{"paper_id":"454cc35b-8aef-433e-a7c4-1a8a991954f4","body_text":"Is exceeding estimated established bladder capacities harmful during voiding cystourethrograms (VCUGs)? | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Is exceeding estimated established bladder capacities harmful during voiding cystourethrograms (VCUGs)? Robert DeFlorio, Monica Epelman, Kimberly Christnacht, Henry Zheng, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4797439/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background The current standard for diagnosing vesicoureteral reflux (VUR) in children is a voiding cystourethrogram (VCUG), which requires an accurate estimation of bladder capacity to be performed appropriately. However, in clinical practice, the amount of contrast instilled into the bladder often exceeds the estimated capacity, raising concerns among parents, radiologists, and technologists. The potential harm caused by exceeding the estimated capacity set by the American Academy of Pediatrics (AAP) and American College of Radiology (ACR) has not been studied. Objective The purpose of this study was to compare the actual bladder capacity of children undergoing VCUG with existing formula-derived estimates, and to describe any adverse effects of bladder overdistention during VCUG. Materials and Methods This retrospective study involved the review of 884 consecutive VCUG performed over a period of 3 years. The data was divided into three age groups: less than age 2, ages 2 through 14, and greater than age 14. Cases with underlying conditions that could artificially increase bladder capacity, such as neurogenic bladders or vesicoureteral reflux, were excluded from the analysis. Descriptive statistics were used to summarize the results. Results Out of the 884 reviewed VCUG studies reviewed over the 3-year period, a total of 440 normal VCUG procedures were included in the analysis. Among these, 284 VCUGs (65%) had bladder volumes that exceeded the expected bladder capacity set by the AAP and ACR. Specifically, out of the 261 VCUGs performed on children under 2 years of age, 164 (63%) VCUG exceeded the expected capacity. In the age group between 2 and 14 years, out of the 165 VCUGs performed, 113 (68%) exceeded the expected bladder capacity. Among the 14 VCUGs performed on children older than 14 years of age, seven (50%) exceeded the bladder capacity. Importantly, no adverse effects were observed or reported during or shortly after the VCUG in the 32 VCUG studies (7.3%) that required a contrast volume of more than two times the AAP estimates of bladder capacity. Additionally, no adverse effects were observed or reported immediately or within the next week in the 22 VCUG studies (5%) that required a contrast volume of more than three times the AAP estimates. This included six children who received 700 mL or more of contrast. Conclusion This study suggests that current guidelines often underestimate bladder capacity, and exceeding the expected bladder capacity appears to be reasonably safe without the occurrence of complications. Figures Figure 1 Introduction There are many possible indications to perform a voiding cystourethrogram (VCUG) in children, including dysuria, dysfunctional voiding, prenatal hydronephrosis, and neurogenic bladder. However, the most common indication would be children presenting with a recurrent urinary tract infection (UTI)[ 1 – 3 ]. Pediatric UTI is a commonly occurring infection. In the United States, it leads to approximately 1.5 million ambulatory visits, 500,000 emergency department visits and 50,000 hospital inpatient admissions annually [ 1 , 4 , 5 ]. The prevalence of UTI can vary depending on factors such as sex, age, and circumcision status. Among pediatric UTI cases, females account for 80–90% [ 1 , 4 , 6 ]. By the age of 6 to 7 years, it is estimated that about 7–8% of females and 1–2% of males will have experienced at least one UTI [ 1 , 7 , 8 ] with an estimated recurrence rate ranging from 20 to 50% [ 9 , 10 ]. Although there are many potential risk factors, vesicoureteral reflux (VUR), the most common urologic anomaly, is a major underlying cause of UTI [ 11 ] and may be present in one third of cases [ 3 , 12 ]. Based on current practice standards, most of these children will undergo a VCUG as part of their evaluation [ 13 ]. Accurate estimation of bladder capacity in children is crucial for VCUG and urodynamic assessment [ 14 – 17 ]. The American Academy of Pediatrics (AAP) [ 17 ] and the American College of Radiology (ACR)[ 15 ] provide guidelines for estimating bladder capacity using the following formulas: for patients < 2 years: weight (kg) x 7; for patients > 2–14 years: (age in years x 30) + 30; and for patients > 14 years: 500 mL. These estimates are based on studies performed by Fairhurst et al [ 18 ] and Hjälmås and colleagues [ 19 , 20 ] with each of the formulas in the guidelines based on patient age and/or weight. However, in our experience at our quaternary care children's hospital, children often have a larger bladder capacity than these estimates suggest. It was hypothesized that this may be in part related to the fact that some of the instilled contrast refluxes into the ureters and renal pelves, thereby artificially increasing the measured bladder capacity. However, this was also very often observed on normal examinations in our patients without reflux or other VCUG abnormalities. Caregivers frequently seek clarification from medical staff regarding the safety and potential risks of a VCUG. These inquiries tend to be more challenging for pediatric patients compared to adults, as clinical staff often need to provide reassurance to guardians about any potential complications. References to literature and previous examinations are commonly utilized as a guide in addressing these concerns. However, there is limited information on exceeding bladder capacity during VCUG studies. Existing literature consists of case reports and a single case series from 1974 documenting 14 instances of bladder rupture during VCUG [ 21 – 24 ]. In this study, we aimed to compare actual instilled volumes to estimated bladder capacities in different age groups in patients with normal VCUG. We also investigated whether there were any immediate post-procedure complications. Additionally, a subset of individuals who underwent VCUG and required more than 3 times the AAP estimated bladder capacity or more than 700 mL of contrast instilled underwent further statistical analysis. The electronic medical records of this population were reviewed for an additional 7 days to identify any symptoms, abnormal vital signs, or other delayed complications after VCUG. Materials and Methods This retrospective study was conducted with institutional review board approval to analyze VCUG procedures performed at our institution over a 3-year period. We also reviewed the hospital medical records of the final study population to gather patient demographics (including patient weight if under age 2 for use in expected bladder volume calculations), indications for VCUG, contrast volume used, and any documentation of immediate post-procedure complications such as pain, hematuria, vomiting, or any