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1.
Previous studies have documented the effectiveness of magnetic resonance imaging for evaluating and following up the development of avascular necrosis of the femoral head. One of the limitations of this technique, however, is the distortion that is encountered with ferromagnetic screws. A traumatic fracture to the femoral head is a risk factor for avascular necrosis. The addition of internal fixation, which is often required in Pipkin-type fractures of the femoral head, creates significant image distortion on magnetic resonance scans used for postoperative follow-up. The artifact and field distortion present in magnetic resonance imaging when ferromagnetic screw fixation is used has been avoided at our institution by the use of titanium hardware. The authors, therefore, recommend the use of titanium screws in the fixation of Pipkin-type fractures in the hip joint.  相似文献   

2.
In this prospective study the authors analysed the prognostic value of monitoring patency of the feedings vessels of the fibular graft, implanted into the femoral head to treat aseptic necrosis. In 26 patients (29 hips) we applied a three phase 99Tc-MDP Bone Scanning in the seventh postoperative day. One week later; 18 patients had a digital subtraction angiography of the lateral femoral circumflex artery and its branches. The patients were followed for average time of 22 months. The average Harris Hip Score of the affected hips improved clinically from 69.5 to 93.5. The vessels were patent prior to the wound closure. Phase I of the bone scan served as "radionuclide angiogram" and demonstrated patent vessels in all about three hips. The digital arteriograms demonstrated patent anastomotic sites in 15 out of 18 hips. Only in four of the fifteen arteriograms the vessels were visualized throughout the length of the graft. Two of the three hips with negative arteriograms have also had negative bone scans, both in patients with haemoglobinopathies. None of the patients required further surgery because of failure of the procedure. This study demonstrated that the phase I of the bone scan at the end of the first week postoperatively is very sensitive means for monitoring the viability of the graft. Digital arteriograms although more specific, were less sensitive. Early postoperative monitoring of the graft viability maintained high predictive value for the outcome of the treatment in the medium-term.  相似文献   

3.
PURPOSE: Electron beam tomography (EBT) permits acquisition of images with high spatial and temporal resolution. The value of EBT and other imaging modalities for the depiction of patent coronary artery bypass grafts (ACVB, IMA) are compared to coronary angiography and an overview of current results is given. MATERIAL AND METHODS: Graft patency can be evaluated with indirect methods stress, such as echocardiography, radionuclide ventriculography, myocardial scintigraphy, positron-emission tomography (PET) and direct imaging modalities, such as Doppler/2D echocardiography, EBT, spiral computed tomography (SCT) and magnetic resonance angiography (MRA). RESULTS: With indirect methods graft patency can be evaluated with sensitivity of 64-100% and specificity of 73-100%. EBT and SCT are equivalent in sensitivity (= 94%) in the assessment of open venous grafts and specificity is up to 100%, but EBT is superior in the diagnosis of patent IMA grafts (sensitivity 100% vs 89%). Visualization of high-grade venous bypass stenosis seems possible with EBT. MRA with gradient echo technique is highly accurate in the assessment of patent venous grafts (sensitivity 77-93%) but has limited value in the evaluation of IMAs (sensitivity = 53%). Promising are ultrafast 3D-MRA methods which permit high accuracy (sensitivity = 94-96%) in assessing venous and arterial grafts. DISCUSSION: Indirect imaging methods cannot differentiate between an occluded bypass, progression of coronary artery disease and myocardial infarction. EBT and SCT are equivalent in the diagnosis of open and occluded venous grafts, but EBT is superior in the assessment of patent IMA grafts. Visualization of high-grade venous bypass stenosis seems possible with EBT. MRA techniques, especially ultrafast 3D-MR methods, are highly accurate in the assessment of patent venous and arterial grafts but are still limited to scientific research.  相似文献   

4.
Four patients with malignant lymphoma who were treated with multiple courses of combination chemotherapy, consisting of cyclophosphamide, Oncovin, procarbazine, and prednisone (COPP), developed avascular necrosis of the femoral head(s). Disorders usually associated with the development of avascular necrosis were absent. The total prednisone dose received by each patient was small. Avascular necrosis of the femoral head should be considered in the differential diagnosis of bone pain in patients receiving multiple courses of combination chemotherapy.  相似文献   

