[Safety of patient care on an interprofessional training ward in visceral surgery]

BACKGROUND

Interprofessional training wards (ITW) are increasingly being integrated into teaching and training concepts in visceral surgery clinics.

OBJECTIVE

How safe is patient care on an ITW in visceral surgery?

MATERIAL AND METHODS

Data collection took place from November 2021 to December 2022. In this nonrandomized prospective evaluation study the frequency and severity of adverse events (AE) in 3 groups of 100 patients each in a tertiary referral center hospital for visceral surgery were investigated. The groups consisted of patients on the ITW and on the conventional ward before and after implementation of the ITW. The Global Trigger Tool (GTT) was used to search for AE. Simultaneously, a survey of the treatment was conducted according to the Picker method to measure patient reported outcome.

RESULTS

Baseline characteristics and clinical outcome parameters of the patients in the three groups were comparable. The GTT analysis found 74 nonpreventable and 5 preventable AE in 63 (21%) of the patients and 12 AE occurred before the hospital stay. During the hospital stay 50 AE occurred in the operating theater and 17 on the conventional ward. None of the five preventable AE (in 1.7% of the patients) was caused by the treatment on the ITW. Patients rated the safety on the ITW better than in 90% of the hospitals included in the Picker benchmark cohort and as good as on the normal ward.

CONCLUSION

The GTT-based data as well as from the patients' point of view show that patient care on a carefully implemented ITW in visceral surgery is safe.

Comparison of the horizontal diameter to a modeled area of traction in eyes with vitreomacular traction: is the diameter close enough to the truth?

PURPOSE

In daily practice, vitreomacular traction (VMT) is described by the horizontal diameter of its attachment site implying a regular round shape of VMT. We investigated the deviation from this circular area of vitreous traction in patients with VMT.

METHODS

A retrospective analysis of optical coherence tomography (OCT) scans was performed. The area of vitreomacular attachment was determined using six radial OCT scans (A_measured). The assumed circular area of traction was calculated based on measuring the maximal horizontal diameter for comparison (A_circular).

RESULTS

Thirty-seven eyes of 37 patients with pure VMT were included. Patients' mean age was 72.8 ± 8.2 years. Mean horizontal VMT diameter was 400.8 ± 230.5 μm (median 361 μm; range 44-991 μm). While there was no difference between mean areas of traction for A_circular and A_measured (P = 0.93), the individual difference (|A_circular - A_measured|) was 0.042 (± 0.044) mm² in mean or relative 73.0% (± 135.8%). A difference of ≥ 30% of A_measured to A_circular was found in 16 eyes (43.2%) and ≥ 100% in 7 eyes (18.9%), respectively.

CONCLUSION

Vitreous attachment sites possess an irregular non-circular shape in a significant number of eyes with VMT. Consequently, the area of traction appears inaccurately described by its horizontal VMT diameter alone. As the area of traction is important for therapeutic recommendation, our results emphasize the need for a more precise description of the area of traction in eyes with VMT.

Risk evaluation for needle-nerve contact related to electrical nerve stimulation in a porcine model

BACKGROUND

For performing peripheral nerve blocks, the risk for needle-nerve contact (NNC) as an adverse event for low and high current thresholds has not yet been clearly defined when nerve stimulator guided techniques were applied. This experimental study aimed to investigate the risk of NNCs when applying stimulation currents between 0.1 and 2 mA (in increments of 0.1 mA).

METHODS

Brachial plexus nerves were exposed surgically in five anesthetized pigs. An insulated needle connected to a nerve stimulator was placed at 10 mm distance to the targeted nerves. Current intensity was adjusted according to randomization (0.1-2.0 mA, increments of 0.1 mA). The needle tip was advanced toward the nerve until a motor response was elicited. The frequencies of NNCs for each of the adjusted current intensities were noted. Risks of NNCs were calculated according to the analysis of 95% confidence intervals (95% CI).

RESULTS

We executed 2000 needle placements with stimulation currents ranging from 0.1 to 2.0 mA. The risks for NNC at low current intensities were 0.85 (95% CI, 0.77-0.91) for 0.3 mA and 0.5 (95% CI, 0.4-0.6) for 0.5 mA, respectively. For high current intensities, risks of 0.13 (95% CI, 0.07-0.21) for 0.9 mA and 0.01 (95% CI, 0-0.05) for 1.1 mA were calculated.

CONCLUSIONS

In this experimental animal study, a relevant reduction in the risk of NNCs could be observed when high current intensities (0.9-1.1 mA) were applied compared to low current intensities (0.3-0.5 mA).

Multicenter phase II trial to investigate safety and efficacy of gemcitabine combined with cetuximab as adjuvant therapy in pancreatic cancer (ATIP)

BACKGROUND

To investigate whether addition of cetuximab to standard adjuvant chemotherapy with gemcitabine improves outcome in pancreatic cancer, specifically whether the rate of disease-free survival (DFS) at 18 months (primary end point) exceeds the previously reported 35% of gemcitabine alone.

PATIENTS AND METHODS

Prospective, open-label, multicenter, nonrandomized phase II study in 76 patients with R0- or R1-resected ductal adenocarcinoma of the pancreas included between October 2006 and November 2008. Gemcitabine and cetuximab were administered for 24 weeks. Secondary end points included overall survival (OS) and toxic effect.

RESULTS

Seventy-three patients received cetuximab. Median DFS was 10.0 [95% confidence interval (CI) 8.9-13.6] months and the DFS rate at month 18 of 27.1% (16.7%-37.6%) was inferior to 35%. Median OS was 22.4 (18.2-27.9) months. Subgroup analyses revealed a nonsignificant increase in DFS for patients with versus without skin toxic effect ≥ grade 2 (median 14.7 versus 8.3 months, P = 0.073) and wild-type versus mutated K-Ras (median 11.5 versus 9.3 months, P = 0.57). Grade 3/4 toxic effects included neutropenia (11.0%), thrombopenia (7%), skin toxic effect (7%) and allergic reactions (7%).

