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Biomedical subjects

R Mertens

Publications and source records attributed to R Mertens.

At least 19 recordsLinked to original sources

Practice variability in the management of subrenal arterial stenoses in seven Belgian hospitals.

This multicentre retrospective study describes the variation of therapeutic options, treatment outcomes and costs for treating subrenal arterial stenoses as observed in daily practice in 1997-99 in seven Belgian hospitals. Data were obtained from clinical record review and from the sickness fund claims database, and included preoperative functional state, presence of acute ischaemia, diabetes and polyvascular disease, state of the lower-leg run-off arteries, anatomical site and type of lesion, type of treatment, result at 30 days and up to 4 years. A total of 442 episodes were studied, but most analyses dealt with a subgroup of 240 lesions in the common iliac up to the superficial femoral artery. The proportion of surgical treatments (as compared to an endovascular or mixed approach) varied from 15% to 81% between the hospitals. In univariate patency analysis, relapse or failure rates at 4 years ranged from 5% for the common iliac artery to 35% for the superficial femoral artery. Polyvascular disease, a poor run-off, multiple stenoses and chronic occlusion were significant risk factors; age and diabetes were not. In the multivariate (stratified Cox regression) analysis, only a location in the superficial femoral artery and a poor preoperative clinical stage were significant risk factors, but type of therapeutic approach was not. The total average cost of treatment was 5,300 Euros, of which 15% was contributed by the patient. Surgery was associated with longer stays (median at 12 days) than endovascular treatments (median 2 days), and was 1.9 times more expensive. In conclusion, the results of the present study suggest that a multidisciplinary approach, orienting the patient to the most appropriate therapeutic pathway, could increase both the quality and the cost-effectiveness of the care.

Adult↗

Evaluation of Charlson's comorbidity index in elderly living in nursing homes.

The object of this article was to validate the predictive value of Charlson's comorbidity index for the prediction of short-term mortality or morbidity in elderly people. The design was a cohort study comparing survival and hospitalization in institutionalized elderly people with different levels of comorbidity at baseline. The setting was 16 Flemish nursing homes for the elderly. The subjects were 2,727 inhabitants of which full data were available for 2,624. The outcome measures were hazard ratios resulting from Cox regression analysis, comparing 6 months survival in patients with moderate and a high level to low level of comorbidity. Odds ratios resulting from multiple logistic regression analysis comparing the occurrence of at least one hospitalization during the follow-up period in surviving patients of the same groups. Mortality adjusted for age group was significantly increased in patients with a moderate (HR = 2.00) and even more in those with a high level (HR = 3.62) of comorbidity. Hospitalization was more frequent in both groups (OR = 1.54 and 2.19, respectively), with statistical significance only being reached for the highest group. Adjustment for age, gender, mobility status, and disorientation did not change the general picture. Charlson's comorbidity index is a predictor of short-term mortality in institutionalized elderly patients and, to a lesser extend, also of hospitalization. These results support its use as a measure for introducing comorbidity as a covariable in longitudinal studies with a geriatric population.

Aged↗

Factors increasing the mortality rate for patients with ruptured abdominal aortic aneurysms.

