Clinical Radiology 69 (2014) 344e349
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Clinical Radiology journal homepage: www.clinicalradiologyonline.net
UK intussusception audit: A national survey of practice and audit of reduction rates Edward Hannon a, *, Rhianydd Williams b, Rosemary Allan b, Bruce Okoye a a b
Department of Paediatric Surgery, St George’s Hospital, Tooting, London, UK Department of Paediatric Radiology, St George’s Hospital, Tooting, London, UK
article in formation Article history: Received 1 August 2013 Received in revised form 8 October 2013 Accepted 16 October 2013
AIM: To define current UK reduction practice and the reductions rates achieved. MATERIALS AND METHODS: Electronic surveys were sent to radiologists at 26 UK centres. This assessed methods of reduction, equipment, personnel, and protocol usage. Standardized audit proforma were also sent to evaluate all reductions performed in 2011. RESULTS: Twenty-two of 26 centres (85%) replied. All used air enema under fluoroscopic guidance. Equipment was not standardized but could be broadly categorized into hand-pumped air-supply systems (seven centres) and pressurized air systems (15 centres). Seventeen centres followed a protocol based on British Society of Paediatric Radiologists (BSPR) guidelines. In 21 of the 22 centres a consultant paediatric radiologist led reductions and only 12 centres reported a surgeon being present. Three hundred and ten cases were reported across 22 centres. Cases per centre ranged from 0e31 (median 14). Reduction rates varied from 38e90% (median 71%). The overall perforation rate was 2.5%. Caseload did not significantly correlate with reduction rate, and there was no significant difference between the two types of equipment used. Median reduction rates were 15% higher in centres with a surgeon present at reduction (p < 0.05). CONCLUSION: Intussusception care in the UK lacks standardization of equipment and personnel involved. National reduction rates are lower than in current international literature. Improved standardization may lead to an improvement in reduction rates and a surgeon should always be present at reduction. Ó 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Introduction Intussusception is the most common abdominal surgical emergency in the infant population. The first-line treatment of choice in uncomplicated cases of intussusception remains non-surgical pneumatic reduction1 with surgical management reserved for those cases with peritonitis, perforation or failed pneumatic reduction. In 1999, a national survey of then current practice by Rosenfeld and McHugh2 concluded there was a lack of * Guarantor and correspondent: E. Hannon, Department of Paediatric Surgery, St George’s Hospital, Blackshaw Rd, Tooting, London SW17 0QT, UK. Tel.: þ44 020 8672 1255; fax: þ44 020 8672 7110. E-mail address: [email protected] (E. Hannon).
standardization in several aspects of intussusception care including diagnostics, reduction equipment and technique, reduction rates, and a lack of regular audits of results. Therefore, in 2003 the British Society of Paediatric Radiologists (BSPR) set out draft guidelines for the safe use of enema reduction3 in an effort to standardize care. These guidelines have resulted in centralization of care in secondary and tertiary paediatric centres following the suggestion that centres treating intussusception must have radiologists with the “appropriate continuing experience” and paediatric surgeons and anaesthetists competent to deal with the complications. However, since 1999, there has been no review of current practice in these centres in the UK. The BSPR guidelines also suggested that a reduction rate of “>65e70%” should be achieved and rates 90% may be achievable.1 To date, there has been no national comparison of reduction rates between centres or national requirement for centralized audit. The aims of the present study were to discover the current practice of intussusception reduction in UK centres and compare this to the reduction rates achieved.
345
20 centres. Only 12 of 22 centres (55%) had a surgeon present at reduction. In one centre, trainees in both radiology and surgery performed enemas using a team approach.
Diagnostics All centres used abdominal ultrasound to diagnose intussusception and fluoroscopy to screen during air enema reduction.
Method of reduction All centres use air enema reduction.
Materials and methods Two named radiologists at each of 26 paediatric surgical centres in the UK were sent electronic and postal copies of a survey of current practice and instructions to perform a standardized retrospective audit of enema reductions for intussusception across the 12 month period, January to December 2011. The survey of practice was designed to assess the following variables in each centre’s reduction practice: (1) personnel present; (2) diagnostic imaging used; (3) method of reduction; (4) equipment used; and (5) protocols and pressures used for reduction. The standardized audit tool gave instructions for data collection of all therapeutic enemas performed for intussusception during 2011. Data were obtained from radiology databases and reporting systems. Exclusions from analysis were any case without a full report and any negative enema performed, i.e., where no intussusception was seen. Cases of recurrent intussusception were included as individual cases and delayed repeated enemas following initial failed reduction were counted as a single case. Audit outcomes included success or failure of reduction, complications, and surgical findings of failed reduction. From the data sent from each centre successful reduction rates were calculated using the formula of Total successful cases 100 Attempted cases Statistical analysis was performed using Graphpad PrismÒ 4.3 and MedCalc for Windows, version 12.1.4.0 (MedCalc Software, Mariakerke, Belgium). The effect of equipment and personnel on reduction rates were compared by centre using a ManneWhitney U-test and on a case-by-case basis using logistic regression.
