A comparison of textured vs smooth surfaced implants in sub fascial breast augmentation.

BACKGROUND: Subfascial placement of breast implants has the advantages of subglandular and submuscular placement without the adverse outcomes. This study examined the differences in outcomes between textured and smooth implants. METHODS: A total of 385 patients underwent subfascial breast augmentation in two cohorts. The initial series (n=209) employed textured implants and the second (n=176) employed smooth implants. In all other respects, patient management was identical. Adverse outcomes, changes in breast morphometry, and patient satisfaction were compared between the two groups. RESULTS: The follow-up period ranged from to 74-272 weeks for smooth implants (mean 164 weeks, STD 50.6) and 78-279 weeks for textured implants (mean= 186 weeks, STD=54). The incidence of capsular contracture was the same for smooth and textured implants (4.7% and 6.2%, P=.64). Changes in breast shape at the lower pole, patient satisfaction, and the incidence of other adverse outcomes were the same in both groups. CONCLUSIONS: Subfascial placement of smooth and textured breast implants yielded similar outcomes.

Testing Mechanical Properties of Silicone Gel-Filled Breast Implants and Their Degradation.

Breast augmentation procedures using silicone implants have become increasingly popular over the past six decades. This article addresses the concerns of patients regarding implant strength by providing clinicians with valuable information in addition to video and pictorial evidence to share, fostering reassurance. The article focuses on the structural integrity and stability of breast implants, which play a critical role in their long-term performance and patient satisfaction. Specifically, it examines the industry standards outlined by the International Organization for Standardization (ISO), with a particular emphasis on ISO14607-2018, which encompasses a range of mechanical and physio-mechanical tests, including the assessment of silicone gel-fill firmness, evaluation of shell integrity, and examination of the impact of environmental conditions on implant performance. Breast implants are not static devices and are subject to aging and fatigue-based degradation. This emphasizes the need for ongoing monitoring and evaluation to ensure the long-term safety and satisfaction of patients. By providing a comprehensive examination of breast implant structure and industry standards, this article equips clinicians with the necessary knowledge to address patient concerns and foster confidence in the safety and longevity of breast augmentation procedures using silicone implants.Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of acute cannabis inhalation on reaction time, decision-making, and memory using a tablet-based application.

BACKGROUND: Acute cannabis use has been demonstrated to slow reaction time and affect decision-making and short-term memory. These effects may have utility in identifying impairment associated with recent use. However, these effects have not been widely investigated among individuals with a pattern of daily use, who may have acquired tolerance. The purpose of this study was to examine the impact of tolerance to cannabis on the acute effects as measured by reaction time, decision-making (gap acceptance), and short-term memory. METHODS: Participants (ages 25-45) completed a tablet-based (iPad) test battery before and approximately 60 min after smoking cannabis flower. The change in performance from before to after cannabis use was compared across three groups of cannabis users: (1) occasional use (n = 23); (2) daily use (n = 31); or (3) no current use (n = 32). Participants in the occasional and daily use group self-administered ad libitum, by smoking or vaping, self-supplied cannabis flower with a high concentration of total THC (15-30%). RESULTS: The occasional use group exhibited decrements in reaction time (slowed) and short-term memory (replicated fewer shapes) from before to after cannabis use, as compared to the no-use group. In the gap acceptance task, daily use participants took more time to complete the task post-smoking cannabis as compared to those with no use or occasional use; however, the level of accuracy did not significantly change. CONCLUSIONS: The findings are consistent with acquired tolerance to certain acute psychomotor effects with daily cannabis use. The finding from the gap acceptance task which showed a decline in speed but not accuracy may indicate a prioritization of accuracy over response time. Cognitive and psychomotor assessments may have utility for identifying impairment associated with recent cannabis use.

Accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking.

