S Saha, M Salman, A May
Department of Vascular Surgery, Colchester General Hospital, Turner road, Colchester, Essex, CO4 5JU.
Corresponding Author: E-mail: sahasunita@hotmail.com
SMJ 2008 53(4): 10
Abstract
When considering the management of popliteal aneurysms, not only the size but also the nature, symptoms and state of collateral and distal circulation must be taken in to account. We present a patient who required operative management of a symptomatic 3cm popliteal aneurysm of the left leg whilst a conservative approach chosen for the right leg which had an asymptomatic 17 x 13.1 cm popliteal aneurysm, the largest of its kind reported within the English literature.
Keywords
Popliteal
aneurysm, Management aneurysm, Size aneurysm
Introduction
Popliteal arteries of normal calibre have a diameter of 0.74 +/- 0.22cm and are said to become aneurysmal once the diameter exceeds 1cm 1. We present a case where a patient described symptoms of acute arterial insufficiency due to a 3cm popliteal aneurysm of left leg but was found to have a massive asymptomatic thrombosed 17cm (length) by 13.1cm (diameter) aneurysm of the right leg. Previously the largest of its kind reported within the English literature was 10cm by 8 cm 2 therefore this aneurysm was considerably larger.
Case
Report
A 79-year-old male presented to the vascular outpatient department with evidence of acute arterial insufficiency of his left lower limb on a background of chronic arterial ulcers and gangrenous toes affecting the same limb. The patient described a long history of a large swelling behind the contralateral knee however did not complain of any symptoms of claudication or pain due to this mass. Examination of the right lower limb revealed a large fluctuant, non-tender, non-pulsatile mass arising from the popliteal fossa extending halfway up the medial thigh. Popliteal pulses were not palpable in either leg. The right foot was warm and well perfused with normal capillary refill time. In contrast no pulses were palpable in the left foot which was noted to be cold, extremely painful and dusky. In view of the history and clinical picture an urgent arterial duplex and CT angiogram were performed. These studies revealed a 3.3cm left popliteal aneurysm obstructing flow to the foot and a massive thrombosed right popliteal aneurysm measuring 17.0cm in length and 13.1 cm in diameter (Figure 1). As the patient described no problematic symptoms from the right popliteal aneurysm it was concluded a conservative approach would be most appropriate. However, a femoro-popliteal bypass procedure was successfully performed to re-establish distal arterial flow in the left leg.
Figure 1: Computed Tomographic Angiogram demonstrating length (A) and width (B) of the right popliteal aneurysm.
A
B
Discussion
Aneurysms of the popliteal artery although not a common occurrence, are the most frequently encountered peripheral artery aneurysm 3. Studies have demonstrated a strong association with abdominal aortic aneurysms which is thought to be due to the similarities in arterial wall composition 3,4. It has also been shown that the incidence of popliteal artery aneurysms is significantly higher in the elderly, males and patients with peripheral vascular disease 3. They may present in the form of localised mass symptoms within the popliteal fossa or complications such as acute ischaemia, oedema, distal thromboembolisation or rarely rupture 5. The natural history of untreated aneurysms is enlargement and eventually the development of complications which increases in frequency in the absence of pedal pulses, with time and size 5 of the aneurysm. Careful consideration of the risks and benefits of surgical intervention such as ligation and exclusion bypass graft versus conservative management is required. This case demonstrates that size should not be the only determining factor when considering the management of popliteal aneurysms. The collateral circulation which may be jeopardised during surgery, thrombosed and asymptomatic nature of the right popliteal aneurysm described in this case are all valid reasons for opting for a conservative approach to management despite its size.
Conclusions
In conclusion, although size does matter, the nature, symptoms and state of distal and collateral circulation must also be taken in to account when deciding if operative management of a popliteal aneurysm is most appropriate.
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