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.

Kidney Failure After Occlusion of Accessory Renal Arteries in Endovascular Abdominal Aneurysm Repair.

PURPOSE: To evaluate the incidence of acute renal failure and chronic kidney disease due to occlusion of accessory renal arteries during endovascular aneurysm repair of infrarenal abdominal aortic aneurysm. MATERIAL AND METHODS: We retrospectively reviewed the course of 181 patients (mean age, 71, SD ± 9  years) who underwent EVAR of infrarenal abdominal aortic aneurysm. The renal vessel anatomy was analyzed in all pre- and postoperative CT scans. Diameter and origin of accessory renal arteries were evaluated. Renal function was determined by pre- and postoperative serum creatinine and eGFR levels. Long-term follow-up (>3 months) of patients was available in 121 cases (66.9%). Acute kidney injury and chronic kidney failure were defined according to guidelines of "Kidney Disease: Improving Global Outcomes" (KDIGO). RESULTS: In 65 of 181 patients (33.9%), 82 accessory renal arteries were identified preoperatively. In 19 of 181 patients (10.5%), one or more accessory renal arteries were covered and subsequently occluded by the implanted stent-graft device. Neither acute kidney injury (10.3% vs 12.5%; p = .785) nor chronic kidney disease (10.7% vs 15.38%; p = .452) was detected significantly more often in patients with covered accessory renal artery. The only significant predictor of acute kidney injury was the preoperative serum creatinine level (1.12 mg/dl vs. 0.98 mg/dl; p = .03). Significant predictors for chronic kidney disease were preoperative serum creatinine, eGFR, and impaired renal function (p < .001). CONCLUSION: Coverage of accessory renal artery due to stent-graft does not lead either to temporary acute kidney injury after endovascular aneurysm repair or to chronic kidney disease. LEVEL OF EVIDENCE: Level II b.

Radiofrequency Ablation of the Marginal Venous System in Patients with Venous Malformations.

PURPOSE: To evaluate radiofrequency ablation (RFA) for closure of marginal veins in pediatric and adult patients with venous malformations. MATERIALS AND METHODS: Medical records, imaging and procedure details were retrospectively reviewed in patients who underwent RFA of the marginal vein in a 17-month period. Additional sclerotherapy (n = 19) and coil embolization of the marginal vein were performed (n = 2). RESULTS: A total of 23 marginal veins were treated in 20 patients. Mean age at treatment was 16 years ± 9.4 (1-37 years). Pre-procedural magnetic resonance imaging revealed thoracoabdominal marginal veins in 3 patients. A type I marginal vein (draining in the great saphenous vein below the popliteal vein) was identified in 1 and type IIa/IIb (draining in a median/lateral accessory saphenous vein) in 2/8 cases. Type III (draining into the profunda femoral vein) was detected in 8, and type IV (draining into gluteal veins) in 1. Mean diameter of the marginal veins was 13.2 mm ± 4 (7-20 mm). Patency was found in 1 during follow-up (22 months ± 9.8). Complete or partial occlusion was achieved in 94.5% of the veins. One patient showed signs of thrombophlebitis after the procedure, and another incomplete paresis of the peroneal nerve. CONCLUSION: RFA is effective as minimally invasive treatment of the marginal venous system. These veins should be treated early in life. Marginal veins with large diameter, residual tributaries and the intrafascial courses usually require adjunct coil embolization and sclerotherapy. LEVEL OF EVIDENCE: Case series, Level IV.

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.

Value of different ultrasound elastography techniques in patients with venous malformations prior to and after sclerotherapy.

AIM: Comparison of different ultrasound elastography techniques for detection of changes after sclerotherapy within venous malformations. MATERIAL AND METHODS: In patients with venous malformations sonography was executed at exactly the same position prior to and after ethanol-gel sclerotherapy. Both examinations included B-Mode, vascular sonography with Color-Coded Duplex Sonography, and additional sonography with different elastography techniques (strain, qualitative and quantitative Acoustic Radiation Force Impulse (ARFI) elastography) with a linear transducer (6-9 MHz). Qualitative elastograms were read in consensus and scored. Differences of elasticity scores were statistically analyzed, p-values <0.05 were regarded significant. RESULTS: Elasticity scores of strain and qualitative ARFI elastography in 25 patients (21 females, averagely 24.4 years old) were comparable before treatment (p = 0.69). After therapy qualitative ARFI scores changed significantly compared to pre-treatment scores (p = 0.0017), whereas strain elastography scores revealed no significant changes (p = 0.13). Quantitative ARFI values obtained after sclerotherapy within the venous malformations were significantly higher compared to pre-treatment values (p = 0.049), and significantly higher to values obtained in surrounding tissue (p = 0.030). Comparison of pre- and post-treatment ARFI values of the surrounding tissue was not significant (p = 0.67). CONCLUSION: Elasticity scores of qualitative ARFI elastography reliably detect ethanol-gel induced changes in venous malformations. Quantitative ARFI may be a tool for therapy planning, and for monitoring sclerotherapy outcome as well as the effect of sclerosing agents on malformation and surrounding tissue in patients with venous malformations.

