Efficacy and Safety of Supracostal Access for Mini Percutaneous Nephrolithotomy in Pediatric Patients

Journal Pre-proof

Efficacy and safety of supracostal access for mini percutaneous nephrolithotomy in pediatric patients P. Ashwin Shekar MCh , M.S. Ansari MCh , Sarita Syal MCh , Kumar Madhavan MCh , Aneesh Srivastava MCh , Rahul Soni MCh , Priyank Yadav MCh PII: DOI: Reference:

S0090-4295(19)31120-3 https://doi.org/10.1016/j.urology.2019.12.018 URL 21910

To appear in:

Urology

Received date: Revised date: Accepted date:

10 October 2019 9 December 2019 13 December 2019

Please cite this article as: P. Ashwin Shekar MCh , M.S. Ansari MCh , Sarita Syal MCh , Kumar Madhavan MCh , Aneesh Srivastava MCh , Rahul Soni MCh , Priyank Yadav MCh , Efficacy and safety of supracostal access for mini percutaneous nephrolithotomy in pediatric patients, Urology (2019), doi: https://doi.org/10.1016/j.urology.2019.12.018

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Inc.

Title: Efficacy and safety of supracostal access for mini percutaneous nephrolithotomy in pediatric patients. Type of manuscript: Original article Authors: 1.

Dr. P Ashwin Shekar, MCh

2.

Dr. M S Ansari, MCh

3.

Dr. Sarita Syal, MCh

4.

Dr. Kumar Madhavan, MCh

5.

Dr. Aneesh Srivastava, MCh

6.

Dr. Rahul Soni, MCh

7.

Dr. Priyank Yadav, MCh

1-7

Department of Urology and Renal Transplantation, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India Corresponding author: Dr Priyank Yadav, MCh Assistant Professor, Department of Urology and Renal Transplantation, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raibareli Road, Lucknow, India Email – [email protected] Telephone Number - +91-522-2494110 Fax - +91-522-2668017 Keywords: PCNL; Urolithiasis; Supracostal. Acknowledgements: None

ABSTRACT Objective: To evaluate the efficacy and safety of supracostal percutaneous nephrolithotomy (PCNL) through the 11th intercostal space and compare it with subcostal PCNL in children with renal calculi. Materials and Methods: Children with renal calculi who underwent PCNL between January 2010 and December 2017 were divided into two groups: supracostal PCNL (group 1) and

1

subcostal PCNL (group 2). Stone location, stone burden, location of the access points, operative time, postoperative visual pain score, success rate, hospital stay, and complications according to the modified Clavien classification were compared. Comparison of medians was done using Mann Whitney U test and the means were compared using t test. Results: Group 1 had 50 patients while group 2 had 60 patients. The stone-free rate was 84.0% and 85.0% in groups 1 and 2 respectively after one session of PCNL (p=0.885). After auxiliary procedures, it increased to 96.0% and 96.6% respectively (p=0.852). The mean fall in hematocrit was 0.9% in group 1 and 1.5% in group 2 (p=0.11) whereas the median pain score was 4 in group 1 and 3 in group 2 (p=0.37). In all, 54 complications were recorded the commonest among which were grade I (81.5%). 29 complications were observed in group 1 while 25 complications were observed in group 2 (p=0.088). One patient developed nephropleural fistula while another patient developed hydropneumothorax. Both belonged to group 1. Conclusion: Supracostal access for PCNL is an effective and safe alternative to subcostal access for children with renal calculi in terms of stone free rate and complications.

INTRODUCTION Percutaneous nephrolithotomy (PCNL) is one of the preferred treatment options for renal and upper ureteric calculi in children.

1

The incidence of pediatric urolithiasis has increased in the recent years and with

technological advancements in PCNL such as mini/ ultramini PCNL, those complex calculi are now being managed via percutaneous approach which were earlier treated only with laparoscopic or open renal surgery. 2 There are two types of access to the pelvicalyceal system in PCNL, namely supracostal and subcostal. Pediatric PCNL, like the adult counterpart, is performed via subcostal access in majority of the cases.

