Intravenous Sodium Fluorescein Research Articles

Sodium fluorescein uptake by the tumor microenvironment in human gliomas and brain metastases.

Intravenous sodium fluorescein (SF) is increasingly used during surgery of gliomas and brain metastases to improve tumor resection. Currently, SF is believed to permeate the brain regions where the blood-brain barrier (BBB) is damaged and to accumulate in the extracellular space but not in tumor or healthy cells, making it possible to demarcate tumor margins to guide resection. By evaluating the immune contexture of a number of freshly resected gliomas and brain metastases from patients undergoing SF-guided surgery, the authors recurrently observed fluorescence-positive cells. Therefore, the aim of this study was to determine if SF accumulates inside the cells of the tumor microenvironment (TME), and if so, in which type of cells, and whether incorporation can also be observed in the leukocytes of peripheral blood. Freshly resected tumor specimens were dissociated to single cells and analyzed by multiparametric flow cytometry. Peripheral blood leukocytes, macrophages, and a glioma cell line were treated with SF in vitro, and their cell uptake was assessed by multiparametric and imaging flow cytometry and by confocal microscopy. The ex vivo and in vitro analyses revealed that SF accumulates intracellularly in leukocytes as well as in tumor cells, but with a high variability of incorporation in the different cell subsets analyzed. Myeloid cells showed the highest level of fluorescence. In vitro uptake experiments showed that SF accumulation increases over time. The imaging analyses confirmed the internalization of the compound inside the cells. SF is not just a marker of BBB damage, but its intracellular detection suggests that it selectively accumulates intracellularly. Future efforts should target the mechanisms of its differential uptake by the different TME cell types in depth.

Fluorescein Mapping in Vulvar Paget Disease.

Vulvar Paget disease often requires extensive and, in some cases, multiple resections to treat. A fluorescein-mapping procedure followed by a staged vulvectomy may be an effective technique to tailor resection and identify clinically occult lesions. We describe a two-step procedure; first, intravenous fluorescein sodium is injected, and the vulva is illuminated with a Wood's lamp. Representative biopsies are obtained and correlated on final pathology with the extent of disease to develop a final plan for excision. Second, using fluorescein to identify the confirmed areas of disease, the appropriate excisional procedure is performed once mapping biopsy pathology is known. We describe our experience with eight patients with vulvar Paget disease undergoing fluorescein mapping biopsies and staged vulvectomy. Using intravenous fluorescein sodium, all patients were found to have Paget disease beyond the visible margins of their gross lesions. No patients experienced a recurrence of Paget disease within a median follow-up time of 32 months, comparable with other directed methods of surgical resection. We report a technique for the injection of fluorescein sodium for the visualization of vulvar Paget disease capable of providing accurate surgical margins and identification of occult satellite lesions with a high degree of safety and a favorable cost profile. This staged approach to vulvectomy could offer improved accuracy of resection for vulvar Paget disease with few drawbacks.

Intraoperative application of yellow fluorescence in resection of intramedullary spinal canal ependymoma.

BackgroundSpinal ependymoma is the most common intramedullary tumor in adults. This study was performed to evaluate whether intraoperative yellow fluorescence use enhances our ability to identify the tumor margin and residual tumor tissue in intramedullary spinal cord ependymoma resection. We also evaluated patients’ clinical conditions at a 3-month follow-up.MethodsWe retrospectively evaluated 56 patients with intramedullary ependymoma. Thirty minutes before anesthesia, the patients received intravenous sodium fluorescein injections. Tumor resection was performed under two illumination modes, traditional white light and yellow fluorescence, and the residual tumor tissue was detected. Magnetic resonance imaging was performed 3 months postoperatively to observe the tumor resection outcome and residual tumor tissue. The McCormick spinal cord function grade was evaluated preoperatively and 3 months postoperatively.ResultsThe total resection rate was 100.0% in all patients. Nine patients had no significant fluorescence imaging. After 3 months, patients with a spinal function grade of I to IV showed significant spinal function improvement. Magnetic resonance imaging showed no residual tumor tissue or recurrence.ConclusionSodium fluorescein aids in total excision of intramedullary spinal cord ependymoma and intraoperative residual tumor tissue identification. At the 3-month follow-up, the patients’ functional outcome in the fluorescein group was good.

