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Biomedical subjects

J Weitz

Publications and source records attributed to J Weitz.

At least 19 recordsLinked to original sources
PubMed2003

Accuracy of diagnostic laparoscopy for early diagnosis of abdominal complications after cardiac surgery.

BACKGROUND: In the early postoperative period after major cardiac surgery using extracorporal circulation, abdominal complications can have serious consequences with a mortality rate of up to 70%. Early diagnosis and the timely institution of therapy are the most important factors to improve the outcome; however, clinical evaluation of the abdomen is difficult in these patients. Diagnostic laparoscopy is a minimally invasive procedure with low procedure-associated morbidity, even in critically ill patients. The aims of our study were to investigate the safety of laparoscopy in critically ill patients suspected to have intraabdominal pathology following cardiac surgery and to evaluate the accuracy of diagnostic laparoscopy compared to laparotomy in this setting. METHODS: A total of 17 patients were included (13 male, four female, age 52-80 years) in the early (3-30 days) postoperative period after cardiac surgery using extracorporal circulation (10 ACVB, four valve replacement, one aorto-coronary-venous-bypass (ACVB)+ valve replacement, two cardiac transplantation). Clinical and laboratory findings included distended abdomen (17 of 17), elevated white blood cells (12 of 17), elevated C-reactive protein (CRP) (13 of 17), and elevated lactate levels (11 of 17). The decision to perform laparotomy was taken in all patients on the basis of their clinical condition. Diagnostic laparoscopy was always performed immediately before laparotomy. The laparoscopic findings were then compared to the laparotomy findings. RESULTS: In one patient, laparoscopy showed no abnormal findings, this was confirmed on laparotomy. Five patients were found to have massive distension of the large bowel without ischemia on both laparoscopy and laparotomy. Colonic ischemia of the right hemicolon was found laparoscopically in six patients, which was confirmed in all cases by open resection and histological workup. Three patients suffered from acute cholecystitis, which was correctly diagnosed by laparoscopy in all cases. In one patient, laparoscopy revealed fibrinous peritonitis without other findings. Open exploration failed to identify the cause of the peritonitis in this patient. Laparoscopy showed no pathological findings in one patient, but laparotomy then revealed necrotizing pancreatitis confined to the lesser sac. There was one laparoscopy-associated intraoperative complication (6%) in this series. CONCLUSIONS: Diagnostic laparoscopy is a minimally invasive procedure that can be performed at low intraoperative risk in critically ill patients and has a high sensitivity (94%) for the correct diagnosis of intraabdominal complications after major cardiac surgery. These results suggest that bedside laparoscopy should be considered for all patients with equivocal abdominal symptoms in this setting.

Aged↗
PubMed2003

Laparoscopically assisted colectomy and ileoanal pouch procedure with and without protective ileostomy.

BACKGROUND: Apart from an obviously better cosmetic situation, there is controversy on the actual benefit of laparoscopic and laparoscopically assisted techniques in restorative proctocolectomy. The need for a protective ileostomy remains unclear. METHODS: Fifty-nine consecutive patients with ulcerative colitis and familial polyposis were included in this prospective cohort study. The colon was mobilized laparoscopically with a four-trocar technique, facilitating vascular dissection, rectal resection, and ileoanal pouch construction to be done through a Pfannenstiel incision. A protective ileostomy was constructed only in patients where the operation was difficult or where the anastomosis was under tension. Intra- and postoperative data were recorded; statistical analyses were performed by exact logistic regression. RESULTS: Laparoscopic mobilisation was successful in 54 patients (91.2%). Two patients had to be primarily converted because of exceeding the set time limit; 3 other patients had to have an additional median laparotomy. These 5 patients all had an increased body mass index (BMI), which was a statistically significant risk factor for failure of the laparoscopic technique. 18.6% of patients developed major complications (n = 11). Nine patients required secondary ileostomies; all of them either were under high dose immunosuppressants (n = 5) or had an increased BMI (average 28.42 kg/m2). Failure of the laparoscopic technique was associated with major complications. CONCLUSION: Laparoscopically assisted restorative proctocolectomy is technically feasible; an increased BMI is a relevant risk factor for failure. The minimally invasive approach probably does not reduce the need for a protective ileostomy in selected patients. The selection criteria for the addition or omission of a protective ileostomy in minimally invasive restorative proctocolectomy remain to be clearly defined.

