Intra-ophthalmic artery chemotherapy triggers vascular toxicity through endothelial cell inflammation and leukostasis

MR Imaging of Adverse Effects and Ocular Growth Decline after Selective Intra-Arterial Chemotherapy for Retinoblastoma

This retrospective multicenter study examines therapy-induced orbital and ocular MRI findings in retinoblastoma patients following selective intra-arterial chemotherapy (SIAC) and quantifies the impact of SIAC on ocular and optic nerve growth. Patients were selected based on medical chart review, with inclusion criteria requiring the availability of posttreatment MR imaging encompassing T2-weighted and T1-weighted images (pre- and post-intravenous gadolinium administration). Qualitative features and quantitative measurements were independently scored by experienced radiologists, with deep learning segmentation aiding total eye volume assessment. Eyes were categorized into three groups: eyes receiving SIAC (Rb-SIAC), eyes treated with other eye-saving methods (Rb-control), and healthy eyes. The most prevalent adverse effects post-SIAC were inflammatory and vascular features, with therapy-induced contrast enhancement observed in the intraorbital optic nerve segment in 6% of patients. Quantitative analysis revealed significant growth arrest in Rb-SIAC eyes, particularly when treatment commenced ≤ 12 months of age. Optic nerve atrophy was a significant complication in Rb-SIAC eyes. In conclusion, this study highlights the vascular and inflammatory adverse effects observed post-SIAC in retinoblastoma patients and demonstrates a negative impact on eye and optic nerve growth, particularly in children treated ≤ 12 months of age, providing crucial insights for clinical management and future research.

Advancements in Nanosystems for Ocular Drug Delivery: A Focus on Pediatric Retinoblastoma

The eye's complex anatomical structures present formidable barriers to effective drug delivery across a range of ocular diseases, from anterior to posterior segment pathologies. Emerging as a promising solution to these challenges, nanotechnology-based platforms-including but not limited to liposomes, dendrimers, and micelles-have shown the potential to revolutionize ophthalmic therapeutics. These nanocarriers enhance drug bioavailability, increase residence time in targeted ocular tissues, and offer precise, localized delivery, minimizing systemic side effects. Focusing on pediatric ophthalmology, particularly on retinoblastoma, this review delves into the recent advancements in functionalized nanosystems for drug delivery. Covering the literature from 2017 to 2023, it comprehensively examines these nanocarriers' potential impact on transforming the treatment landscape for retinoblastoma. The review highlights the critical role of these platforms in overcoming the unique pediatric eye barriers, thus enhancing treatment efficacy. It underscores the necessity for ongoing research to realize the full clinical potential of these innovative drug delivery systems in pediatric ophthalmology.

Risk factors for cataract in retinoblastoma management

AIMS

To investigate the risk factors for cataract following eye-preserving therapies for retinoblastoma.

METHODS

This retrospective, single-centre cohort study included patients diagnosed with retinoblastoma receiving eye-preserving therapies between January 2017 and June 2021. Cataract by the end of the follow-up was the main outcome.

RESULTS

Cataract was found in 31 of 184 (16.8%) included eyes during a mean follow-up of 27.6 months. The cataract and control groups were similar regarding patients' laterality, sex and disease stage. Eyes in the cataract group were more likely to present with endophytic retinoblastoma (p=0.02) and greater intraocular pressure (p=0.001). Competing risk regression analysis (univariate Fine-Gray model) showed that the growth pattern (p=0.01), intraocular pressure (p=0.01), number of intra-arterial chemotherapy (IAC) cycles (p=0.001), melphalan dose per IAC cycle (p=0.001) and number of intravitreous chemotherapy (IvitC) cycles (p=0.001) were associated with cataract occurrence. Multivariate analysis included higher intraocular pressure (p=0.003), a higher melphalan dose per IAC cycle (p=0.001) and an increasing number of IvitC cycles (p=0.04) as independent risk factors for cataract.

CONCLUSIONS

Repeated IAC and/or IvitC with melphalan were the most common eye-preserving therapies that induced cataract formation. The toxic effect of melphalan was an essential factor in cataract development, as indicated by the association of cataract occurrence with the melphalan dose.

Ligation of the ethmoid arteries in superselective intra-arterial infusion of cisplatin for advanced maxillary sinus cancer fed by the ophthalmic artery

BACKGROUND

Superselective cisplatin (CDDP) infusion via the external carotid artery system and concomitant radiotherapy (RADPLAT) provides favorable oncological and functional outcomes in patients with maxillary sinus cancer. However, targeted lesions are occasionally fed by the branch of the internal carotid artery.

METHODS

In RADPLAT for maxillary sinus cancer partly fed by the ophthalmic artery, the ethmoid arteries were ligated in two patients without medial orbital wall involvement. In four patients with that, CDDP was administered via the ophthalmic artery.

RESULTS

A complete response was obtained in all six patients. Locoregional recurrence was not observed in any cases. However, visual acuity was lost in four patients who received the ophthalmic artery infusion.

CONCLUSIONS

Ligation of the ethmoid arteries is recommended in RADPLAT for maxillary sinus cancer with lesions fed by the ophthalmic artery. CDDP administered via the ophthalmic artery may be considered if a patient accepts the possibility of visual loss.

Retinal microvasculature observations of fellow eyes after intra-arterial chemotherapy for unilateral retinoblastoma using optical coherence tomography angiography

Purpose

To investigate the characteristics of the retinal microvasculature of the fellow eyes in patients with unilateral retinoblastoma (RB) after intra-arterial chemotherapy (IAC) through optical coherence tomography angiography.

Methods

This retrospective study enrolled 11 fellow eyes of patients with unilateral RB receiving IAC (group I), nine fellow eyes of patients with unilateral RB receiving IAC and intravenous chemotherapy (IVC) (group II), and 14 age-matched normal eyes (control group). Optical coherence tomography angiography was performed on all individuals. Vascular density of superficial capillary plexus and deep capillary plexus (DCP), foveal avascular zone related parameters, and retinal thickness were measured and compared among the three groups.

Results

There was no statistical difference in age and logMAR visual acuity among the three groups. Compared with the control group, the vascular density of the DCP was lower in group I and II. Decreased vascular density of FD-300 and thinner thickness of outer plexus layer to Bruch's membrane were detected in group II compared with the control group. The vascular density and retinal thickness showed no differences between group I and II.

