Embolization of the Gastroduodenal Artery Before Selective Internal Radiotherapy: A Prospectively Randomized Trial Comparing Platinum-Fibered Microcoils with the Amplatzer Vascular Plug II

Plug-Based Embolization Techniques of Aortic Side Branches during Standard and Complex Endovascular Aortic Repair

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair.

In Vitro Head-to-Head Comparison of Flow Reduction between Fibered and Non-Fibered Pushable Coils

PURPOSE

To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment.

MATERIALS AND METHODS

A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI.

RESULTS

When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils.

CONCLUSION

The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization.

Embolic Materials: Understanding the Ocean of Choices

Embolization is a fundamental procedure that interventional radiologists perform on a daily basis to treat a variety of diseases. The disease processes for which embolization is considered a safe and effective treatment are continuously expanding, as are the embolization materials available for use. To achieve optimal clinical outcomes and minimize complications, it is imperative that the interventional radiologist understands the properties, strengths, and weaknesses of each class of embolic and specific embolic products. This is a continuous process as new materials are always becoming available. This article reviews the different classes of embolic materials, discusses strengths and weaknesses, and reviews areas of innovation.

The Common but Complicated Tool: Review of Embolic Materials for the Interventional Radiologist

Embolization is an important and widely utilized technique in interventional radiology. There are a variety of different categories and individual products which can be utilized to perform embolization. Understanding the different classes of embolic agents, the important features of each of these classes including strengths and limitations, and the variation in individual products within the classes is critical for interventional radiologist to practice safely and effectively. This article reviews the different kinds of embolics and relays some of the pertinent physical and chemical properties of individual products which should be considered when determining which embolic to select for a given purpose.

Temperature-induced configuration changes in hydrogel-coated coils and their relevance in embolization procedures

Background

The present study attempted to demonstrate how the configuration of hydrogel-coated coils is influenced by different temperature exposures.

Thirty detachable hydrogel-coated coils were evaluated in an in vitro water immersion test under five different temperature ranges (22.6 °C, 37 °C, 40–50 °C, 50–60 °C, and 60–70 °C). The configuration changes were classified (configuration I, configuration II, and configuration III) according to the curling that occurred during 30 min of immersion. Configuration stability of five Hydrogel-coated coils was also evaluated in a two-step temperature immersion test.

Results

All hydrogel-coated coils showed some configuration changes during water immersion. However, a logarithmic transformation of the time and temperature data showed a significant (p < 0.05) negative linear correlation between time and temperature for all coil configurations (configuration I: R = 0.97, configuration II: R = 0.98, configuration III: R = 0.97). The time needed to reach configuration III (complete coiling) was 160.4 ± 41.9 s at 37.5 °C (range: 100–205 s), 45.7 ± 22.2 s at 47.5 °C (range: 23–70 s), 20.2 ± 7.2 s at 57.5 °C (range: 14–32 s), and 10.3 ± 2.4 s at 67.5 °C (range: 7–13 s).

Conclusions

Temperatures above 55 °C induced immediate configurational changes in the hydro-coated coils, achieving complete curling within less than 30 s. Temperatures near 36 °C (normal body temperature) require more time to reach optimal coil curling (configuration III). The optimization of HydroCoil preparation can reduce interventional procedural time and improve clinical results.

Meta-analysis of Intraprocedural Comparative Effectiveness of Vascular Plugs Vs Coils in Proximal Splenic Artery Embolization and Associated Patient Radiation Exposure

PURPOSE

To compare vascular plugs to coil embolization of the proximal splenic artery and evaluate differences in radiation exposure to the patients.

METHODS

An electronic literature search was performed for relevant studies from January 2000 to July 2018 that compared the efficacy of vascular plugs vs coils in splenic artery embolization. Only studies that investigated coil or vascular plug use, without combination with other embolic agents, were included. Meta-analysis was performed using a fixed effects model approach with the inverse variance-weighted average method to determine pooled differences in time to vessel occlusion, procedure time, fluoroscopy time, total number of devices used, and radiation exposure. Heterogeneity was assessed using the I square statistic. Pooled outcomes were compared, and quality assessments were evaluated using the Newcastle Ottawa Scale.

RESULTS

Eight studies met inclusion criteria. 81 patients were embolized with vascular plugs and 52 patients with coils only. The most common indication for splenic artery embolization was trauma. Time to vessel occlusion was shorter in the vascular plug group by 7.11 minutes (P = 0.003). Fluoroscopy time was shorter by 13.82 minutes in the vascular plug cohort, and these patients received less radiation (-439 mGy) compared to the coil group (P = 0.006 and P = 0.02, respectively). The number of devices was significantly fewer in the vascular plug group (-3.54; P < 0.001). Procedure time was not statistically significant.

