Showing papers by "Jan Deprest published in 2006"

Twin reversed arterial perfusion: fetoscopic laser coagulation of placental anastomoses or the umbilical cord.

Abstract: Objective To assess the feasibility and outcome of fetoscopic laser coagulation in pregnancies with twin reversed arterial perfusion (TRAP) sequence Methods In a prospective multicenter study, percutaneous fetoscopic laser coagulation of placental anastomoses (n = 18) or the umbilical cord of the acardiac twin (n = 42) was performed in 60 consecutive pregnancies at a median gestational age of 183 (range, 143–247) weeks under local or locoregional anesthesia Results Vascular coagulation with arrest of blood flow was achieved in 82% (49/60) of cases by laser alone and in a further 15% (9/60) by laser coagulation in combination with bipolar forceps The overall survival rate of the pump twin was 80% (48/60) Median gestational age at delivery was 374 (range, 237–414) weeks and the median interval between the procedure and delivery was 182 (range, 11–257) weeks Median birth weight was 2720 (range, 540–3840) g Preterm premature rupture of membranes before 34 weeks' gestation occurred in 18% (11/60) at a median of 62 (range, 1–102) days after the procedure However, only two (3%) women delivered within 28 days of the procedure Conclusions Fetoscopic laser coagulation of placental vascular anastomoses or the umbilical cord of the acardiac twin is an effective treatment of TRAP sequence, with a survival rate of 80%, and 67% of pregnancies with surviving pump twins going beyond 36 weeks' gestation without further complications Copyright © 2006 ISUOG Published by John Wiley & Sons, Ltd

The biology behind fascial defects and the use of implants in pelvic organ prolapse repair.

Abstract: Implant materials are increasingly being used in an effort to reduce recurrence after prolapse repair with native tissues. Surgeons should be aware of the biology behind both the disease as well as the host response to various implants. We will discuss insights into the biology behind hernia and abdominal fascial defects. Those lessons from “herniology” will, wherever possible, be applied to pelvic organ prolapse (POP) problems. Then we will deal with available animal models, for both the underlying disease and surgical repair. Then we will go over the features of implants and describe how the host responds to implantation. Methodology of such experiments will be briefly explained for the clinician not involved in experimentation. As we discuss the different materials available on the market, we will summarize some results of recent experiments by our group.

Fetoscopic surgery: encouraged by clinical experience and boosted by instrument innovation.

Abstract: Today, modern ultrasound equipment and the wide implementation of screening programmes allow the timely diagnosis of many congenital anomalies. For some of these, fetal surgery may be a life-saving option. In Europe, open fetal surgery became poorly accepted because of its invasiveness and the high incidence of postoperative premature labour and rupture of the fetal membranes. In the 1990s, the merger of fetoscopy and advanced video-endoscopic surgery formed the basis for endoscopic fetal surgery. We review the current applications of fetal surgery via both methods of access. The first clinical fetoscopic surgeries were interventions on the umbilical cord and the placenta, often referred to as obstetrical endoscopy. The outcome of a randomized clinical trial demonstrating that fetoscopic laser coagulation of chorionic plate vessels is the most effective treatment for twin-twin transfusion syndrome (TTTS) has revived interest in endoscopic fetal therapy. Operating on the fetus is another more challenging enterprise. Clinical fetal surgery programmes were virtually non-existent in Europe until minimally invasive fetoscopic surgery made such operations clinically possible as well as maternally acceptable. At present, most experience has been gathered with fetal tracheal occlusion as a therapy for severe congenital diaphragmatic hernia. As in other fields, minimally invasive surgery has pushed back boundaries and now allows safe operations to be performed on the fetal patient. Whereas minimal access seems to solve the problem of preterm labour, all procedures remain invasive, and carry a risk to the mother and a substantial risk of preterm prelabour rupture of the membranes (PPROM). The latter problem may prove to be a bottleneck for further developments, although treatment modalities are currently being evaluated.

Prenatal intervention for isolated congenital diaphragmatic hernia.

