Outcomes of embolization procedures for type II endoleaks following endovascular abdominal aortic repair.

OBJECTIVE: The objective of this study was to investigate the mid-term outcomes of embolization procedures for type II endoleak after endovascular abdominal aortic repair, and clarify the risk factors for aneurysm enlargement after embolization procedures. METHODS: This was a retrospective multicenter registry study enrolling patients who underwent embolization procedures for type II endoleaks after EVAR from January 2012 to December 2018 at 19 Japanese centers. The primary end point was the rate of freedom from aneurysm enlargement, more than 5 mm in the aortic maximum diameter, after an embolization procedure. Demographic, procedural, follow-up, and laboratory data were collected. Continuous variables were summarized descriptively, and Kaplan-Meier analyses and a Cox regression model were used for statistical analyses. RESULTS: A total of 315 patients (248 men and 67 women) were enrolled. The average duration from the initial embolization procedure to the last follow-up was 31.6 ± 24.6 months. The rates of freedom from aneurysm enlargement at 3 and 5 years were 55.4 ± 3.8% and 37.0 ± 5.2%, respectively. A multivariate analysis revealed that a larger aortic diameter at the initial embolization procedure and the presence of a Moyamoya endoleak, defined as heterogeneous contrast opacity with an indistinct faint border, were associated with aneurysm enlargement after embolization management. CONCLUSIONS: The embolization procedures were generally ineffective in preventing further expansion of abdominal aortic aneurysms in patients with type II endoleaks after EVAR, especially in patients with a large abdominal aortic aneurysm and/or a presence of a Moyamoya endoleak.

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.

Efficacy of Subtraction Computed Tomography Arteriography During Preoperative Embolization in Spinal Tumors.

Background: This study aimed to evaluate the efficacy of subtraction computed tomography arteriography (s-CTA) during preoperative embolization in spinal tumors. Methods: The study analyzed 17 vertebrae in 13 patients who underwent preoperative embolization before spinal fixation surgery for malignant spinal tumors to decrease blood loss at our hospital from 2019 to 2021. Their ages ranged from 56 to 88 years (average, 73.5 years). Metastatic bone tumors were most common, including five cases originating as lung carcinomas and three as renal cancers. After digital subtraction angiography of selected tumor-feeding arteries and non-subtraction CTA (ns-CTA) were performed, s-CTA was conducted using data obtained from both procedures. A clarity score of the boundary between the normal bone and tumor was derived for each patient, which was then classified into four grades (good, 3 points; fair, 2 points; faint, 1 point; poor, 0 points) by two experienced radiologists, followed by a comparison between the s-CTA and ns-CTA groups using the Wilcoxon signed-rank test. Results: Clarity scores were significantly higher in the s-CTA group than in the ns-CTA group (P < 0.001). The agreement of Cohen's coefficients between the two radiologists was κ = 0.724 in s-CTA scoring and κ = 0.622 in ns-CTA scoring, which were moderately matched. Seven arteries were not embolized due to insufficient tumor contrast enhancement and their poor relation to the surgical invasion zone. No complications were observed during or after embolization. Conclusion: S-CTA successfully distinguished between tumor and normal bone and may help avoid unnecessary embolization.

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.

Role of Aggressive Aneurysm Sac Embolization Before Endovascular Abdominal Aneurysm Repair in Preventing Type II Endoleak and Sac Expansion.

Background: This study aimed to evaluate the effect of aggressive embolization of side branches arising from the aneurysmal sac before endovascular aneurysm repair. Methods: This retrospective study included 95 patients who underwent endovascular infrarenal abdominal aortic aneurysm repair at Tottori University Hospital between October 2016 and January 2021. Of these, 54 underwent standard endovascular aneurysm repair (conventional group), and 41 underwent coiling of the inferior mesenteric and lumbar arteries before undergoing endovascular aneurysm repair (embolization group). The occurrence of type II endoleak, change in aneurysmal sac diameter, and reintervention rate due to type II endoleak during follow-up were evaluated. Results: Compared to the conventional group, the embolization group had a significantly lower incidence of type II endoleak, more frequent aneurysmal sac shrinkage, and lower aneurysmal sac growth related to type II endoleak. Conclusion: Our results demonstrated the effectiveness of aggressive aneurysmal sac embolization before endovascular aneurysm repair to prevent type II endoleak and the consequent long-term aneurysmal sac enlargement.

