WNT2B Deficiency Causes Enhanced Susceptibility to Colitis Due to Increased Inflammatory Cytokine Production.

BACKGROUND & AIMS: Humans with WNT2B deficiency have severe intestinal disease, including significant inflammatory injury, highlighting a critical role for WNT2B. We sought to understand how WNT2B contributes to intestinal homeostasis. METHODS: We investigated the intestinal health of Wnt2b knock out (KO) mice. We assessed the baseline histology and health of the small intestine and colon, and the impact of inflammatory challenge using dextran sodium sulfate (DSS). We also evaluated human intestinal tissue. RESULTS: Mice with WNT2B deficiency had normal baseline histology but enhanced susceptibility to DSS colitis because of an increased early injury response. Although intestinal stem cells markers were decreased, epithelial proliferation was similar to control subjects. Wnt2b KO mice showed an enhanced inflammatory signature after DSS treatment. Wnt2b KO colon and human WNT2B-deficient organoids had increased levels of CXCR4 and IL6, and biopsy tissue from humans showed increased neutrophils. CONCLUSIONS: WNT2B is important for regulation of inflammation in the intestine. Absence of WNT2B leads to increased expression of inflammatory cytokines and increased susceptibility to gastrointestinal inflammation, particularly in the colon.

Robotic-assisted laparoscopic Malone appendicostomy: a 6-year perspective.

PURPOSE: A robotic-assisted laparoscopic approach to appendicostomy offers the benefits of a minimally invasive approach to patients who would typically necessitate an open procedure, those with a larger body habitus, and those requiring combined complex colorectal and urologic reconstructive procedures. We present our experience performing robotic-assisted appendicostomies with a focus on patient selection, perioperative factors, and functional outcomes. METHODS: A retrospective review of patients who underwent a robotic-assisted appendicostomy/neoappendicostomy at our institution was performed. RESULTS: Twelve patients underwent robotic-assisted appendicostomy (n = 8) and neoappendicostomy (n = 4) at a range of 8.8-25.8 years. Five patients had a weight percentile > 50% for their age. Seven patients underwent combined procedures. Median operative time for appendicostomy/neoappendicostomy only was 185.0 min. Complications included surgical site infection (n = 3), stricture requiring minor operative revision (n = 2), conversion to an open procedure due to inadequate appendiceal length (prior to developing our technique for robotic neoappendicostomies; n = 1), and granuloma (n = 1). At a median follow-up of 10.8 months (range 1.7-74.3 months), 91.7% of patients were consistently clean with antegrade enemas. DISCUSSION: Robotic-assisted laparoscopic appendicostomy and neoappendicostomy with cecal flap is a safe and effective operative approach. A robotic approach can potentially overcome the technical difficulties encountered in obese patients and can aid in patients requiring both a Malone and a Mitrofanoff in a single, combined minimally invasive procedure.

Late Diagnosis of Hirschsprung Disease: Clinical Presentation and Long-Term Functional Outcomes.

PURPOSE: Hirschsprung Disease (HD) is typically diagnosed in the neonatal period. A small subset of patients have a prolonged course of abdominal distention and constipation prior to diagnosis. Late HD is defined as having been diagnosed at greater than or equal to one year of age. The literature is limited and offers conflicting data on the implications of a late diagnosis. We aim to investigate the presentation, operative approach, and functional outcomes of a large cohort of patients with a late HD diagnosis. METHODS: All patients with a late diagnosis of HD (after 1 year of age) at our institution between 1997 and 2021 were included. RESULTS: Twenty-eight patients were diagnosed with HD at a median age of 3.4 years. Chronic constipation, failure to thrive, and enterocolitis occurred in 100 %, 31 %, and 14 %, respectively. All patients underwent contrast enema and biopsies during their workup, identifying primarily rectosigmoid disease (n = 27) and total colonic aganglionosis (n = 1). Surgical intervention was performed in 27 patients, with 4 patients (15 %) needing a stoma (3 with plan for staged pull-through, 1 long-term stoma) and 23 patients (85 %) undergoing a single-stage pull-through. Postoperative complications included Hirschsprung-associated enterocolitis (n = 5), ostomy prolapse and revision (n = 2), abdominal distention requiring ileostomy creation (n = 2), redo pull-through (n = 2), retroperitoneal hematoma (n = 1), and cecostomy tube placement (n = 1). At a median follow-up of 5.4 years, 83 % of eligible patients achieved fecal continence with 43 % needing laxatives for persistent constipation. CONCLUSION: Recognizing a late presentation of HD requires a high index of suspicion. Patients with a late diagnosis did not experience an increased rate of permanent stoma, complications, or redo surgery compared to rates reported for the larger HD population. Similar long-term functional outcomes were achieved compared to the larger HD population. LEVEL OF EVIDENCE: IV.

