724726
research-article2017
TAU0010.1177/1756287217724726Therapeutic Advances in UrologyAA Ahmad, O Alhunaidi
Therapeutic Advances in Urology
Original Research
Current trends in percutaneous nephrolithotomy: an internet-based survey Abd Alrahman Ahmad, Omar Alhunaidi, Mohamed Aziz, Mohamed Omar, Ahmed M. Al-Kandari, Ahmed El-Nahas and Mohamed El-Shazly
Ther Adv Urol 2017, Vol. 9(9-10) 219–226 https://doi.org/10.1177/1756287217724726 DOI: 10.1177/ https://doi.org/10.1177/1756287217724726 1756287217724726
© The Author(s), 2017. Reprints and permissions: http://www.sagepub.co.uk/ journalsPermissions.nav
Abstract Background: The aim of this study was to report current practices of percutaneous nephrolithotomy (PCNL) among endourologists. Methods: An internet survey was administered to Endourological Society members. Responders were distributed into three groups according to the number of PCNL cases per year (100). PCNL technical details as well as opinions regarding specific clinical case scenarios were evaluated and compared between groups. Results: We received 300 responses from 47 different countries. Prone position was used in 77% of cases, while 16% used supine position and only 7% used modified lateral decubitus. Most endourologists performed their own access. There were no significant differences between the three groups regarding patient position (p = 0.1), puncture acquisition by urologist or radiologist (p = 0.2) and fluoroscopic puncture technique (p = 0.2). Endourologists with high annual PCNL practice (>100) had least probability to utilize nephrostomy tube (p = 0.0005) or use balloon dilator (p = 0.0001). They also had the highest probability of performing mini-PERC (p = 0.0001). Conclusions: The majority of endourologists performing PCNL obtain their own access. Prone positioning is predominant, while totally tubeless PCNL are uncommon. Mini-PERC is gaining more popularity among endourologists. Most endourologists follow the guidelines for their choice of treatment modality in different sizes and locations of upper tract calculi.
Keywords: percutaneous, nephrolithotomy, trends, survey Received: 3 March 2017; revised manuscript accepted: 3 July 2017
Introduction Upper urinary tract calculi affect up to 8.8% of population in the United States.1 Treatment modalities for renal calculi currently revolve around stone size and location. Percutaneous nephrolithotomy (PCNL) is the gold standard for treating large renal calculi >2 cm.2,3 PCNL has become favored over open nephrolithotomy because of its lower morbidity.4 However, in comparison with ureteroscopy (URS) or extracorporeal shock wave lithotripsy (SWL), PCNL has been considered the most complicated stone surgery technique.5 The routine use of PCNL in some places may be limited by the difficulty in gaining percutaneous access. Renal access can be challenging, and in some centers, it is performed by intervention radiologists.6
Endourologists use different techniques and instruments in performing PCNL. Only a few studies in the literature report trends in the use of PCNL. Questions asked in these studies were limited and did not cover different techniques.7–9 In this study we report current practices of PCNL among endourologists all over the world through detailed questions covering the majority of steps and techniques. Materials and methods Using Survey Monkey, a web-based survey (Supplementary Data; available online at www. surveymonkey.com) was created and administered via blast e-mails to members of the Endourological Society. The survey questionnaire covered demographic data, number of cases performed annually and details pertaining to technique of PCNL
Correspondence to: Mohamed El-Shazly Urology Department, Menoufia University, Gamal Abdelnaser Street, Shebin Elkom 325100, Egypt
[email protected] Mohamed Aziz Mohamed Omar Menoufia University-Egypt, Shebin Elkom, Egypt Abd Alrahman Ahmad Omar Alhunaidi Urology Department, Farwaniya Hospital, Kuwait Ahmed M Al-Kandari Urology Department, Kuwait University, Kuwait Ahmed El-Nahas Urology Department, Mansoura Urology and Nephrology Center, Egypt
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Therapeutic Advances in Urology 9(9-10) Table 1. Geographical distribution of responders. Continent
No. of responders
%
Europe
44
14.6
North America
71
23.6
South America
14
4.6
Africa
60
Asia Australia
Stiff guidewire was used by 40%, while 32% used hydrophilic guidewire and 27% used a Teflon coated guidewire. A safety guidewire was used by 69% of endourologists However, 56% of responders with high case volume did not use a safety guidewire.
