Percutaneous Nephrolithotomy in Young-Old,Old-Old,and Oldest-Old Patients: A Multicenter Study

Abstract

Introduction:

To compare percutaneous nephrolithotomy (PCNL) outcomes between the elderly and young age groups and examined differences between young-old, old-old, and oldest-old patients.

Methods:

A retrospective analysis was conducted on 8191 renal units that underwent PCNL between September 1997 and March 2020 at three Turkish academic institutions. Patients were classified into young (18–64 years) and elderly (65+ years) age groups. The elderly age group was classified into young-old (65–69 years), old-old (70–79 years), and oldest-old (80+ years). Demographics, stone features, and perioperative and postoperative outcomes were compared between groups. The factors affecting stone-free rates and complications were determined in the elderly age group.

Results:

The patients' median age was 47 years (18–100) and the female to male ratio was 1:1.72. The stone-free and complication rates were 78.9% and 16.4%, respectively. General complications, blood transfusion, postoperative urinary tract infections, and major complications rate were similar between the young and elderly age groups (P = .902, P = .740, P = .659, P = .219, respectively). The stone-free rate was higher in the elderly age group (P = .002). Presence of partial or complete staghorn stones and number of stones were independently associated with stone-free rates for elderly age group patients (P = .006, P < .001, respectively). Stone burden (≥400 mm²) and presence of partial or complete staghorn stones were significantly associated with complications for the elderly age group patients (P = .038, P = .014, respectively).

Conclusions:

In the young-old, old-old, and oldest-old age group, PCNL appears like the preferred treatment with high stone-free rates but similar complication rates compared to their younger counterpart.

Introduction

Urinary system stone disease (USSD) is a common health problem for all age groups from children to the elderly.¹ The life expectancy of the elderly, the proportion of older people in populations, and the pace of population aging are progressively increasing worldwide.² It is also known that the prevalence of USSD has increased across all ages in various countries.^3,4 Therefore, urologists will continue to deal with many elderly patients with USSD due to the combination of increased longevity and increased prevalence of USSD. Evidence of this has been confirmed by epidemiological studies.^5,6

For years, guidelines have employed percutaneous nephrolithotomy (PCNL) as the recommended treatment for stones larger than 2 cm and will likely remain the standard in the near future.^7,8 PCNL procedures have demonstrated an increasing trend over the years with technological developments, such as miniaturized instruments, likely playing a role.^8,9

It appears inevitable that the number of PCNL surgeries will steadily increase in the elderly. However, increasing patient age alone has shown to be associated with increased postoperative morbidity and mortality.¹⁰ Surgeons performing PCNL surgery in elderly patients in an operating room are like aerobatics doing dangerous aerobatic maneuvers at high altitude. Nevertheless, only a few cohorts have investigated PCNL outcomes in the elderly age group.^11–13 The elderly age group could be classified as young-old (65–69 years), old-old (70–79 years), and oldest-old (80+ years).¹⁴ In this study, our goals were to compare the PCNL outcomes between the elderly and young patient groups and to examine the differences between the young-old, old-old, and oldest-old patients. To our knowledge, this is one of the largest series in this age group reported to date.

Materials and Methods

The Institutional Review Board (IRB) approval was obtained from the Hacettepe University Faculty of Medicine IRB committee. We retrospectively analyzed the data of 8191 renal units that underwent PCNL from September 1997 to March 2020 at three academic institutions in Turkey. Patients under 18 years and patients who underwent bilateral PCNL were excluded from this study.

