Subureteral Injection Research Articles

Endoscopic correction of vesicoureteral reflux.

Endoscopic subureteral injection of tissue-augmenting substances--a 15-minute outpatient procedure--has become an established alternative to long-term antibiotic prophylaxis and surgical intervention in the treatment of vesicoureteral reflux in children. This report reviews the results of endoscopic treatment of reflux using various tissue-augmenting substances presently available. In terms of effectiveness and long term successful results, PTFE is the most reliable injectable product for the endoscopic treatment of all grades of VUR.

Cost-analysis of management strategies for children with vesico-ureteric reflux.

This study is an economic evaluation of three treatment strategies for vesico-ureteric reflux in children: neo-implantation; subureteric injection; and antibacterial prophylaxis. Cost-analysis was used to compare the strategies, implying that the differences in benefits between them were not measured. Direct and indirect costs are included, taking the analytical viewpoint of the community. For the surgical strategies, data from four different hospitals in Sweden were used, and for the prophylactic strategy, data was gathered through a survey of 31 hospitals. The treatment strategies were ranked in the following order (bilateral reflux in parentheses): (i) subureteric injection SEK 25,000-28,000 (26,000-36,000); (ii) antibacterial prophylaxis SEK 16,000-36,000; and (iii) neo-implantation SEK 65,000-90,000 (72,000-95,000).

Endoscopic treatment of children with vesico-ureteric reflux.

Endoscopic subureteric injection of tissue-augmenting substances has become an alternative to long-term antibiotic prophylaxis and open surgery in the treatment of children with vesico-ureteric reflux. Successful elimination of reflux in about 80% of patients after a single injection (and in 90% after a repeat) has been achieved using the foreign-body non-degradable substances Teflon and silicone. Few patients have required open surgery and recurrence of reflux after initial successful treatment has occurred in only 5-10%. Concern has arisen, however, about possible distant migration and granuloma formation after injection of particulate plastic materials. Cross-linked bovine collagen is a biodegradable alternative substance, but with a lower response rate of 60% after the first treatment and a recurrence rate of 10-20%. Dextranomer in sodium hyaluronan is a new biological substance with microparticles with a response rate of 69% after the first injection. Biological substances have caused few complications. Present literature on injection treatment unfortunately focuses on elimination of reflux, with little attention to subsequent frequency of pyelonephritis or to the long-term development of the kidneys. Furthermore, there are no controlled, randomized studies with subureteric injection as one of the treatment alternatives. Thus, although having the advantage of being a minimally invasive procedure that can be performed on an outpatient basis, this technique needs to be tested in a large prospective study with the long-term renal outcome as the main end-point.

Hyperammonaemic encephalopathy after a subureteric injection for vesicoureteric reflux

A 6 year old boy developed hyperammonaemic encephalopathy following a subureteric injection for treatment of vesicoureteric reflux. The hyperammonaemia may be explained by a postoperative urinary tract infection with a...

