Hirotatsu Sato

Risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair

PURPOSE We aimed to identify the risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair (EVAR). METHODS We retrospectively reviewed contrast-enhanced computed tomography (CT) images of 143 patients who were followed for ≥6 months after EVAR. Sac expansion was defined as an increase in sac diameter of 5 mm relative to the preoperative diameter. Univariate and multivariate analyses were performed to identify associated risk factors for late sac expansion after EVAR from the following variables: age, gender, device, endoleak, antiplatelet therapy, internal iliac artery embolization, and preprocedural variables (aneurysm diameter, proximal neck diameter, proximal neck length, suprarenal neck angulation, and infrarenal neck angulation). RESULTS Univariate analysis revealed female gender, endoleak, aneurysm diameter ≥60 mm, suprarenal neck angulation >45°, and infrarenal neck angulation >60° as factors associated with sac expansion. Multivariate analysis revealed endoleak, aneurysm diameter ≥60 mm, and infrarenal neck angulation >60° as independent predictors of sac expansion (P < 0.05, for all). CONCLUSION Our results suggest that patients with small abdominal aortic aneurysms (<60 mm) and infrarenal neck angulation ≤60° are more favorable candidates for EVAR. Intraprocedural treatments, such as prophylactic embolization of aortic branches or intrasac embolization, may reduce the risk of sac expansion in patients with larger abdominal aortic aneurysms or greater infrarenal neck angulation.

Endovascular Stenting and Stent-graft Repair of a Hemorrhagic Superior Mesenteric Artery Pseudoaneurysm and Dissection Associated with Pancreaticoduodenectomy

This report presents a 73-year-old woman with intraperitoneal bleeding from a superior mesenteric artery (SMA) pseudoaneurysm and dissection after pancreaticoduodenectomy (PD). A self-expanding bare metal stent was placed in the distal SMA across the area of dissection, and a stent-graft was subsequently placed across the pseudoaneurysm emerging from the proximal site by overlapping the bare stent, resulting in complete exclusion of the pseudoaneurysm and control of the dissection. Bleeding was controlled after the endovascular procedure. The combination of endovascular stenting and stent-graft repair is feasible and useful in comorbid cases of SMA pseudoaneurysm and dissection.

Clinical evaluation of transcatheter arterial chemoembolization with 2-day-soluble gelatin sponge particles for hepatocellular carcinoma-comparison with insoluble gelatin sponge particles.

PURPOSE To compare therapeutic effect, adverse events, and embolized hepatic artery impairment in transcatheter arterial chemoembolization between Lipiodol plus insoluble gelatin sponge particles (Gelpart) and Lipiodol plus 2-day-soluble gelatin sponge particles (2DS-GSPs). MATERIALS AND METHODS In a single-center, prospective, randomized controlled trial, patients with hepatocellular carcinoma were assigned to the 2DS-GSP group or the Gelpart group. Radiographic response at 3 months per modified Response Evaluation Criteria In Solid Tumors was evaluated as the primary endpoint; secondary endpoints were safety (per Common Terminology Criteria for Adverse Events, version 4.0) within 3 months and hepatic branch artery impairment at the time of repeat chemoembolization (grade 0, no damage; grade I, mild vessel wall irregularity; grade II, overt stenosis; grade III, occlusion of more peripheral branch artery than subsegmental artery; grade IV, occlusion of subsegmental artery). Grade II, III, or IV indicated significant hepatic artery impairment. RESULTS Thirty-seven patients with 143 nodules were randomized to the 2DS-GSP group and 36 patients with 137 nodules were randomized to the Gelpart group. No significant differences in patient background existed between groups. Target lesion response and overall tumor response in the 2DS-GSP and Gelpart groups were 77.7% versus 76.9% and 78.3% versus 77.8%, respectively, with no significant differences. No significant difference in adverse events existed between groups. Hepatic artery impairment was observed in 5% of patients in the 2DS-GSP group (n = 32) and in 16% in the Gelpart group (n = 33; P< .001). CONCLUSIONS Transcatheter arterial chemoembolization with 2DS-GSPs resulted in the same therapeutic and adverse effects as chemoembolization with Gelpart while causing significantly less hepatic artery impairment.

