Association of Surgeons of Great Britain and Ireland

The annual meeting of the Association of Surgeons of Great Britain and Ireland was held in Dublin, Ireland on 22±24 May
2001 under the Presidency of Mr R. W. G. Johnson. The abstracts of the presentations of the original work presented at the
meeting have been published in a BJS supplement that accompanied the June 2002 issue of the Journal. The following articles
are based on presentations from the Dublin meeting and have been accepted for publication after peer review by the Journal's
referees.

Association of Surgeons

Management of popliteal aneurysm

R. B. Galland and T. R. Magee
Department of Surgery, Royal Berkshire Hospital, Reading RG1 5AN, UK
Correspondence to: Mr R. B. Galland (e-mail: robert.galland@rbbh-tr.anglox.nhs.uk)

Background: The best management of patients with a popliteal aneurysm has yet to be established.
This paper describes an experience of managing both patent and acutely thrombosed popliteal
aneurysms.
Methods: A prospective study was carried out of all patients who presented with a popliteal aneurysm
from January 1988 to December 2001. Since 1993 asymptomatic popliteal aneurysms less than 3 cm in
diameter without distortion have been managed conservatively. Ultrasonography was repeated at 6-
month intervals. These results were compared with conservative management of popliteal aneurysms
greater than 3 cm in diameter in patients who declined or were un®t for operation, and with the
outcome of patients who underwent elective bypass of a popliteal aneurysm.
Results: Fifty-eight patients (two women) presented with 92 popliteal aneurysms. Some 39 had a
thrombosed aneurysm and these patients were signi®cantly more likely to have bilateral aneurysms
(P < 0´001). Of patent popliteal aneurysms managed conservatively, none below 3 cm in diameter
thrombosed. The risk of postoperative complications was greater after repair of a thrombosed than a
patent aneurysm (P < 0´005). Preoperative lysis for a thrombosed popliteal aneurysm was associated
with more complications than operation and on-table lysis (P < 0´05).
Conclusion: Careful monitoring of asymptomatic popliteal aneurysms less than 3 cm in diameter is safe.
Preoperative lysis is associated with increased risks compared with operation alone in patients with a
thrombosed popliteal aneurysm.

Paper accepted 8 June 2002 British Journal of Surgery 2002, 89, 1382±1385

cardiovascular disease and a limited life expectancy2. These

Introduction
facts need to be considered when discussing elective
The likelihood of an asymptomatic popliteal aneurysm operation.
becoming symptomatic is approximately 14 per cent per It is not clear which popliteal aneurysms are at risk of
year1. However, not all of these symptoms will be due to thrombosis. Operation is often advised for aneurysms
thrombosis. Thrombosis of a popliteal aneurysm is greater than 2 cm in diameter or those containing
associated with leg loss in up to 30 per cent of patients1. thrombus3, but there is little hard evidence to support this
Patients whose legs are saved often have residual symptoms. treatment protocol. Amputation has occasionally been
Elective bypass of a popliteal aneurysm is often advised necessary after failed elective bypass1. There is an average
to avoid these complications. However, popliteal aneur- graft patency of approximately 80 per cent 5 years after
ysms occur mainly in older men who have signi®cant elective repair.

1382 British Journal of Surgery 2002, 89, 1382±1385 ã 2002 Blackwell Science Ltd
 R. B. Galland and T. R. Magee · Management of popliteal aneurysm 1383

