Intrathoracic prosthesis in children in preventing post pneumonectomy syndrome: Its role in congenital single lung and post pneumonectomy situations.

BACKGROUND: Postpneumopnectomy syndrome (PPS) is an extreme rotation and malposition of mediastinum causing dynamic and symptomatic central airway compression, arisingafter pneumonectomy or more uncommonly, in congenital single lung physiology. Affected patients present with severe respiratory compromise. Intrathoracic prosthesis placement is an evolving technique in children that mitigate the effects of thoracic dead space. RESEARCH QUESTION: Assessment of clinical recovery and functional benefit in children undergoing placement of intrathoracic prosthesis following pneumonectomy or in congenital single lung situations. STUDY DESIGN AND METHODS: Retrospective chart review of patients at Great Ormond Street Hospital from 2010 to 2020 was performed of all patients who underwent intrathoracic tissue expander placement. We summarize the outcomes of twenty four children, including those with both congenital and postpneumonectomy PPS etiology. RESULTS: 24 Children who underwent placement of intrathoracic prosthesis for PPS in the study period with median age of 3.5 months and weight of 5 kg. Single lung etiology was congenital in 15 children (6 agenesis, 9 hypoplasia), and postpneumonectomy in 9 children. In seven patients, there was associated long segment tracheal stenosis. Pre operative ECMO was required in 2 patients, and pre operative ventilation was required in 12 patients all of whom had congenital single lung. Intrathoracic prosthesis placement was concurrent with intracardiac repair in 5 patients. There were no operative deaths, but one early postoperative death related to septicaemia. Median follow up was 75 months with 10 patients on continued respiratory support and 3 on nocturnal support with good quality of life. Two children needed reoperations for replacement of prosthesis. CONCLUSION: The use of tissue expanders is within the armamentarium of most plastic surgeons' practice. We also therefore advocate for a collaborative team approach involving Plastic and Cardiothoracic Surgery for surgical treatment of these patients. This multidisciplinary strategy has improved management of this rare and debilitating condition of PPS, thereby offering significant improvements in general progress of these sick children having single lung physiology. Evidence is still lacking on functional outcomes in these children and further work is necessary to prove that this is indeed achievable.

Resident Exposure to Aesthetic Surgical and Nonsurgical Procedures During Canadian Residency Program Training.

North American residency programs are transitioning to competency-based medical education (CBME) to standardize training programs, and to ensure competency of residents upon graduation. At the centre of assessment in CBME are specific surgical procedures, or procedural competencies, that trainees must be able to perform. A study previously defined 31 procedural competencies for aesthetic surgery. In this transition period, understanding current educational trends in resident exposure to these aesthetic procedures is necessary. The aim of this study was to characterize aesthetic procedures performed by Canadian plastic surgery residents during training, as well as to describe resident performance confidence levels and degree of resident involvement during those procedures. Case logs were retrieved from all 10 English-language plastic surgery programs. All aesthetic procedures were identified, and coded according to previously defined core procedural competencies (CPCs) in the aesthetic domain of plastic surgery. Data extracted from each log included the procedure, training program, resident academic year, resident procedural role, and personal competence. From July 2004 to June 2014, 6113 aesthetic procedures were logged by 55 graduating residents. Breast augmentation, mastopexy, and abdominoplasty were the most commonly performed CPCs, and residents report high levels of competence and surgical role in these procedures. Facial procedures, in particular rhinoplasty, as well as nonsurgical CPCs are associated with low exposure and personal competence levels. Canadian plastic surgery residents are exposed to most of the core aesthetic procedural competencies, but the range of procedures performed is variable. With the implementation of CBME, consideration should be given to supplementation where gaps may exist in aesthetic case exposure.

Preconsultation Educational Group Intervention Can Address the Knowledge Gap in Postmastectomy Breast Reconstruction.