MULTICENTER SURVEY OF ENDOSCOPIC TREATMENT OF VESICOURETERAL REFLUX USING POLYTETRAFLUOROETHYLENE

Purpose Endoscopic subureteral polytetrafluoroethylene (Teflon) injection has been used successfully to treat primary and secondary vesicoureteral reflux in children. We review the results of subureteral polytetrafluoroethylene injection in terms of its effectiveness, long-term followup and morbidity. Materials and Methods A total of 53 pediatric urologists and/or pediatric surgeons at 41 centers worldwide answered an inquiry regarding experience with subureteral polytetrafluoroethylene injection in vesicoureteral reflux. Data were collected from a completed standard questionnaire. From 1984 to 1996, 1,921 boys and 6,411 girls with a mean age of 4.5 years (12,251 refluxing ureters) were treated endoscopically with subureteral polytetrafluoroethylene injection. Reflux was grades I to V in 407 (3.3%), 3,832 (31.2%), 5,213 (42.5%), 2,218 (18.1%) and 581 (4.7%) ureters, respectively. In the majority of patients subureteral polytetrafluoroethylene injection was performed on an outpatient basis. Most urologists monitored patients with voiding cystourethrography and renal ultrasound at 3 months, 1 year and 3 years. All patients were followed 1 to 13 years. Results Reflux resolved in 9,226 ureters (75.3%) after 1 polytetrafluoroethylene injection, in 1,478 (12%) after 2 and in 250 (2%) after 3 or 4. Vesicoureteral reflux improved to grade I after 1 or 2 injections in 743 (6%) ureters, which needed no further treatment. Subureteral injection failed to correct reflux in 554 ureters (4.5%), which were then treated with ureteral reimplantation. Vesicoureteral junction obstruction requiring ureteral reimplantation developed in 41 ureters (0.33%). More than 90% of patients have been followed for more than 2 years. At followup reflux recurred in 326 (2.8%) endoscopically corrected refluxing ureters. No clinically untoward effects were reported in any patient due to the use of polytetrafluoroethylene as an injectable material. Conclusions The results of this multicenter survey confirm that endoscopic subureteral polytetrafluoroethylene injection is a simple, safe and effective outpatient procedure for treating all grades of vesicoureteral reflux.

Multicenter survey of endoscopic treatment of vesicoureteral reflux using polytetrafluoroethylene.

Endoscopic subureteral polytetrafluoroethylene (Teflon) injection has been used successfully to treat primary and secondary vesicoureteral reflux in children. We review the results of subureteral polytetrafluoroethylene injection in terms of its effectiveness, long-term followup and morbidity. A total of 53 pediatric urologists and/or pediatric surgeons at 41 centers worldwide answered an inquiry regarding experience with subureteral polytetrafluoroethylene injection in vesicoureteral reflux. Data were collected from a completed standard questionnaire. From 1984 to 1996, 1,921 boys and 6,411 girls with a mean age of 4.5 years (12,251 refluxing ureters) were treated endoscopically with subureteral polytetrafluoroethylene injection. Reflux was grades I to V in 407 (3.3%), 3,832 (31.2%), 5,213 (42.5%), 2,218 (18.1%) and 581 (4.7%) ureters, respectively. In the majority of patients subureteral polytetrafluoroethylene injection was performed on an outpatient basis. Most urologists monitored patients with voiding cystourethrography and renal ultrasound at 3 months, 1 year and 3 years. All patients were followed 1 to 13 years. Reflux resolved in 9,226 ureters (75.3%) after 1 polytetrafluoroethylene injection, in 1,478 (12%) after 2 and in 250 (2%) after 3 or 4. Vesicoureteral reflux improved to grade I after 1 or 2 injections in 743 (6%) ureters, which needed no further treatment. Subureteral injection failed to correct reflux in 554 ureters (4.5%), which were then treated with ureteral reimplantation. Vesicoureteral junction obstruction requiring ureteral reimplantation developed in 41 ureters (0.33%). More than 90% of patients have been followed for more than 2 years. At followup reflux recurred in 326 (2.8%) endoscopically corrected refluxing ureters. No clinically untoward effects were reported in any patient due to the use of polytetrafluoroethylene as an injectable material. The results of this multicenter survey confirm that endoscopic subureteral polytetrafluoroethylene injection is a simple, safe and effective outpatient procedure for treating all grades of vesicoureteral reflux.

Treatment of vesicoureteric reflux in a sheep model using subureteric injection of cultured fetal-bladder tissue: Y.Y. Zhang and R.R. Dailey. Pediatr Surg Int 13:32–36, (January), 1988

Treatment of vesicoureteric reflux in a sheep model using subureteric injection of cultured fetal-bladder tissue: Y.Y. Zhang and R.R. Dailey. Pediatr Surg Int 13:32–36, (January), 1988

Vezikoüretral Reflü Tedavisi: Üreteroneosistostomi İle Endoskopik Subüreteral İnjeksiyon Sonuçlarının Karşılaştırılması

