Intussusception is a common childhood problem that results in serious morbidity and mortality throughout the world and is one of the more common causes of intestinal obstruction in infancy and young children [1]. In this review, three-quarters of patients were in the first year of life which is in agreement with other studies done elsewhere [1, 16, 21–24], but at variant with other reports in Nigeria that associated childhood intussusception with the above 5 years age group [25, 26]. Also, Elebute and Adesola [27] reported a high incidence of intussusception in children older than one year of age. This study showed that males were more affected than females with a male to female ratio of 3.3:1 which is comparable to the results of other workers [1, 2, 16, 17, 20, 28–30]. Other authors reported female predominance [31]. However the exact reason for this age group and gender differences is not known.
In this study, more than eighty percent of the patients came from the rural areas located a considerable distance from the study area which is in keeping with other studies [16, 17, 30], This observation has an implication on accessibility to health care facilities and awareness of the disease.
The etiology of intussusception in children remains a dilemma as it largely idiopathic in more than 90% of the cases [3, 5–7, 16, 30, 31]. In our study, idiopathic intussusceptions was reported in 91.1% of patients and the remaining 8.9% of cases showed pathological lead points such as lymphoid hyperplasia of Peyer’s patches in 3 patients and intestinal polyps and post-appendicectomy in 1 patient each, respectively. The incidence of idiopathic intussusception has been reported in several studies to have a seasonal variation, with peaks coinciding with the peak incidence of viral respiratory tract infections and diarrheal diseases [32, 33]. In the present study, we observed a significant seasonal variation with a definite increase during the dry months (May to October), and a low incidence during rainy season (November to April). Other authors also reported similar seasonal variation [16, 22, 26, 30]. Viral illness such as gastroenteritis, upper respiratory infections and other flu-like illness are known predisposing factors to idiopathic intussusception [34, 35]. An increase in the incidence of these diseases during dry months may be responsible for seasonal variation observed. However, an increase in the incidence of these associated diseases was not documented in our patients.
The clinical presentation of intussusception in our patients is not different from those in other studies performed in developing countries [16, 17, 20, 27, 30, 31, 36]. Most of the patients presented later than four days to the surgeon, a figure which is longer compared to reports from developed countries [4, 9, 15, 19] that give duration in terms of hours. Some of our patients presented early but were treated for other medical illnesses in the pediatric wards and were referred to surgeons when abdominal distention set in indicating lack of awareness of the condition among health providers in our setting and in other similar studies in resource limited setting [16, 30, 36]. Most of the patients in this study were therefore picked in the late stages of disease progression when absolute intestinal had set in. The reasons for late presentation in the present study may be attributed to the fact that the diagnosis of intussusception in its initial stages is usually difficult due to vague and non-specific symptoms as a result patients remain undiagnosed for prolong periods, receiving symptomatic treatment in the pediatric wards or in the peripheral hospitals and subsequently present to surgeons late when intestinal obstruction had set in. The unequal distribution of expertise due to low doctor patient ratio in resource-limited setting renders the diagnosis of intussusceptions at the health centers and most peripheral hospitals difficult to achieve as primary health care workers in these areas may not adequately handle challenges when faced with relatively commoner differentials e.g. gastroenteritis in a daily basis. This calls for an urgent awareness campaign among doctors, nurses, and parents in our environment to raise the index of suspicion and increase the rate of early presentation in this condition. Only 42.5% of the patients reported with the classical triad of vomiting, colicky abdominal pain and red currant jelly stools. The low reporting of classical presentation has been shown by other studies from Africa [16, 20]. Kuremu [30] found such symptoms in 17% of his patients. Other authors reported 33%, 32%and 7.5% [17, 37, 38] among their cases. Primary health care providers have to be aware to this, as many patients may be missed in the critical time.
The diagnosis of intussusceptions varies substantially by region. Whereas in developed countries, the diagnosis of intussusceptions is made radiologically (air-contrast enema, abdominal ultrasound, computered tomography etc.) in over 95% of cases, the diagnosis of intussusceptions in developing countries is made clinically or at surgery in the majority of cases [16, 17, 30]. This observation is reflected in our study where more than 70% of our patients were diagnosed clinically. Timely diagnosis in this condition is usually dependent on the primary physicians rather than surgeons. Because of the often nonspecific and diverse presenting signs and symptoms, primary physicians must continue to have a high index of suspicion to diagnose children with intussusception. These nonspecific presenting signs and symptoms of patients have been addressed by some pediatric radiologists through the use of ultrasound to screen for intussusception before invasive techniques [39, 40]. However, Ultrasonography was not always readily available in this series and was employed in only 10.7% of patients as it would not have significantly influenced the course of surgical therapy.
