An estimated 300,000 Americans have AVMs, of whom 12% (approximately 36,000) will exhibit symptoms of greatly varying severity. History
Luschka (1820–1875) and Virchow (1821–1902) first described arteriovenous malformations in the mid-1800s. Olivecrona (1891–1980) performed the first surgical excision of an intracranial AVM in 1932. Society and culture
Notable cases
Indonesian actress Egidia Savitri died from complications of AVM on November 29, 2013. Phoenix Suns point guard AJ Price nearly died from AVM in 2004 while a student at the University of Connecticut. On December 13, 2006, Senator Tim Johnson of South Dakota was diagnosed with AVM and treated at George Washington University Hospital. On August 3, 2011, Mike Patterson of the Philadelphia Eagles collapsed on the field and had a seizure during a practice, leading to him being diagnosed with AVM. Actor Ricardo Montalbán was born with spinal AVM. During the filming of the 1951 film Across the Wide Missouri, Montalbán was thrown from his horse, knocked unconscious, and trampled by another horse which aggravated his AVM and resulted in a painful back injury that never healed. The pain increased as he aged, and in 1993, Montalbán underwent 9+1⁄2 hours of spinal surgery which left him paralyzed below the waist and using a wheelchair.
However, if no underlying cause is discovered, the hematuria should be re-evaluated with urinalysis and urine microscopy within 12 months. Additionally, for all risk categories, if a nephrologic origin is suspected, consultation of a nephrologist should be made. Pathophysiology
The pathophysiology of hematuria can often be explained by damage to the structures of the urinary system, including the kidney, ureter, urinary bladder, and urethra, and in men, the prostate. Common mechanisms include structural disruption to the glomerular basement membrane and mechanical or chemical erosion of the mucosal surfaces of the genitourinary tract. Management
Medical Emergency: Acute clot retention
Acute clot retention is one of three emergencies that can occur with hematuria. The other two are anemia and shock. Blood clots can prevent urine outflow through either ureter or the bladder. This is known as acute urinary retention. Blood clots that remain in the bladder are digested by urinary urokinase producing fibrin fragments. These fibrin fragments are natural anticoagulants and promote ongoing bleeding from the urinary tract. Removing all blood clots prevents the formation of this natural anticoagulant. This in turns facilitates the cessation of bleeding from the urinary tract.The acute management of obstructing clots is the placement of a large (22-24 French) urethral Foley catheter. Clots are evacuated with a Toomey syringe and saline irrigation. If this does not control the bleeding, management should escalate to continuous bladder irrigation (CBI) via a three-port urethral catheter. If both a large urethral Foley catheter and CBI fail, an urgent cystoscopy in the operating room will be necessary.