Development of a reliable surgical quality assurance tool for gastrectomy in oncological trials.

BACKGROUND: Despite its recognized importance, there is currently no reliable tool for surgical quality assurance (SQA) of gastrectomy in surgical oncology. The aim of this study was to develop an SQA tool for gastrectomy and to apply this tool within the ADDICT Trial in order to assess the extent and completeness of lymphadenectomy. METHODS: The operative steps for D1+ and D2 gastrectomy have been previously described in the literature and ADDICT trial manual. Two researchers also performed fieldwork in the UK and Japan to document key operative steps through photographs and semi-structured interviews with expert surgeons. This provided the steps that were used as the framework for the SQA tool. Sixty-two photographic cases from the ADDICT Trial were rated by three independent surgeons. Generalizability (G) theory determined inter-rater reliability. D-studies examined the effect of varying the number of assessors and photographic series they rated. Chi-square assessed intra-rater reliability, comparing how the individual assessor's responses corresponded to their global rating for extent of lymphadenectomy. RESULTS: The tool comprised 20 items, including 19 anatomical landmarks and a global rating score. Overall reliability had G-coefficient of 0.557. Internal consistency was measured with a Cronbach's alpha score of 0.869 and Chi-square confirmed intra-rater reliability for each assessor as < 0.05. CONCLUSIONS: A photographic surgical quality assurance tool is presented for gastrectomy. Using this tool, the assessor can reliably determine not only the quality but also the extent of the lymphadenectomy performed based on remaining anatomy rather than the excised specimen.

Toward the unity of pathological and exertional fatigue: A predictive processing model.

Fatigue is a common experience in both health and disease. Yet, pathological (i.e., prolonged or chronic) and transient (i.e., exertional) fatigue symptoms are traditionally considered distinct, compounding a separation between interested research fields within the study of fatigue. Within the clinical neurosciences, nascent frameworks position pathological fatigue as a product of inference derived through hierarchical predictive processing. The metacognitive theory of dyshomeostasis (Stephan et al., 2016) states that pathological fatigue emerges from the metacognitive mechanism in which the detection of persistent mismatches between prior interoceptive predictions and ascending sensory evidence (i.e., prediction error) signals low evidence for internal generative models, which undermine an agent's feeling of mastery over the body and is thus experienced phenomenologically as fatigue. Although acute, transient subjective symptoms of exertional fatigue have also been associated with increasing interoceptive prediction error, the dynamic computations that underlie its development have not been clearly defined. Here, drawing on the metacognitive theory of dyshomeostasis, we extend this account to offer an explicit description of the development of fatigue during extended periods of (physical) exertion. Accordingly, it is proposed that a loss of certainty or confidence in control predictions in response to persistent detection of prediction error features as a common foundation for the conscious experience of both pathological and nonpathological fatigue.

Approaches to reduce neurologic complications during cardiac surgery.

As outcome measures of cardiac surgery are carefully analyzed, neurologic outcomes are a prominent determinant of overall outcome. Sensitive measures of pre- and postoperative neuropsychologic performance and intraoperative emboli reveal a risk group of patients at an advanced age, with severe generalized atherosclerosis who require cardiac surgery. By using the results of observational studies, we have developed a protocol that uses innovative intraoperative techniques to minimize injury and thus improve outcome.