[Endovascular interventions for multiple trauma]. / Endovaskuläre Interventionen beim Polytrauma.

CLINICAL ISSUE: In recent years interventional radiology has significantly changed the management of injured patients with multiple trauma. Currently nearly all vessels can be reached within a reasonably short time with the help of specially preshaped catheters and guide wires to achieve bleeding control of arterial und venous bleeding. STANDARD TREATMENT/TREATMENT INNOVATIONS: Whereas bleeding control formerly required extensive open surgery, current interventional methods allow temporary vessel occlusion (occlusion balloons), permanent embolization and stenting. DIAGNOSTIC WORK-UP: In injured patients with multiple trauma preinterventional procedural planning is performed with the help of multidetector computed tomography whenever possible. PERFORMANCE: Interventional radiology not only allows minimization of therapeutic trauma but also a considerably shorter treatment time. ACHIEVEMENTS: Interventional bleeding control has developed into a standard method in the management of vascular trauma of the chest and abdomen as well as in vascular injuries of the upper and lower extremities when open surgical access is associated with increased risk. Additionally, pelvic trauma, vascular trauma of the superior thoracic aperture and parenchymal arterial lacerations of organs that can be at least partially preserved are primarily managed by interventional methods. PRACTICAL RECOMMENDATIONS: In an interdisciplinary setting interventional radiology provides a safe and efficient means of rapid bleeding control in nearly all vascular territories in addition to open surgical access.

Aortomonoiliac endografting after failed endovascular aneurysm repair: indications and long-term results.

OBJECTIVES: To present long-term results of endoleak/endograft migration treatment by aortomonoiliac (AMI) endografting after failed endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms. DESIGN: Post hoc analysis of a prospectively gathered database at a tertiary care university hospital. MATERIALS AND METHODS: From March 1995 to November 2010, 23 patients were identified who underwent modification into AMI configuration after failed elective EVAR. Major causes for modification were type I (with/without endograft migration) or type III endoleaks with aneurysm expansion. An average increase in aneurysm size of 1.6 cm (range: -1.5 to 10.5 cm) since initial aneurysm treatment was observed. Interventional outcomes and long-term results were recorded for analysis. RESULTS: Technical success rate of AMI endografting was 95.65% (n = 22). All except two endoleaks could be successfully sealed with this manoeuvre (94.44%). Median time to modification was 5.3 years (interquartile range Q1-Q3: 1.3-9.3 years). No intra-operative conversion to open surgery was necessary and mortality was 0%. Median follow-up was 44 months (interquartile range Q1-Q3: 17-69 months). CONCLUSIONS: Treatment of graft-related endoleaks/endograft migration by AMI endografting after failed EVAR represents a safe and feasible procedure. This approach broadens the minimal invasive opportunities of aneurysm treatment, and open surgical conversion may be avoided except in selected patients.

[Diagnosis of intraocular foreign bodies in multidetector-CT: influence of acquisition parameters on radiation dose and detectability]. / Intraokulare Fremdkörperdiagnostik in der Multidetektor-CT: Auswirkung der Akquisitionsparameter auf Strahlendosis und Erkennbarkeit.

PURPOSE: Determination of the influence of acquisition and reconstruction parameters on radiation dose and detectability of intraocular foreign bodies using multidetector CT (MDCT). MATERIALS AND METHODS: Porcine eyes with intraocular foreign bodies of a 0.3-mm quartz fiber and a 0.1-mm steel wire as well as 0.5 ml of blood in the vitreous were investigated using MDCT. The tube current was 500, 250, 100, and 50 mAs; the collimation was 16 x 0.75 mm and 16 x 1.5 mm; and the pitch was 0.5 and 0.75. Image reconstruction was performed using a soft tissue (H30), a bone algorithm (H60 s), and thin (0.7 and 2 mm, respectively) and thick (2 and 4 mm, respectively) reconstruction increments. The resulting data sets were then used to determine the signal difference to noise ratio (SDNR) between the foreign body and adjacent vitreous. RESULTS: Changes in tube current resulted in a proportional change in the radiation dose but only in the SDNR within a range of 1:2. Reducing the collimation from 1.5 mm to 0.75 mm resulted in a doubling of the SDNR at an approximately identical radiation dose. The series with a lower pitch at the same dose per volume showed a slightly higher SDNR. Reconstruction using a bone algorithm and thin increments resulted in an increase in the mean SDNR by a factor of 1.8 to 2.3. CONCLUSION: When diagnosing small intraocular foreign bodies using MDCT, the following parameters can yield an adequate SDNR while minimizing radiation exposure: tube current 50 mAs, pitch 0.5, collimation 16 x 0.75, bone algorithm, and reconstruction increment 0.7 mm.

