Transjugular intrahepatic portosystemic shunt treatment of variceal bleeding in an unselected patient population

OBJECTIVE

To evaluate transjugular intrahepatic portosystemic shunt (TIPS) in variceal bleeding in a clinical setting.

MATERIALS AND METHODS

Retrospective review of 131 patients (116 with liver cirrhosis) treated with TIPS with covered stent grafts in a single centre from 2002 to 2016.

RESULTS

Survival at 1 and 2 years was 70% and 57% in patents with, and 100% at 2 years in patients without liver cirrhosis, respectively. A high Child-Pugh score and severe hepatic encephalopathy (HE) within 12 months post-TIPS were related to increased mortality. Re-bleeding occurred in 8% within 12 months and was related to TIPS dysfunction and a post-TIPS portosystemic gradient (PSG) of ≥5 mmHg. The main cause of TIPS dysfunction was that the stent did not fully reach the inferior vena cava. There was no correlation between the PSG and the occurrence of HE.

CONCLUSIONS

TIPS was safe and prevented re-bleeding in patients with variceal bleeding, with or without liver cirrhosis, regardless of Child-Pugh class and of how soon after bleeding onset, the TIPS procedure was performed. A post-TIPS PSG of ≥5 mmHg was associated with an increased risk for re-bleeding and there was no correlation between the post-TIPS PSG and the occurrence of HE.

Magnetic Resonance Imaging and Angiography for the Assessment of Coarctation of the Aorta

Fifteen patients ranging in age from 9 to 25 years (median age 10 years), with coarctation of the aorta, were investigated with magnetic resonance (MR) imaging pre- and postoperatively. Three patients were examined because of suggested re-stenosis. Both MR examination and cineangiography were performed in 11 patients. The two techniques were comparable concerning the evaluation of both the site and the severity of coarctation as well as of the occurrence of collateral vessels. MR was considered suitable to replace angiography in the pre- and postoperative assessment of coarctation. The patients were preferably examined with a surface spine coil with ECG-gated sagittal, transverse and parafrontal images. The parafrontal images were necessary in order to minimize mistakes due to partial volume effects at the coarctation site. A surface coil placed over the sternum considerably improved the visualization of the internal mammary arteries.

Magnetic Resonance Imaging in Diffuse Malignant Bone Marrow Diseases

Twenty-four patients with malignant bone marrow involvement or polycythemia vera, 8 patients with reactive bone marrow and 7 healthy individuals were examined with spin-echo magnetic resonance imaging at 0.35 T and 0.5 T. Signs of an increased longitudinal relaxation time, T1, were found when normal bone marrow was replaced by malignant cells, polycythemia vera or reactive marrow. A shortened T1 was indicated in 4 patients in bone marrow regions treated by radiation therapy; the marrow was most likely hypocellular in these cases. The estimated T1 relaxation times were highly correlated to the cellularity of the bone marrow as assessed by histology. Among patients with close to 100 per cent cellularity neither T1 nor T2 discriminated between the various malignancies or between malignant and reactive, non-malignant bone marrow. Characterization of tissues in terms of normalized image intensities was also attempted, the motive being to avoid approximations and uncertainties in the assessment of T1 and T2. The normalization was carried out with respect to the image of highest intensity, i.e. the proton density weighted image. The results were in agreement with those for T1 and T2. It was concluded that MRI is valuable for assesssing bone marrow cellularity, but not for differentiating between various bone marrow disorders having a similar degree of cellularity.

Nonresectable Adenocarcinoma of the Rectum Assessed by Mr Imaging before and after Chemotherapy and Irradiation

Thirty-four patients with nonresectable adenocarcinoma of the rectum, defined as tumor fixation at digital examination, were examined with MR. All 34 patients had, according to MR imaging, perirectal tumor growth. In 23 (68%) of the patients, the tumor has reached an adjacent organ. Eight of these patients had disturbances of the MR characteristics in the adjacent organ which proved to be due to overgrowth, i.e., to tumor invasion into these structures. In the remaining 15 patients, without disturbed MR characteristics, 7 had tumor overgrowth at laparotomy. When there was a visible space between the tumor and adjacent organs, there was no sign of tumor overgrowth at laparotomy, except in one case. In 24 patients, examined both before and after combined irradiation and drug therapy, tumor regression was registered after treatment. MR imaging seems to be useful in the assessment of resectability and to evaluate preoperative anticancer treatment in patients with nonresectable rectal carcinoma.

Magnetic Resonance Imaging for Assessment of Treatment Effects in Mediastinal Hodgkin's Disease

Six patients with mediastinal involvement of Hodgkin's disease were examined with magnetic resonance imaging (MRI) at 0.35 T before and/or at various stages of therapy, with the sequences TR/TE: 500/35, 500/70, 1600/35 and 1600/70. Before therapy the image intensity of tumour involved lymph nodes deviated considerably from fat and muscle, but no clear difference was discerned between histopathologic subtypes or tumour localizations. After efficient therapy, the tumour image intensities and relaxation rates approached those of muscle and fibrous tissue, but remained at pre-therapy values when the patient was not in full remission. A similar pattern was found in a ‘normal-tissue’—‘tumour’ plot, based on vector analysis of the original sets of 4 images. It is concluded that persistent tumour involvement in the mediastinum may be distinguished from fibrosis and that MRI may thus be of value in the follow-up of patients with Hodgkin's disease.

Effect of Superparamagnetic Particles as Oral Contrast Medium at Magnetic Resonance Imaging

Non-biodegradable superparamagnetic particles were used as an oral contrast medium in different concentrations, and evaluated in 25 human volunteers. The aim of the study was to determine the most appropriate concentration of the contrast medium, and to evaluate the effect, distribution, safety and tolerance. With the concentration of 1.0 g/l a substantial reduction of the signal intensity in the bowel was achieved in both T1 and T2 weighted images. The intraabdominal structures were well differentiated from the bowels containing contrast medium. ‘Metal’ artifacts and blurring of adjacent structures, probably due to an increased local concentration, were observed at higher dosages. The distribution of the preparation in the gastrointestinal tract varied between individuals. As a rule a good contrast effect was achieved in the small bowel with the exception of the duodenum. The contrast medium was well accepted and did not cause any side effects of clinical importance. The results suggest that the preparation is well tolerated by humans and may be a useful contrast medium for abdominal MR imaging.

