Sharing and Receiving Eye-Contact Predicts Mate Choice After a 5-Minute Conversation: Evidence from a Speed-Dating Study.

In popular narratives, the first date with a potential mate often centers on their gaze as embodiment of interest and attraction. However, evidence is still lacking on the role of eye-contact as a potent signal in human social interaction in the context of dating. In addition, behavioral mechanisms of mate selection are not well understood. In the present study, we therefore examined mutual eye-contact and its influence on mate choice by applying dual mobile eye-tracking during naturalistic speed-dates. A total of 30 male and 30 female subjects attended four speed-dates each (N = 240). Subjects were more likely to choose those dating partners with whom they shared more eye-contact with. In addition, perceived attractiveness played an important role for mate choice. Interestingly, receiving but not giving eye-contact also predicted individual mate choice. Eye-contact thus acts as an important signal of romantic attraction when encountering a dating partner.

National norms of mental health for Denmark.

INTRODUCTION: To facilitate interpretation and clinical utility of patient-reported outcomes, normative data provide a reference for a person's score on a particular outcome in relation to the general population. This study reports Danish general population norms for four mental health indicators, assessing social functioning (Sheehan Disability Scale, SDS) personal recovery (Brief INSPIRE-O), symptom burden (Symptom Check List-10, SCL-10) and subjective well-being (WHO-5). METHODS: The study was a cross-sectional survey study organized by the State's statistical authority among the general population of adult Danish residents in Denmark, ranging in age between 18 to 79 years. RESULTS: A total of 8003 citizens were contacted including reminders from 2 March 2019 to 11 April 2019 by electronic letters, resulting in 2819 (35%) citizens providing complete responses. Female gender, higher age, Danish origin and living with a partner were associated with increased participation, and decreased participation was observed in male immigrants. We found a mean score of subjective well-being slightly lower than the population norm typically found in Danish general population studies. Elderly persons, Danes, and persons living with a partner reported better subjective mental health. Subjective well-being and personal recovery were positively correlated with social contacts and self-reported general health rating, and negatively correlated with social functioning and symptoms of depression and anxiety. CONCLUSION: This normative data provides a reference for interpreting mental health status. Our findings indicate slightly poorer subjective mental health than previously found. There is a need for special attention to engaging male immigrants in studies on mental health in the general population.

Evaluation of a standardized posttraumatic stress disorder treatment framework in routine mental health care: Effectiveness and predictors of treatment outcome in a consecutive sample.

The primary aim of the present study was to evaluate the effectiveness of standardized care package (CP) treatment for posttraumatic stress disorder (PTSD) in a Danish sample of adult psychiatric outpatients (N = 948). Secondary aims were to identify baseline predictors of treatment outcomes and investigate between-group differences in outcomes with regard to sex and treatment modality (i.e., group vs. individual therapy). The naturalistic, nonrandomized study followed a pre-post design. Patient data from five psychiatric outpatient clinics were collected between March 2011 and November 2017. Data were drawn from self-report questionnaires (i.e., SCL-90-R, WHO-5, BHS) and therapist-reported measures (i.e., GAF-S, GAF-F) administered at baseline and posttreatment. Between-group effects for sex and therapy modality (group vs. individual) were analyzed using analyses of variance, and possible predictors of outcomes were selected through LASSO regression and analyzed via hierarchical regression. Pre-post effects were small to moderate, ds = 0.39-0.69. No differences emerged regarding treatment modality, but women had significantly better outcomes than men. Aside from sex, only baseline symptom severity predicted outcomes. The effectiveness of the CP treatment was generally limited, indicating the need to implement improved therapeutic practices, such as the use of evidence-based treatments, and to provide better training to mental health clinicians. The findings underscore the need for further comparisons of group and individual treatment modalities using evidence-based therapies as well as the need to investigate factors that may affect treatment outcome.

Mentalization-based treatment in groups for adolescents with Borderline Personality Disorder: 3- and 12-month follow-up of a randomized controlled trial.