other new symptom that presented during or immediately after the VCUG. Additionally, we calculated the expected bladder capacity utilizing the formulas set forth by the AAP [ 17 ]and ACR guidelines[ 15 ]. The data was categorized into three groups, which corresponded to the categories used by the AAP and ACR for bladder volume estimates: age under 2 years, age 2 through 14, and age ≥ 14. Subsequently, the data was then analyzed. Patients who received either contrast volume more than three times the AAP estimates (equivalent to 1.5 times the current ACR Practice Parameter recommendation for maximal filling if the patient does not void spontaneously) or ≥ 700 mL, we evaluated their medical charts to identify any adverse effects for an additional 7 days after the VCUG procedure, including pain, hematuria, or new onset voiding symptoms. The VCUG method used at our institution is as follows: All patients are catheterized using aseptic precautions, and the bladder is drained to ensure it is empty at the start of the VCUG. We preferentially use 18% Cystografin (Bracco Diagnostics, Monroe Township, NJ) as the contrast agent for VCUG procedures. The patient lay supine on the fluoroscopy table. The contrast bottle is held 3 feet above the top of the fluoroscopy table, allowing the contrast to be infused by gravity. Instilled volume estimates on each exam are obtained by the technologist by subtracting the volume of contrast remaining in the bottle from the starting volume. If patients are capable of following instructions, we instruct them to hold their urine until they feel the urge to void without experiencing excessive discomfort. At that point, the patient voids on the table under direct fluoroscopic visualization. The technologist records the volume of contrast that was instilled up to the point and it is recorded as the measured bladder capacity for the patient. For children who cannot follow instructions, we fill the bladder with contrast until the patient spontaneously voids, and the technologist records the volume that was instilled to that point as the measured bladder capacity for the patient. Some young children void multiple times during the VCUG. In such cases, the amount of contrast instilled at the time of first void was recorded as the measured bladder capacity. The reasoning for doing so is that the unknown volume of residual urine in the bladder after partial voiding introduces too much uncertainty into bladder volume estimates during continued bladder filling. Results During the 3-year study period, a total of 884 VCUG studies were conducted. Out of these, 444 cases were excluded, yielding a final study population of 440 VCUGs. The selection process for the study are outlined in Fig. 1 and a summary of the demographic characteristics of the study group can be found in Table 1 . In 284 VCUGs (65%) the bladder volume exceeded the expected capacity set forth by the AAP and ACR. Among the 261 VCUGs performed on children under 2 years of age, 164 (63%) VCUG exceeded the expected capacity. For the age group between 2 and 14 years, 113 VCUG (68%) out of 165 performed had volumes exceeding the expected capacity. Among the 14 VCUGs performed on children older than 14 years, 7 (50%) exceeded the expected capacity. Table 1 Patient Demographics Number of VCUG procedures 440 Mean age in years at VCUG 3.1 SD of age in years at VCUG 4.1 Age range at VCUG 1 day to 18 years Median age in years at VCUG 0.8 First quartile age in years at VCUG 0.2 Third quartile age in years at VCUG 5.2 Interquartile range for age in years at VCUG 5.0 Number of VCUG on boys 190 Number of VCUG on girls 248 Number of VCUG on children with ambiguous genitalia 2 SD, standard deviation; VCUG, voiding cystourethrogram In our population, a total of 32 patients (7.3%) exceeded twice the current ACR Practice Parameter for maximal filling, which is equivalent to two times the expected bladder capacity for their age. Notably, the patient did not experience any complications. Among the subset of 22 children (5% of the study population) who had an instilled contrast volume more than three times the estimates provided by AAP and ACR, none of these children experienced any significant issues except for some mild discomfort at the time of the study. Out of the 440 patients who underwent VCUG and were interpreted as normal, 6 (1.4%) had a bladder capacity of 700 mL or more (Table 2 ). These patients had significantly higher bladder volumes than those estimated by the AAP guidelines (150–195% of AAP estimates), with one patient even having a bladder capacity of 975 mL at the age of 17. Table 2 Age, expected bladder volume and instilled contrast volume for those receiving ≥ 700 mL of contrast Bladder volume in mL Age in years AAP estimate in mL Percentage (%) compared with AAP estimates 700 15.8 500 140 700 15.4 500 140 700 16.4 500 140 750 14.9 500 150 750 16.1 500 150 975 17.1 500 195 AAP, American Academy of Pediatrics Discussion Our research findings indicate that 65% of normal VCUGs required higher bladder volumes than the expected capacity provided by the formulas and guidelines set forth by the AAP [ 17 ] and ACR [ 15 ]. There were no immediate adverse events recorded in 7.3% of VCUGs that received more than 2 times the AAP estimates. Additionally, no adverse events were recorded during the longer observation period in the patients that received between three to seven times AAP estimates of contrast, other than some mild discomfort at the time of the study. The AAP formula [ 17 ] is based on prior works from Hjälmås [ 19 , 20 ], Hallman (1950) [ 25 ], and Starfield (1967) [ 26 ]. Holmdahl et al. (1996) [ 27 ] and Chung et al. (2013) [ 28 ] also provided an equation based on research at a later time. The thumb-rule described by Hjälmås (1988) [ 19 ] is slightly different than Berger et al.’s equation published in 1983 [ 29 ]. The Berger study included mainly (125 out of 132) children aged from birth to 7 years and estimated bladder capacity from cystoscopy and nuclear cystography. Berger provided an approximation based on this formula to use as a thumb-rule. Each of these bladder volume formulae are outlined in Table 3 . Table 3 Established equations for expected bladder capacity from various publications and recommendations Publication Formula (Bladder Volume in mL) American Academy of Pediatrics Age < 2 = weight(kg) x 7 American College of Radiology Age > 2–14 = [(age in years x 30) + 30] Age > 14 = 500 mL Fairhurst 1991 (weight in kg x 7) − 1.2 Hjalmas 1988 [(age in years x 30) + 30] +/- 80mL Berger 1983 [(32 x age in years) + 73 Holmdahl 1996 [2.5 x age (months)] + 38 Chung 2011 [1.6 x age(months)] + 45 The guidelines provided by AAP [ 17 ] and ACR [ 15 ] for estimating bladder capacity are based on previous studies and formulas. However, our study suggests that bladder capacities will often exceed these calculations, and using these lower estimates can cause unnecessary anxiety among medical professionals and parents when they need to exceed this calculated volume during VCUG. It is important to note that in our study, there were no complications or ill effects observed, even when bladder volumes exceeded 700 mL. In our study, we