Proximal Embolization Research Articles

Our Experience with the Low-Profile Braided Occluder: A Case Series of Splenic Artery Embolization in Three Trauma Patients

AbstractThe spleen is the most injured intra-abdominal organ, with splenic injuries constituting 42 to 49% of all abdominal injuries. Due to this vulnerability and the fact that splenic ruptures can potentially result in life-threatening hemorrhage, finding quick and efficient ways to control splenic bleeding in a trauma setting can improve patient outcomes. Recently, the U.S. Food and Drug Administration cleared the low-profile braided occluder (LOBO; Okami Medical, Aliso Viejo, California, United States), a vascular occlusion system designed to rapidly occlude vessels by using a high-density, uniform small pore structure. We present a small case series describing the use of the LOBO device for proximal splenic embolization in three trauma patients. Our report suggests that the LOBO device is safe and efficient for proximal splenic artery embolization as all three of our patients had a successful outcome with no complications; furthermore, we believe using the LOBO device may enhance patient and provider safety by decreasing fluoroscopic time and radiation dose, though further studies are needed to support this.

Proximal splenic artery embolization for treatment of refractory ascites, a single-center experience.

Refractory ascites from portal hypertension can be managed with regular large-volume paracentesis (LVP) or transjugular intrahepatic portosystemic shunt (TIPS). Large-volume paracentesis is clinically unsatisfactory and many patients are ineligible or relatively contraindicated for TIPS or Denver shunt. Proximal splenic artery embolization (PSAE) using coils or plugs reduces but does not completely stop splenic arterial inflow, differing from distal splenic artery embolization techniques. By reducing splenic arterial inflow, splenic vein outflow is also decreased, lowering portal pressure and thus treating refractory ascites. In this institutional review board-approved single-center retrospective study, electronic medical records were reviewed to obtain demographics and baseline clinical and laboratory data, paracentesis data before and after PSAE, PSAE procedural details, and follow-up imaging up to 12months post-PSAE. Mixed-effects models were used for statistical analysis. Ten patients with LVP-dependent ascites meeting inclusion criteria underwent PSAE for refractory ascites from 2017 to 2024. Prior to PSAE, four patients had TIPS, three had liver transplants, and the remaining three were neither TIPS nor transplant candidates. In the month before PSAE, patients averaged 3.8±1.7 paracentesis sessions, draining a total of 20.84±10.39L of fluid monthly. Post-PSAE, the number of paracentesis sessions decreased to 2.1±2.7, 1.0±1.7, 0.4±1.1, and 0.0±0.0 at 1, 3, 6, and 12months, respectively (p=0.03). Corresponding ascitic volume drained decreased to 8.7±10.3, 2.7±6.4, 2.0±5.4, and 0.0±0.0L (p=0.01). Over the 12-month follow-up period, 6 of 10 patients became LVP-independent. Proximal splenic artery embolization can improve refractory ascites in certain patients with portal hypertension, thus providing safe and effective treatment as an alternative to TIPS.

Optimizing distal and proximal splenic artery embolization with patient-specific computational fluid dynamics

Splenic artery embolization (SAE) has become a favored alternative to splenectomy, offering a less invasive intervention for injured spleens while preserving spleen function. However, our understanding of the role that hemodynamics plays during embolization remains limited. In this study, we utilized patient-specific computational fluid dynamics (CFD) simulations to study distal and proximal embolization strategies commonly used in SAE. Detailed 3D computer models were constructed considering the descending aorta, various major visceral arteries, and the iliac arteries. Subsequently, the blood flow and pressure associated with different coil placement locations in proximal embolization were studied considering the collateral vessels. Coil induced variations in pressure fields were quantified and compared to baseline. The coil induced flow stagnation was also quantified with particle residence time. Distal embolization was modeled with Lagrangian particle tracking and the effect of particle size, release location, and timing on embolization outcome was studied. Our findings highlight the crucial role of collateral vessels in maintaining blood supply to the spleen following proximal embolization. It was demonstrated that coil location can affect distal pressure and that strategic coil placement guided by patient-specific CFD simulations can further reduce this pressure as desired. Additionally, the results point to the critical roles that particle size, release timing, and location play in distal embolization. Our study provides an early attempt to use patient-specific computer modeling for optimizing embolization strategies and ultimately improving patient outcomes during SAE procedures.

Splenic artery embolization in the treatment of blunt splenic injury: single level 1 trauma center experience.

To describe the experience of a single level 1 trauma center in the management of blunt splenic injuries (BSI). This is a retrospective study with Institutional Review Board approval. The medical records of 450 patients with BSI treated between January 2016 and December 2022 were reviewed. Seventy-two patients were treated with splenic artery embolization (SAE), met the study criteria, and were eligible for data analysis. Spleen injuries were graded in accordance with the American Association for the Surgery of Trauma Organ Injury Scale. Univariate data analysis was performed, with P < 0.05 considered statistically significant. The splenic salvage rate was 90.3% (n = 65/72). Baseline demographics were similar between the groups (P > 0.05). Distal embolization with Gelfoam® had similar rates of splenic salvage to proximal embolization with coils (90% vs. 94.1%, P > 0.05). There was no significant difference in the rate of splenic infarction between distal embolization with Gelfoam® (20%, 4/20) and proximal embolization with coils (17.6%, 3/17) (P > 0.05). There was no significant difference in procedure length (68 vs. 75.8 min) or splenic salvage rate (88.5% vs. 92.1%) between proximal and distal embolization (P > 0.05). There was no significant difference in procedure length (69.1 vs. 73.6 min) or splenic salvage rate (93.1% vs. 86.4%) between Gelfoam® and coil embolization (P > 0.05). Combined proximal and distal embolization was associated with a higher rate of splenic abscess formation (25%, 2/8) when compared with proximal (0%, 0/26) or distal (0%, 0/38) embolization alone (P = 0.0003). The rate of asymptomatic and symptomatic splenic infarction was significantly higher in patients embolized at combined proximal and distal locations (P = 0.04, P = 0.01). The endovascular management of BSI is safe and effective. The overall splenic salvage rate was 90.3%. Distal embolization with Gelfoam® was not associated with higher rates of splenic infarction when compared with proximal embolization with coils. Combined proximal and distal embolization was associated with a higher incidence of splenic infarction and splenic abscess formation. Distal splenic embolization with Gelfoam® is safe and may be beneficial in the setting of blunt splenic trauma.