Mentalization-based treatment in groups (MBT-G) has never been tested in adolescents with Borderline Personality Disorder (BPD) in a randomized controlled trial. The current study aimed to test the long-term effectiveness of MBT-G in an adolescent sample with BPD or BPD features (≥ 4 DSM-5 BPD criteria). Hundred and eleven patients with BPD (n = 106) or BPD features (n = 5) were randomized to either (1) a 1-year modified MBT-G program comprising three MBT introductory sessions, five individual case formulation sessions, 37 weekly MBT group sessions, and six MBT-Parent sessions, or (2) treatment as usual (TAU), defined as at least 12 individual monthly treatment sessions with follow-up assessments at 3 and 12 months post treatment. The primary outcome was the score on the Borderline Personality Features Scale for Children (BPFS-C), and secondary outcomes included clinician-rated BPD symptoms and global level of functioning as well as self-reported self-harm, depression, externalizing and internalizing symptoms, and caregiver reports. There were no statistically significant differences between MBT-G and TAU on the primary outcome measure or any of the secondary outcomes. Both groups showed improvement on the majority of clinical and social outcomes at both follow-up points, although remission rates were modest with just 35% in MBT-G and 39% in TAU 2 years after inclusion into the study. MBT-G was not superior to TAU in improving borderline features in adolescents. Although improvement was observed equally in both interventions over time, the patients continued to exhibit prominent BPD features, general psychopathology and decreased functioning in the follow-up period, which points to a need for more research and better understanding of effective components in early intervention programs. The ClinicalTrials.gov identifier is NCT02068326.

Level of alexithymia as a measure of personality dysfunction in avoidant personality disorder.

BACKGROUND AND OBJECTIVES: Avoidant Personality Disorder (AvPD) is considered a mild to moderate personality disorder. However, few studies have focused on the heterogeneity of AvPD in terms of symptoms and severity. In the current study we set out to replicate and extend earlier findings showing that there is variation among patients with AvPD in terms of alexithymia and, further, that this variation is especially associated with specific facets of personality functioning and is not explained by measures of depression, symptom severity, or co-occurring personality disorder traits. METHOD: We used intake data from a sample of AvPD patients (n = 56) who had been treated in similar outpatient services. Alexithymia was measured using the Toronto Alexithymia Scale (TAS-20). Patients filled out questionnaires that were analysed using linear regression models. RESULTS AND CONCLUSIONS: Using well-established cut-off points for low, intermediate and high levels of alexithymia we found an almost equal distribution of alexithymia groups in our sample. Alexithymia was associated with higher personality dysfunction on twelve out of sixteen facets of personality functioning. For eight of these personality facets the alexithymia total score explained significant variance even after controlling for self-reported depression, symptom severity and clinician ratings of personality disorder. Results suggest that AvPD is heterogeneous and that alexithymia may be important as an indicator of severity of specific personality dysfunction.

Group rumination-focused cognitive-behavioural therapy (CBT) v. group CBT for depression: phase II trial.

BACKGROUND: Although cognitive-behavioural therapy (CBT) is an effective treatment for depression, less than half of patients achieve satisfactory symptom reduction during treatment. Targeting known psychopathological processes such as rumination may increase treatment efficacy. The aim of this study was to test whether adding group rumination-focused CBT (RFCBT) that explicitly targets rumination to routine medical management is superior to adding group CBT to routine medical management in treating major depression. METHODS: A total of 131 outpatients with major depression were randomly allocated to 12 sessions group RFCBT v. group CBT, each in addition to routine medical management. The primary outcome was observer-rated symptoms of depression at the end of treatment measured on the Hamilton Rating Scale for Depression. Secondary outcomes were rumination at post-treatment and depressive symptoms at 6 months follow-up (Trial registered: NCT02278224). RESULTS: RFCBT significantly improved observer-rated depressive symptoms (Cohen's d 0.38; 95% CI 0.03-0.73) relative to group CBT at post-treatment on the primary outcome. No post-treatment differences were found in rumination or in depressive symptoms at 6 months follow-up, although these secondary analyses may have been underpowered. CONCLUSIONS: This is the first randomized controlled trial providing evidence of benefits of RFCBT in major depression compared with CBT. Group RFCBT may be a beneficial alternative to group CBT for major depression.

Mentalization-based treatment in groups for adolescents with borderline personality disorder: a randomized controlled trial.

