Sex-based Disparities in the Management of Pediatric Gonadal Torsion.

INTRODUCTION: In 2015, the U.S. News and World Report (USNWR) implemented a quality metric to expedite surgery for testicular torsion (TT), but not ovarian torsion (OT). This study examined OR timing among children with suspected TT and OT before and after this metric. METHODS: A single-center retrospective cohort study of children (1-18yr) who underwent surgery for suspected gonadal torsion was performed. Time to OR (TTOR) from hospital presentation to surgery start was calculated. An interrupted time series analysis identified changes in TTOR for suspected TT versus OT after the 2015 USNWR quality metric. RESULTS: Overall, 216 patients presented with TT and 120 with OT. Median TTOR for TT was 147 min (IQR:99-198) versus 462 min (IQR:308-606) for OT. Post-quality metric, children with TT experienced a 27.8 min decrease (95% CI:-51.7,-3.9, p = 0.05) in annual median TTOR. No significant decrease was observed for children with OT (p = 0.22). Children with history of a known ovarian mass (N = 62) experienced a shorter TTOR compared to those without (422 vs 499min; p = 0.04). CONCLUSION: Implementation of a national quality metric for TT expedited surgical care for children with TT, but not children with OT. These findings highlight the need for equitable quality metrics for children presenting with suspected gonadal torsion. LEVEL OF EVIDENCE: III. TYPE OF STUDY: Retrospective Comparative Study, Observational Cohort Study.

A Standardized Post-gastrostomy Feeding Protocol for Pediatric Patients Reduces Time to Postoperative Goal Feeding Volume.

BACKGROUND: Gastrostomy creation is a common pediatric surgical procedure, but the time to initiation of feeds and to goal feeding volumes postoperatively varies greatly. Delays in reaching goal feeding volumes promote malnutrition and may prolong hospital length of stay. We hypothesized that implementing an accelerated, standardized post-gastrostomy feeding protocol would allow patients to reach goal feeding volumes sooner, without increasing postoperative complications. METHODS: We conducted a retrospective cohort study of children who underwent gastrostomy tube placement between 1/1/2022 and 11/30/2023. The feeding protocol was implemented on 11/16/2022, with patients separated into pre- and post-protocol cohorts. Abstracted data included comorbidities, time to initiation of enteral feeds, time to goal feeding volume, and postoperative complications. RESULTS: 322 patients were included: 166 pre-protocol and 156 post-protocol. The post-protocol cohort had a greater proportion of patients with gastrointestinal and/or cardiac comorbidities (P < .001). Through the protocol, postoperative enteral feeds were initiated significantly faster (5.4 hrs [IQR 43-7.7] vs 7.0 hrs [IQR 5.6-14.3]; P < .001). The post-protocol cohort also achieved goal feeding volumes sooner (12.8 hrs [IQR 9.1-25.3] vs 26.3 hrs [IQR 21.6-38.9]; P < .001). Postoperative complication rates did not differ between cohorts. Sub-analysis of children with complex cardiac conditions also demonstrated faster time to goal nutrition without an associated increase in postoperative events. DISCUSSION: These findings demonstrate that our accelerated post-gastrostomy feeding protocol was effective in achieving goal enteral nutrition earlier without increasing postoperative adverse outcomes. This protocol may be used by other centers to safely expedite time to goal enteral feeds in children postoperatively.

Differential RNA Expression Between Metastatic and Primary Neuroblastoma Cells.

