Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Partial amniotic carbon dioxide insufflation (PACI) during minimally invasive fetoscopic interventions on fetuses with spina bifida aperta



Percutaneous partial amniotic carbon dioxide insufflation (PACI) is one of the most important means for improving visualization during minimally invasive fetoscopic surgery of fetal spina bifida. The purpose of the present study was to analyze maternal and fetal safety aspects of PACI in a recent patient cohort and to present management improvements.


PACI under general materno-fetal anesthesia was performed during 65 interventions for fetoscopic patch coverage of fetal spina bifida aperta between 21 + 0 and 29 + 1 weeks of gestation. Filtered carbon dioxide was insufflated into the amniotic cavity via three percutaneously introduced trocars. Maternal ventilatory and hemodynamic parameters during PACI as well as insufflation pressures, BMI, parity, and placental position were recorded and statistically analyzed in order to detect potential risk groups.


Maternal respiration parameters during PACI showed a typical variation over time, which was similar in patients with BMI ≤ 25 or BMI > 25. The necessary insufflation pressures were significantly higher in nulliparae than multiparae. There was no statistically significant relationship between insufflation pressure and maternal BMI, or between the expired maternal carbon dioxide concentration (etCO2) and the placental position. PACI was safe for all mothers and fetuses. Postnatal demise in one neonate, one fetus, and two infants occurred unrelated to PACI and resulted from trisomy 13, infection, and severe Chiari II malformations, respectively.


PACI seems safe in order to improve visualization of intraamniotic contents during minimally invasive fetoscopic surgery. Nevertheless, continued assessments of its benefits and risks are important.

This is a preview of subscription content, log in to check access.

We’re sorry, something doesn't seem to be working properly.

Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

Fig. 1


  1. 1.

    Kohl T (2014) Percutaneous minimally invasive fetoscopic surgery for spina bifida aperta. Part I: surgical technique and perioperative outcome. Ultrasound Obstet Gynecol 44(5):515–524

  2. 2.

    Arens C, Koch C, Veit M, Greenberg RS, Lichtenstern C, Weigand MA, Khaleeva A, Schuerg R, Kohl T (2017) Anesthetic management for percutaneous minimally invasive fetoscopic surgery of spina bifida aperta: a retrospective, descriptive report of clinical experience. Anesth Analg 125:219

  3. 3.

    Adzick NS, Thom EA, Spong CY, Brock JW 3rd, Burrows PK, Johnson MP, Howell LJ, Farrell JA, Dabrowiak ME, Sutton LN, Gupta N, Tulian NB, D’Alton ME, Farmer DL (2011) A randomized trial of prenatal versus postnatal repair of myelomeningocele. N Engl J Med 17:993–1004

  4. 4.

    Degenhardt J, Schürg R, Winarno A, Oehmke F, Khaleeva A, Kawecki A, Enzensberger C, Tinneberg HR, Faas D, Ehrhardt H, Axt-Fliedner R, Kohl T (2014) Percutaneous minimal-access fetoscopic surgery for spina bifida aperta: part II—maternal management and outcome. Ultrasound Obstet Gynecol 44(5):525–531

  5. 5.

    Kohl T (2004) Fetoscopic surgery: where are we today? Curr Opin Anaesthesiol 17:315–321

  6. 6.

    Kohl T, Reckers J, Strümper D, Grosse Hartlage M, Gogarten W, Gembruch U, Vogt J, Van Aken H, Scheld HH, Paulus W, Richert CH (2004) Amniotic air insufflation during minimally invasive fetoscopic cardiac interventions is safe for the fetal brain in sheep. J Thorac Cardiovasc Surg 128:467–471

  7. 7.

    Kohl T, Ziemann M, Weinbach J, Tchatcheva K, Gembruch U, Hasselblatt M (2010) Partial amniotic carbon dioxide insufflation during minimally invasive fetoscopic interventions seems safe for the fetal brain in sheep. J LapEndosc Adv Surg Tech 20(7):651

  8. 8.

    Estes JM, Szabo Z, Harrison MR (1992) Techniques for in utero endoscopic surgery: a new approach for fetal intervention. Surg Endosc 6:215–218

  9. 9.

    Fauza DO, Rawn J, Fishman SJ (1999) Fetal response to neutral gas and liquid media for intraamniotic distension. J Pediatr Surg 34(4):591–594

  10. 10.

