Survey of complications of indocyanine green angiography in Japan

Role of sentinel lymph node biopsy with indocyanine green and site of injection in endometrial cancer

PURPOSE OF REVIEW

The aim of the present narrative review is to summarize the state of art on sentinel lymph node biopsy (SLNB) in endometrial cancer, with a special focus on indocyanine green (ICG) as adopted tracer.

RECENT FINDINGS

Over the years, the surgical nodal staging in patients with endometrial cancer has been intensively investigated. Traditionally, systematic pelvic and para-aortic lymphadenectomy represented the gold standard surgical treatment to assess nodal involvement of the tumor. Through the last two decades, SLNB has gradually replaced lymphadenectomy as a more targeted procedure. A great heterogeneity of tracers and injection techniques have been proposed to perform SLNB. However, no universally accepted recommendations are still available.

SUMMARY

SLNB has nowadays almost replaced pelvic lymphadenectomy in low-risk endometrial cancers, offering a better safety profile while being related to a comparable nodal involvement sensitivity. Currently, ICG is considered to be the most used tracer among others. Different injection sites have been proposed, with different detection features. While ICG cervical injection is nowadays the suggested technique for SLNB, noncervical injection techniques, such as hysteroscopic and combined procedures, seem to have a better accuracy in para-aortic nodal assessment, which have a role in high-risk endometrial cancers.

Detection of wound healing disorders after major amputations by measurements of the microcirculation: A prospective single-center study

Introduction

Although major amputations can often be avoided due to evolving methods of endovascular and surgical revascularizations techniques, in patients with chronic limb-threatening ischemia, it is still necessary in some cases. Aim of this study was the detection of wound healing disorders through intraoperative microcirculation measurements in major limb amputations.

Materials and methods

In this single-center clinical study, patients with an indication for major amputation were enrolled prospectively. Cause of amputation, patients' comorbidities including cardiovascular risk profile were assessed. Macrocirculation, as well as microcirculation were assessed. Microcirculation measurements were performed by fluorescence angiography with the administration of indocyanine green. A preoperative measurement was obtained at the amputation level, followed by three additional measurements of the amputation stump postoperatively. Wound healing was monitored and correlated with the microcirculatory findings, based on the perfusion parameters ingress and ingress rate, calculated in the indocyanine green fluorescence video sequences of the amputation stumps.

Results

Forty-five patients were enrolled, including 19 (42%) below-the-knee amputations and 26 (58%) above-the-knee amputations. When considering the need for revision, a change in the microperfusion parameters was observed postoperatively. The mean value for ingress was significantly lower directly postoperatively in stumps requiring revisions (5 ± 0 A.U. versus 40.5 ± 42.5 A.U., p < 0.001). The mean value of ingress rate behaved similarly (0.15 ± 0.07 A.U./s versus 2.8 ± 5.0 A.U./s, p = 0.005). The evaluation of indocyanine green measurements when wound healing disorders occurred also showed nonsignificant differences in the mean values.

Conclusion

Fluorescence angiography after major lower limb amputations appears to be an option of depicting microperfusion. Especially, the early postoperative detection of reduced perfusion can indicate a subsequent need for revision. Therefore, this method could possibly serve as a tool for intraoperative quality control after major limb amputation.

Let go of the myth: safety of indocyanine green for sentinel lymph node mapping in endometrial cancer

OBJECTIVE

Sentinel lymph node mapping by intracervical indocyanine green injection is the preferred method for surgical staging in endometrial cancer. Adverse reactions to indocyanine green are extremely rare, and information about the safety of this tracer in patients with a history of other allergies, asthma, or comorbidities is limited. We aim to evaluate the rate of adverse reactions to indocyanine green injected during sentinel lymph node mapping in patients with endometrial cancer and review the etiology of such reactions.

METHODS

All patients with endometrial cancer undergoing sentinel lymph node mapping with indocyanine green cervical stroma injection at the Mayo Clinic in Rochester, Minnesota between June 2014 and December 2018 were retrospectively evaluated. Any adverse reaction occurring intra-operatively or within 7 days after surgery was identified. A thorough chart review was performed by an allergy specialist physician for any patient with an allergic-type reaction.

RESULTS

We included 923 patients of which 565 (61.2%) had a history of allergy to antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), other medications, and/or environmental exposures. Of 490 patients who had previously received contrast media, 25 (5.1%) had a history of an adverse reaction. No immediate anaphylaxis or other allergic reactions were observed after indocyanine green injection. 10 (1.1%) patients developed a transient skin reaction within 7 days after surgery. None of these patients had a history of contrast media reaction. Based on timing and clinical/peri-operative history of affected patients, it was determined that skin reactions were likely induced by other newly prescribed medications or contact sensitivity, not administration of indocyanine green.

CONCLUSION

Indocyanine green injection for sentinel lymph node mapping in patients with endometrial cancer caused no immediate/delayed anaphylactic or other severe allergic reactions. This included patients with a history of other allergies, asthma, and comorbidities. The myth of iodine's relationship to allergic reactions must be refuted to allow indocyanine green use in patients with a history of contrast media or shellfish allergy.

Novel Application of Conjunctival Anterior Segment Optical Coherence Tomography Angiography to Assess Ocular Redness

PURPOSE

The aim of this study was to determine anterior segment optical coherence tomography angiography (AS-OCTA) parameters to assess ocular redness severity.

METHODS

AS-OCTA analyses of 60 eyes of 40 patients were grouped according to ocular redness stages using the 5-category validated bulbar redness scale in a cross-sectional retrospective study (groups 1-5). A subset of patients with slit-lamp photographs, total 35 eyes of 23 patients, were assessed with 10-category validated bulbar redness scale for comparison. AS-OCTA images of nasal and temporal bulbar conjunctiva were analyzed. Vessel density (VD) represented the blood flow pixels by the total pixels of image (%); vessel diameter index represented the VD by the skeletonized density; fractal dimension, measured with the box-count method, represented the vessel branching complexity. Averaged nasal and temporal parameters for each eye were correlated to validated bulbar redness scales.

RESULTS

There was no statistical difference between groups for age ( P = 0.118), sex ( P = 0.501), eye laterality (OD/OS; P = 0.111), or location (nasal/temporal; P = 0.932). In the 5-category scale, VD significantly increased from group 1 to 2 (31.5 ± 1.9% and 33.4 ± 2.2%, P = 0.023), 2 to 3 (36.0 ± 3.5%, P < 0.001), and 4 to 5 (40.2 ± 2.9 and 46.5 ± 2.8, P < 0.001). The correlations were 0.805 ( P < 0.001) and 0.893 ( P < 0.001) for the 5-category and 10-category scales, respectively. Vessel diameter index showed a significant increase from 1 to 2 (2.90 ± 0.17 and 3.00 ± 0.15; P = 0.004) and 4 to 5 (2.92 ± 0.31 and 3.33 ± 0.08; P = 0.001). The correlations were 0.550 ( P < 0.001) and 0.625 ( P < 0.001) for the respective scales. The fractal dimension showed no significant differences between subsequent groups. The correlations were 0.445 ( P < 0.001) and 0.583 ( P < 0.001), respectively.

CONCLUSIONS

Conjunctival AS-OCTA VD was the most reliable parameter to assess ocular redness.

Laparoscopic choledocholithotomy and transductal T-tube insertion with indocyanine green fluorescence imaging and laparoscopic ultrasound: A case report

BACKGROUND

Laparoscopic choledocholithotomy for a large impacted common bile duct (CBD) stone is a challenging procedure because of the technical difficulty and the possibility of postoperative complications, even in this era of minimally invasive surgery. Herein, we present a case of large impacted CBD stones.

CASE SUMMARY

A 71-year-old man showed a distal CBD stone (45 mm × 20 mm) and a middle CBD stone (20 mm × 15 mm) on computed tomography. Endoscopic retrograde cholangiopancreatography failed due to the large size of the impacted stone and the presence of a large duodenal diverticulum. Laparoscopic choledocholithotomy was decided, and we used a near-infrared indocyanine green fluorescence scope to detect and expose the supraduodenal CBD more accurately. Then, the location, size, and shape of the stones were detected using a laparoscopic intraoperative ultrasound. The CBD was opened with a 2-cm-sized vertical incision. After irrigating several times, two CBD stones were removed with the Endo BabcockTM. T-tube insertion was done for postoperative cholangiography and delayed the removal of remnant sludge. The patient had no postoperative complications.

