Abstract
To evaluate the clinical efficacy of pelvic floor low-frequency electrical stimulation combined with anus lifting training in the treatment of urinary incontinence after radical prostatectomy in a Chinese cohort. Fifty-five patients with urinary incontinence after radical prostatectomy were randomly divided into treatment group and control group. Patients in control group received only anus lifting training therapy, while treatment group combined with pelvic floor low-frequency electrical stimulation. The urinary control including urinary incontinence questionnaire (ICI-Q-SF), urinary incontinence quality of life (I-QOL), visual analogue scale (VAS), and pelvic floor muscle strength assessment (Glazer) of the two groups of patients before treatment and every week was recorded for statistical analysis. There was a statistically significant difference between treatment group and control group in the urinary control curve. The scores of ICI-Q-SF, I-QOL, VAS, and Glazer in the treatment group after 2 weeks were statistically different from those before treatment, and effects were accumulating with the extension of treatment time. Compared with the control group, the scores of treatment group in the 2 to 10 weeks improved more significantly. Especially, in the sixth week, total effective rate of treatment group was significantly better than that of control group (74.07% [20/27], 35.71% [10/28], p < .05). The difference between two groups gradually narrowed after 10 weeks and no significant difference after 10 weeks of treatment between two groups. Pelvic floor low-frequency electrical stimulation combined with anus lifting training after radical prostatectomy can significantly shorten the recovery time of urinary incontinence in patients after radical prostatectomy.
Keywords
Introduction
Prostate cancer is a common malignant tumor of male genitourinary system, and its incidence has increased sharply year by year in the world (Abu-Ghanem et al., 2015). Radical prostatectomy (RP) has become one of the most effective methods for the treatment of prostate cancer (Berhili et al., 2022). Urinary incontinence has become the most important complication after RP due to the possible injury of muscles and nerves related to urinary control around the prostate during the operation. The incidence of urinary incontinence can be as high as 6% to 20% and seriously affect the quality of life of patients (Ouanes et al., 2022). Clinically, the treatment of urinary incontinence after RP is difficult, and no drug with definite effect has been developed (Ouanes et al., 2022).
At present, there are some surgical and conservative treatments for urinary incontinence after RP, including artificial urethral sphincter (AUS) implantation, filler injection, and male sling. Although the effect of AUS is reliable, it is expensive, and the incidence of postoperative complications is more than 30%. Although the transurethral injection of filler is minimally invasive, its efficacy is uncertain and requires long-term repeated injection. Although the sling operation is minimally invasive, its effect is still unreliable, which may lead to outflow tract obstruction, overactive detrusor, frequent urination, and urgency (Sotiropoulos et al., 1976; Yokoyama et al., 2004, 2005). Conservative treatment is still the mainstream means, mainly including drug therapy, pelvic floor muscle rehabilitation training, biofeedback and electrical stimulation, and behavior therapy. Although the pelvic floor muscle training is simple and effective, most patients are difficult to accurately master this action and cannot adhere to it (Hunter et al., 2007). The pelvic floor electromyography can be monitored through the electronic biofeedback therapeutic instrument built in the rectum, which turns muscle activity into audio-visual signals to guide patients to carry out targeted autonomous training. Functional electrical stimulation therapy is a passive physical rehabilitation method, which is an effective compensation therapy for patients who cannot carry out pelvic floor muscle exercise correctly. In 1976, Sotiropoulos first proposed that electrical stimulation therapy might be effective for urinary incontinence (Strasser & Bartsch, 2000). In 2004, Yokoyama’s research results suggested that electromagnetic therapy has a certain effect on postoperative urinary control recovery (Filocamo et al., 2005; Yang et al., 2020). Later in 2007, MacDonald’s research based on the research results of 1028 patients in 11 clinical trials reported that pelvic floor muscle therapy combined with biofeedback therapy improved the recovery rate of urinary control of patients within 1 to 2 months after surgery by 1.54 times (Sciarra et al., 2021). There is no relevant research on whether electrical stimulation combined with anus lifting training can improve the recovery of postoperative urinary control. Most of these studies were performed in White patients (Salciccia et al., 2022).
