Interventionelle Behandlungsoptionen bei vaskulären Malformationen

Klassifikation von vaskulären Malformationen Während Hämangiome zu den vaskulären Tumoren zählen, sind vaskuläre Malformationen angeboren und bilden sich von selbst nicht zurück. Sie werden nach der ISSVA-Klassifikation unterschieden.

Indikation zur Therapie Ziele der Therapie von Gefäßmalformationen sind die Linderung der Symptome, der Organerhalt und die Verhinderung von Krankheitsprogress und Komplikationen.

Nichtinvasive Therapieoptionen Die Kompressionstherapie sowie physiotherapeutische Maßnahmen zählen zu den wichtigsten konservativen Therapieoptionen.

Invasive Therapieoptionen Die chirurgische Resektion, die oberflächliche Lasertherapie und die interventionelle Therapie stellen die invasiven Therapieoptionen dar. Für die Behandlung symptomatischer Gefäßmalformationen stehen mittlerweile zahlreiche minimalinvasive interventionelle Verfahren zur Verfügung. Slow-Flow-Malformationen können relativ komplikationsarm mittels perkutaner Sklerotherapie behandelt werden, die zu einem zeitversetzten entzündlichen Verschluss der Läsion führt. Dysplastische Venen wie die Marginalvene können mittels endoluminaler Verfahren erfolgreich verödet werden. Die zumeist Katheter-gesteuerten Embolisationsverfahren mittels Flüssigembolisaten, Plugs und Coils erlauben den Verschluss von Fast-Flow-Gefäßmalformationen.

Role of clinical and CT findings in the identification of adult small-bowel intussusception requiring surgical intervention

Background

In adults, intussusception has been considered traditionally to have an underlying aetiology. The aim of this study was to determine CT and clinical features of small-bowel intussusceptions that required surgical intervention.

Methods

Adult patients were identified in whom small-bowel intussusceptions were noted on CT images. The appearance, number, type (enteroenteric versus enterocolic), length and maximum short-axis diameter of intussusceptions, and presence of bowel obstruction (short-axis diameter of proximal small bowel greater than 3 cm) were analysed. The outcome was defined as surgical (complicated) or self-limiting (uncomplicated). Associations between complicated and uncomplicated intussusceptions and patient characteristics were investigated.

Results

Among 75 patients (56 male) with a mean age of 45 years, 103 intussusceptions were identified, of which 98 (95 per cent) were enteroenteric and 5 (5 per cent) enterocolic. Only 12 of 103 intussusceptions (12 per cent) in 12 of 75 (16 per cent) patients required surgical therapy and were considered to be complicated, with half of these having a neoplastic lead point. Length (P < 0.001), diameter (P < 0.001) and type (P = 0.002) of intussusception as well as presence of vessels (P = 0.023) within an intussusception on a CT scan, clinical symptoms (P = 0.007) and signs of bowel obstruction (P < 0.001) were associated with a surgical outcome.

Conclusion

Clinical symptoms, signs of bowel obstruction, type and length of intussusception, and a visible tumour within an intussusception on CT scan were critical signs of complicated intussusception, requiring surgical intervention.

Additive value of transarterial embolization to systemic sirolimus treatment in kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor in children, which can be accompanied by life-threatening thrombocytopenia, referred to as Kasabach-Merritt phenomenon (KMP). The mTOR inhibitor sirolimus is emerging as targeted therapy in KHE. As the sirolimus effect on KHE occurs only after several weeks, we aimed to evaluate whether additional transarterial embolization is of benefit for children with KHE and KMP. Seventeen patients with KHE and KMP acquired from 11 hospitals in Germany were retrospectively divided into two cohorts. Children being treated with adjunct transarterial embolization and systemic sirolimus, and those being treated with sirolimus without additional embolization. Bleeding grade as defined by WHO was determined for all patients. Response of the primary tumor at 6 and 12 months assessed by magnetic resonance imaging (MRI), time to response of KMP defined as thrombocyte increase >150 × 10³ /μL, as well as rebound rates of both after cessation of sirolimus were compared. N = 8 patients had undergone additive embolization to systemic sirolimus therapy, sirolimus in this group was started after a mean of 6.5 ± 3 days following embolization. N = 9 patients were identified who had received sirolimus without additional embolization. Adjunct embolization induced a more rapid resolution of KMP within a median of 7 days vs 3 months; however, tumor response as well as rebound rates were similar between both groups. Additive embolization may be of value for a more rapid rescue of consumptive coagulopathy in children with KHE and KMP compared to systemic sirolimus only.