Results Twenty-two of the 26 (85%) centres returned surveys and audit results. Only 11 centres included surgical data.
Survey of practice Personnel In all but one centre a consultant paediatric radiologist was present at reduction and a trainee radiologist was present at
Equipment Although all centres performed pneumatic or air enema reduction, equipment varied, with only two centres specifically using the same equipment. All equipment was made or assembled within individual institutions and could be broadly separated into two groups according to the airdelivery system: hand-pumped using a sphygmomanometer in seven centres versus pressurized air delivery via some form of pressure control valve: used in 15 centres. Measurement of pressure was generally in millimetres of mercury (mmHg) but in two centres millimetres of water (mmH20) was used and subsequently converted into mmHg. Devices to control maximum pressures varied from basic hand-held pressure release valves in the form of a “Y” connector covered by the user’s thumb to the more sophisticated devices where pressure could be set on a digital read-out associated with the pressure control valve and that pressure could not be exceeded.
Protocols and pressures Five of the 22 centres had no protocol for reduction. Seventeen centres followed the original BSPR guidelines for duration and number of attempts at reduction, i.e., three attempts for 3 min each. One centre used three attempts of 2 min each, and the other centres used variable durations and pressures on an individual patient basis. Nineteen centres used the same maximum pressure of 120 mmHg. Three centres allowed higher pressures to be used, up to 130 mmHg in one and to 180 mmHg in two other centres.
Audit results Twenty-two of 26 centres returned audit data. Only 11 of these returned complete surgical data, i.e., the results of failed reductions. In total 310 cases were performed across the 22 centres. The median cases per centre were 14 with a range of 0e31 cases. Cases per centre are shown in Fig 1. Centre 22 was excluded from further analysis as it performed no reductions during the study period. Centre 21, which performed a single case, was also excluded from centre-by-centre comparison of reduction rates to avoid bias. The median reduction rate in the remaining 20 UK centres was 71% (range 38e90%; Fig 2). The relationship between number of cases performed in each centre and the reduction rates is represented in Fig 3. Although a trend towards better results in higher volume centres was observed, this did not reach significance.
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Figure 1 Cases performed per centre.
Only 11 centres returned complete surgical data for outcomes of failed enemas these are in Table 1. Reductions rates were compared according to equipment used (pressurized air supply versus hand-pumped systems) in each centre and for surgeon presence at reduction. The median reduction rate for centres using pressurised air systems were 74% versus 64% for those centres using a handpumped delivery system (Fig 4). This difference did not reach significance (p ¼ 0.52). The median reduction rate was 15% greater in those centres with a surgeon present (77%) compared to those centres where a surgeon was not routinely present (62%). This difference was significant (p < 0.05; Fig 5). Logistic regression supported a significant benefit of surgeon presence with an odds ratio of 2.46 (95% confidence interval, 1.48e4.1) and p < 0.0005.
Perforations There were eight perforations in the study period representing a national perforation rate of 2.5%. However, 13 centres had no perforations, six centres had one perforation, and one centre had two perforations. Given the relatively low numbers of cases performed in many centres and the low numbers of perforations, rates of perforation per centre are difficult to interpret but ranged from 0e15% (in a centre that performed 13 reductions and perforated two).
Discussion The present study represents the first review of current practice of intussusception reduction in the UK since
Figure 2 Reduction rates by centre.
Figure 3 Cases per centre versus reduction rates.
