title: Super-mini percutaneous nephrolithotomy (SMP): a new concept in technique and instrumentation.
abstract: OBJECTIVE
  To present a novel miniature endoscopic system designed to improve the safety and efficacy of percutaneous nephrolithotomy, named the 'super-mini percutaneous nephrolithotomy' (SMP).
  
  
  METHODS
  The endoscopic system consists of a 7-F nephroscope with enhanced irrigation and a modified 10-14 F access sheath with a suction-evacuation function. This system was tested in patients with renal stones of <2.5 cm, in a multicentre prospective non-randomised clinical trial. In all, 146 patients were accrued in 14 centres. Nephrostomy tract dilatation was carried out to 10-14 F. The lithotripsy was performed using either a Holmium laser or pneumatic lithotripter. A nephrostomy tube or JJ stent was placed only if clinically indicated.
  
  
  RESULTS
  SMP was completed successfully in 141 of 146 patients. Five patients required conversion to larger nephrostomy tracts. The mean (sd) stone size was 2.2 (0.6) cm and the mean operative duration was 45.6 min. The initial stone-free rate (SFR) was 90.1%. The SFR at the 3-month follow-up was 95.8%. Three patients required auxiliary procedures for residual stones. Complications occurred in 12.8% of the patients, all of which were Clavien grade ≤II and no transfusions were needed. In all, 72.3% of the patients did not require any kind of catheter, while 19.8% had JJ stents and 5.7% had nephrostomy tubes placed. The mean hospital stay was 2.1 days.
  
  
  CONCLUSIONS
  SMP is a safe and effective treatment for renal stones of <2.5 cm. SMP may be particularly suitable for patients with lower pole stones and stones that ae not amenable to retrograde intrarenal surgery.
authors.affiliation: Department of Urology, Guangdong Key Laboratory of Urology, Minimally Invasive Surgery Center, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Zeng
authors.affiliation: Chinese-American Urology Stone Center, First People's Hospital of Xiaoshan, Hangzhou, China.
authors.forename: ShawPong
authors.initials: S
authors.lastname: Wan
authors.affiliation: Department of Urology, Guangdong Key Laboratory of Urology, Minimally Invasive Surgery Center, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Urology, Guizhou Provincial People's Hospital, Guiyang, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Urology, the First People's Hospital of Kashi, Kashi, Xinjiang, China.
authors.forename: Aierken
authors.initials: A
authors.lastname: Tuerxun
authors.affiliation: Department of Urology, Hubei Provincial People's Hospital, Wuhan, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Song
authors.affiliation: Department of Urology, Hospital of Traditional Chinese Medicine of Zhongshan, Zhongshan, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhong
authors.affiliation: Department of Urology, Changsha Centre Hospital, Changsha, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Kewei
authors.initials: K
authors.lastname: Xu
authors.affiliation: Department of Urology, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Hulin
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Urology, The third Xiangya Hospital of Xiangya Medical College, Central South University, Changsha, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Department of Urology, Venus International Hospital (SK), Kathmandu, Nepal.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Khadgi
authors.affiliation: Department of Urology, Lions Kidney Hospital and Urology Research Institute, New Delhi, India.
authors.forename: Shashi K
authors.initials: SK
authors.lastname: Pal
authors.affiliation: Department of Urology, the First Affiliated Hospital of Guangdong Medical College, Zhanjiang, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Urology, the First Affiliated Hospital of Gannan Medical University, Ganzhou, China.
authors.forename: Guoxi
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Urology, Guangdong Key Laboratory of Urology, Minimally Invasive Surgery Center, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Yongda
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Urology, Guangdong Key Laboratory of Urology, Minimally Invasive Surgery Center, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Wenqi
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Urology, Guangdong Key Laboratory of Urology, Minimally Invasive Surgery Center, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Urology, Dr. Lutfi KIRDAR Kartal Research and Training Hospital, Istanbul, Turkey.
authors.forename: Kemal
authors.initials: K
authors.lastname: Sarica
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004724:Endoscopy / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000295:instrumentation* / Q000379:methods; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: complications; kidney stones; super-mini percutaneous nephrolithotomy