INTRODUCTION: Cannabis intoxication may increase the risk of motor vehicle crashes. However, reliable methods of assessing cannabis intoxication are limited. The presence of eyelid tremors is among the signs of cannabis use identified under the Drug Evaluation and Classification Program of the International Association of Chiefs of Police. Our objectives were to assess the accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking using a blinded, controlled study design. METHODS: Adult subjects (N = 103) were recruited into three groups based on their cannabis use history: daily, occasional, and no current cannabis use. Participants' closed eyelids were video recorded for 30 seconds by infrared videography goggles before and at a mean ± standard deviation time of 71.4 ± 4.6 minutes after the onset of a 15-minute interval of ad libitum cannabis flower smoking or vaping. Three observers with expertise in neuro-ophthalmology and medical toxicology were trained on exemplar videos of eyelids to reach a consensus on how to grade eyelid tremor. Without knowledge of subjects' cannabis use history or time point (pre- or post-smoking), observers reviewed each video for eyelid tremor graded as absent, slight, moderate, or severe. During subsequent data analysis, this score was further dichotomized as a consensus score of absent (absent/slight) or present (moderate/severe). RESULTS: Kappa and intraclass correlation coefficient statistics demonstrated moderate agreement among the coders, which ranged from 0.44-0.45 and 0.58-0.61, respectively. There was no significant association between recent cannabis use and the observers' consensus assessment that eyelid tremor was present, and cannabis users were less likely to have tremors (odds ratio: 0.75; 95 percent confidence interval: 0.25, 2.40). The assessment of eyelid tremor as an indicator of recent cannabis smoking had a sensitivity of 0.86, specificity of 0.18, and accuracy of 0.64. DISCUSSION: Eyelid tremor has fair sensitivity but poor specificity and accuracy for identification of recent cannabis use. Inter-rater reliability for assessment of eyelid tremor was moderate for the presence and degree of tremor. The weak association between recent cannabis use and eyelid tremor does not support its utility in identifying recent cannabis use. LIMITATIONS: Videos were recorded at only one time point after cannabis use. Adherence to abstinence could not be strictly supervised. Due to regulatory restrictions, we were unable to control the cannabis product used or administer a fixed Δ9-tetrahydrocannabinol dose. Participants were predominately non-Hispanic and White. CONCLUSIONS: In a cohort of participants with a range of cannabis use histories, acute cannabis smoking was not associated with the presence of eyelid tremor, regardless of cannabis use history, at 70 minutes post-smoking. Additional research is needed to identify the presence of eyelid tremor accurately, determine the relationship between cannabis dose and timeline in relation to last cannabis use to eyelid tremor, and determine how it should be, if at all, utilized for cannabis Drug Recognition Evaluator examinations.

The Effect of Drains and Compressive Garments Versus Progressive Tensioning Sutures on Seroma Formation in Abdominoplasty.

Seroma is a common problem following abdominoplasty surgery. Both compressive garments with drains and progressive tension sutures have their advocates to minimise seroma formation. This is a retrospective study in which patients underwent an identical surgical procedure, except for use of drains and garments in comparison to progressive tension sutures between 2005 and 2020. Two hundred thirty-two patients were included in the study 61 in the drains and garment group (DG group), and 171 with progressive tension sutures (PTS group) alone. There was a lower incidence of seroma formation in the PTS group (X2 (1, N = 232) = 6.35, P = .012). The weight of tissue excised in the PTS group was greater than the DG group (P < .001). There was there a significantly higher tissue excision weights for patients who developed a seroma, compared with those who did not (P=.02). Patients, who developed a seroma in the PTS group, had significantly greater excision weights than the DG group. Liposuction did not change the incidence of seroma in each group (X2 (4, N = 232) = 6.701, P = .08 n/s). This study demonstrates the effectiveness of progressive tension sutures in reducing the incidence of seroma formation following abdominoplasty, particularly when large excision weights are involved. The addition of small volume liposuction distant to the abdominal flap does not increase the incidence of seroma formation.Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Asking questions that matter - Question prompt lists as tools for improving the consent process for neurotechnology clinical trials.

