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.

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.

Artificially induced pneumothorax with a Veress needle for cryoablation of renal cell carcinoma.

Thermal ablative techniques are used increasingly to treat renal cell carcinoma (RCC). Percutaneous cryoablation of tumors at the upper pole of the kidney may result in pulmonary damage due to the intervening lung parenchyma. We treated two patients with RCC in the upper pole of the kidney by inducing pneumothorax with a pneumoperitoneum needle before proceeding to percutaneous cryoablation. The procedures, performed under computed tomography (CT) fluoroscopy guidance, resulted in complete tumor necrosis. There was no pulmonary damage.

A case of maxillary cancer treated by intra-arterial therapy using a steerable microcatheter.

We report on a 69-year-old man with locally-advanced left maxillary sinus cancer who underwent treatment with intra-arterial chemoradiotherapy. Angiography showed that the main feeding arteries were the left maxillary artery and the ophthalmic artery, arising from the internal carotid artery. Due to acute branching of the ophthalmic artery, conventional microcatheters could not be inserted. Using a steerable microcatheter, we were able to repeatedly administer chemoradiotherapy via the ophthalmic artery. The tumor has mostly disappeared after intra-arterial chemoradiotherapy, and the patient is still alive two years after treatment. A steerable microcatheter is very useful for acute-angled vascular branches.

Efficacy and safety of CT-guided cryoablation after lipiodol marking and embolization for RCC.

PURPOSE: To evaluate the safety and efficacy of CT fluoroscopy-guided percutaneous cryoablation (PCA) after lipiodol marking and embolization (LME) in patients with renal cell carcinoma (RCC). MATERIAL AND METHODS: This study included 29 patients (18 men, 11 women; mean age 69 years, range 22-89 years) with 42 RCCs. They underwent CT fluoroscopy-guided PCA after LME between March 2016 and March 2020. The mean tumor diameter was 21 mm (range 7-50 mm). LME was performed with lipiodol and gelatin particles. PCA was considered successful when the ice ball encapsulated the entire tumor and the margin was sufficient on post-ablation CT scans. RESULTS: LME was successfully performed in 39 of 40 tumors (97.5%). PCA after LME was successful in all 39 of 39 tumors (100%). During the follow-up period (mean 13.9 ± 12.1 months), one of the 39 tumors (2.6%) developed local tumor progression. A significant complication (reversible hypertensive crisis) was encountered in only one of 37 (2.7%) procedures. The mean eGFR was 64.2 ± 26.8 before and 63.3 ± 26.4 after PCA (p = .44). CONCLUSION: LME using iodized oil and gelatin particles to improve visualization of the RCC facilitated tumor localization on unenhanced CT images. PCA after LME might be a safe and effective for treatment in patients with RCC.

Efficacy of arterial infusion of iodized oil on CT-guided cryoablation for renal cell carcinoma.

PURPOSE: To evaluate the effectiveness of the transarterial infusion of iodized oil and gelatin particles for marking before CT-guided percutaneous cryoablation (PCA) in patients with renal cell carcinoma (RCC). MATERIAL AND METHODS: This study included ten patients (seven men, three women; mean age 53 years) with 13 RCCs between July 2016 and September 2017. The transarterial infusion of iodized oil and gelatin particles was considered successful when iodized oil accumulated in the target area on CT. CT value of the tumor before and after marking was measured and two diagnostic radiologists evaluated the visualization scores by using a five-point scale (5 = excellent to 1 = invisible). RESULTS: Preoperative marking was successful in all 13 tumors; the median visualization score was 5 post-lipiodol marking and 4 at the time of PCA. The mean CT density was 597 ± 371 Hounsfield units (HU) just after marking and 437 ± 234 HU at the time of PCA. All 13 CT-guided PCA procedures were successful. There were no significant complications. During follow-up (median 11.5 ± 7.0 months) there were no local recurrences. CONCLUSION: As the transarterial infusion of iodized oil and gelatin particles improved RCC visualization on CT, its delivery before CT-guided PCA may improve its safety and success rate in patients with RCC.

