RETINAL MIGRATION AND SURGICAL OUTCOME AFTER HEMI-TEMPORAL INTERNAL LIMITING MEMBRANE PEELING VERSUS CONVENTIONAL PEELING FOR MACULAR HOLE: A Multicenter, Randomized, Controlled Trial.

PURPOSE: To investigate the anatomical changes and surgical outcomes of hemi-temporal internal limiting membrane (ILM) peeling and conventional ILM peeling for idiopathic macular hole (MH). METHODS: This randomized controlled trial was conducted at 3 centers and included 50 participants with MHs of <400 µm in minimum diameter for a duration of <6 months. All participants had undergone vitrectomy with either hemi-temporal ILM peeling (Hemi group) or 360° ILM peeling (360° group) with an injection of 5% sulfur hexafluoride gas, with or without simultaneous cataract surgery, from July 2017 to January 2021. The rate of MH closure and distance of retinal migration were examined. RESULTS: Of 50 eyes randomized in the 3 centers, the Hemi group comprised 23 eyes, the 360° group 23 eyes, and 4 eyes were eliminated from final analysis. There was a significantly higher rate of primary MH closure in the 360° group (Hemi group: 73.9% vs. 360° group: 100%, P = 0.009). Retinal migration to the optic disk on the nasal side was significantly shorter in the Hemi group at 1, 3, and 6 months postoperatively than in the 360° group. There was no significant difference between the two groups in retinal migration to the optic disk on the temporal side. CONCLUSION: Nasal retinal migration in patients who underwent the hemi-temporal ILM peeling method was significantly less than in those who underwent the 360° ILM peeling method. However, less nasal retinal migration did not contribute to the MH closure rate.

Investigation Into the Subharmonic Response of Three Contrast Agents in Static and Dynamic Flow Environments Using a Commercially Available Diagnostic Ultrasound Scanner.

OBJECTIVE: The objective of this study was to investigate the subharmonic response of Lumason (also known as SonoVue; Bracco, Milan, Italy) to static and dynamic ambient pressures, with a direct comparison to Sonazoid (GE HealthCare, Oslo, Norway) and Definity (Lantheus Medical Imaging, MA, USA). The subharmonic responses of contrast agents can be exploited to perform subharmonic-aided pressure estimation. METHODS: The subharmonic response of each ultrasound contrast agent was evaluated in both a static and dynamic tank using a commercially available Logiq E10 clinical ultrasound scanner (GE HealthCare) equipped with subharmonic imaging (SHI) and an acoustic power-optimization algorithm. A C1-6 curvilinear array that transmits at 2.5 MHz and receives at 1.25 MHz in SHI mode was used to acquire the subharmonic signals. Data was transferred offline into MATLAB (MathWorks) to perform linear regression analysis and statistical testing for significance of the slopes (i.e., agent sensitivity). RESULTS: Sonazoid and Definity showed an inverse linear dependency between subharmonic signal and hydrostatic pressure at all pressure ranges (static and dynamic) tested, with maximum sensitivity under 50 mmHg in the static tank (-0.190 and -0.194 dB/mmHg for Sonazoid and Definity, respectively). Lumason exhibited a tri-phasic subharmonic behavior, beginning with a linear trend from 0 to 90 mmHg (sensitivity = 0.069 dB/mmHg), followed by a plateau from 100 to 130 mmHg, and an inverse linear trend from 140 to 200 mmHg (sensitivity = -0.137 dB/mmHg). CONCLUSION: The subharmonic response of Lumason is tri-phasic and differs from Sonazoid and Definity. Further investigation is needed to solidify understanding of the subharmonic behavior of Lumason to identify its usefulness for subharmonic-aided pressure estimation.

Gas-Sensing Performance of Metal Oxide Heterojunction Materials for SF6 Decomposition Gases: A DFT Study.

