Successful retrieval of a foreign body in an infant's right pulmonary artery using the new boomerang loop-snare technique: A case report.

We report successful percutaneous retrieval of a foreign body located in an infant's right pulmonary artery using the new boomerang loop-snare technique. The case was an 18-month-old girl. A central venous catheter for chemotherapy was inserted from the right subclavian vein during treatment for myelodysplastic syndrome at another hospital. A postprocedural chest X-ray showed a foreign body in her right lung, and contrast-enhanced computed tomography confirmed the linear foreign body was located in the right pulmonary artery. The patient was transferred to our hospital to retrieve the foreign body. Under cooperation with pediatric cardiologists, a 6 Fr sheath was inserted via the right femoral vein, and a guiding catheter was advanced into the right pulmonary artery. Owing to the risk of vascular injury when using endoscopic forceps, we decided to use the loop-snare technique. We successfully crossed over the foreign body using a steerable microcatheter and a long microguidewire. The microguidewire was reinserted into the guiding catheter, and a loop was created by grasping the end of the wire using a microsnare catheter, which was inserted coaxially within the guiding catheter. By pulling the microsnare catheter, we were able to pull the foreign body into the guiding catheter and successfully retrieved it. There were no complications, such as pulmonary artery injuries or thrombi. The recovered foreign body was a piece of a guidewire. The boomerang loop-snare technique using a small-diameter system is useful for the retrieval of a foreign body in infants.

Successful coil embolization of post-hepatectomy arterioportal fistula that reduced ascites and improved liver function.

A 71-year-old man had previously undergone S7 + S8 dorsal segmentectomy and S5 partial hepatectomy for hepatocellular carcinomas. Six months later, he experienced abdominal distention. Abdominal computed tomography (CT) showed massive ascites and a significant hepatic arterioportal shunt. The ascites was thought to be caused by portal hypertension due to a high-flow hepatic arterioportal fistula (HAPF). The fistula, located between the right hepatic artery A7 and the right portal vein, was embolized with microcoils under flow control using a balloon catheter. After embolization, the shunt blood flow disappeared and the hepatopetal venous flow was restored. His body weight and abdominal circumference decreased immediately, and his liver function on blood tests improved after the procedure. CT performed 11 days after embolization showed decreased ascites. A HAPF after hepatectomy is extremely rare. Balloon-assisted embolization using microcoils is a useful endovascular procedure for treating a high-flow HAPF.

Balloon-Assisted Portal Vein Embolization Using n-Butyl-2-Cyanoacrylate-Lipiodol-Iopamidol Mixture in Swine: A Comparison of 2 Formulations.

PURPOSE: To compare 2 ratios of n-butyl-2-cyanoacrylate (nBCA)-ethiodized oil (Lipiodol)-iopamidol (NLI) in balloon-assisted portal vein embolization (PVE) in swine. MATERIALS AND METHODS: In an in vitro study, NLI prepared at a ratio of 2:3:1 (NLI231) or 1:4:1 (NLI141) was injected into 2.5- or 10-mL syringes filled with swine blood, and the viscosity of NLI was measured to determine an appropriate balloon occlusion time. Two portal vein branches in 8 female swine (n = 16 vein branches) were embolized with NLI231 (n = 8) or NLI141 (n = 8) under balloon occlusion. Portal venography was performed before, immediately after, and 3 days after PVE to evaluate the migration of NLI and the recanalization of embolized portal vein branches. Then, the livers were removed for histopathologic evaluation. RESULTS: The times to peak viscosity of NLI231 in the 2.5- and 10-mL syringes were 55.8 seconds (SD ± 7.0) and 85.2 seconds (SD ± 6.3), and those to peak viscosity of NLI141 were 129.2 seconds (SD ± 11.8) and 254.0 seconds (SD ± 21.8), respectively. No migration of NLI231 was observed in all 8 procedures immediately or 3 days after PVE. Migration of NLI141 was observed in 6 of 8 procedures within 3 days after PVE. The migration frequency of the embolic material was lower in the NI231 group than in the NLI141 group (0/8 vs 6/8; P = .051). Histologically, NLI231 occupied the portal veins without any thrombi, whereas NLI141 was accompanied by thrombi in the portal veins. CONCLUSIONS: NLI231 may be more suitable than NLI141 for balloon-assisted PVE in swine.

Successful coil embolization of a ruptured aneurysm of the arc of Riolan artery.

The arc of Riolan (AOR) is an anastomosis between the middle and left colic arteries. Aneurysms of the AOR are very rare visceral artery aneurysms. A 44-year-old man presented with abdominal pain and loss of consciousness. Computed tomography and angiography showed hemorrhagic ascites around the liver and spleen. An irregularly dilated artery was visible within a hematoma in the upper left region of the abdomen, consistent with a ruptured pseudoaneurysm of the AOR. Transcatheter arterial embolization was performed with microcoils. The patient's abdominal pain disappeared after embolization, and no symptoms of intestinal ischemia were observed. To our knowledge, this is the first case of an AOR aneurysm with AOR dilation due to dissection of the celiac artery that was successfully treated by coil embolization.

