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Biomedical subjects

H Keck

Publications and source records attributed to H Keck.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Differential diagnosis of focal liver lesions with MRI using the superparamagnetic contrast medium endorem].

PURPOSE: In a phase III/III-B trial the specific contrast enhancement of benign liver tumors, especially FNH and adenoma, versus malignant liver tumors such as HCC and metastases (colorectal and endocrine tumors) was evaluated using the superparamagnetic iron oxide ENDOREM. MATERIAL AND METHODS: 57 patients were prospectively investigated using T2-(TR/TE=2000/90) and T1-(550/15) weighted spinecho (SE), FLASH-2D-gradientecho (GE), and fat suppressed (FATSAT) sequences before and after administration of ENDOREM (concentration: 0.2 mmol Fe/ml, dose: 15 micromol/kg (b.w.) in transverse slice orientation on a 1.5 Tesla MAGNETOM (Siemens, 63 SP). In 8 patients an in vivo-in vitro correlation 30 minutes after resection was performed. In 12 patients benign primary liver tumors (FNH (n = 10), adenoma (n = 1), and hemangioma (n = 1) were histopathologically proved. Malignant liver tumors (HCC (n = 11, cholangiocarcinoma (n = 1), metastases from colorectal carcinoma (n = 13), and endocrine tumors (n = 4)) were found in 29 patients. 11 patients with liver cirrhosis due to Wilson's disease and 5 with cirrhosis due to other reasons were investigated. RESULTS: Contrast-enhanced studies allowed detection of more lesions in 19 of 41 patients with liver tumors. Benign liver tumors showed significant loss of signal intensity of 43.0% +/- 17.9 for FNH, 32.4% for adenoma and 10.2% for hemangioma in proton density-weighted SE images. Malignant tumors showed only minimal signal loss: HCC: 5.3% +/- 17, cholangiocarcinoma: -1.6%, colorectal: -2.0% +/- 11.1, endocrine metastases: 4.2% +/-4.1. Normal liver parenchyma and spleen tissue demonstrated significant signal loss of 59.2% +/- 14.9 and 42.3 +/- 012.5. In ten patients and 13 lesions of FNH, a capsule was seen in 7.7% plain and 23.1% enhanced. Scar tissue was found in 30.8% plain, 84.6% enhanced. In the patient with adenoma, capsule with contrast enhancement was seen, but no scar was detected, whereas in patients with HCC a capsule was seen in three cases enhanced. Statistical analysis (Friedman-test, Wilcoxon-test) showed a statistically significant difference in signal loss between benign and malignant liver lesions (p < 0.05). CONCLUSION: The use of superparamagnetic iron oxide ENDOREM) allows differentiation of benign and malignant liver tumors on the basis of contrast enhancement, existence and specific enhancement of capsule or scar. In vitro correlation show some limitations of in vivo MRI.

Adenoma, Liver Cell↗
PubMed1994

Fungal infections in liver transplant recipients.

A retrospective analysis of 462 consecutive orthotopic liver transplantations was undertaken to evaluate incidence, risk factors, clinical course, and outcome of fungal infections. Infections involving Aspergillus (6 cases), Candida (5 cases), Mucor (1 case), and Cryptococcus (1 case) were observed in 2.8% (13/462) of our patients. Twelve of the 13 episodes developed during the first 2 postoperative months. None of the potential risk factors for fungal infections described by other authors (i.e., age, rejection treatment, dialysis, mechanical ventilation, graft failure, long operation time, second transplant, serious non-fungal infection) correlated significantly with the episodes in our patients. However, in patients who exhibited three or more of these potential risk factors the incidence of fungal infections was elevated (P < 0.001). Six of seven exogenous infections (Aspergillus, Mucor) began before July 1991 when our department moved from Charlottenburg to Wedding, thus indicating that the incidence of these infections is highly influenced by exposure (P = 0.01). Exposure prophylaxis should therefore by meticulously followed, particularly when severely compromised patients are involved, in order to prevent exogenous infections (i.e., Aspergillus/Mucor). Infections involving such patients are combined with a very high mortality (57%). We observed Candida infection as a pathological overgrowth of physiological oropharynx flora into the esophagus and/or trachea in five patients. In each case treatment led to full recovery.

Adolescent↗
PubMed1994

Donor criteria in hepatic transplantation.

