Hepatic Portal Venous Gas

In a prospective investigation the sensitivity of conventional radiography, sonography, color Doppler flow imaging (CDFI) and CT in the detection of hepatic portal venous gas (HPVG) was compared in 7 patients with different diagnoses. For the identification of HPVG sonography, CDFI and CT have a higher sensitivity than conventional radiography. CT, however, was the most suitable method to identify the underlying cause of HPVG. Patients with iatrogenic HPVG as a result of diagnostic or therapeutic intervention had a good prognosis. In contrast, in all cases with a sudden appearance of HPVG and a noniatrogenic cause, exitus ensued within 1 week.

Validation of IC-VIEW fluorescence videography in a rabbit model of mesenteric ischaemia and reperfusion

BACKGROUND/AIMS

Mortality in mesenteric ischaemia can be reduced by an optimised extent of resection. Up to now, no technique supplementing a surgeon's experience has achieved clinical acceptance. Besides a qualitative interpretation, the new technique of computer-assisted laser-fluorescence videography affords quantification of staining intensities. The aim of this study was to investigate the scientific value of this technique in mesenteric ischaemia in a rabbit model of controlled mesenteric ischaemia and reperfusion.

METHODS

We used an established rabbit model of mesenteric ischaemia (group I, n=6) and reperfusion (group II, n=6). In each animal, three loops (each of 10 cm) of the small intestine were clamped (group I, 40 min; group II, 60 and 20 min reperfusion). For further evaluation, all loops were divided into five segments of 2 x 2 cm (total number of investigated areas, n=180). Measurement of vascular patency was performed by laser-fluorescence videography (pixel intensity per second). As standard, we used radioactive microspheres (impulse per minute per gram). In addition, the extent of ischaemic tissue damage was identified by histological examination. Statistical data were analysed by using regression analysis to define the regression coefficient r.

RESULTS/FINDINGS

Laser-fluorescence videography and the microsphere technique demonstrated a close and linear correlation: ischaemic segments, r=0.90+/-0.07; reperfusion segments, r=0.85+/-0.02; overall, r=0.92+/-0.07. There was no reproducible correlation to cellular damage in histology.

INTERPRETATION/CONCLUSION

Computer-assisted laser-fluorescence videography is a feasible, reliable, and valid experimental method for the detection of mesenteric blood supply and intestinal microcirculation. Clinical application is conceivable in mesenteric ischaemia and infarction as well as the operative transposition of intestine. As limiting values to identify the irreversible necrosis are not yet defined, further studies have to analyse the clinical impact more precisely.

[Loco-regional lysis with thrombosis older than 10 days: experiences and outcome]

Successful treatment of deep vein thrombosis by lysis therapy leads to recanalisation of the occluded vessel saving the venous flaps, thus limiting postthrombotic syndrome. Systemic lysis therapy carries an increased risk of fatal complications (1-2%). However, loco-regional lysis therapy with rtPA stands out as a method of recanalisation without increased complications compared to compression and anticoagulation therapy. According to the leading opinion about systemic lysis therapy it should only be performed if thrombotic age does not exceed 10 days. In this study we examined whether loco-regional lysis therapy is successful with older thrombosis, too. We showed that in thromboses older than 10 days lysis success was slightly decreased whereas postthrombotic syndrome doubled (up to 50%). These results point out loco-regional lysis as a method suitable for thromboses with age up to 10 days only.

Erfahrungen mit der lokoregionalen Fibrinolysetherapie bei Thrombosealter über 10 Tage

Die Behandlung der tiefen Venenthrombose durch Lysetherapie führt bei erfolgreichem Verlauf zur Rekanalisation des Gefäßes mit Erhalt der Venenklappenfunktion und somit zur Limitierung des postthrombotischen Syndroms. Bei der systemischen Lysetherapie kommt es zu erhöhter Komplikationsrate, z. T. mit Todesfolge (1-2%). Die lokoregionale Lysetherapie mit rekombinantem humanen Plasminogenaktivator (rt-PA) stellt demgegenüber eine Methode dar, die Rekanalisation ohne erhöhte Komplikationsrate bewirkt im Vergleich zu Kompressionstherapie und Antikoagulation.

Nach der gängigen Lehrmeinung sollte die systemische Lysetherapie nur bei Patienten mit einem Thrombosealter von unter 10 Tagen durchgeführt werden. In der vorliegenden Studie haben wir untersucht, ob die lokoregionale Lysetherapie auch bei älteren Thrombosen erfolgreich ist. Wir konnten zeigen, dass bei Thrombosen, die älter als 10 Tage sind, der Lyseerfolg nur geringfügig gegenüber frischeren Thrombosen verringert war, die Entstehung des postthrombotischen Syndroms jedoch doppelt so häufig stattfand (ca. 50%). Nach diesen Ergebnissen ist die lokoregionale Lysetherapie eine Methode, die nur bei Thrombosealter <10 Tage empfohlen werden kann.

Can simultaneous inhibition of seedling growth and stimulation of rhizosphere bacterial populations provide evidence for phytotoxin transfer from plant residues in the bulk soil to the rhizosphere of sensitive species?