Rosenfeld and McHugh in 19992 and the first comparative audit of reduction figures in different UK centres. The lack of standardization of care highlighted in 1999 has improved with centralization of care to paediatric surgical centres and the use of draft BSPR guidelines. These guidelines were based on the study and review of the best evidence by Rosenfeld and McHugh. The present results demonstrate standardization across centres in terms of the use of ultrasound for diagnosis, air enema for reduction, and in pressures used in the majority of centres and duration and number of attempts (33 minutes). However, there were five centres (23%) that did not following any protocol. There is still a lack of standardization of care in terms of protocol usage, equipment used, and personnel involved in reduction. Although standardization per se has not been proven to lead to improved reduction rates, the present authors agree with Rosenfeld and McHugh that standardized practice in the relatively rare condition of intussusception should improve processes and, as a result, outcomes, especially if that standardization is based on best evidence. Despite the relatively low number of 22 centres in the survey (26 in total in the UK), spread over a relatively small geographic area, all but two used different equipment. In terms of personnel, the person leading reductions in all but one centre was a paediatric radiology consultant; however, 45% of centres reported surgeons not routinely being present during air enema. The relevance of this variation in practice, equipment, and personnel across UK centres can only be demonstrated when compared to the reduction rates achieved in the UK and these in turn are compared to the international literature. The median reduction rate of UK centres in the present study of 71% meets the BSPR standard of 2003,3 and is higher than the suggested national figure of 61% recently reported by Samad et al. in their prospective surveillance study.4 However, the range of reductions rates by centre, 38e90%, demonstrate the variability of UK results and may be a reflection of the lack of truly standardized care. A national median reduction rate of 71% compares poorly to most current international literature. Daneman and
E. Hannon et al. / Clinical Radiology 69 (2014) 344e349
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Table 1 Surgical outcomes of failed reductions. Attempted
Failed
Outcome
10 17
1 6
14
5
13
3
Ileal resection e ischaemia HSP e ileal resection, Neurofibroma e resected Right hemicolectomy e ischaemia Manual reduction Nil found Manual reduction e ALL Ischaemia e resection not specified Ischaemia e resection not specified Manual reduction Manual reduction Meckel’s diverticulum e resection Manual reduction Manual reduction Right colectomy e “thickened wall” Perforation e right colectomy Perforation e over-sewn Manual reduction Manual reduction Perforation e right colectomy Manual reduction Ischaemia e resection, not specified Resection e not specified 4 Manual reduction Manual reduction Resection e not specified Laparoscopic reduction Laparoscopic reduction Resection e not specified Manual reduction ischaemia e resection not specified 1. Resection e not specified 2. Resection e not specified
13
4
17
3
18 10
4 3
26
3
4
2
21
2
1. 1. 2. 3. 4. 5. 6. 1. 2. 3. 4. 5. 1. 2. 3. 1. 2. 3. 4. 1. 2. 3. 1. 1. 2. 3. 1. 2. 3. 1.
Navarro1 in 2004 reviewed all aspects of intussusception reduction and although they could not conclude which was the most successful technique, they did suggest that reduction rates of 80e90% should be achievable. A smaller, more recent review by Ko et al.5 made similar conclusions that a 90% reduction rate should be achievable, but limited this to idiopathic cases, which would be expected to yield better results. There are several studies reporting similarly lower reduction rates, but many of these are retrospective reviews over long study periods (up to 25 years), and hence, do not
Figure 4 Comparison of reduction rates by equipment used.
Figure 5 Comparison of reduction rates by personnel involved.
represent current practice.6e9 The results of the prospective data collection in the UK4 do support a lower figure in the UK at 62%. Within the present study group, six centres (27%) achieved reduction rates of >80% suggesting such rates are achievable in the UK using air enema reduction under fluoroscopic guidance (as in all centres surveyed). One important variable when comparing reduction rates is reporting bias in terms of how rates are calculated and presented. The present study attempted to standardize data collection using the audit tool and then used the standard calculation of all successful cases/all attempted cases. Bekdash et al.10 addressed the issues of selection bias in reporting reduction rates with a view to defining a standard definition. They suggest that operative findings should be taken into account, i.e., a failed air enema where necrotic bowel or pathological lead point is discovered at subsequent laparotomy is not a “failure” as surgical intervention was inevitable. This is referred to as the “composite reduction rate”. Unfortunately, the present study did not collect sufficient surgical data (11/22 centres) to allow for calculation of the “composite reduction rates” for all centres, but in the 11 centres that did supply data, the median “composite reduction rate” was 86%, much higher than the 71% standard rate in the UK. To ensure unbiased comparison of results in the future and hence improve outcomes, standardized definitions of reduction rate need to be used. In addition, to fully assess a centre’s results for intussusception care, including those patients going directly to theatre without reduction, it is important to assess the decision-making process. It is important for us in the UK to assess why our national reduction rate is lower than documented in other countries including North America,11,12 China,13 and Japan,14 and why success rates are so variable in the UK. The reduction technique is the most debated variable discussed in the literature, and air enema under fluoroscopy guidance is accepted as an effective method.1, 5 As air enema under fluoroscopy is the standard technique used in all UK centres, the technique does not account for inter-centre differences in reduction rates. Pressures used during reduction are also debated but given that the majority of UK
