From the Guidelines
For suspected pyelectasis indicated by a severe ultrasound, a contrast-enhanced CT scan with delayed urographic phase is recommended as the diagnostic tool of choice, rather than relying solely on ultrasound findings. This approach is based on the highest quality and most recent evidence, which suggests that ultrasound may underestimate injuries, with a sensitivity and specificity of 22–67% and 96–100%, respectively 1.
Diagnostic Approach
The use of contrast-enhanced CT scan allows for the identification of almost all injuries and the addition of a delayed phase permits the identification of urinary extravasation 1. This is particularly important in cases of suspected urogenital injuries, where CT scanning should always be considered, especially in patients with associated severe brain injury or major injuries for the high probability of occurrence of associated injuries 1.
Management Considerations
While the provided evidence primarily focuses on diagnostic approaches for trauma-related injuries, the management of pyelectasis, particularly when indicated by severe ultrasound findings, would typically involve addressing the underlying cause of the condition, such as obstruction due to stones, strictures, or tumors. Empiric antibiotic therapy may be initiated if there's suspicion of infection, with adjustments based on culture results, and drainage procedures like percutaneous nephrostomy tube placement may be necessary for infected collecting systems. However, these management strategies are not directly addressed in the provided evidence but are based on general medical knowledge of treating conditions related to pyelectasis.
Importance of Accurate Diagnosis
Accurate diagnosis is crucial because pyelectasis with infection can rapidly progress to sepsis and permanent renal damage if not treated promptly and effectively. Follow-up imaging is essential to ensure resolution of the condition and to guide decisions about removing drainage tubes or adjusting treatment plans. The choice of diagnostic tool and management approach should prioritize minimizing morbidity, mortality, and improving quality of life, which in this context, supports the use of contrast-enhanced CT scans over ultrasound for suspected pyelectasis indicated by severe ultrasound findings.
From the Research
Definition of Pyelectasis
Pyelectasis refers to the dilatation of the renal pelvis and calyces, which can be detected by ultrasound [(2,3,4,5)]. This condition is often diagnosed prenatally or postnatally, and its severity can vary.
Ultrasound Diagnosis
The ultrasound diagnostic criteria for pyelectasis are well established and include the nature of dilated structures, degree of dilatation, ultrasound appearance of the kidneys, and volume of amniotic fluid 2. Ultrasound can also determine if the anomaly is isolated or not, which is important for the management and prognosis of the pregnancy.
Management of Suspected Pyelectasis
The management of suspected pyelectasis indicated by a severe ultrasound involves:
- Initial postnatal study to evaluate the urinary tract using ultrasound 2
- Further management based on suspected diagnosis, such as:
- VCUG (voiding cystourethrogram) in cases of suspected vesico-ureteral reflux [(2,4)]
- MRI (magnetic resonance imaging) at 6 months of age to further define the anatomy of the urinary tract in cases of obstructive uropathy or complex malformation 2
- Radionuclide renogram to evaluate split renal function [(2,4)]
- Follow-up ultrasound to monitor renal development, urinary tract dilatation, and appearance of the renal parenchyma 2
- Functional follow-up using radionuclide renography 2
Clinical Significance of Pyelectasis
Pyelectasis can be associated with an increased risk of asymptomatic bacteriuria, which can lead to symptomatic urinary tract infections, pyelonephritis, and acute kidney failure 5. Additionally, pyelectasis has been linked to an increased risk of aneuploidy, particularly trisomy 21 6. Therefore, ultrasound screening for pyelectasis during pregnancy can have clinical implications, such as identifying cases with an increased risk of asymptomatic bacteriuria and aneuploidy.