Comparison of short-term outcomes following robotic ventral hernia repair in patients with obesity: a review of 9742 patients from the Abdominal Core Health Quality Collaborative database.

Despite the paucity of evidence on robotic ventral hernia repair (RVHR) in patients with obesity, the robotic platform is being used more frequently in hernia surgery. The impact of obesity on RVHR outcomes has not been thoroughly studied. Obesity is considered a major risk factor for the development of recurrent ventral hernias and postoperative complications; however, we hypothesize that patients undergoing robotic repairs will have similar complication profiles despite their body mass index (BMI). We performed a retrospective analysis of patients aged 18-90 years who underwent RVHR between 2013 and 2023 using data from the Abdominal Core Health Quality Collaborative registry. Preoperative, intraoperative, and postoperative characteristics were compared in non-obese and obese groups, determined using a univariate and logistic regression analysis to compare short-term outcomes. The registry identified 9742 patients; 3666 were non-obese; 6076 were classified as obese (BMI > 30 kg/m2). There was an increased odds of surgical site occurrence in patients with obesity, mostly seroma formation; however, obesity was not a significant factor for a complication requiring a procedural intervention after RVHR. In contrast, the hernia-specific quality-of-life scores significantly improved following surgery for all patients, with those with obesity having more substantial improvement from baseline. Obesity does increase the risk of certain complications following RVHR in a BMI-dependent fashion; however, the odds of requiring a procedural intervention are not significantly increased by BMI. Patients with obesity have a significant improvement in their quality of life, and RVHR should be carefully considered in this population.

Reactive high-spin iron(IV)-oxo sites through dioxygen activation in a metal-organic framework.

In nature, nonheme iron enzymes use dioxygen to generate high-spin iron(IV)=O species for a variety of oxygenation reactions. Although synthetic chemists have long sought to mimic this reactivity, the enzyme-like activation of O2 to form high-spin iron(IV) = O species remains an unrealized goal. Here, we report a metal-organic framework featuring iron(II) sites with a local structure similar to that in α-ketoglutarate-dependent dioxygenases. The framework reacts with O2 at low temperatures to form high-spin iron(IV) = O species that are characterized using in situ diffuse reflectance infrared Fourier transform, in situ and variable-field Mössbauer, Fe Kß x-ray emission, and nuclear resonance vibrational spectroscopies. In the presence of O2, the framework is competent for catalytic oxygenation of cyclohexane and the stoichiometric conversion of ethane to ethanol.

IFITM proteins: Understanding their diverse roles in viral infection, cancer, and immunity.

Interferon-induced transmembrane proteins (IFITMs) are broad spectrum antiviral factors that inhibit the entry of a wide range of clinically important pathogens including influenza A virus, HIV-1, and Dengue virus. IFITMs are thought to act primarily by antagonizing virus-cell membrane fusion in this regard. However, recent work on these proteins has uncovered novel post-entry viral restriction mechanisms. IFITMs are also increasingly thought to have a role regulating immune responses, including innate antiviral and inflammatory responses as well as adaptive T-cell and B-cell responses. Further, IFITMs may have pathological activities in cancer, wherein IFITM expression can be a marker of therapeutically resistant and aggressive disease courses. In this review, we summarize the respective literatures concerning these apparently diverse functions with a view to identifying common themes and potentially yielding a more unified understanding of IFITM biology.

Ultrasound Verification of Laparoscopic-Assisted Transversus Abdominis Plane Blocks in Children Undergoing Laparoscopic Procedures.

Purpose: Ultrasound-guided transversus abdominis plane (TAP) blocks have been demonstrated to decrease postoperative pain; however, laparoscopic-assisted TAP (L-TAP) blocks have not been well studied in children. Our study utilized intraoperative ultrasound to verify whether surgeon-administered blocks using only laparoscopic visualization were reliably delivered into the correct plane. Materials and Methods: Patients undergoing laparoscopic procedures were enrolled to receive L-TAP blocks. Preblock and postblock ultrasounds were performed to document the plane of local anesthetic delivery. Ultrasound images were reviewed by two blinded anesthesiologists to determine whether the L-TAP block was administered into the desired plane. Results: Fifty-one patients were enrolled. The average age was 5.9 years (range: 2 days to 17 years) and the mean weight was 25.4 kg (range: 2.64-118.8 kg). The most common procedures were inguinal hernia repair (n = 19), appendectomy (n = 10), and gastrostomy-tube placements (n = 13). Nine surgeons performed 93 L-TAP blocks (average: 10.3 blocks/surgeon). Ultrasound confirmed distribution in the correct plane in 53.5/93 blocks (57.5%; 58.0% for attending surgeons), with 77.4% concurrence between the anesthesiologist reviewers. Conclusion: L-TAP achieves delivery of local anesthetic into the correct tissue plane in over half the cases with minimal training. Further studies are needed to examine the effect of L-TAP blocks on reducing postoperative pain in pediatric patients.