[Interventional therapies of vascular malformations]

Vascular malformations can appear at any age and in every region of the body. Due to their rare appearance and differences in clinical manifestations the appropriate diagnosis and subsequent classification remains challenging. Once the diagnosis is established, various treatment options exist, requiring an interdisciplinary approach. This review provides an overview over state-of-the-art interventional therapies of vascular malformations.

Vascular tumors in infants and adolescents

Malignant vascular tumors as part of the vascular anomalies spectrum are extremely rare in children and young adults. Instead, benign vascular neoplasias are frequently encountered in the pediatric patient population. While vascular malformations are congenital vascular lesions, originating from a mesenchymal stem cell defect, vascular tumors are neoplastic transformations of endothelial and other vascular cells. The appropriate differential diagnosis and nomenclature according to the classification of the International Society for the Study of Vascular Anomalies (ISSVA) is decisive to initiate correct therapy. While infantile hemangioma can be routinely diagnosed by clinical means and rarely require therapy, more rare vascular tumors are frequently difficult to diagnose, require dedicated cross-sectional imaging, and benefit from an interdisciplinary treatment approach. The focus of this review is to provide an overview over the spectrum of vascular tumors, typical imaging characteristics, and summarize treatment options including interventional radiology approaches.

Preoperative computed tomography angiography (CTA) of the body in vascular patients: prevalence and significance of unsuspected extravascular findings

PURPOSE

 Evaluation of the prevalence and significance of unsuspected extravascular findings on computed tomography angiography (CTA) of the body before endovascular or surgical treatment in vascular patients.

MATERIALS AND METHODS

 This study was approved by the local institutional review board. Radiology reports of 806 patients who underwent CTA of the body during January 2004 until December 2014 before endovascular or surgical treatment of vascular diseases were retrospectively reviewed. All unexpected extravascular abnormalities were classified as clinically non-significant (requiring no follow-up) or clinically significant (requiring further follow-up/immediate treatment). The course of patients with significant extravascular findings was retrospectively evaluated.

RESULTS

 Overall 806 patients were included in this study (592 men; mean age: 67 years). In 778 (96.5 %) of 806 patients 3293 incidental extravascular findings were diagnosed. There were 259 suspicious findings in 205 patients (25.4 %) that required further follow-up or immediate treatment. A previously unknown malignant tumor was diagnosed in 23 (2.9 %) patients. 10 patients (1.2 %) were diagnosed with lung cancer. Malignant tumors were detected more often in men than in women (3.5 % versus 0.9 %). Patients with an incidental tumor were significantly older than patients without a tumor (mean age: 72.3 vs. 67.5 years).

CONCLUSION

 Clinically significant unexpected extravascular findings are common in vascular patients. Especially noteworthy are malignant tumors of the lung.

KEY POINTS

  · Clinically relevant extravascular findings were detected in 25.4 % of the patients.. · The incidence of malignant tumors was 2.9 %.. · Lung cancer had the highest incidence among all malignancies (1.2 %)..

CITATION FORMAT

· Turowski LS, Dollinger M, Wohlgemuth WA et al. Preoperative computed tomography angiography (CTA) of the body in vascular patients: prevalence and significance of unsuspected extravascular findings. Fortschr Röntgenstr 2019; 191: 716 - 724.

