Embolization of the Gastroduodenal Artery Before Selective Internal Radiotherapy: A Prospectively Randomized Trial Comparing Standard Pushable Coils with Fibered Interlock Detachable Coils

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.

A case of unsuccessful obliteration of percutaneous transhepatic gastric varices using the IMPEDE embolization plug

Key Clinical Message

Embolization with IMPEDE embolization plug cannot be confirmed on site. Therefore, we propose that the diameter of the device selected be up to 50% larger than the vein diameter to prevent embolization failure and recanalization.

Abstract

Balloon-occluded retrograde transvenous obliteration and percutaneous transhepatic obliteration (PTO) are performed for treating sporadic gastric varices. IMPEDE embolization plug has been recently developed for these procedures; however, no studies have reported its use. This is the first report on its use in PTO of gastric varices.

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.

Microsurgical and Endovascular Management of Congenital Iliac Aneurysms in the Neonatal Period: Two Cases and a Literature Review

Introduction

Congenital aneurysms of major arteries are very rare diagnoses and prognosis can be poor if treatment is not initiated rapidly. This is the presentation of two cases of infants with congenital iliac aneurysms who underwent treatment in the neonatal period. The report then proceeds with a literature review of paediatric iliac aneurysms.

Report

Case 1: A female neonate was diagnosed antenatally with right common iliac (CIA) and internal iliac (IIA) artery aneurysms. Embolisation on day of life (DOL) eight was impossible because of partial thrombosis. The infant was subsequently observed for several months and the aneurysm was injected percutaneously with thrombin on DOL 78. A small residual aneurysm was coil embolised at five months of age. Satisfactory results were observed at one year follow up. Case 2: A female neonate was diagnosed antenatally on routine third trimester ultrasound with voluminous, bilateral CIA aneurysms. The patient underwent surgery on DOL 9 for aneurysm resection and microsurgical vascular reconstruction. The intervention was successful with triphasic flow through the anastomoses on colour Doppler ultrasound at six week follow up.

Discussion

Ten cases of congenital iliac aneurysms have been reported previously, with just two diagnosed in the neonatal period and eight undergoing surgical intervention. Definitive management to avoid aneurysm rupture or thrombosis should be timed carefully, and sometimes delayed with watchful waiting, to maximise success and minimise complications. Surgery is the key treatment modality, but endovascular intervention can be considered in selected cases. Congenital iliac aneurysms should be addressed at the safest time for the patient. Following resection, primary microvascular anastomosis is the ideal reconstructive technique, but other options for neonates have been described. Endovascular treatment should be considered for anatomically amenable saccular aneurysms.

Splenic trauma: endovascular treatment approach

The spleen is a commonly injured organ in blunt abdominal trauma. Splenic preservation, however, is important for immune function and prevention of overwhelming infection from encapsulated organisms. Splenic artery embolization (SAE) for high-grade splenic injury has, therefore, increasingly become an important component of non-operative management (NOM). SAE decreases the blood pressure to the spleen to allow healing, but preserves splenic perfusion via robust collateral pathways. SAE can be performed proximally in the main splenic artery, more distally in specific injured branches, or a combination of both proximal and distal embolization. No definitive evidence from available data supports benefits of one strategy over the other. Particles, coils and vascular plugs are the major embolic agents used. Incorporation of SAE in the management of blunt splenic trauma has significantly improved success rates of NOM and spleen salvage. Failure rates generally increase with higher injury severity grades; however, current management results in overall spleen salvage rates of over 85%. Complication rates are low, and primarily consist of rebleeding, parenchymal infarction or abscess. Splenic immune function is felt to be preserved after embolization with no guidelines for prophylactic vaccination against encapsulated bacteria; however, a complete understanding of post-embolization immune changes remains an area in need of further investigation. This review describes the history of SAE from its inception to its current role and indications in the management of splenic trauma. The endovascular approach, technical details, and outcomes are described with relevant examples. SAE is has become an important part of a multidisciplinary strategy for management of complex trauma patients.