Distraction enterogenesis in the murine colon.

BACKGROUND/PURPOSE: Distraction enterogenesis with intraluminal spring technology has been successfully used to lengthen segments of murine small intestine. We hypothesized that biocompatible springs could also be used to lengthen murine large intestine. METHODS: Age and weight matched C57BL/6 mice underwent surgical insertion of nitinol spring-loaded capsules into the cecum. Segment lengths were measured at initial spring placement and at euthanasia after 7 and 14 days. Histologic adaptations were evaluated at scarification. RESULTS: Cecal segments loaded with compressed springs lengthened an average of 150%, which was significantly longer than control segments loaded with either empty capsules or uncompressed springs. Muscularis layers tended to be thicker in the compressed spring groups compared to control groups. CONCLUSIONS: Insertion of a compressed nitinol spring into the cecum results in significant colonic lengthening in a mouse model. The ability to increase cecum length serves as proof of concept that distraction enterogenesis technology may be feasibly applied to large intestinal models. The use of distraction enterogenesis technology shows promise for application to clinical models in the treatment of pediatric intestinal disease.

Small surgeries, big smiles: using virtual reality to reduce the need for sedation or general anesthesia during minor surgical procedures.

PURPOSE: Children often require anesthesia for simple diagnostic and therapeutic procedures. The aim of this study was to evaluate the feasibility of using virtual reality (VR) to reduce sedation in children undergoing minor surgical procedures. METHOD: In this prospective, non-randomized clinical trial, pediatric patients at a free-standing children's hospital undergoing hormone implant placement, removal, or exchange were recruited to use VR and local anesthesia instead of procedural sedation or general anesthesia (GA). Patients were enrolled between November 2017 and March 2020, and were compared to historic controls who underwent similar procedures without VR between April 2016 and February 2020. Primary outcome measure was successful procedure completion without sedation or GA. Secondary measures included assessments of pain, fear and anxiety, patient compliance, procedural and recovery times. RESULTS: Twenty-eight patients underwent 29 procedures with VR. Hormone implants (72%), removals (7%), or exchanges (21%) were completed without GA, sedation or IV placement. Procedure lengths and pain scores were similar between VR patients and historic controls, but recovery times were significantly shorter in VR patients (18 vs 65 min, p < 0.001). Participant satisfaction scores were high, with 95% recommending VR to others. CONCLUSIONS: VR is a feasible alternative to sedation or GA for select pediatric patients undergoing minor surgical procedures.

Mechanical lengthening of porcine small intestine with decreased forces.

INTRODUCTION: short bowel syndrome is marked by inadequate intestinal surface area to absorb nutrients. Current treatments are focused on medical management and surgical reconfiguration of the dilated intestine. We propose the use of spring-mediated distraction enterogenesis as a novel intervention to increase intestinal length. Given our previous success lengthening intestinal segments using springs with spring constant ~7 N/m that exerts 0.46 N or higher, we sought to determine the minimal force needed to lengthen porcine small intestinal segments, and to explore effects on intestine over time. METHODS: Juvenile Yucatan pigs underwent laparotomy with enterotomy to introduce nitinol springs intraluminally (n = 21 springs). Bowel segments (control, spring-distracted) were retrieved on post-operative day (POD) 7 and 14, and lengths measured. Thickness of cross-sectional intestinal layers were measured using H&E, and submucosal collagen fiber orientation measured using trichrome stained sections. RESULTS: all pigs survived to POD7 and 14. Spring constants of at least 2 N/m exerting a minimum force of 0.10 N significantly lengthened intestinal segments (p <0.0001). The stronger the spring force, the greater the induced thickness of various intestinal layers at POD7 and 14. Collagen fiber orientation was also more disordered because of stronger springs. CONCLUSION: a spring constant of approximately 2 N/m exerting 0.10 N and greater significantly lengthens intestinal segments and stimulates intestinal structural changes at POD7 and 14. This suggests a decreased force is capable of inducing spring-mediated distraction enterogenesis.

