Treatment of a hepatic artery aneurysm by endovascular exclusion using the multilayer cardiatis stent

Combined Endovascular Repair of a Giant Symptomatic Hepatic Aneurysm: A Case Report and Comprehensive Literature Review

Hepatic artery aneurysms (HAAs) are an uncommon vascular disease, which account for 20% of visceral artery aneurysms. The majority are usually asymptomatic and discovered accidentally during imaging control, but occasionally, they can present as acute abdominal pain, haemobilia, obstructive jaundice, or gastrointestinal bleeding due to aneurysm sac expansion or rupture with catastrophic consequences. We present the case of a 51-year-old male patient with a giant common HAA of 11.1 cm who was managed endovascularly. A combined endovascular approach was decided due to the anatomy of the aneurysm. Endovascular embolization with coils in the distal part of the aneurysm and deployment of a stent graft proximally to exclude inflow were used. At six months, the aneurysm size was regressed at 5 cm; however, seven months after the operation, the patient presented with pylorus perforation due to coil migration which was managed by coil removal, peripheral gastrectomy, and Roux-en-Y gastric bypass. We provide a narrative literature review regarding the endovascular repair of giant HAAs. The PubMed, Scopus, and Google Scholar databases were searched for articles up to January 2024. Thirty-eight studies (case reports, case series) were retrieved. The conclusion is that giant HAAs are a rare and severe condition in which their treatment can be challenging with unexpected adverse events. The literature review suggests that the endovascular approach whenever feasible is a safe and effective treatment option with low morbidity and mortality.

Technical considerations of endovascular management of true visceral artery aneurysms

BACKGROUND

True visceral artery aneurysms are potentially complex to treat but with advances in technology and increasing interventional radiology expertise over the past decade are now increasingly the domain of the interventional radiologist. BODY: The interventional approach is based on localization of the aneurysm and identification of the anatomical determinants to treat these lesions to prevent aneurysm rupture. Several different endovascular techniques are available and should be selected carefully, dependent on the aneurysm morphology. Standard endovascular treatment options include stent-graft placement and trans-arterial embolisation. Different strategies are divided into parent artery preservation and parent artery sacrifice techniques. Endovascular device innovations now include multilayer flow-diverting stents, double-layer micromesh stents, double-lumen balloons and microvascular plugs and are also associated with high rates of technical success.

CONCLUSION

Complex techniques such as stent-assisted coiling and balloon-remodeling techniques are useful techniques and require advanced embolisation skills and are further described.

A Study on the Pressure-Lowering Effect of the Multilayer Stent

BACKGROUND

The objective of the study was to investigate the hemodynamic changes of the blood flow in the aneurysm model after the multilayer stent placement using the fluid dynamic method, to analyze the effectiveness and properties of the multilayer stent in the treatment of aortic aneurysms.

METHODS

A water tank was filled with 5 L of experimental liquid after the circular flow pressure test platform with a glass aneurysm model, and a multilayer stent was built. Pressure at the middle part and the distal aneurysm neck part of the model was then measured. At each site, the pressure was measured 20 times at 1-min intervals, and the testing results were averaged for accuracy.

RESULTS

Without the stent, mean pressure at the middle part and at the distal aneurysm neck part of the model was 11.19 ± 0.23 Kpa and 13.31 ± 0.28 Kpa, respectively. With the stent, the mean pressure decreased to 10.60 ± 0.27 Kpa and 12.60 ± 0.29 Kpa, and the average difference was 0.59 ± 0.15 Kpa and 0.71 ± 0.15 Kpa, respectively.

CONCLUSIONS

After the placement of the multilayer stent, pressure inside the model at the middle part and distal neck part could both be diminished, yet the mean dropped pressure may be too small to be sufficient to cause significant impact on preventing the expansion of abdominal aortic aneurysm; therefore, the pressure-lowering effect of the multilayer stent for abdominal aortic aneurysm may not be ideal compared with the traditional covered stents.

Alterations of blood flow pattern after triple stent endovascular treatment of saccular abdominal aortic aneurysm: a porcine model

OBJECTIVE

to determine the blood flow pattern changes after endovascular treatment of saccular abdominal aortic aneurysm with triple stent.

