Intravenous Administration Of Indocyanine Green Research Articles

Near-infrared cholangiography with intragallbladder indocyanine green injection in minimally invasive cholecystectomy.

Laparoscopic cholecystectomy (LC) remains one of the most commonly performed procedures in adult and paediatric populations. Despite the advances made in intraoperative biliary anatomy recognition, iatrogenic bile duct injuries during LC represent a fatal complication and consist an economic burden for healthcare systems. A series of methods have been proposed to prevent bile duct injury, among them the use of indocyanine green (ICG) fluorescence. The most commonly reported method of ICG injection is the intravenous administration, while literature is lacking studies investigating the direct intragallbladder ICG injection. This narrative mini-review aims to assess the potential applications, usefulness, and limitations of intragallbladder ICG fluorescence in LC. Authors screened the available international literature to identify the reports of intragallbladder ICG fluorescence imaging in minimally invasive cholecystectomy, as well as special issues regarding its use. Literature search retrieved four prospective cohort studies, three case-control studies, and one case report. In the three case-control studies selected, intragallbladder near-infrared cholangiography (NIRC) was compared with standard LC under white light, with intravenous administration of ICG for NIRC and with standard intraoperative cholangiography (IOC). In total, 133 patients reported in the literature have been administered intragallbladder ICG administration for biliary mapping during LC. Literature includes several reports of intragallbladder ICG administration, but a standardized technique has not been established yet. Published data suggest that NIRC with intragallbladder ICG injection is a promising method to achieve biliary mapping, overwhelming limitations of IOC including intervention and radiation exposure, as well as the high hepatic parenchyma signal and time interval needed in intravenous ICG fluorescence. Evidence-based guidelines on the role of intragallbladder ICG fluorescence in LC require the assessment of further studies and multicenter data collection into large registries.

Using ICG navigation in resection of a horseshoe kidney

BACKGROUND: In this publication, we present a new area of application of indocyanine green (ICG) imaging in pediatric surgery. We used this advanced method to evaluate the resection margins of a functional segment of the horseshoe kidney after intravenous indocyanine green. CLINICAL CASE DESCRIPTION: The article presents a case of treatment of a horseshoe kidney complicated by vesicorenal reflux in the left segment and loss of function of the left segment. Resection of the left half of the horseshoe kidney was performed using fluoroscopic control with intravenous administration of indocyanine green. The surgery was performed using the RUBINA™ endovideosurgical system manufactured by KARL STORZ (Germany). RUBINA™ components offer a variety of ICG in near-infrared fluorescence signal imaging modes. Depending on the surgeon and the application, ICG in near-infrared fluorescence data can be used in different modes: image overlay mode, backup mode, color mapping mode. After confirming the boundaries of the perfused part of the kidney, laparoscopic resection of the functional half was performed at the level of the isthmus. The use of ICG imaging was very important in identifying healthy tissue that stained intensely green 2 minutes after intravenous indocyanine green administration. This margin check verifies the functioning renal parenchyma and allows the correct selection of the nephrectomy margin. The next day after the operation, an ultrasound examination of the renal remnant and perinephric space was performed — the rotation to the right hour of the horseshoe-shaped kidney was good and no accumulation of fluid was detected in the bed of the removed segment. A control ultrasound examination 6 months after the operation showed the preservation of the parenchyma of the right half of the kidney, which indicates the positive effect of the surgical procedure. CONCLUSION: ICG navigation is a promising method for noninvasive assessment of resection margins in patients with horseshoe kidneys.

Geotemporal Fluorophore Biodistribution Mapping of Colorectal Cancer: Micro and Macroscopic Insights.