Kidney ureter bladder imaging, intravenous urography, ultrasonography (USG), and noncontrast computed tomography (NCCT) were used for preoperative imaging. All patients received prophylactic or therapeutic culture-guided antibiotics after hospital admission. Percutaneous access was planned by fluoroscopic guidance with retrograde pyelography or ultrasonographic guidance and tract dilatation was performed with Amplatz Dilators^® (Cook Medical), balloon dilators, or metal dilators. The primary surgeon decided the sheath diameter and surgical procedure according to patient and kidney stone characteristics. Antegrade pyelography was performed 2–3 days after the surgery for patients with nephrostomy. After ruling out distal ureteral obstruction via antegrade pyelography, nephrostomy was clamped and removed. Patients without early postoperative complications, such as urine leakage from the nephrostomy tract or fever, were discharged from the hospital. If a J stent was placed following PCNL procedure, it was removed postoperatively on the third or fourth week. Residual stone fragments were assessed postoperatively using either USG or NCCT within 4–6 weeks.

Complications within 30 days of the surgical procedure were evaluated by Clavien's classification and were categorized as major (Clavien 3–5) and minor (Clavien 1–2).¹⁵ The American Urological Association classification was used for the classification of complete and partial staghorn stones.¹⁶ Complete clearance in postoperative imaging was accepted as a success. The number of stones was categorized based on the presence of single or multiple stones in preoperative imaging. Patients with partial or complete staghorn stones were classified as multiple stones. The American Society of Anesthesiologists (ASA) score was used to determine the general health conditions of patients during the preoperative period. ASA scores 3–4 were classified as high and ASA scores 1–2 were classified as low.

The patients were classified into two groups: the young (18–64 years) and elderly (65+ years) age groups. Patients who were older than 65 years were further classified into three groups: young-old (65–69 years), old-old (70–79 years), and oldest-old (80+ years).

Age groups were compared in terms of gender, operation side, number of stones (single or multiple), stone burden (cm²), presence of complete or partial staghorn stone, stone location in the kidney (proximal ureter/renal pelvis or calyces), ASA score, stone-free rates, number of tracts (single or multiple), puncture level (supracostal or infracostal), blood transfusion rates, operation time (minutes), postoperative urinary tract infections (UTI), additional treatment requirement, hospitalization time (days), and complication rates. Univariate and multivariate statistical analyses were performed to determine factors affecting stone-free and complication rates.

All statistical analyses were performed using the SPSS 24.0 (IBM Corp., Chicago, IL) software for Windows. Univariate analysis and Chi-Square Test was used for nominal data, while the Mann–Whitney U-test and Kruskal–Wallis test were used for nonparametric variables. Mean ± standard deviation was used for parametric variables, while the median (range of minimum and maximum) was used for nonparametric variables. Binary logistic regression analysis was used in multivariate analysis. A P < .05 was considered statistically significant.

Results

The median age of the patients at the time of surgery was 47 years (18–100) and the female to male ratio was 1:1.72 (3008 female versus 5183 male). The median stone burden and operation time was 400 mm² (25–8500) and 75 minutes (30–360), respectively. It was determined that 587 patients (7.2%) had previously undergone PCNL and 802 patients (9.8%) had undergone open or laparoscopic kidney surgery. A total of 54.2% of patients underwent left side surgery and 45.8% underwent right side surgery. It was determined that the rates of patients with complete or partial staghorn and multiple stones were 12% and 53.5%, respectively. When the location of single stones was evaluated in the kidney, it was determined that 45.9% were localized in the renal pelvis or proximal ureter and 54.1% had calyceal localization.

The stone-free rate was 78.9%. Of the 8191 PCNL procedures, 82.9% were performed with single tract puncture, while 17.1% were performed with multiple tracts. A total of 393 patients (4.8%) needed additional surgeries. As an additional procedure, the number of patients who underwent PCNL, ureterorenoscopy, extracorporeal shock wave lithotripsy, and laparoscopic ureterolithotomy were determined to be 213 (2.6%), 23 (0.3%), 156 (1.9%), and 1 (0%), respectively. We had an overall incidence of 16.4% of adverse events. The number of patients with Clavien Grade 1, 2, 3, 4, and 5 complications were 209 (2.6%), 864 (10.5%), 222 (2.7%), 35 (0.4%), and 7 (0.1%), respectively. The most common grade 1 complication was a fever that required antipyretics, which developed in 328 (4%) patients. Among the grade 2 complications, 265 cases (3.2%) developed postoperative UTI, which required treatment by appropriate antibiotics and 640 (7.8%) patients required blood transfusion. Postoperative J stent placement (N = 121, 1.5%) for prolonged urine leakage was the most common grade 3 complication. Twenty-six (0.3%) patients needed renal angiography and embolization due to prolonged hematuria. As grade 4 complications, postoperative sepsis occurred at a rate of 0.2% (N = 17). Seven patients (0.1%) were lost due to postoperative sepsis and myocardial infarctions. The median hospitalization duration after surgeries was determined to be 4 days (1–67).