CONCLUSION

Addition of cetuximab to adjuvant gemcitabine does not seem to improve DFS or OS of unstratified pancreatic cancer patients. Trends for improved DFS in patients with wild-type K-Ras and skin toxic effect remain to be confirmed.

Impact of propofol on mid-latency auditory-evoked potentials in children

BACKGROUND

Propofol is increasingly used in paediatric anaesthesia, but can be challenging to titrate accurately in this group. Mid-latency auditory-evoked potentials (MLAEPs) can be used to help titrate propofol. However, the effects of propofol on MLAEP in children are unclear. Therefore, we investigated the relationship between propofol and MLAEP in children undergoing anaesthesia.

METHODS

Fourteen healthy children aged 4-16 yr received anaesthesia for elective surgery. Before surgery, propofol was administered in three concentrations (3, 6, 9 µg ml(-1)) through a target-controlled infusion pump using Kataria and colleagues' model. MLAEPs were recorded 5 min after having reached each target propofol concentration at each respective concentration. Additionally, venous propofol blood concentrations were assayed at each measuring time point.

RESULTS

Propofol increased all four MLAEP peak latencies (peaks Na, Pa, Nb, P1) in a dose-dependent manner. In addition, the differences in amplitudes were significantly smaller with increasing propofol target concentrations. The measured propofol plasma concentrations correlated positively with the latencies of the peaks Na, Pa, and Nb.

CONCLUSIONS

Propofol affects MLAEP latencies and amplitudes in children in a dose-dependent manner. MLAEP measurement might therefore be a useful tool for monitoring depth of propofol anaesthesia in children.

Effects of increasing sevoflurane MAC levels on mid-latency auditory evoked potentials in infants, schoolchildren, and the elderly

BACKGROUND

Detection of mid-latency auditory evoked potentials (MLAEPs) is a technology to monitor central nervous structures. As seen in adults and children, general anaesthesia influences the MLAEP latencies. MLAEP detection seems to be a promising tool to assess different levels of anaesthesia depth in adults and children.

METHODS

MLAEPs were recorded in 10 infants (2 months-3 yr), 12 schoolchildren (6-14 yr), and 10 elderly (75-89 yr) under general anaesthesia with increasing concentrations of sevoflurane at steady state. In addition, MLAEPs were detected before and after the application of sufentanil.

RESULTS

At all different ages, MLAEP latencies increased significantly with higher volume percentages of sevoflurane. These results were also detectable when MAC values of sevoflurane were compared with MLAEP peaks. An age-dependent effect could be displayed as elderly people need lower absolute sevoflurane concentrations to achieve the same MLAEP peak increase. Overall, the application of sufentanil under steady-state sevoflurane application at 1 MAC did not importantly affect the MLAEP latencies.

CONCLUSIONS

MLAEP latencies increase at the influence of sevoflurane in a dose-dependent manner and in relation to age. These results imply that MLAEP detection is a reasonable tool for monitoring hypnotic effects at all ages. Further studies are required to standardize MLAEP alterations related to effects of medication used for general anaesthesia at all different ages.

Systematic evaluation of the highest current threshold for regional anaesthesia in a porcine model

BACKGROUND

The purpose of this study was to determine systematically the highest minimal stimulation current threshold for regional anaesthesia in pigs.

METHODS

In an established pig model for regional anaesthesia, needle placements applying electric nerve stimulation were performed. The primary outcome was the frequency of close needle to nerve placements as assessed by resin injects and subsequent anatomical evaluation. Following a statistical model (continual reassessment method), the applied output currents were selected to limit the necessary number of punctures, while providing guidance towards the highest output current range.

RESULTS

Altogether 186 punctures were performed in 11 pigs. Within the range of 0.3-1.4 mA, no distant needle to nerve placement was found. In the range of 1.5-4.1 mA, 43 distant needle to nerve placements occurred. The range of 1.2-1.4 mA was the highest interval that resulted in a close needle to nerve placement rate of > or =95%.

CONCLUSIONS

In the range of 0.3-1.4 mA, all resin deposition was found to be adjacent to nerve epineurium. The application of minimal current intensities up to 1.4 mA does not obviously lead to a reduction of epineural injectate contacts in pigs. These findings suggest that stimulation current thresholds up to 1.4 mA result in equivalent needle tip localisation in pigs.

Meta-analysis of the prognostic significance of perinodal spread in head and neck squamous cell carcinomas (HNSCC) patients

To assess the risk factor of capsular rupture for individual prognosis and potential therapeutic decision making, the present meta-analysis elaborated the prognostic significance of perinodal spread in a large group of patients suffering from head and neck squamous cell carcinomas (HNSCC). A review of the published literature was conducted, and fixed and random effects models were applied for estimation of the summarised odds ratio and 95% confidence intervals, including a test for homogeneity of the odds ratios. Study methodology allowed the enrollment of only nine studies of 115 published papers. Excluded studies lacked regarding primary tumour location, number and location of lymph node metastases, values on five-year survival, or adequate follow-up data. A summarised odds ratio of 2.7 leads to the conclusion that perinodal spread negatively impacts the five-year survival. The lower confidence limit of more than 2 also supports the concept that perinodal spread significantly reduces (doubled risk) the five-year-survival. These results support the conclusion that perinodal spread is a significant adverse risk factor for survival in patients with HNSCC.