Fifty consenting patients undergoing treatment for suspected/confirmed colorectal neoplasia provided near infrared (NIR) video and imagery of transanally recorded and ex vivo resected rectal lesions following intravenous ICG administration (0.25 mg/kg), with a subgroup providing tissue samples for microscopic (including near infrared) analysis. Computer vision techniques detailed macroscopic 'early' (<15 min post ICG administration) and 'late' (>2 h) tissue fluorescence appearances from surgical imagery with digital NIR scanning (Licor, Lincoln, NE, USA) and from microscopic analysis (Nikon, Tokyo, Japan) undertaken by a consultant pathologist detailing tissue-level fluorescence distribution over the same time. Significant intra-tumoural fluorescence heterogeneity was seen 'early' in malignant versus benign lesions. In all 'early' samples, fluorescence was predominantly within the tissue stroma, with uptake within plasma cells, blood vessels and lymphatics, but not within malignant or healthy glands. At 'late' stage observation, fluorescence was visualised non-uniformly within the intracellular cytoplasm of malignant tissue but not retained in benign glands. Fluorescence also accumulated within any present peritumoural inflammatory tissue. This study demonstrates the time course diffusion patterns of ICG through both benign and malignant tumours in vivo in human patients at both macroscopic and microscopic levels, demonstrating important cellular drivers and features of geolocalisation and how they differ longitudinally after exposure to ICG.

Intraoperative assessment of anastomotic blood supply using indocyanine green fluorescence imaging following esophagojejunostomy or esophagogastrostomy for gastric cancer.

This retrospective study aimed to evaluate the feasibility and safety of intraoperative assessment of anastomotic blood supply in patients undergoing esophagojejunostomy or esophagogastrostomy for gastric cancer using Indocyanine Green Fluorescence Imaging (IGFI). From January 2019 to October 2021, we conducted a retrospective analysis of patients who had undergone laparoscopic gastrectomy for the treatment of gastric cancer. The patients were consecutively enrolled and categorized into two study groups: the Indocyanine Green Fluorescence Imaging (IGFI) group consisting of 86 patients, and the control group comprising 92 patients. In the IGFI group, intravenous administration of Indocyanine Green (ICG) was performed, and we utilized a fluorescence camera system to assess anastomotic blood supply both before and after the anastomosis. The demographic characteristics of patients in both groups were found to be comparable. In the IGFI group, the mean time to observe perfusion fluorescence was 26.3 ± 12.0 seconds post-ICG injection, and six patients needed to select a more proximal resection point due to insufficient fluorescence at their initial site of choice. Notably, the IGFI group exhibited a lower incidence of postoperative anastomotic leakage, with no significant disparities observed in terms of pathological outcomes, postoperative recovery, or other postoperative complication rates when compared to the control group (p > 0.05). This study underscores the potential of IGFI as a dependable and pragmatic tool for the assessment of anastomotic blood supply following esophagojejunostomy or esophagogastrostomy for gastric cancer. The use of IGFI may potentially reduce the occurrence of postoperative anastomotic leakage.

MA11.10 Intravenous Indocyanine Green Administration Provides Sufficient Margins in Pulmonary Segmentectomy

MA11.10 Intravenous Indocyanine Green Administration Provides Sufficient Margins in Pulmonary Segmentectomy

Use of indocyanine green in the resection of renal cysts in children

Fluorescent imaging technology with indocyanine green (ICG) is used to improve intraoperative visualization of the anatomical structures of the affected organs and increase the efficiency of laparoscopic or robotic operations. Recently, ICG imaging has been used in pediatric gastroenterology, oncology, and urology.&#x0D; In this study, we present laparoscopic treatment of two cases of simple renal cysts in two male patients aged 10 and 12 years. Resection of the extrarenal portion of the kidney cyst was performed using fluoroscopic control by intravenous administration of ICG. The intrarenal residue was subjected to argon-plasma coagulation. Treatment outcomes were assessed over a follow-up period of 6 and 12 months. The cyst sizes measured before surgery using ultrasound and computed tomography were 50 and 70 mm. Both cysts were located in the lower pole of the right kidney. The operation times were 40 and 45 min. During the surgical intervention, no complications such as bleeding from the kidney parenchyma or damage to neighboring organs occurred. In all cases, the cyst contained a clear liquid without pathological impurities. The cytological examination revealed a low cell content, which was represented by single macrophages and urothelial cells. Histological analysis revealed that the lining of the cyst wall was represented by the transitional epithelium without signs of malignancies. The hospital length of stay was 3 days. Ultrasound examinations performed 1, 3, 6, and 12 months after the operation did not detect signs of disease recurrence. Thus, based on the presented clinical case, the main advantage of using fluorescent technology during kidney cyst resection include a clear definition of the demarcation line between the avascular wall of the cyst and the perfused kidney tissue, which helps prevent bleeding from the renal parenchyma.

