Visceral Artery Pseudoaneurysms Research Articles

Endovascular treatment of traumatic pseudoaneurysm of the ileal branch of the superior mesenteric artery in a 9-year-old girl: Case report and literature review.

Visceral artery aneurysm is a rare and potentially fatal vascular condition that typically affects the superior mesenteric or inferior mesenteric arteries, the splenic, hepatic, and celiac arteries, as well as their branches. Visceral artery aneurysms can usually be treated using endovascular intervention, open surgery, or percutaneous thrombin injection. A 9-year-old girl was admitted to our trauma center with abdominal and bilateral leg pain after a car accident involving a head-on collision. Abdominal computed tomography (CT) showed bowel herniation through a muscle defect in the left lateral abdominal wall. There was a small amount of fluid around the liver and spleen, mild thickening of the small bowel wall, and infiltration in the small bowel mesentery, indicating the possibility of small bowel injury. Emergent exploratory laparotomy was performed. After resection of the ischemic parts of the terminal ileum and sigmoid colon, intestinal continuity was reestablished. Primary repair was performed on a traumatic left lateral abdominal wall hernia. She recovered well postoperatively without any complications. A follow-up abdominal CT scan after 2 months showed a pseudoaneurysm of the ileal branch of the superior mesenteric artery. Despite the absence of any gastrointestinal symptoms, the pseudoaneurysm was treated by endovascular intervention using numerous coils because of the significant risk of delayed rupture or massive bleeding. Follow-up abdominal CT scan after 6 months showed complete occlusion and resorption of the pseudoaneurysm. Although it is technically challenging, endovascular coil embolization may be a feasible technique in children with traumatic visceral artery pseudoaneurysms without complications.

Inferior Pancreaticoduodenal Artery Pseudoaneurysm Causing Biliary Obstruction: A Case Report

Introduction: Visceral arterial aneurysms and pseudoaneurysms are rare but dangerous pathologies, with reported incidence of 0.01–0.2% of the worldwide population, as found on autopsy. Pancreaticoduodenal artery pathology accounts for approximately 2% of all visceral aneurysms; it is commonly caused by chronic inflammatory processes, such as pancreatitis or adjacent pseudocysts. Morbidity and mortality commonly result from rupture of the aneurysm itself, leading to life-threatening hemorrhage into the peritoneum or gastrointestinal tract.Case Report: Here we present the case of a 64-year-old male patient with previous history of alcohol use disorder leading to chronic pancreatitis and prior embolization of an inferior pancreaticoduodenal pseudoaneurysm, who presented to the emergency department (ED) with abdominal pain, nausea, and vomiting, and was found to have a large recurrent inferior pancreaticoduodenal pseudoaneurysm with associated obstructive cholangitis and pancreatitis via contrast-enhanced computed tomography (CT) of the abdomen and pelvis. The patient was managed emergently by interventional radiology angiography with embolic coiling and percutaneous biliary catheter placement, and he subsequently underwent biliary duct stenting with gastroenterology. The patient was successfully discharged after a brief hospitalization after resolution of his pancreatitis and associated hyperbilirubinemia.Conclusion: Pancreaticoduodenal artery aneurysms and pseudoaneurysms are rare and dangerous visceral pathologies. Patients can be diagnosed rapidly in the ED with CT imaging and needurgent endovascular management to prevent morbidity and mortality.

Efficacy and Rationale of Endoscopic Ultrasound-Guided Thrombin Injection in Visceral Artery Pseudoaneurysm Not Amenable to Angioembolization.

Pseudoaneurysm usually occurs after vascular injuries or erosions such as in trauma or inflammation like pancreatitis and is associated with high morbidity and mortality. The aim of study is to assess efficacy and safety of EUS-guided thrombin injection in pseudoaneurysm. Prospective data collection was done at SMS Hospital, Jaipur, from January 2015 to March 2023. All patients with pseudoaneurysm were consecutively enrolled. Twenty patients (M/F, 18:2) with median age of 41 years (25-58 years), were studied. Underlying etiology of pseudoaneurysm was chronic pancreatitis in 75% of the patients, blunt trauma abdomen in 15% of the patients, recurrent acute pancreatitis in 5%, and idiopathic in 5% of the patients. At the time of admission, mean hemoglobin was 6.7 g/dL (3.4-8.2), with median blood transfusion requirement was 2 units (0-6 units). Hemoglobin values after 4-6 weeks showed a significant improvement ( t = 9.21, P < 0.05).Mean dose of human thrombin required for complete obliteration of pseudoaneurysm was 520 ± 188.6 IU per patient (300-800 IU). Amount of thrombin (IU) dose needed to achieve complete obliteration correlated well significantly with the dimension of pseudoaneurysm, P value less than 0.05 ( R = 0.80). Median follow-up duration in this study was 44 months (3-84 months), which was the longest follow-up period by far. Endoscopic ultrasound-guided thrombin injection in visceral artery pseudoaneurysm is a safe and effective alternative for patients not amenable for digital subtraction angiography-guided angioembolization.

