Retrograde embolization of internal iliac artery aneurysms that enlarged after proximal ligation: A report of 5 patients.

The transarterial approach is generally feasible for endovascular treatment of internal iliac artery aneurysms (IIAAs). However, this approach becomes difficult in patients who have undergone exclusion surgery (proximal ligation). We report our experience of performing transcatheter arterial embolization (TAE) using a retrograde approach from the deep femoral artery (DFA) for IIAAs that had enlarged after exclusion surgery. This case series includes 5 male patients (mean age, 57 years; range, 66-81 years) who underwent TAE of IIAAs between March 2015 and March 2024. The procedures were performed at a mean of 47 months (range, 33-108 months) after aortoiliac repair. Preoperative contrast-enhanced computed tomography (CT) or CT during aortography was performed before TAE in all cases to evaluate the development of collateral pathways. TAE was performed via the DFA using a retrograde approach with coils and cyanoacrylate glue in all cases. The procedure was technically successful in all 5 patients (100%). Intra-aneurysmal packing and embolization of the branched vessel was performed in all cases. The follow-up ranged from 6 to 66 months. All patients developed gluteal claudication but no major complications occurred during the follow-up period. No cases of aneurysm dilatation have been recorded to date. In conclusion, retrograde TAE of excluded IIAAs was a feasible and effective treatment in these 5 patients, after evaluating the development of collateral pathways on pretreatment contrast-enhanced CT.

An anomalous left adrenal vein draining into both the left renal vein and inferior vena cava: A case report.

A male patient in his forties was diagnosed with primary aldosteronism following blood tests. The patient requested surgical treatment and was transferred to our department for adrenal vein sampling. Preoperative contrast-enhanced computed tomography (CT) revealed that the left adrenal vein (LAV) did not form a common trunk with the left inferior phrenic vein, and instead drained into both the left renal vein (LRV) and inferior vena cava (IVC) after the bifurcation. Angiography from the LAV showed a branch draining into the IVC. Left-sided sampling was performed. Aldosterone levels were elevated at all 3 sites. Because the sampling results were bilaterally positive, the patient was contraindicated for surgery. There are no reports of an anomalous LAV draining into both the LRV and IVC, making this case extremely unique. Regarding the LAV sampling site, it has been reported that aldosterone levels are higher in the common trunk than in the LAV. Therefore, we increased the number of blood sampling sites. In adrenal vein sampling, we often focus on the anatomy of the right adrenal vein because of difficulties in accessing to it. However, anomalies of the LAV may also occur. Therefore, it is important to determine the anatomy of both adrenal veins using preoperative contrast-enhanced CT to plan an appropriate sampling strategy.

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.

Comparison of Renal Damage Following Renal Artery Embolization with Three Different Embolic Mixtures in Swine.

Purpose: Renal artery embolization is a minimally invasive and effective procedure for renal ablation, a complete necrosis of the renal parenchyma. This study aims to compare the extent of renal damage in swine following renal artery embolization with ethanol and N-butyl-2-cyanoacrylate, commonly used as embolic materials in renal ablation. Material and Methods: Three different embolic mixtures were prepared for renal artery embolization in swine: 33% ethanol-Lipiodol mixture (ethanol:Lipiodol = 1:2; Group A), 67% ethanol-Lipiodol mixture (ethanol:Lipiodol = 2:1; Group B), and 10% N-butyl-2-cyanoacrylate-Lipiodol mixture (N-butyl-2-cyanoacrylate:Lipiodol = 1:9; Group C). Three swine were assigned to each group and underwent embolization of the unilateral renal artery. Renal arteriography was performed before, immediately after, and two days after renal artery embolization. After two days, the kidneys were removed to determine the macroscopic necrosis rate and for histologic examination. Dark tissue regions were considered necrotic. Results: The macroscopic necrosis rate of the kidneys was 50.3%±7.4%, 100%±0%, and 100%±0% in Groups A, B, and C, respectively. The necrosis rates were higher in Groups B and C than in Group A. Histologically, the renal tubules were damaged in the necrotic areas. In addition, the glomeruli were damaged in Groups A and B but were preserved in Group C. Conclusions: Sixty-seven percent ethanol-Lipiodol mixture and 10% N-butyl-2-cyanoacrylate-Lipiodol mixture are effective embolic materials in renal artery embolization for renal ablation in swine. Also, ethanol caused partial glomerular necrosis, whereas N-butyl-2-cyanoacrylate preserved the glomeruli. Therefore, ethanol should be used for renal ablation.

Feasibility of the Glue-in-Plug Technique Using a Novel Liquid Embolic Material in a Swine Model.