INTRODUCTION: Neuroblastoma (NB) is the most common extra-cranial malignancy in children. Poor survival in high-risk NB is attributed to recurrent metastatic disease. To better study metastatic disease, we used a novel mouse model to investigate differential gene expression between primary tumor cells and metastatic cells. We hypothesized that metastatic NB cells have a different gene expression profile from primary tumor cells and cultured cells. METHODS: Using three human NB cell lines (NGP, CHLA255, and SH-SY5Y), orthotopic xenografts were established in immunodeficient nod/scid gamma mice via subcapsular renal injection. Mice were sacrificed and NB cells were isolated from the primary tumor and from sites of metastasis (bone marrow, liver). RNA sequencing, gene set analysis, and pathway analysis were performed to identify differentially expressed genes and molecular pathways in the metastatic cells compared to primary tumor cells. RESULTS: There were 266 differentially expressed genes in metastatic tumor cells (bone marrow and liver combined) compared to primary tumor cells. The top upregulated gene was KCNK1 and the top downregulated genes were PDE7B and NEBL. Top upregulated pathways in the metastatic cells were involved in ion transport, cell signaling, and cell proliferation. Top downregulated pathways were involved in DNA synthesis, transcription, and cellular metabolism. CONCLUSIONS: In metastatic NB cells, our study identified the upregulation of biologic processes involved in cell cycle regulation, cell proliferation, migration, and invasion. Ongoing studies aim to validate downstream translation of these genomic alterations, as well as target these pathways to more effectively suppress and inhibit recurrent metastatic disease in NB.

Precision Oncology in Pediatric Cancer Surgery.

Pediatric precision oncology has provided a greater understanding of the wide range of molecular alterations in difficult-to-treat or rare tumors with the aims of increasing survival as well as decreasing toxicity and morbidity from current cytotoxic therapies. In this article, the authors discuss the current state of pediatric precision oncology which has increased access to novel targeted therapies while also providing a framework for clinical implementation in this unique population. The authors evaluate the targetable mutations currently under investigation-with a focus on pediatric solid tumors-and discuss the key surgical implications associated with novel targeted therapies.

Optimizing the Postoperative Management of Children Undergoing Resection of High-Risk Abdominal Neuroblastoma.

BACKGROUND: Surgical resection is a mainstay of treatment in high-risk neuroblastoma (HR-NB), but there exists wide variability in perioperative management practices. The aim of this study was to evaluate two standardized adult perioperative enhanced recovery practices (ERPs) in pediatric patients undergoing open resection of abdominal HR-NB. METHODS: All patients with abdominal HR-NB surgically resected at a free-standing children's hospital between 12/2010 and 7/2020 were retrospectively reviewed. Perioperative ERPs of interest included avoidance of routine nasogastric tube (NGT) use and the use of neuraxial anesthesia. Primary outcomes included time to enteral intake, urinary catheter use, opioid utilization, and length of stay (LOS). RESULTS: Overall, 37 children, median age 33 months (IQR: 20-48 months), were identified. Avoidance of an NGT allowed for earlier feeding after surgery (P = .03). Neuraxial anesthesia use more frequently required an indwelling urinary catheter (P < .01) for a longer duration (P = .02), with no difference in total opioid utilization (P = .77) compared to patients without neuraxial anesthesia. Postoperative LOS was unaffected by avoidance of routine NGT use (P = .68) or use of neuraxial anesthesia (P = .89). CONCLUSION: Children undergoing open resection of abdominal HR-NB initiated diet sooner when an NGT was not left postoperatively, and the need for a urinary catheter was significantly higher in patients who received neuraxial anesthesia. However, these two ERP components did not decrease postoperative LOS. To optimize the postoperative management of NB patients, postoperative NGTs should be avoided, while the benefit of neuraxial anesthesia is less clear as it necessitates the placement of a urinary catheter without decreasing opioid utilization.

Outcomes of pediatric pilonidal disease treatment: excision with off-midline flap reconstruction versus endoscopic pilonidal sinus treatment.

PURPOSE: Pilonidal disease (PD) is marked by chronic inflammation and frequent recurrence which can decrease quality of life. However, debate remains regarding the optimal treatment for PD in the pediatric population. This study compares two recommended treatment approaches-excision with off-midline flap reconstruction (OMF: Bascom cleft lift flap, modified Limberg flap) and minimally invasive endoscopic pilonidal sinus treatment (EPSiT). METHODS: Single-center retrospective evaluation of patients 1-21 years of age with PD who underwent either excision with OMF reconstruction or EPSiT between 10/1/2011 and 10/31/2021. Outcomes included were disease recurrence, reoperation, and wound complication rates. Comparisons were performed using Chi-square and Mann-Whitney U tests. RESULTS: 18 patients underwent excision/OMF reconstruction and 45 patients underwent EPSiT. The excision/OMF reconstruction cohort was predominantly male (44.4% vs 17.8% p = 0.028), with history of prior pilonidal infection (33.3% vs 6.7%; p = 0.006), and longer median operative time (60 min vs 17 min; p < 0.001). The excision/OMF reconstruction cohort had a higher rate of wound complications (22.2% vs 0%; p = 0.001), but lower rates of disease recurrence (5.6% vs 33.3%; p = 0.022) and reoperation (5.6% vs 31.1%; p = 0.031). CONCLUSION: In pediatric patients with PD, excision with OMF reconstruction may decrease recurrence and reoperation rates with increased operative times and wound complication rates, compared to EPSiT.