Impact of Embolisate Penetration, Type, and Technique on Results After Standalone Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

BACKGROUND AND OBJECTIVES: Middle meningeal artery embolization (MMAE) has emerged as a promising modality for chronic/subacute subdural hematoma treatment; however, consensus regarding embolization technique and embolisate has not been achieved. We thus sought to compare the efficacy of distinct MMAE techniques and embolisate. METHODS: An institutional registry was reviewed to identify patients undergoing standalone MMAE for symptomatic chronic/subacute subdural hematoma. Surgical rescue rate and time preceding 50% hematoma resolution were evaluated across 3 technical groups: aggressive penetration (AP), nonaggressive penetration with proximal coil embolization (NP-PC), and nonaggressive penetration alone (NP). Effect sizes were adjusted for demographic, neurological and radiological features through multivariable logistic and Cox regression. RESULTS: Among 117 procedures, 33.3% achieved AP, 36.8% had NP-PC, and 29.9% had NP. The rate of surgical rescue was 2.6% after AP, 9.3% for NP-PC, and 11.4% for NP. In patients not undergoing rescue surgery, 82.4% achieved hematoma resolution ≥50% at a median imaging follow-up of 56 days; AP or NP-PC were each statistically significantly associated with enhanced hematoma resolution as compared with NP (P = .02). Similarly, sensitivity analysis within medium-size hematoma and antiplatelet/anticoagulation-at-admission subgroups revealed a superiority of resolution after AP or NP-PC. A unique, comparative secondary analysis of liquid embolisate (Onyx vs n-butyl cyanoacrylate) revealed no impact on rate of surgical rescue or hematoma resolution. CONCLUSION: AP was associated with the lowest rate of surgical rescue, while both AP and NP-PC were associated with improved rates of hematoma resolution.

Transanal eco-Doppler evaluation after hemorrhoidal artery embolization.

Hemorrhoidal artery embolization (Emborrhoid) is a novel method for the treatment of severe hemorrhoidal bleeding. Despite having a technical success rate of 93%-100%, the clinical success ranges between 63% and 94%, with a rebleeding rate of 13.6%. To evaluate the effectiveness of this procedure in reducing hemorrhoidal flow and hemorrhoidal bleeding. This prospective observational pilot study was conducted at Division of General Surgery 1 and Tertiary Referral Pelvic Floor Center, Treviso Regional Hospital, Italy. In a 2 months period (February-March 2022), consecutive patients with hemorrhoidal bleeding scores (HBSs) ≥ 4, Goligher scores of II or III, failure of non-operative management, and a candidate for Emborrhoid were included. Endoanal ultrasound with eco-Doppler was performed preoperatively and 1 month after the procedure. The primary endpoint was to quantify the changes in arterial hemorrhoidal flow after treatment. The secondary endpoint was to evaluate the correlation between the flow changes and the HBS. Eleven patients underwent Emborrhoid. The overall pretreatment mean systolic peak (MSP) was 14.66 cm/s. The highest MSP values were found in the anterior left lateral (17.82 cm/s at 1 o'clock and 15.88 cm/s at 3 o'clock) and in the posterior right lateral (14.62 cm/s at 7 o'clock and 16.71 cm/s at 9 o'clock) quadrants of the anal canal. After treatment, the overall MSP values were significantly reduced (P = 0.008) although the correlation between MSP and HBS changes was weak (P = 0.570). A statistical difference was found between distal embolization compared with proximal embolization (P = 0.047). However, the coil landing zone was not related to symptoms improvement (P = 1.000). A significant difference in MSP changes was also reported between patients with type 1 and type 2 superior rectal artery (SRA) anatomy (P = 0.040). No relationship between hemorrhoidal grades (P = 1.000), SRA anatomy (P = 1.000) and treatment outcomes was found. The preliminary findings of this pilot study confirm that Emborrhoid was effective in reducing the arterial hemorrhoidal flow in hemorrhoidal disease. However, the correlation between the post-operative MSP and HBS changes was weak. Hemorrhoidal grade, SRA anatomy and type of embolization were not related to treatment outcomes.

Initial experience of endovascular aneurysm repair at the Dr. Eduardo Liceaga General Hospital of Mexico

Background: Abdominal aortic aneurysm (AAA) is the permanent and irreversible dilation of the lower part of the aorta where the vessel expands, making it susceptible to rupture, which represents a high mortality incident. Methods: A review of clinical records was carried out from September 2021 to March 2023, patients who were diagnosed with aortic aneurysm were included in whom endovascular exclusion of abdominal and thoracic aortic aneurysm was performed at the General Hospital of Mexico by the angiology vascular and endovascular surgery department. Results: 18 endovascular repairs of aortic aneurysms were performed, of which 15.4% were female (n=6) and 84.6% male (n=12). The average proximal neck diameter in the thoracic aorta was 31 mm, average proximal neck diameter in infrarenal AAA 22.2 mm, average aneurysmal diameter in infrarenal segment 63.8 mm, thoracic 31 mm. Regarding the type of endovascular procedure, 11.1% were repaired with the fenestrated endovascular aneurysm repair (FEVAR) technique, and the same proportion with chimney endovascular aneurysm repair (ChEVAR), for a resolution with conventional EVAR of 77.7%. Complications occurred in 3 patients, 2 of which resulted in type 1a and 1b endoleaks that were reoperated and repaired with a proximal cuff, balloon angioplasty, and embolization of the aneurysmal sac with coils. Conclusions: Aortic aneurysm remains a major cause of death in adults because of aortic rupture despite advances over the past two decades that have been made in the endovascular management of large, symptomatic, and ruptured. Timely treatment is essential to prevent rupture and poor patient outcomes.

