Evaluation of a new computerized analysis system developed for the processing of CT follow-up scans after EVR of infrarenal aneurysm.

PURPOSE: The aim of this retrospective study was to present a new computerized analysis system developed for the evaluation of follow-up CT scans after endovascular repair (EVR) of infrarenal aneurysm and to compare it to the conventional evaluation method as regards preciseness and ease of application. The system is based on the extraction of the surface of the stent-graft (SG) and that of the spinal canal and the overlay of surfaces obtained at different points in time. MATERIALS AND METHODS: A total of 116 CT follow-up data sets obtained from 49 patients after EVR of infrarenal aneurysm were evaluated using both, the conventional method and the new computerized system. Two parameters were analyzed: SG length and the distance between the most ventral point of the SG and the vertebral column. The correlation between the results of the two methods and the correlation between the results obtained by two independent observers (radiologist and lay person) using the new system were assessed by statistical analysis. RESULTS: Comparison of the two methods yielded a very high correlation for both parameters, (correlation coefficients of around 0.9 and p<0.001). Comparison of the results obtained by the two observers yielded an equally high correlation (correlation coefficients of around 0.9 and p<0.001). CONCLUSION: Our results show that the new computerized system is as precise and reliable as the conventional method, but allows better visualization and quantification of SG changes by surface overlay. Moreover, it is easier to apply and less time-consuming and can be easily integrated into existing systems.

Transarterial embolization for the management of hemarthrosis of the knee.

BACKGROUND: The purpose of this retrospective study was to evaluate transarterial catheter embolization (TAE) for the management of hemarthrosis of the knee in 35 patients treated at two different hospitals. METHODS: From June 1998 through January 2011, 35 patients (22 men and 13 women, mean age 57 years) underwent TAE for hemarthrosis of the knee using polyvinyl alcohol particles (PVA particles), multi-curled 0.018 in. microcoils or a combination of both. In one patient a detachable microcoil was used. Hemarthrosis developed after arthroscopy in 9, after trauma in 3, after arthroplasty in 18 and after sepsis in 2 patients. 2 patients had severe gonarthrosis and in one patient hemarthrosis was due to Marfan's syndrome. Angiographies showed abnormal and increased vasculature in 23 patients, one or more pseudoaneurysms in 8 and arterio-venous fistula in 2 patients. One patient showed both, pseudoaneurysm and hypervascularization and another one pseudoaneurysm and arterio-venous fistula. RESULTS: Technical success was achieved in 100%. None of the patients developed procedure-related complications such as periarticular skin- or tissue necrosis, including a patient who underwent TAE of two different bleeding sources in two consecutive sessions. Clinical success was 93.4%. Two patients showed recurrent swelling of the knee, 377 and 824 days after TAE respectively. However, only one of them required secondary TAE because of abnormal and increased vasculature. CONCLUSIONS: In our view, TAE is the treatment of choice for the management of hemarthrosis of the knee. It is an effective and minimally invasive technique with very low complication rates.

Benefit, risks and cost-effectiveness of screening for abdominal aortic aneurysm.

PURPOSE: Abdominal aortic aneurysms (AAA) cause a considerable number of deaths. A ruptured AAA is associated with a mortality rate of 80%. The purpose of this study was to summarize the current evidence from published health economic models for the long-term effectiveness and cost-effectiveness of screening programs for AAA. MATERIALS AND METHODS: Medical, economic and health technology assessment (HTA) databases were systematically searched for cost-effectiveness models up to October 2007. Only models with a lifetime time horizon of evaluating AAA screening in men over 65 years were included in the review. Study data were extracted, standardized and summarized in evidence tables and cost-effectiveness plots. RESULTS: We reviewed 8 cost-effectiveness models published between 1993 and 2007 comparing AAA screening and lack of screening in men over 60. One model yielded a loss of life-years at additional costs. The remaining seven models yielded gains in life expectancy ranging from 0.02 to 0.28LYs. Gains in quality-adjusted life expectancy reported by six of the seven models ranged from 0.015 to 0.059 QALYs. Incremental costs ranged from 96 to 721 Euros. Incremental cost-effectiveness ratios (ICER) ranged from 1443 to 13 299 Euros per LY or QALY gained. CONCLUSION: Based on our analysis, the introduction of a screening program to identify AAA will probably gain additional life years and quality of life at acceptable extra costs. The target population for a screening program should be men 65 years and older.

Endovascular repair or medical treatment of acute type B aortic dissection? A comparison.