In order to demonstrate that allelopathic interactions are occurring, one must, among other things, demonstrate that putative phytotoxins move from plant residues on or in the soil, the source, through the bulk soil to the root surface, a sink, by way of the rhizosphere. We hypothesized that the incorporation of phytotoxic plant residues into the soil would result in a simultaneous inhibition of seedling growth and a stimulation of the rhizosphere bacterial community that could utilize the putative phytotoxins as a sole carbon source. If true and consistently expressed, such as relationship would provide a means of establishing the transfer of phytotoxins from residue in the soil to the rhizosphere of a sensitive species under field conditions. Presently, direct evidence for such transfer is lacking. To test this hypothesis, cucumber seedlings were grown in soil containing various concentrations of wheat or sunflower tissue. Both tissue types contain phenolic acids, which have been implicated as allelopathic phytotoxins. The level of phytotoxicity of the plant tissues was determined by the inhibition of pigweed seedling emergence and cucumber seedling leaf area expansion. The stimulation of cucumber seedling rhizosphere bacterial communities was determined by the plate dilution frequency technique using a medium containing phenolic acids as the sole carbon source. When sunflower tissue was incorporated into autoclaved (to reduce the initial microbial populations) soil, a simultaneous inhibition of cucumber seedling growth and stimulation of the community of phenolic acid utilizing rhizosphere bacteria occurred. Thus, it was possible to observe simultaneous inhibition of cucumber seedlings and stimulation of phenolic acid utilizing rhizosphere bacteria, and therefore provide indirect evidence of phenolic acid transfer from plant residues in the soil to the root surface. However, the simultaneous responses were not sufficiently consistent to be used as a field screening tool but were dependent upon the levels of phenolic acids and the bulk soil and rhizosphere microbial populations present in the soil. It is possible that this screening procedure may be useful for phytotoxins that are more unique than phenolic acids.

Percutaneous endoprosthesis for treatment of aortic aneurysms

The purpose of this study was to define the clinical utility of stent-grafts for endoluminal treatment of infrarenal abdominal aortic aneurysms (AAAs). In a prospective study involving three centers, bifurcated stent-grafts for endovascular repair of infrarenal AAAs were implanted in 295 patients. Patient selection was based on anatomic suitability. For analysis of the initial and follow-up results the patients were divided in three subgroups. Group 1 included patients treated between August 1994 and April 1996 with use of the original stent-graft device; group 2 comprised patients treated between May 1996 and December 1997 with the refined stent-graft device, and group 3 comprised patients treated with a newly designed bifurcated stent-graft device. In group 1 (n = 111) the primary technical success was 82%. The procedure had to be converted to surgery in four patients. Endoleaks immediately after the procedure were observed in 16 patients. The initial technical success in subgroup 2 (n = 159) was 96%. One patient required surgical repair, and five others had immediate perigraft flow due to reperfusion via lumbar arteries. For group 3 (n = 28) the primary technical success rate was 89%. Endoleaks due to back-bleeding via lumbar arteries were demonstrated in three patients. Minor and major complications related to the intervention, including two perioperative deaths, were observed in 24 patients (8%). Serious problems such as distal migration or disconnection of the stent-graft were detected during follow-up in five patients. Delayed aortic rupture occurred in three patients who survived after successful surgical repair. Based on the initial results and a limited follow-up of 35 months, we believe endoluminal repair of infrarenal AAA with use of bifurcated endografts may be a feasible alternative to conventional surgery, especially for patients at high surgical risk. However, at the present time there are major concerns with respect to the structural integrity of stent-graft material and the fate of the proximal aortic cuff in the long-term time frame.

Unusual cause of early graft dysfunction after kidney transplantation

BACKGROUND/AIMS

Transplant renal artery stenosis usually develops in the later period after renal transplantation and is usually due to atherosclerosis and fibrosis at the anastomosis. A kinking renal artery stenosis, however, is a rare cause of early graft dysfunction.

METHODS

In a 34-year-old-man early graft failure developed within 1 week after kidney transplantation. In the presence of histologically proven ischemic damage an arterial kinking stenosis was diagnosed by color Doppler sonography. Selective arteriography confirmed the sharp kinking of the transplant renal artery; however, a significant stenosis could not be visualized by arteriography.

RESULTS

Due to progressive loss of renal function surgical resection of scar tissue in the kink of the transplant artery and nephropexy was performed. Immediately thereafter graft function and blood pressure significantly improved so that the successful clinical outcome of this unusual case of early graft failure confirmed the relevance of the arterial kinking stenosis.

CONCLUSIONS

In this unusual case of early graft dysfunction relevant kinking renal artery stenosis could not be adequately visualized by arteriography, although color Doppler sonography clearly demonstrated the stenosis. Therefore, both methods should be considered if parenchymal causes of graft dysfunction are excluded by biopsy and a kinking renal artery stenosis is suspected.

Palliative treatment of a secondary aortoduodenal fistula by stent-graft placement

A 64-year-old male was admitted with suspected aortoduodenal fistula 16 years after transabdominal aortic reconstruction for aortoiliac occlusive disease. Computed tomography (CT) and angiography revealed an aortoduodenal fistula and a suture-line aneurysm at the proximal anastomosis. Due to the patient's poor general condition at the time of diagnosis, endoluminal stent-graft implantation was chosen rather than conventional surgery. Successful placement of the stent graft without leakage of contrast medium and with complete exclusion of the fistula was demonstrated by CT. The patient recovered uneventfully and was discharged 10 days after the intervention. Five months later contrast CT indicated a recurrence of the aortoduodenal fistula. Since the patient was now in good general condition the stent graft was removed surgically and an extra-anatomic axillofemoral bypass was implanted. Endoluminal stent-graft Implantation is effective as palliative therapy for aortoduodenal fistulas and is especially valuable in patients with high risk for conventional surgery.

Homing of intravenously and intralymphatically injected human dendritic cells generated in vitro from CD34+ hematopoietic progenitor cells

Dendritic cells (DC) are professional antigen-presenting cells that can be generated in vitro from CD34+ peripheral blood progenitor cells by recombinant cytokines. These cells have potential implications for immunotherapeutic approaches in the treatment of cancer and other diseases. Physiologically, immature DC in the periphery capture and process antigens, then mature to interdigitating DC and migrate to lymphoid organs, where they activate lymphocytes. However, it is not known if DC generated in vitro have the capacity to traffic in vivo to the lymphoid tissues, such as spleen and lymph nodes. We have investigated whether human radiolabeled DC differentiated in vitro migrate and localize to lymphoid tissues after intravenous and intralymphatic injection. The distribution and localization of the DC were evaluated in five patients with malignant melanoma using serial whole-body gamma camera imaging. Intravenously infused DC demonstrated transient lung uptake followed by localization in the spleen and liver for at least 7 days. DC injected into a lymphatic vessel at the dorsal foot were rapidly detected in the draining lymph nodes where they remained for more than 24 h. These data suggest that DC differentiated in vitro localize preferentially to lymphoid tissue, where they could induce specific immune responses.

