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

Single-Plane Retroperitoneoscopic Adrenalectomy Guided by Indocyanine Green Dye: An Optimized Step

Background: The objective of this study was to explore the perioperative outcomes of single-plane posterior retroperitoneoscopic adrenalectomy (SPRA) guided by indocyanine green dye (ICG) fluorescence imaging. Methods: A retrospective analysis of patients who underwent SPRA from April to September 2023 in our center was conducted. Patients were divided into the ICG group and the non-ICG group, based on whether they received intraoperative ICG fluorescence guided or not. Baseline and perioperative data were recorded and analyzed by R software (R 4.3.1). Results: A total of 23 patients were enrolled in the study, with 12 in the ICG group and 11 in the non-ICG group. The demographics including age, gender, body mass index, or American Society of Anesthesiologists classification showed no significant differences between groups. There were obvious advantages in shortening adrenal gland localization time and total operative time, as well as reducing estimated blood loss in the ICG group compared with the non-ICG group (5.58 ± 0.36 minutes vs 7.55 ± 0.62 minutes, p < 0.001; 27.50 ± 5.46 minutes vs 45.00 ± 10.99 minutes, p < 0.001; 22.91 ± 7.57 mL vs 54.54 ± 18.90 mL, p < 0.001; respectively). Furthermore, patients in the ICG group exhibited significantly lower visual analog pain scale scores at 24 hours postoperatively and at discharge (p = 0.001 and p = 0.006, respectively). The oral intake intervals, hospital stays, and perioperative complications were comparable between groups. Conclusions: ICG-guided SPRA could be a safe and effective procedure for patients with adrenal tumors. This technique improves the accuracy and efficacy of adrenal gland localization and has shown benefits in perioperative outcomes. The use of ICG fluorescence guidance represents a promising clinical application.

Identification of Structures Labeled by Indocyanine Green in the Rat Choroid and Retina Can Guide Interpretation of Indocyanine Green Angiography

Purpose

Indocyanine green (ICG) is an albumin and lipoprotein binding dye absorbing in the far red used in angiography to visualize choroidal vessels (ICG angiography [ICGA]). To guide interpretation, ICG transport in the choroid, RPE, and retina of rats was studied.

Methods

Two conditions were used: RPE/choroid organoculture, incubated for 45 minutes in DMEM medium, 1% fetal bovine serum containing 0.25 mg/mL ICG and RPE/choroid and neural retina flat-mounts at 1 and 6 hours after intravenous ICG injection. Early and late sequences of ICGA were recorded until 6 hours. Ultra-deep red confocal microscope was used to localize ICG in flat-mounts and immunohistochemistry was performed for caveolin-1, tryptase (mast cell marker), and tubulin β3 (a nerve marker).

Results

In the organoculture, ICG penetrated homogeneously in the cytoplasm and stained the membranes of the RPE. At 1 hour after intravenous injection, ICG appeared in fine granules in RPE, partly labeled with caveolin-1 and decreasing at 6 hours. At 1 hour and 6 hours, ICG was found in the retinal vessels, faintly in the inner retina, and in the photoreceptor outer segments at 6 hours. In the choroid, ICG colocalized with mast cells, immunostained with tryptase, and accumulated along the large tubulin β3-labeled nerve bundles. The hypothesis was raised on the interpretation of late ICGA infrared photography in case of transthyretin amyloidosis with neuropathy.

Conclusions

Beside being a vascular dye, ICG is transported from the vessels to the RPE toward the outer retina. It stains mast cells and large choroidal nerves. These observations could help the analysis of ICGA images.

Cavernous nerve mapping methods for radical prostatectomy

INTRODUCTION

Preserving the cavernous nerves, the main autonomic nerve supply of the penis, is a major challenge of radical prostatectomy. Cavernous nerve injury during radical prostatectomy predominantly accounts for post-radical prostatectomy erectile dysfunction. The cavernous nerve is a bilateral structure that branches in a weblike distribution over the prostate surface and varies anatomically in individuals, such that standard nerve-sparing methods do not sufficiently sustain penile erection ability. As a consequence, researchers have focused on developing personalized cavernous nerve mapping methods applied to the surgical procedure aiming to improve postoperative sexual function outcomes.

OBJECTIVES

We provide an updated overview of preclinical and clinical data of cavernous nerve mapping methods, emphasizing their strengths, limitations, and future directions.

METHODS

A literature review was performed via Scopus, PubMed, and Google Scholar for studies that describe cavernous nerve mapping/localization.

RESULTS

Several cavernous nerve mapping methods have been investigated based on various properties of the nerve structures including stimulation techniques, spectroscopy/imaging techniques, and assorted combinations of these methods. More recent methods have portrayed the course of the main cavernous nerve as well as its branches based on real-time mapping, high-resolution imaging, and functional imaging. However, each of these methods has distinctive limitations, including low spatial accuracy, lack of standardization for stimulation and response measurement, superficial imaging depth, toxicity risk, and lack of suitability for intraoperative use.

CONCLUSION

While various cavernous nerve mapping methods have provided improvements in identification and preservation of the cavernous nerve during radical prostatectomy, no method has been implemented in clinical practice due to their distinctive limitations. To overcome the limitations of existing cavernous nerve mapping methods, the development of new imaging techniques and mapping methods is in progress. There is a need for further research in this area to improve sexual function outcomes and quality of life after radical prostatectomy.

Exploring the Applications of Indocyanine Green in Robot-Assisted Urological Surgery: A Comprehensive Review of Fluorescence-Guided Techniques

This comprehensive review aims to explore the applications of indocyanine green (ICG) in robot-assisted urological surgery through a detailed examination of fluorescence-guided techniques. An extensive literature search was conducted in PubMed/MEDLINE, EMBASE and Scopus, using keywords such as "indocyanine green," "ICG", "NIRF", "Near Infrared Fluorescence", "robot-assisted", and "urology". Additional suitable articles were collected by manually cross-referencing the bibliography of previously selected papers. The integration of the Firefly^® technology in the Da Vinci^® robotic system has opened new avenues for the advancement and exploration of different urological procedures. ICG is a fluorophore widely used in near-infrared fluorescence-guided techniques. The synergistic combination of intraoperative support, safety profiles and widespread availability comprises an additional asset that empowers ICG-guided robotic surgery. This overview of the current state of the art illustrates the potential advantages and broad applications of combining ICG-fluorescence guidance with robotic-assisted urological surgery.