Conservative treatment of gastric perforation after microwave ablation of a hepatocellular carcinoma: Case report.

RATIONALE: Microwave ablation (MWA) has been proven to be an efficient and safe method for local tumor control of liver tumors. Reported complications are rare, but include liver abscess, hematoma, pleural effusion, and occasional thermal injury of the adjacent colon. Intestinal perforation usually requires immediate surgical treatment to prevent generalized peritonitis and sepsis. PATIENT CONCERNS AND DIAGNOSIS: Herein, we describe a case of gastric perforation following percutaneous MWA for hepatocellular carcinoma as a bridging therapy prior to liver transplantation. INTERVENTIONS: Due to the clinical condition of the patient, conservative treatment was considered sufficient. Nine months after MWA, successful liver transplantation followed. Intraoperative findings revealed a scar in the gastric wall with tight adhesions to the liver, requiring adhesiolysis and subsequent suturing. Postoperative recovery was uneventful. OUTCOME: At present, the patient is doing well. No further gastrointestinal events occurred. LESSON: To our knowledge, this is the first report of such a complication occurring after MWA. Moreover, in this case, the gastric perforation could be treated conservatively.

[Gadolinium deposition-"gadolinium deposition disease"]. / Gadoliniumablagerungen ­ Morbus Gadolinium.

Gadolinium (Gd)-based contrast agents have been routinely used worldwide in diagnostic MRI since 1988. All routinely applied contrast agents for clinical use were considered extremely safe with regard to tolerance, adverse effects and diagnostic efficacy and when used at Food and Drug Administration-approved doses. With the identification of Gd-associated disorders, namely nephrogenic systemic fibrosis and adverse reactions, and in the longer term Gd-retention in the brain, this view changed and led to the withdrawal or restriction of approval of linear Gd chelates in Europe. Even though Gd deposition in different human body areas was described very early, recently published literature of intracerebral accumulation of contrast agents as well as deposition in bone have created surprising attention. Not only was the fact of Gd deposition in the body well known for many years, but there is currently no clinical evidence of patient symptoms and no resulting health issues of patients have been observed yet. The expression "gadolinium deposition disease" has been termed by active patient advocacy groups with an online presence with reports of individual members stating a broad spectrum of disorders yielding a large symptom complex after administration of Gd-based contrast agents without evidence of any pre-existing or otherwise underlying disease process which could explain the mentioned disorder.

[New developements in endovascular infrarenal aortic aneurysm treatment]. / Aktuelle Neuerungen bei der endovaskulären Versorgung infrarenaler Aortenaneurysmen.

CLINICAL/METHODICAL ISSUE: New technical developments in endovascular aortic repair (EVAR) have broadened the range of patients eligible for minimally invasive aneurysm treatment. Optimization of delivery sheaths and catheters by considerable downsizing of diameters, increase of pushability and stability combined with flexibility are important parameters. PERFORMANCE: Especially patients characterized by small and tortuous iliac access vessels can nowadays be treated by EVAR. Ease and effectiveness of applicability guarantee safety and quality improvement, which results in better treatment of patients. Progress in stent-graft design with integrated options for repositioning, active positioning and aneurysm sealing facilitate treatment of angulated vessel segments or hitherto unsuitable sealing zones. PRACTICAL RECOMMENDATIONS: Interventionalists have to be familiar with all available stent-graft materials and techniques. Profound knowledge helps to choose the best material for a patient's individual anatomy, confident application and long-term satisfactory results.

[Conventional radiological diagnosis of benign none neoplasms]. / Konventionell-radiologische Diagnose von gutartigen Knochentumoren.

BACKGROUND: Benign bone tumors are of special clinical importance because they might be confused with malignant bone tumors. OBJECTIVES: The aim of this article it to present the characteristics of benign bone tumors. The focus is orientated towards conventional x­ray as the essential pillar for primary diagnosis. Consequently, the description of signal intensities of benign bone tumors in magnetic resonance images or less helpful clues like male-female ratios are deliberately omitted. RESULTS: The classification of bone tumors introduced by Lodwick allows the identification of benign growth patterns. Growth patterns will not help, for example, in case of dedifferentiation of benign chondroid tumors towards chondrosarcomas. Therefore, each diagnosis has to incorporate the patient's clinical scenario. Furthermore, benign bone tumors might also cause aggressive growth patterns. Tumors classified as Lodwick Ic or higher should not be automatically regarded as malignant. Naturally, further clarification is mandatory for these tumors. CONCLUSIONS: Differentiation between definitely benign bone tumors and those which need further work up is a critical diagnostic step. In the majority of cases, this is possible based on the appearance in conventional x­ray images. In case of possibly malignant lesions, both the patient's symptoms and the x­ray morphology have to be considered by orthopedic surgeons, pathologists, and radiologists to determine the optimal diagnostic strategy.