Stone burden, operation side, and number of stones were similar between the elderly and young patients (P = .539, P = .729, P = .261, respectively). It was determined that female patients, high ASA score, complete or partial staghorn stones, and pelvic or proximal ureter stones were significantly higher in the elderly age group (P < .001, P < .001, P = .002, P = .001/P = .001, respectively) (Table 1). When the elderly group was evaluated, stone burden, gender, operation side, complete or partial staghorn stones, number of stones, and stone locations were similar between the young-old, old-old, and oldest-old groups (P = .492, P = .357, P = .726, P = .289, P = .292, P = .969/P = .590, respectively). However, ASA scores were significantly higher in oldest-old group (P = .018) (Table 2).

Table 1.

The Demographics and Preoperative Characteristics of Patients According to Age

	<65 Years (young)	≥65 Years (elderly)	P
N (%)	7352 (89.8)	839 (10.2)	—
Stone burden (mm²) (median)	400 (25–8500)	400 (25–7000)	.539^*
(min–max)	400 (25–8500)	400 (25–7000)	.539^*
Gender (%)
Female	35.8	44.5	<.001^**
Male	64.2	55.5	<.001^**
ASA score (%)
Low	98.3	92.8	<.001^**
High	1.7	7.2	<.001^**
Operation side (%)
Left	54.1	54.8	.729^**
Right	45.9	45.2	.729^**
Complete and partial staghorn stone (%)
Yes	11.6	15.3	.002^**
No	88.4	84.7	.002^**
Number of stones (%)
Single	46.3	48.4	.261^**
Multiple	53.7	51.6	.261^**
Stone location^a (%)
Proximal ureter	1.5	3.3	.001^**
Pelvis	43.5	50.9
Upper calyceal	7.5	4.9
Middle calyceal	8.1	8.7
Lower calyceal	39.4	32.2
Stone location^a (%)
Pelvis/proximal ureter	45	54.2	.001^**
Calyces	55	45.8	.001^**

Italic values are statistically significant.

For patients with single stone.

P: univariate analysis (Mann–Whitney U-test).

P: univariate analysis (Chi-square test).

ASA, American Society of Anesthesiologists.

Table 2.

The Comparison of Demographics and Preoperative Characteristics of Elderly Patients

	65–69 Years (young-old)	70–79 Years (old-old)	80+ Years (oldest-old)	P
N (%)	480 (57.2)	324 (38.6)	35 (4.2)	—
Stone burden (mm²) (median)	400 (25–7000)	400 (25–2500)	400 (100–1000)	.492^*
(min–max)	400 (25–7000)	400 (25–2500)	400 (100–1000)	.492^*
Gender (%)
Female	46.5	41.4	45.7	.357^**
Male	53.5	58.6	54.3	.357^**
ASA score (%)
1	96.9	88.6	83.3	.018^**
2	3.1	11.4	16.7	.018^**
Operation side (%)
Left	54.2	56.2	50	.726^**
Right	45.8	43.8	50	.726^**
Complete and partial staghorn stone (%)
Yes	15.9	15.3	5.9	.289^**
No	84.1	84.7	94.1	.289^**
Number of stones (%)
Single	46	51.6	51.4	.292^**
Multiple	54	48.4	48.6	.292^**
Stone location^a (%)
Proximal ureter	2.8	3.7	5.9	.969^**
Pelvis	49.8	51.6	58.8
Upper calyceal	5.2	5	0
Middle calyceal	8.5	9.3	5.9
Lower calyceal	33.8	30.4	29.4
Stone location^a (%)
Pelvis/proximal ureter	52.6	55.3	64.7	.590^**
Calyces	47.4	44.7	35.3	.590^**

Italic values are statistically significant.