ICG technologies in surgical treatment of benign diseases in gynecology

ICG (indocyanine green) angiography is a method of visualizing blood flow and tissue perfusion based on intravenous administration of ICG and assessment of vascular distribution through an infrared fluorescence camera. Since the advent of ICG as a near-infrared fluorophore, fluorescence imaging has become an important tool in many areas of surgery. Several options for ICG angiography have been recently proposed in surgical gynecology. The authors describe application of ICG including assessment of myometrial and endometrial perfusion in myomectomy or resection of adenomyosis, tissue perfusion in surgical treatment of endometriosis, blood flow in hard-to-reach places in laparoscopic procedures and reconstructive surgery. ICG was useful in laparoscopic management of some benign gynecological diseases. In particular, this technology can improve treatment of endometriosis, especially deep infiltrative endometriosis, benign neoplasms.

Intracholecystic versus Intravenous Indocyanine Green (ICG) Injection for Biliary Anatomy Evaluation by Fluorescent Cholangiography during Laparoscopic Cholecystectomy: A Case-Control Study.

(1) Background: Fluorescence cholangiography has been proposed as a method for improving the visualization and identification of extrahepatic biliary anatomy in order to possibly reduce injuries and related complications. The most common method of indocyanine green (ICG) administration is the intravenous route, whereas evidence on direct ICG injection into the gallbladder is still quite limited. We aimed to compare the two different methods of ICG administration in terms of the visualization of extrahepatic biliary anatomy during laparoscopic cholecystectomy (LC), analyzing differences in the time of visualization, as well as the efficacy, advantages, and disadvantages of both modalities. (2) Methods: A total of 35 consecutive adult patients affected by acute or chronic gallbladder disease were enrolled in this prospective case–control study. Seventeen patients underwent LC with direct gallbladder ICG injection (IC-ICG) and eighteen subjects received intravenous ICG administration (IV-ICG). (3) Results: The groups were comparable with regard to their demographic and perioperative characteristics. The IV-ICG group had a significantly shorter overall operative time compared to the IC-ICG group (p = 0.017). IV-ICG was better at delineating the duodenum and the common hepatic duct compared to the IC-ICG method (p = 0.009 and p = 0.041, respectively). The cystic duct could be delineated pre-dissection in 76.5% and 66.7% of cases in the IC-ICG and IV-ICG group, respectively, and this increased to 88.2% and 83.3% after dissection. The common bile duct could be highlighted in 76.5% and 77.8% of cases in the IC-ICG and IV-ICG group, respectively. Liver fluorescence was present in one case in the IC-ICG group and in all cases after IV-ICG administration (5.8% versus 100%; p < 0.0001). (4) Conclusions: The present study demonstrates how ICG-fluorescence cholangiography can be helpful in identifying the extrahepatic biliary anatomy during dissection of Calot’s triangle in both administration methods. In comparison with intravenous ICG injection, the intracholecystic ICG route could provide a better signal-to-background ratio by avoiding hepatic fluorescence, thus increasing the bile duct-to-liver contrast.

Normalization of Time-Intensity Curves for Quantification of Foot Perfusion Using Near-Infrared Fluorescence Imaging With Indocyanine Green