Visceral Artery Aneurysms Embolization and Other Interventional Options: State of the Art and New Perspectives

Visceral artery aneurysms (VAAs) are rare, usually asymptomatic and incidentally discovered during a routine radiological examination. Shared guidelines suggest their treatment in the following conditions: VAAs with diameter larger than 2 cm, or 3 times exceeding the target artery; VAAs with a progressive growth of at least 0.5 cm per year; symptomatic or ruptured VAAs. Endovascular treatment, less burdened by morbidity and mortality than surgery, is generally the preferred option. Selection of the best strategy depends on the visceral artery involved, aneurysm characteristics, the clinical scenario and the operator's experience. Tortuosity of VAAs almost always makes embolization the only technically feasible option. The present narrative review reports state of the art and new perspectives on the main endovascular and other interventional options in the treatment of VAAs. Embolization techniques and materials, use of covered and flow-diverting stents and percutaneous approaches are accurately analyzed based on the current literature. Visceral artery-related considerations and targeted approaches are also provided and discussed.

Electrocoagulation for liver metastases

BACKGROUND

Primary liver tumours and liver metastases from colorectal carcinoma are two of the most common malignant tumours to affect the liver. The liver is second only to the lymph nodes as the most common site for metastatic disease. More than half of the people with metastatic liver disease will die from metastatic complications. Electrocoagulation by diathermy is a method used to destroy tumour tissue, using a high-frequency electric current generating high temperatures, applied locally with an electrode (needle, blade, or ball). The objective of this method is to destroy the tumour completely, if possible, in a single session. With the time, electrocoagulation by diathermy has been replaced by other techniques, but the evidence is unclear.

OBJECTIVES

To assess the beneficial and harmful effects of electrocoagulation by diathermy, administered alone or with another intervention, versus no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, CINAHL, ClinicalTrials.gov, ICTRP, and FDA to October 2020.

SELECTION CRITERIA

We considered all randomised trials that assessed beneficial and harmful effects of electrocoagulation by diathermy, administered alone or with another intervention, versus comparators, in people with liver metastases, regardless of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We assessed risk of bias of the included trial using predefined risk of bias domains, and presented the review results incorporating the certainty of the evidence using GRADE.

MAIN RESULTS

We included one randomised clinical trial with 306 participants (175 males; 131 females) who had undergone resection of the sigmoid colon, and who had five or more visible and palpable hepatic metastases. The diagnosis was confirmed by histological assessment (biopsy) and by carcinoembryonic antigen (CEA) level. The trial was conducted in Iraq. The age of participants ranged between 38 and 79 years. The participants were randomised to four different study groups. The liver metastases were biopsied and treated (only once) in three of the groups: 75 received electrocoagulation by diathermy alone, 76 received electrocoagulation plus allopurinol, 78 received electrocoagulation plus dimethyl sulphoxide. In the fourth intervention group, 77 participants functioning as controls received a vehicle solution of allopurinol 5 mL 4 x a day by mouth; the metastases were left untouched. The status of the liver and lungs was followed by ultrasound investigations, without the use of a contrast agent. Participants were followed for five years. The analyses are based on per-protocol data only analysing 223 participants. We judged the trial to be at high risk of bias. After excluding 'nonevaluable patients', the groups seemed comparable for baseline characteristics. Mortality due to disease spread at five-year follow-up was 98% in the electrocoagulation group (57/58 evaluable people); 87% in the electrocoagulation plus allopurinol group (46/53 evaluable people); 86% in the electrocoagulation plus dimethyl sulphoxide group (49/57 evaluable people); and 100% in the control group (55/55 evaluable people). We observed no difference in mortality between the electrocoagulation alone group versus the control group (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.94 to 1.03; 113 participants; very low-certainty evidence). We observed lower mortality in the electrocoagulation combined with allopurinol or dimethyl sulphoxide group versus the control group (RR 0.87, 95% CI 0.80 to 0.95; 165 participants; low-certainty evidence). We are very uncertain regarding post-operative deaths between the electrocoagulation alone group versus the control group (RR 1.03, 95% CI 0.07 to 16.12; 152 participants; very low-certainty evidence) and between the electrocoagulation combined with allopurinol or dimethyl sulphoxide groups versus the control group (RR 1.00, 95% CI 0.09 to 10.86; 231 participants; very low-certainty evidence). The trial authors did not report data on number of participants with other adverse events and complications, recurrence of liver metastases, time to progression of liver metastases, tumour response measures, and health-related quality of life. Data on failure to clear liver metastases were not provided for the control group. There was no information on funding or conflict of interest. We identified no ongoing trials.