3

While the

supracostal access has obvious advantages compared to subcostal access for staghorn calculi, complex lower calyceal calculi and the upper ureteric calculi, its use has been selective due to the risk of complications,

2

particularly hydrothorax. 4 This resulted in underutilization of supracostal access for PCNL in children even in stones where it may score above subcostal access. Most of the literature on supracostal PCNL still comes from the adult series. Recent reports on supracostal PCNL in adults, particularly tubeless PCNL, have shown that the incidence of complications compared to the subcostal PCNL is lower than reported historically and this has led to renewed interest in supracostal PCNL in children. 5, 6 In the present study, we evaluated the efficacy and safety of supracostal PCNL (performed through the 11th intercostal space) and compared it with subcostal PCNL. MATERIAL AND METHODS The present study was conducted at a tertiary care hospital in northern India and was approved by the Institutional Ethics Committee. Data of patients under 18 years of age who had renal calculi and required PCNL were prospectively collected between January 2010 and December 2017. Such patients were divided into two groups: those who underwent supracostal PCNL (group 1) and those who underwent subcostal PCNL (group 2). All patients essentially underwent mini PCNL (sheath size: 15Fr – 20Fr). Those who underwent standard PCNL (sheath size: 22Fr-26Fr) were excluded from analysis because the difference in sheath size can dramatically alter the incidence of complications such as bleeding and hydrothorax. Patients in whom both supracostal and subcostal access were made were also excluded from the study. PCNL was performed by one of the two surgeons (AS and MSA). A ureteric catheter was routinely placed before the procedure and percutaneous access to the pelvicalyceal system was established under fluoroscopic guidance. Puncture was performed using Bull’s eye technique when subcostal PCNL was done. 7 In case of supracostal PCNL, puncture was done obliquely, directing the needle towards the foot end of the patient once the intercostal space had been entered. All punctures were performed during expiration to avoid inadvertent pleural or pulmonary injury due to downward displacement of lungs during inspiration. A 12 Fr nephroscope was used and the calculi were fragmented using laser or pneumatic lithoclast. After the procedure, a double J stent was placed routinely while nephrostomy was placed in most cases. Postoperative chest X-ray was routinely done in every patient with supra-costal access. All patients were investigated for any fall in the hematocrit on first postoperative day. Success was defined as absence of radio-opaque shadow on postoperative abdominal X-ray or absence of stone density on computed tomography (for radiolucent calculi).

3

Patient characteristics, stone location, stone burden, location of the access points, operative time, postoperative visual pain score, success rate, hospital stay, and complications according to the modified Clavien classification were compared between group 1 and group 2.

8

Normality of distribution of the variables was

checked by Shapiro-Wilk test and Q-Q plots. Median was used for variables which did not show normal distribution while mean was used for variables showing normal distribution. Comparison of medians was done using the Mann Whitney U test and the means were compared using t test. Categorical variables were compared using Chi-square test and Fisher’s exact test. Statistical analysis was done using SPSS (version 23).

RESULTS Between January 2010 and December 2017, 119 patients younger than 18 years underwent PCNL. After excluding patients who underwent standard PCNL or combined supracostal and subcostal PCNL, 110 patients were analyzed. Of these, 50 and 60 had a supracostal and subcostal access respectively. Stone size and location of stone were comparable in both the groups (Table 1). The stone-free rate was 84.0% (42/50) and 85.0% (51/60) in groups 1 and 2 respectively after one session of PCNL. Auxiliary procedures required were relook nephroscopy (8 patients), shock wave lithotripsy or SWL (5 patients), ureteroscopy or URS (2 patients) and retrograde intrarenal surgery or RIRS (2 patients) in both the groups. After the auxiliary procedures, stone-free rates increased to 96.0% (48/50) and 96.6% (58/60) in groups 1 and 2 respectively (p=0.852). Change in hematocrit level (p=0.11), visual pain score/ need of analgesia (p=0.368), and hospital stay (p=0.231) were not statistically significant in two groups (Table 2). A total of 54 (49.1%) complications were documented in the two groups according to modified Clavien classification (Table 3). 29 complications were observed in group 1 while 25 complications were observed in group 2 (p=0.088). Of these, 44 were grade-I complications, 8 were grade-II compliations and 2 were grade IIIa complications. Grade-IIIa complications were recorded in group 1 only; 1 in the form of nephropleural fistula which responded to repositioning of JJ stent and placement of a nephrostomy tube and another hydropneumothorax requiring intercostal tube drainage. 9 Both patients subsequently recovered uneventfully. There were no grade IIIb, grade-IV and grade-V complications. Blood transfusion was required in 3 patients in group 1 and 2 patients in group 2. Upon analysis of each grade of complications, no significant difference was found between the two groups as demonstrated in Table 3. An age wise subgroup analysis did not reveal any

4

significant differences in the mean operative time, stone free rate, hospital stay and complications for PCNL performed in children up to 6 years, 7-12 years and 13-18 years (Table 4).

