[Experiences with power-injectable port systems: complications, patient satisfaction and clinical benefit]

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.

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]

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]

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.

[MR imaging in cardiac amyloidosis--morphology, function and 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.

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 therapy of vertebral fractures]

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.

[Balloon kyphoplasty in the treatment of vertebral fractures]

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.

[Balloon kyphoplasty in the treatment of back pain]

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.

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.

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.

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.

Die Wertigkeit der Ballonkyphoplastie bei der osteoporotischen Wirbelkörperfraktur

BACKGROUND DATA

Patients with osteoporotic vertebral compression fractures frequently complain of pain and a loss of function and mobility. Such fractures are associated with an increased mortality. The common treatment with bed rest, bracing or osteosynthesis does not lead to satisfying results. With two new surgical techniques, vertebroplasty and kyphoplasty, an internal stabilisation of osteoporotic vertebral fractures is possible.

METHODS

All patients were treated by kyphoplasty. With a minimal invasive dorsal approach, an inflatable bone tamp is placed in the fractured vertebral body. This tamp can restore the vertebral body height and create a cavity, which is filled with bone cement under low pressure. The advantage of kyphoplasty compared to vertebroplasty is the restoration of the vertebral height and a decreased cement leakage rate. We performed a prospective, interdisciplinary study with a follow-up of 12 months. We treated 192 vertebral fractures in 102 patients. Augmentation was performed with polymethylmethacrylate in 138 cases and with a new injectable calcium phosphate-cement in 54 vertebral bodies. Outcome data were obtained with two different spine-scores and by the radiomorphometric evaluation of x-rays before and after treatment.

RESULTS

We noticed a significant improvement in pain and function in 89% of the patients. All patients showed a regain of vertebral height of on average 17%. In 7% of all treated vertebral bodies, we noticed cement leakage, which was, however, far below the rates published for vertebroplasty (20-70%). There were two complications, bleeding due to an unknown coagulopathy and a violation of the myelon by malpunction.

CONCLUSION

Kyphoplasty is a reliable and minimally invasive method for stabilizing fractured osteoporotic vertebral bodies. Improvement of pain and function and a regain in height of the treated vertebral body can be accomplished.

Bestimmung der Tibiatorsion - Vergleich von klinischen Winkelmessungen zur Computertomographie

PURPOSE

To determine variability between clinical goniometric methods and computed tomography (CT) in measuring posttraumatic malrotation of the tibia.

MATERIALS AND METHODS

In a prospective study, absolute tibial torsion of both legs after unilateral fracture of the tibia as well as the difference between both legs (intra-individual torsional difference) was postoperatively determined with two goniometric and two CT methods in 40 patients (female : male = 16 : 24, mean age = 46 +/- 34 years).

RESULTS

The mean difference between goniometric and CT methods in determining intra-individual torsional difference was not significant. Nevertheless, variance of values was higher in goniometric measurement (up to +/- 11 degree), with the measurements of torsional difference showing two times greater standard deviation in interobserver variability of goniometric methods as compared to CT.

CONCLUSION

Goniometric methods do not significantly differ from the CT methods for determination of intraindividual torsional difference. The higher variance of interobserver values limits accuracy of goniometric methods. Therefore, goniometric determination of tibial torsion can only be considered an estimate but not a precise measurement.