BiZact™ tonsillectomy: Predictive factors for post-tonsillectomy haemorrhage from a 1717 case series.

OBJECTIVE: To determine primary and secondary post-tonsillectomy haemorrhage (PTH) rates and identify predictive factors in a cohort of consecutive adult and paediatric BiZact™ tonsillectomy cases. SETTING: Retrospective cohort study. Patients from Flinders Medical Centre, Noarlunga Hospital and private otolaryngology practices who underwent BiZact™ tonsillectomy from 2017 to 2020. DATA COLLECTED: patient age, indication for tonsillectomy, surgeon experience, time and severity of PTH, including return to theatre. Each secondary PTH was graded using the Stammberger classification. Logistic regression was utilised to identify predictors of secondary PTH. RESULTS: One thousand seven hundred and seventeen patient medical records were assessed (658 adults and 1059 children). The primary PTH rate was 0.1%, and secondary PTH rate was 5.9%. The majority of secondary PTH cases were Stammberger grade A (80/102, 78.4%) requiring observation only. Few secondary PTH required medical intervention (grade B; 9/102, 8.8%), return to theatre (grade C; 12/102, 11.8%), or blood transfusion (grade D; 1/102, 1.0%), with no death reported (grade E; 0/102, 0.0%). Recurrent secondary PTH occurred in 8 patients (0.5%). Predictive factors of secondary PTH in children were surgeon experience with trainees having greater chance of PTH (OR 2.502, 95% CI 1.345-4.654; p = .004) and age of child (OR 1.095, 95% CI 1.025-1.170; p = .007). Surgeon experience was a predictive factor for adults (OR 3.804, 95% CI 2.139-6.674; p < .001). CONCLUSIONS: BiZact™ tonsillectomy has a low primary PTH rate, with a secondary PTH rate comparable to other 'hot tonsillectomy' techniques. The majority of PTH events were minor and self-reported. There appears to be a learning curve for trainee surgeons.

Diversity of root hydrotropism among natural variants of Arabidopsis thaliana.

Root gravitropism affects root hydrotropism. The interference intensity of root gravitropism with root hydrotropism differs among plant species. However, these differences have not been well compared within a single plant species. In this study, we compared root hydrotropism in various natural variants of Arabidopsis under stationary conditions. As a result, we detected a range of root hydrotropism under stationary conditions among natural Arabidopsis variants. Comparison of root gravitropism and root hydrotropism among several Arabidopsis natural variants classified natural variants that decreased root hydrotropism into two types; namely one type that expresses root gravitropism and root hydrotropism weaker than Col-0, and the other type that expresses weaker root hydrotropism than Col-0 but expresses similar root gravitropism with Col-0. However, root hydrotropism of all examined Arabidopsis natural variants was facilitated by clinorotation. These results suggested that the interference of root gravitropism with root hydrotropism is conserved among Arabidopsis natural variants, although the intensity of root gravitropism interference with root hydrotropism differs.