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.

Percutaneous treatment of symptomatic superior mesenteric vein stenosis using self-expanding nitinol stents.

PURPOSE: To evaluate the technical and clinical success of percutaneous superior mesenteric vein (SMV) stenting in symptomatic patients using self-expanding nitinol stents. METHODS: We retrospectively analyzed the technical and clinical success of percutaneous SMV stenting of 6 symptomatic patients (3 men, mean age 67 years, range 48-81 years). Stenosis of the SMV was caused by postoperative stricture (n=3), pancreas carcinoma (n=1) and pancreatitis (n=2). As a result of the stenosis, 3 patients had symptomatic ascites, 2 patients showed signs of mesenteric ischemia and 1 patient had recurrent gastrointestinal bleeding. Stenting was performed by a percutaneous transhepatic approach using self-expanding nitinol stents. RESULTS: Stenting of the SMV was technically and clinically successful in all patients. No peri-interventional complications occurred. The stent diameters ranged from 6 to 14 mm. During the mean follow-up of 6 months (range, 2-10 months) 1 patient presented early stent occlusion 2 weeks after placement. CONCLUSION: Stenting of a symptomatic SMV stenosis using self-expanding nitinol stents is feasible and clinically effective.

Dual-energy computed tomography after endovascular aortic aneurysm repair: the role of hard plaque imaging for endoleak detection.

OBJECTIVES: To assess the diagnostic accuracy of dual-energy computed tomography (DECT) for detection of endoleaks and aneurysm sac calcifications after endovascular aneurysm repair (EVAR) using hard plaque imaging algorithms. MATERIALS AND METHODS: One hundred five patients received 108 triple-phase contrast-enhanced CT (non-contrast, arterial and delayed phase) after EVAR. The delayed phase was acquired in dual-energy and post-processed using the standard (HPI-S) and a modified (HPI-M) hard plaque imaging algorithm. The reference standard was determined using the triple-phase CT and contrast-enhanced ultrasound. All images were analysed separately for the presence of endoleaks and calcifications by two independent readers; sensitivity, specificity and interobserver agreement were calculated. RESULTS: Endoleaks and calcifications were present in 25.9 % (28/108) and 20.4 % (22/108) of images. The HPI-S images had a sensitivity/specificity of 54 %/100 % (reader 1) and 57 %/99 % (reader 2), the HPI-M images of 93 %/92 % (reader 1) and 96 %/92 % (reader 2) for detection of endoleaks. For detection of calcifications HPI-S had a sensitivity/specificity of 91 %/99 % (reader 1) and 95 %/97 % (reader 2), the HPI-M images of 91 %/99 % (reader 1) and 91 %/99 % (reader 2), respectively. CONCLUSION: Using HPI-M, DECT enables an accurate diagnosis of endoleaks after EVAR and allows distinguishing between endoleaks and calcifications with high diagnostic accuracy. KEY POINTS: • Dual-energy computed tomography allows the diagnosis of aortic pathologies after EVAR. • Hard plaque imaging algorithms can distinguish between endoleaks and aneurysm sac calcifications. • The modified hard plaque imaging algorithm detects endoleaks with high diagnostic accuracy.

Gelfoam for closure of large percutaneous transhepatic and transsplenic puncture tracts in pediatric patients.

