[Quality report 2011 of the German Society of Interventional Radiology (DeGIR)--part 2. Endovascular treatment of aortic aneurysms (EVAR)]

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.

[Interventional endovascular therapy of infrarenal abdominal aortic aneurysm]

The catheter-based interventional therapy (endovascular aortic repair EVAR) of abdominal aortic aneurysms (AAA) has gained an established place in the spectrum of therapeutic options. The procedure is characterized by low peri-interventional morbidity and mortality. Multislice computed tomography (CT) has a dominant role in defining the correct indications and in selecting an appropriate stent graft prior to the intervention. The rate of acute conversions could be reduced from 2.9 % to 0 % in our own elective patient population since 2010. In our vascular centre the proportion of patients treated by EVAR was 39.5 % (102 out of 258). The procedure is used routinely in patients who have an increased risk for general anesthesia or open surgery due to concomitant diseases. It is also used in patients with a reduced local operability due to prior surgery, abdominal diseases or radiation therapy. Arterial closure devices allow a completely percutaneous approach in a certain group of patients. However, after EVAR a life-long surveillance is mandatory because delayed therapy failure has been described. In younger patients who do not have a higher risk open surgery is still an option. The paper describes techniques, results und complications of EVAR.

[Quality report 2011 of the Germyn Society of Interventional Radiology (DeGIR) - report about treatment quality of minimal invasive procedures]

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.

[Certification of vascular centers. Influence on quality and healthcare structures]

Diagnosis and therapy of vascular diseases are increasingly being performed following a multimodal, interdisciplinary and less invasive approach. The introduction of specialized, organ-related centers is a logical consequence in view of a better treatment quality and a more effective use of resources. The German societies of radiology, vascular surgery and angiology jointly developed a process of certification, which has been successfully applied to more than 100 units in Germany. In this article the terms and results of the process are described and possible effects on the quality and structures of the healthcare system are discussed.

[PACS: from project to reality. Report of experiences on full digitalisation of the radiology department of a major hospital]

OBJECTIVE

To assess the time needed and the resulting effects of a complete digitalisation of a radiological department of a major hospital (856 beds, 28,000 in-patients, 35,000 out-patients/year) a pilot study was performed. This had to be done without interrupting routine services.

RESULTS

After intensive preparations were performed and the hospital-network was completed, within a two year period all radiological functions (mammography excluded), reporting stations and archives were changed to a complete digital workflow. All modalities (provided by 3 different companies) are now connected by DICOM-work lists. The picture-files (4 GB/day) are automatically routed to the work-stations (n = 10), where the reporting and file shows are performed, to the digital archive and to the peripheral viewing-stations (n = 44). The distribution of the digital pictures takes place all over the hospital including the ORs and special units. We accomplished, to connect electronically the report and the image data. The clinical file shows are also performed completely digitally. The access to the data of the deep archive is possible by the dept. of radiology without any manual interaction. The film consumption was reduced to an amount of less than 10%, as compared to the prior PACS situation. Since PACS has been introduced the radiological productivity increased by more than 15% and throughput-time was clearly reduced.

CONCLUSIONS

The complete digitalisation increases productivity and attractiveness of a hospital-radiology and helps to shorten diagnostic and therapeutic decision-making. The transfer from a conventional to a digital workflow is possible without interrupting the clinical services. Extensive preparations and ongoing assistance of such projects though are clearly needed.

[Injury of polyester grafts by vascular clamps]

Protected vascular clamps are not new. Clamp associated damage of human arteries has already been published over 20 years ago. The necessity of protective clamps seems to have been forgotten. In our explant archive (230 explants) we have observed an accumulation of graft ruptures in the groin (13 of 25 ruptures). We presume a multifactorial process. Clamp damage could be part of it. The aim of this study is to prove the clamp induced damage of polyester vascular grafts and to examine whether protected clamps can reduce this.

