Prediction For The Success Rates And Complications Of Percutaneous Nephrolithotomy Using Guy’s Stone Score And Modified Clavien Classification

Objective:At present,the gold standardized method to accurately predict the stone-free rates and complications of percutaneous nephrolithotomy(PCNL)is lacking.The present study aims at evaluating the reliability of the prediction for the stone-free rates and complications in patients subjected to PCNL using Guy’s stone score(GS)and modified Clavien classification(MCC),respectively.Method:155 consecutive patients(160 renal units)who underwent PCNL were selected from our hospital between 2015.01 and 2016.12.All patients were classified by GS based on preoperative CT scan findings.The stone-free rates after PCNL were evaluated by plain film of the kidneys-ureter-bladder(KUB).The complications were predicted by MCC.Results:Of 160 renal units with PCNLs,15 renal units were classified as GS1,63 as GS2,73 as GS3,and 9 as GS4.The largest diameter of the stones statistically different among the groups(GS1=25mm,GS2=28mm,GS3=48mm,and GS4=69mm;P<0.001).Operative time(GS1 = 32.5 0±14.10 min,GS2=55.80±29.70 min,GS3=80.80±35.10 min,and GS4=116.30±54.80min;P < 0.001),number of tracts(GS1=1.00,GS2=1.10±0.30,GS3=1.20±0.50,and GS4=2.00±1.30;P < 0.001),immediate success rates(GS1=100.00%,GS2 = 87.30%,GS3=67.10%,and GS4=66.70%;P=0.002)and complications(GS1 =6.70%,GS2=28.60%,GS3=31.50%,and GS4=44.40%;P<0.001)were statistically different among groups,a total of 38 patients with grade 1 MCC showed postoperative fever(12),persistent pain(10),tachycardia(4),bradycardia(2),nausea or vomiting(5),acute urinary retention(1),and acute renal failure(4).A total of 6patients with grade 2 MCC presented as blood transfusion(3),sepsis(2),and acute cystitis(1).The most severe grade of MCC was 3B,a total of 2cases occurred in GS3 and GS4,all of which were considered as renal arteriolar injury after percutaneous renal puncture.However,the final stone-free rates were not significantly different among groups(GS1=100.00%,GS2=92.00%,GS3=86.30%,and GS4=88.90%;P=0.387).Conclusion:GS and MCC accurately predicted the stone-free rates and complications after PCNL for renal stone.