Globally, the prevalence, incidence, and recurrence of kidney stones are increasing [1,2]. With the development of endoscopes and novel instruments, such as lasers, minimally invasive endoscopic surgery is performed to manage kidney stones [3,4]. Although the goal of these stone surgeries is complete stone removal, postoperative residual fragments (RFs) can sometimes be left. Thus, patients can have concerns regarding stone regrowth, stone-related events, and the possible need for interventional procedures for RFs (even though those are asymptomatic and small). Hence, postoperative RFs can affect the health-related quality of life (HRQOL) of patients.

The concerns about the impact of kidney stones on patients’ quality of life (QOL) have increased. Accordingly, questionnaires have been developed to assess a patient’s QOL [5,6]. Penniston et al. [7] developed the Wisconsin Stone Quality of Life Questionnaire (WISQOL), which can evaluate the QOL of patients in whom kidney stones form and those who underwent stone surgery. The WISQOL is commonly used to assess the QOL of patients with kidney stones in North America.

An agreement on the definitions for several categories related to RFs is needed. Successful outcomes in kidney stone surgery emphasized the stone-free (SF) status. Nevertheless, no official consensus exists on defining the clinical SF status [8]. In addition, the choice of imaging modalities and the time of postoperative imaging are not standardized [9]. There is also no consensus regarding the schedule for a second-look intervention [10]. The RF size and location after the interventions can be the major predictors for clinically significant symptoms and stone events requiring inter-vention. Traditionally, inferring, a second-look intervention may be performed because of the possibility of a stone event based on RF location and size [11-13].

The impact of RFs on postoperative HRQOL can determine whether to perform the second-look intervention. Never-theless, the influence of postoperative RFs on the patients’ HRQOL is unclear. The HRQOL was assessed in some studies after extracorporeal shock wave lithotripsy (ESWL), but these studies used the general SF-36 questionnaire, which is not a stone-specific instrument [14,15]. Recent studies analyzed the patients’ HRQOL after interventional treatment using WISQOL, a stone-specific instrument. On the other hand, a study performed in North America did not subdivide the group according to the surgical method [16]. According to a Japanese study, the patients’ QOL can be affected by the treatment type, ureteral stent placement, and hospital stay [17]. Therefore, evaluating the patients’ QOL after subdividing the group according to surgery type is necessary. Using the Korean version of the WISQOL (K-WISQOL) developed and validated in 2020 [18], this study evaluated the QOL of patients who underwent endoscopic kidney stone surgery at the authors’ institution. In addition, the effects of RFs on patients’ HRQOL were assessed using the K-WISQOL according to the surgical method.

1. Research Ethics

The Ethics Committee of Kyungpook National University Hospital (approval number: KNUH 2023-04-042) approved this study. This study was performed according to the ethical standards in the 1964 Declaration of Helsinki and its later amendments. Data collection and analysis were performed after gaining approval from the institutional review board. The institutional review board of Kyungpook National University Hospital waived the need for informed consent because this study was performed retrospectively.

2. Patients and Methods

This study included patients with kidney stones who underwent retrograde intrarenal surgery (RIRS) or per-cutaneous nephrolithotomy (PCNL) from January 2021 to September 2023. Patients with simultaneous ureter stones, those who had other surgeries besides RIRS and PCNL at the same time, and those who did not complete the K-WISQOL were excluded. Finally, 156 patients were enrolled in this study. Of the 156 patients, 95 underwent RIRS, and 61 underwent PCNL for kidney stones. Each group was divided into RF and SF subgroups, depending on the presence of RFs. In the RIRS group, there were 73 patients with SF state and 22 with RFs. In the PCNL group, there were 31 patients with SF state and 30 with RFs. The participants completed the K-WISQOL within four weeks before and after treatment. Non-contrast computed tomography (NCCT) was performed within four weeks before and after the surgery in all patients to evaluate stones. The patient was included in the SF subgroup if the RFs were not identified on postoperative imaging because stone-free was defined as having no residual fragments at postoperative NCCT in this study. The patient was included in the RF subgroup if RFs were identified on postoperative imaging. One surgeon performed all surgeries and verbally explained the presence or absence of residual fragments based on the NCCT at the first outpatient visit after surgery. The laterality, multiplicity of stones, and location and diameter of the largest stone were checked before surgery. The surgeon chose the surgical procedure based on the size and location of the kidney stones, as well as the patient’s comorbidities. Post-surgery, the collected stone specimens were analyzed using a physical method. The characteristics of patients and stones, the hospital stay, operation time, postoperative complications, and K-WISQOL scores between SF and RF subgroups in the RIRS and PCNL groups, respectively, were analyzed retrospectively.