CONCLUSION

Our data supports the vascular plug is superior to coils for embolization of the proximal splenic artery with respect to occlusion time, fluoroscopy time, patient radiation exposure, and number occlusive devices used.

Proximal embolization of splenic artery in acute trauma: Comparison between Penumbra occlusion device versus coils or Amplatzer vascular plug

PURPOSE

To compare intervention duration and fluoroscopy time for proximal embolization of splenic arteries in acute trauma using the Penumbra occlusion device (POD^®), coils or Amplatzer™ vascular plug (AVP).

MATERIAL AND METHODS

A total of 29 patients with splenic injury without vascular injury who were treated by proximal splenic artery embolization using POD^® (n=12), coils (n=9) or AVP (n=8) were retrospectively included. There were 25 men and 4 women with a median age of 34 years (range: 10-69 years). To overcome bias in treatment choice, a propensity score was used using inverse probability weighting. Intervention duration and fluoroscopy time, treatment success and complications were compared.

RESULTS

The median intervention duration was significantly shorter using POD^® (30min) or AVP (47min) than using coils (60min) (P=0.0001 and 0.004, respectively). The median fluoroscopy time was significantly lower using POD^® (11.5min) than using coils (23.6min) (P=0.0076) or AVP (16.5min) (P=0.049). The primary efficacy rate was 100% with POD^® and AVP and 89% with coils (P=0.586). Six complications occurred with a mean follow-up of 12 months for POD^®, 32 months for coils and 40 months for AVP, consisting in 2 abscesses treated by anti-biotherapy with POD^®, one abscess with AVP, 2 material migrations with coils and 1 coil dismantled without consequence.

CONCLUSION

POD^® and AVP allow proximal embolization of splenic artery in acute trauma with shorter intervention duration by comparison with conventional metallic coils with similar technical success. POD^® allows a shorter fluoroscopy time than coils or AVP.

Endovascular management of pancreatitis-related pseudoaneurysms: A review of techniques

Objectives

To present the various techniques used in the management of pancreatitis-related pseudoaneurysms of visceral vessels.

Methods

The retrospective clinical study was carried out at the Department of Diagnostic and Interventional Radiology at Poznan University of Medical Sciences from 2011 to 2016. The fifteen patients included in the study were diagnosed with pseudoaneurysms of visceral arteries, as a complication of chronic pancreatitis. The diagnosis was made using contrast-enhanced computed tomography, followed by angiography. On admission, all patients were symptomatic, with varying degrees of abdominal pain. One patient was haemodynamically unstable. Treatments with endovascular techniques were analysed, along with their efficacy and outcomes. Coil embolisation was performed in 5 patients. Stent graft was used in 1 patient. Liquid embolic agents were used in 7 cases, of which 5 patients were treated with thrombin injection and 2 with Squid. A combination of techniques was used in 2 patients.

Results

The most common artery affected by pseudoaneurysm formation was the splenic artery (7/15; 46.7%), and the size of the pseudoaneurysms ranged from 27 mm to 85 mm. Primary technical success was achieved in 14 out of 15 patients (93.3%). One patient required reintervention. Two patients required splenectomy after embolisation due to splenic ischemia. No recanalisation was present at the follow-up computed tomography performed after 1 to 3 weeks, and no mortality was observed within 30 days.

Conclusion

Vascular complications of pancreatitis require accurate diagnosis and immediate treatment. Endovascular intervention is highly effective and is the preferred treatment option. The technique used is determined based on vascular anatomy and the patient’s haemodynamic status.

A Randomized Trial of Endovascular Embolization Treatment in Pelvic Congestion Syndrome: Fibered Platinum Coils versus Vascular Plugs with 1-Year Clinical Outcomes

PURPOSE

To compare safety and efficacy of vascular plugs (VPs) and fibered platinum coils (FPCs) for embolization in pelvic congestion syndrome (PCS).

MATERIALS AND METHODS

A randomized, prospective, single-center study enrolled 100 women with PCS from January 2014 to January 2015. Patients were randomly assigned to 2 groups, and embolization was performed with FPCs (n = 50) or VPs (n = 50). Mean age of patients was 42.7 years ± 7.60, and mean visual analog scale (VAS) score for pelvic pain before treatment was 7.4 ± 7.60. Primary outcome (clinical success at 1 y using a VAS), number of devices, procedure and fluoroscopy times, radiation doses, costs, and complications were compared, and participants were followed at 1, 3, 6, and 12 months.

