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FIGURE 5.4. a: Renal arteriography after percutaneous nephrolithotomy (PCNL) where severe bleeding was encountered. An arteriovenous (AV) fistula was found. Note the 'blush' of contrast in the lower pole which represents the AV fistula. b: The AV fistula has been embolised. Note the metal embolisation coils.
technique is an indication for renal exploration and control of the bleeding by the techniques described above for penetrating renal injuries.
Arteriovenous fistulae can sometimes occur following open renal surgery for stones or tumours, and arteriography with embolisation again can be used to stop the bleeding in these cases. The bleeding in such cases usually occurs over a longer time course (days or even weeks), rather than as acute haemorrhage causing shock.
5. TRAUMATIC UROLOGICAL EMERGENCIES 63
FIGURE 5.4. Continued
Causes and Mechanisms of Ureteric Injury
The ureters are retroperitoneal in location, and as such are protected from external trauma by surrounding bony structures, muscles and other organs (Elliott and McAninch 2003). For external trauma to injure the ureters, severe force is required. External trauma to the ureter is rare, and may be blunt or penetrating. Blunt external trauma severe enough to injure the ureters will usually be associated with multiple other injuries (for the ureter to be the only organ injured in a high-velocity motor vehicle accident is very rare). Clearly, a knife or bullet wound to the abdomen or chest may damage the ureter, as well as other organs.
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Very occasionally the ureter is the only organ that is injured following blunt external or penetrating trauma. For example, a fall from a height in a patient with a pre-existing PUJ obstruction can result in the hydronephrotic kidney being avulsed from the ureter. Blood may well be absent from the urine in these rare cases, and the diagnosis is made only by having a high index of suspicion and by carrying out renal imaging (CT or IVU) in all cases where there has been a rapid acceleration-deceleration injury. These injuries are said to be more frequent in children (though they are still rare), where the kidneys are more mobile because of a less well developed surrounding cushion of perinephric fat. This allows the kidneys to move more freely relative to the less mobile ureter.