Immediate procedural safety of adjunctive proximal coil occlusion in middle meningeal artery embolization for chronic subdural hematomas: Experience in 137 cases.

Endovascular embolization of the middle meningeal artery (MMA) has emerged as an adjunctive and stand-alone modality for the management of chronic subdural hematomas (cSDH). We report our experience utilizing proximal MMA coil embolization to augment cSDH devascularization in MMA embolization. MMA embolization cases with adjunctive proximal MMA coiling were retrospectively identified from a prospectively maintained IRB-approved database of the senior authors. Of the 137 cases, all patients (n = 89, 100%) were symptomatic and underwent an MMA embolization procedure for cSDH. 50 of the patients underwent bilateral embolizations, with 53% (n = 72) for left-sided and 47% (n = 65) for right-sided cSDH. The anterior MMA branch was embolized in 19 (14%), posterior in 16 (12%), and both in 102 (74.5%) cases. Penetration of the liquid embolic to the contralateral MMA or into the falx was present in 38 (28%) and 31 (23%) cases, respectively, and 46 (34%) cases had ophthalmic or petrous collateral (n = 41, 30%) branches. MMA branches coiled include the primary trunk (25.5%, n = 35), primary and anterior or posterior MMA trunks (20%, n = 28), or primary with the anterior and posterior trunks (54%, n = 74). A mild ipsilateral facial nerve palsy was reported, which remained stable at discharge and follow-up. Absence of anterograde flow in the MMA occurred in 137 (100%) cases, and no cases required periprocedural rescue surgery for cSDH evacuation. The average follow-up length was 170 ± 17.9 days, cSDH was reduced by 4.24 ± 0.5(mm) and the midline shift by 1.46 ± 0.27(mm). Complete resolution was achieved in 63 (46.0%) cases. Proximal MMA coil embolization is a safe technique for providing additional embolization/occlusion of the MMA in cSDH embolization procedures. Further studies are needed to evaluate the potential added efficacy of this technique.

Perioperative proximal splenic artery embolization in cirrhotic patients with splenomegaly

Introduction The purpose of this study was to determine the effect of proximal splenic artery embolization (SAE) in cirrhotic patients with splenomegaly who underwent surgical laparotomy. Material and methods This retrospective observational study included 8 cirrhotic patients with splenomegaly. They underwent proximal SAE before- (n = 6) or after (n = 2) laparotomy. Vascular plugs or coils were placed in the proximal splenic artery. The diameter of the portal vein and the splenic volume were recorded. Clinical outcome assessments included platelet counts, the model for end-stage liver disease (MELD) score, and complications. Results After embolization, the portal venous diameter was significantly smaller (pre: 13.6 ± 2.7 mm, post: 12.5 ± 2.3 mm, p = 0.023), the splenic volume was significantly decreased (pre: 463.2 ± 145.7 ml, post: 373.3 ± 108.5 ml, p = 0.008) and the platelet count was significantly higher (pre: 69.6 ± 30.8 × 103/μl, post: 86.8 ± 27.7 × 103/μl, p = 0.035). Before embolization, the median MELD score was 12; after embolization, it was 11 (p = 0.026). No patient developed post-treatment complications after embolization. Conclusions The reduction of hypersplenism by perioperative proximal SAE may be safe and reduce the surgical risk in cirrhotic patients with splenomegaly.

Correlation of serum D-dimer level and the event microvessel cardiac thrombosis observed on core biopsy in post mortem COVID-19 Patients in Dr. Soetomo Hospital Surabaya, Indonesia

Link of Video Abstract: https://youtu.be/ivpwfj9PxWQ Background: Microvascular coronary thrombosis is an emerging risk factor that worsens the prognosis of COVID-19 patients. This study aims to show for the first time a descriptive of histopathologic findings from post-mortem COVID-19 patients and to analyze whether D-Dimer serum level, a marker of hyper-coagulopathy, correlates with coronary microvascular thrombosis from the cardiac core biopsy. Method: This was an observational analytic study with a retrospective cohort design from July-December 2020. Cardiac core biopsy was taken from patients who died while treated at the isolation ICU at Dr. Soetomo due to severe COVID-19. The samples were taken in 1-hour post-mortem and then analyzed histopathologically with Hematoxylin-eosin staining under a light microscope to evaluate the presence of coronary microvascular thrombosis and other pathological findings from the cardiac biopsy. Clinical information and D-Dimer levels from medical records and analyzed for coronary microvascular thrombosis using Man-Whitney and C-statistic analysis using SPSS 22 software. Result: There were 39 samples of post-mortem patients in this study. The majority were men (71.8%), with a mean age of 48.9 years old. Focal microvessel coronary thrombosis was found in 28%). The median D-Dimer level was increased from the average baseline (3460 mg/dl). However, there was no significant difference in D-dimer levels between focal microvessel coronary thrombosis incidents (p-value 0.827, C statistic AUC 0.523). The lack of focal necrosis in the surrounding tissue suggests that the thrombosis resulted from proximal embolization to distal capillary coronary, which already happened before, rather than the primary in-situ process in microvascular, hence may explain why D-Dimer was not correlated with the finding of coronary microvascular thrombosis in this study. Conclusion: D-dimer serum levels were not associated with focal microvessel thrombi in post-mortem COVID-19 patients. This result supports previous studies that showed D-Dimer was not specific to detect thrombosis in microvascular.