INTRODUCTION: The aim of this retrospective study was to compare the outcome of thoracic endovascular aortic repair (TEVAR) to that of medical therapy in patients with acute type B aortic dissection (TBD). MATERIALS AND METHODS: From July 1996 to April 2008, 88 patients presenting with acute TBD underwent either TEVAR (group A, n=38) or medical therapy (group B, n=50). Indications for TEVAR were intractable pain, aortic branch compromise resulting in end-organ ischemia, rapid aortic dilatation and rupture. Follow-up was performed postinterventionally, at 3, 6 and 12 months and yearly thereafter and included clinical examinations and computed tomography (CT), as well as aortic diameter measurements and assessment of thrombosis. RESULTS: Mean follow-up was 33 months in group A and 36 months in group B. The overall mortality rate was 23.7% in group A and 24% in group B, where 4 patients died of late aortic rupture. In group A, complications included 9 endoleaks and 4 retrograde type A dissections, 3 patients were converted to open surgery and 2 needed secondary intervention. None of the patients developed paraplegia. In group B, 4 patients were converted to open surgery and 2 to TEVAR. The maximal aortic diameter increased in both groups. Regarding the extent of thrombosis, our analyses showed slightly better overall results after TEVAR, but they also showed a tendency towards approximation between the two groups during follow-up. CONCLUSION: TEVAR is a feasible treatment option in acute TBD. However, several serious complications may occur during and after TEVAR and it should therefore be reserved to patients with life-threatening symptoms.

Coil embolization of internal mammary artery injured during central vein catheter and cardiac pacemaker lead insertion.

PURPOSE: This study describes several cases of endovascular coil embolization of the proximal internal mammary artery injured by blind approach to the subclavian vein for central venous catheter or pacemaker lead insertion. MATERIALS AND METHODS: We conducted a retrospective analysis of five patients with iatrogenic arterial lesions of the internal mammary artery (IMA). The lesions occurred in three patients from a puncture of the subclavian vein during insertion of a central venous catheter and in two patients from a puncture of the subclavian vein for insertion of a pacemaker lead. Four patients had acute symptoms of bleeding with mediastinal hematoma and hematothorax and one patient was investigated in a chronic stage. A pseudoaneurysm was detected in all five patients. All four acute and hemodynamic unstable patients required hemodynamic support. RESULTS: In all patients, embolization was performed using a coaxial catheter technique, and a long segment of the IMA adjacent distally and proximally to the source of bleeding was occluded with pushable microcoils. In one patient, additional mechanically detachable microcoils were used at the very proximal part of the IMA. Microcoil embolization of the IMA was successful in all patients, and the source of bleeding was eliminated in all patients. CONCLUSION: Transarterial coil embolization is a feasible and efficient method in treating acute bleeding and pseudoaneurysm of the IMA and should be considered if mediastinal hematoma or hemathorax occurs after blind puncture of the subclavian vein.

Postinterventional volume dynamics following endovascular treatment of infrarenal aortic aneurysms.

AIM: Endovascular treatment of infrarenal aortic aneurysms requires follow-up to rule out complications that would require renewed intervention. The aim of this study was to define those factors which, in the absence of such complications, could be relevant for the remaining risk. METHODS: The CT data sets of 55 patients (73.5+/-8 years; M: F ratio 49: 6) were evaluated volumetrically: immediately postinterventional, 6 months, and annually after the procedure. The median observation period was 30+/-19 months. RESULTS: Risk factors for a further increase in aneurysm volume were: short-term increase in volume >5%, medium-term growth >20%, one-time growth >20%, no decrease in volume, and an initial aneurysm volume >200 mL. Favorable factors were: a one-time decrease in volume >15% and no increase in volume at any follow-up visit. Indifferent factors were: initial decrease in volume, one-time growth <20%, one-time shrinkage <15%, and type II endoleak. Conclusion. Patients require particular attention whose aneurysm volume increased by more than 5% or increased medium-term or increased at once by more than 20%, and who either did not show a decrease in volume at any follow-up or who had a large initial volume. A one-time decrease in volume of more than 15% was positive, as was no increase in volume at any follow-up.

Placement of endovascular stent-grafts for emergency repair of acute traumatic aortic rupture: a single-centre experience.