Implantable neurotechnology devices such as Brain Computer Interfaces (BCIs) and Deep Brain Stimulators (DBS) are an increasing part of treating or exploring potential treatments for neurological and psychiatric disorders. While only a few devices are approved, many promising prospects for future devices are under investigation. The decision to participate in a clinical trial can be challenging, given a variety of risks to be taken into consideration. During the consent process, prospective participants might lack the language to consider those risks, feel unprepared, or simply not know what questions to ask. One tool to help empower participants to play a more active role during the consent process is a Question Prompt List (QPL). QPLs are communication tools that can prompt participants and patients to articulate potential concerns. They offer a structured list of disease, treatment, or research intervention-specific questions that research participants can use as support for question asking. While QPLs have been studied as tools for improving the consent process during cancer treatment, in this paper, we suggest they would be helpful in neurotechnology research, and offer an example of a QPL as a template for an informed consent tool in neurotechnology device trials.

Influence of cannabis use history on the impact of acute cannabis smoking on simulated driving performance during a distraction task.

Objective: This research explores the driving performance of people who use cannabis daily or occasionally during distraction tasks performed following acute cannabis use.Methods: Healthy adults aged 25 to 45 years with different cannabis usage histories were recruited to participate in a within-subjects controlled experiment using a car-based driving simulator. Participants were classified as having daily use (n = 31), occasional use (1 or 2 times per week; n = 24), or no-use (n = 30). Participants completed a practice drive followed by four 5-10 minute driving scenarios during the baseline period. Participants then smoked self-procured cannabis flower ad libitum for up to 15 minutes. Thirty minutes later, they completed four additional 5-10 minute scenarios. Scenarios were paired according to difficulty and randomized across the baseline and post-use periods. Each scenario contained between 0 and 3 repetitions of a distraction task where the participant was prompted by an audio message to select an app from a 4 × 5 grid displayed on a mounted tablet, a step that would require briefly looking away from the roadway. Measures of driving performance (lane departures, standard deviation of lateral position) were assessed during the five-second period following the audio trigger and analyzed using generalized linear mixed models.Results: Those with a pattern of occasional use were significantly more likely to experience a lane departure during distraction periods after acute cannabis use relative to baseline (OR = 3.71, p = 0.04, CI = 1.04, 13.17), while those with daily use did not exhibit a similar increase (OR = 1.56, p = 0.43, CI = 0.52, 4.64). Changes in departure risk were significantly greater for the occasional use group compared to no-use (p = 0.02), but not for the daily use group compared to no-use (p = 0.18). However, following acute use, those who use daily exhibited decreases in speed relative to baseline in comparison to the changes observed in the no-use group (p = 0.02), while differences between occasional and no-use did not reach statistical significance (p = 0.052). Differences in standard deviation of lateral position were not statistically significant, likely due to the short duration of tasks.Conclusions: These results find the largest potential safety concerns associated with a pattern of occasional use, who displayed an increase in lane departures after acute cannabis smoking. Those in the daily use group decreased their speed, which may be interpreted as compensation for drug effects. Further research is needed to understand the effects during longer and more complex secondary tasks.

Biomechanical Principles of Breast Implants and Current State of Research in Soft Tissue Engineering for Cosmetic Breast Augmentation.

Currently there are limited implant-based options for cosmetic breast augmentation, and problems associated with those have been increasingly appreciated, most commonly capsular contracture, which occurs due to a chronic foreign body reaction against non-degradable implant materials such as silicone and polyurethane leading to scar tissue formation, pain, and deformity. The underlying biomechanical concepts with implants create a reciprocal stress-strain relationship with local tissue, whilst acting as a deforming force. This means that with time, as the implant continues to have an effect on surrounding tissue the implant and host's biomechanical properties diverge, making malposition, asymmetry, and other complications more likely. Research directed towards development of alternative therapies based on tissue engineering and regenerative medicine seeks to optimize new tissue formation through modulation of tissue progenitors and facilitating tissue regeneration. Scaffolds can guide the process of new tissue formation by providing both an implant surface and a three-dimensional space that promotes the development of a microenvironment that guides attachment, migration, proliferation, and differentiation of connective tissue progenitors. Important to scaffold design are the architecture, surface chemistry, mechanical properties, and biomaterial used. Scaffolds provide a void in which vascularization, new tissue formation, and remodelling can sequentially occur. They provide a conduit for delivery of the different cell types required for tissue regeneration into a graft site, facilitating their retention and distribution. Whilst recent research from a small number of groups is promising, there are still ongoing challenges to achieving clinical translation. This article summarizes the biomechanical principles of breast implants, how these impact outcomes, and progress in scaffold-guided tissue engineering approaches to cosmetic breast augmentation. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Long-term laryngotracheal complications following cardiac surgery.