Transcatheter arterial embolization of abnormal neovessels in a swine model of knee arthritis.

BACKGROUND: In recent years, transcatheter arterial embolization (TAE) using imipenem/cilastatin (IPM/CS) has attracted attention as a treatment for relieving osteoarthritis (OA) pain. However, IPM/CS is not approved by Japanese medical insurance for use as an embolic material. Therefore, it is necessary to develop new embolic materials for TAE to relieve OA pain. The purpose of this study was to develop a swine model of knee arthritis and embolize abnormal neovessels (ANs) using two different embolic materials. We compared the embolic effects and tissue damage in knees. METHODS: Knee arthritis was induced by intra-articular injection of papain into 12 knees in six female swine. The swine were divided into two groups of three swine each (six knees per group) for embolization of ANs in the knees with either IPM/CS or soluble gelatin sponge particles (SGSs). Three days after embolization, we compared the embolic effects using angiography and the tissue damage histopathologically. RESULTS: ANs were observed in all 12 knees at 42 days after papain injection. The ANs disappeared and the patent arteries were recanalized 3 days after TAE in all 12 knees. Histopathological evaluation revealed synovitis changes, such as synovial thickening and inflammatory cell infiltration, in all 12 knees. There was no evidence of skin or muscle necrosis in either group. The appearance of ANs, recanalization of the parent arteries, and histopathological outcomes were not significantly different between the two groups. CONCLUSION: SGSs were as safe as IPM/CS for TAE of ANs in this swine model of knee arthritis.

Comparison of Uterine Necrosis After Uterine Artery Embolization with Soluble Gelatin Sponge Particles or Tris-acryl Gelatin Microspheres in Swine.

PURPOSE: To compare the recanalization of the uterine arteries and uterine necrosis after uterine artery embolization (UAE) using either soluble gelatin sponge particles (SGS), which dissolve in saline, or tris-acryl gelatin microspheres (MS), which are permanent embolic materials, in swine. METHODS: Fourteen uteri in seven swine were divided into two groups for embolization with either 500-1000 µm SGS (SGS group) or 500-700 µm MS (MS group) (seven uteri per group). The uterine arteries were embolized using SGS or MS, and angiography was performed to evaluate recanalization of the uterine arteries immediately, 1, 2, 3, 4, 5, and 6 h, and 3 days after embolization. On day 3, the uteri were removed to determine the macroscopic necrosis rate and for histopathologic examination. RESULTS: In the SGS group, four uterine arteries were completely recanalized, two were partially recanalized, and one was still occluded 5 h after embolization. In contrast, all seven uterine arteries in the MS group were still occluded 6 h after embolization. The complete recanalization rate at 3 days was significantly greater in the SGS group than in the MS group (100.0% vs. 14.3%, respectively; P = .0047). The mean uterine necrosis rate was not significantly different between the SGS and MS groups (15.0 ± 15.7% vs. 26.8 ± 13.3%, respectively; P = .096). The mean smallest arterial diameter containing embolic materials was 48.2 ± 22.0 µm (range 21-109 µm) for SGS and 446.7 ± 107.0 µm (range 352-742 µm) for MS (P < .0001). CONCLUSION: The uterine arteries recanalized earlier in the SGS group than in the MS group and the uterine necrosis rates were similar in both groups. SGS have the potential for a more distal penetration in comparison with MS.

Balloon-Assisted Embolization of Wide-Neck Aneurysms Using a Mixture of n-Butyl Cyanoacrylate, Lipiodol, and Ethanol in Swine: A Comparison of Four n-Butyl Cyanoacrylate Concentrations.

PURPOSE: To determine the optimal ratio of n-butyl cyanoacrylate (NBCA)-Lipiodol-ethanol (NLE) mixture for balloon-assisted embolization of wide-neck aneurysms. MATERIALS AND METHODS: We created 32 wide-neck aneurysms on both the common carotid arteries and external iliac arteries in eight female swine. Eight aneurysms were randomly assigned to four groups. Under balloon occlusion, the aneurysms were packed using NLE at one of four ratios of NLE: 2:2:1 (NLE221; 40%NBCA); 3:6:1 (NLE361; 30%NBCA); 2:7:1 (NLE271; 20%NBCA); and 1:5:1 (NLE151; 14.3%NBCA). We performed angiography before and after embolization to assess the aneurysms, and we compared adhesion between NLE and the balloon and assessed NLE migration. Three days after embolization, the aneurysms were removed for histopathologic evaluation. RESULTS: Embolization was performed in 27 aneurysms. Adhesion between NLE and the balloon was not observed in any group. NLE migration was found in 0/7 aneurysms in the NLE221 group, 0/6 in the NLE361 group, 5/6 in the NLE271 group, and 7/8 in the NLE151 group. NLE migration was significantly lower in the NLE221 group than in the NLE271 and NLE151 groups (P = 0.0047 and 0.0014, respectively) and was significantly lower in the NLE361 group than in the NLE271 and NLE151 groups (P = 0.0152 and 0.0047, respectively). Media necrosis of the arterial wall close to the aneurysms was observed in all groups. CONCLUSION: NLE with an NBCA concentration of ≥ 30% is a safe and feasible embolic material for balloon-assisted embolization of wide-neck aneurysms in swine in the short term up to 3 days after embolization.