Transarterial embolization (TAE) as add-on to percutaneous radiofrequency ablation (RFA) for the treatment of renal tumors: Review of the literature, overview of state-of-the-art embolization materials and further perspective of advanced image-guided tumor ablation.

Percutaneous radiofrequency ablation (RFA) for the treatment of stage I renal cell carcinoma has recently gained significant attention as the now available long-term and controlled data demonstrate that RFA can result in disease-free and cancer-specific survival comparable with partial and/or radical nephrectomy. In the non-controlled single center trials, however, the rates of treatment failure vary. Operator experience and ablation technique may explain some of the different outcomes. In the controlled trials, a major limitation is the lack of adequate randomization. In case reports, original series and overview articles, transarterial embolization (TAE) before percutaneous RFA was promising to increase tumor control and to reduce complications. The purpose of this study was to systematically review the literature on TAE as add-on to percutaneous RFA for renal tumors. Specific data regarding technique, tumor and patient characteristics as well as technical, clinical and oncologic outcomes have been analyzed. Additionally, an overview of state-of-the-art embolization materials and the radiological perspective of advanced image-guided tumor ablation (TA) will be discussed. In conclusion, TAE as add-on to percutaneous RFA is feasible and very effective and safe for the treatment of T1a tumors in difficult locations and T1b tumors. Advanced radiological techniques and technologies such as microwave ablation, innovative embolization materials and software-based solutions are now available, or will be available in the near future, to reduce the limitations of bland RFA. Clinical implementation is extremely important for performing image-guided TA as a highly standardized effective procedure even in the most challenging cases of localized renal tumors.

Evaluation of a Gadolinium-Based Nanoparticle (AGuIX) for Contrast-Enhanced MRI of the Liver in a Rat Model of Hepatic Colorectal Cancer Metastases at 9.4 Tesla.

PURPOSE: The aim of this study was to compare a Gd-based nanoparticle (AGuIX) with a standard extracellular Gd-based contrast agent (Gd-DOTA) for MRI at 9.4 T in rats with hepatic colorectal cancer metastases. MATERIALS AND METHODS: 12 rats with hepatic metastases were subjected to MRI using a 9.4 T animal scanner. T1w self-gated FLASH sequences (TR/TE = 45/2.5 ms, alpha = 45°, TA = 1: 23 min, FOV = 5.12 × 5.12 cm(2), matrix = 256 × 256) were acquired before and at 10 time points after contrast injection. Each animal received 0.1 mmol/kg BW Gd-DOTA i.v. 2 days later AGuIX was applied at 0.01 mmol/kg BW (representing equal Gd doses). The SNR of normal liver (SNRliver), hyper- and hypoenhancing parts of tumors (SNRtumor, hyperenh/SNRtumor, hypoenhanc), erector spinae muscle (SNRmuscle), CNR and lesion enhancement (LE) were calculated based on ROI measurements. RESULTS: Mean SNRliver (Gd-DOTA: 14.6 +/- 0.7; AGuIX: 28.2+/- 2.6, p < 0.001), SNRtumor, hyperenhanc (Gd-DOTA: 18.6 +/- 1.2; AGuIX: 29.6 +/- 2.8, p < 0.001), SNRtumor, hypoenhanc (Gd-DOTA: 12.0 +/- 0.7; AGuIX: 15.4 +/- 0.7, p < 0.001), SNRmuscle (Gd-DOTA: 12.3 +/- 0.3; AGuIX: 14.0 +/- 0.7, p < 0.001), mean CNR (Gd-DOTA: -2.5 +/- 0.2; AGuIX: -7.5 +/- 1.0, p < 0.001) and LE (Gd-DOTA: 3.8 +/- 0.7; AGuIX: 14.9 +/- 2.8, p = 0.001) were significantly higher using AGuIX. Regardless of the larger molecular size, AGuIX demonstrates an early peak enhancement followed by a continuous washout. CONCLUSION: AGuIX provides better enhancement at 9.4 T compared to Gd-DOTA for equal doses of applied Gd. This is based on the molecule structure and the subsequent increased interaction with protons leading to a higher relaxivity. AGuIX potentially ameliorates the conspicuity of focal liver lesions and may improve the sensitivity in diagnostic imaging of malignant hepatic tumors. KEY POINTS: AGuIX provides superior enhancement as compared to the extracellular compound Gd-DOTA at 9.4 T. AGuIX may improve the detection and diagnostic sensitivity of malignant focal liver lesions. The small size of AGuIX allows for fast renal clearance and prevents undesirable accumulation in the body.