followed the standard method of utilizing gravity for contrast instillation in children during VCUG. This approach significantly reduces the risk of bladder rupture. As a result, we did not observe any cases of bladder rupture in our study, even though 65% of the children exceeded the estimated bladder capacity. Bladder rupture during VCUG due to overdistention from excess contrast is extremely rare and usually occurs in cases of unused bladders, previous surgeries, or underlying diseases. Keihani and Kajbafzadeh documented a case report where a patient’s bladder ruptured during VCUG [ 21 ], however, it is worth noting that in this case, the VCUG was performed using manual instillation of contrast, which increases the risk of bladder rupture. To mitigate this risk, contrast should be administered using the gravity method during VCUG, as manual instillation can lead to a rapid increase in pressure and bladder rupture [ 21 ]. It is important to acknowledge that our study is a single-center study, and therefore, the results may not be applicable to all populations and centers. Some notable limitations of this study include retrospective data collection, and predominantly short-term follow-up clinical information limited to the immediate post-procedure period in most patients, and up to 7 days in the smaller subset that had received the largest volumes of contrast. Additionally, for some of the population we had to rely on the patient reporting the urge to urinate, which could artificially increase or decrease the measured bladder volumes depending on each patient’s perceived tolerance for different bladder volumes. An additional limitation would be the possibly underestimated bladder volumes in the patients that had voided multiple times. However, as our goal was to determine the risks of over distending the urinary bladder, it is felt that underestimating the bladder volumes in these patients would allow more confidence in the true risk of exceeding the current bladder estimates. Conclusion A substantial proportion (65%) of the VCUGs conducted in this study surpassed the estimated bladder capacity set forth by AAP[ 17 ] and ACR[ 15 ]. This was observed in 63% of VCUGs in children under 2 years old and in 68% of the children between 2 to 14 years of age. Despite the expected mild discomfort experienced by the children during the procedure, no adverse effects were observed, even in children where the bladder was filled to more than three times the estimated capacity or had 700 mL or more contrast instilled. Therefore, this study demonstrates that exceeding the current available estimates of bladder volume, as provided by the standard guidelines of the AAP[ 17 ] and ACR[ 15 ], does not pose a cause for concern while using gravity instillation. This data will enable medical staff to provide more accurate and evidence-based information to caregivers. Declarations Author Contribution RD - Prepared manuscriptME - Edited the manuscriptKC - Pulled the data and created the databaseHZ - First draft of the manuscriptCS - Mentored, analyzed data, edited manuscript References Marsh MC, Junquera GY, Stonebrook E, Spencer JD, Watson JR (2024) Urinary Tract Infections in Children. Pediatr Rev 45:260–270 Roberts KB (2011) Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics 128:595–610 Hoberman A, Chesney RW (2014) Antimicrobial prophylaxis for children with vesicoureteral reflux. 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Acta Paediatr 87:549–552 Hellström A, Hanson E, Hansson S, Hjälmås K, Jodal U (1991) Association between urinary symptoms at 7 years old and previous urinary tract infection. Arch Dis Child 66:232–234 Stephens GM, Akers S, Nguyen H, Woxland H (2015) Evaluation and management of urinary tract infections in the school-aged child. Prim Care 42:33–41 Conway PH, Cnaan A, Zaoutis T, Henry BV, Grundmeier RW, Keren R (2007) Recurrent urinary tract infections in children: risk factors and association with prophylactic antimicrobials. JAMA 298:179–186 Miyakita H, Hayashi Y, Mitsui T, Okawada M, Kinoshita Y, Kimata T, Koikawa Y, Sakai K, Satoh H, Tokunaga M, Naitoh Y, Niimura F, Matsuoka H, Mizuno K, Kaneko K, Kubota M (2020) Guidelines for the medical management of pediatric vesicoureteral reflux. Int J Urol 27:480–490 Hoberman A, Charron M, Hickey RW, Baskin M, Kearney DH, Wald ER (2003) Imaging studies after a first febrile urinary tract infection in young children. 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ACR-SPR practice parameter for the performance of fluoroscopic and sonographic voiding cystourethrography in children (2019) https://www.acr.org/-/media/ACR/Files/Practice-Parameters/VoidingCysto.pdf Accessed July 4, 2024 Damasio MB, Donati F, Bruno C, Darge K, Mentzel H-J, Ključevšek D, Napolitano M, Ozcan HN, Riccabona M, Smets AM, Sofia C, Stafrace S, Petit P, Ording Müller L-S (2024) Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography. Pediatr Radiol 54:606–619 Frimberger D, Mercado-Deane MG (2016) Establishing a Standard Protocol for the Voiding Cystourethrography. Pediatrics 138 Fairhurst JJ, Rubin CM, Hyde I, Freeman NV, Williams JD (1991) Bladder capacity in infants. J Pediatr Surg 26:55–57 Hjälmås K (1988) Urodynamics in normal infants and children. Scand J Urol Nephrol Suppl 114:20–27 Hjälmås K (1976) Micturition in infants and children with normal lower urinary tract. A urodynamic study. Scand J Urol Nephrol Suppl 37:1–106 Keihani S, Kajbafzadeh AM (2015) Bladder rupture after voiding cystourethrography: A case report and literature review on pitfalls and bladder volume estimation. Can Urol Assoc J 9:E826–829 McAlister WH, Cacciarelli A, Shackelford GD (1974) Complications associated with cystography in children. Radiology 111:167–172 Lee KO, Park SJ, Shin JI, Lee SY, Kim KH (2012) Urinary bladder rupture during voiding cystourethrography. Korean J Pediatr 55:181–184 Khavari R, Bayne AP, Roth DR (2010) A report of an iatrogenic bladder rupture in a normal healthy child during voiding cystourethrography. Urology 75:684–686 Hallman N (1950) On the ability of enuretic children to hold urine. Acta Paediatr (Stockh) 39:87–93 Starfield B (1967) Functional bladder capacity in enuretic and nonenuretic children. J Pediatr 70:777–781 Holmdahl G, Hanson E, Hanson M, Hellström AL, Hjälmås K, Sillén U (1996) Four-hour voiding observation in healthy infants. J Urol 156:1809–1812 Chung JM, Kim KS, Kim SO, Kim JM, Park S, Park JS, Oh MM, Lee SD (2013) Evaluation of bladder capacity in Korean children younger than 24 months: a nationwide multicenter study. World J Urol 31:225–228 Berger RM, Maizels M, Moran GC, Conway JJ, Firlit CF (1983) Bladder capacity (ounces) equals age (years) plus 2 predicts normal bladder capacity and aids in diagnosis of abnormal voiding patterns. J Urol 129:347–349 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-4797439\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":342086102,\"identity\":\"113bbb3a-def0-4c7d-ae76-86c6b4195085\",\"order_by\":0,\"name\":\"Robert DeFlorio\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nemours Children's Health