Lessons Learned From the First-In-Human Compassionate Use of Connect-EA™ in Ten Patients With Esophageal Atresia.

INTRODUCTION: Delayed primary repair of esophageal atresia in patients with high-risk physiologic and anatomic comorbidities remains a daunting challenge with an increased risk for peri-operative morbidity and mortality via conventional repair. The Connect-EA device facilitates the endoscopic creation of a secure esophageal anastomosis. This follow-up study reports our long-term outcomes with the novel esophageal magnetic compression anastomosis (EMCA) Connect-EA device for EA repair, as well as lessons learned from the ten first-in-human cases. We propose an algorithm to maximize the advantages of the device for EA repair. METHODS: Under compassionate use approval, from June 2019 to December 2022, ten patients with prohibitive surgical or medical risk factors underwent attempted EMCA with this device. All patients underwent prior gastrostomy, tracheoesophageal fistula ligation (if necessary), and demonstrated pouch apposition prior to EMCA. RESULTS: Successful device deployment and EMCA formation were achieved in nine patients (90%). Mean time to anastomosis formation was 8 days (range 5-14) and the device was retrieved endoscopically in five (56%) cases. At median follow-up of 22 months (range 4-45), seven patients (78%) are tolerating oral nutrition. Balloon dilations (median 4, range 1-11) were performed either prophylactically for radiographic asymptomatic anastomotic narrowing (n = 7, 78%) or to treat clinically-significant anastomotic narrowing (n = 2, 22%) with no ongoing dilations at 3-month follow up post-repair. CONCLUSION: EMCA with the Connect-EA device is a safe and feasible minimally-invasive alterative for EA repair in high-risk surgical patients. Promising post-operative outcomes warrant further Phase I investigation. LEVEL OF EVIDENCE: IV, Case series of novel operative technique without comparison group.

Evaluation of a Magnetic Compression Anastomosis for Jejunoileal Partial Diversion in Rhesus Macaques.

PURPOSE: Metabolic surgery remains underutilized for treating type 2 diabetes, as less invasive alternative interventions with improved risk profiles are needed. We conducted a pilot study to evaluate the feasibility of a novel magnetic compression device to create a patent limited caliber side-to-side jejunoileal partial diversion in a nonhuman primate model. MATERIALS AND METHODS: Using an established nonhuman primate model of diet-induced insulin resistance, a magnetic compression device was used to create a side-to-side jejunoileal anastomosis. Primary outcomes evaluated feasibility (e.g., device mating and anastomosis patency) and safety (e.g., device-related complications). Secondary outcomes evaluated the device's ability to produce metabolic changes associated with jejunoileal partial diversion (e.g., homeostatic model assessment of insulin resistance [HOMA-IR] and body weight). RESULTS: Device mating, spontaneous detachment, and excretion occurred in all animals (n = 5). There were no device-related adverse events. Upon completion of the study, ex vivo anastomoses were widely patent with healthy mucosa and no evidence of stricture. At 6 weeks post-device placement, HOMA-IR improved to below baseline values (p < 0.05). Total weight also decreased in a linear fashion (R2 = 0.97) with total weight loss at 6 weeks post-device placement of 14.4% (p < 0.05). CONCLUSION: The use of this novel magnetic compression device to create a limited caliber side-to-side jejunoileal anastomosis is safe and likely feasible in a nonhuman primate model. The observed glucoregulatory and metabolic effects of a partial jejunoileal bypass with this device warrant further investigation to validate the long-term glucometabolic impact of this approach.

