[Radiation exposure of the eye lens in orthopedics and trauma surgery : A pilot study]

BACKGROUND

On 27 June 2017 the Act on new regulation of the law for the protection against the harmful effects of ionizing radiation was passed. One of the main innovations in daily surgical practice in the now legally stipulated provisions is the lowering of the eye lens dose to 20 mSv/year (§§ 78, 212 Radiation Protection Act, StrlSchG).

MATERIAL AND METHODS

To estimate the level of exposure of the eye lens to ionizing radiation that is to be expected in the course of surgical interventions, the dose that surgeons receive during surgery was determined. For this, the radiation exposure adjacent to the eye lens was measured using a forehead dosimeter while performing surgical interventions over a period of 8 weeks in 2 different operating rooms.

RESULTS

As a result, a mean estimated eye lens radiation dose Hp (3) of 190 µSv could be determined during the 2‑month study period. Thus, the estimated cumulative radiation dose in 1 year of approximately 1.2 mSv was significantly below the threshold of 20 mSv/year.

CONCLUSION

By complying with the common radiation protection measures in the context of operative interventions in orthopedics and trauma surgery, the legal limit value of 20 mSv/year is generally not expected to be exceeded.

Radiation exposure of adrenal vein sampling: a German Multicenter Study

OBJECTIVE

Adrenal vein sampling (AVS) represents the current diagnostic standard for subtype differentiation in primary aldosteronism (PA). However, AVS has its drawbacks. It is invasive, expensive, requires an experienced interventional radiologist and comes with radiation exposure. However, exact radiation exposure of patients undergoing AVS has never been examined.

DESIGN AND METHODS

We retrospectively analyzed radiation exposure of 656 AVS performed between 1999 and 2017 at four university hospitals. The primary outcomes were dose area product (DAP) and fluoroscopy time (FT). Consecutively the effective dose (ED) was approximately calculated.

RESULTS

Median DAP was found to be 32.5 Gy*cm2 (0.3–3181) and FT 18 min (0.3–184). The calculated ED was 6.4 mSv (0.1–636). Remarkably, values between participating centers highly varied: Median DAP ranged from 16 to 147 Gy*cm2, FT from 16 to 27 min, and ED from 3.2 to 29 mSv. As main reason for this variation, differences regarding AVS protocols between centers could be identified, such as number of sampling locations, frames per second and the use of digital subtraction angiographies.

CONCLUSIONS

This first systematic assessment of radiation exposure in AVS not only shows fairly high values for patients, but also states notable differences among the centers. Thus, we not only recommend taking into account the risk of radiation exposure, when referring patients to undergo AVS, but also to establish improved standard operating procedures to prevent unnecessary radiation exposure.

The effectiveness of the paclitaxel-coated Luminor® balloon catheter versus an uncoated balloon catheter in superficial femoral and popliteal arteries in preventing vessel restenosis or reocclusion: study protocol for a randomized controlled trial

BACKGROUND

The aim of this investigator-initiated trial is to evaluate the safety and efficacy of the novel Luminor® paclitaxel-coated drug-eluting balloon (DEB) catheter (iVascular, S.L.U., Barcelona, Spain) in inhibiting restenosis and in ensuring long-term vascular patency.

METHODS/DESIGN

This is a multicenter randomized controlled trial to evaluate the Luminor® paclitaxel-coated DEB catheter for stenotic or occlusive lesions (length ≤15 cm) in the superficial femoral artery (SFA) and the popliteal artery (PA) up to the P1 segment compared to the noncoated, plain old balloon angioplasty (POBA) catheter. In total 172 subjects will be treated with either the DEB catheter or the POBA catheter in 11 German study centers in a 1:1 randomization study design. The primary endpoint is late lumen loss (LLL) at 6 months. Secondary endpoints are patency rate, target lesion/vessel revascularization, quality of life (assessed with the Walking Impairment Questionnaire (WIQ) and the EQ-5D), change of Rutherford stage and ankle-brachial index, major and minor amputation rate at the index limb, number of dropouts and all-cause mortality.

DISCUSSION

EffPac represents a randomized controlled trial that will provide evidence on the effectiveness of the Luminor® paclitaxel-coated DEB catheter for the reduction of restenosis compared to the POBA catheter for the SFA and the PA. The results of EffPac will allow direct comparison to other already-completed RCTs applying paclitaxel-coated DEBs from different manufacturers with different coating technologies in the same target vessel.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02540018 , registered on 17 August 2015. Protocol version: CIP Version Final04, 11 February 2016. EUDAMED No: CIV-15-03-013204.