Influence of Initial Treatment Strategy on Outcomes for Children With Rectal Prolapse.

OBJECTIVE: Pediatric rectal prolapse is a common and often self-limited condition with multiple management options. Selecting the optimal approach requires personalization and remains a challenge for pediatricians and pediatric surgeons. METHODS: A single-center retrospective review of 67 children with rectal prolapse undergoing surgical evaluation between 2010 and 2021. Patients with anorectal malformations, Hirschsprung disease, inflammatory bowel disease, and cystic fibrosis were excluded. We used multivariable logistic regression to compare medical management, sclerotherapy, and surgical correction (rectopexy or transanal resection) as initial treatment strategies, with a primary endpoint of prolapse resolution. RESULTS: Younger patients (<5 years) were more likely to be initially treated with medical management alone (P < 0.001). Patients with a psychiatric diagnosis were more likely to be offered either sclerotherapy or surgery upfront (P = 0.009). The resolution rate with surgery as initial management was 79% (n = 11/14). The resolution rate with sclerotherapy as initial management was 54% (n = 13/24), with 33% (n = 8/24) resolving with sclerotherapy alone and 21% (n = 5/24) resolving after a subsequent surgical procedure (P = 0.011). Patients who underwent initial surgical management had an adjusted odds ratio of 8.0 (95% CI: 1.1-59.1; P = 0.042) for resolution of prolapse compared to patients who underwent sclerotherapy initially. Markers of severity (bleeding, need for manual reduction) were not associated with initial therapy offered (P = 0.064). CONCLUSIONS: Surgical intervention (sclerotherapy, rectopexy, transanal resection) resolved rectal prolapse in most children (63%). Surgery as an initial management approach had a significantly higher success rate than sclerotherapy, even after controlling for severity of disease, psychiatric diagnosis, need for manual reduction, and age.

Saving the perineal body-A modification of the posterior sagittal anorectoplasty.

BACKGROUND: Wound dehiscence of the anocutaneous anastomosis and/or reconstructed perineal body is a feared perioperative complication after posterior sagittal anorectoplasty (PSARP). Dehiscence of the perineal body can have long-term negative implications for fecal continence, sexual intimacy, obstetrical outcomes, and the need for reoperative surgery. We describe a modification to the traditional PSARP for repair of an imperforate anus with a rectovestibular, perineal, or absent fistula by sparing the perineal body, eliminating postoperative perineal body dehiscence and potentially improving long-term functional outcomes. METHODS: A retrospective review of female patients with a rectovestibular, perineal, or absent fistula who underwent PSARP with sparing of the perineal body was performed. RESULTS: Six patients underwent PSARP with sparing of the perineal body between 2019 and 2022. There were no perioperative complications. At follow-up, all patients are having regular bowel function without difficulty and have an excellent appearance of their perineal body. CONCLUSIONS: PSARP for a rectovestibular, perineal, or absent fistula can be safely performed with a more limited incision to avoid disruption of the perineal body. This eliminates the need for perineal body reconstruction during the procedure, thereby preventing wound dehiscence. Given the significant long-term adverse sequelae of wound dehiscence and resultant inadequate perineal body, we believe this modification to the PSARP warrants strong consideration.