Percutaneous glue embolization as an alternative treatment for visceral pseudoaneurysms

Visceral artery pseudoaneurysm is a rare, life-threatening medical condition with a high incidence of rupture and bleeding. At most institutions, endovascular intervention is considered the first-line treatment with surgical repair as a secondary option. Percutaneous glue embolization is emerging as a safe alternative technique for minimally invasive treatment of visceral pseudoaneurysms. This case series aims to promote percutaneous glue embolization as a life-saving measure in cases where an endovascular approach cannot be performed successfully, and patients are not surgical candidates.

CIRSE Standards of Practice for the Endovascular Treatment of Visceral and Renal Artery Aneurysms and Pseudoaneurysms

BackgroundEndovascular treatment of visceral and renal artery aneurysms and pseudoaneurysms is an effective, minimally invasive treatment that has been successfully used since the early 1990s, with refined and expanded techniques and tools currently offering excellent outcomes. Due to increased detection of such lesions in recent years, many of which are asymptomatic, revision of the indications for intervention and the correct endovascular treatment approaches has become essential.PurposeThis document will presume that the indication for treatment is clear and approved by the multidisciplinary team and will define the standards required for the performance of each intervention, as well as their relative advantages and limitations. CIRSE Standards of Practice documents are not intended to impose a standard of clinical patient care, but recommend a reasonable approach to, and best practices for, the performance of the endovascular treatment of visceral and renal artery aneurysms and pseudoaneurysms.MethodsThe writing group was established by the CIRSE Standards of Practice Committee and consisted of five clinicians with internationally recognised expertise in endovascular treatments. The writing group reviewed the existing literature on visceral and renal artery aneurysms and pseudoaneurysms, performing an evidence search using PubMed to identify publications in English and relating to human subjects from 1990 to 2022. The final recommendations were formulated through consensus.ResultsEndovascular treatment has an established role in the successful management of visceral and renal artery aneurysms and pseudoaneurysms, and this Standards of Practice document provides up-to-date recommendations for its safe performance.

Visceral arterial pseudoaneurysms in acute necrotizing pancreatitis - a single-centre retrospective study

Visceral arterial pseudoaneurysms in acute necrotizing pancreatitis - a single-centre retrospective study

Visceral Artery Pseudoaneurysm Rates after Pancreatoduodenectomy in Patients Who Received Pre-Operative Radiation for Pancreatic Cancer

The role of pre-operative radiation therapy (RT) for localized pancreatic ductal adenocarcinoma (PDAC) with peri-pancreatic vascular involvement remains controversial, with two recent randomized controlled trials, namely PREOPANC-1 and Alliance A021501, showing conflicting results. Opponents of pre-operative radiation point towards the unclear oncologic benefit and potential added toxicity. While hemorrhage from a pseudoaneurysm (PsA) rupture is a known rare but potentially fatal complication after pancreaticoduodenectomy (PD), with published incidence rates of around 2 to 5%, it has been increasingly common in the pancreatic cancer surgical community for pre-operative RT to be cited as a risk factor for PsA development, despite the absence of data supporting this notion. Certainly, accurate characterization of relevant RT-related toxicities is critical to prevent inaccurate decision-making regarding foregoing its use. As such, we aim to report on the incidence of PsA in a cohort of patients with PDAC who underwent pre-operative RT prior to PD at a high-volume center. Consecutive patients treated with pre-operative RT via stereotactic body radiation therapy (SBRT) or intensity modulated radiation therapy (IMRT) prior to PD for borderline resectable or locally advanced PDAC were retrospectively reviewed. Incidence of radiographic or clinically apparent PsA was reported. We also characterized the timing of PsA identification in relation to surgery and RT, the artery in which the PsA developed, and the clinical outcomes of patients after PsA identification. One hundred seventy-five patients met eligibility criteria for our analysis. Most of our cohort (163 patients, 93%) received SBRT to a median dose of 6.6 Gy x 5 (median BED10 54.78 Gy, range: 48 Gy - 61.92 Gy), and only 12 patients (7%) received IMRT in various fractionation and dose patterns (median BED10 62.94 Gy, range 59.47 Gy - 97.5 Gy). The median time between surgery and last contrast-enhanced abdominal imaging was 17 months (range: 0.23 - 68 months). There were fourteen visceral arteries among thirteen patients (7%) that were found to have a PsA on routine follow-up imaging or after a post-PD hemorrhage. The median time between completion of radiation and surgery to PsA were 19.5 weeks (range: 8.6 to 98.1 weeks) and 13 weeks (range: 1.6 to 87.9 weeks), respectively. The two most commonly involved arteries were the gastroduodenal and superior mesenteric arteries. Rate of PsA development was similar among patients treated with SBRT (7%) and IMRT (8%). In terms of Clavien-Dindo classification of complications, there were six patients with grade 3a complications, five patients with grade 4b complications, and two patients with grade 5 complications. Compared to historical data, pre-operative RT does not appear to significantly increase the risk of PsA development after PD. More data on the impact of pre-operative radiation dose-fraction regimen and longer follow-up are needed.