Reducing the post-pump syndrome by using heparin-coated circuits, steroids, or aprotinin

BACKGROUND

Cardiopulmonary bypass (CPB) induces a systemic inflammatory response called 'post-pump syndrome'. As a part of a complex interaction between white cells and vascular endothelium, proinflammatory cytokines IL-6 and IL-8 are part of a phased immune response that is also balanced by anti-inflammatory cytokines such as IL-10. We compared the influence of heparin-coated circuits, steroids, and aprotinin on these cytokines, looking for ways to reduce the syndrome.

METHODS

40 patients with coronary artery disease (CAD) undergoing elective CABG were prospectively studied in four randomized groups of 10. Group A received prednisolone pre- and postoperatively (2 x 250 mg), group B received aprotinin perioperatively (6 Mio. KIU). In group C, heparin-coated circuits ('Bioline' by Jostra) were used and in group D no special measures were taken (controls). Plasma levels of cytokines were measured before and during CPB and until 12 h after surgery using an ELISA technique.

RESULTS

In group A IL-6 was significantly (p<0.05) suppressed in contrast to the control group (A: peak at 4 h, 155 pg/ml vs. control: peak at 8 h, 565 pg/ml). IL-8 was also suppressed (A: peak at 30', 22 pg/ml vs. control: peak at 30', 55 pg/ml). IL-10 level changed first and was markedly upregulated in contrast to the control (A: peak at 30', 1600 pg/ml vs. control: peak at 30', 130 pg/ml; p<0.05). In group B (aprotinin) the cytokine release was similar to group A. Using heparin-coated circuits (group C) also led to a significant (p<0.05) IL-10 upregulation (C: peak at 2 h, 1380 pg/ml) and IL-6 suppression (C: peak at 4 h, 290 pg/ml). IL-8 was not influenced significantly.

CONCLUSIONS

The results show a similar reduction of the inflammatory cytokine release (IL-6 and IL-8 as markers) using early steroid application and aprotinin in high dosage. Heparin coating reduces IL-6 and increases IL-10 release, whereas IL-8 is not affected. Further studies should investigate the effects of a combined application for reducing inflammatory cytokine release and the post-pump syndrome.

Diagnostic and surgical approach of innominate artery saddle embolus

Patients with an acute arterial occlusion of the right upper extremity and absent axillary pulse should have a Doppler scan examination before a balloon catheter embolectomy is performed. If there is no arterial pulse detectable, an angiography should be performed afterwards to localize the embolus. In the case of a proximal arterial occlusion of the right arm, the authors recommend this procedure to prevent an embolus dislocation by catheter embolectomy and subsequent cerebral embolization. For direct surgical embolectomy the authors recommend a supraclavicular incision.

[Percutaneous revascularization of renal artery stenosis. Balloon angioplasty vs. stent implantation]

Renal artery stenosis (RAS) is the most common cause of secondary hypertension, with a prevalence of about 1% in the general population of people with hypertension. Severe arterial stenosis may also lead to impairment of excretory renal function. In experienced hands renal artery revascularization with or without stent implantation may be a safe and effective treatment in patients with sustained hypertension resistant to intensive antihypertensive treatment. Conventional balloon angioplasty of non-ostial RAS caused by fibromuscular dysplasia with a high technical and functional success rate may be the treatment of choice. However, there is continuous discussion concerning the utility of balloon angioplasty and renal stenting, respectively, in patients with atherosclerotic disease. At the time being, there are 3 randomized European trials ongoing to analyze the benefit of medical treatment versus percutaneous intervention. Several prospective studies dealing with renal artery stenting in ostial RAS found that the implantation of endoprostheses leads to much better morphologic longterm results as compared to those of balloon angioplasty alone and may be a safe and effective alternative to surgery. In addition, the functional results suggest that stent implantation in patients with mild or severe renal dysfunction may slow progression of renal failure and, thus delay the need for renal replacement therapy. It is to note that renal artery stenting does not impede any further surgical intervention. However, prior to any interventional treatment the indication of an eventual catheter procedure in patients with RAS should be discussed between experienced nephrologists and interventionalists based on clinical, functional and duplexsonographic data.

Cerebral and renal embolization after lymphography in a patient with non-Hodgkin lymphoma: case report

An unusual case of lipid embolization to brain and kidney after lymphography in a patient with non-Hodgkin lymphoma of the upper anterior mediastinum is reported. Contrast material-enhanced echocardiography demonstrated a right-to-left shunt to the left atrium without evidence of a patent foramen ovale. Echo contrast particles were transiently present within the tumor surrounding the great vessels.

Survival benefit of patients with inoperable hepatocellular carcinoma treated by a combination of transarterial chemoembolization and percutaneous ethanol injection--a single-center analysis including 132 patients

