[Minimal-Invasive CT-guided spinal interventions--from pain therapy over biopsies to tumor therapy]. / Minimalinvasive CT-gesteuerte Wirbelsäuleninterventionen--von der Schmerztherapie über Gewebeentnahmen zur Tumortherapie.

CT-guided spinal interventions have undergone a remarkable evolution during the last view years, leading to a wider range of indications, as well as to the development of highly specialized new procedures. This review article deals with different aspects of spinal CT-guided pain management, biopsy and tumor therapies and emphasizes a selection of practical considerations of important interventions.

Efficacy and safety of percutaneous transhepatic portal embolization before right liver resection using an ethibloc/lipiodol mixture: a single-center experience.

AIM: The purpose of this study was to evaluate the safety and efficacy of percutaneous transhepatic portal vein embolization of the right portal vein with an Ethibloc/Lipiodol mixture to induce hypertrophy of the left liver lobe in patients with primarily unresectable liver tumor. METHODS: 15 patients (8 primary liver tumors, 7 liver metastases) underwent portal vein embolization. Liver volumetry, duration of hospitalization, complication rates, relevant laboratory values were documented. RESULTS: In 13/15 patients (84.6%) embolization could be performed with a median of 8.8 ml (range 1.5-28 ml) Ethibloc/Lipiodol. One minor procedure-related complication (subcapsular hematoma) occurred, which did not affect the two-step liver resection. No patient developed acute liver failure after embolization or liver resection. The volume of the left liver lobe increased significantly (p = 0.0015) by 25% from a median of 750 ml (587-1,114 ml) to 967 ml (597-1,249 ml). 11/13 (81.8%) of the embolized patients underwent liver resection at a median of 49 days after embolization. Median hospitalization time was 4 days after embolization and 7 days after liver resection. Median overall survival of the 11 operated patients was 376 days. CONCLUSION: Percutaneous transhepatic portal vein embolization using an Ethibloc/Lipiodol mixture is a safe, feasible, and efficient interventional procedure.

[Advances in the staging of renal cell carcinoma with high-resolution imaging]. / Fortschritte im Staging des Nierenzellkarzinoms mittels hochauflösender Bildgebung.

Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches.

Acute pancreatitis after embolization of liver tumors: frequency and associated risk factors.

INTRODUCTION: Acute pancreatitis (AP) is a rare complication after liver embolization (LE) of primary and secondary liver tumors (approximately 1.7%), but it has a significant morbidity and mortality potential if associated with other complications. It usually develops early within 24 h after the LE procedure. STUDY PURPOSE: To calculate the frequency of AP after LE in our institution and to analyze the factors involved in this procedure (anatomical features, embolization materials, cytostatic drugs, technical factors). MATERIALS AND METHODS: 118 LE (bland embolization and transarterial chemoembolization) were performed in our institution. The study group included 59 patients who met the following inclusion criteria: one or more LE events, with complete pre- and post-interventional laboratory studies including: serum Ca(2+), creatinine, blood urea nitrogen, glucose, lactate dehydrogenase, aminotransferases, alkaline phosphatase, amylase, lipase, C-reactive protein, hematocrit and leukocytes. The diagnosis of AP was established according to the criteria of the Atlanta system of classification. For the statistical analysis the association between two response variables (e.g. AP after embolization and risk factor during the embolization, AP after embolization and volume of embolic material) was evaluated using Pearson's chi(2) test and Fisher's exact test. RESULTS: The calculated frequency of AP after LE in our series was 15.2%. Amylase and lipase were elevated up to 8.7 and 20.1 times, respectively, 24 h after LE. We observed a statistically significantly lower incidence of AP in those patients who received 2 ml or less of embospheres compared with those with an embolization volume of >2 ml (Pearson's chi(2) = 4.5000, Pr = 0.034, Fisher's exact test = 0.040). Although carboplatin was administered to 7 of 9 of the patients who developed AP after the embolization procedure, there was no statistical significance (Fisher's exact test = 0.197) for carboplatin as an AP risk factor when compared with all the patients who received this drug (n = 107). CONCLUSION: Although AP after LE seems to have a multifactorial etiology, both the toxicity of the antineoplastic drugs (carboplatin-related toxicity) as well as direct ischemic mechanisms (non-target embolization, reflux mechanisms) may be the most important causes of the inflammatory pancreatic reaction after LE. We suggest that systematic measurement of serum pancreatic enzymes should be performed in cases of abdominal pain following selective LE and transarterial chemoembolization in order to confirm acute pancreatitis after embolization, which can clinically mimic a postembolization syndrome.

