Can you feel the force just right? Tactile force feedback for training of minimally invasive surgery-evaluation of vibration feedback for adequate force application.

BACKGROUND: Tissue handling is a crucial skill for surgeons and is challenging to learn. The aim of this study was to develop laparoscopic instruments with different integrated tactile vibration feedback by varying different tactile modalities and assess its effect on tissue handling skills. METHODS: Standard laparoscopic instruments were equipped with a vibration effector, which was controlled by a microcomputer attached to a force sensor platform. One of three different vibration feedbacks (F1: double vibration > 2 N; F2: increasing vibration relative to force; F3: one vibration > 1.5 N and double vibration > 2 N) was applied to the instruments. In this multicenter crossover trial, surgical novices and expert surgeons performed two laparoscopic tasks (Peg transfer, laparoscopic suture, and knot) each with all the three vibration feedback modalities and once without any feedback, in a randomized order. The primary endpoint was force exertion. RESULTS: A total of 57 subjects (15 surgeons, 42 surgical novices) were included in the trial. In the Peg transfer task, there were no differences between the tactile feedback modalities in terms of force application. However, in subgroup analysis, the use of F2 resulted in a significantly lower mean-force application (p-value = 0.02) among the student group. In the laparoscopic suture and knot task, all participants exerted significantly lower mean and peak forces using F2 (p-value < 0.01). These findings remained significant after subgroup analysis for both, the student and surgeon groups individually. The condition without tactile feedback led to the highest mean and peak force exertion compared to the three other feedback modalities. CONCLUSION: Continuous tactile vibration feedback decreases the mean and peak force applied during laparoscopic training tasks. This effect is more pronounced in demanding tasks such as laparoscopic suturing and knot tying and might be more beneficial for students. Laparoscopic tasks without feedback lead to increased force application.

Beliefs about stress moderate the association between COVID-19-related work demands and burnout symptoms in physicians.

The present study set out to investigate the role of different stress beliefs (positive and negative beliefs about stress, as well as perceived control) on the association between central COVID-19-related work demands and burnout symptoms in physicians during the second lockdown of the SARS-CoV-2 pandemic. N = 154 practicing physicians (mean [SD] age = 37.21 [9.43] years]; 57.14% female) participated in our cross-sectional German-wide online survey and answered questions about sociodemographic factors, their current work situation, their stress beliefs, and their current burnout symptoms. Moderation analyses revealed significant interaction effects between stress beliefs and specific COVID-19-related work demands on the prediction of burnout symptoms, most consistent with respect to perceived control. Positive believes about stress and its controllability were cross-sectional associated with reduced, negative believes about stress however with enhanced associations between COVID-19-related work demands and burnout symptoms. This finding indicates, if confirmed by longitudinal research, the potential of the usage of stress beliefs in prevention programs for physicians in order to mitigating negative effects of chronic stress.

Pelvic exenteration for colorectal and non-colorectal cancer: a comparison of perioperative and oncological outcome.

BACKGROUND: Pelvic exenteration (PE) is the only option for long-term cure of advanced cancer originating from different types of tumor or recurrent disease in the lower pelvis. The aim was to show differences between colorectal and non-colorectal cancer in survival and postoperative morbidity. METHODS: Retrospective data of 63 patients treated with total pelvic exenteration between 2013 and 2018 are reported. Pre-, intra-, and postoperative parameters, survival data, and risk factors for complications were analyzed. RESULTS: A total of 57.2% (n = 37) of the patients had colorectal cancer, 22.3% had gynecological malignancies (vulvar (n = 6) or cervical (n = 8) cancer), 11.1% (n = 7) had anal cancer, and 9.5% had other primary tumors. A total of 30.2% (n = 19) underwent PE for a primary tumor and 69.8% (n = 44) for recurrent cancer. The 30-day in-hospital mortality was 0%. Neoadjuvant treatment was administered to 65.1% (n = 41) of the patients and correlated significantly with postoperative complications (odds ratio 4.441; 95% CI: 1.375-14.342, P > 0.05). R0, R1, R2, and Rx resections were achieved in 65.1%, 19%, 1.6%, and 14.3% of the patients, respectively. In patients undergoing R0 resection, 2-year OS and RFS were 73.2% and 52.4%, respectively. Resection status was a significant risk factor for recurrence-free and overall survival (OS) in univariate analysis. Multivariate analysis revealed age (P = 0.021), ASA ≥ 3 (P = 0.005), high blood loss (P = 0.028), low preoperative hemoglobin level (P < 0.001), nodal positivity (P < 0.001), and surgical complications (P = 0.003) as independent risk factors for OS. CONCLUSION: Pelvic exenteration is a procedure with high morbidity rates but remains the only curative option for advanced or recurrent colorectal and non-colorectal cancer in the pelvis.