5.
Various therapeutic options have been proposed in the treatment of femoral head necrosis ranging from conservative management to total hip arthroplasty. Since microsurgical techniques are routinely used in orthopaedic surgery, the importance of revascularization has increased in recent years. Vascularized bone grafting as well as various osteotomies have been considered for the stages II and III according to Ficat and II, III and IV of the criteria of the ARCO system respectively, which also bases on MRI-findings. We investigated the results of 80 patients with avascular necrosis of the femoral head treated with a vascular pedicled iliac bone graft, perfused by the A. circumflexa ilium profunda, between 1988 and 1996. Mean follow-up was 5.6 years. The evaluation was based on the harris hip score, clinical and radiological examination as well as a subjective assessment using a VAS (visual analog scale). The clinical results according to the harris hip score were good or excellent in 86.1%. These results correlate with the subjective assessment of pain and of the hip joint function with an average of 7.9 points using the VAS (max. 10 points). Unchanged radiological appearance over the follow-up period was observed in 47.5% using the ARCO criterias. Reviewing the studies using vascularized grafts, about 50% of the patients with a stage II and III according to Ficat and II, III and IV of the ARCO respectively show an unchanged stage of the disease 5-6 years after the procedure. Therefore, transplantation of a vascular pedicled iliac bone graft possibly offers the chance to intervene causally in the course of the disease with only little alteration of the biomechanics of the hip joint.  相似文献   

6.
The implantation of a microvascular polyester prosthesis (MPP) (internal diameter 1 mm, length 10 mm) in the carotid arteries was studied in 48 Sprague-Dawley rats. The left carotid artery was resected to 7 mm in length and replaced with MPP by means of sleeve anastomoses. Postoperatively the patency was monitored with Doppler ultrasound at 24 and 72 hr, and at 1, 2, 3, 4, 8, and 12 weeks and was confirmed either by direct inspection intraoperatively or by angiography at the time of removal. At each monitoring time, all the thrombosed and some selected patent grafts were removed and prepared for scanning electron microscopy (SEM) study. The early patency rate was 100% within 24 hr, and the cumulative long-term patency rate was 77.1% at 12 weeks. Rapid and complete endothelial lining (EL) restoration was demonstrated 3 weeks after operation, which provided a smooth and nonthrombogenic surface, and contributed to the long-term patency. Ten of the 11 failed grafts occurred within 3 weeks, that is, before EL, due to thrombosis. These observations indicate that MPP can be successfully used as arterial conduits in rats, and an enhanced patency rate may be expected with the use of anticoagulants or endothelial cell seeding for prevention of early thrombosis.  相似文献   

7.
OBJECTIVE: To review the value of obturator canal bypass with respect to long-term results. DESIGN: Case series and literature review. SETTING: University of Vienna Medical School in Austria. PATIENTS/METHODS: Personal experience with 34 consecutive patients and 125 cases published since 1982 with respect to patient data, patency, and survival are compared and jointly analyzed retrospectively. INTERVENTIONS: Patients received obturator canal bypass for lesions of the pelvic or common femoral vessels precluding orthotopic reconstruction. MAIN OUTCOME MEASURES: The rates of patient survival, limb salvage, and graft patency were analyzed. RESULTS: The postoperative mortality rate in the present series was 14.7%. The limb salvage rate after 5 years was 76.5%. One- and 5-year secondary patency rates were 75.3% and 54.9%, respectively. All grafts in patients without atherosclerosis were patent at a median of 34 months. For 57 cases documented in the literature, 1- and 5-year patency rates were 70.8% and 59.7%, respectively. Combined analysis of 90 obturator canal bypasses revealed rates of 72.7% and 56.9% of patent grafts at 1- and 5-years, respectively. CONCLUSIONS: The use of obturator canal bypass is recommended in deep groin infections and especially in patients with lesions of the pelvic vessels due to other occlusive vascular disease.  相似文献   

8.
Bypass graft patency with ultrafast computed tomography (= Electron Beam Tomography, EBT) was examined in 72 bypass grafts (47 saphenous veins, 25 internal mammary arteries) in 30 patients and compared with coronary angiography. Angiography was performed a mean of 4.4 +/- 3.5 months (range 1-13) from the EBT examination. Contrast material (120 ml) was continuously administered via a peripheral vein and 40 axial slices (3 mm slice thickness, 110 ms scan time) without overlap sequences were obtained, ECG triggered with the single slice scanner mode. Imaging of internal mammary artery grafts began at the thoracic inlet, for saphenous vein grafts, at the undersurface of the aorta. Sixty of 63 angiographically patent bypass grafts were determined patent by EBT (sensitivity 95%), 8 bypass grafts could not be detected by EBT, and 9 were angiographically occluded (specificity 89%). Twenty-four of 25 internal mammary artery grafts were patent at EBT and coronary angiography, one was occluded. In 27 of the 30 patients (90%), all of the angiographically patent grafts could be confirmed as open with EBT. Obstructions of 10 grafts could not be visualized with EBT. Graft insertion into native coronary vessels could be visualized in axial slices, although morphologic quantification of graft insertion stenosis (75-90%) in two cases was not possible. Three dimensional reconstruction of the 40 axial slices allowed graft anatomy to be delineated. Visualization of bypass insertion into the native coronary vessel was less successful because of opacification of the left and right ventricle. Electron beam computed tomography is a minimally invasive procedure capable of evaluating the patency of saphenous vein and internal mammary artery grafts. The morphologic quantification of graft obstruction and visualization of the insertion of the bypasses into the native coronary vessels is less successful with present technology and imaging modalities.  相似文献   

