Maternal-fetal transfer of indocyanine green across the perfused human placenta

Patient-Centered Care in the Management of Cancer During Pregnancy

The management of cancer during pregnancy requires a patient-centered, multidisciplinary approach to balance maternal and fetal well-being given the rarity of this clinical scenario and lack of substantial data. Involvement of oncology and nononcology medical specialists and ethical, legal, and psychosocial supports, as needed, is instrumental in navigating the complexities of care for this patient population. Critical periods of fetal development and physiological changes in pregnancy must be considered when planning diagnostic and therapeutic approaches during pregnancy. The complexity of symptom recognition and interventional approaches contributes to diagnostic delays of cancers during pregnancy. Ultrasound and whole-body diffusion-weighted magnetic resonance imaging are safe throughout pregnancy. Surgery can be safely performed throughout pregnancy, with the early second trimester preferred for intra-abdominal surgery. Chemotherapy can be safely administered after 12-14 weeks of gestation until 1-3 weeks before the anticipated delivery. Most targeted and immunotherapeutic agents are contraindicated during pregnancy because of limited data. Pelvic radiation during pregnancy is absolutely contraindicated, while if radiation to the upper body is needed, administration should only be considered early in pregnancy. To ensure that the total cumulative fetal exposure to ionizing radiation does not exceed 100 mGy, early inclusion of the radiology team in the care plan is required. Closer prenatal monitoring is recommended for maternal and fetal treatment-related toxicities. Delivery before 37 weeks of gestation should be avoided if possible, and vaginal delivery is preferred unless obstetrically indicated or specific clinical scenarios. Postpartum, breastfeeding should be discussed, and the neonate should receive blood work to assess for acute toxicities with follow-up arranged for long-term monitoring.

Lacosamide effects on placental carriers of essential compounds in comparison with valproate: Studies in perfused human placentas

OBJECTIVE

Lacosamide is increasingly being prescribed to pregnant women, although its effects on the developing fetus have not been fully clarified yet. Previously, we have shown that several antiseizure medications, particularly valproate, can affect the expression of carriers of essential compounds in placental cells. Here, our aim was to assess the effect of short ex vivo exposure of human placentas to lacosamide on the expression of carriers of essential nutrients required by the human fetus.

METHODS

Placentas were obtained from cesarean deliveries of women with no known epilepsy. Cotyledons were cannulated and perfused over 180 min in the presence of lacosamide at 2.5 μg/ml (10 μmol·L^-1 , n = 7) or 10 μg/ml (40 μmol·L^-1 , n = 6), representing low and high therapeutic concentrations, respectively, in the maternal perfusate. Valproate (83 μg/ml, 500 μmol·L^-1 , n = 6) and the perfusion solution (n = 6) were used as the respective positive and negative controls. A customized gene panel array was used to analyze the expression of carrier genes in the perfused cotyledons.

RESULTS

Following a 3-h perfusion, the mRNA expression of SLC19A1 (encoding the reduced folate carrier 1) was downregulated in placentas treated with 10 μg/ml lacosamide (50%) as compared with the vehicle (p < .05). Across all groups, a significant difference was observed in the expression of SLC19A3 (thiamine transporter 2; 52%, 20%, and 9% decrease by 10 μg/ml lacosamide, 83 μg/ml valproate, and 2.5 μg/ml lacosamide, respectively; p < .05).

SIGNIFICANCE

Lacosamide at high therapeutic concentrations exerted pharmacological effects on the human placenta. Our findings, if manifested in vivo, suggest that lacosamide could potentially affect folate supply to the fetus and support therapeutic monitoring and careful adjustment of lacosamide plasma concentrations during pregnancy.