System\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Robert\",\"middleName\":\"\",\"lastName\":\"DeFlorio\",\"suffix\":\"\"},{\"id\":342086103,\"identity\":\"0db56e7e-9fa1-43dd-b67c-e25838f52c84\",\"order_by\":1,\"name\":\"Monica Epelman\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nemours Children's Health System\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Monica\",\"middleName\":\"\",\"lastName\":\"Epelman\",\"suffix\":\"\"},{\"id\":342086104,\"identity\":\"04a5eb82-9f52-459a-943e-05306df4014d\",\"order_by\":2,\"name\":\"Kimberly Christnacht\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Colorado System\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Kimberly\",\"middleName\":\"\",\"lastName\":\"Christnacht\",\"suffix\":\"\"},{\"id\":342086105,\"identity\":\"1bda0493-4064-49c3-939d-72933ed61c32\",\"order_by\":3,\"name\":\"Henry Zheng\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nemours Children's Health System\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Henry\",\"middleName\":\"\",\"lastName\":\"Zheng\",\"suffix\":\"\"},{\"id\":342086106,\"identity\":\"b1425bc0-0fbc-4172-a8b9-c1051b2500ec\",\"order_by\":4,\"name\":\"Chetan Shah\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+0lEQVRIiWNgGAWjYDACCShtwMDD+IBYLYwNUC3MBiRrYZMgoBYC+Gc3H3/wcweDvTn72WPVBRXb5AxuH3/A8HFPLW5L7hxLbOw9w5C4sycv7faMM7eNDc7lGDDOeHYcpxYDiRzDBt42hgSDAzlmt3nbbiduOMPDwMxz4BgeLfkfG/+2MdgbnH9jVsz7D6SF/QEBLTmMzUBbGDfcyDFj5m0AaWEwAGqpwe2XG2mGs2XbJBI33HhjLM1z7Lax5Bkeg4MzDhzAqYV/RvKDj2/bbIAOyzH8zFNzW47vDPvDBx8O1OHUArMMlQu04jAhLZiAoC2jYBSMglEwcgAANZRZOWYUWJkAAAAASUVORK5CYII=\",\"orcid\":\"\",\"institution\":\"Nemours Children's Health System\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Chetan\",\"middleName\":\"\",\"lastName\":\"Shah\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2024-07-24 18:59:36\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-4797439/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-4797439/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":63373854,\"identity\":\"ea807581-1443-47a7-aa48-ef85463262f4\",\"added_by\":\"auto\",\"created_at\":\"2024-08-27 12:20:43\",\"extension\":\"jpg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":744467,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eStudy Population including exclusion criteria. VCUG, voiding cystourethrogram.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"Figure1.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4797439/v1/39093c2fc2e7b8467625369a.jpg\"},{\"id\":64611280,\"identity\":\"6f395026-d854-42ee-b4df-339aeb2004d5\",\"added_by\":\"auto\",\"created_at\":\"2024-09-16 14:07:26\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":1089961,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4797439/v1/affb4750-0d6a-4d8e-bb9b-8605be0a5e46.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Is exceeding estimated established bladder capacities harmful during voiding cystourethrograms (VCUGs)?\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003eThere are many possible indications to perform a voiding cystourethrogram (VCUG) in children, including dysuria, dysfunctional voiding, prenatal hydronephrosis, and neurogenic bladder. However, the most common indication would be children presenting with a recurrent urinary tract infection (UTI)[\\u003cspan additionalcitationids=\\\"CR2\\\" citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e]. Pediatric UTI is a commonly occurring infection. In the United States, it leads to approximately 1.5\\u0026nbsp;million ambulatory visits, 500,000 emergency department visits and 50,000 hospital inpatient admissions annually [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. The prevalence of UTI can vary depending on factors such as sex, age, and circumcision status. Among pediatric UTI cases, females account for 80\\u0026ndash;90% [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. By the age of 6 to 7 years, it is estimated that about 7\\u0026ndash;8% of females and 1\\u0026ndash;2% of males will have experienced at least one UTI [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e] with an estimated recurrence rate ranging from 20 to 50% [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e]. Although there are many potential risk factors, vesicoureteral reflux (VUR), the most common urologic anomaly, is a major underlying cause of UTI [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e] and may be present in one third of cases [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e]. Based on current practice standards, most of these children will undergo a VCUG as part of their evaluation [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eAccurate estimation of bladder capacity in children is crucial for VCUG and urodynamic assessment [\\u003cspan additionalcitationids=\\\"CR15 CR16\\\" citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e]. The American Academy of Pediatrics (AAP) [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] and the American College of Radiology (ACR)[\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e] provide guidelines for estimating bladder capacity using the following formulas: for patients\\u0026thinsp;\\u0026lt;\\u0026thinsp;2 years: weight (kg) x 7; for patients\\u0026thinsp;\\u0026gt;\\u0026thinsp;2\\u0026ndash;14 years: (age in years x 30)\\u0026thinsp;+\\u0026thinsp;30; and for patients\\u0026thinsp;\\u0026gt;\\u0026thinsp;14 years: 500 mL. These estimates are based on studies performed by Fairhurst et al [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e] and Hj\\u0026auml;lm\\u0026aring;s and colleagues [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e] with each of the formulas in the guidelines based on patient age and/or weight. However, in our experience at our quaternary care children's hospital, children often have a larger bladder capacity than these estimates suggest. It was hypothesized that this may be in part related to the fact that some of the instilled contrast refluxes into the ureters and renal pelves, thereby artificially increasing the measured bladder capacity. However, this was also very often observed on normal examinations in our patients without reflux or other VCUG abnormalities. Caregivers frequently seek clarification from medical staff regarding the safety and potential risks of a VCUG. These inquiries tend to be more challenging for pediatric patients compared to adults, as clinical staff often need to provide reassurance to guardians about any potential complications. References to literature and previous examinations are commonly utilized as a guide in addressing these concerns. However, there is limited information on exceeding bladder capacity during VCUG studies. Existing literature consists of case reports and a single case series from 1974 documenting 14 instances of bladder rupture during VCUG [\\u003cspan additionalcitationids=\\\"CR22 CR23\\\" citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eIn this study, we aimed to compare actual instilled volumes to estimated bladder capacities in different age groups in patients with normal VCUG. We also investigated whether there were any immediate post-procedure complications. Additionally, a subset of individuals who underwent VCUG and required more than 3 times the AAP estimated bladder capacity or more than 700 mL of contrast instilled underwent further statistical analysis. The electronic medical records of this population were reviewed for an additional 7 days to identify any symptoms, abnormal vital signs, or other delayed complications after VCUG.