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

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

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

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

[Preoperative and palliative embolization of renal cell carcinomas: follow-up of 49 patients]. / Präoperative und palliative Embolisation des Nierenzellkarzinoms: Nachsorge von 49 Patienten.

PURPOSE: To evaluate the influence of preoperative and palliative embolization of renal cell carcinomas on survival, intra- and post-operative procedures, and symptom control for palliative and preoperative indications. MATERIALS AND METHODS: 56 patients who underwent renal cell carcinoma embolization from 1981 to 1999 were included in this retrospective study. RESULTS: 24 women and 32 men were included (mean age 59.4 years). Complete follow-up data was available for 49 patients. 42 patients underwent preoperative embolization at different tumor stages (pT1: 1 patient, pT2: 6, pT3 a: 4, pT3 b: 19, pT3 c: 2, pT4: 5). 14 patients underwent palliative embolization (T1: 0 patients, T2: 5, T3: 4, T4: 4). Indications for preoperative embolization were bleeding of the renal tumor in 6 cases -- non-recurrent bleeding reported, flank pain in 4 patients -- 3 of 4 patients had no further symptoms, recurrent tumor embolization in 1 patient, and 2 patients who wanted to be treated without symptoms. The mean survival time of preoperative embolized patients was 3.1 +/- 5.11 years with a 5-year survival rate of 50 %. The mean survival time of palliative embolized patients was 0.67 +/- 0.76 years with initial metastases (n = 7) and 2.33 +/- 2.40 without metastases (n = 6). CONCLUSION: Palliative embolization of renal cell carcinomas is a safe therapeutic method to treat advanced renal cell carcinomas allowing control of symptoms such as hematuria and flank pain in more than 90 % of our cases. Preoperative embolization yields a patient survival time comparable to that of patients at earlier tumor stages and is dependent on the metastases.

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.

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.

[Kyphoplasty and vertebroplasty in fractures in the elderly: effort and effect]. / Kyphoplastie und Vertebroplastie bei Frakturen im hohen Lebensalter. Aufwand und Ergebnisse.

Kyphoplasty and vertebroplasty are two minimally invasive percutaneous techniques used for treatment of osteoporotic vertebral compression fractures in the thoracic and lumbar spine. The injection of polymethylmetacrylate (PMMA) is often a final attempt at therapeutic treatment of complications due to such fractures. Vertebroplasty involves injection of cement via one or both pedicles under high pressure, thus filling and stabilizing the vertebra without reduction of fracture. Extravertebral cement leakage is a common complication: an intact posterior wall normally prevents cement leakage into the epidural space. Kyphoplasty involves transpedicular inflation of balloon tamps, thus creating a cavity which is then filled with PMMA under low pressure. Restoration of vertebral height is possible and the potential for extravertebral cement leakage lessened.

Restoration of liver function and portosystemic pressure gradient after TIPSS and late TIPSS occlusion.

TIPSS (transjugular intrahepatic portosystemic shunt) may be indicated to control bleeding from esophageal and gastric varicose veins, to reduce ascites, and to treat patients with Budd-Chiari syndrome and veno-occlusive disease. Numerous measures to improve the safety and methodology of the procedure have helped to increase the technical and clinical success. Follow-up of TIPSS patients has revealed shunt stenosis to occur more often in patients with preserved liver function (Child A, Child B). In addition, the extent of liver cirrhosis is the main factor that determines prognosis in the long term. Little is known about the effects of TIPSS with respect to portosystemic hemodynamics. This report deals with a cirrhotic patient who stopped drinking 7 months prior to admission. He received TIPSS to control ascites and recurrent esophageal bleeding. Two years later remarkable hypertrophy of the left liver lobe and shunt occlusion was observed. The portosystemic pressure gradient dropped from 24 mmHg before TIPSS to 11 mmHg and remained stable after shunt occlusion. The Child's B cirrhosis prior to TIPSS turned into Child's A cirrhosis and remained stable during the follow-up period of 32 months. This indicates that liver function of TIPSS patients may recover due to hypertrophy of the remaining non-cirrhotic liver tissue. In addition the hepatic hemodynamics may return to normal. In conclusion, TIPSS cannot cure cirrhosis but its progress may be halted if the cause can be removed. This may result in a normal portosystemic gradient, leading consequently to shunt occlusion.

Blood flow and thrombus formation determine the development of stent neointima.

