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Biomedical subjects

G Tusch

Publications and source records attributed to G Tusch.

35 records · Page 2Linked to original sources
PubMed1996

[Value of 2-field lymphadenectomy in intrathoracic esophageal carcinoma].

Surgical procedures including the extent of systematic lymphadenectomy are still under discussion in the treatment of esophageal cancer. In the own patients' population 92 subtotal en bloc-esophagectomies with a standard two field lymphadenectomy were performed. A total of 1483 lymph nodes were resected in the thoracic and abdominal compartments with an incidence of 16.1% being metastatic. Stage pN1 disease occurred in 57.6% of the patients. The median number of lymph nodes resected in each specimen was 16, independent of tumor stage, -site or R-classification. The number of infiltrated nodes increased with tumor stages. R-classification, tumor stage and number of involved lymph nodes could be analyzed as prognostic factors. After R0-resection a median survival rate of 25.4 months could be achieved, following pN0-stage that of 27.4 months. In case of two metastatic lymph nodes the prognosis decreased significantly to 14.4 months (p < 0.01). Therefore, two field lymphadenectomy may show a therapeutic benefit only in a subgroup of patients with a limited number of lymph nodes infiltrated.

Adult↗
PubMed1996

[Results of surgical therapy of primary and recurrent retroperitoneal liposarcoma].

Between 1978 and 1994, 27 patients with a retroperitoneal liposarcoma underwent a total of 64 operations at our institution with a resectability rate of 96% of the primary and 100% of recurrent tumors. Operative morbidity (7.8%) and mortality (3.1%) were low, although multivisceral reactions were necessary in the majority of cases (73% of all primary tumors). The single most important prognostic factor was a potentially curative resection at first operation (5-year survival: RO: 75%, R1/R2: 34%), but also at first operation for tumor recurrence.

Adult↗
PubMed1996

[Liver transplantation in patients with primary sclerosing cholangitis. Determining timing with reference to risk of malignancy].

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease associated with hepatobiliary malignancies which are in the majority of cases not known prior to transplantation. Applying the Mayo PSC natural history model, patients can be classified in low, medium and high risk groups; particularly patients at medium and high risk are in danger of developing malignancies in a PSC setting. Therefore, regular scoring of patients using the above-mentioned model is suggested, and transplantation should be performed at scores above 4.

Adult↗
PubMed1995

Evaluation of partial classification algorithms using ROC curves.

When using computer programs for decision support in clinical routine, an assessment or a comparison of the underlying classification algorithms is essential. In classical (forced) classification, the classification rule always selects exactly one alternative. A number of proven discriminant measures are available here, e.g.sensitivity and error rate. For probabilistic classification, a series of additional measures has been developed [1]. However, for many clinical applications, there are models where an observation is classified into several classes (partial classification), e.g., models from artificial intelligence, decision analysis, or fuzzy set theory. In partial classification, the discriminatory ability (Murphy) can be adjusted a priori to any level, in most practical cases. Here the usual measures do not apply. We investigate the preconditions for assessment and comparison based on medical decision theory. We focus on problems in the medical domain and establish a methodological framework. When using partial classification procedures, a ROC analysis in the classical sense is no longer appropriate. In forced classification for two classes, the problem is to find a cutoff point on the ROC curve; while in partial classification, you have to find two of them. They characterize the elements being classified as coming from both classes. This extends to several classes. We propose measures corresponding to the usual discriminant measures for forced classification (e.g., sensitivity and error rate) and demonstrate the effects using the ROC approach. For this purpose, we extend the existing method for forced classification in a mathematically sound manner. Algorithms for the construction of thresholds can easily be adapted. Two specific measurement models, based on parametric and non-parametric approaches, will be introduced. The basic methodology is suitable for all partial classification problems, whereas the extended ROC analysis assumes a rank order of the selected alternatives. The method is based on the black box principle and makes use only of the results of the compared algorithms and some general intuitive principles. Therefore, algorithms arising from different "philosophical" approaches may also be compared according to their results. For demonstration purposes, a clinical example from cranial computed tomography is presented. Linear discriminant analysis as a reference is compared to a Bayesian and a fuzzy procedure.

Algorithms↗
PubMed1992

Results of hepatic resection and transplantation for fibrolamellar carcinoma.