RESULTS

Clinical success and subjective improvement were not significantly different at 1-year follow-up (89.7% for FPCs vs 90.6% for VPs; P = .760). Mean number of devices per case was 18.2 ± 1.33 for FPCs and 4.1 ± 0.31 for VPs (P < .001). Three FPCs and 1 VP migrated to pulmonary vasculature approximately 3-6 months after the embolization procedure; all were retrieved without complications. The FPC group had a significantly longer fluoroscopy time (33.4 min ± 4.68 vs 19.5 min ± 6.14) and larger radiation dose (air kerma 948.0 mGy ± 248.45 vs 320.7 mGy ± 134.33) (all P < .001).

CONCLUSIONS

Embolization for PCS resulted in pain relief in 90% of patients; clinical success was not affected by embolic device. VPs were associated with decreased fluoroscopy time and radiation dose.

Proximal Occlusion of Medium-Sized Vessels with the Penumbra Occlusion Device: A Study of Safety and Efficacy

PURPOSE

To retrospectively investigate the safety and efficacy of hybrid proximal coiling of various medium-sized vessels (4 to 8 mm) using the Penumbra Occlusion Device (POD).

MATERIALS AND METHODS

From October 2014 to February 2016, 37 proximal embolizations were performed with PODs in 36 patients (mean age: 50.8, range: 10-86; 29 male, 7 female). Vessel occlusions were achieved under fluoroscopic guidance using a 2.7 French microcatheter. Among the 36 vessels targeted, 16 were splenic arteries, 11 renal arteries, 4 mesenteric arteries, 3 arteriovenous fistulae, 1 iliac artery, and 1 gonadal vein. Intermittent follow-up angiography was performed to assess the flow for final occlusion. Outcomes and complications were assessed by clinical and/or imaging follow-up.

RESULTS

To produce proximal occlusion of the intended vessels, the POD was used alone in 19 embolizations (51.4 %). In 12 procedures (32.4 %), POD was used as a coil constrainer to secure the coil construct. In 6 procedures (16.2 %), additional embolic devices were used to achieve vessel occlusion after initial POD deployment. After a mean follow-up of 3.2 months, no POD migration was observed but two complications occurred (5.4 %): one post embolic syndrome and one extensive infarction with splenic abscess.

CONCLUSION

The POD system allows safe and effective proximal embolization of medium-sized vessels in a variety of clinical settings.

Amplatzer vascular plug as an embolic agent in different vascular pathologies: A pictorial essay

The Amplatzer Vascular Plug (AVP) is a cylindrical plug made of self-expanding nitinol wire mesh with precise delivery control, which can be used for a variety of vascular pathologies. An AVP is an ideal vascular occlusion device particularly in high-flow vessels, where there is high risk of migration and systemic embolization with traditional occlusion devices. We performed 28 embolizations using the AVP from 2009 to 2014 and achieved complete occlusion without complications.

The Amplatzer Vascular Plug: Review of Evolution and Current Applications

The Amplatzer Vascular Plug (AVP) was created for peripheral embolization as a modification of the family of Amplatz septal occluders used in the treatment of congenital heart malformations. The device has evolved over the years and multiple versions have been launched into the market. Each of the versions of the device has some important modifications in terms of the size of the introducer's system, number of layers, and resultant thrombogenicity. It is very important for the operator to become familiar with the unique features of the AVP, and to understand the advantages and limitations of each model in the AVP family to achieve an optimal embolic result. The purpose of this article is to review the evolution and current clinical applications of the AVP in the field of interventional radiology, with emphasis on the advantages and limitations of this device in comparison with other embolization agents.

Radioembolization with Y-90 Glass Microspheres: Do We Really Need SPECT-CT to Identify Extrahepatic Shunts?

Purpose

Selective Internal Radiation Therapy (SIRT) with ⁹⁰yttrium (Y-90) is an increasingly used therapeutic option for unresectable liver malignancies. Nontarget embolization of extrahepatic tissue secondary to vascular shunting can lead to SIRT associated complications. Our aim was to assess whether extrahepatic shunts can reliably be diagnosed based on hepatic digital subtraction angiography (DSA) or whether subsequent SPECT/CT data can provide additional information.

Materials and Methods

825 patients with hepatocellular carcinoma (n = 636), hepatic metastases (n = 158) or cholangiocellular carcinoma (n = 31) were retrospectively analyzed. During hepatic DSA 128 arteries causing shunt flow to gastrointestinal tissue were coilembolized (right gastric artery n = 63, gastroduodenal artery n = 29; branches to duodenum / pancreas n = 36). Technectium-99m-labeled human serum albumin (HSA) was injected in all 825 patients. SPECT/CT data was used to identify additional or remaining shunts to extrahepatic tissue.