9.
The high thrombogenicity of synthetic biomaterials has limited their use for reconstructive microsurgery. Prime factors in the thrombogenicity of synthetic materials in contact with blood include gas nuclei at the blood gas interface as well as the inherent thrombogenicity of the materials themselves. Expanded polytetrafluoroethylene (ePTFE) vascular prostheses were denucleated by placement in acetone and ethanol followed by degassed saline or by placement in degassed saline subjected to hydrostatic pressure. Heparinized grafts were prepared by coating with tridodecylmethylammonium chloride (TDMAC), followed by immersion in heparin. Grafts were installed to reconstruct the femoral artery (1 x 10 mm) or as renal-iliac bypasses (1 x 50 mm) in rats. In the femoral artery reconstruction model, control grafts thrombosed within 10 minutes of implantation. All acetone denucleated femoral grafts remained patent for 60 minutes but were occluded at day 1. All pressure denucleated femoral grafts remained patent for 60 minutes, whereas six were patent at 1 month. In contrast, 11 of 15 heparinized femoral grafts were patent at 1 month. In the renal iliac bypass model, all control grafts were thrombosed within 10 minutes, whereas all heparin bonded grafts remained patent at 1 month. This finding confirms that removal of air from small diameter ePTFE grafts decreases acute thrombogenicity and that heparin bonding further decreases thrombogenicity, suggesting that clinically useful lengths of microvascular prostheses may be possible.  相似文献   

10.
OBJECTIVE: We describe gadolinium-enhanced MR imaging of position and vascular enhancement of the femoral head in pediatric patients who have undergone reduction of hip dislocation. SUBJECTS AND METHODS: Within 24 hr of hip reduction and spica casting, we performed 25 gadolinium-enhanced MR studies in 18 infants and young children (15 girls, three boys) with 23 dysplastic hips. All but two patients underwent closed reductions. We evaluated intraoperative arthrograms for obstacles to reduction and subsequent radiographs for avascular necrosis. RESULTS: MR images showed that all femoral heads were in their respective acetabula, but several structures interfered with concentric reduction. Obstacles to reduction included a pulvinar (n = 16), infolding of the capsule (n = 9), interposition of the labrum (n = 2), and a hypertrophied ligamentum teres and transverse ligament (n = 2). All 50 femoral heads showed enhancement: 35 normally, 10 homogeneously but less than on the contralateral femoral head or the ipsilateral greater trochanter, and five with areas of focally decreased enhancement. Hips that showed decreased enhancement had undergone greater degrees of abduction (r = .38, p < .01). CONCLUSION: Gadolinium-enhanced MR imaging can reveal abnormalities of hip position and proximal femoral epiphyseal and physeal vascularity that can occur after hip reduction. Abnormalities of enhancement were more frequent in patients who had greater femoral abduction. The effect of decreased epiphyseal vascular enhancement is still uncertain.  相似文献   

11.
Fibrin glue has been applied in the anastomosis of vein grafts placed in rat femoral arteries using the telescoping technique at both ends of the graft. 34 out of 35 grafts which were patent 1 to 3 weeks post-operatively were kept for 3 months to assess the long-term patency, and the effect of the glue on the diameters of the graft and femoral artery. All 34 grafts were patent 3 months post-operatively. Excessive enlargement of the graft diameter was alleviated by the fibrin glue without affecting the diameter of the femoral artery. The diameter at the proximal anastomosis was 66% and that at the distal anastomosis was 87% of the diameter of the femoral artery.  相似文献   

12.
We report a case of fracture of a ceramic femoral head, which spontaneously occurred 4 years after implantation of an uncemented total hip replacement in a 48-year-old male patient with avascular necrosis of the hip. At revision surgery, the fractured ceramic head was replaced with a 32-mm metallic femoral head.  相似文献   

