Discussion
This study shows that hydrostatic reduction with intermittent radiography was performed successfully in about 52% of all cases of intussusception admitted in our department. Although this was lower than that of many high-income countries, it still avoided surgery and anesthesia in more than half of the patients. It is, however, well-known that delayed presentations of surgical conditions are common in LMICS, which might explain the relatively lower proportion of hydrostatic reductions in our series. A recent study that included eight large specialty pediatric hospitals in Chennai, India, reported that 59.8% of their cases were managed non-operatively.1 In these hospitals, either US-guided hydrostatic reduction or fluoroscopy guided air enema reduction was used. In a 14-year study from a UK referral center, 44.48% patients were reduced successfully by non-operative treatment and 48% needed surgery.14 However, air enema was used instead of liquid enema. Another study involving four hospitals in Hunan and Henan Provinces of China between 2009 and 2013 reported that among 1715 intussusception cases, air or liquid enema reduction was performed in 80% cases; 16.3% required surgery without intestinal resection; and 2.6% required surgery with intestinal resection.15
Non-operative reduction of intussusception is not practiced in most centers in Bangladesh, including the major referral centers in the capital city. Occasionally, there have been scattered efforts to establish US-guided or fluoroscopy-guided reduction at some centers, but these efforts could not be sustained. An earlier study involving two centers in our country showed a 90% success rate of US-guided hydrostatic reduction of intussusception, although this procedure could not be sustained in these institutes.11 The main reason may be attributed to the lack of interest from the radiologists as this is a time-consuming procedure, and there is an excessive load of patients with other diseases. There is also a fear of potential perforation of gut. Reduction with US guidance requires a continuous presence of the sonologist and demands a significant amount of time. Many sonologists are also not comfortable with apprehended and crying infants, and sometimes this procedure is chaotic. The method of non-operative reduction varies from center to center. Barium was the contrast agent of choice when the procedure was initially introduced. However, barium is no longer advocated owing to concerns over peritoneal staining if perforation occurs.5 Nowadays, pneumatic enema or hydrostatic enema with saline or water-soluble contrast are the dominant techniques, and most centers perform them under US guidance. However, fluoroscopy-guided contrast enema reduction is also widely practiced.5 Numerous studies have compared air and liquid methods with variable results. However, a meta-analysis of more than 32 000 children from 102 studies showed that air enema reduction had higher success rate than hydrostatic reduction, but both had similar perforation rates.16 They opined that air enema is cleaner, less expensive, and has shorter fluoroscopic time and lower radiation exposure. A Cochrane meta-analysis of six randomized controlled trials with a total of 822 participants also found superiority of air enema over liquid enema, although they described the evidence as of low quality.17 A survey on North American pediatric radiologists conducted in 2015 showed that 96% used fluoroscopy and 4% used US guidance for reduction; 78% used air enema and 20% preferred liquid enema to reduce intussusception.16
In the present study, intermittent radiography was used to monitor the progress of hydrostatic reduction rather than for continuous fluoroscopic guidance. The key to success of this procedure was very gentle and controlled insertion of contrast material through a Foley catheter. Contrast was inserted through a 50 mL syringe rather than from a hanging saline bag. This also saved time, and the technician could subjectively assess the resistance to flow during insertion. However, the established method of hanging saline bag can also be adopted for reduction with intermittent radiography guidance. Fluoroscopy is not available in many centers, and it has added hazards of higher exposure of radiation than plain radiography. On the other hand, USG needs continuous presence of a sonologist. X-ray is available everywhere and is cheap; a radiography technician can perform it successfully and safely if properly demonstrated. This procedure has the potential to be introduced even in remote centers that have X-ray facilities, and it will reduce delays to transfer patients to a tertiary center. Delays in the management of intussusception compromise both anatomical and physiological viability of the intestine and lead to bowel necrosis, gangrene, perforation and peritonitis. These lead to increased rates of surgery and to mortality from intussusception in many LMICs.18 Hydrostatic reduction is reasonably safe. The only case who had a perforation (0.32% among 312 attempts between 2014 and 2019) after an attempted hydrostatic reduction had features of peritonitis and was misjudged by a junior resident and was referred for hydrostatic reduction without consulting a senior resident or a consultant. The patient later underwent surgery, where a perforation in the transverse colon was repaired and proximal ileostomy was performed. The patient was then discharged well. After this event, the radiology team also became vigilant in selecting cases of hydrostatic reduction and refused the procedure in several patients who had been referred with features of peritonitis. However, the rate of perforation (0.32%) is lower than many series with US-guided or fluoroscopy-guided reductions and is comparable to the meta-analysis that compares perforation rates of air enema (0.39%) and liquid enema (0.43%) reduction.16 One patient who died after a failed attempt of hydrostatic reduction had a gangrenous segment in the transverse colon. There was no perforation of gut and no spillage of contrast. The gangrenous gut was excised, and a transverse colostomy was performed because of bad general condition. However, on the fourth day of hospitalization, the patient died of sepsis.