Beyond the gut: spectrum of magnetic surgery devices.

Since the 1970s, magnetic force has been used to augment modern surgical techniques with the aims of minimizing surgical trauma and optimizing minimally-invasive systems. The majority of current clinical applications for magnetic surgery are largely centered around gastrointestinal uses-such as gastrointestinal or bilioenteric anastomosis creation, stricturoplasty, sphincter augmentation, and the guidance of nasoenteric feeding tubes. However, as the field of magnetic surgery continues to advance, the development and clinical implementation of magnetic devices has expanded to treat a variety of non-gastrointestinal disorders including musculoskeletal (pectus excavatum, scoliosis), respiratory (obstructive sleep apnea), cardiovascular (coronary artery stenosis, end-stage renal disease), and genitourinary (stricture, nephrolithiasis) conditions. The purpose of this review is to discuss the current state of innovative magnetic surgical devices under clinical investigation or commercially available for the treatment of non-gastrointestinal disorders.

Anti-CCL2 antibody combined with etoposide prolongs survival in a minimal residual disease mouse model of neuroblastoma.

C-C motif chemokine ligand 2 (CCL2) is a monocyte chemoattractant that promotes metastatic disease and portends a poor prognosis in many cancers. To determine the potential of anti-CCL2 inhibition as a therapy for recurrent metastatic disease in neuroblastoma, a mouse model of minimal residual disease was utilized in which residual disease was treated with anti-CCL2 monoclonal antibody with etoposide. The effect of anti-CCL2 antibody on neuroblastoma cells was determined in vitro with cell proliferation, transwell migration, and 2-dimensional chemotaxis migration assays. The in vivo efficacy of anti-CCL2 antibody and etoposide against neuroblastoma was assessed following resection of primary tumors formed by two cell lines or a patient-derived xenograft (PDX) in immunodeficient NOD-scid gamma mice. In vitro, anti-CCL2 antibody did not affect cell proliferation but significantly inhibited neuroblastoma cell and monocyte migration towards an increasing CCL2 concentration gradient. Treatment of mice with anti-CCL2 antibody combined with etoposide significantly increased survival of mice after resection of primary tumors, compared to untreated mice.

A Single Center Experience With Bilateral Wilms Tumor.

BACKGROUND: Wilms tumor (WT) is the most common pediatric renal malignancy and bilateral disease (BWT) occurs in 5% of cases and is associated with poor outcomes. Management of BWT includes chemotherapy and oncologic resection while preserving renal function. Previous literature has demonstrated variable approaches in BWT treatment. The aim of this study was to examine a single institution experience and outcomes with BWT. METHODS: A retrospective chart review was performed for all patients with WT treated at a free-standing tertiary children's hospital between 1998 and 2018. Patients with BWT were identified and treatment courses were compared. Outcomes of interest included need for dialysis post-operatively, need for renal transplantation post-operatively, disease recurrence, and overall survival. RESULTS: Of 120 children with WT, 9 children (6F:3M) of median age 32 months (IQR: 24-50 months) and median weight 13.7 kg (IQR: 10.9-16.2 kg) were diagnosed with and treated for BWT. Pre-operative biopsies were obtained in 4/9 patients, 3 of whom received neoadjuvant chemotherapy and 1 who underwent radical nephrectomy. Of the 5 patients who did not undergo biopsy, 4/5 were treated with neoadjuvant chemotherapy, and 1/5 underwent upfront nephrectomy. Post-operatively, 4/9 children required dialysis, of whom 2 subsequently underwent renal transplantation. Two patients were lost to follow-up, and of the remaining 7 patients, disease recurrence occurred in 5/7 children and overall survival was 71% (n=5). CONCLUSION: Management of BWT varies regarding the use of pre-operative biopsy, neoadjuvant chemotherapy, and extent of disease resection. Further guidelines on treatment protocols may optimize outcomes in children with BWT.

The Evolving Use of Magnets in Surgery: Biomedical Considerations and a Review of Their Current Applications.

