Study of the Influence of Intraperitoneal Insufflation of CO2 by Laparoscopy on the Short-term Evolution of Premature Infants With Ulcerative Necrotizing Enterocolitis

NECO2 is a pilot trial, evaluating the intermediate effectiveness to short/medium term of laparoscopy on the inflammatory reaction of premature newborns with complicated ECUN, requiring surgical treatment. This is a multicenter randomized controlled trial in single blind, in two parallel arms, in ratio 1:1, of superiority. This trial compares laparoscopy plus laparotomy versus laparotomy alone. Children will be randomized into 2 groups: * Laparoscopy + laparotomy group * Laparotomy group The main objective is to evaluate the inflammatory response Day 2 postoperative in preterm infants with ECUN who have undergone surgery. The main criterion is the evolution of the blood C reactive protein level between Day 0 and Day 2 postoperatively. The secondary objectives are:To evaluate in premature babies with ECUN who have had a surgical intervention (laparoscopy + laparotomy or laparotomy alone): A.The postoperative biological inflammatory response at Day 7 B.Post-operative biological inflammatory response from Day 0 to Day 7 C.Post-operative mortality D.Post-operative bowel morbidity E.Post-operative re-intervention rate F.Length of hospital stay G.Post-operative neurological morbidity, medium term (corrected term 41 SA) * To evaluate the tolerance of laparoscopy : H.Intraoperative cardiorespiratory I.Loco-regional lesions linked to the insertion of the trocar Secondary endpoints: A. C reactive protein blood level at Day 7 B. Blood levels of Procalcitonin, Interleukin 6 and Tumor Necrosis Factor-alpha at Day 1, Day 2, Day 4, Day 7 C. Postoperative death from any cause D. Stoma rate, duration of parenteral nutrition, duration of hemodynamic support, duration of invasive ventilation (High frequency oscillatory ventilation/Synchronized Intermittent Mandatory Ventilation), Post-ECUN intestinal stenosis rate E. Re-intervention (laparotomy) and cause (post-ECUN stenosis, stoma closure) F. Length of hospital stay until return home G. Early postoperative neurological lesions observed on transfontanellar ultrasound and MRI at the corrected term of 41 weeks of amenorrhea, H. Oxygen saturation (SaO2), hypercapnia (pCO2) blood pressure (BP), cerebral oxygenation (Near InfraRed Spectroscopy (NIRS)) intraoperatively I. Intraoperative clinical monitoring: exploration of adjacent organs. Post-operative clinical monitoring: digestive signs monitoring of wounds until discharge. Group 1: laparotomy only Group 2: laparotomy and laparoscopy