Hepatic Arterial Embolization with an Indocyanine Green-LipiodolⓇ Mixture before Laparoscopic Anatomical Liver Resection.

Here, we report a case of hepatocellular carcinoma detected on computed tomography and treated with laparoscopic anatomical liver resection in a 69-year-old woman who was being followed-up for hepatitis C. Intraoperative liver segmentation is necessary to accomplish laparoscopic anatomical liver resection. Therefore, the day before surgery, hepatic artery embolization was performed with an indocyanine green-LipiodolⓇ mixture and GelpartⓇ containing indocyanine green to mark the region for hepatectomy. The next day, surgeons visually confirmed the resection segments on indocyanine green fluorescence imaging and performed laparoscopic anatomical liver resection. No major complications resulted from this method. In conclusion, hepatic artery embolization with an indocyanine green-LipiodolⓇ mixture is effective and safe for liver segment identification during laparoscopic anatomical liver resection.

Endovascular management of endotension by graft reinforcement followed by direct sac embolization.

Purpose: To assess the efficacy of graft reinforcement followed by percutaneous direct sac embolization (PDSE) for the treatment of endotension after endovascular abdominal aortic aneurysm repair (EVAR). Materials and methods: A total of 290 patients underwent elective EVAR. All patients regularly underwent scheduled surveillance with contrast-enhanced computed tomography (CT). Two hundred thirty-five patients were followed for ≥24 months after EVAR. Aneurysmal sac expansion of ≥10 mm was observed in 20 patients. The patients with sac expansion of ≥10 mm with no evidence of endoleak were treated with graft reinforcement. Graft reinforcement consisted of graft extension and graft relining. The patients with sac expansion at 6 months after graft reinforcement received PDSE using metallic coils and n-butyl cyanoacrylate-Lipiodol mixture. The aneurysm diameter was measured by CT performed 6 months and every year after the final intervention. Results: Seven patients (7 men, 0 women; mean age, 69.1 ± 4.2 years, Zenith®:5/Excluder®:1/Powerlink®:1) underwent graft reinforcement. Two patients underwent graft reinforcement alone, and five patients underwent PDSE after graft reinforcement. Mean follow-up time after the final intervention was 21.1 months. The sac diameter stabilized after the final intervention in all patients. Conclusion: Graft reinforcement followed by complementary PDSE could be a useful treatment strategy for endotension.

Transgraft sac Embolization Combined with Graft Reinforcement for Refractory Mixed-Type Endoleak.

An 80-year-old female underwent EVAR 4 years ago. She presented type II endoleak with sac expansion from 68 to 80 mm during 3-year follow-up after EVAR. Although she underwent translumbar percutaneous sac embolization, the AAA sac continued to enlarge, suggesting mixed-type endoleak including type I, II, and III. Transgraft direct sac angiography revealed endoleak cavity without demonstrable feeding vessel. Transgraft sac embolization using n-butyl cyanoacrylate and graft reinforcement was performed concurrently, without complications. The graft reinforcement consisted of graft extension for eliminating occult type I endoleak, and relining for eliminating occult type III endoleak. Six months after the procedure, CT showed no signs of sac expansion. Transgraft sac embolization combined with graft reinforcement is one of the available options for persistent and refractory mixed-type endoleak.

Type II endoleak model creation and intraoperative aneurysmal sac embolization with n-butyl cyanoacrylate-lipiodol-ethanol mixture (NLE) in swine.

BACKGROUND: The purpose of this study was to evaluate the feasibility of type II endoleak model creation and efficacy of intraoperative aneurysmal sac embolization using n-butyl-2-cyanoacrylate-lipiodol-ethanol mixture (NLE) for type II endoleak in swine. METHODS: In six swine (mean body weight 53.5 kg), abdominal aortic aneurysm (AAA) was created and then end-to-side anastomosis between the left renal artery and AAA sac was performed. And then, endovascular abdominal aortic aneurysm repair (EVAR) was performed, leading to creation of a type II endoleak model. As control group, EVAR without sac embolization was performed in two swine. In four swine, AAA sac was embolized using NLE immediately after EVAR via the microcatheter placed in AAA sac (NLE embolization group). Follow-up aortography was performed immediately and three days after the procedure, and then the aneurysms were extracted. RESULTS: The AAA sac and type II endoleak model were successfully created in all cases. In control group, type II endoleak persisted three days after the procedure. In NLE embolization group, endoleak disappeared immediately and three days after the procedure. In NLE embolization group, AAA sac was occupied with thrombus and embolic material. Inflammatory changes were recognized in aneurysmal sac wall in NLE embolization group. CONCLUSIONS: This experimental study suggests that creation of a type II endoleak model in swine is feasible and that intraoperative AAA sac embolization with NLE during EVAR might reduce the occurrence of type II endoleak.