CONCLUSION

Laparoscopic choledocholithotomy by transcholedochal approach and transductal T-tube insertion is a safe and feasible option for large-sized impacted CBD stones.

Intraoperative angiography of the neurovascular bundle using indocyanine green and near-infrared fluorescence improves anatomical dissection during robot-assisted radical prostatectomy: initial clinical experience

Landmark artery identification in the neurovascular bundle (NVB) is important for nerve-sparing in radical prostatectomy. We aimed to investigate intraoperative angiography using indocyanine green and near-infrared fluorescence (ICG-NIRF) during robot-assisted radical prostatectomy (RARP) to identify the NVB, visualise vascularisation and haemostasis, and preserve erectile function. Our retrospective, unicentric study was performed in consecutive localised prostate cancer RARP patients (stage T1/T2, prostate-specific antigen < 10 ng/ml) who underwent ICG-NIRF angiography in France (2016-2021). When ready to dissect the NVB, the anaesthesiologist intravenously injected ICG (3 ml); the surgeon used alternating standard light or fluorescence to optimise NVB visualisation and facilitate microdissection. Primary outcomes: safety and feasibility of ICG-NIRF. Secondary outcomes: functional erectile dysfunction (Sexual Health Inventory for Men (SHIM) questionnaire) over 9 months, proportion of bilateral NVBs identified, ICG-related complications. Standard descriptive statistics were used; t test determined the significance of changes in SHIM scores versus baseline. Ninety-one patients received intraoperative angiography. The NVB was identified in all cases, without difficulties. No ICG-related complications or allergies were observed. There was no significant difference in the SHIM score at 9 months compared with baseline (p = 0.331), and erectile dysfunction returned to baseline levels in almost all patients. Intraoperative, real-time ICG-NIRF angiography is simple, non-invasive, and improves identification of key anatomical landmarks to optimise micropreservation of the NVB during RARP and preserve erectile function. Larger clinical studies should confirm preliminary results.

Feasibility and comparison of laparoscopic laser speckle contrast imaging to near-infrared display of indocyanine green in intraoperative tissue blood flow/tissue perfusion in preclinical porcine models

OBJECTIVE

To determine if laser speckle contrast imaging (LSCI) mitigates variations and subjectivity in the use and interpretation of indocyanine green (ICG) fluorescence in the current visualization paradigm of real-time intraoperative tissue blood flow/perfusion in clinically relevant scenarios.

METHODS

De novo laparoscopic imaging form-factor detecting real-time blood flow using LSCI and blood volume by near-infrared fluorescence (NIRF) of ICG was compared to ICG NIRF alone, for dye-less real-time visualization of tissue blood flow/perfusion. Experienced surgeons examined LSCI and ICG in segmentally devascularized intestine, partial gastrectomy, and the renal hilum across six porcine models. Precision and accuracy of identifying demarcating lines of ischemia/perfusion in tissues were determined in blinded subjects with varying levels of surgical experience.

RESULTS

Unlike ICG, LSCI perfusion detection was real time (latency < 150 ms: p < 0.01), repeatable and on-demand without fluorophore injection. Operating surgeons (n = 6) precisely and accurately identified concordant demarcating lines in white light, LSCI, and ICG modes immediately. Blinded subjects (n = 21) demonstrated similar spatial-temporal precision and accuracy with all three modes ≤ 2 min after ICG injection, and discordance in ICG mode at ≥ 5 min in devascularized small intestine (p < 0.0001) and in partial gastrectomy (p < 0.0001).

CONCLUSIONS

Combining LSCI for near real-time blood flow detection with ICG fluorescence for blood volume detection significantly improves precision and accuracy of perfusion detection in tissue locations over time, in real time, and repeatably on-demand than ICG alone.

Intraoperative bowel perfusion quantification with hyperspectral imaging: a guidance tool for precision colorectal surgery

BACKGROUND

Poor anastomotic perfusion can cause anastomotic leaks (AL). Hyperspectral imaging (HSI), previously validated experimentally, provides accurate, real-time, contrast-free intestinal perfusion quantification. Clinical experience with HSI is limited. In this study, HSI was used to evaluate bowel perfusion intraoperatively.

METHODS

Fifty-two patients undergoing elective colorectal surgeries for neoplasia (n = 40) or diverticular disease (n = 12), were enrolled. Intestinal perfusion was assessed with HSI (TIVITA®, Diaspective Vision, Am Salzhaff, Germany). This device generates a perfusion heat map reflecting the tissue oxygen saturation (StO2) amount. Prior to anastomose creation, the clinical transection line (CTL) was highlighted on the proximal bowel and imaged with HSI. Upon StO2 heat map evaluation, the hyperspectral transection line (HTL) was identified. In case of CTL/HTL discrepancy > 5 mm, the bowel was always resected at the HTL. HSI outcomes were compared to the clinical ones.

RESULTS

AL occurred in one patient who underwent neoadjuvant radiochemotherapy and ultralow anterior resection for rectal cancer. HSI assessment was feasible in all patients, and StO2-values were significantly higher at proximal segments than distal ones. Twenty-six patients showed CTL/HTL discrepancy, and these patients had a lower mean StO2 (54.55 ± 21.30%) than patients without discrepancy (65.10 ± 21.30%, p = 0.000). Patients undergoing neoadjuvant radiochemotherapy showed a lower StO2 (51.41 ± 23.41%) than non-neoadjuvated patients (60.51 ± 24.98%, p = 0.010).

CONCLUSION

HSI is useful in detecting intraoperatively marginally perfused segments, for which the clinical appreciation is unreliable. Intestinal vascular supply is lower in patients undergoing neoadjuvant radiochemotherapy, and this novel finding together with the clinical impact of HSI perfusion quantification deserves further investigation in larger trials.

Indocyanine Green Angiography as the Principal Design and Perfusion Assessment Tool for the Supraclavicular Artery Island Flap in Head and Neck Reconstruction

A consecutive case series of supraclavicular artery island flaps was designed using indocyanine green angiography (IcG-A) in head and neck reconstruction to demonstrate its utilization in supraclavicular artery island flap (SCAIF) head and neck reconstruction. IcG-A was used consecutively between April 2014 and July 2015 to evaluate its use in flap design, inset, and intraoperative decision-making in five patients undergoing head and neck reconstruction. Six SCAIFs were harvested in five patients where IcG-A was used as the primary tool for flap design by visually mapping the supraclavicular artery under fluorescence. Each flap was harvested around the mapped course of the artery. Confirmatory Doppler was present in each flap raised with this technique. In all five patients, IcG-A was used to assess flap perfusion after inset. This case series demonstrates IcG-A as another tool for SCAIF design in head and neck reconstruction. The technology provides direct visualization of the pedicle before harvest. It can also be used as an intraoperative tool to visualize the blood supply once the flap is rotated to assess flap perfusion and detect areas that may be compromised, thereby improving flap survival.

Fluorescence-guided radical prostatectomy

Robotic-assisted laparoscopic radical prostatectomy represents one of the most common operations in urologic oncology and involves several critical technical steps including pelvic lymph node dissection, cavernous nerve sparing and vesicourethral anastomosis. The quality of performing these steps is linked to functional and oncological outcomes. Indocyanine green [ICG] is a non-radioactive, water-soluble compound which allows for enhanced visualization with near-infrared fluorescence of both anatomical structures and vasculature during complex abdominal operations such as prostatectomy. During the last decade, several investigators have examined the value and role of ICG fluorescence during prostatectomy. In this review, we sought to evaluate the body of evidence for fluorescence-guided robotic prostatectomy as well as assess potential future areas of investigation with this technology.

Mouthwash as a non-invasive method of indocyanine green delivery for near-infrared fluorescence dental imaging

SIGNIFICANCE

X-ray imaging serves as the mainstream imaging in dentistry, but it involves risk of ionizing radiation.