Mr Imaging with Histopathological Correlation in Vertebral Metastases of Breast Cancer

In 5 patients with advanced breast cancer and spinal metastases MR imaging of the spine was performed before and/or after death. T1-, proton density-, and T2-weighted and “phase contrast” images were obtained in the sagittal plane. Autopsies included histopathologic examination of whole sagittal sections of the vertebral body. The relative signal intensities on the different MR sequences of various tissues identified histologically were evaluated. “Phase contrast” images combined with T1-weighted images were highly sensitive in detecting metastases. All metastatic tumours over 3 mm in size were found with MR imaging. Vertebrae containing connective tissue and reactive bone marrow had an MR appearance similar to that of metastases even though no metastases were found histopathologically.

Detection of Breast Cancer Metastases in the Cervical Spine

Thirty women with breast cancer and indications of possible cervical spine metastases underwent skeletal scintigraphy, conventional radiography, MR imaging and CT. By combining all examinations a diagnosis was settled in each patient and the different imaging techniques were compared. For all of the 26 patients with metastases in the cervical spine the correct diagnosis was found with MR imaging and CT. Both modalities also revealed paravertebral tumour growth, MR (n = 8) more than CT (n = 3). The sensitivity of skeletal scintigraphy in detecting metastases in the cervical spine was rather low, but as these examinations cover the whole body they are still convenient screening procedures, and combined with conventional radiography of selected areas are probably sufficient in many cases. Supplementary examinations with CT or MR would be valuable in patients with equivocal findings at screening for metastases or with clinical indications of metastases that remain unexplained after scintigraphy and radiography.

MR Imaging of Multiple Myeloma in Tumour Mass Measurement at Diagnosis and during Treatment

The bone marrow of the spine, pelvis and proximal femora was examined with MR imaging at diagnosis in 30 cases of multiple myeloma (MM), and during treatment on 69 occasions. The MR pattern was normal, focal or diffuse and correlated to stage. A tumour mass index (TMI) was calculated by estimating the total myeloma mass visualised at MR imaging. The TMI correlated significantly with stage, lytic bone lesions, serum calcium, serum β-2-microglobulin and survival. No abnormalities were seen at MR investigation in 4 of 6 patients classified as stage II because of osteoporosis only. Therapy efficacy evaluation with MR imaging corresponded to clinical evaluation on 54 of the 69 occasions. MR examination of bone marrow in MM patients can be used for tumour mass assessment, both at diagnosis and during follow-up. Valuable information can be obtained when the tumour mass is difficult to estimate using clinical criteria, e.g. in non-secretory MM or when osteoporosis is the only variable indicating an increase in the tumour mass.

Fine Needle Aspiration Biopsy of Hydatid Cysts

Fine needle aspiration biopsy (FNAB) was performed in 31 patients with hydatid disease by 15 operators in 41 biopsy events during the period 1983–93. The FNABs were unintentionally done without prior clinical suspicion of hydatid cysts (HCs) in 18 patients and intentionally (with prior clinical suspicion of HC) in 13 patients for pathologic confirmation required for specific therapy. The FNABs were performed with the guidance of fluoroscopy (n=7), CT (n= 14) or ultrasonography (n= 10). The material included both closed, open and ruptured HCs from different locations such as abdomen, thorax, spine and bone. Pathologic confirmation of HC was achieved by recovering and demonstrating parasitic material in the specimen. In only 7 of 31 patients were the specimens diagnostic at the initial interpretation. This emphasizes the importance of alerting the pathologist about the possibility of hydatid disease.

In 25 of 31 patients (81%) no biopsy reactions occurred. In 5 patients minor allergic reactions occurred and 3 had filling of air into intrathoracic cysts not requiring therapy. One patient, with a FNAB of a liver HC, had a sudden severe drop in blood pressure, which required anti-shock therapy with subsequent recovery without sequelae. All complications occurred with non-intentional biopsy of HC. Suggestions for diagnostic and therapeutic management of patients with HC and advice to avoid or limit potential complications or spread of disease are given where a planned biopsy is necessary for appropriate and effective therapy.

An Attempt to Characterize Malignant Lymphoma in Spleen, Liver and Lymph Nodes with Magnetic Resonance Imaging

An attempt was made to explore whether relaxation times and/or normalized image intensities obtained from magnetic resonance imaging (MRI) can separate malignant and non-malignant lymphomatous tissue. Spin-echo (SE) techniques with repetition times of 500 and 1500 ms and echo times of 35 and 70 ms were used for estimating T1 and T2. Estimation of T1 and T2 with such a low number of spin-echo sequences resulted in considerable variation in the data especially when T1 was long. Similar information was also extracted by normalizing the image intensities to the ‘proton density’ image (1500/35), and the spread of the data was then markedly reduced. Therefore, the method of normalizing was considered a more appropriate way of handling the image data when only a few sequences were available. No significant difference could be discerned in the MRI parameters between normal spleens and spleens infiltrated with malignant lymphoma, between normal livers and livers in patients with malignant lymphoma and between lymph nodes with low or high grade non-Hodgkin lymphoma. Lymphomatous tissue had similar MRI characteristics irrespectively of whether the cells were malignant or not, or located in spleens or in lymph nodes. The main biologic explanation for variation in data seems to be mostly the variable amounts of fibrosis, necrosis, oedema and/or iron content.

Accuracy of Double Contrast Barium Enema and Sigmoideoscopy in the Detection of Polyps in Patients with Diverticulosis

The sensitivity between double contrast barium enema (DCBE) and sigmoideoscopy in diagnosing neoplastic lesions in the sigmoid colon was compared in patients with diverticulosis. In 52 patients with severe diverticulosis (≥15 diverticulas) the DCBE detected one out of 4 polyps found by sigmoideoscopy. In the remaining 54 patients with mild diverticulosis (<15 diverticulas) DCBE detected 7 out of 10 polyps found by sigmoideoscopy. Successful bowel preparation did not influence the outcome of the DCBE. Sigmoideoscopy was incomplete in 17 (16%) of the patients; females were more difficult to examine than males (p= 0.012), as were those with a previous pelvic operation (p= 0.032). We conclude that neither DCBE nor sigmoideoscopy alone is sufficient to detect all neoplastic lesions in the sigmoid colon in patients with sigmoid diverticulosis of the colon.