The objective of this report was to analyze the current surgical results of operative treatment in patients suffering ruptured AAA (abdominal aortic aneurysms) and to define those independent predictive factors for mortality. During a period of 2 years, from January 1996 to December 1997, 144 patients operated on for ruptured AAA in 10 hospitals were included in a multicenter retrospective study. Among the collected variables concerning each patient, those with potential relation to surgical mortality were studied: gender, age, diabetes, hypertension, cardiopathy, pulmonary obstructive disease, preoperative renal dysfunction, symptomatic cerebrovascular disease, peripheral vascular disease, hematocrit on admission, preoperative hypotension < 80 mmHg, loss of consciousness, cardiac arrest, aortic aneurysm location (infrarenal versus non-infrarenal), iliac involvement, aneurysm size, type of rupture, left renal vein ligature, ligature of a patent inferior mesenteric artery, place of aortic cross-clamping, type of grafting, exclusion of both hypogastric arteries, venous technical complications, associated surgery, use of cell saver, intraoperative blood loss, and postoperative complications (renal failure, sepsis, coagulopathy, cardiac complications, pulmonary complications, colon ischemia, prosthetic graft complications, and need for reoperation). Those variables with statistical significance in the univariate analysis were introduced into a multivariate logistic regression model to determine the independent predictors of death. From our results we concluded that surgery for ruptured abdominal aortic aneurysms continues to have an excessively high mortality rate. Even though some preoperative variables could be identified as predictors of mortality, an absolute mortality risk has not yet been determined and the decision to negate surgery should be individualized rather than taken on that basis only. Early diagnosis and treatment of symptomatic aneurysms would improve mortality figures and selective screening should be contemplated.

Age Factors↗

Differential expression of the lung resistance-related protein/major vault protein in the histological compartments of nephroblastomas.

Nephroblastomas (Wilms' tumors) are curable with survival rates above 80%. Some tumors, however, fail to respond to therapy and those patients have a poor prognosis. In a search for molecular markers of drug resistance, we investigated the expression of lung resistance protein (LRP) in tissue samples from 32 children with nephroblastoma by means of immunohistochemistry. LRP is a human major vault protein (MVP) and is associated with multidrug resistance of tumors. LRP/MVP expression was found in the blastemal and epithelial compartments but to a significantly lesser extent in the stromal compartment of Wilms' tumors. Expression was generally heterogeneous with respect to staining intensity and percentage of positive cells. We found significant relationships between LRP/MVP expression and chemotherapeutic pre-treatment of tumors and tumor stage. The immunohistochemical results were validated with a real-time RT-PCR technique and a significant association between protein and mRNA expression was observed.

Antibiotics, Antineoplastic↗

Differential expression of the multidrug resistance-related protein MRP1 in the histological compartments of nephroblastomas.

Nephroblastomas (Wilms' tumors) are curable with survival rates above 80%. Some tumors, however, fail to respond to therapy and those patients have a poor prognosis. In a search for prognostic markers, we investigated the expression of the multidrug resistance-related protein 1 (MRP1) in 32 nephroblastomas by means of immunohistochemistry. The immunohistochemical results were validated with a real-time RT-PCR technique. MRP1 expression was heterogeneous and predominantly found in the blastemal and epithelial compartments compared to the stromal elements of nephroblastomas. We found significant relationships of MRP1 expression to survival of patients and to expression of p53, HSP70, and LRP/MVP. The relationship between MRP1 and p53 expression is a clue that the transcriptional control of MRP1 by p53 reported for other tumor types may also take place in nephroblastomas. The correlation of MRP1 to other drug resistance genes, e.g. HSP70 and LRP/MVP in nephroblastomas indicates that the co-expression of different drug resistance genes may be under a common regulation of still unknown transcription factors.

ATP-Binding Cassette Transporters↗

p53 expression in Wilms' tumor: a possible role as prognostic factor.

Although a correlation between anaplasia and mutations of the p53 tumor suppressor gene has been found in Wilms' tumor (WT) a prognostic significance of p53 in WT remains largely unresolved. The goal of this study was to obtain a better understanding of the role of p53 expression in WT. Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded tumor tissues from 21 patients treated in our clinic between 1984 and 1996. Eight patients presented with stage I, six with stage II, two with stage III, four with stage IV and one patient with stage V disease. According to the presence of anaplasia, four cases were categorized as of unfavorable histology based on the criteria of the National Wilms' Tumor Study Group. Seven out of 21 WTs were positive for p53. One out of the eight patients with stage I and one out of the six patients with stage II disease scored positive for p53 as were 2/2 patients with stage III and 3/4 patients with stage IV disease. Four tumors scored positive for anaplasia (one stage I, one stage II and two stage IV disease) and all four belonged to the p53 positive group. Three of these patients died of progressive disease. Immunopositivity in general was focal in the blastemal and epithelial parts of the tumors, with differences in intensity of staining ranging from moderate to strong. Positivity in the stromal components was restricted to single cells. Statistical analysis revealed significant correlations of p53 expression to anaplasia and to survival, respectively. The association of p53 expression to tumor stage was of borderline significance. To support immunohistochemistry, we performed PCR/SSCP and DNA sequence analyses on two cases, one whose immunopositivity suggested a mutated p53, and another case which was immunonegative. A CGG --> TGG base change in codon 282 of exon 8 was found in the immunopositive tumor. In conclusion, p53 may be of prognostic relevance for poor outcome being present in close association with unfavorable histology of WTs.