AIM

This study presents the feasibility of indocyanine green-assisted near-infrared fluorescence (ICG-NIRF) dental imaging with 785-nm NIR laser in the first (ICG-NIRF-I: 700 to 1000 nm) and second (ICG-NIRF-II: 1000 to 1700 nm) NIR wavelengths.

APPROACH

Sprague Dawley rats with different postnatal days were used as animal models. ICG, as a fluorescence agent, was delivered to dental structures by subcutaneous injection (SC) and oral administration (OA).

RESULTS

For SC method, erupted and unerupted molars could be observed from ICG-NIRF images at a short imaging time (<1  min). ICG-NIRF-II could achieve a better image contrast in unerupted molars at 24 h after ICG injection. The OA could serve as a non-invasive method for ICG delivery; it could also cause the glow-in-dark effect in unerupted molars. For erupted molars, OA can be considered as mouthwash and exhibits outstanding performance for delivery of ICG dye; erupted molar structures could be observed at a short imaging time (<1  min) and low ICG dose (0.05  mg  /  kg).

CONCLUSIONS

Overall, ICG-NIRF with mouthwash could perform in-vivo dental imaging in two NIR wavelengths at a short time and low ICG dose.

Novel Intraoperative Imaging of Gastric Tube Perfusion during Oncologic Esophagectomy—A Pilot Study Comparing Hyperspectral Imaging (HSI) and Fluorescence Imaging (FI) with Indocyanine Green (ICG)

Background: Novel intraoperative imaging techniques, namely, hyperspectral (HSI) and fluorescence imaging (FI), are promising with respect to reducing severe postoperative complications, thus increasing patient safety. Both tools have already been used to evaluate perfusion of the gastric conduit after esophagectomy and before anastomosis. To our knowledge, this is the first study evaluating both modalities simultaneously during esophagectomy. Methods: In our pilot study, 13 patients, who underwent Ivor Lewis esophagectomy and gastric conduit reconstruction, were analyzed prospectively. HSI and FI were recorded before establishing the anastomosis in order to determine its optimum position. Results: No anastomotic leak occurred during this pilot study. In five patients, the imaging methods resulted in a more peripheral adaptation of the anastomosis. There were no significant differences between the two imaging tools, and no adverse events due to the imaging methods or indocyanine green (ICG) injection occurred. Conclusions: Simultaneous intraoperative application of both modalities was feasible and not time consuming. They are complementary with regard to the ideal anastomotic position and may contribute to better surgical outcomes. The impact of their simultaneous application will be proven in consecutive prospective trials with a large patient cohort.

Strategy of harvesting extended thoracodorsal artery perforator flaps for resurfacing the large soft-tissue defects of extremities

BACKGROUND

The authors presented their strategy to harvest extended thoracodorsal artery (TDA) perforator flaps for resurfacing the large soft-tissue defects of extremities.

MATERIALS AND METHODS

Thirty-three free extended TDA perforator flaps were harvested in 33 patients. The mean flap size was 145.2 cm². The maximal flap length and the width were 30 cm and 10 cm, respectively. The color Doppler sonography (CDS) was used for preoperative assessment of perforators. Indocyanine green angiography (ICGA) was used for intraoperative assessment of flap viability in three patients.

RESULTS

The vascular thrombosis, donor-site scar widening, and delayed recipient-site wound healing were not significantly related to the patient and flap characteristics. Flap tip or partial necrosis was significantly related to age and peripheral vascular disease. True positive rate, false negative rate, and positive predictive value of CDS for perforator identification were not different significantly between attending surgeon and residents. In the distance discrepancy of CDS, significant difference was found based on the classifications of perforator size, perforator type, and sonographic operator. The ICGA identified a hypoperfused distal area in a 30 cm long flap.

CONCLUSION

The CDS locates the TDA perforators more precisely when scanned by experienced hands, in larger size or septocutaneous perforators. Using reliable and more perforators, applying muscle-sparing technique, considering suprafascial course of perforator and proper flap orientation are helpful in harvesting extended TDA perforator flaps. ICGA is an option for assessing flap viability, especially in elders and patients with peripheral vascular diseases.

Intraoperative ICG-based fluorescence-angiography in head and neck reconstruction: Predictive value for impaired perfusion of free flaps

The aim of this study was to prove the hypothesis that intraoperative fluorescence-angiography using indocyanine-green (ICGFA) can be used to predict the occurrence of perfusion-associated complications following microvascular reconstruction. Consecutively perioperative data of patients who received microvascular reconstruction of the head and neck region and underwent ICGFA immediately after anastomosis was established were analyzed. The flow parameters analyzed in the investigation were (1) the baseline (Int_Min) and (2) peak intensity (Int_Max) of fluorescence, (3) the quotient of the two aforementioned parameters (F_max/min) as an expression of the relative total increase, (4) the absolute difference in the two parameters (Diff_Int) in terms of amplitude, (5) the duration of the intensity increase (T_Rise) until the peak, and (6) the percent intensity increase per second (Rise/sec_rel). Within the first 2 weeks postoperatively, every flap complication was documented. Subsequently, statistical analysis of the flap outcome was performed based on the flow parameters obtained intraoperatively. Data of 67 patients (male/female: 41/26) with an average age of 64 years (range 29-84 years) were analyzed. In 10 of these patients, postoperative perfusion-associated complications were observed (arterial/venous/microcirculatory: 4/3/3; p = 0.12). The analysis of the intraoperatively obtained flow parameters showed a significant difference in the ratio of maximum and minimum intensity in arterial pedicle perfusion (F_max/min) of patients with and without complications (with vs. without complications: 2.3 ± 1.0 vs. 5.0 ± 4.9; p < 0.01) and strong correlation of the mentioned parameter with the occurrence of perfusion-associated complications (odds ratio = 0.27; p = 0.01). The ratio of maximum and minimum intensity (F_max/min) is a predictor for postoperative venous stasis, arterial hypoperfusion and impaired microcirculation of a microvascular flap. Anastomoses with F_max/min <2.85 should be revised. However, a high technique sensitivity has to be considered, due to which sufficient hemostasis and reduction of motion artefacts have to be taken into account in order to obtain useable data.

Maternal-fetal transfer of indocyanine green: a systematic review

RATIONAL

In a survey of 1101 members of vitreoretinal trained physicians regarding the use of ICG angiography during pregnancy, 434 (83%) of 520 respondents had seen at least one pregnant woman requiring ICG angiography or fluorescein angiography. One hundred and five (24%) withheld ICG angiography, mostly because of fear of teratogenicity or lawsuit. Adverse reactions to fluorescein and ICG are rare and may be classified as toxic, hypersensitivity, and non-specific. This literature review aimed to review evaluate the maternal-to-fetal transfer of ICG and resume the most recent recommendations for ICG use in its obstetric applications.

METHODS

The available literature was examined using PubMed-Medline, and web of science, and using the MeSH terms "fluorescein," "Indocyanine green," and "pregnancy" according to PRISMA-P guidelines.

RESULTS

Studies in humans demonstrated that ICG is not detectable in fetal cord blood or umbilical vein blood collected immediately after birth. ICG maternal-to-fetal transfer is slow and is safe during pregnancy. ICG in the fetus accumulates in the liver and accumulation is enhanced by the administration of OATPs or P-gp inhibitors.

CONCLUSIONS

ICG's transplacental transfer is minimal and is probably medicine-mediated, like rifampin. The placenta is an effective protective barrier to ICG's distribution into the fetus.

Anterior segment optical coherence tomography angiography in the assessment of ocular surface lesions

PURPOSE

Describe the utility of anterior segment optical coherence tomography angiography (AS-OCTA) to assess ocular surface lesions.

METHODS

Retrospective, case-control study of 10 eyes of 9 patients with malignant lesions and 23 eyes of 22 patients with benign lesions. Lesions included 13 epithelial, 10 pigmented and 10 lymphoid lesions. Graders performed an average of 3 depth and diameter measurements of peri-lesional vessels entering each lesion on AS-OCTA. Statistical models to assess differences between groups accounted for bilateral eye inclusion and lesion thickness (on AS-OCT). Receiver operating characteristic (ROC) curve and area under the curve (AUC) were performed for each parameter.