Endovascular Treatment of Visceral Artery Pseudoaneurysms with Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs).

Background and Objectives: Treatment of visceral artery pseudoaneurysms (VAPs) is always indicated regardless of their diameters, as their risk of rupture is significantly higher than that of visceral artery aneurysms. The invasiveness of surgery and its associated complications have led to a shift in favor of radiological interventions as the initial treatment of choice. However, there are still some unanswered questions on endovascular treatment of VAPs regarding the optimal endovascular technique and the efficacy and safety outcomes. The purpose of this multicenter study was to retrospectively evaluate the effectiveness and safety of endovascular treatment of visceral pseudoaneurysms using Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs). Materials and Methods: Consecutive patients who underwent endovascular embolization with EVOH-based NALEAs for visceral artery pseudoaneurysms between January 2018 and June 2023 were retrospectively evaluated. Results: 38 embolizations were performed. Technical success was achieved in all patients. The clinical success rate was high (92.1% overall), with no significant differences between ruptured and unruptured VAPs (p = 0.679). Seven patients (18.4%) experienced procedure-related complications, related to one case of non-target embolization, four splenic abscesses due to end-organ infarction, and two femoral pseudoaneurysms. The rates of procedure-related complications, end-organ infarction, and vascular access-site complications did not significantly differ between ruptured and unruptured VAPs (p > 0.05). Conclusions: Both ruptured and unruptured visceral pseudoaneurysms can be effectively and safely treated with NALEA-based endovascular embolization. We suggest considering the use of NALEAs, particularly in specific clinical cases that highlight their advantages, including patients with coagulopathy, fragile vessels, and embolization targets that are located at a considerable distance from the microcatheter tip and are otherwise difficult to reach.

Visceral artery pseudoaneurysm after blunt trauma

Visceral artery pseudoaneurysms after trauma are relatively rare but are associated with a high mortality rate in the case of rupture; thus, they are typically treated when identified. Traumatic pseudoaneurysms arising from the branches of the superior mesenteric artery are rarely described; however, they are clinically important lesions because of the risk of hemorrhage and bowel ischemia. Herein, we present a case of a visceral artery pseudoaneurysm identified approximately 2 months after abdominal blunt trauma.

Management of Visceral Mycotic Pseudoaneurysms

Visceral arterial pseudoaneurysms are rare, however, if left untreated are associated with high rates of morbidity and mortality. Pseudoaneurysms typically develop as a result of trauma, infection, or underlying inflammatory disease. While management can be dictated by the size and etiology, clear guidelines are not well established, as there are no randomized trials to compare patient outcomes. Up to this point, management has involved antibiotic therapy, surgical debridement, and only more recently, endovascular approaches. We present a case of a 52-year-old male who postoperatively was found to have new liver, mesenteric, and splenic pseudoaneurysms which were all successfully treated through endovascular approach.