Primary and secondary vaginal reconstruction with autologous buccal mucosa and intravaginal wound vacuum therapy.

BACKGROUND: Vaginal reconstruction with autologous buccal mucosa graft offers a promising alternative to the use of skin grafts and vascularized intestinal segments. Given the novelty of this procedure, the optimal approach to postoperative wound management remains unclear with current practices often requiring many months of vaginal stents/molds. This study aims to evaluate a newly developed negative pressure intravaginal wound vacuum placed at the conclusion of the vaginoplasty with the goals of facilitating graft take and healing. METHODS: A retrospective review of patients (age 12-21 years) who underwent eight primary and secondary vaginoplasty procedures using autologous buccal mucosa coupled with intravaginal wound vacuum placement was performed. RESULTS: Vaginal reconstruction with fenestrated full-thickness buccal mucosa graft and intravaginal wound vacuum placement was successfully performed eight times in seven patients at a median age of 15.6 years. Four patients underwent robotic vaginal pull-through with buccal mucosa serving as an interposition graft, and four patients underwent vaginoplasty with buccal graft alone. All cases had excellent engraftment at time of wound vacuum removal on postoperative day seven and had healthy-appearing buccal mucosa at a mean follow-up of 148 days. Postoperatively, one patient developed a stricture at the anastomosis between native vagina and buccal mucosa graft, requiring a second buccal mucosa graft six months after the first operation. CONCLUSIONS: The use of autologous buccal mucosa graft for primary and secondary vaginal reconstruction coupled with intravaginal wound vacuum therapy offers a promising new approach. Negative pressure wound vacuum therapy may provide a more optimal wound healing environment for improved outcomes. TYPE OF STUDY: Retrospective Study LEVELS OF EVIDENCE: Level IV.

Technical Considerations in Primary Repair of a Congenital Prostatic Rectourethral Fistula in an Adult-Sized Patient.

Congenital anorectal malformations are generally diagnosed and repaired as a neonate or infant, but repair is sometimes delayed. Considerations for operative repair change as the patient approaches full stature. We recently encountered a 17-year-old male with an unrepaired congenital rectourethral fistula and detail our experience with his repair. We elected to utilize a combined abdominal and perineal approach, with robotic assistance for division of his rectourethral fistula and pullthrough anoplasty. Cystoscopy was used simultaneously to assure full dissection of the fistula and to minimize the risk of leaving a remnant of the original fistula (also known as a posterior urethral diverticulum). The procedure was well tolerated without complications. His anoplasty was evaluated 60 days postoperatively and was well healed without stricture. At 9 months of follow-up, he has good fecal and urinary continence. Robotic assistance in this procedure allowed minimal perineal dissection while ensuring precise rectourethral fistula dissection. The length of the intramural segment of the fistula was longer than anticipated. Simultaneous cystoscopy, in conjunction with the integrated robotic fluorescence system, helped reduce the risk of leaving a remnant of the original fistula.

The Surgical Program in Innovation (SPIN): A Design and Prototyping Curriculum for Surgical Trainees.

