Management options in the treatment of femoral pseudoaneurysms secondary to intravenous drug abuse: A case series

Highlights

• •Infected femoral pseudoaneurysms are a common presentation in intravenous drug users with little consensus as to their optimum management.
• •Excision and ligation of the femoral artery without revascularisation is the most common operative intervention.
• •With the identification and optimisation of suitable patients, revascularisation can be performed in the emergency setting.
• •Current endovascular approaches appear to be used only as a bridge to a future definitive revascularisation procedure.
• •Ligation of the common femoral artery without revascularisation is both safe and effective as most patients will avoid critical ischaemia.

Abstract

Introduction

Infected femoral pseudoaneurysms are a common presentation in intravenous drug users with little consensus as to the optimum management of these patients. Whilst emergency revascularisation options are available, excision and ligation of the femoral artery remains the most common operative intervention but risks leaving the patient with critical ischaemia or intermittent claudication. This case series reviewed the outcomes of 4 patients who underwent excision-ligation without revascularisation of an infected femoral pseudoaneurysm at a district general hospital.

Presentation

Four patients (2 male, 2 female) with infected femoral pseudoaneurysms presented via the emergency room with diagnosis confirmed with contrast cross-sectional imaging. All patients underwent emergency excision and ligation of the pseudoaneurysm without revascularisation. One patient returned to theatre with critical ischaemia necessitating a hindquarter amputation. The remaining 3 patients were discharged without claudication symptoms.

Conclusion

With the identification of suitable patients and pre-operative optimisation, revascularisation can be performed in the emergency setting with an extra-anatomical bypass appearing to confer the best results. Currently endovascular approaches appear to be used only as a bridge to a future definitive revascularisation procedure, however, there are several case reports documenting successful outcomes when using a stent graft alongside a prolonged course of antibiotics. For the majority of patients, excision-ligation without revascularisation is both safe and effective as few are left with symptoms of limb ischaemia.

1. Introduction

Infected femoral pseudoaneurysms commonly present in patients who are intravenous drug users and are associated with significant morbidity and mortality. Presenting on average with a 2 week history of symptoms [2]^, [3], they are frequently profoundly septic and/or with haemodynamic compromise [4]. While various revascularisation options using autologous or synthetic grafts are available, ligation of the affected vessel is the most common operative intervention [5] but this risks leaving the patient with claudication symptoms or with critical ischaemia necessitating an amputation [6]. With the number of deaths from heroin use the highest on record in the UK and continuing to rise [6]^, [7] these challenging patients are only going to become more common and there is little consensus as to how best to manage them. This case series will look at 4 patients presenting with an infected femoral pseudoaneurysm to a district general hospital and review their management alongside the wider literature.

2. Case 1

A 40 year old female presented with bleeding from a tender swollen right groin, fevers and raised inflammatory markers (Table 1). She was resuscitated and transfused two units of blood and commenced on IV Pipperacillin/Tazobactam 4.5 g TDS. The femoral pseudoaneurysm was identified on Duplex ultrasound and further confirmed with CT angiography before being taken to theatre (Fig. 1). The haematoma was explored via a groin incision, however, heavy bleeding and deeply inflamed tissues made proximal control difficult to achieve so the incision was extended to the abdomen for a pre-peritoneal approach. Once control was gained, her common femoral artery was determined to be damaged beyond repair and was ligated proximal to the inguinal ligament. Despite absent foot pulses her foot was found to be warm and well perfused. After 7 days of IV antibiotics she was stepped down to oral Co-Amoxiclav 500/125 mg TDS for a further week on microbiology advice. When reviewed 4 months later in the outpatient clinic and she remained free from claudication symptoms and had detectable foot pulses with a hand-held Doppler.

Table 1.

Summary Of Patient Demographics, Admission Investigations And Outcomes Upon Discharge.

	Case 1	Case 2	Case 3	Case 4
Age	40	35	33	30
Gender	F	M	M	F
Admission Bloods
Hb g/L	69	110	126	103
WCC x 109/L	14	10	20	58
CRP mg/L	139	178	190	83
PT seconds	15	16	18	N/A
APTT seconds	26.4	28	38	N/A
Fibrinogen seconds	3.8	6.4	5	N/A
Urea mmol/L	3.1	2.9	13.9	N/A
Creatinine μmol/L	54	68	132	N/A
Bilirubin μmol/L	9	N/A	11	N/A
ALP U/L	96	N/A	142	N/A
ALT U/L	14	N/A	112	N/A
Imaging	Doppler and CTA	Doppler and CTA	CTA	Doppler and CTA
Co-existing DVT	Yes	Yes	No	Yes
Operation	CFA ligation	Profunda Femoris Ligation	Profunda Femoris Ligation	CFA ligation
Amputation	No	No	Yes	No
Claudication	No	No	No	No

Fig. 1.

a) Coronal section from CT Angiogram and b) axial section demonstrating right femoral pseudoaneurysm and localised collection.