Abstract: PURPOSE OF REVIEW We aim to review the recent literature regarding early prenatal prediction of outcome in babies diagnosed with isolated congenital diaphragmatic hernia, as well as results of fetal therapy for this condition. RECENT FINDINGS Current survival rates in population-based studies are around 55-70%. Highly specialized centers report 80% and more, but discount the hidden mortality, mainly in the antenatal period. Fetuses presenting with liver herniation and a lung-to-head ratio of less than 1.0 measured in midgestation have a poor prognosis. Other volumetric techniques are being evaluated for use in midtrimester. Recently, a randomized trial failed to show benefit from prenatal therapy, but lacked power to document the potential advantage of prenatal therapy in severe cases. We proposed percutaneous fetal endoluminal tracheal occlusion with a balloon at 26-28 weeks through a 3.3 mm incision. In severe cases, fetal endoluminal tracheal occlusion increased lung size as well as survival, with an early (7 day) survival, late neonatal (28 day) survival and survival at discharge of 75, 58 and 50%, respectively, comparing favorably with 9% in contemporary controls. Airways can be restored prior to birth improving neonatal survival (83.3% compared with 33.3%). The procedure carries a risk for preterm prelabour rupture of the fetal membranes, although that may decrease with experience. SUMMARY Fetuses with severe congenital diaphragmatic hernia can be identified in the second trimester. Fetal endoluminal tracheal occlusion can be considered as a minimally invasive fetal therapy, improving outcome in such highly selected cases.

Relationship between lung-to-head ratio and lung volume in normal fetuses and fetuses with diaphragmatic hernia.

Abstract: Objective To examine the relationship between the fetal lung area and lung area to head circumference ratio (LHR) and lung volume by three-dimensional (3D) ultrasonography in normal fetuses and in fetuses with unilateral congenital diaphragmatic hernia (CDH). Methods In 64 fetuses with CDH at median 26 (range, 20–32) weeks of gestation the contralateral lung volume, lung area and LHR were measured and the values were compared to those of 650 normal fetuses at 12–32 weeks. In the normal fetuses both lungs were assessed but in the 64 fetuses with CDH only the contralateral lung was measured because the ipsilateral lung could be visualized adequately in only 40 (62.5%) of the cases. Regression analysis was used to assess the significance of the association between lung volume and lung area or LHR. In the fetuses with CDH, the observed to expected ratios for lung area and LHR were calculated. The expected lung area and LHR were the normal median for a given lung volume. The significance of the differences between the observed to expected lung area and LHR in fetuses with CDH and normal fetuses was determined. In the 64 fetuses with CDH and in 64 normal fetuses, matched for gestational age, the lung length between the apex and the superior aspect of the diaphragm dome was also recorded. Results In normal fetuses the median lung area and LHR in both the left and right lungs increased significantly with lung volume. In the fetuses with CDH, the lung area and lung volume for gestation were substantially lower than in normal fetuses and the ratios of observed to expected lung area and LHR for a given lung volume were significantly lower than the respective values in normal fetuses. Additionally, the mean lung length was 13% greater and the mean lung area was 44% smaller than the respective values in the normal controls matched for gestational age. Conclusions The finding of a significant association between LHR and lung volume has validated the use of LHR in the assessment of lung growth. However, the study has also demonstrated that in fetuses with CDH, LHR underestimates the actual lung volume, because the herniated viscera cause a greater lateral, rather than vertical, compression of the contralateral lung. Copyright  2006 ISUOG. Published by John Wiley & Sons, Ltd.

Left and right lung volumes in fetuses with diaphragmatic hernia

Abstract: Objective To compare the volume of the ipsilateral and contralateral lungs in fetuses with congenital diaphragmatic hernia (CDH). Methods Left and right lung volumes were measured using three-dimensional (3D) ultrasonography in 42 fetuses with CDH at median 26 (range, 20–32) weeks of gestation. Each value was then expressed as a difference, in standard deviations, from the normal mean for gestation, previously established from the study of 650 normal fetuses at 12–32 weeks (Z-score). The Mann–Whitney U-test was used to determine the significance of the differences between the measurements in fetuses with CDH and normal fetuses and between the ipsilateral and contralateral lungs in fetuses with left- and rightsided CDH. Results There were 34 fetuses with left-sided CDH and eight with right-sided CDH. In CDH both the ipsilateral and contralateral lung volumes were substantially lower than in normal fetuses. In left CDH the left lung volume was 4.03 (median; range, 3.11–4.78) SDs below the normal mean for gestation, and the respective values for the right lung were 3.04 (median; range, 1.78–4.31) SDs (P < 0.001 for both). In right CDH, the left lung volume was 2.91 (median; range, 1.62–4.07) SDs below the normal mean for gestation and the respective values for the right lung were 4.35 (median; range, 3.07–4.99) SDs (P < 0.001 for both). In both left and right diaphragmatic hernia the deficit in the volume of the ipsilateral lung was significantly greater than the deficit in the contralateral lung. Conclusions In fetuses with CDH both the ipsilateral and contralateral lung volumes are substantially lower than in normal fetuses. Copyright  2006 ISUOG. Published by John Wiley & Sons, Ltd.

Fetal magnetic resonance imaging: luxury or necessity?

