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.

Sequential CT arterioportography-arteriosplenography depicts individual haemodynamic changes in children with portal hypertension without cirrhosis

We evaluated sequential computed tomography (CT) arterioportography-arteriosplenography for the assessment of venous pathways in children with portal hypertension without cirrhosis. Institutional Review Board approval was obtained for this retrospective, single-centre study. CT was performed after contrast application via catheters placed in the superior mesenteric artery (CT arterioportography) and the splenic artery (CT arteriosplenography) consecutively. Venous pathways in 22 children were evaluated. In all patients, the detailed haemodynamic consequences of portal hypertension could be characterised. The supply of varices at different locations could be assigned to the superior mesenteric vein or splenic vein system. Retrograde blood flow through the splenic vein and inferior mesenteric vein, portosystemic shunting, and patency of splanchnic veins were determined. CT arterioportography-arteriosplenography allowed a complete evaluation of individual haemodynamic pathways in children with portal hypertension.

Congenital Disseminated Pyogenic Granuloma: Characterization of an Aggressive Multisystemic Disorder

OBJECTIVE

To describe the clinical, radiologic, and histopathologic features of "congenital disseminated pyogenic granuloma" involving various organs with high morbidity related to cerebral hemorrhagic involvement.

STUDY DESIGN

We searched the database of the Vascular Anomalies Center at Boston Children's Hospital from 1999 to 2019 for patients diagnosed as having multiple vascular lesions, visceral vascular tumors, congenital hemangiomatosis, multiple pyogenic granulomas, or multiple vascular lesions without a definite diagnosis. A retrospective review of the medical records, photographs, histopathologic, and imaging studies was performed. Only patients with imaging studies and histopathologic diagnosis of pyogenic granuloma were included.

RESULTS

Eight children (5 male, 3 female) had congenital multifocal cutaneous vascular tumors. Lesions also were found in the brain (n = 7), liver (n = 4), spleen (n = 3), muscles (n = 4), bone (n = 3), retroperitoneum (n = 3), and intestine/mesentery (n = 2). Less commonly affected were the spinal cord, lungs, kidneys, pancreas, and adrenal gland (n = 1 each). The mean follow-up period was 21.8 months. The cerebral and visceral lesions were hemorrhagic with severe neurologic sequelae. The histopathologic diagnosis was pyogenic granuloma with prominent areas of hemorrhage and necrosis. The endothelial cells had enlarged nuclei, pale cytoplasm and were immunopositive for CD31 and negative for D2-40 and glucose transporter 1.

CONCLUSIONS

Congenital disseminated pyogenic granuloma is a distinct multisystemic aggressive disorder that primarily affects the skin, brain, visceral organs, and musculoskeletal system. Differentiation of this entity from other multiple cutaneous vascular lesions is critical because of possible cerebral hemorrhagic involvement.

3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo

PURPOSE

 To assess morphological and hemodynamic characteristics of peripheral vascular malformations on 3 T magnetic resonance imaging (MRI) including qualitative comparison of two fat-saturated sequences: short tau inversion recovery (STIR) and three-dimensional high-resolution volume interpolated gradient recalled echo (GRE).

MATERIALS AND METHODS

 During 9 months, 100 patients with suspected or known vascular malformations were prospectively assessed on a 3 T scanner using T2-weighted STIR and turbo spin echo (TSE), T1-weighted TSE, time-resolved contrast-enhanced magnetic resonance angiography (MRA) with interleaved stochastic trajectories (TWIST) and T1-weighted volume interpolated breath-hold examination (VIBE) after contrast enhancement. The analysis included signal behavior and morphologic and hemodynamic characteristics. Additionally, the image quality of the fat-saturated sequences was evaluated by 2 radiologists.

RESULTS

 86 patients (14 dropouts; 57 female, 29 male; mean age 26.8 years, age range 1-56) were analyzed. 22 had high-flow and 64 low-flow malformations, including 14 with a lymphatic component. In 21 of 22 patients with high-flow malformations, typical characteristics (flow voids, hyperdynamic arteriovenous fistula, dilated main/feeder-arteries and draining veins) were documented. Patients with low-flow malformations had phleboliths in 35 cases, fluid-fluid levels in 47 and dilated draining veins in 23. Lymphatic malformations showed peripheral contrast enhancement of cyst walls in the volume interpolated GRE. The comparison of fat-saturated sequences showed significantly better results of the volume interpolated GRE in all categories except the presence of artifacts which were significantly reduced in the STIR (p < 0.05).