Endovascular embolization of inferior pancreaticoduodenal artery pseudoaneurysm post-laparoscopic cholecystectomy in a patient with celiac artery stenosis – A case report

Inferior pancreaticoduodenal artery (iPDA) pseudoaneurysms are mostly secondary to pancreatitis, abdominal trauma, or iatrogenic procedures. We present a rare case of iPDA pseudoaneurysm secondary to laparoscopic cholecystectomy in a patient with celiac artery stenosis. A 50-year-old man who underwent laparoscopic cholecystectomy 7 days back presented with abdominal pain, blood in drain output, and tachycardia. Abdominal computed tomography (CT) showed a large retroperitoneal hematoma adjacent to head of pancreas with a pseudoaneurysm likely arising from gastroduodenal artery. Proximal stenosis of celiac artery was also present. Digital subtraction angiography (DSA) showed pseudoaneurysm arising from posterior branch of iPDA. Coil embolization was performed with complete obliteration of the aneurysm. However, the patient presented again with increasing abdominal pain and hemoglobin drop after 8 days. CT showed migration of coil loop into the hematoma and residual filling of pseudoaneurysm. Repeat embolization was planned and the pseudoaneurysm with iPDA branch was embolized with 33% glue-lipoidal mixture. On follow-up 3 months later, the patient was found to be stable with no further complications. iPDA pseudoaneurysm is less commonly encountered visceral artery pseudoaneurysm. Trapping of pseudoaneurysm with both proximal and distal vessel occlusion is ideal method for embolization to prevent recurrence.

EUS-Guided Vascular Interventions

Endoscopic ultrasound (EUS) has numerous advanced applications as a diagnostic and therapeutic modality in contemporary medicine. Through intraluminal placement, EUS offers a real-time Doppler-guided endoscopic visualization and access to intra-abdominal vasculature, which were previously inaccessible using historical methods. We aim to provide a comprehensive review of key studies on both current and future EUS-guided vascular applications. This review details EUS-based vascular diagnostic techniques of portal pressure measurements in the prognostication of liver disease and portal venous sampling for obtaining circulating tumor cells in the diagnosis of cancer. From an interventional perspective, we describe effective EUS-guided treatments via coiling and cyanoacrylate injections of gastric varices and visceral artery pseudoaneurysms. Specific attention is given to clinical studies on efficacy and procedural techniques described by investigators for each EUS-based application. We explore novel and future emerging EUS-based interventions, such as liver tumor ablation and intrahepatic portosystemic shunt placement.

Clinical Profile, Management, and Outcome of Visceral Artery Pseudoaneurysms: 5-Year Experience in a Tertiary Care Hospital.

Visceral artery pseudoaneurysms are potentially lethal lesions and tend to rupture in a high proportion of cases, thereby warranting an immediate and active intervention. We present our experience of splanchnic visceral artery pseudoaneurysms in a university hospital over a 5-year time interval with emphasis on etiology, clinical presentation, management (endovascular/surgical), and final outcome. This was a retrospective study in which we searched our image database for pseudoaneurysms of visceral arteries over a period of 5 years. The clinical and operative details were retrieved from the medical record section of our hospital. The lesions were analyzed for the vessel of origin, size, etiology, clinical features, mode of treatment, and outcome. Twenty-seven patients with pseudoaneurysms were encountered. Pancreatitis (8) was the most common cause, followed by previous surgery (7) and trauma (6). Fifteen were managed by the interventional radiology (IR) team, 6 by surgery, and in 6 no intervention was done. Technical and clinical success was achieved in all patients in the IR group with few minor complications. Surgery and no intervention carry a high mortality in such a setting (66 and 50%, respectively). Visceral pseudoaneurysms are potentially fatal lesions, commonly encountered after trauma, pancreatitis, surgeries, and interventional procedures. These lesions are easily salvageable by minimally invasive interventional techniques (endovascular embolotherapy), and surgeries carry a lot of morbidity and mortality in such cases and a prolonged hospital stay.

Percutaneous Imaging Guided Puncture and Embolization of Visceral Pseudoaneurysms

Background: Visceral pseudoaneurysms (PSAs) are usually treated endovascularly. No official guidelines exist regarding the correct management when this management option fails. The aim of this study is to assess the efficacy and safety of percutaneous imaging guided puncture of visceral PSAs in patients where intra-arterial embolization was unsuccessful or unfeasible.Methods: Five patients with visceral artery pseudoaneurysms (VAPAs) were enrolled in the study. The diagnosis was made using a 64-slice multi-detector computed tomography (MDCT) scanner and all patients were previously considered unsuitable for the procedure or underwent the procedure unsuccessfully; all patients had anemia with hemoglobin loss greater than 2 g/dL in the last 24 hours. A 22-gauge Chiba needle was used to get percutaneous access to the lesion, where N-butyl cyanoacrylate (NBCA) and lipiodol or coils and onyx were subsequently injected.Results: Four patients received a mixture of NBCA and lipiodol in a 1:2 ratio (80%, n = 4), and only one participant received coils and onyx. Primary clinical success was 100% and embolization was not repeated in any cases. No life-threatening secondary conditions or major complications were observed throughout the follow-up period; in one patient an asymptomatic embolic agent migration was reported. Secondary clinical success was also obtained in the current study. None of the remaining four participants experienced re-bleeding episodes or any procedure-related problems.Conclusions: Percutaneous embolization of visceral PSAs is a safe and effective treatment alternative that should be considered when the trans-arterial method cannot be used.

