Potential of near-infrared fluorescence image-guided debridement in trauma surgery

Delphi survey of intercontinental experts to identify areas of consensus on the use of indocyanine green angiography for tissue perfusion assessment during plastic and reconstructive surgery

BACKGROUND

In recent years, indocyanine green angiography (ICG-A) has been used increasingly to assist tissue perfusion assessments during plastic and reconstructive surgery procedures, but no guidelines exist regarding its use. We sought to identify areas of consensus and non-consensus among international experts on the use of ICG-A for tissue-perfusion assessments during plastic and reconstructive surgery.

METHODS

A two-round, online Delphi survey was conducted of 22 international experts from four continents asking them to vote on 79 statements divided into five modules: module 1 = patient preparation and contraindications (n = 11 statements); module 2 = ICG administration and camera settings (n = 17); module 3 = other factors impacting perfusion assessments (n = 10); module 4 = specific indications, including trauma debridement (n = 9), mastectomy skin flaps (n = 6), and free flap reconstruction (n = 8); and module 5 = general advantages and disadvantages, training, insurance coverage issues, and future directions (n = 18). Consensus was defined as ≥70% inter-voter agreement.

RESULTS

Consensus was reached on 73/79 statements, including the overall value, advantages, and limitations of ICG-A in numerous surgical settings; also, on the dose (0.05 mg/kg) and timing of ICG administration (∼20-60 seconds preassessment) and best camera angle (61-90^o) and target-to-tissue distance (20-30 cm). However, consensus also was reached that camera angle and distance can vary, depending on the make of camera, and that further research is necessary to technically optimize this imaging tool. The experts also agreed that ambient light, patient body temperature, and vasopressor use impact perfusion assessments.

CONCLUSION

ICG-A aids perfusion assessments during plastic and reconstructive surgery and should no longer be considered experimental. It has become an important surgical tool.

Delayed perfusion evaluation in extremity trauma

After severe trauma to an extremity, it is essential to achieve a stable and non-infected wound in order to facilitate the best outcome following reconstruction. That said, timely, meticulous and adequate debridement is very important. To facilitate the best possible debridement of the wound, it is important to understand the tissue circulation. One available method to evaluate tissue circulation following extremity trauma is indocyanine green (ICG) angiography. Though playing an important role in flap surgeries, ICG may also provide information regarding the perfusion at the zone of injury while circulation quality diminishes. We present a case where ICG angiography initially showed good circulation in a mangled extremity, but later used in alternative way to display lack of flow in the same area of interest.

Fluorescence angiography-assisted debridement of critically perfused glabrous skin in degloving foot injuries: Two case reports

RATIONALE

Degloving foot injuries are challenging to treat and associated with life-long sequelae for patients. An appropriate debridement of ischemic soft tissues with maximal preservation of glabrous skin is key during the reconstruction of these injuries. Indocyanine green (ICG) fluorescence angiography is an established technique for the intraoperative evaluation of tissue perfusion.

PATIENT CONCERNS

Two patients sustained complex foot injuries in traffic accidents, including multiple fracture dislocations and extensive degloving of the plantar skin.

DIAGNOSIS

Clinical inspection revealed significant degloving of the glabrous skin in both patients.

INTERVENTIONS

After fracture fixation, ICG fluorescence angiography-assisted debridement with immediate latissimus dorsi free flap reconstruction was performed.

OUTCOMES

In both cases, this technique allowed a precise debridement with maximal preservation of the glabrous skin. The healing of the remaining glabrous skin was uneventful and the 6-month follow-up was characterized by stable soft tissues and satisfying ambulation.

LESSONS

ICG fluorescence angiography is a safe, user-friendly, and quick procedure with minimal risks, expanding the armamentarium of the reconstructive surgeon. It is highly useful for the debridement of extensive plantar degloving injuries and may also help to minimize the number of procedures and the risk of infection.

Fasciocutaneous anterolateral thigh flaps for complex abdominal wall reconstruction after resection of enterocutaneous fistulas and the role of indocyanine green angiography: a pilot study

Purpose

No previous study reported the use of a fasciocutaneous anterolateral thigh (ALT) flap combined with a biological mesh for abdominal wall reconstruction (AWR) after enterocutaneous fistula (ECF) in a single-staged procedure and the use of Indocyanine Green Angiography (ICGA) intraoperatively. The purpose of this study was to determine the feasibility and safety of this procedure and to examine the added value of ICGA in minimizing postoperative complications.

Methods

A single-institution review of a prospectively maintained database was conducted at Maastricht University Medical Center. To evaluate the feasibility and safety of this procedure, early (≤ 30 days) and late (> 30 days) postoperative complications were assessed. ECF recurrence was considered the primary outcome. To examine the added value of ICGA, complications in the ICGA group and the non-ICGA group were compared descriptively.

Results

Ten consecutive patients, with a mean age of 66.7 years, underwent a single-staged AWR with fasciocutaneous ALT flaps. Mean follow-up was 17.4 months (4.3–28.2). Two early ECF recurrences were observed. Both restored without the need for reoperation. A lower rate of early complications was observed in the ICGA group compared to the non-ICGA group.

Conclusion

The combination of a biological mesh and fasciocutaneous ALT flap is feasible and safe in AWR after ECF repair in a single-staged approach, with an acceptable complication rate in a cohort of complex patients operated in a dedicated center. ECF closure was achieved in all patients. ICGA seems to be of great added value in minimizing postoperative complications during AWR.

Electronic supplementary material

The online version of this article (10.1007/s10029-020-02167-w) contains supplementary material, which is available to authorized users.

Optimizing Indocyanine Green Fluorescence Angiography in Reconstructive Flap Surgery: A Systematic Review and Ex Vivo Experiments

Background. Indocyanine green angiography (ICGA) offers the potential to provide objective data for evaluating tissue perfusion of flaps and reduce the incidence of postoperative necrosis. Consensus on ICGA protocols and information on factors that have an influence on fluorescence intensity is lacking. The aim of this article is to provide a comprehensive insight of in vivo and ex vivo evaluation of factors influencing the fluorescence intensity when using ICGA during reconstructive flap surgery. Methods. A systematic literature search was conducted to provide a comprehensive overview of currently used ICGA protocols in reconstructive flap surgery. Additionally, ex vivo experiments were performed to further investigate the practical influence of potentially relevant factors. Results. Factors that are considered important in ICGA protocols, as well as factors that might influence fluorescence intensity are scarcely reported. The ex vivo experiments demonstrated that fluorescence intensity was significantly related to dose, working distance, angle, penetration depth, and ambient light. Conclusions. This study identified factors that significantly influence the fluorescence intensity of ICGA. Applying a weight-adjusted ICG dose seems preferable over a fixed dose, recommended working distances are advocated, and the imaging head during ICGA should be positioned in an angle of 60° to 90° without significantly influencing the fluorescence intensity. All of these factors should be considered and reported when using ICGA for tissue perfusion assessment during reconstructive flap surgery.