From the Guidelines
Urinary bladder thickening is most commonly caused by conditions such as chronic cystitis, bladder outlet obstruction, neurogenic bladder dysfunction, and bladder cancer, which can lead to inflammation or structural changes in the bladder wall. The causes of urinary bladder thickening can be diverse and include:
- Chronic cystitis, a persistent inflammation of the bladder typically resulting from recurrent urinary tract infections 1
- Bladder outlet obstruction, such as that caused by benign prostatic hyperplasia in men or urethral strictures, which forces the bladder to work harder to expel urine, leading to muscular hypertrophy and wall thickening 1
- Neurogenic bladder dysfunction, where nerve damage disrupts normal bladder function, can also cause thickening over time 1
- Bladder cancer, particularly transitional cell carcinoma, which may present as localized or diffuse wall thickening 1
- Interstitial cystitis, a chronic condition characterized by bladder pain and pressure, often results in bladder wall inflammation and thickening 1
- Radiation cystitis following pelvic radiation therapy, schistosomiasis (a parasitic infection common in certain regions), and systemic conditions like amyloidosis that can deposit abnormal proteins in the bladder wall 1
Diagnosis typically requires a combination of clinical evaluation, imaging studies like ultrasound or CT scan, and sometimes biopsy to determine the exact cause of the thickening 1. According to the most recent and highest quality study, CTU is the most accurate and preferred modality for diagnosis and staging of urothelial malignancies, including bladder cancer 1.
Some key points to consider in the diagnosis and management of urinary bladder thickening include:
- The importance of imaging studies, such as CTU, in evaluating the bladder and upper urinary tract for signs of cancer or other abnormalities 1
- The need for a thorough clinical evaluation, including a physical examination, urinalysis, and voiding diary, to identify underlying causes of urinary dysfunction 1
- The potential for bladder outlet obstruction to cause thickening of the bladder wall, and the importance of evaluating for this condition in patients with urinary symptoms 1
- The role of biopsy in confirming the diagnosis of bladder cancer or other conditions that may cause thickening of the bladder wall 1
From the Research
Causes of Urinary Bladder Thickening
The urinary bladder thickening can be caused by several factors, including:
- Bladder outlet obstruction (BOO) secondary to benign prostatic enlargement (BPE) 2, 3
- High pressure voiding, which causes an increase in the proportion of smooth muscle (hyperplasia/hypertrophy of the detrusor) 2
- Progressive changes in the bladder wall, including fibrosis, hyperactivity, and decreased functional capacity 2
- Cyclic stretch, increased hydrostatic and cyclic hydrodynamic pressure, and hypoxia, which can modulate multiple signaling pathways involved in the remodeling process 3
Bladder Wall Remodeling
The bladder wall remodeling can be divided into three stages:
- Initial hypertrophy phase
- Subsequent compensation phase
- Later decompensation phase 3 This remodeling process involves histological and molecular alterations in the following compartments:
- Urothelium
- Suburothelium
- Detrusor smooth muscle cells
- Detrusor extracellular matrix
- Nerves 3
Diagnostic Tools
Several diagnostic tools can be used to measure bladder wall thickness and detect bladder damage, including:
- Ultrasound (US) parameters, such as bladder wall thickness (BWT) and detrusor wall thickness (DWT) 2
- Estimated Bladder Weight (EBW) 2
- Intravescical Prostate Protrusion (IPP) measurement 2 These tools can help identify bladder changes and suggest therapeutic choices to prevent further organ damage in the bladder wall 2