RESULTS

In the benign and malignant groups, age was 49.5 ± 22.4 and 64.3 ± 10.6 years (p = 0.145) with 45% males and 55% males (p = 0.458), in their respective groups. AS-OCTA showed greater peri-lesional vessel depth and diameter in malignant lesions (315.2 ± 73.0 μm, p < 0.001 and 76.4 ± 18.2 μm, p < 0.001; respectively) compared to benign lesions (199.4 ± 34.1 μm and 44.0 ± 9.4 μm, respectively). Malignant lesions showed deep and dilated peri-lesional vessels, which may represent feeder vessels. Vessel depth showed AUC = 0.980, 90.9% sensitivity and 100.0% specificity with a 236.5 μm cutoff. Vessel diameter showed AUC = 0.960, 100.0% sensitivity and 88.9% specificity with a 53.9 μm cutoff.

CONCLUSION

AS-OCTA shows greater peri-lesional vessel depth and diameter of malignant lesions compared to benign lesions. This imaging modality provides novel and non-invasive functional vascular parameters that can potentially aid the assessment of ocular surface lesions.

Optical coherence tomography angiography application to pigmented iris: Could a new index quantify blood flow?

PURPOSE

To assess the blood flow and vascular visibility of irises in relation to pigmentation and pupil size, using an anterior segment optical coherence tomography angiography (OCTA).

MATERIALS AND METHODS

This is a cross-sectional study. OCTA images were acquired in the nasal and temporal quadrants from a cohort of 30 healthy subjects in photopic (miosis) and scotopic (mydriasis) conditions. Patients were divided according to iris color (less pigmented: group L vs more pigmented: group D). Vascular parameters (vessel density (VD), vessel length density (VLD), fractal dimension (FD)) were applied and compared among groups L and D, location and different pupil status. A novel vascular index called Luminance Index (LI) was developed and applied in order to quantify vascular flow and evaluate its variation in photopic and scotopic conditions. Multivariable analyses were performed to evaluate possible predictors of VD and LI.

RESULTS

No differences were found for all vascular measurements (VD, VDL, FD, LI) between nasal and temporal quadrants. All vascular measurements were higher in group L than in group D (p < 0.05), except for LI and FD in photopic condition. In group L, all vascular parameters increased (p < 0.001) after dark adaptation. In group D, only LI increased after dark adaptation (p < 0.001). Pigmentation and iris thickness were significantly associated with VD in scotopic and photopic conditions, and with LI only in scotopic condition.

CONCLUSIONS

Pigmentation still remains a major issue for vascular visibility. Quantitative and qualitative vascular changes follow pupil size variation. LI could be a new surrogate to quantify blood flow.

Demarcating the Exact Midplane of the Liver Using Indocyanine Green Near-Infrared Fluorescence Imaging During Laparoscopic Donor Hepatectomy

Indocyanine green (ICG) near-infrared fluoroscopy has been recently implemented in pure laparoscopic donor hepatectomy (PLDH). This study aims to quantitatively evaluate the effectiveness of ICG fluoroscopy during liver midplane dissection in PLDH and to demonstrate that a single injection of ICG is adequate for both midplane dissection and bile duct division. Retrospective analysis was done with images acquired from recordings of PLDH performed without ICG (pre-ICG group) from November 2015 to May 2016 and with ICG (post-ICG group) from June 2016 to May 2017. 30 donors from the pre-ICG group were compared with 46 donors from the post-ICG group. The operation time was shorter (P = 0.002) and postoperative peak aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were lower (P = 0.031 and P = 0.019, respectively) in the post-ICG group than the pre-ICG group. Within the post-ICG group, the color intensity differences between the clamped versus nonclamped regions in the natural, black-and-white, and fluorescent modes were 39.7 ± 36.2, 89.6 ± 46.9, and 19.1 ± 36.8 (mean ± SD, P < 0.001), respectively. The luminosity differences were 37.2 ± 34.5, 93.8 ± 32.1, and 26.7 ± 25.7 (P < 0.001), respectively. Meanwhile, the time from when ICG was injected to when the near-infrared camera was turned on for bile duct visualization was 85.6 ± 25.8 minutes. All grafts received from the 46 donors were successfully transplanted. In conclusion, ICG fluoroscopy helps to reduce operation time and lower postoperative AST/ALT levels. ICG injection visualized with black-and-white imaging is most effective for demarcating the liver midplane during PLDH. A single intravenous injection of ICG is sufficient for midplane dissection as well as bile duct division.

Sentinel lymph node biopsy in patients with endometrial cancer and an indocyanine green or iodinated contrast reaction - A proposed management algorithm

OBJECTIVE

To describe the incidence of adverse reactions to indocyanine green (ICG) administered during sentinel lymph node (SLN) biopsy for endometrial cancer, and to propose an ICG management algorithm for these patients.

METHODS

All patients who underwent surgery for endometrial cancer with SLN biopsy using ICG from 1/2017 to 8/2020 were identified using a single-institution prospective database. Surgical adverse events (SAEs) related to the procedure were identified. A review of the literature was performed.

RESULTS

In all, 1414 patients met inclusion criteria and were evaluated. Sixty-seven (4.7%) patients had a history of either an iodine or contrast allergy. No patients had a history of documented ICG allergy. Among patients with an iodine or contrast allergy, 65 (97%) received a corticosteroid with or without diphenhydramine prior to ICG administration. One hundred five patients (7.4%) experienced 116 SAEs. Among these patients, 3 experienced potentially allergic SAEs possibly related to ICG administration. After thorough chart review, however, the likelihood these SAEs were due to ICG appeared low. No patients experienced an anaphylactic response after ICG admission.

CONCLUSION

There were no anaphylactic reactions to ICG intracervical administration during 1414 consecutive SLN biopsies, including in patients with a documented iodine or contrast allergy. Intracervical injection of ICG is safe, and premedication using corticosteroids with or without diphenhydramine prior to SLN biopsy is a reasonable strategy in patients with iodinated contrast allergy.

Effectiveness of Intraoperative Indocyanine Green Fluorescence-Navigated Surgery for Superior Mesenteric Vein Thrombosis that Developed During Treatment for Intravascular Lymphoma: A Case Report

BACKGROUND Superior mesenteric vein thrombosis (SMVT) is a relatively rare form of acute abdominal disease; less than 0.1% of laparotomy surgeries are performed for SMVT. In the presence of severe intestinal ischemia or necrosis caused by SMVT, immediate surgical intervention is required. Macroscopic diagnosis of intestinal viability is sometimes difficult; its over-resection may carry the risk of short bowel syndrome. A near-infrared fluorescence imaging system with indocyanine green (ICG) has recently been developed for intraoperative, real-time evaluation of intestinal perfusion. This is the first report on the use of ICG fluorescence imaging during surgery for intestinal ischemia caused by venous thrombosis. CASE REPORT A 70-year-old man presented with a general feeling of weariness. On examination, he was diagnosed with intravascular large B cell lymphoma. R-CHOP therapy was initiated. On day 3 of initial R-CHOP therapy, the patient experienced sudden severe abdominal pain while in the hospital. Contrast-enhanced computed tomography revealed SMVT and loss of contrast effect in the small intestine. We diagnosed small bowel necrosis caused by SMVT, and exploratory laparotomy was performed, which revealed a continuous ischemia of 150 cm. Intraoperative ICG fluorescence imaging was utilized, and the color boundary was consistent with the ischemic area detected by visualization. The necrotic small intestine was excised and anastomosed. The patient was transferred to the hematology department on postoperative day 10 with no severe complications such as anastomotic leakage or re-thrombosis, and re-embolization was not observed 6 months later. CONCLUSIONS Venous thrombosis should be listed as a differential diagnosis when acute abdominal disease presents during chemotherapy for malignant lymphoma. ICG fluorescence imaging may be useful in the evaluation of intestinal blood flow for venous thrombosis.

