• Users Online: 948
  • Print this page
  • Email this page

Table of Contents
Year : 2019  |  Volume : 30  |  Issue : 5  |  Page : 226-231

Presence of residual stones is not a contraindication for tubeless percutaneous nephrolithotomy

Department of Urology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chia-Yi, Taiwan

Date of Submission27-Nov-2018
Date of Decision07-Feb-2019
Date of Acceptance11-Mar-2019
Date of Web Publication24-Oct-2019

Correspondence Address:
Yeong-Chin Jou
Department of Urology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, No. 539, Chung-Hsiao Road, Chiayi
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/UROS.UROS_137_18

Get Permissions


Objective: The objective of this study was to evaluate the safety of performing tubeless percutaneous nephrolithotomy (PCNL) for patients with residual stones. Materials and Methods: This study was conducted between 2007 and 2015, and a total of 815 patients were included in this study who underwent tubeless PCNL. Postoperatively, 591 patients were found to be stone free (Group 1), whereas residual stones were noted in 224 patients (Group 2). The hospital course and postoperative complications up to 3 months were analyzed by retrospective review. The complications were analyzed by Clavien–Dindo classification and grouped to severe/life-threatening complications (≥Grade 4) and none or nonsevere complications (≤3). All the demographic variables were scrutinized by regression analysis. Results: The mean days of hospital stay were 3.15 and 3.70 in Group 1 and Group 2, respectively (P < 0.001). Sixty-seven patients from Group 1 (11.3%) and 65 patients from Group 2 (29%) suffered postoperative complication (P < 0.001). A multivariate logistic regression model confirmed a higher risk of complications for the residual stone group versus the stone-free stone group (odds ratio [OR]: 2.37,P < 0.001). However, life-threatening complication rate reveals no difference between the two groups (1.4% vs. 3.1%,P = 0.093). Sixteen patients (2.7%) from Group 1 and 12 patients (5.4%) from Group 2 were rehospitalized in 3 months; however, the difference was not statistically significant (P = 0.064). The adjusted logistic regression model also established a nonelevated risk of rehospitalization (OR: 1.11, P = 0.823). Ninety-seven patients in the residual stone group received secondary stone managements in 3 months, but none of them underwent secondary PCNL. Conclusion: Patients from the residual stone group had remarkably longer hospital stay and higher postoperative complication rate because of more complicated stone nature. However, there was no significant difference in the incidence of severe complication and rehospitalization in both the groups. Tubeless PCNL is a relatively safe procedure and not contraindicated for patients with residual stones.

Keywords: Percutaneous nephrolithotomy, residual stones, tubeless

How to cite this article:
Chang SK, Lin CT, Kang CH, Cheng MC, Jou YC, Shen CH, Chen PC, Lai WH. Presence of residual stones is not a contraindication for tubeless percutaneous nephrolithotomy. Urol Sci 2019;30:226-31

How to cite this URL:
Chang SK, Lin CT, Kang CH, Cheng MC, Jou YC, Shen CH, Chen PC, Lai WH. Presence of residual stones is not a contraindication for tubeless percutaneous nephrolithotomy. Urol Sci [serial online] 2019 [cited 2020 Feb 26];30:226-31. Available from: http://www.e-urol-sci.com/text.asp?2019/30/5/226/269884

  Introduction Top

Percutaneous nephrolithotomy (PCNL) was first described by Fernstrom and Johansson in 1976, after which its use became widespread in contemporary urolith surgery.[1] PCNL has been established as one of the standard techniques to treat patients suffering from large or complex stones in the kidney and the upper ureter. Conventionally, a nephrostomy tube was placed in the percutaneous tract after PCNL. The purpose of nephrostomy tube drainage was to aid hemostasis, promote the healing of the nephrostomy tract, avoid urinary extravasation, and promote access to the upper urinary tract for any required endourologic procedures. However, placement of a nephrostomy tube has disadvantages, including an increase in postoperative pain and a prolonged hospital stay. Later on, Wickham et al. introduced tubeless PCNL in 1984 that has been widely used since then.[2] Several studies have demonstrated that this technique is safe and efficient in reducing postoperative pain and shortening the duration of hospital stay.[3],[4] Current consensus suggests that tubeless PCNL is useful in selected patients. The American Urological Association (AUA) guidelines for surgical management of stones suggest that the placement of a nephrostomy tube is optional in patients undergoing uncomplicated PCNL who are presumed to be stone free.[5] The European Association of Urology (EAU) guidelines on urolithiasis recommend that the placement of a nephrostomy tube depends on several factors, including the presence of residual stones, the probability of a second-look procedure, and significant intraoperative blood loss.[6] In general, an indwelling nephrostomy tube is believed to be necessary in the event of residual stones. Because the presence of residual stones may elevate the risk of postoperative infection, such patients may require secondary PCNL. In our hospital, tubeless modification is a routine procedure for all patients undergoing PCNL, irrespective of the presence or absence of residual stones. Herein, we report our experience of a retrospective review conducted to evaluate the safety and efficacy of performing tubeless PCNL in patients with residual stones.

