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Biomedical subjects

K Haag

Publications and source records attributed to K Haag.

At least 19 recordsLinked to original sources
PubMed2001

How much reduction in portal pressure is necessary to prevent variceal rebleeding? A longitudinal study in 225 patients with transjugular intrahepatic portosystemic shunts.

OBJECTIVES: This longitudinal study determines the risk of rebleeding in relation to the reduction of the portosystemic pressure gradient in patients with a transjugular intrahepatic portosystemic shunt (TIPS) for variceal bleeding. METHODS: The study included 225 patients in whom a TIPS revision was indicated by the endoscopic finding of varices with a high risk for rebleeding (n = 167) or a recent variceal rebleed (n = 58). The portosystemic pressure gradient was determined before and after TIPS placement and at revision performed after a mean of 10 +/- 15 months. RESULTS: The portosystemic pressure gradient at revision approached the index pressure gradient before TIPS implantation (23.1 +/- 5.5 mm Hg) by 8.4 +/- 31%. Rebleeding was inversely correlated with the reduction in index pressure gradient found at revision. Thus, 80% of rebleedings occurred with pressure gradients close to the index pressure gradient (< 25% reduction) or with gradients equal to or greater than the index pressure gradient. In contrast, only one patient (0.4%) and three patients (1.3%) rebled with a pressure gradient of < 12 mm Hg or a reduction of the index pressure gradient by > 50%, respectively. Kaplan-Meier analysis of rebleeding, which included the 225 patients at risk, showed a probability of rebleeding of 18%, 7%, and 1% for a reduction of the index pressure gradient by 0%, 25-50%, and > 50%, respectively. CONCLUSIONS: Most rebleedings occurred with pressure gradients similar to the index-pressure gradient measured at first bleeding. Accordingly, a graded reduction by 25-50% sufficiently prevents rebleeding. It can be assumed that, in comparison with the widely used threshold value of 12 mm Hg, a reduction by 25-50% may have a favorable benefit-to-risk ratio with respect to shunt-induced hepatic encephalopathy and liver failure. It should therefore be a goal in the decompressive treatment of portal hypertension and maintained during follow-up of patients with variceal bleeding.

Adult↗
PubMed1999

Total gene deletions and mutant frequency of the HPRT gene as indicators of radiation exposure in Chernobyl liquidators.

This study was conducted to determine the utility of deletion spectrum and mutant frequency (MF) of the hypoxanthine phosphoribosyl transferase gene (HPRT) as indicators of radiation exposure in Russian Liquidators who served in 1986 or 1987 in the clean up effort following the nuclear power plant accident at Chernobyl. HPRT MF was determined using the cloning assay for 117 Russian Controls and 122 Liquidators whose blood samples were obtained between 1991 and 1998. Only subjects from whom mutants were obtained for deletion analysis are included. Multiplex PCR analysis was performed on cell extracts of 1080 thioguanine resistant clones from Controls and 944 clones from Liquidators. Although the deletion spectra of Liquidators and Controls were similar overall, the Liquidator deletion spectrum was heterogeneous over time. Most notable, the proportion of total gene deletions was higher in 1991-1992 Liquidators than in Russian Controls (chi 2 = 10.5, p = 0.001) and in 1993-1994 Liquidators (chi 2 = 8.3, p = 0.004), and was marginally elevated relative to 1995-1996 Liquidators (chi 2 = 3.3, p = 0.07). This type of mutations has been highly associated with radiation exposure. Total gene deletions were not increased after 1992. Band shift mutations were also increased in the 1991-1992 Liquidators but were associated with increased MF of both Liquidators and Controls (p = 0.009), not with increased MF in 1991-1992 Liquidators (p = 0.7), and hence are not believed to be associated with radiation exposure. Regression analysis demonstrated that relative to Russian Controls HPRT MF was elevated in Liquidators overall when adjusted for age and smoking status (37%, p = 0.0001), and also was elevated in Liquidators sampled in 1991-1992 (72%, p = 0.0076), 1993-1994 (22%, p = 0.037), and 1995-1996 (62%, p = 0.0001). In summary, HPRT MF was found to be the more sensitive and persistent indicator of radiation exposure, but the specificity of total gene deletions led to detection of probable heterogeneity of radiation exposure within the exposed population.

Adult↗
PubMed1999

Correlation of duplex sonography findings and portal pressure in 375 patients with portal hypertension.