Combining inhibitors of Brd4 and cyclin-dependent kinase can decrease tumor growth in neuroblastoma with MYCN amplification.

INTRODUCTION: High-risk neuroblastoma is a deadly disease; poor prognosticators are MYCN-amplification and TERT-overexpression. We hypothesized that Gene Set Enrichment Analysis (GSEA) could identify pathways associated with MYCN-amplification and that inhibition of these pathways could decrease tumor growth. METHODS: We analyzed the Neuroblastoma-Kocak dataset (GSE45547, n = 649) and identified pathways associated with MYCN-amplification. Inhibitors were selected from upregulated gene sets for in vitro cytotoxicity testing using ST16-patient-derived primary neuroblastoma cells and in vivo testing using orthotopic ST16-patient-derived xenografts (PDX) in mice. Tumor volume was measured with ultrasound and tumor sections examined after H&E staining. RESULTS: GSEA identified significantly overexpressed gene sets in MYCN-amplified tumors including MYC targets, cell cycle mitotic genes, TERT associated genes, loss of RB1 gene sets, and E2Fs targets. Several genes were potential Bromodomain-containing protein 4 (Brd4) targets, making Brd4 inhibitors - JQ1, AZD5153 - and cyclin-dependent kinase (Brd4's binding partner) inhibitors - dinaciclib - potential therapeutic agents. JQ1 and dinaciclib were synergistic in inducing cytotoxicity in vitro. Dinaciclib-AZD5153 in vivo decreased tumor size compared to control, and increased tumor lymphocyte infiltration and necrosis on histology. CONCLUSIONS: GSEA is a powerful approach to identify upregulated genes and potential therapeutic targets. Dinaciclib-AZD5153 combination therapy can be effective against MYCN-amplified and TERT-overexpressing neuroblastoma tumors.

Laparoscopic versus ultrasound-guided visualization of transversus abdominis plane blocks.

BACKGROUND: Ultrasound-guided (US) transversus abdominis plane (TAP) block is commonly utilized as part of a multi-modal approach for postoperative pain management. This study seeks to determine whether laparoscopic-guided TAP blocks are as effective as US-guided TAP blocks among pediatric patients. METHOD: In this prospective, randomized controlled trial, pediatric patients undergoing laparoscopic procedures were randomly assigned to one of two treatment arms: US-guided TAP block (US-arm) or laparoscopic-guided TAP block (LAP-arm). Primary outcome was PACU pain scores. Secondary outcomes included PACU opioid consumption, block completion time and block accuracy. RESULTS: Twenty-five patients were enrolled in each arm. In the LAP-arm, 59% of blocks were in the transversus abdominis plane compared to 74% of TAP blocks in the US-arm (p = 0.18). Blocks were completed faster in the LAP-arm (2.1 ± 1.9 vs. 7.9 ± 3.4 min, p<0.001). The average highest PACU pain score was 3.4 ± 3.1 for the LAP-arm and 4.3 ± 3.8 for the US-arm (p = 0.37). Overall PACU pain scores and opioid consumption were similar between the groups (1.2 ± 1.3 vs. 1.6 ± 1.6, p = 0.24; 2.2 ± 5.8 vs. 0.9 ± 1.4MME, p = 0.26). CONCLUSION: Laparoscopic TAP blocks have equivalent efficacy in post-operative pain scores, narcotic use, and tissue plane accuracy as compared to US-guided TAP blocks. They are also completed faster and may result in less operating room and general anesthetic time for the pediatric patient.

Intestinal adaptation following spring insertion into a roux limb in mice.

