Biomedical subjects

T Vanderheyden

Publications and source records attributed to T Vanderheyden.

4 recordsLinked to original sources

PubMed2003

Transmitted arterio-arterial anastomosis waveforms causing cyclically intermittent absent/reversed end-diastolic umbilical artery flow in monochorionic twins.

OBJECTIVES: To characterize the phenomenon of retrograde transmission of arterio-arterial anastomosis (AAA) interference patterns on umbilical artery (UA) waveform by (a) documenting the periodicity, (b) correlation with in vivo and in vitro demonstration of AAAs and (c) reproducing these patterns by computer modelling. METHODS: Monochorionic twins (MC) twins underwent placental and umbilical Doppler studies. AAAs were sought by pulse wave Doppler of their bi-directional interference pattern and confirmed by postnatal injection studies. The periodicity of transmitted patterns in the UA was determined. Determinants of the transmitted patterns were ascertained by computer modelling of physiological and fetal variables. RESULTS: Among 83 prospectively studied MC twin pregnancies; a transmitted pattern was observed in 6 (7 per cent) patients for 15-114 days. This was found in 20 per cent (6/30) of smaller MC twins discordant for growth restriction but in no appropriately grown twins. It was only observed in association with AAAs validated both in vivo and in ex vivo. Computer modelling demonstrated that this pattern could be reproduced by summating end diastolic flow with a high pulsatility index in the UA in the presence of a large AAA. Consistent with this, MC twins with a transmitted pattern had larger AAAs (median diameter 4.3 mm interquartile range 4.1-5.2) compared to MC twins discordant for intrauterine growth restriction (2.1 mm interquartile range 1.5 to 2.8) (P<0.05) without a transmitted pattern. Perinatal mortality was similar in the fetuses with and without transmitted patterns (0/12 vs. 2/48 P=0.7).

Adult↗

PubMed2001

Ectopic pregnancy within a rudimentary horn in a case of unicornuate uterus.

We report the MRI features of two cases of unicornuate uterus and occluded rudimentary horn. In one patient pregnancy had occurred in the occluded horn, prompting to urgent resection. The second patient illustrates more conventional findings in occluded rudimentary horn. In both cases MRI was able to correctly characterise the nature of the developmental anomaly. Furthermore, on the basis of signal intensities, differentiation between distended lumen due to blood accumulation and amniotic sac in the case of pregnancy could be made. Because of its high accuracy in determining the type of anomaly present, the lack of ionizing radiation, and the ability to evaluate, with the exception of the fallopian tubes, the entire genitourinary tract, MR imaging is essential and plays a key role in the evaluation of women who are consulting for infertility.

Adult↗

PubMed1998

Discordant prenatal diagnosis of congenital toxoplasmosis in a dizygotic pregnancy.

Prenatal diagnosis of toxoplasmosis gondii in twin pregnancies has been described twice. In both cases they were accomplished by prenatal blood sampling of the foetuses. We report the first prenatal diagnosis with a discordant result in a dizygotic pregnancy. One of the foetuses died in utero and the other was born unaffected at term.

Adult↗

PubMedDate not supplied

Intraoperative sentinel node identification with Technetium-99m-labeled nanocolloid in patients with cancer of the uterine cervix: a feasibility study.

The objective of this study is to determine the feasibility of intraoperative lymphatic mapping in patients with cervical carcinoma. Patients with early-stage cervical cancer, scheduled to undergo a Wertheims radical hysterectomy and pelvic lymphadenectomy, were eligible for the study. Technetium-99-m-labeled nanocolloid was injected intracervically at two locations around the tumor 3-6 hours before the operation. Images were recorded immediately and 2.5 hours later using a gamma camera. During the operation sentinel nodes (SLN) were identified using a handheld or laparoscopic gamma-detection probe (Navigator, Auto-Suture). After resection of the SLNs a standard pelvic (and para-aortic) lymphadenectomy was performed. The results of the histopathology of SLNs and non-SLNs were compared. The procedure was well tolerated by 24 of 25 patients. One or more SLN could be identified in 21 out of 25 patients. In one patient who was preoperatively irradiated, in two patients who had had a cone biopsy, and in one patient without previous interventions, no SLN could be detected. The mean time for identification was 5 minutes. In 16 patients, pathologic examination showed no metastatic disease in both SLNs and non-SLNs, whereas metastases were found in the SLN in five patients (in one case only SLN involved, four cases SLN and respectively 3, 11, 22 and 31 other positive nodes). This study shows that identification of SLNs in cancer of the uterine cervix is feasible with preoperatively administered 99mTc-labeled nanocolloid. To date, no false negative SLNs have been found, but expansion of the study is necessary to determine possible clinical application of this new technique.

Adenocarcinoma↗