Adenomatous Polyposis Coli↗
PubMed2003

[Sporadic and hereditary colorectal cancer. Pathogenetically different with different therapeutic indications].

In recent years, there have been major advances regarding the understanding of the pathogenesis of sporadic and hereditary colorectal cancer on the basis of molecular research. The clinical implications of this knowledge differ for the sporadic and hereditary forms. In sporadic colorectal cancer, gene mutations occur in colorectal cells but not as germline mutations. Even though molecular data currently do not influence the clinical management of this form of colorectal cancer, promising molecular approaches exist for the assessment of prognosis, early detection, prevention, and therapy. Germline mutations are the cause of hereditary colorectal cancers, in which molecular methods have a major impact on diagnosis and therapy. Prophylactic surgery is accepted for patients with familial adenomatous polyposis (FAP), but not for patients with hereditary non-polyposis colorectal cancer (HNPCC), the second main form of hereditary colorectal cancer. Further studies will have to clarity this issue.

Adenomatous Polyposis Coli↗
PubMed2001

Comparative analysis of tumor cell dissemination in mesenteric, central, and peripheral venous blood in patients with colorectal cancer.

BACKGROUND: Metastatic disease in colorectal cancer results from hematogenic dissemination of tumor cells. This dissemination can be explained by 2 concepts: (1) regional spread of tumor cells via portal venous drainage into the liver as the first site of metastasis and (2) early spread of tumor cells into central and peripheral venous blood as evidence of systemic hematogenic tumor cell dissemination. HYPOTHESIS: Tumor cell detection in different blood compartments could help to understand the predominant pattern of hematogenic tumor cell dissemination in colorectal cancer. DESIGN: Prospective consecutive series. SETTING: University hospital. PATIENTS AND METHODS: Mesenteric, central, and peripheral venous blood samples from 40 patients with colorectal cancer were examined by cytokeratin 20 reverse transcriptase polymerase chain reaction. MAIN OUTCOME MEASURES: Sensitivity and specificity of cytokeratin 20 reverse transcriptase polymerase chain reaction, and frequency of tumor cell detection in different blood compartments. RESULTS: Tumor cells were found in mesenteric venous blood of 20 of 40 patients, central venous blood of 6 of 40 patients, and peripheral venous blood of 2 of 19 patients. The detection rate in mesenteric venous blood was significantly higher than that in central and peripheral venous blood (P<.001). CONCLUSIONS: The significantly higher detection rate in mesenteric venous blood emphasizes the importance of the filter function of the liver for circulating tumor cells in portal venous blood. Tumor cell detection in central and peripheral venous blood, however, shows that this filtering process is limited and indicates early systemic hematogenic tumor cell dissemination in colorectal cancer.

Biomarkers, Tumor↗
PubMed2001

Association of decreased perfusion of the ileoanal pouch mucosa with early postoperative pouchitis and local septic complications.

