Remote ischaemic conditioning in necrotising enterocolitis: a phase I feasibility and safety study

OBJECTIVE: Remote ischaemic conditioning (RIC) improves the outcome of experimental necrotising enterocolitis (NEC) by preserving intestinal microcirculation. The feasibility and safety of RIC in preterm infants with NEC are unknown. The study aimed to assess the feasibility and safety of RIC in preterm infants with suspected or confirmed NEC. DESIGN: Phase I non-randomised pilot study conducted in three steps: step A to determine the safe duration of limb ischaemia (up to 4 min); step B to assess the safety of 4 repeated cycles of ischaemia-reperfusion at the maximum tolerated duration of ischaemia determined in step A; step C to assess the safety of applying 4 cycles of ischaemia-reperfusion on two consecutive days. SETTING: Level III neonatal intensive care unit, The Hospital for Sick Children (Toronto, Canada). PATIENTS: Fifteen preterm infants born between 22 and 33 weeks gestational age. INTERVENTION: Four cycles of ischaemia (varying duration) applied to the limb via a manual sphygmomanometer, followed by reperfusion (4 min) and rest (5 min), repeated on two consecutive days. OUTCOMES: The primary outcomes were (1) feasibility defined as RIC being performed as planned in the protocol, and (2) safety defined as perfusion returning to baseline within 4 min after cuff deflation. RESULTS: Four cycles/day of limb ischaemia (4 min) followed by reperfusion (4 min) and a 5 min gap, repeated on two consecutive days was feasible and safe in all neonates with suspected or confirmed NEC. CONCLUSIONS: This study is pivotal for designing a future randomised controlled trial to assess the efficacy of RIC in preterm infants with NEC

Remote ischemic conditioning avoids the development of intestinal damage after ischemia reperfusion by reducing intestinal inflammation and increasing intestinal regeneration

Aim of the study Midgut volvulus is a potentially life-threatening condition which is based on intestinal ischemia and reperfusion (I/R) injury. Remote ischemia conditioning (RIC) applied to a limb can protect distant organs such as heart and kidney. The aims of this study were to investigate the effect of RIC on a model of midgut volvulus and to explore its underlying mechanism of action. Methods Six-weeks old C57BL/6 mice were studied: (a) sham (n = 4): laparotomy alone. (b) Intestinal I/R injury (n = 5): occlusion of the superior mesenteric artery (SMA) for 45 min followed by reperfusion. (c) Intestinal I/R (as in group above) with RIC immediately after reperfusion (n = 5). RIC consisted of 4 cycles of 5 min hind limb ischemia followed by 5 min reperfusion. 24-h after laparotomy, animals were euthanized, and the small intestine (same distance from cecum) was harvested. The intestine was examined for inflammatory cytokines (TNF-alpha and IL-6), epithelial proliferation marker Ki67 and stem cell marker Lgr5 expression. Main results Compared to sham, the small intestine of IR mice had more intestinal damage, increased expression of inflammatory cytokines, decreased intestinal proliferation and stem cell activity. RIC significantly counteracted all these changes. Conclusions Remote ischemia conditioning avoids intestinal damage due to I/R injury. This beneficial effect is associated with decreased intestinal inflammation and enhanced intestinal regeneration. This study implicates that RIC is a novel non-invasive intervention to reduce the intestinal damage occurring in midgut volvulus

Mitochondrial DNA: A Biomarker of Disease Severity in Necrotizing Enterocolitis

Introduction There is a need to develop sensitive markers to diagnose or monitor the severity of intestinal damage in necrotizing enterocolitis (NEC). Mitochondrial deoxyribonucleic acid (mtDNA) is increased in the intestine and blood of adults in response to intestinal ischemia and can trigger secondary organ damage. We hypothesize that mtDNA is increased during experimental NEC and that mtDNA levels are correlated to the degree of intestinal injury.Materials and Methods NEC was induced in C57BL/6 mice ( n = 18) (approval: 44032) by gavage feeding with hyperosmolar formula, hypoxia, and lipopolysaccharide administration from postnatal day (P) 5 to 9. Breastfed pups served as control ( n = 15). Blood was collected by cardiac puncture and terminal ileum was harvested on P9. Reverse transcription quatitative polymerase chain reaction was used to measure mtDNA (markers COX3, CYTB, ND1) and inflammatory cytokines (interleukin 6 [IL-6] and tumor necrosis factor-alpha[TNF-alpha]) in blood and ileum. Intestinal injury was scored blindly by four investigators and classified as no/minor injury (score 0 or 1) or NEC (score >= 2).Results mtDNA is significantly increased in gut and blood of NEC mice ( p < 0.05). Furthermore, mtDNA increases in intestine and blood proportionally to the degree of intestinal injury as indicated by a positive correlation with histological scoring and inflammation ( r = 0.6; p < 0.05) (expression of IL-6 and TNF-alpha).Conclusion Following NEC intestinal injury, mtDNA is released from the intestine into circulation. The blood level of mtDNA is related to the degree of intestinal injury. mtDNA can be a novel marker of intestinal injury and can be useful for monitoring the progression of NEC

Surgical Management of Pediatric Inguinal Hernia: A Systematic Review and Guideline from the European Pediatric Surgeons' Association Evidence and Guideline Committee

Introduction Inguinal hernia repair represents the most common operation in childhood; however, consensus about the optimal management is lacking. Hence, recommendations for clinical practice are needed. This study assesses the available evidence and compiles recommendations on pediatric inguinal hernia. Materials and Methods The European Pediatric Surgeons' Association Evidence and Guideline Committee addressed six questions on pediatric inguinal hernia repair with the following topics: (1) open versus laparoscopic repair, (2) extraperitoneal versus transperitoneal repair, (3) contralateral exploration, (4) surgical timing, (5) anesthesia technique in preterm infants, and (6) operation urgency in girls with irreducible ovarian hernia. Systematic literature searches were performed using PubMed, MEDLINE, Embase (Ovid), and The Cochrane Library. Reviews and meta-analyses were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. Results Seventy-two out of 5,173 articles were included, 27 in the meta-analyses. Laparoscopic repair shortens bilateral operation time compared with open repair. In preterm infants, hernia repair after neonatal intensive care unit (NICU)/hospital discharge is associated with less respiratory difficulties and recurrences, regional anesthesia is associated with a decrease of postoperative apnea and pain. The review regarding operation urgency for irreducible ovarian hernia gained insufficient evidence of low quality. Conclusion Laparoscopic repair may be beneficial for children with bilateral hernia and preterm infants may benefit using regional anesthesia and postponing surgery. However, no definite superiority was found and available evidence was of moderate-to-low quality. Evidence for other topics was less conclusive. For the optimal management of inguinal hernia repair, a tailored approach is recommended taking into account the local facilities, resources, and expertise of the medical team involved