METHODS

we conducted a hemodynamic study of seven Landrace and Large White pigs with saccular aneurysms of the infrarenal abdominal aorta artificially produced according to the technique described. The animals were subjected to triple stenting for endovascular aneurysm. We evaluated the pattern of blood flow by duplex scan before and after stent implantation. We used the non-paired Mann-Whitney test for statistical analysis.

RESULTS

there was a significant decrease in the average systolic velocity, from 127.4cm/s in the pre-stent period to 69.81cm/s in the post-stent phase. There was also change in the flow pattern from turbulent in the aneurysmal sac to laminate intra-stent.

CONCLUSION

there were changes in the blood flow pattern of saccular abdominal aortic aneurysm after endovascular treatment with triple stent.

OBJETIVO

determinar as alterações do padrão do fluxo sanguíneo após tratamento endovascular do aneurisma sacular de aorta abdominal com triplo stent.

MÉTODOS

estudo hemodinâmico de sete suínos das raças Landrace e Large White portadores de aneurismas saculares de aorta abdominal infrarrenal artificialmente produzidos segundo técnica descrita. Os animais foram submetidos a implante de triplo stent para correção endovascular do aneurisma e reavaliados por duplex scan quanto ao padrão do fluxo sanguíneo antes e após o implante dos stents. A análise estatística foi realizada com o teste Mann-Whitney não pareado.

RESULTADOS

verificou-se uma queda significativa da velocidade sistólica média de 127,4cm/s na fase pré-stent para 69,81cm/s na fase pós-stent. Houve ainda mudança no padrão do fluxo de turbilhonar no saco aneurismático para laminar intrastent.

CONCLUSÃO

o estudo demonstrou alterações do padrão do fluxo sanguíneo do aneurisma sacular de aorta abdominal após tratamento endovascular com triplo stent.

The Management of Superior Mesenteric Artery Aneurysm: Experience with 16 Cases in a Single Center

BACKGROUND

Superior mesenteric artery aneurysm (SMAA) represents a rare but potentially fatal condition. This study aimed to present the individual management protocol of SMAA in our center and to discuss a potential preliminary treatment algorithm.

METHODS

SMAA patients treated in our center between January 2007 and December 2014 were retrospectively reviewed on January 2015.

RESULTS

Sixteen patients with SMAA were identified, including 1 female and 15 males, with a mean age of 48.9 ± 12.9 years. Three patients (3/16, 18.8%) were treated by multiple overlapping bare stents and one (1/16, 6.3%) initially by a single bare stent. Two cases (2/16, 12.5%) were treated by a covered stent implantation, but one of those suffered from SMAA rupture 7 days later, whereas the other had inner-stent thrombosis one month after discharge and died from multiple organ-dysfunction syndrome. Nine patients (9/16, 56.2%) received conservative therapy, one of who received multiple overlapping bare stents implantations for persistent abdominal pain. One patient underwent open surgery. There were 2 major complications, with no death during hospitalization and 1 death during follow-up.

CONCLUSIONS

SMAA treatment needs to be individually prescribed, based on clinical manifestation, anatomy, and etiology. Multiple overlapping bare stents are safe and effective in selective patients with SMAA, and covered stents should be used with caution to avoid covering proximal branches; open surgery should be reserved for patients with suspected intestinal necrosis.

Three-Year Outcomes With the Multilayer Flow Modulator for Repair of Thoracoabdominal Aneurysms