BACKGROUND: After ileoanal pouch operation, 5% to 40% of patients with ulcerative colitis and 2% to 8% of patients with familial adenomatous polyposis develop pouchitis. Seven percent to 32% of all patients have local septic complications. Pouch ischemia is discussed as a pathophysiologic factor. Tonometry is a minimally invasive method for estimating intramucosal pH (pHi), with a decreased pHi showing intramucosal acidosis characteristic of hypoperfusion. HYPOTHESIS: Decreased perfusion of the iloanal pouch measured by pHi is associated with local septic complications and the development of pouchitis. DESIGN: Prospective cohort study. SETTING: Surgical department of a university hospital. PATIENTS AND METHODS: The pHi in the ileoanal pouch of 98 patients was measured directly after the pouch procedure and correlated to the clinical course. Endoscopic examination of the pouch with biopsy and blinded histologic assessment, including calculation of a histologic pouchitis score, were routinely performed 3 months postoperatively. MAIN OUTCOME MEASURES: Development of pouchitis and local septic complications in correlation to pHi. RESULTS: A decreased pHi was statistically significantly associated with the development of pouchitis and the rate of local septic complications. All 3 patients with anastomotic stenosis had a pHi less than 7.00. The diagnosis of ulcerative colitis just failed in statistical significance as a risk factor for pouchitis. An increased body mass index just failed as a statistically significant risk factor for complications but was a risk factor for the development of acute pouchitis. CONCLUSION: Pouch hypoperfusion is a risk factor for the development of pouchitis and local septic complications.

Adenomatous Polyposis Coli↗
PubMed2001

Surgical strategies and minimal residual disease detection.

The ultimate goal in the treatment of cancer patients is the elimination of all tumor cells. A cure by surgery alone is possible only if the tumor is still confined locally. Detection of disseminated tumor cells may help to individually tailor the surgical procedure to each patient: extended or limited resections may be indicated depending on the individual state of tumor cell dissemination. In cases of systemic tumor cell dissemination, surgery alone cannot cure the patient. Thus, by detecting disseminated tumor cells, patients with a higher risk for relapse, who might benefit from multimodal therapeutic regimes, could be defined. A second aspect is the possibility of tumor cell shedding induced by manipulation during surgical procedures, which could be demonstrated for several tumor entities. Intraoperative tumor cell dissemination could be prevented by alternative operative strategies. In addition, perioperative antibody or cytotoxic therapy may prevent tumor cell implantation. Well-designed clinical studies are now of major importance to evaluate the clinical impact of individualized patient management and altered surgical procedures.

Colorectal Neoplasms↗
PubMed2001

Molecular tools in the detection of micrometastatic cancer cells--technical aspects and clinical relevance.

The frequent failure to reduce the mortality due to epithelial cancers by common medical intervention results primarily from early dissemination of cancer cells, which is missed by conventional diagnostic procedures used for tumor staging. Individual carcinoma cells present in regional lymph nodes, blood or distant organs (e.g., bone marrow) can be detected by sensitive immunologic or molecular methods. Here, we review recently developed molecular assays for the detection of individual micrometastatic cancer cells and their clinical application in patients with epithelial tumors.

Biomarkers, Tumor↗
PubMed2001

[Tumor related prognostic factors--established and hypothetical aspects].

The prognostic assessment of cancer patients is of special importance clinically and scientifically. Prognostic factors are divided into three groups: patient-, treatment- and tumor-related factors. Only a minority of those factors, for example the UICC TNM classification, have been proven by multivariate studies to be of prognostic significance and have an impact on patient management, even then only as prognostic groups. The individual prognosis of a specific patient, which would allow an individualized therapy, cannot yet be adequately assessed. New prognostic factors may result in improved prognostic predictions; currently it is unclear whether this will be accomplished by molecular prognostic parameters assessed on the basis of the primary tumor or rather by the detection of disseminated cancer cells. Of major importance are well-designed clinical studies, in order to prove the clinical benefit of an individualized patient management.

Biomarkers, Tumor↗
PubMed2001

[Progress in oncological visceral surgery: colon carcinoma].

