[Experiences with power-injectable port systems: complications, patient satisfaction and clinical benefit]. / Komplikationsrate, Patientenzufriedenheit und klinischer Einsatz nach Implantation eines Portkathetersystems mit Zulassung zur Hochdruckinfusion.

PURPOSE: Evaluation of complications, patient satisfaction and clinical benefit of port systems with authorization for high pressure injection of contrast agent during CT/MR examinations. MATERIALS AND METHODS: Ultrasound-guided insertions of central venous port catheters were performed through the lateral subclavian vein at a university teaching hospital. The radiological information system (HIS/RIS) was used to evaluate technical success and complication rates. Assessment of patient satisfaction and clinical benefit was carried out by a questionnaire during a telephone call 6 months after implantation of the port system. RESULTS: A total of 195 port systems in 193 patients were implanted. The catheter remained in place for a mean duration of 169 days (overall 29,210 catheter days). The technical success rate was 99.5 % and the overall complication rate was 17.4 % (24/138; 0.82 per 1000 catheter days). Follow-up revealed 13 early port explantations (9 %). Most of the patients reported high satisfaction in general (satisfied/very satisfied: 94 %). 34/209 contrast-enhanced CT/MRT scans (16 %) were performed using the port for contrast media injection. There were no complications during or after administration of contrast agent via the port system. CONCLUSION: The Powerport system is a safe alternative for peripheral i. v. contrast media injection during CT/MR scans, but has been infrequently used. Most patients reported high overall satisfaction with the port system.

[Misplacement of central venous catheters in the subclavian artery: safe retrieval with a percutaneous closure device (AngioSeal)]. / Fehllage zentraler Venenkatheter in der Arteria subclavia: zuverlässige Entfernung mit einem perkutanen Verschlusssystem (AngioSeal).

PURPOSE: To evaluate the feasibility of retrieval of misplaced central venous catheters in the subclavian artery with a percutaneous closure device (AngioSeal). MATERIALS AND METHODS: According to the radiologic information system of a university hospital, 7 patients (6 women, 1 child) underwent removal of a misplaced central venous catheter (4 × 7 F, 1 × 8 F, 2 × 13 F) in the subclavian artery between January 2008 and June 2012 with the 8 F percutaneous closure device AngioSeal. The body mass index (BMI) of 7 patients was available, 3 of whom were obese (BMI 2 × 35.7 and 1 × 33.0). Both 13 F catheters were removed in a balloon-supported manner as described elsewhere. The Broviak catheter of a 21-month-old boy was removed by surgical support with preparation of the catheter to its vessel entry. Success control was done by a transfemoral DSA in 5 of the 7 patients. 2 patients received clinical follow-up. RESULTS: In all cases the misplaced catheter could be removed successfully. In all 7 patients, there was no arterial bleeding after catheter removal. Complications were not observed. CONCLUSION: Removal of misplaced central venous catheters in the subclavian artery by the percutaneous closure device AngioSeal is safe. Percutaneous catheter removal should be regarded as the method of choice, even in obese patients.

Buttock claudication after interventional occlusion of the hypogastric artery--a mid-term follow-up.

BACKGROUND: Interventional occlusion of the hypogastric artery (HA) can be used for endovascular aneurysm repair (EVAR) in the iliac arteries. Most frequent ischemic complication is buttock claudication (BC). AIM: To investigate the frequency and progression of BC after interventional occlusion of the HA prior to EVAR. METHODS: A retrospective analysis was performed in patients with EVAR and occlusion of the HA between September 2004 and August 2010. Acute and persistent BC symptoms were assessed. RESULTS: Fifty-four catheter occlusions of the HA were performed. In 10 cases, claudication could not be evaluated. During a mean follow-up of 17 months, 23 occlusions (52.3%) of the HA showed BC, in 52% symptoms were persistent. Of the 5 patients, 3 patients who underwent bilateral occlusion had BC and in 2 cases, persistent in the follow-up. CONCLUSION: Buttock claudication after occlusion of the HA prior to EVAR is a frequent complication, which often persists during follow-up. Alternatives that maintain pelvic perfusion should be considered.

Prediction of immediate and long-term benefit after kyphoplasty of painful osteoporotic vertebral fractures by preoperative MRI.