Management of Vesicoureteral Reflux: The Comparison of the Outcomes of Ureteroneocystostomy and Endoscopic Subureteral Injections Endoscopic subureteral injection has become an established alternative to ureteroneocystostomy in the treatment of vesicoureteral reflux. The outcomes of 61 patients with VUR whom treated with either ureteroneocystostomy or endoscopic procedures were compared. Ureteroneocystostomy was perfomed in 44 refluxing ureters of 31 children, subureteral Teflon injection in 34 refluxing ureters of 20, and Silicone injection in 17 refluxing ureters of 10 children. The ages, clinical, radiological, and endoscopic findings, operation time, hospital stay of the patients and outcomes of the treatments were compared. Ages of patients ranged between 1.5 and 17 (mean 6.7) years. There were grade II reflux in 23.5%, grade III reflux in 35.3% and grade IV reflux in 41.2% of the ureters of subureteral teflon injected patients. In subureteral Silicone injected patients these rates were 17.6%, 35.3% and 47.1%, respectively. Grade III, IV and V reflux also were found in 15.9%, 45.4%, 38.7% of the ureters of ureteroneocystostomized patients, respectively. In 70.5% and 88.2% of the ureters reflux was cured after the first and second Teflon injections. These rates were found as 53% and 76.4% after the first and the second Silicone injections, respectively. The reflux was cured completely in 95.45% of the ureters of the ureteroneocystostomized patients. Mean follow-up was 18.7 (ranged 5.5 to 41) months. Mean hospital stay was found as 1 and 12 days after the injections and ureteroneocystostomy, respectively. In conclusion, although ureteroneocystostomy is the gold standard treatment for high grade refluxes, endoscopic subureteral injections may be the first choice for the treatment of moderate grade refluxes because of its non-invasiveness. Vezikoureteral reflunun (VUR) tedavisinde endoskopik subureteral injeksiyonlar ureteroneosistostomilere alternatif olmaktadir. Bu calismada ureteroneosistostomi veya subureteral injeksiyon ile tedavi edilen primer VUR'lu 61 olgunun sonuclan karsilas tini di. Ureteroneosistostomi 31 olgunun 44, endoskopik subureteral Teflon injeksiyonu 20 olgunun 34 ve Silikon injeksiyonu 10 olgunun 17 ureter birimine uygulandi. Olgularin yas dagilimi, klinik, radyolojik ve endoskopik bulgulan, anestezi ve hastanede kalis sureleri ile tedavi sonuclan karsilastinldi. Olgularin yas dagilimi 1,5 ile 17 (ortalama 6.7) yil arasinda degismekteydi. Teflon injeksiyonu yapilan olgularin sirasiyla %23.5, %35.3 ve %41.2 sinde II, III ve IV. derece reflu saptanirken, Silikon injeksiyonu yapilan olgularda bu oranlar sirasiyla %17.6, %35.3 ve %47.1 idi. Ureteroneosistostomi yapilan olgularin ise sirasiyla %15.9, %45.4 ve %38.7'sinde III, IV ve V. derece reflu vardi. Birinci Teflon ve Silikon injeksiyonlarindan sonra ureterlerin %70.5 ve %53 unde reflu onlenirken, ikinci injeksiyonlardan sonra bu oranlar sirasiyla %88.2 ve %76.4 bulundu. Buna karsin ureteroneosistostomi yapilan ureterlerin %95.45 inde reflu tamamen onlendi. Izleme sureleri 5.5 ile 41 (ortalama 18.7) ay arasinda degisen olgularin ortalama hastanede kalis sureleri ureteroneosistostomilerde 12, injeksiyonlarda 1 gun bulundu. Sonuc olarak, yuksek derece VUR nun altin standart tedavisi ureteroneosistostomidir. Endoskopik subureteral injeksiyon, non-invazif olmasi nedeniyle orta derece reflulerin tedavisinde ilk secenek olabilir.

Treatment of vesicoureteric reflux in a sheep model using subureteric injection of cultured fetal-bladder tissue.