The aim of this retrospective study was to evaluate mid- and long-term results of endovascular stent-graft placement for emergency repair of acute traumatic thoracic aortic rupture. From 1996 through 2005, 22 consecutive patients (mean age: 38.7 years) underwent endovascular repair of acute traumatic thoracic aortic rupture located at the aortic isthmus in most cases. All patients were at high surgical risk due to severe associated injuries. The endografts were inserted via femoral or iliac artery access under fluoroscopic guidance. Follow-up was performed postinterventionally, at 6 and 12 months and yearly thereafter, and included clinical examination and computed tomography (CT) scans. Technical and clinical success rates were 86.3%. Mean follow-up was 31.7 months. Three patients developed early type I endoleak due to the inability of the rigid graft to adapt to the curved aortic contour. In two of them conversion to open surgery was necessary. One patient had late type I endoleak and died. No other complications were observed. The outcome was successful in most patients. The mid- and long-term results of our current study are promising. However, early type I endoleak represents a problem, especially in adolescent patients with a marked curvature of the aortic arch.

Technical and clinical success of infrarenal endovascular abdominal aortic aneurysm repair: A 10-year single-center experience.

OBJECTIVE: The aim of our retrospective study was to review our single-center experience with aortic abdominal aneurysm (AAA) repair retrospectively. MATERIAL AND METHODS: From 1995 to 2005, 70 consecutive patients affected by AAA were treated by endovascular stent-graft repair. Mean follow-up was 23.9 months. Follow-up investigations were performed at 6 and 12 months and yearly thereafter. Five different stent-graft designs were compared to each other. Primary technical success (PTS), assisted primary technical success (APTS), primary clinical success (PCS) and secondary clinical success (SCS) were evaluated. RESULTS: All over PTS was achieved in 94.3%, APTS in 97.1%, PCS in 61.4%, APCS in 64.3% and SCS in 70%. There were 3 type I endoleaks, 25 type II endoleaks, 4 type III endoleaks, 8 limb problems, 5 conversions to open surgery, 10 aneurysm sac expansions and 14 device migrations. Patients with newer generation devices showed better results than patients with first generation prosthesis. In addition results were better for grafts with suprarenal fixation (versus infrarenal fixation) and grafts with barbs and hooks (versus grafts without barbs and hooks). Patients with bad anatomic preconditions showed a higher complication rate. CONCLUSION: Contrary to first generation products, new stent-graft designs show acceptable technical and clinical results in endovascular AAA aneurysm repair. However, this therapy still should be reserved only for patients with significant comorbities and suitable anatomic conditions.

Mid-term results after endovascular repair of the atherosclerotic descending thoracic aortic aneurysm.

INTRODUCTION: Thoracic aortic aneurysms (TAA) are the most common condition of the thoracic aorta requiring surgical treatment. Despite significant improvement in anesthetic, surgical techniques and postoperative care, the mortality and morbidity rate in TAA-repair remains high. The aim of this study was to assess the morbidity and mortality rate after endovascular stent-graft treatment of atherosclerotic (non-dissecting) TAAs. METHODS: Thirty-one patients, ASA-classification III-IV, with symptomatic or expanding atherosclerotic TAAs underwent endovascular stent-graft repair between May 1997 and August 2003. Procedures were performed on an emergency basis in 13 patients and elective in 18 patients. Patients were assessed postoperatively by routine CT-scan within 48 h. Further follow up investigations were performed after 3, 6, 12 months and annually thereafter. RESULTS: Stent-graft placement was successful in all but one patient in whom the stent-graft procedure had to be postponed due severe hemodynamic instability. Perioperative mortality rate was 19% including three haemorrhages, two cardiac events and one respiratory failure (6/31). Technical success rate was 55% (17/31). Completion CT scans performed in 30 patients within 2 days of stent-graft procedure showed type I leaks in seven patients (23%), type II leaks in four patients (13%) and type III leaks in two patients (6%). Further complications included one stroke, one paralysis, one spinalis anterior syndrome and five relevant access related complications. New onset endoleaks, all type I, were observed in seven patients (23%) occurring after 3, 4, 7, 8, 17, 25 and 26 months. Mean follow-up was 15 months (range 2-69 months). CONCLUSION: Thoracic aortic atherosclerotic aneurysm stent-grafting is feasible but not without significant morbidity and mortality.

Infection of a total hip arthroplasty with Prevotella loeschii.

