[Psychological stressors, resources and well-being of surgeons in Germany : A cross-sectional study]. / Psychische Belastungen, Ressourcen und Wohlbefinden von Chirurgen in Deutschland : Eine Querschnittsstudie.

BACKGROUND: Psychological stress at work is associated with detrimental and health-impairing consequences for employees. OBJECTIVE: In this study major stress factors and the resource job control at the workplace of surgeons and facets of mental health were examined and compared to benchmark results of a large reference sample. METHOD: Data were collected by a representative online survey among surgeons throughout Germany who were contacted via the Professional Association of German Surgeons. In total 643 surgeons from different organizations and different disciplines completed the questionnaire that was developed using well-validated instruments. RESULTS: Time pressure was the most meaningful stress factor for surgeons. Moreover, the results for medical assistants showed adverse stress combinations of high goal uncertainty and low job control as well as high emotional exhaustion and low job satisfaction. In addition, the results indicated that surgeons in single and group practices as well as in outpatient healthcare centers have less stressors and more job resources. CONCLUSION: The survey results suggest high levels of burnout risk for German surgeons, especially among medical assistants and medical specialists from large hospitals. In order to maintain a high quality in the surgical disciplines, a concerted effort by all players in the healthcare system is necessary.

Power of Judgment: The Significance of Kant's Philosophy for the Medical System Today.

The ways of thinking in the manufacturing sciences are increasingly determining the rationality within medicine as a practical or action-based science. This "technological paradigm" infiltrates the field of medicine with the promise of increasing efficiency while simultaneously improving quality at various points in the system. Simple linear causal relationships generally need to be taken into account when manufacturing products. Even complex manufacturing processes can be broken down into the smallest units and, therefore, also be automated. The situation in complex systems such as the human body, however, is completely different. In order for doctors to be able to carry out their actions within this complex system, medicine as a science provides the physician with rules on the means that should be used to decide which remedy should be used, when and how. This judgment of which remedy should be used, when and how, what is known as the indication, is a central medical moment. This requires a power of judgment sharpened by experience. The indication, in turn, essentially determines the course of a disease and thus the quality of the treatment or the quality of result so often referred to these days.

A multilayered electrospun graft as vascular access for hemodialysis.

Despite medical achievements, the number of patients with end-stage kidney disease keeps steadily raising, thereby entailing a high number of surgical and interventional procedures to establish and maintain arteriovenous vascular access for hemodialysis. Due to vascular disease, aneurysms or infection, the preferred access-an autogenous arteriovenous fistula-is not always available and appropriate. Moreover, when replacing small diameter blood vessels, synthetic vascular grafts possess well-known disadvantages. A continuous multilayered gradient electrospinning was used to produce vascular grafts made of collagen type I nanofibers on luminal and adventitial graft side, and poly-ɛ-caprolactone as medial layer. Therefore, a custom-made electrospinner with robust environmental control was developed. The morphology of electrospun grafts was characterized by scanning electron microscopy and measurement of mechanical properties. Human microvascular endothelial cells were cultured in the graft under static culture conditions and compared to cultures obtained from dynamic continuous flow bioreactors. Immunofluorescent analysis showed that endothelial cells form a continuous luminal layer and functional characteristics were confirmed by uptake of acetylated low-density-lipoprotein. Incorporation of vancomycin and gentamicin to the medial graft layer allowed antimicrobial inhibition without exhibiting an adverse impact on cell viability. Most striking a physiological hemocompatibility was achieved for the multilayered grafts.

[Trust and reliability in surgery]. / Vertrauen und Verlässlichkeit in der Chirurgie.