To establish a relationship between flow, acute thrombus formation, and late intimal formation in implanted arterial stents, canine femoral arteries with normal blood flow were compared to contralateral femoral arteries with restricted blood flow. Thrombocyte activity over the stent segment was evaluated for 3 h after stent placement with nuclear scanning, following administration of In-111 labeled platelets. To evaluate long-term stent patency in relationship to arterial flow, an additional group of dogs were subjected to long-term observation. Matched, symmetrically implanted femoral stents with normal and restricted flow were explanted at 1, 12, and 24 weeks for histological analysis and comparative measurement of neointimal thickness. Angiographic studies were performed before and after nuclear scan in the acute animals and before explant in the chronic animals. Acutely, heparinization prevented subocclusive or occlusive thrombus, regardless of flow. In the absence of heparinization, normal arterial blood flow did not prevent thrombus formation on stents. Chronically, stents with flow restriction had significantly greater neointimal formation in comparison with unrestricted stents. Histological studies suggested that the stent neointima resulted from progressive replacement of stent thrombus.

Relationship between blood flow, thrombus, and neointima in stents.

PURPOSE: To establish a relationship between flow, acute thrombus formation, and late intimal hyperplasia in arterial stents. MATERIALS AND METHODS: To compare short-term stent patency in the canine femoral artery with normal flow to that in the opposite femoral artery with restricted flow, 24 dogs were subdivided in four groups: groups 1 (no intravenous heparin) and 2 (intravenous heparin) had unilateral flow restriction by surgically created stenosis, downstream of a Palmaz stent. Group 3 (no intravenous heparin) and 4 (intravenous heparin) had sham surgical exposure of the corresponding arterial segment, without flow restriction. Thrombocyte activity over the stent segment was evaluated for 3 hours after stent placement with nuclear scanning, after administration of indium-111-labeled platelets. To evaluate long-term stent patency in relationship to arterial flow, 14 additional dogs were subjected to long-term observation. Matched, symmetrically implanted femoral stents with normal and restricted flow, were explanted at 1, 12, and 24 weeks for histologic analysis and comparative measurement of neointimal thickness. Angiographic studies were performed before and after nuclear scanning in the short-term study group and before explant in the long-term animal group. RESULTS: In the short-term, groups 2 and 4 showed neither increased platelet uptake nor angiographically demonstrable thrombus. Group 1 had increased platelet uptake and occlusive or subocclusive angiographic thrombus. Group 3 had increased platelet uptake and angiographic thrombus in one instance. In the long-term, stents with flow restriction had significantly greater neointimal formation in comparison with unrestricted stents. Histologic studies suggested that the stent neointima resulted from progressive replacement of stent thrombus. CONCLUSION: Regardless of flow condition, intravenous heparinization is necessary to prevent thrombus formation in the stent lumen. Within the experimental parameters of this study, low flow and absent heparinization consistently lead to stent thrombosis. Stent implantation under low flow is associated with increased neointima formation. It is not known whether this is preventable by antithrombotic medication.

Acetylsalicylic acid in the prevention of early stenosis and occlusion of transjugular intrahepatic portal-systemic stent shunts: a controlled study.

Stenosis or occlusion of the transjugular intrahepatic portal-systemic stent shunt may be initiated by aggregation and activation of thrombocytes on the surface of the metallic stent material. To find effective prevention of this event, we conducted a controlled trial administering acetylsalicylic acid for 3 mo. Forty-four patients (8 women and 36 men) with portal hypertension were included in this study. The patients were randomized into a group receiving 100 mg acetylsalicylic acid/day (n = 21) or into a control group (n = 23). Treatment was started immediately after transjugular intrahepatic portal-systemic stent shunt. Three months after transjugular intrahepatic portal-systemic stent shunt, 15 patients in the acetylsalicylic acid group and 19 patients in the control group underwent clinical reevaluation, gastroscopy and recatheterization with determination of the portal-systemic pressure gradient. No variceal bleeding occurred in any patients. In four patients in the acetylsalicylic acid group, erosive gastritis was observed in gastroscopy in contrast to only one patient in the control group. Complete patency of the stent was noted in 10 of 15 patients in the acetylsalicylic acid group and in 14 of 19 patients in the control group. Transjugular intrahepatic portal-systemic stent shunt restenosis associated with a significant increase of the portal-systemic gradient occurred in five patients in the acetylsalicylic acid group, which required redilation in all and additional stent placement for expansion of the stented tract in two patients. In the control group, redilation was necessary in five patients with additional stent extension in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphologic and clinical results of the transjugular intrahepatic portosystemic stent-shunt (TIPSS).