Biomarkers, Tumor↗

[Endovascular therapy of superior vena cava syndrome: clinical case].

The treatment of superior vena cava syndrome is usually oriented to the underlying cause, that can be too slow in emergency cases. We report a 49 years old woman with a multiple myeloma that was admitted due to a superior vena cava syndrome caused by a central venous catheter used for chemotherapy for 20 weeks. She was successfully treated with thrombolysis, angioplasty and stent placement. The patient died 7 months later due to the underlying disease. Long term catheters are the responsible for 20 to 30% of superior vena cava syndromes. Endovascular treatment of the syndrome is successful in 60 to 100% of cases with a symptomatic relapse in 4 to 45% of patients.

Angioplasty, Balloon↗

[Ruptured thoracic aorta aneurysm: endovascular treatment].

In 1991, a technique to exclude aortic aneurysms from circulation inserting an endoluminal graft through the femoral artery, was described. This procedure, usually used for elective abdominal aneurysms, can also be used in the thoracic aorta. We report a 41 years old male with a Marfan syndrome, presenting with a descending aorta aneurysm that ruptured to the mediastinum and pleural cavity. He was compensated hemodynamically and an endovascular stent-graft was deployed at the ruptured zone, through the femoral artery. The postoperative evolution of the patient was uneventful. This technique will allow a less invasive treatment of ruptured aortic aneurysms.

Adult↗

Visceral leishmaniasis in a German child who had never entered a known endemic area: case report and review of the literature.

We describe a case of visceral leishmaniasis in a 15-month-old German child. Diagnosis was significantly delayed because the patient had no history of travel to known endemic areas. Congenital or blood transfusion-associated leishmaniasis was ruled out. Possible modes of transmission (including a potential new autochthonous focus of the disease in central Europe) are discussed.

Animals↗

[Carotid endarterectomy under regional anesthesia: initial experience].

BACKGROUND: Endarterectomy is the treatment of choice for internal carotid artery critical stenosis. Some authors have proposed that the use of regional anesthesia has advantages over general anesthesia. AIM: To report our initial experience with carotid endarterectomy under regional anesthesia. PATIENTS AND METHODS: Between 1998 and 1999, patients with critical carotid artery stenosis, asymptomatic or with transient and recovered symptoms, were selected. A C2, C3, C4 root deep cervical block and superficial block was performed, using a mixture of lidocaine and bupivacaine. A carotid endarterectomy with patch and without routine shunt insertion, with standard and neurological monitoring, was performed. RESULTS: During the study period, 94 carotid endarterectomies were done, 22 under regional anesthesia in 21 patients (12 male, age range 58-90 years old). Ninety five percent had hypertension, 52% smoked and 38% had renal dysfunction. One patient was converted to general anesthesia. Seventeen patients were discharged within 48 hours of the procedure and the rest, within 72 hours. There was no mortality or complications. CONCLUSIONS: Endarterectomy under regional anesthesia is less invasive, has excellent results and is well accepted by patients.

Aged↗

Antithrombin treatment of severe hepatic veno-occlusive disease in children with cancer.

