This is a prospective, randomized study that was carried out over a period of 21 months from December, 2018 to August, 2020 at the University of Nigeria Teaching Hospital (UNTH), Enugu, southeast Nigeria. The study was approved by the UNTH Health Research and Ethics committee. Of the seventy-five patients seen within the period, fifty-two infants with uncomplicated intussusception confirmed by abdominal ultrasonography following presentation at the children emergency room of UNTH, Enugu were recruited during the period of the study.
Inclusion criteria included children 1 to 12 months of age and presentation with uncomplicated intussusception confirmed by abdominal ultrasonography. Exclusion criteria were peritonitis determined by clinical features, bowel perforation sign on abdominal radiograph or abdominal ultrasound, non-responsive shock, and recurrent intussusception.
The patients were assigned to two groups. Group A included patients who had ultrasound-guided hydrostatic (saline) reduction. Group B included patients who had ultrasound-guided pneumatic (air) reduction. Eligible patients were randomized based on a simple random sampling technique. A total of 52 folded pieces of paper were prepared and mixed in a bag by a trained Research Assistant who was unaware of the demographic and clinical characteristics of the patients. 26 folded pieces of paper had “A” printed on them and 26 folded pieces of paper had “B” printed on them. The bag was entrusted to the Research Assistant who picked a folded piece of paper from the bag, without looking into the bag, (at the Radiological Suite just before the saline hydrostatic or pneumatic reduction) for each consecutive patient without replacement and assigned them to interventions. The folded pieces of papers were re-mixed in the bag each time. The letter “A” represented group A - those who had ultrasound-guided hydrostatic (saline) reduction, while letter “B” represented group B - those who had ultrasound-guided pneumatic (air) reduction. The sample population was attained when all the folded papers were picked. Written informed consent was obtained from the parents or legal guardians.
On presentation at the children emergency room, the patients were screened for suitability by clinical assessment of their history and physical examination and diagnosis of intussusception confirmed by abdominal ultrasound. The children were placed on nothing by mouth and resuscitation was commenced with intravenous fluids, intravenous antibiotics (Ceftriaxone 50mg/kilogramme body weight/day in 2 divided doses; Metronidazole 7.5mg/kilogramme body weight/dose 8 hourly), passage of nasogastric tube and urethral catheter. Serum electrolytes, urea, and creatinine; and Full Blood count were done. Electrolyte imbalance when present was corrected and haemogram optimized accordingly to ensure a minimum of 10g/dl. When the patient was fully resuscitated and making up to 1-2mls/kilogramme body weight/hour of urine, the diagnosis was confirmed by abdominal ultrasonography at the radiological suite. Adequate preparation was made for immediate surgery in the event of a failed reduction and/or perforation of bowel. Eligible patients proceeded to have enema reduction.
Ultrasound-guided saline hydrostatic reduction
At the radiological suite, the child was placed supine on a couch. An ultrasound machine (GE Versana Essential S/W of Medical Systems (China) Co. LTD) with a linear transducer of 7.5MHz was used by a radiologist to localize the mass. A size 22FG 2-way Foley catheter was inserted into the rectum and balloon inflated with 30mls of sterile water. An adhesive tape was firmly applied (extending from one greater trochanter to the other, holding the buttocks together) to ensure a good anal seal. A 1 litre infusion bag of normal saline (warmed to body temperature by placing it in a bowl of warm water) was suspended on a drip stand, 100cm from the level of the patient. It was connected to the drainage channel of the Foley catheter with an infusion giving set. The fluid was allowed to run while monitoring the mass with ultrasound. The pulse rate and oxygen saturation were monitored and recorded during the procedure. Complete reduction was confirmed by the disappearance of the intussusception mass and reflux of saline into the small bowel. Not more than three attempts at reduction were made. Each attempt was continued as far as the mass was progressively reducing as monitored with ultrasound. However, each attempt was aborted if after 3 minutes the mass was no longer reducing as monitored with ultrasound. Each attempt was aborted by disconnecting the infusion giving set from the Foley’s catheter; hence, reducing the pressure before another attempt was started again. Time to reduction was monitored with a stop watch. At the end of the procedure, the balloon was deflated and the catheter removed and the patient monitored.