3. Korean Version of the Wisconsin Stone Quality of Life Questionnaire Characteristics

The questionnaire consisted of 28 questions with a score of 1-5 points for each item. The total score ranged from 28 to 140 points, with higher scores indicating a higher HRQOL. These 28 questions were grouped intuitively into the following seven domains: (D1) energy and fatigue, (D2) sleep, (D3) work and family, (D4) nutrition and pharma-cological therapies, (D5) physical symptoms, (D6) concerns related to intimacy and travel, and (D7) general emotional well-being.

4. Statistical Analysis

A normality test was performed before comparing the continuous variables because the sample size was small, and normality was not found. Therefore, the continuous variables were recorded as median (interquartile range) and compared using a Mann–Whitney U-test. The categorical variables were recorded as numbers (percentage) and compared using a chi-square or Fisher’s exact test. A Fisher’s exact test was used to compare the categorical variables if the number in each cell was <5. All statistical analyses were performed using IBM SPSS Statistics 19.0 (IBM Co.). A p-value<0.05 indicated statistical significance.

The patients’ baseline characteristics, such as age, gender, body mass index, stone episodes, stone laterality, stone multiplicity and largest stone location, largest stone diameter, and stone composition, were similar in the SF and RF subgroups in the RIRS group (Table 1). The surgical outcomes, such as hospital stay, operation time, duration between the first follow-up and surgery, and complication rates, were similar in the subgroups in the RIRS group. One patient in the SF subgroup underwent percutaneous ne-phrostomy (PCN). Migration of the ureteral stent occurred in this patient two days after surgery, which was removed earlier than intended. After ureteral stent removal, flank pain with hydronephrosis developed because of a ureteral obstruction with a blood clot; thus, a temporary PCN was placed to relieve the pain (Table 2). While the RF subgroup showed significantly higher scores in the preoperative D4 compared to the SF subgroup (14.0 vs. 12.0, p=0.049), the total scores and other domain scores were similar in the two subgroups (Table 2). On the other hand, the post-operative D2 (18.0 vs. 15.0, p=0.021), D3 (24.5 vs. 20.0, p=0.025), D4 (13.0 vs. 11.0, p=0.015), D7 (29.5 vs. 24.0, p=0.024), and total scores (123.0 vs. 108.0, p=0.036) were significantly higher in the RF subgroup (Table 2). On the other hand, the mean changes in the K-WISQOL scores, including the total and all domain scores, were similar in both subgroups (Table 2).

Table 1 Comparison of the patients’ baseline characteristics between the stone-free and residual fragments subgroups in the retrograde intrarenal surgery group.

