Hypocalcaemia following laryngectomy: prevalence and risk factors.

OBJECTIVES: To establish the prevalence of hypocalcaemia following laryngectomy and demonstrate that total thyroidectomy is a risk factor. METHODS: A retrospective cohort study was conducted that included all patients who underwent total laryngectomy from 1st January 2006 to 1st August 2017. Exclusion criteria were: pre-operative calcium derangement, previous thyroid or parathyroid surgery, concurrent glossectomy, pharyngectomy, or oesophagectomy. RESULTS: Ninety patients were included. Sixteen patients had early hypocalcaemia (18 per cent), seven had protracted hypocalcaemia (8 per cent) and six had permanent hypocalcaemia (10 per cent). Exact logistic regression values for hypocalcaemia following total thyroidectomy compared to other patients were: early hypocalcaemia, odds ratio = 15.5 (95 per cent confidence interval = 2.2-181.9; model p = 0.002); protracted hypocalcaemia, odds ratio = 13.3 (95 per cent confidence interval = 1.5-117.1; model p = 0.01); and permanent hypocalcaemia, odds ratio = 22.7 (95 per cent confidence interval = 1.9-376.5; model p = 0.005). CONCLUSION: This is the largest study to investigate the prevalence of hypocalcaemia following laryngectomy and the first to include follow up of longer than three months. Total thyroidectomy significantly increased the risk of hypocalcaemia at all time frames and independent of other variables.

Do patients with p16-positive oropharyngeal squamous cell carcinoma get more bone metastasis than p16-negative patients?

BACKGROUND: Oropharyngeal squamous cell carcinoma is thought to rarely metastasise to bone. This study hypothesised that in p16-positive disease there is a significant incidence of bony metastasis. METHODS: This was an ambispective cohort review. All patients with oropharyngeal squamous cell carcinoma diagnosed and treated at one centre were included. RESULTS: A total of 180 consecutive patients were identified over 5 years. Fifteen patients were excluded because of lack of p16 status, none of whom had bony metastasis. The final analysis included 165 patients: 48 (29.09 per cent) in the p16-negative group and 117 (70.91 per cent) in the p16-positive group. Ten patients (8.55 per cent) in the p16-positive group developed bony metastasis, compared with zero in the p16-negative group; this difference was statistically significant (p = 0.036). CONCLUSION: Expression of p16 was associated with an increased incidence in bony metastasis in this cohort. This is the first study to explore this specific question.

Transneuronal effects triggered by saphenous nerve injury on one side of a rat are restricted to neurones of the contralateral, homologous nerve.

Transection and regeneration of the saphenous nerve on one side of a rat reduces the ability of the contralateral saphenous nerve to evoke plasma extravasation following antidromic nerve stimulation. It is proposed that a transneuronal signal--that is a signal that passes from injured neurones on one side of the body to intact ones on the other via the spinal cord--is involved in triggering this response. The present experiments have shown that the influence of this transneuronal signal is restricted to neurones of homologous nerves on the two sides of an animal, i.e. it passes from saphenous nerve neurones on one side to saphenous nerve neurones on the other; its influence does not seem to extend to neurones in other nerves, for example ones in either the ipsi- or contralateral sural nerves.