OBJECTIVE: The purpose of this study was to determine the potential usefulness of duplex sonography in the grading of portal hypertension. SUBJECTS AND METHODS: Duplex sonography of the portal vein system and measurement of the portal pressure and portosystemic pressure gradient were performed in 375 patients before placement of transjugular intrahepatic portosystemic shunts. Subgroups included patients with recent variceal bleeding (n = 296) and patients with refractory ascites without previous variceal bleeding (n = 79). A matched cohort of 100 patients without portal hypertension was also examined. Differences between the groups in portal and splenic vein diameter, flow velocity, congestion index, and hepatic arterial resistive index were assessed using the Wilcoxon rank sum test. RESULTS: Compared with healthy individuals, our patients had an increased portal vein diameter (+30%, p < .001), decreased portal vein flow velocity (-44%, p < .001), and increased congestion index (+185%, p < .001). A portal vein diameter greater than 1.25 cm or a portal vein flow velocity less than 21 cm/sec indicated portal hypertension with a sensitivity and specificity of 80%. If the congestion index exceeded 0.1, portal hypertension was diagnosed with a 95% sensitivity and specificity. The portal pressure and gradient correlated only weakly (r < .2, p < .05) with sonographic variables. Using multivariate analysis, subgroups with variceal bleeding or refractory ascites did not show differences in hemodynamics, including pressures. CONCLUSION: Duplex sonography contributes to the diagnosis of portal hypertension but does not allow its grading. Similarity of portal hemodynamics between patients with variceal bleeding and patients with refractory ascites suggests that additional factors determine the respective clinical presentation.

Female↗
PubMed1998

[Hepatopulmonary syndrome].

The hepatopulmonary syndrome (HPS) is a reversible pulmonary insufficiency in association with liver disease, most frequently liver cirrhosis. The pathogenesis of HPS is poorly understood. HPS is characterized by arterial hypoxemia caused by intrapulmonary arteriovenous shunts or marked vasodilatation of the pulmonary vessels and ventilation-perfusion mismatch in the absence of intrinsic heart or lung disease. Typical clinical signs are dyspnea in the upright position which improves in supine position (platypnoe) and decrease of arterial pO2 in the upright position (orthodeoxia). The diagnosis of HPS is based on clinical features, arterial blood gas analyses in supine and upright position, contrast echocardiography and lung perfusion scanning. Arteriovenous fistula can be excluded by pulmonary angiography. There is no established medical treatment of HPS. New medical and noninvasive therapies, such as transjugular intrahepatic Stent-shunt (TIPS), lead to improvement of HPS. These treatment modalities need further elucidation. HPS was shown to be reversible after orthotopic liver transplantation (OLTx) in some cases. Severe HPS, therefore, may be an indication rather than a contraindication for OLTx.

Humans↗
PubMed1997

Randomised trial of transjugular-intrahepatic-portosystemic shunt versus endoscopy plus propranolol for prevention of variceal rebleeding.

BACKGROUND: The transjugular-intrahepatic-portosystemic shunt is a new interventional treatment for portal hypertension. The aim of our study was to compare the transjugular shunt with endoscopic treatment for the prophylaxis of recurrent variceal bleeding. METHODS: Between March, 1993, and March, 1996, 126 patients with variceal bleeding were randomly assigned either transjugular shunt (n = 61) or endoscopic treatment (n = 65). Patients were followed up for a median of 14 (IQR 8-25) months and 13 (8-25) months, respectively. In 31 (51%) of the shunted patients, simultaneous transjugular-variceal embolisation was done at the time of shunt placement. Endoscopic treatment consisted of sclerotherapy and/or banding ligation and was combined with propranolol medication. FINDINGS: Technical success was achieved in all patients assigned to the shunt group. During follow-up, the cumulative 1-year variceal rebleeding rates in the shunted and endoscopically treated patients were 15% and 41% and the 2-year rates were 21% and 52% (p = 0.001), respectively. In nine (12%) patients from the endoscopic group treatment failed and the patients received the transjugular-shunt treatment. A total of 19 bleeding episodes from any source occurred in 15 patients in the shunt group compared with 100 episodes in 33 patients in the endoscopic group. There was no difference in survival with estimated 1-year survival rates for shunted and endoscopically treated patients of 90% and 89%, and 2-year survival rates of 79% and 82%, respectively. The incidence of clinically significant hepatic encephalopathy after 1 year was higher in the shunt group (36% vs 18%, p = 0.011). INTERPRETATION: These results suggest, that the transjugular shunt is more effective than endoscopic treatment in prevention of variceal rebleeding but has a considerable risk of hepatic encephalopathy. Survival is similar in the two groups.

Adult↗
PubMed1997

Acute hemoperitoneum after large-volume paracentesis.