Conclusion

The decreased vascular density in the DCP without measurable visual impairment was observed in fellow eyes after IAC or IAC + IVC for unilateral RB. Further studies with a larger sample would be necessary to determine the clinical significance of these findings.

Applications of a novel reciprocating positive displacement pump in the simulation of pulsatile arterial blood flow

Pulsatile arterial blood flow plays an important role in vascular system mechanobiology, especially in the study of mechanisms of pathology. Limitations in cost, time, sample size, and control across current in-vitro and in-vivo methods limit future exploration of novel treatments. Presented is the verification of a novel reciprocating positive displacement pump aimed at resolving these issues through the simulation of human ocular, human fingertip and skin surface, human cerebral, and rodent spleen organ systems. A range of pulsatile amplitudes, frequencies, and flow rates were simulated using pumps made of 3D printed parts incorporating a tubing system, check valve and proprietary software. Volumetric analysis of 430 total readings across a flow range of 0.025ml/min to 16ml/min determined that the pump had a mean absolute error and mean relative error of 0.041 ml/min and 1.385%, respectively. Linear regression analysis compared to expected flow rate across the full flow range yielded an R2 of 0.9996. Waveform analysis indicated that the pump could recreate accurate beat frequency for flow ranges above 0.06ml/min at 70BPM. The verification of accurate pump output opens avenues for the development of novel long-term in-vitro benchtop models capable of looking at fluid flow scenarios previously unfeasible, including low volume-high shear rate pulsatile flow.

A case of retinoblastoma resulting in phthisis bulbi after proton beam radiation therapy

Purpose

Proton beam radiation therapy (PBRT) is a treatment option for advanced retinoblastoma (RB) resistant to chemotherapy and focal ophthalmic treatment. Here we report a case of RB with phthisis bulbi following PBRT.

Observations

A 16-day-old boy with a family history of RB was referred to our institution. Initial examination revealed an extensive white mass in the right eye and a small tumor near the optic disk of the left eye. The patient was diagnosed with bilateral RB and treated with chemotherapy and focal ophthalmic therapy. The right eye showed shrinkage in the treatment course. The tumor control was not achieved bilaterally, and, therefore, PBRT was performed to preserve the eyes. However, the right eye became significantly phthisical following PBRT and ultimately required enucleation.

Conclusions and importance

PBRT for RB may result in phthisis bulbi. Further investigations of its role and possible complications are warranted.

Analysis of Cause-Specific Mortality in Patients with Retinoblastoma

Background. Retinoblastoma (RB) is a rare pediatric tumor with a relatively favorable prognosis. However, RB is associated with cause-specific mortality, some of that should be of great importance to clinicians. In this study, we summarize the characteristics of cause-specific mortality from nontumor disease in patients with RB. Methods. This retrospective case series study identified and analyzed cause-specific mortality in patients with RB. The information of cause-specific mortality of RB patients, including detailed clinical characteristics, diagnosis, treatment process, cause-specific mortality classification, and lag time, was assessed. Results. A total of 12 eligible patients were selected from 264 patients who died among 3780 patients diagnosed with RB. The cause-specific mortality rate was 4.5% for all patients with RB who died and 0.3% for all patients with RB. The main nontumor cause-specific mortalities were diseases of the nervous, circulatory, and respiratory systems, which specifically included intracranial infection, cerebral hemorrhage, paraplegia, and respiratory failure. The longest lag time was 42 days from the last chemoradiotherapy or surgery. Conclusion. Nontumor cause-specific mortality is an essential outcome of RB. Thus, intensive care and differentiation during management need to be taken seriously.

Quantitative evaluation of retinal microvasculature and retrobulbar vessels after intravenous chemotherapy for retinoblastoma

Backgroud

To evaluate the changes in retinal microvasculature and retrobulbar blood flow, using optical coherence tomography angiography (OCTA) and Color Doppler imaging (CDI) after intravenous chemotherapy (IVC) in patients with retinoblastoma (RB).

Methods

This was a retrospective comparative case control series involving 30 patients. Ten bilateral RB patients that had a preserved eye with extramacular tumours (group I), 10 unilateral RB treated with IVC that had a normal fellow study eye (group II), and 10 age-matched healthy controls. The macular retinal thickness, foveal avascular zone (FAZ) area, and the macular and peripapillary retinal vessel densities (RVD) were measured. The peak systolic and end diastolic velocities of the ophthalmic, central retinal and posterior ciliary arteries were determined. A comparison among the three groups was conducted.

Results

Between the three cohorts, OCTA revealed no significant difference in FAZ area, superficial foveal and parafoveal RVD, deep parafoveal RVD and peripapillary RVD, (P > 0.05). By contrast, the mean deep foveal RVD, the full, inner and outer foveal and the parafoveal retinal thickness were significantly lower in group I compared with the controls, (P = 0.0329, 0.0153, 0.0311 0.0352, 0.0215). No significant difference in the blood flow velocities occurred in the retrobulbar circulation (P > 0.05).

Conclusions

In patients with retinoblastoma, OCTA did not detect significant changes of retinal thickness and vessel density in the eyes treated with IVC, but a slight reduction in retinal thickness and the deep foveal RVD seemed to occur in bilateral RB eyes. The retrobulbar blood flow parameters showed no measurable changes.

Primary high-grade serous ovarian cancer cells are sensitive to senescence induced by carboplatin and paclitaxel in vitro

BACKGROUND

Various types of normal and cancer cells undergo senescence in response to carboplatin and paclitaxel, which are considered the gold standard treatments in ovarian cancer management. Surprisingly, the effect of these drugs on ovarian cancer cell senescence remained unknown.

METHODS

The experiments were conducted on primary high-grade serous ovarian cancer cells. Molecular markers of senescence were evaluated using cytochemistry and immunofluorescence. Cell cycle distribution was analyzed using flow cytometry. Expression of cyclins and signaling pathways was tested using western blot. Telomere length and telomerase activity were measured using qPCR, and the colocalization of telomeres with DNA damage foci using immuno-FISH. Oxidative stress-related parameters were quantified using appropriate fluorescence probes. Production of cancerogenic agents was analyzed using qPCR and ELISA.