The main progress in surgical oncology regarding colonic cancer has been made by standardizing the mode of resection: En block resection of the tumor-bearing colon segment together with the draining lymph nodes, including the lymph nodes at the origin of the respective main vessel, is mandatory. Minimal invasive surgery is an option for resection, however, results of ongoing multicenter trials have to clarify the situation. Adjuvant therapy is used for patients in stage III, who are not included in studies. Since quality of surgery has a major influence on prognosis, this factor also needs to be taken into account when judging the impact of adjuvant therapy. New chemotherapeutic agents have been proven to be valid for palliative and probably also for adjuvant treatment. Prophylactic surgery is routine for patients with ulcerative colitis and FAP, the benefit for patients with HNPCC has to be further evaluated. New knowledge on the individual prognosis might optimize treatment; most probably this will be accomplished by detection of minimal residual disease. The impact of the sentinel node concept in colon cancer is unclear. New progress will be possible by an approach adapted to the individual problem together with accumulating and linking experience and knowledge.

Chemotherapy, Adjuvant↗
PubMed2000

Detection of isolated disseminated tumor cells in bone marrow and blood samples of patients with hepatocellular carcinoma.

BACKGROUND: Patients with hepatocellular carcinoma (HCC) often develop recurrences after curative resection or liver transplantation. Therefore, tumor cell dissemination must have occurred preoperatively or intraoperatively. Current staging methods cannot reliably detect micrometastasis. Reverse transcription-polymerase chain reaction (RT-PCR) for alpha-fetoprotein (AFP) has been used to detect circulating liver cancer cells, but results in blood samples have been contradictory. HYPOTHESIS: AFP-RT-PCR is a specific and sensitive assay for the detection of disseminated tumor cells in central venous blood and bone marrow samples of patients with HCC and has prognostic relevance. DESIGN: Prospective consecutive series. SETTING: University hospital. PATIENTS AND METHODS: We performed preoperative, intraoperative, and postoperative analyses of central venous blood samples and preoperative analysis of bone marrow samples of patients with HCC and patients without malignant disease, using a modified AFP-RT-PCR method. Preoperative serum AFP levels were measured. Clinical follow-up ranged from 4 to 20 months. MAIN OUTCOME MEASURES: Sensitivity and specificity of AFP-RT-PCR, correlation of AFP-RT-PCR results to tumor stage and tumor recurrence. RESULTS: In serial dilution experiments, 50 AFP-expressing HepG2 cells were detected in 10 mL of blood. Peripheral blood samples of 20 healthy volunteers and bone marrow samples of 21 patients with benign diseases consistently tested negative for AFP, whereas 4 of 24 patients with HCC showed AFP expression in bone marrow samples. All these patients had advanced disease; however, correlation of positive RT-PCR results to tumor stage was not significant (P = .07). One of the 4 AFP-positive patients developed an intrahepatic recurrence soon after liver transplantation. Central venous blood of patients with HCC (n = 24) and patients with benign liver diseases (n = 13) equally demonstrated AFP-expressing cells. There was no correlation of RT-PCR results to serum AFP levels. CONCLUSIONS: Perioperative screening for micrometastasis in bone marrow of patients with HCC is sensitive and specific with AFP-RT-PCR and may have prognostic relevance. Alpha-fetoprotein is not a suitable marker for the detection of tumor cells in central venous blood samples.

Bone Marrow↗
PubMed2000

[Detection of isolated disseminated tumor cells of colorectal carcinomas in lymph nodes].

The 5-year survival of patients with colorectal cancer UICC stage I and II ranges from 70% to 80%. Therefore, at least 20% to 30% of these patients develop recurrent disease, caused by hematogenic or lymphogenic tumor cell dissemination. Using immunohistochemical or molecular biological methods, disseminated tumor cells can be detected in lymph nodes in a high proportion of patients in UICC stage I or II. The detection of disseminated tumor cells could help to identify a subgroup of patients at risk for disease relapse who could benefit from adjuvant therapy. Lymphogenic tumor cell dissemination seems to be a very common event in early colorectal cancer, preceding hematogenic tumor cell dissemination. Although these observations appear to confirm the therapeutic importance of meticulous lymph node dissection, their prognostic relevance has yet to be determined in prospective studies.

Colorectal Neoplasms↗
PubMed2000

Expression of cytokeratin 20 in thyroid carcinomas and peripheral blood detected by reverse transcription polymerase chain reaction.