In this study, pelvic floor low-frequency electrical stimulation combined with anus lifting training has achieved good results in the treatment of urinary incontinence after RP, providing a reference for clinical treatment in Chinese patients.
Materials and Methods
Clinical Data
From January 2022 to June 2022, 55 patients with urinary incontinence after RP were selected from our hospitals. The clinical factors that may affect the patient’s urinary control were recorded, including the patient’s age at the time of operation, the type of operation, whether neoadjuvant endocrine therapy was performed, whether blood transfusion was performed during the operation, postoperative pathological staging, Gleason score, and whether the patient received transurethral resection of prostate in the past. This study was approved by the Ethics Committee of Hangzhou Hospital of Traditional Chinese Medicine (2020-478) and all participants provided written informed consent prior to enrolment in the study.
Inclusion and Exclusion Criteria
Inclusion criteria: (1) the symptoms after RP were urinary incontinence and the course of disease starting from the occurrence of postsurgery urinary incontinence was >3 months; (2) Pad test (+).
Exclusion criteria: (1) patients have temporary postsurgical urinary incontinence that happens within 1 to 2 months; (2) patients with urinary calculi, urinary infection, or other diseases that cause urinary incontinence; (3) patients with serious primary diseases such as heart, brain, liver, and hematopoietic system or allergic constitution; (4) patients who cannot cooperate, such as psychopath.
Method
This is a randomized clinical prospective study. The control group was treated with anus lifting training. The treatment group was treated with pelvic floor low-frequency electrical stimulation combined with anus lifting training. (1) Anus lifting training: let the patients perform anal and perineal contraction, that is, the abdomen, perineum, and anus contract at the same time, and feel that the anal contraction is strong and powerful. The anal contraction lasts for more than 5 s each time, 30 times per group, and more than 10 groups per day. (2) Low-frequency electrical stimulation of pelvic floor: low-frequency neuromuscular therapeutic instrument (manufacturer: Foshan Shanshan Medical Technology Co., Ltd., model: BioStim Ble) was used according to the manual: clean the skin of the place where the electrodes were placed and wipe it dry and stick the electrodes to the level about 1.5 cm beside the spinous process of the third lumbar spine and 2.0 cm above the intersection of the symphysis pubis of the anterior midline in the anterior midline. The current frequency is 40 Hz, and voltage was based on the patient’s feeling but no pain (all patients were in the range of 10–15 V). The treatment time is 30 min/time, once every other day.
Evaluation and Outcome Measures
The scores of ICI-Q-SF, I-QOL, VAS, and Glazer were recorded before and every week after treatment. Pad test: theoretically, it is an objective reflection of 24-hr urine leakage in patients with urinary incontinence. However, we found that there were many interference factors to the urine leakage, so this study applies it as an objective qualitative indicator: If the weight gain is more than 5.5 g, it is considered positive.
Statistical Analysis
SPSS 26.0 software was used for statistical analysis. The measurement data were described as mean ± standard deviation and were compared between groups by t test. The counting data were described in the way of number of cases (percentage) and were compared between groups by chi-square test. Kaplan–Meier method was used to draw urinary control curve, and log rank method was used to do intergroup comparison. Statistical tests were all bilateral tests. P < .05 was considered statistically significant.
Results
The relevant clinical factors that may affect urinary control in the two groups of patients are presented in Table 1, and statistical tests are carried out. The age of patients ranged from 62 to 83 years, with an average age of 69.16 ± 6.33 years. The course of disease was 3 to 36 months, with an average course of disease of 13.04 ± 8.48 months. According to the order of visiting the hospital, the patients were randomly divided into the treatment group of 27 cases and the control group of 28 cases by the table of random digit. The age range of the observation group was 62 to 82 (68.9 ± 8.2) years, whereas of the control group was 62 to 83 (69.46 ± 6.71) years (p = .724). The course of disease for the observation group was 3 to 36 (13.19 ± 8.88) months, whereas for the control group was 3 to 36 (12.89 ± 8.23) months (p = .900). The results show that there is no significant difference between the two groups of patients in the clinical characteristics that may affect urinary control: Stage (T, p = .782), Stage (N, p = .744), Gleason score (p = .880), neoadjuvant endocrine therapy (p = .509), transurethral resection of prostate (p = .966), intraoperative blood transfusion (p = .959), and operation type (p = .946).
