Name:
Super Mini Percutaneous Nephrolithotomy (SMP): Totally Ultrasound-Guided with a two-step tract dilation technique.
Description:
Super Mini Percutaneous Nephrolithotomy (SMP): Totally Ultrasound-Guided with a two-step tract dilation technique.
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/126b512f-4a58-4492-9666-ded08ca0affa/videoscrubberimages/Scrubber_1.jpg?sv=2019-02-02&sr=c&sig=py6D50fMMBKsFMRti2Ln5wEjGG64HJOfx%2BOkyNJbeyQ%3D&st=2026-03-09T17%3A06%3A33Z&se=2026-03-09T21%3A11%3A33Z&sp=r
Duration:
T00H08M32S
Embed URL:
https://stream.cadmore.media/player/126b512f-4a58-4492-9666-ded08ca0affa
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/126b512f-4a58-4492-9666-ded08ca0affa/1052038575-SMPUSGGUIDEDREVISEDmp4.mp4?sv=2019-02-02&sr=c&sig=0WFvsy0gHFGJE5g58FqGL4LwKxhidFWT40MHmFTUh0I%3D&st=2026-03-09T17%3A06%3A34Z&se=2026-03-09T19%3A11%3A34Z&sp=r
Upload Date:
2024-04-15T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
SPEAKER: Super-mini percutaneous nephrolithotomy totally ultrasound guided with a two-step tract dilation technique. [MUSIC PLAYING] The super-mini percutaneous nephrolithotomy system, developed by Guohua Zeng, with the feature of simultaneous irrigation and suction sheath, improves the visualization and extraction of the stone. The total ultrasound-guided super-mini perc has been demonstrated to avoid the use of radiation, exhibiting a good safety profile.
SPEAKER: And the two-step dilatation technique was described by Li Jianxing. The usual dilation technique uses fluoroscopy, therefore, instruments were designed to work with X-rays. In this video, we demonstrate the technical differences of performing all steps with ultrasound and how to improve safety. Case presentation-- 59 years old male with left flank pain since one month.
SPEAKER: Comorbidities, diabetes and dyslipidemia. Urine culture, negative. CT scan shows a stone in the left kidney and lower calyx the largest diameter is 15 millimeters, and the density is 970 Hounsfield units with an average distance from skin to collector system is 8.5 centimeters. Super-mini perc equipment-- The equipment consists of a 7.5 French hawk nephroscope and a 14 French metal access sheath to create a mini tract, which is then attached to the suction system with a bottle to collect the stone fragments.
SPEAKER: The irrigation port is connected to an irrigation pump essential for adequate visualization. The irrigation fluid pressure is set as 200 to 250 millimeters of mercury. The system works with simultaneous suction in the irrigation suction 14 French sheath to avoid increased intrarenal pressure and extract the fragments. Additional material for two-step dilation technique-- We used plastic fascial dilators 10, 12, 14 French and a plastic peel-away 14 French sheath.
SPEAKER: This table resumes all the equipment needed for this procedure-- the super-mini perc equipment, needle, dilators, and sheaths. Technique-- The surgery is performed in a Valdivia Galdakao position, which allows us to have a retrograde access if necessary. We used a 3.5 megahertz convex abdominal ultrasound probe. We carry out an initial scan with ultrasound, which allows us to configure it adequately in terms of focus and gains.
SPEAKER: Here we observe the stone that is in the lower calyx. We take the distance from the skin to the calyx by puncture. We place a UPJ occlusion balloon catheter. And saline is injected retrogradely through the urethral catheter to create temporary artificial hydronephrosis. The transducer is taken with the left hand and fixed parallel to the 12th rib to avoid acoustic shadow. The right hand takes the needle and remains in the same plane to achieve proper alignment.
SPEAKER: We prefer to use an echogenic needle that facilitates visualization of the needle tip and the puncture was performed with a longitudinal freehand technique. Keeping the probe fixed and avoiding its movement is the key to a successful puncture. The goal is for the needle to be visualized in its entirety on the ultrasound as it enters into the skin, crosses through the subcutaneous, fascial, muscular, and perinephric layers through the kidney and into the targeted calyx, in this case, to the middle calyx.
