Arteriovenous malformation (AVM) is a rare, abnormal connection of blood vessels that results in bypassing of the capillary system.1 This abnormal connection between the arteriole and venous systems is referred to as a nidus.2 The nidus creates abnormal blood flow around the area that results in an increased likelihood of hemorrhaging.2 Reducing the risk of hemorrhages is a common goal for all types of AVMs due to their potential for detrimental effects such as excessive blood loss, shock, low blood pressure, heart failure, and kidney failure.3 This condition is not typically seen and most commonly occurs in the brain or spinal cord; however, it may occur anywhere in the body.4 AVMs comprise only 8% of all vascular anomalies, with cases of the bladder being exceptionally rare.4 Of all cases of AVM that have been diagnosed and reported in the literature, fewer than 20 cases have occurred in the bladder. Bladder vascular malformations are located at the base of the bladder roughly 50% of the time, with 25% of these lesions involving the bladder neck.5 This condition is considered a congenital disorder in which signs and symptoms may arise at any time throughout life or remain asymptomatic.1 The typical signs and symptoms vary depending on the location of the AVM and include bleeding, seizures, headaches, paralysis, loss of speech, loss of memory, and loss of vision.6 Based on the few cases reported in the literature regarding AVM in the bladder, common signs and symptoms experienced are polyuria, hematuria, pelvic pain, and urinary retention.5
Due to the complexity of each case, a multidisciplinary approach to treatment may be necessary.4 Location of the AVM, number of vessels involved, and amount of blood flow restriction all contribute to determining the necessary treatment methods.2 Most treatments aim to at least reduce the risk of hemorrhages due to their potentially fatal effects on the body. Typical treatments include surgical resection, radiosurgery, ablation (removing the AVM surgically), and embolization (blocking the blood flow to the malformation with a glue or other adhesive). Radiosurgery and embolization are commonly combined for treatment when expected results do not occur through a single intervention.4 When a particular AVM is unable to be removed, conservative treatments are used to control symptoms to improve the quality of life for the patient.2 Any combination of treatments may be used to obtain maximal results. Conservative treatments consist of treating the signs and symptoms that are presented in each patient.2
Institutional review board approval was received for this case study. This athlete gave informed consent for his case to be reported for educational purposes.
A 21-year-old male collegiate football athlete presented with signs and symptoms of hematuria (blood in the urine) with clots, fatigue, suprapubic point tenderness, bilateral flank discomfort, and “foamy” urine. These symptoms did not consistently occur, but could typically arise after intense physical activity such as football practice or a game. The symptoms started presenting in July 2016 (Table 1). Blood and urine panels were ordered for analysis when the symptoms first presented. After the blood and urine panel results were found to be unremarkable, a cystoscopy was ordered to further examine the bladder. The cystoscopy was done in September 2017 and led to the diagnosis of the AVM in the bladder.
Timeline of Events
Typically, diagnosis of this condition includes magnetic resonance imaging, magnetic resonance angiography, computed tomography, computed tomography angiography, and Doppler ultrasound with color.4 Based on the symptoms presented in this case, exploratory diagnostic testing was done. The cause of the symptoms was unknown; therefore diagnostic tests were selected based on the symptoms presented and the structures that were potentially involved. Diagnosis for this case included cystoscopy, a procedure that allows the physician to examine the lining of the bladder and urethra. A hollow tube (cystoscope) equipped with a lens is inserted into the urethra and slowly advanced into the bladder. Results showed an AVM present in the bladder mucosa (Figure 1).
The arrow pointing to the red mass shows the arteriovenous malformation found in the bladder through cystoscopy.
Treatments for this case included intravenous transfusions of 0.9% normal saline solution to replace fluids lost during episodes of gross hematuria and continually monitoring symptoms. These treatments started at the end of August 2017. The patient returned to full activity but continued to have hematuria after exercise along with occasional occurrences of a mix of the other symptoms mentioned previously. He continued to get transfusions for treatment as needed. He was instructed to take iron supplements to keep his iron levels from dropping too low. His red blood cell count and iron level continue to be monitored, especially when symptoms are present.