Clinical Factors of Two Groups of Patients (n = 55); Mean ± SD; n (%)
Kaplan–Meier method was used to draw the urinary control curve (Figure 1). The recovery of urinary control in the treatment group was significantly better than that in the control group, with a statistically significant difference (log rank = 4.006, p = .045). In addition, all scores in the same group have improved over time. However, after 10 weeks, the difference between the two groups was gradually smaller, and the difference between the two groups was not statistically significant.
Kaplan–Meier Method Was Used to Draw the Urinary Control Curve. The Difference Between the Two Groups Was Statistically Significant From 2 Weeks to 10 Weeks, and There Was No Significant Difference After 10 Weeks
There was no statistically significant difference in ICI-Q-SF, I-QOL, VAS, and Glazer scores between the two groups before treatment (p > .05), indicating that they were comparable. No adverse reaction occurred during the whole treatment. In the control group, after 4 weeks of treatment, ICI-Q-SF and VAS scores decreased compared with those before treatment (p < .05), I-QOL and Glazer scores increased gradually with the increase of treatment times (p < .05), and all indicators at the end of 3-month follow-up had significant statistical differences compared with those before treatment (p < .05).
In the treatment group, compared with the control group, the ICI-Q-SF and VAS scores of the patients in the 2 to 10 weeks after treatment were significantly lower (p < .05), and the I-QOL and Glazer scores were significantly higher (p < .05). However, at the end of the 3-month follow-up, there was no significant difference between the two groups in all indicators (p > .05) (Table 2).
Comparison of ICI-Q-SF, I-QOL, VAS, and Glazer Scores Between the Two Groups Before and After Treatment (n = 55) (Mean ± SD)
Note. VAS = visual analogue scale; ICI-Q-SF = incontinence questionnaire-urinary incontinence short form; I-QOL = incontinence quality of life.
The difference was statistically significant compared with that before treatment. bThe difference was statistically significant compared with the treatment for 1 week. cThe difference was statistically significant compared with 2 weeks of treatment. dThe difference was statistically significant compared with 4 weeks of treatment. eThe difference was statistically significant compared with 6 weeks of treatment. fCompared with 10 weeks of treatment, the difference was statistically significant.
The difference was statistically significant compared with the control group at the same time.
Compared with the score of ICI-Q-SF before and after treatment, the effect of the treatment group after 6 weeks of treatment (improvement of ICI-Q-SF score) was significantly better than that of the control group (p < .05). The total effective rates of the treatment group and the control group after 6 weeks of treatment were 74.07% (20/27) and 35.71% (10/28), respectively.
Discussion
RP is one of the most common ways to treat prostate cancer, but because it involves the resection of prostate and proximal urethral sphincter, it inevitably destroys the tissue structure of bladder neck and peripheral nerves, causing damage to urinary control function (Del Giudice et al., 2022). At the same time, the distal urethral sphincter may be injured during or after the operation. Common factors such as local tissue ischemia and scar adhesion may directly damage the pudendal nerve and cause postoperative urinary incontinence. The incidence rate can reach 20%, which has a great impact on the quality of life of patients after the operation. The treatment of urinary incontinence after RP is very important for patients (Nygaard & Shaw, 2016).
Behavioral therapy and physical therapy are still the main means (Stafford et al., 2022). After RP an early supportive rehabilitation program like pelvic floor muscle training significantly reduces continence recovery time. Most patients (93.3%) recover urinary control 1 year after surgery (Clarebrough et al., 2019), but this can be achieved sooner with combined noninvasive physical therapy. The addition of guided programs using biofeedback and/or pelvic floor muscle electric stimulation can improve early recovery of urinary continence after RP (Arnsrud Godtman et al., 2022; Westney et al., 2006).