Hemoperitoneum resulting from rupture of mesenteric varices is a rare complication of portal hypertension with a high mortality of up to 70%. This case report describes the symptoms, clinical course, and treatment of 4 patients with acute hemoperitoneum caused by mesenteric variceal bleeding after large-volume paracentesis. Abdominal pain and/or hemorrhagic shock developed in 4 patients (age, 48-68 years), admitted for refractory ascites, 3 hours to 4 days after 1-4 large-volume paracenteses (> 4000 mL). Duplex sonography, performed in 3 of the 4 patients before onset of bleeding, showed retrograde flow in the mesenteric veins, suggesting large-caliber mesenteric collateralization. Treatment consisted of surgical ligation followed by transjugular intrahepatic portosystemic shunt (TIPS) (2 patients) and emergency TIPS with embolization of the bleeding vessel (1 patient). One patient died before any intervention could be initiated. In these 4 patients, the concurrence of large-volume paracentesis and hemoperitoneum suggests their causal relationship. The mechanism may be a sudden reduction in intraperitoneal pressure increasing the pressure gradient across the wall of the mesenteric varices, resulting in rupture and bleeding. The awareness of this complication may accelerate the diagnostic process and treatment.

Acute Disease↗
PubMed1997

The transjugular stent implantation for the treatment of malignant portal and hepatic vein obstruction in cancer patients.

BACKGROUND: The increase in portal vascular resistance is a significant complication of metastatic disease to the liver or locally advanced cancer, e.g., biliary cancer. PATIENTS AND METHODS: This paper describes the successful palliative treatment of two cancer patients with portal hypertension presenting with the symptoms of tense ascites, mesenteric congestion, and severe variceal bleeding. By creating a stenttract between a hepatic vein and a main branch of the portal vein and/or by placing an extendable stent into the portal vein, the transjugular intrahepatic portosystemic stent-shunt (TIPS) technique was used to decompress the portovascular system. RESULTS: The TIPS-technique offers a new, safe and effective palliation for malignant portal hypertension. In both patients, the symptoms of the portal hypertension disappeared after the procedure. This was accompanied by a significant improvement of the patients performance status allowing an early ambulation. CONCLUSION: Our findings demonstrate the feasibility and effectiveness of the TIPS procedure as a minimal invasive treatment for portal vein decompression in selected tumor patients.

Biliary Tract Neoplasms↗
PubMed1997

Transjugular intrahepatic portosystemic shunt (TIPS). Thrombogenicity in stents and its effect on shunt patency.

PURPOSE: To compare the thrombogenicity and patency of the Palmaz stent and the Wallstent, and to evaluate the effect of periprocedural heparin therapy in cirrhotic patients with maintained coagulation capacity who receive a transjugular intrahepatic portosystemic shunt (TIPS). MATERIAL AND METHODS: Twenty-four patients were randomized into 4 groups of 6 patients. Each received a Palmaz-stent or Wallstent TIPS with or without periprocedural heparin therapy. The groups receiving periprocedural heparin were given 24 U/kg b.w. just before stent placement, followed by 24 h therapeutic i.v. heparin. After 24 hours, all patients received i.v. heparin for 1 week followed by subcutaneous treatment with low-molecular-weight heparin (0.3 ml/day) for another 4 weeks. Stent thrombogenicity was determined scintigraphically after i.v. injection of 120-290 mBq of 99mTc-labeled platelets at the time of stent placement and expressed as the stent/heart ratio. Shunt patency was assessed by duplex sonography and confirmed radiologically. RESULTS: The aggregation ratio was highest 90 min after stent implantation. Wallstents showed a significantly higher ratio than Palmaz stents. Heparin reduced the ratio in patients with a Wallstent (-41%) but had no effect on Palmaz stents. Patients with a Wallstent without heparin had a higher rate of early shunt insufficiency (66.6%) than the other patients (0-16.6%). Primary assisted long-term patency was similar in the 4 groups. CONCLUSION: Wallstents were more thrombogenic than Palmaz stents and gave a significantly higher risk of early shunt insufficiency in cirrhotic patients with maintained coagulation capacity. Periprocedural heparin was effective in the prevention of shunt insufficiency and is therefore indicated in such patients.

Anticoagulants↗
PubMed1996

[Current diagnosis of liver diseases: duplex ultrasonography].

In the last 20 years abdominal sonography has become a powerful method in diagnosing diseases in gastroenterology and hepatology. Now, Doppler techniques are also used for the examination of abdominal vessels and especially of the portal circulation in an increasing number of medical centers. Color Doppler flow imaging (CDFI) represents an extension of duplex sonography as it makes velocity informations available not only for a small region but also for a larger segment or even for the whole image. CDFI indications include all aspects of portal hypertension, liver diseases of unknown origin, and focal liver lesions suspicious for hepatocellular carcinoma. This technique when used by skilled operators provides much information that sometimes cannot be gained in any other way. The CDFI will become a complementary procedure as well as an important alternative to angiographic methods in the diagnosis of vascular disturbances in the portal system.