PURPOSE: To evaluate the feasibility of the glue-in-plug (GIP) technique using n-butyl-2-cyanoacrylate‒Lipiodol (NL)-iopamidol (NLI) for short-segment embolization in swine. MATERIALS AND METHODS: The renal arteries, left external iliac artery, subclavian arteries, and common carotid arteries were each embolized in 4 swine using the GIP technique under general anesthesia. First, a type I Amplatzer vascular plug (AVP) (1-2 times the target vessel diameter) was deployed in the target artery. Next, the AVP was filled with NL mixture prepared at a ratio of 1:2 (NL12) (n = 11) or with NLI mixture prepared at a ratio of 2:3:1 (NLI231) (n = 11). Angiography was performed before, immediately after, and 1 hour after embolization to assess embolization and migration of the embolic materials. The embolized arteries were also evaluated histopathologically. RESULTS: The migration distance of the embolic material beyond the plug tip was significantly shorter in the NLI231 group than in the NL12 group immediately after embolization (6.5 mm ± 4.5 vs 1.0 mm ± 1.8, P = .0024) and 1 hour after embolization (8.4 mm ± 5.6 vs 1.0 mm ± 1.8, P = .0013). Angiography revealed no sign of recanalization of the target vessels in any artery in either group. Mild inflammatory cell infiltration was observed around the arterial wall at the embolization site in all arteries in both groups. CONCLUSIONS: The GIP technique using NLI231 may be a feasible procedure for short-segment embolization based on these short-term results.

Duodenal bleeding outside covered stents identified by selective computed tomography during arteriography that was successfully treated by embolization: A case report.

The patient was a man in his 60s who previously underwent placement of covered stents in the duodenum for a duodenal stricture caused by pancreatic cancer invasion. He experienced multiple episodes of hematemesis and hematochezia during hospitalization. Emergency upper and lower gastrointestinal endoscopies were performed but were unable to reveal the bleeding source. Based on these findings, we suspected small intestinal bleeding and emergency angiography was performed for the purpose of hemostasis. Computed tomography during arteriography was performed from the superior mesenteric artery and revealed extravasation outside the covered stents in the descending portion of the duodenum. Angiography of the inferior pancreaticoduodenal artery revealed extravasation in the descending portion of the duodenum, and the inferior pancreaticoduodenal artery was embolized with n-butyl cyanoacrylate. There were no postoperative symptoms indicative of intestinal ischemia or pancreatitis, and there was no rebleeding after embolization. In patients with bleeding outside the duodenal-covered stents, it can be difficult to identify the bleeding source by upper gastrointestinal endoscopy. In this case, selective computed tomography during arteriography and angiography revealed bleeding outside the duodenal-covered stents that was successfully treated by arterial embolization with n-butyl cyanoacrylate.

Percutaneous transsplenic venous embolization of elevated jejunal varices after pancreaticoduodenectomy: A case report.

Recent advances in chemotherapy and radiotherapy have led to an increase in the number of long-term survivors of pancreatic cancer. However, this has also increased the number of patients suffering from ectopic varices and bleeding owing to left-sided portal hypertension and thrombocytopenia caused by splenomegaly after pancreaticoduodenectomy combined with resection of the splenic vein. A 65-year-old woman with varices of the elevated jejunum due to left sided portal hypertension after pancreaticoduodenectomy had repeated melena, which started about 1 year before admission. We describe the first reported case of percutaneous transsplenic venous embolization using metallic coils, which successfully achieved hemostasis of refractory bleeding from the elevated jejunal varices after pancreaticoduodenectomy.

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.

Usefulness of ethiodized oil and gelatin sponge particles for delaying the washout of indocyanine green from the liver in swine.

PURPOSE: To assess the effect of ethiodized oil (EO) and gelatin sponge particles (GS) on delaying the washout of indocyanine green (ICG) from the liver in swine. METHODS: Fifteen swine were divided into 3 groups: injection of a mixture of ICG and water-soluble contrast medium (CM) followed by embolization with GS (group A), injection of a mixture of ICG and EO (group B) and injection of a mixture of ICG and EO followed by embolization with GS (group C). The liver surface was observed using an infrared camera system during and at 1, 2, 3, and 6 h after the procedure to measure ICG contrast. Livers were removed at 6 h for histopathological examination. RESULTS: The contrast ratio between injected and non-injected regions at 6 h was 1.45 ± 0.44 in group A, 1.89 ± 0.37 in group B, and 3.62 ± 0.76 in group C. The contrast ratio in group C was significantly greater than that in groups A and B (P = 0.032 and 0.033, respectively). CONCLUSIONS: EO and GS delayed the washout of ICG from the liver in swine and may extend intraoperative navigation in clinical use. Indocyanine green (ICG) mixed with ethiodized oil (EO) was injected into the left hepatic artery in swine, and the artery was embolized with gelatin sponge particles (GS). We confirmed that ICG remained in the liver parenchyma up to 6 h after the procedure. EO and GS delayed the washout of ICG from the liver in swine.

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.

Contrast-enhanced harmonic endoscopic ultrasonography for predicting the efficacy of first-line gemcitabine and nab-paclitaxel chemotherapy in pancreatic cancer.