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centres use similar pressures with a maximum of 120e130 mmHg, it does not appear that this would account for the differences in reduction rate or perforation rate. Another variable to consider regarding the different techniques used for air enema include the way in which pressure is maintained at the anus and leak prevented. This was not specifically covered in the present survey and, therefore, this cannot be commented on. Equipment used to perform air enema reduction is different across the UK. Its broad categorization based on air supply, pressurized supply versus hand-pumped, demonstrated a higher median reduction rate in the pressurized group, but this did not reach significance. The theory behind the benefit of the pressurized system is that it may provide a better continuous head of pressure than a hand-pumped mechanism. Further investigation comparing equipment at a clinical medical physics level is required. Literature describing different equipment is limited to individual descriptions mainly from resource-poor areas where inventive solutions have been described.15e17 The personnel involved in reduction was another factor compared in the present analysis of UK results. Surgeon involvement in reduction is variable across the UK, despite paediatric surgeons being the primary care giver to those patients with intussusception taking responsibility for resuscitation, work-up, and then possible surgery. The present results suggest that significantly better reduction rates were achieved in those centres where a surgeon was involved. The retrospective review of Okazaki et al.18 investigated personnel performing reduction and also supported the active role of the surgeon. They demonstrated a 30% increase in reduction rates when cases were performed by the consultant surgeon as opposed to the radiologist and achieved some of highest reduction rates in the literature, at 92% in the hands of the surgeon. The present results cannot suggest why reduction rates may be better in centres where a surgeon is present at reduction, but Ozaki et al. conclude that radiologists alone may be more “cautious” in reduction, hence achieving lower rates. Radiologists are more comfortable to continue longer, higher pressure reductions with a surgeon present, who can deal with the potential problems of perforation or patient deterioration. Perforation rates are discussed in the literature as a marker of performance and safety for intussusception reduction. Two recent reviews1,5 suggest perforation rates should be around 1%. The national rate in the present study was 2.5%, which appears high. Given the low incidence of perforation in all series, the present results are influenced by one centre that had two perforations, whereas 13 centres had no perforations making these figures difficult to interpret. As a provisional survey of practice and retrospective audit, there are limitations to the present study. The aim was to include all 26 UK centres in the study to give a true national view of current practice. This was not achieved, although the 85% response rate achieved gives a good cross section and included figures from all parts of the UK. The retrospective data collection could be improved in the future with a national prospective audit of intussusception similar to that of Samad et al.4 but on a centre-by-centre basis. A
mandatory yearly national audit should be established. The reasons for differences in reduction rates are multifactorial. This study cannot comment on the effect of age, differences in patient populations, and timing of presentation on reduction rates, as these data were not collected. There may be bias in data collection in that individual centres were asked to report their own figures and although guidelines were given for performing the audit, an unblinded data collection in each institution was assumed. It is also important to note that in the present study, data were collected by radiologists as opposed to the study of Samad et al.4 where paediatricians and surgeons collected data. This gives the advantage of better detail of the radiological practice in each institution but it is recognised that futures studies should involve radiologists and surgeons reporting, especially given the poor surgical data response achieved. Given the relatively rare incidence of intussusception, a 12 month audit period yielded low numbers per centre, especially when working out perforation rates, which made the results prone to bias. A future study should be conducted over a longer period. In conclusion, this is the first directly comparative audit of practice and reduction rates across UK centres. It demonstrates that although there have been steps towards standardized care for intussusception in the UK, there is still variability in terms of the equipment used, personnel involved, and ultimately reduction rates. UK reduction rates are low compared to current international literature and further standardization of practice across the small number of UK centres, including mandatory presence of a surgeon at reduction, may lead to an increase in reduction rates. Standardized practice and regular national audit would also allow for more straightforward comparison of results in each centre, thus improving quality of care on a national basis.
Acknowledgements The authors thank the following people who collected data in different centres across the country: Melanie Hiorns, Annie Patterson, Bozena Starzyk, Amit Maniyar, Kirsteen McDonald, Joanna Fairhurst, Sophie Swinson, Kate Taylor Robinson, Kandiyil Neghal, David Horton, Marwa Elsayed, Claire Miller, Maria Sellars, Dipalee Durve, Kath Halliday, Ash Chakraborthy, Vivian Tang, Jackie Coonar, Laurence Abernethy, Ian Kenney, Alison Evans, Fiona Dickinson, Greg Irwin.
References 1. Daneman A, Navarro O. Intussusception. Part 2: an update on the evolution of management. Pediatr Radiol 2004;34:97e108. 2. Rosenfeld K, McHugh K. Survey of intussusception reduction in England, Scotland and Wales: how and why we could do better? Clin Radiol 1999;54:452e8. 3. McHugh K. Intussusception reduction. British Society of Paediatric Radiology draft guidelines for suggested safe practice http://www.bspr.org.uk/ intuss.htm; 2003, April (subsequently withdrawn). 4. Samad L, Marven S, El Bashir H, et al. Prospective surveillance study of the management of intussusception in UK and Irish infants. Br J Surg 2012;3:411e5.
E. Hannon et al. / Clinical Radiology 69 (2014) 344e349 € ger J, et al. Current radiological management of 5. Ko HS, Schenk JP, Tro intussusception in children. EurRadiol 2007;17:2411e21. 6. Niramis R, Watanatittan S, Kruatrachue A, et al. Management of recurrent intussusception: nonoperative or operative reduction? J Pediatr Surg 2010;45:2175e80. 7. Chen SC, Wang JD, Hsu HY, et al. Epidemiology of childhood intussusception and determinants of recurrence and operation: analysis of national health insurance data between 1998 and 2007 in Taiwan. Pediatr Neonatol 2010;51:285e91. 8. Whitehouse JS, Gourlay DM, Winthrop AL, et al. Is it safe to discharge intussusception patients after successful hydrostatic reduction? J Pediatr Surg 2010;45:1182e6. 9. Kaiser AD, Applegate KE, Ladd AP. Current success in the treatment of intussusception in children. Surgery 2007;142:469e75. 10. Bekdash B, Marven SS, Sprigg A. Reduction of intussusception: defining a better index of successful non-operative reduction. Pediatr Radiol 2013;43:649e56. 11. Shiels II WE, Maves CK, Hedlund GL, et al. Air enema for diagnosis and reduction of intussusception: clinical experiences and pressure correlates. Radiology 1991;181:169e72.