Variable	SF (n=73)	RF (n=22)	p-value
Age (y)	60.0 [51.5-67.0]	58.0 [47.8-62.8]	0.363a)
Gender Male Female	44 (60.3) 29 (39.7)	15 (68.2) 7 (31.8)	0.503b)
BMI (kg/m2)	24.0 [22.4-25.9]	24.0 [22.3-27.4]	0.761a)
Stone episodes First Recurrent	41 (56.2) 32 (43.8)	15 (68.2) 7 (31.8)	0.315b)
Ureteral stent Absent Present	0 (0.0) 73 (100.0)	0 (0.0) 22 (100.0)	-
Stone laterality Right Left Both Unilaterality Unilateral Bilateral	31 (42.5) 24 (32.8) 18 (24.7) 55 (75.3) 18 (24.7)	8 (36.4) 12 (54.5) 2 (9.1) 20 (90.9) 2 (9.1)	0.133c) 0.145c)
Stone multiplicity Single Multiple	34 (46.6) 39 (53.4)	8 (36.4) 14 (63.6)	0.398b)
Largest stone location Ureteropelvic junction Renal pelvis Upper calyx Mid calyx Lower calyx Staghorn	1 (1.3) 17 (23.3) 14 (19.2) 3 (4.1) 38 (52.1) 0 (0.0)	1 (4.5) 4 (18.2) 2 (9.2) 3 (13.6) 12 (54.5) 0 (0.0)	0.281c)
Longest stone diameter (mm)	10.0 [8.0-14.0]	12.5 [10.0-15.0]	0.063a)
Stone composition Calcium oxalate monohydrate Uric acid Struvite Mucin Mixed	26 (35.6) 6 (8.2) 1 (1.4) 1 (1.4) 39 (53.4)	7 (31.8) 1 (4.6) 0 (0.0) 0 (0.0) 14 (63.6)	0.851c)

Values are presented as the median [interquartile range] or number (%).

In cases of multiple stones, the location and size of the stones were measured based on the largest stone.

Statistically significant at p<0.05.

BMI: body mass index, SF: stone-free, RF: residual fragments.

^a)Mann Whitney U-test.

^b)Chi-square test.

^c)Fisher’s exact test.

Table 2 Comparison of the surgical outcomes and Korean version of the Wisconsin Stone Quality of Life Questionnaire scores between the stone-free and residual fragments subgroups in the retrograde intrarenal surgery group.

Variable	SF (n=73)	RF (n=22)	p-value
Hospital stay (d)	3.0 [3.0-3.0]	3.0 [3.0-3.0]	0.525a)
Operation time (min)	73.0 [60.0-85.0]	82.5 [60.0-105.0]	0.170a)
Duration between the first follow-up and surgery (d)	19.0 [16.0-23.0]	23.0 [17.0-28.0]	0.058a)
Complication No complication Postoperative febrile UTI Intervention ICU care	67 (91.8) 5 (6.8) 1 (1.4) 0 (0.0)	21 (95.5) 1 (4.5) 0 (0.0) 0 (0.0)	1.000b)
Preoperative K-WISQOL scores Energy and fatigue (D1) Sleep (D2) Work and family (D3) Nutrition and pharmacological therapies (D4) Physical symptoms (D5) Concerns related to intimacy and travel (D6) General emotional well-being (D7) Total score	11.0 [9.0-14.0] 16.0 [13.0-18.0] 24.0 [20.0-25.0] 12.0 [10.0-14.0] 16.0 [14.0-18.0] 14.0 [11.0-15.0] 26.0 [20.5-30.0] 117.0 [98.0-130.0]	13.0 [10.3-15.0] 17.0 [15.0-18.0] 25.0 [20.8-25.0] 14.0 [11.5-15.0] 17.0 [14.8-19.0] 14.0 [12.8-15.0] 29.0 [22.0-30.0] 126.5 [112.0-132.3]	0.104a) 0.212a) 0.249a) 0.049a) 0.340a) 0.654a) 0.158a) 0.145a)
Postoperative K-WISQOL scores Energy and fatigue (D1) Sleep (D2) Work and family (D3) Nutrition and pharmacological therapies (D4) Physical symptoms (D5) Concerns related to intimacy and travel (D6) General emotional well-being (D7) Total score	11.0 [9.0-13.0] 15.0 [11.0-18.0] 20.0 [17.0-24.5] 11.0 [9.0-13.0] 15.0 [13.0-18.0] 12.0 [9.0-15.0] 24.0 [19.0-30.0] 108.0 [91.0-124.5]	12.0 [7.8-15.0] 18.0 [14.0-20.0] 24.5 [20.0-25.0] 13.0 [11.8-14.0] 17.0 [14.8-19.3] 13.5 [8.8-15.0] 29.5 [23.8-30.0] 123.0 [105.0-132.8]	0.261a) 0.021a) 0.025a) 0.015a) 0.107a) 0.537a) 0.024a) 0.036a)
Changes in the K-WISQOL scores Energy and fatigue (D1) Sleep (D2) Work and family (D3) Nutrition and pharmacological therapies (D4) Physical symptoms (D5) Concerns related to intimacy and travel (D6) General emotional well-being (D7) Total score	0.0 [-2.0-2.0] -1.0 [-3.5-1.0] -1.0 [-4.5-0.0] 0.0 [-2.5-1.0] 0.0 [-3.0-1.0] 0.0 [-3.0-0.0] 0.0 [-4.5-1.5] -3.0 [-19.5-4.5]	0.0 [-2.8-1.0] 0.0 [-1.5-2.3] 0.0 [-2.5-0.3] -1.0 [-2.0-1.0] 0.0 [-2.0-1.0] 0.0 [-1.5-1.0] 0.0 [-1.0-1.3] -1.0 [-7.8-9.8]	0.652a) 0.085a) 0.334a) 0.989a) 0.344a) 0.617a) 0.304a) 0.349a)