Treatment of the aorto-iliac segment in complex lower extremity arterial occlusive disease.

Endovascular treatment of the aortoiliac segment in occlusive disease has an established role especially in TASC A and B lesions. Recent studies with modern stent technology have shown excellent results with one-year primary patency above 95%. Regarding different endovascular approaches, there is level Ib evidence supporting provisional stenting in stenosed arteries, and primary stenting in occlusion. While open surgery shows higher patency rates in direct comparison to endovascular techniques, the latter show significantly lower complication rates and lower mortality. The recommendations reserving TASC C and D lesions exclusively to surgery are currently challenged, especially in poor surgical candidates.

Quiz case 10. Metastasising retroduodenal gastrinoma.

A 37-year-old male patient with no significant past medical history presented with a 6-month history of intermittent epigastric pain which was partially relieved by antacid medication. Gastroscopy showed a peptic ulcer and the biopsies that were taken did not show signs of malignancy. Conservative treatment was initiated, but healing was prolonged, and the epigastric pain persisted. The patient was referred to our department for further diagnosis.

Open meniscal repair: clinical and magnetic resonance imaging findings after twelve years.

The purpose of this study was to document the longterm clinical, radiographic, and magnetic resonance imaging results after open meniscal repair. Twenty-two patients, with 23 open meniscal repairs, were evaluated after a mean follow-up of 12.9 years using patient history, physical examination, KT-1000 arthrometer testing, the "Orthopaedische Arbeitsgemeinschaft Knie" knee evaluation scheme, Tegner activity score, weightbearing radiographs, and magnetic resonance imaging. Two of the 22 patients had retears and both occurred in unstable knees. Radiographs revealed no degenerative changes in 17 of the 23 compartments. Grade III and IV signal alterations were present on magnetic resonance imaging scans in more than 50% of the repaired menisci. We concluded that the longterm survival rate of repaired menisci was 91%, and that magnetic resonance imaging is unsuitable for diagnosis of the healing process of a repaired meniscus.

[Evaluation of a computer-assisted diagnosis system in breast carcinoma]. / Evaluierung eines computerassistierten Diagnosesystems in der Erkennung des Mammakarzinoms.

PURPOSE: Evaluation of a computerassisted diagnosis (CAD) system (R2 linage Checker 1.2). Comparison of the results of three readers with and without knowledge of the computer results. MATERIALS AND METHODS: The mammograms of 52 patients, bilaterally in two planes each, with histologically proven carcinoma of the breast were included in the study. They were first scanned by the CAD machine and subsequently read by three readers with different degrees of experience in two sessions with and without knowledge of the computer results. RESULTS: Of the 91 views of carcinomas, the readers detected 96%, 89%, and 85%, respectively. With CAD, the values rose to 97%, 93%, and 96%. The increase of the first observer was not significant. As for the 49 areas of malignant microcalcifications, the first reader showed a significant decrease of sensitivity, the other two readers showed no significant change. The sensitivity of CAD was 74% for masses and 86% for microcalcifications at a rate of 1.8 false positive markers per image. All but two tumors were correctly marked in at least one plane. CONCLUSIONS: Use of the CAD machine led to a significant increase of sensitivity in the detection of malignant masses by two of three observers. In the case of malignant microcalcifications, and for the most experienced observer, CAD did not improve the results. The most important problem is the high rate of false positive markers.

[Electrical impedance scanning in the differentiation of suspicious breast lesions: comparison with mammography, ultrasound and histopathology]. / Elektrische Impedanzmessung in der Abklärung von Brustläsionen: Vergleich mit Mammographie, Sonographie und Histopathologie.

PURPOSE: To assess the value of Electrical Impedance Scanning (EIS) in the differentiation of suspicious breast lesions in comparison to mammography (MG) and ultrasound (US). METHODS: In 95 female patients (median 53.1 ys) 95 suspicious breast lesions (BI-RADS TM III - V) in MG or US underwent targeted EIS (TransScan TS 2000(R); TransScan Medical, Israel; Siemens Elema, Sweden). Histopathologic proof (vacuum-assisted biopsy or surgical biopsy) was obtained in all cases. MG, US and EIS were independently assessed by two radiologists in consensus. Chi-square tests as well as variance-analysis for ROC-statistics were performed. RESULTS: Of 95 lesions, 44 were benign, 51 malignant. Sensitivity, specificity, positive and negative predictive values were, respectively for MG 95.3 %, 23.5 %, 51.3 % and 85.7 %, for US 86.5 %, 44.2 %, 57.1 % and 79.1 %, for EIS 77.3 %, 82.3 %, 79.1 % and 80.8 %. The ROC-analysis revealed a significant greater area under the curve for EIS than for MG and US. The sensitivity for EIS was higher in lesions < 10 mm (n = 26; 100 %) and in invasive cancers (n = 31; 80.6 %). The negative predictive value of EIS was higher in BI-RADS TM-IV-lesions (83.9 %) as well as in dense breast parenchyma on the mammogram (86.7 %). CONCLUSION: EIS shows potential adjunctive value to MG and US in the differentiation of suspicious breast lesions.