Humans↗
PubMed1996

[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.

Aneurysm, False↗
PubMed1996

The transjugular intrahepatic portosystemic stent-shunt: a review of the literature and own experiences.

The transjugular intrahepatic portosystemic stent-shunt (TIPS) technique consists of a transhepatic puncture of the portal vein and stenting of the parenchymal tract between the hepatic and portal veins. Complications of both puncture and stenting are observed in approximately 5% of procedures. Most of the complications are without clinical consequences and the procedural mortality is very low in experienced hands (1%). During a 1 year follow up, 35% of patients were seen to develop stenosis and 15% developed occlusion of the stent-shunt. However, in spite of the considerable incidence of stenosis/occlusion, the rate of variceal rebleeding is rare when patients are followed up carefully by duplex sonography, which allows accurate and early detection of shunt insufficiency. One of the major long-term clinical problems of TIPS is the induction or worsening of hepatic encephalopathy. Although most patients respond to medical treatment, some develop debilitating encephalopathy or progressive liver failure. In these patients, reduction of shunt flow by the implantation of a reducing stent, or its occlusion with a balloon catheter, may be indicated. In conclusion, in spite of many complications, TIPS is relatively safe and efficient and hepatic encephalopathy is manageable in most cases.

Contraindications↗
PubMed1995

[Recurrent bleeding from colonic varices in portal hypertension. The successful prevention of recurrence by the implantation of a transjugular intrahepatic stent-shunt (TIPS)].

HISTORY AND CLINICAL FINDINGS: Sclerotherapy was performed in a 52-year-old patient with alcoholic liver cirrhosis (Child-Pugh stage A) for recurrent bleeding from oesophageal varices. Half a year later he again was admitted to hospital because of recurrent passage of bloody stools. The cardiovascular status was stable; the liver was enlarged by 15 cm in the medioclavicular line. INVESTIGATIONS: Endoscopy revealed several varices in the colon near the right flexure. One of the varices had an ulcer of 5 mm size. Duplex sonography revealed portal hypertension with cirrhosis of the liver and partial thrombosis of the main trunk of the portal vein without any sign of cavernous transformation. TREATMENT AND COURSE: Because of the partial portal vein thrombosis it was decided to insert a transjugular intrahepatic portosystemic stent shunt. This obviated the thrombosis and lowered the portosystemic pressure gradient by 6.8%. With the shunt functioning well there were no further bleedings in the subsequent year. CONCLUSION: The only slightly invasive TIPS implantation is an effective therapeutic procedure for bleeding from colon varices caused by portal hypertension.

Colon↗
PubMed1995

[Septic portal vein thrombosis. Its successful therapy by local fibrinolysis and a transjugular portasystemic stent-shunt (TIPS)].

HISTORY AND FINDINGS: A 68-year-old man, without any preceding hepatic or abdominal disease, suddenly developed a severe septic illness with consumptive coagulopathy and upper abdominal pain. B-mode and duplex ultrasonography revealed fresh portal vein thrombosis. Despite extensive conservative measures there was no significant improvement after one week and further thrombus extension with threatened acute mesenteric vein occlusion. TREATMENT AND COURSE: Local fibrinolysis with recombinant plasminogen activator and urokinase via percutaneous transjugular intrahepatic catheterization of the portal vein achieved almost complete dissolution of the thrombus within 3 days. Subsequently the portal vein catheter was changed into a transjugular portosystemic stent shunt (TIPS). CONCLUSIONS: While local or systemic fibrinolysis has been practised in previously reported cases of acute portal vein thrombosis, the described use of TIPS introduces a new element. The shunt between hepatic and portal veins assures therapeutic access to the portal venous bed. It lowers portal vein pressure and can diminish the danger of recurrent thrombosis by raising portal flow. This minimally invasive procedure may be a nearly ideal treatment even in the course of portal vein thrombosis which has a high complication rate.

Aged↗
PubMed1995

The transjugular intrahepatic portosystemic stent-shunt procedure for refractory ascites.