RESULTS

Carboplatin applied with paclitaxel induces senescence of ovarian cancer cells in vitro. This activity was reflected by permanent G2/M growth arrest, a high fraction of cells expressing senescence biomarkers (SA-β-Gal and γ-H2A.X), upregulated expression of p16, p21, and p53 cell cycle inhibitors, and decreased expression of cyclin B1. Neither telomere length nor telomerase activity changed in the senescent cells, and the majority of DNA damage was localized outside telomeres. Moreover, drug-treated cancer cells exhibited increased production of STAT3 protein, overproduced superoxide and peroxides, and increased mitochondrial mass. They were also characterized by upregulated ANG1, CCL11, IL-6, PDGF-D, TIMP-3, TSP-1, and TGF-β1 at the mRNA and/or protein level.

CONCLUSIONS

Our findings imply that conventional chemotherapy may elicit senescence in ovarian cancer cells, which may translate to the development of a cancer-promoting phenotype, despite the inability of these cells to divide.

Intraarterial Chemotherapy for Retinoblastoma - Initial Experiences of a German Reference Centre

BACKGROUND

Adequate management of retinoblastoma requires a multidisciplinary and individual approach to treatment. Intraarterial chemotherapy (IAC) is one of the most commonly used treatment modalities, and enables supraselective application of chemotherapy via the ophthalmic artery and is now established in almost all treatment centres. However, published treatment success rates are heterogeneous. There are some unanswered issues regarding sight-threatening ocular complications and the long-term occurrence of secondary malignancies and metastatic disease. The objective of the present study is to analyse the results of a German national reference centre.

METHODS

Retrospective analysis of all children with an indication for at least one IAC from April 2010 to April 2020. IAC was used either as primary or recurrence therapy. Obligatory follow-up was at least 6 months.

RESULTS

137 eyes of 127 children with an indication for IAC could be included. 12 eyes with a follow-up of less than 6 months and 37 eyes in which IAC was technically not feasible were excluded. In summary, 88 eyes of 79 children were finally analysed. Mean follow-up was 38 months, ranging from 7 to 117 months. In total, 195 procedures were completed. In 30 eyes (34.1%) IAC was conducted as primary and in 58 (65.9%) as secondary therapy. There was an initial IAC treatment response in 75 eyes (85.2%) with a recurrence-free rate of 61.3%. Eye salvage rate was 68.1% with 28 enucleated eyes in total. Ocular complications were observed in 36 eyes (40.9%), with 19 eyes (21.6%) showing severe sight-threatening and 11 eyes (12.5%) presenting minor non-sight-threatening toxic reactions. During follow-up, 1 child developed a secondary malignancy, 1 child developed metastasis and 1 child died as a consequence of trilateral retinoblastoma.

CONCLUSION

In summary, IAC is a potent modality for retinoblastoma treatment and has been very successful, even in advanced disease and heavily pretreated eyes. However, ocular complications should be taken in consideration, especially when the only seeing eye is treated. Long term incidences of secondary malignancies and metastatic diseases should be further investigated in prospective studies.

Risk factors for ophthalmic artery stenosis and occlusion in patients with retinoblastoma treated with intra-arterial chemotherapy

Purpose

To explore the risk factors for ophthalmic artery (OA) stenosis and occlusion after intra-arterial chemotherapy (IAC) with selective ophthalmic artery catheterisation (OAC) in the treatment of retinoblastoma.

Design

Retrospective, single centre case-control study.

Methods

The study was conducted including consecutive patients with unilateral or bilateral intraocular retinoblastoma undergoing IAC between June 2016 and June 2019 with a follow-up time of 4 years. Main outcomes are rate of IAC-induced OA occlusion and OA diameter.

Results

346 attempted OAC infusions were successful. The total incidence of OA occlusion was 15.89%. The occlusion and control groups were similar in patients’ age, sex and disease stage. Median OA diameter was 0.49 mm in those with OA occlusion, and 0.66 mm in those without occlusion. In the occlusion group, the OA diameter difference was significantly larger between the first IAC and the final IAC (0.22mm vs 0.12mm, p=0.001). In both groups, the median number of IAC treatments was 3. Multivariate Cox regression models included initial OA diameter (OR: 0.005, p=0.001), ratio of OA orifice diameter differences between first and last IAC to the initial OA orifice diameter (OR: 4.661, p=0.003), and number of IAC (OR: 1.538, p=0.042) as clinical features significantly associated with OA occlusion.

Conclusions

The OA diameter at first IAC treatment, the ratio of OA orifice diameter differences between first and last IAC to the initial OA orifice diameter and total number of IAC treatments may be three main clinical predictors for OA occlusion after IAC for retinoblastoma.

Evaluation of intravitreal topotecan dose levels, toxicity and efficacy for retinoblastoma vitreous seeds: a preclinical and clinical study

Background

Current melphalan-based intravitreal regimens for retinoblastoma (RB) vitreous seeds cause retinal toxicity. We assessed the efficacy and toxicity of topotecan monotherapy compared with melphalan in our rabbit model and patient cohort.

Methods

Rabbit experiments: empiric pharmacokinetics were determined following topotecan injection. For topotecan (15 μg or 30 µg), melphalan (12.5 µg) or saline, toxicity was evaluated by serial electroretinography (ERG) and histopathology, and efficacy against vitreous seed xenografts was measured by tumour cell reduction and apoptosis induction. Patients: retrospective cohort study of 235 patients receiving 990 intravitreal injections of topotecan or melphalan.

Results

Intravitreal topotecan 30 µg (equals 60 µg in humans) achieved the IC₉₀ across the rabbit vitreous. Three weekly topotecan injections (either 15 µg or 30 µg) caused no retinal toxicity in rabbits, whereas melphalan 12.5 µg (equals 25 µg in humans) reduced ERG amplitudes 42%–79%. Intravitreal topotecan 15 µg was equally effective to melphalan to treat WERI-Rb1 cell xenografts in rabbits (96% reduction for topotecan vs saline (p=0.004), 88% reduction for melphalan vs saline (p=0.004), topotecan vs melphalan, p=0.15). In our clinical study, patients received 881 monotherapy injections (48 topotecan, 833 melphalan). Patients receiving 20 µg or 30 µg topotecan demonstrated no significant ERG reductions; melphalan caused ERG reductions of 7.6 μV for every injection of 25 µg (p=0.03) or 30 µg (p<0.001). Most patients treated with intravitreal topotecan also received intravitreal melphalan at some point during their treatment course. Among those eyes treated exclusively with topotecan monotherapy, all eyes were salvaged.