BACKGROUND: It is unclear if an MR-detectable bone marrow edema is a prerequisite for pain reduction and morphological correction by kyphoplasty. This comparative trial evaluates clinical and radiomorphological outcomes after kyphoplasty of painful osteoporotic vertebral fractures with and without preoperative MR-detectable bone marrow edema for 1 year of follow-up. METHODS: Preoperative MR-images of 45 patients who received kyphoplasty for treatment of painful osteoporotic vertebral fractures were evaluated with regard to presence (n = 27) or absence (n = 18) of vertebral bone marrow edema. Pain scores (VAS 0-100) and radiomorphological measures (midline vertebral height, kyphosis angle) were analysed at baseline, postoperatively and after 12 months. RESULTS: In the "bone edema" group, pain scores improved from 72.7 to 46.8 (postoperative) and 48.0 (12 months, P < 0.001, both). In the group without preoperative bone edema, pain score improved from 70.7 to 60.3 (postoperative, P = 0.013) and to 50.1 (12 months, P = 0.001). Pain scores of both groups were significantly different directly postoperative (P = 0.026), but not after 12 months (P = 0.714). Vertebral height restoration was slightly greater in the "bone edema" group (10.2% vs. 7.8%, P = 0.289). Correction of the kyphosis angle was greater in the "bone edema" group (P = 0.014) compared to the "no bone edema" group (P = 0.838). CONCLUSION: A preoperative MR-detectable vertebral bone marrow edema predicts a better short-term outcome after kyphoplasty, but is not a prerequisite for long-term pain reduction in patients with old, chronically painful osteoporotic vertebral fractures.

[Portal vein embolization using the amplatzer vascular plug II: preliminary results]. / Pfortaderembolisation mit dem Amplatzer Vascular Plug II: erste Ergebnisse.

PURPOSE: In this study we examined the feasibility of portal vein embolization (PVE) by using the Amplatzer Vascular Plug (AVP-II). We measured the time of vessel occlusion after plug deployment and changes in plug length and diameter within 4 weeks of PVE. MATERIALS AND METHODS: In 10 consecutive patients (4 women, age 64 +/- 10 yrs, 48 - 82 yrs) an ipsilateral PVE of the right portal vein was performed prior to intended hemihepatectomy. After embolization with microparticles, the right portal vein was occluded using an AVP-II. We measured the time of complete vessel occlusion by angiography. Follow-up with computed tomography (CT) was performed within 72 h and after 4 weeks. RESULTS: PVE was performed in all 10 patients without acute complications. Complete vessel occlusion was achieved in 9.7 +/- 5.1 min (range 1 - 21 min). On follow-up CT we found enhanced arterial vascularization of the embolized liver segments in 5 / 5 patients within 72 hours and in 6 / 10 patients after 4 weeks. The plug showed a contraction of 20 +/- 9 % and a dilatation of 23 +/- 13 %. Thus, the AVP-II dilated to 94 +/- 8 % (78 - 100 %) of its nominal diameter. The plug diameter was significantly larger in men compared to women (17 +/- 1.7 mm vs. 14 +/- 1.4 mm, p < 0.02). We did not observe any recanalization or migration of the device. The volume of the left liver lobe increased significantly by 27 % (p < 0.001) after 4 weeks. CONCLUSION: PVE with the AVP-II is a feasible and effective method. The AVP-II can dilate within 4 weeks up to its nominal diameter dependent on the grade of oversizing. Dilatation of the diameter is associated with a shortening in length.

[Arterial embolization of hepatic metastases from neuroendocrine tumors]. / Arterielle Embolisation von Lebermetastasen neuroendokriner Tumoren.

Neuroendocrine tumors are slowly growing neoplasms and 75% of patients already present with hepatic metastases at the time of diagnosis. Size and growth of liver metastases is of prognostic value. Due to arterial vascularization of metastases, transarterial embolization (TAE) is a suitable procedure, which can also be combined with chemotherapeutic agents. Indications for embolization or chemoembolization (TACE) are growth of liver metastases or inadequate symptom control. The majority of patients show clinical improvement and partial remission can be achieved in 50% of cases with 5-year survival rates of 50-60%. Response rates, survival or complications are not dependent on the embolization technique (TAE or TACE). Embolization is usually performed in several sessions depending on individual tumor stage and disease progression. Embolization is a cost-effective procedure and is included in the treatment algorithm of international guidelines. Therefore, evaluation of new embolization therapies must be evaluated in randomized controlled studies.

Balloon occlusion of the celiac artery: a test for evaluation of collateral circulation prior endovascular coverage.