CONCLUSION

 3 T MRI with MRA provides detailed morphological and hemodynamic information of different types of peripheral vascular malformations. Contrast-enhanced high-resolution volume interpolated GRE proved superior to STIR in differentiating morphologic features and to be diagnostic in the differentiation of lymphatic parts and joint involvement.

KEY POINTS

  · 3 T MRI with MRA offers detailed information about vascular malformations.. · Fat-saturated MRI provides especially information about morphological characteristics, extent and tissue involvement.. · Volume interpolated GRE proved superior in almost all categories compared to STIR.. · Volume interpolated GRE showed more artifacts.. · Volume interpolated GRE additionally allows differentiation of lymphatic parts and evaluation of joint involvement..

CITATION FORMAT

· Höhn F, Hammer S, Fellner C et al. 3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo. Fortschr Röntgenstr 2021; 193: 446 - 458.

Fast TWIST with iterative reconstruction improves diagnostic accuracy of AVM of the hand

Very high temporal and spatial resolution is mandatory for the diagnosis of arteriovenous malformations (AVM) of the hand. Until now, magnetic resonance imaging (MRI) has not fulfilled both requirements simultaneously. This study presents how the combination of a very fast TWIST MRI (time-resolved angiography with interleaved stochastic trajectories) sequence and iterative reconstructions optimizes temporal as well as spatial resolution. 11 patients were examined at a 3-T MRI scanner with two different TWIST protocols: the standard and the study protocol, acquiring a data set every 5.57 s and 1.44 s respectively. The study data was retrospectively iteratively reconstructed with different regularization factors (0.001, 0.002, 0.004, 0.008). Results were compared using the sign-test. P-values < 0.05 were regarded statistically significant. With a low amount of contrast medium, the temporal resolution of the study protocol enabled the differentiation of arteries from veins in all patients whereas the signal-to-noise ratio (SNR) deteriorated. Depending on the regularization factors, SNR, delineation of arterial feeders and non-involved hand and interdigital arteries, as well as artefact levels varied. Overall, iterative reconstruction with regularization factor 0.004 achieved the best results, consequently showing the ability of MRI as a reliable diagnostic method in AVMs of the hand.

[Diagnostic Criteria and Treatment of Hereditary Hemorrhagic Telangiectasia]

Hereditary hemorrhagic telangiectasia (HHT; Osler-Weber-Rendu syndrome; Morbus Osler) represents a syndrome affecting capillary vessels, leading to arteriovenous shunting. With an average worldwide prevalence of 1:5.000-8.000 HHT is considered an orphan disease. Arteriovenous shunts involve predominantly the nasal mucosa, the intestine, lung, liver and central nervous system. Epistaxis is the primary and most bothersome complaint of patients with HHT. A multistage therapeutic concept includes nasal ointment, laser therapy under local anesthesia and surgery under general anesthesia, as well as drug therapies. In addition, screening to determine affection of internal organs is carried out. Lesions that require therapy should be treated in an interdisciplinary setting. Treatment of lesions of the skin, oral and gastrointestinal mucosa and liver is carried out in regard to patients' symptoms, whereas vascular malformations of the lung and brain might need treatment without being symptomatic, due to possible life-threatening complications.

Contrast-enhanced ultrasound with perfusion analysis in patients with venous malformations before and after percutaneous treatment with ethanol-gel

INTRODUCTION

Percutaneous sclerotherapy is a well-established treatment option for venous malformations (VM). A recently established sclerosing agent is ethanol-gel. Aim of this study was to identify, if contrast-enhanced ultrasound (CEUS) with an integrated perfusion analysis allows for differentiation between untreated VM, healthy tissue, and with gelified ethanol treated malformation tissue.

MATERIAL AND METHODS

In this institutional review board approved prospective study symptomatic VM patients underwent CEUS at exactly the same position before and after sclerotherapy with ethanol-gel. Two experienced sonographers performed all examinations after the bolus injection of microbubbles using a multi-frequency probe with 6 -9 MHz of a high-end ultrasound machine. An integrated perfusion analysis was applied in the center of the VM and in healthy, surrounding tissue. For both regions peak enhancement (peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT) were evaluated. Wilcoxon signed rank test was executed; p-values <0.05 were regarded statistically significant.

RESULTS

In 23 patients including children (mean age 25.3 years, 19 females) before treatment all identified parameters were significantly higher in the VM center compared to healthy tissue (peak: p < 0.01; TTP: p < 0.01; AUC: p < 0.01; MTT: p < 0.01). Comparing the VM center before and after treatment, TTP (p < 0.02) and MTT (p < 0.01) reduced significantly after sclerotherapy. In surrounding tissue only peak changed after treatment in comparison to pre-treatment results (p = 0.04). Comparing data in the VM center with surrounding tissue after sclerotherapy, results still differed significantly for peak (p < 0.01), TTP (p < 0.01), and AUC (p < 0.01), but assimilated for MTT (p = 0.07).