The concept of transjugular intrahepatic portosystemic stent-assisted shunt (TIPSS) using the Palmaz iliac stent has been successfully accomplished in 18 of 24 patients representing a technical success rate of 75%. Fourteen were male, 4 female with a mean age of 60 years (range 34-84 years). According to classification of Child's and Turcotte, 6 were in stage A, 6 in stage B, and 6 in stage C. Five patients were treated on an emergency basis because of massive active bleeding. In 10 patients the portosystemic tract was created between the middle hepatic vein and the right main stem of the portal vein in 8, and the left main stem in 2 patients. In 8 patients, the shunt was established between the right hepatic vein and the right main branch of the portal vein. The portosystemic gradient in 18 patients was 29.9 +/- 6 mm Hg and dropped to an average of 16.9 +/- 4 mm Hg after shunt establishment. Within the early postprocedural period of 30 days, 1 patient died of direct complications of the procedure. Because of catheter dislocation, embolization of the percutaneous transhepatic approach to the portal vein after successful shunt "creation" could not be done and was followed by intraabdominal exsanguination. One patient died of an ARDS after TIPSS. A third developed pulmonary infection. In 13 patients, because of hematomas at the puncture site of the transhepatic approach, only the transjugular approach was elected for establishing TIPSS.(ABSTRACT TRUNCATED AT 250 WORDS)

Palmaz stent in atherosclerotic stenoses involving the ostia of the renal arteries: preliminary report of a multicenter study.

Palmaz balloon-expandable stents were placed in 28 hypertensive patients with atherosclerosis involving the ostia of the renal arteries. Stents were placed to treat elastic recoil immediately after conventional angioplasty in 20 patients and restenosis after percutaneous transluminal angioplasty in eight patients. Technical success (greater than 30% residual stenosis) was achieved in 27 patients. Complications occurred in five patients. At follow-up (1-25 months), hypertension was cured in three patients and improved in 15 patients, with a cumulative cure or improvement of 64% at 6 months. Of 14 patients with a serum creatinine level of 1.5 mg/dL (132.6 mumol/L) or greater before the placement of stents, five demonstrated improved renal function, five showed stabilization of their condition, and four demonstrated deterioration. Follow-up angiography (2-18 months) was performed in 18 patients. Restenosis was present in seven patients and was accompanied by a relapse of hypertension in only three patients. Of the other four patients with restenosis, two had no initial improvement and two had an initial response without a relapse of hypertension. In this preliminary study, renal stents were beneficial in many patients with poor results from conventional angioplasty for ostial atheroma.

[Intrahepatic portacaval anastomosis by the transjugular approach. Use of the Palmaz endoprosthesis]. / Anastomose porto-cave intra-hépatique par voie transjugulaire. Utilisation de l'endoprothèse de Palmaz.

This new, non-operative procedure has been devised to create an intrahepatic shunt between a main portal branch and the right hepatic vein. First, the portal bifurcation is located by sagittal sonography and its position is marked on the skin. Then one of the main portal branches is punctured from the right hepatic vein by the transjugular route, and the puncture tract is expanded by balloon dilatation. This channel is kept open by placement of one or several Palmaz stents. Ten cirrhotic patients (age range: 60-84 years) unfit for surgical portocaval shunting and presenting with recurrent variceal bleeding after sclerotherapy were successfully treated by this method without any related death. During a 1 to 8 months follow-up, 9 of the 10 shunts have remained perfectly patent, but more time is required to determine the place of this method for secondary management of cirrhotic variceal bleeding.

[Hemodynamic consequences of portal decompression: which is the optimal shunt?]. / Hämodynamische Konsequenzen der portalen Decompression: Welches ist der optimale Shunt?

Increased sinusoidal resistance in cirrhosis results in a decrease of the portal and a compensatory increase of the arterial blood supply to the liver. With increasing vascular resistance and development of extrahepatic collaterals stagnation and even reversion of the portal blood flow may occur. In the latter condition, the arterial blood leaves the liver through two routes: 1) through the sinusoids and the hepatic veins, and 2) through the portal vein. Experimental and clinical studies revealed that the arterio-portal pathway is metabolically inferior to the regular arterio-hepatic-venous pathway. This suggests a decrease in liver function with an increased incidence of hepatic encephalopathy (HE) in patients with reversed portal blood flow. Based on these findings, surgical shunts may be classified according to their effect on the arterial liver perfusion. The end-to-side shunt and the distal splenorenal shunt (DSRS) do not cause diversion of the arterial liver perfusion. In contrast, side-to-side shunts, with the portal vein available as an outflow tract, consistently lead to diversion of the arterial blood supply resulting in reversed portal blood flow. Thus, side-to-side shunts are supposed to have an increased incidence of HE due to decreased liver function. This hypothesis is supported by 7 controlled and randomized studies which reveal comparable results of end-to-side shunts and DSRS but significant disadvantages of side-to-side shunts compared to DSRS.