Hepatocellular carcinoma (HCC) is one of the most severe sequelae of chronic liver disease. The only potentially curative therapeutic options are surgical resection and orthotopic liver transplantation. In most HCC patients, however, at clinical presentation the tumors are unresectable because of multicentricity or poor hepatic functional reserve due to pre-existing cirrhosis or not transplantable because of too advanced tumor stage or severe co-morbidity. In clinical practice, therefore, percutaneous ethanol injection (PEI) and transarterial chemoembolization (TACE) are widely used non-surgical therapeutic strategies. We prospectively analyzed the clinical factors determining the prognosis of 132 inoperable HCC patients and assessed the feasibility, therapeutic efficacy and safety of PEI, TACE and a combination thereof. Mean age of patients was 64 years; 95% of patients had liver cirrhosis and 39% were Okuda stage I, 48% stage II and 13% stage III. Fifteen patients were treated by PEI (group 1), 33 by TACE (group 2), 39 by TACE and PEI (group 3) and 45 received best supportive care (group 4). Survival correlated with the Child-Pugh class of liver cirrhosis and the Okuda stage of HCC. Favorable prognostic parameters were alpha-fetoprotein (AFP) levels <100 ng/ml and absence of portal vein thrombosis. Median survival time was 18 months in group 1 [interquartile range (IQR) 10-19], 8 months in group 2 (IQR 5-15), 25 months in group 3 (IQR 13-36) and 2 months in group 4 (IQR 1-9). Multivariate analysis revealed that patients treated with a combination of TACE and PEI have a significantly better survival than patients receiving either PEI or TACE only (p = 0.001). Patients with inoperable HCCs treated by the combination of TACE and PEI have a clear survival benefit. A favorable outcome can be expected in patients with compensated cirrhosis, a low Okuda stage, a baseline AFP level <100 ng/ml and absence of portal vein thrombosis.

Survival benefit of patients with inoperable hepatocellular carcinoma treated by a combination of transarterial chemoembolization and percutaneous ethanol injection--a single-center analysis including 132 patients

Hepatocellular carcinoma (HCC) is one of the most severe sequelae of chronic liver disease. The only potentially curative therapeutic options are surgical resection and orthotopic liver transplantation. In most HCC patients, however, at clinical presentation the tumors are unresectable because of multicentricity or poor hepatic functional reserve due to pre-existing cirrhosis or not transplantable because of too advanced tumor stage or severe co-morbidity. In clinical practice, therefore, percutaneous ethanol injection (PEI) and transarterial chemoembolization (TACE) are widely used non-surgical therapeutic strategies. We prospectively analyzed the clinical factors determining the prognosis of 132 inoperable HCC patients and assessed the feasibility, therapeutic efficacy and safety of PEI, TACE and a combination thereof. Mean age of patients was 64 years; 95% of patients had liver cirrhosis and 39% were Okuda stage I, 48% stage II and 13% stage III. Fifteen patients were treated by PEI (group 1), 33 by TACE (group 2), 39 by TACE and PEI (group 3) and 45 received best supportive care (group 4). Survival correlated with the Child-Pugh class of liver cirrhosis and the Okuda stage of HCC. Favorable prognostic parameters were alpha-fetoprotein (AFP) levels <100 ng/ml and absence of portal vein thrombosis. Median survival time was 18 months in group 1 [interquartile range (IQR) 10-19], 8 months in group 2 (IQR 5-15), 25 months in group 3 (IQR 13-36) and 2 months in group 4 (IQR 1-9). Multivariate analysis revealed that patients treated with a combination of TACE and PEI have a significantly better survival than patients receiving either PEI or TACE only (p = 0.001). Patients with inoperable HCCs treated by the combination of TACE and PEI have a clear survival benefit. A favorable outcome can be expected in patients with compensated cirrhosis, a low Okuda stage, a baseline AFP level <100 ng/ml and absence of portal vein thrombosis.

Cystic adventitial degeneration and entrapment syndrome of the popliteal artery as a differential diagnosis of popliteal stenosis or occlusion in the younger age group

Differential diagnosis in angiographically found popliteal artery stenosis or occlusion comprises some distinct and clinically important entities that should be considered as management and prognosis may vary considerably. We present two patients with the final diagnosis of cystic adventitial disease of the popliteal artery and popliteal artery entrapment syndrome. Angiographic findings and the value of additional diagnostic imaging are discussed.

Imaging of renal artery stenosis

Renal artery stenosis is the cause of progressive ischemic nephropathy and of renovascular hypertension. Due to the invasiveness of arteriography, which is claimed to be the gold standard at the present time, several noninvasive imaging techniques are available. Colour Doppler sonography is cost-effective, but magnetic resonance angiography and computer tomography are more expensive; however, both are potential candidates for the definition of a new gold standard. Evaluation of renal vasculature by means of Doppler sonography includes intra- and extrarenal scanning as well as power Doppler and the use of contrast agents for enhancement of the Doppler signals. Computed tomography angiography is a minimally invasive method for the diagnosis of renal artery stenosis. There is high diagnostic accuracy that is not significantly different from that of angiography with respect to main and accessory renal arteries and detection of clinically significant renal artery stenoses. The main advantages over angiography are the use of an intravenous approach, and direct information provided about the vessel wall and adjacent structures. However, the nephrotoxicity of contrast material remains a major concern. Magnetic resonance angiography of the abdominal aorta and renal arteries has advanced considerably over the past few years. Recently developed breath-hold three-dimensional magnetic resonance angiography provides a new promising, noninvasive technique to evaluate the abdominal aorta and its large branch vessels. Using this technique, high sensitivity and specificity is achieved. The improved image quality and the ability to detect vascular lesions is due to short acquisition time with elimination of respiratory artifacts over an entire imaged volume by single breath-hold acquisition. Computed tomography angiography with its fast acquisition time and high spatial resolution compares favorably with magnetic resonance angiography and colour Doppler sonography. However, as compared with Doppler sonography and magnetic resonance angiography, computed tomography angiography images display only anatomic information and lack of flow sensitivity.

Renal artery occlusion model in dogs for the evaluation of thrombolytic agents

The purpose of this study was to develop a model of renal artery occlusion and to investigate the effects of various thrombolytic agents on an acute occlusion of the renal artery with respect to ischemic tolerance of renal parenchyma. In order to do this, a thrombosis model in dogs (n = 36) was established and a total of 72 dorsal renal arteries occluded using autologous clot material. For the in vitro preparing of a clot, autologous blood (20 mL) was withdrawn and 100 U thrombin immediately added. Then 1 mL of the clot material was injected into the dorsal branch of the exposed renal artery. The dogs were divided into 8 groups (2 control groups, 6 therapy groups with local and systemic thrombolytic therapy). Thrombolysis was performed using urokinase, single-chain urokinase, and recombinant tissue-plasminogen activator. In all cases the clot preparation technique allowed complete and stable occlusion of the renal arteries. Local and systemic application of the thrombolytic agents, however, resulted in complete recanalization of the clot material in all study groups. Recombinant tissue-plasminogen activator turned out to be the most effective agent in terms of recanalization time. The technique described allowed effective and reproducible artery occlusion for in vivo experimental work to study comparatively thrombolytic agents with respect to fibrin specificity, lytic efficacy, and side effects.