To investigate the role of injecting cultured fetal-bladder tissue into the region of the vesicoureteric orifice (VUO) to correct surgically produced vesicoureteric reflux (VUR), 12 Coopworth ewe lambs were studied. Four weeks after incising the intravesical segment of ureter, VUR was demonstrated by micturating cystourethrography. Bladder tissue was obtained from a fetal Coopworth lamb at 10 weeks' gestation, cultured in RPMI 1640, and injected into the region of the VUO of 1 ureter of each lamb using an open surgical approach. The lambs were killed between 1 and 6 months after the injection. Smooth-muscle cells from the cultured fetal bladder tissue were identified by the monoclonal antibodies HHF-35 for muscle alpha-actin and D33 for muscle desmin, and by electron microscopy. One lamb died of a gastrointestinal infection at 8 weeks of age. Of the remaining 11 animals, the injection of fetal-bladder tissue corrected the reflux in 7, while it was reduced in degree in 3 and persisted unchanged in 1. The reflux on the contralateral control side was also corrected in 6 ureters and improved in 2. Using histochemical techniques, grafted fetal-bladder tissue could not be differentiated from host tissue in the region of the VUO. Histopathological studies failed to show any injected tissue in distant organs. This study has shown that surgically-induced VUR in lambs was corrected or improved by the injection of cultured fetal-bladder tissue into the submucosa adjacent to the VUO.

Urodynamic Changes after Endoscopic Correction of Vesicoureteral Reflux

Massive bilateral vesicoureteral reflux (VUR) in a 7-year-old girl with spinal scoliosis was successfully treated by endoscopic correction. She was admitted due to a febrile urinary tract infection and urinary incontinence. A cystometrogram demonstrated normal detrusor function during storage. The endoscopic subureteric injection of polytetrafluoroethylene (Teflon) was performed, resulting in the disappearance of the VUR. A postoperative cystometrogram demonstrated overactive detrusor function during storage, necessitating anticholinergic medication. She has been free of febrile urinary tract infections and incontinence for 2 years postoperatively, although self-catheterization is necessary. In a case of neurogenic vesical dysfunction with massive reflux, endoscopic subureteric injection is not only a therapeutic tool, but also a useful diagnostic option for detecting occult detrusor overactivity during storage prior to open surgery.

Gax 65: A New Injectable Cross-Linked Collagen for the Endoscopic Treatment of Vesicoureteral Reflux-A Double-Blind Study Evaluating Its Efficiency in Children

Purpose In the experimental model glutaraldehyde cross-linked collagen GAX 65 * with a collagen concentration of 65 mg./ml. has proved to have more persistent implant volume and, therefore, a better antireflux effect than GAX 35, * which is injected more commonly. The aim of this study was to evaluate the potential clinical application of GAX 65. Materials and Methods Ten boys and 8 girls an average of 4.6 years old presented with unilateral or bilateral primary reflux and were randomly divided into 2 groups. All refluxing ureters received 1 endoscopic subureteral injection of an average of approximately 2.9 ml. collagen. In group 1, 16 refluxing ureters were treated with GAX 65 and in group 2, 12 were treated with GAX 35. In all patients voiding cystourethrography was performed immediately after injection and 3 months postoperatively, and ultrasound was done on day 1, and at 1 and 3 months. Implant volume was calculated at the day of injection and at 3 months. The distribution of reflux grades was comparable in the 2 groups. Results Both materials had excellent injection properties. Immediately after injection all ureters were reflux-free. Of the 16 ureters treated with GAX 65 14 (87.5%) were reflux-free at the 3-month followup. Three months postoperatively ultrasound revealed an average implant volume increase of one-third. However, of the 12 ureters treated with GAX 35 reflux had resolved in 59.3% and the average implant volume had decreased by half 3 months after injection. Conclusions Three months after endoscopic subureteral injection of GAX 65 vesicoureteral reflux was absent in 87.5% of patients. Therefore, GAX 65 has greater potential for treating reflux in the short term than GAX 35. To define the final efficacy of GAX 65 for treating vesicoureteral reflux, long-term evaluation of this series is necessary. In addition, further studies are mandatory to prove the long-term advantage of this new injectable substance.