Preventive Proximal Splenic Artery Embolization for High-Grade AAST-OIS Adult Spleen Trauma without Vascular Anomaly on the Initial CT Scan: Technical Aspect, Safety, and Efficacy-An Ancillary Study.

The spleen is the most commonly injured organ in blunt abdominal trauma. Its management depends on hemodynamic stability. According to the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS ≥ 3), stable patients with high-grade splenic injuries may benefit from preventive proximal splenic artery embolization (PPSAE). This ancillary study, using the SPLASH multicenter randomized prospective cohort, evaluated the feasibility, safety, and efficacy of PPSAE in patients with high-grade blunt splenic trauma without vascular anomaly on the initial CT scan. All patients included were over 18 years old, had high-grade splenic trauma (≥AAST-OIS 3 + hemoperitoneum) without vascular anomaly on the initial CT scan, received PPSAE, and had a CT scan at one month. Technical aspects, efficacy, and one-month splenic salvage were studied. Fifty-seven patients were reviewed. Technical efficacy was 94% with only four proximal embolization failures due to distal coil migration. Six patients (10.5%) underwent combined embolization (distal + proximal) due to active bleeding or focal arterial anomaly discovered during embolization. The mean procedure time was 56.5 min (SD = 38.1 min). Embolization was performed with an Amplatzer™ vascular plug in 28 patients (49.1%), a Penumbra occlusion device in 18 patients (31.6%), and microcoils in 11 patients (19.3%). There were two hematomas (3.5%) at the puncture site without clinical consequences. There were no rescue splenectomies. Two patients were re-embolized, one on Day 6 for an active leak and one on Day 30 for a secondary aneurysm. Primary clinical efficacy was, therefore, 96%. There were no splenic abscesses or pancreatic necroses. The splenic salvage rate on Day 30 was 94%, while only three patients (5.2%) had less than 50% vascularized splenic parenchyma. PPSAE is a rapid, efficient, and safe procedure that can prevent splenectomy in high-grade spleen trauma (AAST-OIS) ≥ 3 with high splenic salvage rates.

Open Thoracic Drainage Followed by Proximal Splenic Artery Embolization for Massive Hydrothorax Before Living Donor Liver Transplantation

Hepatic hydrothorax is associated with postoperative infectious complications and mortality in patients undergoing living-donor liver transplantation (LDLT). Thus, preoperative management of massive hepatic hydrothorax is essential for improving the outcomes of LDLT. This study aimed to demonstrate our successful cases and strategy for treating massive hepatic hydrothorax. Our strategy for hepatic hydrothorax includes (a) mini-thoracotomy under general anesthesia for the drainage of hydrothorax, (b) preoperative hepatic inflow modulation by proximal splenic arterial embolization, and (c) nutritional and physical intervention to improve the general condition. Two patients with massive hepatic hydrothorax were treated with our strategy. Both patients had end-stage liver disease secondary to primary biliary cholangitis. Their performance status deteriorated due to massive hydrothorax. After the intervention, their performance status significantly improved. After that, LDLTs with right lobe grafts were performed. The duration of the operation was 440 and 343 minutes, with an intraoperative blood loss of 1,700 and 1,600 g, respectively. Their postoperative courses were uneventful, and they were discharged on postoperative days 16 and 14. Our pre-LDLT multimodal management strategy for massive hepatic hydrothorax, including preoperative open thoracic drainage, pre-LDLT portal inflow modulation, and nutritional intervention, improved the preoperative condition of patients undergoing LDLT, resulting in successful outcomes.

孤立性特発性腹腔動脈解離に続発した解離性脾動脈瘤破裂の2例(Ruptured dissected splenic artery aneurysms secondary to isolated spontaneous celiac artery dissection: a report of two cases)

