The endoscopic management of VUR is now widely practised by pediatric urologists.
Various agents like Teflon paste (Mentor, Santa Barbara, California), Macroplastique (Uroplasty Inc., Minneapolis, Minnesota), and cross-linked bovine collagen have been used earlier. Subsequently, Deflux® (Q Med, Uppsala, Sweden) was approved by the United States Food and Drug Administration in 2001 [2]. There has been a steady increase in the usage of Deflux® since then, not only in VUR but a trend towards the use of Deflux ® for other urological conditions have also emerged in the medical literature.
A foreign body type of local reaction is expected around any implant. This is also true for Deflux®, and studies have shown that though there ensues a granulomatous response around the lower ureter, but it is not so intense that it precludes subsequent ureteric reimplantation [3]. All these properties have made Deflux® an ideal option in the armamentarium of the pediatric urologist as a bulking agent for treating VUR.
With this background information, a literature search showed that Życzkowski et al. in 2012 reported two cases very similar to the case being reported. In both the cases, a hard lumpy granuloma was seen at the site of previous Deflux® injection. The excised material sent for histopathological examination revealed chronic inflammatory lymphocytic infiltrate with a cluster of a foreign body surrounded by polynucleic histiocytes as was also found in our case. In one of the two patients, the granuloma was so infiltrative that it required excision of the terminal ureter as it was found unsuitable for reimplantation. This was unlike our case, where a plane of dissection was available, and the “Defluxoma” could be enucleated, albeit requiring a more elaborate incision above the ureteric ostia. The phenomena of granuloma formation is distinct from calcification of the Deflux ® implant which is relatively common. The calcific implant often mimic distal ureteric calculi radiologically but usually are of no clinical consequence unlike granulomas which can take giant dimensions [4, 5].
Granulomas at the site of injection of bulking agent was first described in 1991 by Bonnet et al. in cases where Teflon was used and subsequently other workers also reported similar findings with Teflon [6]. Deflux®, on the other hand, has been quite safe, and no such adverse effects have been reported in the literature, except the two cases described above [1]. This along with our experience of this index case leads us to believe that despite being a synthetic bulking agent with an acceptable safety profile, the formation of giant granulomas (Defluxoma) is still possible, although rarely. The cause of the granuloma formation in the index case still eludes us, although it may be speculated that the patient’s inappropriate immune response, the technique of injection, and the sterility of the implant may have a role. The last two factors are modifiable but cannot be firmly attributed to since we lack any evidence against them. In an ideal situation, the granuloma should have been picked up in the preoperative radiological work-up (USG and MCUG) before the reimplantation surgery; however, in the index case, probably it was missed. A focussed examination by an experienced radiologist may probably would have given us same additional information. If detected in preoperative workup, they can point the surgeon to anticipate difficult planes of dissection, and this may even dictate the choice of access (open versus minimally invasive) and the actual technique of ureteric reimplantation, depending on tissue characteristics remaining after excising the granuloma. Loss of the length of ureter may also occur, and this may further test the preparedness of the surgeon. Our case required an extensive incision around the ureteric ostia to enable us to dissect and free the terminal ureter for subsequent reimplantation. Our case highlights that whenever endoscopic injection therapy is embarked upon a radiological screening for such patients must be performed in the follow-up. By screening, these rare complications may be picked up more readily than in the current scenario.