Fibrolamellar carcinoma (FLC) is a tumor of the liver that can be differentiated from common hepatocellular carcinoma (HCC). Despite the exceptional role of the clinicopathologic signs and symptoms, true appraisal of the prognosis of the tumor is not clear and remains a controversial issue. To determine the long term prognosis of FLC more precisely, a retrospective study of 20 consecutive patients was performed, with analysis of selected pathologic factors, particularly the TNM staging system. Curative tumor removal (R0) was achieved by partial hepatic resection in 14 patients and total hepatectomy with subsequent replacement of the liver in six patients, respectively. The estimated overall five year survival rate was 36.6 percent. There was an advantage of partial versus total hepatectomy, with median survival times of 44.5 versus 28.5 months. Statistically significant better survival rates at five years were observed in patients with solitary tumors and in instances of absent regional lymph node metastases. Although other factors analyzed did not show significant differences, there was a tendency indicating individual tumor stage was the most significant determinant for prognosis. For further discussion of an apparently more favorable outcome of patients with FLC as compared with common HCC, detailed specification of the tumor stages seems mandatory. From the present analysis, the fibrolamellar variant could not be confirmed to be an independent indicator of better patient survival. The treatment of choice remains radical operation. The goal can, at best, be achieved by a therapeutic concept including partial as well as total hepatectomy, depending on the stage of the tumor.

Adolescent↗
PubMed1991

Liver transplantation in HBs antigen (HBsAg) carriers. Prevention of hepatitis B virus (HBV) recurrence by passive immunization.

Liver transplantation in HBs-antigen (HBsAg) positive allograft recipients is associated with a high risk of HBV recurrence some time after surgery. So far, results of measures to prevent recurrent HBV-infection by means of treatment with interferon, hepatitis B vaccination and short-term passive immunization with hepatitis B immunoglobulin (HBIg) or monoclonal antibody to HBsAg (anti-HBs) have been disappointing. In the present study the results of long-term, anti-HBs monitored passive immunization with HBIg is reported. In 23 HBsAg-positive liver transplant recipients an anti-HBs level of greater than or equal to 100 IU/l was maintained for 6 or 12 months, respectively. The rate of recurrent infection was found to be less than 20% under HBIg substitution, whereas 11 graft recipients with no or only short-term HBIg prophylaxis were reinfected by month 15 after transplantation. HBV recurrence was associated with chronic liver disease and recurrent cirrhosis in the allograft.

Adolescent↗
PubMed1988

HLA compatibility and different features of liver allograft rejection.

The influence of human leukocyte antigen (HLA) on acute liver allograft rejection was investigated in 48 adult patients. The diagnosis of rejection was always based on the full triad of histological findings, clinical signs, and the required antirejection treatment. Sixty-two percent of the patients closely observed for 6 months postoperatively revealed acute rejection within the first 3 weeks, mostly on days 7-11. HLA compatibility was not observed to have any significant influence on the incidence of acute rejection. However, different histological and clinical features were revealed in conjunction with DR compatibility. Patients without DR compatibility showed a type of rejection with fever and increase of bilirubin, frequently associated with cholestasis and cholangitis, which sometimes persisted for weeks. Patients with 1 DR compatibility showed a predominant increase of transaminases, which was never associated with cholangitis. The conjunction of different DR compatibilities and various clinical signs may indicate possible pathways from immunological assault to the clinical appearance of acute rejection. A knowledge of a patient's individual compatibility and an expectation of certain rejection patterns may lead to earlier and more reliable diagnosis and treatment.

Adult↗
PubMedDate not supplied

Role of liver transplantation in management of esophageal variceal hemorrhage.