Conclusions

Taken together, these experiments suggest that intravitreal topotecan monotherapy for the treatment of RB vitreous seeds is non-toxic and effective.

Prospective phase II study of children affected by bilateral intraocular retinoblastoma with macular involvement of both eyes or in the only preserved eye. Macular tumor control, eye preservation rate, and visual outcome

BACKGROUND

Conservative treatments of intraocular retinoblastoma often consist of chemotherapy and focal treatments. The protocols vary and currently may combine two or three drugs, with different number of cycles, associated to the ocular treatments. In case of macular/paramacular involvement, tumor location and retinal scars induced by focal treatments often have a major negative impact on final visual outcome.

METHODS

This study aimed to include children affected by bilateral intraocular macular/paramacular retinoblastoma in a prospective phase II study. The protocol consisted of six cycles of a three-drug combination (vincristine, etoposide, carboplatin), and the addition of macula-sparing transpupillary thermotherapy (TTT) to the third cycle. The primary endpoint was the local control rate without external beam radiotherapy (EBR) and/or enucleation.

RESULTS

Nineteen patients (26 eyes) were included from July 2004 to November 2009. Thirteen eyes belonged to group V of the Reese-Ellsworth classification and 10 to group D of the International Intraocular Retinoblastoma Classification. Macular/paramacular tumors were treated with chemotherapy alone in nine eyes, and with chemotherapy associated with macula-sparing TTT in 17 eyes. Four eyes experienced macular relapse. At a median follow up of 77 months, 23 eyes (88.5%) were saved without EBR, two were enucleated and one received EBR. The median visual acuity of the 24 saved eyes was 20/50. No severe adverse effect was observed.

CONCLUSION

Six cycles of a three-drug combination associated with macula-sparing TTT achieved good tumor control, improved eye preservation rates without EBR, and decreased macular damage, often providing satisfactory visual results with long-term follow up.

Incidence and predictors of ophthalmic artery occlusion in intra-arterial chemotherapy for retinoblastoma

BACKGROUND

Retinoblastoma is the most common primary intraocular malignancy in children.

OBJECTIVE

To determine the incidence of ophthalmic artery (OA) occlusion in patients treated with selective ophthalmic artery catheterization (OAC) for chemotherapy infusion for retinoblastoma. Also, to evaluate technical, anatomical, tumorous, and patient-related factors that are predictors of OA occlusion.

METHODS

A retrospective chart review was performed for patients diagnosed with intraocular retinoblastoma and managed with intra-arterial chemotherapy (IAC).

RESULTS

The total study cohort included 208 retinoblastoma tumors of 208 eyes in 197 consecutive patients who underwent 688 attempted IAC infusions overall with a total of 624 successful OAC infusions. The total incidence of ophthalmic artery thrombosis was 11.1% (23/208). The numbers of successful OAC procedures before diagnosing OA occlusion were one OAC in six cases (27.3%), two in seven cases (31.8%), three in four cases (18.2%), four in one case (4.5%), five in two cases (9.1%), and six in one case (4.5%).

CONCLUSIONS

Local factors relating to the chemotherapy and selective microcatheterization of the OA are essential factors in the development of OA thrombosis, as seen by the association of OA thrombosis with the frequency of IAC.

Risk Factors for Acute Choroidal Ischemia after Intra-arterial Melphalan for Retinoblastoma: The Role of the Catheterization Approach

PURPOSE

To identify risk factors for acute choroidal ischemia (ACI) after intra-arterial chemotherapy (IAC) for retinoblastoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Two hundred twenty patients (248 eyes) treated with IAC in Lausanne between November 2008 and September 2019 (665 procedures). All patients were evaluated on a monthly basis with fundus photography and fluorescein angiography before and after each IAC injection.

METHODS

Acute choroidal ischemia, defined as any new choroidal ischemia clinically diagnosed within 35 days after an IAC injection, were noted. Eyes with choroidal complications diagnosed later than 35 days after the last IAC injection (n = 7) or those for which the status of the choroid was not assessable (n = 35) were excluded. Specific procedure parameters and treatment regimens were compared between the group of eyes with and without ACI.

MAIN OUTCOME MEASURES

Procedure-related risk factors for ACI after IAC injection and visual acuity assessment in the group of eyes with ACI.

RESULTS

Acute choroidal ischemia developed in 35 of 206 included eyes after a mean of 2 injections. No differences were found between the two study groups regarding age at first IAC injection, disease grouping at diagnosis, previously administered treatments, number of IAC injections, drug dose, mean injection time, injection method (pulsatile vs. continuous), or concomitant intravitreal melphalan use. Treatment regimen (melphalan vs. combined melphalan plus topotecan; P < 0.05), catheterization route (internal carotid artery vs. external carotid or posterior communicating artery; P < 0.001), and catheterization type (occlusive into the ophthalmic artery [OA] vs. nonocclusive; P < 0.001) were included in multivariate analysis, and occlusive catheterization was identified as an independent risk factor for ACI (P < 0.001). In the subgroup undergoing an occlusive procedure, placement of the catheter tip into the OA distal third versus medial and proximal thirds (P = 0.04) and a mean catheter diameter-to-OA lumen ratio of 0.6 or more (P < 0.001) were correlated significantly with ACI. Complete vision loss was noted in 27% of the eyes with ACI that were old enough for visual assessment (n = 9/33), whereas 33% maintained a useful vision ranging between 0.1 and 0.8 (n = 11/33).

CONCLUSIONS

Catheterization of the OA should be attempted from an ostial position or an external carotid approach to minimize the risk of potentially vision-threatening choroidal complications.

Retinal endothelial cell phenotypic modifications during experimental autoimmune uveitis: a transcriptomic approach

BACKGROUND

Blood-retinal barrier cells are known to exhibit a massive phenotypic change during experimental autoimmune uveitis (EAU) development. In an attempt to investigate the mechanisms of blood-retinal barrier (BRB) breakdown at a global level, we studied the gene regulation of total retinal cells and retinal endothelial cells during non-infectious uveitis.

METHODS

Retinal endothelial cells were isolated by flow cytometry either in Tie2-GFP mice (CD31+ CD45- GFP+ cells), or in wild type C57BL/6 mice (CD31+ CD45- endoglin+ cells). EAU was induced in C57BL/6 mice by adoptive transfer of IRBP1-20-specific T cells. Total retinal cells and retinal endothelial cells from naïve and EAU mice were sorted and their gene expression compared by RNA-Seq. Protein expression of selected genes was validated by immunofluorescence on retinal wholemounts and cryosections and by flow cytometry.