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12. Meyer JS, Dangman BC, Buonomo C, et al. Air and liquid contrast agents in the management of intussusception: a controlled, randomized trial. Radiology 1993;188:507e11. 13. Wang G, Liu XG, Zitsman JL. Nonfluoroscopic reduction of intussusception by air enema. World J Surg 1995;19:435e8. 14. Todani T, Sato Y, Watanabe Y, et al. Air reduction for intussusception in infancy and childhood: ultrasonographic diagnosis and management without X-ray exposure. Z Kinderchir 1990;45:222e6. € m H. Simple and safe device for pneumatic reduction of intus15. Stenstro susception. Acta Radiol 1995;36:215e7. 16. Abraham MK, Joy MG, Menon SS, et al. A simple and safe technique for pneumatic reduction of intussusception. Asian J Surg 2006;29:170e2. 17. Mensah YB, Glover-Addy H, Etwire V, et al. Pneumatic reduction of intussusception in children at Korle Bu Teaching Hospital: an initial experience. Afr J Paediatr Surg 2011;8:176e81. 18. Okazaki T, Ogasawara Y, Nakazawa N, et al. Reduction of intussusception in infants by a pediatric surgical team: improvement in safety and outcome. Pediatr Surg Int 2006;22:897e900.
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Clinical Radiology journal homepage: www.clinicalradiologyonline.net
UK intussusception audit: A national survey of practice and audit of reduction rates Edward Hannon a, *, Rhianydd Williams b, Rosemary Allan b, Bruce Okoye a a b
Department of Paediatric Surgery, St George’s Hospital, Tooting, London, UK Department of Paediatric Radiology, St George’s Hospital, Tooting, London, UK
article in formation Article history: Received 1 August 2013 Received in revised form 8 October 2013 Accepted 16 October 2013
AIM: To define current UK reduction practice and the reductions rates achieved. MATERIALS AND METHODS: Electronic surveys were sent to radiologists at 26 UK centres. This assessed methods of reduction, equipment, personnel, and protocol usage. Standardized audit proforma were also sent to evaluate all reductions performed in 2011. RESULTS: Twenty-two of 26 centres (85%) replied. All used air enema under fluoroscopic guidance. Equipment was not standardized but could be broadly categorized into hand-pumped air-supply systems (seven centres) and pressurized air systems (15 centres). Seventeen centres followed a protocol based on British Society of Paediatric Radiologists (BSPR) guidelines. In 21 of the 22 centres a consultant paediatric radiologist led reductions and only 12 centres reported a surgeon being present. Three hundred and ten cases were reported across 22 centres. Cases per centre ranged from 0e31 (median 14). Reduction rates varied from 38e90% (median 71%). The overall perforation rate was 2.5%. Caseload did not significantly correlate with reduction rate, and there was no significant difference between the two types of equipment used. Median reduction rates were 15% higher in centres with a surgeon present at reduction (p < 0.05). CONCLUSION: Intussusception care in the UK lacks standardization of equipment and personnel involved. National reduction rates are lower than in current international literature. Improved standardization may lead to an improvement in reduction rates and a surgeon should always be present at reduction. Ó 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Introduction Intussusception is the most common abdominal surgical emergency in the infant population. The first-line treatment of choice in uncomplicated cases of intussusception remains non-surgical pneumatic reduction1 with surgical management reserved for those cases with peritonitis, perforation or failed pneumatic reduction. In 1999, a national survey of then current practice by Rosenfeld and McHugh2 concluded there was a lack of * Guarantor and correspondent: E. Hannon, Department of Paediatric Surgery, St George’s Hospital, Blackshaw Rd, Tooting, London SW17 0QT, UK. Tel.: þ44 020 8672 1255; fax: þ44 020 8672 7110. E-mail address: [email protected] (E. Hannon).
standardization in several aspects of intussusception care including diagnostics, reduction equipment and technique, reduction rates, and a lack of regular audits of results. Therefore, in 2003 the British Society of Paediatric Radiologists (BSPR) set out draft guidelines for the safe use of enema reduction3 in an effort to standardize care. These guidelines have resulted in centralization of care in secondary and tertiary paediatric centres following the suggestion that centres treating intussusception must have radiologists with the “appropriate continuing experience” and paediatric surgeons and anaesthetists competent to deal with the complications. However, since 1999, there has been no review of current practice in these centres in the UK. The BSPR guidelines also suggested that a reduction rate of “>65e70%” should be achieved and rates 90% may be achievable.1 To date, there has been no national comparison of reduction rates between centres or national requirement for centralized audit. The aims of the present study were to discover the current practice of intussusception reduction in UK centres and compare this to the reduction rates achieved.