Time-Dependent Effects of Cryoablation for Renal Tumor on Overall and Split Renal Function.

PURPOSE: To evaluate the influence of percutaneous cryoablation for renal cell carcinoma on function of the affected kidney. MATERIALS AND METHODS: Between June 2016 and September 2017 at our institution, 12 inoperable patients underwent 15 cryoablation sessions for 17 small renal tumors. Of these, 9 patients who underwent 11 sessions of cryoablation were the focus of this study. For those patients, time-dependent changes in postoperative renal function were investigated by a retrospective review of clinical records. Evaluated were the estimated glomerular filtration rate (eGFR) and scintigraphy using 99m technetium-mercaptoacetyltriglycine (99mTc-MAG3) before and 1 week, 1-2 months, and more than 6 months after cryoablation. RESULTS: Mean baseline eGFR was 76.88 ± 29.82 mL/min/1.73 m2 (mean ± standard deviation; range, 23.4-112.5). Mean eGFR 1 week, 1-2 months, and more than 6 months after cryoablation were 74.56 ± 26.68 mL/min/1.73 m2 (21.0-101.1), 69.5 ± 25.28 mL/min/1.73 m2 (24.1-105.6), and 75.08 ± 26.25 mL/min/1.73 m2 (29.0-107.3), respectively. Changes were statistically insignificant (P = .6044, P = .6699, and P = .9038, respectively). Regarding split renal function, the mean baseline contribution of the affected kidney determined by 99mTc-MAG3 was 47.27% ± 6.14 (38.8%-57.0%). Mean contributions of the affected kidney 1 week after, 1-2 months after, and more than 6 months after cryoablation were 44.40% ± 5.37 (38.3%-53.6%), 44.57% ± 6.52 (34.35%-55.0%), and 45.41% ± 7.77 (34.4%-56.5%), respectively. Differences from baseline were significant for the earliest 2 periods (P = .0473 and P = .0334, respectively) but not the later period (P = .2532). CONCLUSIONS: Results suggested that total renal function does not worsen after cryoablation; however, function of the affected kidney worsened after cryoablation but later partially recovered.

Protection from injury of organs adjacent to a renal tumor during percutaneous cryoablation.

Renal cryoablation has become accepted as treatment for small renal tumors as an alternative to surgery. However, parallel with the increase in the use of this therapy, there also has been increases in the number of reports of complications related to renal cryoablation. One potential complication is injury to important non-renal structures adjacent to the ablated renal tumor, such as the colon, duodenum, ureter, psoas muscle and so on. To prevent injury of adjacent organs, separating organs from the tumor is desirable. Over the past 15 years, several techniques have been developed to protect against injury of organs adjacent to renal tumors that are targets of cryoablation. The most commonly used technique for this purpose has been hydrodissection. Others include dissection with gas, balloon dissection and probe traction. To avoid injury of a ureter running near the renal tumor, pyeloperfusion is known to be useful. The rate of cases necessitating avoidance of organ injury by using these techniques is relatively high. In some cases, more than two techniques are combined. In the present review, we provided an overview of techniques currently available to protect against organ injuries, and discussed the advantages and disadvantages of each technique.

Prediction of the ablated area prior to radiofrequency ablation for liver tumor under CT guidance.

PURPOSE: To evaluate the usefulness of a method we developed to predict the ablation area at the time of CT guided radiofrequency (RF) ablation for liver tumors on a CT workstation. MATERIAL AND METHODS: Ten tumors (mean diameter 15.5 mm, range, 9.0-21.5 mm) in seven patients with hepatocellular carcinoma for which CT guided RF ablation was performed were subjects of this study. After advancing the electrode, plain CT was obtained. Then a simulated ball to predict the ablated area was created on the workstation. After confirming that the tumor was sufficiently within the ball, ablation was performed. The distance of the edge of the actual ablated area from that of the predicted ablated area was measured at six points in three cross-sectional directions on CT images after ablation. RESULTS: The procedures were successfully performed without complications. No local recurrence occurred. Mean absolute value of the distance of the gap between the actual and predicted ablated areas was 3.06 ± 2.18 mm (range: 0 to 9 mm). At 29 (55.8%) points, the actual ablated area was smaller than the predicted ablated area; it was larger in 17 (32.7%), and was the same in 6 (11.5%) points. CONCLUSION: Our method produces an acceptable simulation during RF ablation under CT guidance.