Color Doppler ultrasound for evaluation of collagen implants after endoscopic injection treatment of refluxing ureters in children.

To determine whether color Doppler ultrasonography (CDUS) would add to the understanding of the bladder wall after endoscopic subureteral collagen injection (SCIN), 25 patients were studied with CDUS. The kidney length and echogenicity, the volume of the collagen, the mean length of the urinary jet, the longitudinal and transverse angles, and the distance between the origin of the jet and the midline of the bladder were measured 1 day, 1 month, and 3 months after SCIN and compared to the results of micturating cystourethrograms (MCUs) performed 3 months after SCIN. The collagen was hyperechogenic compared to the bladder wall at the time of injection, and was isoechogenic 1 and 3 months after SCIN. CDUS showed the relationship between the injected collagen and the position of the ureteral orifice. The measurements of jet length, angle, and distance of the ureteral orifice from the midline did not correlate with vesicoureteral reflux assessed by MCU. Although CDUS may demonstrate the location, the size of the injected collagen implant, and its relationship to the ureteral orifice, it is as yet unable to predict vesicoureteral reflux after SCIN.

Management considerations for treating vesicoureteral reflux in children with solitary kidneys

Objectives. To evaluate the management approach for vesicoureteral reflux (reflux) into a solitary kidney. Methods. Outcomes of all children with solitary kidneys and reflux managed between 1981 and 1996 were reviewed. Solitary kidneys were documented by nuclear renography and ultrasonography; reflux was graded after cystography. Management consisted of observation and antimicrobial prophylaxis or surgery by ureteroneocystostomy or subureteric injection of polytetrafluoroethylene (STING). Follow-up ranged from 3 months to 14 years and included serial cystography, sonography, and serum creatinine measurement. Results. Twenty-one patients with a median follow-up of 26 months were identified. Etiologies included contralateral renal agenesis (14 children), multicystic dysplastic kidney (5 children), or nonfunctioning ureteropelvic junction obstruction (2 children). Low-grade (I to II) reflux was identified in 6 children, and high grade (III to V) was identified in 15. Reflux resolved in 20 patients. Five children with low-grade reflux were managed without surgery and demonstrated reflux resolution after a mean of 20.5 months. Renal function deteriorated in only 1 child. Ureteroneocystostomy was performed in 13 children with grades III to V reflux, and STING was performed in 1 child with grade II reflux. Every surgical patient maintained stable renal function and was infection-free during a mean follow-up of 56 months. Management by observation in 2 children with grades IV to V reflux resulted in spontaneous resolution in one and stable grade IV in the other. Conclusions. Reflux into the solitary functioning kidney may be managed by the same strategies used to manage unilateral reflux in children with two normally functioning kidneys: low-grade reflux by observation/chemoprophylaxis until spontaneous resolution occurs, and higher grades by surgery to protect renal function; however, chemoprophylaxis and serial imaging may be used until well-defined indications for surgery are satisfied. Renal function should be monitored diligently.

Endoscopic Subureteral Collagen Injection for the Treatment of Vesicoureteral Reflux in Infants and Children

Between June 1988 and September 1994, 100 girls and 32 boys 2 months to 15.5 years old (average 4.9 years) with 204 refluxing ureteral units were treated by endoscopic subureteral collagen injection. The collagen injected was of bovine origin and cross-linked with glutaraldehyde (Zyplast * * Collagen Corp., Palo Alto, CA. ). Followup ranged from 3 to 75 months (mean 33). Reflux was absent in 62.7 percent of cases 3 months after 1 endoscopic subureteral injection. Improvement to reflux grades I and II, generally not requiring further treatment, occurred in a further 15.2 percent of cases. A total of 66 ureters was injected twice. The overall cure rate after 1 or 2 injections was 79.4 percent 3 months after injection. There was no correlation between the risk of recurrent reflux and initial degree of reflux. Late recurrence of reflux following a reflux-free period occurred in 11.3 percent of the 204 units during the observation period, which varied from 3 months to 6 1/4 years. Reflux was absent after 1 or 2 injections, including late recurrence, in 70.6 percent of cases and in an additional 13.2 percent recurrent reflux was grade I or II, not necessitating any further treatment. Considering these results, subureteral collagen injection remains an adequate method of treatment for vesicoureteral reflux in children.

