Traumatic nonanastomotic axilloprofundal PTFE-bypass rupture: a case report.

A 76-year-old male patient was admitted to our emergency department with painful swelling of the right lateral chest after a fall. Imaging revealed a hematoma, secondary to rupture of a synthetic axilloprofundal bypass. In an emergency surgical procedure, the spelled hematoma was evacuated and the graft legs were successfully ligated. The patient was discharged after an uneventful hospital stay. Traumatic bypass rupture because of blunt trauma is an exceedingly rare event; however, it must be taken into consideration in a patient with bypass surgery in his/her history.

Introduction

A traumatic disruption of an axillofemoral bypass is a very rare event, with potentially significant mortality. Most of the ruptures occur because of a tear of the proximal anastomosis, with an estimated incidence of up to 5% [1]. We are presenting a patient sustaining a complete rupture of a polytetrafluoroethylene (PTFE) axilloprofundal bypass in his thoracic midportion after proven blunt trauma. Until now, only 3 authors have reported similar cases [2], [3], [4].

Case report

A 76-year-old male patient (GB) was admitted to our emergency department with painful swelling of the right lateral chest. The swelling began after he fell a few hours before being admitted. The patient was well known to us, since he had been in therapy for severe peripheral artery disease over several years at our institution.

In summary, since 2011, the patient had undergone several surgical, including iliocrural PTFE-bypass surgery and several peripheral interventional procedures on the left side. A right-sided axilloprofundal PTFE-bypass surgery (after a chronic occlusion of a femorocrural bypass previously implanted in 1999) was performed in 2009, followed by an infect-complicated postoperative course and lower leg amputation.

The physical examination on admission showed a slightly tender, erythematous, nonpulsatile mass over the right lateral hemithorax, which had obviously developed rapidly over the last couple of hours. This observation was confirmed by chest x-ray (Fig. 1).

Fig. 1

Bed chest x-ray in anteroposterior direction showing an unclear large opacity of the right lateral chest wall.

Doppler sonography (Fig. 2) and a successive CT-angiography (Fig. 3) revealed a chest-wall hematoma (ca 800 mL) and a proximally disrupted axilloprofundal PTFE bypass with clear signs of active contrast agent extravasation. The distal leg of the bypass was occluded.

Fig. 2

Color Doppler sonography demonstrating a thoracic hematoma (HAEM) with arterial extravasation out of the proximal bypass leg (BP).

Fig. 3

Thoracic CT-angiography reconfirms a large, predominantly compact hematoma (H) with clear signs of contrast agent extravasation (white arrow) out of the proximal bypass leg into the chest wall soft tissue, consistent with active bleeding. An axial 3.0-mm slice in arterial after application of 100-ml iodinated contrast media intravenously, is shown.

Meanwhile, rapid worsening of the patient's condition required a transfer to the intensive care unit for management of the on-setting shocking anemia. Furthermore, the patient was at this point overanticoagulated (internationalized normalized ratio 3.9) and had been under medication with a platelet inhibitor. Because of progressive hemodynamic instability, immediate surgery was performed.

After initial evacuation of the spelled hematoma, the site of the rupture was located as expected centrally over the lateral hemithorax behind the pectoral muscles. By the time of surgery, there was no more active extravasation detectable. The detached graft sites were distracted by 4 cm. Subsequently, the graft legs were ligated with Ethibond and Prolene 4-0. We dispensed with a graft reconstruction because of the complete obliteration of the distal bypass leg and the apparently sufficient perfusion of the partly amputated right leg via profundal collaterals and relicts of the common and external iliac artery, respectively. The postoperative course was uneventful and the patient was discharged in good general condition.

Discussion

Postoperative complications after axillofemoral bypass surgery include proximal anastomotic disruption, upper extremity thromboembolism, graft infection, plexus brachialis lesions, arterial steal syndrome, and seroma formation. Aneurysms occur with an estimated incidence of 5%-10% [5]. The incidence of proximal anastomotic disruptions, termed “pullout syndrome,” has been estimated at about 5% [1] occurring mainly in the early postoperative period due to technical errors in anastomosis, mechanical distress, and infections [5], [6], [7].

Apart from several case reports of disrupted bypasses without proven trauma history, 3 authors reported pseudoaneurysms in nonanastomotic regions of an axillofemoral graft because of preceding trauma [2], [3]. The patients were treated either with an interposition graft. A similar case was presented by Mousa et al [4], in which a man suffered incomplete disruption of an axillofemoral bypass at the midshaft level after a fall that was repaired endovascularly. In these patients, no specific underlying graft pathology could be identified.

To our knowledge, this is the first case of a peripheral bypass rupture, specifically of an axilloprofundal PTFE bypass, located in the thoracic midportion after proven blunt trauma. We did not submit graft material for microscopic analysis, because there was no suspicion of infection, a fact that may be considered as a limitation. In our opinion, technical errors might have placed the graft under too much tension in the longitudinal direction, thereby causing disruption—a hypothesis which was already postulated by Akiyama et al [8] in a similar case; however, without proven trauma. Moreover, graft biodegradation over the past years might have predisposed the graft for failure in the setting of trauma, as proposed by Shiraishi et al [5], but this conclusion remains speculative.

Conclusion

Although exceedingly rare, traumatic bypass rupture can occur and must be taken into consideration as a possible differential diagnosis when confronted with a trauma patient with bypass surgery in his/her history, because missing the diagnosis could be deleterious.