Ureteric injury
Ureteric injury is a relatively uncommon, but severe event, which may result in serious complications as a diagnosis is often delayed.
Clinical presentation
Ureteric injuries unreliably demonstrate macro- or micro-scopic hematuria as it may be absent in up to 25% of patients . Classic clinical symptoms and signs may also be absent but patients may present with abdominal/flank pain, renal failure and/or urine leaking from the vagina .
The diagnosis is often based on a high index of clinical suspicion. The detection of ureteric injuries is delayed after days or weeks in approximately two-thirds of patients.
Pathology
There is a wide-range of injury:
- injury to the mucosa of the ureter post lithotripsy
- perforation and false passage
- partial or complete ureteric transection
- complete ureteric avulsion
- loss of ureteric segment
- ligation
- dissection
Etiology
- iatrogenic
- rate of injury is ~2% (range 0.5-3%) for laparoscopic procedures
- most commonly injured after gynecological procedures
- rate of injury is ~2% (range 0.5-3%) for laparoscopic procedures
- traumatic
- uncommon; represents <1% of all urological trauma
- direct trauma from penetrating injury is a more common cause than blunt injury
Classification
Ureteric injury can be classified into three types according to its site:
- upper-third
- upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma
- mid-third
- distal-third
- most common site
- often following iatrogenic injury
AAST trauma grading has not been verified as accurate on imaging studies .
Radiographic features
Fluoroscopy
Excretory intravenous urography if CT is not available: demonstrates contrast leakage and spillage outside the course of the urinary system.
Retrograde pyelography may be performed if both excretory intravenous urography and CT with intravenous contrast are inconclusive and there is still a high suspicion of injury .
CT
CT with intravenous contrast and delayed scan with full reformatted sagittal and coronal images and 3D reconstruction. The delayed scan should be performed between 5-8 minutes after IV contrast to ensure a CT-IVU (a.k.a. excretory phase) set of images is acquired.
Features include :
- intra-abdominal fluid collections without other cause shown
- contrast extravasation from renal hilum/PUJ (usually medially) without associated renal injury
Treatment and prognosis
Immediate diagnosis and appropriate corrective surgical procedure of the cause (e.g. removal of suture on tied ureter or reconstruction of induced ureteric strictures ) will result in a satisfactory outcome. Ureteric stents are often required, if there is an obstruction and surgical treatment is not sufficient, percutaneous nephrostomy may be indicated.
Complications
- hematoma
- abscess and intra-abdominal sepsis
- urinoma
- strictures and obstructive nephropathy/renal failure
- ureterovaginal fistula