Is there a role for small-diameter ureteral access sheaths? Impact on irrigant flow and intrapelvic pressures

doi:10.1016/j.urology.2004.04.060

Urology

Volume 64, Issue 3, September 2004, Pages 439-441

https://doi.org/10.1016/j.urology.2004.04.060 Get rights and content

Abstract

Objectives

To evaluate irrigant flows and intrapelvic pressures with small-diameter access sheaths. Ureteral access sheaths improve irrigant flow and decrease intrarenal pelvic pressures during flexible ureteroscopy. However, no comparisons of individual sheaths have been conducted. Previous studies have demonstrated more favorable results with the 12F sheath than with the 10F sheath.

Methods

Ureteral access sheaths were tested ex vivo in porcine kidneys. An 18F angiocatheter was placed in the renal pelvis and connected to a Hewlett Packard Gauss Pressure transducer. Irrigant was maintained at 100 mm Hg pressure. Irrigant flow and intrapelvic pressures were measured with three flexible ureteroscopes at baseline and using each of four 10F sheaths, with the sheaths positioned in the middle ureter and the ureteroscopes positioned in the renal pelvis. The pressure at which irrigant efflux through the sheath occurred and the rate of irrigant efflux through the access sheath were measured.

Results

Intrapelvic pressures measured greater than 40 mm Hg, and irrigant flows remained at less than 15 mL/min when the Olympus URF-P3 and Storz 11274AAU flexible ureteroscopes were tested with all four sheaths. The intrapelvic pressures, irrigant inflow, and irrigant efflux with the Wolf 7325.172 (7.5F) flexible ureteroscope were optimized in combination with the Cook Peelaway 10F and Applied Access 10F sheaths.

Conclusions

Small ureteral access sheaths should be used only with the Wolf 7325.172 flexible ureteroscope. The Cook Peelaway (10F) and Applied Access (10F) sheaths offered the greatest increase in irrigant flow and decrease in intrapelvic pressures.

Section snippets

Material and methods

Ureteral access sheaths were tested ex vivo in 12 porcine kidneys. The kidneys, ureter, and bladder were harvested en bloc from pigs (mean weight 38 kg) and studied fresh, immediately after retrieval. The anterior bladder was bivalved, and the ureteral orifices were cannulated with a 0.035 Bentson guidewire.

An 18F angiocatheter was placed in the renal pelvis and connected to a Hewlett Packard Gauss Pressure transducer. Irrigant was maintained at 100 mm Hg pressure by gravity flow. Initially,

Results

The intrapelvic pressures were greater than 40 mm Hg for the Olympus URF-P3 and Storz 11274AAU flexible ureteroscopes, irrespective of which 10F sheath was used (Fig. 1). With the Wolf 7325.172, the intrapelvic pressures were lowest with the Cook Peelaway 10F (22 mm Hg) and Applied Access 10F (16 mm Hg) access sheaths. The irrigant flow was less than 15 mL/min for the Olympus URF-P3 and Storz 11274AAU flexible ureteroscopes, irrespective of which 10F sheath was used (Fig. 2). With the Wolf

Comment

One of the proposed advantages of the use of access sheaths during flexible ureteroscopy is to minimize intrapelvic pressure and maximize irrigant flow. Studies have demonstrated that these effects are superior with 12F internal diameter sheaths compared with 10F internal diameter sheaths.2 However, ureteral access sheath manufacturers continue to produce small-diameter 10F sheaths. In this study we evaluated the utility of 10F sheaths with a variety of flexible ureteroscopes.

New flexible

Conclusions

References (6)

J. Kourambas et al.
Does a ureteral access sheath facilitate ureteroscopy?
J Urol
(2001)
J. Rehman et al.
Characterization of intrapelvic pressure during ureteropyeloscopy with ureteral access sheaths
Urology
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J. Rehman et al.
Characterization of intrapelvic pressure during ureteropyeloscopy with ureteral access sheaths
Urology
(2003)

There are more references available in the full text version of this article.