Ultrasound-guided pneumatic reduction
At the radiological suite, the child was placed supine on a couch. An ultrasound machine (GE Versana Essential S/W of Medical Systems (China) Co. LTD) with a linear transducer of 7.5MHz was used by a radiologist to localize the mass. A size 22FG 2-way Foley catheter was inserted into the rectum and balloon inflated with 30mls of sterile water. An adhesive tape was firmly applied (extending from one greater trochanter to the other, holding the buttocks together) to ensure a good anal seal. The part of the aneroid sphygmomanometer containing the hand bulb, release valve and aneroid gauge was connected to the drainage channel of the Foley catheter via a short tube (cut from the tubing of a urine bag). The hand bulb was then squeezed to release air into the bowel while monitoring the mass with ultrasound. The pressure was carefully monitored using the aneroid gauge and not allowed to exceed 120mmHg at any time. The pulse rate and oxygen saturation of the patient were monitored and recorded during the procedure. Complete reduction was confirmed by the disappearance of the intussusception mass and reflux of air into the small bowel. Not more than three attempts at reduction were made. Each attempt was continued as far as the mass was progressively reducing as monitored with ultrasound. However, each attempt was aborted if after 3 minutes the mass was no longer reducing as monitored with ultrasound. Each attempt was aborted by disconnecting the short tube from the Foley’s catheter; hence, reducing the pressure before another attempt was started again. The time to reduction was also monitored with a stop watch. At the end of the procedure, the adhesive tape was removed, the balloon was deflated, the catheter removed and patient monitored.
Those who had a successful reduction of intussusception were taken back to the ward and monitoring continued. The nasogastric tube was removed when the drainage was minimal, no longer bilious and there was no abdominal distension. Oral feeds were commenced when patients were able to pass faeces and/or flatus. The intravenous fluids were stopped when oral intake was fully established; urethral catheter was then removed. Patients were discharged when recurrence was ruled out by the absence of symptoms of intussusception. The parents were warned of the possibility of recurrence of intussusception and the need to present early if symptoms such as abdominal pain, vomiting, passage of blood and mucus and abdominal distension recurred. Patients who did not have successful reduction proceeded to have surgery. Delayed repeat enema was not done.
The patients were followed up at the Paediatric Surgery out-patient department and via phone calls. They were seen on the first, fourth and twenty-fourth week following discharge from the hospital. Each patient was followed up for a minimum of 6 months. The parents/legal guardian were called on phone and reminded of follow up visits. The symptoms of recurrence of intussusception such as abdominal pain, vomiting, passage of blood and mucus and abdominal distension were assessed for during each follow up visit and the parents were warned of the possibility of recurrence of intussusception the need to present early if symptoms such as abdominal pain, vomiting, passage of blood and mucus and abdominal distension recurred.
Outcome measures
The primary outcome measure was the success rate of enema reduction. The secondary measures included the time to enema reduction and complication – recurrence and perforation rates.
Successful reduction was defined as the disappearance of the intussusception mass, reflux of saline/air into the small bowel and resolution of symptoms of intussusception.
The time to reduction was the time from the instillation of the normal saline or insufflation of air to when successful reduction occurred by ultrasound assessment.
Failed reduction was defined as presence of the intussusception mass after 3 attempts (or less than or equal to 3 attempts if perforation occurred) at reduction have been made.
Recurrence was defined as return of symptoms of intussusception 12 hours or more after a successful reduction 18.
Successful reduction and recurrence were assessed by a Senior registrar in Paediatric Surgery who was not involved in the enema reduction.
Data collection
A proforma was used for data collection. This included: patient’s age, sex, weight, duration of symptoms prior to presentation, phone number of parents, date of admission, clinical features, type and outcome of non-operative reduction, details of operative treatment for failed reduction, duration of hospital stay and duration of follow up.
Statistical analysis
Data were captured, stored, retrieved and analyzed using Statistical Package for Social Sciences (SPSS) of IBM SPSS statistics for windows, version 20 (SPSS Inc., Chicago, Illinois). Descriptive data were expressed as percentages, mean ± standard deviation and presented in tables and charts. Shapiro-Wilks test was used to test for normality of the data. The independent samples t-test was used for descriptive numerical data and chi-square was applied to categorical data. Independent samples t-test was used to compare the mean time to reduction while chi-square was used to compare the success, recurrence and perforation rates of the two groups. Relative risk with 95% confidence interval were calculated for the success, recurrence and perforation rates. P-value < 0.05 was considered statistically significant.