Tissue perfusion in DIEP flaps using Indocyanine Green Fluorescence Angiography, Hyperspectral imaging, and Thermal imaging.

Flap necrosis continues to occur in skin free flap autologous breast reconstruction. Therefore, we investigated the benefits of indocyanine green angiography (ICGA) using quantitative parameters for the objective, perioperative evaluation of flap perfusion. In addition, we investigated the feasibility of hyperspectral (HSI) and thermal imaging (TI) for postoperative flap monitoring. A single-center, prospective observational study was performed on 15 patients who underwent deep inferior epigastric perforator (DIEP) flap breast reconstruction (n=21). DIEP-flap perfusion was evaluated using ICGA, HSI, and TI using a standardized imaging protocol. The ICGA perfusion curves and derived parameters, HSI extracted oxyhemoglobin (oxyHb) and deoxyhemoglobin (deoxyHb) values, and flap temperatures from TI were analyzed and correlated to the clinical outcomes. Post-hoc quantitative analysis of intraoperatively collected data of ICGA application accurately distinguished between adequately and insufficiently perfused DIEP flaps. ICG perfusion curves identified the lack of arterial inflow (n=2) and occlusion of the venous outflow (n=1). In addition, a postoperatively detected partial flap epidermolysis could have been predicted based on intraoperative quantitative ICGA data. During postoperative monitoring, HSI was used to identify impaired perfusion areas within the DIEP flap based on deoxyHb levels. The results of this study showed a limited added value of TI. Quantitative, post-hoc analysis of ICGA data produced objective and reproducible parameters that enabled the intraoperative detection of arterial and venous congested DIEP flaps. HSI appeared to be a promising technique for postoperative flap perfusion assessment. A diagnostic accuracy study is needed to investigate ICGA and HSI parameters in real-time and demonstrate their clinical benefit.

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.

Assessment of deep inferior epigastric perforator flap perfusion with near-infrared fluorescence: A pilot study and description of a standardized working protocol.

Fat necrosis (FN) is a common complication after autologous breast reconstruction (ABR) using a free flap, which can influence reconstruction outcome and patient satisfaction. Intraoperative near-infrared fluorescence imaging using indocyanine green (ICG) permits the visualization of flap perfusion. The aim of this study was to assess the effect of near-infrared fluorescence on FN incidence in patients undergoing an ABR with a deep inferior epigastric perforator flap (DIEP) and to propose a standard working protocol for this technique. In this prospective study, patients undergoing one-sided ABR with a DIEP were included. The standard DIEP procedure was complemented with near-infrared fluorescence imaging using the fluorescent tracer ICG to evaluate flap perfusion. This cohort was compared to a retrospective cohort of DIEP procedures without near-infrared fluorescence imaging. Patients and surgery characteristics, as well as postoperative complications, were registered and compared. In both cohorts, 24 patients were included. No significant differences were present between patients and surgery characteristics, including no difference in duration of surgery. In the prospective and retrospective group, the incidence of FN was 4.2% and 33%, respectively (p-value = 0.023). Moreover, microsurgeons were positive about using near-infrared fluorescence as it either provided additional information about perfusion or confirmed the clinical assessment. Our pilot study showed a significant decrease of FN in patients undergoing an ABR with a DIEP when near-infrared fluorescence imaging was used to assess flap perfusion. This study provides a standardized working protocol for near-infrared fluorescence imaging. In the future, large multicenter studies should focus on the quantification of near-infrared fluorescence imaging.

Incomplete Excision of Cutaneous Squamous Cell Carcinoma; Systematic Review of the Literature.

The treatment of choice for cutaneous squamous cell carcinoma is complete surgical excision. Incomplete excision of cutaneous squamous cell carcinoma has an increased risk of local recurrence, deep subclinical progression, and metastasis. This study aimed to investigate the proportion and risk factors of incomplete excised cutaneous squamous cell carcinoma. A systematic review of the literature was performed. Incomplete excision rates for cutaneous squamous cell carcinoma ranged from 0.4% to 35.7%. The pooled incomplete excision risk estimate was 13% (95% confidence interval 9-17%). Risk factors noted in more than one study for incomplete excision included tumor depth and size, type of operator, head and neck localization, and former incomplete excision. We found an overall incomplete excision rate of 13% for cutaneous squamous cell carcinoma. Risk factors should be taken into account in the management of cutaneous squamous cell carcinoma surgical treatment.

Gait initiation in children with Rett syndrome.

Rett syndrome is an X-linked neurodevelopmental condition mainly characterized by loss of spoken language and a regression of purposeful hand use, with the development of distinctive hand stereotypies, and gait abnormalities. Gait initiation is the transition from quiet stance to steady-state condition of walking. The associated motor program seems to be centrally mediated and includes preparatory adjustments prior to any apparent voluntary movement of the lower limbs. Anticipatory postural adjustments contribute to postural stability and to create the propulsive forces necessary to reach steady-state gait at a predefined velocity and may be indicative of the effectiveness of the feedforward control of gait. In this study, we examined anticipatory postural adjustments associated with gait initiation in eleven girls with Rett syndrome and ten healthy subjects. Muscle activity (tibialis anterior and soleus muscles), ground reaction forces and body kinematic were recorded. Children with Rett syndrome showed a distinctive impairment in temporal organization of all phases of the anticipatory postural adjustments. The lack of appropriate temporal scaling resulted in a diminished impulse to move forward, documented by an impairment in several parameters describing the efficiency of gait start: length and velocity of the first step, magnitude and orientation of centre of pressure-centre of mass vector at the instant of (swing-)toe off. These findings were related to an abnormal muscular activation pattern mainly characterized by a disruption of the synergistic activity of antagonistic pairs of postural muscles. This study showed that girls with Rett syndrome lack accurate tuning of feedforward control of gait.