A Rare Case of Laparoscopic Removal of a Giant Renal Pelvic Pus Clot Caused by Citrobacter Freundii Infection.

It is extremely rare for renal pelvic pus clot with a diameter of 3 cm that formed by purulent secretions due to bacterial infection. A 37-year-old female patient developed a giant renal pelvic pus clot with a diameter of 3 cm 5 months after percutaneous nephrolithotomy, caused by Citrobacter freundii infection, resulting in lower back pain and fever. Due to the lack of specialized tissue pulverizers for percutaneous nephrolithotomy, laparoscopic pyelotomy via intraperitoneal approach removed the giant renal pelvis pus clot. However, it was found that some small pus clots had formed around the ureteral stent in the third month after surgery. A second surgery was performed using ureteroscopy to remove these small pus clots, and the ureteral stent was only placed for 3 days. Although there was no recurrence of renal pelvic pus clot during follow-up, multiple positive urine cultures suggest that bacteria may have colonized the renal pelvis. After taking oral antibiotics for a month, this complex urinary tract infection was finally cured. When conventional urological endoscopic techniques are not as effective or when critical equipment is lacking, laparoscopic surgery remains a good alternative option. Setting the upper limit of laparoscopic pneumoperitoneum pressure to 11 mm Hg can prevent the spread of infection. This case emphasizes that in the absence of specialized tissue pulverizer for percutaneous nephrolithotomy, transperitoneal laparoscopy to incise the renal pelvis to remove a giant renal pelvic pus clot is safe and will not cause intra-abdominal infection. This case also suggests that ureteral stents should not be left in place for an extended period to prevent the pus clot recurrence, especially in cases where urine culture results are positive. We recommend keeping the ureteral stent for less than 2 weeks. In addition, longer-term anti-infective treatment is required until the urine culture turns negative.