\\u003c/p\\u003e\"},{\"header\":\"Materials and Methods\",\"content\":\"\\u003cp\\u003e This retrospective study was conducted with institutional review board approval to analyze VCUG procedures performed at our institution over a 3-year period. We also reviewed the hospital medical records of the final study population to gather patient demographics (including patient weight if under age 2 for use in expected bladder volume calculations), indications for VCUG, contrast volume used, and any documentation of immediate post-procedure complications such as pain, hematuria, vomiting, or any other new symptom that presented during or immediately after the VCUG. Additionally, we calculated the expected bladder capacity utilizing the formulas set forth by the AAP [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e]and ACR guidelines[\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe data was categorized into three groups, which corresponded to the categories used by the AAP and ACR for bladder volume estimates: age under 2 years, age 2 through 14, and age\\u0026thinsp;\\u003cspan type=\\\"Underline\\\" class=\\\"Underline\\\" name=\\\"Emphasis\\\"\\u003e\\u0026ge;\\u003c/span\\u003e\\u0026thinsp;14. Subsequently, the data was then analyzed. Patients who received either contrast volume more than three times the AAP estimates (equivalent to 1.5 times the current ACR Practice Parameter recommendation for maximal filling if the patient does not void spontaneously) or \\u003cspan type=\\\"Underline\\\" class=\\\"Underline\\\" name=\\\"Emphasis\\\"\\u003e\\u0026ge;\\u003c/span\\u003e\\u0026thinsp;700 mL, we evaluated their medical charts to identify any adverse effects for an additional 7 days after the VCUG procedure, including pain, hematuria, or new onset voiding symptoms.\\u003c/p\\u003e \\u003cp\\u003eThe VCUG method used at our institution is as follows: All patients are catheterized using aseptic precautions, and the bladder is drained to ensure it is empty at the start of the VCUG. We preferentially use 18% Cystografin (Bracco Diagnostics, Monroe Township, NJ) as the contrast agent for VCUG procedures. The patient lay supine on the fluoroscopy table. The contrast bottle is held 3 feet above the top of the fluoroscopy table, allowing the contrast to be infused by gravity. Instilled volume estimates on each exam are obtained by the technologist by subtracting the volume of contrast remaining in the bottle from the starting volume. If patients are capable of following instructions, we instruct them to hold their urine until they feel the urge to void without experiencing excessive discomfort. At that point, the patient voids on the table under direct fluoroscopic visualization. The technologist records the volume of contrast that was instilled up to the point and it is recorded as the measured bladder capacity for the patient. For children who cannot follow instructions, we fill the bladder with contrast until the patient spontaneously voids, and the technologist records the volume that was instilled to that point as the measured bladder capacity for the patient. Some young children void multiple times during the VCUG. In such cases, the amount of contrast instilled at the time of first void was recorded as the measured bladder capacity. The reasoning for doing so is that the unknown volume of residual urine in the bladder after partial voiding introduces too much uncertainty into bladder volume estimates during continued bladder filling.\\u003c/p\\u003e\"},{\"header\":\"Results\",\"content\":\"\\u003cp\\u003eDuring the 3-year study period, a total of 884 VCUG studies were conducted. Out of these, 444 cases were excluded, yielding a final study population of 440 VCUGs. The selection process for the study are outlined in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e and a summary of the demographic characteristics of the study group can be found in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e. In 284 VCUGs (65%) the bladder volume exceeded the expected capacity set forth by the AAP and ACR. Among the 261 VCUGs performed on children under 2 years of age, 164 (63%) VCUG exceeded the expected capacity. For the age group between 2 and 14 years, 113 VCUG (68%) out of 165 performed had volumes exceeding the expected capacity. Among the 14 VCUGs performed on children older than 14 years, 7 (50%) exceeded the expected capacity.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003ePatient Demographics\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"2\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eNumber of VCUG procedures\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e440\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eMean age in years at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e3.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eSD of age in years at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e4.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eAge range at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1 day to 18 years\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eMedian age in years at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eFirst quartile age in years at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eThird quartile age in years at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eInterquartile range for age in years at VCUG\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5.0\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eNumber of VCUG on boys\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e190\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eNumber of VCUG on girls\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e248\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eNumber of VCUG on children with ambiguous genitalia\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003ctfoot\\u003e \\u003ctr\\u003e\\u003ctd colspan=\\\"2\\\"\\u003eSD, standard deviation; VCUG, voiding cystourethrogram\\u003c/td\\u003e\\u003c/tr\\u003e \\u003c/tfoot\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eIn our population, a total of 32 patients (7.3%) exceeded twice the current ACR Practice Parameter for maximal filling, which is equivalent to two times the expected bladder capacity for their age. Notably, the patient did not experience any complications.\\u003c/p\\u003e \\u003cp\\u003eAmong the subset of 22 children (5% of the study population) who had an instilled contrast volume more than three times the estimates provided by AAP and ACR, none of these children experienced any significant issues except for some mild discomfort at the time of the study.