Recurrent High-Flow Arterio-Venous Malformation of the Thyroid Gland.

BACKGROUND: Vascular malformations and hemangiomas of the thyroid gland are rare disorders. The first case of a patient with recurrent high-flow arterio-venous malformation of the right thyroid gland involving the right endolarynx is presented. PATIENT FINDINGS: In June 2013, a 42-year-old female patient presented to the surgical department with recurrent hoarseness and a soft, vibrating mass on the right side of her neck. In 1993, she underwent right subtotal hemithyroidectomy with embolization on the day before surgery for a high-flow arterio-venous malformation of the thyroid gland. Diagnostic work-up in 2013 demonstrated a complex recurrent high-flow arterio-venous malformation on the right side of her neck involving the endolarynx. Full function of the right vocal fold could not be ascertained. The lesion was embolized again and excised the following day. Intraoperative gross bleeding and scar tissue prevented visualization and monitoring of the recurrent laryngeal nerve. Gross bleeding was also noted on hemithyroidectomy after embolization in 1993. No therapy was needed for the endolaryngeal part of the lesion. Histology showed large arterio-venous malformations with thyroid tissue. She remains well without signs of recurrence 18 month later but with a definitive voice handicap. SUMMARY: This is the first report of a recurrent high-flow arterio-venous malformation originally developing from the right thyroid gland involving the right endolarynx. Counseling, diagnostic, and therapeutic work-up of the patient was possible only with an interdisciplinary team. The endolaryngeal part of the hemangioma dried out after embolization and completion hemithyroidectomy. Her hoarseness has greatly improved but a definitive voice handicap remains. CONCLUSION: High-flow arterio-venous malformations of the thyroid gland are a rare disease, and recurrent lesions have not been reported. Interdisciplinary management of these patients is mandatory due to the complex nature of the underlying pathology. Recurrence might develop after long free intervals.

Mechanical thrombectomy of iliac vein thrombosis in a pig model using the Rotarex and Aspirex catheters.

PURPOSE: To investigate the efficacy and safety of mechanical thrombectomy for iliac vein thrombosis using Rotarex and Aspirex catheters in a pig model. MATERIALS AND METHODS: Iliac vein thrombosis was induced in six pigs by means of an occlusion-balloon catheter and thrombin injection. The presence of thrombi was verified by digital subtraction angiography (DSA) and computed tomography (CT). Thrombectomy was performed using 6F and 8F Rotarex and 6F, 8F, and 10F Aspirex catheters (Straub Medical AG, Wangs, Switzerland). After intervention, DSA and CT were repeated to evaluate the efficacy of mechanical thrombectomy and to exclude local complications. In addition, pulmonary CT was performed to rule out pulmonary embolism. Finally, all pigs were killed, and iliac veins were dissected to perform macroscopic and histological examination. RESULTS: Thrombus induction was successfully achieved in all animals as verified by DSA and CT. Subsequent thrombectomy lead to incomplete recanalization of the iliac veins with residual thrombi in all cases. However, the use of the 6F and 8F Rotarex catheters caused vessel perforation and retroperitoneal hemorrhage in all cases. Application of the Aspirex device caused one small transmural perforation in a vessel treated with a 10F Aspirex catheter, and this was only seen microscopically. Pulmonary embolism was detected in one animal treated with the Rotarex catheters, whereas no pulmonary emboli were seen in animals treated with the Aspirex catheters. CONCLUSION: The Aspirex catheter allowed subtotal and safe recanalization of iliac vein thrombosis. In contrast, the use of the Rotarex catheter caused macroscopically obvious vessel perforations in all cases.

[Quality report 2011 of the German Society of Interventional Radiology (DeGIR)--part 2. Endovascular treatment of aortic aneurysms (EVAR)]. / Qualitätsreport 2011: Bericht über die Behandlungsqualität minimalinvasiver Methoden--Teil 2. Interventionelle Therapie (EVAR) von Aortenaneurysmen.