BACKGROUND: Whether to undergo postmastectomy breast reconstruction (PMBR) is a challenging, preference-sensitive decision. It is therefore paramount to optimize decision quality through ensuring patients' knowledge and aligning treatments with their personal preferences. This study assessed the effects of a preconsultation educational group intervention (PEGI) on patient knowledge, state-trait anxiety, and decisional conflict (patient uncertainty in decision making) during the decision-making process. METHODS: This phase 3 randomized controlled trial assessed effects of a PEGI in women without active breast cancer undergoing delayed PMBR, or prophylactic mastectomy with immediate PMBR. Both groups underwent routine education before consultation. In addition, the intervention group underwent a PEGI composed of presentations from a plastic surgeon and nurse, a value clarification exercise, and shared experiences from PMBR patients before the consultation with the plastic surgeon. Before and 1-week after consultation, outcome measures were assessed using the Decisional Conflict Scale, State-Trait Anxiety Inventory, and the BREAST-Q. RESULTS: Of the 219 women deemed eligible, a total of 156 women were recruited and randomized. Treatment fidelity was 96% and retention was 88%. At baseline, there were no significant differences in terms of demographic or clinical status, knowledge, state-trait anxiety, and decisional conflict. Patient knowledge about PMBR improved in both groups; however, the degree of knowledge attainment was significantly greater in the PEGI group (24.5% improvement in the intervention group compared with 13.5% in the routine education group, P < 0.001). The reduction in decisional conflict from baseline to follow-up was greater in the intervention group compared with the routine education; however, the difference only approached significance (P = 0.09). CONCLUSIONS: The provision of a preconsultation educational group intervention has been shown to significantly close the knowledge gap on PMBR in patients seeking delayed breast reconstruction or prophylactic mastectomy with immediate breast reconstruction compared with routine education alone.

Burn Care and Surgical Exposure amongst Canadian Plastic Surgery Residents: Recommendations for Transitioning to a Competency-Based Medical Education Model.

With the ongoing implementation of a competency-based medical education (CMBE) model for residency programs in North America, emphasis on the duration of training has been refocused onto ability and competence. This study aims to determine the exposure of burn-related core procedural competencies (CPCs) in Canadian Plastic Surgery Residents in order to enhance curricular development and help define its goals. A retrospective review of burn-related resident case logs encompassing all 10 English-speaking plastic surgery residency programs from 2004 to 2014 was performed, including analysis of personal competence scores and resident role by Postgraduate Year (PGY)-year. Case logs of a total of 55 graduating plastic surgery residents were included in the study. Overall, 4033 procedures in burn and burn-related care were logged, accounting for 6.8% of all procedures logged. On average, each resident logged 73 burn procedures, 99% of which were CPCs. The most frequently performed procedure was harvest and application of autograft, allograft, or xenograft, while emergent procedures such as escharotomy and compartment release were performed on average less than one time per resident. Personal competence scores as well as role of the resident (surgical responsibility) increased as PGY-year progressed during residency. Canadian plastic surgery residency programs provide adequate exposure to the majority of the scope of burn care and surgery. However, infrequently encountered but critical procedures such as escharotomy and fasciotomy may require supplementation through dedicated educational opportunities. CMBE should identify these gaps in learning through facilitation of resident competency evaluation. With consideration for the amount of exposure to burn-related CPCs as identified, plastic surgery residency programs can work toward achieving competency in all aspects of burn care and surgery prior to the completion of residency.

A Case of Keloids Complicated by Castleman's Disease: Interleukin-6 as a Keloid Risk Factor.

Keloids are a manifestation of a fibroproliferative scarring disorder of the skin and develop in response to dermal injury in patients with a susceptible background. Local, systemic, and genetic factors contribute to keloid susceptibility. These factors include tension on the edges of the wound, hormonal influences, and ethnicity, respectively. Castleman's disease is a rare lymphoproliferative disorder that is characterized by the unregulated overproduction of interleukin-6, which leads to systemic lymphadenopathy and constitutional inflammatory symptoms. This case report shows that the bilateral auricular keloids of an adult woman were greatly exacerbated by the onset of Castleman's disease. We present our multimodal management algorithm for auricular keloids, which involves core excision and radiation therapy and achieves excellent aesthetic outcomes. The current treatment pathway for auricular keloids and the possible relationship between interleukin-6 and keloid progression will be discussed.