Endovascular repair of thoracoabdominal aortic aneurysms with a novel multibranch stent-graft design: preliminary experience.

AIM: The aim of this paper was to report our preliminary experience in outcome, safety and mid-term results in the treatment of thoracoabdominal aortic aneurysms (TAAA) with a novel multibranchstentgraft (E-xtra DESIGN ENGINEERING, JOTEC, Germany). METHODS: Eight patients (mean age 66 years, 2 female) with TAAA (Crawford type I: 2 cases, type III: 3 cases, type IV: 3 cases), mean aneurysm diameter 61 mm, growth over 5 mm per year were treated. Implantation was performed under general anesthesia and surgical exposition of the common femoral artery. Brachial access was percutaneous in 5/8 patients. Balloon-expandable (Advanta V12) bridging stent-grafts were employed and lined with self-expanding nitinol stents. All patients except type IV TAAA received a spinal drainage catheter. RESULTS: The device was successfully deployed in 8/8 patients. 29/32 visceral branches were engaged. One stenosed celiac trunk was left untreated without further consequences, two renal arteries which could not be cannulated were revascularized with iliorenal bypass. One patient needed surgical revision of groin hematoma, one patient suffered from permanent protopathic sensory deficit. No renal complications occurred. Since the primary implantation was deliberately kept short and amount of contrast agent was minimised, four patients needed a secondary percutaneous procedure (Palmaz stent implantation for type I endoleak, re-PTA or additional bridging stent-graft implantation for type III endoleak). The assisted primary success rate was 8/8. Mean follow-up was 18 months. Success was stable in 7/8 patients, one patient shows type V endoleak with 5mm sac expansion. No mortality or complication occurred during follow-up. CONCLUSION: The JOTEC E-xtra DESIGN ENGINEERING multibranch stent-graft is a promising new candidate for endovascular TAAA treatment with sufficient safety and efficacy. Its short delivery time suggests its use in patients with rapid aneurysm growth or high anxiety.

Bail-out visceral bypass grafting for acute intestinal ischemia after endovascular stent-graft placement in a complicated type B dissection.

We report on the case of a 35-year-old male who underwent emergency stent-graft placement in March 2007 due to a complicated type B dissection. One week after this procedure the patient developed critical visceral malperfusion. Subsequently, autologous iliaco-mesenteric as well as iliaco-hepatic bypass grafting was performed. At 6-month follow-up, aortic remodelling has occurred and visceral perfusion is regular.

[Optical imaging of fluorescence in the near infrared. From passive to enzymatically activated contrast medium]. / Optische Bildgebung von Fluoreszenz im nahen Infrarot. Vom passiven zum enzymatisch aktivierbaren Kontrastmittel.

The molecular imaging of specific targets using optical methods is currently possible in vivo, in part due to the advances in imaging modalities (epifluorescence, fluorescent endoscopy, fluorescence mediated tomography, intravital fluorescence microscopy), and in part due to the development of better contrast media. These are composed of a suitable fluorochrome, usually with emission in the near infrared due to tissue penetration, as well as by molecular specific contrast media from ligands. The latest generation of contrast media is not fluorescent in its unactivated state. Fluorescence first occurs after contact with certain (e.g. disease specific) enzymes by which a minimally unspecific fluorescent background as well as molecular specificity is made possible.

PTA versus carbofilm-coated stents in infrapopliteal arteries: pilot study.

PURPOSE: To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study. METHODS: Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47-80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan-Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions. RESULTS: The inter-reader agreement was high (kappa = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05). CONCLUSION: Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.

[Endoanal magnetic resonance tomography in fecal incontinence]. / Endoanale Magnetresoanztomographie bei fäkaler Inkontinenz.

PURPOSE: Within the recent years several studies have been performed to determine the value of endoanal magnetic resonance imaging (MRI) in faecal incontinence. METHODS: MRI is performed using a 0.5-1.5 T unit. A surface coil with a maximum diameter of 19 mm is placed in the anal canal. T2* 3D gradient-echo-sequences and T2-weighted turbo-spin-echo sequences in coronal, axial und sagittal orientation are acquired. RESULTS: Compared to endoanal ultrasound (EUS), which is the gold standard for diagnosis in faecal incontinence, endoanal MRI is better in visualization of the external sphincter. The accurate delineation of the external sphincter has led to the possibility to evaluate sphincter atrophy. Preliminary results have shown, that endoanal MRI has an accuracy of 90-95% in the demonstration of lesions in the external sphincter. In detection of lesions of the internal sphincter EUS is still superior to endoanal MRI. CONCLUSION: EUS and endoanal MRI are currently the optimal imaging techniques for faecal incontinence, with the advantage of detecting external sphincter atrophy with endoanal MRI.