[Stent-assisted recanalization of femoropopliteal arterial occlusive disease. Influence of stent design on patency rates]

BACKGROUND

Despite enormous technical progress the results of endovascular treatment of the femoropopliteal vasculature are unsatisfactory and its role is still controversially discussed. In the past decade numerous new stent designs have come onto the market but it is unclear whether they have benefits with respect to patency rates.

OBJECTIVES

Comparison of published data on patency rates and target lesion revascularization rates after use of different stent designs in the femoropopliteal vasculature.

MATERIAL AND METHODS

Analysis of 25 published studies and registries from 2006 to 2015 for classical open-cell stents, interwoven stents and partially or fully covered stents.

RESULTS AND CONCLUSION

The published data are heterogeneous and comparative studies for different stent designs are completely missing. Over the past decade the patency rates after femoropopliteal stenting could be improved. According to available data stenting of short lesions < 5 cm does not show any benefit compared to isolated balloon angioplasty. Primary stenting is now recommended for intermediate and longer lesions > 6.4 cm. Due to the heterogeneity of published data a clear benefit for a specific stent design is not obvious; however, data for interwoven stents are promising and show a tendency towards improved patency, at least for certain lesions. Randomized controlled comparative trials are needed to confirm this result.

Successful revascularization of chronic total occlusion of lower extremity arteries: a wire only and bail out use of re-entry device approach

AIM

The management of progressive peripheral artery disease experienced a vast change in paradigms over the last decades for the benefit of minimal invasive therapy as a first-line strategy. With the constant development of new devices, materials and dedicated access strategies, more complex lesions can be managed but the limitations to successfully treat chronic total occlusions are still the challenge to re-enter the true lumen. The aim of this retrospective study was to investigate, if a "wire only" strategy leads to an acceptable success rate in a mixed cohort of CTO lesions and to what extend re-entry devices are used.

METHODS

We retrospectively analyzed patients treated at the Vascular Center Berlin between 2011 and 2013 with chronic total occlusion out of a prospective conducted database (Endovascular MILestones - EMIL) for demographics, risk factors, co-morbidities, technical success rates, lesion characteristics and use of guidewires as well as re-entry systems. A total of 128 patients with 146 lesions, which represent a subgroup of all the cases performed in our center, following a predefined treatment algorithm for chronic total occlusions (CTOs), have been analyzed.

RESULTS

We achieved a technical success in 133 (91.1%) of all cases following a "wire only" strategy. Out of 13 (8.9%) CTOs with technical failure in 7 (53.9%) CTOs a re-entry device (Off-Road®) with a 100% technical success has been used. In 91.1% of chronic total occlusion lesions the use of 2 wires only (88.7%) led to a successful recanalization. A "wire only" strategy followed by the use of a re-entry device as a bail out strategy, led to a total of 140 (96%) lesions to be successfully recanalized.

CONCLUSION

In more than 90% of all cases with chronic total occlusion of peripheral lower extremity arteries, endovascular intervention has been successful following a "wire only" strategy. When deciding to use a re-entry device, in case of a failure of a proper wire re-entry at the reconstitution point, a technical success rate of 100% was achieved. Therefore following a strict wire algorithm and considering the use of a re-entry system as a bail out strategy will lead to a successful minimal invasive management of chronic total occlusion in nearly 100% of the cases with TASC II A - D lesions.

[Arterial closure devices. What device for which clinical situation?]

CLINICAL/METHODICAL ISSUE

Access site complications after endovascular catheterization sometimes require open surgery and negatively impair safety, patient comfort and reimbursement. Increasing numbers of procedures and patients with multiple anticoagulants as well as cost pressure explain the demand for an immediate and stable access site closure.

STANDARD RADIOLOGICAL METHODS

Manual compression followed by compression bandage and bed rest for 4-24 h is still the gold standard but is unable to prevent access site complications in all cases.

METHODICAL INNOVATIONS

Arterial vascular closure devices allow immediate and stable closure of the puncture channel either by suture or by implantation of occluding foreign bodies or gluing fluids.

PERFORMANCE

The safety has been proven in several clinical trials. The main advantage lies in closing large lumen access sites without surgery and in patients treated with multiple anticoagulants as well as in outpatient procedures.

ACHIEVEMENTS

They have become a valuable supplement to the interventional arsenal.

PRACTICAL RECOMMENDATIONS

The physician, however, has to decide between different systems and mechanisms with respect to patient constitution, selected access vessel and level of calcification and diameter. Furthermore, all systems require a defined training prior the first use.