Synthesis of 24-h soluble gelatin sponge particles and their effect on liver necrosis following hepatic artery embolization: Results of in vitro and in vivo studies.

AIM: To synthesize 24-h soluble gelatin sponge particles (SGSP) of 200-500 and 500-1000 µm, and to investigate their ischemic potency following hepatic artery embolization (HAE). METHODS: Low-endotoxin gelatin was freeze-dried and heated at 110, 115, 118, 120, 122 and 125°C to form cross-linked gelatin sponge. We prepared 200-500- and 500-1000-µm SGSP by pulverizing and sieving the gelatin sponge. The dissolution times in saline were measured. Eight healthy pigs underwent HAE of the right and left hepatic arteries with either 200-500- or 500-1000-µm SGSP (n = 4/group). RESULTS: The particles prepared at 110-122°C were soluble whereas particles prepared at 125°C or more were insoluble. The mean dissolution time of the particles increased with increasing temperature. In each pig, sequential arteriography confirmed that recanalization was complete 24 h after embolization. Pathological tests 48 h after HAE revealed coagulation necrosis but least damage to the biliary tract. The liver necrosis rate (mean ± standard deviation) was significantly greater in the 200-500-µm group than in the 500-1000-µm group (9.89 ± 4.04% vs 4.44 ± 0.67%, respectively; P = 0.0027). A significantly greater proportion of arteries with a diameter of 100-200 µm had residual SGSP in the 200-500-µm group than in the 500-1000-µm group (P < 0.002). CONCLUSION: HAE with 200-500-µm SGSP had greater effects on promoting liver necrosis without biliary damage than did HAE with 500-1000-µm SGSP.

Apixaban for the Treatment of Japanese Subjects With Acute Venous Thromboembolism (AMPLIFY-J Study).

BACKGROUND: Anticoagulation is recommended as standard of care for venous thromboembolism (VTE) (pulmonary embolism [PE]/deep vein thrombosis [DVT]), for which unfractionated heparin (UFH) and warfarin are used in Japan. In the multi-regional AMPLIFY study, a fixed-dose regimen of apixaban alone was non-inferior to conventional therapy for treatment of PE/DVT and was associated with significantly fewer bleeding events. METHODS AND RESULTS: Japan phase 3 study (AMPLIFY-J), randomized, active-controlled, open-label study in Japanese subjects with acute PE/DVT, was designed based on AMPLIFY. Key objectives were to investigate safety and efficacy of apixaban in symptomatic PE/DVT subjects during 24-week treatment. UFH/warfarin was used as control treatment. Apixaban was initiated at 10 mg twice daily for 7 days, followed by 5 mg twice daily for 23 weeks. All endpoints and imaging for thrombotic burden were assessed by an event adjudication committee. Eighty subjects were randomized, 33 subjects (41.3%) were aged <65 years. Proportion of major/clinically relevant non-major bleeding was lower in apixaban (7.5%) compared with well-controlled UFH/warfarin (28.2%; median TTR, 70.4%). [corrected]. Recurrent VTE occurred in no subjects in apixaban and in 1 subject in UFH/warfarin. Thrombotic burden results were similar in both groups. Proportions of subjects with adverse events was generally similar in both groups. CONCLUSIONS: Apixaban was well-tolerated and had a favorable safety profile. No clinically important efficacy difference compared with UFH/warfarin was observed.

Change in portal vein hemodynamics after chemoembolization for hepatocellular carcinoma: evaluation through multilevel dynamic multidetector computed tomography during arterial portography.