The early outcome of 201 liver grafts transplanted consecutively between September 1988 and November 1991 was investigated retrospectively. Donors were categorized according to their hospitalization periods in an intensive care unit (ICU) prior to harvesting, their causes of death, and the variables generally believed to be critical in liver donation, such as arterial hypotension (n = 69; 34.3%), cardiopulmonary resuscitation (n = 20; 9.9%), elevated serum-aminotransferases (s-AT) (n = 11; 5.5%), or an age over 50 years (n = 16; 8.0%). Ninety-one donors (45.3%) spent less than 24 h in an ICU; 29 donors (14.4%) and 14 donors (7.0%) had hospitalization periods generally considered critical of 4-6 days and more than 6 days, respectively. The most common causes of death were subarachnoidal bleeding (n = 70; 34.8%), isolated head injuries (n = 68; 33.8%), and polytraumata (n = 33; 16.4%). The postischemic hepatocellular damage was evaluated comparing peak post-transplant s-AT, which did not differ significantly between groups; nor did donor and recipient ages or cold ischemia times. Fourteen grafts (7.0%) showed a reversible preservation injury presenting with post-transplant s-AT elevated above 2000 IU/l. Five cases (2.5%) of a primary non-functioning graft (PNF) underwent early retransplantation successfully. Serum-aminotransferases (AST: 4944 +/- 2280 IU/l; ATL: 3186 +/- 1918 IU/l) were significantly (P < 0.01) elevated as compared to primary functioning grafts (AST: 699 +/- 935 IU/l; ALT: 620 +/- 701 IU/l). The donor structure of both groups reflected the distribution of variables in the entire collective. No significant overrepresentations were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Experience with cuff rearterialization in 600 orthotopic liver grafts in the rat.

The model of orthotopic rat liver transplantation has been a useful tool in transplantation research for two decades. Due to technical problems, the optional hepatic artery anastomosis is not performed in many experiments. Recently developed techniques, however, have made rearterialization a simple procedure. With our technique of cuff rearterialization to the recipient common hepatic artery, in 600 rat liver grafts we achieved high viability, and an early patency rate of 100%. Patency rates after 2 and 21 days were nearly 90%. Cuff rearterialization is simple, rapid to perform, and provides a physiologic model. Compared to strictly venous liver grafts, rearterialized grafts demonstrate improvement in survival, more rapid normalization of liver function parameters, a better preserved liver structure, and less biliary complications. Rearterialization is an important component of a physiologically relevant rat liver transplantation model, and non-specific changes due to arterial ischemia may adversely affect the interpretation of experimental data.

Anastomosis, Surgical↗
PubMed1994

Technique and results of biliary reconstruction using side-to-side choledochocholedochostomy in 300 orthotopic liver transplants.

OBJECTIVE: The authors evaluated the complication rate and outcome of side-to-side common bile duct anastomosis after human orthotopic liver transplantation. SUMMARY BACKGROUND DATA: Early and late biliary tract complications after orthotopic liver transplantation remain a serious problem, leading to increased morbidity and mortality. Commonly performed techniques are the end-to-end choledochocholedochostomy and the choledochojejunostomy. Both techniques are known to coincide with a high incidence of leakage and stenosis of the bile duct anastomosis. The side-to-side bile duct anastomosis has been shown experimentally to be superior to the end-to-end anastomosis. The authors present the results of 316 human liver transplants, in which a side-to-side choledochocholedochostomy was performed. METHODS: Biliary tract complications of 370 transplants in 340 patients were evaluated. Three hundred patients received primary liver transplants with side-to-side anastomosis of donor and recipient common bile duct. Thirty-two patients with biliary tract pathology received a bilioenteric anastomosis, and in eight patients, side-to-side anastomosis was not performed for various reasons. Clinical and laboratory investigations were carried out at prospectively fixed time points. X-ray cholangiography was performed routinely in all patients on postoperative days (PODs) 5 and 42. In patients with suspected papillary stenosis, endoscopic retrograde cholangioscopy and papillotomy were performed. RESULTS: One biliary leakage (0.3%) was observed within the early postoperative period (PODs 0 through 30) after liver transplantation. No stenosis of the common bile duct anastomosis was observed during this time. Late biliary stenosis occurred in two patients (0.6%). T tube-related complications were observed in 4 of 300 primary transplants (1.3%). Complications unrelated to the surgical technique, including papillary stenosis (5.7%) and ischemic-type biliary lesion (3.0%), which must be considered more serious in nature than complications of the anastomosis or T tube-related complications, were observed. Papillary stenosis led to frequent endoscopic interventions and retransplantations in 1.3%. CONCLUSIONS: Side-to-side common bile duct anastomosis represents a safe technique of bile duct reconstruction and leads to a low technical complication rate after human orthotopic liver transplantation. Ischemic-type biliary lesion evoked by preservation injury, arterial ischemia, cholestasis, and cholangitis may represent a new entity of biliary complication, which markedly increases the morbidity after human liver transplantation. Therefore, this complication should be the subject of further research.