PROBLEM: Health professions education does not routinely incorporate training in innovation or creative problem solving. Although some models of innovation education within graduate medical education exist, they often require participants' full-time commitment and removal from clinical training or rely upon participants' existing expertise. There is a need for curricula that teach innovation skills that will enable trainees to identify and solve unmet clinical challenges in everyday practice. To address this gap in surgical graduate education, the authors developed the Surgical Program in Innovation (SPIN). APPROACH: SPIN, a 6-month workshop-based curriculum, was established in 2016 in the Beth Israel Deaconess Medical Center Department of Surgery to teach surgical trainees the basics of the innovation process, focusing on surgeon-driven problem identification, product design, prototype fabrication, and initial steps in the commercialization process. Participating surgical residents and graduate students attend monthly workshops taught by medical, engineering, and medical technology (MedTech) industry faculty. Participants collaborate in teams to develop a novel device, fabricate a protype, and pitch their product to a panel of judges. OUTCOMES: From academic years 2015-2016 to 2017-2018, 49 trainees, including 41 surgical residents, participated in SPIN. Across this period, 13 teams identified an unmet need, ideated a solution, and designed and pitched a novel device. Ten teams fabricated prototypes. The 22 SPIN participants who responded to both pre- and postcourse surveys reported significant increases in confidence in generating problem statements, computer-aided design, fabrication of a prototype, and initial commercialization steps (product pitching and business planning). NEXT STEPS: Incorporating innovation education and design thinking into clinical training will prove essential in preparing future physicians to be lifelong problem finders and solvers. The authors plan to expand SPIN to additional clinical specialties, as well as to assess its impact in fostering future innovation and collaboration among program participants.

Optimizing Duration of Empiric Management of Suspected Central Line-Associated Bloodstream Infections in Pediatric Patients with Intestinal Failure.

OBJECTIVES: To assess whether a 24-hour length of hospitalization and empiric antibiotic therapy to exclude central line-associated bloodstream infection (CLABSI) in children with intestinal failure is potentially as safe as 48 hours, which is the duration most commonly used but not evidence based. STUDY DESIGN: A prospective single-institution observational cohort study was conducted among pediatric patients with intestinal failure from July 1, 2015, through June 30, 2018, to identify episodes of suspected CLABSI. The primary end point was time from blood sampling to positive blood culture. Secondary end points included presenting symptoms, laboratory test results, responses to a parent/legal guardian-completed symptom survey, length of inpatient stay, costs, and charges. RESULTS: Seventy-three patients with intestinal failure receiving nutritional support via central venous catheters enrolled; 35 were hospitalized with suspected CLABSI at least once during the study. There were 49 positive blood cultures confirming CLABSI in 128 episodes (38%). The median time from blood sampling to positive culture was 11.1 hours. The probability of a blood culture becoming positive after 24 hours was 2.3%. Elevated C-reactive protein and neutrophil predominance in white blood cell count were associated with positive blood cultures. Estimated cost savings by transitioning from a 48-hour to a 24-hour admission to rule-out CLABSI was $4639 per admission. CONCLUSIONS: A 24-hour duration of empiric management to exclude CLABSI may be appropriate for patients with negative blood cultures and no clinically concerning signs. A multi-institutional study would more robustly differentiate patients safe for discharge after 24 hours from those who warrant longer empiric treatment.

Alpha-tocopherol in intravenous lipid emulsions imparts hepatic protection in a murine model of hepatosteatosis induced by the enteral administration of a parenteral nutrition solution.

Intestinal failure-associated liver disease (IFALD) is a risk of parenteral nutrition (PN)-dependence. Intravenous soybean oil-based parenteral fat can exacerbate the risk of IFALD while intravenous fish oil can minimize its progression, yet the mechanisms by which soybean oil harms and fish oil protects the liver are uncertain. Properties that differentiate soybean and fish oils include α-tocopherol and phytosterol content. Soybean oil is rich in phytosterols and contains little α-tocopherol. Fish oil contains abundant α-tocopherol and little phytosterols. This study tested whether α-tocopherol confers hepatoprotective properties while phytosterols confer hepatotoxicity to intravenous fat emulsions. Utilizing emulsions formulated in the laboratory, a soybean oil emulsion (SO) failed to protect from hepatosteatosis in mice administered a PN solution enterally. An emulsion of soybean oil containing α-tocopherol (SO+AT) preserved normal hepatic architecture. A fish oil emulsion (FO) and an emulsion of fish oil containing phytosterols (FO+P) protected from steatosis in this model. Expression of hepatic acetyl CoA carboxylase (ACC) and peroxisome proliferator-activated receptor gamma (PPARγ), was increased in animals administered SO. ACC and PPARγ levels were comparable to chow-fed controls in animals receiving SO+AT, FO, and FO+P. This study suggests a hepatoprotective role for α-tocopherol in liver injury induced by the enteral administration of a parenteral nutrition solution. Phytosterols do not appear to compromise the hepatoprotective effects of fish oil.