The Added Value of Intraoperative Near-Infrared Fluorescence Imaging in Elective Laparoscopic Cholecystectomy

Bile duct injury is a major complication of laparoscopic cholecystectomy (LC). Intraoperative cholangiogram is useful, but faster techniques are available to assist the surgeon, like near-infrared fluorescent cholangiography (NIFC) with indocyanine green (ICG). The aim of our study is to evaluate the usefulness of NIFC during LC. This is a retrospective study conducted on prospectively recorded data of the General Surgery department of Trieste Academic Hospital, Italy. All patients underwent elective LC from January 2016 to January 2020. Patients were randomly divided in 2 groups: in one group, only white light imaging was used (n = 98 patients), in the NIFC group (n = 63) ICG was used. NIFC has been chosen more frequently by residents than consultants (P = .002). Operative time and length of stay resulted shorter in ICG group (P = .002 and .006), and this group showed also fewer intraoperative complications (P = .007). NIFC does not require any learning curve and makes surgery faster and safer.

Maternal-fetal transfer of indocyanine green: a systematic review

RATIONAL

In a survey of 1101 members of vitreoretinal trained physicians regarding the use of ICG angiography during pregnancy, 434 (83%) of 520 respondents had seen at least one pregnant woman requiring ICG angiography or fluorescein angiography. One hundred and five (24%) withheld ICG angiography, mostly because of fear of teratogenicity or lawsuit. Adverse reactions to fluorescein and ICG are rare and may be classified as toxic, hypersensitivity, and non-specific. This literature review aimed to review evaluate the maternal-to-fetal transfer of ICG and resume the most recent recommendations for ICG use in its obstetric applications.

METHODS

The available literature was examined using PubMed-Medline, and web of science, and using the MeSH terms "fluorescein," "Indocyanine green," and "pregnancy" according to PRISMA-P guidelines.

RESULTS

Studies in humans demonstrated that ICG is not detectable in fetal cord blood or umbilical vein blood collected immediately after birth. ICG maternal-to-fetal transfer is slow and is safe during pregnancy. ICG in the fetus accumulates in the liver and accumulation is enhanced by the administration of OATPs or P-gp inhibitors.

CONCLUSIONS

ICG's transplacental transfer is minimal and is probably medicine-mediated, like rifampin. The placenta is an effective protective barrier to ICG's distribution into the fetus.

Comprehensive Review of Fluorescence Applications in Gynecology

Since the introduction of indocyanine green (ICG) as a fluorophore in near-infrared imaging, fluorescence visualization has become an essential tool in many fields of surgery. In the field of gynecology, recent new applications have been proposed and found their place in clinical practice. Different applications in gynecology were investigated, subcategorized, and overviewed concerning surgical applications and available dyes. Specific applications in which fluorescence-guided surgery was implemented in gynecology are described in this manuscript—namely, sentinel node biopsy, mesometrium visualization, angiography of different organs, safety issues in pregnant women, ureters visualization, detection of peritoneal metastases, targeted fluorophores for cancer detection, fluorescent contamination hysterectomy, lymphography for lower limb lymphedema prevention, tumor margin detection, endometriosis, and metastases mapping. With evolving technology, further innovative research on the new applications of fluorescence visualization in cancer surgery may help to establish these techniques as standards of high-quality surgery in gynecology. However, more investigations are necessary in order to assess if these innovative tools can also be effective to improve patient outcomes and quality of life in different gynecologic malignancies.

Techniques for sentinel node biopsy in breast cancer

INTRODUCTION

Sentinel node biopsy (SNB) is the standard of care in women with breast cancer (BC) and clinically non suspicious axillary lymph nodes (LNs), due to its high negative predictive value (NPV) in the assessment of nodal status. SNB has significantly reduced complications related to the axillary lymph node dissection, such as lymphedema and upper limb dysfunction.

