Safety and Risk of Superselective Transcatheter Arterial Embolization for Acute Lower Gastrointestinal Hemorrhage with N-Butyl Cyanoacrylate: Angiographic and Colonoscopic Evaluation.

PURPOSE: To retrospectively evaluate the safety and risk of transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for urgent acute arterial bleeding control in the lower gastrointestinal tract by angiography and colonoscopy. MATERIALS AND METHODS: NBCA TAE was performed in 16 patients (mean age, 63.7 y) with lower gastrointestinal bleeding (diverticular hemorrhage, tumor bleeding, and intestinal tuberculosis). Angiographic evaluation was performed by counting the vasa recta filled with casts of NBCA and ethiodized oil (Lipiodol) after TAE. Patients were classified as follows: group Ia, with a single vas rectum with embolization of 1 branch (n = 6); group Ib, with a single vas rectum with embolization of ≥ 2 branches (n = 8); group II, with embolization of multiple vasa recta (n = 2). All patients underwent colonoscopy within 1 month, and ischemic complications (ulcer, scar, mucosal swelling, fibrinopurulent debris, and necrosis) were evaluated. RESULTS: The procedure was successful in all patients. No ischemic change was observed in any patients in group Ia and in two patients in group Ib. Ischemic changes were observed in six group Ib patients and both group II patients. Group Ib patients experienced ischemic complications that improved without treatment. One patient in group II underwent resection for intestinal perforation after embolization of three vasa recta. One patient in group II with sigmoid stricture with embolization of six vasa recta required prolonged hospitalization. CONCLUSIONS: NBCA embolization of ≥ 3 vasa recta can induce ischemic bowel damage requiring treatment. NBCA TAE of one vas rectum with ≥ 2 branches could also induce ischemic complications. However, these were silent and self-limited.

Coil embolization with side-holed catheter to preserve peripheral flow for visceral artery pseudoaneurysm: an experimental study in Swine.

PURPOSE: To evaluate the safety and efficacy of coil embolization with an indwelling catheter with side holes to control visceral artery bleeding while simultaneously preserving peripheral artery flow. MATERIALS AND METHODS: A 6-F anticoagulant-coated catheter with two symmetrically arranged side holes was used with coil embolization to induce hemostasis in the superior mesenteric artery (SMA) of 13 pigs. The SMA was punctured with a metal needle to induce bleeding. The catheter was advanced into the SMA immediately after the puncture, and the midpoint between its tip and side holes was adjusted to conform to the puncture site. The SMA was embolized by using microcoils placed around the catheter to achieve hemostasis. Hemostasis and gross ischemic changes of the intestine were visually observed during the abdominal surgery. Peripheral blood flow was assessed by using abdominal aortography for as long as 2 hours in 13 pigs and was assessed again at 7 days in three pigs. RESULTS: Antegrade peripheral artery flow through the indwelling catheter was preserved without stagnation for as long as 2 hours in all 13 pigs and at 7 days in two of three pigs. One catheter occlusion was seen at the 7-day time point. There were no observable instances of recurrent bleeding, ischemic changes in the intestine, or vascular adverse events during or after the procedure. CONCLUSIONS: The hemostatic method described here is a technically feasible method of controlling acute visceral artery bleeding while preserving peripheral artery flow and may be particularly useful in cases of absence of collateral circulation. Further experiments are warranted for clinical application.

Thermal influence of radiofrequency ablation for bone: an experimental study in normal rabbit bone.