The management of esophageal variceal hemorrhage ranges from conservative to surgical modalities. Before introduction of liver transplantation as a potentially curative therapy of the underlying etiology, decompressive portosystemic shunt operations have been the mainstay of mostly palliative procedures. Our own experience with surgery for advanced hepatic disease and portal hypertension over 20 years includes 803 liver transplantations and 201 portosystemic shunts, emphasizing our primary objective of treatment. The results after shunt surgery were favorable in Child class A candidates when performed electively and with selective decompression. After liver replacement the clinical status of the patient, including hepatic function and extrahepatic complications, had a strong influence on postoperative outcome, with the chance of excellent long-term survival. The additional risk of previous shunt surgery for subsequent transplantation could be reduced over time. Based on this experience and reports from others there are enough reasonable arguments for shunt and transplantation. Instead of the choice being controversial, the two forms of therapy should supplement each other and be available in the same center that specializes in the treatment of patients with diseases that eventually lead to liver failure and portal hypertension. Selection of either approach must depend on etiology, stage of the disease, and proper timing. Shunt procedures may be indicated in stable patients with the risk of bleeding after sclerotherapy failure, in those with contraindications to transplantation, or as a bridge to transplantation. The role of liver transplantation has been clearly established in patients with progressive or endstage (otherwise intractable) hepatobiliary disease.

Adolescent↗
PubMedDate not supplied

Role of liver transplantation in the treatment of unresectable liver cancer.

Resection remains the treatment of choice in liver cancer. In order to avoid liver transplantation in conventionally unresectable tumors ex-situ ("bench" procedure), in-situ and ante-situm resection technique should be preferred whenever feasible. Despite the deficiency of donor organs, a single center experience with 198 patients reveals that liver transplantation continues its role as a therapeutic option for selected patients. At present "favorable" indications for transplantation are International Union against Cancer (UICC) - stage II hepatocellular carcinoma as well as the subtype fibrolamellar carcinoma, uncommon tumors such as epitheloid hemangioendothelioma, hepatoblastoma, and liver metastases from neuroendocrine tumors. Due to unsatisfying results, intrahepatic bile duct-, stage III and IV hepatocellular carcinoma, hemangiosarcoma, and liver metastases from nonendocrine primaries should be excluded from liver transplantation alone. For these advanced tumors, especially in cases of extrahepatic involvement, a combination of liver transplantation and multivisceral resection has been proven feasible. However, a significant improvement in patient survival may only be expected only by currently investigated multimodality treatment protocols which will require further randomized studies.

Bile Duct Neoplasms↗
PubMedDate not supplied

Surgical treatment of cholangiocellular carcinoma.

Intrahepatic cholangiocellular carcinoma (CCC) is known to be associated with severe symptoms and a particularly poor prognosis. Nonsurgical methods have failed to change this situation up to now. Surgical therapy, so far, is the only chance for effective treatment, but it has had limited success. The relative infrequency of this tumor does not allow extensive statistics and limits our present knowledge. In this contribution the outcome of 50 patients who underwent liver resection or liver transplantation in our institution is reported. Their courses have been reevaluated according to pathohistologic classification and TNM tumor staging. The median survival rates were 12.8 months in the group of patients after liver resection (n = 32) and 5.0 months after liver transplantation (n = 18). Liver transplantation, however, was performed only in patients with unresectable tumors. The longest survival after transplantation was 25 months; after resection four patients survived more than 5 years. In the resection group and the transplantation group survival rates correlated with tumor size and tumor stages according to TNM, although the differences were not statistically significant. Liver resection thus has its place in resectable situations. Liver transplantation for unresectable lesions of this tumor type--always deemed critically in the past--seems not to be indicated with our present stage of knowledge, unless adjuvant protocols appear promising and are tested.

Bile Duct Neoplasms↗
PubMedDate not supplied

Score-aided decision making in patients with severe liver damage after hepatic transplantation.

This article describes how a system of scoring risk factors contributes to deciding whether a patient showing signs of liver failure soon after hepatic transplantation should be treated expectedly or should undergo immediate retransplantation. Of 78 adult patients receiving a first liver graft, 25 had evidence of severe damage of the graft and were further investigated. Nine had failure due to irreversible initial nonfunction, and 2 of the 9 died before a second graft was available. Seven were retransplanted with 3 long-term survivors. The other 16 patients showed reversible severe damage and survived without retransplantation. Since retransplantation for irreversible initial nonfunction is successful only in the first postoperative days, there is an urgent need to identify the degree of the observed damage. We devised a scoring system which identified and weighted factors that were predictable in determining irreversibility. Measurements of highest relevance are transaminases, bile volume, the slope of the enzyme GLDH, and the amount of fresh blood and fresh-frozen plasma required for support on the day of operation and the following day. Logistic regressional analysis produced a numerical score which was applied to a decision tree and produced probabilities and utilities to indicate whether reoperation is advisable. We use this scoring system and believe it assists our decisions in the early posttransplant period.