【症例1】52歳の男性。腹痛を主訴に近医を受診したところ，腹部造影CTで急性膵炎および脾動脈瘤破裂と診断され当院紹介となった。当院CTでは腹腔動脈起始部の解離と仮性動脈瘤を認めた。血管内治療を試みたが，脾動脈遠位の屈曲・蛇行が強く，金属コイルとNBCA併用による近位塞栓で終了とした。不完全塞栓であったため最終的には手術治療を要した。【症例2】53歳の男性。受傷2日前に突然の腹痛を自覚。受傷当日，乗用車運転中に意識消失し対向車と正面衝突し搬送となった。来院時ショック状態であり，腹部超音波検査では腹腔内液体貯留を認め，造影CTでは腹腔動脈起始部より脾動脈遠位に至る偽腔開存型解離および解離性脾動脈瘤破裂と周囲血腫を認めた。腹腔動脈起始部は正中弓状靱帯圧迫症候群により狭小化していた。血管内治療を施行したところ，脾動脈解離の真腔は偽腔に圧排され完全閉塞し，偽腔より横隔脾間膜内への造影剤漏出を認めた。偽腔の近位・遠位を金属コイルで塞栓し止血を得た。経過観察後のCTでは脾門部に仮性動脈瘤の出現を認め，金属コイル・NBCA塞栓術を追加し根治し得た。孤立性特発性腹腔動脈解離に伴う解離性脾動脈瘤破裂は非常に稀ではあるが，内因性腹部出血の鑑別の一つとして考慮すべきであり，発症様式や全身状態により各施設で最適な止血方法を選択する必要がある。 Here we report the features of two cases of ruptured dissected splenic artery aneurysm associated with isolated spontaneous celiac artery dissection encountered in our institute. Case 1: A 52–year–old male was referred to us following diagnosis with acute pancreatitis with pancreatic pseudocyst, dissection of the origin of the celiac artery, and a dissecting pseudoaneurysm of the splenic artery on computed tomography(CT). Endovascular treatment was attempted, but the distal splenic artery was difficult to reach due to high flexion and tortuosity; therefore, proximal embolization alone was performed. Follow–up CT showed incomplete embolization, and radical surgical treatment was subsequently performed. Case 2: A 53–year–old male lost consciousness while driving a passenger car and was injured in a head–on collision with an oncoming car. CT showed dissection from the origin of the celiac artery to the proximal splenic artery and rupture of the splenic artery aneurysm. The celiac artery was narrowed due to median arcuate ligament syndrome. Endovascular treatment was performed, the proximal and distal portions of the false lumen were embolized with coil and cyanoacrylate, and hemostasis was achieved. Follow–up CT revealed a pseudoaneurysm at the splenic hilum, and embolization was performed again. Although, very rare cases, we should consider as one of the differentials diagnoses. 孤立性特発性腹部内臓動脈解離は稀な病態であるが，腹腔動脈解離は上腸間膜動脈解離に次いで多いとされている 1。孤立性特発性腹腔動脈解離（isolated spontaneous celiac artery dissection: ISCAD）はmulti detector–row CT（MDCT）の普及により報告数が近年増加しているものの，無症候から症候性に至るまで臨床経過は様々である。一般的には初回治療として保存的治療を選択することが多いが，合併症を有する例では侵襲的治療が選択される 2。今回我々は，解離性脾動脈瘤破裂を伴ったISCADの2例を経験したため，文献的考察とともに報告する。 本稿は倫理委員会の承認を要しない症例報告である。また，個人情報保護法に基づき匿名化されており，患者家族から論文の出版に関する同意を得ている。 患 者：52歳の男性 主 訴：左側腹部痛 既往歴：特記事項なし 飲酒歴：焼酎500〜1,000mL/日 喫煙歴：20〜30本/日×30年間 現病歴：来院10日前より左側腹部痛を自覚していたが，徐々に増悪したために前医へ救急搬送された。造影CT検査で急性膵炎および脾動脈瘤破裂と診断され，当院へ転送となった。 来院時現症：意識レベルJapan coma scale（JCS）I–0，Glasgow coma scale（GCS）E4V5M6，呼吸数18/分，心拍数110/分，血圧140/80mmHg，体温37.2℃（腋窩），SpO2 100%（室内気）腹部は平坦・軟であり左側腹部の自発痛はほぼ消失していた。血液検査では白血球17,000/μL，CRP 6.92mg/dLと軽度の炎症所見を認めた。Amyは70U/Lと基準値内であった。 腹部造影CT動脈相では，腹腔動脈起始部は解離しておりISCADの所見を認めた（補足図1a）。動脈解離は腹腔動脈から脾動脈中程まで連続しており，脾動脈起始部は偽腔に圧排され高度に狭小化しており，偽腔は瘤状に拡張していた。さらに，破裂した偽腔周囲には最大径約25mmの不整に拡張した仮性動脈瘤を認めた（補足図1b）。また，膵体尾部の腫大と膵周囲の脂肪織濃度上昇を認め，急性膵炎の所見を認めた（補足図1c）。 初療経過：循環動態は安定していたため，仮性動脈瘤に対し動脈塞栓術（transcatheter aterial embolization: TAE）の方針とした。腹腔動脈造影では，腹腔動脈起始部から脾動脈へ及ぶ解離を認め，解離性脾動脈瘤を形成していた。解離性脾動脈瘤の周囲には最大径47mmの血腫を認め，仮性動脈瘤を形成していた（補足図2a）。脾動脈の真腔は拡張した偽腔に圧排されて狭小化しておりアプローチ不能であったため，偽腔よりアプローチした。偽腔から解離性脾動脈瘤遠位の選択を試みたが，屈曲と蛇行が強く困難であった。そのため，アイソレーションを断念し，仮性動脈瘤に連続する解離性脾動脈瘤内をコイル6本でパッキングし，解離性脾動脈瘤近位に2本のコイルを留置して50%NBCA 2mLを注入した。NBCAは解離性脾動脈瘤の尾側に停滞した。その後の造影では，解離性脾動脈瘤の一部に造影効果を認めたが，これ以上の塞栓は技術的に困難と判断し手技を終了した（補足図2b）。 入院後経過：TAE後は腹痛の再燃や貧血の進行なく経過したが，第4病日の造影CTではコイル塞栓部腹側に結節状の造影効果が残存し，塞栓部の遠位にも血流を認めた（補足図2c）。不完全塞栓であったがTAEによる再アプローチは困難と考え，待機的に第8病日に手術となった。開腹時，活動性出血はほぼ認めなかった。膵体尾部に膵炎の影響と思われる高度癒着を認め，瘤との剥離は困難であった。脾動静脈を根部で結紮し，膵体尾部・脾臓合併切除を行った（補足図3a, b）。術中出血量2,320mL，濃厚赤血球輸血計4単位使用した。術後経過は良好で第25病日に退院となった。切除膵の病理組織診断では，膵炎の炎症が脾動脈へ波及し，脾動脈外膜が破壊されている所見を認めた。 患 者：53歳の男性 主 訴：意識消失，腹痛 既往歴：糖尿病，高血圧 現病歴：受傷2日前の早朝に突然の激しい腹痛とめまいを自覚したが，自宅で様子を見ていた。受傷当日，乗用車を運転中に意識消失感が出現し，車を停車させたところで対向車と正面衝突し救急要請となった。救急隊接触時ショック状態であり，ドクターヘリで当院搬送となった。 来院時現症：意識レベルJCS I–1，GCS E4V5M6，呼吸数18/分，心拍数121/分，血圧81/54mmHg，体温35.2℃（腋窩温），SpO2 99%（酸素10Lリザーバーマスク），瞳孔径は両側3.0mmで対光反射は迅速であった。腹部超音波検査でモリソン窩，脾周囲，膀胱直腸窩に液体貯留を認めた。体表上は明確な外傷痕は認めず，腹部も平坦軟であったが，上腹部に軽度の圧痛を認めた。血液・生化学検査では，白血球の上昇（25,100/μL）と貧血（Hb 10.2mg/dL）を認めたほか，Cr 1.08mg/dL，CRP 2.29mg/dL，乳酸32mg/dLと上昇を認めた。Amyは110U/Lと基準値内であった。 初療経過：ドクターヘリ医師接触時は血圧測定不能であったが，現場より初期輸液，O型赤血球輸血開始後，来院時収縮期血圧は80mmHg以上に上昇したため，直ちに腹部造影CTを施行した。腹部造影CTでは血性腹水貯留を認め，腹腔動脈起始部は正中弓状靱帯圧迫症候群（median arcuate ligament syndrome: MALS）により狭小化（補足図4a）しており，かつ解離（ISCAD）を認めた（補足図4b）。ISCADは脾動脈遠位に及び，解離性脾動脈瘤の破裂に伴う仮性動脈瘤が形成されていた。さらに，横隔脾間膜内には大量の血腫を伴っていた（補足図4c）。来院時は、“外傷性”腹腔内出血として初療を進めていたが，受傷機転が軽微なこと，腹部に外傷痕を認めないこと，来院2日前からの腹痛と意識消失のエピソードがあることを考慮し，解離性脾動脈瘤破裂による出血性ショックと最終的に判断した。開腹止血術も考慮したが，輸液・輸血により循環動態の安定化が得られたこと，CT上腸管損傷などの絶対的に手術介入を要する病態がないことからTAEの方針とした。腹腔動脈造影では仮性動脈瘤はやや遅れて描出された（補足図5a）。膵尾枝や大膵動脈は描出されず，遠位で僅かに脾実質が造影された。腹腔動脈造影を施行したところ，腹腔動脈解離に続く解離性脾動脈瘤の真腔は偽腔に圧排されて狭小化し，完全閉塞していた。そのため，偽腔内へガイドワイヤーを進め，偽腔内から仮性動脈瘤の遠位をコイル計5本，近位をコイル計7本にてアイソレーションした（補足図5b）。最終的に腹腔動脈造影，上腸間膜動脈造影で仮性動脈瘤が描出されないことと，短胃動脈から脾実質の造影効果が保たれていることを確認して手技を終了した。 入院後経過：循環動態は安定して経過し，貧血進行もなく，止血は得られたと判断した。第8病日の造影CTでは，脾門部に短胃動脈を血液流入路とする仮性動脈瘤の出現を認めた。瘤径は小さく血栓化を期待し経過観察を行ったが，第18病日のCTで瘤径14×16mmと増大を認めたため再度TAEを施行した。腹腔動脈から胃十二指腸動脈，胃大網動脈を介してアプローチし，仮性動脈瘤近位と遠位で金属コイル2本と40%NBCAにて塞栓を行った（補足図6a, b）。脾臓血流は，短胃動脈・後胃動脈を介して温存された。その後は経過良好で，第21病日に退院となった。 今回我々は，ISCADを伴う解離性脾動脈瘤破裂の症例で，それぞれ異なる治療アプローチを要した2症例を経験した。ISCADはMDCTの普及により近年報告数が増加しており，初回治療として降圧，鎮痛，抗血小板療法，抗凝固療法などによる保存的治療を選択されることが多い。腹腔内出血などの合併症を有する例では侵襲的治療が選択されるが，確立した治療法はなく，症例により手術あるいは血管内治療が選択されている 2, 3, 4。 侵襲的治療の適応として，症状持続，腹腔動脈径拡大（≧15～20mm）や瘤化，真腔の狭小化や閉塞による臓器虚血，動脈瘤破裂が挙げられる 5。ISCAD 169例のシステマティックレビューでは血管内治療が11.8%に，開腹手術が8.9%に行われており，近年では血管内治療が主流となっている 6。また，別のシステマティックレビュー（68症例）では，解離の進展範囲に関し腹腔動脈限局が22.6%，脾動脈への進展が50.9%，総肝動脈への進展が45.3%と報告されている 5。破裂症例は腹腔動脈1.2%，脾動脈2.9%に認め全例死亡している 5, 6。このように，ISCADから破裂に至る症例は非常に稀であり，文献検索した範囲では腹腔動脈起始部の解離が遠位へ進展し破裂した例は4例のみであった 2, 3, 7, 8。 今回提示した2症例では，ISCADが脾動脈遠位まで解離を来し，かつ解離性動脈瘤破裂に至った点と，その背景にそれぞれ膵炎やMALSを有していた点で非常に稀な症例であった。これまでにISCADの成因として，動脈硬化，血管炎，線維筋性異形成，結合織疾患（Marfan，Ehlers–Danlos症候群），結節性多発動脈炎，segmental arterial mediolysis，梅毒や真菌感染症などが報告されている 2。 症例1では，循環動態が安定していたことからTAEを第一選択としたが，脾動脈の屈曲・蛇行と狭小化が著しく，不完全塞栓となり最終的に手術を要した。ISCADの解離が脾動脈へ進展した結果解離性脾動脈瘤を形成し，さらに脆弱性の高い偽腔に急性膵炎の炎症が波及し破裂を来し，仮性動脈瘤を形成したものと考えられた。ISCADそのものの成因として膵炎が背景となっていたかに関しては報告が存在しない。症例2は，MALSに続発したISCADが脾動脈に進展し，解離性脾動脈瘤の形成から破裂に至った症例であった。MALSがISCADの発生に関与した症例は過去に報告されており，MALSに腹腔動脈解離が合併し膵十二指腸動脈瘤破裂に至った例 9や，MALSに腹腔動脈解離を伴い血管内治療を施行した例 10，および血管内治療に加え腹腔鏡による弓状靭帯切離を施行した例 11の3症例のみが存在している。MALSからISCADを生ずる機序は，腹腔動脈起始部の物理的狭小化によって血管内腔の圧上昇を来し，内膜と中膜の解離を生じるためと考えられる。無症候性のMALSが多く存在することは知られており，剖検例の検討では約1/3にMALSによる腹腔動脈圧迫を認めたとの報告もある 12, 13。また，CTなどの画像検査で約7%に腹腔動脈の無症候性狭窄が発見されたとの報告もある 14。ゆえに，症例2のように無症候性のMALSにISCADを潜在的に有している例も少なからず存在する可能性がある。なお，CTでISCADが偶発的に見つかった場合でも，循環動態が安定しており破裂や仮性動脈瘤を伴っていない場合にはルーチンでの血管造影は不要であり，MDCTでの形態的評価と経時的な経過観察で十分と考える。症例2ではTAEを第一選択としたが，もし仮に初期輸液にて循環動態の安定化が得られなかった場合，CT撮像ができないまま外傷性腹腔内出血として開腹止血術を先行させていた可能性があり，その場合ISCADによる内因性の解離性脾動脈瘤破裂との診断がつかなかった可能性がある。このように内臓動脈瘤破裂は，発症様式や全身状態においても選択される治療法が異なる病態であり，施設のリソースや各科のバックアップ体制なども考慮し，個々の施設で最適な止血方法を選択する必要があると考える。血管内治療，外科的治療のいずれを選択するにしても，初療を担う救急医がリーダーとして治療方針を決定し，専門的治療につなげることが要求されるため，内因性腹部出血の鑑別の一つとして常にこのような病態を念頭に置く必要がある。 また，MALSにおいては，根本原因である弓状靭帯圧迫を解除しないと，腹腔動脈，脾動脈塞栓に伴い，理論的に側副路への負担が増し将来的に瘤化から破裂を来す危険が残存する。現在ではより低侵襲な腹腔鏡下切離術が可能であり，ステントグラフト治療と組み合わせた根治的治療が将来的に期待されよう。 ISCADによる解離性脾動脈瘤破裂の2例を経験した。内因性腹部出血の鑑別としてISCADの破裂を念頭に入れる必要がある。 本稿における利益相反はない。 Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Proximal Splenic Artery Embolization for Refractory Ascites and Hydrothorax Post-Liver Transplant.