Correction of primary and secondary vesicoureteral reflux by subureteric Teflon injection.

Polytetrafluoroethylene (Teflon) has been used for various purposes since 1963 and in urologic practice for the treatment of vesicoureteral reflux (VUR) since the 1980s. In this study we report on our experience with Teflon injection for the treatment of 28 children with primary or secondary reflux. An overall success rate of 91.3% was achieved in the treatment of primary and 66.6% in secondary reflux. With these results we conclude that Teflon injection is a good alternative in the treatment of VUR.

Endoscopic treatment of primary vesicoureteric reflux in infants by subureteric injection of polytetrafluoroethylene. A 9-year follow-up.

Fifty-two infants (75 ureters) with primary high-grade vesicoureteric reflux (VUR) treated endoscopically by subureteric injection of Polytef paste (STING) were followed up for 1-9 years. There were 30 boys and 22 girls and their ages ranged from 2 to 12 months. Forty-five percent of ureters had grade III VUR, 40% had grade IV and 15% had grade V VUR. Reflux ceased in 49 (65%) ureters after a single injection. Twenty-four percent of ureters in this series required more than one injection of Polytef paste to correct VUR. STING failed to correct VUR in 3 (4%) ureters. Eighty percent of the 49 ureters corrected after a single injection of Polytef required < 0.2 ml of paste per ureter to correct reflux. Ninety-three percent of ureters continue to show absence of VUR 1-9 years after endoscopic correction. Three of the 5 recurrences were only of grade I or grade II severity and required no treatment. No untoward effects were seen in these children with the use of Teflon as an injectable biomaterial. This day care procedure is simple, safe and effective in correcting high grades of reflux in infants.

Correction of vesico-ureteric reflux by subureteric fibrin injection in dogs.

To study the histological and radiological potential of the biomaterial fibrin in the treatment of vesico-ureteric reflux by a subureteric injection. For histological studies the bladders of 22 non-refluxing adult female dogs were exposed and in 20 of these two-component fibrin glue was injected into the right subureteric intramuscular portion of the bladder and teflon was injected into the lamina propria of the left ureter; two of them acted as controls. Two dogs were killed on alternate days over the course of 21 post-operative days and the bladders and distal portions of the ureters were examined histologically. For radiological studies micturating cystograms were obtained from 15 female puppies. In only eight puppies was vesico-ureteric reflux naturally present. In six of these two-component fibrin was injected into the right and teflon into the left subureteric areas, and in two puppies fibrin was injected into the subureteric areas, while the left sides acted as controls. Micturating cystograms and intravenous urograms were obtained from all puppies 3 weeks post-operatively. Histopathological studies showed persistence of increased amounts of endogenous collagen at the fibrin-injected sites; at the Teflon-injected sites a mass surrounded by dense granulation tissue was seen. Radiological studies revealed complete disappearance of reflux in the study group of six fibrin and Teflon-injected puppies; in two control puppies fibrin was injected into the right subureteric area only; the left sides were left untouched to show that maturation did not play a role in abolishing the spontaneously occurring reflux. Follow-up intravenous urography showed no evidence of vesico-ureteric obstruction in the treated ureters. Fibrin has the properties of a substance inducing a controlled increase in the number of endogenous collagen fibres.