Protein single-crystal diffraction with 5 A synchrotron X-rays at the sulfur K-absorption edge

. Sulfur atoms, an integral part of many proteins, are possible candidates for anomalous scattering in phase determination by multiple-wavelength methods. The main difficulty encountered is that a wavelength of about 5 A is required to obtain a large anomalous signal from these atoms, leading to very large absorption effects. Initial experiments have been carried out using a synchrotron X-ray source, evacuated beam tubes, a diffractometer inside a vacuum chamber, a special sample holder and a suitable scattering geometry. The results are encouraging, showing that Bragg reflections can be measured, and that changes in their intensities around the absorption edge are observable.

[What effect does the hydroxyapatite coating have in cementless knee arthroplasty?]

The goal of this study was to compare the migration of noncemented diffusion sintered titanium fibermesh-coated tibial components with (HA group) and without (non-HA group) additional hydroxyapatite coating. For this purpose digital radiostereometry (DIRSA) was used to compare the migration after 2 and 9 years for the two groups. After 2 years the mean maximum subsidence of the HA-coated components (0.24+/-0.18 mm) was about one-half of the mean maximum subsidence of the non-HA-coated group (0.55+/-0.55 mm). After 9 years the maximum subsidence of the HA-coated components was still smaller, but not as pronounced as before. The same trend was also found for the endpoint maximum total point motion (MTPM). After 2 years the mean MTPM of the HA-coated components was 0.66+/-0.38 mm and of the non-HA group 0.73+/-0.50 mm. After 9 years the mean MTPM for the HA-coated components was 0.54+/-0.15 mm and for the non-HA-coated components 0.74+/-0.20 mm. None of the HA-coated tibial components but one of the non-HA group had to be revised and exchanged due to aseptic loosening.

Prospective pilot study of neoadjuvant chemotherapy with 5-fluorouracil, folinic acid and oxaliplatin in resectable liver metastases of colorectal cancer. Analysis of 42 neoadjuvant chemotherapies

PURPOSE

Since there are currently no data available from a prospective trial, the primary objective of this prospective study was to investigate whether the rate of R0-liver resections without morbidity would be at least 50 % in patients with neoadjuvant chemotherapy for colorectal liver metastases.

PATIENTS AND METHODS

42 patients were treated with a biweekly FOLFOX regimen. Chemotherapy consisted of a 2-hour infusion of folinic acid (FOL) 500 mg/m2, followed by a 24-hour infusion of 5- fluorouracil (F) 2000 mg/m2 daily for two days. Oxaliplatin (OX) 85 mg/m 2 was given simultaneously with FOL. Treatment allocation was randomized with either 3 or 6 cycles for the final 30 patients. A liver resection was performed 2 to 5 weeks after the final infusion.

RESULTS

An objective response was observed in 20 of 42 patients (response rate was 27 % higher after 6 cycles). Liver resection (R0) could be performed in 34 patients. Postoperative complications were reported in 14 patients (13 occurring within 30 days after resection) and severe complications in 5 cases (including two deaths after extended resection). Liver failure and persistent biliary fistula were the most frequently documented complications. There was no relevant difference in safety criteria between 3 and 6 applications.

CONCLUSION

The use of neoadjuvant chemotherapy in resectable liver metastases induced significant remissions without increasing morbidity. The rate of severe complications and cases of no R0-resection in this study was 31 % and was with that significantly lower than 50 % (95 % CI 17.6 %-47.1 %). The risk to the patient is therefore acceptable when undergoing neoadjuvant treatment in a prospective intergroup trial.

Extracorporeal shock wave therapy in the treatment of lateral epicondylitis : a randomized multicenter trial

BACKGROUND

On the basis of observational trials, numerous investigators have recommended extracorporeal shock wave therapy as an alternative treatment for chronic lateral epicondylitis of the elbow. However, there has been no evidence of its efficacy from well-designed randomized clinical trials. The objective of this study was to find out whether extracorporeal shock wave therapy in combination with local anesthesia was superior to placebo therapy in combination with local anesthesia.

METHODS

A randomized multicenter trial with a parallel-group design was conducted. Following administration of local anesthesia, either extracorporeal shock wave therapy with three treatments of 2000 pulses each and a positive energy flux density (ED+) of 0.07 to 0.09 mJ/mm (2) or placebo therapy was applied on an outpatient basis. Treatment allocation was blinded for patients and for observers. The primary end point was based on the rate of success, as determined with the Roles and Maudsley score and whether additional treatment was required, twelve weeks after the intervention. Crossover was possible after assessment of the primary end point. Secondary end points were the Roles and Maudsley score, subjective pain rating, and grip strength after six and twelve weeks and after twelve months. The planned number of 272 patients was included in the study.

RESULTS

The primary end point could be assessed for 90.8% of the patients. The success rate was 25.8% in the group treated with extracorporeal shock wave therapy and 25.4% in the placebo group, a difference of 0.4% with a 95% confidence interval of -10.5% to 11.3%. Similarly, there was no relevant difference between groups with regard to the secondary end points. Improvement was observed in two-thirds of the patients from both groups twelve months after the intervention. Few side effects were reported.

CONCLUSIONS

Extracorporeal shock wave therapy as applied in the present study was ineffective in the treatment of lateral epicondylitis. The previously reported success of this therapy appears to be attributable to inappropriate study designs. Different application protocols might improve clinical outcome. We recommend that extracorporeal shock wave therapy be applied only in high-quality clinical trials until it is proved to be effective.

