Lipiodol intravasation during uterosalpingography with pulmonary complications

Evaluating Fallopian Tube Patency: What the Radiologist Needs to Know

Impaired tubal patency accounts for up to 35% of cases of subfertility and infertility. Hysterosalpingography (HSG) or hysterosalpingo-contrast sonography (HyCoSy) represents a first-line test in evaluating fallopian tube patency. Despite the association of HSG with ionizing radiation, HSG is a reference standard in assessing fallopian tube patency and tubal conditions such as tubal occlusion, salpingitis isthmica nodosa, and hydrosalpinx. HSG is widely available and utilizes either a water-soluble contrast medium (WSCM) or an oil-soluble contrast medium (OSCM). Compared with WSCM, HSG with OSCM results in a higher incidence of non-in vitro fertilization pregnancies and, therefore, may be preferred in women younger than 38 years with unexplained subfertility. HSG may also be helpful in assessment after sterilization or before fallopian tube recanalization. US-based tubal tests are free of ionizing radiation and include HyCoSy, with either air-saline or microbubble US contrast material, and hysterosalpingo-foam sonography (HyFoSy), a tubal patency test that utilizes a gel foam. A comprehensive US infertility evaluation of the pelvis and fallopian tubes can be achieved in one setting by adding coronal three-dimensional imaging of the uterus, saline infusion sonohysterography, and HyCoSy or HyFoSy to routine pelvic US. MR HSG and virtual CT HSG also depict tubal patency and uterine and adnexal pathologic conditions and may be considered in select patients. While laparoscopic chromopertubation remains the standard for tubal patency evaluation, its disadvantages are its invasiveness and cost. Knowledge of the different fallopian tube tests and radiologic appearance of normal and abnormal fallopian tubes results in fewer pitfalls, accurate interpretation, and optimal patient care. Online supplemental material is available for this article. ^©RSNA, 2021.

Pickering emulsions with ethiodized oil and nanoparticles for slow release of intratumoral anti-CTLA4 immune checkpoint antibodies

BACKGROUND

Intratumorous immunotherapy for cancer is currently thriving. The aim of such local strategy is to improve the therapeutic index of these treatments, for higher on-target/on-tumor activity and less on-target/off-tumor adverse events. Strategies allowing for slow release of anti-CTLA4 in the tumor microenvironment could improve their clinical efficacy.The purpose of the study was to develop a radiopaque delivery platform to improve the targeting and exposure of intratumorous anti-CTLA4 antibodies for cancer immunotherapy.

METHODS

Pickering emulsions of anti-CTLA4 antibodies were formulated with radiopaque ethiodized oil and poly-lactic-co-glycolic acid (PLGA) nanoparticles. We characterized the microscopic aspect and stability of such emulsions using Turbiscan. We monitored the release of anti-CTLA4 over time from these emulsions and evaluated their structure using mass spectrometry. We then tested the functionality of the released antibodies by preforming ex vivo competitive binding assays. Finally, we assessed the in vivo efficacy of intratumorous anti-CTLA4 Pickering emulsions.

RESULTS

Pickering emulsions of ethiodized oil and PLGA nanoparticles (PEEPs) resulted in a radiopaque water-in-oil emulsion with average internal phase droplet size of 42±5 µm at day 7. Confocal microscopy showed that anti-CTLA4 antibodies were effectively encapsulated by ethiodized oil with PLGA nanoparticles located at the interface between the aqueous and the oily phase. Turbiscan analysis showed that emulsions were stable with continuous and progressive release of anti-CTLA4 antibodies reaching 70% at 3 weeks. Structural and functional analysis of the released antibodies did not show significant differences with native anti-CTLA4 antibodies. Finally, intratumorous anti-CTLA4 PEEPs were able to eradicate tumors and cure mice in a syngeneic immunocompetent preclinical tumor model.

CONCLUSION

Pickering emulsions of ethiodized oil and PLGA is an innovative radiopaque delivery platform that does not alter the functionality of anti-CTLA4 immune checkpoint antibodies. Beyond local anti-CTLA4 applications, these emulsions might be used with other therapeutic molecules for optimal intratumorous or intra-arterial delivery of novel cancer immunotherapies.

Safety of oil-based contrast medium for hysterosalpingography: a systematic review

Recent meta-analyses have shown that a hysterosalpingography (HSG) with oil-based contrast increases pregnancy rates in subfertile women. However, the frequency of complications during or after an HSG with oil-based contrast in subfertile women and/or their offspring is still unclear. This systematic review and meta-analysis, without restrictions on language, publication date or study design, was performed to fill this knowledge gap. The results show that the most frequently reported complication was intravasation of contrast, which occurred in 2.7% with the use of oil-based contrast (31 cohort studies and randomized controlled trials [RCT], 95% CI 1.7-3.8, absolute event rate 664/19,339), compared with 2.0% with the use of water-based contrast (8 cohort studies and RCT, 95% CI 1.2-3.0, absolute event rate 18/1006). In the cohort studies and RCT there were 18 women with an oil embolism (18/19,339 HSG), all without serious lasting consequences. Four cases with serious consequences of an oil embolism were described (retinal oil embolism [n = 1] and cerebral complaints [n = 3]); these reports did not describe the use of adequate fluoroscopy guidance during HSG. In conclusion, the most frequently reported complication after an HSG with oil-based contrast is intravasation occurring in 2.7%. In total four cases with serious consequences of oil embolisms in subfertile women were published.