PURPOSE: To analyze the quality of treatment for endovascular aortic aneurysm repair using the data of the DeGIR quality management system. MATERIALS AND METHODS: A retrospective analysis of all data registered in the DeGIR quality management system of the year 2011 was performed regarding the treatment quality for endovascular aortic aneurysm repair. Registry of data within this system was voluntary. Quality aims of correct indication, treatment strategy and results were examined. Special interest was directed towards treatment success, complication rates and radiation exposure. RESULTS: Out of 82,881 data sets from the year 2011 overall 1167 cases of EVAR were registered. 12.4% of these cases encompassed emergency treatments. The most frequent indication was an abdominal aneurysm with 85% of cases. The median aortic diameter was 56.5 mm. 253 cases showed an aortic diameter between 50 and 55 mm. Technical success was achieved in 94.6% of all cases including emergency indications for aortic rupture. The overall complication rate of all cases was 4% with 2.5% major complications. Examining only the elective cases a mortality rate of 0.34% was found. EVAR of ruptured aneurysms yielded a mortality rate of 12%. Median dose area product and fluoroscopy time were 10,676.5 cGy × cm2 und 17.32 min respectively. CONCLUSION: Data analysis of the DeGIR quality management system proved a very high technical success rate for the registered cases of endovascular aortic aneurysm repair accompanied by a low complication rate. Improvement of data quality will need further mandatory fields within the software to be implemented. KEY POINTS: The voluntary DeGIR quality management system has reached a high acceptance among radiologists. Endovascular aortic aneurysm repair by radiologists has shown a very high technical success rate and a very low complication rate.

Experimental scoring systems for macroscopic articular cartilage repair correlate with the MOCART score assessed by a high-field MRI at 9.4 T--comparative evaluation of five macroscopic scoring systems in a large animal cartilage defect model.

OBJECTIVE: To develop a new macroscopic scoring system which allows for an overall judgment of experimental articular cartilage repair and compare it with four existing scoring systems and high-field magnetic resonance imaging (MRI). METHODS: A new macroscopic scoring system was developed to assess the repair of cartilage defects. Cartilage repair was graded by three observers with different experience in cartilage research at 2-3 time points and compared with the protocol A of the international cartilage repair society (ICRS) cartilage repair assessment score, the Oswestry arthroscopy score, and macroscopic grading systems designed by Jung and O'Driscoll. Parameters were correlated with the two-dimensional (2D) magnetic resonance observation of cartilage repair tissue (MOCART) score based on a 9.4 T MRI as an external reference standard. RESULTS: All macroscopic scores exhibited high intra- and interobserver reliability and high internal correlation. The newly developed macroscopic scoring system had the highest intraobserver [0.866 ≤ intraclass correlation (ICC) ≤ 0.895] and the highest interobserver reliability (ICC = 0.905) for "total points". Here, Cronbach's alpha indicated good homogeneity and functioning of the items (mean = 0.782). "Total points" of the 2D MOCART score correlated with all macroscopic scores (all P < 0.0001). The newly developed macroscopic scoring system yielded the highest correlation for the MRI parameter "defect fill" (rho = 0.765; all P < 0.0001). CONCLUSIONS: "Total points" and "defect fill", two clinically relevant indicators of cartilage repair, can be reliably and directly assessed by macroscopic evaluation, using either system. These data support the use of macroscopic assessment to precisely judge cartilage repair in preclinical large animal models.

A scoring system for the assessment of angiographic findings in non-occlusive mesenteric ischemia (NOMI).

PURPOSE: To establish a standardized scoring system for angiographic findings in patients with non-occlusive mesenteric ischemia (NOMI). MATERIALS AND METHODS: In 36 patients (mean age: 72 years), 53 angiographies of the superior mesenteric artery (SMA) were performed for suspected NOMI after cardiac or major aortic surgery. All examinations were performed using a standardized DSA technique. Two experienced radiologists performed a consensus reading blinded to the clinical information, on two occasions with an interval of two weeks. In order to investigate the reproducibility of the criteria, the images were assessed once by an intensivist and a medical student. Image analysis was performed with respect to vessel morphology, reflux of contrast medium into the aorta, small bowel parenchymal contrast enhancement and distension and the delay between arterial injection and portal vein filling. RESULTS: Almost perfect intra-observer correlation was obtained for the assessment of the contrast medium reflux (κ = 0.82) and substantial correlation for the time of portal vein filling (κ = 0.66). Moderate correlations were obtained for the vessel morphology (κ = 0.51), small bowel enhancement (κ = 0.63) and distension (κ = 0.53). Contrast medium reflux into the aorta (κ = 0.77 and 0.63) and the time of portal vein filling (κ = 0.42 and 0.58) resulted in the highest inter-observer correlations between the radiologists and the intensivist as well as the radiologists and the student. CONCLUSION: In patients with suspected NOMI, using our scoring system yields high intra- and inter-observer correlations, allowing a standardized evaluation of angiographic findings.

[Quality report 2011 of the Germyn Society of Interventional Radiology (DeGIR) - report about treatment quality of minimal invasive procedures]. / DeGIR-Qualitätsreport 2011 - Bericht über die Behandlungsqualität minimalinvasiver Methoden.

