Transanal protrusion of intussusception is defined as the invagination of an intestinal segment into the segment adjacent to it, with exteriorization of the head of the intussusceptum through the anus . Most case reports on TAPI occurred in females [6, 9], which is contrary to intussusceptions with no transanal protrusions which have a male predominance [10, 11]. The average age of occurrence is 5 to 12 months [6, 8, 11]. Our patient was a 10-months old female, so she exhibited the right profile for a TAPI. A high index of suspicion of TAPI is therefore warranted when faced with children of the same age group and gender, presenting with similar symptoms. TAPI is an uncommon manifestation of childhood intussusception with anal protrusion rates ranging from 8 to 29% [8, 12, 13]. A study on 198 children with intussusception revealed 8 (4.0%) children who had a prolapsed rectal mass, with the prolapse extending beyond the anal verge in 2 (1.0%) of the children . This is important because when the prolapse actually extends beyond the anal verge, as was the case in our patient, it is more likely to be misdiagnosed as a rectal prolapse.
The pathogenesis behind TAPI is not fully understood. However, proposed mechanisms include: increased intestinal peristalsis following enteritis and associated conditions, leading to rapid movement of the intussusception into the rectum ; anatomical defects like non-fixation of ascending and descending colons which predispose to an intussusception, with a delay in definitive treatment allowing time for transanal protrusion to occur .
The diagnosis of intussusception is challenging due to its varied unspecific clinical presentation, ranging from a painless intussusception to constipation, dehydration from diarrhoea and vomiting, intestinal prolapse, rectal bleeding, sepsis, shock, syncope, and altered mental status [2, 9]. The classic triad of severe intermittent abdominal pain, red currant jelly stools and vomiting occurs in less than 20% of cases . Some cases of TAPI occur in the absence of cardinal signs of intussusception . Also, the relatively high frequency of rectal prolapse in childhood increases the diagnostic challenge of TAPI . These cause a delay in the diagnosis and referral to a surgeon for proper management. A delay in presentation for effective management is a common trend in most developing countries with patients presenting after as much as 45 days after the onset of symptoms . In resource limited settings, delays in presentation are accentuated by the absence of a universal health coverage with patients having to auto-finance their cost of care. When they do get the means, their first stop is usually at primary health care centres. Here, most of the health personnel are not aware of this condition, and they delay effective management by treating for other conditions such as gastroenteritis and rectal prolapse, thereby increasing the risk of necrosis, perforation and death [14, 15]. Our case portrays the typical trend of events in resource limited settings; first the parents tried auto-medication at home, then they went to a primary health centre where the child was being managed for rectal prolapse and was only referred after the onset of complications such as necrosis and significant electrolyte and hemodynamic derangements. Lack of finances prolonged their stay at home thereby worsening the prognosis as valuable time was spent raising funds rather than seeking effective treatment. The child was operated 11 days after onset of symptoms following several failed probabilistic managements, with an unfavourable outcome.
Radiological investigations are the mainstay for the confirmation of the diagnosis of intussusception. They include Computed Tomography scannings, plain abdominal radiography, ultrasound, and contrast or air enemas which have a combined diagnostic and therapeutic effect . Ultrasound scans by experienced users are very reliable in the diagnosis of intussusception . However, lack of equipment and/or shortage of trained personnel limit the use of ultrasounds in resource limited settings [18, 19], posing a huge diagnostic challenge of TAPI, preoperatively. When present, lack of access to reliable maintenance and repairs have proven to be major obstacles to the use of ultrasounds , as was the case in this report. In resource limited settings like ours, over 90% of cases are diagnosed clinically or per operatively [2, 17]. This absence of confirmatory diagnostic work-up could cause a further delay in effective treatment and increase the advent of adverse outcomes.
Air Enema Reduction (AER) is the recommended treatment for TAPI presenting less than 48 h after onset of symptoms . This practice is more common in high income countries, and is associated with decreased length of hospitalization, shorter recovery period, and decreased risk of complications associated with major abdominal surgery . However, lack of specialized facilities and trained personnel, and late presentation makes an open abdominal surgery the preferred approach in resource-poor settings. Some authors propose surgical management as the only means of management for TAPI .
High rates of mortality are associated with: less than one year of age, delayed presentation greater than 24 h, associated peritonitis, bowel resection, and surgical site infection . Our patient was 10-month-old, she presented after 11 days, had a significant portion of her bowel resected and died on post-operative day three secondary to sepsis. In line with the findings of Chayla and co, she had a poor prognosis from the onset, given that these conditions are usually associated with high mortality . Patients satisfying one or more of these conditions should be treated with the utmost care to reduce mortality. Also, efforts should be made to raise awareness of primary health care workers in recognizing and in applying timely referral so as to decrease the morbidity, such as extensive bowel resection, and mortality associated with this disease. Diagnostic equipment should receive regular maintenance, and ultrasound use should be encouraged to aid in posing a timely diagnosis.
A high index of suspicion and an improved referral system is essential for an early diagnosis and treatment of TAPI, so as to decrease morbidity and mortality from this disease. Health policies should implement continuous medical education (CME) sessions to re-inforce the clinical capacities of primary health care workers to correctly diagnose intussusception and primary health centres should acquire and implement predefined management algorithms which favour timely referral.