Social interactions are hardly possible without trust. Medical and in particular surgical actions can change the lives of people directly and indirectly existentially. Thus, the relationship between doctor and patient is a special form of social interaction, and will be hard to find anywhere else. The nature of the doctor-patient relationship also determines the success of a treatment. The core and the importance of trust, as a central part of this relationship, will be reconstructed in the present paper. The increasing possibilities of information acquisition in modern societies, and the ever-present need for transparency, impact more and more on the doctor-patient relationship. At first glance, concepts of trust seem to be of secondary importance. The current developments regarding the remuneration of services in the medical system likewise bear the risk to increasingly determine the importance of trust in the doctor-patient relationship. However, it is necessary to delineate reliability from trust. Due to the conditions which are constitutive for the operational disciplines, a climate of trust, even in a modern information society, is more necessary than ever.

[The validity of routine data on quality assurance: A qualitative systematic review]. / Die Validität von Routinedaten zur Qualitätssicherung : Eine qualitative systematische Übersichtsarbeit.

BACKGROUND: The assessment of the quality of medical practice is a legitimate requirement by society. Reliable methods for measurement of the quality of performance are sought worldwide. Quality is often quantified by using administrative data and in Germany this method has been implemented by the health insurance company AOK. OBJECTIVES: (1) How is the AOK quality system rated by senior consultant surgeons? (2) How valid are quality statements derived from administrative data? METHODS: This article was compiled following the PRISMA (i.e. preferred reporting items for systematic reviews and meta-analyses) statement for qualitative systematic reviews. In order to answer the first question the Professional Association of German Surgeons (Berufsverband der Deutschen Chirurgen) initiated two surveys and to answer the second question a structured literature search following the PICO (i.e. patient problem or population, intervention, comparison control or comparator and outcomes) format was initiated. In addition numerous websites were contacted. RESULTS: Of the responding senior consultant surgeons 95% considered that the AOK method of quality measurement by administrative data is not objective. One third was definitely wrongly classified. The literature search revealed that no validation data exist for the AOK indicators, including the Elixhauser comorbidity risk score. Altogether, the sensitivity of indicators is poor when good sensitivity is defined by the Institute for Applied Quality Improvement and Research in Health Care (AQUA Institute) as ≥ 80 < 90%. CONCLUSIONS: Quality statements resulting from administrative data alone are unreliable.

Interaction of thrombocytes with poly(ether imide): The influence of processing.

The processing of polymers for blood contacting devices can have a major influence on surface properties. In this study, we fabricated poly(ether imide) (PEI) membranes and films to investigate the effects of the processing on physicochemical surface properties by atomic force microscopy (AFM), scanning electron microscopy, contact angle as well as zeta potential measurements. A static platelet adhesion test was performed to analyze the thrombogenicity of both devices. While contact angle measurements showed similar levels of hydrophobicity and zeta potential values were equivalent, mean surface roughness as well as surface energies in the dispersive part were found to be increased for the PEI membrane. The static platelet adhesion test showed a significantly decreased number of adherent platelets per surface area on the PEI film (178.98 ± 102.70/45000 µm2) compared to the PEI membrane (504 ± 314.27/45000µm2) and, consequently, revealed evidence for higher thrombogenicity of the PEI membrane. This study shows that processing can have a significant effect on platelet adhesion to biomaterials, even though, molar weight was identical. Thrombogenicity of polymer-based cardiovascular devices, therefore, have to be evaluated at the final product level, following the entire processing procedure.

Naturalistic study of course, effectiveness, and predictors of outcome among female adolescents in residential treatment for eating disorders.

Few empirical data address naturalistic outcomes of residential eating disorder (ED) treatment. Study aims were to evaluate course, effectiveness, and predictors of outcome in a residential treatment program. We evaluated 80 consecutively admitted female adolescents with the SCID-IV. Primary outcomes were treatment completion, subsequent readmission, clinical global impressions, and changes in body weight. Mean length of stay was 51 days, and 80% of patients were discharged according to treatment plans. Mean expected body weight (EBW) for AN patients increased from 80% to 91%. Patients reported significant improvements in ED symptoms, depression, and quality of life. Low admission %EBW and previous psychiatric hospitalizations were associated with premature termination. Overall, findings support that residential treatment is largely acceptable to patients, and that residential care may provide an opportunity for substantive therapeutic gains.