RESULTS

Retinal endothelial cell sorting in wild type C57BL/6 mice was validated by comparative transcriptome analysis with retinal endothelial cells sorted from Tie2-GFP mice, which express GFP under the control of the endothelial-specific receptor tyrosine kinase promoter Tie2. RNA-Seq analysis of total retinal cells mainly brought to light upregulation of genes involved in antigen presentation and T cell activation during EAU. Specific transcriptome analysis of retinal endothelial cells allowed us to identify 82 genes modulated in retinal endothelial cells during EAU development. Protein expression of 5 of those genes (serpina3n, lcn2, ackr1, lrg1 and lamc3) was validated at the level of inner BRB cells.

CONCLUSION

Those data not only confirm the involvement of known pathogenic molecules but further provide a list of new candidate genes and pathways possibly implicated in inner BRB breakdown during non-infectious posterior uveitis.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.

Intra-arterial chemotherapy in retinoblastoma - A paradigm change

Intra-arterial chemotherapy (IAC), also known as superselective ophthalmic artery chemotherapy or chemosurgery, is currently widely accepted as one of the primary treatment modalities for intraocular retinoblastoma worldwide. Following the introduction of the technique in 1998, IAC has evolved over the past decades to be safer and more effective. Accumulated evidence shows that IAC is more effective in providing eye salvage in group D and E retinoblastoma as compared to conventional systemic intravenous chemotherapy (IVC). In contrast to IVC, IAC has the added benefits of reduced overall treatment duration and minimal systemic toxicity. This review provides a comprehensive update on the history, technique, indications, contraindications, and outcome of IAC. We have also identified the strengths, weaknesses, opportunities and threats (SWOT analysis) of the technique in this review.

Rabbit Model of Intra-Arterial Chemotherapy Toxicity Demonstrates Retinopathy and Vasculopathy Related to Drug and Dose, Not Procedure or Approach

Purpose

To use our intra-arterial chemotherapy (IAC) rabbit model to assess the impact of IAC procedure, drug, dose, and choice of technique on ocular structure and function, to study the nature and etiology of IAC toxicity, and to compare to observations in patients.

Methods

Rabbits received IAC melphalan (0.4-0.8 mg/kg), carboplatin (25–50 mg), or saline, either by direct ophthalmic artery cannulation, or with a technique emulating nonocclusion. Ocular structure/function were assessed with examination, electroretinography (ERG), fundus photography, fluorescein angiography, optical coherence tomography (OCT), and OCT angiography, prior to and 5 to 6 weeks after IAC. Blood counts were obtained weekly. We reviewed our last 50 IAC treatments in patients for evidence of ocular or systemic complications.

Results

No toxicity was seen in the saline control group. With standard (0.4 mg/kg) melphalan, no vascular/microvascular abnormalities were seen with either technique. However, severe microvascular pruning and arteriolar occlusions were seen occasionally at 0.8 mg/kg doses. ERG reductions were dose-dependent. Histology showed melphalan dose-dependent degeneration in all retinal layers, restricted geographically to areas of greatest vascular density. Carboplatin caused massive edema of ocular/periocular structures. IAC patients experienced occasional periocular swelling/rash, and only rarely experienced retinopathy or vascular events/hemorrhage in eyes treated multiple times with triple (melphalan/carboplatin/topotecan) therapy. Transient neutropenia occurred after 46% of IAC procedures, generally after triple therapy.

Conclusions

IAC toxicity appears to be related to the specific drug being used and is dose-dependent, rather than related to the IAC procedure itself or the specific technique selected. These rabbit findings are corroborated by our clinical findings in patients.

Conservative management of retinoblastoma: Challenging orthodoxy without compromising the state of metastatic grace. "Alive, with good vision and no comorbidity"

Retinoblastoma is lethal by metastasis if left untreated, so the primary goal of therapy is to preserve life, with ocular survival, visual preservation and quality of life as secondary aims. Historically, enucleation was the first successful therapeutic approach to decrease mortality, followed over 100 years ago by the first eye salvage attempts with radiotherapy. This led to the empiric delineation of a window for conservative management subject to a "state of metastatic grace" never to be violated. Over the last two decades, conservative management of retinoblastoma witnessed an impressive acceleration of improvements, culminating in two major paradigm shifts in therapeutic strategy. Firstly, the introduction of systemic chemotherapy and focal treatments in the late 1990s enabled radiotherapy to be progressively abandoned. Around 10 years later, the advent of chemotherapy in situ, with the capitalization of new routes of targeted drug delivery, namely intra-arterial, intravitreal and now intracameral injections, allowed significant increase in eye preservation rate, definitive eradication of radiotherapy and reduction of systemic chemotherapy. Here we intend to review the relevant knowledge susceptible to improve the conservative management of retinoblastoma in compliance with the "state of metastatic grace", with particular attention to (i) reviewing how new imaging modalities impact the frontiers of conservative management, (ii) dissecting retinoblastoma genesis, growth patterns, and intraocular routes of tumor propagation, (iii) assessing major therapeutic changes and trends, (iv) proposing a classification of relapsing retinoblastoma, (v) examining treatable/preventable disease-related or treatment-induced complications, and (vi) appraising new therapeutic targets and concepts, as well as liquid biopsy potentiality.

Comprehensive review on how platinum- and taxane-based chemotherapy of ovarian cancer affects biology of normal cells

One of the most neglected aspects of chemotherapy are changes, and possible consequences of these changes, that occur in normal somatic cells. In this review, we summarize effects of selected drugs used to treat ovarian cancer (platin derivatives-cisplatin and carboplatin; and taxanes-paclitaxel and docetaxel) on cellular metabolism, acquisition of reactive stroma features, cellular senescence, inflammatory reactions, apoptosis, autophagy, mitophagy, oxidative stress, DNA damage, and angiogenesis in various types of normal cells, including fibroblasts, epithelial cells, endothelial cells, and neurons. The activity of these drugs against the normal cells is presented from a broader perspective of their desirable anti-tumoral effects.

