Evaluating Endoleaks in the Dermatology Office

Endoleaks are common complications following endovascular aneurysm repairs (EVARs) that may occur any time after surgery. There are 5 types of endoleaks with various etiologies. A type V endoleak (also known as endotension) is not considered a true endoleak but instead is characterized by continued aneurysm expansion without a leak, which is demonstrated via imaging tests.¹ Type V endoleaks typically require open aneurysm repair.² We report the case of a 69-year-old woman who presented to our dermatology office for treatment of a suspected lipoma overlying the right mid sternum that was confirmed to be a type V endoleak via computed tomography angiography.

Case Report

A 69-year-old woman was referred to our dermatology office by her primary care physician for evaluation of a subcutaneous mass overlying the right mid sternum, which was a suspected lipoma. The patient reported that the mass had been present for approximately 2 weeks and was enlarging but otherwise asymptomatic. Her medical history was remarkable for hypertension, an ascending aortic aneurysm, and a subsequent aortic valve replacement approximately 2.5 years prior. Her current medications included amlodipine, lisinopril, nebivolol, ibuprofen, and aspirin. She denied use of alcohol, tobacco, or illicit drugs. A review of systems was noncontributory.

Physical examination revealed a single 3.5×4.5-cm, soft, nonmobile subcutaneous mass located at the site of the thoracotomy scar (Figure 1). The mass appeared to have a central attachment to the sternum. No erythema, swelling, or exudate was noted, and the patient denied tenderness on palpation. The diagnosis of lipoma was questioned, and the patient was referred for ultrasonography and computed tomography angiography. Ultrasonography showed a nonspecific chest wall mass with internal blood flow, and computed tomography angiography showed a large, low-attenuation collection of blood around the entire circumference of the ascending aorta, extending from the aortic root to the arch of the aorta. There was extension of the collection of blood through either the sternocostal junction or the sternotomy defect into the subcutaneous tissue anterior to the sternum (Figure 2). Findings were most consistent with a type V endoleak, and the patient was referred to a cardiothoracic surgeon for treatment. We later learned that our patient died during surgery attempting to repair the aneurysm approximately 2 weeks after her presentation to our office.

^{Figure 1. Nontender nonmobile subcutaneous mass located overlying the right mid sternum.}

Comment

An endoleak is a common complication following an EVAR that is characterized by persistent blood flow within the aneurysm sac. Endoleaks have been described as the Achilles’ heel of EVARs.¹ The goal of an EVAR is to create a complete seal so that the flow of blood completely excludes the aneurysm, thus ultimately preventing an aneurysm rupture. An endoleak results when there is failure to obtain a complete seal due to a variety of different mechanisms. White et al³ first described and classified endoleaks in 1997. The initial terminology used to classify endoleaks was based on timing (primary or secondary/late) and location (graft related/perigraft or non–graft related/retrograde). Today, endoleaks are classified into 5 types, 3 of which are considered true endoleaks and 2 of which are not.⁴ Type I endoleaks result from a failure to create an adequate seal at one of the attachments of the graft to the vessel wall. Type II endoleaks are due to retrograde flow through collateral vessels into the aneurysm sac. They are much more common than type I, occurring in 10% to 25% of abdominal endograft cases. The last true endoleak, type III, occurs due to device failure in the form of disjunction of the components of the graft system (type IIIa) or a defect in the graft fabric (type IIIb). Type IV and type V endoleaks are not considered to be true endoleaks. Type IV endoleaks are due to the porosity of the graft material and have virtually been eliminated by changes in graft materials to decrease porosity. Type V endoleaks are characterized by continued blood flow into the aneurysm without any evidence of a leak on any imaging modality. Type V endoleaks are poorly understood but are believed to be due to pulsation of the graft wall, which is transmitted through the perivascular space to the aneurysm wall.⁴

Figure 2. Transverse (A) and sagittal (B) sections of the computed tomography angiography illustrating a type V endoleak.

Treatment of type V endoleaks is controversial. It is important to characterize the endoleak by various imaging modalities, and if a type V endoleak is confirmed, an open aneurysm repair often is required.² A case of nonsurgical management of a type V endoleak has been described but is rare.⁵ In this case, the patient was referred to our dermatology office by her primary care physician for what appeared to be a benign lipoma, but it proved to be a type V endoleak on further examination. It is imperative that dermatologists are aware of endoleaks as common complications of EVARs, as they can be life threatening and usually require surgical intervention.