Background: In reconstructive surgery, adequate perfusion of flaps is essential for successful outcomes. Assessing normal flap perfusion and differentiating it from problematic perfusion is important and time-consuming. Laser speckle contrast imaging (LSCI), an optical technique for quantitative microcirculation assessment, can be used to non-invasively monitor flap perfusion. We designed a wireless handheld LSCI device and investigated its clinical feasibility in Deep Inferior Epigastric Perforator (DIEP) flap reconstruction surgery. Methods: In a case series study with 15 patients and 20 DIEP flaps, perfusion was measured perioperatively across the 4 Hartrampf zones at 4 specific time points and on the first post-operative day. Results: In unilateral reconstructions, the perfusion in dissected flaps showed a perfusion gradient across the zones, with the highest perfusion in zone I and lowest perfusion in zone IV. The decrease in perfusion between unilateral flap elevation and temporary occlusion measurements was detected in unilateral flaps, but not in bilateral flaps. The device could detect flap failure in 2 cases by measuring anomalous perfusion values. Conclusions: The results indicate that our device is potentially valuable for flap monitoring. It detected differences in perfusion throughout the flap zones, a decrease in perfusion when clamping the pedicle and anomalous perfusion in flaps that failed. Motion artefact correction is needed to measure reliably during motion caused by patient breathing, pulse and operator motion. Further studies are needed to determine whether the wireless perfusion imager enables the early detection of complications, which could aid in prevention or prompt reintervention to salvage a flap.

Objective: Advancing microcirculatory perfusion assessment methods is crucial for evaluating organ status during ex-vivo organ preservation and expanding the donor pool. This study demonstrates the feasibility of microcirculatory perfusion imaging in an ex-vivo liver model under normothermic machine perfusion, using two non-contact imaging techniques: laser Doppler perfusion imaging (LDPI) and laser speckle contrast imaging (LSCI).Methods and procedures: An ex-vivo porcine liver was perfused with oxygenated blood for 3 hours. Blood samples were collected every 30 minutes from the hepatic artery and portal vein to evaluate the liver’s overall status. Each of the five liver lobes was imaged every 15 minutes using both the in-house developed LDPI and wireless LSCI devices. Temporally averaged perfusion maps were analyzed to assess spatiotemporal blood flow. Then, correlations between LDPI and LSCI perfusion indices were evaluated.Results: Spatiotemporal perfusion images showed detailed superficial microcirculatory perfusion across five imaged lobes. High correlations between LDPI and LSCI indices were observed in lobes 3−5 ( R2=0.81 ), which were well-perfused. Blood lactate levels increased over time, indicating a shift in metabolic activity due to ischemia. Also, correlation of LSCI perfusion indices with pH ( R2max.=0.95 ) was observed.Conclusion: The ex-vivo liver model mimics in-vivo perfusion under controlled experimental conditions. LDPI and LSCI provide rapid, independent assessments of local microcirculatory blood flow, demonstrate a high inter-technique correlation, and reflect the overall deterioration of liver status, as evidenced by blood gas parameters.Significance: A compact, wireless LSCI system—validated against LDPI—enables non-invasive evaluation of microcirculatory status and serves as a complementary tool for assessing deep tissue viability. Clinical and Translational Impact Statement—We introduce a wireless, compact, and non-contact LSCI system (validated by LDPI) enabling microcirculatory assessment during machine perfusion, complementing deep tissue medical imaging methods and blood gas analysis to enhance organ viability evaluation and support pre-transplantation treatment decisions (Category: Pre-Clinical Research).

Perfusion of the flap is essential in Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction surgery for flap survival, yet perioperative assessment of flap perfusion to detect perfusion-related problems is challenging. Laser Speckle Contrast Imaging (LSCI) is an optical technique for quantitative microcirculation assessment. Mounted LSCI devices are bulky and impractical to use during surgery, or in other clinical settings where investigation of microcirculation is needed. Therefore, a handheld wireless perfusion imager (WIPI) was developed including a 660 nm laser and an RGB camera for image registration. With this device, flap perfusion during surgery (at baseline, after fully raising the flap, and during ischemia) was compared for different Hartrampf zones. The results indicate that poorly perfused DIEP flap zones may be detected in an early stage using a handheld LSCI device.