Fallstricke in der Dermatologie: Hautläsionen am Shuntarm einer Dialysepatientin durch Steal-Phänomen

Wir berichten über eine 78-jährige dialysepflichtige Patientin, welche sich mit stark schmerzhaften Nekrosen distal eines Dialyseshunts vorstellte und bei der abschließend ein Steal-Phänomen diagnostiziert wurde. Beim Steal-Syndrom handelt es sich um eine seltene Komplikation eines Gefäßshunts durch Minderperfusion der Extremität distal der AV-Anastomose. Diabetiker sind aufgrund des höheren peripheren Gefäßwiderstandes und der Mikroangiopathie eher gefährdet, ein Steal-Syndrom nach Shuntanlage zu entwickeln. Der vorgestellte Fall soll verdeutlichen, dass das Steal-Syndrom dringlich in die differenzialdiagnostischen Überlegungen bei kutanen Nekrosen am Shuntarm einzuschließen ist und die Patienten schnellstmöglich gefäßchirurgisch vorzustellen sind, um einen Zeitverlust bis zur therapeutischen Intervention mit der Gefahr des irreversiblen Gewebsverlust und damit verbunden ggf. konsekutiv erforderliche Amputationen zu vermeiden.

First Report of Pythium Root Rot of Rau Ram (Polygonum odoratum)

Polygonum odoratum (= Persicaria odorata), known as rau ram or sang hum, is native to southeastern Asia and is a common herb in Vietnamese cuisine (1). It has been studied most extensively for its aromatic compound content (2). In Florida, rau ram commonly is grown hydroponically in greenhouses using large, cement beds with recirculated water. The plants form dense mats from which new growth is trimmed for market. During January of 2002, a severe dieback was observed in one production house in Saint Lucie County, FL. Plants with less severe symptoms were yellowed and stunted. Roots of symptomatic plants were largely decayed with root symptoms beginning as a tip necrosis. The cortex of severely affected roots slipped off easily, leaving a stringy vascular system. Plating of symptomatic tissue from 20 randomly selected plant samples was performed with multiple general and selective media including potato dextrose agar, corn meal agar with pimaricin, ampicillin, rifampicin, and pentachloronitrobenzene (PARP) (3). All colonies produced were identified as Pythium helicoides Drechsler on the basis of sporangial, oogonial, and antheridial characteristics (4). Isolates had proliferous, obovoid, papillate sporangia, and were homothallic with smooth-walled oogonia and thick-walled, aplerotic oospores. Multiple antheridial attachments per oogonium were common with the antheridium attached along its entire length. Pathogenicity tests were conducted using P. odoratum plants grown from commercial transplants. Two tests were performed. Each test was conducted using eight inoculated and eight control plants. In the first test, plants were maintained in 10-cm pots immersed in sterilized pond water for the duration of the test. Plants were inoculated with five 7- × 70-mm sections of freshly growing mycelial culture per plant using 10-day-old cultures of Pythium helicoides grown on water agar. Chlorosis was observed at approximately 2 months after inoculation. Root necrosis was observed in inoculated plants approximately 5 months after inoculation. This test was performed in the greenhouse with temperatures ranging from 20 to 30°C. The second test was performed in growth chambers at 35 to 40°C. Plants were maintained in 10-cm pots immersed in Hoagland's solution and were inoculated with four 6-mm plugs per plant. Symptoms were observed on inoculated plants at this temperature within 1 week of inoculation. No chlorosis or root decay was observed in noninoculated, immersed plants. The pathogen was reisolated from inoculated, symptomatic tissue. To our knowledge, this is the first report of root rot of P. odoratum caused by Pythium helicoides. References: (1) R. E. Bond. Herbarist 55:34, 1989. (2) N. X. Dung et al. J. Essent. Oil Res. 7:339, 1995. (3) M. E. Kannwischer and D. J. Mitchell. Phytopathology 68:1760, 1978. (4) A. J. van der Plaats-Niterink. Monograph of the Genus Pythium. Vol. 21, Studies in Mycology. Centraalbureau voor Schimmelcutltures, Baarn, The Netherlands, 1981.

Upregulation of intraepithelial lymphocyte (IEL) function in the small intestinal mucosa in sepsis

Host defense mechanisms preventing bacterial invasion are particularly important in the gastrointestinal tract, since most gram-negative infections originate from there. Intraepithelial lymphocytes (IEL) seem to play an important role in this immune surveillance of the intestine, although their function in sepsis is not fully understood. To evaluate the characteristics of IEL in sepsis, C57BL/6 mice received a non-lethal dose of LPS and IEL were harvested at various time points thereafter. Although IEL displayed no phenotypic changes after endotoxemia, they displayed enhanced cytolytic activity and increased proliferation after LPS injection In addition, IEL from septic mice showed enhanced gamma interferon (IFN-gamma) production after LPS administration. The production of IFN-gamma may have induced the increased intestinal NOS-2 mRNA expression which was observed after endotoxemia. In conclusion, endotoxemia leads to functional activation of IEL without phenotypic changes. The activation of IEL and the subsequently increased NOS-2 expression may be important mechanisms in maintaining the mucosal barrier after sublethal LPS challenge.