Infection is a serious complication of total hip replacement. It has been proposed that 6% of all infections after total hip arthroplasty may be of dental origin through hematogenous spread. However, no conclusive evidence that the mouth is a definitive source for infection of a total hip replacement has been reported. In the current case, Prevotella loeschii, a pigmented bacteroides species was identified in a total hip replacement. Prevotella loeschii is an organism which exclusively inhabits the dental region. Hematogenous spread of Prevotella loeschii may occur after penetration of the mucosal barrier in cases of endodontic or periodontic lesions, pericoronitis, or complications of tooth extraction. The involvement of Prevotella loescheii in an infection in a patient who had a total hip arthroplasty is strong evidence for the mechanism of a hematogenous infection from a dental source.

[Stress fractures in athletes]. / Stressfrakturen bei Athleten.

Stress fractures may pose a diagnostic dilemma for radiologists since they are sometimes difficult to demonstrate on plain films and may simulate a tumour. They were first described in military personnel and professional athletes. Recently, there is an increasing incidence in the general population due to increasing sportive activities. Stress fractures occur most often in the lower extremities, especially in the tibia, the tarsal bone, the metatarsal bone, the femur and the fibula. In the upper extremities, they are commonly found in the humerus, the radius and the ulna. Some fractures of the lower extremities appear to be specific for particular sports, for example, fractures of the tibia affect mostly distance runners. Whereas stress fractures of the upper extremities are generally associated with upper limb-dominated sports. A correct diagnosis requires a careful clinical evaluation. The initial plain radiography may be normal. Further radiological evaluation could be performed by means of computerised tomography, magnetic resonance imaging and bone scanning. The latter two techniques are especially helpful for establishing a correct initial diagnosis.

Serial CT volume measurements after endovascular aortic aneurysm repair.

PURPOSE: To evaluate the efficacy of transluminal stent-graft placement in aortic aneurysms using postoperative enhanced spiral computed tomographic (CT) volumetric measurements of the aneurysm sac, the intra-aneurysmal vascular channel (IAVC), the thrombus, and the stent-graft. METHODS: Among 53 patients (45 men; mean age 74 years, range 59-85) who underwent elective endovascular aortic aneurysm repair, 37 patients with 27 abdominal and 10 thoracic aortic aneurysms completed at least a 6-month follow-up that included computerized CT volumetric analysis prior to discharge and at 3, 6, 12, 24, and 36 months. A variety of bifurcated (n = 23) and tube (n = 14) stent-grafts were observed for signs of endoleak and aneurysm enlargement. RESULTS: Mean follow-up was 16 months (range 6-48). Total aneurysm volumes and thrombus volumes decreased, whereas IAVC and stent-graft volumes increased over time. Between the postoperative and 12-month imaging studies, reductions in total aneurysm (p 0.011) and thrombus (p < 0.001) volumes were significant. No statistically significant difference in volume changes for the aneurysm sac (p = 0.555) or the thrombus (p = 0.920) was found when comparing the 24 patients without primary leak to the 12 with primary type-II leak. In all 5 cases with secondary leak, the volume of the aneurysm sac increased after initial shrinkage. CONCLUSIONS: Postoperative CT volumetric analysis is an effective tool for evaluating the outcome of endovascular aortic aneurysm repair. Thrombus volume measurements are more accurate than total aneurysm volumes. In patients in whom contrast agents are contraindicated, volume measurements can also be obtained without the use of contrast.

Radiographic evaluation of cervical spine trauma. Plain radiography and conventional tomography versus computed tomography.

Different imaging modalities are available for the diagnosis of cervical spine injuries. There is a controversial discussion about whether plain radiography (PR), conventional tomography (CTO) or computed tomography (CT) should primarily be used. PR and CTO are more often available and less costly than CT. Especially in second-care hospitals, CT is not always available. The diagnostic work-up in these centres has to rely on conventional techniques. The aim of this study was to define the role of PR supplemented by CTO in the diagnosis of cervical spine trauma in comparison to CT. Twenty-five patients were identified who underwent plain radiography (PR), conventional tomography (CTO) and computed tomography (CT) for the diagnosis of a cervical fracture. In 19 patients a fracture of the cervical spine was identified. All images were reviewed by two independent observers to estimate the interobserver variability. The highest detection rate was achieved by CT (18/18 fractures detected for observer 1/2), followed by CTO (16/16 fractures) and then PR (15/14 fractures). When the detection rates of PR and CTO are combined, 18 fractures were detected by each of the observers. The results were analysed for the dens and the rest of the cervical spine independently. For PR and CTO the detection rates were lower for fractures of the dens than for the rest of the cervical spine. We conclude that the combination of PR and CTO accurately detects fractures of the cervical spine compared with CT. If a fracture of the dens is suspected, the patients should be referred to CT due to its superior accuracy in this region.