BACKGROUND: Borderline personality disorder (BPD) typically onsets in adolescence and predicts later functional disability in adulthood. Highly structured evidence-based psychotherapeutic programs, including mentalization-based treatment (MBT), are first choice treatment. The efficacy of MBT for BPD has mainly been tested with adults, and no RCT has examined the effectiveness of MBT in groups (MBT-G) for adolescent BPD. METHOD: A total of 112 adolescents (111 females) with BPD (106) or BPD symptoms ≥4 DSM-5 criteria (5) referred to child and adolescent psychiatric outpatient clinics were randomized to a 1-year MBT-G, consisting of three introductory, psychoeducative sessions, 37 weekly group sessions, five individual case formulation sessions, and six group sessions for caregivers, or treatment as usual (TAU) with at least 12 monthly individual sessions. The primary outcome was the score on the borderline personality features scale for children (BPFS-C); secondary outcomes included self-harm, depression, externalizing and internalizing symptoms (all self-report), caregiver reports, social functioning, and borderline symptoms rated by blinded clinicians. Outcome assessments were made at baseline, after 10, 20, and 30 weeks, and at end of treatment (EOT). The ClinicalTrials.gov identifier is NCT02068326. RESULTS: At EOT, the primary outcome was 71.3 (SD = 15.0) in the MBT-G group and 71.3 (SD = 15.2) in the TAU group (adjusted mean difference 0.4 BPFS-C units in favor of MBT-G, 95% confidence interval -6.3 to 7.1, p = .91). No significant group differences were found in the secondary outcomes. 29% in both groups remitted. 29% of the MBT group completed less than half of the sessions compared with 7% of the control group. CONCLUSIONS: There is no indication for superiority of either therapy method. The low remission rate points to the importance of continued research into early intervention. Specifically, retention problems need to be addressed.

Mind the gap: In-session silences are associated with client attachment insecurity, therapeutic alliance, and treatment outcome.

OBJECTIVE: The association between in-session silences and client attachment, therapeutic alliance, and treatment outcome was investigated in two treatments for bulimia nervosa. METHOD: 69 women and one man were randomized to two years of psychoanalytic psychotherapy (PPT) or 20 sessions of cognitive behavioral therapy (CBT). Client attachment was assessed using the Adult Attachment Interview. Early, middle and late sessions (N = 175) were evaluated with the Vanderbilt Therapeutic Alliance Scales, and quality of in-session silences was coded with the Pausing Inventory Categorization System (PICS). Multilevel Poisson and linear regression analyses were performed. RESULTS: Coders identified 6236 pauses, which were more frequent in PPT than in CBT. Higher pausing frequency and higher relative frequency of obstructive pauses were associated with client insecure attachment as well as with poorer treatment alliance, and accounted for part of the relation between client attachment and therapeutic alliance. Good outcome clients had higher relative frequency of productive pauses, especially in mid-treatment, and lower relative frequency of obstructive pauses, especially in late treatment. CONCLUSION: The study further validates the PICS. Findings indicate that therapists may be able to use in-session silences as an indicator of client attachment insecurity and as a prognostic sign of eventual treatment outcome.

Hemicraniectomy in older patients with extensive middle-cerebral-artery stroke.

BACKGROUND: Early decompressive hemicraniectomy reduces mortality without increasing the risk of very severe disability among patients 60 years of age or younger with complete or subtotal space-occupying middle-cerebral-artery infarction. Its benefit in older patients is uncertain. METHODS: We randomly assigned 112 patients 61 years of age or older (median, 70 years; range, 61 to 82) with malignant middle-cerebral-artery infarction to either conservative treatment in the intensive care unit (the control group) or hemicraniectomy (the hemicraniectomy group); assignments were made within 48 hours after the onset of symptoms. The primary end point was survival without severe disability (defined by a score of 0 to 4 on the modified Rankin scale, which ranges from 0 [no symptoms] to 6 [death]) 6 months after randomization. RESULTS: Hemicraniectomy improved the primary outcome; the proportion of patients who survived without severe disability was 38% in the hemicraniectomy group, as compared with 18% in the control group (odds ratio, 2.91; 95% confidence interval, 1.06 to 7.49; P=0.04). This difference resulted from lower mortality in the surgery group (33% vs. 70%). No patients had a modified Rankin scale score of 0 to 2 (survival with no disability or slight disability); 7% of patients in the surgery group and 3% of patients in the control group had a score of 3 (moderate disability); 32% and 15%, respectively, had a score of 4 (moderately severe disability [requirement for assistance with most bodily needs]); and 28% and 13%, respectively, had a score of 5 (severe disability). Infections were more frequent in the hemicraniectomy group, and herniation was more frequent in the control group. CONCLUSIONS: Hemicraniectomy increased survival without severe disability among patients 61 years of age or older with a malignant middle-cerebral-artery infarction. The majority of survivors required assistance with most bodily needs. (Funded by the Deutsche Forschungsgemeinschaft; DESTINY II Current Controlled Trials number, ISRCTN21702227.).

