Inferior epigastric artery is a vessel keen to iatrogenic laceration after various medical procedures due to its superficial route. In the majority of cases a pseudoaneurysm is formed, the patient remaining stable. However, in one case of IEA laceration after percutaneous biopsy a large haematoma was formed, surgical control failed and patient died [5].
Surgical ligation of the lacerated vessel was not attempted in our case due to obscuration of the vessel by a large haematoma and therefore retention sutures were placed around the lacerated lesion. In a similar case reported by Todd et al after laparotomy, surgical access to the haematoma allowed direct ligation of the vessel. However the patient turned unstable and the patient died 36 hrs later [5]. We believe that the IEA pseudoaneurysm formation 41 days after the biopsy was probably due to the gradual absorbance of the formed haematoma or of one of the retention sutures which resulted in relaxation of the tamponating forces on the lacerated vessel.
Patients with IEA pseudoaneurysms may be hemodynamically stable or unstable, depending on the tamponating force that the extravasating blood receives from the surrounding tissues [1]-[4, 10].
Treatment options of IEA pseudoaneurysms include surgical ligation of the lacerated vessel [3], transcatheter embolization [2, 4, 6], percutaneous thrombin injection [10] or direct compression [1].
Percutaneous thrombin injection is a widely accepted method for the treatment of pseudoaneurysms of the common femoral artery (CFA) that usually occurs after catheterization for interventional procedures [7]. There is only one case in the literature of a spontaneous IEA pseudoaneurysm which was treated successfully with percutaneous thrombin injection [8]. We decided to apply this type of therapy in our patient due to her debilitating condition.
Thrombin failure has been reported in the literature. Sheiman et al, in a study of 54 patients with simple CFA iatrogenic pseudoaneurysms treated with percutaneous US-guided thrombin injection concluded that their failure rate of 9% was due to an underlying sonographically occult vascular injury due to vessel laceration or infection. They also speculated that need for a dose more than 1000U of thrombin for pseudoaneurysm thrombosis is an indirect indicator of a large arteriotomy site defect requiring closer clinical follow-up [12].
In the reported case of IEA pseudoaneurysm that was treated with percutaneous thrombin injection, Shabani et al. refer a rare case of spontaneous pseudoaneurysm [8]. The authors do not refer previous traumatic mechanism or shear forces; therefore we may presume that the IEA has not been previously seriously lacerated. In our case 1500 U of thrombin were given but treatment failed for unknown reasons. A possible explanation may be that damaged endothelium at sites of a large arteriotomy or laceration expresses thrombomodulin which complexes with thrombin to activate protein C. Activated protein C is known to activate an anticoagulation pathway [13] and reduce the relative size and number of fibrin fibers within maturing thrombus [14]. This mechanism may help to explain why the clot which developed within the unsuccessfully treated pseudoaneurysm underwent spontaneous thrombolysis within 24 hrs leading to pseudoaneurysm recurrence.
Percutaneous coil embolization has shown to be effective in the hemorrhage control in all the reported cases [2, 4, 6]. In all cases the proximal and distal portions of the feeding vessel has been embolized with coils and complete thrombosis of the pseudoaneurysm has been achieved. Ferer et al, recommend surgical treatment for the cases of large pseudoaneurysms and percutaneous embolization for smaller lesions [15]. In a more recent study Lam et al, reported two cases of large pseudoaneurysms that have been successfully embolized [2].
We attempted initially the thrombin approach due to the fact it is a simple, quick and safe technique, minimally invasive, painless and very effective. We believe that the significant vessel wall laceration was the cause of the thrombin failure. Nevertheless, the patient was successfully treated with percutaneous embolization which is a more invasive, established intravascular therapeutic approach. We suggest this approach sequence as the most appropriate in the cases of IEA pseudoaneurysms.