Vascular Anomalies (Part I): Classification and Diagnostics of Vascular Anomalies

BACKGROUND

 Vascular anomalies are a diagnostic and therapeutic challenge. They require dedicated interdisciplinary management. Optimal patient care relies on integral medical evaluation and a classification system established by experts in the field, to provide a better understanding of these complex vascular entities.

METHOD

 A dedicated classification system according to the International Society for the Study of Vascular Anomalies (ISSVA) and the German Interdisciplinary Society of Vascular Anomalies (DiGGefA) is presented. The vast spectrum of diagnostic modalities, ranging from ultrasound with color Doppler, conventional X-ray, CT with 4 D imaging and MRI as well as catheter angiography for appropriate assessment is discussed.

RESULTS

 Congenital vascular anomalies are comprised of vascular tumors, based on endothelial cell proliferation and vascular malformations with underlying mesenchymal and angiogenetic disorder. Vascular tumors tend to regress with patient's age, vascular malformations increase in size and are subdivided into capillary, venous, lymphatic, arterio-venous and combined malformations, depending on their dominant vasculature. According to their appearance, venous malformations are the most common representative of vascular anomalies (70 %), followed by lymphatic malformations (12 %), arterio-venous malformations (8 %), combined malformation syndromes (6 %) and capillary malformations (4 %).

CONCLUSION

 The aim is to provide an overview of the current classification system and diagnostic characterization of vascular anomalies in order to facilitate interdisciplinary management of vascular anomalies.

KEY POINTS

  · Vascular anomalies are comprised of vascular tumors and vascular malformations, both considered to be rare diseases.. · Appropriate treatment depends on correct classification and diagnosis of vascular anomalies, which is based on established national and international classification systems, recommendations and guidelines.. · In the classification, diagnosis and treatment of congenital vascular anomalies, radiology plays an integral part in patient management..

CITATION FORMAT

· Sadick M, Müller-Wille R, Wildgruber M et al. Vascular Anomalies (Part I): Classification and Diagnostics of Vascular Anomalies. Fortschr Röntgenstr 2018; 190: 825 - 835.

Vascular malformations of upper and lower extremity - from radiological interventional therapy to surgical soft tissue reconstruction - an interdisciplinary treatment

This article presents our experience in managing peripheral vascular malformations of upper and lower extremities over a 4-year period in a series of 46 patients of the Department of Plastic Surgery treated in the Interdisciplinary Center of Vascular Anomalies (ICVA) at the University of Regensburg. The patients presented vascular malformations of upper and lower extremity and were selected from our prospective vascular anomalies file archive from 2012 to 2016. During this period in the ICVA at University of Regensburg were performed more than 1400 radiological interventional treatments in patients with vascular malformations.The purpose of this retrospective study was to review combined embolotherapy, sclerotherapy (embolo/sclerotherapy), and surgical procedures (surgical excision and soft tissue reconstruction) to manage vascular malformations. Treatments were principally induced to reduce pain, daily physical limitations, social discomfort and recover tegument continuity after ulceration.The 46 patients were first examined with noninvasive radiological procedures. After diagnosis was posed, embolo/sclerotherapy, surgical procedures and clinically as well as radiological follow-ups were coordinated and established by the multidisciplinary team. All vascular malformations were categorized according to the classification approved at the April 2014 General Assembly of International Society for the Study of Vascular Anomalies (ISSVA) in Melbourne, Australia. Arteriovenous malformations (AVMs) were further classified following the Cho-Do and Schobinger classification.Embolo/sclerotherapy shows to be the most appropriate procedure in vascular malformations treatment. Nevertheless was found that in case of complications or lack of improvement as well as to improve functional or aesthetical results, a following partial or complete surgical excision and immediate soft tissue reconstruction seems to be the gold-standard treatment. In addition, the precise clinical and radiological diagnosis as well as an intensive postoperative patient care have a significant positive influence on the clinical outcome and patient satisfaction while decreasing morbidity and recurrence during early and late follow-up.Vascular malformations require a multidisciplinary approach and individual treatment after complex excision and indispensable reconstruction.