AUTHORS' CONCLUSIONS

The evidence on the beneficial and harmful effects of electrocoagulation alone or in combination with allopurinol or dimethyl sulphoxide in people with liver metastases is insufficient, as it is based on one randomised clinical trial at low to very low certainty. It is very uncertain if there is a difference in all-cause mortality and post-operative mortality between electrocoagulation alone versus control. It is also uncertain if electrocoagulation in combination with allopurinol or dimethyl sulphoxide may result in a slight reduction of all-cause mortality in comparison with a vehicle solution of allopurinol (control). It is very uncertain if there is a difference in post-operative mortality between the electrocoagulation combined with allopurinol or dimethyl sulphoxide group versus control. Data on other adverse events and complications, failure to clear liver metastases or recurrence of liver metastases, time to progression of liver metastases, tumour response measures, and health-related quality of life were most lacking or insufficiently reported for analysis. Electrocoagulation by diathermy is no longer used in the described way, and this may explain the lack of further trials.

[Embolization of splenic artery aneurysms: Treatment of choice. About a case and review of the literature]

Splenic artery aneurysms constitute 60% of digestive artery aneurysms. They are often discovered incidentally and by imaging. Currently, endovascular treatment is considered the first-line treatment, as it is less invasive with less morbidity and mortality than surgery. An aggressive approach in their management is certainly justified because the overall mortality of ruptured splenic aneurysms is 25%. False splenic aneurysms have a greater potential for rupture than true aneurysms because they grow faster. Endovascular treatment is generally indicated for aneurysms larger than 2cm or with an increase in size of more than 0.5cm/year. Embolization is rarely associated with an infarction of the spleen due to the good supply of short gastric vessels. Embolization is performed using different materials including coils, which can be used alone or with other embolic agents. Post-embolization syndrome can be seen with persistent pain, fever and other systemic symptoms. Endovascular treatment compared to open surgery is associated with better quality of life and appears to be the most cost-effective strategy. Endovascular treatment and especially coil embolization are starting to be the standard treatment. Surgical and laparoscopic treatment are reserved for ruptured aneurysms which are burdened with significant mortality, especially in pregnant women. We report the case of a 66-year-old female patient in whom a splenic artery aneurysm was discovered incidentally during an ultrasound for an ovarian cyst.

Elective Embolization of Splenic Artery Aneurysms with an Ethylene Vinyl Alcohol Copolymer Agent (Squid) and Detachable Coils

PURPOSE

To report the safety and efficacy of the embolization of splenic artery aneurysms (SAAs) with coils plus ethylene vinyl alcohol copolymer (EVOH) agent.

MATERIALS AND METHODS

A single-center retrospective study was conducted from 2016 to 2019 to collect SAAs. Twelve asymptomatic patients (mean age, 59 years) with 15 SAAs (mean size, 23.6 mm; size range, 15-40 mm) were treated with embolization. Embolization was performed with EVOH (Squid 8/34) and fibered detachable coils. Transfemoral embolization was performed with a microcatheter to achieve a splenic artery occlusion embolizing the SAA and its efferent and afferent branches. Follow-up was based on color Doppler ultrasound at 24 hours and on computed tomography (CT) angiography at 1 (n = 12) and 6 months (n = 12) after embolization. Mean number of coils and Squid vials used for each patient, major/minor complications, technical success, 30-day clinical success, cases of revascularization/reintervention, and mortality were assessed. Technical success was defined as complete exclusion of the aneurysmal segment and cessation of blood flow into the sac. Clinical success at 1 month was based on the absence of clinical symptoms and the exclusion of aneurysm revascularization on CT angiography.

RESULTS

The mean number of coils and Squid vials was 5.75 (standard deviation [SD], 1.58; range, 3-9) and 1.41 (SD, 0.49; range, 1-2), respectively. Both technical and 30-day clinical success were 100%, with no cases of aneurysm revascularization (CT angiography performed in all patients at 1 month and 6 months and in 3 patients at 24 months). No major complications or fatal events were recorded. In terms of minor complications, 2 cases of mild pancreatitis (transient amylases increase) and 1 case of focal splenic ischemia without clinical sequelae were recorded.