Imaging of Solid Kidney Tumours in Children

Eighteen children aged 6 months to 12 years with 20 solid renal tumours; 13 Wilms' tumours (WT), 2 clear cell sarcomas of the kidney, 1 malignant rhabdoid tumour of the kidney and 2 cases of bilateral nephroblastomatosis with Wilms' tumour underwent evaluation with US, CT and MR imaging. Contrast-enhanced CT and non-enhanced MR were equally accurate in determining the size and origin of the tumour but were unreliable in separation of stages I, II and III. US could only accurately assess the size of the tumours. MR characteristics varied somewhat between WTs and non-WTs but contrast-enhanced MR imaging might be useful for separation of WTs from nephroblastomatosis.

Field-Echo Pulse Sequences Used under Suspended Respiration for Detection of Liver Metastases

To obtain a fast MRI sequence for detection of liver metastases under suspended respiration, two healthy volunteers were examined with the field echo sequence FLASH, using a large number of repetition times, echo times, flip angles and matrix sizes. The spleen was used to simulate liver metastases and contrast-to-noise ratios between liver and spleen were calculated and the sequence with the highest ratio was considered optimal. The different FLASH sequences were also compared with spin echo sequences using short repetition and echo times. A FLASH sequence with a repetition time of 140 ms, an echo time of 14 ms, a flip angle of 80 to 100 degrees and a matrix size of 128×256 was considered the most suitable for detecting liver metastases. This sequence, together with other FLASH and spin echo sequences, were used for examination of five patients with liver metastases from endocrine gastrointestinal tumours.

Magnetic Resonance Imaging, Chest Radiography, Computed Tomography and Ultrasonography in Malignant Lymphoma

Magnetic resonance imaging (MRI) was compared with chest radiography, computed tomography (CT) and ultrasonography (US) for demonstration of spleen and liver engagement and enlarged lymph nodes in patients with malignant lymphoma. The investigation comprised 24 patients with Hodgkin's disease (HD) and 39 with non-Hodgkin lymphoma (NHL). MRI demonstrated enlarged lymph nodes, distinctly separated from vessels, fat, muscle, liver and occasionally also pancreas without any contrast medium. The distinction between lymph nodes and spleen was, however, poor in the images. In the mediastinum, MRI was superior to chest radiography and had an accuracy similar to that of CT. In the abdomen and the pelvis MRI had slight advantages over CT in detection of enlarged lymph nodes. Compared with US the MRI results were similar in the abdomen and somewhat better in the pelvis. MRI and US were better than CT in revealing HD infiltrates in the spleen. Infiltration of NHL in the spleen was slightly better disclosed at US than at CT and MRI; most of the NHL infiltration, confirmed at histopathology, could, however, not be revealed with any of the modalities, except when the size of the spleen was considered. Regions in the spleen, displayed with low image intensity in the T2 weighted image, were most likely due to increased amount of fibrotic tissue in the lymphomatous lesions. Good demonstration of lymph nodes and lymphomatous lesions in the spleen with MRI required two sequences; one with short TR and TE (T1 weighted image) and one with long TR and TE (T2 weighted image).

Superparamagnetic Particles as Oral Contrast Medium in MR Imaging of Malignant Lymphoma

Non-biodegradable superparamagnetic particles, in plain and viscous aqueous suspensions, were used as an oral contrast medium in 34 patients with known or suspected malignant lymphoma. The contrast effect, the occurrence of artifacts, and the distribution were evaluated in the plain and the viscous aqueous suspensions, and the diagnostic information received from abdominal MR examinations performed without bowel contrast medium was compared with that of post-contrast examinations. Magnetic particles in the concentration of 0.5 g/l displayed a good contrast effect at 0.5 T, and helped in differentiating the intestine from adjacent tissues, resulting in increased diagnostic information in abdominal MR imaging. In the patients given the viscous aqueous suspension the occurrence of artifacts caused by the magnetic particles decreased considerably, and the distribution was homogeneous and improved compared with that in patients given the plain aqueous suspension.

Paraesophageal Varices Presenting as a Retrocardiac Mediastinal Mass

This report is a reminder that portal hypertension with paraesophageal varices can present as a retrocardiac mass on the chest radiograph. Schistosoma mansoni, the probable etiology in this case, causes periportal fibrosis and is the most common explanation for portal hypertension worldwide. Modern imaging techniques were most helpful in the diagnostic work-up, ultrasonography revealing pathognomonic hyperechoic periportal bands, and CT and MR imaging showing the extent of collaterals.

Magnetic Resonance Imaging of the Transplanted Kidney

Interstitial fibrosis is a frequent finding in biopsies from long-term renal allografts, and may be due to chronic cyclosporine nephrotoxicity or chronic rejection. In this study, long-term renal transplants were investigated with magnetic resonance (MR) imaging, and the results were correlated to histopathology and graft function. Seventeen patients were investigated with MR one to 10 years after transplantation and with simultaneous ultrasonographically guided cortical needle biopsy and function tests. Histopathology included semiquantitative grading of degree of fibrosis and quantitation of ratios of tubular structures to interstitial tissue. The correlation between the histopathological assessment of interstitial fibrosis and graft function was good. Poor differentiation between the renal cortex and the renal medulla at MR imaging was correlated to high degree of interstitial fibrosis in the kidney transplants as well as to reduced graft function. MR examination may thus be of value in the evaluation of long-term renal transplants with chronic functional changes.

Magnetic Resonance Imaging of Acute Myocardial Infarction in Pigs Using Gd-Dtpa

Six pigs with coronary artery occlusion were investigated with MR imaging before and subsequently for about 2.5 hours at repeated intervals after the intravenous administration of Gd-DTPA (0.4 mmol/kg). The animals were sacrificed after a total occlusion time of 6 hours and the hearts were excised. The excised hearts were then reexamined in the MR equipment and stained with TTC (triphenyl tetrazolium) in order to define areas of infarction. Four control hearts with 6-hour-old infarctions were only imaged ex vivo without any previous administration of contrast media. In vivo, there was no clear demarcation of infarction with or without Gd-DTPA. Ex vivo, without any contrast media, the infarctions were poorly discriminated with a discretely increased signal intensity relative to normal myocardium in the T2 weighted images. Gd-DTPA was found to accumulate in the infarctions, which caused an elevated signal intensity most pronounced in the T1 weighted images. This considerably improved the delineation of the infarcted area.