Purpose: Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) is gaining popularity for the quantification of tissue perfusion, including foot perfusion in patients with lower extremity arterial disease (LEAD). However, the absolute fluorescence intensity is influenced by patient—and system-related factors limiting reliable and valid quantification. To enhance the quality of quantitative perfusion assessment using ICG NIR fluorescence imaging, normalization of the measured time-intensity curves seems useful. Materials and Methods: In this cohort study, the effect of normalization on 2 aspects of ICG NIR fluorescence imaging in assessment of foot perfusion was measured: the repeatability and the region selection. Following intravenous administration of ICG, the NIR fluorescence intensity in both feet was recorded for 10 mins using the Quest Spectrum platform®. The effect of normalization on repeatability was measured in the nontreated foot in patients undergoing unilateral revascularization preprocedural and postprocedural (repeatability group). The effect of normalization on region selection was performed in patients without LEAD (region selection group). Absolute and normalized time-intensity curves were compared. Results: Successful ICG NIR fluorescence imaging was performed in 54 patients (repeatability group, n = 38; region selection group, n = 16). For the repeatability group, normalization of the time-intensity curves displayed a comparable inflow pattern for repeated measurements. For the region selection group, the maximum fluorescence intensity (Imax) demonstrated significant differences between the 3 measured regions of the foot (P = .002). Following normalization, the time-intensity curves in both feet were comparable for all 3 regions. Conclusion: This study shows the effect of normalization of time-intensity curves on both the repeatability and region selection in ICG NIR fluorescence imaging. The significant difference between absolute parameters in various regions of the foot demonstrates the limitation of absolute intensity in interpreting tissue perfusion. Therefore, normalization and standardization of camera settings are essential steps toward reliable and valid quantification of tissue perfusion using ICG NIR fluorescence imaging.

Novel thoracoscopic segmentectomy combining preoperative three-dimensional image simulation and intravenous administration of indocyanine green

OBJECTIVESThe aim of this study is to assess prospectively the validity and feasibility of segmentectomy using preoperative simulation and intravenous indocyanine green (ICG) with near-infrared (NIR) light thoracoscope to ensure a sufficient surgical margin.METHODSThis study was a prospective, single-centre, phase II, feasibility study. From February to July 2021, 20 patients were enrolled in this study. All patients underwent preoperative three-dimensional computed tomography angiography and bronchography using simulation software. The dominant pulmonary artery of the targeted segment was selected to determine the dissection line and measure the surgical margin to the tumour. Intraoperatively, after the planned dissection of the pulmonary artery, ICG (0.3 mg/kg) was administered intravenously and observed with NIR, and dissection was performed along the line determined by preoperative simulation. Postoperatively, the pathological margin was compared with the simulation margin.RESULTSAll surgeries were performed via an uniport (3.5–4.0-cm skin incision). The regions of segmentectomy were S2, S3, S6, S9 + 10 and S10 of the right side and S1 + 2 + 3, S3, S3 + 4 + 5, S6 and S8 of the left side. The difference between the simulation margin and the pathological margin was not significant (simulation 30.5 ± 10.1 vs pathological 31.0 ± 11.0 mm, P = 0.801). The simulation margin was well correlated with the pathological margin (R2 = 0.677). The proportion of cases successfully achieving the pathological margin of error of plus or minus 10 mm of the simulation margin was 90% (18 of 20 cases).CONCLUSIONSThe combination of preoperative three-dimensional computed tomography simulation and ICG–NIR was effective for securing a sufficient margin in segmentectomy.

Colorectal Liver Metastases Confirmation and Delineation Using Indocyanine Green Perfusion Quantification, Computer Vision and Machine Learning Methods

Fluorescence guided surgery utilizes near infrared imaging systems to detect the presence of intravenously administered Indocyanine Green (ICG), an albumin-binding fluorophore, to create a perfusion angiogram. Simple snapshot observation for ICG after predosing alone has identified colorectal metastases within the liver, the excretory organ for ICG, albeit with poor sensitivity. Dynamic perfusion pattern analysis using computer vision and machine learning methods may do better re predictive accuracy and margination. Patients with colorectal liver metastases (CLM) undergoing diagnostic and therapeutic procedures at a high-volume hepatobiliary unit were imaged continuously for up to ten minutes following intraoperative intravenous ICG administration (0.05mg/kg) using the Pinpoint/Stryker near infra-red imaging system(Fig1a). Motion (camera movement and tissue deformation) in the resulting multispectral videos was compensated by application of the estimated pixel movement between frames in the white light imagery in reverse. Fluorescence intensity/time curves were subsequently extracted for each pixel(Fig1b) in the corresponding near infrared sequences. Machine learning was then applied to classify tissue (liver vs CLM) using a single feature algorithm. 2d representations were created based on time/fluorescence centre of mass(Fig1c) with diverging colour maps of outflow slope(Fig1d) for boundary delineation. Metastases were successfully detected and classified in all cases (n=6). 2d boundary maps accurately recreated the visualised tissue morphology in perfusion time-series including clear boundary demarcations. Fluorescence angiograms, in combination with computer vision and machine learning methods, can be used to confirm and delineate colorectal liver metastases. The 2D boundary maps, created through interrogation of tissue perfusion, can provide real time intra-operative guidance.