CONCLUSIONS

Embolization in SAAs using coils plus EVOH was safe and effective without SAA revascularization.

Transarterial (chemo)embolisation versus no intervention or placebo for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma or other extrahepatic primary cancers. Liver metastases are significantly more common than primary liver cancer, and long-term survival rate after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of people; therefore, other treatments have to be considered. One possible option is based on the concept that the blood supply to hepatic tumours originates predominantly from the hepatic artery. Transarterial chemoembolisation (TACE) of the hepatic artery can be achieved by administering a chemotherapeutic drug followed by vascular occlusive agents, and can lead to selective necrosis of the liver tumour while it may leave normal parenchyma virtually unaffected. This can also be performed without chemotherapy, which is called bland transarterial embolisation (TAE).

OBJECTIVES

To assess the beneficial and harmful effects of TAE or TACE compared with no intervention or placebo in people with liver metastases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, and four more databases (December 2019). We also searched two trials registers and the US Food and Drug Administration database (September 2019).

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of TAE or TACE compared with no intervention or placebo for liver metastases.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodological procedures. We extracted information on participant characteristics, interventions, study outcomes, study design, and trial methods. Two review authors independently extracted data and assessed risk of bias. We assessed the certainty of evidence with GRADE. We resolved disagreements by discussion.

MAIN RESULTS

We included one randomised clinical trial with 61 participants (43 male and 18 female) with colorectal cancer with liver metastases: 22 received transarterial embolisation (TAE; hepatic artery embolisation), 19 received transarterial chemoembolisation (TACE; 5-fluorouracil hepatic artery infusion chemotherapy with degradable microspheres), and 20 received 'no active therapeutic intervention' as a control. Most tumours were synchronous, unresectable metastases involving up to 75% of the liver. Participants were followed for a minimum of seven months. The trial was at high risk of bias. Very-low-certainty evidence found inconclusive results for mortality at 44 months between the TAE and TACE versus no intervention groups (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.74 to 1.06; 61 participants). Local recurrence was reported in 10 participants without any details about the group allocation. Very-low-certainty evidence found little or no difference in mortality between the TAE and no intervention groups (RR 0.91, 95% CI 0.75 to 1.10; 42 participants). Median survival was 7 months from trial entry (range 2 to 44 months) in the TAE group and 7.9 months (range 1 to 26 months) in the control group, and 8.7 months after diagnosis (range 2 to 49 months) in the TAE group and 9.6 months (range 1 to 27 months) in the control group. The trial authors reported the differences were not statistically significant. There were no reported side effects in the control group. In the TAE group, 18 participants experienced short-term symptoms of 'post-embolisation syndrome', which were relieved with symptomatic treatment; one participant also had a local puncture site haematoma. Very-low-certainty evidence found little or no difference in mortality between the TACE and no intervention groups (RR 0.83, 95% CI 0.65 to 1.07; 39 participants). Median survival in the TACE group was 10.7 months (range 3 to 38 months) from trial entry, and 13.0 months (range 3 to 38 months) after diagnosis. The trial authors reported that differences between groups were not statistically significant. All participants experienced short-term nausea, with or without vomiting, immediately after treatment; one participant developed a wound infection, and one developed deep vein thrombosis. The trial did not measure failure to clear liver metastases, time to progression of liver metastases, tumour response measures, or health-related quality of life. Cancer Research Campaign, a non-profit organisation, provided a grant for the trial; Pharmacia Ltd. delivered the Port-a-Cath arterial delivery systems and degradable starch microspheres. We identified one ongoing trial comparing TACE plus chemotherapy versus chemotherapy alone in people with unresectable colorectal liver metastases who failed with first-line chemotherapy (NCT03783559).

AUTHORS' CONCLUSIONS

Based on one, small randomised trial at high risk of bias, the evidence is very uncertain about the effect of TAE or TACE versus no active therapeutic intervention on mortality for people with liver metastases as the true effect may be substantially different. The trial did not measure failure to clear liver metastases, time to progression of liver metastases, tumour response measures, or health-related quality of life. Short-term, minor adverse events were recorded in the intervention groups only. Large trials, following current standards of conduct and reporting, are required to explore the benefits and harms of TAE or TACE compared with no intervention or placebo in people with resectable and unresectable liver metastasis.