  Materials and Methods Top

This study enrolled a total of 815 consecutive patients who were diagnosed with renal stones or upper ureteral stones and received tubeless PCNL at our institution from January 2007 to December 2015. The study was approved by the Institutional Review Board of Ditmanson Medical Foundation Chia-Yi Christian Hospital without the need of obtaining the informed consent from participating patients (Approval No. IRB2019073 obtained on September 17, 2019). All the tubeless PCNL procedures were performed as one-stage, single-access tract surgeries with patients in the prone position according to standard operating techniques by the same well-experienced team of endourologic surgeons. The expected renal access tract was punctured using a needle under ultrasound guidance and dilated using serial coaxial metal dilators 26 French, allowing a 24-F nephroscope to pass through. Stone fragmentation was accomplished by manipulating holmium: YAG laser, ballistic lithotripter, or a combination of both. After completing the stone removal procedure, a 7-F double-J catheter was antegradely placed. The visible intrarenal and tract bleeding points were fulgurated.[7] All patients underwent routine postoperative kidney–ureter–bladder film or computerized tomography to check for the presence of residual stones and to confirm the position of the double-J catheter. In patients with residual stones, extracorporeal shockwave lithotripsy (ESWL), ureteroscopic lithotripsy (URSL), or conservative follow-up were planned based on the clinical situation and the patient's performance status.

The clinical results of these 815 patients were obtained by a retrospective chart review. These patients were categorized into two groups based on the postoperative stone-free or residual stone status. The analysis comprised length of hospital stay and incidence of any complication in 3 months after the procedure. The postoperative complications were classified into five grades by the Clavien–Dindo classification. In this review, we grouped Grades 1–3 as nonsevere complications and Grade 4 and above as severe complications. The rates of rehospitalization and subsequent stone management procedures for patients in the residual stone group were postoperatively analyzed for a period of 3 months.

Continuous variables were presented as numbers and percentages, whereas categorical data were presented as mean ± standard deviation. Continuous data were analyzed by Student's t-test. Fisher's exact test or Chi-square test was used to analyze categorical data. The stepwise multinomial logistic regression was constructed to determine the risk factors associated with different categorical outcomes. The results were described as odds ratios (ORs). A multivariate linear regression was established to differentiate the variables associated with continuous outcomes. The values were designated as beta-coefficients. Statistical significance was defined as P < 0.05. The statistical package for the social sciences (SPSS, version 21.0, IBM Corporation, Armonk, New York, USA) was used to perform all the statistical analyses.

  Results Top

A total of 815 patients, including 540 (66.3%) males and 275 (33.7%) females, were included in this study. Of these 815 patients, 591 were included in the stone-free group (Group 1) and 224 were included in the residual stone status (Group 2). Group 1 had 398 males and 193 females, whereas Group 2 had 142 males and 82 females. The mean age of the study patients was 54.08 ± 11.99 years (range: 22–95 years), and the mean stone size was 3.54 ± 2.01 cm (range: 0.5–13.7 cm). The mean age of the patients in Group 1 was 53.74 ± 12.22 years and that of the patients in Group 2 was 55.00 ± 11.38 years. The mean stone size in Group 1 patients was 2.85 ± 1.40 cm, whereas it was 5.37 ± 2.25 cm in Group 2 patients. No statistically significant differences were found in the patients' demographic data between the two groups in terms of gender, age, and stone location, except for stone size and proportion of complete staghorn stones. Patients in the residual stone group (Group 2) had a larger mean stone size than the stone-free group (Group 1). Group 2 patients also had a higher fraction of complete staghorn stones [Table 1].
Table 1: Demographic data and stone characteristics of postoperative patients in the stone-free and residual stone groups