\\u003c/p\\u003e \\u003cp\\u003eOut of the 440 patients who underwent VCUG and were interpreted as normal, 6 (1.4%) had a bladder capacity of 700 mL or more (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e). These patients had significantly higher bladder volumes than those estimated by the AAP guidelines (150\\u0026ndash;195% of AAP estimates), with one patient even having a bladder capacity of 975 mL at the age of 17.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eAge, expected bladder volume and instilled contrast volume for those receiving\\u0026thinsp;\\u003cspan type=\\\"Underline\\\" class=\\\"Underline\\\" name=\\\"Emphasis\\\"\\u003e\\u0026ge;\\u003c/span\\u003e\\u0026thinsp;700 mL of contrast\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBladder volume in mL\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eAge in years\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eAAP estimate in mL\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003ePercentage (%) compared with AAP estimates\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e700\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e15.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e500\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e140\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e700\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e15.4\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e500\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e140\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e700\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e16.4\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e500\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e140\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e750\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e14.9\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e500\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e150\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e750\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e16.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e500\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e150\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e975\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e17.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e500\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e195\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003ctfoot\\u003e \\u003ctr\\u003e\\u003ctd colspan=\\\"4\\\"\\u003eAAP, American Academy of Pediatrics\\u003c/td\\u003e\\u003c/tr\\u003e \\u003c/tfoot\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eOur research findings indicate that 65% of normal VCUGs required higher bladder volumes than the expected capacity provided by the formulas and guidelines set forth by the AAP [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] and ACR [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. There were no immediate adverse events recorded in 7.3% of VCUGs that received more than 2 times the AAP estimates. Additionally, no adverse events were recorded during the longer observation period in the patients that received between three to seven times AAP estimates of contrast, other than some mild discomfort at the time of the study.\\u003c/p\\u003e \\u003cp\\u003eThe AAP formula [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] is based on prior works from Hj\\u0026auml;lm\\u0026aring;s [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e], Hallman (1950) [\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e], and Starfield (1967) [\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e]. Holmdahl et al. (1996) [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e] and Chung et al. (2013) [\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e] also provided an equation based on research at a later time. The thumb-rule described by Hj\\u0026auml;lm\\u0026aring;s (1988) [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e] is slightly different than Berger et al.\\u0026rsquo;s equation published in 1983 [\\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e]. The Berger study included mainly (125 out of 132) children aged from birth to 7 years and estimated bladder capacity from cystoscopy and nuclear cystography. Berger provided an approximation based on this formula to use as a thumb-rule. Each of these bladder volume formulae are outlined in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab3\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 3\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eEstablished equations for expected bladder capacity from various publications and recommendations\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"2\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePublication\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eFormula (Bladder Volume in mL)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eAmerican Academy of Pediatrics\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eAge\\u0026thinsp;\\u0026lt;\\u0026thinsp;2\\u0026thinsp;=\\u0026thinsp;weight(kg) x 7\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eAmerican College of Radiology\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eAge\\u0026thinsp;\\u0026gt;\\u0026thinsp;2\\u0026ndash;14 = [(age in years x 30)\\u0026thinsp;+\\u0026thinsp;30]\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eAge\\u0026thinsp;\\u0026gt;\\u0026thinsp;14\\u0026thinsp;=\\u0026thinsp;500 mL\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eFairhurst 1991\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e(weight in kg x 7) \\u0026minus;\\u0026thinsp;1.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eHjalmas 1988\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e[(age in years x 30)\\u0026thinsp;+\\u0026thinsp;30] +/- 80mL\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBerger 1983\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e[(32 x age in years) + 73\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eHolmdahl 1996\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e[2.5 x age (months)]\\u0026thinsp;+\\u0026thinsp;38\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eChung 2011\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e[1.6 x age(months)]\\u0026thinsp;+\\u0026thinsp;45\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe guidelines provided by AAP [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] and ACR [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e] for estimating bladder capacity are based on previous studies and formulas. However, our study suggests that bladder capacities will often exceed these calculations, and using these lower estimates can cause unnecessary anxiety among medical professionals and parents when they need to exceed this calculated volume during VCUG. It is important to note that in our study, there were no complications or ill effects observed, even when bladder volumes exceeded 700 mL.