External Validation And Comparison Of The Scoring Systems (S.T.O.N.E, GUY, CROES, S-ReSC) For Predicting Percutaneous Nephrolithotomy Outcomes For Staghorn Stones: A Single Center Experience With 160 Cases

Izmir Bozyaka Training and Research Hospital,Urology Department

PURPOSE: The aim of this study was validation and comparison of stone scoring systems (S.T.O.N.E, GUY, CROES, S-ReSC) used to predict postoperative stone-free status and complications after percutaneous nephrolithotomy (PCNL) for staghorn stones.

MATERIALS-METHODS: A total of 567 patients who underwent PCNL for renal stones between January 2012 and August 2015 were included in the recent retrospective study. Four hundred and seven patients who had more than one access and had not staghorn and partial staghorn stones were excluded from the study. Guy, S.T.O.N.E., S-ReSC and CROES nephrolithometry scores were calculated for each patient, and their potential association with stone-free status, operative and fluoroscopy time, and length of hospital stay (LOS) were evaluated. Postoperative complications were graded according to the modified Clavien classification, and the correlation of scoring systems with postoperative complications was also investigated.

RESULTS: One hundred and sixty patients who one access and staghorn and partial staghorn stones were included the study. The mean CROES, S.T.O.N.E, Guy and S-ReSC scores were 143.5±33.6, 9.7±1.6, 3.5±0.5 and 6.2±2.0 respectively. The overall stone-free rate was 59%. All scoring systems were significantly correlated with stone-free status in univariate analysis. However, Guy and S-ReSC were the only
significant independent predictor in multivariate analysis. And all four nomograms failed to predict CR (complication rates).

CONCLUSION: Recent study demonstrated that GUY and S-ReSC scoring systems could effectively predict postoperative stone-free status for staghorn stones. However all four scoring systems failed to predict CR.

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Şekil 1. ROC analizine göre skorlama sistemlerinin taşsızlığı göstermedeki eğrisi.

Figure 1. Receiver operating characteristic (ROC) curves of scoring systems to predict postoperative stone-free status

CROES: Clinical Research Office of the Endourological Society, S-ReSC: Seoul National University Renal Stone Complexity

CROES: Clinical Research Office of the Endourological Society, S-ReSC: Seoul National University Renal Stone Complexity

Tablo 1. Hastaların demografik ve perioperatif özellikleri

	Ortalama±SS	Minimum-Maximum
Yaş (yıl)	50.3±12.5	19-82
VKİ (kg/m2)	26.5±4.6	18-43
Taş yükü (mm2)	952.9±674.7	102-2869
Operasyon süresi (dk.)	124.5±44.1	45-300
Skopi süresi (sn.)	78.5±49.5	3-300
Hastanede kalış süresi (gün)	4.3±2.8	2-20
Nefrostomi süresi (gün)	2.4±0.8	0-5
CROES skoru	143.5±33.6	79-201
S.T.O.N.E skoru	9.7±1.6	7-13
Guy skoru	3.5±0.5	3-4
S-ReSC skoru	6.2±2.0	1-9
	n	%
Taşsızlık	94/160	59
Kadın/Erkek	111/49	69.4/30.6
ESWL öyküsü	17	10.6
Komple/Parsiyel staghorn	76/84	47.5/52.5
Sol/Sağ	89/71	55.6/44.4
Clavien
0	102	63.8
1	20	12.5
2	15	9.4
3A	20	12.5
3B	3	1.9
Renal anomali	12	7.5
Kanama miktarı (>250 cc)	68	42.5

SS, standart sapma

Table 1. Demographic and preoperative characteristics of patients

	Mean±SD	Minimum-Maximum
Age (years)	50.3±12.5	19-82
BMI (kg/m2)	26.5±4.6	18-43
Stone burden (mm2)	952.9±674.7	102-2869
Operation time (minute)	124.5±44.1	45-300
Scopy time(second)	78.5±49.5	3-300
Length of hospital stay (days)	4.3±2.8	2-20
Nephrostomy time (days)	2.4±0.8	0-5
CROES score	143.5±33.6	79-201
S.T.O.N.E score	9.7±1.6	7-13
Guy score	3.5±0.5	3-4
S-ReSC score	6.2±2.0	1-9
	n	%
Stone free rate	94/160	59
Female/Male	111/49	69.4/30.6
Previous ESWL	17	10.6
Complete/partial staghorn	76/84	47.5/52.5
Left/Right	89/71	55.6/44.4
Clavien
0	102	63.8
1	20	12.5
2	15	9.4
3A	20	12.5
3B	3	19
Renal anomaly	12	7,5
Bleeding (>250 cc)	68	42,5

SD, standard deviation

Tablo 2. Postoperatif taşsızlıkla ilgili parametrelerin çoklu varyasyon analizi

	OR	p	95% CI
Yaş	0.963	0.010	0.936-0.991
Tam/parsiyel staghorn	0.736	0.204	0.459-1.181
CROES skoru	0.997	0.760	0.975-1.019
S.T.O.N.E skoru	0.933	0.794	0.608-1.429
Guy skoru	2.765	0.002	1.444-5.295
S-ReSC skoru	1.317	0.006	1.083-1.600