Medical Assistant-Based Care Management for High-Risk Patients in Small Primary Care Practices: A Cluster Randomized Clinical Trial.

BACKGROUND: Patients with multiple chronic conditions are at high risk for potentially avoidable hospitalizations, which may be reduced by care coordination and self-management support. Medical assistants are an increasingly available resource for patient care in primary care practices. OBJECTIVE: To determine whether protocol-based care management delivered by medical assistants improves care in patients at high risk for future hospitalization in primary care. DESIGN: Two-year cluster randomized clinical trial. (Current Controlled Trials: ISRCTN56104508). SETTING: 115 primary care practices in Germany. PATIENTS: 2076 patients with type 2 diabetes, chronic obstructive pulmonary disease, or chronic heart failure and a likelihood of hospitalization in the upper quartile of the population, as predicted by an analysis of insurance data. INTERVENTION: Protocol-based care management, including structured assessment, action planning, and monitoring delivered by medical assistants, compared with usual care. MEASUREMENTS: All-cause hospitalizations at 12 months (primary outcome) and quality-of-life scores (12-Item Short Form Health Survey [SF-12] and EuroQol instrument [EQ-5D]). RESULTS: Included patients had an average of 4 co-occurring chronic conditions. All-cause hospitalizations did not differ between groups at 12 months (risk ratio [RR], 1.01 [95% CI, 0.87 to 1.18]) and 24 months (RR, 0.98 [CI, 0.85 to 1.12]). Quality of life (differences, 1.16 [CI, 0.24 to 2.08] on SF-12 physical component and 1.68 [CI, 0.60 to 2.77] on SF-12 mental component) and general health (difference on EQ-5D, 0.03 [CI, 0.00 to 0.05]) improved significantly at 24 months. Intervention costs totaled $10 per patient per month. LIMITATION: Small number of primary care practices and low intensity of intervention. CONCLUSION: This low-intensity intervention did not reduce all-cause hospitalizations but showed positive effects on quality of life at reasonable costs in high-risk multimorbid patients. PRIMARY FUNDING SOURCE: AOK Baden-Württemberg and AOK Bundesverband.

Treatment of severe bone defects during revision total knee arthroplasty with structural allografts and porous metal cones-a systematic review.

Aseptic loosening and focal osteolysis are the most common reasons for knee arthroplasty failure. The best treatment remains unclear. We reviewed the literature on the treatment of revision knee arthroplasty using bony structural allografts (476 cases) and porous metal cones (223 cases) to determine if a difference in the revision failure rates was discernable. The failure rates were compared using a logistic regression model with adjustment for discrepancies in FU time and number of grafts used (femoral, tibial, or both). In this analysis, the porous implant shows a significantly decreased loosening rate in AORI 2 and 3 defects. The overall failure rate was also substantially lower in the porous metal group than the structural allograft group; little difference in the infection rates was noted.

Development of the circadian clockwork in the kidney.

The circadian molecular clock is an internal time-keeping system composed of centrally synchronized tissue-level pacemakers. Here, we explored the ontogeny of the clock machinery in the developing kidney. Pregnant rats were housed at 12-12 h light-dark cycles. Offsprings were killed at 4-h intervals on embryonic day 20 and at postnatal weeks 1, 4, and 12. Canonical clock gene (Clock, Bmal1, Rev-erbα, Cry1, Cry2, Per1, Per2) and kidney-specific clock-controlled gene (αENaC, SGK1, NHE3, AVPR2) expression was profiled by RT-PCR. To investigate the role of nutritional cues, the feeding pattern was modified postpartum. Clock, Rev-erbα, Per2, αENaC, SGK1, NHE3, and AVPR2 showed circadian expression at the end of intrauterine development. By 1 week, all genes oscillated with a distinct acrophase shift toward the time of peak feeding activity. Daily 4-hour withdrawal of mothers induced a 12-hour phase shift of Clock and Bmal1 expression, while disrupting oscillations of the other genes. After weaning, oscillation phases shifted back toward the adult pattern, which was fully expressed at 12 weeks. Thus, functional circadian molecular clockwork evolves in the late fetal and early postnatal kidney. During the nursing period, oscillations are entrained by nutritional cues. The coupling of the circadian expression of tubular regulators of fluid and electrolyte excretion to the feeding-entrained clockwork may be important to maintain homeostasis during this critical period.