Presentation of Original Research at the European Congress of Radiology 2010: Frequency of Publication in Medline-Indexed Journals Within 5 Years After Presentation

OBJECTIVES

 To determine the rate at which original studies presented orally at the European Congress of Radiology (ECR) 2010 were published in Medline-indexed journals and to identify factors predictive of publication.

METHODS

 A total of 869 abstracts were included in the study. A Medline search of articles published between March 2010 and February 2015 was conducted to identify articles written by the first, second, and/or last authors of all abstracts published in the Scientific Program of ECR 2010. The publication year, journal, country of origin, subspecialty and nature of the research (i. e., human, animal or technical) were recorded.

RESULTS

 Between March 2010 and February 2015 a total of 450 abstracts (publication rate, 51.8 %) were subsequently published in 125 Medline-indexed journals, chiefly in European Radiology (11.1 %). 443/450 (98.4 %) articles were published in English language. The subspecialties of molecular imaging and cardiac imaging had the highest publication rates (75.0 % and 62.0 %, respectively), while computer application studies had the lowest (27.6 %). The nature of research, origin of the abstract and subspecialty significantly influenced the subsequent publication rate.

CONCLUSION

 More than half of the original studies presented orally at ECR 2010 were subsequently published in Medline-indexed journals. More articles were published in the journal European Radiology than in any other identified journal.

KEY POINTS

  · ECR 2010 had a high subsequent publication rate. · Most subsequently published articles were published in radiology journals. · Nearly all articles were published in the English language.

CITATION FORMAT

· Dollinger M, Zeman F, Müller-Wille R et al. Presentation of Original Research at the European Congress of Radiology 2010: Frequency of Publication in Medline-Indexed Journals Within 5 Years After Presentation. Fortschr Röntgenstr 2017; 190: 327 - 333.

Impact of low dose settings on radiation exposure during pediatric fluoroscopic guided interventions

PURPOSE

To evaluate the effects of lowering the detector entrance exposure in children undergoing interventional radiology procedures.

MATERIALS AND METHODS

The study retrospectively investigated radiation dose levels in pediatric patients aged 0-18 years before (n = 39) and after (n = 26) lowering detector entrance dose, undergoing embolization of peripheral Arteriovenous malformations, Portal Vein Interventions or Percutaneous Transhepatic Cholangio Drainage (PTCD) between 2014 and 2017. Patient characteristics, fluoroscopy time, protocols used as well as resulting Skin Dose and Dose Area Product (DAP) were compared in each cohort. Image quality was assessed by two independent readers.

RESULTS

The two patient cohorts did not differ in terms of patient demographics. Similarly, fluoroscopy time did not differ before and after implementation of the low dose settings. An overall reduction of skin dose of 75.1% for AVM embolizations, 80.5% for Portal Vein Interventions and 85.3% for PTCD placement was observed. The DAP decrease was 82.5% for AVM embolizations, 72.2% for Portal Vein Interventions and 79.8% for PTCD placement. Image quality was generally considered to be good with an insignificant difference between pre and post implementation of the low dose approach and good agreement between the two readers. Manual inroom-switching to higher dose levels was possible, however this was not performed more frequently after implementation of the low dose settings.

CONCLUSION

Lowering the detector entrance dose in pediatric interventional radiology procedures results in a significant decrease of the radiation dose burden.

Vascular Anomalies (Part II): Interventional Therapy of Peripheral Vascular Malformations

BACKGROUND

 The International Society for the Study of Vascular Anomalies (ISSVA) categorizes vascular anomalies into vascular tumors and vascular malformations. Vascular malformations are further divided into slow-flow (venous, lymphatic, and capillary malformation) and fast-flow malformations (arteriovenous malformation and arteriovenous fistula). This interdisciplinary classification has therapeutic implications.

METHODS

 The objective of this article is to provide concise information about the current terminology and treatment strategies of peripheral vascular malformations, based on the currently available literature, with a focus on interventional therapy of venous malformations (VM), lymphatic malformations (LM), arteriovenous malformations (AVM) and arteriovenous fistulae (AVF).