CONCLUSION

All with CEUS identified parameters seem to be excellent tools for differentiating between VM and healthy tissue. TTP and MTT could distinguish between with ethanol-gel sclerotized VM portions and untreated malformation parts and thereby might assist the monitoring of sclerotherapy with ethanol-gel.

Complicated chylous pericardial and thoracic effusion as the first clinical manifestation of thoracic lymphatic malformation

Lymphatic malformations are benign focal proliferations of lymphatic vessels with a congenital origin. We present a case of an 18-year-old patient with post-traumatic chylopericardium and recurrent left-sided chylothorax, who was unresponsive to a variety of therapeutic measures until he was diagnosed with a complicated thoracic lymphatic malformation.

Author Correction: Rectosigmoidal manifestations of venous malformations: MR imaging findings and interdisciplinary therapeutic modalities

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

[Management of Visceral Artery Aneurysms with Preservation of Organ Perfusion: More Than Twenty Years Experience]

BACKGROUND

Visceral artery aneurysms (VAA) are rare and often incidental findings. Indications for treatment are symptomatic patients, pseudoaneurysms and a true aneurysm of diameter of ≥ 2.5 cm for mesenteric arteries and ≥ 3 cm for renal artery aneurysms. Pregnancy and liver transplantation play an important role in aneurysm rupture. Technical success after open or endovascular procedure and maintenance of organ perfusion are crucial. The aim of this review is to evaluate our data and experience of more than 20 years and to develop a strategy to deal with visceral artery aneurysm in elective and emergency cases.

PATIENTS

Between 1995 and 2018, 179 patients (84 males, 95 females, median age 62 [18 - 87] years) were diagnosed with VAA at the Regensburg University Hospital. The site of aneurysm was the splenic artery in 113 (63%) patients (pts), hepatic and renal arteries in 22 and 21 pts (12% each), and gastropancreaticoduodenal artery in 14 (8%) and superior/inferior mesenteric artery in 9 (5%) cases. Surveillance without intervention occurred in 110 (62%) pts, and 34 (19%) pts underwent open and 35 (19%) endovascular repair. In all patients, preoperative imaging was performed, preferably by computed tomography angiography (CTA).

RESULTS

A total of 69 patients underwent open or endovascular repair. 51 (74%) pts were treated electively, 18 (26%) pts presented urgently with acute bleeding. 16 emergency pts received endovascular treatment, and in 2 pts open surgery was performed. After emergency treatment, two pts exhibited segmental liver malperfusion without consequences. In one case, segmental bowel resection was necessary. 32/51 (63%) patients were treated electively by open surgery, 19/51 (37%) by endovascular procedures. There were no liver or bowel infarctions. Four splenectomies and one unilateral nephrectomy were necessary in patients with splenic or renal artery aneurysms. Moreover, three partial renal infarctions were noticed postoperatively (overall 8/21 [38%]). After endovascular repair of splenic or renal artery aneurysms, two cases of splenic and three cases of renal segmental infarction were observed. Splenectomy had to be performed twice (overall 7/14 [50%]). Organ perfusion was monitored by CTA, and preferentially by contrast enhanced ultrasound.

CONCLUSION

The endovascular approach is the preferred option in an emergency to control bleeding in pseudoaneurysms. Patients for elective splenic or renal artery aneurysm repair have to be evaluated very carefully to achieve technical success with occlusion of the aneurysm and excellent organ perfusion. Imaging techniques such as ultrasound, especially CEUS, are strongly recommended in postoperative follow-up. Partial or complete splenic infarction leads to vaccination.

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.

Preoperative Embolization of Venous Malformations Using n-Butyl Cyanoacrylate

Purpose:

The purpose of this study was to evaluate the safety and efficacy of preoperative percutaneous n-butyl cyanoacrylate (nBCA) embolization of venous malformations in children.

Material and Methods:

Clinical data were retrospectively reviewed in children who underwent embolization using nBCA followed by resection of venous malformations.