Dose escalated, hypofractionated radiotherapy using helical tomotherapy for inoperable non-small cell lung cancer: preliminary results of a risk-stratified phase I dose escalation study.

To improve local control for inoperable non-small cell lung cancer (NSCLC), a phase I dose escalation study for locally advanced and medically inoperable patients was devised to escalate tumor dose while limiting the dose to organs at risk including the esophagus, spinal cord, and residual lung. Helical tomotherapy provided image-guided IMRT, delivered in a 5-week hypofractionated schedule to minimize the effect of accelerated repopulation. Forty-six patients judged not to be surgical candidates with Stage I-IV NSCLC were treated. Concurrent chemotherapy was not allowed. Radiotherapy was delivered via helical tomotherapy and limited to the primary site and clinically proven or suspicious nodal regions without elective nodal irradiation. Patients were placed in 1 of 5 dose bins, all treated for 25 fractions, with dose per fraction ranging from 2.28 to 3.22 Gy. The bin doses of 57 to 80.5 Gy result in 2 Gy/fraction normalized tissue dose (NTD) equivalents of 60 to 100 Gy. In each bin, the starting dose was determined by the relative normalized tissue mean dose modeled to cause < 20% Grade 2 pneumonitis. Dose constraints included spinal cord maximum NTD of 50 Gy, esophageal maximum NTD < 64 Gy to < or = 0.5 cc volume, and esophageal effective volume of 30%. No grade 3 RTOG acute pneumonitis (NCI-CTC v.3) or esophageal toxicities (CTCAE v.3.0 and RTOG) were observed at median follow-up of 8.1 months. Pneumonitis rates were 70% grade 1 and 13% grade 2. Multivariate analysis identified lung NTD(mean) (p=0.012) and administration of adjuvant chemotherapy following radiotherapy (p=0.015) to be independent risk factors for grade 2 pneumonitis. Only seven patients (15%) required narcotic analgesics (RTOG grade 2 toxicity) for esophagitis, with only 2.3% average weight loss during treatment. Best in-field gross response rates were 17% complete response, 43% partial response, 26% stable disease, and 6.5% in-field thoracic progression. The out-of-field thoracic failure rate was 13%, and distal failure rate was 28%. The median survival was 18 months with 2-year overall survival of 46.8% +/- 9.7% for this cohort, 50% of whom were stage IIIB and 30% stage IIIA. Dose escalation can be safely achieved in NSCLC with lower than expected rates of pneumonitis and esophagitis using hypofractionated image-guided IMRT. The maximum tolerated dose has yet to be reached.

Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers.

In shape-memory polymers, changes in shape are mostly induced by heating, and exceeding a specific switching temperature, T(switch). If polymers cannot be warmed up by heat transfer using a hot liquid or gaseous medium, noncontact triggering will be required. In this article, the magnetically induced shape-memory effect of composites from magnetic nanoparticles and thermoplastic shape-memory polymers is introduced. A polyetherurethane (TFX) and a biodegradable multiblock copolymer (PDC) with poly(p-dioxanone) as hard segment and poly(epsilon-caprolactone) as soft segment were investigated as matrix component. Nanoparticles consisting of an iron(III)oxide core in a silica matrix could be processed into both polymers. A homogeneous particle distribution in TFX could be shown. Compounds have suitable elastic and thermal properties for the shape-memory functionalization. Temporary shapes of TFX compounds were obtained by elongating at increased temperature and subsequent cooling under constant stress. Cold-drawing of PDC compounds at 25 degrees C resulted in temporary fixation of the mechanical deformation by 50-60%. The shape-memory effect of both composite systems could be induced by inductive heating in an alternating magnetic field (f = 258 kHz; H = 30 kA x m(-1)). The maximum temperatures achievable by inductive heating in a specific magnetic field depend on sample geometry and nanoparticle content. Shape recovery rates of composites resulting from magnetic triggering are comparable to those obtained by increasing the environmental temperature.

Morphological studies on the culture of kidney epithelial cells in a fiber-in-fiber bioreactor design with hollow fiber membranes.