RESULTS AND CONCLUSION

 Accurate classification is crucial for appropriate therapy of peripheral vascular malformations. Modern imaging technologies and refined interventional treatment strategies are now central parts in the multidisciplinary management of these patients. Slow-flow and fast-flow vascular malformations can be treated successfully by percutaneous sclerotherapy and endovascular embolotherapy as first-line interventions.

KEY POINTS

  · The ISSVA classification is essential for the correct diagnosis of vascular malformations. · The Schobinger classification as well as the Cho classification should be used for description of arteriovenous malformations (AVM). · Sclerotherapy and embolotherapy are the primary treatments of choice for vascular malformations.

CITATION FORMAT

· Müller-Wille R, Wildgruber M, Sadick M et al. Vascular Anomalies (Part II): Interventional Therapy of Peripheral Vascular Malformations. Fortschr Röntgenstr 2018; DOI: 10.1055/s-0044-101266.

Contrast-enhanced ultrasound to evaluate organ microvascularization after operative versus endovascular treatment of visceral artery aneurysms

PURPOSE

To evaluate the organ microvascularization after operative versus endovascular treatment of visceral artery aneurysms (VAAs) by contrast-enhanced ultrasound (CEUS) and colour-coded duplex sonography (CCDS).

METHOD AND MATERIALS

Between April 1995 to January 2016, 168 patients (78 males, 90 females; median age: 62 years) were diagnosed with VAAs at our hospital site. 60/168 patients (36%) fulfilled treatment criteria and had either open (29/60, 48%) or endovascular (31/60, 52%) aneurysm repair. Patients' characteristics and presentations were consecutively reviewed. Technical success and organ microvascularization were determined by CCDS/CEUS and correlated to computed tomography angiography (CTA) or magnetic resonance imaging (MRI).

RESULTS

18/60 patients (30%) presented with acute bleeding. 16/18 emergency patients (89%) were treated by endovascular means. After emergency treatment, two patients showed segmental liver malperfusion by CEUS and CTA. One small bowel resection had to be performed.42/60 patients (70%) were electively treated. 27/42 patients (64%) had open and 15/42 (36%) endovascular aneurysm repair. There were no liver or bowel infarctions after elective treatment of hepatic or mesenteric artery aneurysms (n = 13) in CCDS/CEUS and in CTA. Treatment of patients with splenic or renal artery aneurysms led to partial or complete organ loss in 42% (8/19) after operative and in 50% (5/10) after endovascular treatment (p < 0.05).

CONCLUSION

The endovascular approach is the preferred therapeutic option in emergency to control bleeding. In contrast to hepatic or mesenteric procedures, patients for elective splenic or renal artery aneurysm repair have to be evaluated very carefully because of a high rate of partial or complete organ loss demonstrated by CEUS - either after open or endovascular aneurysm repair.

Outcome of primary percutaneous stent-revascularization in patients with atherosclerotic acute mesenteric ischemia

Background Patients with acute mesenteric ischemia (AMI) often exhibit severe co-morbidities and significant surgical risks, leading to high perioperative morbidity. Purpose To investigate the feasibility of primary percutaneous stent-revascularization (PPSR) in atherosclerotic AMI and its impact on patients' outcome. Material and Methods Retrospective analysis of 19 consecutive patients (7 women, 12 men; median age, 69 years) with AMI caused by atherosclerotic, non-embolic stenoses/occlusions of the splanchnic arteries and PPSR. Alternative minimally invasive techniques were excluded. Clinical characteristics including the Charlson Comorbidity Index adjusted by age (CCIa) and symptom duration, technical and clinical success of PPSR, clinical course, 30-day mortality, and follow-up were evaluated and compared to literature data for surgical approaches. Technical success was defined as residual stenosis of <30% in diameter. Clinical success was defined as resolution of symptoms of AMI and/or normalization of serum lactate after sole PPSR. Results The majority of patients presented with severe co-morbidities (CCIa >4 in 17 of 19 patients, 89%). Median symptom duration was 50 h. Technical and clinical success rates of PPSR were 95% (21 of 22 arteries) and 53% (10 of 19 patients). Seven patients underwent subsequent laparotomy with bowel resection in four cases. Thirty-day mortality was 42% (8 of 19 patients). Conclusion In our study population of patients with atherosclerotic AMI, severe co-morbidities, prolonged acute symptoms, and significant perioperative risks PPSR of splanchnic stenoses were technically feasible and the clinical outcome was acceptable.