Proximal splenic artery embolization (pSAE) has been advocated as a valuable tool to ameliorate portal hyper-perfusion (PHP). The purpose of this study was to determine the safety and efficacy of pSAE to treat refractory ascites (RA) and/or refractory hydrothorax (RH) in the setting of PHP post-liver transplant. A total of 30 patients who underwent pSAE for RA and/or RH after liver transplantation (LT) between January 2007 and December 2017 were analyzed retrospectively. The patients were divided into groups according to the time frame from pSAE to clinical resolution in order to identify predictors of RA/RH response to the procedure. Twenty-four (80%) patients responded to pSAE within three months, whereas 6 (20%) still required additional treatments for RA/RH at three months post-pSAE. In all cases clinical symptoms resolved within six months. Complications after pSAE were as follows: 2 cases of splenic infarction (6.6%), one case of post-splenic embolization syndrome (3.3%), one case of hepatic artery thrombosis (3.3%) and one case of portal vein (PV) thrombosis (3.3%). Increased intraoperative PV flow volume and increased pre-pSAE PV velocity, as well as higher estimated glomerular filtration rate were associated with early RA/RH resolution. pSAE is safe and effective in treating RA and RH due to PHP after LT. This study suggests that clinical parameters indicating more severe PHP and better kidney function are possible predictors for early response to pSAE.