Cited by (41)

Comparison of irrigation flows between different irrigation methods for flexible ureteroscopy: An in vitro study
2022, Progres en Urologie
Citation Excerpt :
Recently, attention has focused on intrarenal pressure and its levels reached during endourological procedures such as f-URS [11–24]. Some factors have been identified to impact it during f-URS such as irrigation pressure, occupation of the working channel, and use of a UAS [12–14,17,18,20–22,24]. However, none of these studies focused on the influence of the method of irrigation on intrarenal pressure.
To compare the irrigation flows between different irrigation methods for f-URS.
We compared the automatic irrigation system Endoflow II to gravity-based irrigation, and gravity-based irrigation with pressure cuff. Irrigation pressures were set at 40 and 100 cmH₂O. A LithoVue f-URS with a 3.6 Fr working channel was used for the experiments. The f-URS was placed in straight alignment without active deflection on the operating table. For each irrigation pressure level, we evaluated the influence of the occupation of the working channel of the f-URS with an empty working channel, a 272 μm laser fiber, a 1.9 Fr nitinol basket. The outflow from f-URS was measured by the volume of irrigation fluid collected using a graduated glass at 1 min, 2 min, 3 min and 5 min.
Irrigations flows remained constant over the time for the Endoflow II and the gravity-based irrigation methods regardless of the irrigation pressure and setting. For the pressure cuff method, the irrigation flow remained constant only when the working channel was occupied either by the nitinol basket or the laser fiber. Irrigation flow with the Endoflow II were constantly higher than gravity-based irrigation methods. Irrigation flow significantly increased with increased irrigation pressure. In the presence of any instruments at any irrigation pressure, the flow decreased as the size of the instrument in the working channel increased.
Automatic irrigation system Endoflow II provided higher irrigation flows than gravity-based irrigation methods. The irrigation flow decreased as the size of the instrument in the working channel increased. Further studies conducted in vivo are needed to investigate if the differences found between irrigation methods result in higher intrarenal pressure during procedures.
4.
Comparer les débits d’irrigation entre différentes méthodes d’irrigation couramment utilisées en urétéroscopie souple (URS-S).
L’URS-S LithoVue avec un CO de 3,6 Fr a été utilisé pour l’ensemble des expériences. L’URSS était maintenu rectiligne pour chacune des expériences. Pour chacune des méthodes d’irrigation étudiées (système d’irrigation automatique EndoflowII, irrigation par gravité et irrigation par gravité avec brassard à pression), les pressions d’irrigation utilisées étaient de 40 et 100 cmH₂O. Pour chaque niveau de pression d’irrigation, nous avons évalué l’influence de l’occupation du CO de l’URS-S: CO libre, CO occupé par une fibre laser de 272 μm, CO occupé par un panier en nitinol de 1,9 Fr. Le débit d’irrigation sortant de l’URS-S était mesuré par le volume de liquide d’irrigation collecté dans une éprouvette graduée à 1 min, 2 min, 3 min et 5 min.
Les débits d’irrigation étaient constants au cours du temps pour l’Endoflow II et la méthode d’irrigation par gravité, quelles que soient la pression l’irrigation et l’occupation du CO. Pour la méthode d’irrigation avec brassard de pression, le débit d’irrigation ne restait constant que lorsque le CO était occupé par le panier ou la fibre laser. Le débit d’irrigation augmentait avec l’augmentation de la pression d’irrigation pour l’ensemble des méthodes d’irrigation, quelle que soit l’occupation du CO. Le débit d’irrigation avec l’Endoflow II était constamment plus élevé que les deux autres méthodes d’irrigation. Pour l’ensemble des méthodes d’irrigation et quel que soit le niveau de pression d’irrigation, le débit d’irrigation diminuait lors de l’occupation du CO, et ce, d’autant plus que la taille de l’instrument occupant le CO augmentait.
Les débits d’irrigations avec le système d’irrigation automatique Endoflow II étaient constamment plus élevés que les méthodes d’irrigation par gravité. D’autres études, menées in vivo, sont nécessaires pour déterminer si ces différences trouvées entre les méthodes d’irrigation entraînent une augmentation de la pression pyélique pendant une URS-S.
4.
Development and Testing of an Anatomic in vitro Kidney Model for Measuring Intrapelvic Pressure During Ureteroscopy
2021, Urology
To create an in vitro anatomic bench model that can mimic in vivo intrapelvic pressure (IPP) during ureteroscopy (URS) and compare it against existing in vivo and ex vivo data.
A silicone kidney model (Simagine Health) that permits intrarenal endoscopic navigation was engineered to have a fluid-tight seal for the ureteral opening and a Tuohy-Borst valve in the renal pelvis incorporating a 0.2 mm pressure sensor (Opsens). To calibrate the model, a Cobra ureteroscope (Wolf) was inserted to the pelvis with 200cmH₂O irrigation, and the valve adjusted until an IPP of 54cmH₂O was obtained (prior human data). All experiments were conducted with a laser fiber in the working channel, with and without ureteral access sheaths (UAS) (11/13F, 13/15F) at irrigation setting of 61, 102, 153, and 193cmH₂O using an automated system (Rocamed). Study outcome was mean steady-state IPP for each UAS/irrigation condition.