INTRODUCTION: Visceral ischemia is a possible complication after endovascular coverage of the celiac artery (CA). A selective mesenteric angiography during simultaneous balloon occlusion of the CA imitates endovascular coverage and might therefore be suited for evaluation of collateral circulation. We report the feasibility of a balloon occlusion test (BOT) of the CA for this purpose. REPORT: We performed a BOT in 5 patients selected for endovascular surgery with intended coverage of the CA. The BOT could demonstrate sufficient collateral circulation in all cases, which was not evident without occlusion of the CA. The most important collateral vessels were the pancreaticoduodenal arcades and the dorsal pancreatic artery. All patients tolerated the BOT well without abdominal symptoms or pathological laboratory findings. DISCUSSION: Our report suggests that a BOT of the CA is a feasible and safe procedure. It can demonstrate collateral pathways before definite coverage is performed. This test might be useful for selection of patients prior intended coverage of the CA.

[MR imaging in cardiac amyloidosis--morphology, function and late enhancement]. / Magnetresonanztomografie bei kardialer Amyloidose--Morphologie, Funktion und late enhancement.

PURPOSE: Since limited data is available using MR imaging in cardiac amyloidosis, the purpose of our study was to evaluate morphological and functional differences of the heart using cardiac MRI. MATERIALS AND METHODS: 19 consecutive patients (14 males, 5 females, mean age 59 +/- 6 years) with histologically proven cardiac amyloidosis were evaluated with MRI at 1.5 T. Results were compared with data of 10 healthy, age-matched control subjects (5 males, 5 females, mean age 60 +/- 6 years). Functional and morphological data including late enhancement (LE) was acquired. RESULTS: Compared to the control group, patients with cardiac amyloidosis had thickened atrial walls and dilated atriums. Both ventricles and the interventricular septum were thickened. The LV hypertrophy was focal in 11 / 19 (58 %) and global in 4 / 19 (21 %) of patients. A myocardial edema occurred in 2 / 19 patients with cardiac amyloidosis (11 %). An edema of the myocardium was visible in 2 / 19 (11 %) of patients. The LV ejection fraction was statistically significantly decreased. The prevalence of LE was 74 % (14 / 19 of patients). LE was detected predominantly in the LV anterior wall and in the interventricular septum. Within the segments LE was located predominantly in a subendocardial location. Between patients with and without LE no statistically significant differences of functional and morphological results were able to be established. CONCLUSION: There are three major outcomes of our assessment: 1. The LV hypertrophy is focal in the majority of patients with cardiac amyloidosis. 2. No statistically significant differences can be established in regard to the functional and morphological features between patients with and without LE. 3. Myocardial edema is a possible feature in cardiac amyloidosis.

Dynamic contrast-enhanced MRI in Paget's disease of bone--correlation of regional microcirculation and bone turnover.

The purpose of this study was to evaluate regional microcirculation in Paget's disease of bone (PD) with dynamic contrast-enhanced MR imaging (DCE-MRI). Additionally, we correlated regional bone perfusion with alkaline phosphatase as serum marker of bone turnover. We examined 71 patients with PD (27 men, 44 women, 67+/-10 years) localized at the axial and appendicular skeleton. Contrast uptake was analyzed using a two-compartment model with the output variables amplitude A and exchange rate constant k(ep). Color-coded parametric images were generated to visualize microcirculation. Serum levels of alkaline phosphatase (AP) were compared with DCE-MRI parameters. Amplitude A and exchange rate constant k(ep) were significantly increased in PD compared to unaffected bone (A(PD) 0.81+/-0.24 vs. A(control) 0.34+/-0.1 and k(ep PD) 4.0+/-2.86 vs. k(ep control) 1.73+/-0.88, p<0.001). There was a significant correlation (r(s)=0.5-0.7) of DCE-MRI parameters and AP at the axial (pelvis, spine) and appendicular skeleton (femur, tibia). The long bones showed increased circulation of the advancing peripheral zones and no vascularization of the central part, which had been replaced by fatty tissue. Regional microcirculation in PD is inhomogeneous with focal areas of excessive hypervascularity, especially in the advancing peripheral zone. There is a significant correlation of bone circulation and bone turnover in PD. DCE-MRI might therefore be a diagnostic tool for monitoring therapeutic effects of bisphosphonates in Paget's disease of bone.

[Balloon kyphoplasty in the therapy of vertebral fractures]. / Ballonkyphoplastie in der Therapie von Wirbelkörperfrakturen.