Does treatment of varicocele improve male fertility? results of the 'Deutsche Varikozelenstudie', a multicentre study of 14 collaborating centres

Treatment of varicocele is suggested in infertile men if sperm parameter values are abnormal. The effectiveness of the treatment with respect to fertility remains to be clarified. A multicentre, prospective randomized study on varicocele treatment in infertile men to demonstrate the superiority of sclerotization of the varicocele in preventing persistence, was started in 1995 with the collaboration of 15 German andrological centres. The primary endpoint was the incidence of pregnancy 1 year after randomisation. The number of cases needed to achieve the goal of the study was calculated at 460. However, three years after starting the study, only 67 patients had been randomized. Different reasons contributed to the poor recruitment. There was no significant increase in pregnancy rate in the treated group, compared to the controls, the confidence interval being 20.8% to 15.7%. The authors would like to encourage further collaborative study groups to start another prospective, randomized study with the aim of avoiding the costs and risks of varicocele treatment when its success remains unclear.

The use of sequential designs in genome scans for asthma susceptibility loci with affected sib pairs

We use optimized group sequential study designs to analyze data from two genome scans (German and CSGA) for asthma susceptibility loci with affected sib pairs from Genetic Analysis Workshop (GAW) 12. Results are compared with those from a fixed sample design and the sequential probability ratio test (SPRT). The SPRT does not reach significance at any position. Using the fixed sample design, evidence for linkage is found on chromosomes 6 and 9 in the German and on chromosome 1 in the CSGA scan. The group sequential designs identify the same regions on chromosomes 1 and 6 with a reduced sample size.

Modification of the sample size and the schedule of interim analyses in survival trials based on data inspections

A method is presented which allows us to adapt the sample size as well as the number and time points of interim analyses to the treatment difference observed at an interim look during the course of a clinical trial with censored survival time as the endpoint. The method allows the inclusion of data inspections during the course of the trial and redesign of the trial on the basis of the observed treatment difference without affecting the type I error risk. Formulae for recalculating the required number of events and the number of further patients to be randomized as a function of the observed hazard rates and the detectable hazard ratio are given.

Optimized group sequential study designs for tests of genetic linkage and association in complex diseases

The study of genetic linkage or association in complex traits requires large sample sizes, as the expected effect sizes are small and extremely low significance levels need to be adopted. One possible way to reduce the numbers of phenotypings and genotypings is the use of a sequential study design. Here, average sample sizes are decreased by conducting interim analyses with the possibility to stop the investigation early if the result is significant. We applied optimized group sequential study designs to the analysis of genetic linkage (one-sided mean test) and association (two-sided transmission/disequilibrium test). For designs with two and three stages at overall significance levels of.05 and.0001 and a power of.8, we calculated necessary sample sizes, time points, and critical boundaries for interim and final analyses. Monte Carlo simulation analyses were performed to confirm the validity of the asymptotic approximation. Furthermore, we calculated average sample sizes required under the null and alternative hypotheses in the different study designs. It was shown that the application of a group sequential design led to a maximal increase in sample size of 8% under the null hypothesis, compared with the fixed-sample design. This was contrasted by savings of up to 20% in average sample sizes under the alternative hypothesis, depending on the applied design. These savings affect the amounts of genotyping and phenotyping required for a study and therefore lead to a significant decrease in cost and time.

Adaptive group sequential designs for clinical trials: combining the advantages of adaptive and of classical group sequential approaches

A general method is presented integrating the concept of adaptive interim analyses into classical group sequential testing. This allows the researcher to represent every group sequential plan as an adaptive trial design and to make design changes during the course of the trial after every interim analysis in the same way as with adaptive designs. The concept of adaptive trial designing is thereby generalized to a large variety of possible sequential plans.

[Comparison of extracorporeal shockwave therapy (ESWT) with roentgen irradiation in supraspinatus tendon syndrome--a prospective randomized single-blind parallel group comparison]

AIM

Extracorporal shock wave therapy (FSWT) is applied in the case of supraspinatus tendinitis if conservative therapies have failed. So far there has been no controlled study comparing the effectiveness of ESWT with an established conservative method of therapy such as X-ray stimulation radiotherapy.

METHOD

Thirty patients with chronic supraspinatus tendinitis were admitted into the prospective randomised study. After randomisation, the patients were treated either three times with 2000 pulses (energy flux density ED+ 0.33 mJ/mm2) with a Storz Minilith SL1 after one week, or with X-ray stimulation radiotherapy with 6 x 0.5 Gy on the ICRU reference point (1 neutral fraction/day) with cobalt 60 gamma rays. Primary endpoint was the age-corrected constant score.

RESULTS

In the ESWT group the average age-corrected constant score rose from 50.1 points before ESWT to 91.5 points after 12 weeks and to 97.8 after 52 weeks. In the radiotherapy group it improved from 47.6 through 79.5 points to 87.4 points.

CONCLUSION

No statistically significant differences were proven between ESWT and radiotherapy. ESWT appears to be at least equivalent to radiotherapy in treating chronic supraspinatus tendinitis syndrome and can avoid a dose of radiation for patients and staff. A comprehensive randomised study is, however necessary to ensure the equivalence of ESWT.

Relation of sexual dysfunction to hormone levels, diseases and drugs used in andrological patients

In 169 patients visiting our department complaining of sexual dysfunction, the medical history was taken using a semistructured interview. A clinical investigation and a hormone analysis were added. The age of patients, hormone values, and items of the interview were collected into a common database. The items were categorized as either dichotomous (yes/no) or ordinal. Statistical analysis was performed using regression analysis with the aim to generate hypotheses of relations. An increase of FSH levels and a decrease of testosterone levels with age occurred. None of the relations of hormone levels or diseases to symptoms of sexual dysfunction produced odds ratios (OR) statistically significant different from 1. However, the risk of having a reduced libido and reduced morning erections was lower in psychoneurological diseases, the risk of reduced arousal and libido was lower in men with diabetes mellitus, but the risk of reduced morning erections was higher in these men. The testosterone levels were not associated with the risk of having reduced penile rigidity, duration of erection, arousal and sexual libido, reduced morning erections and the ability to masturbate. Smoking was not associated with reduced arousal, libido and morning erections. However, a significant increase of testosterone levels with number of cigarettes used was observed. We conclude that sexual dysfunction in patients visiting an andrological department for diagnosis and treatment is mostly not associated to any single evaluable factor.