Infrared thoracoscopic pulmonary segmentectomy with intravenous indocyanine green administration using preoperative simulation.

Infrared thoracoscopy with intravenous indocyanine green administration is one of the useful methods to identify an appropriate intersegmental line during thoracoscopic pulmonary segmentectomy. In this procedure, we have introduced preoperative simulation to calculate the distance between the target tumour and intersegmental plane using Ziostation2 (Ziosoft, Tokyo, Japan) to ensure sufficient surgical margin without palpation. By using this preoperative simulation, we obtained sufficient surgical margin in a patient with a 16-mm part-solid nodular shadow undergoing infrared thoracoscopic upper division (S1-3) segmentectomy of left upper lobe with intravenous indocyanine green administration. The discrepancy between the virtual and the actual surgical margin was <10 mm. This preoperative simulation can help us obtain sufficient surgical margin without palpation of the tumour in infrared thoracoscopic segmentectomy.

Assessment of Tissue Viability Following Amputation Surgery Using Near-Infrared Fluorescence Imaging With Indocyanine Green

Patients with chronic limb threatening ischemia have a risk of undergoing a major amputation within 1 year of nearly 30% with a substantial risk of re-amputation since wound healing is often impaired. Quantitative assessment of regional tissue viability following amputation surgery can identify patients at risk for impaired wound healing. In quantification of regional tissue perfusion, near-infrared (NIR) fluorescence imaging using Indocyanine Green (ICG) seems promising. This pilot study included adult patients undergoing lower extremity amputation surgery due to peripheral artery disease or diabetes mellitus. ICG NIR fluorescence imaging was performed within 5 days following amputation surgery using the Quest Spectrum PlatformⓇ. Following intravenous administration of ICG, the NIR fluorescence intensity of the amputation wound was recorded for 10 minutes. The NIR fluorescence intensity videos were analyzed and if a fluorescence deficit was observed, this region was marked as "low fluorescence." All other regions were marked as "normal fluorescence." Successful ICG NIR fluorescence imaging was performed in 10 patients undergoing a total of 15 amputations. No "low fluorescence" regions were observed in 11 out of 15 amputation wounds. In 10 out of these 11 amputations, no wound healing problems occurred during follow-up. Regions with "low fluorescence" were observed in 4 amputation wounds. Impaired wound healing corresponding to these regions was observed in all wounds and a re-amputation was necessary in 3 out of 4. When observing time-related parameters, regions with low fluorescence had a significantly longer time to maximum intensity (113 seconds vs. 32 seconds, P=0.003) and a significantly lesser decline in outflow after five minutes (80.3% vs. 57.0%, P=0.003). ICG NIR fluorescence imaging was able to predict postoperative skin necrosis in all four cases. Quantitative assessment of regional perfusion remains challenging due toinfluencing factors on the NIR fluorescence intensity signal, including camera angle, camera distance and ICG dosage. This was also observed in this study, contributing to a large variety in fluorescence intensity parameters among patients. To provide surgeons with reliable NIR fluorescence cut-off values for prediction of wound healing, prospective studies on the intra-operative use of this technique are required. The potential prediction of wound healing using ICG NIR fluorescence imaging will have a huge impact on patient mortality, morbidity as well as the burden of amputation surgery on health care.

The role of indocyanine green cholangiography in minimally invasive surgery.