Click here to view

The perioperative and postoperative parameters are summarized in [Table 2]. The length of hospital stay was found to be statistically significantly different between the two groups (3.15 ± 1.56 days in Group 1 vs. 3.70 ± 1.85 days in Group 2, P < 0.001). In total, 132 patients suffered from postoperative complications after tubeless PCNL (67 in Group 1 and 65 in Group 2). Among them, 117 patients had Clavien grade ≤3 complications, including transient obstructive uropathy and urinary tract infection with postoperative fever, whereas 15 patients had severe septic complications of Clavien grade ≥4. The incidences of postoperative complications were 11.3% and 29% in Groups 1 and 2, respectively, which were statistically significant (P < 0.001). Only 1.4% of the patients in Group 1 and 3.1% of the patients in Group 2 suffered from severe complications (Clavien grade ≥4), and this difference was not statistically significant (P = 0.093). Regarding rehospitalization in 3 months posttubeless PCNL, 16 cases (2.7%) in Group 1 and 12 cases (5.4%) in Group 2 required hospitalization, but the difference was not statistically significant (P = 0.064).
Table 2: Clinical outcomes in the stone-free and residual stone groups

Click here to view

The multivariate logistic regression analysis revealed that only body mass index, stone size >4 cm, and stone position were significant predictors of residual stones. Neither age nor gender was predictable for stone freeness. ORs were computed and are presented in [Table 3]. Full-model linear regression analysis [Table 4] executed on factors that might affect hospital stay showed that patients in Group 2 had a significantly longer hospital stay than patients in Group 1 (0.49 days, P = 0.001). In addition, the presence of postoperative urinary tract infection prolonged the hospital stay (1.08 days, P < 0.001). Regarding postoperative complications, only the presence of residual stones significantly increased the occurrence (OR: 2.37, P < 0.001) [Table 5]. The logistic regression concerning rehospitalization in 3 months did not demonstrate any significant variable as a factor associated with risk events [Table 6].
Table 3: Risk factors for residual stones in the multivariate logistic regression

Click here to view
Table 4: Multivariate linear regression for variable prediction in hospital stay

Click here to view
Table 5: Risk factors for complications in the multivariate logistic regression

Click here to view
Table 6: Risk factors for rehospitalization in the multivariate logistic regression

Click here to view

Auxiliary procedures were performed in 97 patients in the residual stone group in 3 months posttubeless PCNL. This accounted for 43.3% of additional procedures for residual stones. In total, 95 patients underwent ESWL, whereas 2 patients underwent URSL. None of the patients required secondary PCNL for residual stones.

  Discussions Top

Tubeless PCNL has been a widely preferred procedure for treating renal stones since its first demonstration by Wickham et al. in 1984.[2] Efficacy, safety, reduced postoperative pain, and shorter hospital stay comprise the advantages of this procedure, which have been reported in the current literature.[8],[9] Although tubeless PCNL is efficacious, for safety considerations, some limitations have been advocated in its use for the management of upper uroliths. Both AUA and EAU guidelines recommend that tubeless PCNL is a preferable treatment for stone-free patients, and a nephrostomy tube placement is performed for patients with residual stones.[5],[6] A literature review revealed that only a few publications have reported the outcomes of tubeless PCNL in patients with residual stones. This study reports the results of tubeless PCNL in patients with residual stones.

Our results demonstrated that the residual stone group had a higher incidence of the presence of stones and a higher percentage of staghorn stones. This group also had a significantly longer hospital stay (3.70 ± 1.85 days) than the stone-free group (3.15 ± 1.56 days). This may be because the stones were more complicated in the residual stone group (higher percentage of staghorn stones and lower percentage of ureteral stones). The postoperative hospital stay was found to be longer in this study because all the patients enrolled in this study have the Taiwan National Health Insurance, which pays most of the medical fees (90%); therefore, patients in Taiwan stay in the hospital for a longer time period. A significantly higher rate of postoperative complications (29%) was observed in patients with residual stones than that in those without stones (11.3%) after tubeless PCNL. However, the incidence of complications in the residual stone group was found to be similar to that reported in the current research.[10] Furthermore, most of the postoperative complications were nonsevere and were below Clavien Grade 3, defined as those requiring pharmacological treatment or endoscopic intervention without life-threatening status.[11] The nonsevere complication events (not Clavien grade > ;3) accounted for 89% of the total complications in the residual stone group. Severe complications occurred primarily due to sepsis or progression to shock status. All these severe complications belonged to Clavien Grade 4, defined as life-threatening complications with organ dysfunction requiring intermediate care or intensive care unit management.[11] These complications occurred in only 3.1% of the patients in the residual stone group, which were higher, but not statistically significant, than that in the stone-free group.

Concerning rehospitalization in 3 months after tubeless PCNL, only 5.4% of the patients in the residual stone group were required to be hospitalized for the management of postoperative complications, including urinary tract infection, sepsis, and obstructive uropathy, as opposed to 2.7% of the patients in the stone-free group; this difference was not statistically significant. Approximately 80% of the patients who suffered from postoperative complications were managed in outpatient services, regardless of them being stone free or having residual stones. The auxiliary procedures performed in 3 months after tubeless PCNL included 95 ESWLs and 2 URSLs. None of the patients received secondary PCNL in 3 months postprimary PCNL in this study.