Comparison of low-contrast detail perception on storage phosphor radiographs and digital flat panel detector images.

A contrast detail analysis was performed to compare perception of low-contrast details on X-ray images derived from digital storage phosphor radiography and from a flat panel detector system based on a cesium iodide/amorphous silicon matrix. The CDRAD 2.0 phantom was used to perform a comparative contrast detail analysis of a clinical storage phosphor radiography system and an indirect type digital flat panel detector unit. Images were acquired at exposure levels comparable to film speeds of 50/100/200/400 and 800. Four observers evaluated a total of 50 films with respect to the threshold contrast for each detail size. The numbers of correctly identified objects were determined for all image subsets. The overall results show that low-contrast detail perception with digital flat panel detector images is better than with state of the art storage phosphor screens. This is especially true for the low-exposure setting, where a nearly 10% higher correct observation ratio is reached. Given its high detective quantum efficiency the digital flat panel technology based on the cesium iodide scintillator/amorphous silicon matrix is best suited for detection of low-contrast detail structures, which shows its high potential for clinical imaging.

Multisegmental pneumatocysts of the lumbar spine mimic osteolytic lesions.

Circumscribed radiolucencies within the vertebral bones can be due to a variety of changes including benign and malignant tumours or tumour-like lesions. Radiolucencies due to degenerative intraosseous pneumatocyst are very uncommon but have to be taken into the differential diagnosis in well-circumscribed lytic lesions of the vertebral bodies. We describe the first case of multisegmental pneumatocysts in the lumbar spine mimicking osteolytic lesions. On computed tomography, the air-equivalent attenuation values of the lesions and the close vicinity to the degenerated vertebral endplates with vacuum phenomenon led to the correct diagnosis.

Radiographic assessment in total knee arthroplasty.

Sixty-five total knee arthroplasties were evaluated by the Knee Society Radiological Evaluation System which was developed to encourage uniform reporting of the results of total knee arthroplasty. All patients were examined by three independent experienced radiologists 8.9 years after surgery (range, 3-16 years) to analyze the interobserver variability. For measurement of angles, high interobserver correlation was calculated for the prosthetic component angles and the femorotibial shaft angle. The comparison of the means indicated no significant differences except for the femorotibial shaft angle. For measurement of radiolucent lines, interobserver correlation was low for all components. The differences of the means were significantly different for all components. The results of interobserver variability of the patellar evaluation revealed high interobserver correlation for the patellar angle and for patellar subluxation and dislocation evaluation. For assessment of patellar mediolateral and superoinferior displacement, a low interobserver correlation was found. For radiographic assessment of total knee arthroplasty, the measurement of angles, including alpha, beta, femorotibial shaft angle, sagittal femoral and tibial component angle, patellar angle, and patellar subluxation and dislocation evaluation are recommended. The method of assessing radiolucent lines should be reconsidered.

[Color-coded doppler sonographic demonstration of intrahepatic venous collaterals in Budd-Chiari syndrome]. / Farbkodierte Doppler-Sonographische Darstellung von intrahepatischen Venenkollateralen beim Budd-Chiari-Syndrom.

By means of colour Doppler ultrasound, veno-venous shunts were found in 3 cases, leading to the diagnosis of Budd-Chiari Syndrome. Pulsed and colour Doppler ultrasound showed a reduction in venous blood flow and the reversal of blood flow in the venous collaterals. Venous spectral Doppler wave forms in the veno-venous shunts were flattened and aphasic in all cases. Sonographic findings were confirmed by cavography. Our cases show that pulsed and colour Doppler ultrasound are a valuable tool in the initial diagnosis of veno-venous shunts associated with Budd-Chiari Syndrome.

False aneurysm 14 years after total hip arthroplasty.

Many reports of complications after total hip arthroplasty have been published concerning typical orthopaedic problems. Relatively little attention has been paid to serious vascular injuries, such as the development of a false aneurysm. To our knowledge, 10 cases have been described in the English literature. The mean time interval between surgery and initial manifestation of the aneurysm was 9 months in these cases. Our patient developed first symptoms of a false aneurysm 14 years after surgery. A minimally invasive technique was used to cut the aneurysm from perfusion. Removal of the total hip arthroplasty was performed through a retroperitoneal and lateral approach.