Evaluation of Polydimethylsiloxane as an Alternative in the Endoscopic Treatment of Vesicoureteral Reflux

Endoscopic correction of vesicoureteral reflux is an attractive alternative to open repair. In terms of effectiveness and long-term successful results polytetrafluoroethylene (Polytef) is the most reliable injectable product. However, legitimate concerns regarding particle migration still exist for polytetrafluoroethylene. Polydimethylsiloxane (Macroplastique) was evaluated as an alternative to polytetrafluoroethylene. Seven mongrel female dogs underwent endoscopic suburothelial injections of 0.35 to 0.50 cc polydimethylsiloxane paste by the O’Donnell technique to a unilateral nonrefluxing ureteral orifice. To facilitate migratory surveillance the paste was mixed with 57carbon monoxide radiolabeled 80pm. microspheres and injected in 5 of the 7 animals. Animals were sacrificed at 1, 3 and 6-month intervals. All major organs were retrieved and processed.After intensive histological evaluation the remaining tissue underwent dissolution and centrifugation in sodium hypochlorite. The resulting insoluble pellet was further analyzed. In dogs injected with radiolabeled paste tissue samples and insoluble pellets of each organ system were analyzed for y counts. Smears of the insoluble pellets of all animals were examined on light and phase contrast microscopy. At autopsy no gross abnormalities were noted. Tissue reaction at injection sites revealed a well encapsulated foreign body reaction with predominantly giant cells, fibroblasts and collagen deposition.Limited local migration of polydimethylsiloxane particles into the periureteral lymphatics of 1 animal sacrificed at 1 month was noted and a single particle visually indistinguishable from polydimethylsiloxane also was found within the splenic capsule. The endoscopic procedure in this animal was complicated in that 2 separate injections were required and histological evaluation confirmed that the injections were performed uniquely deep into the bladder muscularis. Radioactive counts and dissolution of all major organ systems demonstrated no migration in the remaining 6 animals. Endoscopic subureteral injection of polydimethylsiloxane is technically feasible, and it may prove to be biocompatible and without risk of distant migration if injected correctly.

Particles Found in Lung and Brain Following Subureteral Injection of Polytetrafluoroethylene Paste are not Teflon Particles

We injected 0.3ml. of polytetrafluoroethylene paste (Polytef) behind the left submucosal ureter in 4 mini-pigs and 4 dogs, and 2 dogs and 2 mini-pigs underwent sham operation and acted as controls. Two mini-pigs were injected with 0.5ml. polytetrafluoroethylene (Teflon) suspended in 50ml. of normal saline into a peripheral vein and 2 dogs were injected with 0.5ml. polytetrafluoroethylene into a bladder vein. In addition, 4 dogs were injected with 0.1ml. polytetrafluoroethylene paste suspended in 20ml. saline into the right carotid artery. The lungs and brain from half of the animals who had subureteral and intravascular injection of polytetrafluoroethylene paste as well as sham operated animals were dissolved in sodium hypochlorite solution. The resulting organ suspensions were then centrifuged and the smear preparations of the precipitate were examined by polarized light microscopy, scanning electron microscopy and x-ray microanalysis. Polytetrafluoroethylene paste suspended in saline acted as positive control for polytetrafluoroethylene particles. Lungs and brain from the remaining animals were fixed in formalin solution. The brain and lungs of animals who underwent subureteral injection with a minimal amount of polytetrafluoroethylene paste carefully placed in the submucosal plane showed no evidence of polytetrafluoroethylene on histological examination, polarized light microscopy, scanning electron microscopy and x-ray microanalysis.

Histological Behavior of Glutaraldehyde Cross-Linked Bovine Collagen Injected Into the Human Bladder for the Treatment of Vesicoureteral Reflux

Endoscopic subureteral collagen injection has become an accepted means for the treatment of vesicoureteral reflux in children. The aim of this study was to evaluate the histological behavior of glutaraldehyde cross-linked bovine collagen implants. The specimens were harvested from 29 patients who underwent reimplant surgery 2 to 30 months (mean 9.5) after unsuccessful subureteral injection therapy.In addition to routine hematoxylin and eosin staining, a new staining method (solophenyl red 3BL) able to demonstrate selectively neoformation of types I and III human collagen, was applied. Invasion of host fibroblasts into the bovine implant and the formation of endogenous types I and III collagen were demonstrated in all 29 cases. Adverse histological reactions were rare and, if present, they were predominantly of an inflammatory nature.