Recently, the team of urology directed by Dr. Ying Zhan, the vice-president of Tongji Wenchang hospital, performed a new mPCNL with the intelligent controlled perfusion and attraction system (ICPAS) on a right upper-middle kidney mold-stone patient. The combination of conventional mPCNL and intelligent pressure control technology further improves the safety and efficiency of minimally invasive surgical lithotripsy. This new technology was carried out initially in Hainan province of China.

    This patient has been suffered from intractable recurrent stone for many years and was repeatedly treated with EWSL and mPCNL. So the procedure required us to reduce renal damage as much as we can. This man underwent the left mPCNL in our hospital one week ago. The CT scan showed that the right upper-middle kidney mold-stone was a little big about 4cm*2cm and the renal parenchyma was thick because of no hydronephrosis. The high bleeding risk and inefficient intraoperative may increase the difficulty of surgery.

    Considering the complex condition, we discreetly decided to pre-use the equipment prepared for the meeting presentation of 2016 IAU Wenchang Forum one week later—mPCNL by holmium laser lithotripsy with ICPAS.
      
    The characteristics of ICPAS：
    1. ICPAS is made up of new nephroscope, new composite steel sheaths and pressure controlled perfusion and attraction pump. The double deck sheaths with the unique design make water inflow from the inner and attract outside from the middle of two layers just like water cycle of TURP. The procedure combined with ICPAS and holmium laser or pneumatic ballistic lithotripsy can maintain low  positive perfusion pressure or low negative attraction pressure. ICPAS can automatically adjust water inflow (600ml / min ~ 800ml / min) and water yield (600ml / min ~ 800ml / min) by control unit (maximum deviation≤5%) so that the pressure in the pelvis remains dynamic microbalance (20mmHg ~ 25mmHg). A pressure relief valve (threshold pressure is 15mmHg ~ 20mmHg) is also designed. ICPAS has many great advantages to improve safety like lower pelvis pressure, less sepsis and other complications, especially for the infection stone or stone with bacteriuria.
    2. Stone fragments can be attracted from a distance to the inner cavity of the nephroscope and exhausted fastly at the same time. ICPAS can shorten the operation time obviously, especially for staghorn calculi with single channel.
    3. Other advantages on the website of ShenDa Co.

    During the operation we found the stone was extremely hard and oddly shaped. The surgery was as difficult as we predicted but the stone was easily removed under the continuous beat by laser and suction by ICPAS. There was no renal mucosa injury and no ureteral stent placed after the operation. The patient and his families were very satisfied. 

   Conventional mPCNL has been widely used for urolithiasis but the high renal pelvis pressure and inefficient stone fragment clearance rate are still unsolved in the surgery. Conventional mPCNL is very difficult to deal with the branched renal calculi and the risk of bleeding or urine sepsis is much higher than the mPCNL combined with ICPAS. From now on, we can greatly improve the operation safety by maintaining internal pressure of the renal pelvis on a stable level and shortening the operation time at the same time. 

    One week later, Dr.Ying Zhan carried out an renal stone operation with TV live broadcast and talked about ICPAS with other doctors and scholars who attented the academic conference . Everyone expressed great interest and believed that the conventional mPCNL will be developed with dramatic pace again with ICPAS in the future.