Definition and severity grading of postoperative lymphatic leakage following inguinal lymph node dissection.

PURPOSE: Lymphatic complications occur frequently after radical inguinal lymph node dissection (RILND). The incidence of lymphatic leakage varies considerably among different studies due to the lack of a consistent definition. The aim of the present study is to propose a standardized definition and grading of different types of lymphatic leakage after groin dissection. METHODS: A bicentric retrospective analysis of 82 patients who had undergone RILND was conducted. A classification of postoperative lymphatic leakage was developed on the basis of the daily drainage output, any necessary postoperative interventions and reoperations, and any delay in adjuvant treatment. RESULTS: In the majority of cases, RILND was performed in patients with inguinal metastases of malignant melanoma (n = 71). Reinterventions were necessary in 15% of the patients and reoperations in 32%. A new classification of postoperative lymphatic leakage was developed. According to this definition, grade A lymphatic leakage (continued secretion of lymphatic fluid from the surgical drains without further complications) occurred in 13% of the patients, grade B lymphatic leakage (persistent drainage for more than 10 postoperative days or the occurrence of a seroma after the initial removal of the drain that requires an intervention) in 28%, and grade C lymphatic leakage (causing a reoperation or a subsequent conflict with medical measures) in 33%. The drainage volume on the second postoperative day was a suitable predictor for a complicated lymphatic leakage (grades B and C) with a cutoff of 110 ml. CONCLUSION: The proposed definition is clinically relevant, is easy to employ, and may serve as the definition of a standardized endpoint for the assessment of lymphatic morbidity after RILND in future studies.

Tissue sealants for the prevention of lymphoceles after radical inguinal lymph node dissection in patients with melanoma: A systematic review and individual patient data meta-analysis.

BACKGROUND AND OBJECTIVES: Postoperative lymphoceles and further wound complications occur frequently after radical inguinal lymph node dissection (ILND). In various studies, tissue sealants have shown to reduce the incidence of postoperative morbidity. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the effectiveness of tissue sealants in reducing the incidence of postoperative lymphoceles following ILND in patients with melanoma was conducted. Individual patient data was requested to pool the data for meta-analysis appropriately. RESULTS: Thousand seven hundred twenty-nine manuscripts were screened for eligibility. Six RCTs published between 1986 and 2012 were identified including 194 patients for ILND. Only four RCTs were included in the meta-analysis. No study properly defined the term "lymphocele." Tissue sealants failed to influence the duration of drain placement (mean difference [MD] = -3.05 days; z = 1.18; P = 0.24), total drainage volume (MD = 598.39 mL; z = 1.49; P = 0.14), the incidence of postoperative seroma, wound infection and skin necrosis. CONCLUSIONS: No improvement was identified with the use of tissue sealants, however, a valid comparison of the results of included trials was difficult owing to the lack of a definition of the term "lymphocele." Other surgical techniques and trials using validated endpoint definitions are required to reevaluate these findings.

[Videoendoscopic Minimally Invasive Inguinal Lymphadenectomy: an Alternative to Open Inguinal Lymphadenectomy with fwer Complications]. / Videoendoskopische minimalinvasive inguinale Lymphknotenentfernung: eine komplikationsärmere Alternative zur offenen inguinalen Lymphadenektomie.

OBJECTIVE: Radical inguinal lymphadenectomy is a standardised operation, which is exhibits high morbidity of up to 77%. These complications often lead to a delay in the planned adjuvant therapy. The objective of this video is to present videoendoscopic inguinal lymphadenectomy (VEIL), which seems to show less morbidity. INDICATION: There is no difference between the indications for open lymphadenectomy and VEIL. Prior excision of a sentinel lymph node is not a contraindication. METHOD: After blunt dissection of the subcutaneous tissue with exposure of Scarpa's fascia, 3 - 4 ports are placed in the preformed space. The femoral lymph nodes are dissected under insufflation of CO2 and the tissue is removed in a retrieval bag. CONCLUSION: Several studies have shown that VEIL offers a good alternative to open lymphadenectomy, with fewer complications, particularly with respect to wound healing.

Non-invasive positive pressure ventilation improves lung volumes in the obesity hypoventilation syndrome.