In this study, there was a statistically significant difference between the urinary control curves of the two groups. In the short term, the recovery of urinary control in the treatment group was significantly better than that in the control group, but the difference gradually narrowed after 6 weeks. The calculation of urinary control rate showed that the difference between the two groups was 7.54% from 2 weeks after operation, and then increased. The maximum difference was 30.56% at 6 weeks after treatment, and then decreased gradually. There was no statistically significant difference after 10 weeks. This study suggests that electrical stimulation combined with anus lifting training can accelerate the recovery speed and shorten the recovery time, but with the extension of the treatment time, the total effectiveness does not increase significantly, and the final treatment effect of the two groups was still similar.
It is known that the external sphincter of urethra and levator ani muscle are mainly innervated by the pudendal nerve. The pudendal nerve from anterior crus of spinal cord at segment S1-S3 innervates the striated sphincter and pelvic floor muscle, and some of them consciously control the contraction of these muscles. If the striated muscle innervation is retained during the operation, it may help to recover the urinary control function after the operation (Mariotti et al., 2009). In this study, according to the instrument manual, we located the patient with about 1.5 cm at the level near the spinous process of the third lumbar vertebrae and 2.0 cm above the intersection of the symphysis pubis of the anterior midline in the anterior midline. Strengthen the pelvic floor muscle group through low-frequency electrical stimulation, especially stimulate the innervating nerve of the levator ani muscle, including increasing the contraction force of the pelvic floor muscle through nerve reflex, and achieve the purpose of preventing and treating muscle atrophy. Electric stimulation can excite pudendal nerves, improve muscle nutrition, and blood circulation, ensure normal metabolism, mobilize compensatory hyperplasia of muscle fibers, enhance terminal motor units, restore nerve excitation and conduction level, to normalize the activity of pelvic nerves, and further strengthen the contractility of urethral sphincter (Moore et al., 1999).
In this study, the treatment group has obvious effect after 2 weeks of treatment, which shows that the combination of pelvic floor low-frequency electrical stimulation can significantly improve the symptoms of urinary incontinence in patients after RP and shorten the recovery time. However, after 6 weeks of treatment, the therapeutic effects of two groups gradually approached each other, indicating that although the combination of the two methods could improve the recovery speed, the long-term effect seemed to be close, that is, pelvic floor low-frequency electrical stimulation combined with anus lifting training could not improve the long-term effect. We speculated that electrical stimulation accelerated the speed of muscle or nerve recovery but could not improve the muscle strength and urethral closure pressure, so the long-term effect was equivalent. Guided pelvic floor muscle exercise could improve the recovery of urinary continence at both early and long-term stages (Wu et al., 2019). Thus, it is also possible that our research period is not long enough, and the patient sample size is not big enough, and the long-term effects of the two groups may still be different. Due to ethical reasons, it is impossible to take electrical stimulation as a single variable for experimental observation this time. Animal experiments can be conducted to further explore the pathophysiological mechanism.
One limitation of our study is that we observe more patients have low-grade tumors in the clinic. This is because patients tend to choose radical surgery instead of conservative treatment in China. We will need to include more patients with high-grade tumors in the future. The other limitation of our study is that we could not follow up for a longer period such as 6 to 9 months. Patients will stop visiting the clinic once their symptoms improve because patients need to pay out-of-pocket charges for the treatment.
In conclusion, the effect of pelvic floor low-frequency electrical stimulation combined with anus lifting training after RP is significantly better than that of single anus lifting training.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the grants from Zhejiang Province medical and health science technology plan project (Grant No. 2021KY921), Research Center for Medical and Health Science and Technology Development of the National Health Commission (NO.HDSL202001045), and project title “Application of appropriate electrophysiological technology in the prevention and treatment of andrological diseases.”
Research Ethics and Patient Consent
This study was approved by the Ethics Committee of Hangzhou Hospital of Traditional Chinese Medicine (2020-478). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. All participants provided written informed consent prior to enrollment in the study.