DISCUSSION Historically, supracostal approach for PCNL has been associated with high incidence of thoracic complications and due to this, just over 16% of all PCNL are performed via supracostal approach.

10

However,

recent reports have clearly demonstrated the safety of supracostal PCNL especially with the use of smaller access sheaths and certain technical modifications based on anatomical considerations.

6, 11

Most of the data on

supracostal PCNL however, comes from adult series and there is lack of evidence for its safety in children. In the present study, we have too demonstrated that when compared to subcostal PCNL, supracostal PCNL not only has similar efficacy, but also similar rate of complications and hence its use should be considered more often, particularly where a single subcostal access may fail to clear all renal calculi. The success rate of supracostal PCNL in children has been evaluated by few authors, but mostly in combination with subcostal access rather than in isolation. Oner et al reviewed 77 children who underwent single upper pole access vs. single other pole access.

12

Supracostal access was required in 8 out of 10 patients

with upper pole access against 3 out of 67 patients with other pole access. Stone clearance was 100% in the former against 82% in the latter. Kumar et al reported their experience of PCNL in 12 children with staghorn calculi.

13

Supracostal access was made in 4 patients and overall stone free rate was 58% after first PCNL

through a single tract and there were no thoracic complications. Goyal et al reported their experience on PCNL in children using adult instruments and performed a primary supracostal puncture in 27.2% of the patients.

14

The overall stone free rate was 85.4% and comparison

of supracostal vs subcostal approach was not done. Bhageria et al performed head to head comparison of supracostal and subcostal PCNL in 102 children. 3 The stone clearance after first PCNL was 78% in the former and 86% in the latter. This difference was not statistically significant. In the present study, the stone free rate after a single procedure was 84.0% in the supracostal PCNL group against 85.0% in the subcostal PCNL group. This difference was not statistically significant meaning that the success was comparable between the two groups.

5

Even in patients who have previously undergone pyelolithotomy or nephrolithotomy, a supracostal access can be easily performed compared to patients with no prior renal surgery without compromising the overall stone free rate. 15 The advantage of upper calyceal access for removal of complex calyceal calculi as well as renal pelvis and upper ureteric calculi is already known. A supracostal puncture maximizes this benefit for the patient compared to subcostal puncture which rarely provides access to upper calyx.

The most common complications after supracostal PCNL are still grade I complications, which were found in 44/54 patients (81.5%) in our study. Bhageria et al reported 59% grade 1 complications in their series.

3

Grade 2 complications were found in 8/54 patients (14.8%) in the present study. The main concern with supracostal PCNL has been the risk of complications, particularly blood loss and pleural/ pulmonary injury. These have been reported by various authors in series of pediatric PCNL.

12, 14, 15, 16

Ozden et al performed 7

supracostal PCNL among 100 PCNLs and reported hydrohemopneumothorax in 2 cases. Gunes et al, who reported one hydrohemopneumothorax among 25 children.

18

17

This is in contrast to

Some studies have reported

astonishingly high rates of transfusion in supracostal PCNL. Bhageria et al reported a transfusion rate of 22% in supracostal PCNL against 3% in subcostal PCNL.

3

Similarly, the rate of blood transfusion was reported to be

high, about 19.6% particularly with adult size instruments in a series by Purkait et al where 25% of the punctures were supracostal but another series from the same institute by Goyal et al which had 27% supracostal punctures reported a transfusion rate of 7.6%. 14, 19 This difference was observed probably due to bilateral PCNL in the series by Purkait et al. However, the two sides were operated at an interval of 10-14 days between each other rather than a simultaneous procedure. In the present study, transfusion was required in 5/110 patients (4.5%). Major complications (grade 3 or more) requiring some form of intervention were seen only in 2 patients (3.7%) in our study. Bhageria et al reported grade 3 complication in 7.4% patients and which included hydrothorax requiring chest tube drainage, both occurring in patients with supracostal puncture.

3

We had one

patient with nephropleural fistula after supracostal puncture who was managed successfully with a percutaneous nephrostomy. Another patient with hydropneumothorax recovered with intercostal tube drainage. In literature, several reasons have been proposed for high risk of thoracic complications with supracostal PCNL. These include puncture during inspiration, anatomical variation leading to extension of costodiaphragmatic recess of the pleural cavity, medial punctures, punctures above 11 th rib and displacement of access sheath during the procedure leading to hydrothorax.