Abstract: During its latest annual meeting, the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) dedicated two sessions to the use of magnetic resonance imaging (MRI) in obstetrics and gynecology. In doing so, it acknowledged the increasingly important role of MRI in our practices. Today, with hardware becoming increasingly affordable, patients get more and easier access to this type of imaging, and insurance companies or other authorities do not question its use for a wider range of indications. At the same time MRI has become faster so that fetal movements are less of a problem, and fetal imaging is no longer beyond our reach. Modern equipment allows the taking of ‘snap-shot’ images with resolution and contrast detail never before witnessed. Nevertheless, the examination is certainly not used widely in pregnancy, despite a reassuring guideline on the safety of MRI from the American College of Radiology, which should dispel any doubt amongst skeptics1–3. We believe it is time for a change. In units where radiologists and fetal medicine specialists, or other players in the field of perinatal therapy, become more familiar with fetal images, enthusiasm increases. So, too, does that of our Society: the White Journal publishes an ever-increasing number of papers involved with MRI applications, as is evident in this issue. At one point, some faculty members at the last ISUOG World Congress in Vancouver even suggested changing the name of our Society to the International Society of Imaging in Obstetrics and Gynecology. Admittedly, this was somewhat overzealous, but it reflects well the idea that, whatever the nature of the technology, we use imaging techniques as tools to solve clinical questions. However, for most of us there remain many barriers that prevent us from fully embracing fetal MRI. First, we very rarely feel the clinical need. Sonography is undoubtedly satisfactory for everyday screening activities and even for imaging the majority of fetal malformations. Furthermore, MRI is a tool in ‘other’ hands: in all units, fetal MRI is conducted by radiologists and their technicians. This constitutes both a physical and a logistical barrier. We do not always know what to expect from each other: gynecologists are not trained in the physics behind the impressive MRI examination technology; radiologists cannot be expected to have the entire subspecialty background on which a maternal–fetal medicine specialist relies. However, the time has come for us to liaise with each other and explore the advantages and limitations of this procedure, to define in which situations fetal MRI can supplement our ultrasound findings, and to explore new applications, stretching beyond anatomical evaluation, and including functional studies. Thus, the editorial office judged it time for a brief round-up of what has been established (recently) and what is in the pipeline, with respect to MRI in the field of fetal medicine.

Fetal pain perception and pain management.

Abstract: This paper gives an overview of current science related to the concept of fetal pain. We have answered three important questions: (1) does fetal pain exist? (2) does management of fetal pain benefit the unborn child? and (3) which techniques are available to provide good fetal analgesia?

Diagnosis and management of heterokaryotypic monochorionic twins.

Abstract: The diagnosis, management, and outcome of six consecutive heterokaryotypic monochorionic twins were evaluated. All suspected cases, based on discordant ultrasound findings, underwent amniocentesis of both sacs. Two cases also had chorionic villous sampling (CVS). Dual amniocentesis was superior to CVS in diagnosing heterokaryotypic monochorionic twins. In four cases, the X-chromosome was involved and autosomal aneuploidy was noted in the others. In five cases, the anomalous twin was selectively reduced by cord coagulation. All pregnancies ended with a phenotypically normal liveborn and all children are developing normally at 1-7 years of age.

Clinical implications of the biology of grafts: conclusions of the 2005 IUGA Grafts Roundtable

Abstract: With few exceptions, the current expansion of graft utilization in pelvic reconstructive surgery is not a product of evidence-based medicine. Abdominal sacrocolpopexy and suburethral sling procedures are two situations under which synthetic graft utilization is indicated, based on randomized prospective trials and reported clinical outcomes. Otherwise, indications and contraindications for graft utilization are unclear. Current published data on the biology of synthetic and biologic grafts are limited and overall not very helpful to the reconstructive surgeon who is faced with the selection of a graft for use during a reconstructive procedure. This Roundtable presented the opportunity for a series of basic science researchers to present their data to a group of reconstructive surgeons and provide publishable background information on the various currently available grafts. The occurrence of healing abnormalities after graft implantation is becoming increasingly recognized as a potentially serious problem. To date, definitions and a classification system for healing abnormalities do not exist. Based on the input from basic scientists and experienced surgeons, a simple classification is suggested based on the site of healing abnormality, timing relative to graft implantation, presence of inflammatory changes, and the viscera into which the graft is exposed. Many opportunities for clinical and basic science research exist. As the use of grafts in reconstructive surgery is expanded, surgeons are encouraged to familiarize themselves with currently published data, and determine whether a graft should, or should not be, utilized during a reconstructive procedure, and if so, the type of graft best indicated in each specific clinical situation.

The effect of imatinib mesylate on the contractility of isolated rabbit myometrial strips.