Results

An unexpected uptake of HSA in extrahepatic tissue was found by SPECT/CT in 54/825 (6.5%) patients (located in stomach n = 13, duodenum n = 26, distal bowel segments n = 12, kidney n = 1, diaphragm n = 2). These patients underwent repeated DSA and newly identified shunt vessels were coilembolized in 22/54 patients, while in 12/54 patients a more distal catheter position for repeat injection of HSA was chosen. In 20/54 patients the repeated SPECT/CT data still revealed an extrahepatic HSA uptake. These patients did not receive SIRT.

Conclusion

Most extrahepatic shunts can be identified on DSA prior to Y-90 therapy. However, SPECT-CT data helps to identify additional shunts that were initially not seen on DSA.

Gastric Perforation Following Prophylactic Embolization of Right Gastric and Gastroduodenal Arteries Prior to Selective Internal Radiation Therapy

Prophylactic gastroduodenal artery (GDA) and right gastric artery (RGA) embolization for prevention of gastric ulceration in patients with hepatic metastases from colorectal cancer undergoing Selective Internal Radiation Therapy (SIRT) are relatively safe. Herein, we present a case of gastric perforation following prophylactic embolization of the GDA and RGA for SIRT in a 43-year-old male with sigmoid colon adenocarcinoma and multiple hepatic metastases.

Endoluminal occlusion devices: technology update

Endoluminal occlusion has been performed since the early beginning of interventional radiology. Over recent decades, major technological advances have improved the techniques used and different devices have been developed for changing conditions. Most of these occlusion devices have been implemented in the vascular territory. Early embolization materials included glass particles, hot contrast, paraffin, fibrin, and tissue fragments such as muscle fibers and blood clots; today, occlusion materials include metallic devices, particles, and liquid materials, which can be indicated for proximal or distal occlusion, high-flow and low-flow situations, and in large-caliber and small-caliber vessels, based on need. Technological progress has led to a decreased size of delivery catheters, and an increase in safety due to release systems that permit the withdrawing and replacement of embolization material. Furthermore, bioactive embolization materials have been developed to increase the efficacy of embolization or the biological effect of medication. Finally, materials have been modified for changing indications. Intravascular stents were initially developed to keep an artery open; however, by adding a covering membrane, these stents can be used to occlude the wall of a vessel or other endoluminal structures. This article gives an overview of the devices most utilized for occlusion of endoluminal structures, as well as their major purpose in the endovascular territory.

Selective internal radiation therapy of hepatic tumors: procedural implications of a patent hepatic falciform artery

Selective internal radiation therapy (SIRT) using 90-yttrium is a local therapy for unresectable liver malignancies. Non-targeted 90-yttrium diversion via a patent hepatic falciform artery (HFA) is seen as risk for periprocedural complications. Therefore, this study aimed to evaluate the impact of a patent HFA on SIRT. 606 patients with SIRT between 2006 and 2012 were evaluated retrospectively. SIRT preparation was performed by digital subtraction angiography including ^99mTc-HSAM administration and subsequent SPECT/CT. Patients with an angiographically patent HFA were analyzed for procedural consequences and complications. 19 of 606 patients (3%) with an angiographically patent HFA were identified. Only 11 of these 19 patients received 90-yttrium in the hepatic vessel bed containing the HFA. Initial coil embolization of the HFA succeeded only in three of 11 patients. Out of the eight remaining patients four had no abdominal wall ^99mTc-HSAM accumulation. The other four patients presented with an abdominal wall ^99mTc-HSAM accumulation, for those a reattempt of HFA embolization was performed or ice packs were administered on the abdominal wall during SIRT. In summary, all patients tolerated SIRT well. A patent HFA should not be considered a SIRT contraindication. In patients with abdominal wall ^99mTc-HSAM accumulation HFA embolization or ice pack administration seems to prevent complications.

Radioembolization with yttrium-90 microspheres work up: Practical approach and literature review

Radioembolization (RE) is a selective internal radiotherapy technique in which yttrium-90 blended microspheres are infused through the hepatic arteries. It is based on the fact that primary and secondary hepatic tumors are vascularized mostly by arterial blood flow whereas healthy hepatocytes obtain their blood supply mostly from the portal network. This enables high radiation doses to be delivered, sparing the surrounding non-malignant liver parenchyma. Most of the complications are caused by unexpected particles passing into the gastrointestinal tract through branches originating from the main hepatic arterial supply. Knowledge of this hepatic arterial network and of its variations and the technical considerations this raises are required in preparation for treatment. This work describes the specific anatomical features and techniques for this anatomy through recent literature illustrated by cases from our own experience.

Selective internal radiation therapy of hepatic tumours: is coiling of the gastroduodenal artery always beneficial?