OBJECTIVE: To evaluate the heat effects of radiofrequency ablation (RFA) on normal bone by mechanical testing, MRI, and histology. MATERIALS AND METHODS: The institutional animal care and use committee approved the animal study. Thirty-two adult Japanese white rabbits were included in our study. Bone biopsy needles were inserted from the distal end of the right (RFA side) and the left (control side) femurs using a fluoroscopic guide. A 17-gauge internally cooled RFA electrode with a 2-cm active tip was inserted through the needle to the right femur, and RFA was performed for 12 min using a 200-W generator. Animals were divided into four groups and 8 animals from each group were euthanized on day 1, day 7, day 30, and day 60 after RFA. MRI was performed prior to euthanasia. Three-point bending test was performed to measure flexural strength. Student's t test was used to evaluate for significant differences between RFA and control side for each group. Femurs underwent histological examination by hematoxylin and eosin staining after the bending test. RESULTS: MRI showed a high-intensity rim around the bone on T2WI. Three-point bending test showed no statistically significant differences (P < 0.05) between the RFA and the control side in any of the groups. Histologically, osteocytes of cortical bone showed cell death, but the lamellar structure was preserved in all groups and bone remodeling was observed. CONCLUSION: Heat by RFA did not change normal bone strength within 2 months, despite the heat effects in the cortical bone and cell death.

Transcatheter arterial embolization of acute arterial bleeding in the upper and lower gastrointestinal tract with N-butyl-2-cyanoacrylate.

PURPOSE: To assess the clinical utility and safety of transcatheter arterial embolization with N-butyl-2-cyanoacrylate (NBCA) for urgent control of acute arterial bleeding in the upper and lower gastrointestinal tract. MATERIALS AND METHODS: Therapeutic NBCA embolization was performed in 37 patients (39 cases; mean age, 67.8 years) with acute upper (n = 16) or lower (n = 23) gastrointestinal tract bleeding after endoscopic management had failed. Transcatheter arterial embolization was performed using 1:1 to 1:5 mixtures of NBCA and iodized oil. The most common etiologies of bleeding were colonic diverticulosis (n = 13), malignancy (n = 11), and benign ulcer (n = 7). Coagulopathy was present in 11 patients, and 23 patients were hemodynamically unstable before NBCA embolization. Histologic examination for bowel ischemia was also performed in five patients who underwent excision of the lesion after NBCA embolization. RESULTS: The technical success rate was 100%. Recurrent bleeding occurred in two patients. Complete hemostasis was achieved in all 11 patients with coagulopathy. Ulcers induced by transcatheter arterial embolization were noted in 6 of 20 patients who underwent endoscopic examination; the ulcers were successfully treated with conservative measures. Histologic examination revealed that despite inflammatory reactions in and around the vessels, no intestinal necrosis secondary to NBCA embolization was found. Hepatic abscess occurred in two cases, and ischemia of the lower limb occurred in one case; these complications were managed by percutaneous drainage and bypass surgery. CONCLUSIONS: Transcatheter arterial embolization with NBCA is a good treatment option with a high rate of complete hemostasis and a low recurrent bleeding rate, even in patients with coagulopathy.

Percutaneous ethanolamine oleate sclerotherapy for aggressive vertebral hemangioma: A case report.

Vertebral hemangiomas are the most common benign lesion of the spine which are often an asymptomatic incidental finding. However, a few hemangiomas are aggressive and characterized by bone expansion and extraosseous extension into the paraspinal and epidural spaces. We report the case of a patient presenting an aggressive vertebral hemangioma causing back pain and bilateral numbness of the legs. Among various treatment modalities, a minimally invasive percutaneous sclerotherapy procedure using ethanolamine oleate under computed tomography and fluoroscopic guidance was safely and successfully performed with good clinical outcomes.

Usefulness of Practitioner-Led Pancreatic Cancer Screening.