The values are presented as the median [interquartile range] or number (%).

The intervention was the percutaneous nephrostomy insertion.

Change in the K-WISQOL score=postoperative-preoperative K-WISQOL score.

Statistically significant at p<0.05.

UTI: urinary tract infection, ICU: Intensive care unit, K-WISQOL: Korean version of the Wisconsin Stone Quality of Life Questionnaire, SF: stone-free, RF: residual fragments.

^a)Mann Whitney U-test.

^b)Fisher’s exact test.

In the PCNL group, a higher proportion of renal pelvis stones (41.9%) was found in the SF subgroup, while more staghorn stones (46.7%) were identified in the RF subgroup (p=0.021). The mean stone size was significantly larger in the RF subgroup than in the SF subgroup (30.0 vs. 25.0, p=0.015) (Table 3). Consequently, the operation time in the RF subgroup was significantly longer than that in the SF subgroup (92.5 vs. 80.0, p=0.010). One patient in the SF subgroup underwent angioembolization because of postoperative persistent tract site bleeding, and one patient in the RF subgroup was admitted to an intensive care unit due to postoperative pulmonary embolism (Table 4). The pre- and postoperative K-WISQOL scores and mean changes in the K-WISQOL scores were similar in both subgroups (Table 4).

Table 3 Comparison of the patients’ baseline characteristics between the stone-free and residual fragments subgroups in the percutaneous nephrolithotomy group.

Variable	SF (n=31)	RF (n=30)	p-value
Age (y)	61.0 [50.0–64.0]	53.5 [48.3-63.3]	0.254a)
Gender Male Female	18 (58.1) 13 (41.9)	20 (66.7) 10 (33.3)	0.488b)
BMI (kg/m2)	23.7 [22.6-26.8]	25.3 [22.0-27.5]	0.564a)
Stone episodes First Recurrent	19 (61.3) 12 (38.7)	14 (46.7) 16 (53.3)	0.252b)
Nephrostomy Absent Present	6 (19.4) 25 (80.6)	5 (16.7) 25 (83.3)	0.785b)
Ureteral stent Absent Present	28 (90.3) 3 (9.7)	23 (76.7) 7 (23.3)	0.182c)
Stone laterality Right Left Unilaterality Unilateral Bilateral	6 (19.4) 25 (80.6) 31 (100.0) 0 (0.0)	11 (36.7) 19 (63.3) 30 (100.0) 0 (0.0)	0.132b)
Stone multiplicity Single Multiple	18 (58.1) 13 (41.9)	14 (46.7) 16 (53.3)	0.373b)
Largest stone location Ureteropelvic junction Renal pelvis Upper calyx Mid calyx Lower calyx Staghorn	1 (3.2) 13 (41.9) 1 (3.2) 9 (29.1) 0 (0.0) 7 (22.6)	3 (10.0) 3 (10.0) 3 (10.0) 7 (23.3) 0 (0.0) 14 (46.7)	0.021c)
Longest stone diameter (mm)	25.0 [20.0-27.0]	30.0 [20.0-46.3]	0.015a)
Stone composition Calcium oxalate monohydrate Uric acid Struvite Brushite Mixed	6 (19.4) 6 (19.4) 3 (9.6) 0 (0.0) 16 (51.6)	5 (16.7) 3 (10.0) 1 (3.3) 1 (3.3) 20 (66.7)	0.488c)
Tract size 18 Fr 24 Fr 30 Fr	9 (29.0) 6 (19.4) 16 (51.6)	5 (16.7) 4 (13.3) 21 (70.0)	0.344c)

The values are presented as median [interquartile range] or number (%).