The authors previously found that size greater than 3 cm Table 1 Comparison of demographic data in patients with
popliteal aneurysms that presented either thrombosed or patent
and distortion within or outside the aneurysm were
signi®cant risk factors for thrombosis4. Since that time all Thrombosed Patent
patients with an asymptomatic popliteal aneurysm have
No. of patients 39 19
been managed conservatively until the diameter reached Sex ratio (M : F) 38 : 1 18 : 1
3 cm, unless distortion was noted on angiography. Median (range) age (years) 69 (47±86) 66 (46±86)
The aims of this paper were ®rst to de®ne the outcome Other aneurysm present
of conservative management of asymptomatic popliteal Aortic 19 6
Contralateral popliteal 28 4*
aneurysms less than 3 cm in diameter and, second, to Femoral 1 1
compare these results with elective bypass of the aneurysm.
Finally, the management and outcome following popliteal *P < 0´001 versus thrombosed (c2 test)
aneurysm thrombosis is described.
86) years. Some 39 patients presented with a thrombosed
Patients and methods
aneurysm. Demographic details are shown in Table 1.
Patients with a thrombosed popliteal aneurysm were
Popliteal aneurysm was de®ned as a localized dilatation of signi®cantly more likely to have bilateral aneurysms (28 of
the popliteal artery greater than 2 cm in diameter or greater 39 versus 4 of 19; c2 = 13´3, 1 d.f., P < 0´001). Overall 25
than 150 per cent of the normal proximal arterial calibre5,6. patients (43 per cent) had an associated abdominal aortic
All patients with a popliteal aneurysm who presented aneurysm. There was no difference in the prevalence of
between January 1988 and December 2001 were included. aortic aneurysm in patients with thrombosed or patent
Data were collected prospectively and missing information popliteal aneurysms. Signi®cant cardiovascular disease was
was obtained by referral to case notes. noted in 40 (69 per cent) of the 58 patients.
Clinical management changed during the study. All Of 39 aneurysms that had thrombosed, 30 presented
patients had ultrasonography of the popliteal fossa and acutely (acute ischaemia in 28 and sudden claudication in
intravenous or intra-arterial digital subtraction angio- two). Five patients presented with rest pain or gangrene,
graphy to de®ne the anatomy and run-off. Patients who two with chronic claudication and two had an asymptomatic
presented electively and were not offered immediate repair occlusion. The latter two patients were being investigated
had ultrasonography every 6 months. Elective repair for symptoms in the other leg when the thrombosed
was offered if the aneurysm became symptomatic. For aneurysm was discovered. In two patients the popliteal
aneurysms that remained asymptomatic elective repair was aneurysm had been misdiagnosed. One presented with leg
advised if the aneurysm reached more than 2 cm in diameter ulceration that had been diagnosed and treated as due to a
until January 1993. From then, in the absence of distortion, deep venous thrombosis. The other had been thought to
the size threshold for advising repair was increased to 3 cm. have a Baker's cyst some months before thrombosis.
For patients who presented with a thrombosed popliteal
aneurysm, operation was carried out as an emergency or
Asymptomatic popliteal aneurysm
urgent procedure until November 1988. Following intro-
duction of intra-arterial thrombolysis, these patients were None of the patients with a popliteal aneurysm less than
managed by lysis followed by operation7,8. From September 2 cm in diameter developed thrombosis or any other
1992, patients with a thrombosed aneurysm were offered symptoms. Seven patients who had a an aneurysm greater
urgent or emergency operation combined with on-table than 3 cm in diameter either declined operation or were un®t
thrombolysis. for the procedure. One of these patients subsequently died,
Statistical analysis was carried out using the c2 test. in three the aneuyrsm thrombosed, and three others
Patency following operation and the likelihood of symp- developed discomfort behind the knee. None of seven
toms developing with conservative treatment were analysed popliteal aneurysms in the 2±3-cm group thrombosed and
using the Kaplan±Meier and log rank tests. only one developed symptoms (discomfort and swelling of
the calf). No statistically signi®cant difference was seen with
respect to either thrombosis or symptom development in this
Results
small group of patients (P = 0´37 and P = 0´32, respectively).
In the 14 years, 58 patients presented with 92 athero-
sclerotic popliteal aneurysms. Median follow-up was Surgical repair
50 months (range 3 months to 11 years). There were two Operation was carried out for 55 of the 92 popliteal
women. The median age of the patients was 68 (range 46± aneurysms. There were 30 vein grafts (23 popliteal±

ã 2002 Blackwell Science Ltd www.bjs.co.uk British Journal of Surgery 2002, 89, 1382±1385
1384 Management of popliteal aneurysm · R. B. Galland and T. R. Magee

Table 2 Thirty-day results after bypass for popliteal aneurysm (55 procedures)