Feasibility and reproducibility of the PsAMRIS-H score for psoriatic arthritis in low-field-strength dedicated extremity magnetic resonance imaging

OBJECTIVES

The psoriatic arthritis magnetic resonance imaging scoring system (PsAMRIS-H) for the evaluation of inflammatory and destructive changes in PsA hands was validated on 0.6-T scanners. The applicability of the PsAMRIS-H on a low-field MRI system as a well-accepted, low-cost imaging modality was evaluated.

METHOD

In 65 consecutive patients (31 males, median age 52 years), 73 scans on a 0.2-T dedicated extremity MRI system were obtained for evaluation of PsA. Images were scored for synovitis, tenosynovitis, periarticular enhancement, bone erosion, bone oedema, and proliferation, and the PsAMRIS-H score was calculated. The intraclass correlation coefficient (ICC) was calculated and the paired t-test conducted.

RESULTS

Intra-reader reliability for the total PsAMRIS-H score was good, with an ICC of 0.81 and 0.77 for readers 1 and 2, respectively, and inter-reader agreement was moderate (0.57 for each reader). However, the PsAMRIS-H score differed significantly between the two readers (22 vs. 31; p < 0.05). When individual components of the PsAMRIS were evaluated, intra- and inter-reader agreement was poor to moderate, especially for tenosynovitis and periarticular inflammation.

CONCLUSIONS

Low-field 0.2-T MRI is capable of quantifying the PsAMRIS-H with good intra-reader reproducibility. However, low signal-to-noise ratio (SNR), low spatial resolution, and system artefacts limit the application of the PsAMRIS-H, leading to low inter- and intra-reader agreement for individual features.

[Angiographic diagnosis of acral circulatory disorders of the upper extremities]

Acral ischemic lesions rarely affect the upper extremities. While in the lower limbs atherosclerosis is responsible for the majority of lesions, vasculitis and autoimmune diseases play an important role in the pathogenesis of ischemic lesions of the upper limbs. A considerable number of acral circulatory disorders present with Raynaud's phenomenon and often without associated necrosis. Raynaud's phenomenon is mainly idiopathic but may also be secondary to underlying conditions, such as autoimmune diseases and vasculitis. Because of its high spatial resolution and the often discrete morphological findings digital subtraction angiography (DSA) is still an important diagnostic method in the radiological evaluation of acral circulatory disorders of the hand. Angiographic features of vasculitis are not strictly pathognomonic but certain morphologic DSA findings are very typical and may allow for a radiologic diagnosis. For instance, atherosclerosis results in irregular contours of vessel walls in DSA in contrast to autoimmune diseases and vasculitis, which are usually characterized by smooth vessel walls and optional vasospasm, the latter being especially typical for thromboangiitis obliterans and scleroderma. In thromboangiitis obliterans occlusions of the distal hand arteries, corkscrew collateral vessels and subsequent development of fine collateral networks are typical findings. Abrupt or filiform occlusions of distal finger arteries with sparse collateralization and symmetric affection of both hands are suggestive of scleroderma. Disseminated segmental ectasis and stenosis as well as microaneurysms (63% of all patients) are very common in patients with panarteriitis nodosa.

[Peripheral arterial disease. Diagnosis and therapy according to current guidelines]

Guidelines conduce to establish consistent standards of therapy and contribute to the orientation and safeguard of the attending physician. Peripheral arterial disease (PAD) may be classified according to its stage as intermittent claudication, chronic critical limb ischemia or acute limb ischemia. Since these diseases are common and life-threatening, current guidelines are of major interest for the attending physician, not least because of forensic reasons. This overview describes the current principles of diagnosis and therapy as well as recent developments in peripheral endovascular intervention. Current national and international guidelines, particularly the Transatlantic Intersociety Consensus (TASC), were taken into account.

[Chronic critical ischemia of the lower leg: pretherapeutic imaging and methods for revascularization]

Each year 1-2% of patients with peripheral arterial occlusive disease (pAOD) develop critical limb ischemia (CLI), characterized by rest pain and peripheral ulcer or gangrene. This aggravation of the disease is accompanied by an increase of the 1-year mortality rate up to 25% and a similarly increased frequency of major amputation. We can choose between conservative, endovascular, and surgical procedures for an adequate therapy of the underlying vascular stenoses or occlusions. Yet, clear therapeutic recommendations only exist for suprapopliteal lesions. However, in a number of cases, especially in diabetics, target lesions have an infrapopliteal location. Since endovascular procedures have undergone significant improvement in the last few years, the following review discusses methods for infrapopliteal revascularization taking into consideration the newest publications on this topic.