Anterior Segment Optical Coherence Tomography for Targeted Transconjunctival Suture Placement in Overfiltering Trabeculectomy Blebs.

PURPOSE: To demonstrate the utility of swept-source anterior segment optical coherence tomography (SS-AS-OCT) in guiding placement of transconjunctival sutures in hypotonous patients after a trabeculectomy. PATIENTS AND METHODS: This is a longitudinal case series of 10 eyes from 10 patients who required transconjunctival sutures after a trabeculectomy. SS-AS-OCT was used to aid in the placement of the sutures to improve the function of the overfiltering bleb. RESULTS: SS-AS-OCT reliably identified localized areas of overfiltering, allowing for targeted suture placement in 8 eyes. The 2 eyes in which localized areas of overfiltering were not found required further surgical intervention. CONCLUSIONS: SS-AS-OCT enhances transconjunctival suturing for overfiltering blebs when focal fluid accumulation is visualized.

The role of autonomic efferents and uncoupling protein 1 in the glucose-lowering effect of leptin therapy.

OBJECTIVE: Leptin reverses hyperglycemia in rodent models of type 1 diabetes (T1D). Direct application of leptin to the brain can lower blood glucose in diabetic rodents, and can activate autonomic efferents and non-shivering thermogenesis in brown adipose tissue (BAT). We investigated whether leptin reverses hyperglycemia through a mechanism that requires autonomic innervation, or uncoupling protein 1 (UCP1)-mediated thermogenesis. METHODS: To examine the role of parasympathetic and sympathetic efferents in the glucose-lowering action of leptin, mice with a subdiaphragmatic vagotomy or 6-hydroxydopamine induced chemical sympathectomy were injected with streptozotocin (STZ) to induce hyperglycemia, and subsequently leptin treated. To test whether the glucose-lowering action of leptin requires activation of UCP1-mediated thermogenesis in BAT, we administered leptin in STZ-diabetic Ucp1 knockout (Ucp1 (-/-)) mice and wildtype controls. RESULTS: Leptin ameliorated STZ-induced hyperglycemia in both intact and vagotomised mice. Similarly, mice with a partial chemical sympathectomy did not have an attenuated response to leptin-mediated glucose lowering relative to sham controls, and showed intact leptin-induced Ucp1 expression in BAT. Although leptin activated BAT thermogenesis in STZ-diabetic mice, the anti-diabetic effect of leptin was not blunted in Ucp1 (-/-) mice. CONCLUSIONS: These results suggest that leptin lowers blood glucose in insulin-deficient diabetes through a manner that does not require parasympathetic or sympathetic innervation, and thus imply that leptin lowers blood glucose through an alternative CNS-mediated mechanism or redundant target tissues. Furthermore, we conclude that the glucose lowering action of leptin is independent of UCP1-dependent thermogenesis.

Disrupted Leptin Signaling in the Lateral Hypothalamus and Ventral Premammillary Nucleus Alters Insulin and Glucagon Secretion and Protects Against Diet-Induced Obesity.