Omega-3 fatty acids are protective in hepatic ischemia reperfusion injury in the absence of GPR120 signaling.

BACKGROUND: A single dose of IV fish oil (FO) before hepatic ischemia reperfusion injury (HIRI) increases hepatocyte proliferation and reduces necrosis in wild type (WT) mice. It has been suggested that the GPR120 receptor on Kupffer cells mediates FO's ability to reduce HIRI. The purpose of this study was to determine whether GPR120 is required for FO to reduce HIRI. METHODS: Sixty-four (n = 8/group) adult male WT (C57BL/6) and GPR120 knockout (KO) mice received IV FO (1 g/kg) or saline 1 h prior to HIRI or sham operation. Mice were euthanized 24 h postoperatively for analysis of hepatic histology, NFκB activity, and serum alanine transaminase (ALT) levels. RESULTS: FO pretreated livers had less necrosis after HIRI than saline pretreated livers in both WT (mean ±â€¯SEM 25.9 ±â€¯7.3% less, P = 0.007) and KO (36.6 ±â€¯7.3% less, P < 0.0001) mice. There was no significant difference in percent necrosis between WT-FO and KO-FO groups. Sham groups demonstrated minimal necrosis (0-1.9%). Mean [95% CI] ALT after HIRI was significantly higher (P = 0.04) in WT-Saline mice (1604 U/L [751-3427]) compared to WT-FO (321 U/L [150-686]) but was not significantly higher in KO-Saline mice compared to KO-FO. There were no differences in ALT between WT-FO and KO-FO mice who underwent HIRI or between groups who underwent sham surgery. There were no differences in NFκB or IKKß activation among groups as measured by Western blot analysis. CONCLUSIONS: IV FO pretreatment was able to reduce HIRI in GPR120 KO mice, suggesting the hepatoprotective effects of FO are not mediated by GPR120 alone.

Fish oil protects the liver from parenteral nutrition-induced injury via GPR120-mediated PPARγ signaling.

Intravenous fish oil lipid emulsions (FOLE) can prevent parenteral nutrition (PN)-induced liver injury in murine models and reverse PN-induced cholestasis in pediatric patients. However, the mechanisms by which fish oil protects the liver are incompletely characterized. Fish oil is rich in omega-3 fatty acids, which are ligands for the G-protein coupled receptor 120 (GPR120), expressed on hepatic Kupffer cells. This study tested the hypothesis that FOLE protects the liver from PN-induced injury through GPR120 signaling. Utilizing a previously described murine model of PN-induced liver injury in which mice develop steatosis in response to an oral parenteral nutrition diet, FOLE was able to preserve normal hepatic architecture in wild type mice, but not in congenic GPR120 knockout (gpr120-/-) mice. To further characterize the requirement of intact GPR120 for FOLE-mediated hepatic protection, gene expression profiles of key regulators of fat metabolism were measured. PPARγ was identified as a gene that is up-regulated by the PN diet and normalized with the addition of FOLE in wild type, but not in gpr120-/- mice. This was confirmed at the protein expression level. A PPARγ expression array further identified CD36 and SCD1, both down-stream effectors of PPARγ, to be up-regulated in PN-fed wild type mice yet normalized upon FOLE administration in wild type but not in gpr120-/- mice. Together, these results suggest that FOLE protects the liver, in part, through activation of GPR120 and the downstream effectors PPARγ and CD36. Identification of key genetic determinants of FOLE-mediated hepatic protection may provide targets for small molecule-based hepatic protection strategies.

A Diet With Docosahexaenoic and Arachidonic Acids as the Sole Source of Polyunsaturated Fatty Acids Is Sufficient to Support Visual, Cognitive, Motor, and Social Development in Mice.

