Compartment syndrome as a late presentation of brachial artery pseudoaneurysm following shaft of humerus fracture

Abstract

Peripheral artery pseudoaneurysm is rare in upper extremities compared with lower extremities. Early diagnosis and prompt management are two cornerstones of successful outcomes in these cases. Delay can lead to limb and life-threatening complications. We present a case of compartment syndrome of upper limb as a sequel to pseudoaneurysm of brachial artery for which we had to do shoulder disarticulation. The patient recovered uneventfully.

Background

Pseudoaneuyrsm is rare in upper extremity.¹ Pseudoaneuyrsm is a localised collection of blood between tunica media and adventitia following penetrating injury to a peripheral artery.² It may also occur following minor trauma in patients prone to haemorrhage,³ it can also occur as a sequel to infections, arteritis and congenital defects in arteries.⁴

Pseudoaneurysm of brachial artery though rare have been reported in literature as a sequel to penetrating stab wounds, gunshot injuries⁴ and chronic kidney disease patients (those requiring arteriovenous access for haemodialysis).⁵ Both aneurysm and pseudoaneurysm do occur in patients with arteriovenous access and have a reported incidence rate ranging from 5% to 60%.^6–8 However, in the absence of any well-defined criteria to differentiate between them, the true frequency of each remains a mystery.⁵ Majority of these aneurysms and pseudoaneurysms remain stable throughout the duration of haemodialysis requiring only periodic observation.⁵ Only few case reports^{9 10} exist which emphasise occurrence of brachial artery pseudoaneurym in conjunction to fracture shaft of humerus.

A typical pseudoaneurysm is characterised by a pulsatile mass, audible murmur and a palpable thrill.¹¹ Diagnosis is usually confirmed by various imaging modalities such as colour Doppler, CT angio and MRI. Common differential diagnosis include pulsating haematoma, sarcomas, A-V malformation.¹² With specificity and sensitivity approaching 100% colour Doppler is the non-invasive investigation of choice.¹³ Left untreated or misdiagnosed, it can lead to various complications such as infection, bony erosions, ischaemia, venous oedema and nerve compression¹⁴ which may pose a serious risk to limb and life.

Pseudoaneurysm presenting as compartment syndrome is rarest of its complications and to our knowledge, this is the first case report of compartment syndrome of upper limb associated with pseudoaneurysm of brachial artery, occurring as a consequence to fracture shaft of humerus and leading to shoulder disarticulation.

Case presentation

A 65-year-old man presented to us in emergency with an enormous spindle-shaped swelling of arm (figure 1). The swelling was tense and warm with venous engorgement around shoulder. He had gross oedema over forearm and hand with blisters and ulcerations. Had a doubtful distal circulation with an absent radial pulse and blackish discolouration of the outer three fingers. The hand was cold compared with opposite side and fingers and hand had decreased sensation. There was a history of fall 3 months ago which resulted in fracture humerus (figure 2A) for which he was conservatively managed by a physician with U splint. Patient was known to be a case of schizophrenia for which he had been taking some unsupervised irregular medications for past 5 years, hence had a decreased cognizance and was non-compliant with the instructions and used to tear off the splint. After 15 days, when the pain subsided, he did not continue with the splint. After one and half month, family members noticed a swelling at the fracture site which gradually increased in size. They again consulted a local hospital which advised a Fine Needle Aspiration Cytology (FNAC) without any proper radiological evaluation which resulted in a sudden copious flow of blood, swelling continued to increase rapidly in size to gain its present dimensions. Patient presented to us with compartment syndrome after 5 days of FNAC.

Figure 1.

Showing spindle-shaped swelling of arm with blisters over forearm.

Figure 2.

Plain anteroposterior (AP) radiograph showing fracture shaft of humerus following initial trauma (A), radiograph at presentation showing soft tissue lucency with resorption of fracture ends (arrow sign) (B).

Investigations

Digital radiograph (figure 2B) evaluation showed resorption of the fracture ends and soft tissue swelling at the fracture site mimicking soft tissue tumour with pathological fracture of the humerus. Hence, MRI (figure 3A) was done which showed displaced fracture shaft of humerus with large surrounded lobulated mass lesion of size 12.8×12.6×12.4 cm in adjacent intramuscular compartment. T2 and Short Tau Inversion Recovery (STIR) Sequence showed no continuation of the brachial artery between proximal and distal ends. CT angiography (figure 3B) revealed a lesion which enhanced only centrally and was continuous in the small segment of brachial artery giving impression of a thrombus. He had a haemoglobin level of 63 g/L, a high total leucocyte count (TLC) of 14.4×10⁹/L and high-serum creatinine level of 2 mg/dL at presentation indicating sepsis and hypovolaemic renal failure.