Retrograde Popliteal Endovascular Stent- Graft Repair for a Growing Persistent Sciatic Artery Aneurysm (Type IIa): Case Report and Review of the Literature

Editor: The sciatic artery, connecting the internal iliac artery to the femoral artery, is the main blood route to the lower extremity in the early-stage embryo. This vessel degenerates and disappears with the development of the external iliac artery to the superficial femoral artery (SFA) (1,2). A persistent sciatic artery (PSA) is a postnatal remnant that occurs with an incidence of 0.01%–0.06% (1,2). It is classified into two types: the complete type, in which the lower extremity obtains blood flow predominantly from the sciatic artery; and the incomplete type, in which the popliteal artery obtains blood flow from the SFA (3). Among all PSAs, the complete type is reported to occur with an incidence of 63%–79% (1,4). According to the classification of PSA, PSA combined with an incompletely developed small SFA is classified as type IIa (5,6). We present a patient with an aneurysm of the complete (ie, type IIa) PSA that was treated with endovascular stent-graft repair. Preparation of this retrospective case report was exempted from institutional review board approval. A 75-year-old woman had undergone a left nephrectomy for renal-cell carcinoma 4 years earlier. Although she was asymptomatic, the patient underwent follow-up computed tomography (CT) to check for recurrence. A dense soft-tissue mass 40 mm in diameter was found in her right buttock. A CT scan obtained 1 year later revealed that the mass had increased in diameter to 50 mm. The patient was diagnosed with a right completetype (ie, type IIa) PSA aneurysm based on the contrastenhanced CT findings (Fig 1). Physical examination revealed a pulsatile mass in the right buttock. The ankle-brachial indices on the right and left were 1.12

Successful endovascular treatment of iliac arteriovesical fistula with secondary stent-graft infection.

A 58-year-old woman initially presented with massive gross hematuria and iliac arteriovesical fistula (IAVF). Endovascular stent-graft repair achieved complete exclusion of the IAVF and controlled the bleeding, but sepsis subsequently developed because of endograft infection. Endovascular embolization of the infected stent graft was performed after extraanatomic bypass surgery. The patient recovered and showed no signs of graft infection or recurrent fistulization at 14 months after treatment. Endovascular embolization of infected stent grafts combined with extraanatomic bypass may be an acceptable treatment option for graft-related sepsis in cases that are resistant to conservative treatment and pose high surgical risk for graft excision.

Utility of 99mTc–Human Serum Albumin Diethylenetriamine Pentaacetic Acid SPECT for Evaluating Endoleak After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE The purpose of this study was to assess the utility of (99m)Tc-human serum albumin diethylenetriamine pentaacetic acid ((99m)Tc-HSAD) SPECT in the detection of endoleaks after endovascular abdominal aortic aneurysm repair. SUBJECTS AND METHODS Fifteen patients (11 men, four women) with aneurysm sac expansion of 5 mm or greater after endovascular abdominal aortic aneurysm repair underwent three-phase CT, (99m)Tc-HSAD SPECT, and CT during aortography. Sensitivity calculations for three-phase CT and (99m)Tc-HSAD SPECT were performed with CT during aortography as the reference standard. The volume of each endoleak was measured with CT during aortography. Seven subjects underwent embolization with N-butyl cyanoacrylate (NBCA)-Lipiodol (ethiodized oil, Guerbet and metallic coils. Three-phase CT and (99m)Tc-HSAD SPECT were repeated after embolization to assess their efficacy. RESULTS Endoleaks were interpreted as perigraft radioisotope accumulation in 12 patients (80.0%) on (99m)Tc-HSAD SPECT images, in 13 patients (86.7%) on three-phase CT images, and in 15 patients (100%) on CT during aortography. The mean endoleak volume visualized with (99m)Tc-HSAD SPECT was 8.37 cm(3) (range, 5.2-15.1 cm(3)), and the volume not visualized was 3.47 cm(3) (2.5-4.6 cm(3)), a statistically significant difference (p = 0.019). In two patients, (99m)Tc-HSAD SPECT depicted endoleaks evident at delayed phase CT during aortography but not at three-phase CT, suggesting they were slow-filling endoleaks. Accumulation of (99m)Tc-HSAD corresponding to endoleaks disappeared after embolization, but CT evaluation of embolization was impeded by artifacts of NBCA-Lipiodol and metallic coils. CONCLUSION Technetium-99m-labeled HSAD SPECT proved less sensitive than three-phase CT but depicted endoleaks with volumes 5.2 cm(3) or greater as perigraft radioisotope accumulation. Slow-filling endoleaks can be visualized with (99m)Tc-HSAD SPECT, which can be used to evaluate the efficacy of embolization.