High detection rate of T-cell receptor beta chain rearrangements in T-cell lymphoproliferations by family specific polymerase chain reaction in combination with the GeneScan technique and DNA sequencing

The distinction between benign polyclonal and malignant monoclonal lymphoid disorders by morphology or immunophenotyping is frequently difficult. Therefore, the demonstration of clonal B-cell or T-cell populations by detecting identically rearranged immunoglobulin (Ig) or T-cell receptor (TCR) genes is often used to solve this diagnostic problem. Whereas the detection of rearranged Ig genes is well established, TCR gamma (gamma) and beta (beta) gene rearrangements often escape detection with the currently available polymerase chain reaction (PCR) assays. To establish a sensitive, specific, and rapid method for the detection of rearranged TCR-beta genes, we developed a new PCR approach with family-specific Jbeta primers and analyzed the resulting PCR products by high-resolution GeneScan technique. The superior efficiency of this new method was demonstrated by investigating 132 DNA samples extracted from lymph node and skin biopsy specimens (mostly formalin fixed) and blood samples of 62 patients who had a variety of T-cell lymphomas and leukemias. In all but 1 of the tumor samples (98.4%) a clonal amplificate was detectable after TCR-beta PCR and the same clonal T-cell population was also found in 15 of 18 (83%) of the regional lymph nodes and in 7 of 11 (64%) of the peripheral blood samples. Direct comparison of these results with those obtained currently by the most widely applied TCR-gamma PCR revealed an approximate 20% lower detection rate in the same set of samples than with the TCR-beta PCR method. These results indicate that the new TCR-beta PCR is most suitable for a rapid and reliable detection of clonal T-cell populations. (Blood. 2000;96:640-646)

Arrhythmia risk stratification in idiopathic dilated cardiomyopathy based on echocardiography and 12-lead, signal-averaged, and 24-hour holter electrocardiography

BACKGROUND

To date, considerable controversy exists regarding noninvasive arrhythmia risk stratification in idiopathic dilated cardiomyopathy (IDC). Methods and Results Between 1992 and 1997, 202 patients with IDC without a history of sustained ventricular tachycardia (VT) underwent echocardiography, signal-averaged electrocardiogram (ECG), and 24-hour Holter ECG in the absence of antiarrhythmic drugs. During 32 +/- 15 months of prospective follow-up, major arrhythmic events, including sustained VT, ventricular fibrillation, or sudden death, occurred in 32 (16%) of 202 patients. After adjusting for baseline medical therapy and antiarrhythmic therapy during follow-up, multivariate Cox regression analysis identified a left ventricular (LV) end-diastolic diameter >/=70 mm and nonsustained VT on Holter as the only independent arrhythmia risk predictors. The combination of an LV end-diastolic diameter >/=70 mm and nonsustained VT was associated with a 14. 3-fold risk for future arrhythmic events (95% confidence interval 2. 3-90). To further elucidate the prognostic value of LV ejection fraction, multivariate Cox analysis was repeated with ejection fraction forced to remain in the model. In the latter model, an ejection fraction </=30% combined with nonsustained VT on Holter was found to be a significant arrhythmia risk predictor with a relative risk of 14.6 (95% confidence interval 2.2-97).

CONCLUSIONS

The combination of an LV end-diastolic diameter >/=70 mm and nonsustained VT on Holter, and the combination of LV ejection fraction </=30% and nonsustained VT on Holter, identify a subgroup of patients with IDC with a 14-fold risk for subsequent arrhythmic events. These findings have important implications for the design of future studies evaluating the role of prophylactic defibrillator therapy in patients with IDC.

Genetics of hereditary colon cancer - a basis for prevention?

Hereditary colorectal cancer syndromes are among the best in vivo models to study colorectal carcinogenesis and the influence of putative modifiers of the cancer risk. The present knowledge regarding the wide range of colorectal cancer (CRC) susceptibilities and the histological and molecular changes they elicit is leading to a very dynamic and integrated concept of tumorigenesis in the colon and to new views about prevention and early treatment of cancer.

Heart rate variability and baroreflex sensitivity in idiopathic dilated cardiomyopathy

OBJECTIVE

To examine the relation between cardiac autonomic tone, assessed by baroreflex sensitivity and heart rate variability, and left ventricular function, arrhythmias on Holter monitoring, and clinical variables in patients with idiopathic dilated cardiomyopathy.

DESIGN

A prospective observational study.

PATIENTS

160 patients with idiopathic dilated cardiomyopathy and preserved sinus rhythm in the absence of antiarrhythmic drug treatment. Measures of heart rate variability obtained by digital 24 hour Holter recordings included the mean of all coupling intervals between normal beats (RRm), the standard deviation of the mean of normal RR intervals (SDNN), and the square root of the mean of the squared differences between adjacent normal RR intervals (rMSSD). Baroreflex sensitivity testing was performed using the phenylephrine method.

RESULTS

Mean SDNN (SEM) was 112 (46) ms, and baroreflex sensitivity was 7.5 (5.0) ms/mm Hg. SDNN showed a weak correlation with baroreflex sensitivity (r = 0.19, p < 0.05) and with left ventricular ejection fraction (r = 0.29, p < 0.05). SDNN showed no significant correlation with age (r = -0.07), the presence of non-sustained ventricular tachycardia (r = -0.13), or left ventricular end diastolic diameter (r = -0.07). In addition, baroreflex sensitivity showed no significant correlation with age (r = -0.13), non-sustained ventricular tachycardia (r = -0.08), left ventricular end diastolic diameter (r = 0.09), or ejection fraction (r = 0.14).