PURPOSE: Evaluation of the efficacy and safety of Gelfoam for the closure of transhepatic or transsplenic parenchymal puncture tracts with large-bore sheaths in pediatric patients. MATERIALS AND METHODS: Between January 2012 and May 2013, 8 percutaneous transhepatic accesses and 3 percutaneous transsplenic accesses were closed using percutaneous Gelfoam in pediatric patients. The primary study endpoints to determine treatment efficacy and safety were patient survival, technical success defined as successful closure of the puncture tract without signs of bleeding, and complication rates. The secondary study endpoints were the occurrence of local and systemic inflammation. RESULTS: Overall survival was 100 % with a median follow-up of 256 days. The procedure was technically successful in 10 of 11 procedures. One patient suffered from bleeding, which was successfully managed by a single blood transfusion. No re-bleeding was detected during follow-up and no surgical interventions were necessary. No signs of local or systemic infections related to the Gelfoam application occurred. CONCLUSION: Percutaneous Gelfoam application is an effective and safe technique for the closure of transhepatic or transsplenic accesses in pediatric patients. KEY POINTS: Interventional closure of large transhepatic and transsplenic parenchymal accesses in children after interventional treatment is recommended to avoid bleeding. Gelfoam application does not cause artifacts in magnetic resonance imaging and does not increase the risk of local or systemic inflammation in comparison to permanent embolic agents. Thus, especially children under immunosuppressive therapy can benefit from the application of Gelfoam.

Interobserver Agreement in MR Enterography for Diagnostic Assessment in Patients with Crohn's Disease.

PURPOSE: To evaluate the extent to which MRE can be used as an observer-independent, objective imaging method for the diagnosis and evaluation of CD with respect to the detection of inflammatory changes of the small bowel and lymphadenopathy as diagnostic criterion and bowel distension as a quality criterion. MATERIALS AND METHODS: MRE scans of 84 patients (42 female, median age 37 years) were evaluated independently by 4 experienced radiologists. Analysis of inflammatory changes of the bowel wall, lymphadenopathy and adequate bowel distension was conducted separately for the jejunum, ileum and terminal ileum. The Kendall's W-test was used for the statistical comparison of concordance. RESULTS: In a total of 55 patients, inflammatory activity of the bowel wall was detected and MRE was found to have a high interobserver reproducibility concerning inflammatory changes of the intestinal wall (Kendall's W 0.527 - 0.823). Concerning lymphadenopathy (31 cases, 36.9 %), a low to moderate consensus could be shown with a Kendall's W value of 0.402 - 0.505. For the assessment of adequate bowel distension, a moderate concordance between the operators could be found (Kendall's W 0.497 - 0.581). CONCLUSION: MRE has proven high interobserver agreement with respect to the diagnosis of inflammatory disease activity of the bowel as a diagnostic criterion in patients with CD. Concerning adequate bowel distension as a quality criterion of the examination itself and lymphadenopathy as a diagnostic criterion, moderate interobserver agreement could be found. This is thought to have a rather small effect on the diagnostic significance and conclusiveness of the method in the daily routine. KEY POINTS: ▶ MR enterography as observer independent diagnostic procedure in patients with Chron's Disease. ▶ Highest interobserver concordance for the criterion of inflammatory bowel wall affection. ▶ Moderate interobserver concordance for lymphadenopathy and bowel distension.

Percutaneous management of postoperative bile leaks with an ethylene vinyl alcohol copolymer (Onyx).

PURPOSE: The management of postoperative bile leakage is challenging especially if the leak rises from the cut surface of the liver and endoscopic treatment fails. Percutaneous transhepatic treatment of bile leaks with biliary drainage is accepted but often requires long-term placement of the drains and is associated with treatment failures. This series evaluates selective embolization of bile ducts with an ethylene vinyl alcohol copolymer (Onyx) in patients with postoperative bile leaks as an alternative treatment option. MATERIALS AND METHODS: Between January and September 2012, five consecutive patients with persistent postoperative bile leaks underwent percutaneous transhepatic Onyx application and were analyzed regarding procedural management, complications and success rates. RESULTS: The persistent bile leaks were situated at the cystic stump (after cholecystectomy, n = 2), at the cut surface of the liver (after extended liver resection, n = 2) and at the surface of the liver after surgical exploration and perihepatic abscess (n = 1). Bile drainage alone (endoscopic or percutaneous) failed in all patients and open redo-surgery was deemed potentially harmful. Bilomas were externally drained in all patients before Onyx application. For the closure of bile leaks, Onyx was injected through a microcatheter in a previously built coil nest to keep Onyx in place. All bile leaks were initially closed immediately. In the 2nd week after Onyx embolization, 2 patients showed recurrent small bile leaks without clinical symptoms. In the 4th week after Onyx application, all leaks were closed. No complications occurred. CONCLUSION: All leaking bile ducts were initially closed immediately after Onyx application. In the 2nd week after Onyx application, 2 patients showed small bile leaks without clinical symptoms. All leaks were closed in the 4th week after Onyx application.