We investigated a nested reverse transcriptase polymerase chain reaction (RT-PCR) system to detect CK20 mRNA in thyroid carcinomas, benign thyroid diseases and peripheral blood to improve diagnosis of thyroid carcinoma and to detect disseminated tumour cells. Frozen tissue samples of 46 thyroid carcinomas and 30 benign thyroid diseases (14 multinodular goiters, 14 follicular adenomas, two Hashimoto's thyroiditis) were obtained intraoperatively. Preoperative blood samples were drawn from 31 patients with thyroid cancer, nine patients with benign thyroid disorders and 20 healthy volunteers. Nine out of nine medullary, 9/12 follicular, 7/19 papillary and 2/6 anaplastic carcinomas expressed CK20 transcripts. CK20 mRNA was undetectable in 30 tissue sections of benign thyroid diseases. Circulating tumour cells were found in the blood of 3/8 patients with medullary carcinoma, 2/8 patients with follicular carcinoma, 2/11 patients with papillary carcinoma and 1/4 patients with an anaplastic carcinoma. Nine blood samples of patients with benign thyroid diseases and 20 healthy volunteers tested negative. For the first time CK20 mRNA could be detected in tissue sections of thyroid carcinomas and peripheral blood samples of patients with thyroid cancer. It was not detectable in benign thyroid diseases. Our results therefore strongly suggest that CK20 RT-PCR assays may improve the diagnosis of thyroid carcinoma and is able to detect circulating tumour cells in peripheral blood of thyroid carcinoma patients.

Adenocarcinoma, Follicular↗
PubMed2000

Detection of hematogenic tumor cell dissemination in patients undergoing resection of liver metastases of colorectal cancer.

OBJECTIVE: To determine the extent of pre- and intraoperative hematogenic tumor cell dissemination in patients undergoing liver resection for metastatic colorectal cancer. SUMMARY BACKGROUND DATA: For patients with hepatic metastases of colorectal cancer, liver resection is the only potentially curative therapy. However, 38% to 53% of patients develop extrahepatic tumor recurrence, probably caused by tumor cells disseminated before or during surgery not detected by current staging systems. METHODS: Blood samples harvested before, during, and after surgery from 41 patients and bone marrow samples from 30 patients undergoing resection of liver metastases of colorectal cancer were analyzed for disseminated tumor cells using cytokeratin 20 reverse transcriptase-polymerase chain reaction. RESULTS: Tumor cells were detected in the blood samples of 26 of the 41 patients (63.4%) and in the bone marrow samples of 8 of the 30 patients (26.7%). Tumor cells were detected significantly more often during surgery than before or after surgery. Intraoperative tumor cell dissemination was detected in 41.7% of patients undergoing resection of two or more liver segments but only 14.3% of patients undergoing resection of one liver segment. Compared with resection of primary colorectal cancer, major liver resection carries an increased risk for intraoperative tumor cell dissemination. CONCLUSIONS: Detection of disseminated tumor cells in patients undergoing liver resection for metastases of colorectal cancer using cytokeratin 20 reverse transcriptase-polymerase chain reaction might help to identify patients at high risk for tumor recurrence who may benefit from adjuvant therapy. Major liver resection of metastases leads to frequent intraoperative tumor cell shedding, possibly preventable by alternative surgical strategies.

Adult↗
PubMed2000

Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer.