Polyunsaturated fatty acids serve multiple functions in neurodevelopment and neurocognitive function. Intravenous lipid emulsions are administered to children that are dependent on parenteral nutrition to provide the essential fatty acids needed to sustain growth and development. One of these emulsions, derived from fish-oil, is particularly poor in the traditional essential fatty acids, linoleic and alpha-linolenic acids. However, it does contain adequate amounts of its main derivatives, arachidonic acid (ARA) and docosahexaenoic acid (DHA), respectively. This skewed composition has raised concern about the sole use of fish-oil based lipid emulsions in children and how its administration can be detrimental to their neurodevelopment. Using a custom-made diet that contains ARA and DHA as a sole source of polyunsaturated fatty acids, we bred and fed mice for multiple generations. Compared to adult, chow-fed mice, animals maintained on this special diet showed similar outcomes in a battery of neurocognitive tests performed under controlled conditions. Chow-fed mice did perform better in the rotarod test for ataxia and balance, although both experimental groups showed a conserved motor learning capacity. Conversely, mice fed the custom diet rich in DHA and ARA showed less neophobia than the chow-fed animals. Results from these experiments suggest that providing a diet where ARA and DHA are the sole source of polyunsaturated fatty acids is sufficient to support gross visual, cognitive, motor, and social development in mice.

Effects of dietary omega-3 fatty acids on bones of healthy mice.

BACKGROUND & AIMS: Altering the lipid component in diets may affect the incidence of metabolic bone disease in patients dependent on parenteral nutrition. Consumption of polyunsaturated fatty acids (PUFA) can impact bone health by modulating calcium metabolism, prostaglandin synthesis, lipid oxidation, osteoblast formation, and osteoclastogenesis. The aim of this study was to evaluate the dietary effects of PUFA on murine bone health. METHODS: Three-weeks-old male (n = 30) and female (n = 30) C57BL/6J mice were randomized into one of three dietary groups. The diets differed only in fat composition: soybean oil (SOY), rich in ω-6 PUFA; docosahexaenoic acid alone (DHA), an ω-3 PUFA; and DHA with arachidonic acid, an ω-6 PUFA, at a 20:1 ratio (DHA/ARA). After 9 weeks of dietary treatment, femurs were harvested for micro-computed tomographic analysis and mechanical testing via 3-point bending. Separate mice from each group were used solely for serial blood draws for measurement of biomarkers of bone formation and resorption. RESULTS: At the microstructural level, although some parameters in cortical bone reached differences that were statistically significant in female mice, these were too small to be considered biologically relevant. Similarly, trabecular bone parameters in male mice were statistically different in some dietary groups, although the biological interpretation of such subtle changes translate into a lack of effect in favor of any of the experimental diets. No differences were noted at the mechanical level and in blood-based biomarkers of bone metabolism across dietary groups within gender. CONCLUSIONS: Subtle differences were noted at the bones' microstructural level, however these are likely the result of random effects that do not translate into changes that are biologically relevant. Similarly, differences were not seen at the mechanical level, nor were they reflected in blood-based biomarkers of bone metabolism. Altogether, dietary consumption of PUFA do not seem to affect bone structure or metabolism in a healthy model of growing mice.

Vascular Endothelial Growth Factor Enhances Compensatory Lung Growth in Piglets.