The online monitoring of GIS equipment can be realized through detecting SF6 decomposition gasses. Metal oxide heterojunctions are widely used as gas-sensing materials. In this study, the structural and electrical properties of In2O3-ZnO and TiO2-ZnO heterojunctions were analyzed based on density functional theory calculations. After heterojunction structural optimization, the electrical conductivity of these two heterojunctions was enhanced compared to each intrinsic model, and the electrical conductivity is ranked as follows: In2O3-ZnO heterojunction > TiO2-ZnO heterojunction. The gas-sensing response of these two heterojunctions to four SF6 decomposition gasses, H2S, SO2, SOF2, and SO2F2, was investigated. For gas adsorption systems, the adsorption energy, charge transfer, density of states, charge difference density, and frontier molecular orbitals were calculated to analyze the adsorption and gas-sensing performance. For gas adsorption on the In2O3-ZnO heterojunction surface, the induced conductivity changes are in the following order: H2S > SO2F2 > SOF2 > SO2. For gas adsorption on the TiO2-ZnO heterojunction surface, H2S and SOF2 increase conductivity, and SO2 and SO2F2 decrease conductivity.

Measurement of inward leakage of full-face masks in EN and ISO standards: comparison of gas and aerosol test agents.

In Europe, respiratory protective devices must be certified before they can be marketed. Among the parameters of interest, inward leakage (IL) characterizes the tightness between the face seal and the face, to verify that the device is well-designed. European standard EN 13274-1 (2001) and International Organization for Standardization (ISO) standard ISO 16900-1 (2019) specify that IL should be measured using sodium chloride (NaCl) aerosol or sulfur hexafluoride (SF6) gas. For reusable masks made of nonporous materials, both test agents are considered equally acceptable. However, the few studies that have compared IL values measured with various aerosols and gases have come to divergent conclusions. This work then aimed to measure IL with the test agents recommended by the standards to determine whether they are really equivalent. Since krypton (Kr) is an interesting candidate for replacing SF6 in standard tests, IL was assessed with SF6 and Kr simultaneously, and with NaCl aerosol using various calculation methods. Tests were carried out on 5 models of full-face masks donned on a headform connected to a breathing machine simulating 3 sinusoidal breathing rates of various intensities. The respirator fit on the headform was evaluated using a controlled negative pressure method to determine a manikin fit factor. Four scenarios were then tested to represent very poor, bad, good, and excellent fit. Gas concentration was measured using a mass spectrometer, and IL was calculated for SF6 and Kr. A combination of 3 devices allowed the determination of the number-based concentration of particles with diameters between 20 nm and 2 µm, and IL was calculated for each of the 33 channels, as well as using a cumulative number concentration. In addition, to comply with standards, a conversion was carried out to calculate IL using a cumulative mass concentration. The results of this work evidenced that the IL values measured with NaCl were systematically lower than those determined with gases. IL was also shown to vary with particle size, with a maximum value exceeding that calculated with cumulative concentrations (in number or mass). As part of the revision of the standards, protocols for measuring inward leakage should be redefined. On the one hand, acceptability thresholds should be re-evaluated according to the nature of the test agent (gas or aerosol), as it is clear that the 2 options do not give the same results for a given configuration. On the other hand, the aerosol leakage measurement protocol needs to be reworked to enable the measurement of a well-defined, robust, and reproducible inward leakage value.

The value of contrast-enhanced ultrasound in differentiating benign from malignant retroperitoneal masses.

OBJECTIVES: To evaluate the value of contrast-enhanced ultrasound (CEUS) perfusion patterns in the differentiation of benign and malignant retroperitoneal masses (RMs). METHODS: Between 2006 and 2023, 122 consecutive patients with an RM visualizable by B-mode US were investigated additionally with CEUS. On CEUS, the extent of enhancement (classified as marked, reduced, or absent) and the homogeneity of enhancement (HE; classified as homogeneous or inhomogeneous) were evaluated. Subsequently, the malignancy rate according to CEUS perfusion patterns was determined. RESULTS: On CEUS, marked enhancement was significantly more frequently associated with malignancy than with benignity (p < 0.0001, Fisher's exact test). All lesions with no enhancement were benign. Regarding HE, there was no significant difference between benign and malignant lesions (p = 0.07, Fisher's exact test). CONCLUSION: On CEUS, marked enhancement in an RM may be indicative of a malignant lesion. Furthermore, absent enhancement can be considered to be an indication of benignity. The use of CEUS can be helpful in the evaluation of the malignancy of retroperitoneal masses.

Ultrasound Contrast Agent Needle Priming: Impact on Sonographic Biopsy Needle Visibility in a Porcine Liver Model.