The Use of Technetium-99m–Labeled Human Serum Albumin Diethylenetriamine Pentaacetic Acid Single-Photon Emission CT Scan in the Follow-up of Type II Endoleak Treatment

An 84-year-old woman presented with persistent type II endoleak with sac expansion from 57 mm to 75 mm during 4-year follow-up after endovascular abdominal aortic aneurysm repair. The patient underwent transabdominal embolization with coils and N-butyl cyanoacrylate/ethiodized oil (Lipiodol; Guerbet, Villepinte, France) mixture (2.5 mL). Because of the anticipated embolization artifacts on follow-up computed tomography (CT), technetium-99m-labeled human serum albumin diethylenetriamine pentaacetic acid single-photon emission computed tomography ((99m)Tc-HSAD SPECT) was performed before and after the intervention. Perigraft accumulation on (99m)Tc-HSAD SPECT corresponding to the endoleak disappeared after embolization. CT scan performed 12 months after embolization showed no signs of sac expansion. (99m)Tc-HSAD SPECT may be useful for evaluating therapeutic effect after embolization for endoleak.

Prophylactic Intraoperative Embolization of Abdominal Aortic Aneurysm Sacs Using N-Butyl Cyanoacrylate/Lipiodol/Ethanol Mixture with Proximal Neck Aortic Balloon Occlusion during Endovascular Abdominal Aortic Repair.

PURPOSE To determine the feasibility of prophylactic intraoperative abdominal aortic aneurysm (AAA) sac embolization using a mixture of N-butyl cyanoacrylate/Lipiodol/ethanol (NLE) with proximal neck aortic balloon occlusion during endovascular aneurysm repair (EVAR) to prevent the occurrence of endoleak and aneurysm sac expansion. MATERIALS AND METHODS Prophylactic intraoperative AAA sac embolization was performed in 24 patients with an infrarenal neck angulation > 60° (n = 16) or AAA sac diameter > 60 mm (n = 17). AAA sac pressure was continuously measured with a 3-F catheter inserted into the AAA sac. The systolic sac pressure index (SPI) was calculated as the ratio of systolic AAA sac pressure to the simultaneously measured systolic aortic pressure, and was measured with and without proximal neck aortic balloon occlusion. The aneurysm sac was embolized with NLE during proximal neck aortic balloon occlusion immediately after EVAR. Endoleak and AAA sac diameter were evaluated by enhanced computed tomography and subtraction magnetic resonance imaging at 6 months and yearly after EVAR. RESULTS Mean SPIs after EVAR with and without proximal neck aortic balloon occlusion were 0.36 and 0.57, respectively. There were no adverse events related to intraoperative sac embolization. Follow-up imaging (mean, 12.1 mo) revealed three minor endoleaks (12.5%) and no aneurysm sac expansion. CONCLUSIONS Prophylactic intraoperative sac embolization with NLE during proximal neck aortic balloon occlusion was safe and feasible and may reduce endoleaks and prevent sac expansion after EVAR in patients with unfavorable anatomic factors.

Tracheo-innominate artery fistula successfully treated by endovascular stent-graft repair

We report two patients who developed a tracheo-innominate artery fistula (TIF) after tracheostomy. Contrast-enhanced computed tomography revealed a pseudoaneurysm of the innominate artery protruding into the trachea. Stent grafts were deployed for the innominate artery via two different access routes: the transfemoral approach and the right carotid artery approach. Endovascular stent-graft repair resulted in complete exclusion of the TIF and control of the bleeding from the tracheal stoma. At 12- and 16-month follow-ups, neither patient had clinical signs of graft infection, recurrent fistulization, or ischemic complications. It is feasible and useful to employ the carotid artery approach for stent-graft implantation in patients who have vascular anatomical limitations for the transfemoral approach. Endovascular repair of TIF by stent grafting is a minimally invasive treatment that can be tolerated by patients in poor clinical condition, and is a feasible alternative to surgical treatment.