6

11, 20

The incidence of complications during

supracostal PCNL in the present study was low, comparable to the subcostal group due to several reasons. Firstly, the size of the access sheath was limited to 15-20 Fr. Secondly, all punctures were performed during expiration. Thirdly, the tract was made obliquely, towards the foot end of the patient after negotiating the intercostal space. It is not uncommon for the kidney to lie high within the abdominal cavity, particularly on the left side and a supracostal access is sometimes needed for accessing the middle or even the lower calyx. An oblique supracostal puncture can be particularly helpful in such cases. Yadav et al reported a large series of 660 pediatric PCNLs and made subcostal puncture in 12.4% procedures.

21

The supracostal puncture was made

through the 11th intercostal space at the junction of medial 2/3 and lateral 1/3 of the 11 th rib. The tract was dilated up to 24 Fr. However, they did not encounter a single pleural complication in such a large series which is in contrast to majority of the contemporary studies. 12, 14, 15, 16 The limitations of the present study are small sample size, lack of randomization and absence of matching between the two groups. Moreover, the surgeries were performed by two surgeons and this can potentially cause bias in outcomes or complications. Despite these limitations, the present study highlights the evolving trends in the surgical management of pediatric stone disease such as reduction in the size of access sheath and decrease in the incidence of complications compared to previously reported studies. It must be noted that the present study does not advocate a supracostal access for most renal calculi, especially when a subcostal approach can be sufficient. However, this study does suggest that reluctance to supracostal access should be discontinued, particularly for complex renal calculi, large calculi in pelvis, high lying kidneys and some upper ureteric calculi where access to the superior calyx (sometimes even the middle calyx) is not possible without supracostal access. It is deemed necessary that further studies be carried out to randomize the patients between supracostal and subcostal PCNL to clearly define the outcomes and complications of these two techniques.

CONCLUSION The stone free rate after a single procedure as well as the rate of complications does not differ significantly between supracostal and subcostal approaches to percutaneous nephrolithotomy in children.

REFERENCES

7

1.

Ansari MS. Pediatric urolithiasis: A challenging problem. Indian J Urol. 2010;26(4):515.

2.

Abhishek, Kumar J, Mandhani A, Srivastava A, Kapoor R, Ansari MS. Pediatric urolithiasis: experience from a tertiary referral center. J Pediatr Urol. 2013;9(6 Pt A):825-30.

3.

Bhageria A, Nayak B, Seth A, Dogra PN, Kumar R. Paediatric percutaneous nephrolithotomy: single-centre 10-year experience. J Pediatr Urol. 2013;9(4):472-5.

4.

Mousavi-bahar SH, Mehrabi S, Moslemi MK. The safety and efficacy of PCNL with supracostal approach in the treatment of renal stones. Int Urol Nephrol. 2011;43(4):983-7.

5.

Sourial MW, Francois N, Box GN, Knudsen BE. Supracostal access tubeless percutaneous nephrolithotomy: minimizing complications. World J Urol. 2018;

6.

Keshavamurthy R, Kumar S, Karthikeyan VS, Mallya A, Nelivigi GG. Tubeless Pediatric Percutaneous Nephrolithotomy: Assessment of Feasibility and Safety. J Indian Assoc Pediatr Surg. 2018;23(1):16-21.

7.

Miller NL, Matlaga BR, Lingeman JE. Techniques for fluoroscopic percutaneous renal access. J Urol. 2007;178(1):15-23.

8.

Tefekli A, Ali karadag M, Tepeler K, et al. Classification of percutaneous nephrolithotomy complications using the modified clavien grading system: looking for a standard. Eur Urol. 2008;53(1):184-90.

9.

Arora S, Raj A, Ansari MS. Nephropleural fistula after percutaneous nephrolithotomy in a pediatric patient: diagnosis and management. Urology. 2015;85(1):e3-4.

10. De la rosette J, Assimos D, Desai M, et al. The Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study: indications, complications, and outcomes in 5803 patients. J Endourol. 2011;25(1):11-7. 11. Sharma K, Sankhwar SN, Singh V, et al. Evaluation of factors predicting clinical pleural injury during percutaneous nephrolithotomy: a prospective study. Urolithiasis. 2016;44(3):263-70. 12. Oner S, Karagozlu akgul A, Demirbas M, Onen E, Aydos M, Erdogan A. Upper pole access is safe and effective for pediatric percutaneous nephrolithotomy. J Pediatr Urol. 2018;14(2):183.e1183.e8. 13. Kumar R, Anand A, Saxena V, Seth A, Dogra PN, Gupta NP. Safety and efficacy of PCNL for management of staghorn calculi in pediatric patients. J Pediatr Urol. 2011;7(3):248-51.