Approximately 500,000 vertebral fractures occur as a result of osteoporosis every year in Europe. One third of the patients thus affected complain of severe back pain and seek treatment. In the past, the treatment of such fractures was limited to conservative methods, such as the use of braces and analgesics and long-term immobilisation followed by physiotherapy. Since 1998 balloon kyphoplasty, a minimally invasive procedure, has also been available for their treatment. During balloon kyphoplasty a balloon system is introduced into a fractured vertebral body to achieve bitranspedicular augmentation, after which low-viscosity bone cement is injected into the vertebral body, where it sets very quickly. In general the patient can be fully mobilized 24-48 h after the procedure and in most cases the symptoms are then considerably attenuated; many patients are actually free of pain. Published studies and our own experience indicate that balloon kyphoplasty is a safe method of treating painful vertebral compression fractures sustained in various ways and that complications are rare with this procedure.

Wound complications following kidney and liver transplantation.

Advances in surgical techniques and immunosuppression (IS) have led to an appreciable reduction in postoperative complications following transplantation. However, wound complications as probably the most common type of post-transplantation surgical complication can still limit these improved outcomes and result in prolonged hospitalization, hospital readmission, and reoperation, consequently increasing overall transplant cost. Our aim was to review the literature to delineate the evidence-based risk factors for wound complications following kidney and liver transplantation (KTx, LTx), and to present the preventive and therapeutic modalities for this bothersome morbidity. Generally, wound complications are categorized as superficial and deep wound dehiscences, perigraft fluid collections and seroma, superficial and deep wound infections, cellulitis, lymphocele and wound drainage. The results of several studies showed that the most important risk factors for wound complications are IS and obesity. Additionally, there are surgical and/or technical factors, including type of incision, reoperation, and surgeon's expertise, as well as comorbidities such as advanced age, diabetes mellitus, malnutrition, and uremia. Preventive management of wound complications necessitates defining their etiological factors so that their detrimental effects on healing processes can be addressed and reduced. IS modalities and agents, especially sirolimus (SRL), and steroids (ST) should be adjusted according to the patient's co-existing risk factors. SRL should be administered three months after transplantation and ST should be tapered as soon as possible. A body mass index (BMI) lower than 30 kg/m2 is advisable for inclusion in a transplantation program, but higher BMIs do not exclude recipients. Surgical risk factors can be prevented by applying precise surgical techniques. Therapeutic modalities must focus on the most efficient and cost-effective medications and/or interventions to facilitate and improve wound healing.

[Balloon kyphoplasty in the treatment of back pain]. / Die Ballonkyphoplastie in der Behandlung des Rückenschmerzes.

BACKGROUND: Experience of just under 5 years has shown that balloon kyphoplasty can be just as successfully employed as the longer-stablished vertebroplasty for the treatment of back pain due to recent or prior osteoporotic fractures as well as new traumatic fractures. MATERIAL AND METHOD: Among 345 patients with a total of 690 treated vertebral bodies, the change in pain symptomatology was analyzed for a follow-up period of 12 months in 40 study patients who underwent kyphoplasty and a control group of 20 patients. In addition, the pain experienced by a further 29 patients with new traumatic vertebral body fractures was monitored over a 12-month period. These fractures were partly managed by fixateur interne alone and by a combination of fixateur interne and kyphoplasty. RESULTS: The 40 patients treated by kyphoplasty had a baseline VAS score of 26.2+/-2.00, which increased to 44.4+/-3.11 after 12 months, while the respective scores for the control group were 33.6+/-4.21 and 34.3+/-4.35. In the 29 patients with new traumatic vertebral body fractures, the initial VAS score was 62 and after 12 months a distinct reduction of pain was noted with a score of 20 (100 = maximum pain, 0 = no pain). The number of times that the 40 patients managed by kyphoplasty had to consult their general practitioner was significantly reduced by the pain therapy. CONCLUSION: Balloon kyphoplasty verifiably improved the pain symptomatology after vertebral fracture over a period of 12 months. Comparison with the control group, which received the same osteoporosis drug therapy, confirmed the effect of this minimally invasive treatment form.

Osseous integration of calcium phosphate in osteoporotic vertebral fractures after kyphoplasty: initial results from a clinical and experimental pilot study.