BACKGROUND AND AIM OF THE STUDY: Long-term laryngotracheal complications have not been described in adult patients undergoing cardiac surgery. The purpose of this study was to determine the incidence of and risk factors for laryngotracheal complications following cardiac surgery. METHODS: A retrospective chart review of patients at high risk for laryngotracheal complications following cardiac surgery between 2006 and 2016 was performed. High-risk patients were reviewed to determine the presence of laryngotracheal complications including laryngotracheal stenosis, keyhole deformity, or vocal cord immobility. Logistic regression was used to identify predictors of long-term laryngotracheal complications. RESULTS: Of 11,417 patients who underwent cardiac surgery, 1099 were identified as at high risk. Of these, 24 (2.2%) developed laryngotracheal complications following their surgery and intensive care unit (ICU) stay. Laryngotracheal stenosis and keyhole deformity were present in 13 (1.2%) and 6 (0.5%) patients, respectively. Logistic regression demonstrated older age (age ≥ 70 odds ratio [OR] 0.31, 95% confidence interval [CI] 0.12-0.83) was protective, while readmission to ICU for ventilation (OR 3.11, 95% CI 1.17-8.25) and receiving a tracheostomy (OR 7.83, 95% CI 2.22-27.6) were associated with laryngotracheal complications. CONCLUSIONS: The incidence of long-term laryngotracheal complications following cardiac surgery was 2.2%. Readmission to ICU for ventilation and having a tracheostomy performed were associated with laryngotracheal complications.

An Analysis of Ptosis following Subfascial Breast Augmentation: Calculations That Explain Dogma.

BACKGROUND: Implant placement can improve ptosis due to the position of the nipple, inframammary crease, and base of the breast acting together. The interrelationship between these was quantified via changes in morphometry following subfascial augmentation, and explains the circumstances under which dogma holds true. METHODS: One hundred seventy-five patients underwent a series of static measurements before and 3 months after subfascial breast augmentation. Ptosis in the nipple and base of the breast was calculated before and after surgery. RESULTS: All measurements except that of the the lateral sternal margin increased after surgery. All grades of ptosis reduced following surgery. There was lowering of the base in grade 1 patients, but not for other grades. Increased base ptosis correlated with reduced lateral sternal margin (1.9 cm compared with 2.9 cm; left, H5 = 24.7, p < 0.01; right, H5 = 24.5, p < 0.01). Implant volume did not correlate with change in ptosis at the nipple or base. Reduced ptosis was associated with implants that are a narrow match of implant to breast (0.52 to 0.95) (left, H5 = 28.3, p < 0.01; right, H5 = 24.9, p < 0.01). Decreasing ptosis correlated with lower lateral sternal margin compared to breasts that increased ptosis. Change in ptosis following surgery does not correlate with having children. CONCLUSIONS: Subfascial placement has varying effects on ptosis. Non-ptotic or mildly ptotic breasts appear to improve due to a disproportionate descent of the inframammary crease relative to the nipple and base. Patients with little breast tissue are more susceptible to an increase in "bottoming out," particularly if broad implants are used. A ratio matching implant to the base width has predictive value on outcome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Application of Enhanced Recovery After Surgery in Patients Undergoing Kidney Transplant: the Belfast Protocol.