The novel use of magnetic force to optimize modern surgical techniques originated in the 1970s. Since then, magnets have been utilized as an adjunct or alternative to a wide array of existing surgical procedures, ranging from gastrointestinal to vascular surgery. As the use of magnets in surgery continues to grow, the body of knowledge on magnetic surgical devices from preclinical development to clinical implementation has expanded significantly; however, the current magnetic surgical devices can be organized based on their core function: serving as a guidance system, creating a new connection, recreating a physiologic function, or utilization of an internal-external paired magnet system. The purpose of this article is to discuss the biomedical considerations during magnetic device development and review the current surgical applications of magnetic devices.

Recovery After Thyroid and Parathyroid Surgery: How Do Our Patients Really Feel?

INTRODUCTION: Counseling on the immediate postoperative experience for outpatient procedures is largely based on anecdotal experience. We devised a short messaging service (SMS) survey using mobile phone text messages to evaluate real-time patient recovery following outpatient thyroid or parathyroid surgery. MATERIALS AND METHODS: Daily automated SMS surveys were sent the evening of the operation until postoperative day 10. Pain, opioid use, voice quality, and energy levels were assessed. Impaired voice and energy was defined as a score < 2/3 of normal. RESULTS: One hundred fifty five patients were enrolled with an overall response rate of 81.6%. One hundred thirty three patients had an individual response rate > 50% and were included in the final analysis. Median patient age was 60 y with 102 females (76.7%). Seventy patients (52.6%) underwent parathyroidectomy and 66 (49.6%) thyroidectomy and 10 (7.5%) neck dissection. Forty eight patients (36.1%) did not use any opioids postoperatively. Independent risk factors for higher total pain scores included thyroidectomy and patients with preoperative opioid or tobacco use, while increased opioid use was associated with age < 60 y, body mass index > 30 kg/m2, preoperative opioid or tobacco use, and history of anxiety or depression. Patients with loss of intraoperative recurrent laryngeal nerve signaling had a significantly worse overall voice score (54.65 versus 92.67, P < 0.001). Up to 10% of patients were still using opioids and/or reported impaired voice and energy levels beyond 1 wk postoperatively. CONCLUSIONS: Real-time SMS survey is an effective and potentially valuable way to monitor patient recovery following surgery. A subset of patients reported impaired voice and energy and was still using opioids beyond 1 wk after thyroid and parathyroid surgery and these patients may benefit from closer follow-up and earlier intervention.

Overtransfusion of packed red blood cells during massive transfusion activation: a potential quality metric for trauma resuscitation.

Objectives: The goal of this study was to explore the incidence of overtransfusion in trauma patients requiring massive transfusion protocol (MTP) activation and identify modifiable risk factors. We hypothesized that overtransfusion is common after MTP activation. Methods: Patients admitted to a level I trauma center from July 2016 to December 2019 and who required MTP activation were selected. The primary outcome was overtransfusion, defined as a hemoglobin (Hg) ≥11 g/dL at 24 hours (±2 hours). A Cox regression model was used to identify independent risk factors for overtransfusion. Results: 140 patients met inclusion criteria. The median age was 39.0 years, with the majority (74.3%) being male. The median (IQR) Injury Severity Score (ISS) was 24.0 (58.0) and 38.4% had a penetrating mechanism. The median (IQR) admission Hg was 12.6 (11.7) g/dL. Overall, 71.4% of patients were overtransfused by the conclusion of MTP, 43.6% 24 hours later, and 29.5% at discharge. Overtransfusion did not correlate with the number of units of blood transfused nor with the duration of MTP. Overtransfused patients at 24 hours after the conclusion of MTP were significantly more likely to present with a penetrating injury (52.5% vs. 27.3%, p=0.003) and have a significantly lower ISS (median (IQR) 18.5 (44.0) vs. 26.0 (58.0), p=0.035.) In a Cox regression model, penetrating mechanism (adjusted HR (AHR): 2.93; adjusted p=0.004) and admission base excess (BE) (AHR: 1.15; adjusted p=0.001) were the only variables independently associated with overtransfusion. Conclusions: Overtransfusion of trauma patients requiring MTP activation is highly common, leading to overutilization of a limited resource. Penetrating trauma and BE may be modifiable risk factors that can help limit overtransfusion. Overtransfusion should be tracked as a data point by blood banks and trauma centers and be further studied as a potential quality metric for the resuscitation of massively transfused trauma patients. Level of evidence: III.