EVIDENCE ACQUISITION

The gold standard technique for SNB is the blue dye (BD) and technetium labelled nanocolloid (Tc-99m) double technique. However, nuclear medicine is not available in all Institutions and several new tracers and devices have been proposed, such as indocyanine green (ICG) and superparamagnetic iron oxides (SPIO). All these techniques show an accuracy and detection rate not inferior to that of the standard technique, with different specific pros and cons. The choice of how to perform a SNB primarily depends on the surgeon's confidence with the procedure, the availability of nuclear medicine and the economic resources of the Institutions. In this setting, new tracers, hybrid tracers and imaging techniques are being evaluated in order to improve the detection rate of sentinel lymph nodes (SNs) and minimize the number of unnecessary axillary surgeries through an accurate preoperative assessment of nodal status and to guide new minimally invasive diagnostic procedures of SNs. In particular, the contrast-enhanced ultrasound (CEUS) is an active field of research but cannot be recommended for clinical use at this time.

EVIDENCE SYNTHESIS

The ICG fluorescence technique was superior in terms of DR, as well as having the lowest FNR. The DR descending order was SPIO, Tc, dual modality (Tc/BD), CEUS and BD.

CONCLUSIONS

This paper is a narrative review of the most common SNB techniques in BC with a focus on recent innovations.

Management of pregnancy in women with cancer

As the incidence of cancer in pregnancy has been increasing in recent decades, more specialists are confronted with a complex oncologic-obstetric decision-making process. With the establishment of (inter)national registries, including the International Network on Cancer, Infertility and Pregnancy, and an increasing number of smaller cohort studies, more evidence on the management of cancer during pregnancy is available. As fetal, neonatal, and short-term pediatric outcomes after cancer treatment are reassuring, more women receive treatment during pregnancy. Prenatal treatment should adhere to standard treatment as much as possible to optimize maternal prognosis, always taking into account fetal well-being. In order to guarantee the optimal treatment for both mother and child, a multidisciplinary team of specialists with expertise should be involved. Apart from oncologic treatment, a well-considered obstetric and perinatal management plan discussed with the future parents is crucial. Results of non-invasive prenatal testing are inconclusive in women with cancer and alternatives for prenatal anomaly screening should be used. Especially in women treated with chemotherapy, serial ultrasounds are strongly recommended to follow-up fetal growth and cervical length. After birth, a neonatal assessment allows the identification of any cancer or treatment-related adverse events. In addition, placental histologic examination aims to assess the fetal risk of metastasis, especially in women with malignant melanoma or metastatic disease. Breastfeeding is discouraged when systemic treatment needs to be continued after birth. At least a 3-week interval between the last treatment and nursing is recommended to prevent any treatment-induced neonatal effects from most non-platinum chemotherapeutic agents.

Indocyanine Green Fluorescence Versus Blue Dye or Radioisotope Regarding Detection Rate of Sentinel Lymph Node Biopsy and Nodes Removed in Breast Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Either blue dye (BD) or radioisotope (RI) is mainly used for sentinel lymph node biopsy (SLNB) in breast cancer patients. Unlike the BD, RI has lower false-negative rate of SLNB. However, its lymphoscintigraphy, difficulty in preoperative injection, and undetected sentinel lymph nodes in some cases cause surgeons to rely only on BD. Currently, indocyanine green (ICG) fluorescence method (ICG-SLNB) is increasingly used as an alternative to the conventional mapping methods in many centers. This systematic review compared ICG with the conventional method of BD or RI in terms of detection rate of SLNB and the number of sentinel lymph nodes (SLNs) removed in.

METHODS

  We searched all relevant studies published between January 2000 and October 2019. All data on for evaluation of SLN detection rate, number of SLNs removed per patient, and tumor positive rate of SLNB were extracted.

RESULTS

A total of 30 studies, including 4,216 SLN procedures were retrieved. There was a statistically significant difference between ICG and BD method in terms of SLN detection rate (OR, 6.73; 95% CI, 4.20-10.78). However, there was no significant difference between ICG and RI in this regard (OR, 0.90; 95% CI, 0.40-2.03). The number of SLNs removed per patient were 2.35 (1.46-5.4), 1.92 (1.0-3.64), and 1.72 (1.35-2.08) for ICG, BD, and RI, respectively. Only in 8 studies, the tumor positive rates in SLNB could be analyzed (ICG, 8.5-20.7%; BD, 12.7-21.4%; RI, 11.3-16%).

