Hyperspectral analysis for perioperative perfusion monitoring—a clinical feasibility study on free and pedicled flaps

Abstract

Objectives In reconstructive surgery, flap monitoring is crucial for early identification of perfusion problems. Using hyperspectral imaging (HSI), this clinical study aimed to develop a non-invasive, objective approach for perfusion monitoring of free and pedicled flaps. Material and methods HSI of 22 free (FF) and 8 pedicled flaps (PF) in 30 patients was recorded over time. Parameters assessed were tissue oxygenation/superficial perfusion (0–1 mm) (StO2 (0–100%)), near-infrared perfusion/deep perfusion (0–4 mm) (NIR (0–100)), distribution of haemoglobin (THI (0–100)), and water (TWI (0–100)). Measurements up to 72 h were correlated to clinical assessment. Results Directly after flap inset, mean StO2 was significantly higher in FF (70.3 ± 13.6%) compared with PF 56.2 ± 14.2% (p = 0.05), whereas NIR, THI, and TWI were similar (NIR_p = 0.82, THI_p = 0.97, TWI_p = 0.27). After 24 h, StO2, NIR, THI, and TWI did not differ between FF and PF. After 48 h, StO2, NIR, and TWI did not differ between FF and PF whereas THI was significantly increased in FF compared with PF(p = 0.001). In three FF, perfusion decreased clinically and in HSI, 36(1), 40(2), 5(3), and 61(3) h after flap inset which was followed by prompt intervention. Conclusions StO2 < 40%, NIR < 25/100, and THI < 40/100 indicated arterial occlusion, whereas venous problems revealed an increase of THI. In comparison with FF, perfusion parameters of PF were decreased after flap transfer but remained similar to FF later on. Clinical relevance HSI provides objective and non-invasive perfusion monitoring after flap transplantation in accordance to the clinical situation. With HSI, signs of deterioration can be detected hours before clinical diagnosis.

Hyperspectral imaging for perioperative monitoring of microcirculatory tissue oxygenation and tissue water content in pancreatic surgery — an observational clinical pilot study

“…Recent data on skin HSI monitoring in septic patients points to an association with organ dysfunction (Kazune et al, 2019a ; Kazune et al, 2019b ; Dietrich et al, 2021 ). Surgical data showed that relevant intraoperative changes in organ oxygenation and perfusion quality can be identified by HSI monitoring (Jansen-Winkeln et al, 2018 ; Kohler et al, 2019 ; Thiem et al, 2021 ). Future studies should therefore examine the relationship between HSI monitoring data and the function of different organ systems during haemodynamic compromise to answer whether skin HSI indicates coherent microcirculatory impairment of multiple organ systems.…”

Continuous Electrical Stimulation Affects Initial Growth and Proliferation of Adipose-Derived Stem Cells

“…In the maxillofacial area, external electrical stimulation might be used to increase growth and proliferation of osteogenic stem cells in order to overcome xenogenous, alloplastic, allogeneic and autologous grafting procedures with their immanent limitations and risks [36][37][38][39]. Though, electrical stimulation of bone regeneration in this area has largely been unexplored and reported with inconsistent results [40][41][42].…”

Hyperspectral Imaging to Study Dynamic Skin Perfusion after Injection of Articaine-4% with and without Epinephrine—Clinical Implications on Local Vasoconstriction

“…In this study, a novel hyperspectral camera (TIVITA ® , Diaspective Vision GmbH, Am Salhaff, Germany), specially developed for extracorporeal perfusion diagnostics, was used as described by our group beforehand [ 17 , 18 ]. The camera system is composed of a 120 W halogen illumination source and a radiometrically calibrated 32-bit complementary metal-oxide semiconductor spectrometer, capturing images at a resolution of 480 × 640 pixels.…”