Choroidal Ischemia Sparing the Watershed Zone following Intra-Arterial Chemotherapy for Retinoblastoma

Purpose

Intra-arterial chemotherapy (IAC) has become a mainstay in the management of retinoblastoma, especially in advanced or refractory disease. However, IAC is not without complications, and chemotherapy toxic effects can lead to partial or complete choroidal ischemia, often causing vision loss.

Methods

This is a case report.

Results

A 4-month-old girl with bilateral retinoblastoma was treated with secondary IAC (melphalan 5 mg) for recurrent tumor following intravenous chemotherapy. One month later, complete tumor control was achieved. However, she demonstrated broad choroidal ischemia in the nasal and temporal quadrants but sparing of the watershed zone superior and inferior to the optic disc and in the papillomacular region. Fluorescein angiography revealed poor perfusion of the choriocapillaris with visibility of the large choroidal vessels in the nasal and temporal areas but preserved perfusion of the watershed zone. The watershed zone remained intact on the 10-month follow-up, and the final visual acuity was fix and follow without strabismus.

Conclusion

The pathophysiology of choroidal ischemia is not well understood, but the fortuitous watershed zone preservation in this case could represent uneven distribution of the chemotherapeutic drug, resulting in partial chemo-dilution of the medication in the watershed region, which represents the final downstream overlapping choroidal perfusion from both medial and lateral posterior ciliary arteries.

Choroidal infarction following ophthalmic artery chemotherapy

Background

Methylenetetrahydrofolate reductase (MTHFR) genetic mutations and intra-procedural inhaled nitrous oxide (N₂O) independently increase blood levels of homocysteine, a compound associated with thrombosis. Patients with MTHFR mutations who also receive N₂O during ophthalmic artery chemotherapy (OAC) for retinoblastoma may have a heightened thrombotic risk.

Case presentations

Single-center retrospective review of pediatric patients with advanced retinoblastoma who received OAC and developed choroidal infarcts. Four retinoblastoma patients with advanced intraocular disease (2 males, 2 females: 13-58 months) experienced choroidal infarcts within the one-month period after OAC, in which procedural N₂O induction was used (duration between 21 and 58 min). All 4 patients had MTHFR (chromosome 1p, position 36.22) genetic abnormalities: one was homozygous for the C677T mutation, one was C677T heterozygous, one was A1298C heterozygous, and one was heterozygous for both C677T and A1298C. In all 4 patients, indirect ophthalmoscopy and fundus photography showed marked disturbance of the retinal pigment epithelium and optical coherence tomography (OCT) confirmed thinning of the choroid. Follow-up time ranged from 15 to 46 months (median 21 months).

Conclusions

Choroidal infarction in eyes treated with OAC developed in children who were both deficient in at least one working allele of the MTHFR gene (heterozygous or homozygous) and received N₂O induction during OAC.

Lessons from Retinoblastoma: Implications for Cancer, Development, Evolution, and Regenerative Medicine

Retinoblastoma is a rare childhood cancer of the developing retina, and studies on this orphan disease have led to fundamental discoveries in cancer biology. Retinoblastoma has also emerged as a model for translational research for pediatric solid tumors, which is particularly important as personalized medicine expands in oncology. Research on retinoblastomas has been combined with the exploration of retinal development and retinal degeneration to advance a new model of cell type-specific disease susceptibility termed 'cellular pliancy'. The concept can even be extended to species-specific regeneration. This review discusses the remarkable path of retinoblastoma research and how it has shaped the most current efforts in basic, translational, and clinical research in oncology and beyond.

Changes in cross-sectional area of pulmonary vessels on chest computed tomography after chemotherapy in patients with advanced non-squamous non-small-cell lung cancer

PURPOSE

Chemotherapy is associated with a risk of vascular damage. Novel anti-angiogenic agents, which can directly affect tumor angiogenesis, are increasingly being used. However, the effects of these agents on normal vasculature are not well understood. Here, we evaluated the effects of chemotherapy in general, and the anti-angiogenic agent bevacizumab, more specifically, on the pulmonary vasculature in patients with advanced non-squamous non-small-cell lung cancer (NSCLC). For this, we used the cross-sectional area of pulmonary vessels (CSA), which is an easily measurable indicator of small pulmonary vasculature on non-contrast chest computed tomography (CT).

METHODS

We retrospectively reviewed CT scans of the lungs of 75 chemo-naïve patients with advanced non-squamous NSCLC, for measurement of CSA, before and after first-line platinum-based chemotherapy, using a semi-automatic image-processing program. Measured vessels were classified in two groups: small vessels with CSA <5 mm(2) and large vessels with CSA between 5 and 10 mm(2). The CSAs for each group of vessels were calculated and summed separately, and expressed as a percentage of the total lung area (%CSA<5 and %CSA5-10).

RESULTS

Chemotherapy was associated with a selective decrease in small-diameter vessels, with a significant decrease in %CSA<5, but not %CSA5-10. When comparing chemotherapy with bevacizumab (n = 38) and without bevacizumab (n = 37), there was no significant difference in the reduction of %CSA<5.

CONCLUSIONS

Platinum-based chemotherapy might induce small pulmonary vascular damage. Use of bevacizumab does not enhance the reduction in area of pulmonary vessels.

In search of underlying mechanisms and potential drugs of melphalan-induced vascular toxicity through retinal endothelial cells using bioinformatics approach

We aimed to explore molecular mechanism and drug candidates of vascular toxicities associated with melphalan after treating human retinal endothelial cells (RECs). GSE34381 microarray data was firstly downloaded and used to identify the differentially expressed genes (DEGs) in human REC treated with melphalan vs. untreated cells by limma package in R language. The transcription network was constructed based on TRANSFAC database and the top five transcription factors (TFs) were select with a measure of regulatory impact factor, followed by the construction of function modules. Gene ontology enrichment analyses were performed to explore the enriched functions. Connectivity Map analysis was conducted to predict the potential drugs overcoming the melphalan's actions on REC. Totally, 75 DEGs were identified, including 70 up-regulated and five down-regulated genes. Transcription network with 1311 nodes and 1875 edges was constructed and the top five TFs were CREM, MYC, FLI1, NF-κB1, and JUN. Functional modules indicated that NF-κB1 and MYC were the important nodes. The upregulated genes as well as the genes involved in the modules mainly participated in biological process of immune response, cell proliferation, and cell motion. Five small molecules were predicted to be potential drug candidates, including doxorubicin, fipexide, daunorubicin, tiabendazole, and GW-8510. Based on these results, we speculate that NF-κB1 and MYC might involve in the molecular mechanism of vascular toxicity induced by melphalan through regulating their target genes. Five small molecules might be drug candidates to overcome the melphalan-induced vascular toxicity via targeting to MYC and JUN.

