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Pediatric Imaging |
1 From the Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-ku, Seoul 138-736, South Korea. From the 1999 RSNA scientific assembly. Received March 13, 2000; revision requested April 26; revision received June 14; accepted July 11. Address correspondence to C.H.Y. (e-mail: chyoon@www.amc.seoul.kr).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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MATERIALS AND METHODS: The study group consisted of 49 consecutive patients (aged 2 months to 7 years; 36 boys, 13 girls) who underwent 52 reductions of intussusception during 9 months. Intussusception was diagnosed in all patients with the known US criteria, and all patients underwent a US-guided pneumatic reduction attempt wholly within the US examination room. A pressure of 60 mm Hg was maintained for 30 seconds, with US guidance. The procedure was considered to be successful when US showed the disappearance of the intussusceptum and the edematous terminal ileum with an abrupt transition into the normal proximal ileum. When the intussusception was not reduced, the procedure was repeated, with pressure increased to 120 mm Hg.
RESULTS: The overall success rate of US-guided pneumatic reduction was 92% (48 of 52 reductions), with no immediate recurrence. Of the two patients who had intussusceptions that were unreducible, one had residual ileoileal intussusception at surgery, and the other had an ileal polyp as a lead point. Perforation occurred in two (4%) of 52 cases; one patient underwent right hemicolectomy due to bowel necrosis and had a pinpoint perforation in the normal proximal transverse colon, and the other underwent manual reduction of ileoileocolic intussusception, with microperforation in the proximal transverse colon.
CONCLUSION: US-guided pneumatic reduction seems to be a feasible and effective method for the treatment of intussusception in children because of its radiation-sparing effect and high success rate.
Index terms: Gastrointestinal tract, interventional procedures, 70.1269 • Interventional procedures, in infants and children, 70.1269 • Intussusception, 70.73 • Ultrasound (US), guidance, 70.12986
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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There seems to be no consensus on the best procedure for use in the nonsurgical reduction of intussusception (2,3,14–16). After we weighed the advantages and disadvantages of various reduction procedures, we decided to combine US guidance and pneumatic reduction to apply the advantages of both types of procedures. With pneumatic reduction, there is a high success rate, while with US guidance, there is no radiation exposure. In addition, we thought that diagnosis and treatment could be accomplished at the same time if we could perform US-guided pneumatic reduction wholly within the US examination room. The purpose of this prospective study was to assess the feasibility and effectiveness of US-guided pneumatic reduction of childhood intussusception.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Abdominal radiography was performed in all patients before US to rule out the presence of free air. We did not analyze abdominal radiographs for the diagnosis of intussusception. The US system used in this study was a commercially available real-time unit (ATL DHI 3000; Advanced Technology Laboratories, Bothell, Wash) with a 10–5-MHz transducer. The entire procedure of US diagnosis and reduction of intussusception was performed within the US examination room. US diagnosis of intussusception was made on the basis of known criteria, which included the presence of the doughnut or target sign on a transverse scan, the pseudokidney sign on a longitudinal scan, or both (17,18).
Patients in shock and those with peritonitis or perforation were excluded from attempted pneumatic reduction. Pneumatic reduction was performed without sedation. Usually, two radiologists were able to perform the procedure, with the main operator performing graded compression US and the assisting radiologist performing inflation and deflation in addition to holding the patient. However, if the situation required it, one more assistant, nurse, or technician was added to the team.
The methods we used were as follows. A Foley catheter (10–18 F) was inserted into the patient’s rectum, and 20–25 mL of air was injected to inflate the balloon. The Foley catheter was gently pulled down as low as possible. Tape was applied to secure the catheter to each buttock. Finally, the buttocks were firmly taped together to ensure a tight anal seal with the patient in a supine position. By means of a pressure-monitoring device linked to a T connector and with US guidance, air was injected manually to the initial intracolonic pressure of 60 mm Hg, held for 30 seconds, and then released.