CONCLUSIONS

The weak correlation between baroreflex sensitivity and heart rate variability suggests that these two indices explore different aspects of cardiac autonomic control in patients with idiopathic dilated cardiomyopathy. The weak or absent correlation between baroreflex sensitivity, heart rate variability, and other potential non-invasive risk predictors, including left ventricular ejection fraction, left ventricular end diastolic diameter, and non-sustained ventricular tachycardia on Holter monitoring, indicate that these variables may have independent prognostic value in idiopathic dilated cardiomyopathy.

Prediction of major arrhythmic events and sudden cardiac death in dilated cardiomyopathy. The Marburg Cardiomyopathy Study design and description of baseline clinical characteristics

The Marburg Cardiomyopathy Study (MACAS) is a prospective observational study designed to determine the value of the following potential non-invasive arrhythmia risk predictors in more than 200 patients with idiopathic dilated cardiomyopathy (IDC) over a 5-year follow-up period: New York Heart Association functional class, left ventricular end-diastolic diameter and ejection fraction, left bundle branch block and atrial fibrillation on ECG, QTc and JTc-dispersion on 12-lead ECG, abnormal time-domain analysis and spectral turbulence analysis of the signal-averaged ECG, ventricular arrhythmias and heart-rate variability on 24-hour Holter ECG, baroreflex sensitivity, and microvolt T wave alternans during exercise. This report describes the rationale of MACAS as well as the clinical characteristics of the first 236 patients enrolled between March 1996 and October 1999. The prognostic significance of the potential arrhythmia risk predictors in MACAS will be determined by multivariate Cox analysis at the end of 5-year follow-up. Primary endpoints are total mortality and major arrhythmic events defined as sustained ventricular tachycardia, ventricular fibrillation or sudden cardiac death. The results of MACAS will have important implications for the design of future studies evaluating the role of prophylactic defibrillator therapy in idiopathic dilated cardiomyopathy.

Functional reconstruction of the TM joint in cases of severely displaced fractures and fracture dislocation

In a clinical and axiographic study the outcome of patients with severely displaced fractures and fracture dislocations of the mandibular condyle was evaluated. Two operation methods were compared one via an intraoral approach without joint revision and another via a preauricular approach with open reduction of the joint. In the group with joint revision, resorbable material was used for osteosynthesis. Twenty-eight patients (32 joints) treated without revision of the joint and 26 patients (29 joints) with open reduction of the joint were evaluated. The mean observation time following surgery was 3 years and 10 months (range 1-7.5 years). Clinical examination utilized the Helkimo-index, while the electronic axiographical results were evaluated by using a five point scheme of joint-mobility. Concerning clinical evaluation, 20 out of 28 patients (71%) without joint revision and 23 out of 26 (89%) patients with joint revision had none or only slight dysfunction of the stomatognathic system. When focusing on arthralgia and pain in motion (part D and E of Helkimo's-index) significantly better results were achieved by open joint revision (Helkimo D: p< or =0.007; Helkimo E: p = 0.0029). No patient exhibited severe dysfunction (group D3). In axiographic evaluation optimal results (group A1) were achieved in seven joints (24%) with revision and four joints (12%) without revision. Twelve out of 29 joints with revision (41%) and six out of 32 joints without revision (19%) were classified as group A2 with a slightly shortened condylar excursion. Revision of joints with disc reduction and reconstruction of ligaments in cases of severely displaced or dislocated fractures resulted in better mobility and less pain. This was seen clinically and in the axiographic results. Looking at the long-term outcome of patients better mobility of the joint without internal derangement due to surgical repair also protects the contralateral (nonoperated) joint. When managing severe TMJ-trauma we suggest that both, bony and soft tissue structures should be reconstructed if there are any signs of internal derangement. However, the limits between bony reconstruction with or without joint revision are still not defined. Our results appear to be promising concerning mobility and absence of pain of the joints after open reduction. Further research comparing the two operative treatment regimes in a randomized controlled clinical trial will be necessary.

Significance of accelerated idioventricular rhythm in idiopathic dilated cardiomyopathy

Holter monitoring was performed in 202 patients with idiopathic dilated cardiomyopathy, which revealed accelerated idioventricular rhythm in 16 patients (8%) and nonsustained ventricular tachycardia in 70 patients (35%). During 32 +/- 15-month prospective follow-up, no significant difference was observed for major arrhythmic events and transplant-free survival between patients with and without accelerated idioventricular rhythm, whereas patients with nonsustained ventricular tachycardia had a significantly higher incidence of major arrhythmic events and a lower transplant-free survival rate.

Relevance of locoregional chemotherapy in patients with liver metastases from colorectal primaries

Progression of colorectal cancer can occur primarily isolated in the liver. But, only the minority of the affected patients is eligible for surgery. Initially, systemic chemotherapy was ineffective in the treatment of unresectable hepatic metastases. For this reason, intraarterial chemotherapy was introduced as treatment alternative to the systemic chemotherapy. Long-term intraarterial chemotherapy regimens with FUDR in patients with colorectal liver metastases, using implantable pumps and ports, resulted in improved response rates, which was confirmed by several randomized trials. However, an improvement in median survival has not yet been demonstrated after regional chemotherapy of hepatic metastases. Since the intraarterial therapy with floxuridine (FUDR) had been reported to result in a high rate of local toxicity, 5-fluorouracil (5-FU) was introduced into regional chemotherapy of the liver. A randomized trial demonstrated superiority of intraarterial 5-FU versus intraarterial FUDR therapy. Despite these reports about high response rates, the benefit of intraarterial chemotherapy remains questionable, because it has not yet resulted in a prolongation of median survival. For this reason, long-term regional chemotherapy cannot be considered as standard treatment and should therefore not be conducted outside controlled clinical trials. Further evaluations on this technique should only be performed in experienced centers.