Proximal splenic artery embolization using a vascular plug in grade IV or V splenic trauma – a single centre 11-year experience

Proximal splenic artery embolization using a vascular plug in grade IV or V splenic trauma – a single centre 11-year experience

Endovascular management of renal angiomyolipomas: Do coils have a benefit in terms of clinical success rates?

PURPOSE This study evaluated single center results of endovascular treatment in renal angiomyolipoma (AML) to determine whether there is clinical relevance of adding proximal coil embolization to distal particle embolization in terms of safety, efficacy and retreatment rates. METHODS A retrospective analysis was performed to evaluate patients undergoing transarterial embolization for renal AMLs from January 2007 to October 2020. Parameters regarding patient and tumor characteristics, embolization technique, treatment outcome and complications were recorded. Patients were divided into two groups as A (only particle group) and B (particle + coil group) based on the type of embolic agent used for treatment. Comparative analysis was performed between the two groups in terms of tumor size reduction, retreatment and complication rates. RESULT Forty-two patients (37 (88.1%) female, 5 (11.9%) male) harboring 48 AMLs were included in the study. The mean age was 43.46 (range 20 to 78). The technical success rate was 95.8% (46 of 48 procedures). The mean size reduction was 1.94±1 cm (p < 0.001) after treatments however, no significant difference was seen between groups in terms of tumor size reduction. Retreatment rates were 3.1% (1 of 32 cases) in group A and 14.3% (2 of 14 cases) in group B (p = 0.21). No significant difference was found between groups in terms of bleeding and complication rates during the perioperative period. Mean follow-up duration was 26.48±25.71 (range from 2 to 102) months. CONCLUSION In this study, no clear supplementary benefit was observed in terms of safety, and efficacy with the adjunction of coils to distal particle embolization in the management of AMLs.