A hollow fiber-in-fiber-based bioreactor system was tested for the applicability to host kidney epithelial cells as a model system for a bioartificial kidney. Hollow fibers were prepared from polyacrylonitrile (PAN), polysulfone-polyvinylpyrollidinone (PVP) blend (PSU) and poly(acrylonitrile-N-vinylpyrollidinone) copolymer P(AN-NVP). Hollow fibers with smaller and larger diameters were prepared so that the smaller fitted into the larger, with a distance of 50-100 microm in between. The following material combinations as outer and inner fiber were applied: PAN-PAN; PSU-PSU, PSU-P(AN-NVP). Madin-Darby kidney epithelial cells (MDCK) were seeded in the interfiber space and cultured for a period up to 14 days. Light, scanning, and transmission electron microscopy were used to follow the adhesion and growth of cells, and to characterize their morphology. As a result, we found that MDCK cells were able to grow in the interfiber space in mono- and multilayers without signs of systemic degeneration. Comparison of the different materials showed that PAN and P(AN-NVP) provided the best growth conditions, indicated by a tight attachment of cells on hollow fiber membrane, and subsequent proliferation and development of structural elements of normal epithelia, such as tight junctions and microvilli. In conclusion, the fiber-in-fiber design seems to be an interesting system for the construction of a bioartificial kidney.

Morbidity and mortality after neoadjuvant therapy for lung cancer: the risks of right pneumonectomy.

BACKGROUND: The risks of complications in patients undergoing thoracotomy after neoadjuvant therapy for nonsmall cell lung cancer remain controversial. We reviewed our experience to define it further. METHODS: All patients undergoing thoracotomy after induction chemotherapy from 1993 through 1999 were reviewed. Univariate and multivariate methods for logistic regression model were used to identify predictors of adverse events. RESULTS: Induction chemotherapy included mitomycin, vinblastine, and cisplatin (179 patients), carboplatin and paclitaxel (152 patients), and other combinations (139 patients). Eighty-five patients (18%) received preoperative radiation. Operations were pneumonectomy (97 patients), lobectomy (297 patients), lesser resection (18 patients), and exploration only (58 patients). Total mortality was 7 of 297 (2.4%) and 11 of 97 (11.3%) for all lobectomies and pneumonectomies, respectively, but mortality was 11 of 46 (23.9%) for right pneumonectomy. Complications developed in 179 patients (38%). By multiple regression analysis, right pneumonectomy (p = 0.02), blood loss (p = 0.01), and forced expiratory volume in one second (percent predicted) (p = 0.01) predicted complications. No factor emerged to explain this high right pneumonectomy mortality rate. CONCLUSIONS: Pulmonary resection after neoadjuvant therapy is associated with acceptable overall morbidity and mortality. However, right pneumonectomy is associated with a significantly increased risk and should be performed only in selected patients.

Results of expandable metal stents for malignant esophageal obstruction in 100 patients: short-term and long-term follow-up.

BACKGROUND: Expandable metal stents palliate malignant dysphagia in most cases, but early complications and outcomes in long-term survivors have not been well described. This report summarizes our experience with expandable metal stents for malignant dysphagia. METHODS: Over a 48-month period, 127 stents were placed in 100 patients with dysphagia from esophageal cancer (93%) or lung cancer. Most had undergone prior treatment. Dysphagia scores, duration of palliation, complications, and reintervention were evaluated. RESULTS: Immediate improvement in dysphagia was observed in 85% of patients with no procedure-related deaths. Dysphagia score decreased from 3.3 before stent to 2.3 (p < 0.005). Average interval to reintervention was 80 days. In 40 patients surviving more than 120 days, 31 (78%) required reintervention. Major complications occurred in 3 patients receiving poststent chemoradiation (tracheoesophageal fistula, T1 vertebral body abscess, mediastinal abscess). Other complications included unsatisfactory deployment requiring immediate removal (3 patients), migration (11 patients), pain requiring removal (2 patients), food impaction (10 patients), and tumor ingrowth (37 patients). CONCLUSIONS: Expandable metal stents offer excellent short-term palliation of malignant dysphagia. In long-term survivors, recurrent dysphagia requiring reintervention is common. In a small subset of patients receiving chemoradiation after stent placement, major complications were observed.