PURPOSE: The visibility of biopsy needles in contrast-specific imaging mode can be improved by priming them with an ultrasound contrast agent (previously demonstrated in a phantom model/ex vivo). The purpose of this study was to validate this priming method in a porcine in vivo model. MATERIALS AND METHODS: Using a small syringe, full-core biopsy needles were primed with sulfur hexafluoride, an ultrasound contrast agent, with non-primed needles serving as controls (n = 30 + 30). Liver punctures were performed in a porcine model following intravenous administration of the same ultrasound contrast agent. Needle visibility, both in their entirety and at the tips, was evaluated in split-screen mode using contrast-specific imaging and B-mode (low mechanical index). The assessment included quantitative analysis, calculating the contrast-to-noise ratio, and qualitative evaluation through structured grading by three radiologists. RESULTS: After needle priming, the contrast-to-noise ratio was superior for the needle in its entirety in contrast-specific imaging mode (p < 0.001) and slightly inferior in B-mode (p = 0.008). No differences were observed for the needle tips in either imaging mode. Qualitatively, the needle visibility was deemed clinically superior after needle priming throughout in contrast-specific imaging mode (p < 0.001), whereas no clinically relevant differences in B-mode for either the needle in its entirety (p = 0.11) or the needle tip (p = 1) were observed. CONCLUSION: In this in vivo porcine liver model experiment, priming biopsy needles with ultrasound contrast agent improved needle visibility in contrast-specific imaging mode but slightly reduced it in B-mode. These findings support the method's use for biopsies requiring target visualization in contrast-specific imaging mode.

Analysis of early response to chemotherapy for non-Hodgkin's lymphoma by quantitative contrast-enhanced ultrasound: A prospective case-control crossectional study.

OBJECTIVE: To investigate the value of quantitative contrast-enhanced ultrasonography (CEUS) in assessing and predicting early therapy response of non-Hodgkin's lymphoma (NHL). METHODS: Fifty-six cases of NHL were studied using CEUS before and after three cycles of R-CHOP / CHOP. Quantitative parameters such as arrival time (ATM), time to peak (TTP), △T = TTP-ATM, area under the gamma curve (Area), curve gradient (Grad), wash-out time (WT), base intensity (BI), peak intensity (PI) and ΔI = PI-BI were compared between the lymphoma and normal lymph nodes before and at mid-treatment, respectively. Changes in quantitative CEUS parameters were also compared between complete response (CR) and incomplete response(non-CR) groups. Besides, the correlation analysis was performed between pretreatment PI and changes in quantitative parameters. RESULTS: After three cycles of R-CHOP/CHOP, S/L (P < 0.001), PI (P = 0.002), ΔI (P < 0.001), Grad (P < 0.001), and Area (P < 0.001) of NHL were significantly decreased. The CR group and non-CR group only differed in ATM before treatment. In contrast, there was no statistical difference in any of the parameters between the two groups at mid-treatment. Finally, a significant correlation was observed between pre-treatment PI and PI△% (r = 0.736, P < 0.001). CONCLUSIONS: CEUS is promising for the assessment of response of NHL to R-CHOP/CHOP. Intra-lesion perfusion changes take precedence over morphological changes suggesting treatment efficacy. Pre-treatment ATM values may help to suggest efficacy outcomes and pre-treatment PI values may be a valid predictor of lymphoma perfusion response.

Mineralization of SF6 and NF3 fluorinated compounds for greenhouse gas abatement by oxalates.

Fluorinated compounds (FCs) such as sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3) have garnered attention due to their environmental impact. This study investigates the mineralization and removal of two potent FCs: SF6 and NF3. The results confirm that utilizing various oxalate salts leads to the formation of corresponding metallic fluorides: lithium fluoride (LiF), sodium fluoride (NaF), and potassium fluoride (KF), validating the occurrence of mineralization reactions. Among the oxalate salts, sodium oxalate demonstrates the highest mineralization efficiency in both SF6 and NF3 removal. Real-time Fourier transform infrared spectroscopy (FT-IR) gas-phase analysis confirms rapid and complete gas removal within a short reaction time using the selected oxalate salts. Meticulous mass balance calculations revealed that oxalates (LiF, NaF, and KF) yielded sulfur (S) at rates of 92.09%, 91.85%, and 84.98% following SF6 mineralization. Additionally, the conversion rates of oxalates to the corresponding metallic fluorides (LiF, NaF, and KF) after SF6 mineralization were 98.18%, 95.82%, and 95.21%, respectively. Similarly, after NF3 mineralization, these conversion rates stood at 92.18%, 90.67%, and 90.02%, respectively. The removal efficiencies for SF6 (1000 ppm) were 4.98, 12.01, and 7.23 L/g, while those for NF3 (1000 ppm) were 14.1, 12.6, and 11.7 L/g, respectively. Notably, sodium oxalate exhibits superior effectiveness, achieving 100% SF6 conversion within 30 min and 100% NF3 conversion within 50 min. This work underscores the potential of oxalate mineralization as a promising strategy for efficient and rapid removal of potent fluorinated compounds, paving the way for environmentally benign FC remediation techniques with broader implications for sustainable gas treatment technologies.

