Dynamic perfusion assessment during perforator flap surgery: an up-to-date

Near-Infrared Fluorescence with Indocyanine Green to Assess Bone Perfusion: A Systematic Review

Background: Adequate perfusion of a bone flap is essential for successful reconstruction of osseous defects. Unfortunately, complications related to inadequate bone perfusion are common. Near-infrared fluorescence (NIRF) imaging enables intraoperative visualization of perfusion. NIRF has been investigated in reconstructive surgery to aid the surgeon in clinical perioperative assessment of soft tissue perfusion. However, little is known on the beneficial use of NIRF to assess bone perfusion. Therefore, the aim of this review was to search for studies evaluating NIRF to assess bone perfusion. Methods: A systematic review, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, was performed. Studies up to October 2021 were included. We extracted data regarding the study population, size and design, reported objective fluorescence parameters and the methodology used for fluorescence imaging and processing. Results: Ten articles were included. Studies reported unevenly on the protocol used for NIRF imaging. Five studies reported objective parameters. Absolute and relative perfusion parameters and parameters derived from maximum fluorescence were reported. The clinical significance of these parameters has not been evaluated in humans. Conclusion: The evidence on bone perfusion as measured with NIRF is limited. More clinical studies are required.

In Vivo Perforasome Perfusion in Hemi-DIEP Flaps Evaluated with Indocyanine-green Fluorescence Angiography and Infrared Thermography

There are no in vivo studies that evaluate the effect of perforator dissection on the perfusion territory of a perforator (perforasome). In this study, indocyanine green fluorescence angiography (ICG-FA) and infrared thermography (IRT) were used intraoperatively to evaluate perforasome perfusion in hemi-DIEP flaps.

Methylene Blue and Proflavine as Intraarterial Marker for Functional Perforazome-Comparative Study

Methylene blue (MB) is both a dye and a medicine known and used for a long time including as lymphatic tracer in melanoma and breast cancer for revealing sentinel lymph nodes. Proflavine (PRO) is an acriflavine dye, used as bacteriostatic disinfectant against many gram-positive bacteria that was also successfully applied to evaluate morphopathological changes in tissues. This study was performed on a group of twenty-eight Wistar rats and had as its main objective the in vivo evaluation of the use of MB and PRO as perforator tracers. The two dyes proved to be effective functional perforasome tracers with medium inflammatory infiltrate in the skin of the island perforator flap which heals perfectly at 14 days with complete absence of the inflammatory reaction. At the same injected amount, PRO seems to determine a greater inflammatory reaction compared with MB, but in smaller concentration, the inflammatory response is absent in the case of PRO. In conclusion, both substances tested within this in vivo study are good functional perforasome tracers, but PRO has the advantage of the absence of inflammatory reaction when using lower concentrations, while preserving unalerted its efficiency as tracer.

The Value of Dynamic Infrared Thermography in Pedicled Thoracodorsal Artery Perforator Flap Surgery

Dynamic infrared thermography (DIRT) is a noninvasive imaging technique that can provide indirect and real-time information on skin perfusion by measuring skin temperature. Although used in flap surgery, there are no reports on its value in procedures using a pedicled thoracodorsal artery perforator (TDAP) flap. The aim of this study was to assess the usefulness of DIRT in preoperative perforator mapping and in monitoring intra- and postoperative flap perfusion of pedicled TDAP flaps.

Comparison of arterial and venous implantable Doppler postoperative monitoring of free flaps: Systematic review and meta-analysis of diagnostic test accuracy

BACKGROUND

Early detection of vascular compromise following free flap microsurgical reconstruction is essential. This can lead to timely reoperations and flap salvage. Both arteries and veins are monitored postoperatively with implantable ultrasound Dopplers based on surgeon preference with no consensus as to which method is best. This systematic review and meta-analysis compared arterial to venous implantable Dopplers for postoperative monitoring of microsurgical free flap reconstruction.

METHODS

Five databases (MEDLINE via PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus) were systematically and independently searched. PRISMA and Cochrane guidelines were strictly followed. Clinical characteristics, donor and recipient sites, specific arterial or venous vessels, diagnostic data, outcomes, and complications were recorded.

RESULTS

The seven studies included in the meta-analysis were published from 1994 to 2018, with results from 38 of the possible 64 outcomes and complications queried. A total of 763 flaps with implantable Doppler probes on 527 arteries and 388 veins were included in the study. Compared to patients monitored with venous implantable Dopplers, arterial monitoring was associated with a risk of false-positives reduced by 74% (RR:0.26, 95% CI:0.12, 0.55, I² = 40%, p = .0004) and risk of signal loss reduced by 63% (RR:0.37, 95% CI:0.24, 0.59, I² = 26%, p < .0001). Patients being monitored with a venous implantable Doppler did not show significantly different sensitivities, specificities, true-positives, false-negatives, true-negatives, positive predictive values, negative predictive values, time to signal loss, take-backs, salvage rates, flap failures, flap failure rates, arterial, venous, vascular, and hematoma compromise compared to an arterial implantable Doppler.

CONCLUSION

These findings suggest arteries may be the best vessels to monitor when using an implantable Doppler following free flap microsurgical reconstruction. Caution is advised when interpreting these findings for clinical significance due to no significant differences in take-backs, SR, flap failures, and FFR.

An important superficial vein of the radial aspect of the forearm: An anatomical study

Introduction

The superficial veins of upper limbs are seldom talked about. They are always avoided quoting them to be variable in anatomy. Other than the cephalic and basilic veins, no other superficial vein has caught the eyes of anatomists and other health professionals significantly. This article tries to explain the importance of a superficial vein that closely traces the radial vessels and explains its possible use in microvascular reconstruction.

Materials and Methods

The forelimbs of 26 upper limbs of fresh frozen cadavers were dissected out. The anatomy of the superficial vein that follows the radial vessels was traced out from wrist to cubital fossa. Their relation to the deep venous system and cephalic veins was followed and documented.

Results

All the 26 upper limbs showed the existence of the superficial vein that follows the radial vessels. The study also revealed the existence of venous perforators which are in turn the communication channels between the deep and superficial venous systems.

Conclusion

The existence of the surface vein can logically hold an explanation for flap failure or success when one vein anastomosis is contemplated for radial forearm-free tissue transfers.

Clinical use of near-infrared fluorescence imaging with indocyanine green in thoracic surgery: a literature review

Invisible near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has advantage in detecting for certain anatomy. The method is currently used in some types of surgery, such as sentinel lymph node (SLN) mapping, intraoperative solid tumor identification, and organ perfusion assessment. However, the literature of clinical application in thoracic surgery is lacking. This paper presents the advantages, current applications and potential developments of NIR fluorescence imaging with ICG in thoracic surgery.