Real-time image guidance in laparoscopic liver surgery: first clinical experience with a guidance system based on intraoperative CT imaging.

BACKGROUND: Laparoscopic liver surgery is particularly challenging owing to restricted access, risk of bleeding, and lack of haptic feedback. Navigation systems have the potential to improve information on the exact position of intrahepatic tumors, and thus facilitate oncological resection. This study aims to evaluate the feasibility of a commercially available augmented reality (AR) guidance system employing intraoperative robotic C-arm cone-beam computed tomography (CBCT) for laparoscopic liver surgery. METHODS: A human liver-like phantom with 16 target fiducials was used to evaluate the Syngo iPilot(®) AR system. Subsequently, the system was used for the laparoscopic resection of a hepatocellular carcinoma in segment 7 of a 50-year-old male patient. RESULTS: In the phantom experiment, the AR system showed a mean target registration error of 0.96 ± 0.52 mm, with a maximum error of 2.49 mm. The patient successfully underwent the operation and showed no postoperative complications. CONCLUSION: The use of intraoperative CBCT and AR for laparoscopic liver resection is feasible and could be considered an option for future liver surgery in complex cases.

Image quality influences the assessment of left ventricular function: an intraoperative comparison of five 2-dimensional echocardiographic methods with real-time 3-dimensional echocardiography as a reference.

OBJECTIVES: Transesophageal echocardiography has become a standard tool for evaluating left ventricular function during cardiac surgery. However, the image quality varies widely between patients and examinations. The aim of this study was to investigate the influence of the image quality on 5 commonly used 2-dimensional methods. METHODS: Transesophageal real-time 3-dimensional echocardiography (3DE) served as a reference. Left ventricular function was evaluated in 63 patients with sufficient real-time 3DE image quality. The image quality was rated using the ratio of the visualized border divided by the total endocardial border. These ratings were used to generate groups of poor (0%-40%), fair (41%-70%), and good (71%-100%) image quality. The ejection fraction (EF), end-diastolic volume, and end-systolic volume were analyzed by the Simpson method of disks (biplane and monoplane), eyeball method, Teichholz method, and speckle-tracking method. Furthermore, the fractional area change was determined. Each correlation with real-time 3DE was evaluated. RESULTS: Correlations of the EF and volumes, respectively, as determined by long-axis view methods increased with improving image quality: the Simpson biplane method was found to be the most accurate method, with good image quality for the EF (r = 0.946) and volumes (end-diastolic volume, r = 0.962; end-systolic volume, r = 0.989). Correlations of the EF and fractional area change by short-axis view methods decreased with improving image quality, with the Teichholz EF found to be most accurate with poor (r = 0.928) in contrast to good (r = 0.699) image quality. CONCLUSIONS: With good image quality, the Simpson biplane method is the most accurate 2-dimensional method for assessing the left ventricular EF. Short-axis view methods, especially the Teichholz method yield better correlations with poor image quality. The eyeball method was unaffected by image quality.

Loosening after acetabular revision: comparison of trabecular metal and reinforcement rings. A systematic review.

The best method of revision acetabular arthroplasty remains unclear. Consequently, we reviewed the literature on the treatment of revision acetabular arthroplasty using revision rings (1541 cases; mean follow-up (FU) 5.7 years) and Trabecular Metal, or TM, implants (1959 cases; mean FU 3.7 years) to determine if a difference with regard to revision failure could be determined. Failure rates of the respective implants were compared statistically using a logistic regression model with adjustment for discrepancies in FU time. In our study, TM shows statistically significant decreased loosening rates relative to revision rings for all grades including severe acetabular defects and pelvic discontinuity. The severe defects appear to benefit the most from TM.