METHOD

Five unprotected (Aesculap(R) FB512R, FB502, FB517, Ulrich CC1235, CV3535) and 5 protected vascular clamp types (Aesculap(R) FB667, FB668, Edwards(R) - formally Baxter(R) - Fogarty(R) CV5050, CV5201, Edwards(R) Cosgrove(R) CV1033) were tested. A longitudinal burst test was performed after maximal clamp closure on 6 different, multifilament polyester yarns of 2 different vascular grafts manufacturers (B. Braun(R), Edwards(R)).

RESULTS

The yarn tests with protected clamps showed no difference to those of the unclamped yarns. After clamping with unprotected vascular clamps the stress-strain-diagrams differed significantly. The mean, maximum burst strength was up to 75 % lower. Video documentation revealed filament ruptures. Damage of the yarn surface was seen on a simple woven graft in scanning electron microscopy (SEM).

DISCUSSION

The application of unprotected vascular clamps on polyester vascular grafts is common in Germany (56 %). The observed damage of multifilament polyester yarns makes it necessary to re-consider the use of unprotected vascular clamps. The benefit for biological vessels has already been shown.

[Clinical value of native and contrast enhanced MRI in staging prostatic carcinoma before planned radical prostatectomy]

PURPOSE

To assess the clinical value of MRI with and without contrast agent in the staging of prostatic carcinoma. Relevance for surgical management.

METHODS

60 patients with carcinoma proven by biopsy or suspected prostatic carcinoma were evaluated with MRI. The examinations were performed in a 1.5 T (Philips ACS-NT Gyroscan) imager with multiplanar orientations before and after intravenous application of 0.1 mmol/kg/bw Gadodiamide (Omniscan-Nycomed/Amersham). The gold standard was histology after radical prostatectomy and in case of non-operability the consensual final staging.

RESULTS

Compared to histology MRI revealed a sensitivity of 75% and a specificity of 82% in the differentiation of locally advanced carcinoma (T 3/4). Including the non-surgical cases MRI showed a sensitivity of 82.5% and a specificity of 86%. Interindividual analysis showed no difference in diagnostic accuracy between the non-enhanced and the contrast-enhanced techniques. In 23% of cases (n = 14) MRI induced changes in patient management.

CONCLUSIONS

MRI is an accurate procedure in the local staging of prostatic carcinoma. In combination with clinical findings, PSA, and grading scores MRI has a significant influence on treatment selection. Contrast agent administration does not seem to increase the diagnostic accuracy significantly.

[Stent wire fractures and mesh loosening in explanted endovascular prosthesis]

Vascular grafts are available since the middle of the 50's. Explant retrieval studies still reveal not published material degradation today, after over 40 years of product development. Endovascular grafts exist since the beginning of the 90's. New developments and modifications have lead to numerous devices. The importance of explant retrieval studies grows.

MATERIALS AND METHODS

Among 33 stentgrafts, retrieved 5 to 43 months after implantation, the majority were 18 MinTec devices (17 Stentor, 1 Cragg). These 18 explants were examined by endoscopy, stereomicroscopy and scanning electron microscopy.

RESULTS

The following material degradation was observed. The textile coating showed holes along the longitudinal seam, the ligatures in-between the stentframes burst, allowing the frames to dislocate. Occasional fractures of the stent wire were seen accompanied by bowl-shaped alterations of the surface.

CONCLUSION

The Stentor device is, since its modification 1996, not available any longer. It was one of the most applied devices world-wide. The possible material deficiencies must be known by those performing patient follow-up. The occurrence of alterations within 43 months shows the importance of a continued follow-up besides clinical trials.

Semiclosed iliac recanalisation by an inguinal approach--modified surgical techniques integrating interventional procedures

OBJECTIVES

Technical success and early outcome of modified surgical techniques integrating interventional procedures for iliac recanalisation performed through an incision in the groin.