OBJECTIVE: This study aimed to clarify the effect of embolization with lipiodol on portal vein hemodynamics. METHODS: Time-density curves of the main portal vein on multilevel dynamic multidetector computed tomography during arterial portography were used to analyze peak computed tomography value (PV), time to PV (TPV), arrival time of contrast medium at the main portal vein (ATMPV), slope [(PV - 150) / (TPV - ATMPV)], and slope ratio (slope after embolization / slope before embolization). RESULTS: In 20 patients with hepatoma, ATMPV and TPV were significantly prolonged and the time-density curve slope was significantly less after embolization. The difference in TPV increased (P = 0.02) and the slope ratio decreased with increasing embolized volume rate (P < 0.001). Strong correlation (R = -0.86) was found between the slope ratio and the embolized volume rate. CONCLUSIONS: Time-density curves revealed significant portal vein flow delay after embolization; the degree of which was correlated with the extent of the embolized volume.

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.

Successful treatment of endoscopically unmanageable rectal varices by balloon-occluded antegrade transvenous sclerotherapy followed by microcoil embolization.

The present report describes two cases of endoscopically unmanageable rectal varices that were treated by balloon-occluded antegrade transvenous sclerotherapy (BATS) followed by microcoil embolization. Follow-up endoscopy confirmed eradication of the rectal varices. Balloon-occluded rectal venography showed stasis of contrast material and sclerosing agent for 30 minutes in both cases of rectal varices, which indicated that the inflow vessel was a single dilated superior rectal vein without other minor inflow vessels. BATS appears to be a feasible therapeutic option for the treatment of rectal varices of this hemodynamic type.

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.

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.

Percutaneous transportal outflow-vessel-occluded sclerotherapy for gastric varices unmanageable by balloon-occluded retrograde transvenous obliteration.

In this report we introduce percutaneous transportal outflow-vessel-occluded sclerotherapy (PTOS) for gastric varices unmanageable by balloon-occluded retrograde transvenous obliteration (BRTO) in two cases and evaluate its safety and efficacy. The PTOS is a technique which could obstruct gastric varices subsequent to the occlusion of the outflow route, being based on the rationale of BRTO. In the PTOS procedure, coil embolization of the outflow vessel is first conducted through a microcatheter advanced beyond the gastric varices via the percutaneous transhepatic approach; sclerosing agent (5% ethanolamine oleate) is then injected into the gastric varices after confirmation of static blood flow in the varices. Two patients underwent initial BRTO that eventually failed because of the presence of numerous fine and abruptly angled outflow vessels (case 1), and the presence of a tortuous and elongated outflow vessel accompanied by numerous small collateral outflows that could not be occluded (case 2). Cases 1 and 2 received PTOS using 5% ethanolamine oleate (15 mL and 10 mL, respectively). Portal venous pressure following PTOS showed an increase from 29 to 34 mmHg in case 1 and remained at 24 mmHg in case 2. No major complication was encountered in either patient. One-year follow-up gastroendoscopy showed no recurrence of gastric varices in either patient. Although PTOS is slightly more invasive than BRTO, PTOS can be used as an alternative catheter treatment procedure for gastric varices that are unmanageable by BRTO.

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.

Permissive untreated pseudoaneurysm concept in damage control interventional radiology for traumatic pancreaticoduodenal artery injury.

Background: Angioembolization for traumatic pancreaticoduodenal artery injury with unstable circulation, which characteristically requires a prolonged procedure time, does not yet have a standardized strategy for damage control interventional radiology. Case Presentation: We encountered two cases of rare traumatic pancreaticoduodenal artery injury wherein the patients were saved by a multidisciplinary team with a shared goal of clinical success, rather than the procedural success of angioembolization. Both patients treated with angioembolization had residual pseudoaneurysm or faint extravasation in the pancreaticoduodenal artery arcade. We prioritized critical care with preemptive plasma transfusion and aggressive blood pressure control, and planned repeat angiography. The patients showed no clinical signs of rebleeding or pseudoaneurysm based on computed tomography during follow-up. Conclusion: Our findings suggest that the permissive untreated pseudoaneurysm concept can be useful in developing damage control interventional radiology strategies for trauma cases with challenging time limitations, such as traumatic pancreaticoduodenal artery injury with circulatory collapse.