Late occurrence of cysts in autosomal dominant medullary cystic kidney disease

Medullary cystic kidney disease (MCD) is characterized by multiple renal cysts at the corticomedullary boundary area, by autosomal dominant inheritance, and by onset of chronic renal failure in the third decade of life. We report on a family with three affected individuals of both sexes in two generations presenting with end-stage renal failure at age 22-31 years. Primarily diagnoses considered included unclassified hereditary nephropathy and autosomal dominant polycystic kidney disease. Careful evaluation of all findings, initiated after investigation of renal morphology with CT, revealed features characteristic for MCD and led to the final diagnosis of MCD. We conclude that MCD is an important differential diagnosis for polycystic kidney disease in young adults with end-stage renal failure. Establishing the correct diagnosis has considerable impact for genetic counselling.

[Functional tricuspid atresia in a newborn infant with cardiac rhabdomyoma]

Cardiac rhabdomyomas are benign tumours closely associated with tuberous sclerosis. We report on a neonate with a cardiac rhabdomyoma, which simulated tricuspid atresia with duct-depending pulmonary perfusion due to almost complete obliteration of right ventricular cavum. Under infusion of prostaglandin E1 the newborn stabilized and was successfully operated on the 3rd day of life. We conclude that successful tumour resection is possible in neonates with cardiac rhabdomyomas causing relevant hemodynamic obstruction.

[Interventional occlusion of systemicopulmonary collateral arteries using metal spirals]

Major systemicopulmonary collateral arteries (spca) frequently contribute to collateral lung perfusion in patients with pulmonary atresia and ventricular septal defect or in children with tetralogy of Fallot. Since the surgical access to these vessels is difficult, corrective surgery may become impossible. We report our experience with interventional occlusion of spca in 10 patients. In these patients (age range 13 months-19.5 years) selective injections demonstrated a total of 27 spca. Sixteen of these were coil-occluded by interventional cardiac catheterization. Total occlusion was achieved in 15 cases, in one case we found a small residual shunt. Occlusion was performed using platinum coils (2 cases), Gianturco coils (11 cases) and detachable steel coils (4 cases, including 1 with prior incomplete occlusion by Gianturco coils). 4 patients required 2 interventional cardiac catheterizations. Complications occurred only in procedures that were performed with conventional coils (peripheral pulmonary embolizations of platinum coils in 2 patients, dislocation of the delivery catheter with a partially extruded coil to the descending aorta in 1 patient). Operative ligation had to be performed in 6 spca, since those vessels were not suitable for interventional occlusion. The remaining 5 spca were left unoccluded, since they were of minor hemodynamic relevance due to a subsequent decrease in size. At the end of the follow-up period corrective surgery had been completed in 8 of our 10 patients. In the remaining 2 patients corrective surgery is planned in the near future. According to our experience interventional occlusion of spca is a major improvement in the management of a selected cohort of patients with pulmonary atresia and ventricular septal defect or tetralogy of Fallot. The introduction of detachable steel coils facilitates the embolization of those vessels.

Comparative diagnostic accuracy of magnetic resonance imaging and immunoscintigraphy for detection of bone marrow involvement in patients with malignant lymphoma

PURPOSE

To compare the diagnostic accuracy of magnetic resonance imaging (MRI) and immunoscintigraphy (IS) for detection of bone marrow infiltration in malignant lymphoma.

PATIENTS AND METHODS

In 32 patients with Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL), MRI of the axial skeleton and whole-body IS using technetium-99m (99mTc)-labeled monoclonal antibodies were reviewed and compared with iliac crest biopsies. Criterion for marrow infiltration was a positive biopsy or concordant positive results of MRI and IS.

RESULTS

In 16 patients (50%), MRI, IS, and iliac crest biopsies were negative for marrow infiltration. Iliac crest biopsy showed infiltration in only four patients (13%). Infiltration was missed in two of 32 patients with IS and in one patient with MRI. In one additional patient, MRI was false-positive because of pelvic hematopoietic hyperplasia. A subset of nine patients (28%) with negative biopsies had bone marrow involvement according to MRI and IS with identical location and pattern of infiltration. In eight of these nine patients, diagnostic imaging indicated marrow involvement only in noncrest marrow. Subsequent biopsy confirmed infiltration in five patients. The clinical course suggested true-positive imaging results in the remaining four patients. Two patients (6%) remained equivocal. Overall concordance of MRI and IS for marrow infiltration was 88% (28 of 32 patients).

CONCLUSION

Diagnostic imaging is essential for optimal staging in malignant lymphoma, as blind biopsies appear to have low sensitivity for bone marrow infiltration because of frequent involvement in noncrest marrow. both imaging modalities show a high rate of detection of bone marrow infiltration.

Two-center German experience with aortic endografting

PURPOSE

To report the results of a two-center study of endovascular abdominal aortic aneurysm (AAA) exclusion using a polyester-covered nitinol stent-graft.

METHODS

Candidates were evaluated with arteriography and computed tomography. Criteria for endovascular therapy were a proximal aortic neck > 10 mm in length and < 25 mm in diameter, no bilateral internal iliac artery involvement in the aneurysm, no markedly tortuous common iliac arteries (CIAs) or CIAs < 7 mm in diameter, and no superior mesenteric artery occlusive disease. Patients were treated with the Mialhe Stentor and Vanguard stent-grafts in either tube or bifurcated versions.