BACKGROUND: The aim of this study was to assess the impact of the Belfast Protocol for enhanced recovery after surgery on hospital length of stay (LOS) after kidney transplant. METHODS: A prospectively collected database was analyzed for all consecutive renal transplant recipients in 2010 and compared with consecutive renal transplant recipients in 2018 before and immediately after the full implementation of the Belfast Protocol. RESULTS: There were 73 renal transplants in 2010 and 115 in 2018. Between 2010 and 2018 there was a significant decrease in LOS from 12 to 7 days (P < .0001). Compared with 2010, in 2018 there was a significant increase in donor age (47 vs 54 years, P < .0001) and kidney transplant from donation after circulatory death donors (0% vs 9%, P < .0001). Although there was no change in the proportion of living donors (59% vs 50%, P = .32), in 2018 there were more blood group incompatible living donors (0% vs 7%, P = .21). Compared with 2010, in 2018 there was a significant increase in recipient age (43 vs 54 years, P = .0002), diabetic nephropathy (5% vs 16%, P = .03), and recipient body mass index >35 kg/m2 (0% vs 9%, P = .02). CONCLUSIONS: Implementation of the Belfast Protocol has decreased LOS in renal transplant recipients despite increasingly complex donor and recipient profiles.

Simulated driving performance among daily and occasional cannabis users.

OBJECTIVE: Daily cannabis users develop tolerance to some drug effects, but the extent to which this diminishes driving impairment is uncertain. This study compared the impact of acute cannabis use on driving performance in occasional and daily cannabis users using a driving simulator. METHODS: We used a within-subjects design to observe driving performance in adults age 25 to 45 years with different cannabis use histories. Eighty-five participants (43 males, 42 females) were included in the final analysis: 24 occasional users (1 to 2 times per week), 31 daily users and 30 non-users. A car-based driving simulator (MiniSim™, National Advanced Driving Simulator) was used to obtain two measures of driving performance, standard deviation of lateral placement (SDLP) and speed relative to posted speed limit, in simulated urban driving scenarios at baseline and 30 min after a 15 min ad libitum cannabis smoking period. Participants smoked self-supplied cannabis flower product (15% to 30% tetrahydrocannabinol (THC). Blood samples were collected before and after smoking (30 min after the start of smoking). Non-users performed the same driving scenarios before and after an equivalent rest interval. Changes in driving performance were analyzed by repeated measures general linear models. RESULTS: Mean whole blood THC cannabinoids concentrations post smoking were use THC = 6.4 ± 5.6 ng/ml, THC-COOH = 10.9 ± 8.79 ng/mL for occasional users and THC = 36.4 ± 37.4 ng/mL, THC-COOH = 98.1 ± 90.6 ng/mL for daily users. On a scale of 0 to 100, the mean post-use score of subjective high was similar in occasional users and daily users (52.4 and 47.2, respectively). In covariate-adjusted analysis, occasional users had a significant increase in SDLP in the straight road segment from pre to post compared to non-users; non-users decreased by a mean of 1.1 cm (25.5 cm to 24.4 cm) while occasional users increased by a mean of 1.9 cm (21.7 cm to 23.6 cm; p = 0.02). Daily users also increased adjusted SDLP in straight road segments from baseline to post-use (23.2 cm to 25.0 cm), but the change relative to non-users was not statistically significant (p = 0.08). The standardized mean difference in unadjusted SDLP from baseline to post-use in the straight road segments comparing occasional users to non-users was 0.64 (95% CI 0.09 - 1.19), a statistically significant moderate increase. When occasional users were contrasted with daily users, the baseline to post changes in SDLP were not statistically significant. Daily users exhibited a mean decrease in baseline to post-use adjusted speed in straight road segments of 1.16 mph; a significant change compared to slight speed increases in the non-users and occasional users (p = 0.02 and p = 0.01, respectively). CONCLUSION: We observed a decrement in driving performance assessed by SDLP after acute cannabis smoking that was statistically significant only in the occasional users in comparison to the nonusers. Direct contrasts between the occasional users and daily users in SDLP were not statistically significant. Daily users drove slower after cannabis use as compared to the occasional use group and non-users. The study results do not conclusively establish that occasional users exhibit more driving impairment than daily users when both smoke cannabis ad libitum.

