title: Telemetric monitoring of tracheal pressure after tracheal occlusion for treatment of severe congenital diaphragmatic hernia.
abstract: BACKGROUND
  Prenatal tracheal occlusion using endoscopic techniques obstructs the normal egress of lung fluid during pulmonary development and stimulates lung growth in cases of congenital diaphragmatic hernia (CDH). Although FETO might be an effective strategy for treatment of CDH, the mechanism especially due to the supposed increasing transpulmonary pressure is unknown.
  
  
  OBJECTIVE
  The purpose of this study was to monitor the pressure below the attached balloon in the fetal lamb telemetrically.
  
  
  METHODS
  Four time-dated pregnant Merino ewes underwent fetal and maternal surgery. A special prepared silicone catheter was placed below the epiglottis by laryngoscopy on day 110 or 140 of gestation. The tracheal pressure below the fixed catheter could be monitored telemetrically using the Data Sciences TA11-PA-C40 pressure device. Hundred and twenty measurement points were recorded over a period of 2 min.
  
  
  RESULTS
  A maximum of lung pressure rate was found immediately after implantation (23.7 +/- 4.6 mm Hg). During the first hour, the pressure decreased to an average value of 16.9 mmHg. About 70 h after the block, this value decreased to a minimum level of 8.3 +/- 0.4 mmHg.
  
  
  CONCLUSIONS
  Decreasing pressure variation might indicate that lung growth has stopped and that the ideal point of time to remove the balloon is achieved. Increasing pressure has to be related to the morphometric analysis of the lung's structural development and maturation, comparing the efficacy of FETO in preventing or reversing pulmonary hypoplasia. Further investigation of continuous telemetric monitoring of tracheal pressure in the fetal lamb is required.
authors.affiliation: Department of Obstetrics and Perinatal Medicine, Philipps-University of Marburg, Baldingerstrasse, 35033 Marburg, Germany. hellmeye@med.uni-marburg.de
authors.forename: L
authors.initials: L
authors.lastname: Hellmeyer
authors.forename: C
authors.initials: C
authors.lastname: Exner
authors.forename: B
authors.initials: B
authors.lastname: Folz
authors.forename: M
authors.initials: M
authors.lastname: Hiller
authors.forename: F
authors.initials: F
authors.lastname: Sierra
authors.forename: P
authors.initials: P
authors.lastname: Lukasewitz
authors.forename: T
authors.initials: T
authors.lastname: Steinfeld
authors.forename: J A
authors.initials: JA
authors.lastname: Werner
authors.forename: G
authors.initials: G
authors.lastname: Heldmaier
authors.forename: S
authors.initials: S
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D021721:Balloon Occlusion; D004195:Disease Models, Animal; D005260:Female; D005333:Fetus / Q000601:surgery; D006548:Hernia, Diaphragmatic / Q000628:therapy*; D065630:Hernias, Diaphragmatic, Congenital; D018670:Monitoring, Ambulatory / Q000379:methods*; D011247:Pregnancy; D011312:Pressure; D012720:Severity of Illness Index; D012756:Sheep; D013686:Telemetry; D014132:Trachea / Q000502:physiology*