Gd-DTPA-Enhanced MR Imaging in Mediastinal Hodgkin's Disease

Gd-DTPA-enhanced MR imaging of 15 patients with primary mediastinal Hodgkin's disease was done before, during and after treatment. A total of 43 MR examinations were performed. After successful treatment, 13 patients had residual masses with reduced signal intensity (SI) ratio in the T2-weighted images. The majority of these also had decreased contrast enhancement as compared with the corresponding primary tumour. There was a significant positive correlation between the contrast enhancement and the SI ratios in the T2-weighted images of the primary tumours and/or the residual masses. Necrosis was seen in 3 of the primary tumours and one patient had a cystic residual mass. These necrotic/cystic lesions were easier to detect with the use of Gd-DTPA. Low SI ratio in the T2-weighted image and low contrast enhancement of the residual mass seem to indicate residual inactivity. Gd-DTPA facilitates the differentiation between cystic/necrotic and solid lesions.

MR-Cholangiography with a Double Contrast Technique

The combination of superparamagnetic particles (SPP) as a ‘negative’ contrast agent for the liver parenchyma and Cr-HIDA as a ‘positive’ one for the bile ducts was tested in dogs. The maximum effect of SPP was present about 30 minutes after injection with a reduction of the image intensity of the liver close to the background noise level at the highest dosages. This effect lasted for about 4 to 5 hours and it had disappeared after 24 hours. Before any contrast administration or after Cr-HIDA the bile ducts were not discernible, but a high signal in the gallbladder was present 15 to 30 minutes after injection of Cr-HIDA. After SPP the wider bile ducts were discernible because of the lowering of the signal intensity in the liver. When SPP were followed by Cr-HIDA, the bile had a higher signal intensity, and even tiny bile ducts were visible. After cholecystokinin visualization of the choledochus duct was achieved as well as contrast filling of the duodenum. The blood, urine and liver function tests were found normal during the experiments. The combination of superparamagnetic particles and Cr-HIDA seems to be a promising method for MR-cholangiography. An evaluation of the anatomic structures of the liver should be possible with this method in different pathologies.

Mr Imaging of Acute Myocardial Infarction in Pigs Using GD-Dtpa-Labeled Dextran

Myocardial infarctions were induced in 12 pigs. In 6 pigs, dextran-(Gd-DTPA)15 (≈0.1 mmol Gd/kg b.w.) was injected i.v. 4 to 4.5 hours after coronary artery occlusion. ECG gated MR images were obtained repeatedly before (n = 4) and after (n = 6) contrast medium injection. Relaxation times in blood samples were measured repeatedly. The animals were sacrificed 2 hours after contrast medium administration. The hearts were excised, reexamined in the MR equipment and stained with triphenyltetrazolium chloride (TTC) in order to define areas of infarction. The remaining 6 pigs were sacrificed 6 hours after occlusion without administration of contrast medium. These hearts were only imaged ex vivo. In vivo, the infarctions could not be identified with or without dextran-(Gd-DTPA)15. Ex vivo, without contrast medium, the infarctions had an increased signal intensity, most pronounced in the T2-weighted images. Dextran-(Gd-DTPA)15 caused a prolonged, pronounced shortening of T1 and T2 in blood samples. The infarct demarcation improved in the T1-weighted images after injection of dextran-(Gd-DTPA)15, due to a moderate enhancement in normal myocardium and a stronger enhancement at the periphery of the infarctions, while the central parts of the infarctions were only weakly enhanced.

Selection of Patients with Lower Limb Arterial Occlusive Disease for Endovascular Treatment of the Iliac Arteries with Duplex Scanning

The aim of this study was to evaluate the role of duplex scanning in selection of patients with lower limb arterial occlusive disease for endovascular treatment of the iliac arteries. From January 1995 through May 2000, 183 patients having chronic lower limb arterial insufficiency who underwent duplex scanning of the lower extremity arteries with available aortoiliac scans within 3 months before conventional aortoiliac diagnostic angiography and/or endovascular intervention of the iliac arteries were studied retrospectively. The findings obtained from duplex scanning and angiography were analyzed in a blinded manner by 2 investigators. Limbs having category 1, 2, and 3 lesions according to duplex scan findings were interpreted as being suitable for endovascular intervention. The comparison between duplex scan findings and angiography was analyzed by the third investigator.

During 93 percutaneous transluminal angioplasty (PTA) procedures, 133 arterial segments, common or external iliac, were dilated with stent placement in 70. Bilateral interventions were performed in 25 cases, and of 68 unilateral interventions, 57 were at only 1 arterial segment. The accuracy, sensitivity, specificity, and negative and positive predictive values of duplex scanning to appropriately categorize the iliac artery lesions into suitable or unsuitable for endovascular intervention were 90%, 95%, 83%, 90%, and 92%, respectively when the inconclusive duplex scans were excluded (11%). In 6 patients with lesions suitable for PTA according to duplex scanning and angiography, PTA was not performed owing to clinical reasons. The accuracy of duplex scanning in predicting the performance of endovascular intervention was 88%.

It is concluded that iliac artery endovascular procedures in limbs with chronic occlusive disease can be reliably planned according to duplex scan findings.

Propositions for Refinement of the Hybrid Surgical Technique for Treatment of Thoraco-Abdominal Aortic Aneurysm

Traditional open repair of thoraco-abdominal aortic aneurysms Crawford type II-IV carries a high perioperative risk and mortality. The hybrid technique for combined surgical and endovascular treatment offers an interesting alternative with reduced risk of paraparesis and possibly a reduced mortality rate. Propositions for refinement of this approach are outlined based on a single centre experience.

Transcutaneous port for levodopa/carbidopa intestinal gel administration in Parkinson's disease

OBJECTIVE

To evaluate the safety and tolerability of the T-Port(®) for intestinal infusion of levodopa/carbidopa gel in patients with advanced Parkinson's disease (PD).