Management of retinoblastoma in children: current status

In recent years, there have been dramatic changes in the management of intraocular retinoblastoma. Intraocular retinoblastoma is a highly curable malignancy and current treatments are aimed to preserve vision while reducing the late effects such as treatment-induced secondary malignancies. The advent of intra-arterial chemotherapy changed the treatment paradigm from systemic treatment with chemotherapy to local treatment, and new questions emerged. While intra-arterial chemotherapy achieved encouraging results, only experience from major referral centers is reported, so its indications, advantages and risks are still to be elucidated. Many factors should be considered when choosing the appropriate conservative therapy. When the disease has extended outside the eye, the chances of cure are significantly lower and treatment should be tailored by the presence of pathology risk factors such as invasion of the choroid, the optic nerve, and the sclera. Adjuvant therapy is decided upon this information. Children with overt extraocular disease are treated with higher dose neoadjuvant therapy followed by delayed enucleation and adjuvant therapy.

Use of intra-arterial chemotherapy for retinoblastoma: results of a survey

AIM

To obtain baseline knowledge about the current use of intra-arterial chemotherapy (SSOAIC) in centers worldwide.

METHODS

A survey including questions about the use of SSOAIC was emailed to retinoblastoma experts.

RESULTS

Seventy-nine (response rate 69.9%) doctors from 63 centers in 35 countries responded. Thirty-one centers from 19 countries use SSOAIC. Twelve performed more than 50 procedures. Melphalan is the most commonly used drug but 15 centers use more than one drug. First line therapy for advanced unilateral disease is the most common use of SSOAIC (74.2%). Centers with larger experience (>50 applications) were less likely using melphalan alone (P=0.06) and significantly more likely using SSOAIC in more situations such as second line in preference to radiotherapy P=0.05. Nineteen (61.2%) stated that SSOAIC improved their results and 21 (77.8%) reported less toxicity compared to other treatments. Three centers reported that SSOAIC did not improve their results. There were regional variations in the use of SSOAIC which is used more frequently as secondary treatment in Europe compared to the USA and Japan. Ten centers identified cost is the major limiting factor for SSOAIC.

CONCLUSION

SSOAIC is used in an increasing number of centers worldwide with regional variations. Centers with more experience in SSOAIC use it in more situations including other drugs than melphalan. The majority of the centers using this technique reported improved results and few complications.

Modulation of radiation injury response in retinal endothelial cells by quinic acid derivative KZ-41 involves p38 MAPK

Radiation-induced damage to the retina triggers leukostasis, retinal endothelial cell (REC) death, and subsequent hypoxia. Resultant ischemia leads to visual loss and compensatory retinal neovascularization (RNV). Using human RECs, we demonstrated that radiation induced leukocyte adhesion through mechanisms involving p38MAPK, p53, and ICAM-1 activation. Additional phenotypic changes included p38MAPK-dependent tyrosine phosphorylation of the focal adhesion scaffolding protein, paxillin (Tyr118). The quinic acid derivative KZ-41 lessened leukocyte adhesion and paxillin-dependent proliferation via inhibition of p38MAPK-p53-ICAM-1 signaling. Using the murine oxygen-induced retinopathy (OIR) model, we examined the effect of KZ-41 on pathologic RNV. Daily ocular application of a KZ-41-loaded nanoemulsion significantly reduced both the avascular and neovascular areas in harvested retinal flat mounts when compared to the contralateral eye receiving vehicle alone. Our data highlight the potential benefit of KZ-41 in reducing both the retinal ischemia and neovascularization provoked by genotoxic insults. Further research into how quinic acid derivatives target and mitigate inflammation is needed to fully appreciate their therapeutic potential for the treatment of inflammatory retinal vasculopathies.

Intra-arterial chemotherapy for retinoblastoma. Challenges of a prospective study

PURPOSE

To report the efficacy and complications of intra-ophthalmic artery melphalan (IAM) for treatment of patients with advanced intra-ocular retinoblastoma.

METHODS

Patients with newly diagnosed, unilateral, group D retinoblastoma were included in a phase II protocol. Children with relapsed-refractory disease after systemic chemoreduction were later treated under the same guidelines.Melphalan (3–5 mg/procedure) was injected through a 1.2 F microcatheter placed into the ophthalmic artery every 21 days.

RESULTS

Eleven patients (12 eyes, eight as primary treatment) received 33 IAM procedures. The phase II protocol closed prematurely because of low accrual. The IAM technique was overall safe and could be performed successfully in 31 of 33(94%) attempts. After the second administration of IAM, very good partial response was achieved in all treated eyes. With a median follow-up time of 29.5 months (range 6–57), ocular salvage was achieved in 7 of 12 (58%) eyes. No systemic adverse events were observed. Two patients developed diffuse arteriolar sclerosis, hyperpigmentation of the retinal pigment epithelium and partial retinal atrophy after the second IAM. Both eyes were preserved with no tumour activity, good motility and perception of light, 56 and 30 months after the last IAM treatment. Multinucleated macrophages with intracytoplasmic foreign material were found in the choroid and the retina in 2 of 5 enucleated eyes.

CONCLUSION

Our study reports the activity and reproducibility of IAM in advanced retinoblastoma but also underlines the challenges of performing prospective studies on this treatment modality. Toxicity was limited to only ocular vascular events.

Superselective intraophthalmic artery chemotherapy in a nonhuman primate model: histopathologic findings

IMPORTANCE

We describe the histopathologic findings in a nonhuman primate (NHP) model of superselective intraophthalmic artery chemotherapy (SSIOAC), detailing ocular and orbital vascular adverse effects.

OBJECTIVE

To further document, using comprehensive ocular and orbital histopathology, previously reported toxic effects observed with real-time ophthalmoscopy during SSIOAC in a NHP model.

DESIGN

Comparative interventional case series.

SETTING

Preclinical trial approved under the guidelines of the Institutional Animal Care and Utilization committee.

PARTICIPANTS

Six adult male rhesus macaques (Macacca mulatta).