Abstracting and Indexing↗
PubMedDate not supplied

Surgical treatment of hepatocellular carcinoma: experience with liver resection and transplantation in 198 patients.

Surgical therapy offers the only chance for long-term cure of patients with hepatocellular carcinoma. The role of partial and total hepatectomy with subsequent liver replacement was analyzed in a consecutive series of 198 patients. It was the aim of this study to compare both treatment modalities on the basis of various clinicopathological prognostic factors including the TNM system of pathological classification. One hundred thirty-one resections and 61 transplantations were performed for the following histological diagnoses: hepatocellular carcinoma without coexisting liver disease (86) or associated with various hepatic abnormalities (79), fibrolamellar carcinoma (19), and mixed hepatocholangiocellular carcinoma (8). Overall actuarial survival rates at 5 years were 35.8% following resection and 15.2% after transplantation, respectively. For partial hepatectomy, factors significantly associated with improved long-term outcome were: age 30-50 years, hepatocellular carcinoma without coexisting liver disease, fibrolamellar carcinoma, solitary tumor, unilobar location, absence of vascular invasion, portal vein thrombosis or extrahepatic spread, primary tumor categories pT 2/3, stage groups II/III, and curative operation (R0). Regarding total hepatectomy, the corresponding figures were: pT2, absence of portal vein thrombosis or extrahepatic spread (negative regional lymph nodes, no distant metastases), stage group II, and curative surgery. It could be clearly shown by uni- and multivariate analyses that the pTNM classification is of clinical value regarding the assessment of prognostic significance after resection and transplantation. A group of 13 patients had secondary resection (8) or transplantation (6) for intrahepatic tumor recurrence. Whereas in all resected patients cancer recurred again, 5 of 6 transplant recipients are alive and disease-free at 12-40 months. The results of this study demonstrate that liver resection is the treatment of choice for primary liver cancer while transplantation may be indicated, especially in cases of nonresectable or recurrent lesions. Thus, the therapeutic spectrum for hepatocellular carcinoma should include both partial and total hepatectomy, being integrated into one common concept.

Adult↗
PubMedDate not supplied

Benign liver tumors: differential diagnosis and indications for surgery.

The differential diagnosis for hemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma may be difficult. Reliable diagnosis is mandatory for the decision of whether to apply surgery or observation. Experience with long-term observation in nonoperated patients with hemangioma and FNH is limited. A group of 437 patients from a single institution were analyzed with regard to a diagnostic algorithm, the indications for surgery, and observation. There were 238 hemangiomas, 150 cases of FNH, 44 adenomas, and 5 mixed tumors. Of the 437 patients, 173 underwent surgery; 103 with hemangioma and 54 with FNH were observed at our own institution, whereas 117 patients underwent follow-up elsewhere or were lost. Among the operated patients with confirmed histology, a good diagnostic yield was found for a combination of ultrasonography (US), contrast (bolus)-enhanced computed tomography (CT), and labeled red blood cell (RBC) scanning: sensitivity 85.7%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value (NPV) 81.8%, and accuracy 91.3%. For FNH and combination of US and CT plus cholescintigraphy showed a sensitivity 82.1%, specificity 97.1%, PPV 95.8%, NPV 84.6%, and accuracy 90.3%. Surgical mortality was 0.6%. Observation of patients with hemangioma and FNH for a median of 32 months revealed no increase in tumor size in 80% and a decrease in fewer than 7%. There was no tumor rupture and no evidence of malignant transformation. We concluded that liver hemangioma and FNH can be differentiated from adenoma with high sensitivity, specificity, and accuracy by labeled RBC scanning and cholescintigraphy in combination with US and contrast-enhanced CT. In the case of symptoms or an equivocal diagnosis with respect to adenoma or hepatocellular carcinoma, surgery can be performed with very low risk. Because in asymptomatic patients with observed hemangioma or FNH no increase of tumor size can be expected for many years, the indications for surgery must be carefully evaluated.

Adenoma, Liver Cell↗