Low-protein diet accelerates wound healing in mice post-acute injury.

BACKGROUND: Wound healing processes are influenced by macronutrient intake (protein, carbohydrate and fat). The most favourable diet for cutaneous wound healing is not known, although high-protein diets are currently favoured clinically. This experimental study investigates the optimal macronutrient balance for cutaneous wound healing using a mouse model and the Geometric Framework, a nutrient modelling method, capable of analyzing the individual and interactive effects of a wide spectrum of macronutrient intake. METHODS: Two adjacent and identical full-thickness skin excisions (1 cm2) were surgically created on the dorsal area of male C57BL/6 mice. Mice were then allocated to one of 12 high-energy diets that varied in protein, carbohydrate and fat content. In select diets, wound healing processes, cytokine expression, energy expenditure, body composition, muscle and fat reserves were assessed. RESULTS: Using the Geometric Framework, we show that a low-protein intake, coupled with a balanced intake of carbohydrate and fat is optimal for wound healing. Mice fed a low-protein diet progressed quickly through wound healing stages with favourable wound inflammatory cytokine expression and significantly accelerated collagen production. These local processes were associated with an increased early systemic inflammatory response and a higher overall energy expenditure, related to metabolic changes occurring in key macronutrient reserves in lean body mass and fat depots. CONCLUSIONS: The results suggest that a low-protein diet may have a greater potential to accelerate wound healing than the current clinically used high-protein diets.

The significance of regional metastasis location in head and neck cutaneous squamous cell carcinoma.

BACKGROUND: Regional metastasis of head and neck cutaneous squamous cell carcinoma (HNcSCC) can be seen in either parotid and/or cervical lymph nodes. The aim of this study was to assess whether there was a difference in prognosis between parotid and cervical nodal metastases. METHODS: Patients with regional metastasis from HNcSCC were identified from an institutional database. Disease-specific (DSS) and overall survival (OS) were calculated using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: Five hundred and thirty-five patients were identified with median follow-up of 26.4 months (3-255 months). Two hundred and thirty-five patients had parotid metastasis, 96 patients had neck metastasis, and 204 patients had both. On multivariable analysis, any regional metastasis to the neck when compared to parotid alone conferred worse DSS (HR 1.8, p = 0.007) and OS (HR 1.3, p = 0.024). CONCLUSION: Regional metastasis of HNcSCC to the neck confers worse outcomes compared to metastasis to the parotid alone.

Endoscopic Repair of a Temporal Bone Pneumatocele.

OBJECTIVE: Pneumatoceles of the temporal bone are rare entities. A symptomatic external auditory canal pneumatocele repaired endoscopically is demonstrated. METHODS: A 79-year-old man presented with fluctuating hearing loss and difficulty wearing in-ear hearing aids. The patient had two previous tube insertions which both failed within days. Examination of the left ear revealed a cyst filling the superior aspect of the lateral canal and obscuring the view of the majority of the tympanic membrane. Pre-op audiogram demonstrated a symmetric bilateral mild to moderate sensorineural hearing loss. The patient underwent a transcanal endoscopic composite cartilage myringoplasty. On incising the pneumatocele, a pars flaccida defect was identified in continuity with the pneumatocele. After excising the pneumatocele, a posterosuperior based tympanomeatal flap was raised and the defect repaired with a composite tragal cartilage perichondrial graft. RESULTS: The patient had an uneventful recovery. On first postoperative review, the tympanomeatal flap had healed and the cartilage graft was intact with partial integration and epithelialization. There was no evidence of pneumatocele recurrence and his existing hearing aids were able to be worn with satisfactory amplification. The formation of the pneumatocele was presumed secondary to a ball-valve effect of skin through the pars flaccida defect and progressive raising of the epithelial layer in continuity with the canal skin. CONCLUSION: Surgical repair of temporal bone pneumatoceles is warranted in symptomatic patients. Identifying and addressing the underlying cause of their development is essential to surgical management.SDC video link: http://links.lww.com/MAO/B267.

Soft Tissue Metastases in Head and Neck Cutaneous Squamous Cell Carcinoma.

OBJECTIVE: Soft tissue metastases (STM) in head and neck cutaneous squamous cell carcinoma (HNcSCC) are non-nodal based metastases to the parotid and cervical soft tissues of the head and neck. This is a unique subgroup of regional metastases amongst patients with cSCC and have been shown to be associated with poor prognosis. Detailed studies of this subgroup are lacking in the literature. A retrospective cohort analysis was performed to characterize the prognostic significance of STM in HNcSCC based on individual clinicopathological features. METHODS: Patients with HNcSCC with STM were identified from the Sydney Head and Neck Cancer Institute database. Clinicopathological characteristics were extracted from the histopathological reports. Recurrence and follow-up data were analyzed to determine disease-free and overall survival using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: After excluding all patients with lymph node metastasis with no STM, there were 200 patients identified (161 parotid, 32 cervical, and seven with concurrent parotid and cervical STM) with a 5-year overall survival of 36%. In univariable analysis, age of patients, size of the deposits, location of the deposits, and patients that were not offered adjuvant radiotherapy have worse overall survival. However, on multivariable analysis, age and the number of STM deposits were independent factors that predict for worse survival. CONCLUSION: The presence of STM in patients with HNcSCC is associated with poor prognosis. Increasing number of STM deposits, as well as involved margin of the regional excision, negatively impacted on the overall prognosis. LEVEL OF EVIDENCE: Level III - retrospective cohort study. Laryngoscope, 131:E1209-E1213, 2021.

Sentinel Node Biopsy in 105 High-Risk Cutaneous SCCs of the Head and Neck: Results of a Multicenter Prospective Study.

BACKGROUND: Regional nodal metastases from cutaneous squamous cell carcinoma (cSCC) is strongly associated with a poor prognosis, but these metastases are difficult to predict clinically. Sentinel node biopsy (SNB) has been used for a wide range of malignancies to assess for regional nodal metastasis, but is not widely used for cSCC. METHODS: Patients presenting with high-risk cSCC of the head and neck with clinically N0 necks were offered SNB at the time of primary cSCC excision or secondary wide local excision. Patients with positive sentinel nodes were offered completion lymph node dissection, and all the patients were followed up at regular intervals for up to 5 years. RESULTS: In this study, 105 lesions underwent SNB, and 10 sentinel nodes (9.5%) were positive. In an additional five patients, regional recurrence developed after a negative sentinel node, with a total subclinical nodal metastasis rate of 14.3%. Nodal metastases were significantly associated with reduced disease-specific survival. The significant predictors of metastasis were four or more high-risk features or tumors with a concurrent invasion deeper than 5 mm and PNI. CONCLUSION: For high-risk cSCC, SNB is a safe and feasible staging technique. The total number of high risk features and certain combinations of high-risk features predicted metastasis better than individual high-risk features.