Long-Term Effects of Proximal Splenic Artery Embolization on Splenic Volume and Platelet Count

The spleen is the most commonly injured visceral organ in blunt abdominal trauma. Post-splenectomy infection risk has led to the shift toward spleen preserving procedures and splenic artery embolization (SAE) is now the treatment of choice for hemodynamically stable patients with splenic injury. This study aims to assess the long-term effect of SAE on splenic volume and platelet count. Using CPT codes, 66 patients who underwent SAE were identified, and 14 of those who had the necessary imaging and laboratory follow-up were included in the study. Indications for SAE were portal hypertension in 8 patients, bleeding in 4 patients, and thrombocytopenia in 1, and one patient had a separate indication. Splenic volume was calculated by automated volumetric software (Aquarius, TeraRecon, Inc.). Paired t-tests were performed to compare splenic volume and platelets before and after SAE. Fourteen patients (7 males, 7 females) with a mean age of 51±11.95years underwent SAE and were followed by a repeat computed tomography scan at an average of 733.57days. Nine SAEs were performed using vascular plugs, 3 using micro coils, and 2 out of that were with Gelfoam slurry, and 2 using coils only. All embolizations were technically successful with complete cessation of flow. Mean splenic volumes pre- and post-SAE were 903.5±523.73cm3 and 746.5±511.95cm3, respectively, representing a mean decrease of 8.31% compared to baseline [P=0.346]. Minimum platelet counts (x103) pre-SAE (within 3months) and post-SAE (2weeks to 3months after the procedure) were 55.79±57.11 and 116±145.40, respectively. The minimum platelet count showed a statistically significant mean increase of 134.92% (P=0.033). The splenic volume is not altered significantly by SAE in the long term. Similarly, the platelet count is also not significantly altered at 3months follow-up. This study, although small, suggests that SAE is a safe intervention that can preserve splenic volume and function in the long term.

Ideal Size Range for Embolic Agents in Interventional Oncology Experiments Involving Rat Models of Hepatocellular Carcinoma

PurposeTo optimize future translational research, this study aimed to determine the ideal range of sizes for embolic agents in interventional oncology experiments utilizing rat models of hepatocellular carcinoma (HCC). Materials and MethodsFifty-five male Sprague-Dawley rats were divided into 2 groups to evaluate the distribution of microparticles and tumor response rates. After implanting hepatoma cells into the rodent liver, fluorescent microparticles of sizes ranging from 5 to 35 μm were administered via the hepatic artery. In the first group, the distribution of microparticles was evaluated in hepatoma-free rats, and the tumor necrosis rates following administration of a predetermined aliquot of microparticles (0.4 mL) were measured in tumor-bearing rats. Thereafter, the 3 microparticle sizes associated with the best tumor response rates were chosen for analysis of the tumor necrosis rates following hepatic artery embolization until angiographic stasis is achieved in the second group. ResultsThe tendency for microparticles to distribute in nontarget organs increased as the microparticle size decreased below 15 μm. Tumor necrosis rates tended to be higher in rats treated with 15–19-μm microparticles than in those treated with 19–24-μm or 19–24-μm microparticles. The in-group deviation of the tumor necrosis rates was highest for microparticle sizes of 19–24 and 25–35 μm, which implies the proximal embolization of the hepatic artery for larger microparticle sizes. However, there was no statistical significance among the 3 groups (P = .095). ConclusionsThe 15–19-μm embolic agents were the most favorable for causing tumor necrosis without nontarget toxicity in the transarterial treatments of rat HCC models.

The Safety and Efficacy of Hepatic Transarterial Embolization Using Microspheres and Microcoils in Patients with Symptomatic Polycystic Liver Disease.

Purpose: We investigated the long-term safety and efficacy of hepatic transarterial embolization (TAE) in patients with symptomatic polycystic liver disease (PLD). Materials and Methods: A total of 26 patients were included, mean age of 52.3 years (range: 33–78 years), undergoing 32 TAE procedures between January 2012 and December 2019 were included in this retrospective study. Distal embolization of the segmental hepatic artery was performed with 300–500 µm embolic microspheres associated with proximal embolization using microcoils. The primary endpoint was clinical efficacy, defined by an improvement in health-related quality of life using a modified Short Form-36 Health Survey and improvement in symptoms (digestive or respiratory symptoms and chronic abdominal pain), without invasive therapy during the follow-up period. Secondary endpoints were a decrease in total liver volume and treated liver volume and complications. Results: Hepatic embolization was performed successfully in 30 of 32 procedures with no major adverse events. Clinical efficacy was 73% (19/26). The mean reduction in hepatic volume was −12.6% at 3 months and −27.8% at the last follow-up 51 ± 15.2 months after TAE (range: 30–81 months; both ps < 0.01). The mean visual analog scale pain score was 5.4 ± 2.8 before TAE and decreased to 2.7 ± 1.9 after treatment. Three patients had minor adverse events, and one patient had an adverse event of moderate severity. Conclusion: Hepatic embolization using microspheres and microcoils is a safe and effective treatment for PLD that improves symptoms and reduces the volume of hepatic cysts.

Early diagnosis and treatment of splenic artery steal syndrome after liver transplantation

Objective: to study the incidence of splenic artery steal syndrome (SASS) in our own series of liver transplant surgeries and to determine diagnostic and therapeutic tactics. Materials and Methods. During the 3.5 years of existence of the liver transplant program in the Republic of Tatarstan, 77 cadaveric liver transplantations (LTx) have been performed. Postoperative SASS occurred in 4 cases (5.2%). Among the patients were 3 women and 1 man; mean age was 38 years. Doppler ultrasonography of the liver vessels and celiacography were used for diagnosis. Proximal splenic embolization was used as a way to correct the syndrome. Results. In all clinical cases, SASS was timely diagnosed and corrected by endovascular image-guided intervention. The patients were discharged with good hepatic graft function. The complication did not affect the length of hospital stay. Conclusion. SASS remains a severe vascular complication of LTx, which can lead to graft dysfunction and possible loss. Timely detection and treatment prevent severe consequences for the liver recipient.