The patented MPCNL irrigation and clearance system is safe and highly efficient in managing renal stones.

Epidemiology ObjectivesTo explore characteristics of urinary stone composition in China, and determine the effects of gender, age, body mass index (BMI), stone location, and geographical region on stone composition. Patients and methodsWe prospectively used Fourier-transform infrared spectroscopy to analyse stones from consecutive patients presenting with new-onset urolithiasis at 46 hospitals in seven geographical areas of China, between 1 June 2010 and 31 May 2015. Chi-squared tests and logistic regression analyses were used to determine associations between stone composition and gender, age, BMI, stone location, and geographical region. ResultsThe most common stone constituents were: calcium oxalate (CaOx; 65.9%), carbapatite (15.6%), urate (12.4%), struvite (2.7%), and brushite (1.7%). CaOx and urate stones occurred more frequently in males, whereas carbapatite and struvite were more common in females (P < 0.01). CaOx and carbapatite were more common in those aged 30-50 and 20-40 years than in other groups. Brushite and struvite were most common amongst those aged <20 and >70 years. The detection rate of urate increased with age, whilst cystine decreased with age. Obese patients were more likely to have urate stones than carbapatite or brushite stones (P < 0.01). CaOx, carbapatite, brushite, and cystine stones were more frequently found in the kidney than other types, whereas urate and struvite were more frequent in the bladder (P < 0.01). Stone composition varied by geographical region. ConclusionsThe most common stone composition was CaOx, followed by carbapatite, urate, struvite, and brushite. Stone composition differed significantly in patients grouped by gender, age, BMI, stone location, and geographical region.

Objectives: To investigate the safety, efficacy, and practicability of minimally invasive percutaneous nephrolithotomy (MPCNL) with the aid of a patented irrigation clearance system in treating renal staghorn calculi. Methods: From August 2009 to July 2014, 4 hospitals had executed a prospective multicenter study with a total of 912 cases. The patients were randomly divided into 3 groups: suctioning MPCNL, standard percutaneous nephrolithotomy (PCNL), and traditional MPCNL groups. Multiple operative and perioperative parameters were compared. Results: Blood loss and intrapelvic pressure in the suctioning MPCNL group were significantly less than those in the standard PCNL group. The average operation time, intrapelvic pressure, and amount of bleeding in the suctioning MPCNL group were better than those in the traditional MPCNL group. The suctioning MPCNL used one tract more frequently and 2 or 3 tracts less frequently than the standard MPCNL and traditional MPCNL groups. The stone-free rate by one surgery in the suctioning MPCNL group was significantly higher than that in standard PCNL and traditional MPNCL groups. Conclusions: Suctioning MPCNL using our patented system shows several advantages in treating renal staghorn calculi, including minimal invasion, shorter operation time, lower intrapelvic pressure, less bleeding and the need for a smaller number of ­percutaneous tracts, and higher stone clearance rate by one ­surgery.

Our patented system is technically feasible, safe, and efficient for treating upper urinary calculi. The advantages include breaking stones effectively and low complication rates because of its automatic control of RPP.