Percutaneous ethanol injection for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma or other extrahepatic primary cancers. Liver metastases are significantly more common than primary liver cancer, and the reported long-term survival rate after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients; therefore, other treatments have to be considered. One of these is percutaneous ethanol injection (PEI), which causes dehydration and necrosis of tumour cells, accompanied by small-vessel thrombosis, leading to tumour ischaemia and destruction of the tumour.

OBJECTIVES

To assess the beneficial and harmful effects of percutaneous ethanol injection (PEI) compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched the following databases up to 10 September 2019: the Cochrane Hepato-Biliary Group Controlled Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; MEDLINE Ovid; Embase Ovid; Science Citation Index Expanded; Conference Proceedings Citation Index - Science; Latin American Caribbean Health Sciences Literature (LILACS); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). We also searched clinical trials registers such as ClinicalTrials.gov, the International Clinical Trials Registry Platform (ICTRP), and the US Food and Drug Administration (FDA) (17 September 2019).

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of percutaneous ethanol injection and its comparators (no intervention, other ablation methods, systemic treatments) for liver metastases.

DATA COLLECTION AND ANALYSIS

We followed standard methodological procedures as outlined by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, study design, and trial methods. Two review authors performed data extraction and assessed risk of bias independently. We assessed the certainty of evidence by using GRADE. We resolved disagreements by discussion.

MAIN RESULTS

We identified only one randomised clinical trial comparing percutaneous intratumour ethanol injection (PEI) in addition to transcatheter arterial chemoembolisation (TACE) versus TACE alone. The trial was conducted in China and included 48 trial participants with liver metastases: 25 received PEI plus TACE, and 23 received TACE alone. The trial included 37 male and 11 female participants. Mean participant age was 49.3 years. Sites of primary tumours included colon (27 cases), stomach (12 cases), pancreas (3 cases), lung (3 cases), breast (2 cases), and ovary (1 case). Seven participants had a single tumour, 15 had two tumours, and 26 had three or more tumours in the liver. The bulk diameter of the tumour on average was 3.9 cm, ranging from 1.2 cm to 7.6 cm. Participants were followed for 10 months to 43 months. The trial reported survival data after one, two, and three years. In the PEI + TACE group, 92%, 80%, and 64% of participants survived after one year, two years, and three years; in the TACE alone group, these percentages were 78.3%, 65.2%, and 47.8%, respectively. Upon conversion of these data to mortality rates, the calculated risk ratio (RR) for mortality at last follow-up when PEI plus TACE was compared with TACE alone was 0.69 (95% confidence interval (CI) 0.36 to 1.33; very low-certainty evidence) after three years of follow-up. Local recurrence was 16% in the PEI plus TACE group and 39.1% in the TACE group, resulting in an RR of 0.41 (95% CI 0.15 to 1.15; very low-certainty evidence). Forty-five out of a total of 68 tumours (66.2%) shrunk by at least 25% in the PEI plus TACE group versus 31 out of a total of 64 tumours (48.4%) in the TACE group. Trial authors reported some adverse events but provided very few details. We did not find data on time to mortality, failure to clear liver metastases, recurrence of liver metastases, health-related quality of life, or time to progression of liver metastases. The single included trial did not provide information on funding nor on conflict of interest.

AUTHORS' CONCLUSIONS

Evidence for the effectiveness of PEI plus TACE versus TACE in people with liver metastases is of very low certainty and is based on one small randomised clinical trial at high risk of bias. Currently, it cannot be determined whether adding PEI to TACE makes a difference in comparison to using TACE alone. Evidence for benefits or harms of PEI compared with no intervention, other ablation methods, or systemic treatments is lacking.

Microscopic Assessment of Healing and Effectiveness of a Foam-Based Peripheral Occlusion Device