13.
Ninety-four hips involved with total avascular necrosis in the treatment of congenital dislocation of the hips were reviewed in a search for etiological factors and effective salvage procedures. Pre-reduction traction and adductor tenotomy did not prevent avascular necrosis. Abduction of the hip in the "frog" position was the incriminating common denominator. This position may cause (1) interference of the blood supply to the femoral head by compression of the medial branch of the deep profundus artery; and (2) pressure on the intraepiphyseal grooves by the glenoid labrum. The containment of the femoral head by acetabuloplasty (preferably) below age 8, followed at a later date (over age 10) by transfer distally of the greater trochanter, with the abductor muscles, offers a satisfactory salvage procedure.  相似文献   

14.
PURPOSE: The purpose of this study was to review the treatment of patients with failed or infected axillofemoral bypass grafts and to determine the efficacy of remedial procedures in maintaining graft patency and limb preservation. METHODS: Thirty-four patients with 37 failed or infected axillofemoral grafts were retrospectively reviewed. In nine cases there was no attempt at revascularization, and in the remaining 28 cases, a total of 52 remedial procedures was performed. Nine were performed in patients with graft infection and 43 in patients with graft thrombosis. In patients with axillofemoral graft failure, 21 thrombectomies, 13 graft revisions, and 9 secondary reconstructions were performed. Eighty-eight percent of patients were monitored at least 2 years or until graft failure. RESULTS: Eight of nine patients receiving no remedial procedure required major amputation. The limb salvage rate was 64% +/- 11% at 30 months in the 25 patients undergoing remedial procedures. Twenty-eight percent of failed axillofemoral grafts remained patent at 2 years after initial failure with single or multiple thrombectomies or revisions. Life-table primary patency after secondary reconstructions (81% +/- 10.9% at 24 months) was significantly better than after thrombectomy alone (10% +/- 4.2% at 24 months) or graft revision (16% +/- 10.6% at 24 months) by log-rank test (p < 0.001 and p < 0.005, respectively). Patients undergoing reconstruction with descending thoracic aorta to femoral artery bypass had an 89% +/- 11% patency rate at 24 months. Graft infection resulted in a perioperative mortality rate of 22% and amputation in 57% of survivors. CONCLUSION: Axillofemoral graft failure most often results in limb loss without remedial procedures. Thrombectomy and revision procedures had poor long-term patency rates and salvaged only a minority of grafts despite multiple procedures. Reconstruction by use of an alternate source of inflow such as the descending thoracic aorta resulted in better long-term patency rates in patients well enough to tolerate a major reoperative procedure.  相似文献   

15.
BACKGROUND AND AIMS: The aim of the present study was to compare power Doppler imaging with traditional color Doppler imaging and with contrast enhanced computer tomography in the evaluation of intratumoral vascularity of hepatocellular carcinomas at diagnosis and in response to percutaneous ethanol injection. PATIENTS AND METHODS: Sixteen patients with hepatocellular carcinoma underwent colour Doppler, power Doppler and computed tomography at diagnosis. Seventeen patients were studied by the three techniques one month after percutaneous ethanol injection treatment. RESULTS: At baseline evaluation, power Doppler and color Doppler were always in agreement and, with the exception of one case, were also in agreement with the computerized tomography scan. On the contrary, power Doppler and computerized tomography are more sensitive than color Doppler in the evaluation of residual vascularized tumoral tissue after percutaneous ethanol injection. In 3 patients, residual vascularity was demonstrated only by computerized tomography while color and power Doppler were negative. In another 3 cases, a positive power Doppler signal, with a typical arterial Doppler spectrum, was observed while color Doppler and computerized tomography were negative. In these patients, cancer relapse was clinically evident after a few months and treatment was repeated to obtain complete necrosis. CONCLUSIONS: We conclude that only the integration of the results of all these techniques can reliably evaluate tumoral vascularity after percutaneous ethanol injection.  相似文献   

