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Focused ultrasound guided relocation of kidney stones.

Abrol N, Kekre NS - Indian J Urol (2015 Jan-Mar)

Bottom Line: Focused ultrasound-guided relocation of fragments is a recently described technique aimed at improving results of intervention for stone disease.Though it is safe in application in pigs, technology is awaiting approval for clinical testing in human beings.This technology has many potential clinical applications in the management of stone disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, Christian Medical College, Vellore, India.

ABSTRACT

Purpose: Complete removal of all fragments is the goal of any intervention for urinary stones. This is more important in lower pole stones where gravity and spatial orientation of lower pole infundibulum may hinder spontaneous passage of fragments. Various adjuvant therapies (inversion, diuresis, percussion, oral citrate, etc.) are described to enhance stone-free rate but are not widely accepted. Focused ultrasound-guided relocation of fragments is a recently described technique aimed at improving results of intervention for stone disease. Purpose of this review is to discuss development of this technology and its potential clinical applications.

Materials and methods: Pubmed search was made using key words "Focused ultrasound" and "kidney stone". All English language articles were reviewed by title. Relevant studies describing development and application of focused ultrasound in renal stones were selected for review.

Results: Focused ultrasound has proven its efficacy in successfully relocating up to 8 mm stone fragments in vitro and in pigs. Relocation is independent of stone composition. The latest model allows imaging and therapy with a single handheld probe facilitating its use by single operator. The acoustic energy delivered by the new prototype is even less than that used for extracorporeal shock wave lithotripsy. Therapeutic exposure has not caused thermal injury in pig kidneys.

Conclusion: Focused ultrasound-guided relocation of stones is feasible. Though it is safe in application in pigs, technology is awaiting approval for clinical testing in human beings. This technology has many potential clinical applications in the management of stone disease.

No MeSH data available.


Related in: MedlinePlus

Diagrammatic representation of the therapy beam and the imaging beam. Coaxial arrangement placed the therapy beam within the imaging beam for real-time monitoring. (Modified from Shah et al.[19])
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Figure 2: Diagrammatic representation of the therapy beam and the imaging beam. Coaxial arrangement placed the therapy beam within the imaging beam for real-time monitoring. (Modified from Shah et al.[19])

Mentions: Based on the above-mentioned physical principal, an experimental ultrasound model (Research System) was developed by joining two separate machines; one for ultrasound imaging and guidance and the other for focused ultrasound. This device has a handheld probe of focal depth of 4.5-8.5 cm [Figures 1 and 2]. The central probe is for imaging and guidance. The peripheral focused probe consisting of an eight-element annular array with a frequency of 2 MHz is for the therapeutic effect. A laptop computer controls excitation timing of each element.


Focused ultrasound guided relocation of kidney stones.

Abrol N, Kekre NS - Indian J Urol (2015 Jan-Mar)

Diagrammatic representation of the therapy beam and the imaging beam. Coaxial arrangement placed the therapy beam within the imaging beam for real-time monitoring. (Modified from Shah et al.[19])
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300567&req=5

Figure 2: Diagrammatic representation of the therapy beam and the imaging beam. Coaxial arrangement placed the therapy beam within the imaging beam for real-time monitoring. (Modified from Shah et al.[19])
Mentions: Based on the above-mentioned physical principal, an experimental ultrasound model (Research System) was developed by joining two separate machines; one for ultrasound imaging and guidance and the other for focused ultrasound. This device has a handheld probe of focal depth of 4.5-8.5 cm [Figures 1 and 2]. The central probe is for imaging and guidance. The peripheral focused probe consisting of an eight-element annular array with a frequency of 2 MHz is for the therapeutic effect. A laptop computer controls excitation timing of each element.

Bottom Line: Focused ultrasound-guided relocation of fragments is a recently described technique aimed at improving results of intervention for stone disease.Though it is safe in application in pigs, technology is awaiting approval for clinical testing in human beings.This technology has many potential clinical applications in the management of stone disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, Christian Medical College, Vellore, India.

ABSTRACT

Purpose: Complete removal of all fragments is the goal of any intervention for urinary stones. This is more important in lower pole stones where gravity and spatial orientation of lower pole infundibulum may hinder spontaneous passage of fragments. Various adjuvant therapies (inversion, diuresis, percussion, oral citrate, etc.) are described to enhance stone-free rate but are not widely accepted. Focused ultrasound-guided relocation of fragments is a recently described technique aimed at improving results of intervention for stone disease. Purpose of this review is to discuss development of this technology and its potential clinical applications.

Materials and methods: Pubmed search was made using key words "Focused ultrasound" and "kidney stone". All English language articles were reviewed by title. Relevant studies describing development and application of focused ultrasound in renal stones were selected for review.

Results: Focused ultrasound has proven its efficacy in successfully relocating up to 8 mm stone fragments in vitro and in pigs. Relocation is independent of stone composition. The latest model allows imaging and therapy with a single handheld probe facilitating its use by single operator. The acoustic energy delivered by the new prototype is even less than that used for extracorporeal shock wave lithotripsy. Therapeutic exposure has not caused thermal injury in pig kidneys.

Conclusion: Focused ultrasound-guided relocation of stones is feasible. Though it is safe in application in pigs, technology is awaiting approval for clinical testing in human beings. This technology has many potential clinical applications in the management of stone disease.

No MeSH data available.


Related in: MedlinePlus