Inducing intravesical hyperthermia of the ex-vivo porcine bladder wall: radiofrequency-induction versus recirculation using a custom-made device

Figures & data

Figure 1. Experimental set-up. The heat-exchanger was used for C-HT, the radiofrequency source for RF-HT. Temperatures were measured at several locations. C-HT: conductive hyperthermia; RF-HT: radiofrequency induced hyperthermia; TC: thermocouple.

Figure 2. Flow diagram of experimental groups. C-HT: conductive hyperthermia; H₂O: sterile water; NaCl: sodium chloride (i.e., saline); RF-HT: radiofrequency induced hyperthermia.

Table 1. Bladder wall temperatures per location and technique.

Measurement		RF-HT				C-HT (46 °C)				C-HT (44 °C)
Location		T90	T50	CEM43T90	mean T	T90	T50	CEM43T90	mean T	T90	T50	CEM43T90	mean T
Bladder neck	Mucosa	40.40	42.35	0.27	41.95	40.26	41.83	0.22	41.70	39.65	40.69	0.10	40.59***
	Detrusor	39.67	41.62	0.10	41.43	39.05	40.74	0.04	40.33*	38.50	39.81	0.02	39.58**
	Serosa	38.46	39.34	0.02	39.53	37.96	39.12	0.01	39.10	37.82	38.66	0.01	38.62**
Bladder side wall	Mucosa	39.91	41.91	0.14	41.49	40.53	42.26	0.33	42.02*	39.66	40.94	0.10	40.87*
	Detrusor	39.33	40.29	0.06	40.61	39.55	40.13	0.08	40.36	39.09	39.41	0.04	39.63*
	Serosa	38.22	39.24	0.01	39.18	38.37	38.82	0.02	39.22	38.07	38.42	0.01	38.77*
Bladder dome	Mucosa	40.18	41.12	0.20	41.86	40.52	42.24	0.32	41.92	39.85	41.06	0.13	40.86
	Detrusor	38.70	39.74	0.03	40.17	39.39	40.09	0.07	40.23	38.77	39.48	0.03	39.55
	Serosa	37.99	38.58	0.01	38.83	38.02	38.95	0.01	39.07	37.79	38.62	0.01	38.65

All temperatures are in °C. C-HT: conductive hyperthermia; CEM₄₃T₉₀: cumulative equivalent minutes of T₉₀ above 43 °C (heating occurred for 10 min); Detr: detrusor; RF-HT: radiofrequency-induced hyperthermia; T: temperature; T₅₀: temperature above which 50% of the measured values are observed; T₉₀: temperature above which 90% of the measured values are observed; V: volume in mL.

* p < .05 compared to RF-HT.

** p < .01 compared to RF-HT.

*** p < .001 compared to RF-HT.

Figure 3. Boxplot of temperatures in the bladder wall after RF-HT, C-HT₄₆, and C-HT₄₄. Dashed horizontal line represents the target temperature of 40.5 °C. Bold horizontal bars represent the median value. C-HT₄₄: conductive hyperthermia with an inflow temperature of 44 °C; C-HT₄₆: conductive hyperthermia with an inflow temperature of 46 °C; RF-HT: radiofrequency induced hyperthermia. *p < .05 compared to RF-HT. **p < .01 compared to RF-HT. ***p < .001 compared to RF-HT.