S1718 Delayed Gastrointestinal Hemorrhage From Visceral Artery Pseudoaneurysm in Necrotizing Pancreatitis After LAMS Removal

Introduction: Delayed bleeding from visceral artery pseudoaneurysm (PA) formation is an uncommon complication of lumen-apposing metal stent (LAMS) placement. Risk factors for gastrointestinal bleeding (GIB) in patients with LAMS remain largely undefined. We report a case of delayed GIB due to rupture of a splenic artery PA 16 months after LAMS removal. Case Description/Methods: A 34-year-old female with a history of severe necrotizing pancreatitis presented to our hospital with massive hematemesis. 23 months prior to presentation, she underwent uncomplicated placement of a 15x10 mm LAMS and 2 7 Fr x 4 cm double pigtail plastic stents for drainage of walled-off pancreatic necrosis. She was briefly lost to follow-up and returned for LAMS removal 5 months later. Contrast was injected into the residual cyst cavity and contrast filling was noted of what appeared to be a splenic vessel without active bleeding (Figure A). CT angiogram showed no PA but proximity of the splenic hilar vasculature to the LAMS (Figure B). The LAMS was successfully removed 2 months later without complication. On presentation, she was tachycardic but normotensive. Laboratory studies were notable for hemoglobin 8.8 g/dL (baseline 14 g/dL). Upper endoscopy showed brisk bleeding in the proximal gastric body near the area of prior LAMS. Her bleeding was refractory to endoscopic hemostatic maneuvers, and she underwent emergent mesenteric angiography. Angiography revealed active arterial extravasation arising from the inferior segmental branch of the splenic artery ( Figure C) which was successfully embolized with no further bleeding. Discussion: Visceral artery PA development after LAMS placement is thought to occur due to friction of the inner flange against regional vasculature surrounding the necrotic cavity as it collapses. Close anatomical proximity of LAMS to regional vasculature increases the risk of PA development. In our case, the LAMS was placed near the rich vascular supply of the splenic hilum. Most reported bleeding events related to LAMS have occurred within 8 weeks of placement. Our case is notable for the prolonged delay between LAMS removal and bleeding presentation. Adherent scar tissue between the gastric wall and vasculature could potentially cause delayed PA development after LAMS removal. This case reinforces that high clinical suspicion for PA bleeding is necessary for patients who have previously undergone distant LAMS removal who present with massive GIB.Figure 1.: (A) Fluoroscopic image of contrast injection into residual cyst cavity demonstrating opacification of likely splenic vasculature; (B) Coronal images demonstrating the proximity of the LAMS to the vasculature of the splenic hilum (yellow arrow); (C) Super-selective angiography demonstrating active extravasation into the lateral aspect of the stomach from a pseudoaneurysm (White arrow) involving an inferior segmental branch of the splenic artery.

Successful Endovascular Embolisation of an Unusual Giant Pseudoaneurysm of the Middle Colic Artery

Visceral artery pseudoaneurysms (VAPAs) are extremely rare and pseudoaneurysms in the superior mesenteric artery (SMA) and its branches, particularly the middle colic artery, are the rarest. These account for 6–8% of all VAPAs with an incidence of 0.01%. They can be associated with an inflammatory disease (such as pancreatitis), infection or arise as a post-surgical complication, but they can also be due to a traumatic damage to the artery caused by a full-thickness slit in the arterial wall. They can be asymptomatic or manifest with symptoms such as abdominal pain, nausea and vomiting, local pressure symptoms (such as a pulsatile mass or a bruit) and gastrointestinal bleeding. Imaging techniques play a key role in the diagnosis of VAPAs and angiography still represents the gold standard, although nowadays it has a pivotal role for treatment with the possibility to perform an endovascular embolisation. In fact, although rare, VAPAs are of clinical importance mainly because they can cause life-threatening intra-abdominal or retroperitoneal haemorrhage and so prompt treatments are crucial, whether they are symptomatic, haemorrhagic or incidentally found. In the past, surgery was the treatment of choice, but in recent years with the improvement and development of interventional vascular techniques, surgery has been replaced by transcatheter endovascular embolisation due to its low morbidity and mortality and high success rate. In this article, we report the case of an unusual giant spontaneous pseudoaneurysm of the middle colic artery in a patient with a scoliotic abdominal aortic aneurysm successfully treated by endovascular embolisation.