Purpose: To evaluate midterm outcomes of endovascular repair of types II and III thoracoabdominal aortic aneurysms (TAAA) using the Multilayer Flow Modulator (MFM) in patients unsuitable for open surgery or fenestrated stent-grafts. Methods: In the prospective, multicenter, nonrandomized STRATO trial (EudraCT registration: 2009-013678-42; ClinicalTrials.gov identifier NCT01756911), 23 patients (mean age 75.8 years; 19 men) with Crawford type II and III TAAA (mean diameter 6.5 cm) were implanted between April 2010 and February 2011. Outcomes included all-cause mortality and stable aneurysm thrombosis with associated branch vessel patency. Results: Through 36 months, there were 7 deaths (none confirmed as aneurysm-related), and no cases of spinal cord injury, device migration or fracture, or respiratory, renal, or peripheral complications. Three patients were lost to follow-up and 2 devices were explanted. The device was patent in the 11 remaining patients at 3 years. Stable aneurysm thrombosis was achieved for 15 of 20 patients at 12 months, 12 of 13 at 24 months, and 10 of 11 at 36 months. The rate of branch patency was 96% at 12 months (primary patency), 100% at 24 months, and 97% at 36 months. Nine patients suffered from endoleaks (attachment site or device overlap); 9 patients underwent 11 reinterventions (3 surgical). Maximum aneurysm diameter was stable for 18 of 20 patients at 12 months, 11 of 13 at 24 months, and 9 of 11 at 36 months. For 10 patients with computed tomography at 36 months, the mean ratio of aneurysm flow volume to total volume had decreased by 83%; the mean ratio of thrombus volume to total volume increased by 159%. Conclusion: Through 3 years, endovascular repair with the MFM appears to be safe and effective while successfully maintaining branch vessel patency.

Multilayer Flow Modulator Treatment of Abdominal and Thoracoabdominal Aortic Aneurysms With Side Branch Coverage: Outcomes From a Prospective Single-Center Moroccan Registry

PURPOSE

To evaluate endovascular repair of thoracoabdominal aortic aneurysms (TAAA) and abdominal aortic aneurysms (AAA) using the Multilayer Flow Modulator (MFM) in high-surgical-risk patients with at least one covered branch vessel.

METHODS

In this prospective single-center nonrandomized trial, 18 patients (mean age 61.1 years; 16 men) with TAAA (n=10, mean diameter 74.4 mm) and AAA (n=8, mean diameter 67.8 mm) were treated with the MFM between June 2009 and September 2012. The primary safety endpoints were all-cause mortality at 30 days and 12 months and neurological complications. The primary efficacy endpoint was overall procedure success, defined as patency of covered branch vessels, reductions in aneurysm diameter, and sac thrombus formation.

RESULTS

The technical success rate was 100% (53 study devices implanted, mean stented length 273 mm). Through mean follow-up of 13.4 months, all 61 covered branch vessels remained patent; there were no neurologic complications, ruptures, or instances of device migration, kinking, or fracture. Three patients died, 2 of unrelated causes and one of an undetermined cause. Only one reintervention with an additional MFM implanted at 5 years was required for a type I endoleak in a young patient with natural growth. Carefully planned and executed diameter and volume measurements demonstrated aneurysm shrinkage and progressive sac thrombus formation for both patient groups.

CONCLUSION

Through midterm follow-up, treatment of high-surgical-risk TAAA and AAA patients with the MFM appears to be safe and effective, maintaining branch vessel patency and reducing rupture risk through reduction of aneurysm diameter and modulation of flow dynamics. Longer term follow-up is needed.

Medical Textiles as Vascular Implants and Their Success to Mimic Natural Arteries

Vascular implants belong to a specialised class of medical textiles. The basic purpose of a vascular implant (graft and stent) is to act as an artificial conduit or substitute for a diseased artery. However, the long-term healing function depends on its ability to mimic the mechanical and biological behaviour of the artery. This requires a thorough understanding of the structure and function of an artery, which can then be translated into a synthetic structure based on the capabilities of the manufacturing method utilised. Common textile manufacturing techniques, such as weaving, knitting, braiding, and electrospinning, are frequently used to design vascular implants for research and commercial purposes for the past decades. However, the ability to match attributes of a vascular substitute to those of a native artery still remains a challenge. The synthetic implants have been found to cause disturbance in biological, biomechanical, and hemodynamic parameters at the implant site, which has been widely attributed to their structural design. In this work, we reviewed the design aspect of textile vascular implants and compared them to the structure of a natural artery as a basis for assessing the level of success as an implant. The outcome of this work is expected to encourage future design strategies for developing improved long lasting vascular implants.