Intra-individual comparison of Sonazoid contrast-enhanced ultrasound and SonoVue contrast-enhanced ultrasound in diagnosing hepatocellular carcinoma.

PURPOSE: To assess whether the diagnostic performance of Sonazoid contrast-enhanced ultrasound (SZUS) is non-inferior to that of SonoVue contrast-enhanced ultrasound (SVUS) in diagnosing hepatocellular carcinoma (HCC) in individuals with high risk. MATERIALS AND METHODS: This prospective study was conducted from October 2020 to May 2022 and included participants with a high risk of HCC who underwent SZUS and SVUS. All lesions were confirmed by clinical or pathological diagnosis. Each nodule was classified according to the Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System version 2017 (CEUS LI-RADS v2017) for SVUS and SZUS and the modified CEUS LI-RADS (using Kupffer phase defect instead of late and mild washout) for SZUS. The diagnostic performance of both two modalities for all observations was compared. Analysis of the vascular phase and Kupffer phase imaging characteristics of CEUS was performed. RESULTS: One hundred and fifteen focal liver lesions from 113 patients (94 HCCs, 12 non-HCC malignancies, and 9 benign lesions) were analysed. According to CEUS LI-RADS (v2017), SVUS and SZUS showed similar sensitivity (71.3% vs. 72.3%) and specificity (85.7% vs. 81.0%) in HCC diagnosis. However, the modified CEUS LI-RADS did not significantly improve the diagnostic efficacy of Sonazoid compared to CEUS LI-RADS v2017, having equivalent sensitivity (73.4% vs. 72.3%) and specificity (81.0% vs. 81.0%). The agreement between SVUS and SZUS for all observations was 0.610 (95% CI 0.475, 0.745), while for HCCs it was 0.452 (95% CI 0.257, 0.647). CONCLUSION: Using LI-RADS v2017, SZUS and SVUS showed non-inferior efficacy in evaluating HCC lesions. In addition, adding Kupffer phase defects to SZUS does not notably improve its diagnostic efficacy.

Contrast-enhanced Ultrasound Using Intradermal Microbubble Sulfur Hexafluoride in Non-invasive Axillary Staging in Breast Cancer: Are we Missing a Chance?

BACKGROUND/AIM: In the context of surgical de-escalation in early breast cancer (EBC), this study aimed to evaluate the contrast enhancement ultrasound (CEUS) sentinel lymph node (SLN) procedure as a non-invasive axillary staging procedure in EBC in comparison with standard SLN biopsy (SLNB). PATIENTS AND METHODS: A subanalysis of the AX-CES study, a prospective single-arm, monocentric phase 3 study was performed (EudraCT: 2020-000393-20). The study included patients with EBC undergoing upfront surgery and SLN resection, with no prior history of locoregional treatment, and weighing between 40-85 kg. All patients underwent the CEUS SLN procedure as a non-invasive axillary staging procedure, with CEUS SLN accumulation marked using blue dye. After the CEUS SLN procedure, all patients underwent the standard mapping procedure. Data on success rate, systemic reactions, mean procedure time, mean surgical procedure, mean procedure without axillary staging, CEUS SLN appearance (normal/pathological), SLN number, and concordance with standard mapping procedure were collected. RESULTS: After the CEUS SLN procedure, 29 LNs among 16 patients were identified and marked. In all cases, CEUS SLN revealed at least one LN enhancement. Six (37.50%) LNs were defined as pathological after the CEUS SLN procedure. Definitive staining of CEUS SLN pathology revealed metastatic involvement in four (66.67%) of the cases. Two SLNs were identified during the CEUS SLN procedure; however, owing to the low disease burden, no change in the surgical plan was reported. CONCLUSION: The CEUS SLN procedure shows promise as a technique for non-invasive assessment of the axilla, potentially enabling safe axillary de-escalation in EBC by estimating the axillary disease burden.