RESULTS

Between August 1994 and November 1996, 149 patients (mean age 67 years, range 49 to 90) were admitted to the study. Overall primary technical success (aneurysm exclusion without endoleak) was 87% (130 patients): 78% (7 patients) for tube grafts and 88% (123 patients) for bifurcated endografts. The rate of local, remote, or systemic complications was 10.8%, with a 30-day mortality rate of 0.7%. During an average 13.5-month follow-up, there were no late deaths. Four of 20 endoleaks sealed spontaneously, 14 were treated with endoluminal techniques, and 2 remain untreated by patient request. Three graft limb thromboses occurred; one was treated surgically, one with lytic therapy, and one was untreated. Secondary patency was 96%.

CONCLUSIONS

Endoluminal repair of infrarenal AAAs using straight or bifurcated grafts is a feasible alternative to conventional surgical repair. Longer follow-up and more experience with refined endograft models will elucidate the durability of this endovascular approach to treating AAAs.

Treatment of ostial renal-artery stenoses with vascular endoprostheses after unsuccessful balloon angioplasty

BACKGROUND

Percutaneous transluminal renal angioplasty is a safe and effective treatment for nonostial stenoses of the renal arteries, but it has proved to be disappointing for ostial stenoses. Therefore, we prospectively studied the use of intravascular stents for the treatment of critical ostial stenoses after unsuccessful balloon angioplasty.

METHODS

Stainless-steel endoprostheses were placed across 74 renal-artery stenoses located within 5 mm of the aortic lumen in 68 patients with hypertension. Twenty patients had mild or severe renal dysfunction. The indications for stent placement were elastic recoil (63 arteries) or dissection (1 artery) of the vessel after angioplasty, or restenosis after initially successful balloon angioplasty (10 arteries). Patients were followed for a mean of 27 months with measurements of blood pressure and serum creatinine, duplex sonography, and intraarterial angiography.

RESULTS

Initial technical success was achieved in all patients. Minor complications (local hematomas) occurred in only three patients; there were no major complications. Eighty-four percent of the patients were free of primary occlusion 60 months after the procedure. Restenosis of more than 50 percent of the vessel diameter occurred in 8 of 74 arteries (11 percent). Reintervention resulted in a secondary patency rate of 92 percent. Long-term normalization of blood pressure was achieved in 11 patients (16 percent). Serum creatinine levels did not change significantly after successful stent implantation in patients with previously impaired renal function.

CONCLUSIONS

Accurate placement of renal-artery stents is technically feasible without major complications. The favorable early and long-term results suggest that primary stent placement is an effective treatment for renal-artery stenosis involving the ostium.

Endoluminal stent-grafts for infrarenal abdominal aortic aneurysms

BACKGROUND

The treatment of aortic aneurysms with endovascular stents or stent-graft prostheses is receiving increasing attention as an alternative to major abdominal surgery. To define the clinical value of this technique, we prospectively studied the use of stent-graft endoprostheses made of nitinol and covered with polyester fabric for the treatment of infrarenal abdominal aortic aneurysms.

METHODS

We treated a total of 154 patients at three academic hospitals. Twenty-one patients with aortic aneurysms not involving the aortic bifurcation received straight stent-grafts, and 133 patients with aortic aneurysms involving the bifurcation and the common iliac arteries received bifurcated stent-grafts. After a unilateral surgical arteriotomy, the endoprostheses were advanced through the femoral arteries and placed under fluoroscopic guidance. Computed tomography and intraarterial angiography were performed during an average follow-up of 12.5 months.

RESULTS

The primary success rate, defined as complete exclusion of the abdominal aortic aneurysm from the circulation, was 86 percent in the group receiving straight grafts and 87 percent in the group receiving bifurcated grafts. In three patients the procedure had to be converted to an open surgical operation. Minor (n=13) or major (n=3) complications associated with the procedure (including 1 death) occurred in 10 percent of the patients. All patients had a postimplantation syndrome, with leukocytosis and elevated C-reactive protein levels.

CONCLUSIONS

Our results suggest that endovascular treatment of infrarenal abdominal aortic aneurysms is technically feasible and can effectively exclude abdominal aortic aneurysms from the circulation. With further refinement, endoluminal repair may emerge as an interventional strategy to treat infrarenal aortic aneurysms, especially in patients at high surgical risk.

Magnetic resonance imaging (MRI) for detection of active sacroiliitis--a prospective study comparing conventional radiography, scintigraphy, and contrast enhanced MRI

OBJECTIVE

Sacroiliitis is often difficult to diagnose in the absence of radiographic alterations. For the diagnosis of active sacroiliitis, plain radiography, scintigraphy, and contrast enhanced magnetic resonance imaging (MRI) were evaluated in a prospective study.

METHODS

In 44 consecutive patients with complete clinical and laboratory evaluation, plain radiographs, quantitative sacroiliac (SI) scintigraphy, and MRI were performed to evaluate the contribution of these imaging techniques to the diagnosis of active sacroiliitis. Scintiscanning and MRI were done in 20 control subjects to define the normal range of imaging findings. We determined the sensitivity and specificity for each imaging method using a reference standard based on clinical symptoms of inflammatory low back pain with or without laboratory signs, and on clinical and radiographic followup during 1.5-2.5 years to confirm diagnosis.

RESULTS

MRI was most sensitive (95%) and superior to quantitative SI scintigraphy (48%) or conventional radiography (19%) for the detection and confirmation of active sacroiliitis. For the assessment of inflammatory signs, MRI had higher specificity (100%) than scintigraphy (97%) or plain radiography (47%). At repeat MRI after 2-30 months, there was persistent pathologic signal intensity in the subchondral bone area despite clinically successful antiinflammatory drug therapy.

CONCLUSION

For the assessment of active changes in the synovial portion and the subchondral bone marrow, contrast enhanced MRI is superior to quantitative SI scintigraphy or conventional radiography. MRI picks up an additional 75% of early cases not diagnosed by plain radiography. Scintigraphy is only of limited value. Persistent pathologic signal intensity in the subchondral bone marrow seems to be closely associated with previous inflammatory episodes, thus limiting specificity of MRI for active sacroiliitis. Based on our findings we suggest an algorithm for the evaluation of patients with suspected active sacroiliitis.