BACKGROUND: Vascular endothelial growth factor has been found to accelerate compensatory lung growth after left pneumonectomy in mice. The aim of this study was to determine the natural history and the effects of vascular endothelial growth factor on compensatory lung growth in a large animal model. METHODS: To determine the natural history of compensatory lung growth, female Yorkshire piglets underwent a left pneumonectomy on days of life 10-11. Tissue harvest and volume measurement of the right lung were performed at baseline (n = 5) and on postoperative days 7 (n = 5), 14 (n = 4), and 21 (n = 5). For pharmacokinetic studies, vascular endothelial growth factor was infused via a central venous catheter, with plasma vascular endothelial growth factor levels measured at various time points. To test the effect of vascular endothelial growth factor on compensatory lung growth, 26 female Yorkshire piglets underwent a left pneumonectomy followed by daily infusion of vascular endothelial growth factor at 200 µg/kg or isovolumetric 0.9% NaCl (saline control). Lungs were harvested on postoperative day 7 for volume measurement and morphometric analyses. RESULTS: Compared with baseline, right lung volume after left pneumonectomy increased by factors of 2.1 ± 0.6, 3.3 ± 0.6, and 3.6 ± 0.4 on postoperative days 7, 14, and 21, respectively. The half-life of VEGF ranged from 89 to 144 minutes. Lesser doses of vascular endothelial growth factor resulted in better tolerance, volume of distribution, and clearance. Compared with the control group, piglets treated with vascular endothelial growth factor had greater lung volume (P < 0.0001), alveolar volume (P = 0.001), septal surface area (P = 0.007) and total alveolar count (P = 0.01). CONCLUSION: Vascular endothelial growth factor enhanced alveolar growth in neonatal piglets after unilateral pneumonectomy.

Vascular endothelial growth factor accelerates compensatory lung growth by increasing the alveolar units.

BackgroundDeficiency of vascular endothelial growth factor (VEGF) is associated with hypoplastic lung diseases, such as congenital diaphragmatic hernia. Provision of VEGF has been demonstrated to be beneficial in hyperoxia-induced bronchopulmonary dysplasia, and hence could induce lung growth and improve the outcome in hypoplastic lung diseases. We aimed to determine the effects of exogenous VEGF in a rodent model of compensatory lung growth after left pneumonectomy.MethodsEight-to-ten-week-old C57Bl6 male mice underwent left pneumonectomy, followed by daily intra-peritoneal injections of saline or VEGF (0.5 mg/kg). Lung volume measurement, pulmonary function tests, and morphometric analyses were performed on post-operative day (POD) 4 and 10. The pulmonary expression of angiogenic factors was analyzed by quantitative polymerase chain reaction and western blot.ResultsLung volume on POD 4 was higher in the VEGF-treated mice (P=0.03). On morphometric analyses, VEGF increased the parenchymal volume (P=0.001), alveolar volume (P=0.0003), and alveolar number (P<0.0001) on POD 4. The VEGF group displayed higher levels of phosphorylated-VEGFR2/VEGFR2 (P=0.03) and epidermal growth factor (EGF) messenger RNA (P=0.01).ConclusionVEGF accelerated the compensatory lung growth in mice, by increasing the alveolar units. These changes may be mediated by VEGFR2 and EGF-dependent mechanisms.

Pretreatment with intravenous fish oil reduces hepatic ischemia reperfusion injury in a murine model.

BACKGROUND: Ischemia reperfusion injury is a barrier to liver surgery and transplantation, particularly for steatotic livers. The purpose of this study was to determine if pretreatment with a single dose of intravenous fish oil decreases hepatic ischemia reperfusion injury and improves recovery of injured livers. METHODS: Sixty adult male C57BL/6 mice received 1 g/kg intravenous fish oil (Omegaven, Fresenius Kabi) or isovolumetric 0.9% NaCl (saline) via tail vein 1 hour before 30 minutes of 70% hepatic ischemia. Animals were killed 4, 8, or 24 hours postreperfusion, and livers were harvested for histologic analysis. RESULTS: Four hours postreperfusion, saline-treated livers demonstrated marked ischemia diffusely around the central veins, while intravenous fish oil-treated livers demonstrated only patchy necrosis with intervening normal parenchyma. Eight hours postreperfusion, all livers demonstrated pale areas of cell loss with surrounding regenerating hepatocytes. Ki67 staining confirmed 14.4/10 high-powered field (95% confidence interval, 3.2-25.6) more regenerating hepatocytes around areas of necrosis in intravenous fish oil-treated livers. Twenty-four hours postreperfusion, all livers demonstrated patchy areas of necrosis, with an 89% (95% confidence interval, 85-92) decrease in the area of necrosis in intravenous fish oil-treated livers. CONCLUSION: Intravenous fish oil treatment prior to hepatic ischemia reperfusion injury decreased the area of hepatic necrosis and increased hepatocyte regeneration compared to saline treatment in a mouse model.