In cases of multiple stones, the location and size of the stones were measured based on the largest stone.

Statistically significant at p<0.05.

BMI: body mass index, SF: stone-free, RF: residual fragments.

^a)Mann Whitney U test.

^b)Chi-square test.

^c)Fisher’s exact test.

Table 4 Comparison of the surgical outcomes and the Korean version of the Wisconsin Stone Quality of Life Questionnaire scores between the stone-free and residual fragments subgroups in the percutaneous nephrolithotomy group.

Variable	SF (n=31)	RF (n=30)	p-value
Hospital stay (d)	7.0 [7.0-8.0]	7.0 [6.0-8.0]	0.976a)
Operation time (min)	80.0 [75.0-95.0]	92.5 [80.0-110.0]	0.010a)
Duration between the first follow-up and surgery (d)	19.0 [15.0-26.0]	21.0 [15.0-28.0]	0.816a)
Complication No complication Postoperative febrile UTI Intervention ICU care	28 (90.3) 2 (6.5) 1 (3.2) 0 (0.0)	29 (96.7) 0 (0.0) 0 (0.0) 1 (3.3)	0.492b)
Preoperative K-WISQOL scores Energy and fatigue (D1) Sleep (D2) Work and family (D3) Nutrition and pharmacological therapies (D4) Physical symptoms (D5) Concerns related to intimacy and travel (D6) General emotional well-being (D7) Total score	12.0 [9.0-14.0] 16.0 [13.0-18.0] 23.0 [18.0-25.0] 12.0 [11.0-14.0] 16.0 [13.0-18.0] 13.0 [11.0-15.0] 27.0 [22.0-30.0] 119.0 [94.0-130.0]	12.0 [10.0-15.0] 17.0 [15.0-19.0] 24.0 [20.0-25.0] 13.0 [11.0-15.0] 16.0 [14.0-18.0] 14.0 [11.0-15.0] 26.5 [22.0-30.0] 119.5 [109.5-133.3]	0.488a) 0.159a) 0.393a) 0.597a) 0.766a) 0.520a) 0.872a) 0.507a)
Postoperative K-WISQOL scores Energy and fatigue (D1) Sleep (D2) Work and family (D3) Nutrition and pharmacological therapies (D4) Physical symptoms (D5) Concerns related to intimacy and travel (D6) General emotional well-being (D7) Total score	12.0 [9.0-15.0] 18.0 [12.0-19.0] 22.0 [20.0-25.0] 13.0 [11.0-15.0] 16.0 [14.0-20.0] 14.0 [11.0-15.0] 29.0 [23.0-30.0] 124.0 [99.0-133.0]	13.0 [11.8-15.0] 18.0 [16.0-19.0] 24.5 [21.0-25.0] 13.0 [11.8-15.0] 17.0 [15.8-20.0] 14.0 [12.0-15.0] 29.00 [25.5-30.0] 128.5 [114.0-133.0]	0.210a) 0.228a) 0.083a) 0.537a) 0.457a) 0.905a) 0.796a) 0.367a)
Changes in the K-WISQOL scores Energy and fatigue (D1) Sleep (D2) Work and family (D3) Nutrition and pharmacological therapies (D4) Physical symptoms (D5) Concerns related to intimacy and travel (D6) General emotional well-being (D7) Total score	0.0 [-2.0-2.0] 0.0 [-2.0-1.0] 0.0 [-4.0-3.0] 0.0 [-1.0-2.0] 1.0 [-1.0-3.0] 0.0 [-1.0-2.0] 0.0 [-1.0-5.0] 3.0 [-3.0-11.0]	0.0 [-1.0-2.0] 0.0 [-1.0-2.0] 0.0 [-1.0-1.3] 0.0 [-1.0-2.0] 1.5 [0.0-3.0] 0.0 [-1.0-1.0] 0.5 [0.0-4.0] 3.0 [-2.5-15.3]	0.457a) 0.474a) 0.724a) 0.866a) 0.636a) 0.607a) 0.855a) 0.885a)

Values are presented as median [interquartile range] or number (%).