3. Case 2

A 35 year old man was admitted with a tender, erythematous, right groin swelling on a background of known IV drug abuse, with raised inflammatory markers. Initial duplex scanning identified a large femoral haematoma and a co-existing DVT but no pseudoaneurysm. Due to difficulty obtaining IV access he was initially commenced on oral Co-Amoxiclav 500/125 mg, which was switched to IV Meropenam 1 g TDS following insertion of a central line. Due to persistent pyrexia, he had a contrast CT scan to exclude a psoas abscess, which identified a large 7 × 8 cm actively bleeding femoral pseudoaneurysm (Fig. 2). Prior to being taken to theatre he had a large bleed from his groin with a 2 l blood loss and required emergency surgery. Proximal control was gained via pre-peritoneal approach and his external iliac artery clamped while the groin wound was explored. The pseudoaneurysm was found to be arising from his profunda femoris artery which was thus ligated and his foot remained perfused but with absent pulses and he remained symptom free and was discharged 10 days later with a further week of oral ciprofloxacin 500 mg BD and Clindamycin 450 mg QDS. This patient did not attend any follow-up appointments.

Fig. 2.

Right profunda femoris pseudoaneursym with contrast extravasation.

4. Case 3

A 33 year old male presented to the emergency room systemically septic with raised inflammatory markers and a right groin swelling, he was commenced on IV Meropenam 1 g TDS and Linezolid 450 mg BD and a contrast CT scan confirmed a pseudoaneurysm of the profunda femoris artery alongside a complex deep groin and pelvic collection (Fig. 3). He was taken to the emergency theatre and both his SFA and profunda femoris arteries were ligated. He subsequently developed thigh compartment syndrome and critical ischaemia secondary to a new occlusion of his external iliac artery and returned to theatre for an above knee amputation, which was later refashioned to a hindquarter amputation. Secondary to his sepsis, he developed infective endocarditis and completed a further 6 week course of Flucloxacillin 1 g PO QDS.

Fig. 3.

Axial section from CTA showing right femoral pseudoaneurysm with diffuse heavily inflamed tissues and gas extending into the posterior thigh compartment and into the pelvis.

5. Case 4

A 30 year old woman presented to the emergency room in septic shock with multi-organ failure with a pH of 6.8 and a lactate of 14 mmol/L. She was resuscitated with CPR for a cardiac arrest in ICU and commenced on broad spectrum IV antibiotics (Pipperacillin/Tazobactam 4.5 g TDS). Once stabilised she had a Pan-CT scan to identify a source of her sepsis. This detected a large right groin haematoma and a femoral pseudoaneurysm along with a co-existing ileo-femoral DVT. She was taken to theatre and her common femoral artery was ligated. She remained without claudication symptoms at her last follow-up 16 months later.

In each of these cases post-operative perfusion was assessed by clinical assessment and with the use of a hand-held Doppler. None of the patients received any further cross-sectional imaging nor did they receive any intra-operative anti-coagulation.

6. Discussion

Femoral artery pseudoanuerysms secondary to intravenous drug abuse are usually infected [5] and the patients themselves often systemically unstable creating a challenging management dilemma. Primary revascularisation surgery in these circumstances is associated with multiple complications [8], the infected operative field makes a prosthetic graft unsuitable and most will not have a suitable vein graft at the surgeons disposal [4]. These factors, coupled with potential haemodynamic comprise makes them high risk for complex revascularisation procedures and in these circumstances excision and ligation without revascularisation is often life saving and damage control surgery.

For the majority of patients there is evidence that such procedures can be performed safely and without significant long-term complications. In this series, 1 patient required a major amputation and 3 were left without claudication symptoms despite no revascularisation. This is consistent with other published studies; Arora et al. demonstrated no patients requiring an amputation with 33% suffering post-operative claudication [3] while the out of the cohort of 16 patients reviewed by Naqi et al., 17% required a major amputation and a quarter were left with claudication symptoms [5].

