically vein and blood clot were noted with no infection, inflammation or atherosclerosis. This suggests that our patient's general tendency to form aneurysms is unrelated to atherosclerotic change and supports the view that aneurysms are a multifactorial, systemic disease.
This case also highlights the importance of routine follow up after of bypass grafting, in this instance leading to the successful treatment of a rare and potentially fatal complication.
References
- . Infrainguinal aneurysm formation in arterialized autologous saphenous vein grafts. J Vasc Surg. 1998 Nov;28:944–948
- . Progressive enlargement of a Miller vein cuff. J Vasc Surg. 1996 Aug;24(2):302–303
- . Ubiquitous Elevation of Matrix Metalloproteinase-2 Expression in the Vasculature of Patients With Abdominal Aneurysms. Circulation. 2001 Jul;104(3):304–309
- . Prevalence of true vein graft aneurysms: implications for aneurysm pathogenesis. J Vasc Surg. 1999 Mar;29(3):403–408
PII: S1533-3167(06)00067-7
doi:10.1016/j.ejvsextra.2006.07.001
© 2006 Elsevier Ltd. All rights reserved.
