Percutaneous Repair of Abdominal Aortic Pseudoaneurysm by Catheter-Based Delivery of Thrombin

Endovascular Treatment of a Contained Rupture of a Penetrating Aortic Ulcer in a Young Patient

Penetrating aortic ulcer (PAU) is a component of acute aortic syndromes (AASs), encompassing a range of potentially life-threatening aortic conditions such as dissection, intramural hematoma (IMH), and PAU itself. Ruptured PAU constitutes an emergency requiring surgical intervention. Here, we present a case involving a 47-year-old male patient admitted to our emergency department due to severe abdominal pain, malaise, and tenderness of the abdominal wall, which commenced abruptly several hours prior. An emergency CT scan revealed a large pseudoaneurysm of the infrarenal abdominal aorta, which was found with moderate atherosclerosis and no evidence of other dilated or aneurysmal segments. The patient underwent successful endovascular treatment and was discharged four days later without complications. Follow-up examination after two months demonstrated a patent graft and reduction of the aneurysmal sac.

Infrarenal Abdominal Aortic Pseudoaneurysm: Is It a Real Emergency?

Abdominal aortic pseudoaneurysm is a rare but life-threatening condition that occurs due to penetrating or blunt trauma. Clinical manifestations are variable, and the time interval from the initial trauma to diagnosis is variable. A prompt diagnosis and an aggressive management approach are required to avoid catastrophic complications. Possible treatment options are open surgical repair, endovascular repair, pseudoanerysmal sac thrombosis induction through direct thrombin injection, and coil embolization. Here, we present the case of a 75-year-old man affected by an infrarenal abdominal aortic pseudoaneurysm presenting with abdominal and lumbar pain for 3 days, who was successfully treated with an endograft.

Catheter-directed endovascular application of thrombin: Report of 3 cases and review of the literature

PURPOSE

To report 3 new cases of catheter-directed endovascular application of thrombin and explore trends by analysis of published case series.

MATERIALS AND METHODS

Institutional Review Board approved this retrospective study. All cases of non-tumoral arterial embolization performed from January 2003 to January 2015 at our institution were retrospectively reviewed. Thrombin was used in 7 of 589 cases. In 3 cases intra arterial thrombin was injected via catheter to treat active hemorrhage. Four cases were excluded due to percutaneous injection into visceral pseudoaneurysms (n=3) and making ex vivo autologous clot to be injected via catheter (n=1). Fisher's exact and the Wilcoxon rank sum tests were used to assess for association with acute nontarget thrombosis.

RESULTS

Catheter-directed thrombin was used in 3/589 (0.5%) cases at our institution. All three cases were technically successful with no further bleeding (100%). Nontarget thrombosis of proximal branches occurred in 2 patients (67%) with no significant clinical consequences. Including our 3 cases, a total of 28 cases were reviewed. Of the variables examined-location (p=0.99), size (p=0.66) and etiology of vascular lesion (p=0.92), pseudoaneurysm neck anatomy (p=0.14), thrombin units (p=0.47), volume (p=0.76) or technique of use of small doses (p=0.99), use of other embolic material (p=0.67) and use of adjunct techniques (p=0.99)-none were found to be significantly associated with acute nontarget thrombosis. Technical success was 96% with no reports of reperfusion after treatment.

CONCLUSIONS

Catheter-directed endovascular thrombin can be an additional tool to treat pseudoaneurysms not amenable to conventional embolization. Further studies are required to optimize technique and outcomes.

Posttraumatic infrarenal abdominal aortic pseudoaneurysm treated with bifurcated endovascular graft stent

Posttraumatic infrarenal aortic pseudoaneurysms are rare and potentially lethal lesions. We report the case of a 32-year-old man presenting with infrarenal aortic pseudoaneurysm eight months after being stabbed in the back and right flank. His pseudoaneurysm was close to the iliac bifurcation, so we decided to deploy a bifurcated endovascular graft stent, the TriVascular Ovation endovascular stent. Imaging one month after the procedure revealed no endoleak and slight shrinkage of the pseudoaneurysm.

Saccular aneurysm of superior vena cava treated with percutaneous, transcatheter thrombin injection

We report the case of successful endovascular treatment of large saccular aneurysm of SVC in a patient with vascular malformation of right hand and chest. Considering the high risk of surgery, the patient was referred for percutaneous intervention. Venography showed communication between the aneurysm and SVC, just below brachiocephalic confluence. That is why the decision of balloon-protected transcatheter thrombin injection was made. Selective catheter was placed in the aneurysm and balloon occlusion catheter in SVC. Both catheters were withdrawn right after thrombin injection. During follow-up, aneurysm slightly enlarged in early observation and after a year shrinkage was observed.

Self-assembled DNA-based giant thrombin nanoparticles for controlled release

Protein-aptamer interactions have been used in a wide range of fields, including medical diagnosis and protein delivery. Herein, we report a method for thrombin delivery with thrombin-binding aptamer (TBA), which is one of the well-known aptamers for thrombin, by generating giant thrombin nanoparticles (GTNPs). GTNPs can be synthesized by crosslinking thrombin with DNA nanostructures that possess several TBA molecules. To generate GTNPs, two different DNA nanostructures were used. Y-shaped DNA with TBA and X-shaped DNA with TBA were used for 250 and 650 nm GTNPs, respectively. Controlled release of thrombin from GTNPs was performed by adding complementary DNA (cDNA) to TBA. To investigate thrombin release from GTNPs, the sizes of the GTNPs were measured using dynamic light scattering, atomic force microscopy (AFM), and scanning electron microscopy (SEM). We confirmed a decrease in the size of GTNPs with various concentrations of cDNA, suggesting the release of thrombin. Based on these results, we expect that our method can be used to control the amount of thrombin released effectively. Our method is also widely applicable for effective protein delivery.