BACKGROUND/PURPOSE: Intraluminal springs have recently been shown to lengthen segments of intestine in a process known as distraction enterogenesis. We hypothesized that biocompatible springs could be used to lengthen defunctionalized murine small intestine and would lead to identifiable intestinal adaptations at the molecular level. METHODS: Age and weight matched C57BL/6 mice underwent surgical insertion of nitinol spring-loaded capsules into a Roux limb of jejunum. Segment lengths were measured at initial spring placement and at euthanasia after 14 and 21 days. Histology and gene expression of the Roux limb were evaluated at scarification and compared to untreated control segments. RESULTS: Intestinal segments loaded with compressed springs lengthened an average of 240%, which was significantly longer than control segments loaded with either empty capsules or uncompressed springs. Muscularis thickening was greater in spring-treated mice compared to controls without springs. Crypt depth and Lgr5+ expression was greater in mice that received compressed spring treatments when compared to control groups. CONCLUSIONS: Insertion of a compressed nitinol spring into a Roux limb results in significant intestinal lengthening, smooth muscle thickening, and Lgr5+ expression in a mouse model. The ability to increase small bowel length in a defunctionalized murine model may be used to understand the mechanism of distraction enterogenesis.

Mesenteric neovascularization during spring-mediated intestinal lengthening.

BACKGROUND: Short gut syndrome, a condition characterized by inadequate absorption of nutrients owing to decreased bowel length, has minimal avenues for treatment. We have proposed spring-mediated distraction enterogenesis to lengthen bowel in porcine jejunum as a treatment for short gut. We aim to evaluate the extent of mesenteric neovascularization in segments of lengthened bowel via spring-mediated enterogenesis. METHODS: Female juvenile Yucatan pigs underwent laparotomy and insertion of gelatin-encapsulated compressed nitinol springs, held in place with plication sutures, into the jejunum. At surgery and sacrifice, macroscopic mesenteric blood vessels were counted between the plication sites. Histologic samples of the mesentery were obtained to evaluate microscopic vasculature. RESULTS: A statistically significant increase in macroscopic mesenteric blood vessels was seen after intestinal lengthening (before: 1.9 ±â€¯0.7 vessels, after: 4.7 ±â€¯1.2 vessels, p = 0.001). A statistical significance is also seen in the density of arterioles (control: 3.0 ±â€¯3.0 vessels/mm, spring: 7.0 ±â€¯9.0 vessels/mm, p = 0.01) and venules (control: 4.0 ±â€¯3.0 vessels/mm, spring: 8.0 ±â€¯8.0 vessels/mm, p = 0.003). CONCLUSION: Intestinal segments lengthened by intraluminal springs demonstrated total greater number of macroscopic vessels and microscopic blood vessels per length of mesentery as compared to control. This suggests local changes within the mesentery to recruit blood supply to growing intestine. LEVEL OF EVIDENCE: N/A TYPE OF STUDY: Treatment study.

Adenovirus targets transcriptional and posttranslational mechanisms to limit gap junction function.

Adenoviruses are responsible for a spectrum of pathogenesis including viral myocarditis. The gap junction protein connexin43 (Cx43, gene name GJA1) facilitates rapid propagation of action potentials necessary for each heartbeat. Gap junctions also propagate innate and adaptive antiviral immune responses, but how viruses may target these structures is not understood. Given this immunological role of Cx43, we hypothesized that gap junctions would be targeted during adenovirus type 5 (Ad5) infection. We find reduced Cx43 protein levels due to decreased GJA1 mRNA transcripts dependent upon ß-catenin transcriptional activity during Ad5 infection, with early viral protein E4orf1 sufficient to induce ß-catenin phosphorylation. Loss of gap junction function occurs prior to reduced Cx43 protein levels with Ad5 infection rapidly inducing Cx43 phosphorylation events consistent with altered gap junction conductance. Direct Cx43 interaction with ZO-1 plays a critical role in gap junction regulation. We find loss of Cx43/ZO-1 complexing during Ad5 infection by co-immunoprecipitation and complementary studies in human induced pluripotent stem cell derived-cardiomyocytes reveal Cx43 gap junction remodeling by reduced ZO-1 complexing. These findings reveal specific targeting of gap junction function by Ad5 leading to loss of intercellular communication which would contribute to dangerous pathological states including arrhythmias in infected hearts.

Human skin-derived precursor cells xenografted in aganglionic bowel.

