Ureteral injuries are most commonly iatrogenic in origin, typically during gynecological or urological surgeries . Usually the urine leakage is localized or only diffuses into the peritoneal cavity, and uretero-fallopian fistula is very rare. Few cases reported UFFs were caused by major surgery procedures like endometrioma removal, rectal cancer resection and open ureterolithotomy [2,3,4,5]. Interestingly, in this case, UFF was caused by an interventional procedure-fallopian tube embolization, and led to severe hydronephrosis and nephrectomy.
Fallopian tube embolization was firstly designed as a birth control method in 1970s to meet the one-child policy in China. Comparing with traditional bilateral ligation, it was minimally invasive, quicker and easier, and quickly became popular in China. In 2016, Chinese couples were allowed to have two children, and therefore the application of this birth control method was significantly reduced. To our knowledge, in English literature there is no report of fallopian tube embolization except for an animal study using rabbits in 2001 .
Fallopian tube embolization could be done under hysteroscopy or fluoroscopy, or without imaging guidance at all. Commonly used embolic agent was a mixture of phenol, atabrine and iodipamide. Phenol serves as an erosion agent, atabrine stimulates the growth of granulation tissue, iodipamide is a contrast media that helps localizing the embolization site, and also helps stimulating granulation tissue, which effectively blocks the fallopian tube .
Previous studies reported that the success rate of fallopian tube embolization varied between 88.7 and 94.8%. It had similar success rate with bilateral tubal ligation, and had no risk of incision infection. Acute pain and fever may occur after fallopian tube embolization, chronic pain, irregular menstruation, uterus perforation and ectopic pregnancy have been reported during long-term follow-ups . This method has one serious drawback: the standard dosage of embolic agent was never established, and it was possible for extra corrosive agents to perforate the fallopian tube. The extravasation of embolic agents might lead to adhesion between adjacent tissues and organs in pelvis. Laparoscopic examinations revealed that many patients had significant pelvic adhesion formation after fallopian tube embolization . In our case, it was most likely that the embolic agent used caused fallopian tube perforation, and the extravasation of embolic agent caused the erosion of ureter and the adhesion of adjacent tissue, resulting in ureter stricture, uretero-fallopian tube fistula and left hydronephrosis.
UFFs are very rare complications which usually happened after major surgery procedures. In this case however, the UFF was secondary to an interventional procedure-fallopian tube embolization, and eventually led to the removal of a kidney. This rare and unusual case warned us that interventional operation of fallopian tube could also lead to severe complications. Increased awareness of fallopian perforation secondary to embolization should prompt hysteroscopy or fluoroscopy guidance, and careful evaluation of embolic agent dosage.