New strategy for MS treatment with autoantigen-modified liposomes and their therapeutic effect.

As current treatments for multiple sclerosis (MS) remain chemotherapeutic ones directed toward symptoms, the development of a curative treatment is urgently required. Herein, we show an autoreactive immune cell-targetable approach using autoantigen-modified liposomes for the curative treatment of MS. In these experiments, experimental autoimmune encephalomyelitis (EAE) induced by autoantigenic myelin oligodendrocyte glycoprotein (MOG) peptide was used as a model of primary progressive MS, and MOG-modified liposomes encapsulating doxorubicin (MOG-LipDOX) were used as a therapeutic drug. The results showed that the progression of encephalomyelitis symptoms was significantly suppressed by MOG-LipDOX injection, whereas the other samples failed to show any effect. Additionally, invasion of inflammatory immune cells into the spinal cord and demyelination of neurons were clearly suppressed in the MOG-LipDOX-treated mice. FACS analysis revealed that the number of both MOG-recognizable CD4+ T cells in the spleen was obviously decreased after MOG-LipDOX treatment. Furthermore, the number of effector Th17 cells in the spleen was significantly decreased and that of regulatory Treg cells was concomitantly increased. Finally, we demonstrated that myelin proteolipid protein (PLP)-modified liposomes encapsulating DOX (PLP-LipDOX) also showed the therapeutic effect on relapsing-remitting EAE. These findings indicate that autoantigen-modified liposomal drug produced a highly therapeutic effect on EAE by delivering the encapsulated drug to autoantigen-recognizable CD4+ T cells and thus suppressing autoreactive immune responses. The present study suggests that the use of these autoantigen-modified liposomes promises to be a suitable therapeutic approach for the cure of MS.

Development of tissue factor-targeted liposomes for effective drug delivery to stroma-rich tumors.

Tissue factor (TF), which is well known as a trigger molecule of extrinsic coagulation, is found in not only tumor cells but also in stromal cells in tumor tissues. Thus, TF is a candidate molecule to potentially enable targeting of both tumor cells and stromal cells for anti-cancer drug delivery. Herein, we prepared liposomes conjugated with the Fab' fragment of anti-TF antibody (TF Ab-Lip) and evaluated the capability for drug delivery to stroma-rich tumors for realizing a whole tumor tissue-targetable strategy. When the targetability of TF Ab-Lip to TF-expressing KLN205 squamous tumor cells and NIH3T3 fibroblast cells were examined, TF Ab-Lip was significantly taken up into both cells compared with non-targeted liposomes. Corresponding to this result, doxorubicin-encapsulated TF Ab-Lip (TF Ab-LipDOX) showed potent cytotoxicity against KLN205 cells. In vivo experiments using KLN205 solid tumor-bearing mice indicated that TF Ab-Lip became highly accumulated and distributed widely in not only the tumor cell region but also in the stromal one in the tumor. Treatment with TF Ab-LipDOX significantly suppressed the growth of KLN205 solid tumors. Furthermore, TF Ab-Lip targetable both mouse and human TF (mhTF Ab-Lip) became distributed throughout stroma-rich human pancreatic BxPC3 tumors and the treatment of the BxPC3 tumor-bearing mice with mhTF Ab-LipDOX showed highest tumor-suppressive effect. These data suggest that TF Ab-Lip could achieve effective accumulation for stroma-rich tumor treatment.

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.

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.

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.