SPEAKER: Obtaining urine indicates a successful puncture. Currently, our access to the kidney is generally through the middle calyx. Access through the lower calyx increases the risk of short dilation or dilation failure as the kidney tends to be more mobile. An extra stiff guide is introduced, which is hyper echogenic. And we can see its entire trajectory in the ultrasound and corroborate its adequate placement in the renal cavities.
SPEAKER: We proceed to make an incision in the skin and subcutaneous tissue. This helps us to reduce resistance at the time of dilation. First part of two-step tract dilation-- to avoid excessive dilation, the third safety step is to measure the distance from the skin to the stone. As a safety step during the dilation of the mini tract, we must visualize in real time the progress of the 10, 12, and 14 French fascial dilators, which are hiding in the guide when entering the kidney in calyceal system.
SPEAKER: A plastic peel-away sheath 14 French is used. It's graduation in centimeters increases safety by avoiding excessive dilation. The ability to hide the guidewire during tract dilation allows us to see the depth of dilators in real time, enabling safe and complete dilation. But dilating in one shot with a metal sheath, as in fluoroscopy, does not clearly hide the guidewire.
SPEAKER: This makes it challenging to control the dilation depth, and the artifacts produced by the metal increase the difficulty. So the first dilation with a plastic sheath increases safety. And when it is completed, we continue with the next step. With the assistance of a rigid ureteroscope, we performed a nephroscopy to confirm that we are in the renal cavities and proceeded to place a pair of guide wires in the ureter.
SPEAKER: After placing the two guides, the position of the peel-away sheath is left at the entrance of the calyceal system. And the distance is measured to place the metal sheath. The safety guide is fixed and covered with a sterile field and allows the track to be saved in case of accident. Second part of the two-step dilation-- we can see the metal sheath placed towards the direction in which the dilatation was performed.
SPEAKER: The advancement of the metal sheath is controlled by ultrasound. The key to avoiding a short or excessive dilatation is to advance 1 centimeter in addition to the previous distance measured in the peel-away sheath. This additional centimeter and final dilation is a reasonable distance, which allows us to avoid a short dilation.
SPEAKER: The dilation must be complete and quick to avoid bleeding that can block the side holes where irrigation flows through the tip of the metallic irrigation suction sheath, resulting in poor flow and failure of the irrigation pump. Then we remove the obturator and observe the metal sheath on the work guide. Before connecting the suction irrigation attachment, we insert the mini nephroscope 7.5 French and perform nephroscopy.
SPEAKER: We must ensure that dilation is complete and in the collector system and remove the work guide. We continue placing the suction irrigation attachment. The mini nephroscope is introduced. In the nephroscopy, the stone is located in the renal cavities. The fragmentation is carried out with laser. In lithotripsy and fragmentation of the stone, we make a backward movement on the metal sheath so that the fragments are sucked by the reservoir.
SPEAKER: We can observe this in the endoscopic view. We perform the movement as many times as necessary to remove all the fragments and leave the renal cavity stone free. Here we can observe the movements of the equipment and the use of the left hand to perform the suction and the fragments are thrown into the reservoir. We finish the lithotripsy, remove the laser fiber, and perform a nephroscopy, checking the pelvis and all the renal cavities, thus confirming that no stone fragments or residual stones are found and perform an ultrasound scan to corroborate the absence of residual stones.
SPEAKER: Once we finish the nephroscopy, the equipment is removed under direct vision, observing the entire trajectory of the tract. The totally tubeless procedure, at the end, we remove the safety guide and the metal sheath. We can see a millimetric wound. In the reservoir, we can observe the fragmented stone. We have performed the described technique on 15 adult patients. The average stone burden was 2,263 square millimeters.
SPEAKER: The mean operative time was 79 minutes. And all cases were total tubeless. There were no cases of short dilation, tract loss, or collecting system injury. And only three patients had complications that were Clavien-Dindo 1. The 80% were ambulatory procedures. A CT scan was performed one month after the surgery. And the stone-free rate was 93%.
SPEAKER: This totally ultrasound-guided dilation technique is safe and reproducible and can increase the safety of the procedure. Super-mini perc allows a very good stone-free rate and can be an ambulatory and totally tubeless surgery.
