Prolene is thy culprit; boycott him – post renal transplant lower ureteric calculus with prolene acting as a nidus – a rare case report

Background: We present a rare case report of ureteric calculi over a prolene suture used for ureteroneocystostomy after a renal transplant done elsewhere; to bring to light the ill practice of using prolene still being followed; with an aim to spread awareness and curb this practice once and for all.
Case Presentation: A 35yr old male presented with painless gross haematuria after 3 years of live-related renal-transplantation done elsewhere. CT-Intravenous-urography revealed 5mm calculus at the vesicoureteric-junction (VUJ). Sr. creatinine was not raised.
Hence, Medical-expulsive-therapy (MET) was given for 6 weeks in the COVID era. As calculus persisted, he was taken for ureterorenoscopy that revealed 8mm calculus embedded on the prolene suture at ureteric orifice. The stone was fragmented, removed and the suture was cut using an endoscissor.
Conclusion: Though MET would be the right management for a calculus of 5mm size; in this patient, the stone was not passed per urethrally as it was formed over a prolene nidus. This fact was ascertained only after ureterorenoscopy.
Though, similar cases of vesical calculi have been reported in the past, this is the only case reported of a ureteric calculus formed over prolene suture in the early post-transplant period.
In our centre, we use polyglactin suture and have not noticed a single post-renal-transplant calculus case with suture acting as a nidus even on long-term follow-up. Ideal suture material would be polydioxanone (PDS) or polyglactin (vicryl). Prolene would be a very inappropriate suture material leading to calculi formation, should be avoided in favour of PDS/vicryl.