UNLABELLED: Hepatic veno-occlusive disease (VOD) is a well-known complication of chemotherapy in Wilms tumor patients, particularly young children. Although this complication resolves uneventfully in most patients, fatal cases have been reported. Severe VOD after transplantation has a high mortality rate ranging from 45% to 98%. New hemostatic therapeutic strategies have significantly improved the prognosis of VOD. Chemotherapy-related VOD in Wilms tumor usually has a good prognosis. We describe two patients with Wilms tumor and one with acute lymphoblastic leukemia, who developed severe veno-occlusive disease of the liver according to the Baltimore criteria while undergoing chemotherapy; the symptoms were hepatomegaly, ascites, hyperbilirubinemia, weight gain and, in one patient, short-term lethargy. Elevated LDH levels of 872 to 12,000 U/l were observed in our patients. All patients had thrombocytopenia between 29,000 and 40,000/microl and decreased antithrombin (AT) and protein C levels; two patients had gastrointestinal bleeding. All patients developed a coagulopathy because of severe hepatic dysfunction. Two patients received low-dose heparin at the onset of VOD. The thrombolytic therapy was rapidly changed to AT supplementation (20-80 IU/kg bw 2x per day) without heparin when thrombocytes were very low or gastrointestinal bleeding occurred. Resolution of VOD was observed in all patients receiving AT alone. The chemotherapy was discontinued in a patient with accidental actinomycin D overdosage in view of the severity of symptoms. The remaining two patients received chemotherapy according to the therapy protocol after restitution. All patients survived without sequelae with a median follow-up of 28 months (range 8-48 months). CONCLUSION: Hepatic veno-occlusive disease is a rare but increasingly recognized complication in pediatric cancer patients receiving conventional chemotherapy. AT supplementation constitutes a good alternative treatment of severe VOD in comparison with other thrombolytic therapies, particularly in patients at high risk of bleeding.

Antineoplastic Agents↗

The clinical outcome after inferior vena cava thrombosis in early infancy.

UNLABELLED: The clinical outcome after inferior vena cava thrombosis in early infancy is unknown. We report the clinical long-term follow-up of 12 patients presenting inferior vena cava thrombosis within their first months of life (gestational age: 24-41 weeks; follow-up: 7+/-3 years). Accompanying renal venous thrombosis occurred in 9, and adrenal bleeding in 4 patients. A central venous catheter was related to the thrombosis in only four patients. Heterozygous factor V Leiden mutation was found in two of the eight infants without central venous catheter. Thrombolysis was performed in seven and effective in three infants; one infant required surgical thrombectomy. In three of eight infants with ineffective or with no therapy, spontaneous recanalization occurred during follow-up. No patient died of the thrombosis. Although no long-term anticoagulatory prophylaxis was performed, none of the children with persisting occlusion (n = 5) or stenosis (n = 1) of the inferior vena cava developed symptomatic thrombo-embolic complications. However, extensive internal collaterals (n = 6), visible varicosis (n = 5), pain in the legs (n = 3) and persisting renal disease (n = 3) with arterial hypertension (n = 2) were observed during follow-up. CONCLUSION: Inferior vena cava thrombosis of early infancy frequently persists and may cause considerable long-term morbidity. New strategies for early and long-term therapy are necessary.

Child↗

Clinical aspects of alveolar rhabdomyosarcoma with translocation t(1;13)(p36;q14) and hypotetraploidy.

Although most cases of alveolar rhabdomyosarcoma (RMS) are characterized by the chromosomal translocation t(2;13)(q35;q14), several cases have been reported with a variant t(1;13)(p36;q14). We present the clinical, morphological and cytogenetic features of an alveolar RMS in a 4-year-old boy. Chromosomal analysis revealed a hypertriploid to hypotetraploid karyotype with a t(1;13)(p36;q14) in all tumor cells. It appears that alveolar RMS with t(1;13) occurs in younger children and displays a higher incidence to upper and lower extremity than tumors with t(2;13).