METHODS

This prospective study was carried out in 24 patients with PD (15 males, mean age 61.8 years, mean duration PD 18.7 years). All adverse device effects were evaluated at 2 weeks, 3 months and 6 months and until explantation or death.

RESULTS

Post-operative complications were similar to endoscopic gastrojejunostomy placement (four peritoneal irritation, one pocket pain). Eight patients with prior experience with the endoscopic gastrojejunostomy preferred the T-Port. The total device experience was 83.6 years, and the average survival time was 3.6 (range 1.1-5.2) years. Six T-Ports were still in use, and two patients had died due to non-device-related reasons. Sixteen T-Ports had been explanted due to 15 stoma reactions (14 inflammations and one infection) and one tilting of the T-Port. The T-Ports were replaced with endoscopic gastrojejunostomy system as replacements with T-Ports were not part of the study. Only two device malfunctions occurred (one catheter breakage at 3 year post-implant and one T-Port leakage of levodopa/carbidopa gel). No tube kinking, dislocation or blockage occurred. The number of adverse device effects proved to be significantly lower as compared to the endoscopic gastrojejunostomy literature data.

CONCLUSIONS

The T-Port is safe and well tolerated, and the low number of tube problems is a potential advantage compared with the endoscopic gastrojejunostomy system. Proper cleaning and local treatment of the stoma site around the T-Port are essential to prolong its longevity.

The value of intravascular phased-array imaging in endovascular treatment of thoracic aortic pathology

BACKGROUND

Careful pre-, intra- and postoperative diagnostics in endovascular treatment of thoracic aortic pathology is crucial for a favourable outcome. Computer tomography (CT) and digitally subtracted angiography (DSA) do not always provide sufficient diagnostic information.

PURPOSE

To report our primary experiences of using intraluminal phased-array imaging (IPAI) as an additive tool for diagnostics and endovascular treatment of thoracic aortic pathology.

MATERIAL AND METHODS

Eleven patients, nine men and two women (mean age 60, range 45) were examined intraoperatively with IPAI in stentgraft procedures of thoracic aortic pathology.

RESULTS

IPAI could detect and visualize the entries and re-entries in the intima. Aortic branch vessels could be visualized for patency both during and immediately after stentgraft deployment. It was also possible to detect ceased blood flow in the false lumen or aneurysmal sac after stentgraft deployment.

CONCLUSION

IPAI is a helpful tool for diagnostics and for guiding stentgraft placing in the treatment of thoracic aortic pathology.

Intravascular ultrasound with a vector phased-array probe (AcuNav) is feasible in endovascular abdominal aortic aneurysm repair

BACKGROUND

The ideal imaging method for endovascular aneurysm repair (EVAR) should provide all data regarding diagnosis, measurements, and guiding of stent-graft deployment. Contrast-enhanced computed tomography (CT) is used for preoperative EVAR planning, together with intraoperative angiography. However, the administered contrast volume might result in contrast-induced nephropathy (CIN).

PURPOSE

To develop a technique for aortic measurements, vessel wall evaluation, and stent-graft positioning by using a vector phased-array intravascular ultrasound probe with color Doppler function (AcuNav) in elective EVAR.

MATERIAL AND METHODS

Thirteen elective EVAR patients were included. AcuNav was compared to pre- and postoperative CT examinations, perioperative angiography, and postoperative duplex.

RESULTS

Measurements for stent-graft sizing were easily obtained and facilitated by the color Doppler function and corresponded well with CT and angiography. The combined information from AcuNav and fluoroscopy provided exact positioning of the stent graft. An aortic placement of the probe provided superior imaging results compared to an inferior vena cava approach. Detection of endoleak was found to be difficult. No complications were registered.

CONCLUSION

The use of AcuNav combined with fluoroscopy in EVAR was found to be safe, effective, and feasible in planning and guiding EVAR procedures. Best results were seen with the probe placed in the artery. AcuNav might be used to replace contrast-enhanced CT and angiography, hence reducing the risk of CIN, especially in high-risk patients.

Fractures of self-expanding metallic stents in periampullary malignant biliary obstruction

BACKGROUND

Self-expanding metallic stents are widely used for relieving biliary duct obstruction in patients with unresectable periampullary malignancies. However, only a few studies have assessed the occurrence of fractures in these stents.

PURPOSE

To determine the prevalence and significance of stent fracture after placement of self-expanding metallic stents for periampullary malignant biliary obstruction.

MATERIAL AND METHODS

Over a 5-year period, 48 patients underwent placement of self-expanding metallic stents for periampullary malignant biliary obstructions. Stents were introduced 2-6 weeks after a percutaneous transhepatic biliary decompression. The medical records and relevant images were reviewed for stent patency, stent fracture, type of stent, and stent-related complications.

RESULTS

Stent fracture was detected in four of the 48 patients (8%): in one patient at 1 month and in three patients between 10 and 21 months after stenting. All four fractures involved one type of nitinol stent used in 38 patients. In one of the patients, fracture was complicated by life-threatening gastrointestinal bleeding. The mean survival time for all patients was 251 days (standard deviation [SD]+/-275 days) and the mean overall patency time for all stents was 187 days (SD+/-205 days).

CONCLUSION

Stent fracture occurs after placement of self-expanding nitinol stents for periampullary malignant biliary obstruction. The low reported incidence of this complication may be due to a lack of awareness of and difficulty in detecting stent fracture. Fracture should be considered as a possible contributing factor in recurrent biliary obstruction after self-expanding metallic stent insertion.

Outcome after endovascular revascularization of atherosclerotic renal artery stenosis

BACKGROUND

With an aging population, more patients might be treated for atherosclerotic renal artery stenosis (ARAS). The goal of this treatment is to achieve a dialysis-free life or a well-controlled blood pressure with reduced risks of cardiovascular complications.

PURPOSE

To analyze the clinical outcome of percutaneous transluminal renal artery angioplasty without stenting (PTRA) or with stenting (PTRS) for ARAS at one center.

MATERIAL AND METHODS

The study group comprised 152 patients who underwent 203 PTRA/PTRS. All had hypertension, and 45% had azotemia. A retrospective collection of baseline and postprocedural number of antihypertensive drugs, blood pressure, and serum creatinine were analyzed during a follow-up of 3-18 months.