\\u003c/p\\u003e \\u003cp\\u003e In our study, we followed the standard method of utilizing gravity for contrast instillation in children during VCUG. This approach significantly reduces the risk of bladder rupture. As a result, we did not observe any cases of bladder rupture in our study, even though 65% of the children exceeded the estimated bladder capacity. Bladder rupture during VCUG due to overdistention from excess contrast is extremely rare and usually occurs in cases of unused bladders, previous surgeries, or underlying diseases. Keihani and Kajbafzadeh documented a case report where a patient\\u0026rsquo;s bladder ruptured during VCUG [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e], however, it is worth noting that in this case, the VCUG was performed using manual instillation of contrast, which increases the risk of bladder rupture. To mitigate this risk, contrast should be administered using the gravity method during VCUG, as manual instillation can lead to a rapid increase in pressure and bladder rupture [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eIt is important to acknowledge that our study is a single-center study, and therefore, the results may not be applicable to all populations and centers. Some notable limitations of this study include retrospective data collection, and predominantly short-term follow-up clinical information limited to the immediate post-procedure period in most patients, and up to 7 days in the smaller subset that had received the largest volumes of contrast. Additionally, for some of the population we had to rely on the patient reporting the urge to urinate, which could artificially increase or decrease the measured bladder volumes depending on each patient\\u0026rsquo;s perceived tolerance for different bladder volumes. An additional limitation would be the possibly underestimated bladder volumes in the patients that had voided multiple times. However, as our goal was to determine the risks of over distending the urinary bladder, it is felt that underestimating the bladder volumes in these patients would allow more confidence in the true risk of exceeding the current bladder estimates.\\u003c/p\\u003e\"},{\"header\":\"Conclusion\",\"content\":\"\\u003cp\\u003eA substantial proportion (65%) of the VCUGs conducted in this study surpassed the estimated bladder capacity set forth by AAP[\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] and ACR[\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]. This was observed in 63% of VCUGs in children under 2 years old and in 68% of the children between 2 to 14 years of age. Despite the expected mild discomfort experienced by the children during the procedure, no adverse effects were observed, even in children where the bladder was filled to more than three times the estimated capacity or had 700 mL or more contrast instilled. Therefore, this study demonstrates that exceeding the current available estimates of bladder volume, as provided by the standard guidelines of the AAP[\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e] and ACR[\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e], does not pose a cause for concern while using gravity instillation. This data will enable medical staff to provide more accurate and evidence-based information to caregivers.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003ch2\\u003eAuthor Contribution\\u003c/h2\\u003e\\u003cp\\u003eRD - Prepared manuscriptME - Edited the manuscriptKC - Pulled the data and created the databaseHZ - First draft of the manuscriptCS - Mentored, analyzed data, edited manuscript\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e\\u003cspan\\u003eMarsh MC, Junquera GY, Stonebrook E, Spencer JD, Watson JR (2024) Urinary Tract Infections in Children. Pediatr Rev 45:260\\u0026ndash;270\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eRoberts KB (2011) Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics 128:595\\u0026ndash;610\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHoberman A, Chesney RW (2014) Antimicrobial prophylaxis for children with vesicoureteral reflux. N Engl J Med 371:1072\\u0026ndash;1073\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eCopp HL, Shapiro DJ, Hersh AL (2011) National ambulatory antibiotic prescribing patterns for pediatric urinary tract infection, 1998\\u0026ndash;2007. Pediatrics 127:1027\\u0026ndash;1033\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eSpencer JD, Schwaderer A, McHugh K, Hains DS (2010) Pediatric urinary tract infections: an analysis of hospitalizations, charges, and costs in the USA. Pediatr Nephrol 25:2469\\u0026ndash;2475\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eSood A, Penna FJ, Eleswarapu S, Pucheril D, Weaver J, Abd-El-Barr AE, Wagner JC, Lakshmanan Y, Menon M, Trinh QD, Sammon JD, Elder JS (2015) Incidence, admission rates, and economic burden of pediatric emergency department visits for urinary tract infection: data from the nationwide emergency department sample, 2006 to 2011. J Pediatr Urol 11:246e241\\u0026ndash;246e248\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eM\\u0026aring;rild S, Jodal U (1998) Incidence rate of first-time symptomatic urinary tract infection in children under 6 years of age. Acta Paediatr 87:549\\u0026ndash;552\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHellstr\\u0026ouml;m A, Hanson E, Hansson S, Hj\\u0026auml;lm\\u0026aring;s K, Jodal U (1991) Association between urinary symptoms at 7 years old and previous urinary tract infection. Arch Dis Child 66:232\\u0026ndash;234\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eStephens GM, Akers S, Nguyen H, Woxland H (2015) Evaluation and management of urinary tract infections in the school-aged child. Prim Care 42:33\\u0026ndash;41\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eConway PH, Cnaan A, Zaoutis T, Henry BV, Grundmeier RW, Keren R (2007) Recurrent urinary tract infections in children: risk factors and association with prophylactic antimicrobials. JAMA 298:179\\u0026ndash;186\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eMiyakita H, Hayashi Y, Mitsui T, Okawada M, Kinoshita Y, Kimata T, Koikawa Y, Sakai K, Satoh H, Tokunaga M, Naitoh Y, Niimura F, Matsuoka H, Mizuno K, Kaneko K, Kubota M (2020) Guidelines for the medical management of pediatric vesicoureteral reflux. Int J Urol 27:480\\u0026ndash;490\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHoberman A, Charron M, Hickey RW, Baskin M, Kearney DH, Wald ER (2003) Imaging studies after a first febrile urinary tract infection in young children. N Engl J Med 348:195\\u0026ndash;202\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eChandra T, Bajaj M, Iyer RS, Chan SS, Bardo DME, Chen J, Cooper ML, Kaplan SL, Levin TL, Moore MM, Peters CA, Saidinejad M, Schooler GR, Shet NS, Squires JH, Trout AT, Pruthi S (2024) ACR Appropriateness Criteria\\u0026reg; Urinary Tract Infection-Child: 2023 Update. J Am Coll Radiol 21:S326\\u0026ndash;s342\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eGuerra LA, Keays MA, Purser MJ, Wang SY, Leonard MP (2018) Pediatric cystogram: Are we considering age-adjusted bladder capacity? Can Urol Assoc J 12:378\\u0026ndash;381\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eAmerican College of Radiology. ACR-SPR practice parameter for the performance of fluoroscopic and sonographic voiding cystourethrography in children (2019) \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://www.acr.org/-/media/ACR/Files/Practice-Parameters/VoidingCysto.pdf\\u003c/span\\u003e\\u003cspan