According to the definition of ICS, detrusor underactivity (DU) refers to a “Contraction of inadequate strength and/or duration resulting in prolonged emptying and/or failure to achieve complete emptying in the absence of urethral obstruction”. Basically, DU can be classified into idiopathic, neurogenic, myogenic and mixed types, based on different etiology. Despite a number of innovative therapies emerged, management of neurogenic DU still remains a challenge. This study aims to assess the effect of acupuncture on neurogenic DU.

This was a single-center, prospective study conducted between Jun. 2017 and Sep. 2019, and approved by the Ethics Committee. Inclusion criteria of the study were the patients 1) more than 18 years old; 2) with a history of neuropathy; 3) with chronic urinary retention required a catheterization including clean intermittent catheterization (CIC) and indwelling catheter; 4) with DU diagnosed based on the urodynamic criteria of bladder contractility index (BCI) <100 for men and a maximal flow rate (Qmax) ≤12 ml/s combined with a detrusor pressure at Qmax ≤10 cmH2O for women, respectively1. The exclusion criteria included the patients 1) with bladder outlet obstruction; 2) with a previous invasive procedure, such as sacral neuromodulation, and pudendal nerve stimulation; 3) with mental, or coagulation disorder. 
In terms of the acupuncture procedure, the acupoints including bilateral BL33, BL35, SP6 and ST36 were selected and sterile disposable, stainless needles (HWATO, Suzhou medical appliance factory, China) 100mm long and 0.4mm in diameter were used. After the needles were inserted into those acupoints, a portable electro-acupuncture machine (model HWATO SDZ-II, electronic acupuncture treatment instrument, Suzhou medical appliance factory, China) was connected to the handles of needles located in BL33 and BL35 to provide the electrical stimulation for 30 minutes with a frequency of 10Hz continuous wave stimulation (Figure 1), three times a week for eight weeks. The primary outcome was the response rate which was defined as the proportion of patients with a voiding efficiency (VE) of ≥50%. The secondary outcomes included post-void residual urine volume (PVR), Qmax, destrusor pressure at Qmax (Pdet@Qmax). Additionally, the adverse events were also recorded.

A total of 37 patients with a mean age of 42±18 years were received acupuncture intervention. Of those, 12 were male and 25 were female. Six patients had hydronephrosis. After eight weeks, four  male and 21 female patients could void spontaneously, and 18 of them achieved a VE of ≥50%. As a result, the response rate was 48.6%. Furthermore, the change in PVR, Qmax, and Pdet@Qmax were -316±187ml, 10.1±5.8 ml/s, and 18±13cmH2O respectively. In terms of the six patients with hydronephrosis, the hyronephrosis was disappeared in one patient and improved in three patients after 8-week treatment. Additionally, subcutaneous hematomas were found in three patients and no severe adverse events were reported.

The main finding of current study is that almost half of patients showed good response to acupuncture, and the urodynamic parameters were improved significantly after treatment. The potential therapeutic mechanism of acupuncture might be the stimulation on S3 via BL33 and the pudendal nerve via BL35 and SP6. The important limitation of our study is lack of control, which will be solved in our future study.

Our study suggests that acupuncture may be an effective procedure to recover spontaneous voiding, as well as improve PVR, Qmax, and Pdet@Qmax in patients with neurogenic DU.

Jeong SJ, Kim HJ, Lee YJ, Lee JK, Lee BK, Choo YM, et al. Prevalence and clinical features of detrusor underactivity among elderly with lower urinary tract symptoms: a comparison between men and women. Korean J Urol 2012;53:342-348.