Prospective randomized clinical trial was conducted at Alexandria Main University Hospitals between May 2018 and April 2022 on patients with OD. Ethics approval was obtained from local ethics committee, Faculty of Medicine, Alexandria University, Egypt (serial number: 0106397). A written consent was secured from all participants. The study protocol was registered in the Alexandria University post-graduate research registry. The study adhered to CONSORT guidelines.
The study enrolled a sample of 60 eligible patients who were randomly assigned to either the BFT group (n = 30) or the Bi-PTNS (n = 30) using computerized randomization. The inclusion and exclusion criteria are as illustrated in (Table 1). The sample size was determined through a power calculation, aiming to achieve a statistical power of 80% to detect meaningful differences between the treatment groups. The calculation was based on relevant parameters extracted from previous studies, which served as a reference for effect size, significance level, and anticipated variability [17, 18].
Table 1
showing the study’s inclusion and exclusion criteria.
Inclusion Criteria |
Clinical diagnosis of OD was based on the presence of at least two or more of the following symptoms in ≥ 25% of defecation attempts: 1- Straining 2- Lumpy or hard stool 3- Sense of incomplete evacuation 4- Sensation of anorectal obstruction/blockage 5- Manual maneuvers to help defecation. Patients who fulfilled the clinical criteria for diagnosis of OD were investigated using imaging (defecography) and anal physiology studies. All eligible patients were advised on initial measures including dietary and life style modifications, laxatives, bowel habit training and psychological counselling for a duration of 6–12 weeks. |
Exclusion criteria |
1- Patients with evidence of structural causes of OD include rectocele, enterocele and rectal prolapse. 2- Patients who showed improvement following initial measures 3- Previous pelvic surgery or trauma 4- History of pelvic irradiation 5- Known neurogenic causes include Multiple Sclerosis, Parkinson Disease and Hirschsprung Disease 6- Contra-indications to Bi-PTNS e.g. neuropathy, PPM and soft tissue conditions affecting the site of electrodes application. 7- Patients with mental health problems who cannot engage in BFT. 8- Metabolic disorders include chronic hypokalemia, hypercalcemia and hypothyroidism, chronic kidney diseases. 9- Rheumatoid disorders 10- Inflammatory bowel diseases 11- Slow transit constipation 12- Ano-rectal congenital anomalies |
The patients were subjected to thorough clinical evaluation by a blinded colorectal clinician. Clinical examinations, including assessment of perineal decent, perineal sensation, rest and squeezing anal sphincter muscle tone, were conducted. Female patients were assessed for the presence of rectovaginal fistula, rectovaginal septum weakness, rectocele, cystocele and uterine prolapse. Patients with suspected structural abnormalities were further investigated by dynamic magnetic resonance imaging (MR defecography). Images were obtained at rest, at maximum anal sphincter contraction, during straining, and during defecation/evacuation in the midsagittal plane. Patients with suspected anismus were subjected to Nerve conduction studies and Electromyography (EMG). At the initial assessment, all patients received education and illustration about defecation physiology and anatomy of the pelvic floor. They were also educated about diet and bowel habit and defecation behaviors. All patients included in the study had reported failure of the conservative and lifestyle changing measures for at least 6 weeks. Pre-treatment Wexner constipation and PAC-QoL scores were recorded.
Patients were assigned to one of the study groups by an independent blinded researcher. In BFT group, rectal and abdominal sensors were used to detect pelvic floor muscle signals, with 10 to 12 sessions in total, 3 sessions weekly lasting 30 min each, patients were asked to contract and relax their pelvic floor muscles guided by audiovisual response recorded on the BFT machine. Sessions were continued for 30 minutes unless the patient report pain or asks to stop. Bi-PTNS: trans cutaneous Bi-PTNS was performed for 30 minutes duration unless the patient report pain or asks to stop the session, three times weekly of average 10 to 12 sessions were given according to the patient improvement. Transcutaneous stimulation was achieved by surface adhesive electrodes placed at the site of posterior tibial nerve with negative electrode put behind the medial malleolus and the positive one 10 cm above it. The treatment sessions were performed by the same practitioner who has had over 10 years of experience in pelvic floor physiotherapy.
The two groups of patients were treated by the same physicians and evaluated at the end of treatment period. All research subjects received the same standard medication, treatment strategies, and necessary behavioral education before BFT or Bi-PTNS. An independent researcher collected the data on post-treatment efficiency of each group using Wexner and PAC-QoL scores. Patients were assessed immediately after completing the assigned treatment course and 12 weeks later. The average scores were utilized for analysis. None of the patients were lost to follow up.
Statistical analysis of the acquired data was conducted using IBM SPSS software package version 20. Qualitative data were described using number and percent. The Kolmogorov-Smirnov test was employed to ascertain the normality of distribution. Quantitative data were described using range (minimum and maximum), mean and standard deviation or median and interquartile range (IQR). Significance of the obtained results was set at the 5% level. Chi-square test was used for categorical variables to compare between different groups. Categorial variables were subjected to the Chi-square test, with Fisher’s Exact or Monte Carlo correction applied when more than 20% of cells exhibited expected counts below 5. For normally distributed quantitative variables, the student t-test was applied for inter-group comparisons, and the paired t-test was used for inter-group analysis across different periods.