In keeping with other studies from developing countries [16, 17, 20, 27, 30, 31, 36], surgical intervention was the main stay of treatment performed in all of our patients. This is in contrary to studies in developed countries where intussusception is usually managed by nonsurgical reduction and surgical reduction is indicated only when perforation of bowel is suspected or when radiological reduction fails [41–43]. Nonsurgical reductions of intussusception had been shown to decrease length of hospitalization, shorten recovery, and reduce the risk of complications associated with major abdominal surgery [15]. However, despite the reports on the benefit of nonsurgical treatment, surgery still has a definite role in the management of intussusceptions. Such cases with features of peritonitis at presentation, or those that fail to reduce with non-operative means and patients with pathological lead points and/or bowel complications may invariably require surgery [44]. In this study, nonsurgical reduction was not performed due to late presentation and dearth of specialized facilities and trained personnel. The lack of qualified personnel in the radiological unit coupled with lack of enthusiasm in radiological reduction has shifted much work to the surgeon.
In the present study, ileo-colic intussusception was the most frequent type seen at laparotomy. This is in agreement with other studies performed elsewhere [1, 5, 16, 17, 20, 30, 31, 33],[36]. We could not establish the reason for this observation.
The rate of bowel resection in our study was found to be 46.4%, a figure which is higher than 33% and 39% reported in Kenya [30] and Tanzania respectively [16]. The higher rate of bowel resection in our study is attributed to the late presentation to the surgeon, which is a reflection of the low level of health awareness in our community. The late presentation may lead to increasing edema of the bowel wall and advancing intussusception, which clearly reduces the chances of nonsurgical reduction [44]. It is obvious that the duration of symptoms displays a significant factor of morbidity for complications and, necessarily, bowel resection. Intensive health education with a view of promoting increased health awareness and encouraging early presentation of patients to hospital will reduce the bowel resection rate and morbidity and mortality associated with the disease.
The presence of complications has an impact on the final outcome of patients presenting with intussusception. In keeping with other studies [1, 16, 17, 20, 30, 36, 44], surgical site infection was the most common postoperative complications in the present study. In the present study, we found a total recurrence rate of 8.3%, which is consistent with the previously published recurrence rates of 8 - 10% [45–47]. In this study, the presence of complications was found to be associated with high mortality and prolonged length of hospital stay.
The overall median duration of hospital stay in the present study was 14 days which is higher than that reported by Ekenze et al.[44] in Nigeria. The reasons for prolonged length of hospital stay in our can be explained by the presence of large number of patients with postoperative complications and bowel resection in our study. However, due to the poor socio-economic conditions in most developing countries including Tanzania, the duration of inpatient stay for our patients may be longer than expected.
The overall mortality rate in this study was 14.3%, a figure which is higher than 8.5% reported by Ekenze et al.[44] in Nigeria. Harouna et al.[48] observed a high mortality rate of 55% among cases of paediatric intussusceptions in Niger. This was attributed to delayed presentation and advanced peritonitis, coupled with inadequate facilities to manage these challenging cases. The high mortality rate in our study was attributed to age < 1 year, delayed presentation (> 24 hours), associated peritonitis, bowel resection and presence of surgical site infection. Addressing these factors responsible for high mortality in our patients is mandatory to be able to reduce mortality associated with this disease.
The follow-up of patients in this study was generally poor as more than fifty percent of patients were lost to follow up, and data on long-term complications were not available. This observation concurs with other studies performed in developing countries [16, 20, 30]. Poor follow-up of patients in our study may be explained by the fact that the majority of patients were lost to follow-up at the end of the study period.
The high morbidity and mortality rates in this study are attributed to delayed presentation of disease, lack of diagnostic and therapeutic facilities and trained personnel seen in developed world. Findings from this study is a typical example of diagnostic and therapeutic challenges seen in most developing countries where delayed presentation of the disease coupled with lack of diagnostic and therapeutic facilities and trained personnel for non-operative reduction and poor referral system are among the hallmarks of the disease [16, 20].