345
20 centres. Only 12 of 22 centres (55%) had a surgeon present at reduction. In one centre, trainees in both radiology and surgery performed enemas using a team approach.
Diagnostics All centres used abdominal ultrasound to diagnose intussusception and fluoroscopy to screen during air enema reduction.
Method of reduction All centres use air enema reduction.
Materials and methods Two named radiologists at each of 26 paediatric surgical centres in the UK were sent electronic and postal copies of a survey of current practice and instructions to perform a standardized retrospective audit of enema reductions for intussusception across the 12 month period, January to December 2011. The survey of practice was designed to assess the following variables in each centre’s reduction practice: (1) personnel present; (2) diagnostic imaging used; (3) method of reduction; (4) equipment used; and (5) protocols and pressures used for reduction. The standardized audit tool gave instructions for data collection of all therapeutic enemas performed for intussusception during 2011. Data were obtained from radiology databases and reporting systems. Exclusions from analysis were any case without a full report and any negative enema performed, i.e., where no intussusception was seen. Cases of recurrent intussusception were included as individual cases and delayed repeated enemas following initial failed reduction were counted as a single case. Audit outcomes included success or failure of reduction, complications, and surgical findings of failed reduction. From the data sent from each centre successful reduction rates were calculated using the formula of Total successful cases 100 Attempted cases Statistical analysis was performed using Graphpad PrismÒ 4.3 and MedCalc for Windows, version 12.1.4.0 (MedCalc Software, Mariakerke, Belgium). The effect of equipment and personnel on reduction rates were compared by centre using a ManneWhitney U-test and on a case-by-case basis using logistic regression.
Results Twenty-two of the 26 (85%) centres returned surveys and audit results. Only 11 centres included surgical data.
Survey of practice Personnel In all but one centre a consultant paediatric radiologist was present at reduction and a trainee radiologist was present at
Equipment Although all centres performed pneumatic or air enema reduction, equipment varied, with only two centres specifically using the same equipment. All equipment was made or assembled within individual institutions and could be broadly separated into two groups according to the airdelivery system: hand-pumped using a sphygmomanometer in seven centres versus pressurized air delivery via some form of pressure control valve: used in 15 centres. Measurement of pressure was generally in millimetres of mercury (mmHg) but in two centres millimetres of water (mmH20) was used and subsequently converted into mmHg. Devices to control maximum pressures varied from basic hand-held pressure release valves in the form of a “Y” connector covered by the user’s thumb to the more sophisticated devices where pressure could be set on a digital read-out associated with the pressure control valve and that pressure could not be exceeded.
Protocols and pressures Five of the 22 centres had no protocol for reduction. Seventeen centres followed the original BSPR guidelines for duration and number of attempts at reduction, i.e., three attempts for 3 min each. One centre used three attempts of 2 min each, and the other centres used variable durations and pressures on an individual patient basis. Nineteen centres used the same maximum pressure of 120 mmHg. Three centres allowed higher pressures to be used, up to 130 mmHg in one and to 180 mmHg in two other centres.
Audit results Twenty-two of 26 centres returned audit data. Only 11 of these returned complete surgical data, i.e., the results of failed reductions. In total 310 cases were performed across the 22 centres. The median cases per centre were 14 with a range of 0e31 cases. Cases per centre are shown in Fig 1. Centre 22 was excluded from further analysis as it performed no reductions during the study period. Centre 21, which performed a single case, was also excluded from centre-by-centre comparison of reduction rates to avoid bias. The median reduction rate in the remaining 20 UK centres was 71% (range 38e90%; Fig 2). The relationship between number of cases performed in each centre and the reduction rates is represented in Fig 3. Although a trend towards better results in higher volume centres was observed, this did not reach significance.
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E. Hannon et al. / Clinical Radiology 69 (2014) 344e349
Figure 1 Cases performed per centre.
Only 11 centres returned complete surgical data for outcomes of failed enemas these are in Table 1. Reductions rates were compared according to equipment used (pressurized air supply versus hand-pumped systems) in each centre and for surgeon presence at reduction. The median reduction rate for centres using pressurised air systems were 74% versus 64% for those centres using a handpumped delivery system (Fig 4). This difference did not reach significance (p ¼ 0.52). The median reduction rate was 15% greater in those centres with a surgeon present (77%) compared to those centres where a surgeon was not routinely present (62%). This difference was significant (p < 0.05; Fig 5). Logistic regression supported a significant benefit of surgeon presence with an odds ratio of 2.46 (95% confidence interval, 1.48e4.1) and p < 0.0005.
Perforations There were eight perforations in the study period representing a national perforation rate of 2.5%. However, 13 centres had no perforations, six centres had one perforation, and one centre had two perforations. Given the relatively low numbers of cases performed in many centres and the low numbers of perforations, rates of perforation per centre are difficult to interpret but ranged from 0e15% (in a centre that performed 13 reductions and perforated two).