Splenic Artery Pseudoaneurysm—A Concern for the Anesthesiologist

AbstractPseudoaneurysms as compared with aneurysms lack a true wall and have a higher propensity of rupture. Visceral artery pseudoaneurysms are uncommon and are life-threatening. We, hereby, report anesthetic management of a rare case of splenic artery pseudoaneurysm that accompanied the dilatation of aorta from its origin extending up to its bifurcation.

Abstract No. 75 Endovascular treatment of visceral artery aneurysms and pseudoaneurysms: comparing outcomes of self-expandable vs balloon-expandable stent grafts

Endovascular treatment of visceral aneurysms is effective and successful with low rates of complications. Depending on location and anatomy, endovascular treatment is either embolization or stent graft exclusion. This single-center retrospective study compares the outcomes of Self Expandable (SE) vs. Balloon Expandable (BE) stent grafts (SGs) in the treatment of visceral artery aneurysms (VAAs) and pseudoaneurysms (VAPAs).

Imaging-Guided Percutaneous Puncture and Embolization of Visceral Pseudoaneurysms: Feasibility and Outcomes.

Visceral artery pseudoaneurysms (VAPAs) are the most frequently diagnosed pseudoaneurysms (PSAs). PSAs can be asymptomatic or symptomatic. The aim of our study was to evaluate the safety and effectiveness of percutaneous embolization of VAPAs performed on patients with an unfeasible trans-arterial approach. Fifteen patients with fifteen visceral PSAs, with a median dimension of 21 mm (IQR 20–24 mm), were retrospectively analyzed. No patients were suitable for trans-arterial catheterization and therefore a percutaneous approach was chosen. During percutaneous treatments, two embolic agents were used, either N-butyl cyanoacrylate (NBCA) (Glubran II, GEM Milan, Italy) mixed with Lipiodol (Lipiodol, Guerbet, France) or thrombin. The outcomes of this study were technical success, primary clinical success, and secondary clinical success. In our population the 15 PSA were located as follows: 2 in the left gastric artery, 1 in the right gastric artery, 3 in the right hepatic artery, 2 in a jejunal artery, 1 in left colic artery branch, 1 in a right colic artery branch, 1 in the gastroepiploic artery, 1 in the dorsal pancreatic artery, 1 in an ileocolic artery branch, 1 in an iliac artery branch, and 1 in a sigmoid artery branch. 80% of PSAs (12/15) were treated with a NBCA:lipiodol mixture and 20% of PSAs (3/15) were treated with thrombin. Technical, primary, and secondary clinical successes were obtained in 100% of the cases. No harmful or life-threatening complications were observed. Minor complications were registered in 26.6% (4/15) of the patients. Percutaneous embolization of visceral PSA is a safe and effective treatment and should be considered as an option when the endovascular approach is unsuccessful or unfeasible.

Assessing the aneurysm occlusion efficacy of a shear-thinning biomaterial in a 3D-printed model

Metallic coil embolization is a common method for the endovascular treatment of visceral artery aneurysms (VAA) and visceral artery pseudoaneurysms (VAPA); however, this treatment is suboptimal due to the high cost of coils, incomplete volume occlusion, poor reendothelialization, aneurysm puncture, and coil migration. Several alternative treatment strategies are available, including stent flow diverters, glue embolics, gelfoam slurries, and vascular mesh plugs—each of which have their own disadvantages. Here, we investigated the in vitro capability of a shear-thinning biomaterial (STB), a nanocomposite hydrogel composed of gelatin and silicate nanoplatelets, for the minimally-invasive occlusion of simple necked aneurysm models. We demonstrated the injectability of STB through various clinical catheters, engineered an in vitro testing apparatus to independently manipulate aneurysm neck diameter, fluid flow rate, and flow waveform, and tested the stability of STB within the models under various conditions. Our experiments show that STB is able to withstand at least 1.89 Pa of wall shear stress, as estimated by computational fluid dynamics. STB is also able to withstand up to 10 mL s−1 pulsatile flow with a waveform mimicking blood flow in the human femoral artery and tolerate greater pressure changes than those in the human aorta. We ultimately found that our in vitro system was limited by supraphysiologic pressure changes caused by aneurysm models with low compliance.