16.
RATIONALE AND OBJECTIVES: The appearance of the intracranial vasculature was compared on power and color Doppler ultrasound (US) scans obtained with and without a microbubble contrast agent. MATERIALS AND METHODS: Nine patients (three men, six women) aged 42-70 years (mean age, 53 years) participated in the study. Seven patients underwent both color Doppler US and power Doppler US before and after intravenous administration of contrast agent, and two underwent only color Doppler US. All patients had previously undergone cerebral angiography. RESULTS: Before contrast material was administered, power Doppler US was more sensitive than color Doppler US in the detection of intracranial vessels (P < .05); neither technique depicted the entire circle of Willis in eight of nine patients. Postcontrast power Doppler US depicted more vascular segments than postcontrast color Doppler US (P < .01) or precontrast power Doppler US (P < .01). Use of intravenous contrast material enabled the entire circle of Willis to be evaluated from a single temporal bone acoustic window with both power Doppler US and color Doppler US in all patients. Contrast-enhanced power Doppler US depicted vessels not shown by enhanced color Doppler US. CONCLUSION: Contrast-enhanced power Doppler US depicted more vessels, better demonstrated specific vascular segments, and provided better vascular definition of the intracranial vasculature than contrast-enhanced color Doppler US or unenhanced power Doppler US.  相似文献   

17.
Laser Doppler flowmetry was used intraoperatively to monitor femoral head perfusion during open reduction of 13 congenital hip dislocations in 11 patients. Laser Doppler determinations ranged from 12 to 400 mV before reduction and 30 to 300 mV after reduction. Three patients had magnitude changes in excess of 50%. One had increased perfusion, and two had decreased blood flow. Avascular necrosis of the hip occurred in one patient that was not predicted by laser Doppler flowmetry. Femoral head perfusion measured 175 mV for the dislocated hip and 180 mV after reduction of the femoral head and completion of the pelvic osteotomy. The authors conclude that laser Doppler flowmetry is not a reliable method for monitoring femoral head perfusion during open reduction of the hip for developmental hip dysplasia.  相似文献   

18.
PURPOSE: To assess the efficacy of Doppler ultrasonography (US) as a noninvasive method for monitoring patency of the transjugular intrahepatic portosystemic shunt (TIPS). METHODS: Twenty-nine patients who had received TIPS for bleeding esophagogastric varices and/or refractory ascites with portal hypertension underwent Doppler US studies within 2 weeks after TIPS. Further studies were performed in 15 of them at 6 months, in 9 at 1 year, and in 4 at 2 years for a total of 57 US studies. The US findings were compared with the angiographic findings obtained at the same time. RESULTS: In 45 of the 57 studies, shunt patency was found by Doppler US, correlating to 44 patencies and one occlusion on angiography. Doppler signal in the shunt could not be detected in 12 studies resulting in the diagnosis of shunt occlusion. This correlated with angiographic occlusion in 8 studies and patency in the remaining 4. All angiographically patent shunts that were occluded by Doppler US had various degrees of stenosis. A number of technical factors were found to be responsible for Doppler US false-positive or false-negative diagnoses, some related to the type of stent used. The Doppler US sensitivity was therefore 92%, the specificity 89%. CONCLUSION: Doppler US is a reliable noninvasive method to evaluate patency of TIPS.  相似文献   

19.
Anginal chest pain after implantation of coronary stents in bypass grafts is a concern because it suggests the possibility of occlusion. Coronary angiography is the definitive method for determining patency of a stent; however, this procedure is relatively contraindicated in a patient receiving warfarin sodium, who has a therapeutic international normalized ratio. An alternative method for determining patency of a stent is by ultrafast computed tomography. This new, minimally invasive technique shows promise for determining blood flow within the large vessels of the thorax. Herein we describe a case in which a metallic stent placed in a vein graft was noninvasively established to be patent, despite chest pain in the patient. This method may be clinically applicable for determining patency of stents in vein grafts in the setting of patients with chest pain who have undergone complete anticoagulation.  相似文献   

20.
PURPOSE: To evaluate the success rates of the implantation of stent grafts in the treatment of peripheral aneurysms. MATERIALS AND METHODS: In 13 patients with 15 aneurysms at the common iliac artery (n = 6), external iliac artery (n = 1), hypogastric artery (n = 2), femoral artery (n = 2) or popliteal artery (n = 4), implantation of dacron-covered nitinol stents was performed. The patients were followed up for three to 20 months (mean, 8.8 months) with intravenous digital subtraction angiography, CT or colour-coded Doppler sonography. RESULTS: In all cases, the aneurysm was successfully occluded after stent implantation. In one case with a popliteal aneurysm, kinking of the vessel caused thrombosis of the stent. The stent was successfully reopened. The aneurysm however, had to be surgically treated 9 months later. The primary and secondary patency rates at 6 months were 93% and 100%, respectively. CONCLUSION: The method described might be an alternative therapy to surgery. There are some limitations in respect of treatment of popliteal aneurysms.  相似文献   

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