Methods: This retrospective study involved 215 children aged 12 years and below with the initial diagnosis of AA and PA. Clinical factors studied were demographics, presenting symptoms, body temperature on admission (BTOA), white cell count (WCC), absolute neutrophil count (ANC), platelet count and urinalysis. Simple and multiple logistic regressions were used to determine the odds ratio of the statistically significant clinical factors. Results: The mean age of the included children was 7.98 ± 2.37 years. The odds of AA increased by 2.177 times when the age was ≥ 8 years (P = 0.022), 2.380 times when duration of symptoms ≥ 2 days (P = 0.011), 2.447 times with right iliac fossa (RIF) pain (P = 0.007), 2.268 times when BTOA ≥ 38 °C (P = 0.020) and 2.382 times when neutrophil percentage was ≥ 76% (P = 0.045). It decreased by 0.409 times with non-RIF pain (P = 0.007). The odds of PA was increased by 4.672 times when duration of symptoms ≥ 2 days (P = 0.005), 3.611 times when BTOA ≥ 38 °C (P = 0.015) and 3.678 times when neutrophil percentage ≥ 76% (P = 0.016). There was no significant correlation between WCC and ANC with AA and PA.
Conclusion: Older children with longer duration of symptoms, RIF pain and higher BTOA are more likely to have appendicitis. The risk of appendiceal perforation increases with longer duration of symptoms and higher BTOA.
METHODS: A 2D model in the axisymmetric coordinates was developed to simulate the electro-thermophysiological responses of the tissue during a single probe bipolar RFA. Two different probe configurations were considered, namely the configuration where the active electrode is longer than the ground and the configuration where the ground electrode is longer than the active. The mathematical model was first verified with an existing experimental study found in the literature.
RESULTS: Results from the simulations showed that heating is confined only to the region around the shorter electrode, regardless of whether the shorter electrode is the active or the ground. Consequently, thermal coagulation also occurs in the region surrounding the shorter electrode. This opened up the possibility for a better customized treatment through the development of RF probes with adjustable electrode lengths.
CONCLUSIONS: The electrode length was found to play a significant role on the outcome of single probe bipolar RFA. In particular, the length of the shorter electrode becomes the limiting factor that influences the mechanics of single probe bipolar RFA. Results from this study can be used to further develop and optimize bipolar RFA as an effective and reliable cancer treatment technique.