In 1994 the German Society of Interventional Radiology (DeGIR) introduced a voluntary quality mangement program. Out of a total of 82 881 of the year 2011, 36 467 patients, who received interventional recanalisation of pelvic or lower extremity arteries were chosen for an in depth analysis. In 33 104 (90.8 %) cases indication for interventional treatment was determined by at least one further discipline or even a multidisciplinary conference. Most treated patients were classified as Fontaine II or higher. Technical success rate over all procedures and regions was 96.2 % showing a very low failure rate of only 3.8 %. The overall complication rate was 3.2 %, periinterventional morbidity (complication C, D or E according to SIR classification) was 1.37 % and periinterventional mortality was 0.07 % (24 cases). X-ray exposure was recorded as well showing an average fluoroscopy time of 12 minutes and a dose-area product of 5034 cG × cm2. The voluntary quality management system was well accepted by the interventional radiologists. The software allows to compare the individual data of a single institution with the pooled data of all 192 participating radiology departments.

Subintimal revascularization of chronic iliac artery occlusions using a reentry-catheter.

PURPOSE: To demonstrate the value of a Reentry-Catheter for true lumen access after subintimal revascularization of chronic iliac artery occlusions. MATERIALS AND METHODS: Subintimal revascularization was performed in 5 patients (mean age: 67 ± 12 years; female: 3, male: 2) with total iliac artery occlusion (TASC B to D), but without gaining access to the true lumen distal to the occlusion. Subsequently, a Reentry-Catheter was used to establish reentry and a new subintimal tract. Patients were followed up after 6, 12 and 24 months for clinical re-evaluation to determine the Rutherford score and the ankle brachial index (ABI). In addition, duplex ultrasound was performed to evaluate vessel patency. RESULTS: The primary technical success rate was 100 %. In all cases angioplasty was followed by stent placement to establish the subintimal tract. The mean Rutherford score decreased from 3.6 ± 0.9 to 0.33 ± 0.57 after 24 months, while the ABI increased from 0.67 ± 0.06 to 1.2 ± 0. Vessel patency was observed in all patients available for follow-up examinations. CONCLUSION: The Reentry-Catheter reliably allowed access to the true lumen after subintimal revascularization of occluded iliac arteries. Results in this small patient cohort showed a significant reduction in the Rutherford score, increase in the ABI, and a good patency rate after two years.

[Multimodal approach in coincidence of covered ruptured abdominal aortic aneurysm and aortocaval fistula]. / Multimodales Vorgehen bei einem gedeckt rupturierten Bauchaortenaneurysma mit aortocavaler Fistel.

HISTORY AND ADMISSION FINDINGS: A 71-year-old patient had been referred to our hospital with the diagnosis, made by angio-computed tomography (CTA), of a covered ruptured abdominal aortic aneurysm (AAA) resulting in an aortocaval fistula (ACF). INVESTIGATIONS: The physical examination revealed macrohematuria and high-output heart failure with increasing circulatory insufficiency. DIAGNOSIS, TREATMENT AND COURSE: An open endovascular procedure was not possible because the AAA had extended into both internal iliac arteries. A bifurcated prosthesis connecting to both femoral arteries was then successfully implanted and the infrahepatic aortocaval fistula closed by a patch through the AAA. Ischemic colitis, diagnosed on postoperative day 2 (POD 2), was successfully treated with antibiotics. CTA, done on POD 5, revealed a small residual ACF, filling retrogradely from the right external iliac artery via the surgically closed aneurysmal sack. Closure of the residual ACF was achieved with an Amplatz occluder inserted into the right external iliac artery, introduced percutaneously via the right femoral artery. The postoperative course was uneventful and the patient discharged on POD 13. CONCLUSION: The coincidence of AAA and ACF is rare. However, the morbidity and mortality are high and require early diagnosis and immediate treatment.

[Hemodialysis fistulas: possibilities of vascular ultrasound]. / Dialyseshunt : Möglichkeiten der Gefässsonographie.

Vascular ultrasound is an established technique in shunt diagnostics for hemodialysis fistulas that allows non-invasive diagnosis of vascular morphology and hemodynamics. Early detection of shunt stenoses in hemodialysis fistulas or thrombotic occlusions facilitates an interventional decision. High occlusion rates of up to 45% within 1 year in hemodialysis fistulas due to reduced flow volume justify follow up with vascular ultrasound examination. The use of high resolution transducers in vascular ultrasound enables complications, such as stenoses and occlusions to be recognized early therefore allowing preemptive therapy. In the present review the examination technique and strategy, the most important complications and treatment options will be discussed.