PURPOSE: One in 5000 newborns is diagnosed with Hirschsprung disease each year in the United States. The potential of employing neural crest stem cells to restore the enteric nervous system has been investigated. Skin-derived precursor cells (SKPs) are multipotent progenitor cells that can differentiate into neurons and gliocytes in vitro and generate enteric ganglion-like structures in rodents. Here we examined the behavior of human SKPs (hSKPs) after their transplantation into a large animal model of colonic aganglionosis. METHODS: Juvenile minipigs underwent a chemical denervation of the colon to establish an aganglionosis model. The hSKPs were generated from human foreskin and were cultured in neuroglial-selective medium. Cells were labeled with a fluorescent dye and were injected into the porcine aganglionic colon. After one week, transplanted hSKPs were assessed by immunofluorescence for markers of multipotency and neuroglial differentiation. RESULTS: In culture, hSKPs expressed nestin and S100b indicative of neuroglial precursors. After xenografting in pigs, hSKPs were identified in the myenteric and submucosal plexuses of the colons. The hSKPs expressed nestin and early neuroglial differentiation markers. CONCLUSIONS: Human SKPs transplanted into aganglionic colon demonstrated immunophenotypes of neuroglial progenitors, suggesting their potential use for Hirschsprung disease.

Treating children with achalasia using per-oral endoscopic myotomy (POEM): Twenty-one cases in review.

BACKGROUND: Per-oral endoscopic myotomy (POEM), a modern treatment for achalasia, has only recently emerged as an option for pediatric patients. Here we describe and characterize the success of POEM in children with achalasia. METHODS: A single-institution prospective cohort study was performed of patients <18 years old who underwent POEM from 2014 to 2019. Main outcomes were success at one year (Eckardt ≤3), procedure duration, complications, reintervention. RESULTS: The median age of patients (n = 21) was 13 years (range 2-17). Median procedure duration was 92 min (range 52-259) with case duration plateau of 87.4 min and learning rate of 15.5 cases. Intraoperative complications included capnoperitoneum requiring needle decompression and mucosotomy requiring additional clips. One patient experienced chest pain with small capnoperitoneum seen on chest radiography, and three patients had extraluminal carbon dioxide found incidentally on routine radiography. All were managed with observation. Pre- versus 1-month postprocedure Eckardt scores were significantly improved (7 ±â€¯2 versus 1 ±â€¯2, p < 0.0001, and median ±â€¯SD) with 100% symptomatic relief at one year. To achieve this, 13 patients required further dilation(s), one required laparoscopic Heller myotomy, and two required repeat POEM. CONCLUSIONS: POEM is a viable and safe treatment for pediatric patients with achalasia. We demonstrate improvement in symptoms and procedure proficiency with minimal intra- and postoperative complications. TYPE OF STUDY: Prospective cohort study. LEVEL OF EVIDENCE: Level II.

Enhancing sustained-release local therapy: Single versus dual chemotherapy for the treatment of neuroblastoma.

BACKGROUND: Neuroblastoma is the most common pediatric extracranial solid malignancy with limited effective treatment. We have shown that sustained-release, single drugs delivered locally through a silk-based biomaterial are effective in decreasing orthotopic neuroblastoma xenograft growth. We further optimized this approach and hypothesized that increasing doses of local chemotherapy or delivering 2 chemotherapeutic agents simultaneously inhibit additional tumor growth. METHODS: MYCN-amplified and non-MYCN-amplified neuroblastoma cells were treated with combinations of cisplatin, vincristine, doxorubicin, and etoposide to determine cytotoxicity and synergy. Drug-loaded silk material was created, and the amounts of drug released from the material over time were recorded. Murine orthotopic neuroblastoma xenografts were generated; tumors were implanted with single- or dual-agent chemotherapy-loaded silk. Ultrasound was used to monitor tumor growth, and tumor histology was evaluated. RESULTS: In vitro, vincristine/cisplatin combination was synergistic and significantly decreased cell viability relative to other combinations. Both drugs loaded into silk could be released effectively for over 2 weeks. Locally implanted vincristine/cisplatin silk induced increased tumor growth suppression compared with either agent alone in MYCN-amplified tumors (P < .05). The dose-dependent effect seen in MYCN-amplified tumors treated with combination therapy diminished at higher doses in non-MYCN-amplified tumors, with little benefit with doses >50 µg to 500 µg for vincristine-cisplatin, respectively. Tumor histology demonstrated tumor cell necrosis adjacent to drug-loaded silk material and presence of large cell neuroblastoma. CONCLUSION: Local delivery of sustained release chemotherapy can suppress tumor growth especially at high doses or with 2 synergistic drugs. Locally delivered dual therapy is a promising approach for future clinical testing.

