Aneurysm sac enlargement 16 years after endovascular aortic aneurysm repair due to late type IIIb endoleak: A case report

Type IIIb endoleak due to stent suture line fabric breakage in the Endurant stent graft: a case report

Background

Early type IIIb endoleak is a very rare complication of endovascular aneurysm repair (EVAR).

Case presentation

An 87-year-old man was diagnosed with infrarenal abdominal aortic aneurysm. The patient underwent EVAR using the Endurant stent graft. Postoperative color duplex ultrasound revealed a regular row of pulsatile blood flow from the main body and left leg. The blood flow appeared to be bleeding from the stent suture lines because of its regularity. Type IIIb endoleak was suspected due to stent suture line fabric breakage but was not treated surgically or endovascularly because of the patient’s poor general health status. Six months later, contrast-enhanced CT demonstrated a deformation and enlargement of the aneurysm sac as well as an oozing of the contrast medium on the main body and left limb. Thereafter, he died of a subdural hematoma due to a fall. Autopsy showed no visible abnormal erosion or holes on the graft fabric, suggesting that suture line fabric breakage may have existed during the manufacturing process.

Conclusions

Although rare, type IIIb endoleaks can occur even in the perioperative period after EVAR. Early type IIIb endoleaks may not resolve spontaneously and should be treated promptly, if possible.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-022-01415-8.

A reproducible swine model of a surgically created saccular thoracic aortic aneurysm

A reproducible swine thoracic aortic aneurysm (TAA) model is useful for investigating new therapeutic interventions. We report a surgical method for creating a reproducible swine saccular TAA model. We used eight female swine weighing 20-25 kg (LWD; ternary species). All procedures were performed under general anesthesia and involved left thoracotomy. Following aortic cross-clamping, the thoracic aorta was surgically dissected and the media and intima were resected, and the dissection plane was extended by spreading the outer layer for aneurysmal space. Subsequently, only the adventitial layer of the aorta was sutured. At 2 weeks after these procedures, angiography and computed tomography were performed. After follow-up imaging, the model animals were euthanized. Macroscopic, histological, and immunohistological examinations were performed. All model animals survived, and a saccular TAA was confirmed by follow-up imaging in all cases. The mean length of the shorter and the longer aortic diameter after the procedure were 14.01 ± 1.0 mm and 18.35 ± 1.4 mm, respectively (P<0.001). The rate of increase in the aortic diameter was 131.7 ± 13.8%, and the mean length of aneurysmal change at thoracic aorta was 22.4 ± 1.9 mm. Histological examination revealed intimal tears and defects of elastic fibers in the media. Immunostaining revealed MMP-2 and MMP-9 expressions at the aneurysm site. We report our surgical method for creating a swine saccular TAA model. Our model animal may be useful to investigate new therapeutic interventions for aortic disease.

Type IIIb Endoleak After Endovascular Aneurysm Repair Using the Zenith Stent Graft

We present 3 cases of type IIIb endoleak after endovascular aneurysm repair (EVAR) using the Zenith stent graft system. Type III endoleak, like type I endoleak, is a high-pressure, high-risk leak that increases sac pressure up to or even above arterial pressure, and is associated with an increased frequency of open conversions or risk of aneurysm rupture. Type IIIb endoleak is rare but there is much concern that the incidence of type IIIb endoleak is likely to increase hereafter; the mechanism of type IIIb endoleak is deterioration of graft fabric in conjunction with stent sutures. Type IIIb endoleak is difficult to diagnose before rupture. The possibility of type IIIb endoleak should be highly suspected when the continued growth of an excluded aneurysm sac without direct radiologic evidence is observed during follow-up. Type IIIb endoleak can be repaired by relining of the stent graft with additional stent grafts.

Case Report of Late Type IIIb Endoleak with Willis Covered Stent (WCS) and Literature Review

OBJECTIVE

We report a case of late type IIIb endoleak with Willis covered stent (WCS) developed 14 months after endovascular paraclinoid aneurysm repair.

METHODS

A 52-year-old woman presented with episodic headache, caused by a giant paraclinoid aneurysm. She underwent a successful 3.5 x 16mm WCS positioning to treat the aneurysm. Fourteen months later, the patient was admitted with the same symptoms. Digital subtraction angiography examination showed recurrence of the aneurysm, which was similar to the preoperative one. DynaCT (Siemens, Erlangen, Germany) indicated the intact of the metal structure of the stent without migration. Type IIIb endoleak (defect in the graft fabric) was confirmed with a whole aneurysm neck located in the middle part of the stent. The type IIIb endoleak was treated with another WCS (4.0 x 16mm). The immediate digital subtraction angiography imaging indicated that the endoleak disappeared and the aneurysm was completely occluded. Re-examination done 1 year after the second treatment showed a complete exclusion of the aneurysm sac.

CONCLUSIONS

Type IIIb endoleaks can be safely treated by the endovascular positioning of another WCS. Continuous surveillance after endovascular paraclinoid aneurysm repair for intracranial aneurysms is warranted to make ensure the safety of WCS.