AIM

To assess the effect of gastroduodenal artery (GDA) occlusion prior to selective internal radiation therapy (SIRT) with regards to arterial hepato-intestinal collateralization (HIC).

MATERIALS AND METHODS

Six hundred and six patients were scheduled for SIRT between 2006 and 2012 at University Hospital Essen, Germany. Digital subtraction angiography (DSA) followed by administration of 99m-technetium labelled human serum albumin microspheres ((99m)Tc-HSAM) and single-photon emission computed tomography combined with computed tomography (SPECT/CT) was initially performed. Depending on vascular anatomy and hepatic tumour load, GDA coil embolization was considered. In subsequent (99m)Tc-HSAM rescans or therapeutic DSA, HIC and its consequences for SIRT were analysed.

RESULTS

The GDA was occluded in 86 of 606 patients (14%). Twenty-two of these 86 patients did not undergo SIRT due to the patients' clinical status or SIRT contraindications. In 28 of the remaining 64 patients, newly apparent or reopened HIC were seen either at the site of the proximal GDA (n = 21) or in the periphery of the hepatic arteries (n = 7). In 25 of these 28 patients, the HIC could be occluded or the catheter position could be changed achieving a safe (90)Y application. However, due to the newly visible HIC in three of 28 patients, SIRT was regarded as unsafe and was abandoned.

CONCLUSION

Coil embolization of the GDA may induce arterial hepato-intestinal collaterals. Although most of these collaterals do not impede (90)Y administration, SIRT may become unfeasible in specific occasions. Hence, segmental or lobar SIRT instead of a whole-liver approach with coiling of the GDA is recommended.

Gastroduodenal artery recanalization after transcatheter fibered coil embolization for prevention of hepaticoenteric flow: incidence and predisposing technical factors in 142 patients

BACKGROUND

Prophylactic occlusion of extrahepatic vessels prior to radioembolization or chemotherapy infusion is an effective method to prevent gastrointestinal complications. Unfortunately, vascular recanalization can occur.

PURPOSE

To retrospectively determine the rate and technical factors associated with gastroduodenal artery (GDA) recanalization after transcatheter occlusion with fibered coils.

MATERIAL AND METHODS

Patients with hepatic malignancy who underwent fibered coil occlusion of the GDA origin for radioembolization or hepatic arterial chemotherapy infusion with at least one subsequent hepatic angiogram between March 2006 and January 2011 were included. One hundred and forty-two patients (men, 71; women, 71) met study criteria. Hepatic arteriograms were reviewed to determine the frequency of arterial recanalization. Additional parameters included: patients' demographics, GDA diameter, length of coil pack, distance between GDA origin and most cephalad coil, persistent flow at the conclusion of the initial GDA occlusion procedure, platelet count, and international normalized ratio (INR). Chi-square test and pooled t-test were used to compare the two groups. Prospective multivariate analysis was performed with a logistic regression model.

RESULTS

Twenty-nine of 142 patients (20.4%) experienced GDA recanalization. The distance between the GDA origin and most cephalad coil was significantly greater in the recanalization group than in the non-recanalization group (9.6 mm vs. 12.6 mm, P = 0.01). A prospective multivariate analysis established that the further the coil was from the origin the more likely the GDA was to recanalize. The two groups did not differ on the basis of any other factors examined.

CONCLUSION

GDA origin recanalization after fibered coil occlusion is common. The distance between the GDA origin and most cephalad coil appears to be a predisposing factor for recanalization. Familiarity with this phenomenon is beneficial to reduce the likelihood of gastrointestinal tract complications during hepatic locoregional therapy.

Superiority of proximal embolization of the gastroduodenal artery with the Amplatzer vascular plug 4 before yttrium-90 radioembolization: a retrospective comparison with coils in 134 patients

PURPOSE

To evaluate the effectiveness of proximal embolization of the gastroduodenal artery (GDA) using the Amplatzer Vascular Plug 4 (AVP 4) compared with pushable coils to avoid hepaticoenteric collaterals of the GDA stump, which may serve as pathways for nontarget embolization.

MATERIALS AND METHODS

One hundred thirty-four patients scheduled for 90-yttrium radioembolization (Y-90 RE) using either plugs (n = 67) or standard coils (n = 67) for GDA occlusion were retrospectively analyzed. Parameters recorded were length of the perfused GDA stump, distance device to the GDA origin, perfused proximal side branches after embolization, and durability of vessel occlusion at Y-90 RE.