Aneuploidy↗

Methicillin-resistant Staphylococcus aureus and antimicrobial use in Belgian hospitals.

OBJECTIVE: To investigate relationships between the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and the use of different classes of antimicrobials in Belgian hospitals. DESIGN: Using Pearson correlation coefficients, the number of new nosocomial MRSA-colonized or -infected patients in the second half of 1994 and the first half of 1995 reported by the national MRSA surveillance program was compared with use of various antimicrobial classes as reported by the National Institute for Sickness and Disability Insurance. Relationships between different classes of antimicrobials were evaluated in a correlation matrix. MRSA incidence, antimicrobial use, and potential confounding factors were included in a multiple linear regression analysis. SETTING: 50 hospitals in Belgium. RESULTS: The use of a number of different classes of antimicrobials was interrelated. In the multivariate analysis, the incidence of nosocomial MRSA increased with increasing use of ceftazidime and cefsulodin (P=.0003), amoxicillin with clavulanic acid (P=.02), and quinolones (P=.005). No association was found between MRSA incidence and total antimicrobial use. CONCLUSIONS: The relationships between antimicrobial use and MRSA are complex. Interventions aimed at promoting more rational prescribing patterns should be supported by adequate experimental and epidemiological evidence. Advice for preventing and controlling MRSA has focused mainly on hygienic measures and precautions to avoid cross-transmission; the role of relieving antimicrobial pressure needs to be clarified.

Anti-Bacterial Agents↗

[Popliteal vein aneurysm].

The popliteal vein aneurysm is a rare condition that can lead to local symptoms, thrombosis and pulmonary embolism. We report the case of a 67 years old, otherwise healthy white male, who presented to us with localised swelling and pain in the left popliteal fossa. Duplex ultrasound and venography were obtained, confirming the diagnosis of popliteal vein aneurysm. The patient underwent tangential aneurysmectomy and lateral venorrhaphy, recovery was uneventful remaining asymptomatic. The reconstruction was demonstrated patent on a duplex scan. The popliteal vein aneurysm is a potentially fatal condition for which surgical treatment is recommended.

Aged↗

[Ilio femoral thrombosis: an infrequent complication of an aortic and iliac aneurysm. Report of two cases].

Death due to rupture of and abdominal aortic or iliac aneurysm, is their most frequent complication. We report two male patients, both over seventy years old, who presented with unexplained unilateral ilio-femoral deep vein thrombosis. During diagnostic work up an aortic and iliac aneurysm, compressing the deep venous system with secondary thrombosis, was found. In both patients a prophylactic inferior vena caval filter was inserted and standard elective surgery was then performed. No perioperative complications occurred and both patients remain asymptomatic during follow up. Deep vein thrombosis due to compression by an abdominal aortic and iliac aneurysm is infrequent. It must be ruled out together with intrabdominal cancer, in the elderly patient presenting with unexplained deep vein thrombosis.

Aged↗

Surgical prophylaxis in Belgian hospitals: estimate of costs and potential savings.

Between 1991 and 1995 the Belgian National Program for Surveillance of Hospital Infections (NSIH) collected data on perioperative antibiotic prophylaxis in 72 acute care hospitals. From the costs of prophylactic antibiotics for six categories of surgical procedure and from discharge summaries for hospitalization episodes nationwide, annual drug costs were estimated for 73% of Belgian surgical activity. Costs of antibiotics used in these surgical activities were estimated at 386-410 million Belgian francs (Bf) per year (US$12.1-12.9 million). After agreeing recommendations for best practice, the hypothetical costs of 'optimal' antimicrobial prophylaxis were calculated for the same selection of surgical procedures. It was calculated that savings of at least 194 million Bf (US$6.1 million) could be made if recommendations were followed closely. Only the costs borne by the National Health Insurance Institute for reimbursement of the dispensed drugs were considered in this study. Other direct costs, such as those related to drug storage, dispensing and administration, were not included.

Anti-Bacterial Agents↗