Complications after hysterosalpingography with oil- or water-based contrast: results of a nationwide survey

STUDY QUESTION

What is the incidence of complications after hysterosalpingography (HSG) using oil-based contrast versus water-based contrast?

SUMMARY ANSWER

Among 5165 women undergoing HSG, the most frequently reported complication after HSG with oil- and water-based contrast was intravasation of contrast medium (4.8% versus 1.3%, respectively), which was without further consequences, and pulmonary embolization or death did not occur.

WHAT IS KNOWN ALREADY

An HSG with oil-based contrast increases pregnancy rates in women with unexplained infertility. However, there have been some concerns regarding complications, including the risks of intravasation of the contrast medium, oil embolism and infection. Here, we present the incidence of complications after HSG with different types of contrast media used in the Netherlands in the year 2017.

STUDY DESIGN SIZE DURATION

In January 2018, an electronic survey was sent to all 73 clinics in the Netherlands that perform HSG. The survey consisted of 12 questions addressing the number of HSGs performed in 2017, the amount and type of contrast medium used, the occurrence of post-procedural complications and what their clinical consequences were. Non-responding clinics were sent multiple reminders.

PARTICIPANTS/MATERIALS SETTING METHODS

We calculated the incidence of the complications and reported on their clinical consequences. Furthermore, we examined the average amount of contrast used as well as the administration of prophylactic antibiotics.

MAIN RESULTS AND THE ROLE OF CHANCE

The response rate was 96% (67/70) (during the study, one site closed and was not included while two clinics no longer performed HSGs). In the 67 clinics, 3289 HSGs with oil-based contrast and 1876 HSGs with water-based contrast were performed in 2017. The median amount of contrast used was 8.0 ml (interquartile range (IQR) 7.0-10.0) for oil-based contrast and 10.0 ml for water-based contrast (IQR 10.0-10.0). Antibiotic prophylaxis was administered in 61% (41/67) of the clinics. Intravasation occurred in 4.8% of the HSGs performed with oil-based contrast and in 1.3% of the HSGs with water-based contrast (relative risk (RR), 3.6; CI, 2.4-5.4). Pulmonary embolism or death was not reported. Pelvic inflammatory disease (PID) occurred in 0.3% of the HSGs performed with oil-based contrast versus 0.4% with water-based contrast. PID occurred in 0.3% of the HSGs in clinics using antibiotic prophylaxis and 0.2% in clinics not using antibiotic prophylaxis. Allergic reactions were reported in one HSG performed with oil-based contrast (0.03%) compared with two HSGs performed with water-based contrast (0.1%). Anaphylactic reactions did not occur. The overall complication rate was 5.1% in the clinics that used oil-based contrast versus 1.8% in the clinics that used water-based contrast (RR, 2.8; CI, 1.9-4.0; P-value, <0.0001).

LIMITATIONS REASONS FOR CAUTION

Half of the clinics did not routinely register complications, and the incidence of the complications in their clinic was based on the recall of the clinician. Estimated complication rates in the clinics with and without systematic registration did not significantly differ. The survey asked about the frequency of intravasation but no classification system is being used in daily practice, which may create differences in reporting. There was no standard screening of post-HSG thyroid function for the mother and the foetus.

WIDER IMPLICATIONS OF THE FINDINGS

In this nationwide cohort study, the complication rates after HSG were low. Intravasation occurred more frequently with the use of oil-based contrast compared with water-based contrast but did not lead to any problems or symptoms in any of the women. We therefore conclude that safety concerns should not be a reason to deny the use of oil-based contrast in women with unexplained infertility. The data also support that fluoroscopy appears to be an essential safety measure during HSG.

STUDY FUNDING/COMPETING INTERESTS

This work was partly funded by Guerbet, France. I.R. reports receiving travel fee for presenting at the Congress of the American Society for Reproductive Medicine 2019 from Guerbet. V.M. reports receiving travel and speaker's fee as well as research grants from Guerbet. K.D. reports receiving travel and speaker's fee from Guerbet. B.W.M. is supported by an National Health and Medical Research Council (NHMRC) Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research grants from Merck KGaA and Guerbet. The other authors do not report conflicts of interest.

TRIAL REGISTRATION NUMBER

N19.056.