Hemodynamic insight into overlapping bare-metal stents strategy in the treatment of aortic aneurysm

Clinical trials have shown overlapping bare-metal stents provoke effective thrombus clot within the aneurysm sac and shrinkage of the aneurysm by directly regulating the hemodynamics. To gain insight into the hemodynamic mechanism of the technique, three cases of simplified thoracic aortic aneurysm models (with no stent, a single stent and two overlapped stents deployed within the aneurysm sac) were studied and compared in terms of time-varying velocity and shear rate, time-averaged wall shear stress (TAWSS), oscillating shear index (OSI) and relative residence time (RRT). The results demonstrated that the overlapping stents' strategy was more effective in reducing the velocity of blood flow within the aneurysm, especially for the area near the aneurysm wall. Stenting induced a dramatic change trend of shear rate during the cardiac cycle, in which a very high shear rate (>10,000 s(-1)) during the systole and a quite low shear rate (<1000 s(-1)) during the diastole were observed, respectively. Moreover, reduced TAWSS and OSI and elevated RRT values were observed on the aneurysm wall after stent placement. The effects of stenting on the shear rate, TAWSS, OSI and RRT in the aneurysm would be significantly enhanced by two overlapped stents. The present findings therefore indicated that, the overlapping bare-metal stents can isolate the aneurysm effectively and may create a favorable hemodynamic environment provoking platelets activation and aggregation within the aneurysm, which may promote thrombus formation/growth there, hence contribute to degradation of the aneurysm.

Percutaneous thrombin embolization of a pancreatico-duodenal artery pseudoaneurysm after failing of the endovascular treatment

Pancreatico-duodenal artery (PDA) pseudoaneurysms are rare vascular conditions with high mortality rates after rupture and they are frequently secondary to pancreatitis, surgery, trauma or infection. Due to the high risk of rupture and bleeding, it is mandatory to treat all pseudoaneurysms, regardless of their size or symptomatology. First option of treatment is open surgical repair, but it has high mortality rate, especially in hemodynamically unstable patients. In the recent years, percutaneous ultrasonography (US)- or computed tomography-guided thrombin injection was proposed as an alternative method for treating visceral aneurysms and pseudoaneurysms, but few reports described this therapy in case of peri-pancreatic pseudoaneurysms. We present a rare case of pseudoaneurysm of the PDA in a patient with no previous history of pancreatitis nor major surgery but with an occlusive lesion of the celiac axis. To the best of our knowledge this is the first reported case of PDA pseudoaneurysm successfully treated in emergency by single transabdominal US-guided injection of thrombin after failed attempts of percutaneous catheterization of the feeding vessel of the pseudoaneurysm.

Disconnection of multilayer stents 2 years after treatment of a hepatic artery aneurysm

PURPOSE

To report midterm failure of tandem peripheral multilayer stents used to treat a common hepatic artery aneurysm (HAA) that had a good early result.

CASE REPORT

A 71-year-old man with multiple comorbidities had a 3.4-cm HAA treated with 2 Cardiatis peripheral multilayer stents (8×100 and 9×60 mm) that overlapped by 3 cm. At the 12-month follow-up, the stents were patent, with signs of collateral patency and full thrombosis of the aneurysm sac without expansion. At the 18-month visit, the sac had expanded to 4.5 cm without signs of revascularization, but there was an initial stent dislocation; a wait and watch approach was elected. On the 24-month imaging, the HAA had enlarged to 6 cm, with disconnection of the 2 stents. A new multilayer stent (9×100 mm) was positioned to "bridge" the gap; however, the proximal part of the new stent did not correctly expand despite multiple attempts to overcome the infolding. The 3 stents became completely thrombosed, but thanks to rich mesenteric collaterals, perfusion of the proper hepatic artery was adequate.

CONCLUSION

The multilayer peripheral stent appears to be an alternative for the treatment of visceral aneurysms in patients with a high surgical risk, but it is not a conventional stent. There are unknowns about its function, behavior, and application. Therefore, more experience is needed to validate the effectiveness of the multilayer stent.

Endovascular treatment of an anastomotic iliac pseudoaneurysm after surgical aortic repair using a Cardiatis multilayer stent

The Cardiatis multilayer stent (Cardiatis, Isnes, Belgium) is a cobalt, self-expandable bare stent made of two interconnected layers without any covering that allows a pressure decrease and thrombus formation into an aneurysmal sac, while improving laminar flow in the main artery and surrounding vital branches. We report a case of an anastomotic iliac pseudoaneurysm successfully treated with the deployment of a Cardiatis multilayer stent.