Adolescent↗
PubMed1994

The validity of the MEGX test in correlation with histology after orthotopic rat liver transplantation.

Lidocaine metabolism (MEGX test) as an indicator for liver function in the assessment of different degrees of liver disease and as a predictor for liver outcome after transplantation is well established. Since reduced liver function is associated with an alteration in parenchymal and non-parenchymal cells, we evaluated whether MEGX values correlate with histology in an in vivo model of orthotopic rat liver transplantation (ORLT) to assess histological damage without taking biopsy specimens. Livers from syngeneic Lewis rats were transplanted with rearterialization after 15-30 h of cold storage in UW solution and rinsing with Carolina Rinse Solution prior to implantation. Forty-eight hours after transplantation, the MEGX test was performed and metabolites were measured with a commercial kit as described elsewhere. Biopsy specimens were taken and graded three degrees of damage (mild, moderate, and severe) in a double blind fashion by a pathologist. MEGX values were assigned to the histological results. Statistical analyses were done with a Mann-Whitney test (n = 58) for mean values. The mean MEGX values attributed to histologies with a mild, moderate, severe degree of damage were 159.96, 78.46 and 44.42 ng/ml, respectively. When the histological groups were compared with the mean MEGX values, mild vs moderate, mild vs severe and moderate vs severe were significant (P - 0.0001). In conclusion, MEGX values correlate significantly with histological grading in a linear fashion after ORLT. The MEGX test may be of clinical value because it reflects the histological pattern of livers and may reduce the necessity to take biopsy specimens before and after transplantation.

Alanine Transaminase↗
PubMed1994

Selection of small hepatocellular carcinoma improves long-term results of hepatic transplantation for malignancy.

Liver transplantation for advanced hepatocellular carcinoma is often followed by early tumour recurrence and death. At the beginning of the liver transplantation programme at Berlin Virchow we decided to offer liver transplantation only to patients with solitary tumours not exceeding a maximum diameter of 5 cm or to patients with two or three tumour nodes with a maximum diameter of 4 cm. From September 1988 to October 1993 435 liver transplants were performed in 403 patients. Of these, 32 patients (8%) had a histologically confirmed hepatocellular carcinoma (29 males, 3 females, median age 56 years). The overall actuarial survival according to Kaplan-Meier for the whole series of 32 patients with hepatocellular carcinoma was 82%, 78%, and 78% at 1, 2 and 3 years, respectively. Tumour size alone did not seem to be a relevant factor when comparing patients with tumours up to or larger than 3 cm in diameter. Patients with solitary tumours had a better prognosis than patients with multiple tumours. The largest difference was found between patients with stage I-III (UICC) tumours and those with stage IVA tumours: 1-, 2- and 3-year survival rates were 89% throughout in the former group, while the corresponding figures for patients with stage IVA tumours were 63%, 47% and 47%. Efforts should be made to identify stage IVA tumours preoperatively in order to use the precious resource of scarce donor livers in an optimal way.

Actuarial Analysis↗
PubMed1994

[Therapy of unilobar Caroli syndrome by liver resection].

Caroli's disease is characterized by uni- or bilobar cystic enlargement of the intrahepatic biliary tract. Clinical symptoms include recurrent cholangitis, right upper quadrant abdominal pain and jaundice. The diagnosis is usually established preoperatively based on abdominal ultrasound, computertomography and ERCP. Eight patients suffering from unilobar Caroli's disease underwent liver resection during a period of six years. The postoperative course was uneventful, and after a median follow-up of 39.6 months in one case only a temporary jaundice occurred. Liver resection is the method of choice for Caroli's syndrome when feasible. Apart from the curative intention liver resection represents also a prophylactic method since the risk of malignant transformation to cholangiocellular carcinoma in the cystic walls after draining procedures is considerably high. For diffuse spread of Caroli's disease in the liver orthotopic liver transplantation has emerged as therapeutic option.

Adult↗
PubMed1994

Treatment of the Budd-Chiari syndrome with orthotopic liver transplantation and long-term anticoagulation.