Discussion The present study represents the first review of current practice of intussusception reduction in the UK since
Figure 2 Reduction rates by centre.
Figure 3 Cases per centre versus reduction rates.
Rosenfeld and McHugh in 19992 and the first comparative audit of reduction figures in different UK centres. The lack of standardization of care highlighted in 1999 has improved with centralization of care to paediatric surgical centres and the use of draft BSPR guidelines. These guidelines were based on the study and review of the best evidence by Rosenfeld and McHugh. The present results demonstrate standardization across centres in terms of the use of ultrasound for diagnosis, air enema for reduction, and in pressures used in the majority of centres and duration and number of attempts (33 minutes). However, there were five centres (23%) that did not following any protocol. There is still a lack of standardization of care in terms of protocol usage, equipment used, and personnel involved in reduction. Although standardization per se has not been proven to lead to improved reduction rates, the present authors agree with Rosenfeld and McHugh that standardized practice in the relatively rare condition of intussusception should improve processes and, as a result, outcomes, especially if that standardization is based on best evidence. Despite the relatively low number of 22 centres in the survey (26 in total in the UK), spread over a relatively small geographic area, all but two used different equipment. In terms of personnel, the person leading reductions in all but one centre was a paediatric radiology consultant; however, 45% of centres reported surgeons not routinely being present during air enema. The relevance of this variation in practice, equipment, and personnel across UK centres can only be demonstrated when compared to the reduction rates achieved in the UK and these in turn are compared to the international literature. The median reduction rate of UK centres in the present study of 71% meets the BSPR standard of 2003,3 and is higher than the suggested national figure of 61% recently reported by Samad et al. in their prospective surveillance study.4 However, the range of reductions rates by centre, 38e90%, demonstrate the variability of UK results and may be a reflection of the lack of truly standardized care. A national median reduction rate of 71% compares poorly to most current international literature. Daneman and
E. Hannon et al. / Clinical Radiology 69 (2014) 344e349
347
Table 1 Surgical outcomes of failed reductions. Attempted
Failed
Outcome
10 17
1 6
14
5
13
3
Ileal resection e ischaemia HSP e ileal resection, Neurofibroma e resected Right hemicolectomy e ischaemia Manual reduction Nil found Manual reduction e ALL Ischaemia e resection not specified Ischaemia e resection not specified Manual reduction Manual reduction Meckel’s diverticulum e resection Manual reduction Manual reduction Right colectomy e “thickened wall” Perforation e right colectomy Perforation e over-sewn Manual reduction Manual reduction Perforation e right colectomy Manual reduction Ischaemia e resection, not specified Resection e not specified 4 Manual reduction Manual reduction Resection e not specified Laparoscopic reduction Laparoscopic reduction Resection e not specified Manual reduction ischaemia e resection not specified 1. Resection e not specified 2. Resection e not specified
13
4
17
3
18 10
4 3
26
3
4
2
21
2
1. 1. 2. 3. 4. 5. 6. 1. 2. 3. 4. 5. 1. 2. 3. 1. 2. 3. 4. 1. 2. 3. 1. 1. 2. 3. 1. 2. 3. 1.
Navarro1 in 2004 reviewed all aspects of intussusception reduction and although they could not conclude which was the most successful technique, they did suggest that reduction rates of 80e90% should be achievable. A smaller, more recent review by Ko et al.5 made similar conclusions that a 90% reduction rate should be achievable, but limited this to idiopathic cases, which would be expected to yield better results. There are several studies reporting similarly lower reduction rates, but many of these are retrospective reviews over long study periods (up to 25 years), and hence, do not
Figure 4 Comparison of reduction rates by equipment used.
Figure 5 Comparison of reduction rates by personnel involved.