Near-infrared fluorescent cholangiography (NIFC) using indocyanine green (ICG) is increasingly used to aid in the identification of extrahepatic biliary anatomy. The use of ICG cholangiography for laparoscopic cholecystectomy is suggested to be safe and feasible. This article aimed at reviewing the dosage and timing of the intravenous administration of ICG, its efficacy and potential usage. MEDLINE and PubMed searches were performed using the key words "fluorescent cholangiography," "ICG cholangiography," "near-infrared fluorescent cholangiography" and "laparoscopic cholecystectomy" to identify relevant articles published in English during the years of 2010 to 2020. Reference lists from the articles were reviewed to identify additional pertinent articles. Several factors can influence the quality of the fluorescence imaging, including the dose and timing of ICG injection, liver function, the thickness of fatty tissue and the presence of inflamed tissues due to acute pathology. Various devices tested also have a different sensitivity to the fluorescence signal. RCTs showed fluorescence cholangiography were comparable to traditional intraoperative cholangiogram in visualizing the extrahepatic biliary anatomy. However, there is still no consensus in the dosing of ICG and the time interval between ICG injection and detection of biliary fluorescence. Fluorescence cholangiography's ability to enhance such visualization can potentially reduce bile duct injury risks and shorten the operative time. However, no valuable data for bile duct injury prevention or detection could be retrieved. NIFC is demonstrated as a safe, non-irradiating technique to identify and aid in the visualization of extrahepatic biliary anatomy. Laparoscopic cholecystectomy with real-time NIFC enables a better visualization and identification of biliary anatomy and therefore it is potentially as a means of increasing the safety of laparoscopic cholecystectomy. Whether this translates into reducing complication rates must still be determined. The dosage and timing of the intravenous administration of ICG relative to the operative procedure still requires optimization to ensure reliable images.

Comparative study on the diagnostic value of intravenous/peritumoral injection of indocyanine green for metastatic lymph node location in patients with head and neck squamous cell carcinoma (HNSCC).

BackgroundAccurate assessment of regional lymph node (LN) status is essential for the treatment of head and neck squamous cell carcinoma (HNSCC) patients. In this study, we aimed to compare the difference between intravenous injection of indocyanine green (ICG) and peritumoral injection of ICG in the location of metastatic LNs.MethodsTwenty-nine patients were enrolled in this study with 13 patients receiving intravenous injection of ICG and 16 patients receiving peritumoral injection of ICG. During the surgery, the fluorescence-positive LNs in vivo were sent to undergo frozen section after fluorescence intensity was recorded. After the cervical LN dissection, all LNs were sorted by region, and the fluorescence intensity was recorded before the LNs were sent for paraffin section.ResultsDuring the surgery, both intravenous or peritumoral injections with near-infrared (NIR) fluorescence imaging of ICG had their respective pros and cons in vivo, with the sensitivity and specificity being 62.5%/75% and 98.1%/89.1% respectively. After the surgery, both methods could reduce the pathological workload by preselecting the LNs at-risk in the premise of accurate assessing the cervical LN stage. However, intravenous ICG administration was more valuable in determining all types of LN status according to the fluorescence intensity [area under the curve (AUC): 0.91 vs. 0.78, P<0.001].ConclusionsWith the assistance of NIR fluorescence imaging using ICG, both administration methods could reduce the postoperative complication and the pathological workload, whereas the intravenous mode of ICG administration is superior in application value.

Evaluation of Intraoperative Near-Infrared Fluorescence Visualization of the Lung Tumor Margin With Indocyanine Green Inhalation

Identification of the tumor margin during surgery is important for precise minimal resection of lung tumors. Intravenous injection of indocyanine green (ICG) has several limitations when used for intraoperative visualization of lung cancer. To describe a technique for intraoperative visualization of lung tumor margin using ICG inhalation and evaluate the clinical applicability of the technique in mouse and rabbit lung tumor models as well as lung specimens of patients with lung tumors. In lung tumor models of both mice and rabbits, the distribution of inhaled ICG in the lung tumor margin was investigated in vivo and ex vivo using a near-infrared imaging system. Lung tumor margin detection via inhalation of ICG was evaluated by comparing the results obtained with those of the intravenous injection method (n = 32, each time point for 4 mice). Based on preclinical data, use of ICG inhalation to help detect the tumor margin in patients with lung cancer was also evaluated (n = 6). This diagnostic study was conducted from May 31, 2017, to March 30, 2019. The use of tumor margin detection by inhaled ICG was evaluated by comparing the inhaled formulation with intravenous administration of ICG. From 10 minutes after inhalation of ICG to 24 hours, the distribution of ICG in the lungs was significantly higher than that in other organs (signal to noise ratio in the lungs: 39 486.4; interquartile range [IQR], 36 983.74-43 592.5). Ex vivo and histologic analysis showed that, in both lung tumor models, inhaled ICG was observed throughout the healthy lung tissue but was rarely found in tumor tissue. The difference in the fluorescent signal between healthy and tumor lung tissues was associated with the mechanical airway obstruction caused by the tumor and with alveolar macrophage uptake of the inhaled ICG in healthy tissues. Inhalation at a 20-fold lower dose of ICG had a 2-fold higher efficiency for tumor margin detection than did the intravenous injection (2.9; IQR, 2.7-3.2; P < .001). The results of this study suggest that lung-specific inhalation delivery of ICG is feasible and may be useful for the intraoperative visualization of lung tumor margin in clinical practice.