We have previously demonstrated that a clinical model can be safely used in a management strategy in patients with suspected pulmonary embolism (PE). We sought to simplify the clinical model and determine a scoring system, that when combined with D-dimer results, would safely exclude PE without the need for other tests, in a large proportion of patients. We used a randomly selected sample of 80% of the patients that participated in a prospective cohort study of patients with suspected PE to perform a logistic regression analysis on 40 clinical variables to create a simple clinical prediction rule. Cut points on the new rule were determined to create two scoring systems. In the first scoring system patients were classified as having low, moderate and high probability of PE with the proportions being similar to those determined in our original study. The second system was designed to create two categories, PE likely and unlikely. The goal in the latter was that PE unlikely patients with a negative D-dimer result would have PE in less than 2% of cases. The proportion of patients with PE in each category was determined overall and according to a positive or negative SimpliRED D-dimer result. After these determinations we applied the models to the remaining 20% of patients as a validation of the results. The following seven variables and assigned scores (in brackets) were included in the clinical prediction rule: Clinical symptoms of DVT (3.0), no alternative diagnosis (3.0), heart rate >100 (1.5), immobilization or surgery in the previous four weeks (1.5), previous DVT/PE (1.5), hemoptysis (1.0) and malignancy (1.0). Patients were considered low probability if the score was <2.0, moderate of the score was 2.0 to 6.0 and high if the score was over 6.0. Pulmonary embolism unlikely was assigned to patients with scores < or =4.0 and PE likely if the score was >4.0. 7.8% of patients with scores of less than or equal to 4 had PE but if the D-dimer was negative in these patients the rate of PE was only 2.2% (95% CI = 1.0% to 4.0%) in the derivation set and 1.7% in the validation set. Importantly this combination occurred in 46% of our study patients. A score of <2.0 and a negative D-dimer results in a PE rate of 1.5% (95% CI = 0.4% to 3.7%) in the derivation set and 2.7% (95% CI = 0.3% to 9.0%) in the validation set and only occurred in 29% of patients. The combination of a score < or =4.0 by our simple clinical prediction rule and a negative SimpliRED D-Dimer result may safely exclude PE in a large proportion of patients with suspected PE.

Algorithms↗
PubMed2000

Detection of hematogenous micrometastasis in patients with transitional cell carcinoma.

PURPOSE: Cytokeratin 20 (CK 20) is selectively expressed in urothelium, gastric intestinal epithelium, in Merkel cells and in a variety of malignant neoplasms. CK 20 RT-PCR assay has been extensively used to detect isolated cancer cells in peripheral blood, lymph nodes and bone marrow samples of patients with colorectal carcinoma. Since CK-20 is also actively expressed in transitional cell carcinoma (TCC), we analyzed, whether CK 20 Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is suitable to detect residual tumor cells in patients with transitional cell carcinoma of the bladder and the upper urinary tract. MATERIALS AND METHODS: Nested Reverse Transcriptase Polymerase Chain Reaction assay was used to analyze CK 20 transcripts in peripheral venous blood samples and tumor biopsies of 49 patients with transitional cell carcinoma. Blood samples of 22 healthy volunteers served as negative controls. RESULTS: CK 20 mRNA was detectable in blood samples of 12 of 49 patients with TCC. All blood samples of the control group tested negative. The detection rate for CK 20 mRNA significantly correlated (p = 0.0019, Cochran-Armitage Trend Test) to the stage of disease and increased from 0% in stage pTa to 63% in stage pT4. CONCLUSIONS: These results suggest that CK 20 is a suitable marker for the detection of disseminated TCC cells in peripheral venous blood samples and may be helpful in the molecular staging of TCC patients. The prognostic relevance has to be evaluated in further followup.

Aged↗
PubMed2000

[Diagnosis and significance of minimal residual disease in patients with colorectal carcinoma].

Progression of malignant tumours to metastatic disease after surgery in curative intent is due to usually few and with conventional diagnostic techniques undetectable residual malignant cells. These cells must have been spread either before or during surgery. The more sensitive and specific detection of these malignant cells in various clinically relevant compartments of the patients organism became possible through new immunocytochemical and molecular tools. Various clinical studies underline the strong prognostic impact of the detection of disseminated cancer cells. However, many technical aspects did not yet allow sufficient standardization of these procedures and led to significantly varying results among different scientific groups. It is one of our primary aims to test, whether the detection of disseminated cancer cells might guide the indication for adjuvant therapies and might predict the efficacy of therapies in patients with solid cancers.

Blood↗