CONCLUSION

ICG-SLNB could be an additional or an alternative method for axillary node mapping in breast cancer.<br />.

Randomized Trial of Near-infrared Incisionless Fluorescent Cholangiography

BACKGROUND

Incisionless near-infrared fluorescent cholangiography (NIFC) is emerging as a promising tool to enhance the visualization of extrahepatic biliary structures during laparoscopic cholecystectomies.

METHODS

We conducted a single-blind, randomized, 2-arm trial comparing the efficacy of NIFC (n = 321) versus white light (WL) alone (n = 318) during laparoscopic cholecystectomy. Using the KARL STORZ Image1 S imaging system with OPAL1 technology for NIR/ICG imaging, we evaluated the detection rate for 7 biliary structures-cystic duct (CD), right hepatic duct (RHD), common hepatic duct, common bile duct, cystic common bile duct junction, cystic gallbladder junction (CGJ), and accessory ducts -before and after surgical dissection. Secondary calculations included multivariable analysis for predictors of structure visualization and comparing intergroup biliary duct injury rates.

RESULTS

Predissection detection rates were significantly superior in the NIFC group for all 7 biliary structures, ranging from 9.1% versus 2.9% to 66.6% versus 36.6% for the RHD and CD, respectively, with odds ratios ranging from 2.3 (95% CI 1.6-3.2) for the CGJ to 3.6 (1.6-9.3) for the RHD. After dissection, similar intergroup differences were observed for all structures except CD and CGJ, for which no differences were observed. Significant odds ratios ranged from 2.4 (1.7-3.5) for the common hepatic duct to 3.3 (1.3-10.4) for accessory ducts. Increased body mass index was associated with reduced detection of most structures in both groups, especially before dissection. Only 2 patients, both in the WL group, sustained a biliary duct injury.

CONCLUSIONS

In a randomized controlled trial, NIFC was statistically superior to WL alone visualizing extrahepatic biliary structures during laparoscopic cholecystectomy.

REGISTRATION NUMBER

NCT02702843.

Methodological Approaches to Evaluate Fetal Drug Exposure

BACKGROUND

Drug prescriptions are usual during pregnancy, however, women and their fetuses still remain an orphan population with regard to drugs efficacy and safety. Most xenobiotics diffuse through the placenta and some of them can alter fetus development resulting in structural abnormalities, growth or functional deficiencies.

METHODS

To summarize the different methodologies developed towards the prediction of fetal drug exposure.

RESULTS

Neonatal cord blood concentration is the most specific measurement of the transplacental drug transfer at the end of pregnancy. Using the cord blood and mother drug concentrations altogether, drug exchanges between the mother and fetus can be modeled and quantified via a population pharmacokinetic analysis. Thereafter, it is possible to estimate the fetus exposure and the fetus-to-mother exposure ratio. However, the prediction of placental transfer before any administration to pregnant women is desirable. Animal studies remain difficult to interpret due to structural and functional inter-species placenta differences. The ex-vivo perfusion of the human placental cotyledon is the method of reference to study the human placental transfer of drugs because it is thought to mimic the functional placental tissue. However, extrapolation of data to in vivo situation remains difficult. Some research groups have extensively worked on physiologically based models (PBPK) to predict fetal drug exposure and showed very encouraging results.

CONCLUSION

PBPK models appeared to be a very promising tool in order to predict fetal drug exposure in-silico. However, these models mainly picture the end of pregnancy and knowledge regarding both, development of the placental permeability and transporters is strongly needed.