Combined surgical therapy for pulmonary sequestration and aberrant artery from the abdominal aorta

Pulmonary sequestration with feeding vessels from the abdominal aorta is relatively rare. A 56-year-old woman with chronic left thoracic pain was referred to our hospital. Computed tomography showed multiple pulmonary cysts in the left lung and an aberrant artery from the abdominal aorta. She was diagnosed with pulmonary sequestration. She underwent embolization of the aberrant artery and wedge resection of the sequestrated lung under indocyanine green guidance. The surgical treatment combining preoperative embolization of the artery and intraoperative indocyanine green-guided lung resection might be safe and minimally invasive for patients with lung sequestrations accompanied by feeding vessels from the abdominal aorta.

Use of intraoperative fluorescence to enhance robot-assisted radical prostatectomy

Robot-assisted radical prostatectomy has become the standard of care for the removal of localized prostate cancer. Positive outcomes depend upon the precise removal of the prostate and associated tissue without damage to nearby structures. This process can be aided by fluorescence-guided surgery to enhance the visual contrast between different structures. Here the authors have conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify ten investigations into the use of fluorescence-guided surgery in robot-assisted radical prostatectomy. These studies used fluorescent tracers to identify structures, including the prostate, neurovascular bundle and lymph nodes. These studies demonstrate the safe and effective use of fluorescence-guided surgery in robot-assisted radical prostatectomy and pave the way for further developments in this field.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY-GUIDED PHOTODYNAMIC THERAPY FOR ACUTE CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

To compare the anatomic results of optical coherence tomography angiography (OCTA)-guided half-dose photodynamic therapy (PDT) versus indocyanine green angiography (ICGA)-guided PDT in eyes with acute central serous chorioretinopathy.

METHODS

This study is a prospective, single-center, noninferiority, double-masked, randomized, controlled clinical trial. Fifty-one eyes of 45 patients with acute central serous chorioretinopathy were recruited, and randomized to an ICGA-guided group and an OCTA-guided group. The primary outcome measures were the rates of complete subretinal fluid (SRF) resolution at 1 month and 3 months.

RESULTS

Forty-six eyes of 40 patients finished the follow-up and were analyzed. In the OCTA-guided group, the SRF was completely resolved in 13 (56.5%) eyes within 1 month and in 21 (91.3%) eyes within 3 months. In the ICGA-guided group, the SRF was resolved in 16 (69.6%) of the eyes within 1 month and in 22 (95.7%) of the eyes by 3 months. Optical coherence tomography angiography-guided PDT was demonstrated noninferior to ICGA-guided PDT for SRF resolution rate at 3 months (P = 0.016), but not at 1 month (P = 0.311) for acute central serous chorioretinopathy patients. Subretinal fluid did not recur in any of the eyes in the OCTA-guided group, but did recur in 2 eyes (8.7%) of the ICGA-guided group during the 3-month follow-up period.

CONCLUSION

Optical coherence tomography angiography-guided PDT seemed to be noninferior to ICGA-guided PDT for resolution of SRF at 3 months in eyes with acute central serous chorioretinopathy.

Autofluorescence and Indocyanine Green in Thyroid Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

To estimate the impact of optical techniques on prevention of post-operative hypocalcemia and hypoparathyroidism after total thyroidectomy.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A literature search was conducted in Pubmed, EMBASE, SCOPUS, and Cochrane databases. The main inclusion criteria for eligible articles for meta-analysis were patients with benign or malignant thyroid pathologies who underwent total thyroidectomy, utilization of optical techniques to support PGs preservation, the availability of calcium and/or PTH levels. The primary outcome was to evaluate the variation of calcium and PTH levels when adopting optical technologies compared to standard naked-eye surgery.

RESULTS

In total, 13 papers with 1484 procedures were included. Pooled proportion for short- and medium-term hypocalcemia rates were 8% (95% CI, 5%:11%) and 1% (95% CI, 0%:4%) for optical techniques, while for naked-eye surgery were 15% (95% CI, 9%:23%) and 5% (95% CI, 2%:9%), respectively.

CONCLUSIONS

Optical technologies reduced short and medium term hypocalcemia compared to conventional surgery.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:1683-1692, 2021.

Time Course in Ocular Blood Flow and Pulse Waveform in a Case of Ocular Ischemic Syndrome with Intraocular Pressure Fluctuation

We report on a 70-year-old Japanese man with complaints of worsening left visual acuity who was diagnosed with ocular ischemic syndrome (OIS) associated with internal carotid artery (ICA) stenosis. A gonioscopy examination showed rubeosis iridis and elevated intraocular pressure (IOP) in the left eye (50 mmHg) at the baseline visit. The optic nerve head (ONH) and choroidal blood flow measured by laser speckle flowgraphy (LSFG) was impaired in the left eye compared with that in the right eye. Additionally, the blowout score (BOS), which indicates the variation of the mean blur rate (MBR) during systolic and diastolic periods, was decreased in the left eye. After treatment with an injection of bevacizumab and administration of Rho-associated kinase-inhibitor ripasudil eye drops, both ocular blood flow and BOS in each vascular bed gradually increased along with IOP reduction. The visual acuity also improved. The current case demonstrated increased blood flow and decreased fluctuation of blood flow in the ONH and choroid before and after the treatment in OIS with rubeosis iridis. The LSFG technique is useful to non-invasively assess the ocular circulation and pulse waveform in OIS.

Robotic Partial Nephrectomy with Indocyanine Green Fluorescence Navigation

Partial nephrectomy (PN) is a recommended type of treatment of localised renal tumors. Real-time intraoperative imaging technique, such as fluorescence imaging with indocyanine green (ICG) administration helps to improve intraoperative and postoperative outcomes in patients who underwent PN. Our work presents results of patients who underwent robotic PN with ICG navigation. A total of 37 patients underwent robotic PN with application of ICG between April 2015 and May 2019. A total amount of 5 mg of ICG was applied intravenously, and then robotic PN was performed with fluorescent imaging. ICG was used by the surgeon's decision according to unfavourable anatomical properties of tumor or to high R.E.N.A.L. nephrometry score. An exact border between perfused and nonperfused tissue was detected, and exact tumor's branch of the renal artery was clamped. Robotic PN with ICG-fluorescence imaging navigation was performed in 37 cases with a preoperative average diameter of tumor of 31 mm. The mean surgery time was 133 minutes, and the mean estimated blood loss was 190 mL. Arterial clamping was performed in 35 cases. The mean duration of warm ischemia was 14 minutes. Application of ICG enabled specific tumor-supplying vessel clamping in 25 cases. Two complications of grade II according to the Clavien-Dindo classification occurred intraoperatively, and one complication of grade III was observed. Renal function changes showed favourable results for the cases with superselective clamping. Finally, an administration of ICG eases superselective clamping of tumor-specific branch of renal artery and helps to preserve normal renal function with acceptable oncological results.

Indocyanine green fluorescence method for sentinel lymph node biopsy in breast cancer

BACKGROUND/OBJECTIVE

Breast biopsy and analysis of sentinel lymph nodes (SLNs) accurately predict tumor status in the affected basin and help in avoiding unnecessary axillary lymph node dissection, which is associated with remarkable morbidity risk. Blue dye and radioisotope are the most widely used mapping agents, but non-radioactive tracers of comparable accuracy warrant further investigation. This study aimed to investigate utilization of indocyanine green (ICG) fluorescence in sentinel node localization compared with blue dye and to assess the incremental value of ICG.

METHODS

A total of 39 consecutive patients underwent sentinel lymph node biopsy (SLNB) (40 cases: 38 unilateral and 1 bilateral) with combined blue dye and ICG for localization. The obtained fluorescence images of the lymphatic system were investigated.

RESULTS

All 84 lymph nodes removed in 40 procedures were identified by ICG, but only 37 were identified by blue dye. The ICG method identified an average of 2.1 SLNs in 39 of 40 cases with a detection rate of 97.5%, but only 0.93 SLN per case with blue dye. Subcutaneous lymphatic channel patterns were also detected by fluorescent imaging in 37 procedures, which all revealed lymphatic drainage toward the axilla except in one case with internal mammary pathway.

CONCLUSION

This study demonstrated the accuracy and safety of ICG for SLNB and its superiority to blue dye method in SLN localization. Therefore, ICG fluorescence method is safe and effective addition in breast clinical settings, wherein blue dye alone is used.