The US criteria for successful reduction after deflation of air included the disappearance of the intussusceptum, the single concentric ring representing the swollen terminal ileum instead of the multiple concentric rings of intussusception, and the abrupt transition of bowel wall thickness between the swollen terminal ileum and the proximal normal ileum when scanned along the long axis of the ileum (Fig 1). When the intussusception was not reduced, the pressure was increased by increments of 20 mm Hg to an upper limit of 120 mm Hg. Air was insufflated and deflated three times at each increment. We deflated the air whenever there was an abrupt decrease in pressure during air insufflation, sudden abdominal distention, or clinical improvement, in addition to every 30 seconds of inflation at each increment of the pressure setting. To detect free intraperitoneal air caused by bowel perforation, we performed intermittent US of the epigastrium to look for a ring-down artifact in the subphrenic area obscuring the inferior hepatic margin (Fig 2).
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Four patients in whom reduction failed were referred for surgery. To achieve successful reduction, an initial pressure setting of 60 mm Hg was required for 28 of 48 cases; 80 mm Hg, for 10; 100 mm Hg, for six; and 120 mm Hg, for four. There was no immediate recurrence of intussusception. In three cases in which intussusception recurred, the interval between intussusception reductions was more than 48 hours.
Of the four failed reductions, two failed even at the maximum pressure setting of 120 mm Hg. One patient had a residual ileoileal intussusception at US, which showed the swollen terminal ileum without an abrupt transition into the proximal normal ileum and residual multiple concentric rings at the proximal ileum (Fig 3). The other patient had an ileal polyp as a lead point. The other two failed cases of reduction were complicated by perforation during the procedure, which led to an overall perforation rate of 4% (two of 52 cases). In one of these patients, whose pressure was set at 60 mm Hg, pneumoperitoneum was diagnosed at US. This diagnosis was confirmed with abdominal radiography after which abdominal decompression was performed by using an 18-gauge needle. The patient underwent right hemicolectomy due to bowel necrosis and had a pinpoint perforation in the normal proximal transverse colon. In the other patient, whose pressure was set at 80 mm Hg, pneumoperitoneum was diagnosed during the US procedure. Abdominal decompression was then performed by using the same method as with the first patient. The patient underwent manual reduction of an ileocolic intussusception; a microperforation in the normal proximal transverse colon was noted.
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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It may be difficult to decide which is the best reduction technique. The question addressed in the present study is whether US-guided pneumatic reduction is feasible and effective in the treatment of pediatric intussusception. Our study findings demonstrate that US-guided pneumatic reduction is a feasible and effective technique for nonsurgical reduction of pediatric intussusception; it has a high success rate and requires no radiation exposure to either the patient or medical personnel. In this study, the overall success rate of US-guided pneumatic reduction was 92%, with no immediate recurrence of intussusception and no radiation exposure. The entire procedure was performed completely within the US examination room.
A few authors have occasionally attempted nonfluoroscopic pneumatic reduction of intussusception. Wang et al (19) reported on 224 patients with intussusception. However, Wang et al were able to use US to determine the clinical diagnosis and to perform the subsequent reduction in only 40 patients, although patients who were examined with US usually seemed to be treated in a different clinical area. Todani et al (20) applied nonfluoroscopic pneumatic reduction of intussusception in 127 patients; however, the diagnoses and the success of the reductions were based on the US and clinical findings.
Of our two US criteria for successful reduction, the first was the disappearance of the multiple concentric rings of intussusception, which also became a single concentric ring of a swollen terminal ileum (Fig 1e). The second criterion for successful reduction was the abrupt transition between the swollen terminal ileum and the proximal normal ileal loop visible on the scan obtained along the long axis of the ileum (Fig 1d). This finding corresponded well with the surgical findings after manual reduction of intussusception. By acknowledging the abrupt transition, we were able to rule out any residual ileoileal intussusception with a high degree of confidence. To our knowledge, the second criterion used in our study has not been previously described in the literature.
In comparison with US-guided hydrostatic reduction, US-guided pneumatic reduction also seems to be technically preferable. Because there is less spillage when an anal air leak occurs, we did not need a device to prevent spillage onto the table (9). Moreover, intracolonic pressure is much easier to maintain and measure by using a manometer. However, the presence of a large amount of intraluminal or intraperitoneal air could interfere with subsequent US. Therefore, confirmation of the reduction was made only after deflation of the air.