MATERIALS

Sixty-one consecutive iliac arteries in 59 patients with long occlusions in 16, occlusions of the common iliac in 11, occlusions of the external iliac in 24 and multiple stenoses of the iliac in 10 cases underwent semiclosed recanalisation through a groin incision.

METHODS

Passage of the lesion by guidewire permits retrograde ring-stripper endarterectomy over the wire as a guiding splint or thrombectomy with a double lumen balloon catheter. Residual lesions are corrected by balloon or stent angioplasty. Adequate outflow is established by femoral patch plasty.

RESULTS

Conversion to a standard operation was required in 10 limbs (failure to recanalise the lesion in nine, rupture after angioplasty in one). Initial technical success was achieved in the remaining 51 limbs (recanalisation by ring stripper endarterectomy in 36, thrombectomy in 14, both in six, additional intraoperative angioplasty in 42). Five postoperative thromboses were successfully treated by a combined surgical and interventional approach accounting for a 1-month 100% secondary patency.

CONCLUSION

Iliac recanalisation through the groin by modified ring stripper endarterectomy or modified thrombectomy in combination with intraoperative angioplasty is a safe and effective procedure. Long-term results are required to evaluate the procedure.

[The possibilities and risks of outpatient PTA in patients with peripheral arterial obstructive disease]

PURPOSE

To evaluate risk and feasibility of outpatient PTA in patients with iliac-femoral artery disease we conducted a prospective study.

MATERIAL AND METHOD

Out of a total group of 263 patients we selected 100 p. (38%) according to pre-defined criteria. The following criteria and others excluded the patients from outpatient procedures: insulin-dependent diabetes, poorly controlled hypertension, cardiac failure grade III and IV, chronic haemodialysis, severe overweight, elective stent implants.

RESULTS

90 of 100 patients for whom we had planned an outpatient procedure, could leave the day-clinic after a maximum of 10 hours of observation. For 10 patients we changed the procedure to an inpatient stay because of prolonged heparinisation, sudden elevation of arterial pressure, secondary stent implants and the need for local fibrinolysis therapy. Complications showed a trend to be lower in the outpatient group than in the inpatient group (2.0% vs 4.3%).

CONCLUSIONS

Performing iliac-femoral PTA on an outpatient basis demands strict selection criteria and a close tie-up to a day clinic. In 2/3 of our patients we preferred to perform PTA on an inpatient basis. A higher incidence of risks was seen in the inpatient group.

[Radiology information systems: improved performance evaluation, economics and quality assurance?]

By means of complete service control and standardized accounting processes, radiological information systems clearly contribute to improved results. They provide the prerequisites for the establishment of expanded networks and allow comparisons with comparable institutions. The quality of patient care can be improved since, for example, the production time from referral to finished result becomes shorter. Direct access to patient and findings data from several positions is possible. Preliminary results can be viewed immediately. The patient's history is accessible to authorized users at all times. The exact reproducibility and assignment of services leads to more clarity. By means of the information available form RIS, rapid adaptive processes can be undertaken. The system assists the to fulfill the requirements of health regulations. The above-mentioned relationships demonstrate that the EDP systems are well accepted by physicians, medical assistants, and administrators and represent an indispensable aid for solving problems.

[Popliteal aneurysms--surgical management versus conservative procedure]

217 patients with 349 popliteal aneurysms (PA) were studied. 45% presented with symptomatic complications, mainly thrombosis (21% acute, 15% chronic) and embolisation (7%). The mean diameter was significantly larger in acutely thrombosed (2.69 cm) than in patent PA (2.15 cm). The amputation rate in patients requiring emergency treatment was 36.1% after 2 years. The difference to patients undergoing bypass surgery in an asymptomatic stage (4-year graft patency 89%, limb salvage 100%) is highly significant. Of 128 PA treated conservatively, 53% were free of complications after 5 years. We conclude that prophylactic surgery of PA is justified in cases at high risk of developing complications, but that characteristics of those cases are not yet well defined.