BACKGROUND: Our objective was to study the long-term effects of non-invasive positive pressure ventilation (NPPV) on lung function and gas exchange in patients with the obesity hypoventilation syndrome (OHS). DESIGN: Prospective observational study in OHS patients performing NPPV over a period of 24 months. RESULTS: We studied 35 clinically stable OHS patients with a mean body mass index (BMI) 45.9+/-8.8 kg/m(2) and daytime PaCO(2) at room air of 6.92+/-0.48 kPa at baseline. Nocturnal NPPV was initiated with pressure-cycled devices on IPAP 24+/-3 cm H(2)O, EPAP 6+/-2 cm H(2)O and respiratory frequency of 18.8+/-3.7/min. After 12 and 24 months of NPPV hypercapnia was persistently normalized and hypoxemia was markedly improved while no changes in calculated alveolar-arterial oxygen difference occurred. Augmented ventilation was followed by a significant reduction in hemoglobin and hematocrit (P<0.001 each). Daily duration of ventilator use significantly correlated with the decrease in PaCO(2) after 12 months (r = 0.37; P<0.05) and 24 months (r = 0.47; P<0.05). Vital capacity (VC) and expiratory reserve volume (ERV) significantly increased after 12 and 24 months NPPV compared to the baseline values, though BMI was only slightly reduced. The 2-year survival rate was 91% with three patients (9%) discontinuing NPPV during the study period. CONCLUSION: Long-term domiciliary NPPV normalizes hypercapnia and markedly improves hypoxemia as well as polycythemia in OHS patients. In addition, NPPV leads to a significant reduction in restrictive ventilatory disturbance, predominantly by increasing ERV. Application of high inspiratory pressures and good adherence to therapy are presumed to be the basis for the beneficial effects of NPPV in OHS.

Impact of ventilation parameters and duration of ventilator use on non-invasive home ventilation in restrictive thoracic disorders.

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) is an accepted treatment option for chronic ventilatory failure due to restrictive thoracic disorders. OBJECTIVE: The impact of ventilation setting and the duration of ventilator use on changes in physiological and functional parameters has not yet been evaluated. METHODS: Effects of NPPV on body plethysmographic parameters, blood gas tension and inspiratory muscle function up to 12 months were analyzed in 44 patients with thoracic cage abnormalities in a clinical stable condition. Furthermore, the influence of ventilator parameters and the duration of ventilator use on these changes was determined. RESULTS: A significant improvement in blood gas parameters (PaCO(2), PaO(2) and base excess; p < 0.001), lung volumes (VC, TLC and FEV(1); p < 0.001) and inspiratory muscle function (PI(max), P(0.1); p < 0.01 and p < 0.05) was found after 3.8 +/- 0.8 months of treatment. As shown by a subgroup analysis, changes were already achieved within the first 3 months of NPPV and then remained stable over time. Improvements in VC were positively correlated with IPAP (r = 0.55; p < 0.001). Reduction in PaCO(2) was positively correlated with the quotient (IPAP - EPAP)/weight (r = 0.55; p < 0.001). No correlation could be detected between changes in functional parameters and the duration of ventilator use. CONCLUSIONS: NPPV can improve blood gas parameters, lung volume and inspiratory muscle function in thoracic restrictive disorders. To best utilize the potential of NPPV treatment, it seems to be more effective to optimize pressure levels than to extend the duration of ventilation.

Long-term reduction of hyperinflation in stable COPD by non-invasive nocturnal home ventilation.

OBJECTIVE: The role of non-invasive positive pressure ventilation (NPPV) in stable COPD with chronic ventilatory failure remains controversial. The impact of long-term home nocturnal NPPV treatment on deflation has not yet been evaluated in detail. METHODS: Retrospective explorative study of 46 patients with stable COPD undergoing NPPV treatment. Effects of NPPV on body plethysmographic parameters, blood gas tensions and inspiratory muscle function after 6.2 (+/-1.7) and 12.7 (+/-2.1) months of treatment. Further, evaluation of 1-year survival, compliance and ventilation parameters. RESULTS: One-year survival was 89.1%. The effectiveness of ventilation was proven by a significant reduction in nocturnal and daytime PaCO2. We observed a decrease in the ratio of residual volume (RV) to total lung capacity (TLC) on the average of 5.2+/-9.8% (or 15.2+/-29.7% pred.; P<0.01) at six and 3.9+/-9.0% (or 12.9+/-18.6% pred.; P<0.001) at 12 months. As a consequence, we found significant improvements in inspiratory capacity (IC), vital capacity (VC) and forced expiratory volume in one second (FEV1). For patients with the most severe hyperinflation (RV/TLC>75%), we found a significant positive correlation between inspiratory positive airway pressure (IPAP) and reductions in PaCO2 (r=0.56; P<0.05) and RV/TLC (r=0.50; P<0.05). CONCLUSIONS: In severe hypercapnic stable COPD long-term nocturnal NPPV can reduce hyperinflation with sustained improved daytime blood gas parameters.