Fluorescence-enabled assessment of adrenal gland localization and perfusion in posterior retroperitoneoscopic adrenal surgery in a preclinical model.

The posterior retroperitoneoscopic adrenal access represents a challenge in orientation and working space creation. The aim of this experimental acute study was to evaluate the impact of computer-assisted quantitative fluorescence imaging on adrenal gland identification and assessment of intraoperative remnant perfusion for adrenal resection in the posterior retroperitoneoscopic approach. Six pigs underwent simultaneous (n = 5) or sequential (n = 1) bilateral posterior retroperitoneoscopic adrenalectomy (n = 12). Fluorescence imaging was obtained via intravenous administration of 3mL of Indocyanine Green (ICG) and by switching the camera systems to near-infrared mode (D-LIGHT P, KARL STORZ; Germany). Fluorescence-based visualization of adrenal glands before vascular division (n = 4), after the main vascular pedicle ligation (negative control, n = 1) or after adrenal resection (n = 7), was followed by completion adrenalectomy. The fluorescence signal intensity dynamics were recorded and analyzed using proprietary software. For each pixel, the slope of fluorescence signal intensity evolution over time was translated into a color-coded perfusion cartography, which was superimposed onto real-time images obtained with the corresponding left and right camera systems. Quantitative fluorescence signal analysis in the regions of interest (ROIs) served to assess adrenal remnant perfusion in divided adrenal glands. In the retroperitoneum, the vascular anatomy was illuminated in fluorescence imaging first. The adrenal glands were promptly highlighted after primary intravenous ICG administration (n = 9) or showed a fluorescence signal intensity increase upon reinjection (n = 3). Quantitative fluorescence analysis showed a statistically significant difference between perfused and ischemic segments in divided glands (p = 0.0156). Fluorescence imaging provides real-time guidance during minimally invasive adrenal surgery. Prior to dissection, it allows to easily discriminate the adrenal gland from surrounding retroperitoneal structures. After adrenal gland division, ICG injection associated with a computer-assisted quantitative analysis helps to distinguish between well-perfused and ischemic segments. Further studies are underway to establish the correlation between remnant perfusion and viability.

Routine near infra-red indocyanine green fluorescent cholangiography versus intraoperative cholangiography during laparoscopic cholecystectomy: a case-matched comparison.

The aim is to evaluate safety and efficacy of near infra-red (NIR) indocyanine green (ICG) fluorescence structural imaging during laparoscopic cholecystectomy (LC) (Group A) and to compare perioperative data, including operative time, with a series of patients who underwent LC with routine traditional intraoperative cholangiography (IOC) (Group B). Forty-four patients with acute or chronic cholecystitis underwent NIR-ICG fluorescent cholangiography during LC. ICG was administered intravenously at different time intervals or by direct gallbladder injection during surgery. Fluorescence intensity and anatomy identification were scored according to a visual analogue scale between 1 (least accurate) and 5 (most accurate). Group B patients (n = 44) were chosen from a prospectively maintained database of patients who underwent LC with routine IOC, matched for age, sex, body mass index, and diagnosis with group A patients. No adverse reactions were recorded. In group A, mean time between intravenous administration of ICG and surgery was 10.7 ± 8.2 (range 2-52)h. Administered doses ranged from 3.5 to 13.5mg. Fluorescence was present in all cases, scoring ≥ 3 in 41 patients. Mean operative time was 86.9 ± 36.9 (30-180)min in group A and 117.9 ± 43.4 (40-220)min in group B (p = 0.0006). No conversion to open surgery nor bile duct injuries were observed in either group. LC with NIR-ICG fluorescent cholangiography is safe and effective for early recognition of anatomical landmarks, reducing operative time as compared to LC with IOC, even when residents were the main operator. NIR-ICG fluorescent cholangiography was effective in patients with acute cholecystitis and in the obese. Data collection into large registries on the results of NIR-ICG fluorescent cholangiography during LC should be encouraged to establish whether this technique might set a new safety standard for LC.