Portal vein angioplasty using a transjugular, intrahepatic approach for treatment of extrahepatic portal vein stenosis after liver transplantation

Symptomatic portal vein stenosis is an uncommon complication after liver transplantation. Portal vein angioplasty has been successfully established for treatment of portal vein stenosis using mesenteric or percutaneous, transhepatic approaches. We herein report on a patient who suffered from variceal bleeding due to portal hypertension 3 months after liver transplantation. After successful endoscopic sclerotherapy, an extrahepatic portal vein stenosis was diagnosed, and portal vein angioplasty was considered as primary therapeutic option. Instead of mesenteric or percutaneous, transhepatic approaches, we adopted a transjugular, intrahepatic access to introduce a 14-mm balloon catheter into the portal vein. Using this technique, angioplasty was successfully performed. After intervention, no further episodes of variceal bleeding occurred. We favour the transjugular, intrahepatic technique for portal vein angioplasty because it does not require general anesthesia, in contrast to the mesenteric approach, and it reduces the risk of intra-abdominal bleeding, compared to the percutaneous, transhepatic approach.

Arterial complications after liver transplantation

From September 1988 through April 1998, 1,000 liver transplantations were performed on 911 patients. During the postoperative control examinations of 837 patients, we found 23 (2.74 %) with hepatic artery thromboses, 27 stenoses of the hepatic artery (3.22 %), and 6 aneurysms of the graft artery. Seventeen patients underwent retransplantation because of arterial complications. Depending on the clinical symptoms, we treated both the local situation as well as the resulting complications of inadequate arterial graft flow. The aneurysms were primarily treated surgically. The first choice of treatment of stenoses was balloon angioplasty. Early postoperative artery thromboses were also treated surgically by thrombectomy in selected cases. For the resulting biliary and local septic complications we preferred endoscopic and drainage procedures. Our clinical experiences have led us to find pretransplantation angiography recommendable, especially in the case of splanchnic artery stenoses, for bypassing from the aorta for arterial perfusion of the graft.

Postoperative tracheal extubation after orthotopic liver transplantation

BACKGROUND

The duration of postoperative mechanical ventilation and its influence on pulmonary function in liver transplant recipients is still debated controversially.

METHODS

We retrospectively analyzed the incidence of immediate tracheal extubation, prolonged mechanical ventilation (>24 h following surgery), and episodes of reintubation in 546 patients who underwent orthotopic liver transplantation (OLT) at our institution.

RESULTS

Immediate tracheal extubation in the operating theater was achieved in 18.7% of patients, and prolonged mechanical ventilation was required by 11.2% of patients. In these, median time of extubation was 49.5 h, whereas the remaining 70.1% of patients required ventilation support for a median 5 h after OLT. As risk factors for prolonged mechanical ventilation we identified the indications of acute liver failure and retransplantation, as well as factors such as mechanical ventilation prior to OLT, massive intraoperative bleeding, and severe reperfusion injury of the liver graft. The incidence of reintubation was 8.8% in patients who were immediately extubated following surgery, and 13.1% in patients who underwent extubation within 24 h. The incidence was significantly increased in patients requiring prolonged mechanical ventilation (36.1%).

CONCLUSIONS

Immediate tracheal extubation was safe and well tolerated. The incidence of reintubation was not increased when compared to patients in whom extubation succeeded later. However, special attention should be given to transplant recipients presenting in reduced clinical condition at the time of OLT, undergoing complicated surgery, or receiving liver allografts with severe reperfusion injury because of an increased risk for prolonged mechanical ventilation.

Arterial complications after liver transplantation

From September 1988 through April 1998, 1,000 liver transplantations were performed on 911 patients. During the postoperative control examinations of 837 patients, we found 23 (2.74 %) with hepatic artery thromboses, 27 stenoses of the hepatic artery (3.22 %), and 6 aneurysms of the graft artery. Seventeen patients underwent retransplantation because of arterial complications. Depending on the clinical symptoms, we treated both the local situation as well as the resulting complications of inadequate arterial graft flow. The aneurysms were primarily treated surgically. The first choice of treatment of stenoses was balloon angioplasty. Early postoperative artery thromboses were also treated surgically by thrombectomy in selected cases. For the resulting biliary and local septic complications we preferred endoscopic and drainage procedures. Our clinical experiences have led us to find pretransplantation angiography recommendable, especially in the case of splanchnic artery stenoses, for bypassing from the aorta for arterial perfusion of the graft.

Enhanced cytolytic activity of intestinal intraepithelial lymphocytes in patients with Crohn's disease

BACKGROUND AND AIMS

Dysfunction of the immune system with inappropriate responses of lymphocytes to various antigens has been implicated in the development of Crohn's disease. Therefore, the functional and phenotypic characteristics of intestinal intraepithelial lymphocytes (IEL) in comparison to peripheral blood lymphocytes (PBL) were analyzed in patients with and without Crohn's disease.

PATIENTS AND METHODS

Six patients with Crohn's disease and six control patients were studied. Isolated IEL and PBL were tested for cytolytic activity against the human adenocarcinoma cells DLD-1 and the human leukemia cells K562 in a 51Cr-release assay. Two-color flow cytometry was performed for phenotype analysis of isolated lymphocytes.

RESULTS

IEL from patients with Crohn's disease showed significantly increased cytolytic activity against epithelial-derived target cells when compared with IEL from control patients. In contrast, no functional changes were detectable among PBL from patients with Crohn's disease. IEL from patients with Crohn's disease contained a significantly higher percentage of CD8+ lymphocytes when compared with IEL from control patients, whereas no phenotypic changes were observed among PBL.

CONCLUSIONS

In Crohn's disease, the functional and phenotypic changes of T cells are limited to lymphocytes of the intestinal mucosa. Furthermore, it is conceivable that the increased cytolytic activity of IEL contributes to the tissue damage in this disease.