Local delivery of dinutuximab from lyophilized silk fibroin foams for treatment of an orthotopic neuroblastoma model.

Immunotherapy targeting GD2 is a primary treatment for patients with high-risk neuroblastoma. Dinutuximab is a monoclonal antibody with great clinical promise but is limited by side effects such as severe pain. Local delivery has emerged as a potential mechanism to deliver higher doses of therapeutics into the tumor bed, while limiting systemic toxicity. We aim to deliver dinutuximab locally in a lyophilized silk fibroin foam for the treatment of an orthotopic neuroblastoma mouse model. Dinutuximab-loaded silk fibroin foams were fabricated through lyophilization. In vitro release profile and bioactivity of the release through complement-dependent cytotoxicity were characterized. MYCN-amplified neuroblastoma cells (KELLY) were injected into the left gland of mice to generate an orthotopic neuroblastoma model. Once the tumor volume reached 100 mm3 , dinutuximab-, human IgG-, or buffer-loaded foams were implanted into the tumor and growth was monitored using high-resolution ultrasound. Post-resection histology was performed on tumors. Dinutuximab-loaded silk fibroin foams exhibited a burst release, with slow release thereafter in vitro with maintenance of bioactivity. The dinutuximab-loaded foam significantly inhibited xenograft tumor growth compared to IgG- and buffer-loaded foams. Histological analysis revealed the presence of dinutuximab within the tumor and neutrophils and macrophages infiltrating into dinutuximab-loaded silk foam. Tumors treated with local dinutuximab had decreased MYCN expression on histology compared to control or IgG-treated tumors. Silk fibroin foams offer a mechanism for local release of dinutuximab within the neuroblastoma tumor. This local delivery achieved a significant decrease in tumor growth rate in a mouse orthotopic tumor model.

Epigenetic Targeting of TERT-Associated Gene Expression Signature in Human Neuroblastoma with TERT Overexpression.

Neuroblastoma is a deadly pediatric solid tumor with infrequent recurrent somatic mutations. Particularly, the pathophysiology of tumors without MYCN amplification remains poorly defined. Utilizing an unbiased approach, we performed gene set enrichment analysis of RNA-sequencing data from 498 patients with neuroblastoma and revealed a differentially overexpressed gene signature in MYCN nonamplified neuroblastomas with telomerase reverse transcriptase (TERT) gene overexpression and coordinated activation of oncogenic signaling pathways, including E2Fs, Wnt, Myc, and the DNA repair pathway. Promoter rearrangement of the TERT gene juxtaposes the coding sequence to strong enhancer elements, leading to TERT overexpression and poor prognosis in neuroblastoma, but TERT-associated oncogenic signaling remains unclear. ChIP-seq analysis of the human CLB-GA neuroblastoma cells harboring TERT rearrangement uncovered genome-wide chromatin co-occupancy of Brd4 and H3K27Ac and robust enrichment of H3K36me3 in TERT and multiple TERT-associated genes. Brd4 and cyclin-dependent kinases (CDK) had critical regulatory roles in the expression and chromatin activation of TERT and multiple TERT-associated genes. Epigenetically targeting Brd4 or CDKs with their respective inhibitors suppressed the expression of TERT and multiple TERT-associated genes in neuroblastoma with TERT overexpression or MYCN amplification. ChIP-seq and ChIP-qPCR provided evidence that the CDK inhibitor directly inhibited Brd4 recruitment to activate chromatin globally. Therefore, inhibiting Brd4 and CDK concurrently with AZD5153 and dinaciclib would be most effective in tumor growth suppression, which we demonstrated in neuroblastoma cell lines, primary human cells, and xenografts. In summary, we describe a unique mechanism in neuroblastoma with TERT overexpression and an epigenetically targeted novel therapeutic strategy. SIGNIFICANCE: Epigenetically cotargeting Brd4 and Cdks suppresses human neuroblastoma with TERT overexpression by inhibiting the TERT-associated gene expression networks.

Autologous Transplantation of Skin-Derived Precursor Cells in a Porcine Model.