RESULTS

Technical success rate was 95%, and clinical benefit was seen in 63% of patients. Complications included a 30-day mortality rate of 1.5%, a total complication rate of 35%, and major adverse events in 13%. The major adverse events were highly related to azotemia. Major adverse events within 30 days, with permanent disability, were seen in 5% and almost exclusively in patients with moderate or severe renal impairment. A subgroup analysis of 28 patients with renal duplex resistive index (RI) pre-PTRA/S and 6 months' follow-up showed a benefit of PTRA/PTRS in 17 (68%) of the 25 patients with RI <80 and in all three (100%) of the patients with RI >or=80.

CONCLUSION

Endovascular treatment of ARAS has an excellent technical success rate, with a clinical improvement rate of >60%. However, it is associated with a considerable complication rate. Serious complications are seen mainly in azotemic patients. Predictors of clinical response could not be identified. Renal duplex RI is questioned as a predictor of clinical outcome.

The future of imaging in the management of abdominal aortic aneurysm

The development of endovascular techniques depends on the concomitant development of imaging techniques. Imaging with ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MR) is evolving at rapid pace. Angiography has largely been replaced by these techniques as a diagnostic tool in the clinical setting. New methods, e.g., rotational angiography and intravascular ultrasound, will play an important role in endovascular treatment of vascular disease. It is necessary to have easy access to ultrasonography, CT and MR images in future hybrid angiographic/surgical suites and the operator must be able to do advanced immediate reconstructions in a sterile environment. The combined use of advanced imaging, open and endovascular techniques will further improve the treatment of vascular disease in the future.

Massive postpartum hemorrhage treated with transcatheter arterial embolization: technical aspects and long-term effects on fertility and menstrual cycle

BACKGROUND

Transcatheter arterial embolization (TAE) is considered a safe, life-saving procedure in postpartum hemorrhage (PPH), but its long-term effect on menstruation and fertility is unclear.

PURPOSE

To investigate technical aspects and the evaluation of complications, focused on menstrual cycle and fertility, using TAE in patients with PPH.

MATERIAL AND METHODS

A retrospective study including 20 patients (seven with vaginal and 13 with cesarean delivery) with severe PPH treated with bilateral TAE of the uterine artery was carried out. All patients were asked to answer a questionnaire regarding their post-embolization history. In six patients, the radiation dose was measured.

RESULTS

All 20 cases underwent bilateral TAE of the uterine artery. Gelfoam was used as the embolic agent. However, after cesarean delivery in six patients who had clear contrast medium extravasation and/or pseudoaneurysm-like lesion, metallic coils had to be used in order to achieve hemostasis. No major short- or long-term complications were registered. Normal menses resumed in all patients. Four patients had a total of five full-term and two preterm pregnancies, and all delivered healthy infants by cesarean section with no recurrence of PPH. The mean radiation dose to the ovaries was 586 mGy (range 204-729 mGy).

CONCLUSION

TAE in patients with PPH is safe and has no major short- or long-term side effects. A patient managed with TAE can expect return of normal menses and preservation of future fertility and successful pregnancies. PPH after cesarean section might need to be embolized with metallic coils in addition to Gelfoam in order to achieve secure hemostasis.

Liver embolization with trisacryl gelatin microspheres (embosphere) in patients with neuroendocrine tumors

PURPOSE

To report our experience of liver embolization with trisacryl gelatin microspheres (Embospheretrade mark) in patients with metastatic neuroendocrine tumors.

MATERIAL AND METHODS

Fifteen patients underwent selective embolization of the right or left hepatic artery with Embosphere. One lobe was embolized in seven patients and both lobes, on separate occasions, in eight patients. Seven patients had midgut carcinoids, two had lung carcinoids, one suffered from a thymic carcinoid, and five had endocrine pancreatic tumors. Eight patients suffered from endocrine symptoms, seven of whom had carcinoid syndrome and one WDHA (watery diarrhea, hypokalemia, achlorhydria) syndrome.

RESULTS

Partial radiological response was seen after eight embolizations (in six different patients), stable disease was observed after 13 embolizations (after three of these, necroses occurred), while radiological progression was noted after only two embolizations. Only two patients experienced a biochemical response. Clinical improvement of carcinoid syndrome was observed after five embolizations. There were no major complications. Fever >38 degrees C was seen after all but four embolizations, and urinary tract infections were diagnosed after eight embolizations.

CONCLUSION

Selective hepatic artery embolization with Embosphere particles is a safe treatment for patients with metastatic neuroendocrine tumors and may lead to partial radiological response as well as symptomatic improvement of disabling endocrine symptoms.

Remodeling of the thoracic aorta after stent grafting of type B dissection: a Swedish multicenter study

AIM

Endovascular repair of complicated type B dissections has evolved as a promising alternative to open repair. Previous studies have indicated that continued false lumen flow is a predictor of continued aortic dilatation and risk of rupture during follow-up. This multicenter study was conducted to analyze the postoperative changes of the false lumen after endografting of complicated type B dissections.

METHODS

All patients treated with endovascular stent grafts for thoracic type B dissections at 5 major Vascular Centers in Sweden were identified through local databases. Review of charts and all available pre- and postoperative CT scans were performed to identify demographics, indications for repair as well as postoperative changes of the aorta and false lumen.

RESULTS

A total of 129 patients treated for type B dissections between 1994 and December 2005 were identified. Median radiological follow-up was 14 months. Fourteen patients died perioperatively leaving 115 patients available for analysis. Seventy-four of these had CT imaging of sufficient quality for morphological analysis. The vast majority of acute patients were treated for rupture or end-organ ischemia whereas most chronic patients were treated for asymptomatic aneurysms. In 80% of patients, the false lumen thrombosed along the stent graft but it remained perfused distal to the stent graft fixation in 50% of patients. Only 5% of patients presented with aortic enlargement of the stent grafted area when adequate proximal sealing was achieved. The distal, uncovered aorta displayed expansion in 16% of patients.

CONCLUSIONS

The stent grafted thoracic aorta after type B dissection appears to be stabilized by covering the primary entry site with a stent graft in the majority of both acute and chronic dissections. The uncovered portion of the aorta distal to the stent graft, however, remains at risk of continuous dilatation. Stent grafting for complicated type B thoracic dissections seems to be a treatment option with reasonable morbidity and mortality even though the incidence of severe complications is still significant.