Parenteral Soybean Oil Induces Hepatosteatosis Despite Addition of Fish Oil in a Mouse Model of Intestinal Failure-Associated Liver Disease.

BACKGROUND: Replacement of parenteral soybean oil (SO) with fish oil (FO) is an effective therapy for intestinal failure-associated liver disease (IFALD) in children. However, practitioners remain concerned about the risk of essential fatty acid deficiency (EFAD) and sometimes treat IFALD with a combination of 50% SO and 50% FO emulsions. The purpose of this study was to determine if mixing 50% SO and 50% FO emulsions would prevent hepatosteatosis in a murine model of parenteral nutrition (PN)-induced hepatosteatosis. METHODS: C57BL/6 mice were randomized to receive oral PN with parenteral saline, FO, SO, or a mixture of 50% FO and 50% SO for 19 days. Fatty acid analysis, histologic evaluation, Nonalcoholic Steatohepatitis Clinical Research Network (NSCRN) scores, and reverse-transcriptase polymerase chain reaction for key lipogenic genes were performed. RESULTS: The PN + saline group was the only group with EFAD, with a serum and hepatic triene/tetraene ratio of 0.53. NSCRN scores were highest in the PN + SO group (5.5; 95% confidence interval [CI], 4.9-6.1), followed by the PN + FO/SO (4.5; 95% CI, 3.5-5.5) group, with the lowest score in the PN + FO (2.0; 95% CI, 1.1-2.9) group. Acetyl CoA carboxylase α and acetyl CoA carboxylase ß expression was lower in the PN + FO group than in the PN + FO/SO or PN + SO groups. CONCLUSIONS: Our data demonstrate that a mixed fat emulsion of 50% SO and 50% FO is inferior to 100% FO in reducing hepatosteatosis in this model. These data suggest that use of parenteral SO with parenteral FO, in a 1:1 ratio, may still contribute to liver injury, although it is less hepatotoxic than pure SO.

Technique and perioperative management of left pneumonectomy in neonatal piglets.

BACKGROUND: Although commonly performed in adult swine, unilateral pneumonectomy in piglets requires significant modifications in the surgical approach and perioperative care because of their smaller size and limited physiological reserve. METHODS: Nineteen neonatal piglets underwent a left pneumonectomy. They were allowed 5-7 d of preoperative acclimation and nutritional optimization. Preoperative weight gain and laboratory values were obtained before the time of surgery. A "ventro-cranial" approach is adopted where components of the pulmonary hilum were sequentially identified and ligated, starting from the most ventral and cranial structure, the superior pulmonary vein. The principle of gentle ventilation was followed throughout the entire operation. RESULTS: The median age of the piglets at the time of surgery was 12 (10-12) d. The median preoperative weight gain and albumin level were 20% (16-26%) and 2.3 (2.1-2.4) g/dL, respectively. The median operative time was 59 (50-70) min. Five of the first nine piglets died from complications, two from poor preoperative nutritional optimization (both with <10% weight gain and 2 g/dL for albumin), one from an intubation complication, one from intra-operative bleeding, and one in the postoperative period from a ruptured bulla. No mortality occurred for the next 10 cases. CONCLUSIONS: Successful outcomes for unilateral pneumonectomy in piglets require special attention to preoperative nutritional optimization, gentle ventilation, and meticulous surgical dissection. Preoperative weight gain and albumin levels should be used to identify appropriate surgical candidates. The "ventro-cranial" approach allows for a technically straightforward completion of the procedure.