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Objective:Peripheral nerve repair is required after traumatic injury. This common condition represents a major public health problem worldwide. Recovery after nerve repair depends on several factors, including the severity of the injury, the nerve involved, and the surgeon’s technical skills. Despite the precise microsurgical repair of nerve lesions, adequate functional recovery is not always achieved and, therefore, the regeneration process and surgical techniques are still being studied. Pre-clinical animal models are essential for this research and, for this reason, the focus of the present systematic review (according to the PRISMA statement) was to analyze the different animal models used in pre-clinical peripheral nerve repair studies.Data sources:Original articles, published in English from 2000 to 2018, were collected using the Web of Science, Scopus, and PubMed databases.Data selection:Only preclinical trials on direct nerve repair were included in this review. The articles were evaluated by the first two authors, in accordance with predefined data fields.Outcome measures:The primary outcomes included functional motor abilities, daily activity and regeneration rate. Secondary outcomes included coaptation technique and animal model.Results:This review yielded 267 articles, of which, after completion of the screening, 49 studies were analyzed. There were 1425 animals in those 49 studies, being rats, mice, guinea pigs, rabbits, cats and dogs the different pre-clinical models. The nerves used were classified into three groups: head and neck (11), forelimb (8) and hindlimb (30). The techniques used to perform the coaptation were: microsuture (46), glue (12), laser (8) and mechanical (2). The follow-up examinations were histology (43), electrophysiological analysis (24) and behavioral observation (22).Conclusion:The most widely used animal model in the study of peripheral nerve repair is the rat. Other animal models are also used but the cost-benefit of the rat model provides several strengths over the others. Suture techniques are currently the first option for nerve repair, but the use of glues, lasers and bioengineering materials is increasing. Hence, further research in this field is required to improve clinical practice.

Ischemia reperfusion injury is associated with tissue damage and inflammation, and is one of the main factors causing flap failure in reconstructive microsurgery. Although ischemia-reperfusion (I/R) injury is a well-studied aspect of flap survival, its biological mechanisms remain to be elucidated. To better understand the biological processes of ischemia reperfusion injury, and to develop further therapeutic strategies, the main objective of this study was to identify the gene expression pattern and histological changes in an I/R injury animal model. Fourteen rats (n = 7/group) were randomly divided into control or ischemia-reperfusion group (8 hours of ischemia). Microsurgical anastomoses were objectively assessed using transit-time-ultrasound technology. Seven days after surgery, flap survival was evaluated and tissue samples were harvested for anatomopathological and gene-expression analyses.The I/R injury reduced the survival of free flaps and histological analyses revealed a subcutaneous edema together with an inflammatory infiltrate. Interestingly, the Arginase 1 expression level as well as the ratio of Arginase 1/Nitric oxide synthase 2 showed a significant increase in the I/R group. In summary, here we describe a well-characterized I/R animal model that may serve to evaluate therapeutic agents under reproducible and controlled conditions. Moreover, this model could be especially useful for the evaluation of arginase inhibitors and different compounds of potential interest in reconstructive microsurgery.

At 20 minutes postoperatively, blood flows greater than 0.30 ml/minute are highly suggestive of patency, and flows less than 0.21 ml/minute are highly suggestive of failure. The authors therefore recommend a minimal cutoff flow value of 0.30 ml/minute for vessels ranging from 0.6 to 1.2 mm in diameter to predict long-term postoperative vascular patency.

IntroductionDrowning is one of the most frequent accidents in children. We aimed to describe demographic and epidemiological characteristics of drowned children who required admission to a pediatric intensive care unit (PICU) to identify risk factors to guide possible preventive measures to avoid severe drowning.MethodsWe conducted an observational study for 29 years (retrospective between 1991 and 2004; prospective between 2005 and 2019) that included all children (0–15 years old) requiring PICU admission after drowning. Data regarding patient characteristics, accident circumstances, and neurological outcomes at PICU discharge were analyzed.ResultsA total of 160 patients were included, with no significant decrease over the study period. There was a predominance of males (75%), young age (60%; 1–5 years), summer months (91.1%; May–September), tourists (14.12 [95% confidence interval, 9.2–21.7] times higher risk of drowning than residents), swimming pool accidents (88.8%), and inadequate supervision (77.9%). The mortality was 18.7%, and 7.5% of admitted children had severe neurological sequelae. The initial resuscitation maneuvers by accident witnesses were incorrect in nearly half of the patients in whom these could be analyzed.ConclusionsEmphasis should be placed on implementing preventive measures, focused on the described risk groups, and insisting on adequate supervision, swimming training programs, and training of the general population in safe rescue and cardiopulmonary resuscitation.

The authors report uptake of indocyanine green in five of seven rats at an average of 13 weeks after lymph node transplantation, consistent with the reestablishment of lymphatic drainage into the transplanted nodes.

The aim of this study was to evaluate the prognostic factors of patients admitted to a pediatric intensive care unit (PICU) after drowning.

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