The Budd-Chiari syndrome (BCS) with hepatic vein occlusion is a rare disorder that can effectively be treated with orthotopic liver transplantation. In this retrospective analysis we report on 7 patients who received 9 liver grafts for terminal BCS. One patient died after 4 months due to cytomegalovirus-pneumonia. The actuarial survival rate is 85.7% compared to more than 90% in all other 376 patients transplanted between September 1988 and April 1993 at our institution. Anticoagulation management consisted of early postoperative intravenous heparin and continuation with dicoumarin. One patient with thrombocytosis received hydroxyurea. Under this regimen one postoperative hemorrhage requiring laparotomy was observed. Discontinuation of oral anticoagulation due to gastrointestinal bleeding caused hepatic artery and portal vein thrombosis in 1 patient who had to be retransplanted. One recurrence requiring retransplantation as well was due to an insufficient dicoumarin intake. In conclusion, terminal BCS represents a good indication for orthotopic liver transplantation with a closely-monitored anticoagulation to avoid such adverse side effects as thrombosis and hemorrhage.

Adolescent↗
PubMed1993

[Liver transplantation as a routine procedure? Indications and results in 270 patients].

AIM: To represent the current state of the art of orthotopic liver transplantation (OLT). The constantly expanding spectrum of indications are discussed in detail, and the specific risks of the individual indications considered. Major points discussed: On the basis of the authors' own results obtained at the Rudolf Virchow Hospital, University of Berlin, the current survival rates following orthotopic liver transplantation are shown. In addition to established indications for liver transplantation (primary biliary cirrhosis, primary sclerosing cholangitis, acute hepatic failure, various metabolic diseases, small hepatocellular carcinomas and a number of posthepatic cirrhoses) the indication and results of liver transplantation in HbsAg-positive and alcoholic cirrhosis are presented in detail. In contrast to reports in the Anglo-American literature, the incidence and severity of graft re-infections with the hepatitis virus was appreciably reduced through the use of anti-HBs hyperimmunoglobulin preparations in HBsAg-positive cirrhotics. The results obtained were comparable with those achieved for other indications.

Follow-Up Studies↗
PubMed1993

[Aorto-intestinal fistula versus angiodysplasia. A difficult differential diagnosis in gastrointestinal bleeding].

A 63-year-old patient had recurrent tarry stools and haemoglobin levels of around 7.0 g/dl. Ten years previously he had undergone an aortobifemoral bypass operation for peripheral vascular disease in the legs. Eight gastroscopies and five coloscopies over ten weeks failed to discover a bleeding source. Although an aorto-intestinal fistula was considered early on, extensive diagnostic tests failed to reveal it. Digital subtraction angiography was suggestive of an angiodysplasia of the terminal ileum, a diagnosis supported when coloscopy during exploratory laparotomy visualized blood trickling from the terminal ileum. As a result of this finding a right hemicolectomy was performed. But recurrent bleedings necessitated relaparotomy which finally revealed a fistula between the ascending duodenum and the proximal bypass graft anastomosis. Nine months after resection of the proximal anastomotic area and interposition of a Dacron prosthesis the patient has been free of symptoms.

Angiodysplasia↗
PubMed1993

Transplantation of shipped donor livers.

Between September 1988 and November 1991, 201 donor hepatectomies and transplantations were performed. Fifty-four livers (26.9%) were harvested by other teams and shipped for transplantation; 147 livers (73.1%) were procured by teams from our transplant center. Comparing the maximal postoperative serum-aminotransferases (s-AT), we evaluated the postischemic damage of shipped organs (AST 951 +/- 931 IU/l; ALT 820 +/- 666 IU/l) and nonshipped organs (AST 753 +/- 1256 IU/l; ALT 636 +/- 896 IU/l); this did not differ significantly. Donor-related factors, such as critical parameters (i.e., cardiac arrest, arterial hypotension, age over 50 years, or elevated preoperative s-AT), length of stay in the intensive care unit before harvesting, and cause of death showed similar patterns in both groups. The mean cold ischemia time in the group of shipped livers (12 h 10 min +/- 4 h 22 min) and in the nonshipped livers (10 h 6 min +/- 3 h 53 min) did not differ significantly. Five cases (2.5%) of a primary non-functioning graft presenting with significantly (P < 0.001) elevated s-AT (AST 4944 +/- 2280 IU/l; ALT 3186 +/- 1918 IU/l) necessitated an early retransplantation. One organ was shipped and four organs were nonshipped, thus corresponding to their portion of all grafts. These data indicate that the transplantation of shipped livers is a safe procedure procedure, provided that procurement is done by experienced centers.

Adolescent↗