For patients with single stone.

P: univariate analysis (Kruskal–Wallis).

P: univariate analysis (Chi-square test).

ASA, American Society of Anesthesiologists.

Hospitalization duration, operation time, puncture level, complications, blood transfusion, postoperative UTI, and major complications rates were similar between the young and elderly age groups (P = .408, P = .532, P = .172, P = .902, P = .740, P = .659, and P = .219, respectively). It was determined that the stone-free rate was higher in the elderly age group (P = .002), while postoperative hemoglobin decrease, multiple tract PCNL, and additional procedure rates were higher in the young age group (P = .004, P = .006, and P = .002, respectively) (Table 3). Perioperative and postoperative outcomes were similar in the elderly age group (Table 4).

Table 3.

Perioperative and Postoperative Outcomes in Groups

	<65 Years (young)	≥65 Years (elderly)	P
Hospitalization (days) (median)	4 (1–60)	4 (1–67)	.408^*
(min–max)	4 (1–60)	4 (1–67)	.408^*
Operation time (minutes) (median)	75 (30–360)	75 (30–260)	.532^*
(min–max)	75 (30–360)	75 (30–260)	.532^*
Hemoglobin decrease (g/dL) (median)	1.2 [(−5.3) to 8.6]	1.1 [(−2.9) to 5.3]	.004^*
(min–max)	1.2 [(−5.3) to 8.6]	1.1 [(−2.9) to 5.3]	.004^*
Success (%)
Stone free	78.4	83.2	.002^**
Residue	21.6	16.8	.002^**
Number of tracts (%)
Single	82.4	86.9	.006^**
Multiple	17.6	13.1	.006^**
Puncture level (%)
Supracostal	5.5	4.4	.172^**
Infracostal	94.5	95.6	.172^**
Complications (%)
Positive	16.4	16.2	.902^**
Negative	83.6	83.8	.902^**
Major complications (%)
≥Clavien grade 3	3.1	3.9	.219^**
<Clavien grade 3	96.9	96.1	.219^**
Blood transfusion (%)
Positive	7.8	8.1	.740^**
Negative	92.2	91.9	.740^**
Postoperative urinary tract infection (%)
Positive	3.3	3	.659^**
Negative	96.7	97	.659^**
Additional procedure (%)
Positive	5	2.6	.002^**
Negative	95	97.4	.002^**

Italic values are statistically significant.

P: univariate analysis (Mann–Whitney U-test).

P: univariate analysis (Chi-square test).

Table 4.

The Comparison of Perioperative and Postoperative Outcomes in Elderly Age Group

	65–69 Years (young-old)	70–79 Years (old-old)	80+ Years (oldest-old)	P
Hospitalization (days) (median)	4 (1–67)	4 (1–67)	3 (1–7)	.295^*
(min–max)	4 (1–67)	4 (1–67)	3 (1–7)	.295^*
Operation time (minutes) (median)	75 (30–260)	75 (30–260)	70 (30–135)	.610^*
(min–max)	75 (30–260)	75 (30–260)	70 (30–135)	.610^*
Hemoglobin decrease (g/dL) (median)	1.1 [(−2.9) to 5.3]	1.2 [(−2.9) to 5]	1.1 [(−1.1) to 3.2]	.582^*
(min–max)	1.1 [(−2.9) to 5.3]	1.2 [(−2.9) to 5]	1.1 [(−1.1) to 3.2]	.582^*
Success (%)
Stone free	82.6	84.1	82.4	.844^**
Residue	17.4	15.9	17.6	.844^**
Number of tracts (%)
Single	87.5	86.7	81.2	.608^**
Multiple	12.5	13.3	18.8	.608^**
Puncture level (%)
Supracostal	5	4	0	.344^**
Infracostal	95	96	100	.344^**
Complications (%)
Positive	16.5	16.7	8.6	.455^**
Negative	83.5	83.3	91.4	.455^**
Major complications (%)
≥Clavien grade 3	4	4.3	0	.458^**
<Clavien grade 3	96	95.7	100	.458^**
Blood transfusion (%)
Positive	7.9	9	2.9	.443^**
Negative	92.1	91	97.1	.443^**
Postoperative urinary tract infection (%)
Positive	2.7	3.4	2.9	.853^**
Negative	97.3	96.6	97.1	.853^**
Additional procedure (%)
Positive	3.3	1.9	0	.266^**
Negative	96.7	98.1	100	.266^**