represent current practice.6e9 The results of the prospective data collection in the UK4 do support a lower figure in the UK at 62%. Within the present study group, six centres (27%) achieved reduction rates of >80% suggesting such rates are achievable in the UK using air enema reduction under fluoroscopic guidance (as in all centres surveyed). One important variable when comparing reduction rates is reporting bias in terms of how rates are calculated and presented. The present study attempted to standardize data collection using the audit tool and then used the standard calculation of all successful cases/all attempted cases. Bekdash et al.10 addressed the issues of selection bias in reporting reduction rates with a view to defining a standard definition. They suggest that operative findings should be taken into account, i.e., a failed air enema where necrotic bowel or pathological lead point is discovered at subsequent laparotomy is not a “failure” as surgical intervention was inevitable. This is referred to as the “composite reduction rate”. Unfortunately, the present study did not collect sufficient surgical data (11/22 centres) to allow for calculation of the “composite reduction rates” for all centres, but in the 11 centres that did supply data, the median “composite reduction rate” was 86%, much higher than the 71% standard rate in the UK. To ensure unbiased comparison of results in the future and hence improve outcomes, standardized definitions of reduction rate need to be used. In addition, to fully assess a centre’s results for intussusception care, including those patients going directly to theatre without reduction, it is important to assess the decision-making process. It is important for us in the UK to assess why our national reduction rate is lower than documented in other countries including North America,11,12 China,13 and Japan,14 and why success rates are so variable in the UK. The reduction technique is the most debated variable discussed in the literature, and air enema under fluoroscopy guidance is accepted as an effective method.1, 5 As air enema under fluoroscopy is the standard technique used in all UK centres, the technique does not account for inter-centre differences in reduction rates. Pressures used during reduction are also debated but given that the majority of UK
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centres use similar pressures with a maximum of 120e130 mmHg, it does not appear that this would account for the differences in reduction rate or perforation rate. Another variable to consider regarding the different techniques used for air enema include the way in which pressure is maintained at the anus and leak prevented. This was not specifically covered in the present survey and, therefore, this cannot be commented on. Equipment used to perform air enema reduction is different across the UK. Its broad categorization based on air supply, pressurized supply versus hand-pumped, demonstrated a higher median reduction rate in the pressurized group, but this did not reach significance. The theory behind the benefit of the pressurized system is that it may provide a better continuous head of pressure than a hand-pumped mechanism. Further investigation comparing equipment at a clinical medical physics level is required. Literature describing different equipment is limited to individual descriptions mainly from resource-poor areas where inventive solutions have been described.15e17 The personnel involved in reduction was another factor compared in the present analysis of UK results. Surgeon involvement in reduction is variable across the UK, despite paediatric surgeons being the primary care giver to those patients with intussusception taking responsibility for resuscitation, work-up, and then possible surgery. The present results suggest that significantly better reduction rates were achieved in those centres where a surgeon was involved. The retrospective review of Okazaki et al.18 investigated personnel performing reduction and also supported the active role of the surgeon. They demonstrated a 30% increase in reduction rates when cases were performed by the consultant surgeon as opposed to the radiologist and achieved some of highest reduction rates in the literature, at 92% in the hands of the surgeon. The present results cannot suggest why reduction rates may be better in centres where a surgeon is present at reduction, but Ozaki et al. conclude that radiologists alone may be more “cautious” in reduction, hence achieving lower rates. Radiologists are more comfortable to continue longer, higher pressure reductions with a surgeon present, who can deal with the potential problems of perforation or patient deterioration. Perforation rates are discussed in the literature as a marker of performance and safety for intussusception reduction. Two recent reviews1,5 suggest perforation rates should be around 1%. The national rate in the present study was 2.5%, which appears high. Given the low incidence of perforation in all series, the present results are influenced by one centre that had two perforations, whereas 13 centres had no perforations making these figures difficult to interpret. As a provisional survey of practice and retrospective audit, there are limitations to the present study. The aim was to include all 26 UK centres in the study to give a true national view of current practice. This was not achieved, although the 85% response rate achieved gives a good cross section and included figures from all parts of the UK. The retrospective data collection could be improved in the future with a national prospective audit of intussusception similar to that of Samad et al.4 but on a centre-by-centre basis. A
mandatory yearly national audit should be established. The reasons for differences in reduction rates are multifactorial. This study cannot comment on the effect of age, differences in patient populations, and timing of presentation on reduction rates, as these data were not collected. There may be bias in data collection in that individual centres were asked to report their own figures and although guidelines were given for performing the audit, an unblinded data collection in each institution was assumed. It is also important to note that in the present study, data were collected by radiologists as opposed to the study of Samad et al.4 where paediatricians and surgeons collected data. This gives the advantage of better detail of the radiological practice in each institution but it is recognised that futures studies should involve radiologists and surgeons reporting, especially given the poor surgical data response achieved. Given the relatively rare incidence of intussusception, a 12 month audit period yielded low numbers per centre, especially when working out perforation rates, which made the results prone to bias. A future study should be conducted over a longer period. In conclusion, this is the first directly comparative audit of practice and reduction rates across UK centres. It demonstrates that although there have been steps towards standardized care for intussusception in the UK, there is still variability in terms of the equipment used, personnel involved, and ultimately reduction rates. UK reduction rates are low compared to current international literature and further standardization of practice across the small number of UK centres, including mandatory presence of a surgeon at reduction, may lead to an increase in reduction rates. Standardized practice and regular national audit would also allow for more straightforward comparison of results in each centre, thus improving quality of care on a national basis.
Acknowledgements The authors thank the following people who collected data in different centres across the country: Melanie Hiorns, Annie Patterson, Bozena Starzyk, Amit Maniyar, Kirsteen McDonald, Joanna Fairhurst, Sophie Swinson, Kate Taylor Robinson, Kandiyil Neghal, David Horton, Marwa Elsayed, Claire Miller, Maria Sellars, Dipalee Durve, Kath Halliday, Ash Chakraborthy, Vivian Tang, Jackie Coonar, Laurence Abernethy, Ian Kenney, Alison Evans, Fiona Dickinson, Greg Irwin.
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