[Diagnosis of hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) is a frequent complication of chronic liver disease. The major causes of chronic liver diseases are hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, as well as chronic alcohol misuse. The clinical presentations of HCC patients are unspecific, with signs and symptoms of chronic liver disease. Early diagnosis of HCC in an asymptomatic and potentially curable stage is of highest priority. The present strategy for the detection of early HCC in patients with chronic liver disease is 6-monthly determination of alpha-fetoprotein (AFP) and ultrasound study of the liver. If these are abnormal, further diagnostic steps include computer tomography, magnetic resonance tomography, lipiodol-angiography and histopathology. By this sequential diagnostic strategy it should be possible to identify HCC in patients with chronic liver disease at an early and potentially curable stage.

[Therapy of hepatocellular carcinoma]

The therapeutic modalities in patients with hepatocellular carcinoma (HCC) depend on the number, size and location of the lesions as well as the stage of the underlying liver disease and the physical condition of the patient. In patients with small and solitary lesions, resection, liver transplantation and in some cases percutaneous ethanol injection (PEI) can be curative. In more advanced stages of the disease with larger or multiple lesions, PEI and/or transarterial chemotherapy with or without embolization (TACE or TAC) can slow the progression of the disease. In disseminated disease, a radiotherapeutic approach can be taken in selected cases. The therapeutic strategy in patients with HCCs should be individualized, frequently involving a combination of therapeutic modalities. In contrast to the earlier dismal prognosis, for most HCC patients there is today a therapeutic strategy that results in prolongation of life and in some cases even cure.

Diagnosis of renovascular disease by intra- and extrarenal Doppler scanning

The purpose of this prospective, angiographically controlled study was to determine the diagnostic value of color Doppler sonography with two differing approaches of scanning in patients with clinical clues for renal artery stenosis (RAS). In 135 hypertensive patients peak systolic velocity in the main renal arteries and the resistive index (RI) of the intrarenal arteries were measured. The RI side-to-side-difference (delta RI) greater than 0.05 or peak systolic velocity greater than 2 m/s were used to discriminate normal from stenotic renal arteries, defined as angiographically confirmed RAS > 50%. In 88 of 135 patients 107 RAS were demonstrated by selective arteriography. Five renal artery occlusions occurred, which were all diagnosed by color Doppler sonography. Seventy-six RAS were detected by increased peak systolic velocity, and an additional 19 stenoses were identified by delta RI. The combined analysis of peak systolic velocity and delta RI resulted in a sensitivity of 89% and specificity of 92%. The positive predictive value was 92% and the negative predictive value was 88%. Our data suggest that only the combination of intra- and extrarenal scanning with color Doppler sonography represents an effective screening method for significant renal artery stenosis in hypertensive patients.

[Hemosuccus pancreaticus--a rare cause of upper gastrointestinal bleeding. Successful treatment in two cases by radiologic-interventional embolization of the splenic artery]

HISTORY AND CLINICAL FINDINGS

Two patients were admitted to hospital for diagnosis of recurrent upper gastrointestinal bleeding. Both had chronic pancreatitis with alcohol abuse. Their general condition was satisfactory. Physical examination showed no diagnostic abnormalities other than mild epigastric pain on pressure in one patient.

INVESTIGATIONS

In case 1 angiography revealed pseudoaneurysm of the splenic artery as a complication of chronic pancreatitis to be the cause of the bleeding. In case 2 sonography demonstrated multiple pancreatic pseudocysts after recurrent pancreatitis. Duplex sonography revealed one of the cyst to be a partly thrombosed pseudoaneurysm of the splenic artery and the source of the bleeding.

TREATMENT AND COURSE

In both cases a fistula between splenic artery and pancreatic duct having been shown to be the source of the bleeding, transcatheter embolisation of the splenic artery with platinum coils was successfully undertaken. Both patients remained symptom-free 4 and 10 months later.

CONCLUSION

Although haemosuccus pancreaticus is a rare cause of upper gastrointestinal bleeding, given certain features in the patient's history and the clinical findings, it should be included in the differential diagnosis.

Allelopathic interactions involving phenolic acids

A major concern regarding allelopathic interactions involving phenolic acids in no-till systems pertains to the fact that concentrations of individual phenolic acids recoverable from field soils are well below levels required for inhibition of germination and seedling growth in laboratory bioassays. Field soils contain a variety of phenolic acids as well as other toxic and nontoxic organic compounds that are available to interact with seeds and roots; whereas in laboratory bioassays, with few exceptions, single phenolic acids have been tested. Studies of mixtures of phenolic acids and other toxic (e.g., methionine) and nontoxic (e.g., glucose) organic compounds in laboratory bioassays indicate that the action of a single phenolic acid is not representative of the actions of such mixtures. Specifically, as the number of phenolic acids added to soil increased, concentrations of the individual phenolic acids required to bring about a growth inhibition declined. The addition of other organic compounds (e.g., glucose, methionine) to the soil also reduced the concentration of a phenolic acid (e.g., p-coumaric acid) required for growth inhibition. These results support the hypothesis that in the field mixtures of phenolic acids and other organic compounds can cause inhibitory effects even though the concentrations of individual compounds are well below their inhibitory levels.

[Endoluminal therapy of infrarenal abdominal aortic aneurysms: a new interventional technique]

PURPOSE

With a series of 31 transluminal stent-graft procedures, we assessed the feasibility and clinical effectiveness of a new stent-graft for the treatment of infrarenal abdominal aortic aneurysms (AAAs).

METHODS

We treated the patients (male; mean age 71 years) with straight or bifurcated nitinol stents covered with woven dacron graft material for infrarenal eccentric saccular AAA (n = 4) or AAA involving the bifurcation and the common iliac arteries (n = 27). The 18-F delivery system was advanced via a surgical arteriotomy and the stent-graft was placed under fluoroscopic control. Follow-up period ranged from 8 days to 9 months.

