Keywords:
Abdomen, Interventional non-vascular, Urinary Tract / Bladder, CT, Ablation procedures, Complications, Neoplasia
DOI:
10.26044/ranzcr2023/C-66
Conclusion
DISCUSSION
Chyluria is the presence of chyle within the urinary bladder due to an abnormal communication between the lymphatic system and the urinary tract. In tropical / sub-tropical continents such as Africa and Asia, chyluria is most commonly filariasis-related due to Wucheria bancrofti, followed by tuberculosis and pyuria3. In Western countries, chyluria is most commonly seen secondary to renal trauma, diabetes mellitus, neoplasia and congenital lymphatic malformations4. Chyluria is only a relatively recently recognised phenomenon following renal microwave ablation5, however it is becoming increasingly recognised as an uncommon and (thankfully) mostly asymptomatic, post-ablation outcome.
Renal microwave ablation is quickly establishing a leading position in the treatment of size-appropriate suspicious renal lesions and renal cell carcinoma, thanks to its minimally invasive approach for patients who may otherwise have been unable to undergo surgery2. If the lesion is geographically separate from adjacent structures, post-procedural complication rates are low. Major complications are rare but include thermal injury to bowel and ureter, or large volume haemorrhage, whilst minor complications tend to be more common and include pain, haematoma and haematuria2. The use of hydrodissection can further reduce the risk of damage to adjacent organs. It may interest some to consider tumour location and ablation energies as causes for certain post-procedural complications, however, it has been demonstrated previously that neither tumour location nor ablation defect size were accurate predictors of chyluria6.
All 3 patients included in this case series were asymptomatic with chyluria, which seemingly arose more than 12 months following their respective ablations. Symptoms related to chyluria are broad and non-specific, and can range from being completely asymptomatic, to minor symptoms including flank pain, haematuria and dysuria, to more important clinical symptoms such as hypoproteinaemia and malnutrition4.
It became evident during the data collection phase of the study that many reporting Radiologists either failed to mention urinary bladder fat-fluid level, or perhaps mistook the finding for intravesical gas secondary to instrumentation. Given the broad range of non-specific symptoms, it is important that clinicians be aware of chyluria as a post-procedural finding that is significant and worth mentioning following renal microwave ablation, so that any potential negative symptoms can be appropriately addressed.
While many patients do not present with symptoms and indeed remain asymptomatic despite persisting chyluria following renal microwave ablation, it is becoming a more common post-procedural finding in light of increasing volumes of microwave ablation being performed. Chyluria is important for the clinicians and Radiologist to be aware of given the potential for clinically relevant side effects.