Migration of PTFE paste particles to the kidney after treatment for vesico‐ureteric reflux

Abstract

An 18-month-old girl was admitted for left pyelonephritis; voiding cysto-urethrography (VCUG) showed left stage III re¯ux and IVU showed symmetrical excretion with a size asymmetry (right 8.2 cm, left 6.3 cm). Follow-up under prophylactic antibiotics was started, with no recurrent UTIs documented. A VCUG assessment one year later showed persistent stage III re¯ux. She was treated using submucosal injections of PTFE paste (0.5 mL PTFE). The postoperative course was unremarkable. A VCUG 6 months later showed that the re¯ux had resolved. The child, regularly followed for asthma, had no further UTIs. When aged 9 years, she presented with chronic left¯ank pain. Ultrasonography showed a very small left kidney and the intravesical PTFE was no longer identi®able. VCUG again con®rmed the good long-term result of the cure of re¯ux, but MAG-3 scintigraphy showed reduced left renal function (<10%). An endoscopic left-sided nephroureterectomy was performed and the postoperative course was uneventful, with complete pain relief. Macroscopic examination of the kidney (6r3r2 cm, with a 7.5 cm ureter) revealed upper cortical cicatricial depressions and total cortical atrophy of the inferior pole. Microscopically, the cortical atrophy was caused by chronic pyelonephritis and, in the inferior pole, an evolutive gigantocellular resorption process (granulomatous) developed through contact with exogenous round particles (5±100 mm) with ®nely crenellated borders, slightly birefringent in polarized light (Fig. 1a,b). Spectrometric analysis con®rmed that these particles were PTFE. CommentThe endoscopic treatment of re¯ux by injection with submucosal PTFE paste was introduced by Matouschek in 1981 [1]. A problem with this technique is that it introduces foreign bodies, and thus raises questions of local and general tolerance [2]. The migration of the PTFE particles to the lungs and brain has been con®rmed experimentally [3]. Cases of acute pneumopathy, with PTFE in lung biopsies, have been described in adults [4]. In children, migration to the terminal ureter and the perivesical lymphatic vessels, with no clinical consequences, has been reported; we have encountered three such cases. The clinical consequences of particle migration are unknown; long-term follow-up studies are rare [5]. Thus the present case represents the ®rst of clinical symptomatology and destruction of the kidney associated with presence of PTFE in the renal parenchyma. The relationship among these three elements remains to be con®rmed and there are several questions.There are several possible routes by which the particles could migrate. The ®rst is through the injection track, with secondary intraparenchymal in®ltration by the PTFE particles. There was a pelvic and peritubular distribution of the particles but this proposal supposes that the urothelium is breached, so that the PTFE becomes incorporated into the tissues. Furthermore, the delay between injection and symptoms (7 years) seems too long for this route. The second route is vascular, probably not lymphatic but...

Biocompatibility of Injectable Microspheres

“…At necropsy many occluded periurethral veins were found [87]. Steyaert [88] described the case of a nine year-old girl whose left kidney had to be removed. At the age of 18 month, a left stage III ureteral reflux had been treated with 0.5g of Polytef®.…”

Endoscopic treatment of reflux: management pros and cons

“…As we review this issue, it is hard to forget the experience with polytetrafluoroethylene paste. Despite impressive correction rates in European series that included hundreds of patients [57][58][59][60][61], the risk of particle migration [62][63][64][65][66][67] kept this option of endoscopic injection from approval in many countries and stunted its acceptance for many years, until the development of presumably safer injectables. The lessons learned from this, as well as recent postmarketing pharmacologic misadventures [68][69][70], should serve us as a reminder of the importance of closely monitoring patients, being vigilant about unexpected adverse effects to new products assumed to have a favorable long-term safety profile.…”

Role of periureteral injections in children with vesicoureteral reflux

“…On account of their small size (4-100 mm), polytef particles were shown to migrate to other organs in animal models and in humans, which include pelvic lymph nodes, kidneys, lungs, and brain [9,10]. Local and distant giant cell reaction and granuloma formation have also been reported.…”