INTRODUCTION: This study evaluated the radiological changes at the bone-cement interface of calcium phosphate cement (CPC) and polymethylmethacrylate (PMMA) 12 months after kyphoplasty. In a pilot experiment, we additionally performed a histomorphometric analysis in osteopenic foxhounds to analyze the process of osseous integration of CPC and PMMA. METHODS: Twenty postmenopausal female patients with 46 vertebral compression fractures (VCF) were treated by kyphoplasty, utilizing CPC (N=28) or PMMA (N=18) for intravertebral stabilization. After a 12-month follow-up, we measured the density changes of border voxels at the bone-cement interface by computed tomography (CT) using dedicated software algorithms. We defined the border-voxel density (BVD) as a parameter of cement resorption at the interface. We also investigated the bone-implant interface in three osteopenic foxhounds by histomorphometry 3, 6, and 12 months after cement implantation. RESULTS: Twelve months after kyphoplasty, only CPC showed a significant decrease of the BVD compared to PMMA (p<0.01), indicating a slow progress of resorption at the interface. Histomorphometry of the dog vertebrae showed near total bone coverage of CPC implants, whereas the PMMA surface exhibited only 30% direct bone contact (p<0.01). We also observed a time-dependent increase in the number of discernable osteons close to the interface of CPC, but no bone tissue within PMMA (p<0.01). CONCLUSIONS: The decrease of the BVD 12 months after kyphoplasty may indicate osseous integration of CPC by: (1) the ingrowth of bone tissue and (2) osteonal penetration close to the interface.

[Balloon kyphoplasty in the treatment of vertebral fractures]. / Ballonkyphoplastie in der Therapie von Wirbelkörperfrakturen.

Approximately 500,000 vertebral fractures occur as a result of osteoporosis every year in Europe. One third of the patients thus affected complain of severe back pain and seek treatment. In the past, the treatment of such fractures was limited to conservative methods, such as the use of braces and analgesics and long-term immobilisation followed by physiotherapy. Since 1998 balloon kyphoplasty, a minimally invasive procedure, has also been available for their treatment. During balloon kyphoplasty a balloon system is introduced into the fractured vertebral body to achieve bitranspedicular augmentation, after which low-viscosity bone cement is injected into the vertebral body, where it sets very quickly. In general the patient can be fully mobilized 24-48 h after the procedure and in most cases the symptoms are then considerably attenuated; many patients are actually free of pain. Published studies and our own experience indicate that balloon kyphoplasty is a safe method of treating painful vertebral compression fractures sustained in various ways and that complications are rare with this procedure.

Transarterial embolization of primary and secondary tumors of the skeletal system.

Percutaneous transcatheteral embolizations of primary and secondary bone tumors are important minimal invasive angiographic interventions of the skeletal system. In most of the cases embolization is performed for preoperative devascularization or as a palliative measure to treat tumor-associated pain or other tumor bulk symptoms. The transarterial embolization of primary and secondary tumors of the skeletal system has been developed to a safe and very effective method. Indications, techniques, results and complications of this minimal invasive interventional therapy for treatment of primary and secondary bone tumors are described and discussed and compared with the newer literature and our own results.

[Treatment of malignant biliary obstructions via the percutaneous approach]. / Interventionen bei malignen Gallenwegstenosen.

This paper gives an overview of experience and success of percutaneous transhepatic interventions in malignant biliary obstruction. Even after exhaustion of surgical and endoscopic therapy options, the percutaneously inserted stents provide effective palliation. The palliative treatment of malignant jaundice using a stent is an established procedure in clinical practice, particularly whenever the endoscopic, transpapillary approach is not possible due to high obstructions or previous surgery. The technical success rate is very high (about 95-100%), and the complication rate is about 10-30%. Since the patency rate of stents is higher than that of plastic endoprostheses, their primary use is justified despite higher costs, provided the patients are adequately selected.

CT volumetry of intravertebral cement after kyphoplasty. Comparison of polymethylmethacrylate and calcium phosphate in a 12-month follow-up.

This study was intended to measure the volume of intravertebral cement after balloon kyphoplasty with high resolution computed tomography (CT) and dedicated software. Volume changes of biocompatible calcium phosphate cement (CPC) were detected during a follow-up of 12 months. Measurements were compared with a control group of patients treated with polymethylmethacrylate (PMMA). Twenty-three vertebrae (14 CPC, 9 PMMA) of 12 patients were examined with CT using an identical imaging protocol. Dedicated software was used to quantify intravertebral cement volume in subvoxel resolution by analyzing each cement implant with a density-weighted algorithm. The mean volume reduction of CPC was 0.08 ml after 12 months, which corresponds to an absorption rate of 2 vol%. However, the difference did not reach significance level (P>0.05). The mean error estimate was 0.005 ml, indicating excellent precision of the method. CT volumetry appears a precise tool for measurement of intravertebral cement volume. CT volumetry offers the possibility of in vivo measurement of CPC resorption.