Leptin signaling in the central nervous system, and particularly the arcuate hypothalamic nucleus, is important for regulating energy and glucose homeostasis. However, the roles of extra-arcuate leptin responsive neurons are less defined. In the current study, we generated mice with widespread inactivation of the long leptin receptor isoform in the central nervous system via Synapsin promoter-driven Cre (Lepr(flox/flox) Syn-cre mice). Within the hypothalamus, leptin signaling was disrupted in the lateral hypothalamic area (LHA) and ventral premammillary nucleus (PMV) but remained intact in the arcuate hypothalamic nucleus and ventromedial hypothalamic nucleus, dorsomedial hypothalamic nucleus, and nucleus of the tractus solitarius. To investigate the role of LHA/PMV neuronal leptin signaling, we examined glucose and energy homeostasis in Lepr(flox/flox) Syn-cre mice and Lepr(flox/flox) littermates under basal and diet-induced obese conditions and tested the role of LHA/PMV neurons in leptin-mediated glucose lowering in streptozotocin-induced diabetes. Lepr(flox/flox) Syn-cre mice did not have altered body weight or blood glucose levels but were hyperinsulinemic and had enhanced glucagon secretion in response to experimental hypoglycemia. Surprisingly, when placed on a high-fat diet, Lepr(flox/flox) Syn-cre mice were protected from weight gain, glucose intolerance, and diet-induced hyperinsulinemia. Peripheral leptin administration lowered blood glucose in streptozotocin-induced diabetic Lepr(flox/flox) Syn-cre mice as effectively as in Lepr(flox/flox) littermate controls. Collectively these findings suggest that leptin signaling in LHA/PMV neurons is not critical for regulating glucose levels but has an indispensable role in the regulation of insulin and glucagon levels and, may promote the development of diet-induced hyperinsulinemia and weight gain.

Aorto-Tracheopexy in the Treatment of Hunter Syndrome.

Hunter syndrome is a multisystem genetic disease in which a significant proportion of morbidity and mortality arise from respiratory dysfunction. Notably, tracheal abnormalities in Hunter syndrome can compromise clinical stability, and management is primarily supportive. We describe here the first successful implementation of aorto-tracheopexy in a 19-year-old patient as a surgical strategy to resolve progressive respiratory deterioration.

Leptin induces fasting hypoglycaemia in a mouse model of diabetes through the depletion of glycerol.

AIMS/HYPOTHESIS: Leptin has profound glucose-lowering effects in rodent models of type 1 diabetes, and is currently being tested clinically to treat this disease. In addition to reversing hyperglycaemia, leptin therapy corrects multiple lipid, energy and neuroendocrine imbalances in rodent models of type 1 diabetes, yet the precise mechanism has not been fully defined. Thus, we performed metabolic analyses to delineate the downstream metabolic pathway mediating leptin-induced glucose lowering in diabetic mice. METHODS: Mice were injected with streptozotocin (STZ) to induce insulin-deficient diabetes, and were subsequently treated with 20 µg/day recombinant murine leptin or vehicle for 5 to 14 days. Energy-yielding substrates were measured in the liver and plasma, and endogenous glucose production was assessed by tolerance to extended fasting. RESULTS: STZ-leptin-treated mice developed severe hypoketotic hypoglycaemia during prolonged fasting, indicative of suppressed endogenous ketone and glucose production. STZ-leptin mice displayed normal gluconeogenic and glycogenolytic capacity, but had depleted circulating glycerol and NEFA. The depletion of glycerol and NEFA correlated tightly with the kinetics of glucose lowering in response to chronic leptin administration, and was not mimicked by single leptin injection. Administration of glycerol acutely reversed fasting-induced hypoglycaemia in leptin-treated mice. CONCLUSIONS/INTERPRETATION: The findings of this study suggest that the diminution of circulating glycerol reduces endogenous glucose production, contributing to severe fasting-induced hypoglycaemia in leptin-treated rodent models of type 1 diabetes, and support that depletion of glycerol contributes to the glucose-lowering action of leptin.

Pediatric Stinger Syndrome: Acute Brachial Plexopathy After Minor Trauma.

The "stinger" or "burner" is a form of transient brachial plexopathy termed for its characteristic knife-like pain extending from the neck to the fingertips. Muscle weakness and paresthesia are oftentimes associated symptoms and are similarly temporary. Commonly observed in athletes of contact sports, the stinger results from high force trauma causing either traction/direct compression to the brachial plexus or extension/compression of the cervical nerve roots. We describe a pediatric case of a stinger in a 14-year-old boy, which was caused by a relatively low force trauma accident. Our management strategy and recommendations are discussed.

The use of de-epithelialized skin flap in the surgical repair of terminal myelocystoceles.