Pioneering polyploids: the impact of whole-genome duplication on biome shifting in New Zealand Coprosma (Rubiaceae) and Veronica (Plantaginaceae).

The role of whole-genome duplication (WGD) in facilitating shifts into novel biomes remains unknown. Focusing on two diverse woody plant groups in New Zealand, Coprosma (Rubiaceae) and Veronica (Plantaginaceae), we investigate how biome occupancy varies with ploidy level, and test the hypothesis that WGD increases the rate of biome shifting. Ploidy levels and biome occupancy (forest, open and alpine) were determined for indigenous species in both clades. The distribution of low-ploidy (Coprosma: 2x, Veronica: 6x) versus high-ploidy (Coprosma: 4-10x, Veronica: 12-18x) species across biomes was tested statistically. Estimation of the phylogenetic history of biome occupancy and WGD was performed using time-calibrated phylogenies and the R package BioGeoBEARS. Trait-dependent dispersal models were implemented to determine support for an increased rate of biome shifting among high-ploidy lineages. We find support for a greater than random portion of high-ploidy species occupying multiple biomes. We also find strong support for high-ploidy lineages showing a three- to eightfold increase in the rate of biome shifts. These results suggest that WGD promotes ecological expansion into new biomes.

Using target sequence capture to improve the phylogenetic resolution of a rapid radiation in New Zealand Veronica.

PREMISE: Recent, rapid radiations present a challenge for phylogenetic reconstruction. Fast successive speciation events typically lead to low sequence divergence and poorly resolved relationships with standard phylogenetic markers. Target sequence capture of many independent nuclear loci has the potential to improve phylogenetic resolution for rapid radiations. METHODS: Here we applied target sequence capture with 353 protein-coding genes (Angiosperms353 bait kit) to Veronica sect. Hebe (common name hebe) to determine its utility for improving the phylogenetic resolution of rapid radiations. Veronica section Hebe originated 5-10 million years ago in New Zealand, forming a monophyletic radiation of ca 130 extant species. RESULTS: We obtained approximately 150 kbp of 353 protein-coding exons and an additional 200 kbp of flanking noncoding sequences for each of 77 hebe and two outgroup species. When comparing coding, noncoding, and combined data sets, we found that the latter provided the best overall phylogenetic resolution. While some deep nodes in the radiation remained unresolved, our phylogeny provided broad and often improved support for subclades identified by both morphology and standard markers in previous studies. Gene-tree discordance was nonetheless widespread, indicating that additional methods are needed to disentangle fully the history of the radiation. CONCLUSIONS: Phylogenomic target capture data sets both increase phylogenetic signal and deliver new insights into the complex evolutionary history of rapid radiations as compared with traditional markers. Improving methods to resolve remaining discordance among loci from target sequence capture is now important to facilitate the further study of rapid radiations.

Polyploidy on Islands: Its Emergence and Importance for Diversification.

Whole genome duplication or polyploidy is widespread among floras globally, but traditionally has been thought to have played a minor role in the evolution of island biodiversity, based on the low proportion of polyploid taxa present. We investigate five island systems (Juan Fernández, Galápagos, Canary Islands, Hawaiian Islands, and New Zealand) to test whether polyploidy (i) enhances or hinders diversification on islands and (ii) is an intrinsic feature of a lineage or an attribute that emerges in island environments. These island systems are diverse in their origins, geographic and latitudinal distributions, levels of plant species endemism (37% in the Galapagos to 88% in the Hawaiian Islands), and ploidy levels, and taken together are representative of islands more generally. We compiled data for vascular plants and summarized information for each genus on each island system, including the total number of species (native and endemic), generic endemicity, chromosome numbers, genome size, and ploidy levels. Dated phylogenies were used to infer lineage age, number of colonization events, and change in ploidy level relative to the non-island sister lineage. Using phylogenetic path analysis, we then tested how the diversification of endemic lineages varied with the direct and indirect effects of polyploidy (presence of polyploidy, time on island, polyploidization near colonization, colonizer pool size) and other lineage traits not associated with polyploidy (time on island, colonizer pool size, repeat colonization). Diploid and tetraploid were the most common ploidy levels across all islands, with the highest ploidy levels (>8x) recorded for the Canary Islands (12x) and New Zealand (20x). Overall, we found that endemic diversification of our focal island floras was shaped by polyploidy in many cases and certainly others still to be detected considering the lack of data in many lineages. Polyploid speciation on the islands was enhanced by a larger source of potential congeneric colonists and a change in ploidy level compared to overseas sister taxa.