address=\\\"https://www.acr.org/-/media/ACR/Files/Practice-Parameters/VoidingCysto.pdf\\\" targettype=\\\"URL\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e Accessed July 4, 2024\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eDamasio MB, Donati F, Bruno C, Darge K, Mentzel H-J, Ključevšek D, Napolitano M, Ozcan HN, Riccabona M, Smets AM, Sofia C, Stafrace S, Petit P, Ording M\\u0026uuml;ller L-S (2024) Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography. Pediatr Radiol 54:606\\u0026ndash;619\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eFrimberger D, Mercado-Deane MG (2016) Establishing a Standard Protocol for the Voiding Cystourethrography. Pediatrics 138\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eFairhurst JJ, Rubin CM, Hyde I, Freeman NV, Williams JD (1991) Bladder capacity in infants. J Pediatr Surg 26:55\\u0026ndash;57\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHj\\u0026auml;lm\\u0026aring;s K (1988) Urodynamics in normal infants and children. Scand J Urol Nephrol Suppl 114:20\\u0026ndash;27\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHj\\u0026auml;lm\\u0026aring;s K (1976) Micturition in infants and children with normal lower urinary tract. A urodynamic study. Scand J Urol Nephrol Suppl 37:1\\u0026ndash;106\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eKeihani S, Kajbafzadeh AM (2015) Bladder rupture after voiding cystourethrography: A case report and literature review on pitfalls and bladder volume estimation. Can Urol Assoc J 9:E826\\u0026ndash;829\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eMcAlister WH, Cacciarelli A, Shackelford GD (1974) Complications associated with cystography in children. Radiology 111:167\\u0026ndash;172\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eLee KO, Park SJ, Shin JI, Lee SY, Kim KH (2012) Urinary bladder rupture during voiding cystourethrography. Korean J Pediatr 55:181\\u0026ndash;184\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eKhavari R, Bayne AP, Roth DR (2010) A report of an iatrogenic bladder rupture in a normal healthy child during voiding cystourethrography. Urology 75:684\\u0026ndash;686\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHallman N (1950) On the ability of enuretic children to hold urine. Acta Paediatr (Stockh) 39:87\\u0026ndash;93\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eStarfield B (1967) Functional bladder capacity in enuretic and nonenuretic children. J Pediatr 70:777\\u0026ndash;781\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eHolmdahl G, Hanson E, Hanson M, Hellstr\\u0026ouml;m AL, Hj\\u0026auml;lm\\u0026aring;s K, Sill\\u0026eacute;n U (1996) Four-hour voiding observation in healthy infants. J Urol 156:1809\\u0026ndash;1812\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eChung JM, Kim KS, Kim SO, Kim JM, Park S, Park JS, Oh MM, Lee SD (2013) Evaluation of bladder capacity in Korean children younger than 24 months: a nationwide multicenter study. World J Urol 31:225\\u0026ndash;228\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eBerger RM, Maizels M, Moran GC, Conway JJ, Firlit CF (1983) Bladder capacity (ounces) equals age (years) plus 2 predicts normal bladder capacity and aids in diagnosis of abnormal voiding patterns. J Urol 129:347\\u0026ndash;349\\u003c/span\\u003e\\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-4797439/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-4797439/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003ch2\\u003eBackground\\u003c/h2\\u003e \\u003cp\\u003eThe current standard for diagnosing vesicoureteral reflux (VUR) in children is a voiding cystourethrogram (VCUG), which requires an accurate estimation of bladder capacity to be performed appropriately. However, in clinical practice, the amount of contrast instilled into the bladder often exceeds the estimated capacity, raising concerns among parents, radiologists, and technologists. The potential harm caused by exceeding the estimated capacity set by the American Academy of Pediatrics (AAP) and American College of Radiology (ACR) has not been studied.\\u003c/p\\u003e\\u003ch2\\u003eObjective\\u003c/h2\\u003e \\u003cp\\u003eThe purpose of this study was to compare the actual bladder capacity of children undergoing VCUG with existing formula-derived estimates, and to describe any adverse effects of bladder overdistention during VCUG.\\u003c/p\\u003e\\u003ch2\\u003eMaterials and Methods\\u003c/h2\\u003e \\u003cp\\u003eThis retrospective study involved the review of 884 consecutive VCUG performed over a period of 3 years. The data was divided into three age groups: less than age 2, ages 2 through 14, and greater than age 14. Cases with underlying conditions that could artificially increase bladder capacity, such as neurogenic bladders or vesicoureteral reflux, were excluded from the analysis. Descriptive statistics were used to summarize the results.\\u003c/p\\u003e\\u003ch2\\u003eResults\\u003c/h2\\u003e \\u003cp\\u003eOut of the 884 reviewed VCUG studies reviewed over the 3-year period, a total of 440 normal VCUG procedures were included in the analysis. Among these, 284 VCUGs (65%) had bladder volumes that exceeded the expected bladder capacity set by the AAP and ACR. Specifically, out of the 261 VCUGs performed on children under 2 years of age, 164 (63%) VCUG exceeded the expected capacity. In the age group between 2 and 14 years, out of the 165 VCUGs performed, 113 (68%) exceeded the expected bladder capacity. Among the 14 VCUGs performed on children older than 14 years of age, seven (50%) exceeded the bladder capacity. Importantly, no adverse effects were observed or reported during or shortly after the VCUG in the 32 VCUG studies (7.3%) that required a contrast volume of more than two times the AAP estimates of bladder capacity. Additionally, no adverse effects were observed or reported immediately or within the next week in the 22 VCUG studies (5%) that required a contrast volume of more than three times the AAP estimates. This included six children who received 700 mL or more of contrast.\\u003c/p\\u003e\\u003ch2\\u003eConclusion\\u003c/h2\\u003e \\u003cp\\u003e This study suggests that current guidelines often underestimate bladder capacity, and exceeding the expected bladder capacity appears to be reasonably safe without the occurrence of complications.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Is exceeding estimated established bladder capacities harmful during voiding cystourethrograms (VCUGs)?\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2024-08-27 12:20:38\",\"doi\":\"10.21203/rs.3.rs-4797439/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"10d09db0-61ee-4103-9e08-d78c829c8236\",\"owner\":[],\"postedDate\":\"August 27th, 2024\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2024-09-16T13:59:19+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2024-08-27 12:20:38\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-4797439\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-4797439\",\"identity\":\"rs-4797439\",\"version\":[\"v1\"]},\"buildId\":\"qtupq5eGEP_6zYnWcrvyt\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}