Italic values are statistically significant.

P: univariate analysis (Kruskal–Wallis).

^**P: univariate analysis (Chi-square test).

Presence of partial or complete staghorn stones and number of stones were independently associated with stone-free rates for patients in the elderly age group (P = .006, odds ratio [OR] = 2.045; P < .001, OR = 3.378; respectively). Stone burden (≥400 mm²) and the presence of partial or complete staghorn stones were found to be significantly associated with complications for patients in the elderly age group (P = .038, OR = 0.569; P = .014, OR = 0.478; respectively) (Table 5).

Table 5.

Univariate and Multivariate Analysis for Factors Affecting Complications and Stone-Free Rates for Elderly Age Group

	Stone-free			Complications
	(%)	P^*	P^** OR (95% CI)	(%)	P^*	P^** OR (95% CI)
Operation side
Left	83.4	.670	—	15.8	.726	—
Right	82.3	.670	—	16.8	.726	—
Gender
Female	84.2	.477	—	19.3	.030	.085 0.661 (0.413–1.059)
Male	82.3	.477	—	13.7	.030	.085 0.661 (0.413–1.059)
Complete or partial staghorn stone
Yes	63.1	<.001	.006 2.045 (1.229–3.402)	28.2	<.001	.014 0.478 (0.265–0.860)
No	86.7	<.001	.006 2.045 (1.229–3.402)	14.4	<.001	.014 0.478 (0.265–0.860)
Previous PCNL history
Yes	77.4	.242	—	17	.875	—
No	83.6	.242	—	16.2	.875	—
Previous open kidney surgery
Yes	83.1	.987	—	17.6	.740	—
No	83.2	.987	—	16.1	.740	—
Number of stones
Single	91.5	<.001	<.001 3.378 (2.047–5.574)	13.5	.025	.183 0.682 (0.388–1.198)
Multiple	75.3	<.001	<.001 3.378 (2.047–5.574)	19.3	.025	.183 0.682 (0.388–1.198)
Stone burden (mm²)
<400	87.9	.005	.976 0.993 (0.620–1.589)	13.1	.002	.038 0.569 (0.334–0.970)
≥400	80.3	.005	.976 0.993 (0.620–1.589)	21.8	.002	.038 0.569 (0.334–0.970)
Tract number
Single	84.5	.217	—	13.6	.043	.448 0.785 (0.421–1.466)
Multiple	79	.217	—	22.2	.043	.448 0.785 (0.421–1.466)
Puncture level
Supracostal	77.8	.376	—	21.6	.361	—
Infracostal	83.4	.376	—	16	.361	—

Italic values are statistically significant.

P: univariate analysis (Chi-square test).

P: multivariate analysis (binary logistic regression).

CI, confidence interval; OR, odds ratio; PCNL, percutaneous nephrolithotomy.