Fluorescein sodium fluorescence: role in stereotactic brain biopsy

Background Stereotactic brain biopsy for eloquent area brain tumours is associated with complications like hemorrhage due to multiple sampling and increased operative time due to dependence on neuropathologist for frozen section assessment. In order to curb these limitations, we investigated the use of Fluorescein sodium fluorescence in confirming pathological tissue samples in stereotactic brain biopsy of gadolinium-enhancing tumours. Methods This prospective observational study included 23 consecutive patients who underwent stereotactic biopsy of gadolinium-contrast-enhancing brain lesions with intravenous fluorescein sodium administration. 93 specimens were obtained and examined for the presence of fluorescence using a microscope with fluorescence visualisation capability. Later the nature of the samples was confirmed on histopathology. The sensitivity and specificity of flourescein sodium fluorescence were calculated based on histopathological confirmation. Results 58 (62.3%) fluorescent and 35 (37.6%) nonfluorescent samples were obtained. All fluorescent specimens contained diagnostic tissue appropriate for tumor grading. Of 35 nonfluorescent specimens, 12 (34.3%) did not contain tumor, 11 (31.4%) contained minor hypercellularity or gliosis, and 12 (34.3%) contained tumor with a high proportion of necrosis. The sensitivity and specificity for fluorescein fluorescence were 83% and 100%, respectively. Conclusions Fluorescein fluorescence is a handy tool to detect the pathological tissue in stereotactic brain biopsy and may improve its diagnostic accuracy and expedite the procedure.

Cost-effectiveness of agents used for evaluation of ureteral patency during intraoperative cystoscopy in gynecologic and urogynecologic surgery

Intraoperative evaluation of ureteral patency is often performed in gynecologic and urogynecologic surgery. Many agents are used to help assess the patency, each with its own associated cost, ease of use, and adverse reactions. Some agents, such as dextrose, are used as an instillation fluid to create a viscosity difference and aid the visualization of a ureteral jet. Others, such as oral phenazopyridine or the intravenous use of sodium fluorescein and indigo carmine, cause a color change of the urine to directly aid the visualization of ureteral jets. Recently, numerous studies have examined the efficacy and surgeon satisfaction of these agents. The studies have also emphasized certain options as associated with a lower cost. However, there have not been any cost studies comparing these agents. To compare the cost-effectiveness of the following 4 agents that are commonly used in assessing ureteral patency intraoperatively: oral phenazopyridine, dextrose instillation, intravenous sodium fluorescein, and intravenous indigo carmine. We constructed a decision-analytic model to compare cystoscopy using oral phenazopyridine, dextrose instillation, intravenous sodium fluorescein, and intravenous indigo carmine. Failure to see efflux resulted in work-ups for ureteral obstruction. The probabilities were obtained from published studies, and the probability of successfully seeing efflux ranged from 0.92 with oral phenazopyridine to 0.99 with intravenous indigo carmine. The costs of the agents, adverse effects, and ureteral obstruction work-ups were obtained from the University of North Carolina at Chapel Hill Department of Pharmacy, the Healthcare Cost and Utilization Project 2016 database and the FAIR Health Consumer database. The cost of a ureteral obstruction work-up used in our model ranged from $9755 for intraoperative evaluation with retrograde pyelograms and stents to $29,034 for hospitalization. Our primary outcome was the incremental cost-effectiveness ratio per unnecessary work-up for ureteral obstruction avoided. Sensitivity analyses were performed to identify the key uncertainties. Oral phenazopyridine, followed by an intravenous agent if needed, had a mean cost of $110 per patient. Dextrose averaged $151 more per patient, with only a slight improvement in avoiding unnecessary ureteral obstruction work-ups and a higher cost associated with adverse reactions (incremental cost-effectiveness ratio, $62,000). Intravenous agents cost approximately $1000 more per patient and were less effective at preventing unnecessary work-ups. Sensitivity analyses did not identify any thresholds that would significantly change the outcomes. Our model suggests that oral phenazopyridine and dextrose instillation are the least expensive and the most effective agents to aid in the visualization of ureteral patency during intraoperative cystoscopy, although dextrose is associated with higher costs owing to a higher rate of adverse reactions (primarily urinary tract infections). Intravenous sodium fluorescein and indigo carmine are historically popular first-choice agents. However, they were found to be more expensive and less effective as primary agents in our model and should likely be reserved for use as secondary agents in the event that the visualization of ureteral jets is unclear with the initial use of phenazopyridine or dextrose.

Time of ureteral ejection of sodium fluorescein in the cystoscopic assessment of ureteral patency in patients undergoing total laparoscopic hysterectomy

Objective:To evaluate the time of ureteral ejection of intravenous sodium fluorescein in the assessment of ureteral patency in patients undergoing total laparoscopic hysterectomy (TLH).Material and Methods:Fifty-four women undergoing TLH were studied in a public teaching hospital in Culiacan, Sinaloa, Mexico. They underwent cystoscopic evaluation of ureteral patency after intravenous administration of 100 mg of sodium fluorescein. The present study analyzed the time elapsed in minutes from the intravenous administration of fluorescein to the outflow of stained urine by one or both ureteral meatus, the degree of urine staining, and the impact of body mass index (BMI) (BMI; normal, overweight, and obesity) on ejection time.Results:The overall average time elapsed to visualize the ejection of fluorescein through at least one ureteral meatus was 7.5 minutes [95% confidence interval (CI): 6.3-8.7]. There were no significant differences in the time of ureteral ejection of fluorescein taking BMI into account (p=0.579), with a mean time for normal BMI of 8.1 minutes (95% CI: 5.1-11.2), for overweight of 7.0 minutes (95% CI: 5.5-8.5), and for obesity of 7.8 minutes (95% CI: 5.3-10.3).Conclusion:Intravenously administered 10% sodium fluorescein dye is rapidly eliminated and strongly stains urine, which makes it useful for identifying ureteral patency during cystoscopy after TLH. Fluorescein excretion is not affected by patient BMI.

Preclinical Evaluation of Bispecific Adaptor Molecule Controlled Folate Receptor CAR-T Cell Therapy With Special Focus on Pediatric Malignancies.

Chimeric antigen receptor (CAR)-T cell therapy has transformed pediatric oncology by producing high remission rates and potent effects in CD19+ B-cell malignancies. This scenario is ideal as CD19 expression is homogeneous and human blood provides a favorable environment for CAR-T cells to thrive and destroy cancer cells (along with normal B cells). Yet, CAR-T cell therapies for solid tumors remain challenged by fewer tumor targets and poor CAR-T cell performances in a hostile tumor microenvironment. For acute myeloid leukemia and childhood solid tumors such as osteosarcoma, the primary treatment is systemic chemotherapy that often falls short of expectation especially for relapsed and refractory conditions. We aim to develop a CAR-T adaptor molecule (CAM)-based therapy that uses a bispecific small-molecule ligand EC17, fluorescein isothiocyanate (FITC) conjugated with folic acid, to redirect FITC-specific CAR-T cells against folate receptor (FR)-positive tumors. As previously confirmed in rodents as well as in human clinical studies, EC17 penetrates solid tumors within minutes and is retained due to high affinity for the FR, whereas unbound EC17 rapidly clears from the blood and from receptor-negative tissues. When combined with a rationally designed CAR construct, EC17 CAM was shown to trigger CAR-modified T cell activation and cytolytic activity with a low FR threshold against tumor targets. However, maximal cytolytic potential correlated with (i) functional FR levels (in a semi-log fashion), (ii) the amount of effector cells present, and (iii) tumors' natural sensitivity to T cell mediated killing. In tumor-bearing mice, administration of EC17 CAM was the key to drive CAR-T cell activation, proliferation, and persistence against FR+ pediatric hematologic and solid tumors. In our modeling systems, cytokine release syndrome (CRS) was induced under specific conditions, but the risk of severe CRS could be easily mitigated or prevented by applying intermittent dosing and/or dose-titration strategies for the EC17 CAM. Our approach offers the flexibility of antigen control, prevents T cell exhaustion, and provides additional safety mechanisms including rapid reversal of severe CRS with intravenous sodium fluorescein. In this paper, we summarize the translational aspects of our technology in support of clinical development.

Abstract LB-109: Adaptor controlled CAR-T cell immunotherapy for treatment of folate receptor-alpha/beta positive solid and liquid tumors

Abstract Personalized immunotherapy has reached a pivotal milestone with the recent approval of CD19-directed chimeric antigen receptor (CAR) T-cell therapies for certain B-cell malignancies. Other than on-target off-tumor autoimmunity, the commonly seen toxicity is severe cytokine release syndrome (sCRS) which is somewhat managed with tocilizumab and corticosteroids. Although the landscape of CAR-T cell development includes >200 clinical trials in various tumor types, success against solid tumors remains a significant challenge. Much of the unmet medical need has been attributed to limited “ideal” tumor-specific targets, tumor heterogeneity, CAR-T cell infiltration/survival, and the presence of an immunosuppressive tumor microenvironment. Due to frequent overexpression in many human cancers, the folate receptor (FR) has become an exploratory target for anti-FRα/β CAR-T cell therapies. We are developing a CAR-T adaptor molecule (CAM)-based therapy that uses the small-molecule bispecific ligand, EC17 (folate-FITC). In this setting, EC17 effectively “paints” FR+ tumors with the FITC antigen to attract anti-FITC CAR-T cells and induce an immune response. As previously confirmed in mice as well as in human clinical studies, EC17 penetrates solid tumors within minutes and is retained due to high affinity for the FR; whereas unbound EC17 rapidly clears from the blood and from receptor-negative tissues. When tested against human xenografts, EC17/CAR-T therapy showed consistent antitumor activity with low or no adverse reactions. However, sCRS was observed under defined experimental conditions. Further testing revealed that sCRS of grade ≥3 (out of a 0-5 scale) can be mitigated or even prevented using intermittent “on-and-off” dosing and/or dose titration of the EC17 CAM. But, under extreme conditions where dose cessation failed, we discovered that intravenous sodium fluorescein (NaFl) could be used as a fast-acting rescue agent to temporarily displace CAR-T cells from their targets and reverse the sCRS symptoms. For translation into first-in-human testing, we selected a high-affinity anti-FITC CAR construct comprising (i) a humanized FITC scFv (E2; 0.75 nM Kd), (ii) an IgG4 hinge-CH2-CH3 spacer fused to a CD28-transmemeber domain, (iii) a second-generation 4-1BB:zeta-endodomain, and (iv) a cell-surface human EGFRt tag. Co-culture experiments were performed using this construct to establish EC17-dependent dose response and confirm target specificity as well as FR expression threshold using a panel of FR-positive cancer cell lines. Clinically relevant EC17 dosing regimens were evaluated using tumor-free and tumor-bearing mice to study CAR-T cell proliferation, cytokine production and the onset/mitigation of sCRS. We confirmed that EC17 administration in the presence of FR+ tumors was the key to drive in vivo CAR-T cell proliferation towards a more persistent phenotype. In addition, higher levels of CAR-T cells were detected in metastatic tumors versus adjacent normal tissues. Finally, EC17/CAR-T cell therapy demonstrated remarkable efficacy against some of the more aggressive and chemo-resistant FR+ tumors of various histology. In summary, our CAM-driven CAR-T cell approach provides antitumor activity with multiple safety control mechanisms. Citation Format: Yingjuan June Lu, Haiyan Chu, Leroy W. Wheeler, Mellissa Nelson, Elaine M. Westrick, Marilynn R. Vetzel, Patrick J. Klein, Adam J. Johnson, Jason K. Yokoyama, Joshua A. Gustafson, Michael C. Jensen, Yong-Gu Lee, Philip S. Low, Christopher P. Leamon. Adaptor controlled CAR-T cell immunotherapy for treatment of folate receptor-alpha/beta positive solid and liquid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-109.

Sodium Fluorescein for Ureteral Jet Detection: A Prospective Observational Study.

Background and Objectives:Laparoscopic hysterectomy poses the risk of lower urinary tract injury, and intraoperative recognition of urinary tract injury is often difficult. We sought to evaluate sodium fluorescein coloration of ureteral jets during cystoscopy after laparoscopic hysterectomy and to evaluate surgeons' satisfaction with this method of injury detection.Methods:This was an observational study, in which data were collected prospectively. A total of 30 women who underwent laparoscopic hysterectomy from August 2016 to February 2017 at the Centre Hospitalier de l'Université Laval (CHUL) de Québec. Twenty-five milligrams of 10% intravenous sodium fluorescein was administered after vaginal cuff closure. Cystoscopy was then systematically performed, and the time to visualization (time from injection to coloration of ureteral jet), the quality of coloration, and the duration of cystoscopy were recorded. Side effects were systematically recorded and rigorously analyzed.Results:Most frequent indications for hysterectomy were fibroids and endometriosis with uterine weight from 76 to 885 g. Ninety-three percent of patients (n = 28) had bilateral ureteral jet coloration, whereas 1 patient had no coloration bilaterally, and another patient had a complete unilateral obstruction immediately diagnosed and resolved intraoperatively after removal of the vaginal sutures. In 90% of cases (n = 27), surgeons were highly satisfied with the use of sodium fluorescein. The average time between visualization of both left and right ureteral jets was 1 minute. Side effects included hypotension (n = 3) and yellow coloration of urine (n = 15).Conclusion:Our study suggests that sodium fluorescein is an effective dye for documenting ureteral patency and improving visualization of ureteral jets during cystoscopy upon completion of laparoscopic hysterectomy.

Investigation of the usefulness of fluorescein sodium fluorescence in stereotactic brain biopsy.

Intraoperative frozen section assessment, to confirm acquisition of pathological tissues, is used in stereotactic brain biopsy to minimise sampling errors. Limitations include the dependence on dedicated neuro-oncology pathologists and an increase in operative duration. We investigated the use of intraoperative fluorescein sodium, and compared it to frozen section assessment, for confirming pathological tissue samples in the stereotactic biopsy of gadolinium-contrast-enhancing brain lesions. This prospective observational study consisted of 18 consecutive patients (12 men; median age, 63years) who underwent stereotactic biopsy of gadolinium-contrast-enhancing brain lesions with intravenous fluorescein sodium administration. Twenty-three specimens were obtained and examined for the presence of fluorescence using a microscope with fluorescence visualisation capability. Positive and negative predictive values were calculated based on the fluorescence status of the biopsy samples with its corresponding intraoperative frozen section and definitive histopathological diagnosis. Nineteen specimens (83%) were fluorescent and four (17%) were non-fluorescent. All 19 fluorescent specimens were confirmed to be lesional on intraoperative frozen section assessment and were suitable for histopathological diagnosis. Three of the non-fluorescent specimens were confirmed to be lesional on intraoperative frozen section assessment. One non-fluorescent specimen was non-diagnostic on frozen section and histological assessments. The positive predictive value was 100% and the negative predictive value was 25%. Fluorescein sodium fluorescence is as accurate as frozen section assessment in confirming sampling of pathological tissue in the stereotactic biopsy of gadolinium-contrast-enhancing brain lesions. Fluorescein sodium fluorescence-guided stereotactic biopsy is a useful addition to the neurosurgical armamentarium.

Use of confocal laser endomicroscopy with a fluorescently labeled fatty acid to diagnose colorectal neoplasms.

Endoscopic treatment for early colorectal cancer closely correlates with patient prognosis. However, endoscopic differentiation between carcinomas and non-neoplastic lesions remains difficult. Here, we topically stained colorectal neoplasms with a fatty acid analogue (BODIPY-FA) and quantified the fluorescent signals using confocal laser endomicroscopy (CLE) and fluorescence microscopy. We also analyzed protein expression in colorectal cancer tissues. We found that expression of fatty acid synthase was elevated, while the expression of fatty acid transporters was reduced in colorectal cancer. In colorectal cancer mouse models and patients, the BODIPY-FA signals were higher in normal epithelia than in carcinomas or colonic intraepithelial neoplasias. BODIPY-FA staining revealed both the arrangement of intestinal glands and the intracellular structures under CLE screening. In a double-blind trial, CLE images stained with BODIPY-FA exhibited greater consistency (κ = 0.68) and overall validity (74.65%) than those stained using intravenous fluorescein sodium (κ = 0.43, 55.88%) when the results were compared with histological diagnoses. These findings suggest that topical use of BODIPY-FA with CLE is a promising imaging approach for early colorectal neoplasm screening.

Evaluating ureteral patency in the post-indigo carmine era: a randomized controlled trial

Many gynecologic, urologic, and pelvic reconstructive surgeries require accurate intraoperative evaluation of ureteral patency. We performed a randomized controlled trial to compare surgeon satisfaction with 4 methods of evaluating ureteral patency during cystoscopy at the time of benign gynecologic or pelvic reconstructive surgery: oral phenazopyridine, intravenous sodium fluorescein, mannitol bladder distention, and normal saline bladder distention. We conducted an unblinded randomized controlled trial of the method used to evaluate ureteral patency during cystoscopy at time of benign gynecologic or pelvic reconstructive surgery. Subjects were randomized to receive 200 mg oral phenazopyridine, 25 mg intravenous sodium fluorescein, mannitol bladder distention, or normal saline bladder distention during cystoscopy. The primary outcome was surgeon satisfaction with the method, assessed via a 100-mm visual analog scale with 0 indicating strong agreement and 100 indicating strong disagreement with the statement. Secondary outcomes included comparing visual analog scale responses about ease of each method and visualization of ureteral jets, bladder mucosa and urethra, and operative information, including time to surgeon confidence in the ureteral jets. Adverse events were evaluated for at least 6 weeks after the surgical procedure, and through the end of the study. All statistical analyses were based on the intent-to-treat principle, and comparisons were 2-tailed. In all, 130 subjects were randomized to phenazopyridine (n= 33), sodium fluorescein (n= 32), mannitol (n= 32), or normal saline (n= 33). At randomization, patient characteristics were similar across groups. With regard to the primary outcome, mannitol was the method that physicians found most satisfactory on a visual analog scale. The median (range) scores for physicians assessing ureteral patency were 48 (0-83), 20 (0-82), 0 (0-44), and 23 (3-96) mm for phenazopyridine, sodium fluorescein, mannitol, and normal saline, respectively (P < .001). Surgery length, cystoscopy length, and time to surgeon confidence in visualization of ureteral jets were not different across the 4 randomized groups. During the 189-day follow-up, no differences in adverse events were seen among the groups, including urinary tract infections. The use of mannitol during cystoscopy to assess ureteral patency provided surgeons with the most overall satisfaction, ease of use, and superior visualization without affecting surgery or cystoscopy times. There were no differences in adverse events, including incidence of urinary tract infections.

Application of fluorescein sodium in the resection of vermis pilocytic astrocytomas

BackgroundPilocytic astrocytomas (PAs) are slow growing neoplasms and usually located at the cerebellum. There has been certainty regarding the truthful benefit of surgical resection for patients with PA. Gross total resection (GTR) of PAs, especially those being situated in deep regions, remains a surgical challenge. Generally, they are considered as benign and usually develop in young patients. PAs, belonging to WHO I can be cured by radical resection. The patients with PA have excellent prognosis if complete resection can be conducted. The use of fluorescein in vermis PA surgery has not been yet reported. Our data presents fluorescein facilitates surgical resection of vermis PA.MethodsFive milligrams per kilogram of fluorescein sodium was intravenously injected directly before general anesthesia for the three patients with PA. The yellow 560 filter was employed for microsurgical tumor resection. Surgical outcomes were assessed concerning the extent of resection.ResultsMost portion of PA in the three cases was found to be highly fluorescent after intravenous fluorescein sodium injection, which markedly enhanced tumor visibility. Gross total resection in all of the patients was achieved without further neurological deficits. No adverse effects and complications resulting from fluorescein sodium were observed over the postoperative course.ConclusionsIntraoperative guidance by fluorescein sodium as a new, simple, safe, and practical procedure can enhance the fidelity of tumor tissue and increase the possibility of completely resecting PAs.

Fluorescein sodium use during spinal ependymoma resection

Spinal ependymomas (SEs) are common adult intramedullary tumors; however, determining the absolute boundary between the tumor and the tumor residual may be difficult.We assessed outcomes following the use of fluorescein sodium (FS) during surgical removal of SEs.We performed a retrospective analysis of 112 patients with SEs who were treated at Beijing Tsinghua Changgung Hospital between December 2014 and December 2016.Each patient received intravenous FS (3-4 mg/kg) to determine the SE boundaries during surgery.Tumor removal efficiencies and tumor residuals were assessed using magnetic resonance imaging (MRI) at 10 days and 3 months after surgical recovery; McCormick's spinal function classification was also performed at the 3-month follow-up.The complete tumor removal rate was 92%(103/112).Ninetyfour patients underwent tumor removal under fluorescent light, which provided distinctive tumor fluorescence.Tumor removal under white light was performed in 18 patients; fluorescent images were invisible or indistinctive in these 18 patients.At the 3-month follow-up, sensory function (85.8%(91/106)) and movement (84.3% (86/102)) were improved in patients with pre-surgical dysfunction; urination and defecation functions were improved in 66.7%(16/24).The McCormick spinal cord functional classifications, at the 3-month follow-up, showed significant differences in the percentages of patients with disease classified to each grade (Ⅰ-Ⅳ), compared with preoperative classifications (each, P < 0.05).There was no MRI evidence of tumor relapse or residuals at the 3-month follow-up.FS use during the surgical treatment of SE enables complete tumor removal and detection of tumor residuals.

Intravenous fluorescein angiography–associated adverse reactions

ObjectivesTo assess (i) the adverse reactions (ARs) associated with intravenous fluorescein angiography (IVFA); (ii) the relationship between a known history of IVFA-associated AR and ARs on the subsequent IVFA test; and (iii) the dose–response relationship between intravenous sodium fluorescein (NaFl) injection and ARs associated with IVFA. DesignRetrospective chart review. ParticipantsA total of 2247 patients with 3381 consecutive IVFAs between May 2013 and April 2014. MethodsFisher’s exact tests or χ2 tests were used to compare the percentage difference of IVFA-associated ARs for different categorical variables. Logistic regressions were used to assess the relationship between a known history of IVFA-associated AR and any AR(s) on a subsequent IVFA test. ResultsThe overall percentage for IVFA-associated ARs was 3.3%. Adjusted for age and sex, patients who had a previous IVFA-associated AR(s) were 6.2 times more likely (adjusted odds ratio 95% CI 3.4–11.2, p < 0.0001) to have an AR compared to those who did not. Among 17 patients who had 2 repeated IVFA tests and an AR on the first IVFA test, the rate of AR on the second test was lower in patients who received a reduced dosage of NaFl (n = 14) compared to those with the standard dosage (n = 3) (35.7% vs 66.7%); however, this finding was not statistically significant (p = 0.5368). ConclusionsThe rate of IVFA-associated ARs in this study was low. Patients who had a known IVFA-associated AR were more likely to re-experience an AR on a subsequent test compared to those who did not. In addition, a reduced NaFl dose did not significantly reduce the chance of experiencing an AR on a subsequent test, which is likely because of the insufficient power of this comparison.

Novel technique for identification of ureters using sodium fluorescein.

The unique property of sodium fluorescein has made it ideal for use in medical applications such as diagnostic ophthalmology and intravenous angiography. It is mainly excreted via the renal system and although extensively used in these diagnostic applications, it has not been widely used to aid in the visualization of the ureters. It is possible to visualize the urinary tract by shining a source of light and studying the fluorescence using a special filter. The goal of our study was to assess the real-time visualization of ureters using intravenous sodium fluorescein under the stimulus of a 530nm wavelength light. Nine 250 gm Wister rats were given an intravenous dose of 0.01ml of sodium fluorescein. A laparotomy was immediately performed following the administration of dye. Anesthesia was performed with an intraperitoneal dose of ketamine-xylazine. The retroperitoneum was exposed and observed under an alternating white xenon and a 530nm excitation light with an objective to visualize the organs captured within the fluorescence of the compound (sodium fluorescein). Under xenon light, the location of the kidneys and urinary bladder were visualized, but not the ureters. The light was then changed to a 530nm wavelength mode when the location and orientation of the ureters was visualized along with the peristaltic movements. Fluorescence visualization of the ureters was noted 5-10min following kidney visualization. In addition, the vascular structures in close proximity to the ureters were also visualized. None of the rats underwent any retroperitoneal dissection, and in one case, partial mobilization of a kidney was undertaken. All rats were euthanized at the completion of the procedure. Intravenous administration of sodium fluorescein enables fluorescence visualization of the ureters in a rat model, after activation with a 530nm light transmitter.

Role of intraoperative neurophysiological monitoring during fluorescence-guided resection surgery

Acta Neurochirurgica has promoted fluorescence-guided microneurosurgery of central nervous system (CNS) tumours with a number of articles. (a) The peroral 5-ALA (Gliolan/ BLUE 400) painting method, introduced by Stummer et al. [19, 22] and now standard in many departments, has been discussed in intracranial malignant gliomas [5, 12, 18–20, 24], metastases [9, 17], meningiomas [3], validity of stereotactic biopsies [25], and differential diagnosis of brain lesions [10, 13]. (b) The age-old intravenous sodium fluorescein, now permanently brought from retinal angiography to microneurosurgery (YELLOW560) [14], has been introduced in malignant gliomas [1, 16] and in hemangioblastomas [15]. (c) ICG or indocyanine angiography (INFRARED 800), standard in neurovascular microsurgery, has been introduced in various CNS tumours [4, 7, 11, 23]. These examples are just a prelude to the future explosion of targeted visualization of brain tumour tissues and their adjacent brain tissues, based on transcriptomes, signalomes, proteomes, glycomes, and other omes. Many of us are ardent users of 5-ALA in diffuse grade III– IV gliomas. But, ‘Is it safe?’ asked Sir Laurence Olivier in Marathon Man . Others are suspicious for at least three reasons: (a) pink glioma stain is seen in a somewhat blurred microanatomical landscape (less so with sodium fluorescein), (b) pinkish areas in the resection cavity walls may hide behind thin grayish layers, and (c) pinkish areas may be spotty and diffuse, raising the worry whether they represent glioma tissue only or infiltrated white matter [8] that is still functional, and in the worst case, eloquent white matter tracts. So, what is the safety of 5-ALA-guided neuronavigated microneurosurgery of diffuse gliomas when aiming at (a) seemingly complete removal, and (b) preservation of functional connectivity of the adjacent brain tissue [6] (i.e., the optimal removal in terms of possible adjuvant therapies and survival [21])?. Pastor et al. in this issue and Della Puppa et al. in a recent 2013 Acta article [5] report on 36 and 31 gliomas, respectively, in or near eloquent areas, removed using neuronavigation, 5-ALA guidance and intraoperative monitoring (IOM) such as transcranial, cortical and subcortical stimulation mapping, as well as electrocorticography (ECoG), motor evoked potential (MEPs), sensory evoked potential (SEPs) and visual evoked potential (VEPs). Pastor et al. used general anesthesia (propofol + remifentanyl) without muscle relaxant to allow stimulation mapping, while Della Puppa et al. adopted awake surgery in six cases. Why use 5-ALA + IOM in this setting, rather than 5-ALA + 3D navigated ultrasound (US) or intraoperative 3 T magnetic resonance imaging (MRI) (if you can afford one)? Because IOM reflects the connectomic functions to be preserved, while US and MRI reflect the connectomic architecture. A gross total resection (> 98 %) was achieved in 67 % and 74 %, respectively. IOM warning signs during removals, as well as neurological worsening or improvement until 3 months, were recorded. These series in their complexities are important reading for neurooncological surgeons. Which IOMwarning signs and how grave (> 50% decrease? total disappearance?)—under general anesthesia without muscle relaxant—would make me interrupt the removal of that particular pinkish area? I try to rely on cortical and subcortical stimulation with electromyography (EMG) responses rather than SEPs, but the ideal setting would be IOM + awake craniotomy [2], the latter not always being applicable.

Intravenous Sodium Fluorescein 10% for Laser Ablation of Subtle Retinal Neovascularization in FEVR

Intravenous Sodium Fluorescein 10% for Laser Ablation of Subtle Retinal Neovascularization in FEVR

Confocal Laser Endomicroscopy

Confocal laser endomicroscopy (CLE) is a newly developed endoscopic technique that enables imaging of the mucosal layer during endoscopy at a subcellular level of resolution. The method can therefore be used for the assessment of changes in vascular architecture, connective tissue, and cellular components in the mucosa, enabling endoscopists to collect real-time in vivo histological images or “virtual biopsies” of the gastrointestinal (GI) mucosa during endoscopy. Confocal microscopy consists of focusing a laser beam (such as an argon-ion laser that generates an excitation wavelength of 488 nm, blue laser light) onto the plane of interest and filtering the returned light by means of a small pinhole which rejects out-of-focus light. The illumination and detection systems are in the same focal plane and are termed “confocal”. After passing the pinhole, the fluorescent light is detected by a photodetection device (a photomultiplier tube or avalanche photodiode), transforming the light signal into an electrical one that is recorded by a computer. All detected signals from the illuminated spot are captured and measured. As the laser scans over the plane of interest, a whole image is obtained pixel-by-pixel and line-by-line, whereas the brightness of a resulting image pixel corresponds to the relative intensity of detected fluorescent light. The gray-scale image created is an optical section representing one focal plane within the examined specimen. Because confocal images depend on fluorescence, a fluorescent dye (contrast agent) is required to make objects visible. The contrast agents can be applied systemically (fluorescein, tetracycline) or topically (acriflavine, cresyl violet) by using a spraying catheter. Of these, intravenous fluorescein sodium (10%) and topically applied acriflavine (0.2%) have been most commonly used in humans. CLE can be performed currently with 2 devices: (1) integrated into an endoscope (Pentax, Tokio, Japan, herein termed eCLE) and (2) as a stand-alone probe (herein termed pCLE) capable of passage through the accessory channel of most endoscopes (Cellvizio, Mauna Kea Technologies, Paris, France). In this special issue on CLE, we have invited a few papers that address the current potential indications for pCLE imaging in clinical gastroenterology and its potential impact in the future, particularly in the screening or surveillance of GI neoplasia. A paper in this special issue by H. Bertani et al. reviews the role of pCLE in Barrett's esophagus for detection of esophageal dysplasia and carcinoma from a clinical practice perspective. Another paper by Mascolo et al. evaluates the accuracy of pCLE in the detection of aberrant crypt foci (ACF), comparing in double-blind manner the microendoscopic and histopathological features resulting from colonic biopsy. By pCLE, the authors identified specific crypt architecture modifications associated with changes in cellular infiltration and vessels architecture, highlighting a good correspondence between pCLE features and histology. A paper by V. Ussui and B. Wallace reviews the role of CLE as applied to colorectal polyps detected during colonoscopy. It describes the importance of probe-based confocal endomicroscopy on colorectal polyps with a particular emphasis on distinguishing hyperplastic from neoplastic polyps. One paper of this special issue, by F. Salvatori et al., reviews the current data on the clinical application of CLE in the study of colonic mucosa in patients with ulcerative colitis. Finally, a paper, by R. Cannizzaro et al. describes the use of CLE to analyze the angiogenic process in colo4rectal and gastric cancer patients and the possibility of a translational approach combining the confocal imaging with the diagnosis in vivo and the specific molecular profile of the patient with the targeted antiangiogenic treatment. Giovanni D. De Palma Michael B. Wallace Marc Giovannini

Confocal Laser Endomicroscopy: Technical Advances and Clinical Applications

Since its introduction in 2004, confocal laser endomicroscopy (CLE) has emerged as a valuable tool for gastrointestinal endoscopic imaging. Endomicroscopy enables the endoscopist to obtain real time in vivo histology during ongoing endoscopy thereby creating “optical biopsies.” To date, numerous studies have shown potential applications of endomicroscopy in the clinical setting, including in vivo diagnosis of esophageal squamous cell carcinoma, Barrett’s esophagus, celiac disease, and colonic polyps. Moreover, recent data suggest the potential application of endomicroscopy in the field of molecular imaging. Additionally, in recent months new applications and developments in the field of confocal imaging were introduced including endomicroscopy of the liver, pancreatic, and bile ducts. Furthermore, by introducing a new needle-based confocal imaging system, which is small enough to be introduced through a 22gauge puncture needle, a wide field for new applications of endomicroscopic imaging has been opened. Currently, 2 CE- and US Food and Drug Administration (FDA)approved devices for endomicroscopy are available (Figures 1 and 2; Supplementary Table 1). In this review, we introduce both systems and discuss new technical advances and clinical applications of CLE.