The 5-year survival rate for pancreatic cancer has improved (10%) but remains worse than that for other cancers. Early pancreatic cancer diagnosis is challenging, and delayed diagnosis can delay treatment, which impairs survival. Practitioners do not promptly refer cases to a general hospital, causing delayed discovery. Herein, we aimed to examine the usefulness of the Pancreatic Cancer Project in Matsue, whose objective is to detect pancreatic cancer in patients presenting at any medical institution in Matsue City. Clinical data were extracted from medical records, and abdominal ultrasonography and tumor marker blood level assessments were performed (n = 234; median age, 71 [range, 41-94] years; 51% male). Cases with abnormal abdominal ultrasonography or blood test findings were referred for specialist imaging and followed up. The pancreatic cancer detection rate was 6.0% (n = 14); all cases were referred to a general hospital by practitioners within 1 month. Patients had stage IA (n = 1), IIA (n = 6), IIB (n = 2), III (n = 1), and IV (n = 4) disease. Overall, pancreatic cancer could be detected at an earlier stage (I-II), but referral to a general hospital by visiting practitioners should be prompt. The Pancreatic Cancer Project in Matsue may help improve the detection and prognosis of pancreatic cancer.

Transfemoral approach using a 3.5-French catheter system for use in transcatheter arterial chemoembolization in patients with hepatocellular carcinoma: technical assessment.

BACKGROUND/AIMS: To evaluate the technical feasibility of the transfemoral approach using a 3.5-Fr catheter system for transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). METHODOLOGY: This study included 81 patients with unresectable HCC who underwent transfemoral TACE using a 3.5-Fr catheter system without a sheath between August 2008 and June 2010. A 2.0-Fr microcatheter was used within a 3.5-Fr catheter in all cases. After completion of TACE, manual compression was applied to the puncture site for 5min, and patients were kept supine for 1h. The success rate and periprocedural complications of TACE were evaluated. RESULTS: Transfemoral TACE with a 3.5-Fr catheter system was carried out in 103 transfemoral TACE sessions. TACE was performed for 103 subsegmental arteries, 19 segmental arteries, 13 lobar arteries, 8 right inferior phrenic arteries, 1 left inferior phrenic artery, and 1 inferior pancreatico-duodenal artery. Image quality in all hepatic angiograms using 3.5-Fr catheters was satisfactory. Technical success was achieved in 97 (94%) out of 103 procedures. In only 1 patient, it took 10min to achieve hemostasis. There were no periprocedural complications. CONCLUSIONS: Transfemoral TACE using a 3.5-Fr catheter system is technically feasible and enables early ambulation safely in patients with HCC.

Compressed Amplatzer Vascular Plug II Embolization of the Left Subclavian Artery for Thoracic Endovascular Aortic Repair is Efficient and Safety Method Comparable to Conventional Coil Embolization.

BACKGROUND: Left subclavian artery (LSA) embolization is occasionally required to prevent type II endoleak in the thoracic endovascular aortic repair (TEVAR) procedure. This is a retrospective study comparing compressed Amplatzer Vascular Plug II embolization (CAE) and conventional coil embolization (CCE) in preventing retrograde flow into the aneurysmal sac through the LSA after TEVAR. METHODS: We retrospectively reviewed the records of patients who underwent CAE or CCE of the LSA during TEVAR from June 2013 to March 2016 in our hospital. The efficacy, safety and cost of each method were compared between two groups. RESULTS: Thirty patients underwent LSA embolization during TEVAR. Six CCEs in 6 patients were performed from June 2013 to November 2013, while twenty-four CAEs in 24 patients were performed from December 2013 to March 2016. Technical success was achieved in all patients in both groups. No embolization-related complications or type II endoleaks from LSA were recorded during the follow-up period in all patients. In both groups, all embolic materials were detected in the proximal portion of the LSA from the LSA orifice to the vertebral artery origin and no vertebral artery occlusions were detected. The mean compression ratio of AVP II was 58 ± 5.9% of predicted length of standard procedure. In the CAE group, one AVP II was sufficient to achieve complete LSA occlusion in all patients. On the other hand, multiple coils (10.2 ± 2.7) were used in the CCE group (P < .01), resulting in a significantly lower cost incurred in the CAE group (CAE: 129,000 JPY vs. CCE: 639,600 ± 140,060 JPY; P < .01). CONCLUSION: The CAE is a useful and cost-effective procedure for TEVAR-related LSA embolization.