Schema therapy versus treatment as usual for outpatients with difficult-to-treat depression: study protocol for a parallel group randomized clinical trial (DEPRE-ST).

BACKGROUND: About one third of patients with depression are in a condition that can be termed as "difficult-to-treat". Some evidence suggests that difficult-to-treat depression is associated with a higher frequency of childhood trauma and comorbid personality disorders or accentuated features. However, the condition is understudied, and the effects of psychotherapy for difficult-to-treat depression are currently uncertain. The aim of this trial is to investigate the beneficial and harmful effects of 30 sessions of individual schema therapy versus treatment as usual for difficult-to-treat depression in the Danish secondary, public mental health sector. METHODS: In this randomized, multi-centre, parallel-group, superiority clinical trial, 129 outpatients with difficult-to-treat depression will be randomized (1:1) to 30 sessions of individual schema therapy or treatment as usual; in this context mainly group-based, short-term cognitive behaviour or psychodynamic therapy. The primary outcome is the change from baseline in depressive symptoms 12 months after randomization, measured on the observer-rated 6-item Hamilton Rating Scale for Depression. The secondary outcomes are health-related quality of life assessed with the European Quality of Life 5 Dimensions 5 Level Version, functional impairment assessed with the Work and Social Adjustment Scale, psychological wellbeing assessed with the WHO-5 Well-being Index, and negative effects of treatment assessed with the Negative Effects Questionnaire. Exploratory outcomes are improvement on patient self-defined outcomes, personal recovery, anxiety symptoms, anger reactions, metacognitive beliefs about anger, and perseverative negative thinking. Outcomes will be assessed at 6, 12, and 24 months after randomization; the 12-month time-point being the primary time-point of interest. Outcome assessors performing the depression-rating, data managers, statisticians, the data safety and monitoring committee, and conclusion makers for the outcome article will be blinded to treatment allocation and results. To assess cost-effectiveness of the intervention, a health economic analysis will be performed. DISCUSSION: This trial will provide evidence on the beneficial and harmful effects, as well as the cost-effectiveness of schema therapy versus treatment as usual for outpatients with difficult-to-treat depression. The results can potentially improve treatment for a large and understudied patient group. TRIAL REGISTRATION: ClinicalTrials.gov NCT05833087. Registered on 15th April 2023 (approved without prompts for revision on 27th April 2023).

Gastric bypass leads to improvement of diabetic neuropathy independent of glucose normalization--results of a prospective cohort study (DiaSurg 1 study).

OBJECTIVE: Surprisingly, 40% to 95% of patients with type 2 diabetes mellitus (T2DM) show early remission of hyperglycemia after obesity surgery. It is unknown to what extent other diabetes-associated comorbidities such as distal peripheral neuropathy (DPN) might be influenced by obesity surgery. This pilot study aimed at providing further evidence for the impact of Roux-en-Y gastric bypass (RYGB) on both glycemic control and DPN in non-severely obese patients with insulin-dependent T2DM. METHODS: In the present prospective cohort study, 20 patients with long-standing, insulin-dependent T2DM and a body mass index (BMI) between 25 and 35 kg/m underwent laparoscopic RYGB. Body mass index, glycosylated hemoglobin (HbA1c), and DPN [quantified by the Neuropathy Symptom Score (NSS) and the Neuropathy Deficit Score (NDS)] were investigated. RESULTS: Six months after surgery, the preoperative BMI of 32.8 ± 2.1 kg/m (mean ± standard deviation) dropped to 25.6 ± 2.5 kg/m (P < 0.001). Preoperative HbA1c levels decreased from 8.5 ± 1.2% to 7.1 ± 1.2% (P < 0.001), with 15% of patients having a normalized HbA1c level lower than 6.2%. Of 12 patients with documented DPN, the median NSS was 8 (range, 0-10) preoperatively and 0 (range, 0-9) postoperatively (P = 0.004), with 8 patients scoring an NSS of 0. The median NDS was 6 (range, 2-8) preoperatively and 4 (range, 0-8) postoperatively (P = 0.027), with 1 patient scoring an NDS of 0. All patients had an improvement or normalization in either 1 or both scores. CONCLUSIONS: As expected, BMI and HbA1c levels improved significantly after RYGB. More interestingly, neuropathy scores, such as NSS and NDS, improved significantly early after surgery. Symptomatic neuropathy was completely reversible in 67% of the patients. These findings add further evidence to the fact that RYGB might be a valuable treatment option not only for improving glycemic control but also for reducing diabetes-associated comorbidities, such as DPN. This points to a complex metabolic effect of RYGB that exceeds glucose normalization. However, the results still need to be confirmed in controlled trials.