Regional confidence bands for ROC curves

The performance of a diagnostic test is characterised by its specificity and sensitivity. For a quantitative diagnostic test these criteria depend on the selected cut-off point. The receiver operating characteristic (ROC) curve of a quantitative diagnostic test is generated by plotting sensitivity against specificity as the cut-off point runs through the whole range of possible test values. In practice, the ROC curve is estimated from clinical data. One important goal is to select an optimal cut-off point. For this purpose the sample variability has to be taken into account. Recently, Campbell has introduced nonparametric asymptotic simultaneous confidence bands that are valid for the whole ROC curve. In this paper a nonparametric asymptotic approach for the construction of regional confidence bands for ROC curves is proposed. It can be applied for any specificity interval of interest. Our approach is based on the asymptotic theory of empirical and quantile processes. To investigate the small sample properties of the different approaches, a Monte Carlo study was conducted using normal and log-normal data. A method for sample size calculation is presented. Finally, the approaches are applied to a tumour marker in the diagnosis of bone marrow metastases.

Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract

In the present study the activity of a 20% methanolic extract of stinging nettle roots (Urtica dioica L., Urticaceae) on the proliferative activity of human prostatic epithelial (LNCaP) and stromal (hPCPs) cells was evaluated using a colorimetric assay. A concentration-dependent and significant (p < 0.05) antiproliferative effect of the extract was observed only on LNCaP cells during 7 days, whereas stromal cell growth remained unaltered. The inhibition was time-dependent with the maximum of growth reduction (30%) at a concentration of 1.0E-6 mg/ml on day 5 compared to the untreated control. On day 4 and 6, the reduction in proliferation of LNCaP cells showed the minimal effective dose at 1.0E-9 mg/ml. No cytotoxic effect of ME-20 on cell proliferation was observed. The antiproliferative effect of ME-20 of stinging nettle roots observed both in an in vivo model and in an in vitro system clearly indicates a biologically relevant effect of compounds present in the extract.

Randomized, multicenter trial of fluorouracil plus leucovorin administered either via hepatic arterial or intravenous infusion versus fluorodeoxyuridine administered via hepatic arterial infusion in patients with nonresectable liver metastases from colorectal carcinoma

PURPOSE

To assess the efficacy and tolerability of three treatments for patients with documented adenocarcinoma of the colon and/or rectum who have undergone complete resection of primary tumor and have nonresectable liver metastases that do not exceed 75% of the liver volume.

PATIENTS AND METHODS

A total of 168 patients at 25 treatment centers were enrolled onto this prospective, multicenter, randomized study. The three treatment arms were as follows: (1) fluorouracil (5-FU)/leucovorin (LV) administered via hepatic arterial infusion (HAI), (2) 5-FU/LV administered via intravenous (IV) infusion, and (3) fluorodeoxyuridine (FUDR) administered via HAI.

RESULTS

Median times to disease progression for the three treatment arms were as follows: 9.2 months for patients treated with HAI 5-FU/LV, 6.6 months for IV 5-FU/LV, and 5.9 months for HAI FUDR. Median survival times for patients treated with HAI 5-FU/LV, IV 5-FU/LV, and HAI FUDR were 18.7 months, 17.6 months, and 12.7 months, respectively. There was a nearly two-fold increase in time to progression in addition to a survival benefit among patients with an intrahepatic tumor burden of less than 25% who were treated with HAI 5-FU/LV. The most common adverse events were stomatitis, nausea and vomiting, skin irritation, diarrhea, and elevated serum levels of liver enzymes. Some patients exhibited severe reactions, including biliary sclerosis and chemical hepatitis.

CONCLUSION

Although the use of HAI 5-FU/LV as a means of treating liver metastases after resection of colorectal carcinoma warrants further investigation, it cannot be recommended as a routine therapeutic measure at this time.

Antiproliferative effect of a polysaccharide fraction of a 20% methanolic extract of stinging nettle roots upon epithelial cells of the human prostate (LNCaP)

In Germany, plant extracts are often used in the treatment of early stages of benign prostate hyperplasia (BPH). The effects of different concentrations of the polysaccharide fraction of the 20% methanolic extract of stinging nettle roots (POLY-M) on the cellular proliferation of lymph node carcinoma of the prostate (LNCaP) cells were determined by measurement of the genomic DNA content of the samples. All concentrations of POLY-M showed an inhibitory effect on the growth of the LNCaP cells during 7 days except the two lowest concentrations. The reduced proliferation of POLY-M treated LNCaP cells was significantly (p < 0.05) different from the untreated control. The inhibition was time- and concentration-dependent with the maximum suppression (50%) on day 6 and at concentrations of 1.0E-9 and 1.0E-11 mg/ml. No cytotoxic effect of POLY-M on cell proliferation was observed. The in vitro results show for the first time an antiproliferative effect of Urtica compounds on human prostatic epithelium and confirm our previous in vivo findings.

Relevance of neoadjuvant and adjuvant treatment for patients with resectable liver metastases of colorectal carcinoma

BACKGROUND

Excellent results after resection of colorectal liver metastases are associated with a high rate of recurrence. Influenced by positive results of palliative and adjuvant treatment in advanced cancer, various chemotherapy regimens were evaluated to improve long-term results.

METHODS

The databases Medline and Cancerlit (1982-1998) gave information about 675 patients who were treated either by means of systemic, intra-arterial, intraportal or intraperitoneal administration before or after liver resection.