Abstract: Background: C-kit receptor expressing interstitial cells generate and coordinate the electrical signals that control peristalsis in the gut. However, the function of interstitial ce

The effect of imatinib mesylate on the contractility of isolated rabbit myometrial strips

Abstract: Background: C-kit receptor expressing interstitial cells generate and coordinate the electrical signals that control peristalsis in the gut. However, the function of interstitial cells in the myometrium is not known. Methods: (1) Sections of rabbit myometrium were subjected to immunohistochemical staining for the c-kit receptor. (2) Spontaneously contracting myometrial strips from New Zealand White rabbits near term were mounted in an organ bath and attached to a tension-recording device. The effect of increased concentrations of the c-kit receptor antagonist imatinib mesylate on these contractions was observed. The main outcome measures were the change in frequency, amplitude and duration of contraction. Results: (1) Multipolar cells expressing c-kit were identified in the fibromuscular septum confirming the presence of interstitial cells in rabbit myometrium. (2) Imatinib decreased the amplitude of contractions by approximately 20% at 100 µM. No effect was seen at lower concentrations. No effect of imatinib on frequency or duration of contractions was observed at any of the concentrations studied. Conclusions: In isolated rabbit myometrium, acute inhibition of the c-kit receptor by imatinib mesylate affects only the amplitude of spontaneous contractions at concentrations, the equivalent of ×10–100 the normal therapeutic concentration.

Ultrasound-guided injection and occlusion of the trachea in fetal sheep.

Abstract: Objectives To access the fetal sheep trachea by ultrasound-guided transthoracic injection in order to deliver gene therapy vectors or occlude the trachea with a detachable balloon. Methods Fetal sheep were operated on at a mean gestational age of 102 (range, 81-116) days (term 145 days). Under ultrasound guidance, either a 20-G spinal (for vector delivery) or a 16-G Kellett (for placement of an occlusive balloon) needle was inserted via the fetal thorax into the fetal trachea. Results Using the 20-G spinal needle the trachea was accessed successfully in 33/36 fetuses, with 97% survival. Failure to inject was related to fetal Position and gestational age. Blood vessel damage causing significant morbidity occurred in two fetuses (6%). Tracheal occlusion was achieved by puncturing the trachea with the 16-G needle and advancing an endoluminal balloon in three out of five attempts in a mean time of 17 (range, 16-19) min, with 100% survival. In one case, the balloon became sited within the accessory lobe bronchus and was not inflated. At postmortem examination 21 days later, all balloons remained inflated and occluded the trachea, and the lung-to-body weight ratio and airways morphometric indices were consistent with relative pulmonary hyperplasia in the obstructed lungs. Conclusions Ultrasound-guided transthoracic tracheal puncture is a reliable technique in fetal sheep, with low morbidity and mortality. Using this technique, a detachable endotracheal balloon can be placed to provoke pulmonary growth. Advances in needle design and balloon size may improve the success rate. Copyright (c) 2006 ISUOG. Published by John Wiley & Sons, Ltd.

Fetoscopic surgery for in-utero management of congenital diaphragmatic hernia

Abstract: Until recently two possibilities were available to the expectant parents of a fetus diagnosed with a congenital diaphragmatic hernia: termination of pregnancy or continuation of the pregnancy until term with a potential change in the place of delivery. Open fetal surgery has been used to treat a growing number of congenital malformations with life-threatening or highly morbid consequences including congenital diaphragmatic hernia. However, its effectiveness is limited by the occurrence of preterm labour, chorioamniotic membrane separation, preterm prelabour rupture of the membranes and altered fetal homeostasis. These problems were the impetus for the development of minimal access fetal surgery. Developments in endoscopic surgical technology over the past three decades have provided the opportunity to develop techniques adapted for prenatal fetal intervention.

OC38: Preventive collagen plugging of fetal membrane defects following fetoscopic endoluminal tracheal occlusion (FETO)

Abstract: significant. In 4 fetuses, the hyperoxygenation test was reactive before and remained so after balloon removal. Out of these 4, 3 survived. However in one baby, a reactive test became non-reactive and this baby died of pulmonary hypoplasia. In 2 patients a nonreactive test became reactive, and both babies survived. In 4 patients a non-reactive test remained non-reactive; 1 survived. Conclusion: There is no strict relation between in utero reversal of TO at 34 weeks and the reactivity of the contralateral fetal pulmonary artery to oxygen. Fetuses undergoing FETO who have a reactive test at any stage prior to birth were more likely to survive (5/7). A negative test prior to birth was predictive of neonatal death (3/4 neonatal deaths). Additional data are required certainly in function of prediction of pulmonary hypertension.