The Pediatric Surgical Team: a Model for Increased Surgeon Index Case Exposure.

BACKGROUND/PURPOSE: High surgical volume for both surgeons and hospital systems has been linked to improved outcomes for many surgical problems, yet case volumes per pediatric surgeon are diminishing nationally in complex pediatric surgery. We therefore sought to review our experience in a geographically isolated setting where a surgical team approach has been used to improve per-surgeon exposure to index pediatric surgical cases. METHODS: As a surgical group, we incorporated a surgical team approach to complex pediatric surgical cases in 2010. We obtained institutional review board approval to review our pediatric surgeon index case volume experience. We then compared our surgeon experience to published surgical volumes for complex pediatric surgical cases. RESULTS: A surgical team approach (2 or 3 board certified pediatric surgeons/urologists working as co-surgeons or assistant surgeon) was used in the majority of cases for tracheoesophageal fistula/esophageal atresia (77%), congenital pulmonary airway malformation (73.5%), cloaca (75%), anorectal malformation (43.6%) biliary atresia (77.8%), Hirschsprung's disease (51.9%), congenital diaphragmatic hernia (67.6%), robotic choledochal cyst (100%), and complex oncology (adrenal tumors, neuroblastoma, Wilms tumor and Hepatoblastoma surgery) (85-100%). Over the 5-year period, surgeon index case exposure for all index pediatric surgical cases was above the published national median for pediatric surgeons, except for in splenic operations when contrasted to published experience. CONCLUSIONS: A surgical team approach to complex pediatric surgery may help maintain exposure to adequate index case volumes. This model may be useful for maintaining competence in geographically-isolated practice settings and low-volume pediatric hospitals that provide surgical care; the model has implications for systems development and workforce allocation within pediatric surgery. LEVEL OF EVIDENCE: 4.

Plant radiation history affects community assembly: evidence from the New Zealand alpine.

The hypothesis that early plant radiations on islands dampen diversification and reduce habitat occupancy of later radiations via niche pre-emption has never, to our knowledge, been tested. We investigated clade-level dynamics in plant radiations in the alpine zone, New Zealand. Our aim was to determine whether radiations from older colonizations influenced diversification and community dominance of species from later colonizations within a common bioclimatic zone over the past ca 10 Myr. We used stem ages derived from the phylogenies of 17 genera represented in alpine plant communities in the Murchison Mountains, Fiordland, and assessed their presence and cover in 262 (5 × 5 m) vegetation plots. Our results show clear age-related community assembly effects, whereby congenerics from older colonizing genera co-occur more frequently and with greater cover per unit area than those from younger colonizing genera. However, we find no evidence of increased species richness with age of colonization in the alpine zone. The data support priority effects via niche pre-emption among plant radiations influencing community assembly.

Lack of toxicity of stainless steel retinal tacks during 21 years of follow-up.

Retinal tacks were historically used in the repair of complex retinal detachment associated with giant retinal tear. The authors describe a patient with retinal detachment associated with giant retinal tear who was treated successfully with pars plana vitrectomy, use of stainless steel retinal tacks, endolaser photocoagulation, and gas-fluid exchange. Twenty-one years after treatment, the retina has remained attached, the tacks are in place, and best-corrected visual acuity is 20/30 in the operated eye. Although retinal tacks are no longer used, this case report suggests that intraocular stainless steel may cause minimal or no retinal toxicity during long-term follow-up.