RESULTS

In general, the feasibility of an adjuvant treatment was tested. Proof has been furnished for the practicability of systemic and arterial therapy and for immunotherapy after liver resection whereas, for peritoneal and portal treatment, further studies are necessary. In a few non-randomised trials, it has been possible to discern a trend towards an improvement due to adjuvant postoperative therapy using historical or matched-pair control groups. Until now, only one of five randomised studies has been published. Six months of postoperative adjuvant intra-arterial treatment using 5-fluorouracil (1000 mg/m(2) for 5 days every 28 days) and folinic acid (200 mg/m(2) for 5 days every 28 days) was compared with observation only. Neither in the intention-to-treat nor in the as-treated analysis was median survival time (34.5 months versus 40. 8 months and 39.7 months versus 44.8 months, respectively) significantly increased. As neoadjuvant treatment was successful in primary non-resectable patients, this approach is now being tested in resectable patients.

CONCLUSION

Despite several theoretical reasons for post- or preoperative treatment in resectable patients, every approach should be tested using of controlled studies.

Optimization of testing times and critical values in sequential equivalence testing

In long-term clinical trials, interim analyses are planned to reduce the number of patients needed. To meet this issue in a practical way, group sequential designs are used. Most of these trials are conducted with the objective of demonstrating differences in efficacy of treatments, for example, to show superiority of a new drug or experimental treatment to a control. However, an increasing number of trials are designed to establish equivalence in efficacy or bioequivalence. This paper deals with group sequential test procedures in two-sided equivalence trials. Optimized designs with respect to sample size behaviour are constructed. Tables containing optimal testing times and corresponding optimal critical values or values to construct an underlying alpha-spending function, respectively, are provided. An example illustrates their use when planning interim analyses in equivalence trials.

[Implants in avascular iliac crest bone transplants. Prospective study of 176 implants]

Total and subtotal defects of the upper and lower alveolar ridge require bone grafts to make masticatory rehabilitation possible using alloplastic dental implants. The aim of this study was to establish the survival rate of dental implants inserted in avascular iliac bone grafts. Furthermore, we aimed to discover whether the prognosis of implants can be influenced by choosing one-stage or a two-stage procedure. In a prospective study, jaw defects in 40 patients were treated with avascular mono- or bicortical bone transplants taken from the right iliac wing. A total of 134 of 176 dental implants were inserted into an onlay osteoplasty. In 19 cases, 95 implants could have been inserted in a one-stage procedure, while in the other 13 cases 39 implants have been inserted in a two-stage procedure. One-stage insertion of implants was done in cases of definite primary stability only; otherwise, the two-stage method was preferred. After treatment, all patients were examined at least once every year. Both the rate of loss of implants and the time-dependent crestal bone loss were recorded. Of the 134 implants, 88% (i.e., 118 implants) were still in situ 6.8 years after abutment connection, and after 8.5 years 78% (i.e., 104 implants) were in situ. The interval of confidence was 95%. Projected over 8 years, 83 implants inserted in a one-stage procedure (i.e., 87%) were still functioning, while differently only 26 of the implants inserted in a two-stage procedure (i.e., 66%) were still functioning. The probability that implants stay in situ for a particular time corresponds to the results of former studies. The results of other studies with regard to one-stage or two-stage procedures could not be confirmed. The probability of total retention time for implants inserted in a two-stage procedure is lower than for those inserted in a one-stage procedure. The unfavorable starting point with the lack of primary stability of the implants in local bone within the two-stage procedure might be a reason for this.

[Multicenter phase II study of the Liver Metastases Study Group of weekly intra-arterial 24-hour high dose therapy with 5-FU and folinic acid (FA) in liver metastases of colorectal tumors]

This prospective multicenter trial was performed to determine the response rate, toxicity and applicability of continuous 24 h hepatic arterial infusion of high-dose 5-FU and folinic acid. An improved response rate (60.5% in non-pretreated patients) was however associated with many systemic side-effects (340/509), mainly nausea and diarrhea. Therefore this treatment should be applied only in selected patients in specialized centers.

[Intra-arterial (5-FU/FA and FUDR) versus systemic chemotherapy (5-FU/FA) of non-resectable colorectal liver metastases]

The relative efficacy of HAI FUDR, HAI 5-FU/FA, and i.v. 5-FU/FA chemotherapy for the treatment of unresectable colorectal liver metastases was compared in a prospective randomized clinical trial. The response rate after HAI treatment was significantly higher as compared to i.v. treatment with no statistical benefit regarding survival and time to progression. HAI FUDR treatment was inferior as compared to HAI or i.v. 5-FU/FA. i.v. 5-FU/FA-therapy is therefore the method of choice outside clinical trials.

[The status of regional long-term chemotherapy in liver metastasis]

In numerous tumors, metastasis can be limited to the liver. In non-resectable patients, regional treatment modalities, especially arterial cytostatic infusion, are favored in contrast to systemic chemotherapy, whereas intraportal or intraperitoneal application is not successful. Improved results with high response rates have been reported after development of intra-arterial (i.a.) long-term regimens with FUdR in patients with colorectal liver metastases using implantable pumps and ports. However, a survival benefit could only be demonstrated in comparison with a control group only treated symptomatically. Because of several reports on major local toxicity of i.a. FUdR treatment (i.e. chemical hepatitis and biliary sclerosis) several other effective i.a. 5-FU regimens have been developed. A randomized study has demonstrated superiority of i.a. 5-FU versus i.a. FUdR. In comparison with systemic treatment, superiority has only been demonstrated in patients with an intrahepatic tumor burden of < 25%. Publications about regional treatment of patients with breast, gastric cancer or carcinoid liver metastases are rare. Despite the high response rates reported, the benefit of arterial chemotherapy remains questionable. Overall, local long-term chemotherapy cannot be recommended outside of studies as a primary treatment. However, extensive experience and new drugs support the idea of conducting further regional studies.