RESULTS

The implantation of the stent-grafts was technically successful in 30/31 cases. Procedure-related complications were acute hepatic failure due to gastric bleeding in a patient with liver cirrhosis, graft occlusion due to emboli originating from the left atrium (n = 1), macro-embolisation (n = 3), local haematoma (n = 1) and av-fistula (n = 1) requiring surgery. A post-implantation syndrome with leukocytosis and elevated C-reactive protein was observed in all patients.

CONCLUSIONS

Endoluminal repair of infrarenal AAA with use of dacron covered nitinol stent-grafts is feasible, safe and clinically effective. However, careful long-term evaluation is necessary.

[Initial clinical experiences with endovascular stent-grafts for treatment of infrarenal abdominal aortic aneurysm]

With a series of 34 transluminal stent-graft procedures, we assessed the feasibility and clinical effectiveness of a new stent-graft for the treatment of infrarenal abdominal aortic aneurysms (AAAs). We treated 34 male patients (mean age 71 years) with straight of bifurcated nitinol stents covered with woven Dacron graft material for infrarenal excentric saccular AAA (n = 3) or AAA involving the bifurcation and the common iliac arteries (n = 31). The 18-F delivery system was advanced via a surgical arteriotomy and the stent-graft was placed under fluoroscopic control. Follow-up period ranged from 8 days to 13 months. The implantation of the stent-grafts was technically successful with exclusion of AAA in 31/34 cases (91%). In 2 patients, there was a persisting leak at the distal end of the endoprosthesis after treatment; in another, marked coiling of the external iliac artery impeded the delivery system to be advanced and consecutive rupture resulted in conversion to surgical repair. Other procedure-related complications were acute hepatic failure due to gastric bleeding in a patient with liver cirrhosis, graft occlusion due to emboli originating from the left atrium (n = 1), local hematoma (n = 1), and AV-fistula (n = 1) requiring surgery. A post-implantation syndrome with leucocytosis and elevated C-reactive protein was observed in all patients. Endoluminal repair of infrarenal AAA with use of Dacron covered nitinol stent-grafts is feasible, safe and clinically effective. However, careful long-term evaluation is necessary before it will become clinical practice.

Abdominal aortic aneurysms: preliminary technical and clinical results with transfemoral placement of endovascular self-expanding stent-grafts

PURPOSE

To evaluate treatment of infrarenal abdominal aortic aneurysm (AAA) with a new endoluminal stent-graft.

MATERIALS AND METHODS

In 26 male patients, straight or bifurcated nitinol stents covered with woven Dacron graft material were implanted to treat eccentric saccular AAA (n = 3) or AAA involving the bifurcation and common iliac arteries (n = 23), with follow-up from 8 days to 8 1/2 months.

RESULTS

Implantation was technically successful in all but one of the 26 (96%) patients (leak of the stent-graft for more than 3 months necessitated implantation of an additional covered stent). In seven of the 26 patients, minor residual perfusion persisted immediately after implantation, but complete thrombosis occurred within 7 days. Five procedure-related complications occurred: distal embolization (n = 2); local hematoma, which necessitated surgery (n = 1); acute hepatic failure due to gastric bleeding, in a patient with liver cirrhosis (n = 1); and stent-graft occlusion due to emboli originating from the left atrium (n = 1).

CONCLUSION

Exclusion of AAA from circulation was feasible, safe, and clinically effective with the new stent-graft.

[Vascular stents and development of endoluminal therapy of aortic aneurysm]

Intravascular stents have played an important role in improving early and long-term patency in the treatment of arterial occlusive disease, particularly in the iliac arteries after failed balloon angioplasty. The development of covered stents opened a new dimension for non-operative therapy of aneurysmal disease. Transluminally placed stent-grafts represent a blending of technologies with use of intravascular stents and prosthetic vascular grafts. Stent-graft combinations were first envisioned by Dotter in 1969 as devices that would ultimately be useful to treat aneurysms, pseudoaneurysms and arterio-venous fistulas. Animal studies of endovascular stented grafts demonstrated the potential feasibility of these devices to treat arterial lesions. Parodi et al. first implanted stent-grafts in patients with abdominal aortic aneurysms and demonstrated its clinical feasibility. Newly developed stent-grafts allowed to treat successfully a limited number of patients with AAA. Although much has been reported about the healing properties of prosthetic grafts in extraluminal locations, there are only little data concerning the arterial response to a prosthetic graft placed within the lumen or anchored into the wall of a human vessel. Therefore, long-term evaluation of these new devices will be crucial.

Budd-Chiari syndrome: technical, hemodynamic, and clinical results of treatment with transjugular intrahepatic portosystemic shunt

PURPOSE

To evaluate use of the transjugular intrahepatic portosystemic shunt (TIPS) as a nonsurgical approach for the management of Budd-Chiari syndrome (BCS).

MATERIALS AND METHODS

Twelve patients with fulminant (n = 2), subacute (n = 5), or chronic (n = 5) BCS underwent TIPS placement. Hepatic venous obstruction was demonstrated at computed tomography and color duplex sonography. BCS was confirmed histologically in all patients. Hemodynamic parameters and clinical characteristics were assessed.

RESULTS

TIPS creation was successful in all patients. Treatment reduced the portal venous pressure gradient by 75% and resulted in a mean shunt flow of 2,300 mL/min +/- 650 (standard deviation). No serious procedure-related complications were observed. The two patients with fulminant BCS died of septicemia or progressive liver failure despite intervention. The other 10 patients showed clinical improvement with reduction or disappearance of ascites. During follow-up, shunt dysfunction occurred in five of 10 patients with recurrence of ascites requiring repeat intervention.

CONCLUSION

TIPS placement is safe and effective in patients with portal hypertension caused by subacute or chronic BCS.