The IMPEDE Embolization Plug is a catheter-delivered vascular occlusion device that utilizes a porous shape memory polymer foam as a scaffold for thrombus formation and distal coils to anchor the device within the vessel. In this study, we investigated the biological response of porcine arteries to the IMPEDE device by assessing the extent of healing and overall effectiveness in occluding the vessel at 30, 60, and 90 days. Compared to control devices (Amplatzer Vascular Plug and Nester Embolization Coils), the host response to IMPEDE showed increased cellular infiltration (accommodated by the foam scaffold), which led to advanced healing of the initial thrombus to mature collagenous connective tissue (confirmed by transmission electron microscopy (TEM)). Over time, the host response to the IMPEDE device included degradation of the foam by multinucleated giant cells, which promoted fibrin and polymer degradation and advanced the healing response. Device effectiveness, in terms of vessel occlusion, was evaluated histologically by assessing the degree of recanalization. Although instances of recanalization were often observed at all time points for both control and test articles, the mature connective tissue within the foam scaffold of the IMPEDE devices improved percent vessel occlusion; when recanalization was observed in IMPEDE-treated vessels, channels were exclusively peri-device rather than intradevice, as often observed in the controls, and the vessels mostly remained >75% occluded. Although total vessel occlusion provides the optimal ischemic effect, in cardiovascular pathology, there is a progressive ischemic effect on the downstream vasculature as a vessel narrows. As such, we expect a sustained ischemic therapeutic effect to be observed in vessels greater than 75% occluded. Overall, the current study suggests the IMPEDE device presents advantages over controls by promoting an enhanced degree of healing within the foam scaffold, which decreases the likelihood of intradevice recanalization and ultimately may lead to a sustained ischemic therapeutic effect.

Cryotherapy for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma. Liver metastases are significantly more common than primary liver cancer and long-term survival rates reported for patients after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients. Cryotherapy is performed with the use of an image-guided cryoprobe which delivers liquid nitrogen or argon gas to the tumour tissue. The subsequent process of freezing is associated with formation of ice crystals, which directly damage exposed tissue, including cancer cells.

OBJECTIVES

To assess the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and six other databases up to June 2018.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of cryotherapy and its comparators for liver metastases, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, and data on the outcomes important for our review, as well as information on the design and methodology of the trials. Two review authors independently assessed risk of bias in each study. One review author performed data extraction and a second review author checked entries.

MAIN RESULTS

We found no randomised clinical trials comparing cryotherapy versus no intervention or versus systemic treatments; however, we identified one randomised clinical trial comparing cryotherapy with conventional surgery. The trial was conducted in Ukraine. The trial included 123 participants with solitary, or multiple unilobar or bilobar liver metastases; 63 participants received cryotherapy and 60 received conventional surgery. There were 36 women and 87 men. The primary sites for the metastases were colon and rectum (66.6%), stomach (7.3%), breast (6.5%), skin (4.9%), ovaries (4.1%), uterus (3.3%), kidney (3.3%), intestines (1.6%), pancreas (1.6%), and unknown (0.8%). The trial was not reported sufficiently enough to assess the risk of bias of the randomisation process, allocation concealment, or presence of blinding. It was also not possible to assess incomplete outcome data and selective outcome reporting bias. The certainty of evidence was low because of risk of bias and imprecision.The participants were followed for up to 10 years (minimum five months). The trial reported that the mortality at 10 years was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group. The calculated by us relative risk (RR) with 95% Confidence Interval (CI) was: RR 0.88, 95% CI 0.77 to 1.02. We judged the evidence as low-certainty evidence. Regarding adverse events and complications, separately and in total, our calculation showed no evidence of a difference in recurrence of the malignancy in the liver: 86% (54/63) of the participants in the cryotherapy group and 95% (57/60) of the participants in the conventional surgery group developed a new malignancy (RR 0.90, 95% CI 0.80 to 1.01; low-certainty evidence). The frequency of reported complications was similar between the cryotherapy group and the conventional surgery group, except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the conventional surgery group. However, the authors did not report whether there was any evidence of a difference. There were no intervention-related mortality or bile leakages.We identified no evidence for health-related quality of life, cancer mortality, or time to progression of liver metastases. The study reported tumour response in terms of the carcinoembryonic antigen level in 69% of participants, and reported results in the form of a graph for 30% of participants. The carcinoembryonic antigen level was lower in the cryotherapy group, and decreased to normal values faster in comparison with the control group (P < 0.05).

FUNDING

the trial did not provide information on funding.

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of cryotherapy versus conventional surgery in people with liver metastases is of low certainty. We are uncertain about our estimate and cannot determine whether cryotherapy compared with conventional surgery is beneficial or harmful. We found no evidence for the benefits or harms of cryotherapy compared with no intervention, or versus systemic treatments.

