The timing of drain removal—empiricism or science?

Surgical drains are commonly used in plastic surgery. Drains are subsequently removed at arbitrary volumes depending on local protocols. The rational for when to remove a drain has not been scientifically determined. We compared removal of drains at ≤30?ml/24?h vs. ≤50?ml/24?h for 158 wounds, in 90 patients. Postoperative complications, length of hospital stay and resulting cost–benefit were considered. Prospective data were collected for two consecutive similar cohorts of patients undergoing abdominoplasty, bilateral breast reduction and breast augmentation. In the first cohort, drains were removed when drainage was ≤30?ml/24?h and the second cohort when ≤50?ml/24?h. Demographics, days of drainage, surgeon grade and duration of postoperative hospital stay were recorded. Patient records were then analysed and complications recorded, including haematoma, infection, seroma, wound breakdown and fat necrosis. The median postoperative stay for all three operations for both drainage cohorts was similar with no statistically significant difference; however, the drainage time in breast augmentation was significantly less in the <50?ml/24?h group. There were no significant differences in outcome measures between the patients undergoing abdominoplasty, breast reduction or breast augmentation. Drain removal at ≤50 vs. ≤30?ml/24?h did not result in an increase in postoperative morbidity or adverse outcome in any of the three different operation types.     

Methods of Retaining the Suture in a Sub-Cuticular Stitch Using Non Absorbable Suture – Innovations and Diversity of Techniques

Subcuticular sutures have been extensively used for closure of wounds, particularly when good cosmesis is required. Both absorbable and nonabsorbable sutures are used in subcuticular sutures. Nonabsorbable sutures have some distinct advantages over absorbable sutures from cosmetic point of view, when used in subcuticular sutures. The challenge remains in keeping the nonabsorbable suture secure and in situ. We present six different methods of securing the suture in position while closing the wound with a nonabsorbable suture (2-0/3-0 polypropylene, polyamide, or polyethylene).     

Biostatistics Series Module 3: Comparing Groups: Numerical Variables

Numerical data that are normally distributed can be analyzed with parametric tests, that is, tests which are based on the parameters that define a normal distribution curve. If the distribution is uncertain, the data can be plotted as a normal probability plot and visually inspected, or tested for normality using one of a number of goodness of fit tests, such as the Kolmogorov–Smirnov test. The widely used Student''s t-test has three variants. The one-sample t-test is used to assess if a sample mean (as an estimate of the population mean) differs significantly from a given population mean. The means of two independent samples may be compared for a statistically significant difference by the unpaired or independent samples t-test. If the data sets are related in some way, their means may be compared by the paired or dependent samples t-test. The t-test should not be used to compare the means of more than two groups. Although it is possible to compare groups in pairs, when there are more than two groups, this will increase the probability of a Type I error. The one-way analysis of variance (ANOVA) is employed to compare the means of three or more independent data sets that are normally distributed. Multiple measurements from the same set of subjects cannot be treated as separate, unrelated data sets. Comparison of means in such a situation requires repeated measures ANOVA. It is to be noted that while a multiple group comparison test such as ANOVA can point to a significant difference, it does not identify exactly between which two groups the difference lies. To do this, multiple group comparison needs to be followed up by an appropriate post hoc test. An example is the Tukey''s honestly significant difference test following ANOVA. If the assumptions for parametric tests are not met, there are nonparametric alternatives for comparing data sets. These include Mann–Whitney U-test as the nonparametric counterpart of the unpaired Student''s t-test, Wilcoxon signed-rank test as the counterpart of the paired Student''s t-test, Kruskal–Wallis test as the nonparametric equivalent of ANOVA and the Friedman''s test as the counterpart of repeated measures ANOVA.     

Contactins in the central nervous system: role in health and disease

Contactins are a group of cell adhesion molecules that are mainly expressed in the brain and play pivotal roles in the organization of axonal domains, axonal guidance, neuritogenesis, neuronal development, synapse formation and plasticity, axo-glia interactions and neural regeneration. Contactins comprise a family of six members. Their absence leads to malformed axons and impaired nerve conduction. Contactin mediated protein complex formation is critical for the organization of the axon in early central nervous system development. Mutations and differential expression of contactins have been identified in neuro-developmental or neurological disorders. Taken together, contactins are extensively studied in the context of nervous system development. This review summarizes the physiological roles of all six members of the Contactin family in neurodevelopment as well as their involvement in neurological/neurodevelopmental disorders.     

The Association of Respiratory Symptoms and Indoor Housing Conditions Among Migrant Farmworkers in Eastern North Carolina

Farm labor housing has been described as among the worst in the nation, oftentimes with poor and unsanitary indoor living conditions. The objective of this study was to evaluate the association between indoor environmental risk factors and respiratory health among migrant farmworker occupants (N = 352) living in employer-provided housing. A cross-sectional sample of adult Latino male farm laborers were administered a questionnaire to identify the prevalence of major respiratory symptoms. Self-reported and independent observations were made to evaluate environmental respiratory risk factors and indoor housing conditions, including but not limited to, the presence of cockroaches, rodents, pesticides, and visible signs of mold. Spirometry was performed to evaluate lung function using FEV₁ (forced expiratory volume in 1 second), FVC (forced vital capacity), and FEV₁ /FVC ratio. Bivariate analysis was applied to evaluate associations between respiratory symptoms and selected indoor environmental risk factors. Findings for respiratory health included prevalence of wheeze (11.4%), coughing up phlegm (17.3%), tightness of chest (16.8%), and runny or stuffy nose (34.4%). Respiratory risks identified inside the dwellings included the use of pesticides or bug sprays for cockroaches (31.5%), rat or mouse poison (19.5%), visible signs of water damage in the bathroom (22.5%), and mold in the sleeping room (11.1%). Spirometry values were normal for most occupants, although statistically significant associations were found between mold and coughing up phlegm when not having a cold (P = .0262); presence of mold and asthma (P = .0084); pesticides used in the home and tightness of chest (P = .0001); and use of tobacco and coughing up phlegm (P = .0131). Although causal inference can be difficult to establish from a cross-sectional study, findings from this study represents suggestive evidence that indoor environmental risk factors may be contributory factors for respiratory health problems among this vulnerable workgroup population.     

Late Port Site Metastasis from Occult Gall Bladder Carcinoma After Laparoscopic Cholecystectomy for Cholelithiasis: The Role of 18F-FDG PET/CT

Late port site metastasis of gall bladder carcinoma (GBC) after laparoscopic cholecystectomy is a rare finding. Rarer still is such a presentation where the GBC remained occult at histopathology. ¹⁸F-flurodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) can play an important role in this setting by supporting the diagnosis of port site metastasis, by demonstrating additional sites of metastasis, if any, and by ruling out any other primary site. We here present two such patients with late port site metastasis of occult GBC after laparoscopic cholecystectomy for cholelithiasis and discuss the role of ¹⁸F-FDG PET/CT in this setting.