Total Amputation Died Other complication

Thrombosed popliteal aneurysm 36 4 1 13

Operation alone or on-table lysis 22 4 0 5
Preoperative lysis 14 0 1 8
Elective repair of patent popliteal aneurysm 19 0 0 0

per cent respectively; P = 0´63). For patients whose

1·0
aneurysm had thrombosed, preoperative lysis had no overall
0·9
bene®t compared with operation alone; 3-year graft patency
0·8
rate was 76 and 67 per cent respectively (P = 0´29).
0·7
Following elective repair, graft patency at 3 years was 73
0·6 per cent compared with 71 per cent following repair of a
Probability

0·5 thrombosed aneurysm (P = 0´42). When the likelihood of

0·4 thrombosis of a popliteal aneurysm 2±3 cm in diameter
0·3 treated conservatively was compared with graft patency
0·2
Conservative
following elective repair, there was no signi®cant difference
Elective operation
0·1 (P = 0´59) (Fig. 1). Patients treated conservatively fared no
worse than those who had elective operation.
0 6 12 18 24 30 36 42 48 A total of six patients died during follow-up, including
Time (months) ®ve who had bypass of a thrombosed popliteal aneurysm
No. at risk
Conservative 7 6 5 3 3 and one who was deemed un®t for repair of an aneurysm
Elective operation 18 18 14 13 13 11 8 8 greater than 3 cm in diameter.

Fig. 1 Comparison of likelihood of thrombosis of popliteal Discussion

aneurysms 2±3 cm in diameter treated conservatively with those Rupture of a popliteal aneurysm, although potentially life
having elective bypass
threatening, is rare; it is thrombosis, resulting in an acutely
ischaemic leg, that most concerns vascular surgeons. Once
popliteal, ®ve femoropopliteal and two femorotibial). thrombosis occurs there is a signi®cant risk of death and
Synthetic material was used in 25 procedures (15 popli- amputation of approximately 5 per cent and up to 30 per
teal±popliteal, ten femoropopliteal). Table 2 shows 30-day cent respectively1.
results. Four patients with a thrombosed aneurysm under- Although lysis of a thrombosed popliteal aneurysm has
went major amputation after failed bypass. No patient who been recommended, it is not without risks. Stroke and
had elective repair required amputation. Some 17 major major bleeding occur in 1 and 5 per cent of patients
complications were seen. These included four episodes of respectively9. Furthermore, acute deterioration of the leg
haemorrhage, acute leg deterioration during lysis in three during lysis due to destabilization of a large volume of
patients and two myocardial infarctions, one of which was thrombus seems to be a particular risk in popliteal
fatal. Two patients developed foot drop despite fasciotomy, aneurysms10. Complications were signi®cantly more likely
one patient had a deep venous thrombosis and ®ve had with preoperative lysis in this series compared with
wound infections. No signi®cant complications were seen operation alone. There was no signi®cant increase in
in the 19 patients who had elective operation. This long-term patency, although others have suggested that the
compared with complications in 13 of 36 thrombosed patency rate following successful thrombolysis of a
popliteal aneurysms (c2 = 8´9, 1 d.f., P < 0´005). Com- thrombosed popliteal aneurysm is greater than that after
plications were more common in those with a thrombosed early operation alone (W. Dorigo, R. Pulli, F. Turini, G.
aneurysm who had preoperative lysis than in patients who Pratesi, G. Credi, A. A. Innocentia, C. Pratesi, unpublished
underwent operation alone (c2 = 4´4, 1 d.f., P < 0´05). observation). However, lysis can clear run-off effectively
The type of operation had no in¯uence on graft patency. and it has been suggested that lysis followed by antic-
There was no difference in patency rates in patients who had oagulation may be all that is required to preserve the leg11.
elective repair of symptomatic (patent) compared with Early exploration and lysis of run-off during operation, if
asymptomatic aneurysms (3-year graft patency 70 and 80 necessary, seems a more attractive alternative12.

British Journal of Surgery 2002, 89, 1382±1385 www.bjs.co.uk ã 2002 Blackwell Science Ltd
 R. B. Galland and T. R. Magee · Management of popliteal aneurysm 1385

The average 5-year patency following elective popliteal enlargement to more than 3 cm diameter warrants early
aneurysm bypass is approximately 80 per cent1. This reconstruction.
compares with 65 per cent for bypass after operation for
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ã 2002 Blackwell Science Ltd www.bjs.co.uk British Journal of Surgery 2002, 89, 1382±1385