Direct Effective Dose Calculations in Pediatric Fluoroscopy-Guided Abdominal Interventions with Rando-Alderson Phantoms - Optimization of Preset Parameter Settings

Objective

The aim of the study was to calculate the effective dose during fluoroscopy-guided pediatric interventional procedures of the liver in a phantom model before and after adjustment of preset parameters.

Methods

Organ doses were measured in three anthropomorphic Rando-Alderson phantoms representing children at various age and body weight (newborn 3.5kg, toddler 10kg, child 19kg). Collimation was performed focusing on the upper abdomen representing mock interventional radiology procedures such as percutaneous transhepatic cholangiography and drainage placement (PTCD). Fluoroscopy and digital subtraction angiography (DSA) acquisitions were performed in a posterior-anterior geometry using a state of the art flat-panel detector. Effective dose was directly measured from multiple incorporated thermoluminescent dosimeters (TLDs) using two different parameter settings.

Results

Effective dose values for each pediatric phantom were below 0.1mSv per minute fluoroscopy, and below 1mSv for a 1 minute DSA acquisition with a frame rate of 2 f/s. Lowering the values for the detector entrance dose enabled a reduction of the applied effective dose from 12 to 27% for fluoroscopy and 22 to 63% for DSA acquisitions. Similarly, organ doses of radiosensitive organs could be reduced by over 50%, especially when close to the primary x-ray beam.

Conclusion

Modification of preset parameter settings enabled to decrease the effective dose for pediatric interventional procedures, as determined by effective dose calculations using dedicated pediatric Rando-Alderson phantoms.

The Influence of Preoperative Aneurysmal Thrombus Quantity and Distribution on the Development of Type II Endoleaks with Aneurysm Sac Enlargement After EVAR of AAA

PURPOSE

To determine the influence of preoperative aneurysmal thrombus quantity and distribution on the development of type II endoleak with aneurysm sac enlargement after endovascular aneurysm repair (EVAR).

MATERIALS AND METHODS

We retrospectively analyzed the pre- and postoperatively performed CT scans of 118 patients who had follow-up imaging for at least 1 year after EVAR available. We assessed preoperative thrombus perimeter (T Peri), diameter (T Dia), cross-sectional area (T CSA), and volume (T Vol). The preoperative thrombus distribution was classified into no thrombus, semilunar-shaped (anterior, right side, left side, posterior) thrombus, and circumferential type thrombus. The number of preoperative patent aortic side branches (ASB) was identified. Endpoint was type II endoleak with aneurysm volume (A Vol) increase of ≥5 % during follow-up.

RESULTS

During follow-up (2 years, range 1-9 years), 17 patients with type II endoleak had significant A Vol increase. Less preoperative T Peri, T Dia, T CSA, and T Vol were associated with A Vol increase. A circumferential thrombus distribution significantly protected against aneurysm enlargement (p = 0.028). The variables with the strongest significance for A Vol increase were preoperative T Vol/A Vol ratio (OR 0.95; p = 0.037) and number of patent ASB (OR 3.52; p < 0.001).

CONCLUSION

A low preoperative T Vol/A Vol ratio and a high number of patent ASB were associated with aneurysm sac enlargement after EVAR.

