Can the Malnutrition Universal Screening Tool (MUST) Predict Healing Complications Following Microvascular Reconstruction of the Head and Neck?

Study Design: Retrospective cohort study. Objective: Malnutrition has been found to have negative effects on the immune system and inflammatory responses, impairing the wound healing process. Free flap failure is a serious complication in patients undergoing microvascular reconstruction, as it increases patient morbidity, length of stay in the hospital, patient, and hospital costs, as well as causes the need for further surgical interventions1. Malnutrition is estimated to be present in 35-50% of head and neck cancer patients with higher rates in those experiencing hypo-oropharyngeal disease. This is often caused by functional and pain limitations from due to disease burden causing odynophagia and dysphagia. The Malnutrition Universal Screening Tool (MUST) is recommended for risk screening and provides three scores for risk classification: high, intermediate, and low2. We argue that the use of MUST as a preoperative assessment tool is useful to predict postoperative surgical site infection and delayed wound healing in patients that will undergo reconstruction with free flaps for head and neck defects. Methods: A retrospective cohort study was designed to include all subjects who underwent head and neck microvascular free tissue transfer at a single institution between 2013 and 2019. Primary and secondary reconstructions were included, for benign or malignant pathology, osteonecrosis, osteomyelitis, congenital defects, and trauma. The nutritional risk was evaluated using MUST, which analyzes body mass index, weight loss, and acute disease effect, to classify patients as low, intermediate, and high risk. We further divided the subjects into two comparison groups- low-intermediate and high risk. The primary outcome was surgical site complications and delayed wound healing. Data was analyzed as frequencies and means with standard deviations, as well as Fisher's exact test and t-test. P-values <0.05 were considered statistically significant. Analyses were done utilizing IBM SPSS Statistics Version 29. Results: 131 subjects were included for data analysis, with 54 being considered low MUST risk, 12 intermediate risk (66 low-intermediate), and 65 were high risk. The mean BMI overall was 25.5 ±5.3, and 27.2 in the low-intermediate group, and 23.7 in the high-risk group. Eighty-two subjects experienced <5-pound weight loss in the preceding 6 months to surgery, while 17 lost between 5-10 pounds, and 23 lost 10< pounds. Cancer/osteonecrosis was the etiology for 54 (82%) subjects of the low-intermediate group, and 61 (92%) of the high-risk group (P = .089). The subjects classified in High-risk group according to the MUST score had 11% more surgical site complications (P = .120) and 13.7% more delayed wound healing and dehiscence(P = .09); only 3 subjects in the study presented total flap loss and they were all in the High-risk group. Surgical site complication, delayed wound healing rates and partial or total flap loss were not increased by any specific medical comorbidity or history such as radiation or chemotherapy. Conclusions: In conclusion, Subjects with high MUST score had increased complications and poor wound healing, and subjects with acute disease effect that induces a phase of nil per os for > 5 day have higher risk of total flap loss and surgical site complication.

Comparison of the outcomes of split thickness skin graft versus thickness skin graft for closure of the radial forearm free flap donor site: A systematic review.

BACKGROUND: Radial forearm free flap (RFFF) donor site closure is traditionally performed with split thickness skin grafts (STSG), which can be associated with poor aesthetics, wrist stiffness, paresthesia, reduced strength, and tendon exposure. Full thickness skin grafts (FTSG) are potentially beneficial as they provide a more durable coverage, and the skin graft donor site can be closed primarily, which is more aesthetic. The aim of this systematic review is to compare the outcomes of STSG versus FTSG for closure of the RFFF donor site. METHODS: A systematic review was performed, following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The primary objective was to answer: do subjects undergoing RFFF harvest, utilizing FTSG to close the RFFF donor site, compared to STSG, achieve superior aesthetics at the RFFF donor site? Included papers compared FTSG and STSG with statistical data. Means were compared with t-test and proportions with Fisher's exact test. RESULTS: The initial search resulted in 1851 studies. After applying the inclusion/exclusion criteria, the search resulted in eight studies, with 366 total skin grafts, 197 STSG and 169 FTSG. Six studies evaluated aesthetics utilizing a Likert scale, with the scaled average aesthetic score for FTSG being 7.9/10 compared to 6.9/10 for STSG (p < .001). Tendon exposure was measured in five studies, with a rate of 13.1% for STSG versus 10.6% for FTSG (p = .555). No significant difference in function was observed, however, methods to quantify function were heterogeneous. CONCLUSION: FTSG compared to STSG, resulted in statistically significant improved aesthetics, with comparable rates of tendon exposure and function.

Multi-color quantum dot tracking using a high-speed hyperspectral line-scanning microscope.

Many cellular signaling processes are initiated by dimerization or oligomerization of membrane proteins. However, since the spatial scale of these interactions is below the diffraction limit of the light microscope, the dynamics of these interactions have been difficult to study on living cells. We have developed a novel high-speed hyperspectral microscope (HSM) to perform single particle tracking of up to 8 spectrally distinct species of quantum dots (QDs) at 27 frames per second. The distinct emission spectra of the QDs allows localization with ∼10 nm precision even when the probes are clustered at spatial scales below the diffraction limit. The capabilities of the HSM are demonstrated here by application of multi-color single particle tracking to observe membrane protein behavior, including: 1) dynamic formation and dissociation of Epidermal Growth Factor Receptor dimers; 2) resolving antigen induced aggregation of the high affinity IgE receptor, FcεR1; 3) four color QD tracking while simultaneously visualizing GFP-actin; and 4) high-density tracking for fast diffusion mapping.