Discussion

A worldwide increase in life span and prevalence of USSD has resulted in a higher number of PCNL surgeries being performed in elderly patients.^5,6 A recent meta-analysis compared PCNL between young (<65 years old) and elderly (≥65 years old) patients and showed that there was no difference in terms of efficacy, operating time, and average length of stay, except for blood transfusions.¹⁷ Our study revealed higher stone-free rates in the elderly age group compared with their younger counterpart. However, there was no difference in terms of hospitalization duration, operation time, puncture level, general complications, blood transfusion, postoperative UTI, and major complications rate between the young and elderly age group in our cohort.

We found an 81.5% stone-free rate in the elderly age group. A review of the literature revealed that a stone-free rate of 60.7%–89% has been reported in the elderly age group series.^{11,13,18–21} Residual fragments <4 mm was defined as success by some studies in the literature.^20,21 However, various definitions of success should be considered while interpreting the results of clinical trials. Although residual fragments can be seen as clinically insignificant, they might act as a nidus for recurrent stones in the future and cause pain and infections.²² The potential complications and additional treatments due to residual fragments necessitate a complete stone-free status after PCNL. Therefore, success was defined as complete stone-free status and any residual fragments were considered as failure in our study. The fact that the stone-free rates were significantly higher in the elderly age group may be due to the surgeons' meticulousness during the procedure. In addition, this high stone-free rate also provided significantly lower additional procedure rates in the elderly age group.

The main issue concerning PCNL in the elderly age group may be the higher probability of complications, which may be considered high. In the literature, the complication rate ranges from 14.1% to 19.9% in the elderly group,^11,13,17,19 while the complication rate was 16.2% in our study. Moreover, there was no difference between the elderly age group and the young age group. Stratification of the elderly age group into young-old, old-old, and oldest-old did not reveal any differences in terms of the general and major complications according to Clavien's classification.

Bleeding and blood transfusions are the most common complications after PCNL.²³ In the literature, blood transfusions have been reported to range from 2.2% to 10.6% in the elderly age group, especially in the recent series,^11,17,18,24 while it was 8.1% in the present study. Despite the similar transfusion rates between the young and elderly age groups, the decrease in hemoglobin levels was significantly higher in the young age group. This finding could be a result of the surgeons' braver approach, which may have significantly increased the number of tracts in the young age group. The same surgeons were likely very careful with the elderly age group, therefore, there were no differences in blood transfusion rates, and the decrease in hemoglobin levels in the young-old, old-old, and oldest-old group suggests that PCNL can also be applied safely in the elderly age group in health care centers with experienced surgeons.

In our study, partial or complete staghorn stones were significantly associated with both complications and stone-free rates in the elderly age group. Forced maneuvers or multiple tracts may have been needed to remove staghorn stones, which may have played a role in the high complication and low stone-free rates for the elderly patients. The high rate of partial or complete staghorn stones and reasonable complication rates in the elderly age group supports the safety and efficacy of PCNL in this fragile group.

There were some limitations in our study. The first and most important limitation was the retrospective design. Second, comorbidities and medications, such as anticoagulants, were not included in the study due to the lack of data. Another limiting factor was the lack of stone analysis information. Aside from the aforementioned limitations, we believe that the results of the existing study provide a significant contribution to the literature as there have only been a small number of studies that examine the results of PCNL in the elderly age group, especially one similar to the size of our patient series, which spans across three academic centers in Turkey.

In the young-old, old-old, and oldest-old age groups, PCNL appears to be the preferred treatment method with similar complication rates and high stone-free rates compared with their younger counterpart. We found that most complications were low grade. In our study, multiple stones and partial or complete staghorn stones were independently associated with stone-free rates, while partial or complete staghorn stones and high stone burden (≥400 mm²) were significantly associated with complications in the elderly age group. In the era of an aging population, a patient's age alone might not be considered as preference criteria in clinical decision making for PCNL.

Availability of Data and Material

The data that support the findings of this study are available from the corresponding author, H.B.H., upon reasonable request.

Footnotes

Acknowledgment

The authors thank Minimal Invasive Urology Society—Turkey for its contribution to this article.

Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was received for this article.

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