A prospective comparison of duplex ultrasonography, captopril renography, MRA, and CTA in assessing renal artery stenosis

PURPOSE

To prospectively compare the diagnostic accuracy of duplex ultrasonography, captopril renography, computed tomography angiography (CTA), and 3D Gd magnetic resonance angiography (MRA) in diagnosing hemodynamically significant renal artery stenosis (RAS).

MATERIAL AND METHODS

The standard of reference was measurement of transstenotic pressure gradient. Fifty-eight hypertensive patients with suspicion of RAS were evaluated, when possible, by all five techniques. Sensitivity and specificity to detect RAS were compared for each technique on both a patient and kidney basis. Discrepancies were evaluated separately and classified as borderline, method dependent, or operator dependent.

RESULTS

The prevalence of RAS was 77%. The sensitivity/specificity of ultrasonography, captopril renography, CTA, and MRA in detecting kidneys with RAS was 73/71%, 52/63%, 94/62%, and 93/91%, respectively. Ultrasonography had a significantly lower sensitivity than CTA and MRA (P<0.001) but higher than captopril renography (P = 0.013). Borderline RAS was the main cause for discrepancies.

CONCLUSION

MRA and CTA were significantly better than duplex ultrasonography and captopril renography in detecting hemodynamically significant RAS. The ultrasonography criteria for RAS based on the evaluation of renal peak systolic velocity and renal/aortic ratio are questionable. Captopril renography cannot be recommended for assessing RAS.

Split renal function in patients with suspected renal artery stenosis: a comparison between gamma camera renography and two methods of measurement with computed tomography

PURPOSE

To validate a method for calculating split renal function from computed tomography (CT) compared with gamma camera renography, and to test a new method for the measurement based on a volume-rendering technique.

MATERIAL AND METHODS

Thirty-eight patients, aged 65.7 +/- 11.6 (range 37.8-82.1) years, who had undergone both CT angiography and gamma camera renography for a suspected renal artery stenosis were included in this study. Split renal function was calculated from the CT examinations by measuring area and mean attenuation in the image slices of the kidneys, and also by measuring volume and mean attenuation from a 3D reconstruction of the kidneys. Gamma camera renography with 99mTc-MAG3 with or without captopril enhancement was used as a reference.

RESULTS

The 2D CT method had good correlation with renography (r=0.93). Mean difference was 4.7 +/- 3.6 (0-12) percentage points per kidney. There was also excellent correlation between the two CT methods (r=1.00).

CONCLUSION

CT is equivalent to renography in determining split renal function, and the measurement from the CT examination can be made more quickly and equally accurately with a 3D technique.

Renal artery stenosis evaluated with 3D-Gd-magnetic resonance angiography using transstenotic pressure gradient as the standard of reference. A multireader study

PURPOSE

To evaluate 3D-Gd-magnetic resonance angiography (MRA) in detecting hemodynamically significant renal artery stenosis (RAS).

MATERIAL AND METHODS

Thirty patients evaluated for atherosclerotic RAS by MRA and digital subtraction angiography (DSA) were retrospectively included. Standard of reference for hemodynamically significant RAS was a transstenotic gradient of 15 mmHg. DSA visualized 60 main renal arteries and 9 accessory arteries. Pressure gradient measurement (PGM) was available from 61 arteries. Three radiologists evaluated all examinations independently in a blinded fashion.

RESULTS

RAS was present in 26 arteries. On MRA, each reader identified 4 of 9 accessory renal arteries, a detection rate of 44%. The three readers correctly classified 22/25/22 of the 26 vessels with a significant gradient as > or =60% RAS and 31/25/32 of the 35 with no significant gradient as < 60% RAS on MRA. Interobserver agreement was substantial. MRA image quality was adequate for RAS evaluations in all patients. ROC curves indicated that MRA is an adequate method for evaluating RAS. When screening for RAS, a 50% diameter reduction cut-off is better than 60%. RAS with 40-80% diameter reductions accounted for 65% of discrepancies.

CONCLUSION

MRA is an adequate method for evaluating RAS limited mainly by poor detection rate for accessory renal arteries.

Distal percutaneous transluminal angioplasty through infrainguinal bypass grafts

AIM

to evaluate the results of transluminal angioplasty (PTA) performed through infrainguinal bypass grafts for stenotic or occlusive lesions at the distal anastomosis and/or in the runoff arteries.

DESIGN

retrospective clinical study.

MATERIAL AND METHODS

forty-one patients underwent 57 procedures at the distal anastomosis (n=13), in the runoff arteries (n=32) or at both locations (n=12) at a median of 9.6 months (range, 2-76 months) after infrainguinal bypass grafting. Nineteen procedures were on the popliteal artery, the rest on the crural arteries. Eleven procedures related to occlusions less than 5 cm in length.

RESULTS

technical success was achieved in 91%. Primary and primary assisted graft patency rates at 3 years were 32% and 53%, respectively. There were no significant differences in patency rates with regard to the graft material, the type of lesion, the level of PTA, the status of runoff and the use of thrombolysis before PTA. No patients underwent amputation as a direct consequence of failed PTA or graft occlusion. One patient underwent acute surgical intervention due to graft occlusion at the time of attempted PTA.

CONCLUSION

the results of PTA at the distal anastomosis and/or in the runoff arteries in limbs with infrainguinal bypass seemed to be inferior to the results of surgical revisions reported in literature. However, as failed PTA did not jeopardise vein-patch angioplasty or jump grafting, it is a reasonable alternative to surgical intervention in selected cases.

Endovascular approach to treating secondary arterioureteral fistula

Two patients with the rare entity of arterio-ureteral fistula are presented. Both highlight the predisposing factors of radiation, major surgery in the region, history of vascular surgery and presence of double-J-stent. Both patients presented with the clinical sign of intermittent gross hematuria. Both patients were successfully treated by endovascular intervention using graft covered stent.