8

14. Goyal NK, Goel A, Sankhwar SN, et al. A critical appraisal of complications of percutaneous nephrolithotomy in paediatric patients using adult instruments. BJU Int. 2014;113(5):801-10. 15. Aldaqadossi HA, Kotb Y, Mohi K. Efficacy and Safety of Percutaneous Nephrolithotomy in Children with Previous Renal Stone Operations. J Endourol. 2015;29(8):878-82. 16. Anand A, Kumar R, Dogra PN, Seth A, Gupta NP. Safety and efficacy of a superior caliceal puncture in pediatric percutaneous nephrolithotomy. J Endourol. 2010;24(11):1725-8. 17. Ozden E, Mercimek MN, Yakupoǧlu YK, Ozkaya O, Sarikaya S. Modified Clavien classification in

percutaneous

nephrolithotomy:

assessment

of

complications

in

children.

J

Urol.

2011;185(1):264-8. 18. Gunes A, Yahya ugras M, Yilmaz U, Baydinc C, Soylu A. Percutaneous nephrolithotomy for pediatric stone disease--our experience with adult-sized equipment. Scand J Urol Nephrol. 2003;37(6):477-81. 19. Purkait B, Kumar M, Sokhal AK, Bansal A, Sankhwar SN, Gupta AK. Percutaneous nephrolithotomy of bilateral staghorn renal calculi in pediatric patients: 12 years experience in a tertiary care centre. Urolithiasis. 2017;45(4):393-399. 20. Maheshwari PN, Chopade DK, Andankar MG. Comment on "Supracostal approach in percutaneous nephrolithotomy: experience of 102 cases". J Endourol. 2003;17(7):529-30. 21. Yadav SS, Aggarwal SP, Mathur R, et al. Pediatric Percutaneous Nephrolithotomy-Experience of a Tertiary Care Center. J Endourol. 2017;31(3):246-254.

9

Table 1: Comparison of the two groups for baseline characteristics. Group 1 (Supracostal PCNL)

Group 2 (Subcostal PCNL)

P value

No. of patients

50

60

-

Median age in years (IQR)

9 (5, 14)

7 (3, 13)

0.29

Median stone size in mm (IQR)

25 (11, 34)

26 (10, 36)

0.41

6

<0.001

15

0.903

Stone location 

Upper calyx 19



Middle calyx



Lower calyx 3

16

0.004



Renal pelvis and upper ureter

8

11

0.747



Multiple/ staghorn

8

10

0.925

40.2 +/- 3.5

39.3 +/- 3.1

0.19

Mean preoperative hematocrit (%)

12

IQR: Interquartile range

10

Table 2: Comparison of outcomes between the two groups.

Mean operative time (min)

Group 1 (Supracostal PCNL)

Group 2 (Subcostal PCNL)

P value

45.6 +/- 11.2

41.4 +/- 10.9

0.31

Access site 

Upper calyx

31

2



Middle calyx

19

45



Lower calyx

0

13

Stone free rate after 1 session

84.0%

85.0%

0.885

Stone free rate after auxiliary procedure

96.0%

96.6%

0.852

Mean fall in hematocrit (%)

0.9 +/- 0.3

1.5 +/- 0.4

0.11

Median VAS score (IQR)

4 (3-5)

3 (2-6)

0.37

Mean hospital stay (days)

4.9 +/- 1.3

4.2 +/- 1.5

0.23

VAS: Visual analog scale; IQR: Interquartile range

11

<0.001

Table 3: List of complications observed in group 1 and 2 as per modified Clavien classification. Complication grade

Group 1 (Supracostal PCNL)

Group 2 (Subcostal PCNL)

Pvalue

I

23

21

0.241

II

4

4

0.789

IIIa

2

0

0.118

IIIb

0

0

-

IV

0

0

-

V

0

0

-

Total

29

25

0.088

Table 4: Age wise sub-group analysis for all children undergoing PCNL. Parameter No. of patients Supracostal/Subcostal access Mean operative time in minutes (with SD) Stone free rate Mean hospital stay (Days) Complications  Grade 1  Grade 2  Grade 3 and above

0 – 6 years 27 15/12

7 – 12 years 40 17/23

13 – 18 years 43 18/25

P value

41.9 +/- 10.4

44.7 +/- 13.2

41.45 +/- 12.2

0.316

96.3% 4.8 +/- 1.2

96% 4.2 +/- 1.3

96.5% 4.4 +/- 1.5

0.44 0.391

10 2 1

17 4 1

17 2 0

0.954

12

0.423