Tibial nerve stimulation to inhibit the micturition reflex by an implantable wireless drivermicrostimulator in cats / 中华泌尿外科杂志

ABSTRACT

Objective Objective To evaluate the effects of a new type of tibial nerve microstimulator on the micturition reflex in cats.Methods From March to May in 2017,the implantable wireless driver micro-stimulator was implanted around the tibial nerve in 9 α-chloralose anesthetized domestic shorthairs cats (2.5-3.5 kg,6-12 months old).The stimulator was placed near the neurovascular bundle parallel to the tibial nerve and its cathode perpendicular to the cushion.The intensity which can induce toe movement was defined as threshold (T).The ureters were isolated via an abdominal incision.The ureters were cut and drained externally.The bladder was inserted via a double lumen catheter through the urethra.The catheter was then secured by a ligature around the urethra.One lumen of the catheter was used to infuse the bladder with either 0.9％ normal saline (NS) or 0.25％ AA at a rate of 1 to 2 ml/min after connecting to a pump.The other lumen was connected to a pressure transducer to measure the bladder pressure.The bladder capacity was used to test the inhibitory effect of the stimulator.After the appearance of the first large-amplitude (＞ 30 cmH2O) bladder contraction,the bladder infusion was stopped.First,after emptying the bladder,2 or 3 cystometrograms with NS were performed without stimulation to obtain the control bladder capacity.After the bladder was stabilized,TNS (6 Hz,1-2 T) was applied during 2 sequential cystometrograms.Second,after emptying the bladder,0.25 ％ AA was infused into the bladder to irritate and induce bladder overactivity.After the bladder stabilized,TNS (6 Hz,1-2 T) was applied again during 2-3 sequential cystometrograms.If bladder capacity increased significantly,the stimulationhad an inhibitory effect on the micturition reflex.Results During normal saline infusion,the bladder baseline was (17.03 ± 4.10) ml.TNS at 1T did not change the bladder capacity [(18.56 ±0.81)ml] (P ＞0.05).TNS at 2T significantly increased the bladder capacity [(25.05 ± 1.19) ml] (P ＜ 0.05).Compared to normal saline infusion,bladder overactivity was irritated by the intravesical infusion of 0.25％ acetic acid,which significantly reduced the bladder capacity [(9.34 ± 0.75) ml] (P ＜ 0.05).Compared to acetic acid infusion,TNS at 1T did not change the bladder capacity [(11.32 ± 0.82) ml] (P ＞ 0.05).TNS at 2T significantly increased the bladder capacity [(14.82 ± 1.15) ml] (P ＜ 0.05).Conclusions The implantable wireless driver tibial nerve micro-stimulator appears to be effective in inhibiting the micturition reflex during physiologic and pathologic conditions.The implantable wireless driver tibial nerve microstimulator was excepted to be used to treat overactive bladder (OAB).