BACKGROUND: Terminal myelocystocele is a severe form of spinal dysraphism characterized by cystic expansion of the terminal spinal cord that herniates through a deficiency of the posterior sacral spinal elements to fuse with the subcutaneous fat. Postnatal enlargement of the subcutaneous fluid-filled sac may result in progressive neurological deficit and threaten the viability of the overlying skin. Surgical repair entails spinal cord untethering, resection of nonfunctional neural elements and watertight reconstruction of the terminal thecal sac. Young age at the time of surgery, large dural defect, attenuated tissues and locally altered CSF dynamics frequently mean that wound complications including CSF leakage and pseudomeningocele formation are common. TECHNIQUE: With consideration of these requirements, we describe our surgical technique in terminal myelocystocele repair, which combines a novel surgical incision and for the first time in a neurosurgical setting, the use of a de-epithelialized skin flap to augment the closure. We report successful operative outcomes in three infant patients with terminal myelocystocele.

Leptin administration enhances islet transplant performance in diabetic mice.

Islet transplantation is an effective method to obtain long-term glycemic control for patients with type 1 diabetes, yet its widespread use is limited by an inadequate supply of donor islets. The hormone leptin has profound glucose-lowering and insulin-sensitizing action in type 1 diabetic rodent models. We hypothesized that leptin administration could reduce the dose of transplanted islets required to achieve metabolic control in a mouse model of type 1 diabetes. We first performed a leptin dose-response study in C57Bl/6 mice with streptozotocin (STZ)-induced diabetes to determine a leptin dose insufficient to reverse hyperglycemia. Subsequently, we compared the ability of suboptimal islet transplants of 50 or 125 syngeneic islets to achieve glycemic control in STZ-induced diabetic C57Bl/6 mice treated with or without this dose of leptin. The dose-response study revealed that leptin reverses STZ-induced diabetes in a dose-dependent manner. Supraphysiological leptin levels were necessary to restore euglycemia but simultaneously increased risk of hypoglycemia, and also lost efficacy after 12 days of administration. In contrast, 1 µg/day leptin only modestly reduced blood glucose but maintained efficacy throughout the study duration. We then administered 1 µg/day leptin to diabetic mice that underwent transplantation of 50 or 125 islets. Although these islet doses were insufficient to ameliorate hyperglycemia alone, coadministration of leptin with islet transplantation robustly improved control of glucose and lipid metabolism, without increasing circulating insulin levels. This study reveals that low-dose leptin administration can reduce the number of transplanted islets required to achieve metabolic control in STZ-induced diabetic mice.

Ldlr-/- mice display decreased susceptibility to Western-type diet-induced obesity due to increased thermogenesis.

The low-density lipoprotein receptor (Ldlr) is a key molecule involved with lipid clearance. The Ldlr(-/-) mouse has been used extensively as a model for studying atherosclerosis. This study sought to characterize the energy balance phenotype of Ldlr(-/-) mice with respect to weight gain, body composition, energy expenditure (EE), glucose homeostasis, and leptin sensitivity. Adult Ldlr(-/-) mice and Ldlr(+/+) controls on a C57Bl/6J background were fed either a chow or a high-fat, high-sucrose Western-type diet (WTD) for eight wk. Physiological studies of food intake, EE, activity, insulin sensitivity, and leptin responsiveness were performed. The effect of these diet interventions on circulating leptin and on leptin gene expression was also examined. On the chow diet, Ldlr(-/-) mice had lower EE and higher activity levels relative to controls. On the WTD, Ldlr(-/-) mice gained less weight relative to Ldlr(+/+) mice, specifically gaining less fat mass. Increased thermogenesis in Ldlr(-/-) mice fed the WTD was detected. Additionally, leptin responsiveness was blunted in chow-fed Ldlr(-/-) mice, suggesting a novel role for the Ldlr pathway that extends to leptin's regulation of energy balance. In addition to its known role in lipid transport, these results demonstrate the importance of the Ldlr in energy homeostasis and suggest a direct physiological link between altered lipid transport and energy balance.