Fluid leakage through the Tuohy-Borst valve, which could be adjusted, was critical to simulate ureteric outflow during URS. IPP values for each condition corresponded with data from in vivo and ex vivo models. In the no UAS condition, IPP increased with increasing irrigation pressures, and surpassed 40cmH₂O when ≥153cmH₂O. When using a UAS, IPP was below 40cmH₂O for all irrigation pressures.
An in vitro kidney model can simulate in vivo and ex vivo IPP profiles, and be tailored to different conditions by controlling fluid outflow. This bench model can be useful for testing of new technologies and their impact on IPP.
Safety of the flexible ureteroscopy without ureteral access sheath
2014, Urologia Colombiana
Evaluar el impacto de la utilización de la camisa de acceso ureteral en la tasa libre de cálculos durante la ureterorenoscopia flexible en pacientes tratados por cálculos del tracto urinario superior.
Se realizó un estudio descriptivo donde se incluyó un componente analítico de correlación de variables. La población definida en el presente estudio incluye individuos con cálculos renales o ureterales proximales con indicación de nefrolitotomía flexible láser en un solo tiempo quirúrgico, la población corresponde a 60 pacientes los cuales se diferencian en dos grupos, en quienes se utilizó camisa de acceso ureteral durante el procedimiento (44 pacientes) y en quienes no se utilizó por falla en el acceso (16 pacientes).
Comparando las dos técnicas en cuanto a tiempo quirúrgico, tamaño de los cálculos, complicaciones y tasa libre de cálculos no se observan diferencias significativas; al realizar el análisis exploratorio multivariado, las dimensiones explican el 94% de la variabilidad del modelo y los individuos presentan correlación entre las categorías de no uso de camisa, no ocurrencia de complicaciones, tiempo quirúrgico menor a 90 minutos y cálculos con diámetros menores a 10 mm.
La nefrolitotomía flexible laser sin camisa de acceso ureteral es un procedimiento seguro en pacientes con litiasis menor de 10 mm, no hay variaciones representativas con respecto al uso de la camisa ureteral, por lo cual podría ser una alternativa quirúrgica para el tratamiento de la litiasis de tracto urinario superior en pacientes en quienes no sea posible el acceso con la camisa ureteral.
© 2014 Sociedad Colombiana de Urología. Publicado por Elsevier España, S.L. Todos los derechos reservados.
To evaluate the impact of the use of a ureteral access sheath during flexible ureterorenoscopy on stone-free rate in patients treated for upper urinary tract stones.
A descriptive study was conducted with an analytical variable correlation component. The population as defined in this study includes individuals with kidney or proximal ureteral stones, with an indication of flexible laser nephrolithotomy to manage stones in one surgical time. The population consisted of 60 patients, who were divided into two groups; those in which ureteral access sheath was used for the procedure (44 patients), and those in which it was not used secondary to access failure (16 patients).
Comparing the two techniques in terms of operation time, stone size, and stone-free rate, there were no significant differences observed. After performing exploratory multivariate analysis, the dimensions explained 94% of the variability of the model, and a correlation was found between the categories: non-use of ureteral access sheath with no occurrence of complications, operation time less than 90 minutes and stones with diameters less than 10 mm.
Flexible laser nephrolithotomy with no ureteral access sheath is safe in patients with stones smaller than 10 mm, with no significant variations compared to the use of ureteral sheath. This means that it could be a surgical alternative for the treatment of upper urinary tract stones in patients in which ureteral access with an ureteral access sheath fails.
© 2014 Sociedad Colombiana de Urología. Published by Elsevier España, S.L. All rights reserved.
The Saudi urological association guidelines on urolithiasis
2024, Urology Annals
Intrarenal pressure study using 7.5 French flexible ureteroscope with or without ureteral access sheath in an ex-vivo porcine kidney model
2023, World Journal of Urology
In vivo ureteroscopic intrarenal pressures and clinical outcomes: a multi-institutional analysis of 120 consecutive patients
2023, BJU International

View all citing articles on Scopus

^☆: M. Monga is a study investigator funded by Cook, ACMI, Applied Medical, Storz, Wolf, and Olympus and has a patent application with Applied Medical.

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Adult urology: editorial commentIs there a role for small-diameter ureteral access sheaths? Impact on irrigant flow and intrapelvic pressures☆

Abstract

Objectives

Methods

Results

Conclusions

Section snippets

Material and methods

Results

Comment

Conclusions

J Urol

Urology

Urology

Adult urology: editorial comment
Is there a role for small-diameter ureteral access sheaths? Impact on irrigant flow and intrapelvic pressures☆