Antireflux ureteral stent proof of concept assessment after minimally invasive treatment of obstructive uropathy in animal model.

OBJECTIVES: To assess the efficacy of a new anti-reflux intraureteral stent design in a swine model after minimally invasive treatment of ureteral stricture to reduce ureteral stent morbidity, previous to manufacture this design in a biodegradable fashion. METHODS: Twenty-eight female pigs were included. The study began with a cystoscopic, nephrosonographic and contrast fluoroscopic assessment. Afterwards, obstructive uropathy model in right ureter was created. Obstruction was confirmed 6 weeks later and animals were randomly distributed into 2 groups. Group I underwent laser endopyelotomy and Group-II laparoscopic pyeloplasty A 3Fr anti-reflux intraureteral stent was placed 6 weeks. Follow-up evaluations were performed at 3-6 weeks. The final follow-up was completed at 5 months and included the aforementioned diagnostic methods and pathological study. RESULTS: None of the study animals showed any vesicoureteral reflux signs or ureteral orifice injury. There were no urinomas or ureteric fistulas. The dislodgement rate was 10.7%. After 6 weeks of stenting, 71.4% of ureters showed ureteral peristalsis below the stent, and 100% at the final follow-up. After pathological assessment, no differences were shown at UPJ and healing in the incised area was correct in both groups. CONCLUSIONS: The new stent design avoids vesicoureteral reflux and bladder trigone irritation, consequently might reduce morbidity associated with double pigtail ureteral stents. This study also shows that it is only necessary temporary scaffolding the incised ureteral segment and not the entire length of the ureter after minimally invasive surgery. It is also necessary to manufacture this design in a biodegradable material, thus avoiding its removal.

Antireflux ureteral stent proof of concept assessment after minimally invasive treatment of obstructive uropathy in animal model / Evaluación preliminar de un catéter ureteral antirreflujo tras el tratamiento minimamente invasivo de la uropatia obstructiva en modelo animal

OBJECTIVES: To assess the efficacy of a new anti-reflux intraureteral stent design in a swine model after minimally invasive treatment of ureteral stricture to reduce ureteral stent morbidity, previous to manufacture this design in a biodegradable fashion. METHODS: Twenty-eight female pigs were included. The study began with a cystoscopic, nephrosonographic and contrast fluoroscopic assessment. Afterwards, obstructive uropathy model in right ureter was created. Obstruction was confirmed 6 weeks later and animals were randomly distributed into 2 groups. Group I underwent laser endopyelotomy and Group-II laparoscopic pyeloplasty A 3Fr anti-reflux intraureteral stent was placed 6 weeks. Follow-up evaluations were performed at 3-6 weeks. The final follow-up was completed at 5 months and included the aforementioned diagnostic methods and pathological study. RESULTS: None of the study animals showed any vesicoureteral reflux signs or ureteral orifice injury. There were no urinomas or ureteric fistulas. The dislodgement rate was 10.7%. After 6 weeks of stenting, 71.4% of ureters showed ureteral peristalsis below the stent, and 100% at the final follow-up. After pathological assessment, no differences were shown at UPJ and healing in the incised area was correct in both groups. CONCLUSIÓN: The new stent design avoids vesicoureteral reflux and bladder trigone irritation, consequently might reduce morbidity associated with double pigtail ureteral stents. This study also shows that it is only necessary temporary scaffolding the incised ureteral segment and not the entire length of the ureter after minimally invasive surgery. It is also necessary to manufacture this design in a biodegradable material, thus avoiding its removal