    Gratacós E, Wu J, Devlieger R, Bonati F, Lerut T, Vanamo K, Deprest JA (2002) Nitrous oxide amniodistension reduces operation time while inducing no changes in fetal acid-base status in a sheep model for endoscopic fetal surgery. Am J Obstet Gynecol 186:538–543

  11. 11.

    Pelletier GJ, Srinathan SK, Langer JC (1995) Effects of intraamniotic helium, carbon dioxide, and water on fetal lambs. J Pediatr Surg 30:1155–1158

  12. 12.

    Kohl T, Tchatcheva K, Weinbach J, Hering R, Kozlowski P, Stressig R, Gembruch U (2010) Partial amniotic carbon dioxide insufflation (PACI) during minimally invasive fetoscopic surgery: early clinical experience in humans. Surg Endosc 24:432–444

  13. 13.

    Kohl T, Schürg R, Maxeiner H, Tchatcheva K, Degenhardt J, Kawecki A, Stressig R, Axt-Fliedner R, Weigand M, Gembruch U (2012) Partielle amniotische Kohlendioxid-Insufflation (PACI) während fetoskopischer Operationen an Ungeborenen mit Spina bifida. Ultraschall Med 33:A708

  14. 14.

    Weinbach J (2010) Frühe klinische Erfahrungen mit der Kohlendioxidinsufflation der Fruchthöhle während minimal-invasiver fetoskopischer Eingriffe an Ungeborenen. Inaugural-Dissertation Universitätsklinikum Bonn

  15. 15.

    Ziemann M (2016) Partielle Kohlendioxid Insufflation der Fruchthöhle (PACI) bei minimal-invasiver Fetalchirurgie an Ungeborenen mit Spina bifida aperta: analyse apparativ gemessener Beatmungs- und Kreislaufparameter sowie klinische Beobachtungen. Inaugural-Dissertation Universitätsklinikum Bonn

  16. 16.

    Jang PR, Brace RA (1992) Amniotic fluid composition changes during urine drainage and tracheoesophageal occlusion in fetal sheep. Am J Obstet Gynecol 167:1732–1741

  17. 17.

    Gratacós E, Wu J, Devlieger R, Van de Velde M, Deprest JA (2001) Effects of amniodistension with carbon dioxide on fetal acid-base status during fetoscopic surgery in the sheep model. Surg Endosc 15:368–372

  18. 18.

    Luks FI, Deprest J, Marcus M, Vandenberghe K, Vertommen JD, Lerut T, Brosens I (1993) Carbon dioxide pneumoamnios causes acidosis in fetal lamb. Fetal Diagn Ther 9:105–109

  19. 19.

    Saiki Y, Litwin DE, Bigras JL, Waddell J, Konig A, Baik S, Navsarikar A, Rebeyka IM (1997) Reducing the deleterious effects of intrauterine CO2 during fetoscopic surgery. J Surg Res 69:51–54

  20. 20.

    Kohl T (2016) Letter to the Editor: Impact of partial amniotic carbon dioxide insufflation (PACI) on middle cerebral artery blood flow in mid-gestation human fetuses undergoing minimally-invasive fetoscopic surgery for spina bifida. Ultrasound Obstet Gynecol 47(4):521–522

  21. 21.

    Bruner JP, Richards WO, Tulipan NB, Arney TL (1999) Endoscopic coverage of fetal myelomeningocele in utero. Am J Obstet Gynecol 180:153–158

  22. 22.

    Diehl W, Diemert A, Grasso D, Sehner S, Wegscheider K, Hecher K (2017) Fetoscopic laser coagulation in 1020 pregnancies with twin-to-twin transfusion syndrome demonstrates improvement of double survival rates. Ultrasound Obstet Gynecol. https://doi.org/10.1002/uog.17520

Download references

Author information

Correspondence to Thomas Kohl.

Ethics declarations


Mrs Ziemann and Khaleeva as well as Drs. Fimmers, Schürg, Weigand, and Kohl have no conflicts of interest or financial ties to disclose.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ziemann, M., Fimmers, R., Khaleeva, A. et al. Partial amniotic carbon dioxide insufflation (PACI) during minimally invasive fetoscopic interventions on fetuses with spina bifida aperta. Surg Endosc 32, 3138–3148 (2018). https://doi.org/10.1007/s00464-018-6029-z

Download citation


  • Fetoscopy
  • Fetal surgery
  • Spina bifida aperta
  • Insufflation
  • Carbon dioxide
  • Fetus