Pulmonary Transit Time Assessment by CEUS in Healthy Rabbits: Feasibility, and the Effects of UCAs Dilution Concentration.

To evaluate the inter-observer variability and the intra-observer repeatability of pulmonary transit time (PTT) measurement using contrast-enhanced ultrasound (CEUS) in healthy rabbits, and assess the effects of dilution concentration of ultrasound contrast agents (UCAs) on PTT. Thirteen healthy rabbits were selected, and five concentrations UCAs of 1:200, 1:100, 1:50, 1:10, and 1:1 were injected into the right ear vein. Five digital loops were obtained from the apical 4-chamber view. Four sonographers obtained PTT by plotting the TIC of right atrium (RA) and left atrium (LA) at two time points (T1 and T2). The frame counts of the first appearance of UCAs in RA and LA had excellent inter-observer agreement, with intra-class correlations (ICC) of 0.996, 0.988, respectively. The agreement of PTT among four observers was all good at five different concentrations, with an ICC of 0.758-0.873. The reproducibility of PTT obtained by four observers at T1 and T2 was performed well, with ICC of 0.888-0.961. The median inter-observer variability across 13 rabbits was 6.5% and the median variability within 14 days for 4 observers was 1.9%, 1.7%, 2.2%, 1.9%, respectively; The PTT of 13 healthy rabbits is 1.01 ± 0.18 second. The difference of PTT between five concentrations is statistically significant. The PTT obtained by a concentration of 1:200 and 1:100 were higher than that of 1:1, while there were no significantly differences in PTT of a concentration of 1:1, 1:10, and 1:50. PTT measured by CEUS in rabbits is feasible, with excellent inter-observer and intra-observer reliability and reproducibility, and dilution concentration of UCAs influences PTT results.

A Preliminary Study on the Application of Contrast-Enhanced Ultrasonography in Children With Peripheral Neuroblastic Tumors.

The purpose of this study was to retrospectively analyze the characteristics of contrast-enhanced ultrasound (CEUS) images and quantitative parameters of time-intensity curves (TICs) in children's peripheral neuroblastic tumors (pNTs). By comparing the imaging features and quantitative parameters of the TICs of neuroblastoma (NB) and ganglioneuroblastoma (GNB) patients, we attempted to identify the distinguishing points between NB and GNB. A total of 35 patients confirmed to have pNTs by pathologic examination were included in this study. Each child underwent CEUS with complete imaging data (including still images and at least 3 min of video files). Twenty-four patients were confirmed to have NB, and 11 were considered to have GNB according to differentiation. The CEUS image features and quantitative parameters of the TICs of all lesions were analyzed to determine whether there were CEUS-related differences between the two types of pNT. There was a significant difference in the enhancement patterns of the CEUS features (χ2 = 5.303, p < 0.05), with more "peripheral-central" enhancement in the NB group and more "central-peripheral" enhancement in the GNB group. In the TIC, the rise time and time to peak were significantly different (p < 0.05). The receiver operating characteristic curve showed that the probability of ganglion cell NB increased significantly after RT > 15.29, with a sensitivity of 0.636 and a specificity of 0.958. When the peak time was greater than 16.155, the probability of NB increased significantly, with a sensitivity of 0.636 and a specificity of 0.958. The CEUS features of NB and GNB patients are very similar, and it is difficult to distinguish them. Rise time and time to peak may be useful in identifying GNB and NB, but the sample size of this study was small, and the investigation was only preliminary; a larger sample size is needed to support these conclusions.

Contrast-enhanced ultrasound of polyp malignant transformation with multiple metastases in a patient with Peutz-Jeghers syndrome.

Multi-systemic metastasis in patients with Peutz-Jeghers syndrome (PJS) is very rare, and there are nearly no relevant imaging reports, especially in contrast-enhanced ultrasound (CEUS). We present here a 40-year-old male patient who underwent several partial small bowel resections and endoscopic polypectomy for intestinal polyps. After reviewing the patient's clinical diagnosis and treatment process, CEUS with sulfur hexafluoride microbubbles (SonoVue, Bracco, Milan, Italy) in the liver and gastrointestinal tract was performed. We imaged multiple abnormal masses with sonographic features consistent with malignancies. Combined with other imaging examinations and 18 gauge core-needle puncture biopsy of liver masses, multiple metastases outside the gastrointestinal tract were considered. This case report suggests CEUS may be an easy, effective, and supplementary method for evaluating PJS patients with suspected multi-systemic malignant lesions including the gastrointestinal tract.