Intravenous indocyanine green dye is insufficient for robust immune cell labelling in the human retina

It is not currently possible to reliably visualise and track immune cells in the human central nervous system or eye. Previous work demonstrated that indocyanine green (ICG) dye could label immune cells and be imaged after a delay during disease in the mouse retina. We report a pilot study investigating if ICG can similarly label immune cells within the human retina. Twelve adult participants receiving ICG angiography as part of routine standard of care were recruited. Baseline retinal images were obtained prior to ICG administration then repeated over a period ranging from 2 hours to 9 days. Matched peripheral blood samples were obtained to examine systemic immune cell labelling and activation from ICG by flow cytometry with human macrophage cultures as positive controls. Differences between the delayed near infrared ICG imaging and 488 nm autofluorescence was observed across pathologies, likely arising from the retinal pigment epithelium (RPE). Only one subject demonstrated ICG signal on peripheral blood myeloid cells and only three distinct cell-sized signals appeared over time within the retina of three participants. No significant increase in immune cell activation markers were detected after ICG administration. ICG accumulated in the endosomes of macrophage cultures and was detectable above a minimum concentration, suggesting cell labelling is possible. ICG can label RPE and may be used as an additional biomarker for RPE health across a range of retinal disorders. Standard clinical doses of intravenous ICG do not lead to robust immune cell labelling in human blood or retina and further optimisation in dose and route are required.

Immediate Reactions to Fluorescein and Indocyanine Green in Retinal Angiography: Review of Literature and Proposal for Patient's Evaluation

Introduction

Contrast rapid sequence angiography with fluorescein or indocyanine green (ICG) is a diagnostic procedure commonly used in ophthalmology. Adverse reactions to fluorescein and ICG are rare and may be classified as toxic, of hypersensitivity and non-specific. The evaluation and management of a patient with an adverse reaction is a challenge for the majority of ophthalmologists, as is the assessment of risk factors that may contraindicate the procedure.

Purpose

We aim to review the concepts underlying adverse reactions to fluorescein and ICG, especially those of hypersensitivity, and present a proposal or the evaluation of the patients in need to perform retinal angiography and for the treatment of immediate reactions to fluorescein and ICG.

Methods

The available literature was examined using PubMed-Medline, and using the MeSH terms "fluorescein", "Indocyanine green", "ophthalmic dyes", "retinal angiography", "adverse reactions", and "allergic reaction".

Conclusion

This review may help ophthalmologists to identify patients with higher risk of a hypersensitivity reaction and give them tools to recognize patients with suspected hypersensitivity that may benefit from an allergy study.

Anaphylactic Shock After Indocyanine Green Video Angiography During Cerebrovascular Surgery

BACKGROUND

Indocyanine green (ICG) video angiography has been widely used in cerebrovascular surgery. ICG injection is generally safe, with a low incidence of complications. ICG-related anaphylactic reactions during neurosurgery have been rarely reported. We report the cases of 2 patients who had experienced anaphylactic shock in response to intravenous ICG injection (DID Indocyanine Green [Dongindang, Inc., Gyeonggi-do, Republic of Korea]) during intracranial aneurysm (IA) surgery.

CASE DESCRIPTION

The first patient, a 69-year-old woman with an unruptured IA, had been undergoing clipping surgery under general anesthesia. Immediately after ICG injection, her blood pressure suddenly decreased from 140/80 mm Hg to 50/30 mm Hg and she developed a skin rash on her abdomen and all extremities. Chest compression was initiated, and her vital signs gradually recovered to their pre-ICG levels within 10 minutes. The second patient was a 58-year-old woman with an unruptured IA who had been undergoing clipping surgery. After ICG injection, her blood pressure had decreased from 130/80 mm Hg to 60/40 mm Hg, and a rash-like skin lesion was observed on her abdomen. After intravenous injection of norepinephrine and dexamethasone, her blood pressure recovered to its pre-ICG level within 30 minutes and remained stable thereafter. The postoperative ICG skin provocation test findings were positive for both patients; however, only 1 patient showed markedly increased serum tryptase levels.

CONCLUSION

Despite the rarity of ICG-related anaphylaxis, clinicians should be aware of this unexpected, but potentially life-threatening, drug reaction in patients undergoing cerebrovascular surgery.

Indocyanine green fluorescence-guided thoracoscopic pulmonary resection for intralobar pulmonary sequestration: a case report

Background

The potential complications of pulmonary sequestration are serious and may include recurrent pulmonary infection, hemoptysis, and tumorigenesis. Therefore, the gold standard of treatment has been surgery. Although an adequate boundary between the nonfunctional lung and normal lung is required for the resection of pulmonary sequestration, the boundaries have been conventionally identified intraoperatively with inflation/deflation of the target segment by clamping and unclamping the relevant bronchus. The technique of visualizing the demarcation line based on near-infrared fluorescence imaging with indocyanine green was recently developed.

Case presentation

A 42-year-old Japanese woman with right Pryce III intralobar sequestration was admitted to our hospital. We planned video-assisted thoracoscopic wedge resection of the right sequestration using near-infrared fluorescence imaging with indocyanine green because of the small volume of the nonfunctional region. The aberrant artery was recognized in the pulmonary ligament; the artery was cut off after ligation. Indocyanine green at 5 mg/body was rapidly injected into the peripheral vein, and the boundary of the sequestration was clearly identified under near-infrared fluorescence imaging.

Conclusion

Near-infrared fluorescence imaging with indocyanine green is safe and useful for the identification of the boundary of a pulmonary sequestration.

Fluorescent indocyanine green angiography: Preliminary results in microsurgery monitoring

INTRODUCTION

Pedicled flaps and free-tissue transfer flaps are used routinely to reconstruct hard and soft tissue defects in head and neck, limb, hand, thoracic and abdominopelvic reconstructive surgery. But failure remains a constant concern, particularly in free-tissue transfers. Usually failure is due to blood supply compromise. Indocyanine green (ICG), a fluorescent dye is a suitable tracer for vessel perfusion. The objective of this study is to evaluate the fluorescent indocyanine green angiography (FA ICG) in free flaps procedures.

MATERIEL AND METHODS

Patients who had microsurgical flap reconstruction were included during the study period in a single center. The FA ICG was used at specific times. Intra-veinous injections of 0.1mg/kg of INFRACYANINE^® (concentration 2.5mg/mL) were done intraoperatively. The Fluobeam^® device programmed on sensitivity and mapping to interpret the data, was used. These different injections allowed to checked skin paddle perforators vessels, osseous perforators vessels, arterial and venous patency after anastomosis and the cutaneous, muscular and osseous perfusion.

RESULTS

A total of 12 patients enrolled were 10 males and 1 female. Their mean age was 54.5 years (range 25-75 years). Of the 12 flaps, 8 were free flaps with 4 fibular flaps (3 for mandibular reconstruction and one for femur reconstruction); 2 radial forearm flaps for maxillary reconstruction; one latissimus free flap for tibia skin coverage and one retroauricular fasciocutaneous free flap for thumb skin coverage. We got to modify specific steps during surgery with 8 patients by using the FA ICG to anticipate potential complications: modifying the draw of the skin paddle, recut of this paddle, modifying the osteotomies, re-doing the anastomosis or modifying the position of the pivot point.

DISCUSSION

Evaluation of microvascular flap perfusion is still based on subjective clinical features. Clinical monitoring is observer-dependent and does not allow information sharing, test reproducibility, and consistent postoperative follow-up. The successful of salvage rate is linked to the delay between the onset of ischemia and its clinical assessment. FA ICG could be a reliable method for monitoring free-tissue transfers. This technique is objective, non invasive and facilitate a complex reconstructive procedure to augment is liability. This technique may be used such a pedagogical tool for young practitioners in their first microsurgery procedures.