Assessment of statistical significance and clinical relevance.

In drug development, it is well accepted that a successful study will demonstrate not only a statistically significant result but also a clinically relevant effect size. Whereas standard hypothesis tests are used to demonstrate the former, it is less clear how the latter should be established. In the first part of this paper, we consider the responder analysis approach and study the performance of locally optimal rank tests when the outcome distribution is a mixture of responder and non-responder distributions. We find that these tests are quite sensitive to their planning assumptions and have therefore not really any advantage over standard tests such as the t-test and the Wilcoxon-Mann-Whitney test, which perform overall well and can be recommended for applications. In the second part, we present a new approach to the assessment of clinical relevance based on the so-called relative effect (or probabilistic index) and derive appropriate sample size formulae for the design of studies aiming at demonstrating both a statistically significant and clinically relevant effect. Referring to recent studies in multiple sclerosis, we discuss potential issues in the application of this approach.

Reperfusion of liver graft during transplantation: techniques used in transplant centres within Eurotransplant and meta-analysis of the literature.

It remains unclear which liver graft reperfusion technique leads to the best outcome following transplantation. An online survey was sent to all transplant centres (n = 37) within Eurotransplant (ET) to collect information on their technique used for reperfusion of liver grafts. Furthermore, a systematic review of all literature was performed and a meta-analysis was conducted based on patients' mortality, number of retransplantations and incidence of biliary complications, depending on the technique used. Of the 28 evaluated centres, 11 (39%) reported performing simultaneous reperfusion (SIMR), 13 (46%) perform initial portal vein reperfusion (IPR), 1 (4%) performs an initial hepatic artery reperfusion (IAR) and 3 (11%) perform retrograde reperfusion (RETR). In 21 centres (75%), one reperfusion technique is used as a standard, but in only one centre is this decision based on available literature. Twenty centres (71%) said they would agree to participate in randomized controlled trials (RCT) if required. For meta-analysis, IAR vs. IPR, SIMR vs. IPR and RETR vs. IPR were compared. There was no difference between any of the techniques compared. There is no consensus on a preferable reperfusion technique. Available evidence does not help in the decision-making process. There is thus an urgent need for multicentric RCTs.

Navigation system for minimally invasive esophagectomy: experimental study in a porcine model.

BACKGROUND: Navigation systems potentially facilitate minimally invasive esophagectomy and improve patient outcome by improving intraoperative orientation, position estimation of instruments, and identification of lymph nodes and resection margins. The authors' self-developed navigation system is highly accurate in static environments. This study aimed to test the overall accuracy of the navigation system in a realistic operating room scenario and to identify the different sources of error altering accuracy. METHODS: To simulate a realistic environment, a porcine model (n = 5) was used with endoscopic clips in the esophagus as navigation targets. Computed tomography imaging was followed by image segmentation and target definition with the medical imaging interaction toolkit software. Optical tracking was used for registration and localization of animals and navigation instruments. Intraoperatively, the instrument was displayed relative to segmented organs in real time. The target registration error (TRE) of the navigation system was defined as the distance between the target and the navigation instrument tip. The TRE was measured on skin targets with the animal in the 0° supine and 25° anti-Trendelenburg position and on the esophagus during laparoscopic transhiatal preparation. RESULTS: On skin targets, the TRE was significantly higher in the 25° position, at 14.6 ± 2.7 mm, compared with the 0° position, at 3.2 ± 1.3 mm. The TRE on the esophagus was 11.2 ± 2.4 mm. The main source of error was soft tissue deformation caused by intraoperative positioning, pneumoperitoneum, surgical manipulation, and tissue dissection. CONCLUSION: The navigation system obtained acceptable accuracy with a minimally invasive transhiatal approach to the esophagus in a realistic experimental model. Thus the system has the potential to improve intraoperative orientation, identification of lymph nodes and adequate resection margins, and visualization of risk structures. Compensation methods for soft tissue deformation may lead to an even more accurate navigation system in the future.