Figure 3.

MRI (coronal view) showing abnormally-enlarged lobulated mass (arrow sign) with displaced fracture shaft of humerus (A), CT angiography (coronal) showing centrally enhancing lesion (arrow sign) in continuity to brachial artery with diminished flow distally (B).

Treatment

After taking a full informed consent from patient as well as attendants, a shoulder disarticulation was planned. Intraoperatively, we observed substantial amounts of clots (figure 4A) and necrosis of surrounding tissue. We debrided all non-vital tissues and diarticulated the shoulder joint. Operation was uneventful.

Figure 4.

Intraoperative operative photograph showing clots (A); Clinical photograph day 5 showing healthy operative site (B).

Outcome and follow-up

Patient had healthy surgical site on fifth postop day(figure 4B), but we observed an further increase in serum creatinine level from second day onwards. Nephrology consultation was taken and patient was managed conservatively with fluids and diuretics. Serum creatinine and total lung capacity gradually came back to normal and patient was discharged on 15th postop day. Patient continues to do good at latest follow-up.

DISCUSSION

Any artery can develop a pseudoaneurysm but is very less common in upper compared with lower extremities. Site, size, accessibility and number of aneurysms dictates its management,¹⁵ with primary goal being to rescue the limb from ischaemia with or without arterial reconstruction procedure.^{4 16} Though colour Doppler is the investigation of choice selective upper limb arteriography is considered the gold standard.¹⁷

Small pseudoaneuysms (<2 cm diametre) remain asymptomatic and can just be observed with regular follow-up.¹⁸ Modalities of management of symptomatic aneurysm can be divided into non-surgical and surgical. There is a general consensus of surgery yielding superior results.¹⁹ Different non-surgical procedures include ultrasound (US)-guided compression, percutaneous thrombin injection, endovascular stenting. Aneurysm resection, ligation and direct repair of defect²⁰ are common surgical practices.

With an immediate success rate of 86%–95%^{21 22} US-guided compression may seem as a fascinating option, however, it is best suited for small aneurysms with low pressure flow and when the aneurysm has a narrow stalk and is of relatively shorter duration.²¹ It frequently fails in patients on anticoagulation therapy. Success also depends on hand fatigue of the operator and pain tolerance of patients and has a reported recurrence rate of 20%.²¹ US-guided thrombin injection has a reported success rate of 100%²³ but number of studies and subjects were too small to give any conclusive evidence. Provided that the aneuryms does not hamper distal circulation or has a substantial amount of collateral circulation embolisation with copper coil can be performed.²⁴

Endovascular polytetrafluoroethylene (PTFE) stent graft prevents rupture and occlusion of pseudoaneuyrsm with promising midterm results²⁵ but in deficiency of long-term studies there use remains guarded.

Open surgical methods give best long-term results, surgical method depends on location and size of lesion. If the lesion involves a non-critical distal vessel, it can be ligated⁴ and resected out without the fear of distal limb ischaemia. Single small lesion distal to brachial bifurcation can be ligated, however in presence of multiple lesion reconstruction is necessary.^{4 18} If the lesion is large and involves the main brachial trunk the lesion can be excised or left insitu(if already thrombosed) and arterial continuity maintained in form of direct end to end anastomosis or an axillo-radial or axillo-ulnar bypass interposition graft using reversed saphenous vein.^{4 18} In case of a ruptured aneurysm threatening life, one is forced to do an emergency amputation in order to save life.

This is the first case report describing association of compartment syndrome with brachial artery pseudoaneurysm. When clinically obvious pressure monitoring is not required to establish the diagnosis of compartment syndrome.²⁶Non-union fracture ends may have caused contusion or laceration of the artery from direct impact¹⁸ leading to formation of pseudoanerysm and we believe that FNAC of tense aneurysm caused its rupture leading to compartment syndrome. We received the patient in state of sepsis and renal failure and hence prioritising life over limb a shoulder disarticulation was planned and executed.

Learning points.

• Non-union of a fracture can lead to pseudoaneurysm formation hence all fractures even if managed conservatively should have a regular follow-up.

• Pseudoaneurysm can present as compartment syndrome threatening limb or life or both.

• All bone and soft tissue swellings must undergo complete radiological evaluation before any invasive procedure such as biopsy or FNAC.

• Management of pseudoanerysm depends on size, site, accessibility and general condition of the patient.