Influence of bone marrow on membrane-guided bone regeneration of segmental long-bone defects in rabbits

Defects 10 mm long were created in long bone in the diaphysis of both radii of 18 rabbits (test and control side). On the test side, ingrowth of bone marrow into the defects was hindered or delayed by: plugging the opening of the cut bone ends with gutta-percha points (n = 7); plugging with Gelfoam (n = 6); or by removing the bone marrow by flushing with saline (n = 5). The defects on both test and control side were covered with an expanded polytetrafluoroethylene membrane, shaped as a tube. Healing was followed with radiographs for four to five months, after which the animals were killed and ground sections of the areas of the defects were prepared for histological examination. On the control side, nine of 18 animals had complete osseous bridging of the defect, and a small transverse non-mineralised zone remained in the centre of the healed defect in the other animals. This zone consisted of loose connective and cartilagenous tissue as well as connective tissue obviously derived from the outside of the membrane. By preventing or delaying the ingrowth of bone marrow we retarded the regeneration of mineralised bone, particularly in the gutta-percha and flushed bone marrow groups. The principle of guided tissue regeneration may be used to achieve regeneration of extensive long-bone defects. Any attempts to delay or prevent bone marrow ingrowth into the defects did retard regeneration of segmental long-bone defects.

Investigation of the excluded stomach after Roux-en-Y gastric bypass

BACKGROUND

One problem with Roux-en-Y gastric bypass (RYGBP) is that it leaves the bypassed segment not readily available for endoscopic or radiographic examinations.

MATERIALS AND METHODS

Three males, 50, 54 and 64 years old, suffered from repeated, gastrointestinal bleeding of unknown origin requiring transfusion 1/2, 1 and 7 years after RYGBP. Access to the stomach was obtained by an ultrasound-guided percutaneous gastrostomy.

RESULTS

We could perform endoscopy, barium studies and gastric acid output measurements through the gastrostomy. Histological gastritis, low acid output and absence of H. pylori infection were found.

CONCLUSION

We were able to exclude severe gastric disease in our patients.

Imaging of abdominal neuroblastoma in children

PURPOSE

The aims of the study were: 1) to assess the efficacy of different imaging methods for use prior to treatment; 2) to compare the surgico-histopathologically-based International Neuroblastoma Staging System (INSS) staging with the imaging results; and 3) to suggest a localisation scheme for abdominal neuroblastoma.

MATERIAL AND METHODS

Thirty-one children with an abdominal neuroblastoma (median age 2 years), underwent abdominal US, CT of chest and abdomen, MR imaging of abdomen and spine, chest radiography, skeletal survey, radionuclide bone scintigraphy, MIBG scintigraphy, and bone marrow biopsy.

RESULTS

In the evaluation of local disease, CT and MR were superior to US. There was no significant difference between CT and MR in assessment of the location or size of the tumour. Evaluation of invasive growth and lymphadenopathy was uncertain irrespective of imaging modality. Intraspinal extension was more distinctly demonstrated with MR. Tissue characterization with CT and MR did not contribute in the assessment of the tumours. Contrast enhancement at CT and MR examinations both improved demarcation between tumour and kidney, and was a necessity for evaluation of vessel encasement with CT. The local disease was best assessed by either CT or MR, while metastatic disease was best revealed by CT, MR, scintigraphy or bone marrow biopsy.

CONCLUSION

Imaging may be a valuable basis for clinical assessment and pretreatment staging of abdominal neuroblastoma.

Diverticulitis of the sigmoid colon. A comparison of CT, colonic enema and laparoscopy

PURPOSE

To evaluate the use of laparoscopy, CT, colonic enema (CE), and laboratory tests (white blood cell count (WBC), sedimentation rate (SR), and C-reactive protein (CRP) in diagnosing diverticulitis of the sigmoid colon.

MATERIAL AND METHODS

The diagnostic methods were prospectively evaluated in 88 patients, 30 of whom were referred for laparoscopy.

RESULTS

Fifty-two patients were found to have sigmoid diverticulitis: 20 patients by laparoscopy, 21 by CT, and 11 by CE combined with one positive laboratory test. Laparoscopy proved to be superior to the other diagnostic methods in diagnosing diverticulitis of the sigmoid colon. CT had a high specificity (1.0; 95% CI: 0.92-1.0) but low sensitivity (0.69; 95% CI: 0.56-0.79) in detecting diverticulitis. CE had a higher sensitivity (0.82; 95% CI: 0.71-0.90) but a lower specificity (0.81; 95% CI: 0.67-0.91) than CT.

CONCLUSION

CT was the best method for diagnosing abdominal pathology outside the colon. CT can be recommended as the first examination in seriously ill patients where abscesses and other causes of the symptoms than diverticulitis must first be ruled out. Laparoscopy is probably the most accurate method in diagnosing diverticulitis.

Scintigraphy and ultrasonography in differentiating osteomyelitis from bone infarction in sickle cell disease

PURPOSE

To demonstrate the combined use of scintigraphy and ultrasonography (US) in differentiating osteomyelitis from bone infarction in sickle cell disease.

MATERIAL AND METHODS

Two patients with sickle cell disease were examined with a combination of bone, bone marrow, white blood cell and/or gallium scintigraphy and US.

RESULTS

The scintigraphic studies demonstrated areas of suspected osteomyelitis at the distal femur in both patients and at the proximal right tibia in one of them. US revealed subperiosteal fluid collections in these areas. Aspiration guided by US established the presence of pus at the femur in both instances, which was successfully treated with the US-guided insertion of a drainage catheter and aspiration only, respectively. Thick blood, due to bone infarction, was aspirated at the tibia.

CONCLUSION

The scintigraphic studies were useful in locating all areas of suspected osteomyelitis. The role of US was to confirm the presence of a subperiosteal fluid collection and to guide aspiration, which can show the distinction between a haematoma and an abscess.

Imaging and compartmental classification of solid pelvic tumours in children

Thirty-five children aged from 1 day to 16 years (median 5 years) with solid pelvic tumours were investigated with US, CT and MR. All three methods gave similar estimates of tumour size. For defining location of the tumours, the pelvis was divided into three midline compartments (anterior, middle and posterior) and a right and left lateral compartment. CT and MR were accurate and equally reliable in determining the tumour location, US was less accurate. Evaluation of confinement to organ of origin was uncertain, regardless of imaging modality. Tissue characteristics with CT and MR did not contribute to the differentiation of the various tumour types, and contrast medium enhancement did not improve the discrimination. Compartmental localization was equally well assessed by CT and MR and, together with sex, was found to correlate with the tumour type.