Experimental models of maternal-fetal interface and their potential use for nanotechnology applications

During pregnancy, the placenta regulates the transfer of oxygen, nutrients, and residual products between the maternal and fetal bloodstreams and is a key determinant of fetal exposure to xenobiotics from the mother. To study the disposition of substances through the placenta, various experimental models are used, especially the perfused placenta, placental villi explants, and cell lineage models. In this context, nanotechnology, an area of study that is on the rise, enables the creation of particles on nanometric scales capable of releasing drugs aimed at specific tissues. An important reason for furthering the studies on transplacental transfer is to explore the potential of nanoparticles (NPs), in new delivery strategies for drugs that are specifically aimed at the mother, the placenta, or the fetus and that involve less toxicity. Due to the fact that the placental barrier is essential for the interaction between the maternal and fetal organisms as well as the possibility of NPs being used in the treatment of various pathologies, the aim of this review is to present the main experimental models used in studying the maternal-fetal interaction and the action of NPs in the placental environment.

Adverse placental effects of valproic acid: Studies in perfused human placentas

OBJECTIVE

In utero exposure to valproic acid (VPA) has been associated with worse pregnancy outcomes compared to all other antiepileptic drugs. We have previously shown that VPA alters the expression of placental transporters for hormones and nutrients in vitro and in pregnant mice. Here, our aim was to characterize the effects of short exposure to VPA on the expression of carriers for compounds essential for fetal development in human placentas ex vivo, under controlled conditions.

METHODS

Placentas were obtained from cesarean deliveries of women with no known epilepsy. Cotyledons were cannulated and perfused in the absence or the presence of VPA (42, 83, or 166 μg/mL; n = 6/group) in the maternal perfusate over 180 minutes. A customized gene panel array was used to analyze the expression of carrier genes in the perfused cotyledons. We additionally measured in the perfused placentas folic acid concentrations and histone acetylation.

RESULTS

VPA significantly altered the mRNA levels of major carriers for folic acid, glucose, choline, thyroid hormones, and serotonin (P < .05) and reduced placental folate concentrations by 25%-35% (P = .059). The effects were observed at therapeutic concentrations sufficient to enhance placental histone acetylation, and some were concentration-dependent.

SIGNIFICANCE

Our results point to the placenta as a novel target of VPA, implying potential involvement of the placenta in VPA's adverse fetal outcomes.

The Effects of Magnesium Sulfate on the Inflammatory Response of Placentas Perfused With Lipopolysaccharide: Using the Ex Vivo Dual-Perfused Human Single-Cotyledon Model

OBJECTIVES

Multiple mechanisms have been proposed for the neuroprotective effects of magnesium sulfate (MgSO₄). We aimed to examine the effects of lipopolysaccharide (LPS) and MgSO₄ on the placental expression of nuclear factor κ light chain enhancer of activated B cells (NF-κB), interleukin (IL) 6, adrenocorticotropic hormone (ACTH), and nitric oxide synthase (NOS); all known to participate in the inflammatory cascade.

METHODS

Placentas were obtained and selected cotyledons cannulated and dually perfused ex vivo. Placentas were perfused with 4 perfusion protocols: culture medium (M-199; controls), LPS (1 μg/mL), MgSO₄ (6 g/dL), and LPS + MgSO₄. Each perfusion experiment continued for 3 hours. Sixteen perfusion experiments were analyzed, 4 separate placentas were studied for each protocol. The protein levels in the perfused cotyledons were studied by Western blot analysis and compared between the groups. Interleukin 6 levels were studied in the maternal and fetal perfusate.

RESULTS

The expression of NF-κB p65, IL-6, ACTH, and NOS proteins levels were significantly increased in placentas perfused with LPS as compared to placentas perfused with M-199, MgSO₄ ( P < .01 for all). Placentas perfused with LPS+ MgSO₄ had similar proteins levels as in the controls and MgSO₄ groups. Lipopolysaccharide significantly increased IL-6 levels in maternal perfusate.

CONCLUSIONS

In the human placenta, MgSO₄ blocks the increase in the proteins levels of NF-κB, IL-6, ACTH, and NOS in response to inflammatory stimuli. Magnesium sulfate attenuates excessive placental inflammatory response. The decrease in placental ACTH levels following perfusion with MgSO₄ may point to an additional non-anti-inflammatory mechanism of MgSO₄.