Displacement of Submacular Hemorrhage Using Subretinal Cocktail Injection versus Pneumatic Displacement: A Real-World Comparative Study.

INTRODUCTION: The objective of this study was to compare the outcome of submacular hemorrhage (SMH) displacement using pneumatic displacement with intravitreal expansile gas versus pars plana vitrectomy (PPV) with subretinal injection of tissue plasminogen activator (tPA), anti-vascular endothelial growth factor (VEGF) agent, and air as primary surgery. METHODS: Retrospective interventional case series of 63 patients who underwent surgical displacement of SMH secondary to neovascular age-related macular degeneration (nAMD) or polypoidal choroidal vasculopathy (PCV) from May 1, 2015, to October 31, 2022. Medical records were reviewed for diagnosis, logMAR visual acuity (VA), central subfield thickness (CST), and postoperative displacement rates and complications up to 12 months after operation. RESULTS: The diagnosis was nAMD in 24 (38.1%) and PCV in 39 (61.9%) eyes. There were 40 (63.5%) eyes in the pneumatic displacement group (38 received C3F8, 2 received SF6) and 23 (36.5%) eyes in the subretinal cocktail injection. Mean baseline VA was 1.46 and 1.62, respectively (p = 0.404). The subretinal injection group had more extensive SMH (p = 0.005), thicker CST (1,006.6 µm vs. 780.2 µm, p = 0.012), and longer interval between symptom and operation (10.65 vs. 5.53 days, p < 0.001). The mean postoperative VA at 6 months was 0.67 and 0.91 (p = 0.180) for pneumatic displacement and subretinal injection groups, respectively, though VA was significantly better in the pneumatic group at 12-month visit (0.64 vs. 1.03, p = 0.040). At least 10 mean change in VA were >10 letters gain in both groups up to 12 months. Postoperative CST reduction was greater (625.1 µm vs. 326.5 µm, p = 0.008) and complete foveal displacement (87.0% vs. 37.5%), p < 0.001, odds ratio [OR] = 11.1) and displacement to arcade or beyond (52.5% vs. 17.5%, p = 0.009, OR = 5.15) were more frequent in the subretinal injection group. Two patients with failed pneumatic displacement were successfully treated with subretinal cocktail injection as a second operation. CONCLUSION: Surgical displacement of SMH leads to clinically meaningful improvement in VA. PPV with subretinal cocktail injection is more effective than pneumatic displacement in displacing SMH with similar safety profile despite longer interval before operation, higher CST, and more extensive SMH at baseline. Retinal surgeons could consider this novel technique in cases with thick and extensive SMH or as a rescue secondary operation in selected cases.

Comparison of 20% SF6 and 6% C3F8 Gas for Anterior Chamber Tamponade in Endothelial Keratoplasty.

PURPOSE: The aim of this study was to compare the rates of rebubbling after Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping endothelial keratoplasty (DSEK) between patients who had anterior chamber (AC) graft tamponade with 20% sulfur hexafluoride gas (SF6) and 6% perfluoropropane gas (C3F8). METHODS: The charts of 431 patients undergoing EK from June 8, 2010, to April 16, 2023, were reviewed. Patients undergoing EK alone as well as combined procedures with cataract extraction and intraocular lens implantation were included. Eyes with tube shunts, anterior chamber intraocular lenses, and large peripheral iridotomy with posterior loss of bubble, and patients undergoing cyclophotocoagulation or synechialysis were excluded. All rebubble procedures were performed within 1 month after initial surgery. RESULTS: A total of 346 eyes using SF6 and 167 eyes using C3F8 were analyzed. Overall, 46 eyes (9%) required rebubbling; 33 eyes (10%) in the SF6 group and 13 eyes (8%) in the C3F8 group. For those patients undergoing DMEK, the odds of requiring rebubbling in the C3F8 group were about 22% lower than that of patients in the SF6 group (operating room [OR]: 0.782; P < 0.001). For patients undergoing DSEK, however, the gas type did not significantly affect rebubbling rates ( P = 0.99). CONCLUSIONS: For DMEK, utilization of 6% C3F8 as an AC tamponade was associated with a significantly lower odds of graft rebubbling compared with 20% SF6. Gas type did not result in a significant difference for DSEK. Utilization of 6% C3F8 for graft tamponade could be considered to reduce graft detachment rates in DMEK.