Robotic-Assisted Sentinel Lymph Node Mapping With Indocyanine Green in Pelvic Malignancies: A Systematic Review and Meta-Analysis

Objective: Newer technologies such as near-infrared (NIR) imaging of the fluorescent dye indocyanine green (ICG) and daVinci Xi Surgical System have become promising tools for sentinel lymph node (SLN) mapping. This meta-analysis was conducted to comprehensively evaluate the diagnostic value of SLN in assessing lymph nodal metastasis in pelvic malignancies, using ICG with NIR imaging in robotic-assisted surgery. Materials and Methods: A literature search was conducted using PubMed for studies in English before April 2019. The detection rate, sensitivity of SLN detection of metastatic disease, and factors associated with successful mapping (sample size, study design, mean age, mean body mass index, type of cancer) were synthesized for meta-analysis. Results: A total of 17 articles including 1,059 patients were finally included. The reported detection rates of SLN ranged from 76 to 100%, with a pooled average rate of 95% (95% CI: 93-97; 17 studies). The sensitivity of SLN detection of metastatic disease ranged from 50 to 100% and the pooled sensitivity was 86% (95% CI: 75-94; 8 studies). There were no complications related to ICG administration reported. Conclusions: NIR imaging system using ICG in robotic-assisted surgery is a feasible and safe method for SLN mapping. Due to its promising performance, it is considered to be an alternative to a complete pelvic lymph node dissection.

Near-infrared fluorescence imaging for the prevention and management of breast cancer-related lymphedema: A systematic review

Sentinel lymph node identification by near infrared (NIR) fluorescence with indocyanine green (ICG) is recognized in the literature as a useful technique. NIR fluorescence technology could become key in the prevention and management of lymphedema after axillary dissection for breast cancer. Here, we conducted a systematic review focusing on ICG imaging to improve lymphedema prevention and treatment after axillary surgery. A systematic literature review was performed using MEDLINE and Embase to identify articles focused on ICG imaging for breast-cancer-related lymphedema (BCRL). Qualitative analysis was performed to summarize the characteristics of reported ICG procedures. In situ tissue identification and functionality assessment based on fluorescence signal were evaluated. Clinical outcomes were appraised when reported. Studies relating to axillary reverse mapping, lymphography and upper limb supermicrosurgery combined with ICG imaging were identified. We included a total of 33 relevant articles with a total of 2016 patients enrolled. ICG imaging for axillary reverse mapping was safe for all 951 included patients, with identification of arm nodes in 80%-88% of patients with axillary lymph nodes dissection. However, the papers discuss the oncologic safety of the approach and how - regardless of the contrast agent - concerns limit its adoption. ICG lymphography is openly supported in BCRL management, with 1065 patients undergoing this procedure in 26 articles. The technique is reported for lymphedema diagnosis, with high sensitivity and specificity, staging, intraoperative mapping and patency control in lymphaticovenular anastomosis. The substantial advantages/disadvantages of ICG imaging procedures are finally described.

Indocyanine Green (ICG) in Urologic Surgery

Indocyanine green (ICG) is a dye used for fluorescent-guided surgery. This review article addresses the recent surge in reported uses of ICG in various surgical fields and provides a comprehensive and up to date review of the uses of ICG in urologic surgery.

Detection of Sentinel Lymph Nodes with Near-Infrared Imaging in Malignancies

Optical molecular imaging, a highly sensitive and noninvasive technique which is simple to operate, inexpensive, and has the real-time capability, is increasingly being used in the diagnosis and treatment of carcinomas. The near-infrared fluorescence dye indocyanine green (ICG) is widely used in optical imaging for the dynamic detection of sentinel lymph nodes (SLNs) in real time improving the detection rate and accuracy. ICG has the advantages of low scattering in tissue absorbance, low auto-fluorescence, and high signal-to-background ratio. The detection rate of axillary sentinel lymph nodes biopsy (SLNB) in breast cancers with ICG was more than 95 %, the false-negative rate was lower than 10 %, and the average detected number ranged from 1.75 to 3.8. The combined use of ICG with nuclein or blue dye resulted in a lower false-negative rate. ICG is also being used for the sentinel node detection in other malignant cancers such as head and neck, gastrointestinal, and gynecological carcinomas. In this article, we provide an overview of numerous studies that used the near-infrared fluorescence imaging to detect the sentinel lymph nodes in breast carcinoma and other malignant cancers. It is expected that with improvements in the optical imaging systems together with the use of a combination of multiple dyes and verification in large clinical trials, optical molecular imaging will become an essential tool for SLN detection and image-guided precise resection.

Vital Dyes in Vitreomacular Surgery

Vital dyes contain complex molecules with chromophores that stain living tissues and have greatly enhanced identification and removal of transparent vitreoretinal tissues during surgery. Several "chromovitrectomy" dyes are frequently used by vitreoretinal specialists, including indocyanine green, trypan blue, brilliant blue G, and triamcinolone acetonide; other dyes are also under investigation. Trypan Blue was approved by the U.S. Food and Drug Administration (FDA) for epiretinal membrane removal, and preservative-free triamcinolone acetonide was approved by the FDA for intraocular use. However, currently available chromovitrectomy dyes have their limitations, and of particular concern for some of them is the possibility for acute and chronic toxicity to the neurosensory retina and retinal pigmented epithelium. The potentially irreversible acute toxicity and other limitations, such as lack of long-term safety profiles, highlight the need for further advancements. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:788-798.].

Low-dose indocyanine green fluorescence-navigated segmentectomy: prospective analysis of 20 cases and review of previous reports

Background

A technique of visualizing the demarcation line based with indocyanine green (ICG) was recently developed, and its utility was reported. We demonstrated the safety and utility of low-dose (5 mg/body) ICG fluorescence-navigated video-assisted thoracic surgery (VATS) segmentectomy.

Methods

Patients who had undergone lung segmentectomy for early-stage non-small cell lung cancer (NSCLC) or small pulmonary metastasis were included in this study. ICG at 5 mg/body was rapidly injected into the peripheral vein, and the lung was observed using near-infrared (NIR) fluorescence thoracoscopy. We evaluated the identification rate of the demarcation line based on NIR fluorescence imaging with ICG and the perioperative outcomes.

Results

Lung segmentectomy NIR fluorescence imaging with ICG was performed in 20 patients. The identification of the target segmental line was possible in 18 (90%) of the 20 patients. The median duration of chest tube placement was one day, and the median length of postoperative stay was 8 days. Complications occurred in 5 (25%) of the 20 patients. All cases were prolonged air leak that required pleurodesis. There were no complications resulting from NIR fluorescence imaging with ICG.

Conclusions

NIR fluorescence imaging with ICG is safe and useful for the identification of the demarcation line for lung segmentectomy. Low-dose ICG might achieve a sufficient rate of identification of the segmental line.

Parathyroid gland management using optical technologies during thyroidectomy or parathyroidectomy: A systematic review

New optical technologies enhancing localization or assessing viability of parathyroid glands (PG) during endocrine surgery have been reported in clinical studies. These technologies could become complementary to the surgeon's eyes and may improve surgical outcomes in thyroidectomy and parathyroidectomy. Here, we conducted a systematic review focusing on PG identification and functional assessment using optical methods to enhance surgery. A systematic literature review was performed using MEDLINE and Embase database. Two authors selected studies and extracted data; qualitative analysis was performed to summarize the characteristics of reported optical tools for thyroidectomy or parathyroidectomy. Identification and vascularisation of PG during surgery were evaluated. Clinical and biochemical outcomes were appraised when reported. Studies relating to parathyroidectomy or thyroidectomy combined with autofluorescence, fluorescent methylene blue, 5-aminolevulinic acid, indocyanine green (ICG), optical coherence tomography, laser speckle contrast imaging, dynamic optical contrast imaging and Raman spectroscopy were identified with MEDLINE and Embase. We included a total of 47 relevant articles with a total of 1615 patients enrolled. Each optical technique is described and appreciated related to its surgical purpose. Autofluorescence and ICG imaging of PG are the most widely reported optical technologies for identification and assessment of vascularisation of PG. Results are mainly based on observational studies and argue for the feasibility of both techniques in endocrine surgery but prospective randomized studies have not been performed. In vivo applications are still limited for the other methods and further investigations correlating these techniques with post-operative parathormone measurements are still needed before considering these technologies in clinical practice.