RESULTS

Length of the residually perfused GDA stump was 3.89 ± 2.86 mm for the AVP 4, which was significantly shorter compared with 5.78 ± 3.85 mm for coils (p = 0.005). Distance of the plug to the GDA origin was 1.41 ± 2.60 mm, which was also significantly shorter than 4.73 ± 3.44 mm for coils (p < 0.001). This resulted in significantly fewer patients with residually perfused side branches in the AVP 4 group (n = 2; 3.0%) compared with the coil group (n = 18; 26.9%; p < 0.001). At Y-90 RE, no GDA reperfusion was found after plug embolization compared with 2 cases after coil embolization (3.0%; p = 0.156). Only one patient had a radiation-induced duodenal ulcer after coil embolization, whereas no Y-90-related toxicity was identified after plug embolization.

CONCLUSION

Use of the AVP 4 for embolization of the GDA allowed an optimal proximal and more effective target vessel occlusion compared with coil embolization, which can avoid complications caused by extrahepatic gastrointestinal deposition of Y-90 microspheres by way of residually perfused proximal side branches.

Selective internal radiotherapy (SIRT) of hepatic tumors: how to deal with the cystic artery

PURPOSE

Selective internal radiotherapy (SIRT) with the beta emitter yttrium-90 (Y90) is a rapidly developing therapy option for unresectable liver malignancies. Nontarget irradiation of the gallbladder is a complication of SIRT. Thus, we aimed to assess different strategies to avoid infusion of Y90 into the cystic artery (CA).

METHODS

After hepatic digital subtraction angiography and administration of technetium-99m-labeled human serum albumin ((99)mTc-HSA), 295 patients with primary or secondary liver tumors underwent single-photon emission computed tomography/computed tomography (SPECT/CT). Different measures were taken before repeated Y90 mapping and SIRT to avoid unintended influx into the CA where necessary. Clinical symptoms, including pain, fever, or a positive Murphy sign, were assessed during patient follow-up.

RESULTS

A significant (99)mTc-HSA accumulation in the gallbladder wall (higher (99)mTc-HSA uptake than in normal liver tissue) was seen in 20 patients. The following measures were taken to avoid unintended influx into the CA: temporary/permanent occlusion of the CA with gelfoam (n = 5)/microcoil (n = 1), induction of vasospasm with a microwire (n = 4), or altering catheter position (n = 10). Clinical signs of cholecystitis were observed in only one patient after temporary CA occlusion with gelfoam and were successfully treated by antibiotics. Cholecystectomy was not required for any patient.

CONCLUSION

It is important to identify possible nontarget irradiation of the gallbladder. The risk for radiation-induced cholecystitis can be easily minimized by temporary or permanent CA embolization, vasospasm induction, or altering the catheter position.

Protective embolization of the gastroduodenal artery with a one-HydroCoil technique in radioembolization procedures

PURPOSE

Protective occlusion of the gastroduodenal artery (GDA) is required to avoid severe adverse effects and complications in radioembolization procedures. Because of the expandable features of HydroCoils, our goal was to occlude the GDA with only one HydroCoil to provide particle reflux protection.

METHODS

Twenty-three subjects with unresectable liver tumors, who were scheduled for protective occlusion of the GDA before radioembolization therapy, were included. The primary end point was to achieve a proximal occlusion of the GDA with only one detachable HydroCoil. Evaluated parameters were duration of deployment, and early (during the intervention) and late (7-21 days) occlusion rates of GDA. Secondary end points included complete duration of the intervention, amount of contrast medium used, fluoroscopy rates, and adverse effects.

RESULTS

In all cases, the GDA was successfully occluded with only one HydroCoil. The selected diameter/length range was 4/10 mm in 2 patients, 4/15 mm in 6 patients, and 4/20 mm in 15 patients. HydroCoils were implanted, on average, 3.75 mm from the origin of the GDA (range 1.5-6.8 mm), with an average deployment time of 2:47 (median 2:42, range 2:30-3:07) min. In 21 (91%) of 23 patients, a complete occlusion of the GDA was achieved during the first 30 min after the coil implantation; however, in all patients, a late occlusion of the GDA was present after 6 to 29 days. No clinical or technical complications were reported.

CONCLUSION

We demonstrated that occlusion of the GDA with a single HydroCoil is a safe procedure and successfully prevents extrahepatic embolization before radioembolization.

Effectiveness of repeat angiographic assessment in patients designated for radioembolization using yttrium-90 microspheres with initial extrahepatic accumulation of technitium-99m macroaggregated albumin: a single center's experience

PURPOSE

To evaluate the efficacy of a workflow consisting of repeat assessment in patients planned for yttrium-90 ((90)Y) radioembolization in case of nontarget visceral technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) accumulation despite initial prophylactic coil embolization of nonhepatic arteries.