FIL SSF intraocular lens opacification after gas tamponade: A case series.

PURPOSE: To report three cases of postoperative opacification of sutureless scleral-fixed hydrophilic intraocular lens (FIL SSF IOL, Soleko, Italy) after gas tamponade. Two cases occurred after pars plana vitrectomy and one case after Descemet membrane endothelial keratoplasty. CASE REPORT: Two diabetic patients underwent a FIL SSF IOL implantation after posterior capsular rupture during cataract surgery. Rhegmatogenous retinal detachment (RRD) was observed in one patient during the initial surgery. A second patient developed a RRD five months after surgery. Both RRDs were treated with pars plana vitrectomy and perfluoroethane (C2F6) gas tamponade. A few days after the surgery, C2F6 was observed in the anterior chamber of both patients. Two months after gas tamponade, opacification of the anterior surface of the IOL was observed. The third patient was a 74-year-old woman, who underwent a combined Descemet membrane endothelial keratoplasty (DMEK) and FIL SSF IOL implantation. Two rebubblings with sulfur hexafluoride (SF6) retreatments were required due to corneal graft detachment. One month later, an opacification of the anterior surface of the IOL was observed. Explantation with implantation of iris-claw IOL was decided, which resulted in an improvement of BVCA. Analysis of the IOL showed a positive Von Kossa staining, indicating calcification of the IOL. We performed a review of all the cases of FIL SSF IOL implantation in our centers. The overall rate of FIL SSF IOL opacification was 2.1% (3/140). Amongst patients treated with gas tamponade, the rate of opacification was 27.3% (3/11). Although FIL SSF IOL implantation appears to be an effective option for the treatment of aphakia, caution should be exercised regarding the risk of opacification following gas tamponade, especially since these patients are at risk of retinal detachment.

SF 6 COMPARED WITH C 2 F 6 FOR INFERIOR RHEGMATOGENOUS RETINAL REPAIR : The Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To compare SF 6 relative with C 2 F 6 in the anatomical and functional outcomes following pars plana vitrectomy for uncomplicated primary pseudophakic rhegmatogenous retinal detachment with inferior causative breaks. METHODS: This is a retrospective, comparative study on eyes with pseudophakic rhegmatogenous retinal detachment with inferior causative breaks that had small-gauge pars plana vitrectomy repair using SF 6 and C 2 F 6 tamponade between 2011 and 2020 at a tertiary centre in the United Kingdom. Primary outcome was single surgery anatomical success, and the secondary outcome was best-corrected visual acuity. Propensity score matching, using preoperative findings as covariates to account for relevant confounders, was performed. RESULTS: From 162 pseudophakic rhegmatogenous retinal detachment eyes with inferior causative breaks, the median (interquartile range) follow-up was 82 (52-182) days. The single surgery anatomical success was 156 (96.3%) overall: 47 of 47 (100.0%) and 109 of 115 (94.8%) in the SF 6 and C 2 F 6 groups, respectively ( P = 0.182). Relative to the SF 6 group, the C 2 F 6 group had a higher mean number of tears (SF 6 : 3.1[2.0], C 2 F 6 : 4.5[2.7], P = 0.002) and greater retinal detachment extent (SF 6 : 5.3[2.9], C 2 F 6 : 6.2[2.6] clock hours, P = 0.025). Following propensity score matching analysis, 80 eyes were matched with 40 in each group to homogenize preoperative factors. No significant difference was found in single surgery anatomical success and best-corrected visual acuity between the groups following propensity score matching. CONCLUSION: Primary pars plana vitrectomy with gas tamponade leads to a high single surgery anatomical success rate in uncomplicated pseudophakic rhegmatogenous retinal detachment with inferior causative breaks with no additional benefit associated with long-acting tamponade when comparing C 2 F 6 with SF 6 .

Contrast-enhanced ultrasound with microbubbles containing sulfur hexafluoride and perfluorobutane with Kupffer phase for the detection of colorectal liver metastases.

