Near-infrared Fluorescence Imaging of Ureters With Intravenous Indocyanine Green During Radical Cystectomy to Prevent Ureteroenteric Anastomotic Strictures

High Rates of Discordant Ureteral Perfusion During Open Ureteral Reconstruction With Indocyanine Green: Does Near-Infrared Fluorescence Imaging Change Management or Stricture Outcomes?

OBJECTIVE

To determine the role of near-infrared fluorescence imaging (NIFI) combined with indocyanine green (ICG) to assess ureteral tissue perfusion in a benign genitourinary reconstruction cohort with a high prevalence of prior abdominopelvic radiation and surgery.

MATERIALS AND METHODS

A prospective, single-surgeon series, between June 2018 and April 2022, of patients who underwent open genitourinary reconstructive surgeries in which NIFI/ICG was utilized to intraoperatively assess ureteral tissue perfusion prior to ureteral anastomosis. Primary outcome was ureteroanastomotic stricture (UAS). Secondary outcomes included impact of NIFI/ICG on surgical decision-making and ureter resection length.

RESULTS

Thirty nine patients, median age 66, underwent 40 multimodality reconstructive surgeries during which NIFI/ICG was utilized in the open setting. Radiation-induced etiology was present in 32 of 40 (80%) patients. UAS occurred in 1 of 57 (1.8%) anastomoses with median follow-up of 23.4 months. Use of NIFI/ICG changed intraoperative decision-making in 63% of cases. Change in intraoperative decision-making was more common in patients with prior abdominopelvic radiation (66%) compared to non-radiated patients (13%), P = .007. Discordance between subjective (white-light) and objective (NIFI/ICG) ureteral perfusion (white-light) occurred in 61% of ureters. Mean length of resected ureter was higher following objective assessment with NIFI/ICG (3.6 cm) versus subjective assessment (white light) conditions (1.8 cm), P = .001.

CONCLUSION

Use of NIFI/ICG was associated with low rates of UAS at 2-year follow-up in a cohort with high prevalence of prior radiation. NIFI/ICG was associated with longer lengths of ureter resection and ureteral perfusion assessment discordance compared to subjective surgeon assessment under white-light conditions.

Semiquantitative Tissue Perfusion Assessment Using Indocyanine Green in Complex Open Urethral Reconstruction

OBJECTIVE

Current assessment of critical tissue in genitourinary reconstruction, including graft beds and tissue flaps, primarily relies upon qualitative visual and tactile assessment by experienced surgeons. Here we explore the feasibility of using intravenous indocyanine green (ICG) for semiquantitative assessment of perfusion in complex open urethral reconstruction.

METHODS

A standardized protocol for intravenous use of ICG and near-infrared fluorescence was established. Black and white mode was used for qualitative assessment of perfusion based on signal brightness. Quantitative perfusion mode was used to assess relative perfusion to tissue of interest compared to a control area with similar tissue type outside of the studied area. Real-time perfusion was visualized as percentage of perfusion relative to control.

RESULTS

In case 1, the graft bed was assessed during dorsal onlay graft substitution urethroplasty. Perfusion to graft bed was compared to that of erectile bodies proximally. A proposed perfusion cutoff of 60% was noted to correlate with clinical judgment of graft bed quality. In case 2, tissue perfusion of Blandy flap in perineal urethrostomy was assessed before and after mobilization. A cutoff of 40% was proposed based on existing flap-based reconstruction literature with the goal to tailor flap and ultimately avoid tissue ischemia and necrosis. In case 3, in a complex staged substitution urethroplasty after hypospadias repair, the use of ICG facilitated a limited excision and shorter graft inlay in this staged reconstruction.

CONCLUSION

The application of near-infrared fluorescence tools in open genitourinary reconstruction has the potential to advance quantitative assessment of graft, flaps, and other critical tissue planes, and help establish meaningful perfusion threshold and correlate with clinical outcomes.

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.

Pelvic radiation-induced urinary strictures: etiology and management of a challenging disease

Radiation is a common treatment modality for pelvic malignancies. While it can be effective at cancer control, downstream effects can manifest months to years after treatment, leaving patients with significant morbidity. Within urology, a particularly difficult post-radiation consequence is urinary tract stricture, either of the urethra, bladder neck, or ureter. In this review, we will discuss the mechanism of radiation damage and treatment options for these potentially devastating urinary sequelae.

Fluorescence Guided Surgery

Fluorescence guided surgery (FGS) is an imaging technique that allows the surgeon to visualise different structures and types of tissue during a surgical procedure that may not be as visible under white light conditions. Due to the many potential advantages of fluorescence guided surgery compared to more traditional clinical imaging techniques such as its higher contrast and sensitivity, less subjective use, and ease of instrument operation, the research interest in fluorescence guided surgery continues to grow over various key aspects such as fluorescent probe development and surgical system development as well as its potential clinical applications. This review looks to summarise some of the emerging opportunities and developments that have already been made in fluorescence guided surgery in recent years while highlighting its advantages as well as limitations that need to be overcome in order to utilise the full potential of fluorescence within the surgical environment.

Urinary diversions for benign and oncologic indications: what did we learn about short term complications in the last 24 months?

PURPOSE OF THE REVIEW

Urinary diversion (UD) with or without cystectomy is a procedure with high short term complication rates. In this review, we summarize the most relevant findings of the last 2 years.

RECENT FINDINGS

The use of a prophylactic mesh decreases the risk of parastomal hernia after ileal conduit (IC) surgery without adding mesh-related complications according to a recent randomized multicentre trial. Robot-assisted surgery is increasingly applied for UD and is evolving from extra- to intra-corporeal reconstruction in both continent and incontinent diversions, but there is still a need for appropriately designed studies assessing both short- and long-term complications. Promising techniques to decrease ureterointestinal stricture rates have been reported from small series, such as retrosigmoid placement of the proximal IC to avoid transpositioning of the left ureter, or in robot-assisted surgery the use of indocyanine green with near-infrared light to improve visualisation of distal ureteral viability.

SUMMARY

Most recent reports derive from observational data. Appropriate randomized studies are warranted for the evaluation of new techniques to be implemented in a surgical area that still is associated with high complication rates.

Fluorescence-guided cancer surgery-A new paradigm

Fluorescence-guided surgery is an emerging and promising operative adjunct to assist the surgeon in various aspects of oncosurgery, ranging from assessing perfusion, identification, and characterization of tumors and peritoneal metastases, mapping of lymph nodes/leaks, and assistance for fluorescence-guided surgery (FGS). This study aims to provide an overview of principles, currently available dyes, platforms, and surgical applications and summarizes the available literature on the utility of FGS with a focus on abdomino-thoracic malignancies.