Clinical Essentials "In Vitro Shock Wave Lithotripsy Expert Consensus" Key Points Intensive Reading

In vitro shock wave lithotripsy (SWL) is an important method of minimally invasive treatment of upper urinary tract stones, and its effectiveness and safety have been widely recognized

The purpose of preoperative examination: (1) to confirm the diagnosis of stones; (2) Assess the indications for SGUL; (3) Exclude contraindications to SGUL; (4) Evaluate the likelihood of the patient receiving SGUL

Preoperative investigations: including laboratory tests and imaging (ultrasound + plain abdominal x-ray or non-contrast CT of the abdomen should be selected for

Preoperative preparation: (1) Assess the patient's condition: According to the scope of relative contraindications to SWL, the patient's renal function, the occurrence of urinary tract infection, the taking of anticoagulants, the control status of hypertension and diabetes, etc.

Treatment position: the commonly used position is mainly prone position, supine position, side lying position

Treatment pathway: Path selection should follow the principle of "short impact path, high safety", paying special attention to the degree

Positioning technology: SHL positioning and monitoring methods mainly have X-ray and ultrasonic, the ideal SLL is to use X-ray and ultrasonic dual positioning system, select X-ray stone finding, ultrasonic tracking

Parameter setting: The selection of treatment parameters requires both safety and efficacy, including shock frequency and shock wave energy, number of shock waves and number of treatment periods
.

The recommended impact frequency is 60 times/min, and the "step-by-step energy enhancement technique" is applied to increase the energy
step by step.

The "gap rest method" is mainly applied to the kidney or ureteral calculus above the flat kidney SWL, shock 300 to 500 times, pause for 2 to 3 min, which is conducive to improving the efficiency of lithotripsy and reducing the probability
of renal bleeding.

The number of treatment periods of stone SHL at the same site does not exceed 3 times
.

Number of single-stage shocks: no more than 2500 kidney stones and no more than 3000 ureteral stones
.

Skin coupling: Coupling technology and the choice of couplant need to be paid attention to ensure that the water bladder is closely aligned
with the human skin.

The quality of the coupling of the water bladder to the skin directly affects the gravel effect
.

Postoperative follow-up: After SHL, follow-up
is performed at 1, 2 weeks, and 3 months, respectively.

Imaging studies include ultrasound and plain x-rays of the abdomen, with non-contrast CT
of the abdomen if necessary.

After SWL surgery, if there are serious adverse reactions, the time of review should be shortened and the number of re-examinations
should be increased.

Laboratory tests include blood count and urine routine
.

The regrowth of residual stones is due to specific pathogenic factors, and attention should be paid to the diagnosis and prevention
of the etiology of stones.

For uric acid stones, cystine stones, and calcium-containing stones with hypocitriuria, potassium citrate is recommended to prevent recurrence of
stones.

Efficacy assessment: Evaluation indicators include stone clearance rate, reflux rate, auxiliary treatment rate and efficiency quotient
.

Ultrasound and plain abdominal x-ray examination are the mainstay, and non-contrast CT
of the abdomen is performed if necessary.

Residual stones with a diameter of > 4 mm are considered stone residues; A single stone with a diameter of ≤ 4 mm was found to be clinically meaningless residues
.

Uncrushed stones mean that the main body of the stone does not change much
.

References:

Urology Group, Shockwave Medical Committee, Chinese Society of Research Hospitals.
Expert consensus on extracorporeal shock wave lithotripsy[J].
Journal of Urology (Electronic Edition),2022,14(1):1-3,7.

Editor: Wang Mumu

Reviewer: LR

Execution: Wang Mumu