Heat distribution in the spinal canal during radiofrequency ablation for vertebral lesions: study in swine.

PURPOSE: To prospectively evaluate the safety of radiofrequency (RF) ablation for vertebral lesions by monitoring the temperature in swine vertebral models with and without a cortical bone defect. MATERIALS AND METHODS: The institutional animal care and use committee approved the animal studies. In vivo and ex vivo studies were performed. In the in vivo study, 20 lumbar vertebrae from six swine were locally heated by using 1- or 2-cm active-tip internally cooled electrodes. In the ex vivo study, 12 fresh pig cadaver lumbar vertebrae were extracted from four swine, and spinal tumor models with or without cortical bone defect were created by stuffing a cavity with muscle tissue and locally heated by using a 1-cm active-tip internally cooled electrode. The temperature was monitored in the spinal canal and around the vertebral body during ablation. Mann-Whitney U test was used to indicate a significant difference between groups by using 1- and 2-cm active tip in the in vivo study and between groups with and without cortical defect in the ex vivo study. RESULTS: In the in vivo study in which 1- and 2-cm active-tip needles were used, the temperature in the spinal canal rose to 38.2 degrees C +/- 2.7 (standard deviation) and 45.5 degrees C +/- 6.2, respectively. The latter was significantly higher than the former (P < .001). In the ex vivo study in which tumor models with or without a cortical bone defect were used, the temperature in the spinal canal rose to 48.4 degrees C +/- 6.2 and 31.3 degrees C +/- 3.4, respectively. The former was significantly higher than the latter (P < .001). CONCLUSION: For in vivo cases with a 2-cm active tip and ex vivo cases with a vertebral posterior bone defect, the temperature rose to over 45 degrees C, potentially injuring the spinal cord and peripheral nerves.

Development of a re-positionable aortic stent-valve: a preliminary study in swine.

BACKGROUND: Placement of aortic stent-valves in the proper position is difficult due to the high velocity and oscillation of blood flow and anatomical characteristics. To address this problem, a re-positionable stent-valve was designed and examined in a preliminary animal experiment. METHODS: Protocols for this animal study were approved by the institutional Animal Care and Use Committee. An umbrella-shaped polyurethane valve was attached at the tip of newly devised re-positionable metallic stent. The prosthesis (re-positionable stent-valve) was implanted in 5 female pigs via the right carotid artery using a 10-F introducer (Group A). As a control, the stent-without-valve was implanted in 4 female pigs (Group B). Efficacy of the valve was assessed by aortography and aortic pressure measurement. Animals were sacrificed 1 hour after stent-valve implantation for macroscopic examination. RESULTS: The stent-valve was successfully implanted in all pigs. In Group A, aortography showed good function of the polyurethane valve. No significant change in diastolic pressure was noted during valve testing. In Group B, aortography and aortic pressure measurement showed massive aortic regurgitation following dysfunction of the native aortic leaflets. Post-mortem examination showed small amounts of thrombus inside the polyurethane umbrella in Group A. CONCLUSION: Placement of the re-positionable stent-valve seems feasible and effective. However, the problem of thrombus formation inside the umbrella valve should be solved in future studies.

Antiplatelet Therapy is Associated with Stent Patency After Iliocaval Venous Stenting.

