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.

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.

Background and Objective: Over the last decade, an increasing effort has been put towards the implementation of optical guidance techniques to aid surgeons during cancer surgery. Diffuse reflectance spectroscopy (DRS) and fluorescence spectroscopy (FS) are two of these new techniques. The objective of this study is to investigate whether in vivo optical spectroscopy is able to accurately discriminate colorectal liver metastases (CRLM) from normal liver tissue in vivo. Materials and Methods: DRS and FS were incorporated at the tip of a needle and were used for in vivo tissue differentiation during resection of CRLM. Measurements were taken in and around the tumor lesions and measurement sites were marked and correlated to histology (i.e., normal liver tissue or tumor tissue). Patients with and without neoadjuvant systemic chemotherapy were included into the study. Results: Four hundred and eighty-four measurements were taken in and near 19 liver lesions prior to resection. Overall sensitivity and specificity for DRS was 95% and 92%, respectively. Bile was the most discriminative parameter. The addition of FS did not improve the overall accuracy. Sensitivity and specificity was not hampered by neo-adjuvant chemotherapy; sensitivity and specificity after neo-adjuvant chemotherapy were 92% and 100%, respectively. Conclusion: We have successfully integrated spectroscopy technology into a disposable 15 Gauge optical needle and we have shown that DRS and FS can accurately discriminate CRLM from normal liver tissue in the in vivo setting regardless of whether the patient was pre-treated with systemic therapy. This technique makes in vivo guidance accessible for common surgical practice. Lasers Surg. Med. 48:820–827, 2016.