BACKGROUND: Previous studies have suggested that the transjugular placement of an intrahepatic stent to establish a portosystemic shunt is an effective treatment of uncomplicated ascites accompanying variceal bleeding. We studied the stent shunt for use in patients with liver cirrhosis and ascites refractory to medical treatment. METHODS: Fifty of 62 consecutive patients with cirrhosis and refractory ascites (18 with Child-Pugh class B liver disease and 32 with class C) were treated with the stent shunt--an expandable stent of metallic mesh placed between a major branch of the portal vein and one of the hepatic veins. Patients were followed for a mean (+/- SD) of 426 +/- 333 days. Those with advanced cancer, severe heart failure, or severe liver failure were excluded. RESULTS: The stent shunt was successfully placed in all patients and reduced the pressure gradient between the portal vein and the inferior vena cava by an average of 63 percent. Thirty-seven patients (74 percent) had complete responses (total remission of ascites within three months), and nine patients (18 percent) had partial responses (ascites detected by ultrasound but with no need for paracentesis). Four patients did not respond, including two who died within two weeks of shunt placement. After the procedure, 25 patients had hepatic encephalopathy, as compared with 20 patients before the procedure; although encephalopathy improved in 3 patients, new encephalopathy developed in 8 patients. In the 28 of the 33 patients followed for more than six months who were evaluated, the mean serum creatinine concentration was 1.5 +/- 0.09 mg per deciliter (133 +/- 8 mumol per liter) before placement of the stent shunt, 1.5 +/- 1.6 mg per deciliter (133 +/- 141 mumol per liter) one week after the procedure, and 0.9 +/- 0.3 mg per deciliter (80 +/- 27 mumol per liter) after six months (P = 0.008 for the comparison of concentrations before and six months after the procedure). Renal function did not improve in the six patients with organic kidney disease. Procedure-related complications developed in 16 patients, including intraabdominal bleeding requiring blood transfusions in 2 patients. Thrombotic occlusion of the stent shunt occurred within two weeks in 5 patients, and later insufficiency of the shunt occurred in 16 patients, including 12 with recurrence of ascites after complete remission. During followup, an additional 29 patients died--10 of progressive liver disease and 19 of other causes. Survival for at least one year was associated with a patient's being under 60 years of age, having a serum bilirubin level before placement of the stent shunt of less than 1.3 mg per deciliter (22 mumol per liter), and having a complete response. CONCLUSIONS: Our findings in an uncontrolled prospective study suggest that the transjugular intrahepatic porto-systemic stent-shunt procedure was an effective treatment for many patients with liver cirrhosis and refractory ascites, but mortality from underlying diseases was substantial.

Ascites↗
PubMed1995

The reducing stent: treatment for transjugular intrahepatic portosystemic shunt-induced refractory hepatic encephalopathy and liver failure.

PURPOSE: To examine the efficacy of a stent device in reducing the diameter of transjugular intrahepatic portosystemic shunts (TIPS) in patients with progressive liver failure or with shunt-induced hepatic encephalopathy. MATERIALS AND METHODS: Seven patients with TIPS (four with severe hepatic encephalopathy, three with progressive liver failure) underwent transjugular implantation of a stent designed to reduce the flow through the original TIPS channel. RESULTS: Implantation of the reducing stent proceeded without complication. Duplex sonography showed that stent flow decreased by 41% +/- 18 (mean +/- standard deviation). The four patients with hepatic encephalopathy showed substantial improvement. Concentrations of plasma ammonium and serum bilirubin improved considerably. In contrast, functional impairment progressed in the three patients treated for liver failure. The patients soon died. CONCLUSION: With the limited experience of treating these seven patients, the authors suggest that shunt-induced hepatic encephalopathy can be effectively treated with implantation of a reducing stent. Hepatic failure, however, is a deleterious complication that seems to be irreversible.

Aged↗
PubMed1995

Noncavernomatous portal vein thrombosis in hepatic cirrhosis: treatment with transjugular intrahepatic portosystemic shunt and local thrombolysis.

PURPOSE: To evaluate the use of the transjugular intrahepatic portosystemic shunt (TIPS) and local, low-dose thrombolysis in the treatment of complete, noncavernomatous portal vein occlusion. MATERIALS AND METHODS: TIPS implantation and portal vein recanalization was attempted in seven patients with noncavernomatous portal vein obstruction and recurrent variceal bleeding. TIPS placement was followed by thrombolytic therapy to restore portal venous blood flow. Hemodynamic effects and clinical characteristics after the procedure and during follow-up were assessed. RESULTS: The implantation of TIPS and the recanalization of the portal vein trunk were successful in all patients. The treatment reduced the portal venous pressure gradient and restored portal blood flow. No bleeding complications were observed. CONCLUSION: TIPS placement and recanalization of the main portal vein is a safe and effective treatment option for patients with liver cirrhosis and noncavernomatous portal vein occlusion.

Combined Modality Therapy↗