[Staging of musculoskeletal tumors in diagnostic imaging]. / Staging muskuloskeletaler Tumoren in der Bildgebung.

The staging of primary malignant bone and soft tissue tumors requires adherence to a unified staging system. The staging system of the American Joint Commission for Cancer, the Enneking system, and the Hajdu system are described in respect of the radiologic staging criteria. Plain film radiography can estimate the biological aggressiveness of a bone tumor and in many cases narrow the differential diagnosis. Computed tomography is most sensitive in depicting cortical erosions and calcified periosteal reactions as well as in screening for distant metastasis. Angiography is mainly employed for vascular tumors and for the monitoring of interventional procedures such as tumor embolization. For both bone and soft tissue tumors, magnetic resonance tomography is the method of choice for the staging of intra- and extramedullary tumor extension, for the differentiation of neighboring compartments, and in the detection of invasion of the regional neurovascular bundle. After administration of contrast agents, the mode of enhancement gives further information on the nature of the tumor. With consistent application of the staging criteria in preoperative imaging, limb-saving therapy can be employed more often and the prognosis of the disease can be improved.

[Temporary and permanent vena cava filter for prevention of pulmonary embolism]. / Temporäre und permanente Vena-cava-Filter zur Prophylaxe von Pulmonalembolien.

Inferior vena cava filters have been used for prophylaxis of pulmonary embolism since the end of the sixties. Complication rates depend on the types of filters used and are reported to be 2% with the Guenther-Filter and 21% with the Titanium-Greenfield-Filter. Depending on the exact indication both filter types are useful instruments for the prevention of pulmonary embolism.

[Preoperative staging of colorectal carcinoma]. / Präoperatives Staging des Kolorektalen Karzinoms.

Carcinoma of the colorectum is one of the most frequent neoplasias, with an incidence of 40 in 100,000. For the effective use of new, differentiated, less invasive treatment options, exact preoperative staging of the tumor is essential. The introduction of endosonography in rectal tumor staging allows for exact differentiation of the rectal wall layers and thus of tumor stages 1-3 with median accuracy of 89%. Magnetic resonance imaging of the rectum, especially in double-contrast technique, can also be employed in high and stenosing tumors and leads to an average accuracy of 85% for the stages 1-4. Computed tomography is the method of choice in screening for metastases. In lymph node staging, all modalities show only moderate accuracy around 75%.

Shortening of the patellar tendon length does not influence the patellofemoral alignment in a cadaveric model.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction with the use of autograft tissue represents the standard treatment. The use of a bone-patellar tendon-bone transplant for symptomatic ACL deficiency achieves good long-term results. The purpose of the study was to investigate in a cadaveric model whether reproducible patellar tendon shortening changes the patellofemoral alignment. MATERIALS AND METHODS: Using five cadaveric knees, an MRI investigation was performed with the patellar tendon left unchanged, shortened 5 mm and shortened 10 mm, respectively, in both 20 and 45 degrees of knee flexion. The lateral patellofemoral and the congruence angles were measured and compared using a one-way analysis of variance for repeated measurements. RESULTS: Shortening the patella tendon by approximately 20% did not significantly influence the patellofemoral alignment. CONCLUSION: Although anterior cruciate ligament-reconstruction using the patellar tendon has become a standard procedure, postoperative problems such as anterior knee pain, and patellofemoral osteoarthritis occur quite often. In this cadaver study we did not find a significant difference for the patellofemoral alignment, irrespective of the patellar tendon length.

Patellar alignment evaluated by MRI.

We analyzed the congruence of the articular cartilage surfaces and the corresponding subchondral bone in the patellar joint. 20 volunteers underwent MRI investigations of the right patellar joint in 20 degree and 45 degree flexion in the axial plane. The sulcus, congruence, and lateral patellofemoral angles, measured on MRI slices centered through the midtransverse patella, were recorded. In 20 degree and 45 degree knee flexion, the bony sulcus and lateral patellofemoral angles were significantly different from the respective cartilagineous angle. We conclude that 1) measurement of the bony sulcus and lateral patellofemoral angles does not allow conclusions about the articular cartilage surface and its thickness, 2) the bony congruence angle corresponds well to the articular cartilage surface as an indicator of patellar centralization.