Using the Multilayer Stent as a Supplement to EVAR in Combined Abdominal Aortic Aneurysm and Iliac Artery Aneurysm With Inadequate Distal Landing Zone—A Case Report

Combined abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) is a common condition. The recently approved Cardiatis Multilayer stent (Cardiatis, Isnes, Belgium) is an innovative stent system for peripheral aneurysm management that has been applied in several clinical cases. After deployment, the unique stent design reduces mean velocity and vorticity within the aneurysm sac, causing thrombus formation and thus exclusion of the aneurysm while the vessels branching from the aneurysm remain patent. We describe a case of combined AAA and IAA with successful endovascular aneurysm repair of the AAA and treatment of the internal iliac artery with the Cardiatis Multilayer stent at 12 months of follow-up.

Flow-diverting stents for the treatment of arterial aneurysms

BACKGROUND

Anatomic factors may limit the application of stent grafts for the treatment of arterial aneurysms. Flow- diverting stents (FDSs) are specially designed to reduce flow velocity in the aneurysm sac and promote thrombosis while maintaining flow in the main artery and branch vessels. FDSs include the Pipeline Embolization Device (ev3, Plymouth, Minn), the SILK Arterial Reconstruction Device (Balt Extrusion, Montmorency, France), and the Cardiatis Multilayer Stent (Cardiatis, Isnes, Belgium). The first two have been mainly used for the treatment of intracranial aneurysms. The aim of this study was to review the current role of FDSs in the treatment of extracranial arterial aneurysms.

METHODS

A systematic electronic health database search was conducted using PubMed, Ovid, Medline, and the Cochrane Database on all accessible published articles through March 2012. An additional search for abstracts presented in international congresses for vascular surgery was also performed. Full-text articles and abstracts were analyzed separately due to the heterogeneity of the data.

RESULTS

Results of the use of FDSs in arterial aneurysms were reported in 12 full-text articles including 35 patients (26 men, age 65.4) with 38 aneurysms. The aneurysms were located in the hepatic (n = 12), splenic (n = 6), renal (n = 5), celiac (n = 4), superior mesenteric (n = 3), subclavian (n = 2), gastroduodenal (n = 1), and popliteal arteries (n = 1) and in the descending thoracic (n = 1), suprarenal (n = 1) and infrarenal aorta (n = 2). The 30-day mortality was 5.7% (2 of 35 patients). Three stent thromboses occurred (8.3%), none of them with clinical consequences. Thirty patients with 33 aneurysms and patent FDSs were monitored for an average of 9.2 months. Thrombosis occurred in 90.6%, and volume reduction was observed in 81% of the aneurysms. No branch vessel occlusion occurred. Twelve abstracts were identified, including 133 patients (mean age, 64.7 years). They included 62 peripheral, 28 visceral, and 43 abdominal and thoracoabdominal aneurysms. The Cardiatis Multilayer Stent was used in all cases. Thrombosis was achieved in all but two peripheral and visceral aneurysms. Volume reduction was observed in 82.7%, and no branch vessel occlusion occurred. In aortic aneurysms, better results regarding aneurysm thrombosis, reduction of the volume, and patency of collateral branches were reported at 12 months rather than at 6 months postoperatively. No aneurysm rupture has yet been described.

CONCLUSIONS

Initial clinical experience with the use of FDSs in the treatment of visceral and peripheral aneurysms yielded satisfactory results in technical success, aneurysm thrombosis and shrinkage, and in patency of branch vessels. The results in aortic aneurysms are still under investigation. No aneurysm rupture has yet been described. There is a significant incidence of FDS thrombosis. Volume reduction of the aneurysm is a clearer evidence of the clinical success after treatment with FDSs than aneurysm thrombosis.

Multiple multilayer stents for thoracoabdominal aortic aneurysm: a possible new tool for aortic endovascular surgery

Purpose

Endovascular surgery data are confirming the paramount role of modern endovascular tools for a safe and sure exclusion of thoracoabdominal lesions.

