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Background and rationaleThe unborn fetus has
become a patient to whom diagnosis and therapy is offered prior
to birth. Both diagnosis and therapy are preferentially
non-invasive. Sometimes a fetal anomaly or disease may require an
invasive procedure to establish the diagnosis or cure the
condition. Under ultrasound guidance, a needle can be inserted
into the amniotic cavity, to sample the amniotic fluid, fetal
blood or administer transfusion blood or medication. This has
acceptable risks and is widely practiced. In some rare conditions
the fetus needs to be operated on during its intra-uterine life.
Fetal surgery then requires maternal laparotomy, hysterotomy, and
temporary exposure of the fetus. Such a procedure is
unfortunately associated with adverse fetal side effects and
therefore poor outcome while being very invasive to the mother. A
minimally invasive endoscopic approach seems therefore an
attractive alternative. In the 1990s the diameter of endoscopes
could be dramatically reduced and videotechnology boosted
endoscopic surgery. However virtually no purpose designed
instruments for use in fetoscopy were available and from an
economical viewpoint, there are not much incentives for the
medical industry to develop these. The field is small and
appreciated as high risk. In addition a strong scientific basis
for the theoretical benefits of operative fetoscopy was lacking,
and the clinical experience in the late 1990s was limited and
scattered.
Objectives and primary approachesThe general aim
of the project was to bridge the gap between actual experimental
procedures and routine established clinical practice within three
to four years. For that purpose a consortium of a medical
industrial partner and leading clinicians was set up. They
focussed on essential technical developments, balancing
technology and safety- and performance requirements, to allow
their clinical use in intra-uterine endoscopic fetoplacental
interventions. This mainly involved development of the
following:
- new small diameter and high resolution autoclavable
optics
- safe devices for amniotic distension
- novel tools for hemostasis or coagulation of pathologic
vessels, amenable for minimal access to the pregnant
uterus
- fibre-optical monitoring devices for monitoring the fetal
patient
- different catheter and fetal access techniques to improve
in utero stem-cell transplantation
- techniques for sealing the amniotic membranes.
These developments were first investigated in an
experimental setting, and subsequently validated in the clinical
situation.
As hoped, fetoscopy became an important tool in today’s
fetal medicine, and in order to monitor its safety and efficacy,
the group initiated an internet based registry, open to all fetal
medicine specialist. The most widely practised application of
modern fetoscopy is the fetoscopic coagulation of abnormal
communicating vessels on the placenta of identical twins
suffering from the so-called twin-to-twin transfusion syndrome. A
special more extended registry for this treatment modality was
set up, as to validate the efficacy of this new therapy as
compared to the standard treatment.
Deliverables for exploitation:A whole range of new
medical instruments were developed, tested and subsequently
released for production.
- These include endoscopes, accompanying sheats, trocars for
cannula introduction and some purpose designed instruments such
as forceps, scissors, etc… Hardware (i.e. devices
without which endoscopy in the amniotic cavity is not
possible), including devices for distention of the cavity were
purpose designed and tested.
- Two specially designed bipolar forceps and monopolar
coagulation device for cord coagulation in abnormal
monochorionic twins were introduced to the market.
- All the above instruments may also find their place in
other clinical fields (besides fetal medicine), such as
hysteroscopy (for the endoscopes) and pediatric surgery (for
instruments and devices).
- Preclinically the efficacy and safety of a fetal membrane
sealing technique, using collagen, was studied. According to
the contractual agreements, no non-human primate experiments
were allowed, and therefore its application in clinical cases
is still under way. An in vitro culture system for the study of
fetal membrane wound healing was developed which will further
be used by scientists, reducing the need for animal
experiments.
- As part of the workpackage on catheterisation techniques
(aiming at in utero stem cell transplantation), new analytical
techniques to assess small differences in engraftment, and two
methods that may enhance engraftment were developed.
- Via our website, information on fetoscopy is given to the
public. For medical professionals, a registry on fetoscopic
procedures and two clinical studies on the treatment of
twin-to-twin transfusion syndrome are accessible. The website
hosts these clinical studies and all related documents for data
entry. This is the largest dataset worldwide on this condition.
It is expected that by 2003 a randomised trial will be finished
and determine whether TTS is better treated by fetoscopic laser
coagulation than amniodrainage, or perhaps what subgroup would
benefit from either therapy.
The name Eurofoetus achieved a reputation of a scientific
“authority” in the field of fetoscopy and invasive
fetal medicine. Over 400 fetoscopies have been done by the
clinical partners. Only one center in Europe performing operative
fetoscopy is not a member of the Eurofoetus group, but meanwhile
became partner in a new application within the FP5 programme. The
clinicians of the group are considered as world authorities in
fetoscopy: they are opinion leaders and trainers of clinicians
who want to establish a formal fetoscopy programme. They are
speakers at all relevant international meetings, contribute to
the international literature on this topic. The publication list
of the group is impressive, with a total of 70 full length
publications.
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