Intraoperative evaluation of blood flow for soft tissues in orthopaedic surgery using indocyanine green fluorescence angiography: A pilot study.

ObjectivesIndocyanine green (ICG) fluorescence angiography is an emerging technique that can provide detailed anatomical information during surgery. The purpose of this study is to determine whether ICG fluorescence angiography can be used to evaluate the blood flow of the rotator cuff tendon in the clinical setting.MethodsTwenty-six patients were evaluated from October 2016 to December 2017. The participants were categorized into three groups based on their diagnoses: the rotator cuff tear group; normal rotator cuff group; and adhesive capsulitis group. After establishing a posterior standard viewing portal, intravenous administration of ICG at 0.2 mg/kg body weight was performed, and fluorescence images were recorded. The time from injection of the drug to the beginning of enhancement of the observed area was measured. The hypovascular area in the rotator cuff was evaluated, and the ratio of the hypovascular area to the anterolateral area of the rotator cuff tendon was calculated (hypovascular area ratio).ResultsICG fluorescence angiography allowed for visualization of blood flow in the rotator cuff in all groups. The adhesive capsulitis group showed significantly earlier enhancement than the other groups. Furthermore, the adhesive capsulitis group had a significantly smaller hypovascular area ratio than the other groups.ConclusionICG fluorescence angiography allowed for evaluation of real-time blood flow of the rotator cuff in arthroscopic shoulder surgery. The techniques of ICG fluorescence angiography are simple and easy to observe, observer reliability is high, and it has utility for evaluating blood flow during surgery.Cite this article: N. Doi, T. Izaki, S. Miyake, T. Shibata, T. Ishimatsu, Y. Shibata, T. Yamamoto. Intraoperative evaluation of blood flow for soft tissues in orthopaedic surgery using indocyanine green fluorescence angiography: A pilot study. Bone Joint Res 2019;8:118–125. DOI: 10.1302/2046-3758.83.BJR-2018-0151.R1.

Indocyanine green fluorescence imaging for resection of pulmonary metastasis of hepatocellular carcinoma.

Indocyanine green (ICG) accumulates in hepatocellular carcinoma (HCC), and tumor fluorescence can be observed under irradiation with near infrared light (NIR). This study investigated the clinical utility of ICG fluorescence imaging during resection of pulmonary metastases of HCC. From April 2010 to June 2018, six patients with suspected pulmonary metastasis of HCC were enrolled prospectively. Prior to surgery, all patients underwent the ICG hepatic function test following intravenous administration of ICG (0.5 mg/kg body weight). During surgery, metastatic HCC was identified by observation of ICG fluorescence, allowing assessment of the surgical margin. Tumor fluorescence was also evaluated on cut sections. A total of 11 metastatic HCCs were resected in six patients at nine operations. Eight lesions were removed by wedge resection and 3 lesions were managed by lobectomy. During surgery, tumor fluorescence could be confirmed through the visceral pleura in 6 out of 7 lesions treated by wedge resection, while NIR irradiation was difficult for 1 lesion. For these 6 lesions, the median distance from the tumor to the visceral pleura and the median surgical margin were 0 mm (range, 0-2 mm) and 14 mm (range, 11-17 mm), respectively. When cut sections were examined, all tumors emitted fluorescence. All lesions were histologically confirmed to be metastatic HCC. In patients with pulmonary metastasis of HCC, ICG fluorescence imaging is useful for identifying the tumor and securing its margin when the lesion is peripheral and wedge resection is planned.