The intervention was angioembolization.

Intensive care unit care was due to postoperative pulmonary embolism.

Change in the K-WISQOL score=postoperative-preoperative K-WISQOL score.

Statistically significant at p<0.05.

UTI: urinary tract infection, ICU: Intensive care unit, K-WISQOL: Korean version of the Wisconsin Stone Quality of Life Questionnaire, SF: stone-free, RF: residual fragments.

^a)Mann Whitney U-test.

^b)Fisher’s exact test.

Kidney stone disease (KSD) can significantly affect patients. In addition to the classic symptoms of pain, nausea, and vomiting, KSD negatively impacts the HRQOL, even in the absence of stone-related events. Thus, it negatively affects physical well-being, daily life, work, relationships, and family life [19]. The outcome assessment in treating KSD is traditionally recorded using objective outcome measures, such as SF status and complication rate. On the other hand, patient-reported outcome measures have emerged as an improved tool to address HRQOL as a part of the evolution to shift healthcare to a more patient-orientated respect [6]. In recent years, there has been a continuous rise in the use of patient-reported outcome measures in urology. The two most commonly used questionnaires are the 36-Item Short Form health survey (SF-36) and the Patient-Reported Outcomes Measurement Information System. Stone-di-sease-specific tools, such as the WISQOL, have been established and used to evaluate the QOL of patients with kidney stones [20].

Penniston and Nakada [21] conducted the first study on QOL in kidney stone formers in 2007. They analyzed 189 adults with a history of urolithiasis using a mail survey. The SF-36 was used to evaluate the patients’ QOL, and the responding kidney stone formers had lower scores in the ‘bodily pain’ and ‘general health’ domains than those without kidney stones [21]. Bensalah et al. [5] also showed that patients with urolithiasis had lower scores in 5 out of 8 SF-36 domains. They compared these patients with the American general population in a physical composite summary and suggested that KSD negatively impacts the perception of physical and mental well-being [5]. The QOL of patients with kidney stones might be worse, even without kidney stone episodes, because kidney stones are a recurrent disease with serious related symptoms. Thus, the QOL of patients with kidney stones could be worse if RFs remain after interventional procedures.

Several studies have analyzed the effects of RF on the patients’ HRQOL. Sahin et al. [14,15] monitored patients who had undergone ESWL for kidney stones over one to three months post-treatment. They reported that the HRQOL can be affected by the size of the RF. Streeper et al. [16] examined patients who had undergone surgical treatments for renal stones, including Double J stent insertion, uretero-scopic lithotripsy, PCNL, shock wave lithotripsy, and nephrectomy, ranging from one to 24 months following their procedures. In this study, the HRQOL was similar in the RF and SF subgroups, and additional surgical treatment to reach the SF status worsened the HRQOL. Similarly, Okada et al. [17] examined patients who received ESWL, uretero-scopy lithotripsy, and endoscopic combined intrarenal surgery within one month after treatment. This study showed that improving patients’ HRQOL after surgery was unrelated to the SF status, but the SF status was identified as a factor influencing emotional recovery.

The HRQOL can be influenced by RFs and interventional procedures. Atis et al. [22] reported that patients with renal stones managed by ESWL showed more favorable HRQOL scores than patients managed by RIRS in the short term. Di Mauro et al. [23] reported that patients who underwent RIRS reported higher anxiety and depression scores compared to patients who underwent PCNL. The social and vitality scores differed significantly in the two groups. Therefore, the enrolled patients were divided into two groups depending on the surgical method, RIRS or PCNL, to minimize the effect of the operation type on the patients’ HRQOL. Furthermore, the impact of RFs on HRQOL was analyzed in the same surgery group.