Histopathological differences of experimental aneurysms treated with bare platinum, fibered, and bioactive coils

PURPOSE

To evaluate the histopathological features of experimental aneurysms embolized with bare platinum, fibered, and bioactive coils.

MATERIAL AND METHODS

Twelve experimental aneurysms were constructed in three swine. The aneurysms were divided into four groups and were embolized using a bare platinum coil alone (P group, n = 2), a bioactive coil alone (B group, n = 2), a combination of fibered and bare platinum coils (F/P group, n = 4) and a combination of fibered and bioactive coils (F/B group, n = 4). Histopathological data for all aneurysms recorded at 63 days were analyzed in terms of neointima formation, fibrosis, foreign-body giant-cell infiltration, and organization.

RESULTS

Fibrosis was significantly greater in group B compared with that in group F/P (p = .02).　 Inflammation with foreign-body giant-cell infiltration was significantly greater in groups F/P and F/B compared with that in groups P and B (p = .007).

CONCLUSION

The present study revealed that the embolic effect of fibered coils was not a thrombus but instead was a foreign-body response in the chronic phase.

The Endovascular Management of an Iatrogenic Superior Gluteal Artery Rupture Following Bone Marrow Biopsy

We herein report an uncommon case of a life-threatening retroperitoneal hematoma after a bone marrow biopsy. Two hours after iliac crest bone harvesting, the patient experienced syncope and severe hypotension. Urgent contrast-enhanced computed tomography demonstrated extravasation from the superior gluteal artery. Transcatheter coil embolization was performed successfully, without complications. Life-threatening complications caused by retroperitoneal bleeding after bone marrow biopsy are very rare. There are few reports on the use of endovascular treatment in the management of life-threatening hemorrhagic complications after bone marrow biopsy.

Point-by-point parent artery/sinus obliteration using detachable, pushable, 0.035-inch coils

BACKGROUND

Parent artery occlusion for intractable aneurysms or sinus packing for dural arteriovenous fistulas (DAVFs) is sometimes difficult and requires many expensive coils to accomplish complete occlusion. To help solve these problems, we reviewed our experience using 0.035-inch coil (0.035 coil; Boston Scientific, San Leandro, CA, USA), which has been used in cardiovascular and abdominal lesions.

METHODS

These 0.035 coils were preferably used in addition to the detachable and fibered coils for patients with intractable aneurysms, traumatic vessel blowout, and DAVF. Our strategy was as follows: (1) detachable coils were deployed first for the ideal anchoring of the coils; (2) small fibered coils were additionally deployed to stabilize the coil mass; (3) 0.035 coils were deployed to complete the occlusion.

RESULTS

From January 2012 to December 2013, seven consecutive patients were treated by endovascular embolization with 0.035 coils. Reasons for intervention were parent artery occlusion for carotid blowout (n = 1), internal carotid artery aneurysm (n = 2), traumatic vertebral artery injury (n = 2), vertebral AVF (n = 1), and transverse sinus-sigmoid sinus DAVF (n = 1). In our cases, a mean of 20.1 ± 8.5 coils per vessel were placed, and mean total coil length was 258.4 ± 91.5 cm per vessel. All procedures were safely performed and complete occlusions achieved.

CONCLUSIONS

From our initial experience and treatment results, we believe endovascular parent artery occlusion or sinus packing with 0.035 coils to be useful in terms of reducing the number and expense of coils and also accomplishing immediate occlusion.

Design and verification of a shape memory polymer peripheral occlusion device

Shape memory polymer foams have been previously investigated for their safety and efficacy in treating a porcine aneurysm model. Their biocompatibility, rapid thrombus formation, and ability for endovascular catheter-based delivery to a variety of vascular beds makes these foams ideal candidates for use in numerous embolic applications, particularly within the peripheral vasculature. This study sought to investigate the material properties, safety, and efficacy of a shape memory polymer peripheral embolization device in vitro. The material characteristics of the device were analyzed to show tunability of the glass transition temperature (Tg) and the expansion rate of the polymer to ensure adequate time to deliver the device through a catheter prior to excessive foam expansion. Mechanical analysis and flow migration studies were performed to ensure minimal risk of vessel perforation and undesired thromboembolism upon device deployment. The efficacy of the device was verified by performing blood flow studies that established affinity for thrombus formation and blood penetration throughout the foam and by delivery of the device in an ultrasound phantom that demonstrated flow stagnation and diversion of flow to collateral pathways.