OBJETIVOS: Evaluar un nuevo diseño de catéter intraureteral-antirreflujo en modelo porcino tras el tratamiento mínimamente invasivo de estenosis ureterales. MÉTODOS: Se emplearon 28 ejemplares de la especie porcina. El estudio se inicia con la evaluación cistoscópica, nefrosonográfica y fluoroscópica de la vía urinaria. Posteriormente, se procede a la creación del modelo de estenosis en el uréter derecho. La obstrucción se confirma 6 semanas después y los animales son distribuidos aleatoriamente en dos grupos homogeneos. El Grupo-I, fue tratado mediante endopielotomía láser, y el Grupo-II mediante una pieloplastia laparoscópica. En ambos grupos se coloca durante 6 semanas, un catéter ureteral antirreflujo de 3Fr. Los seguimientos de los animales del estudio se realizaron a las 3-6 semanas. Con un seguimiento final a los 5 meses, que incluye un estudio anatomopatológico. RESULTADOS: Ninguno de los animales del estudio mostró reflujo vesicoureteral o signos de lesión en el orificio ureteral. No se produjeron ni fístulas ni urinomas. La tasa de migración alcanzó un 10,7%. Tras 6 semanas de cateterización el 71,4% de los uréteres mostraron peristaltismo ureteral distal y un 100% a los 5 meses. Tras el estudio anatomopatológico, no se evidencian diferencias en la zona de la unión pieloureteral y la cicatrización fue correcta en ambos grupos. CONCLUSIONES: El nuevo catéter ureteral impide el reflujo vesicoureteral y la irritación del trígono vesical, por lo que previsiblemente podría reducir la morbilidad asociada a los catéteres ureterales. El estudio también muestra que solo es necesaria la cateterización temporal del segmento incidido y no de todo el uréter. Evidentemente es necesario desarrollar este nuevo diseño en su versión biodegradable, para su empleo clínico futuro

Utilización de la tecnología láser en el tratamiento de las estenosis ureterointestinales / The use of laser technology for the treatment of ureterointestinal stenosis

Las estenosis ureterointestinales representan un problema importante en los pacientes sometidos a una cistectomía radical y una derivación urinaria utilizando segmento intestinal, bien sea éste intestino delgado o grueso. Con la incorporación de la tecnología láser en la urología, se han abierto unas posibilidades terapéuticas para la sección de estas estenosis ureterointestinales. Se han empleado distintos tipos de láser para realizar la incisión que son el Nd:YAD, el KTP:YAG, el Ho: YAG, el Er:YAG y el Th:YAG. La experiencia es limitada con respecto a su uso y los resultados no conllevan orientaciones terapéuticas claras. La sección de las estenosis ureterointestinales mediante el láser tiene ventajas e inconvenientes, pero la aplicación de esta fuente de energía junto con distintas técnicas de sección endoscópica, como la técnica de endoureterotomía mediante invaginación endoluminal de F. Lovaco proporciona unos resultados satisfactorios a cortomedio plazo (AU)

Objectives: Ureteral-intestinal anastomosis represent an important problem in patients undergoing radical cystectomy with urinary diversion using intestinal segments, either small or large intestine. With the incorporation of laser technology in urology, new therapeutic possibilities have been opened for the section of these ureteral intestinal stenosis. Various types of laser had been employed to perform the incision, Nd:YAG, KTP:YAG, Ho:YAG, Er:YAG, and Th:YAG. The experience is limited in terms of use and results don't give clear therapeutic orientation. The section of ureteral-intestinal stenosis with laser has advantages and disadvantages, but the application of this energy source with various techniques of endoscopic section, such as the Lovaco's technique of endoluminal invagination and endoureterotomy gives satisfactory results in the short-midterm (AU)

[The use of laser technology for the treatment of ureterointestinal stenosis]. / Utilización de la tecnología láser en el tratamiento de las estenosis ureterointestinales.

OBJECTIVES: Ureteral-intestinal anastomosis represent on important problem in patients undergoing radical cystectomy with urinary diversion using intestinal segments, either small or large intestine. With the incorporation of laser technology in urology, new therapeutic possibilities have been opened for the section of these ureteral intestinal stenosis. Various types of laser had been employed to perform the incision, Nd:YAG, KTP:YAG, Ho:YAG, Er:YAG, and Th:YAG. The experience is limited in terms of use and results don't give clear therapeutic orientation. The section of ureteral-intestinal stenosis with laser has advantages and disadvantages, but the application of this energy source with various techniques of endoscopic section, such as the Lovaco's technique of endoluminal invagination and endoureterotomy gives satisfactory results in the short-midterm.