Postoperative fluorescence bronchoscopic surveillance in non-small cell lung cancer patients.

BACKGROUND: Second lung primaries occur at a rate of 1% to 3% per patient-year after complete resections for non-small cell lung carcinoma (NSCLC). Fluorescence bronchoscopy appears to be a sensitive tool for surveillance of the tracheobronchial tree for early neoplasias. METHODS: Patients who were disease-free after complete resection of a NSCLC were entered into a fluorescence bronchoscopy surveillance program. All suspicious lesions were biopsied along with two areas of normal mucosa to serve as negative controls. RESULTS: A total of 73 fluorescence bronchoscopies were performed after conventional bronchoscopy in 51 patients at a median of 13 months postresection. The majority (46 of 51) of patients had stage I or II NSCLC, whereas 10% (5 of 51) had stage IIIA. Three intraepithelial neoplasias and one invasive carcinoma were identified in 3 of 51 patients (6%), all current or former smokers. Of the four lesions identified, three were in the 20 patients with prior squamous cell carcinomas. No intraepithelial neoplasias were identified by white-light bronchoscopy, whereas two of three were detected by fluorescence examination. The one invasive cancer detected was apparent on both white-light and fluorescence bronchoscopic examinations. CONCLUSIONS: Surveillance with fluorescence bronchoscopy identified lesions in 6% of postoperative NSCLC patients thought to be disease-free. Patients with prior squamous cell carcinomas appear to be a population that may warrant future prospective study of postoperative fluorescence bronchoscopic surveillance.

The role of positron emission tomography in evaluating mediastinal lymph node metastases in non-small-cell lung cancer.

Positron emission tomography (PET) is a modality that differentiates malignant from benign processes based upon metabolism rather than anatomy. A number of studies have confirmed improved accuracy of PET over computed tomography (CT), but until a few recent studies, most had failed to include satisfactory histologic confirmation. The objective of this study was to compare PET and CT to histologic staging of the mediastinum in patients with non-small-cell lung cancer (NSCLC). Histologic examination of mediastinal lymph nodes (MLNs) was performed on 40 patients with NSCLC at mediastinoscopy and/or at surgical resection. PET scans were interpreted by one of two nuclear medicine physicians, blinded to histology, using CT scans for anatomic localization. CT scans were independently evaluated for mediastinal lymphadenopathy. The overall accuracy, sensitivity, and specificity of PET were 78% (31 of 40), 67% (four of six), and 79% (27 of 34), respectively. The overall accuracy, sensitivity, and specificity of CT were 68% (27 of 40), 50% (three of six), and 71% (24 of 34), respectively. PET was superior to CT at correctly identifying mediastinal nodal metastases; however, both modalities were inferior to the gold standard of surgical staging. PET is more accurate than CT in staging the mediastinum of patients with NSCLC. PET failed to identify lymph node metastasis in 33% of patients with histologically proven MLN involvement, and false positives were present in 15%. At present, mediastinoscopy should remain the standard of care for preoperative mediastinal staging for NSCLC.

Endoscopic repair of bronchial dehiscence after lung transplantation.

We report a case of bronchial dehiscence after right single lung transplantation and describe a novel means of management: bronchoscopic closure of the defect with alpha-cyanoacrylate glue.

A new module arrangement for plasmapheresis.

On-line plasmapheresis using microporous membranes for filtration normally requires two external circulations (double treatment) before the detoxified plasma can be returned to the patient. The duomodule, a new filter arrangement developed by our group, integrates both steps in one equipment module using only one external circuit. Separations of aqueous polyethylene glycol (PEG) solutions as well as human plasma were carried out using the duomodule arrangement. The results revealed a considerable decrease of higher molecular substances in the feed solutions and a significant increase of these components in the permeate solution accumulated in the external compartment of the module. In conclusion, the duomodule arrangement seems to be an useful tool for the therapeutic apheresis.