Impact of liver cirrhosis on liver enhancement at Gd-EOB-DTPA enhanced MRI at 3 Tesla.

PURPOSE: The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on dynamic, Gd-EOB-DTPA enhanced MRI at 3T. MATERIALS AND METHODS: 93 patients with normal (n=54) and cirrhotic liver (n=39; Child-Pugh class A, n=18; B, n=16; C, n=5) underwent contrast-enhanced MRI with liver specific contrast media at 3T. T1-weighted volume interpolated breath hold examination (VIBE) sequences with fat suppression were acquired before contrast injection, in the arterial phase (AP), in the late arterial phase (LAP), in the portal venous phase (PVP), and in the hepatobiliary phase (HBP) after 20 min. The relative enhancement (RE) of the signal intensity of the liver parenchyma was calculated for all phases. RESULTS: Mean RE was significantly different among all evaluated groups in the hepatobiliary phase and with increasing severity of liver cirrhosis, a decreasing, but still significant reduction of RE could be shown. Phase depending changes of RE for each group were observed. In case of non-cirrhotic liver or Child-Pugh Score A cirrhosis mean RE showed a significant increase between AP, LAP, PVP and HBP. For Child-Pugh B+C cirrhosis RE increased until PVP, however, there was no change in case of B cirrhosis (p=0.501) and significantly reduced in case of C cirrhosis (p=0.043) during HBP. CONCLUSION: RE of liver parenchyma is negatively affected by increased severity of liver cirrhosis, therefore diagnostic value of HBP could be limited in case of Child Pugh B+C cirrhosis.

[Liquid embolic agents--Onyx as problem solver]. / Flüssigembolisate--Onyx als Problemlöser.

CLINICAL/METHODICAL ISSUE: Liquid embolic agents are used for permanent occlusion of capillaries but optimal administration properties are lacking. STANDARD RADIOLOGICAL METHODS: The lack of visualization by fluoroscopy and the risk of serious complications are disadvantages of conventional embolic agents, such as ethanol and Histoacryl. METHODICAL INNOVATIONS: Onyx is a liquid embolic agent consisting of ethylene vinyl alcohol copolymer dissolved in various concentrations of dimethyl sulfoxide (DMSO) and suspended micronized tantalum powder to provide contrast for fluoroscopy. PERFORMANCE: The physicochemical characteristics of Onyx allow controlled application, forming a defined cast and permanent occlusion. Disadvantages are the high costs. Furthermore, the solvent DMSO requires special catheter material and causes pain during Onyx application. ACHIEVEMENTS: Onyx has been primarily used for interventional neuroradiological treatment but peripheral applications are becoming increasingly more common. PRACTICAL RECOMMENDATIONS: Currently, Onyx is mainly used for embolotherapy of endoleaks after endovascular aortic aneurysm repair, for treatment of acute arterial bleeding and for treatment of arteriovenous malformations.

Interobserver agreement in mr enterography for diagnostic assessment in patients with Crohn's disease.

PURPOSE: To evaluate the extent to which MRE can be used as an observer-independent, objective imaging method for the diagnosis and evaluation of CD with respect to the detection of inflammatory changes of the small bowel and lymphadenopathy as diagnostic criterion and bowel distension as a quality criterion. MATERIALS AND METHODS: MRE scans of 84 patients (42 female, median age 37 years) were evaluated independently by 4 experienced radiologists. Analysis of inflammatory changes of the bowel wall, lymphadenopathy and adequate bowel distension was conducted separately for the jejunum, ileum and terminal ileum. The Kendall's W-test was used for the statistical comparison of concordance. RESULTS: In a total of 55 patients, inflammatory activity of the bowel wall was detected and MRE was found to have a high interobserver reproducibility concerning inflammatory changes of the intestinal wall (Kendall's W 0.527 ­ 0.823). Concerning lymphadenopathy (31 cases, 36.9 %), a low to moderate consensus could be shown with a Kendall's W value of 0.402 ­ 0.505. For the assessment of adequate bowel distension, a moderate concordance between the operators could be found (Kendall's W 0.497 ­ 0.581). CONCLUSION: MRE has proven high interobserver agreement with respect to the diagnosis of inflammatory disease activity of the bowel as a diagnostic criterion in patients with CD. Concerning adequate bowel distension as a quality criterion of the examination itself and lymphadenopathy as a diagnostic criterion, moderate interobserver agreement could be found. This is thought to have a rather small effect on the diagnostic significance and conclusiveness of the method in the daily routine.