MATERIALS AND METHODS

In 341 patients with primary and secondary liver cancer, pretreatment hepatic angiograms, as well as single-photon emission computed tomography coregistered with magnetic resonance imaging scans, were obtained. Extrahepatic tracer deposition was identified in 33 patients (9.7%) necessitating repeat assessment. Images were reviewed to correlate the site of MAA accumulation with causative gastrointestinal vessels, and repeat angiograms served as reference standard.

RESULTS

At repeat angiography, the source of extrahepatic flow was identified and eliminated in 31 of 33 patients (93.9%). In 20 patients (60.6%), successful embolization of nontarget vessels was achieved, in 13 patients (39.4%), MAA was administered more distally. Afterward, extrahepatic MAA deposition was eliminated in 30 patients (90.9%).

CONCLUSION

The algorithm of repeat assessment in case of extrahepatic MAA accumulation has proven highly effective to eliminate extrahepatic shunting, thus decreasing the risk of postradioembolization complications due to inadvertent visceral microsphere deposition.

Embolization of Bleeding Duodenal Ulcer Using Amplatzer Vascular Plug II and Hydrogel Coils: Case Report

Purpose: To present a case of upper gastrointestinal bleeding (UGIB) that was treated with percutaneous endovascular embolization using Amplatzer vascular plug and hydrogel coils after failed endoscopic treatment. Case Report: A 78-year-old male was referred for endovascular treatment of massive recurrent UGIB from a duodenal ulcer. Attempts at endoscopic treatment were unsuccessful. Based on our knowledge of the site of the bleeder in the duodenum from prior endoscopy, we decided to empirically embolize the gastroduodenal artery (GDA) and the right gastroepiploic artery using a combination of coils (Azur peripheral hydrocoil; Terumo Medical Corporation, Somerset, New Jersey) and Amplatzer vascular plug II (AVP II; AGA Medical, Plymouth, Minnesota). Conclusion: We present this case of UGIB where effective, rapid, precise, and controlled embolization of the GDA was achieved using AVP II device in combination with coils. To our knowledge, the use of AVP II in embolization of GDA for treatment of emergent UGIB has not been described in the literature.

Splenic artery syndrome after orthotopic liver transplantation: treatment with the Amplatzer vascular plug

PURPOSE

To evaluate the safety and efficacy of the Amplatzer vascular plug (AVP) for embolization of the splenic artery in patients with hepatic hypoperfusion after orthotopic liver transplantation (OLT).

MATERIALS AND METHODS

Thirteen patients (9 men and 4 women) with a mean age of 56 years (range 22-70) who developed splenic artery syndrome after OLT with decreased liver perfusion and clinically relevant impairment of liver function (increased transaminase or serum bilirubin levels, thrombocytopenia, and/or therapy-refractory ascites) were treated by embolization of the proximal third of the splenic artery using the AVP. The plugs ranged in diameter from 6 to 16 mm, and they were introduced through femoral (n = 9), axillary (n = 3), or brachial (n = 1) access using a 5F or 8F guiding catheter.

RESULTS

The plugs were successfully placed, and complete occlusion of the splenic artery was achieved in all patients. Placement of two plugs was necessary for complete occlusion in 3 of the 13 patients. Occlusion took on average 10 min (range 4-35). There was no nontarget embolization or plug migration into more distal segments of the splenic artery. All patients showed improved arterial perfusion, including the liver periphery, on postinterventional angiogram. After embolization, liver function parameters (transaminase and bilirubin levels) improved with normalization of concomitant thrombocytopenia and a decrease in ascites volume.

CONCLUSION

Our initial experience in a small patient population with SAS suggests that the AVP enables precise embolization of the proximal splenic artery, thus providing safe and effective treatment for poor liver perfusion after OLT due to SAS.

Distal pancreatectomy with en bloc resection of the celiac trunk for extended pancreatic tumor disease: an interdisciplinary approach

PURPOSE

Infiltration of the celiac trunk by adenocarcinoma of the pancreatic body has been considered a contraindication for surgical treatment, thus resulting in a very poor prognosis. The concept of distal pancreatectomy with resection of the celiac trunk offers a curative treatment option but implies the risk of relevant hepatic or gastric ischemia. We describe initial experiences in a small series of patients with left celiacopancreatectomy with or without angiographic preconditioning of arterial blood flow to the stomach and the liver.

MATERIALS AND METHODS

Between January 2007 and October 2009, six patients underwent simultaneous resection of the celiac trunk for adenocarcinoma of the pancreatic body involving the celiac axis. In four of these cases, angiographic occlusion of the celiac trunk before surgery was performed to enhance collateral flow from the gastroduodenal artery. Radiologic and surgical procedures, findings, and outcome were analyzed retrospectively.