Interestingly, the postoperative D2, D3, D4, and D7 domain scores and total WISQOL scores were significantly better in the RF subgroup after RIRS than the SF subgroup, while the preoperative scores were not statistically different, except for the D4 domain scores, between the two groups. Although the reason why the postoperative WISQOL scores were higher in the RF subgroup is unclear, it might be due to several unmeasured factors, such as more exquisite patients and more basketing, which can induce post-operative pain or irritating symptoms because of the higher chance of urothelial mucosal abrasion, as well as more cases of improper ureteral stent position in the SF subgroup. Nevertheless, the overall QOL was similar in the two groups after RIRS because the mean changes in scores were similar.

According to the assumption, patients with RFs after PCNL might have lower HRQOL scores than the SF subgroup. On the other hand, the mean changes in the total WISQOL scores and all subdomain scores after PCNL were similar in the SF and RF subgroups. This study assumed that patients who underwent PCNL usually have relatively large-sized stones and a higher risk of experiencing stone-related symptoms. After surgery, the patients could visually confirm that many stone fragments had been removed. Even if some RFs remained, a considerable portion of the large calculus had been removed, and the stone-related symptoms relatively decreased, which became a factor in improving the QOL for patients with RFs.

This study assessed the patients’ QOL after kidney stone surgery using the K-WISQOL. By incorporating patient-re-ported outcomes, physicians can gain valuable insights into the real-life impact of the surgical procedures on the individuals’ daily lives beyond merely evaluating the surgical success rates. Although this study found that postoperative RFs did not impair the patients’ QOL, RFs can cause damage in some patients. Proper follow-up and additional treatment strategies must be planned and discussed with patients because asymptomatic RFs can regrow and progress to symptomatic RFs over time [12,24-26]. Repeat interventional therapy may be beneficial if RFs have a risk of becoming symptomatic or causing obstruction, which can cause renal function deterioration over time.

Achieving the SF status in a single procedure is important, but attempting excessive surgery to remove kidney stones can lead to serious complications, such as sepsis or renal damage. This study showed that the factor affecting the patients’ QOL in the short term after stone surgery is not the presence of RFs. Therefore, if the complete removal of kidney stones is challenging in a single procedure and clinically insignificant residual fragments are expected, planning a proper surgical strategy and discontinuing surgery at an appropriate point might be a better choice, considering the patient’s QOL.

Further research is needed to confirm the long-term effects of RFs on the patients’ QOL. Although the short-term follow-up provided valuable initial insights, monitoring patients over an extended period is essential for under-standing how RFs might influence patients’ well-being over the long term. Long-term follow-up data will enable researchers to identify any delayed effects of RFs and determine if the initial negative impact persists or changes over time.

The retrospective nature and relatively short follow-up are notable limitations. Future studies will be enhanced by prospective data collection and extended follow-ups to understand the relationship between RFs and the patients’ QOL. In addition, exploring other patient-related factors, such as pain, complications, and psychological well-being, could provide a more comprehensive assessment of the QOL.

This study highlights the importance of considering the patients’ QOL in the context of kidney stone surgery. RFs might not influence the patients’ short-term QOL outcomes after RIRS and PCNL. Thus, healthcare providers can make more informed decisions in tailoring treatment approaches that optimize surgical success and patients’ well-being. Nevertheless, further research with an extended follow-up is warranted to understand the long-term effects of RFs.

This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (2022R1I1A3069482) (2023R1A2C3003807), by the Korean Fund for Regenerative Medicine (KFRM) grant funded by the Korea government (the Ministry of Science and ICT, the Ministry of Health & Welfare) (23A0206L1), and by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HR22C1832).

No potential conflict of interest relevant to this article was reported.

No funding to declare.

S.H.L.: conceptualisation and manuscript writing, J.K.K.: data collection, J.W.C.: data collection, Y.S.H.: statistical analysis, J.N.L.: study design and coordination, S.H.C.: investigation, H.T.K.: investigation, T.H.K.: study design and coordination, E.S.Y.: data curation, T.G.K.: funding acquisi-tion and critical revision, B.S.K.: conceptualisation and critical revision. All authors read and approved the final manuscript.