The case presented here is important for athletic trainers to know about because of the unique nature and rare occurrence of AVM in the bladder.7–10 AVMs of the bladder are considered uncommon; therefore, it is important to provide case studies when they do occur to obtain a better understanding of how they can affect the body.7 This may lead to the establishment of diagnosis and treatment guidelines for this specific location in the body. Not all cases of AVM present in the same way, which is why it is crucial to gain further understanding of the condition whenever possible to contribute to future treatments and diagnoses.7,10
Few studies have been conducted to analyze the signs, symptoms, treatments, and diagnoses of AVMs in the bladder. The majority of research on AVMs has been conducted on their occurrence in the brain.9,10 These AVMs are considered the most fatal due to the risk of death or permanent impairments from hemorrhage. The lack of reported cases of AVM of the bladder results in less understanding of cases of this nature.7–10 For this reason, it is important to analyze this case to obtain a better understanding of its presentation. This may lead to improving diagnosis and treatment of this condition.
Implications for Clinical Practice
Recognizing the signs and symptoms associated with AVM is important for proper referrals and to create a multidisciplinary plan of care. Being able to detect this condition will allow for proper testing and treatments to be initiated to decrease symptoms and/or lead to removal of the AVM when possible. It is important for athletic trainers to recognize the potential severity of the symptoms and know to refer athletes for further diagnostic testing. Because AVMs increase the potential for hemorrhages, early detection is important to decrease the chance for detrimental outcomes.
AVM is a rare vascular condition that most commonly occurs in the brain and spinal cord. Cases in the bladder rarely occur and are therefore not as well studied. It is necessary to raise awareness of this case to determine optimal treatments and diagnosis techniques. If treatments to cure the condition are unable to be completed or are unsuccessful, conservative treatments to control and improve signs and symptoms are ideal. The location of the AVM, number of vessels involved, and amount of blood flow restriction determines the treatments necessary. Signs and symptoms vary based on the location of the AVM. This case can provide a greater understanding of AVMs and their presentation to improve future detection and treatment.
- Cleveland Clinic. Arteriovenous Malformation (AVM). https://my.clevelandclinic.org/health/diseases/16755-arteriovenous-malformation-avm. Published 2018.
- Fitzwater AK, Snowden GM. Intraventricular hemorrhage secondary to arterial venous malformation. Appl Radiol. 2013;42(11):38–40.
- Dabilgou AA, Kyelem JMA. [Hemorrhagic rupture of a giant arteriovenous malformation in a young man in Ouagadougou]. Pan Afr Med J. 2018;29:38. PMID:29875920
- Sadick M, Müller-Wille R, Wildgruber M, Wohlgemuth W. Vascular Anomalies (Part I): Classification and Diagnostics of Vascular Anomalies. RöFo. 2018;190(09):825–835.
- Gnanappiragasam D, Gnanappiragasam S, McDermott TE. An unusual case of urinary bladder arteriovenous malformation. Ir Med J. 2016;109(7):439. PMID:27834090
- Addo EA, Emtage J, Massis K, Hernandez DJ. A congenital high flow arteriovenous malformation of the bladder presenting with polypoid cystitis and ureteral obstruction. Urol Case Rep. 2015;3(6):181–184. https://doi.org/10.1016/j.eucr.2015.07.004 PMID: doi:10.1016/j.eucr.2015.07.004 [CrossRef]
- Hammad FT, Shawish F, Kazim E. Congenital pelvic arteriovenous malformation presenting with urinary retention: a case report. Med Princ Pract. 2011;20(3):294–296. https://doi.org/10.1159/000323837 PMID: doi:10.1159/000323837 [CrossRef]21455004
- Alpert JB, Machnicki SC. Pulmonary arteriovenous malformation (AVM). Appl Radiol. 2011;40(5):36–38.
- Darsaut TE, Magro E, Gentric J-C, et al. Treatment of brain AVMs (TOBAS): study protocol for a pragmatic randomized controlled trial. Trials. 2015;16(1):497. https://doi.org/10.1186/s13063-015-1019-0 PMID: doi:10.1186/s13063-015-1019-0 [CrossRef]26530856
- Stapf C, Mast H, Sciacca RR, et al. The New York Islands AVM Study: design, study progress, and initial results. Stroke. 2003;34(5):e29–e33. doi:10.1161/01.STR.0000068784.36838.19 [CrossRef]12690217
Timeline of Events
|July 2016||Hematuria,” foamy” urine, fatigue, bilateral flank pain, cystoscopy, urine and blood panel testing|
|August 2017||Hematuria, intravenous transfusion|
|September 2017||Hematuria, fatigue, cystoscopy, intravenous transfusion, diagnosis|
|September 2018||Hematuria, suprapubic point tenderness|