Occult lung cancer treatment.

Occult lung carcinomas are rare and provide a particular challenge for treatment. They are lesions not evident on routine chest roentgenogram and chest computed tomography. Surgical resection remains the gold standard for the treatment of occult lung primaries; however, for nonsurgical candidates, multiple promising treatment strategies are on the horizon.

Minimally invasive esophagectomy.

BACKGROUND: Open esophagectomy can be associated with significant morbidity and delay return to routine activities. Minimally invasive surgery may lower the morbidity of esophagectomy but only a few small series have been published. METHODS: From August 1996 to September 1999, 77 patients underwent minimally invasive esophagectomy. Initially, esophagectomy was approached totally laparoscopically or with mini-thoracotomy; thoracoscopy subsequently replaced thoracotomy. RESULTS: Indications included esophageal carcinoma (n = 54), Barrett's high-grade dysplasia or carcinoma in situ (n = 17), and benign miscellaneous (n = 6). There were 50 men and 27 women with an average age of 66 years (range 30 to 94 years). Median operative time was 7.5 hours (4.5 hours with > 20 case experience). Median intensive care unit stay was 1 day (range 0 to 60 days); median length of stay was 7 days (range 4 to 73 days) with no operative or hospital mortalities. There were four nonemergent conversions to open esophagectomy; major and minor complication rates were 27% and 55%, respectively. CONCLUSIONS: Minimally invasive esophagectomy is technically feasible and safe in our center, which has extensive minimally invasive and open esophageal experience. Open surgery should remain the standard until future studies conclusively demonstrate advantages of minimally invasive approaches.

Laparoscopic repair of giant paraesophageal hernia: 100 consecutive cases.

OBJECTIVE: To summarize the authors' laparoscopic experience for paraesophageal hernia (PEH). SUMMARY BACKGROUND DATA: Laparoscopic antireflux surgery and repair of small hiatal hernias are now routinely performed. Repair of a giant PEH is more complex and requires conventional surgery in most centers. Giant PEH accounts for approximately 5% of all hiatal hernias. Medical management may be associated with a 50% progression of symptoms and a significant death rate. Conventional open surgery has a low death rate, but complications are significant and return to routine activities is delayed in this frequently elderly population. Recently, short-term outcome studies have reported that minimally invasive approaches to PEH may be associated with a lower complication rate, a shorter hospital stay, and faster recovery. METHODS: From July 1995 to February 2000, 100 patients (median age 68) underwent laparoscopic repair of a giant PEH. Follow-up included heartburn scores and quality of life measurements using the SF-12 physical component and mental component summary scores. RESULTS: There were 8 type II hernias, 85 type III, and 7 type IV. Sac removal, crural repair, and antireflux procedures were performed (72 Nissen, 27 Collis-Nissen). The 30-day death rate was zero; there was one surgery-related death at 5 months from a perioperative stroke. Intraoperative complications included pneumothorax, esophageal perforation, and gastric perforation. There were three conversions to open surgery. Major postoperative complications included stroke, myocardial infarction, pulmonary emboli, adult respiratory distress syndrome, and repeat operations (two for abscess and one each for hematoma, repair leak, and recurrent hernia). Median length of stay was 2 days. Median follow-up at 12 months revealed resumption of proton pump inhibitors in 10 patients and one repeat operation for recurrence. The mean heartburn score was 2.3 (0, best; 45, worst); the satisfaction score was 91%; physical and mental component summary scores were 49 and 54, respectively (normal, 50). CONCLUSION: This report represents the largest series to date of laparoscopic repair of giant PEH. In the authors' center with extensive experience in minimally invasive surgery, laparoscopic repair of giant PEH was successfully performed in 97% of patients, with a minimal complication rate, a 2-day length of stay, and good intermediate results.