A REVIEW OF ULTRASOUND-GUIDED PNEUMATIC ENEMA IN THE REDUCTION OF INTUSSUSCEPTION IN CHILDREN: INSIGHTS FROM A TEACHING HOSPITAL IN NIGERIA

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I.S. Chukwu, U.O. Ezomike, I.C. Obianyo, E.P. Nwankwo, S.O. Ekenze

Sub-department of Paediatric Surgery, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria

Abstract

Background: Pneumatic reduction, as a non-operative mode of treating intussusception, is traditionally done under fluoroscopy guidance. However, fluoroscopy guidance is fraught with exposure to ionizing radiation and fluoroscopy machines may not be routinely available especially in low-and middle-income countries. The aim of this study was to evaluate the efficacy, safety and predictive factors of successful reduction of intussusception using the ultrasound-guided pneumatic technique.

Materials & Methods: This was a prospective cohort study of children, 3 to 36 months of age, who were confirmed to have intussusception by abdominal ultrasonography and had pneumatic (air) reduction under ultrasound guidance between December 2018 to December 2020. Patients with bowel perforation, peritonitis, non-responsive shock or recurrent intussusception were excluded. Success rate, time to reduction, complication (recurrence and perforation) rate, and predictive factors for successful reduction were evaluated.

Result: Thirty (36.1%) out of 83 patients who presented with intussusception during this period had ultrasound-guided pneumatic reduction. The mean age was 6.1±1.6 (range: 4 to 9) months. Male to female ratio was 2.3:1. About onethird of the patients presented within <48 hours of onset of symptoms. 21 patients (70%) had a successful reduction. The mean time to reduction was 10.51 ± 4.19 (range: 3 to 16) minutes. One patient had recurrence giving a recurrence rate of 3.3%. There was no case of perforation. Patients who had successful reduction significantly had palpable abdominal mass (p = 0.0139), serum sodium >135mmol/l (p = 0.0419) and serum potassium >3.5mmol/l (p = 0.0318). Only serum potassium >3.5mmol/l (Odd ratio (OR), 6.9; 95%confidence interval (CI), 1.2 – 40.3; p = 0.03) was significantly associated with successful reduction on multivariable analysis.

Conclusion: Ultrasound-guided pneumatic reduction of ileocolic intussusception is feasible, effective and safe. It may be used in the treatment of children who present with ileocolic intussusception. Serum potassium>3.5mmol/l may suggest the likelihood of successful reduction.

Keywords: Intussusception; Pneumatic reduction; Ultrasound-guided; Children

Introduction

Intussusception is the invagination of a segment of bowel (intussusceptum) into an adjacent segment of the bowel (intussuscipiens).¹ In ileocolic intussusception, which is common in children 3 – 36 months of age, the terminal ileum is the intussusceptum while the colon is the intussuscipiens. Intussusception is the commonest cause of intestinal obstruction in infancy and early childhood and as such, it is a pediatric surgical emergency.^1-3 Treatment may be operative or nonoperative, with the non-operative mode of treatment, when not contra-indicated, being currently preferred.⁴ Non-operative reduction of intussusception may be effected with either hydrostatic or pneumatic reduction.

Interestingly, it is established that pneumatic reduction is faster when compared with hydrostatic reduction.3 Fluoroscopy has been traditionally used to guide pneumatic reduction of intussusception, however, ultrasound is portable, cheaper, readily available and has no ionizing radiation. Ultrasound is able to visualize the entire peritoneal cavity compared with fluoroscopy which visualizes only the intraluminal content.^5,6 Ultrasound-guided pneumatic reduction is not commonly reported. A recent systematic review called for more papers on efficacy and safety of ultrasoundguided pneumatic reduction. Moreover, most reports on ultrasound-guided pneumatic reduction were done on patients who presented early (within 24 – 48 hours).^3,7,8 This may not be of much benefit to clinicians in the low-and-middle income countries (LMICs) where late presentation (mostly after 48 hours) is still rife.^9,10 Papers reporting time to reduction are scant. The only report from Nigeria on experience with ultrasound-guided pneumatic reduction of intussusception in children was retrospective.1

The purpose of this study was to evaluate the efficacy and safety; and to identify the factors associated with successful reduction of intussusception using the ultrasound-guided pneumatic reduction technique. We hypothesized that ultrasound-guided pneumatic reduction of intussusception has a high success rate, and short time to reduction and low complication rates; and we sought to identify patient factors that may be related to successful reduction using this technique. Identifying such factors will guide counselling and discussion of outcome of care with the parents of children who would benefit from ultrasound-guided pneumatic reduction of intussusception.

MATERIALS AND METHODS
This is a prospective cohort study that was performed at the Paediatric Surgery Unit of the University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla, Enugu, Nigeria between December 2018 to December 2020 on children who presented to the children emergency room, during the period of the study, with intussusception confirmed by abdominal sonography. The study was approved by the UNTH Health Research and Ethics committee. Written informed consent was obtained from the parents or legal guardians. This study is compliant with Strengthening the Reporting of Observational studies in Epidemiology (STROBE)¹¹ and Strengthening the Reporting of Cohort Studies in Surgery (STROCSS)¹² guidelines.

Children, 3 to 36 months of age, who were clinically diagnosed to have intussusception which was confirmed by abdominal ultrasonography were included in the study. Patients who had bowel perforation, peritonitis, non-responsive shock or recurrent intussusception at presentation were excluded. Time to presentation was not used as a criterion for eligibility.

Screening for eligibility was done clinically by way of history taking, physical examination and intussusception confirmed by abdominal ultrasonography. The patients were resuscitated with intravenous fluids; size 10 nasogastric tube for gastric decompression and 8Fr 2-way urethral catheter to monitor urine output were passed. Intravenous antibiotics – Ceftriaxone 50mg/

kilogram body weight/day in two divided doses and Metronidazole 7.5mg/kilogram body weight/dose 8 hourly – were commenced. Serum electrolytes, urea, and creatinine; and Full Blood count were sought for (at presentation). Electrolyte imbalance was corrected when present and haemogram optimized to a minimum of 10g/dl. The patients proceeded to the radiological suite for pneumatic (air) reduction under ultrasound guidance when they were fully resuscitated. Preparation was made for immediate surgery if there was failed reduction and/or bowel perforation occurred.