20
109
36.3
2
0.6
practice as well as opinions regarding specific clinical case scenarios. We asked our respondents to specify their range of PCNL practice in the total number of cases that they perform on an annual basis. We categorized them based on their annual cases flow to 100. PCNL technical details were evaluated and compared between the three groups. Statistical analysis was performed using JMP™ (SAS Campus Drive Building T Cary, NC, USA). PCNL technical details were evaluated and compared between the three groups using Chisquare and Wilcoxon signed-rank tests with p < 0.05 considered statistically significant. Results We had 300 responses from Endourological Society members from 47 countries. The distribution of responders according to their location is shown in Table 1. As shown in Table 2, the majority of respondents (77%) placed patients in the prone position, while 16% placed them in supine position and 7% or placed them in a modified lateral position. These results did not vary when categorized according to the case flow (p = 0.1). Access was performed by the urologist themselves in 82% of cases, performed by a radiologist in 7% and by both in 11% with no statistical difference among the three categories of respondents (p = 0.2). Access was achieved under fluoroscopic guidance in 75%, by both fluoroscopic and ultrasonic guidance in 21%, while only 4% reported that they depend on ultrasound solely to guide their access. This practice did not differ between subgroups of respondents (p = 0.9).
Balloon dilators were used by 41%, compared with 32% who used Alken’s metal telescoping dilators followed by Amplatz polyurethane progressive dilators in 14% and one-shot Amplatz polyurethane dilators in 13%. It was observed that 47% of our respondents perform mini-PERC. The majority of those who practice it were among the practitioners with higher cases flow (44%). There was a statistically significant difference between the more experienced group and the other two groups in omitting use of guidewire and post-PCNL nephrostomy (Table 2). On a question regarding use of prophylactic antibiotic, 76% of respondents used single dose antibiotics before surgery, 15% used a 3-day course and 8% used a 7-day course prior to surgery. PCNL monotherapy with multiple access was the most common staghorn stone treatment modality used by 47% of responders, followed by combined PCNL and flexible ureteroscopy by 33%, while PCNL monotherapy with single access was used by 20%. Interestingly 40% of our responders used combined flexible ureteroscopy and PCNL to clear complex staghorn stones. Table 3 presents questions asked for choice of management modalities in view of guidelines. It was observed that 96% used PCNL for treatment of lower calyceal stones ⩾2 cm. Flexible ureteroscopy (46%) followed by PCNL (40%) followed by SWL (14%) were the choice for treatment of 1–2 cm lower calyceal stones. For lower calyceal stones 3 days
5 (5%)
4 (5%)
32.1% 0.8
42.7% 20.9%
4 (4%)
4.1%
Primary modality of stone-free rate:
CT
34 (31%)
28 (31%)
28 (27%)
0.5
U/S
10 (9%)
13 (15%)
16 (15%)
12.3%
KUB or fluoroscopy
64 (60%)
48 (54%)
59 (58%)
58.1%
29.5%
Timing of stone-free rate assessment:
Intra-op
13 (12%)
12 (13%)
19 (18%)
2nd–3rd POD
42 (39%)
43 (49%)
47 (46%)
2 weeks
33 (30.5%)
25 (28%)
20 (20%)
26.2%
3 months
20 (18.5%)
9 (10%)
17 (16%)
15.2%
13.92% 0.3
44.6%
CT, computed tomography; KUB, kidney ureter bladder plain X ray; N/A, not applicable; PCNL, percutaneous nephrolithotomy; POD, postoperative day; U/S, ultrasound.
Variations in trends depending on the region of responders were shown in Table 4. Discussion In the treatment of renal calculi, PCNL is a complex minimally invasive approach.10 Obtaining renal access is an important initial step. Our results indicate that the majority of responders from the Endourological Society established their own renal access. Interestingly, in our survey, 67% of North American responders obtained their own access. This figure is higher than other previous reports such as the Bird and colleagues survey in 2003 who reported 11% only. This is because their responders were all actively practicing members of the north central section of the American Urological Association including general urologists and trainees. Another study by Jayram and Matlaga, reported that 20.4% of North American certifying urologists obtained their own access in 2012. In this survey, responders were endourologists who are members of the Endourological Society with greater expertise in endourology that can explain our results compared with previous surveys.8,9 Ultimately the quality of access has a