Nephrostomy tubes have been traditionally placed at the end of PCNL with the intention of providing a tamponade to stop bleeding from the tract, promote urinary drainage in the event of ureteral obstruction, and maintain access in case a second-look procedure is needed.[10] A second-look procedure is necessary for patients with residual stones, and placement of a nephrostomy tube after operation has been suggested by some authors.[12] However, with the improvement of endoscopic and lithotripsy tools, almost all visible stones can be removed using modern percutaneous equipment. Residual stones generally remain because they are unreachable through the primary tract, which implies that it is very difficult to approach the residual stones for a second-look PCNL through the same tract. A new access tract in the secondary PCNL or retrograde intrarenal surgery may be appropriate for staged stone management, and the necessity of nephrostomy tube placement should be reconsidered.

This study has few limitations and constraints. First, the retrospective nature and a relatively short follow-up period (3 months) compromised the validity of the study. Second, this study does not report the differences in complications observed between tubeless PCNL and traditional PCNL in patients with residual stones because tubeless modification is a standard routine procedure for all patients who underwent PCNL at our hospital, and traditional PCNL has never been performed longer than a decade.

  Conclusion Top

In this study, patients who underwent tubeless PCNL with residual stones had a longer hospital stay and a higher rate of occurrence of nonsevere complications possibly due to the more complicated nature of the stones in this group. However, all patients with complications recovered well after appropriate treatment without any sequela. Tubeless PCNL is a relatively safe modification for patients with residual stones and is not contraindicated in these patients.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Fernström I, Johansson B. Percutaneous pyelolithotomy. A new extraction technique. Scand J Urol Nephrol 1976;10:257-9.  Back to cited text no. 1
Wickham JE, Miller RA, Kellett MJ, Payne SR. Percutaneous nephrolithotomy: One stage or two? Br J Urol 1984;56:582-5.  Back to cited text no. 2
Desai MR, Kukreja RA, Desai MM, Mhaskar SS, Wani KA, Patel SH, et al. Aprospective randomized comparison of type of nephrostomy drainage following percutaneous nephrostolithotomy: Large bore versus small bore versus tubeless. J Urol 2004;172:565-7.  Back to cited text no. 3
Cormio L, Gonzalez GI, Tolley D, Sofer M, Muslumanoglu A, Klingler HC, et al. Exit strategies following percutaneous nephrolithotomy (PCNL): A comparison of surgical outcomes in the clinical research office of the endourological society (CROES) PCNL global study. World J Urol 2013;31:1239-44.  Back to cited text no. 4
Assimos D, Krambeck A, Miller NL, Monga M, Murad MH, Nelson CP, et al. Surgical management of stones: American Urological Association/Endourological Society guideline, part II. J Urol 2016;196:1161-9.  Back to cited text no. 5
Türk C, Petřík A, Sarica K, Seitz C, Skolarikos A, Straub M, et al. EAU guidelines on interventional treatment for urolithiasis. Eur Urol 2016;69:475-82.  Back to cited text no. 6
Jou YC, Cheng MC, Sheen JH, Lin CT, Chen PC. Cauterization of access tract for nephrostomy tube-free percutaneous nephrolithotomy. J Endourol 2004;18:547-9.  Back to cited text no. 7
Wang J, Zhao C, Zhang C, Fan X, Lin Y, Jiang Q, et al. Tubeless vs. standard percutaneous nephrolithotomy: A meta-analysis. BJU Int 2012;109:918-24.  Back to cited text no. 8
Ni S, Qiyin C, Tao W, Liu L, Jiang H, Hu H, et al. Tubeless percutaneous nephrolithotomy is associated with less pain and shorter hospitalization compared with standard or small bore drainage: A meta-analysis of randomized, controlled trials. Urology 2011;77:1293-8.  Back to cited text no. 9
Ghani KR, Andonian S, Bultitude M, Desai M, Giusti G, Okhunov Z, et al. Percutaneous nephrolithotomy: Update, trends, and future directions. Eur Urol 2016;70:382-96.  Back to cited text no. 10
Dindo D, Demartines N, Clavien PA. Classification of surgical complications: A new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 2004;240:205-13.  Back to cited text no. 11
Maheshwari PN, Andankar MG, Bansal M. Nephrostomy tube after percutaneous nephrolithotomy: Large-bore or pigtail catheter? J Endourol 2000;14:735-7.  Back to cited text no. 12


  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
Materials and Me...
Article Tables

 Article Access Statistics
    PDF Downloaded55    
    Comments [Add]    

Recommend this journal