PURPOSE: To examine the effectiveness of antithrombotic medications to prevent venous stent malfunction for iliocaval occlusive disease. MATERIALS AND METHODS: A retrospective analysis was performed on 62 patients who underwent technically successful endovascular iliocaval stent placement between May 2008 and April 2017. Clinical records were reviewed for demographic information, procedure details, post-stenting antithrombotic prophylaxis and stent patency on follow-up. Stent malfunction was defined as > 50% stenosis or occlusion at follow-up. Risk factors for stent malfunction were assessed with univariable and multiple Cox proportional hazard models. RESULTS: The median follow-up period was 11.6 months (range 0.1-76.4). Overall primary and secondary cumulative patency rates at 12 months were 70.0% and 92.4%, respectively. After stent placement, 97% of patients received anticoagulation with warfarin, enoxaparin or a factor Xa inhibitor. In addition, 61% received antiplatelet prophylaxis with aspirin, clopidogrel or a combination. In multiple Cox regression analysis, post-stenting antiplatelet use remained significantly associated with primary stent patency (HR = 0.28, P = 0.022). CONCLUSION: After iliocaval venous stenting, stent patency was best predicted by concomitant antiplatelet and anticoagulation therapy rather than anticoagulation alone. This novel finding warrants further research underlying mechanisms leading to venous stent thrombosis, and has implications for optimal medical management after venous stenting.

Portal Vein Stenting for Portal Vein Stenosis After Pancreatoduodenectomy: A Case Report.

Portal vein stenosis, which results in serious clinical conditions such as gastrointestinal variceal bleeding and liver failure, is caused by hepatobiliary pancreatic cancer or major postoperative complications after hepatobiliary pancreatic surgery. In recent years, portal vein stenting under interventional radiology has been applied as a more useful treatment method for portal vein stenosis than invasive surgery. We herein report the successful use of a vascular stent for portal vein stenosis after pancreatoduodenectomy. A 66-year-old man with distal cholangiocarcinoma underwent subtotal stomach-preserving pancreatoduodenectomy with resection of the portal vein because of direct invasion to the main portal vein at our hospital. The portal vein was reconstructed without a venous graft. He developed jejunal bleeding near the pancreatojejunostomy on postoperative day (POD) 2. Although embolization of the responsible vessel achieved hemostasis, an intraoperatively inserted drainage tube was needed for a long period of time postoperatively because the embolized afferent jejunum was perforated. He was discharged on POD 39 after removal of the drainage tube. On POD 282, he was readmitted with melena and severe fatigue. Computed tomography revealed an obstruction of the reconstructed portal vein and varices at the hepaticojejunostomy site. We diagnosed variceal bleeding and performed percutaneous transhepatic stenting in the obstructed portal vein. The patient was discharged in good clinical condition on day 15 after stenting. In conclusion, portal vein stenting is a useful and less invasive therapy for portal vein stenosis.

Non-Surgical Management of Bile Leakage After Hepatectomy: A Single-Center Study.

BACKGROUND: Bile leakage after hepatectomy is a common complication. The purpose of the present study was to retrospectively evaluate the usefulness of non-surgical management of bile leakage after hepatectomy, using 12-year data from a single center study. METHODS: Data from 15 patients (13 men, two women; mean age 67.1 ± 7.0 years) who had undergone non-surgical management for bile leakage between January 2005 and November 2017 were retrospectively reviewed. RESULTS: We categorized bile leakage as central (n = 5) or peripheral (n = 10) leakage based on communication with the biliary tree. Percutaneous bile leakage drainage and/or endoscopic naso-biliary drainage (ENBD) (n = 2) or the rendezvous technique (n = 3) was successfully performed in five central-type cases, while all peripheral-type cases were treated with drainage alone; only one case required additional ethanol ablation. Bacterial bile cultures were positive in 11 cases and negative in four cases. The drainage catheters were removed after complete resolution in 13 cases (86.7%), while two patients with cases of peripheral-type leakage died due to cancer progression while the drain was in place. No case needed conversion to reoperation. The mean duration of drainage therapy in all cases was 210.1 ± 163.0 days (range 17-531 days), with 316.8 ± 180.8 days in the central type and 156.7 ± 131.5 days in the peripheral type; this duration was not significantly different (P = 0.129). CONCLUSION: Non-surgical treatment is a minimally invasive and effective management strategy for postoperative bile leakage and the modality used depends on the type of bile leakage encountered.