direct impact on the outcome of the procedure. In a study comparing urologist versus interventional radiologist-obtained renal access, significantly fewer access-related complications and better stone-free rates were achieved when the urologist gained access.11 In another series with over 1200 patients, similar access-related complications and stone-free rates were achieved, despite more complex stones and challenging access in the urologists’ access group.12 Many reports in the literature have discussed the success and safety of ultrasonic-guided access either in conjunction with fluoroscopy or solo ultrasonic-guided PCNL. Advocates of ultrasonic-guided access reported that its advantages over fluoroscopic guidance were avoidance of radiation risks and lower possible risk of adjacent organ injury.13–16 The choice of access guidance modality was not reported in previous surveys.7–9 However our data reflect that the trend among endourologists is still with the use of fluoroscopicguided access. The results of the present study emphasized the popularity of the prone position over supine
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AA Ahmad, O Alhunaidi et al. Table 3. Questions related to guidelines of stone management. Variable
Number of responders
100
No. (%)
No. (%)
No. (%)
108 (36)
89 (30)
103 (34)
p-value
0.02
Preferred approach: 2 cm renal pelvic stone
Total percent
SWL
22 (20)
14 (15)
9 (9)
14
PCNL
59 (55)
60 (68)
78 (76)
66
RIRS
27 (25)
15 (17)
16 (15)
20
Preferred approach: 2 cm lower calyceal stone
SWL
2 (2)
PCNL
100 (93)
87 (98)
100 (97)
96
6 (7)
2 (2)
3 (3)
3.5
RIRS
0
0
0.3
Preferred approach: 1–2 cm lower calyceal stone
0.5
SWL
21 (19)
9 (9)
12 (11)
0.03
PCNL
32 (30)
40 (45.5)
48 (47)
40
RIRS
55 (51)
40 (45.5)
43 (42)
46
Preferred approach: 1.5 cm
SWL
1 (3)
2 (2)
1 (1)
LAP
18 (16)
7 (8)
12 (11)
PCNL
29 (26)
44 (49)
54 (53)
URS
60 (55)
36 (41)
36 (35)
0.004
SWL, extra-corporeal shock wave lithotripsy; LAP, laparoscopic; PCNL, percutaneous nephrolithotomy; RIRS, retrograde intrarenal surgery; URS, ureteroscopy.
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Therapeutic Advances in Urology 9(9-10) Table 4. Regional variations in trends. North America
Asia
Europe
p-value
Prone: (82%)
Prone: (73%)
Prone: (70%)
0.3
Supine: (10%)
Supine: (20%)
Supine: (25%)
0.07, 0.06
Modified lateral: (8%)
Modified lateral: (7%)
Modified lateral: (5%)
Urologist: (67%)
Urologist: (85%)
Urologist: (81%)
0.06, 0.09
Radiologist: (18)
Radiologist: (2%)
Radiologist: (3%)
0.6
Both: (15%)
Both: (13%)
Both: (16)
Fluoroscopy: (77%)
Fluoroscopy: (73%)
Fluoroscopy: (61%)
0.3
Ultrasound: (3%)
Ultrasound: (3%)
Ultrasound: (5%)
0.8
Combined: (20%)
Combined: (24%)
Combined: (34%)
0.09
Ultrasonic: (67%)
Ultrasonic: (34%)
Ultrasonic: (46%)
0.03, 0.02
Pneumatic: (26%)
Pneumatic: (60%)
Pneumatic: (33%)
0.05
Laser: (7%)
Laser: (6%)
Laser: (21%)
No: (57%)
No: (68%)
No: (81%)
0.04
Yes: (43%)
Yes: (32%)
Yes: (19%)
0.03
Tubeless
38%
10%
8%
0.03
Dilatation
Balloon (60%)
Balloon (33%)
Balloon (44%)
0.05
Metal (27%)
Metal (50%)
Metal (35%)
One shot (13%)
One shot (17%)
One shot (21%)
Mini-PERC
35%
45%
33%
0.05
Hospital stay
Mean 2.1 days
2.4 days
2.3 days
0.1
Prone/supine
Access done by:
Access guidance methods
Type of lithotripter
Combined techniques
PCNL. This may be explained by the higher stone-free rate and familiarity of the prone position.17,18 In previous surveys, the choice of patient position was not addressed.7–9 Our data confirmed that the combined PCNL with flexible ureteroscopy approach is gaining more popularity. This agrees with other studies reporting the advantages of the combined antegrade and retrograde approaches in the management of complex renal stones.19,20 There is a known debate regarding exit strategy in PCNL. Many studies reported safety of tubeless PCNL.19,21 Although studies indicated that tubeless PCNL may be well tolerated, it has not become routine practice, and importantly, the term ‘tubeless’ is often misleading and a postoperative stent or ureteral catheter is usually maintained. On the other hand, the advantages of tubeless PCNL were challenged with a 1-day nephrostomy tube.22–24 Our data and previous
surveys, emphasized that absolute tubeless PCNL did not gain popularity.7–9 Questions for the choice of treatment options in different stone sizes and locations were also not covered in previous reports.7–9 The results emphasized that most endourologists follow the current guidelines in the management of urolithiasis.25 Interestingly, our data indicated that the use of retrograde intrarenal surgery (RIRS) has an increasing role in contemporary practice in management of lower calyceal stones