Bildgebende Verfahren in der Frühdiagnostik rheumatischer Veränderungen der Hände

PURPOSE

Besides the use of conventional x-rays in the diagnostic work-up of initial changes in patients suffering from rheumatoid arthritis (RA), 3-phase bone scintigraphy (3P-Sz) is as well established as magnetic resonance imaging (MRI). The aim of this study was to compare the diagnostic value of ultrasound of the hands with proven methods such as conventional x-rays, low-field MRI and 3P-Sz.

METHODS

A total of 30 patients were studied using a 1 day protocol with ultrasound, 3P-Sz, MRI and x-ray of the hands. Images were visually assessed by two blinded nuclear medicine physicians and radiologists and classified as RA typical and non-RA typical changes. All methods were compared to the summarized findings interpreted by a rheumatologist after 2 years.

RESULTS

Of the 30 patients, 19 presented with clinical symptoms of initial changes due to rheumatoid arthritis. Ultrasound revealed 14/19 patients with the correct diagnosis. Conventional x-rays indicated 11/19 patients, while 3P-Sz (100%) and low-field MRI (95%) showed high sensitivity. It was possible to differentiate between inflammation and inconspicuous findings.

CONCLUSIONS

An experienced examiner can use ultrasound effectively for the initial diagnosis of RA. Based on its low cost, ultrasound is a valid alternative to conventional x-rays.

Ein Vergleich von C-Bogen-CT und Standardbildgebung an Osteosynthesen frakturierter Präparate des distalen Radius

BACKGROUND

The purpose of this study was to evaluate the value of C-arm CT imaging of the distal radius with standard patient positioning in intraoperative assessment of plate osteosynthesis.

MATERIALS AND METHODS

Four complete distal radius specimens from human cadavers were fractured (type C), and internal fixation with palmar plates (stainless steel) was then carried out in each. On the basis of C-arm fluoroscopy, radiography and C-arm CT (Siremobil Iso-C3D, scans with forearm bones positioned parallel to the z-axis), 19 observers subsequently evaluated the positions of screws near the joint and any steps within the joint, after which the bones were surgically exposed and the imaging results checked against direct visual observations.

RESULTS

No statistically significant differences were detected either between the modalities or between the evaluator groups.

CONCLUSION

With standard patient positioning, the performance of C-arm CT was equivalent to and not better than that of current standard procedures, i.e. intraoperative fluoroscopy and postoperative radiography. Further studies should examine whether this holds true in clinical practice with representative patient collectives when titanium implants are used and/or optimized patient positioning is practised.

[Stenting of the SFA--indications, techniques, results]

Aggressive risk factor modification, change of eating habits, exercise programs, and forceful antiplatelet therapy are the most important tools for the treatment of PAOD in symptomatic patients suffering from intermittent claudication. There are however no guidelines for revascularization at this stage. Endovascular treatment has been increasingly utilized over the last decade and increasingly displaced vascular surgery. Amongst numerous endovascular techniques beside PTA, stents meanwhile play the most important role due to constant technical progress. Results regarding the rate of restenosis or patency rates still remain worse compared to other vascular beds. This paper gives a review over recent results, currently available stent techniques, and possible indications for the endovascular therapy of an artery, which has turned out to be the biggest ordeal for material and construction of stents.

Frühmanifestationen rheumatischer Gelenkerkrankungen an den Weichgewebestrukturen der Hand

PURPOSE

The aim of this study was to evaluate typical magnetic resonance imaging (MRI) findings in early rheumatic diseases manifesting at the soft tissues of the hand using a retrospective analysis.

MATERIAL AND METHODS

A total of 186 MRI examinations of patients with clinical suspicion of a rheumatic disease were evaluated in a consensus reading by two experienced radiologists. All imaging patterns were assessed with respect to their type and localization. Under blinded and non-blinded conditions diagnoses were correlated with final clinical diagnosis.

RESULTS

The most frequent diagnoses were rheumatoid arthritis (RA, 45.7%) and psoriatic arthritis (PsA, 15.6%). The mean correlation between clinical and MRI diagnosis (r) was 0.75 in blinded and 0.853 in non-blinded reading (p <0.001). The following extra-articular imaging patterns were found: synovitis (59.1%), tendovaginitis (91.4%), dactylitis (14.5%), and bone marrow edema (18.3%). Only dactylitis was specific for a particular rheumatic disease (PsA; r=0.934; sensitivity 84.9%, specificity 82.4%).

CONCLUSION

Inflammatory conditions of the hand can be reliably detected with MRI. In many cases the definite diagnosis can only be made when taking clinical, serological, and radiographic results into account (+13.7% increase of significance).