The Negative Effect of Preoperative Transcatheter Arterial Chemoembolization on Long-Term Outcomes for Resectable Hepatocellular Carcinoma: A Propensity Score Matching Analysis.

BACKGROUND: Preoperative transcatheter arterial chemoembolization (TACE) is administered to improve long-term outcome after surgical resection of hepatocellular carcinoma (HCC). However, the survival benefit of preoperative TACE is controversial. We conducted a retrospective case-control study to evaluate the effect of preoperative TACE on prognosis. METHODS: A total of 121 patients who underwent curative resection of HCC were divided into two groups according to whether they received preoperative TACE. We determined the control group (n = 34) and TACE group (n = 34) through propensity score matching. The primary endpoint of this study was overall survival, and the secondary endpoints were recurrence-free survival. RESULTS: The overall survival rate and the recurrence free survival rate were significantly lower in the TACE group than in the control group (P = 0.014 and P = 0.043, respectively). Furthermore, recurrence free survival within less than 2 years after resection was significantly worse in the TACE group than in the control group (P = 0.035). CONCLUSION: Preoperative TACE seemed to worsen the long-term outcomes of the patients who underwent surgical resection for the treatment of resectable HCC. Therefore, preoperative TACE should not be considered as a standard therapy in patients with resectable HCC.

Balloon-assisted coil embolization of the celiac trunk before endovascular aortic repair of thoracoabdominal aortic aneurysm.

PURPOSE: Celiac trunk coil embolization before thoracic endovascular aneurysm repair (TEVAR) of a thoracoabdominal aortic aneurysm involving the celiac trunk can prevent type II endoleaks. One disadvantage of conventional coil embolization is the risk of coil displacement. We performed coil embolization under balloon occlusion of the celiac trunk to address this issue. MATERIALS AND METHODS: Between December 2008 and January 2011, 5 patients (3 men and 2 women, mean age 76 years) were included in this study. For all patients, after confirming the collateral blood flow from the superior mesenteric artery via the pancreaticoduodenal arcades by using the balloon occlusion test, celiac trunk coil embolization proceeded under balloon occlusion of the proximal part of the celiac trunk. RESULTS: Balloon-assisted coil embolization of the celiac trunk was completed for all patients without any complications. All coils were deployed as planned in the short segment of the celiac trunk without displacement. Coil migration, ischemic complications, and endoleaks via the celiac trunk did not arise in any of the patients over a follow-up period of 77-637 (mean 258) days. CONCLUSIONS: Balloon-assisted coil embolization of the celiac trunk before TEVAR could be a feasible treatment option for suitable patients.

Influence of ethanol-induced pulmonary embolism on hemodynamics in pigs.

AIMS AND OBJECTIVES: Ethanol is widely used for the embolization treatment of vascular malformations, but it can also cause serious complications such us pulmonary hypertension, cardiopulmonary collapse and death. The complications are considered secondary to pulmonary vasospasm and ethanol-induced sludge embolism, etc., We studied the hemodynamic effects of intravenous absolute ethanol injection and ethanol sludge injection in pigs. MATERIALS AND METHODS: A total of 5 pigs underwent intravenous injection of ex vivo generated ethanol-induced sludge in which residual ethanol was removed (Group S) and 4 pigs underwent intravenous injection of absolute ethanol (Group E). Hemodynamic parameters related to the pulmonary and systemic circulation were compared between the groups. RESULTS: Transient pulmonary hypertension was observed in both groups and the hemodynamic changes were similar in both groups. CONCLUSIONS: Sludge can induce transient pulmonary hypertension or cardiopulmonary collapse, without ethanol and may be the mechanism by which ethanol induces its adverse hemodynamic effects.

Development of a new hanging-type esophageal stent for preventing migration: a preliminary study in an animal model of esophagotracheal fistula.

PURPOSE: Covered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method. METHODS: A total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs. RESULTS: Creation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12 days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall. CONCLUSIONS: Our new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.