OR, Odds ratio, CI, confidence interval

Table 2. Multivariate analysis of potential independent predictors for postoperative stone-free outcomes

	OR	p	95% CI
Age	0.963	0.010	0.936-0.991
Complete/partial staghorn	0.736	0.204	0.459-1.181
CROES score	0.997	0.760	0.975-1.019
S.T.O.N.E score	0.933	0.794	0.608-1.429
Guy score	2.765	0.002	1.444-5.295
S-ReSC score	1.317	0.006	1.083-1.600

OR, Odds ratio, CI, confidence interval

Tablo 3. Postoperatif komplikasyonlar ile ilgili parametrelerin çoklu varyasyon analizi

	OR	p	95% CI
Taş yükü (mm2)	1.000	0.286	1.000-1.001
Operasyon süresi (dk.)	1.006	0.205	0.997-1.015
Hastanede kalış süresi (gün)	1.558	<0.001	1.220-1.989
Nefrostomi süresi (gün)	0.768	0.351	0.442-1.336
Kanama miktarı(>250cc)	1.638	0.186	0.788-3.405
CROES skoru	0.985	0.164	0.965-1.006
S.T.O.N.E skoru	0.855	0.448	0.570-1.282
Guy skoru	0.957	0.925	0.385-2.381
S-ReSC skoru	1.050	0.600	0.876-1.258

OR, Odds ratio, CI, confidence interval

Table 3. Multivariate analysis of potential independent predictors for postoperative complication

	OR	p	95% CI
Stone burden	1.000	0.286	1.000-1.001
Operation time	1.006	0.205	0.997-1.015
Hospitalization time	1.558	<0.001	1.220-1.989
Nephrostomy time	0.768	0.351	0.442-1.336
Bleeding (>250cc)	1.638	0.186	0.788-3.405
CROES score	0.985	0.164	0.965-1.006
S.T.O.N.E score	0.855	0.448	0.570-1.282
Guy score	0.957	0.925	0.385-2.381
S-ReSC score	1.050	0.600	0.876-1.258

OR, Odds ratio, CI, confidence interval

Tablo 4. Modifiye Clavien Sınıflamasına Göre Komplikasyonlar

Evre	Komplikasyonlar	No	%
0	-	102	63,8
1	-Ağrı (opiyoidle geçen)	5
	-İ.V sıvı tedavisi ile düzelen böbrek fonksiyon bozukluğu	4
	-Nefrostomi klemplenmesi ile geçen kanama	7
	-Kan tranfüzyon ihtiyacı olmayan kanama	4
	Total	20	12,5
2	-Kan transfüzyonu gerektiren kanama	10
	-Ateş (antibiyotikle tdv edilen)	2
	-Antibiyotikle tedavi edilen semptomatik İYE	3
	-Total	15	9,4
3A	-Destekleyici tedavi ve gelişmiş izleme gerektiren organ yetmezliği olmadan Febril İYE	11
	-Genel anestezi olmadan ameliyat sonrası üreter stent gereksinimi olan kanama	2
	-Lokal anestezi altında interkostal drenaj tarafından yönetilen hidrotoraks	1
	-Postoperatif uzun süreli nefrostomi tüpü veya üreteral stent yerleştirme ile yönetilen renal pelvis perforasyon	4
	-İdrar kaçağı (genel anestezi olmadan üreter stent ile yönetilen)	2
	-Total	20	12,5
3B	-Anjioembolizasyon ile kontrol edilen kanama	1
	-Balon dilatasyon ile tedavi edilen üreter darlığı	2
	-Total	3	1,9
4A
4B
5

Table 4. Complications according to the modified Clavien classification system

Grade	Complications	No	%
0	-	102	63,8
1	- Postoperative pain managed by opioid with or without adjunct analgesic regimen	5
	- Deranged renal function that requires IV fluid management only	4
	- Bleeding that requires a single episode of nephrostomy clamping	7
	- Bleeding managed using IV fluid without need for blood transfusion	4
	--Total	20	12,5
2	- Bleeding requiring blood transfusion	10
	- Postoperative fever (>38.0 8C) managed with antibiotics in the ward	2
	- Symptomatic UTI managed using antibiotics	3
	- -Total	15	9,4
3A	- Febrile UTI or suspected sepsis without organ failure requiring supportive therapy and enhanced monitoring	11
	- Bleeding managed by postoperative ureteric stenting without general anaesthesia	2
	- Hydrothorax managed by intercostal draining under local anaesthesia	4
	- Renal pelvic perforation managed by prolonged nephrostomy tube or postoperative placement of nephrostomy	1
	- Urine leakage managed by ureteric stenting without general anaesthesia	2
	- -Total	20	12,5
3B	- Bleeding managed by angioembolisation	1
	- Ureteric stricture managed by balloon dilation	2
	- - Total	3	1,9
4A
4B
5