Complete regression of branching vascular network in polypoidal choroidal vasculopathy by ranibizumab and photodynamic therapy, two case reports

BACKGROUND

Polypoidal choroidal vasculopathy (PCV) consists of polyps that potentially cause massive subretinal hemorrhage and their branching vascular network (BVN) of feeder vessels. Although conventional indocyanine green angiography (IA) has shown anti-vascular endothelial growth factor (VEGF) agents and/or photodynamic therapy (PDT) to successfully induce polyp closure, the BVN appears resistant to these therapies and serves as the origin of recurrent active polyps. Recently introduced optical coherence tomography angiography (OCT-A) enables more frequent angiographic evaluation of polyps and the BVN than does conventional IA since it does not require intravenous fluorescent dye injection and is thus considered non-invasive.

CASE PRESENTATION

Case 1. A 70-year-old male with PCV in his left eye suffered from vision deterioration (20/40) due to persistent subretinal fluid despite 42 intravitreal injections of ranibizumab (IVRs) over 5 years and 7 months. PDT was performed as an adjunct therapy 3 days after the 43rd IVR. IA at 3 months after PDT showed successful polyp closure but persisting BVN. However, more frequent evaluation with OCT-A starting at 1 week after PDT demonstrated complete regression of both the BVN and polyp. OCT-A at every subsequent outpatient visit depicted gradual re-perfusion of the BVN and the restoration of most of its original network at 3 months, which was compatible with IA findings. Neither OCTA nor IA revealed polyp recurrence at 3 months. Case 2. A 65-year-old female suffering from left vision deterioration due to PCV underwent 5 intravitreal injections of aflibercept. Since her subretinal fluid persisted, the treatment was switched to a combination of IVR and PDT. OCT-A revealed marked regression of the BVN and polyp at 2 weeks, but the BVN had regained its original shape at 2 months without any sign of polyp recurrence.

CONCLUSIONS

Differently from previous observations obtained by IA alone, more frequent non-invasive OCT-A examination revealed complete but transient regression of the BVN just after combination therapy with IVR and PDT.

Detection of microvascular retinal changes in type I diabetic mice with optical coherence tomography angiography

Optical coherence tomography (OCT) angiography is a dye-free and non-invasive angiography which allows visualization of retinal and choroid vascular flow, enabling observation of highly permeable and three dimensional vasculature. Although OCT angiography is providing new insights in human retinal and choroidal diseases, a few studies have been reported in experimental mice. In this study, to determine the potential of OCT angiography in experimental mice, we sought to examine whether OCT angiography can detect vascular change in type I diabetic mice. To conduct age dependent analysis, 2 and 6 month old male type 1 diabetic Ins2^Akita/+ and age matched C57BL/6J mice were used. OCT angiography was performed by Heidelberg Spectralis OCT Angiography Module with 30° lens + mouse adapter lens. We acquired the OCT angiography image from the peripheral nasal position. For analysis of OCT angiography images, OCT angiography positive area were used for vascular density. We analyzed vascular density from the retinal surface (inner limiting membrane) to 120 μm depth with 4 μm steps in order to correlate vascular density vs depth (N = 4 per group). Vascular density of both mouse strains demonstrated three different peaks. By comparing with the OCT image, the first peak (superficial), second peak (intermediate) and third peak (deep) were located in nerve fiber layer/ganglion cell layer, inner plexiform layer/inner nuclear layer and outer plexiform layer/outer nuclear layer, respectively. We calculated vascular density of these peaks separately. In C57BL/6J mice, the vascular density in all three layers do not show significant difference between 2- and 6-month-old. On the other hand, 6-month-old Ins2^Akita/+ mice showed a significant decrease of the vascular density in all three layers compared to 2-month-old Ins2^Akita/+ mice. Also, the vascular density of 6-month-old Ins2^Akita/+ mice in the deep layer showed a significant decrease compared to 2- and 6-month-old C57BL/6J mice. Thus, OCT angiography successfully detects retinal vascular difference between type I diabetic mice and control mice, and age-dependent vasculature change in type I diabetic mice. The diabetic mice demonstrated reduced vascular density due to reduced density of flowing deep vessels. Importantly, we observed this difference without retinal blood leakage, hemorrhage or neovascularization. Our analysis (vascular density vs retinal depth) suggests that OCT angiography is useful for in vivo detection of retinal vasculature alteration in experimental mice.

Laser-Assisted Indocyanine Green Imaging for Assessment of Perioperative Maxillary Perfusion During Le Fort I Osteotomy: A Pilot Study

PURPOSE

To determine the changes in maxillary perfusion during different stages of Le Fort I osteotomies as measured by laser-assisted indocyanine green imaging (LAICGI) and to determine whether various clinical factors affect maxillary vascular perfusion.

MATERIALS AND METHODS

The medical records of those who had undergone Le Fort I osteotomy with LAICGI at the University of Illinois from 2016 to 2017 were reviewed retrospectively. The maxillary perfusion levels using LAICGI were measured before induction, after induction, after down fracture, after segmentalization (for segmental osteotomies), and after wound closure. The effects of clinical variables, including gender, race, American Society of Anesthesiologists physical status, type of Le Fort I osteotomy, intraoperative status of the descending palatine vessels, maxillary movements (anteroposterior, vertical, transverse), and hemodynamic data (mean arterial blood pressure, heart rate), were analyzed.

RESULTS

Compared with the preoperative baseline values, the indocyanine green (ICG) levels decreased after down fracture and mobilization, segmentalization, and wound closure; no statistically significant differences were found among these 3 points. Segmentalization did not affect the ICG levels compared with the nonsegmentalized cases. Male gender and the amount of maxillary impaction were significantly associated statistically with decreased ICG levels, although the difference was not clinically significant.

CONCLUSIONS

Compared with the baseline levels, maxillary perfusion, as measured by LAICGI, decreased from down fracture to wound closure. Segmentalization did not appear to influence maxillary perfusion, although male gender and impaction were associated with decreased perfusion. Because of its safety and convenience, LAICGI shows promise as a method of assessing maxillary perfusion in future largescale prospective studies linking perioperative perfusion to the occurrence of aseptic necrosis.

Optimizing the image of fluorescence cholangiography using ICG: a systematic review and ex vivo experiments

Background

Though often only briefly described in the literature, there are clearly factors that have an influence on the fluorescence intensity, and thereby the usefulness of the technique. This article aims to provide an overview of the factors influencing the fluorescence intensity of fluorescence imaging with Indocyanine green, primarily focussed on NIRF guided cholangiography.

Methods

A systematic search was conducted to gain an overview of currently used methods in NIRF imaging in laparoscopic cholecystectomies. Relevant literature was searched to gain advice on what methods to use. Ex vivo experiments were performed to assess various factors that influence fluorescence intensity and whether the found clinical advices can be confirmed.

Results

ICG is currently the most widely applied fluorescent dye. Optimal ICG concentration lies between 0.00195 and 0.025 mg/ml, and this dose should be given as early as achievable—but maximum 24 h—before surgery. When holding the laparoscope closer and perpendicular to the dye, the signal is most intense. In patients with a higher BMI and/or cholecystitis, fluorescence intensity is lower, but NIRF seems to be more helpful. There are differences between various marketed fluorescence systems. Also, no uniform method to assess fluorescence intensity is available yet.

Conclusions

This study identified and discussed several factors that influence the signal of fluorescence cholangiography. These factors should be taken into account when using NIRF cholangiography. Also, surgeons should be aware of new dyes and clinical systems, in order to benefit most from the potential of NIRF imaging.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6233-x) contains supplementary material, which is available to authorized users.

Evolution in sentinel lymph node biopsy in breast cancer

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in clinically node-negative (cN0) breast cancer patients without neoadjuvant chemotherapy (NAC). The application of SLNB in patients receiving NAC has also been explored. Evidence supports its use after NAC in pretreatment cN0 patients. Nonetheless, its routine use in all the pretreatment node-positive patients who become cN0 after NAC is unjustified due to the unacceptably high false-negative rate, which can be improved in a subset of patients. Axillary surgery omission in selected patients with a low risk of ALN metastasis has gained more and more research interest because the SLNs are tumor-free in more than 70% of all patients. To avoid drawbacks of conventional mapping methods, novel techniques for SLN detection have been developed and shown to be highly accurate in patients with early breast cancer. This article reviews the progress in SLNB in patients with breast cancer.