BACKGROUND: Hirschprung's disease is characterized by aganglionic bowel and often requires surgical resection. Cell-based therapies have been investigated as potential alternatives to restore functioning neurons. Skin-derived precursor cells (SKPs) differentiate into neural and glial cells in vitro and generate ganglion-like structures in rodents. In this report, we aimed to translate this approach into a large animal model of aganglionosis using autologous transplantation of SKPs. METHODS: Juvenile pigs underwent skin procurement from the shoulder and simultaneous chemical denervation of an isolated colonic segment. Skin cells were cultured in neuroglial-selective medium and labeled with fluorescent dye for later identification. The cultured SKPs were then injected into the aganglionic segments of colon, and the specimens were retrieved within seven days after transplantation. SKPs in vitro and in vivo were assessed with histologic samples for various immunofluorescent markers of multipotency and differentiation. SKPs from the time of harvest were compared to those at the time of injection using PCR. RESULTS: Prior to transplantation, 72% of SKPs stained positive for nestin and S100b, markers of neural and glial precursor cells of neural crest origin, respectively. Markers of differentiated neurons and gliocytes, TUJ1 and GFAP, were detected in 47% of cultured SKPs. After transplantation, SKPs were identified in both myenteric and submucosal plexuses of the treated colon. Nestin co-expression was detected in the SKPs within the aganglionic colon in vivo. Injected SKPs appeared to migrate and express early neuroglial differentiation markers. CONCLUSIONS: Autologous SKPs implanted into aganglionic bowel demonstrated immunophenotypes of neuroglial progenitors. Our results suggest that autologous SKPs may be potentially useful for cell-based therapy for patients with enteric nervous system disorders. TYPE OF STUDY: Basic science.

Optimization of In-Continuity Spring-Mediated Intestinal Lengthening.

BACKGROUND: Spring-mediated intestinal lengthening has been studied in numerous animal models to effectively achieve up to a 3-fold increase in length. In this study we are interested in optimizing this method of spring lengthening. METHODS: Juvenile mini-Yucatan pigs underwent laparotomy for spring implantation. Springs were secured by plicating the intestine around the springs. In one set of experiments, varying degrees of plication were compared to determine the necessary narrowing needed to confine the spring. In another set of experiments, dissolvable sutures were used for the plication to allow for spontaneous spring passage postoperatively. Intestinal segments were retrieved and evaluated for lengthening and histological changes. RESULTS: Pigs tolerated their diet advancement to a regular diet postoperatively. 10% plication resulted in a 1.3-fold increase in length, while 50% plication resulted in a 2.7-fold increase in length (p<0.05). At two months postoperatively, the majority of springs had safely passed out of the intestine. All lengthened intestine showed significant growth histologically. CONCLUSIONS: A 50% reduction in lumen diameter achieves optimal spring-mediated intestinal lengthening. Springs can safely pass out of the intestine, thus avoiding a second operation for spring removal. These results may be important in developing future therapies for short bowel syndrome. LEVEL OF EVIDENCE: Level I experimental study.

Cutaneous Patches to Monitor Myoelectric Activity of the Gastrointestinal Tract in Postoperative Pediatric Patients.

PURPOSE: Limited means exist to assess gastrointestinal activity in pediatric patients postoperatively. Recently, myoelectric gastrointestinal activity recorded by cutaneous patches has been shown in adult patients to be predictive of clinical return of gastrointestinal function postoperatively. The aim of this case series is to demonstrate the feasibility of this system in pediatric patients and to correlate myoelectric signals with return of bowel function clinically. METHODS: Pediatric patients undergoing abdominal surgery were recruited to have wireless patches placed on the abdomen within two hours postoperatively. Myoelectric data were transmitted wirelessly to a mobile device with a user-interface and forwarded to a cloud server where processing algorithms identified episodes of motor activity, quantified their parameters and nominally assigned them to specific gastrointestinal organs based on their frequencies. RESULTS: Three patients (ages 5 months, 4 year, 16 year) were recruited for this study. Multiple patches were placed on the older subjects, while the youngest had a single patch due to space limitations. Rhythmic signals of the stomach, small intestine, and colon could be identified in all three subjects. Patients showed gradual increase in myoelectric intestinal and colonic activity leading up to the first recorded bowel movement. CONCLUSION: Measuring myoelectric intestinal activity continuously using a wireless patch system is feasible in a wide age range of pediatric patients. The increase in activity over time correlated well with the patients' return of bowel function. More studies are planned to determine if this technology can predict return of bowel function or differentiate between physiologic ileus and pathologic conditions.