Many authors (4–7) have suggested that fluoroscopy-guided pneumatic reduction is a safe and efficient technique for the treatment of intussusception. However, there is still concern about radiation exposure during the procedure, especially when it is prolonged or repeated, although the amount needed to rapidly reduce intussusceptions in most cases is usually modest. Another concern is that fluoroscopic images may fail to depict lead points and residual ileoileal intussusception (8). On the contrary, in our study of US, an identifiable lead point was detected. One case of ileal polyp was depicted with US and was proved at surgery. Also, our study findings demonstrated that residual ileoileal intussusception could be differentiated from a single concentric ring following reduction. However, it is important to note that performing bowel US or performing this procedure with US may be difficult for most general radiologists.
Although there might be concern regarding patient cooperation, the procedure was easily performed by two radiologists, with the main operator performing graded compression US and the assisting radiologist performing inflation and deflation in addition to holding the patient. However, in some situations, especially when patients were irritable, one more assistant, nurse, or technician assisted.
One of the major complications related to nonsurgical reduction is perforation. In our two cases of perforation, free intraperitoneal air was promptly depicted during intermittent US of the epigastrium. US has also become a useful tool for the accurate depiction of a small amount of intraperitoneal air (21,22). Even a small amount of intraperitoneal free air can be easily depicted with US on the nondependent portion (ie, epigastric subphrenic area in a supine position) as an echogenic line with a posterior ring-down artifact.
Tension pneumoperitoneum is the only acute complication of pneumatic reduction and was seen in our two cases of perforation; immediate abdominal decompression was performed in both cases. It is also prudent to have an 18-gauge needle at the side of the table at all times in case respiratory distress develops (23). Most detected perforations are thought to be perforations that occur before enema therapy (3). Similarly, all of our cases of perforations occurred at the lower pressure settings. At surgery, both patients showed pinpoint or microperforation in the proximal transverse colon, but contamination of the peritoneal cavity was inconsequential. Experimental and clinical data from previous studies (23,24) agree with our surgical findings. The previously reported (4,7) perforation rates with various techniques were 0.14%–2.80%. Our relatively high perforation rate of 4% may be related to a technical learning curve (15,23).
The present study has some limitations that prevent us from generalizing the results. Our study design was not intended for a comparison of reduction techniques, and the number of patients in our group was relatively small. A randomized controlled study in which various reduction techniques are compared both for their success rate and incidence of complications should be performed to determine the best technique.
In conclusion, US-guided pneumatic reduction seems to be a feasible and effective method for the treatment of intussusception in children because of its radiation-sparing effect and high success rate.
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FOOTNOTES |
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REFERENCES |
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This article has been cited by other articles:
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  H Williams Imaging and intussusception Arch. Dis. Child. Ed. Pract., February 1, 2008; 93(1): 30 - 36. [Full Text] [PDF]
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 N H Park, S I Park, C S Park, E J Lee, M S Kim, J A Ryu, and J M Bae Ultrasonographic findings of small bowel intussusception, focusing on differentiation from ileocolic intussusception Br. J. Radiol., October 1, 2007; 80(958): 798 - 802. [Abstract] [Full Text] [PDF]
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 J. H. Lee, S. H. Choi, Y. K. Jeong, W. J. Kwon, A. K. Jeong, B. S. Kang, and S. H. Shin Intermittent sonographic guidance in air enemas for reduction of childhood intussusception. J. Ultrasound Med., September 1, 2006; 25(9): 1125 - 1130. [Abstract] [Full Text] [PDF]
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 N J West, I R Daniels, and N D Carr Lessons to be learned: a case study approach: Chronic intussusception in childhood Perspectives in Public Health, September 1, 2003; 123(3): 181 - 184. [Abstract] [PDF]
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). (b) Transverse right upper abdominal scan shows that injected air (arrows) pushes and distorts the intussusceptum (arrowheads). (c) After deflation of air, transverse scan of the ileocecal valve (arrows) shows swelling, with a patent lumen. (d) Longitudinal scan of the terminal ileum shows an abrupt transition of bowel wall thickness between the swollen terminal ileum (arrows) and proximal normal ileum (arrowheads). (e) Transverse scan of the terminal ileum shows a single concentric ring (arrowheads), which represents the swollen terminal ileum instead of multiple concentric rings of intussusception (in a).