OBJECTIVE: To compare contrast-enhanced ultrasound (CEUS) with microbubbles containing sulfur hexafluoride (SHF) and perfluorobutane (PFB) for the detection of colorectal liver metastasis (CRLM). METHODS: In this prospective study, conducted from September to November 2021, patients with colorectal cancer were consecutively recruited and underwent same-day ultrasound, SHF-CEUS, and PFB-CEUS. The reference standard was contrast-enhanced MRI and follow-up imaging. The size, depth, echogenicity, and calcification of each focal liver lesion were recorded. The number and conspicuity of CRLMs, based on washout appearance during the late phase (LP) (> 120 s)/Kupffer phase (KP), were evaluated offsite by two blinded readers. RESULTS: Overall, 230 lesions (CRLMs, n = 219; benign lesions, n = 11) in 78 patients were evaluated. Lesion conspicuity (p = 0.344) and accuracy in the detection of CRLM were comparable for SHF- and PFB-CEUS (0.877 for SHF vs. 0.770 for PFB, p = 0.087). More CRLMs ≥ 10 mm were identified by LP contrast washout in SHF-CEUS than in KP PFB-CEUS (p < 0.001). More CRLMs < 10 mm were identified by KP washout in PFB-CEUS than in LP SHF-CEUS (p < 0.001). Conspicuity was better on PFB-CEUS than on SHF-CEUS (p = 0.027). In hyperechoic lesions, lesions located deeper than 80 mm, and calcified lesions, CRLM conspicuity on PFB-CEUS was inferior to that on SHF-CEUS (p < 0.05). CONCLUSIONS: The overall accuracy of detection and conspicuity of washout in CRLMs were comparable between SHF and PFB-CEUS. PFB-CEUS has the advantage of identifying washout in small CRLMs. However, larger, hyperechogenic, deep-seated, or calcified lesions were better identified using SHF-CEUS. CLINICAL RELEVANCE STATEMENT: Accuracy of detection and conspicuity of washout in CRLMs were comparable between SHF- and PFB-CEUS. PFB-CEUS has the advantage in detecting small CRLMs, whereas SHF-CEUS is better for detecting larger, hyperechogenic, deep-seated, or calcified lesions. KEY POINTS: Contrast-enhanced ultrasound with sulfur hexafluoride in the late phase and perfluorobutane microbubbles in the Kupffer phase were comparable in terms of accuracy in the detection and conspicuity of colorectal liver metastases. Small colorectal liver metastases (< 10 mm) were more often identified in the Kupffer phase contrast-enhanced ultrasound imaging when using perfluorobutane microbubbles. Larger, hyperechogenic, deep-seated, or calcified lesions were better identified in the late phase contrast-enhanced ultrasound imaging (> 120 s) when using sulfur hexafluoride microbubbles.

Comparison of efficacy of three gases for anterior chamber tamponade in Descemet's membrane endothelial keratoplasty.

PURPOSE: To compare the efficacy of three different gases for intraocular tamponade: 100% air, 10% perfluoropropane (C3F8), and 10% sulfur hexafluoride (SF6), in Descemet's membrane endothelial keratoplasty (DMEK). MATERIALS AND METHODS: The medical records of 138 patients who underwent DMEK were reviewed retrospectively, with the primary outcome being the rebubbling rate in the first week following surgery. Other clinical outcomes, such as best-corrected visual acuity (BCVA), central corneal thickness (CCT), incidence of rebubbling after the first week, endothelial cell density (ECD), graft detachment, graft failure, pupillary block, and intraocular pressure (IOP) changes were also analyzed. RESULTS: Of the 138 patients, 57 were in group 1 (treated with air), 44 in group 2 (treated with 10% C3F8), and 37 in group 3 (treated with 10% SF6). Group 3 showed significantly lower rates of graft detachment and rebubbling compared to groups 1 and 2 (P<0.001). However, there was no significant difference in postoperative BCVA among the groups. At one year, the mean endothelial cell loss was 32% in group 1, 30% in group 2, and 33% in group 3 (P=0.715). One patient in group 1 experienced pupillary block and increased IOP, while there were no such occurrences in the other groups. There was no difference between the groups in terms of graft failure. CONCLUSION: The use of 10% SF6 in DMEK surgery may be a good option due to its efficacy in preventing graft detachment, low rebubbling rate, and potential for minimizing complications.