In our study, the magnitude of intussusception admission was 2.38% of all admissions, and it had an increasing trend. A recent systematic review estimated that the annual incidence of hospital admissions for intussusception ranged from 34 to 90 per 100 000 children under 1 year of age.19There has been recent concern about the increased incidence of intussusception due to vaccination against rotavirus. However, it has been suggested from a modeling analysis based on 135 countries that rotavirus vaccines had a favorable benefit–risk profile in LMICs.20 We could not analyze the impact of rotavirus vaccination during the increasing trend in our series because vaccination was not recorded. Moreover, it is difficult to comment on whether the increase in the number of cases in our series was an actual rise of patients or occurred due to an increase in number of patients seeking medical advice.
Although we could not analyze the overall success rate of attempted hydrostatic reduction in our patients, the analysis of patients from 2014 to 2019 (434 patients in 6 years) showed an 82.37% success rate. The meta-analysis of 102 studies estimated the success rates of air enema and liquid enema to be 82.7% and 69.6%, respectively.16 We did not use any anesthesia or sedation for hydrostatic reduction. The use of anesthesia or sedation is not described well in most series. However, some centers are known to use sedatives, such as propofol, morphine or ketamine, for hydrostatic reduction.21 22 Overall, 46% of our patients underwent surgery in our study. A recent review of 1158 cases from seven African countries showed that more than 87% of the patients with intussusception in these countries underwent surgery.8 Mortality from intussusception in our series was 3.57%. However, intussusception (9.94%) was the most common cause of infant mortality, which is also consistent with findings from other countries for this age group. Centers that use ‘surgery only’ for the treatment of intussusception reported mortality rates ranging from 8% to 32%, a sharp contrast to less than 1% mortality rate in high-income countries who have facilities for hydrostatic or air enema reduction and where patients usually present early.23 24 Although delayed presentation is very common in LMICs, hydrostatic reduction with this simpler technique may avoid unnecessary surgery and anesthesia in select cases who present early. However, ‘hydrostatic or air enema reduction alone’ cannot always be successful, and patients who develop peritonitis, bowel perforation or shock usually need surgeries.17 Clark et al, in their systematic review, showed that mortality for African countries was 10%, and that for the rest of the world was less than 0.05%–1.0%.19 A recent WHO-funded report from an active, hospital-based surveillance from seven sub-Saharan countries showed that hospital mortality rate was 13% among 1017 admissions. Female gender, longer duration of symptoms prior to presentation and undergoing intestinal resection were associated with higher mortality.25 The male to female ratio of our intussusception admissions was 2.46: 1.0, and this ratio among mortalities was 3.8:1.0, which implies that more boys died from intussusception than girls in our series. However, this difference was not statistically significant (p=0.43). Among the patients who died in our series, 54.17% died before any hydrostatic reduction or surgery could be performed. These patients presented very late with features of shock or sepsis and died during the resuscitation process. Many patients in the LMICs are initially maltreated by unqualified village. Often, in such cases, they are treated as bacillary dysentery, and by the time they are referred to surgical facilities, bowel compromise and its sequelae become irreversible.23 24
The present study has several limitations. This was a retrospective study, and we could not evaluate signs and symptoms and their duration in the patients, and their relations with modes of treatment. We also could not evaluate presence or absence of pathological lead points because these were not properly documented. Because we lacked a unique patient identity number and the previous history of intussusception was also not always recorded, we did not calculate the recurrence of hydrostatic reduction in these patients. However, in our experience, recurrence was very uncommon and a recent meta-analysis reported similar low recurrence rates among different modalities of reductions.26 We also could not analyze the number of repeated attempts of hydrostatic reduction after the initial failed attempt due to lack of data entry; however, repeated attempts at reduction were also performed very rarely. Nevertheless, we believe this study showed a feasible alternative for the centers in the LMICs who could not establish hydrostatic reduction. Although this procedure is old-fashioned and subjective, it can be reproduced in many resource-limited settings which could not yet adopt other methods of reduction and can avoid unnecessary surgery and anesthesia in children. Some patients were out of evaluation for some variables because of lack of sufficient data, but the number of patients in whom these were evaluated is substantial. It provides sufficient data for the assumption of the success of hydrostatic reduction with intermittent radiography. Other centers may perform prospective comparative studies to evaluate our results.
In conclusion, hydrostatic reduction with intermittent radiography was successfully performed in about half of the patients of intussusception. Both the number of admissions for intussusception and the number of successful hydrostatic reductions increased with time. There was a gradually decreasing trend of intestinal resection–anastomosis.