BACKGROUND AND AIMS: The purpose of this study was to assess prognosis with different intratumoral vascularity on contrast-enhanced endoscopic harmonic ultrasonography (CH-EUS) in pancreatic cancer patients receiving chemotherapy. METHODS: Patients with unresectable pancreatic cancer who underwent CH-EUS before first-line gemcitabine and nab-paclitaxel (GEM and nab-PTX) therapy were classified into four groups according to vascularity on the early and late phases of contrast enhancement: "Group A″, poor on both phases; "Group B″, rich and poor on the early and late phases, respectively; "Group C″, poor and rich on the early and late phases; "Group D″, rich on both phases. Subgroups were compared in terms of progression-free survival (PFS) and overall survival (OS). We also assessed whether the results with CH-EUS correlate with those of contrast-enhanced computed tomography (CE-CT). RESULTS: On CH-EUS, 57, 64, 0, and 24 patients were classified into Groups A, B, C, and D, respectively. The median PFS of patients in groups A, B, and D was 3.9, 7.6, and 10.8 months, respectively, and the median OS were 9.5, 13.1, and 18.6 months, respectively. Both PFS and OS were longest in Group D (p < 0.001 and p < 0.001, respectively). The results of CE-CT were consistent with those of CH-EUS, and there was a correlation between CE-CT and CH-EUS. CONCLUSIONS: Evaluation of intratumoral vascularity by CH-EUS may be useful for predicting the efficacy of chemotherapy in patients with pancreatic cancer. A better response to GEM and nab-PTX can be expected in patients showing rich vascularity at both the early and late phases.

Determination of the Optimal Ratio and the Relationship Between Viscosity and Adhesion of n-Butyl Cyanoacrylate-Lipiodol-Iopamidol for Balloon-Assisted Embolization of Wide-Neck Aneurysms in Swine.

PURPOSE: To determine the optimal ratio of n-butyl cyanoacrylate-Lipiodol-iopamidol (NLI) for balloon-assisted embolization of wide-neck aneurysms in swine. MATERIALS AND METHODS: Sixteen NLI mixtures were prepared for in vitro studies. The viscosity of each mixture was measured for 30 min. We evaluated whether the mixtures could be injected through a microcatheter and whether they adhered to the microcatheter. In vivo, 15 wide-neck aneurysms were created on the arteries in 4 female swine. Under balloon occlusion, 7 aneurysms were embolized with NLI141 (NBCA:Lipidol:iopamidol = 1:4:1) and 8 were embolized with NLI231. We performed angiography to evaluate adhesion of NLI to the balloons or microcatheters and NLI migration. RESULTS: In vitro, the iopamidol content needed to comprise at least 1/6 of the mixture in order for NLI to be non-adhesive with increased viscosity. NLI could not be injected through a microcatheter if the iopamidol content exceeded 1/6 of the mixture. Only NLI141 and NLI231 did not adhere to the microcatheter with increased viscosity, and could be injected through a microcatheter. In vivo, neither NLI mixture adhered to the balloons or microcatheters. The migration of NLI was observed in 6 of 7 aneurysms embolized with NLI141 and in none of 8 aneurysms embolized with NLI231. CONCLUSION: Our in vitro study revealed that the ratios of NLI that were non-adhesive and could be injected through a microcatheter were 1:4:1 and 2:3:1. The optimal ratio of NLI for balloon-assisted embolization of wide-neck aneurysms in swine was considered to be 2:3:1.

Feasibility and Safety of n-Butyl Cyanoacrylate-Lipiodol-Iopamidol as an Alternative Liquid Embolic Material.

PURPOSE: To evaluate the feasibility and safety of n-butyl cyanoacrylate (NBCA)-Lipiodol-Iopamidol (NLI) as a liquid embolic material. MATERIALS AND METHODS: In vitro, the ratio of NLI components was adjusted and the configuration of the mixtures was assessed visually in saline. In vivo, 14 wide-necked aneurysms were created on the common carotid and external iliac arteries of four female swine. Under balloon occlusion, 12 aneurysms were embolized with NLI prepared at a NBCA-Lipidol-Iopamidol ratio of 2:3:1 (NLI231), and two were embolized with NBCA-Lipiodol (NL) prepared at a NBCA-Lipiodol ratio of 1:2 (NL12) as a trial group. We performed angiography to evaluate the effectiveness of embolization and adhesion of the embolic material to the balloons or microcatheters. RESULTS: In vitro, NLI231 (33% NBCA) was considered to be the optimal ratio for aneurysm embolization based on its configuration and stability. In vivo, embolization using NLI231 was successful and no adhesion between the embolic material and the balloons or microcatheters was observed in all 12 aneurysms. Embolization with NL12 was impossible in the other two aneurysms due to leakage and adhesion of NL. CONCLUSION: The configuration of NLI changed at each ratio. NLI231 is a feasible and safe liquid embolic material for balloon-assisted embolization of wide-necked aneurysms in swine.