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.

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.

Internal iliac artery embolization during an endovascular aneurysm repair with detachable interlock microcoils

Objective

The purpose of this study was to evaluate the effectiveness of detachable interlock microcoils for an embolization of the internal iliac artery during an endovascular aneurysm repair (EVAR).

Materials and Methods

A retrospective review was conducted on 40 patients with aortic aneurysms, who had undergone an EVAR between January 2010 and March 2012. Among them, 16 patients were referred for embolization of the internal iliac artery for the prevention of type II endoleaks. Among 16 patients, 13 patients underwent embolization using detachable interlock microcoils during an EVAR. Computed tomographic angiographies and clinical examinations were performed during the follow-up period. Technical success, clinical outcome, and complications were reviewed.

Results

Internal iliac artery embolizations using detachable interlock microcoils were technically successful in all 13 patients, with no occurrence of procedure-related complications. Follow-up imaging was accomplished in the 13 cases. In all cases, type II endoleak was not observed with computed tomographic angiography during the median follow-up of 3 months (range, 1-27 months) and the median clinical follow-up of 12 months (range, 1-27 months). Two of 13 (15%) patients had symptoms of buttock pain, and one patient died due to underlying stomach cancer. No significant clinical symptoms such as bowel ischemia were observed.

Conclusion

Internal iliac artery embolization during an EVAR using detachable interlock microcoils to prevent type II endoleaks appears safe and effective, although this should be further proven in a larger population.

Prospective randomized trial comparing pushable coil and detachable coil during percutaneous implantation of port-catheter system for hepatic artery infusion chemotherapy

The purpose of this study was to prospectively compare the efficacy and controllability of pushable coil and detachable coil during embolization of gastroduodenal artery (GDA) while performing percutaneous implantation of port-catheter system for hepatic artery infusion chemotherapy. Fifty patients (M:F = 42:8, age: 31-81 years) with advanced hepatocellular carcinoma undergoing port-catheter system implantation were randomized into pushable coil group and detachable coil group. During catheter fixation, GDA was embolized as close to the origin as possible. Success rate, number of coils used, number of coils removed due to malposition after deployment, time to occlusion, uncoiled GDA length, pushability, and complications were compared. Pushability was graded as no tension, slight tension, and difficult to advance. Embolization was successful in 49 patients. One failure resulted from repeated regurgitation of pushable coil into hepatic artery. Number of coils used and removed coils, time to occlusion, and uncoiled GDA length were 1-3 (mean 2.32), 5 coils in 3 patients, 4-20 min (mean 8.00), and 0-15.0 mm (mean 3.36) in pushable coil group, and 1-5 (mean 2.12), 2 coils in 2 patients, 2-15 min (mean 7.40), and 0-10.2 mm (mean 2.92) in detachable coil group, respectively, without significant difference. Pushability was no tension (n = 24) and slight tension (n = 1) in pushable coil group and no tension (n = 16), slight tension (n = 7), and difficult to advance (n = 2) in detachable coil group. One hepatic artery dissection occurred in the failed case during coil removal. Pushable coils and detachable coils had similar efficacy and controllability during GDA embolization, although there was a trend favoring detachable coil.

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.

Embolization of a large high-flow renal arteriovenous fistula using 035″ and 018″ detachable coils

Transcatheter embolization of renal arteriovenous fistula (AVF) is a minimally invasive procedure that, in some occasions, can replace surgery and potentially save the kidney. The embolization techniques for the renal AVFs have evolved considerably with the availability of newer hardwares. Still, the risk of inadvertent migration of the embolization materials to the pulmonary circulation is a concern. This article describes a novel technique of coiling the feeding segmental artery to a large high-flow renal AVF using 035″ and 018″ detachable coils only, and briefly reviews the previously described strategies to safely embolize renal AVFs.

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.

The "embowire" technique: concept and description of a novel embolization technique for narrow vessels

We describe a new, useful embolization technique applied to occlude narrow vessel branches (≤ 1.5 mm (0.06") in diameter) by deployment of one hydrocoil, through a microcatheter, in a way similar to the way in which one might navigate through the vascular lumen with a guidewire.

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.