Case report

A 57-year-old female presented with severe comorbidity affected by a 58 mm thoracoabdominal aortic aneurysm (TAAA). After patient-informed consent and local Ethical Committee and Italian Public Health Ministry authorization, three multilayer stents were implanted in the thoracoabdominal aortic tract, obtaining at a 20-month computed tomography scan follow up, a complete exclusion of the TAAA, with normal patency of visceral vessels.

Conclusion

Multilayer stents can be used in thoracoabdominal aortic aneurysm, with positive results.

Endovascular treatment of visceral artery aneurysms and pseudoaneurysms: our experience

PURPOSE

The aim of this study was to analyse our 8 years of experience with endovascular treatment of visceral aneurysms and pseudoaneurysms.

MATERIALS AND METHODS

From January 2002 to September 2009, we used an endovascular approach to treat 30 patients (22 men, eight women) affected by aneurysm (n=18) or pseudoaneurysm (n=13) of the splenic (n=11), hepatic (n=6), renal (n=5), pancreaticoduodenal (n=3), left gastric (n=2), gastroduodenal (n=1), rectal (n=1) or middle colic (n=1) arteries and the coeliac axis (n=1). Of these, 26/31 were treated with metal coils, 3/31 with Cardiatis multilayer stent, 1/31 with a coated stent and 1/31 with coils and Amplatzer plug. Procedures were performed electively in 10/30 cases and during haemorrhage in 20/30 cases. Follow-up was performed clinically (cessation of bleeding) and at 1, 6 and 12 months by colour-Doppler ultrasound (CDUS) and computed tomography (CT) angiography.

RESULTS

In 31/31 aneurysms and pseudoaneurysms we obtained immediate exclusion. In four patients with aneurysm and in four with pseudoaneurysm, parenchymal ischaemia occurred; one was treated with surgical splenectomy. One patient with pseudoaneurysm of the coeliac axis died 10 days later because of new bleeding. During follow-up, all aneurysms and pseudoaneurysms remained excluded.

CONCLUSIONS

Percutaneous treatment is effective and safe, with a small number of complications, especially when compared with traditional surgery.

Placement of endovascular stent across the branching arteries: long-term serial evaluation of stent-tissue responses overlying the arterial orifices in an experimental study

PURPOSE

This study was designed to investigate the effects of stenting across the branching arteries on the patency and stent-tissue responses over the branching arterial orifices.

METHODS

Thirteen dogs were observed after placing aortic stents across the celiac arteries (CA), superior mesenteric arteries (SMA), and renal arteries (RA). The animals were grouped according to stent types: large-cell group (n = 6) and small-cell group (n = 7). Angiography was performed to evaluate the branching artery patency at 2, 6, and 12 months after stent insertion, and the stent-tissue responses covering the orifices were evaluated on histopathologic examination.

RESULTS

All branching arteries were patent on follow-up angiography; however, three patterns of stent-tissue responses over the orifices were observed: neointimal layering, bridging septa, and papillary hyperplasia. Although neointimal layering and bridging septa were evenly observed, severe papillary hyperplasia was more frequent at SMA and CA than RA. Four RA showed less than 50% ostial patency, and localized infarct was observed in six kidneys (24%). The ostial patency tended to decrease with small-cell stent during the follow-up period.

CONCLUSIONS

Various stent-tissue responses over the branching artery orifices are induced by the aortic stent covering the branching arteries and may not be easily detected by conventional angiography. Subclinical renal infarct also may occur despite patent renal angiography.

The role of interventional radiology in the management of abdominal visceral artery aneurysms

Abdominal visceral artery aneurysms (VAA) include true and false aneurysms. The majority are asymptomatic and are discovered on cross-sectional imaging performed for unrelated clinical indications. With the maturation of techniques and devices used for embolization procedures and the treatment of aneurysms in other locations, most VAAs are now suitable for treatment by minimally invasive transcatheter techniques. The choice of technique used greatly depends on the local anatomy of the VAA and the experience of the interventional radiologist in complex vascular interventional techniques.

Hepatic Aneurysm: A Review

Originally described over 220 years ago, the clinical scenario of hepatic aneurysms remains incompletely understood. Moreover, its optimal treatment has yet to be defined. The present paper reviews the literature regarding this pathological state of the abdomen and discusses what is known regarding the presentation, diagnosis, and anatomy of hepatic arterial aneurysms.