The length of time the patient has been a user of intravenous drugs can seemingly predict their outcome from a ligation of the common femoral artery. Qui et al. found that most patients with a drug use history of over 5 years had no claudication symptoms at all [9]. It is believed that patients with longstanding intravenous drug abuse develop an adequate collateral blood supply and as they are frequently young are often free from underlying atherosclerotic disease [10] thus less likely to require a subsequent amputation following ligation of the common femoral artery. Studies demonstrate the incidence of major amputation in patients presenting with infected femoral pseudoaneurysms is in the region of 30% [4]^, [11], compared with figures as high of 86% of military patients who have required CFA and SFA and SFA ligation following trauma [4].

The options for revascularisation are either using a prosthetic or autologous graft. As demonstrated with 3 of the 4 patients in this series, finding a suitable vessel is often difficult as many will have a co-existing deep and/or superficial venous thrombosis [2]^, [4]. In the event of a suitable graft being used, outcomes when implanted within the infected tissue planes are associated with 50% reinfection rate [11]. This can be avoided with the use of extra anatomical bypasses and have been suggested to reduce the amputation rate to 7% [12], however, despite this, synthetic grafts are still prone to reinfection and will frequently occlude [11]^, [13].

Benjamin et al. described 5 cases where a deep vein was used as an Obturator bypass graft in the revascularisation of mycotic femoral pseudoaneurysms [11]. They concluded that autologous extra-anatomical bypass grafts have a low re-infection rate and can be well tolerated without clinical signs of venous insufficiency [11]. In the absence of a suitable vein, Klonaris et al. proposed using the internal iliac artery for arterial reconstruction as either a patch or a interposition graft [2] and all 9 of these patients were free from claudication and amputation at long-term follow up (median 19 months; range 4–36 months) [2]. However, the patients selected in both of these studies were haemodynamically stable allowing for detailed imaging and pre-operative optimisation [11] which may not be reproducible in many emergency cases.

There is little research into the endovascular treatment of mycotic pseudoaneurysms, with the majority of the literature detailing cases where a stent graft was initially deployed as a bridge to a definitive revascularisation procedure [14]^, [15]^, [16]^, [17]^, [18]. Lagattolla et al. wrote of the treatment of a mycotic femoral pseudoaneurysm secondary to TB with a fully covered stent as an interim while the TB was treated however it ultimately became infected and had to be removed prior to bypass surgery [19]. There are case reports of patients who have remained systemically well and symptom free over a year following such a bridging procedure that a bypass was not required and in these instances the patients had intensive targeted IV antibiotic therapy for at least 4 weeks after stent graft insertion [14]^, [15]. While these papers concede, despite this, that operative intervention should be the primary management strategy, it raises the possibility that an endovascular approach could be used in the emergency setting to stabilise and treat the patient until such a time where they may be suitable for an elective extra-anatomical bypass.

All the patients in this series were initially treated with broad-spectrum antibiotics, which were later, adjusted according to positive culture growths and close liaison with the microbiology team. Despite Staphylococcus aureus being the most common causative organism [10]^, [20] the wider literature advises early administration of broad-spectrum antibiotics to cover for more atypical organisms such as Campylobacter and Listeria species [21] which should be considered as these patients may well be immunosuppressed.

In summary, there remains no consensus regarding the optimum management of these patients, nor is there anything in the literature with regards to the use of post-operative anti-coagulant or anti-platelet agents following surgery. These patients frequently fail to attend follow-up appointments and this inability to provide close monitoring might preclude a clinician from prescribing anti-coagulant or antiplatelet therapy due to risk of a catastrophic haemorrhage.

With the identification of suitable patients, revascularisation can be performed in the emergency setting but the anaesthetic considerations of a prolonged surgery must be considered alongside the risk of graft reinfections and other future complications. The use of an autologous graft may be most appropriately reserved for patients who are haemodynamically stable and able to have sufficient pre-operative investigations and optimisation with the literature suggesting an extra-anatomical bypass to confer the best results in this cohort. Similarly, ligation of the common femoral artery without revascularisation can be both safe and effective as many patients will avoid an amputation and most will be without claudication symptoms [4]^, [6]^, [22].

Conflicts of interest

Nothing to declare.

Sources of funding

Nothing to declare.

Ethical approval

Nothing to declare.

Consent

Multiple attempts to contact patients made but unable to reach them. All details have been completely anonymised with no patient identifiable information present.

Author contribution

All authors contributed equally to the design, data collection, literature review and writing of the paper.

Guarantor

Mr Vish Bhattacharya: Consultant Vascular Surgeon Queen Elizabeth Hospital, Gateshead.