Irreversible Electroporation of Malignant Hepatic Tumors--Alterations in Venous Structures at Subacute Follow-Up and Evolution at Mid-Term Follow-Up

Purpose

To evaluate risk factors associated with alterations in venous structures adjacent to an ablation zone after percutaneous irreversible electroporation (IRE) of hepatic malignancies at subacute follow-up (1 to 3 days after IRE) and to describe evolution of these alterations at mid-term follow-up.

Materials and Methods

43 patients (men/women, 32/11; mean age, 60.3 years) were identified in whom venous structures were located within a perimeter of 1.0 cm of the ablation zone at subacute follow-up after IRE of 84 hepatic lesions (primary/secondary hepatic tumors, 31/53). These vessels were retrospectively evaluated by means of pre-interventional and post-interventional contrast-enhanced magnetic resonance imaging or computed tomography or both. Any vascular changes in flow, patency, and diameter were documented. Correlations between vascular change (yes/no) and characteristics of patients, lesions, and ablation procedures were assessed by generalized linear models.

Results

191 venous structures were located within a perimeter of 1.0 cm of the ablation zone: 55 (29%) were encased by the ablation zone, 78 (41%) abutted the ablation zone, and 58 (30%) were located between 0.1 and 1.0 cm from the border of the ablation zone. At subacute follow-up, vascular changes were found in 19 of the 191 vessels (9.9%), with partial portal vein thrombosis in 2, complete portal vein thrombosis in 3, and lumen narrowing in 14 of 19. At follow-up of patients with subacute vessel alterations (mean, 5.7 months; range, 0 to 14 months) thrombosis had resolved in 2 of 5 cases; vessel narrowing had completely resolved in 8 of 14 cases, and partly resolved in 1 of 14 cases. The encasement of a vessel by ablation zone (OR = 6.36, p<0.001), ablation zone being adjacent to a portal vein (OR = 8.94, p<0.001), and the usage of more than 3 IRE probes (OR = 3.60, p = 0.035) were independently associated with post-IRE vessel alterations.

Conclusion

Venous structures located in close proximity to an IRE ablation zone remain largely unaffected by this procedure, and thrombosis is rare.

CT features of early type II endoleaks after endovascular repair of abdominal aortic aneurysms help predict aneurysm sac enlargement

PURPOSE

To determine computed tomographic (CT) features of early type II endoleaks associated with aneurysm sac enlargement after endovascular aortic aneurysm repair (EVAR) of abdominal aortic aneurysm.

MATERIALS AND METHODS

Institutional review board approval was not required for this retrospective study. The authors reviewed imaging and clinical data from 56 patients (seven women, 49 men; mean age ± standard deviation, 71 years ± 7.9; age range, 52-85 years) with early type II endoleak who had undergone EVAR between December 2002 and December 2011 and who had been followed up with imaging and clinical evaluation for at least 6 months. The number and diameter of all feeding and/or draining arteries were measured, and endoleaks were classified according to their sources into simple inferior mesenteric artery (IMA), simple lumbar artery (LA), complex LA, and complex IMA-LA type II endoleaks. Volume and attenuation of the nidus were measured. Aneurysm enlargement was defined as an increase in the aneurysm volume of more than 5% during follow-up. Simple and multivariate logistic regression analyses were performed to identify independent clinical and imaging variables associated with aneurysm enlargement.

RESULTS

Twenty-three of the 56 patients (41%) showed aneurysm sac enlargement during follow-up (mean follow-up, 3.0 years ± 2.0). With the multivariate model, the variables that showed the strongest indicators for aneurysm sac enlargement were complex IMA-LA type II endoleak (odds ratio [OR] = 10.29, P = .004) and the diameter of the largest feeding and/or draining artery (OR = 4.55, P = .013). Patients without complex IMA-LA type II endoleak in whom the largest feeding and/or draining artery was larger than 3.8 mm and patients with a complex IMA-LA type II endoleak in whom the largest feeding and/or draining artery was larger than 2.2 mm were at high risk for aneurysm sac enlargement.

CONCLUSION

The strongest indicators for aneurysm sac enlargement are complex IMA-LA type II endoleak and the diameter of the largest feeding and/or draining artery.