The following is a summary of “Preputial pedicle flap ICG blood flow assessment during proximal hypospadias repair: development of a standardized protocol,” published in the May 2024 issue of Pediatrics by Raines et al.

The success of hypospadias repair is highly dependent on the blood supply to the preputial flap. Traditionally, surgeons have relied on subjective assessment to evaluate flap perfusion, which may not always be accurate. Indocyanine green (ICG) has been utilized in various surgeries for perfusion assessment, yet no standardized protocol exists for its application in hypospadias repairs. This study aims to develop a standardized protocol for using ICG in proximal hypospadias repairs and establish perfusion patterns of preputial flaps.

In a pilot study, ICG was used in patients with proximal hypospadias undergoing first-stage repair with a preputial flap. The Stryker SPY PHI system and the novel quantification software SPY-QP were employed for ICG imaging. An adaptive approach facilitated the development and implementation of a standardized protocol. According to the protocol, ICG was administered at three critical time points to assess flap perfusion. For patients who had progressed to the second stage of repair, ICG was also used to reassess the flap before the tubularization of the urethra.

A total of 14 patients underwent first-stage hypospadias repair with preputial flaps and intraoperative ICG use. The median ICG uptake of the prepuce after degloving (dose 1) was 58.5% (IQR 43-76). Following flap harvest and mobilization (dose 2), ICG uptake decreased to a median of 34% (IQR 26-46). ICG uptake remained stable after securing the flap in place and closing the skin (dose 3), with a median of 34% (IQR 25-48). ICG was able to reveal subtle perfusion details in the preputial flaps that were not visible to the naked eye, influencing intraoperative decisions in one case.

To date, five patients have undergone second-stage repair. Flap assessment before urethral tubularization indicated hypervascularity, with a median ICG uptake of 159%.

In conclusion, a standardized protocol for ICG use in proximal hypospadias was successfully developed and implemented. ICG uptake in the preputial flap decreased with increased manipulation and mobilization. ICG was able to detect perfusion changes that were not visible to the naked eye, suggesting that reliance on subjective assessment alone may be insufficient. ICG presents a valuable tool for surgeons to enhance preputial flap outcomes and could significantly improve the learning experience for trainees and early-career urologists in these complex procedures.

Source: sciencedirect.com/science/article/abs/pii/S1477513124002730