Results:

A total of 17 embolizations were performed in 14 patients (9 females, mean age: 5.5 years; median age: 3 years; range 0.1-16 years). The venous malformations involved the lower extremity and the knee joint (n = 7), the trunk (n = 4), head and neck (n = 2), and hand (n = 1). n-Butyl cyanoacrylate was diluted with iodized oil at a ratio of 1:3 to 1:5. The mean and median volume of nBCA per procedure were 2.1 and 2 mL, respectively (range: 0.5-8 mL). There were no complications associated with the procedures. The mean and median time between final embolization and resection were 3.6 and 2 days, respectively. All children underwent successful resection of the symptomatic lesions. The estimated mean and median blood loss were 75 and 50 mL, respectively (range: 5-350 mL). The postprocedure course was uneventful, the days to discharge ranged between 1 and 6 days (mean 3 days).

Conclusion:

Initial results suggest that preoperative percutaneous n-butyl cyanoacrylate embolization of venous malformations is safe and effective in children, with the potential for minimizing blood loss and inpatient stay.

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.

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.

Interventional Removal of Intravascular Medical Devices: Methods and Technical Success

PURPOSE

Evaluation of the technical success rate and complications when retrieving dislocated intravascular foreign bodies.

MATERIAL AND METHODS

Between 1999 and 2015 38 patients (21 female; 17 male; Age: 17 - 92; Average 54.3 years) underwent an extraction of intravascular dislocated foreign bodies, which were not lost during a radiological intervention. The extracted material included 29 port catheters, 3 tips of tunneled dialysis catheters, 2 stents, 2 guide wires, 1 CVC tip and 1 AS occluder device. Various catheters for repositioning and extraction were used. The access was transarterial as well as transvenous. Technical success was defined as complete removal of the foreign body.

RESULTS

The technical success rate was 92.1 % (35 of 38). In 17 patients an additional catheter was necessary to reposition the foreign body in order to make it accessible for the extraction catheter. In one case a stent was relocated and remodeled within the patient and was not extracted. In another case we experienced a dislocation of a small fragment of the port catheter into the distal parts of the pulmonary artery, which couldn't be extracted. A guide wire could not be extracted as it was already adhered with the vessel wall. Peri-interventional complications were not documented.

CONCLUSION

The percutaneous extraction of dislocated intravascular foreign bodies is technically successful and poor of complications. Interventional therapy can avoid surgical removal.

KEY POINTS

• The percutaneous extraction of dislocated intravascular foreign bodies is technically successful and safe.• In most cases surgical removal can be avoided.• The gooseneck-snare catheter was mainly used for the extraction of intravascular foreign bodies. Citation Format: • Ayx I, Goessmann H, Hubauer H et al. Interventional Removal of Intravascular Medical Devices: Methods and Technical Success. Fortschr Röntgenstr 2016; 188: 566 - 573.

Lymphatic and other vascular malformative/overgrowth disorders are caused by somatic mutations in PIK3CA

OBJECTIVES

To test the hypothesis that somatic phosphatidylinositol-4,5-bisphospate 3-kinase, catalytic subunit alpha (PIK3CA) mutations would be found in patients with more common disorders including isolated lymphatic malformation (LM) and Klippel-Trenaunay syndrome (KTS).

STUDY DESIGN

We used next generation sequencing, droplet digital polymerase chain reaction, and single molecule molecular inversion probes to search for somatic PIK3CA mutations in affected tissue from patients seen at Boston Children's Hospital who had an isolated LM (n = 17), KTS (n = 21), fibro-adipose vascular anomaly (n = 8), or congenital lipomatous overgrowth with vascular, epidermal, and skeletal anomalies syndrome (n = 33), the disorder for which we first identified somatic PIK3CA mutations. We also screened 5 of the more common PIK3CA mutations in a second cohort of patients with LM (n = 31) from Seattle Children's Hospital.

RESULTS

Most individuals from Boston Children's Hospital who had isolated LM (16/17) or LM as part of a syndrome, such as KTS (19/21), fibro-adipose vascular anomaly (5/8), and congenital lipomatous overgrowth with vascular, epidermal, and skeletal anomalies syndrome (31/33) were somatic mosaic for PIK3CA mutations, with 5 specific PIK3CA mutations accounting for ∼ 80% of cases. Seventy-four percent of patients with LM from Seattle Children's Hospital also were somatic mosaic for 1 of 5 specific PIK3CA mutations. Many affected tissue specimens from both cohorts contained fewer than 10% mutant cells.

CONCLUSIONS

Somatic PIK3CA mutations are the most common cause of isolated LMs and disorders in which LM is a component feature. Five PIK3CA mutations account for most cases. The search for causal mutations requires sampling of affected tissues and techniques that are capable of detecting low-level somatic mosaicism because the abundance of mutant cells in a malformed tissue can be low.

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.