INTERVENTIONS

The right eye of each NHP was treated with 3 cycles of SSIOAC using either melphalan (5 mg/30 mL) or carboplatin (30 mg/30 mL). Both eyes in each animal were enucleated 6 hours after the final procedure, before euthanasia and formalin perfusion of the NHP; we then performed orbital dissection of the arterial vasculature and optic nerves.

MAIN OUTCOME MEASURES

Histopathologic examination of the eyes, optic nerves, and orbital vessels of the 6 treated NHPs.

RESULTS

We found leukostasis with retinal arteriole occlusion in all treated eyes. Retinal endothelial cells stained positive for 2 inflammatory markers, intercellular adhesion molecule 1 and interleukin 8. Transmission electron microscopy revealed occlusion of the retinal vessels with ultrastructural changes in the endothelial cells and surrounding pericytes. Additional findings included nerve fiber layer infarcts, central retinal artery thrombosis, hypertrophy and occlusion of choroidal arteries with disruption of the internal elastic lamina, patchy choroidal inflammation, and birefringent intravascular foreign bodies. Orbital findings included ophthalmic artery and central retinal artery wall dissection, fracturing of the internal elastic lamina, intimal hyperplasia, and eyelid vessel damage. Optic nerves displayed hemorrhage, leukostasis, and foreign body crystallization. Control eyes, optic nerves, and orbital vessels were normal.

CONCLUSIONS AND RELEVANCE

Histopathologic examination of our nonhuman primate model for SSIOAC revealed significant toxic effects in the ocular and orbital vasculature. These findings substantiate previous observations with real-time retinal imaging and parallel reported vascular toxic effects in children with retinoblastoma treated with SSIOAC.

Pathological findings in enucleated eyes after intravitreal melphalan injection

The aim of this study is to evaluate the pathological findings of the eye after intravitreal melphalan for viable vitreous seeding from retinoblastoma. All enucleated eyes receiving an intravitreal injection of melphalan (10-50 μg in 0.05 cc) were evaluated for histological changes. Of 25 treated cases, 8 eyes needed enucleation because of phthisis, parent request, or new tumor development. One of the cases was excluded from the study because of a history of intra-arterial chemotherapy with melphalan. There was no case of needle-site scleral involvement by retinoblastoma cells. In two eyes receiving 50 μg melphalan, no viable retinoblastoma cell was detectable in the eye. Severe gliosis, vascular occlusion, retinal necrosis, hemorrhage and neovascularization were seen. Histologically, intravitreal melphalan for recalcitrant or recurrent vitreous seeds from retinoblastoma appears to provide acceptable vitreous seed control. It seems that higher doses could be destructive causing ischemic necrosis in the retina, severe gliosis and secondary neovascular changes as well as having a destructive effect on retinoblastoma cells.

Novel quinic acid derivative KZ-41 prevents retinal endothelial cell apoptosis without inhibiting retinoblastoma cell death through p38 signaling

PURPOSE

To determine whether a novel NF-κB inhibitor, KZ-41, can inhibit melphalan's actions on retinal endothelial cell (REC) inflammation and apoptosis, without eliminating the chemotherapeutic efficacy of melphalan on cell death of retinoblastoma cells (Y79).

METHODS

RECs were cultured in M131 medium supplemented with growth factors and antibiotics. Once cells reached confluence, they were treated with or without 10 μM KZ-41, following treatment with 4 μg/mL melphalan. Cell proteins were extracted and analyzed for intracellular adhesion molecule 1 (ICAM-1) levels and Cell Death ELISA. RECs were also transfected with or without NF-κB siRNA or treated with SB202190 (p38 [mitogen activated protein kinase] MAPK inhibitor) before melphalan treatment to determine the involvement of NF-κB and p38 MAPK in REC apoptosis and ICAM-1 levels. We also cultured retinoblastoma cells (Y79) in RMPI-1640 medium supplemented with 20% fetal bovine serum and performed a Cell Death ELISA after melphalan + KZ-41 treatment to determine if the treatments altered melphalan's ability to promote cell death of Y79 cells.

RESULTS

KZ-41 inhibited melphalan-stimulation of ICAM-1 levels and REC apoptosis, whereas KZ-41 did not alter melphalan's effects on Y79 cells. KZ-41's protective effects on REC were mediated through p38 MAPK activation. Although KZ-41 blocked both NF-κB- and p38 MAPK-dependent ICAM-1 stimulation; the p38 MAPK/ICAM-1 pathway appears to be the primary pathway involved in melphalan-induced REC apoptosis.

CONCLUSIONS

KZ-41 protects REC against melphalan-induced upregulation of ICAM-1 and apoptosis through p38 MAPK-dependent pathways.

Validating a nonhuman primate model of super-selective intraophthalmic artery chemotherapy: comparing ophthalmic artery diameters

PURPOSE

Superselective intraophthalmic artery chemotherapy (SSIOAC) is being used for treatment of retinoblastoma; however, the hemodynamic consequences and toxicities are not fully known. We developed a nonhuman primate (NHP) model of SSIOAC and reported our clinical observations. For validation, we compared ophthalmic artery (OA) diameters between NHPs and children (<6 years).

METHODS

Endovascular cannulation of the right OA was performed three times each in six adult male Rhesus macaques. Angiographic OA images were obtained and measured, and postmortem OAs were histologically sectioned and measured. Retrospectively, computed tomography (CT) and magnetic resonance (MR) angiography images of the head in children and adolescents (as an adult reference) were used to measure the OA luminal diameter at its origin.

RESULTS

The median angiographic diameter of treated NHP OA origins (n = 6) was 1.06 mm (range 0.94-1.56). Histologic measurements (8 of 12 NHP OAs) gave a median diameter of 1.09 mm (range 0.95-1.41). In 98 children (from 169 consecutive CT and MR angiography studies; median age 1.01 years, range 0.01-5.74), 186 OAs were measurable at the origin (median luminal diameter 1.28 mm, range 0.82-2.00; P = 0.16 for the angiographic NHP diameters versus pediatric cohort). Angiographic measurements of 34 OAs (of 20 consecutive studies of adolescents; median age 16.55 years, range 14.40-18.18) gave a median luminal diameter of 1.45 mm (origin, range 1.13-1.66; P < 0.0001, adolescent versus pediatric).

CONCLUSIONS

Measurements of the OA luminal diameter at its origin were similar between our NHP and pediatric cohort, validating our NHP model for testing both the hemodynamic consequences and toxicities of SSIOAC.