Observations Concerning the Match between Breast Implant Dimensions, Breast Morphometry, and a Patient-reported Outcome.

BACKGROUND: Outcome studies in breast augmentation do not assess how an implant has been matched to the soft tissue envelope. The study hypothesis is that there is a relationship between breast and implant dimensions and the subjective outcome of patient satisfaction. METHODS: In a study of patients undergoing subfascial breast augmentation (n = 341), morphometric measurements and a postsurgical survey of satisfaction with breast size were performed 3 months postoperatively. A ratio empirically derived from breast width, implant width, and projection (Rib) was calculated in patients who wished to have smaller, bigger, or no change in their implant size. RESULTS: 76% were content with breast size, 16.7% wished to be larger, and 7.3% wished to be smaller. Rib differed between groups who did not want to change size (n = 259, mean = 5.8, SD = 0.9), those who wished to be bigger (n = 57, mean = 5.6, SD = 1.1), and those who wished to be smaller (n = 25, mean = 5.3, SD = 1.3, H(341) = 14.0, P < 0.01). Rib differed between groups whose result was as expected (mean = 5.6, SD = 0.9), compared with those who expected to be bigger (mean = 5.4, SD = 1.2) or who expected a smaller outcome (mean = 5.6 SD = 1.0, H(341) = 18.3, P < 0.01). CONCLUSIONS: These data provide an objective measurement by which studies concerning breast augmentation can be reported and compared. The method may guide standardization of clinical research regarding breast implant surgery.

Experimental evaluation of a linear angular momentum multiplexed radio link for moving platforms.

Linear angular momentum multiplexing (LAMM) has recently been proposed for high spectral-efficiency communications between moving platforms, such as between trains and ground infrastructure. We present performance results obtained from a scale experimental system comprising a 2 × 2 antenna system operating at 2.35 GHz. The link transmitted two independent video streams, using RF pre-coding and software-defined radios to modulate and up/down-convert the signals. Linear motion is introduced to demonstrate the translation-invariance of the technique. We interpret the measured data with the aid of an analytical model to show that crosstalk between the two channels is at levels low enough to consistently support the video streams without interruption. Specifically, our results show spectral efficiency is consistently higher when LAMM coding is enabled compared with an uncoded channel.

Plane Change Vs Capsulotomy: A Comparison of Treatments for Capsular Contraction in Breast Augmentation Using the Subfascial Plane.

BACKGROUND: The management of capsular contraction following breast augmentation has numerous, often conflicting potential treatment protocols, each designed to reduce the incidence of further recurrence. The use of the subfascial plane has not been investigated as an alternative to other treatment options. OBJECTIVES: To examine the outcomes from patients presenting with recurrent capsular contraction after being treated for the first capsule by placement of an implant into the subfascial (SF) plane. METHODS: Retrospective analysis of 111 case notes of patients who presented with capsular contraction. 65 had undergone SF augmentation, 17 submuscular (SM) and 29 subglandular (SG) placement of implant at the primary procedure. At a secondary procedure, those with SF implants underwent open capsulotomy and those with SM and SG implants underwent a change in plane to SF. RESULTS: There is a significant difference in the proportion of patients that developed a capsule following the second surgery between the groups that had undergone capsulotomy (SF = 16.9%) or plane change (SM = 47% and SG = 37.9%, X2 (2,111) = 8.6, P = 0.02). When recurrence at the same site was examined, there was also a significant difference between the groups (X2 (2111) = 10.7, P < 0.01). A ruptured implant significantly increased the incidence of further capsular contraction when in the SG plane (X2 (2,29) = 12.1, P < 0.01). CONCLUSIONS: In the absence of implant rupture, changing the plane of an implant to a SF position at revision surgery does not reduce the incidence of subsequent capsular contracture compared with open capsulotomy. Open capsulotomy is a reasonable choice following recurrence of capsular contraction following initial SF placement. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .