Injection Of Indocyanine Green Dye Research Articles

No dye, no glory: FFA and ICGA in uveitis

Uveitis is a potentially sight‐threatening condition characterized by inflammation of the uvea. Accurate diagnosis of uveitis is crucial for appropriate management and preservation of vision. The diagnosis of uveitis can be challenging due to the overlapping clinical features with other ocular diseases. In this context, imaging techniques such as fluorescein angiography (FA) and indocyanine green angiography (ICGA) have become indispensable tools in the differential diagnosis of uveitis.FA is a widely used imaging modality in the diagnosis and management of uveitis. It involves the intravenous injection of fluorescein dye, which highlights the blood vessels of the retina and choroid. FA can reveal the presence of leakage, staining, and non‐perfusion areas in the retinal and choroidal vasculature, which are indicative of the inflammatory process in uveitis. Moreover, FA can detect complications such as occlusive vasculitis or choroidal neovascularization. FA can also be used to monitor the response to treatment and detect complications of uveitis such as cystoid macular oedema.ICGA is another imaging modality that complements FA in the diagnosis of uveitis. ICGA involves the intravenous injection of indocyanine green dye, which better highlights the choroidal vasculature. ICGA can identify areas of choroidal hypoperfusion, which are often seen in posterior uveitis such as Vogt‐Koyanagi‐Harada disease or Birdshot retinochoroiditis. ICGA can also delineate areas of choroidal neovascularization. Furthermore, ICGA can help differentiate between active and inactive uveitis, which is crucial in determining the appropriate course of treatment.In addition to their diagnostic value, FA and ICGA can provide valuable information on the pathogenesis of uveitis. FA and ICGA can reveal the presence of subclinical inflammation in asymptomatic patients, which can guide the early initiation of treatment and prevent irreversible damage to the retina and choroid. Additionally, FA and ICGA can identify the location and extent of inflammation in uveitis, which can help in the selection of appropriate treatment modalities such as corticosteroids, immunomodulators and biologic agents.In conclusion, FA and ICGA are invaluable tools in the differential diagnosis and management of uveitis. These imaging modalities can provide vital information on the presence, location and extent of inflammation in uveitis, which can guide the selection of appropriate treatment modalities and prevent irreversible visual loss.

Study of the Efficacy of Indocyanine Green Enhanced Transpupillary Thermotherapy as a Treatment Modality for Retinoblastoma

Background Retinoblastoma represents approximately 4% of all pediatric malignancies and is the most common ocular malignancy in children. It has one of the highest survival rates among all pediatric malignancies owing to improving treatment methods over the years. Objectives The purpose of our work was to evaluate the efficacy of intravenous indocyanine green dye injection combined with diode laser transpupillary thermotherapy (TTT) as a treatment modality for Group (B) intraocular retinoblastoma compared to the standard protocol of treatment. Patients and Methods A prospective interventional comparative study was conducted in the Ocular Oncology Clinic, Ophthalmic Department, Ain Shams University Hospital in the period from August 2017 to December 2020. The study was conducted on twenty tumors, classified as Group (B) retinoblastoma according to International Classification of Intraocular Retinoblastoma (ICRB). It includes; Tumors >3 mm (in basal dimension or thickness), tumors located in the macula (≤3 mm to foveola), juxta-papillary tumors (≤1.5 mm to disc) or tumors surrounded by subretinal fluid (≤5 mm from the tumor margin). They were divided into two main groups: Group I: It included ten (10) tumors; newly diagnosed or recurrent. This group was treated with systemic chemotherapy plus ICG enhanced diode laser TTT, Group II (control group): It included ten (10) tumors; newly diagnosed or recurrent. This group was treated with systemic chemotherapy plus conventional diode laser TTT. Results The study found that ICG has significantly improved uptake of diode laser, eliminating the need for increasing the laser power to the photocoagulation levels which would disrupt the inner retinal layers. ICG-TTT allowed rapid tumor regression and decreased the number of laser sessions needed to achieve tumor regression.ICG-TTT was successful with 3 challenging recurrent masses on a hypopigmented scar and achieved complete regression. There was no statistically significant difference between the two groups as regards the disease-free survival curves using Kaplan Meier analysis. During the period of post chemotherapy follow up, 3 tumors in Group I (30%) and 2 tumors in group II (20%) developed recurrence. And one case in group I (10%) developed a new mass in a remote site. Conclusion The study concluded that ICG-TTT is both efficient and safe despite some potential complications.

Follow the River to the Lake: Sentinel Lymph Node Identification Using the Robotic Platform in Endometrial Cancer Patients.

Sentinel lymph node biopsy for the management of endometrial cancer patients has been introduced into surgical staging of these patients. Several articles and guidelines have evaluated and found sentinel lymph node biopsy as an efficient and oncological safe procedure. The aim of this article is to highlight the most important tips and tricks in order to optimize sentinel lymph node identification and dissection based on our experience. Each step of sentinel lymph node identification technique is analyzed. Tips and tricks, such as site and time of indocyanine green dye injection are essential in optimal identification of sentinel lymph node in patients with endometrial cancer. The standardization of the technique and the recognition of anatomic landmarks are essential as they lead to an improved and effective identification of sentinel lymph node.

Protocol for Indocyanine Green Angiography.

Indocyanine green (ICG) angiography was first approved by the Food and Drug Administration for human use in the 1956. Prior to its use in chorioretinal angiograms, ICG was used to measure blood flow and track cardiac output. It was only in 1969 when two researchers, Kyuga Kogure and Earl Choromokos from the University of Miami, first used ICG to create more accurate angiograms. In the following years, researchers were able to hone the underlying science of this new form of angiography. As time passed and technology advanced, the application of ICG in clinical practice became widespread. Today ICG is used to diagnose and monitor the progression of retinal and choroidal diseases affecting millions of individuals across the globe. ICG utilizes the injection of indocyanine green dye into a patient's bloodstream to visualize abnormalities of the choroid and retina by evaluating choroidal circulation. ICG angiography is useful in the diagnosis and management of occult choroidal neovascularization in age-related macular degeneration and may be used in other inflammatory conditions with central serous chorioretinopathy. ICG angiography offers advanced imaging for improved monitoring and treatment of a wide variety of choroidal and retinal diseases.

Intraoperative Optical and Fluorescence Imaging of Blood Flow Distributions in Mastectomy Skin Flaps for Identifying Ischemic Tissues.

Insufficient blood flow causes mastectomy skin flap necrosis in 5 to 30 percent of cases. Fluorescence angiography with the injection of indocyanine green dye has shown high sensitivities (90 to 100 percent) but moderate specificities (72 to 50 percent) in predicting mastectomy skin flap necrosis. However, a number of challenging issues limit its wide acceptance in clinical settings, including allergic reaction, short time-window for observation, and high cost for equipment and supplies. An emerging inexpensive speckle contrast diffuse correlation tomography technology enables noninvasive, noncontact, and continuous three-dimensional imaging of blood flow distributions in deep tissues. This preliminary study tested the hypothesis that speckle contrast diffuse correlation tomography and indocyanine green-fluorescence angiography measurements of blood flow distributions in mastectomy skin flaps are consistent. Eleven female patients undergoing skin-sparing or nipple-sparing mastectomies were imaged sequentially by the dye-free speckle contrast diffuse correlation tomography and dye-based commercial fluorescence angiography (SPY-PHI). Resulting images from these two imaging modalities were co-registered based on the ischemic areas with the lowest blood flow values. Because the ischemic areas have irregular shapes, a novel contour-based algorithm was used to compare three-dimensional images of blood flow distribution and two-dimensional maps of indocyanine green perfusion. Significant correlations were observed between the two measurements in all contours from a selected area of 10 × 10 mm 2 with the lowest blood flow ( r ≥ 0.78; p < 0.004), suggesting that speckle contrast diffuse correlation tomography provides the information for identifying ischemic tissues in mastectomy skin flaps. With further optimization and validation in large populations, speckle contrast diffuse correlation tomography may ultimately be used as a noninvasive and inexpensive imaging tool for intraoperative assessment of skin flap viability to predict mastectomy skin flap necrosis. Diagnostic, II.

Sentinel Lymph Node Sampling in Robot-Assisted Staging of Endometrial Cancer.

Sentinel lymph node (SLN) sampling in endometrial cancer staging has become an acceptable standard. Indocyanine green dye injected into the cervix and detected by near-infrared light is technically simple and sensitive. We aimed to evaluate SLN sampling in robot-assisted surgical staging of endometrial cancer at a university-affiliated teaching hospital. A retrospective chart review, from January 2016 to December 2017, of patients who underwent robot-assisted surgical staging with cervical injection of indocyanine green dye detected by near-infrared light. The map rate, sensitivity, false negatives, and negative predictive value were calculated. A total of 105 charts were reviewed; 79 patients met inclusion criteria. The mean age was 65 (range 38-93) and the mean body mass index was 33.3 (range 16-49). Most patients (72.2%) had stage I disease and grade 1 or 2 histology (77.1%). Eight (10.1%) patients had lymph node metastasis. Seventy-two (91.1%) patients had positive mapping to at least 1 SLN. Sixty-two (78.5%) patients had bilateral mapping. Forty-four patients had concurrent pelvic ± para-aortic lymph node dissection and were included in the sensitivity analysis. Five of 44 cases had LN metastasis. The sensitivity was 80%, and the negative predictive value of SLN sampling was 97.5%. SLN mapping and sampling at a university-affiliated teaching hospital have comparable map rate, sensitivity, and negative predictive value as demonstrated in multiple trials. The technique has the potential to standardize endometrial cancer staging across different practice settings.

Evaluation of Sentinel Lymph Node Sampling in Complex Atypical Hyperplasia

<h3>Study Objective</h3> Primary objective - to evaluate safety and efficacy of sentinel lymph node (SLN) sampling during robot assisted total laparoscopic hysterectomy and bilateral salpingo-oophorectomy (TLH/BSO) of patients with complex atypical hyperplasia (CAH). Secondary objective - to determine the risk of endometrial carcinoma in patients with preoperative diagnosis of CAH. <h3>Design</h3> Retrospective chart review performed from May 2012 to February 2020 of CAH patients who underwent TLH/BSO. Demographic data, operative data, histopathology, SLN ultra-staging data collected. Intra-operative and 30-day postoperative complications evaluated using Clavien-Dindo classification. <h3>Setting</h3> Single institution. <h3>Patients or Participants</h3> Inclusion criteria was preoperative diagnosis of CAH, ages 18-90, robotic assisted TLH/BSO. 74 charts reviewed 57 patients included. <h3>Interventions</h3> Of 57 patients, 25 patients underwent SLN sampling under near infra-red light after cervical injection of indocyanine green dye. 32 patients in control group that did not have lymph node sampling. <h3>Measurements and Main Results</h3> Two-sided t-test, Chi squared test and Fisher's exact test used in data analysis. The incidence of cancer was 32/57 (56.1%). Thirteen (52%) patients in SLN group had cancer vs 19 (59.4%) in the control group. The rate of deep (>50%) myometrial invasion in SLN group was 30.8% vs 5.3% in control group (P=0.05). The map rate of SLN was 100% (76% Bilateral, 24% Unilateral). Zero SLN sampled were positive for metastatic disease. 30-day complication rate in SLN group was 0% vs 6.3% in control group (P=0.5). Sixteen (28%) patients had borderline (bordering on carcinoma) pathology on preoperative sampling. Eight (50%) had SLN sampling. Twelve (75%) had a postoperative diagnosis of cancer. There were no identified preoperative risk factors for cancer. <h3>Conclusion</h3> The incidence of endometrial cancer in patients with preoperative diagnosis of CAH was 56%. Zero patients had metastatic disease to SLN. SLN dissection was not associated with more operative time or complications. Patients with a preoperative borderline pathology seem to have a higher risk of cancer.

ROBOTIC-ASSISTED LIVING DONOR HYSTERECTOMY - TECHNIQUE AND OUTCOME (DALLAS UTERUS TRANSPLANT STUDY)

To share our experience in performing the first series of robotic-assisted living donor hysterectomies with transvaginal extraction of the uterine graft in the world. Our institution has performed 19 living donor hysterectomies for uterus transplantation with the first 13 cases performed with an open laparotomy technique and the last 6 cases performed with a robotic-assisted technique. This video uses footage from a robotic-assisted living donor hysterectomy to review the essential steps and techniques involved. These steps include bilateral vascular dissection of the uterine arteries from the anterior branch of the internal iliac artery, the inferior uterine veins from the uterus to the inlet in the internal iliac veins, and the superior uterine veins without compromising the outflow of the ovaries. For the procedure, a da Vinci Xi robotic platform in a 4-arm configuration, alternating between a 0° and a 30° scope was used. Bilateral ureteral stents were placed allowing for indocyanine green dye injection (retrograde injection via the Foley catheter), which facilitates the identification of the ureters during surgery. A uterine manipulator (Rumi II Koh-Efficient Uterine Manipulator; CooperSurgical, Trumbull, CT) was used for retraction of the uterus. We also review donor complications, and graft and recipient outcomes. Uterus transplantation is a proven treatment for absolute uterine factor infertility. Proof of concept was achieved with both uteri from both living and deceased donors.

From systematic lymphadenectomy to sentinel lymph node mapping: a review on transitions and current practices in endometrial cancer staging.

Endometrial cancer care has undergone major changes in the past 30 years. In 1988, staging transitioned from clinical to surgical. Moreover, the surgical approach of choice is no longer open surgery, but minimally invasive surgery. An improvement in terms of nodal evaluation followed. Full systematic lymphadenectomy has been continuously replaced by sentinel lymph node mapping. Although sentinel lymph node mapping with a cervical injection of indocyanine green dye is rapidly gaining clinical acceptance, we lack consistent recommendations on a well-defined procedure that accurately and indolently assesses the lymph node status. Such recommendations are indispensable, as nodal status is the most important predictive factor of survival and is essential for tailoring adjuvant treatment to the risk of recurrence. This paper focuses on transitions in endometrial cancer care and highlights current data on sentinel lymph node mapping in endometrial cancer. We demonstrate that sentinel lymph node mapping is a safe and accurate strategy for nodal status evaluation with appropriate sensitivity, false-negative rate and negative predictive value in high- as well as low-risk settings. Furthermore, we elaborate on type and dose of tracer, site of injection, number of sentinel lymph nodes to be removed, sentinel lymph node mapping learning curve, operation mode and sentinel lymph node ultrastaging. In the future, guidelines with consistent recommendations on the above outlined features of sentinel lymph node mapping should be established to allow for a uniform and wide-spread application of the sentinel lymph node mapping procedure.

Systemic Sentinel Lymph Node Detection Using Fluorescence Imaging After Indocyanine Green Intravenous Injection in Colorectal Cancer: Protocol for a Feasibility Study.

BackgroundNodal staging is a major concern in colorectal cancer as it is an important prognostic factor. Several techniques that could potentially improve patient treatment and prognosis have been developed to increase the accuracy of nodal staging. Sentinel lymph node detection has been shown to accurately reflect nodal status in various tumors and has become the standard procedure in nodal staging of breast cancer and melanoma. However, in colorectal cancer, sentinel lymph node detection techniques are still controversial as the sensitivity reported in the literature varies from one study to another. Recently, indocyanine green fluorescence–guided surgery has been reported to be a useful technique for detection of macroscopic and microscopic metastatic deposits in lymph nodes after intravenous administration of indocyanine green dye. However, no studies have focused on the potential role of sentinel lymph node detection after systemic administration of indocyanine green dye, so-called systemic sentinel lymph nodes, or on the correspondence between the identification of the sentinel lymph node by standard local injection techniques and the detection of fluorescent lymph nodes with this new approach.ObjectiveThe aim of this protocol is to validate the concept of sentinel lymph nodes identified by fluorescence imaging after intravenous injection of indocyanine green dye and to compare the sentinel lymph nodes identified by fluorescence imaging with sentinel lymph nodes detected by the standard blue dye technique.MethodsThis study (SeLyNoFI; Sentinel Lymph Nodes Fluorescence Imaging) is a diagnostic, single-arm, open-label feasibility study, including patients with colorectal adenocarcinoma with or without metastatic disease who are admitted for elective colorectal resection of the primary tumor. This study evaluates the feasibility of a new approach for improving the accuracy of nodal staging using fluorescence imaging after intravenous administration of indocyanine green dye. Sensitivity, positive predictive value, and accuracy of the classical blue dye technique and of the investigatory fluorescence imaging technique will be calculated. Translational research will be proposed, if applicable.ResultsAs of June 2020, this study has been registered. Submission for ethical review is planned for September 2020.ConclusionsThe potential correlation between the two different approaches to detect sentinel lymph nodes offers new strategies for improving the accuracy of nodal staging in colorectal cancer. This new concept of the systemic sentinel lymph node and a greater understanding of the interactions between systemic sentinel lymph nodes and standard sentinel lymph nodes may provide important information regarding the underlying mechanism of primary tumor lymphatic drainage. The enhanced permeability and retention effect can also play a role in the fluorescence of systemic sentinel lymph nodes, especially if these lymph nodes are inflamed. In this case, we can even imagine that this new technique will highlight more instances of lymph node–positive colorectal cancer.International Registered Report Identifier (IRRID)PRR1-10.2196/17976

Ureteric mapping with Indocyanine green: A new tool to prevent ureteral injury in complex gynecological surgery

Introduction: The aim of this video is to show that ureteric injection of Indocyanine green dye in difficult gynecological operations is a useful tool to identify and safeguard ureters. Case description: A 56-year-old lady with a large 10.5 × 14.5 × 13 cm3 multiloculated endometriotic cyst in the right adnexa was scheduled for robotic-assisted hysterectomy with bilateral salphingooophorectomy. She had undergone a laparotomy and three laparoscopic surgeries for endometriosis and fibroid uterus. Before starting surgery, cystoscopy was performed and with 6 Fr ureteral catheter inserted into ureteral orifice, 5 mL of 0.5% Indocyanine green dye (Aurolab, Madurai, India) was injected into both ureters. Intraoperatively bilateral adnexal cysts were seen densely adherent to omentum, sigmoid colon, sigmoid mesocolon, bladder, and lateral pelvic wall. Bladder and rectosigmoid were pulled up both anteriorly and posteriorly, respectively, and densely adherent to uterus and to adnexal cysts. During surgery, the course of ureter was identified by the green fluorescence emitted by the Indocyanine green dye under near-infrared light on da Vinci Xi camera. During this difficult surgery, the real-time visualization of ureteric course helped to identify and safeguard ureter during adhesiolysis and surgery could be completed without any injury to ureter. Patient did not experience any side effects due to the ureteric Indocyanine green injection. Conclusion: Endometriosis can distort the pelvic anatomy making surgery very challenging. Identifying the course of ureter during surgery can help in avoiding injuries and reduce surgical morbidity.

Application of Ice for Postoperative Total Knee Incisions - Does this Make Sense? A Pilot Evaluation of Blood Flow Using Fluorescence Angiography.

IntroductionTotal knee arthroplasty (TKA) is a common procedure with significant advances over the past several years, many pertaining to improved perioperative pain control. Cryotherapy is one method thought to decrease swelling and pain postoperatively. To our knowledge no study has directly visualized the effect cryotherapy has on skin blood flow following TKA. The primary aim was to determine if cryotherapy (icing) affects peri-incisional skin blood flow and if this is lessened with an alternate placement of the ice. We hypothesized that blood flow would decrease following cryotherapy, and this decrease would be greater with ice placed directly over the incision as compared to placement along the posterior knee.MethodsThis study included 10 patients who underwent TKA. During the postoperative hospitalization, they were given an injection of indocyanine green dye. A baseline image was recorded of the skin blood flow. Images were then collected following a five-minute interval placement of ice over the incision. The experiment was then repeated with the ice placed along the posterior knee. ResultsThere was an approximate 40% decrease in skin blood flow following placement of the ice compared to baseline. We observed a greater decrease in blood flow when ice was placed over the incision as compared to when ice was placed posterior to the knee (p ≤ 0.020).ConclusionWe found a significant decrease in peri-incisional blood flow with icing of the knee. Physicians should be cognizant of this when recommending cryotherapy to patients after surgery, especially in at-risk wounds.

A prospective evaluation of the sentinel node mapping algorithm in endometrial cancer and correlation of its performance against endometrial cancer risk subtypes

ObjectiveSentinel node mapping is emerging as the alternative to lymphadenectomy in endometrial cancer. The objective of our study is to validate of the sentinel node mapping surgical algorithm and also to compare the performance of the algorithm against endometrial cancer risk subtypes DesignThis is a prospective interventional study carried out at a Single University teaching hospital. All patients with apparent early stage endometrial cancer who underwent robotic assisted surgical staging were included. Intracervical injection of Indocyanine Green dye and sentinel node identification and biopsy was done for all study patients. The node positive rate when using SLN mapping alone versus SLN mapping algorithm were compared. The node positivity was compared against various risk subtypes of endometrial cancer. Results69 patients were included in the study. In 95.7% patients SLN was detected with a bilateral detection rate of 87.9%. 10 patients had nodal positivity, among which 7 were identified by SLN mapping alone. The algorithm captured all 10 patients with positive LNs, yielding a node positivity rate of 14.9%, sensitivity and NPV of 100%. For SLN mapping alone the sensitivity was 77.8%, false negative rate (FNR) 22.2%, and NPV 96.6%. In low- and intermediate-risk subtypes SLN mapping as well as algorithm identified all node positive patients, but in high-risk endometrial cancers the SLN mapping technique alone had a sensitivity of 57.1% and false-negative rate of 42.9% when compared with 100% sensitivity for the SLN mapping algorithm. ConclusionsWhen doing SLN mapping and biopsy during endometrial cancer staging surgery it is essential that the steps mentioned in the SLN mapping algorithm are followed as SLN mapping alone seems to have a limitation in detecting positive nodes especially in high risk subtypes of endometrial cancer. Even with the lack of survival data, based on the performance of SLN mapping surgical algorithm (even if ultrastaging facility is not available), it seems to be a better technique in detecting metastatic nodes, giving prognostic information, and enabling accurate adjuvant treatment.

Heterogeneity of blood flow and metabolism during exercise in patients with chronic obstructive pulmonary disease

The study investigated whether the capacity to regulate muscle blood flow (Q) relative to metabolic demand (VO2) is impaired in COPD. Using six NIRS optodes over the upper, middle and lower vastus lateralis in 6 patients, (FEV1:46±12%predicted) we recorded from each: a) Q by indocyanine green dye injection, b) VO2/Q ratios based on fractional tissue O2 saturation and c) VO2 as their product, during constant-load exercise (at 20%, 50% and 80% of peak capacity) in normoxia and hyperoxia (FIO2:1.0). At 50 and 80%, relative dispersion (RD) for Q, but not for VO2, was greater in normoxia (0.67±0.07 and 0.79±0.08, respectively) compared to hyperoxia (0.57±0.12 and 0.72±0.07, respectively). In both conditions, RD for VO2 and Q significantly increased throughout exercise; however, RD of VO2/Q ratio was minimal (normoxia: 0.12–0.08 vs hyperoxia: 0.13–0.09). Muscle Q and VO2 appear closely matched in COPD patients, indicating a minimal impact of heterogeneity on muscle oxygen availability at submaximal levels of exercise.

Usefulness of sentinel lymph node biopsy for the detection of metastasis in the early stage of extramammary Paget's disease.

Invasive cases of extramammary Paget's disease have a poor prognosis, owing to its rapid progression and resistance to irradiation and chemotherapy. Morton et al. introduced a technique to identify sentinel lymph nodes by local injection of vital dyes and reported its benefit for managing the progress of malignant melanoma. Since the rate of lymph node metastasis of extramammary Paget's disease is not uncommon (reported from 8.5% to 26%), this study tested the hypothesis that sentinel lymph node biopsy would be useful to detect lymph node metastasis in the clinically early stage of extramammary Paget's disease. Eighteen patients with primary extramammary Paget's disease were enrolled in the study. The precise location of sentinel lymph nodes was visualized using either intraoperative patent blue dye injection or indocyanine green dye injection in combination with a hand-held gamma-detecting probe after a 99mTc phytate injection. Of the 18 patients, sentinel lymph node metastasis was identified in 2 (Cases 2 and 15) of the 2 patients with deep invasion and in 1 (Case 12) of the 7 patients with minimal dermal invasion, however, it was absent in 9 patients who had been categorized into the intraepidermal group. This study demonstrates that extramammary Paget's disease possibly causes metastasis via regional lymphatic systems to which the lesion belongs, even in the early stages of no nodule or tumor formation, and that sentinel lymph node biopsy is useful to detect lymph node metastasis.

V1269 A NOVEL USE OF ICG-NIRF FOR IDENTIFICATION OF SENTINEL LYMPH NODES AND ENHANCED NERVE SPARING DURING ROBOTIC RADICAL PROSTATECTOMY

INTRODUCTION AND OBJECTIVES: Indocyanine green (ICG) has been previously been described in the urologic literature using an intravenous technique during robotic partial nephrectomy. There are now pilot series describing interstitial injection during prostatectomy using the dye as an agent to perform real-time fluorescence lymphangiography. Previousy described methods employ conjugated ICG in which the dye is mixed with a radio-isotope and carrier protein. These methods have demonstrated safety and feasibility but are rather cumbersome and costly in that they require several additional hours per patient to prepare, administer, and perform pre-operative scintigraphy. We present out initial clinical series using a simplified approach with injection of free ICG at the time of prostatectomy which we have found also allows for pelvic lympangiography as well as enhanced visualization of pelvic nerves including the neruovacular bundles. METHODS: We utilize percutaneous injection of 0.5 ml of ICG dye with a concentration of 2.5mg/ml into the lateral lobes of the prostate using a spinal needle to perform a realtime fluorescence lymphangiography to identify sentinel drainage from the prostate. We then also evaluate the effects of tissue diffusion of ICG within the prostate to help differentiate the neurovascular bundles. RESULTS: In all ten patients, we were able to visualize the lymphatic drainage of each prostate identifying the potential sentinel lymph nodes. In all ten patients the neurovascular bundles were hypofluorescent relative to the prostate allowing us to easily differentiate them and perform a successful sparing procedure. CONCLUSIONS: In conclusion, we describe a technique of interstitial injection of ICG dye during robotic prostatectomy which is simple, quick, reproducible, may lead to more accurate pathologic staging of prostate cancer, improved oncologic outcomes, and may also allow more precise nerve sparring with subsequent improvements in sexual and urinary function.

Indocyanine green enhanced subthreshold diode-laser micropulse photocoagulation treatment of chronic central serous chorioretinopathy

To assess the efficacy and safety of indocyanine green (ICG) dye-enhanced subthreshold diode-laser micropulse (SDM) photocoagulation in patients with chronic central serous chorioretinopathy (CCSC) with no spontaneous resolution 6 months after the onset of the disease. Interventional prospective non-comparative case series of seven patients presenting with CCSC with well-defined active leaking sites (ALS) suitable for laser treatment and with serous neuroepithelial detachment persisting for 6 or more months. SDM treatment was performed 15 minutes after the injection of 25 mg of ICG in 2 cc of 5% glucose solution. ALS were treated with a series of 50 500-ms exposures separated by 500-ms pauses. Each 500-ms exposure delivered a train of 250 micropulses at 10% duty cycle and 500 mW power. ICG angiographic images were taken after the treatment without new ICG injection, to check for the presence of laser-induced spots of background hypofluorescence at the treated leakage sites. Within 7-14 days after treatment, all the patients showed improved visual acuity and reduction of serous neuroepithelial detachment on OCT. No signs of laser lesions were visible at fundus examination and on fluorescein angiography. In a period ranging from 4 to 8 weeks, the neuroepithelial detachment was completely resolved in five patients and reduced in two patients. At the 12-month follow-up visits, no recurrence had occurred in the patients, with resolution of the serous neuro-epithelial detachment, and no worsening of the serous detachment or of VA was noted in the patients with incomplete recovery. These preliminary results suggest that ICG dye-enhanced SMD photocoagulation appears to be an effective treatment, and can represent a viable approach for the management of CSCC with persistent serous neuroepithelial detachment. Post-treatment ICG angiography, without new ICG dye injection, can be used to verify the placement of the SDM laser applications.

Functional evaluation of retina and optic nerve in the rat model of chronic ocular hypertension

Purpose. To functionally characterize the rat retina and optic nerve after chronic elevation of the intraocular pressure (IOP) using electroretinography (ERG) and computerized pupillometry. Methods. Chronic elevation of the IOP was induced in Brown Norway rats by combined injection of indocyanine green dye (ICG) into the anterior chamber and diode laser treatment, followed by ERG and pupil light reflex (PLR) monitoring. Results. Laser treatment induced significant elevation of the IOP in operated eyes for 6 weeks, with maximal values observed 14 days postoperatively (ctrl=18·4±2·4 and operated=35±8·4 mmHg; mean± sd). Preoperative values for the PLR ratio were 68·5±4% (mean± sem; %). Three days postoperatively the PLR ratio decreased to 60·3±10·3%, but was not significantly different compared to preoperative values ( p>0·05, Kruskal-Wallis non-parametric test with Dunn's post-test). However, 7, 14 and 21 days postoperatively the PLR function dramatically decreased to 14·6+8·6, 11·5±6·7 and 12·6±4%, respectively, and was significantly smaller compared to preoperative values ( p<0·01). At day 28 the PLR significantly recovered and was not significantly different compared to preoperative values (PLR ratio=38·5±8·6, p>0·05). However, 35 days after surgery the PLR started to decrease once again in the operated eyes (PLR ratio=17·2±7·4%) and was significantly smaller again compared to preoperative values ( p<0·05). The PLR values continued to decrease until the end of experiment (60 days postoperatively). ERG analysis of operated eyes revealed significantly decreased amplitudes of a- and b-waves 10d postoperatively, while oscillatory potentials (OPs) and flicker ERG (flERG) amplitudes were not detectable. However, 28 days postoperatively OPs significantly, but temporarily recovered, while a-wave, b-wave and flERG amplitudes did not significantly change compared to values observed 10d postoperatively. The ERG analysis of the operated eyes revealed significantly reduced amplitudes 60 days postoperatively. Histological analysis revealed degeneration of all retina layers and optic nerve axons. Conclusions. Chronic ocular hypertension in rats produces dramatic damage to all retinal layers and optic nerves observed by morphological and functional methods which significantly correlate with the IOP elevation. Outer retina of glaucomatous rats seems to be more susceptible to the damage due to chronic elevation of the IOP. Chronic hypertensive rat eyes have capacity to temporarily recover function of the inner retina and optic nerve.

Evaluation of brain toxicity following near infrared light exposure after indocyanine green dye injection

Indocyanine green (ICG) has excellent safety records and is widely used in medical diagnosis. Recently, a new method has been developed to estimate cerebral blood flow (CBF) using ICG in combination with near-infrared spectroscopy (NIRS). The new technique may be of wide clinical interest, as it is noninvasive and easy to perform at the bedside in stroke patients. Additionally, ICG with the use of specific wavelength lasers is documented to be effective in photodynamic therapy (PDT). Under normal conditions ICG does not cross the intact blood brain barrier (BBB). However, in patients with brain injuries where the BBB may be disturbed, ICG could accumulate in brain parenchyma and in combination with NIR-light exposure, phototoxicity could occur. The aim of the present study was to examine the possible toxicity of ICG in combination with NIRS in a specific setting for CBF measurements. In five rats with mannitol induced BBB breakdown no traces of ICG were found during spectrophotometric analysis of the brain cell suspensions. In ten rats with disrupted BBB there were no significant increases of brain temperature or histological signs of brain damage following 1 h NIR-light exposure after ICG injection. The existing literature concerning the application of ICG in combination with NIR light is reviewed.

Rapid Injection of Indocyanine Green Dye for Evaluation of Choroidal Venous Circulation

Purpose: The purpose of this study was to investigate the effects of rapid intravenous administration of a small bolus of indocyanine green (ICG) dye on early phase findings of ICG angiography. Methods: Rabbit eyes were used. Ten normal eyes, 5 eyes with occlusion of vortex veins, and 5 eyes with chorioretinal atrophy were examined by ICG angiography, and early-phase findings after a rapid injection of a small bolus of dye were compared with those obtained with an ordinary injection. Results: In normal eyes, after the rapid injection it was possible to visualize some small bright fluorescent boluses in the choroidal veins from 6 to 12 seconds after injection, while with the ordinary injection they were unclear. In eyes with occlusion of vortex veins, the rapid injection resulted in visualization of the choroidal veins with delayed filling against the background, and the region of the choroidal veins with delayed filling could easily be determined. In eyes with chorioretinal atrophy, only the rapid injection clearly revealed the choroidal veins with delayed filling. Conclusions: The rapid injection made it possible to detect the choroidal veins with delayed filling that were not clearly and easily visible using an ordinary injection. Rapid injection of ICG dye is useful for a detailed examination of choroidal circulation.