RESULTS

Complete tumor removal (R0) succeeded in two patients, whereas four patients underwent R1-tumor resection. After surgery, one of the two patients without angiographic preparation experienced an ischemic stomach perforation 1 week after surgery. The other patient died from severe bleeding from an ischemic gastric ulcer. Of the four patients with celiac trunk embolization, none presented ischemic complications after surgery. Mean survival was 371 days.

CONCLUSION

In this small series, ischemic complications after celiacopancreatectomy occurred only in those patients who did not receive preoperative celiac trunk embolization.

Bleeding gastric ulcer after prophylactic coiling of transarterial chemoembolization

Transarterial chemoembolization is standard treatment for unresectable hepatocellular carcinoma. Prophylactic embolization of variant hepatic or gastric arteries before treatment of liver tumors reduces inadvertent injury to adjacent organs. This report presents a patient with multiple hepatocellular carcinomas, who developed an episode of acute gastric ulcer bleeding because of coil migration into the stomach 2 years after prophylactic embolization of the accessory right gastric artery for transarterial chemoembolization. This report discusses the purpose of prophylactic embolization, complications of coil embolization, various presentations and possible mechanisms of coil migration, and treatment of gastrointestinal bleeding. It also reviews pertinent literature.

Utility of the Amplatzer Vascular Plug in splenic artery embolization: a comparison study with conventional coil technique

PURPOSE

To retrospectively evaluate the role of the Amplatzer Vascular Plug (AVP) in proximal splenic artery embolization (SAE) compared with coils.

MATERIALS AND METHODS

Forty patients had proximal SAE performed with AVP(s) or coils as the primary embolic agent for splenic artery steal syndrome (n=23), trauma (n=5), portal hypertension (n=5), bleeding due to pancreatic pathology (n=4), and pre-splenectomy (n=3). Comparisons were made of occlusion and procedure time, cost, and radiation dose.

RESULTS

Eighteen proximal SAE procedures were successfully performed with AVP. Twenty-two procedures were performed with coils, including one failed AVP attempt, which was completed with coils. Precise deployment without migration was achieved in all 18 AVP cases. Seven of 22 (31.8%) coil procedures had distal migration without consequence. There was no statistically significant difference in mean occlusion time (24.4 min for AVP vs. 31.5 min for coils, P=0.13), procedure time (43.7 min for AVP vs. 53.8 min for coils, P=0.16), or cost ($1474.13 for AVP vs. $1722.51 for coils, P=0.69). There was significant difference in radiation dose (842 mGy for AVP vs. 1,309 mGy for coils, P=0.04). Fourteen of the 18 (78%) AVP devices required additional embolic material.

CONCLUSIONS

AVP with additional embolic agents is a useful alternative for proximal SAE because of precise deployment, resistance to migration, and radiation reduction. AVP use may be limited by vessel tortuosity. The occlusion time, procedure time, and cost were reduced but this was not statistically significant due to the need for additional embolic material.

Occlusion of arteriovenous fistulas of in-situ saphenous vein bypass grafts using the amplatzer vascular plug 4: initial experience

We examined the safety and efficacy of vessel occlusion of the Amplatzer Vascular Plug 4 (AVP-4) in patients with arteriovenous fistulas after in-situ saphenous vein bypass grafts. We treated 18 fistulas of seven patients (four women, mean±standard deviation age 76±7 years, range 63-88 years). All fistulas were detected within 14 days after surgery. Initial diagnosis and follow-up was established by sonography. We measured the diameter of the feeding vessel and the time of vessel occlusion after plug deployment. Additionally, we recorded procedure time and the dose area product. Additional interventional procedures were necessary in three patients. We successfully used 19 AVP-4 for occlusion of all fistulas without thromboembolic complications. There was no need for recapturing the device, and we did not observe dislocation. Mean occlusion time was 9.6 min (range 5-22 min). Mean diameter of the feeding vessels was 3.5 mm (range 2.6-5.1 mm). Plug sizes ranged from 4-8 mm (mean 5.5 mm) resulting in an oversizing of 33-88%. Mean procedure time for patients with and without additional intervention was 91±38 min and 35±18 min, respectively. Mean dose area product was 11,790 cGy/cm2 (range 1,850-23,500 cGy/cm2). Permanent occlusion of the fistulas was confirmed by ultrasound after a mean follow-up of 4 months (1-6 months). Occlusion of arteriovenous fistulas with an AVP-4 seems to be effective and safe in patients with in-situ saphenous vein bypass grafts. The AVP-4 is well suited for this purpose because of the appropriate diameter of the feeding vessels.