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Article of the Week: Antibiotic prophylaxis in ureteroscopic lithotripsy

Every Week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.

Antibiotic prophylaxis in ureteroscopic lithotripsy: a systematic review and meta‐analysis of comparative studies

Tuo Deng*†‡, Bing Liu§, Xiaolu Duan*†‡, Chao Cai*†‡, Zhijian Zhao*†‡, Wei Zhu*†‡Junhong Fan*†‡, Wenqi Wu*†‡ and Guohua Zeng*†‡

 

*Department of Urology, Minimally Invasive Surgery Center, The First Afliated Hospital of Guangzhou Medical University, Guangzhou, China, Guangzhou Institute of Urology, Guangzhou, China, Guangdong Key Laboratory of Urology, Guangzhou, China, and §The First Afliated Hospital of Jinan University, Guangzhou, China

 

Abstract

Objective

To explore the efficacy of antibiotic prophylaxis and the different strategies used to prevent infection in ureteroscopic lithotripsy (URL) by conducting a systematic review and meta‐analysis.

Materials and Methods

A systematic literature search using Pubmed, Embase, Medline, the Cochrane Library, and the Chinese CBM, CNKI and VIP databases was performed to find comparative studies on the efficacy of different antibiotic prophylaxis strategies in URL for preventing postoperative infections. The last search was conducted on 25 June 2017. Summarized unadjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the efficacy of different antibiotic prophylaxis strategies.

Results

A total of 11 studies in 4 591 patients were included in this systematic review and meta‐analysis. No significant difference was found in the risk of postoperative febrile urinary tract infections (fUTIs) between groups with and without antibiotic prophylaxis (OR: 0.82, 95% CI 0.40–1.67; P = 0.59). Patients receiving a single dose of preoperative antibiotics had a significantly lower risk of pyuria (OR: 0.42, 95% CI 0.25–0.69; P = 0.0007) and bacteriuria (OR: 0.25, 95% CI 0.11–0.58; P = 0.001) than those who did not. Intravenous antibiotic prophylaxis was not superior to single‐dose oral antibiotic prophylaxis in reducing fUTI (OR: 1.00, 95% CI 0.26–3.88; P = 1.00).

Conclusions

We concluded that preoperative antibiotic prophylaxis did not lower the risk of postoperative fUTI, but a single dose could reduce the incidence of pyuria or bacteriuria. A single oral dose of preventive antibiotics is preferred because of its cost‐effectiveness. The efficacy of different types of antibiotics and other strategies could not be assessed in our meta‐analysis. Randomized controlled trials with a larger sample size and more rigorous study design are needed to validate these conclusions.

Editorial: Antibiotics and ureteroscopy: a single prophylactic dose is enough, but could we give even less?

Antibiotic resistance is internationally recognized as a threat to global health. As a consequence, there is an ongoing need to review antibiotic prescribing practice, both for treatment and prophylaxis. ‘Antibiotic stewardship’, whereby antimicrobial use, and the associated increase in bacterial resistance, is reduced, is essential worldwide [1].

In this issue of BJUI, Deng et al. [2] present the results of their systematic review and meta‐analysis of the efficacy of antibiotic prophylaxis vs no treatment in patients undergoing upper tract ureteroscopy/ureterorenoscopy. In total, 4591 patients were analysed (from 11 studies, comprising five randomized controlled trials, one prospective comparative study and five retrospective comparative studies), of whom 2700 patients received antibiotic prophylaxis and the remaining 1891 had no prophylactic antibiotics at all.

Having excluded patients with pre‐operative urinary tract infection (UTI) or bacteriuria, they found that patients who received a single dose of pre‐operative antibiotic had a significantly lower risk of pyuria and bacteriuria than those without antibiotic, but that there was no difference in the risk of post‐operative febrile UTIs between the groups with and without the use of prophylactic antibiotic. There was also no advantage to intravenous antibiotic administration compared with oral administration in reducing febrile UTIs, nor any difference between a single dose of antibiotic drug vs a more prolonged post‐operative regime [2].

This is an important article, potentially leading many urological surgeons to change their current practice with regard to prescribing post‐operative antibiotics, and raising the question of whether antibiotic prophylaxis is needed in patients who have sterile urine pre‐operatively and no specific operative risk factors.

The next question for endourologists to answer will be ‘What is the most appropriate management of asymptomatic bacteriuria detected during pre‐operative investigations?’ Whilst current practice is to treat pre‐operative bacteriuria in patients managed in urology departments, Herr [3] has shown it is reasonable not to give prophylactic antibiotics to asymptomatic patients undergoing flexible cystoscopy, even if there is bacteriuria on pre‐procedure urine analysis. Herr evaluated >3000 outpatients undergoing flexible cystoscopies (of whom 78% had sterile urine and 22% had asymptomatic bacteriuria). The cystoscopies were performed without any antibiotic prophylaxis at all. Overall, 1.9% of patients experienced febrile UTIs, all of which resolved rapidly with oral antibiotics and without any complications (no sepsis or hospital admission). Although the rate was higher in patients with prior infected urine (UTI rate 3.7% compared with 1.4% in patients with sterile urine), Herr concluded that prophylactic antibiotics are not necessary in asymptomatic patients regardless of the presence of bacteriuria, and therefore advised that pre‐procedure urine analysis itself is not required [3].

These findings challenge the belief that pre‐operative urine analysis is essential in asymptomatic patients. Kavoussi et al. [4] studied this issue in patients undergoing insertion of an artificial urinary sphincter or inflatable penile prosthesis, of whom 41% had no pre‐operative urine culture; the authors demonstrated a low risk of 1.5% of prosthesis infection in patients receiving standard peri‐operative antibiotics. This suggests that, even in ‘high stakes’ prosthetic implantation (where the consequences of infection are considerable, requiring explanation and later re‐insertion of a new device), surgery can be performed without pre‐operative urine cultures [4].

Perhaps even more contentiously, Cai et al. [5] have questioned the need for treatment of asymptomatic bacteriuria before urological procedures when ‘standard antibiotic prophylaxis’ is given pre‐operatively. They analysed 2201 patients treated in accordance with European Association of Urology guidelines for antibiotic prophylaxis, of whom 70.1% had sterile urine and 30.4% had asymptomatic bacteriuria pre‐operatively. They reported no increased risk in patients with pre‐operative asymptomatic bacteriuria, with 10.4% of affected patients having a symptomatic post‐operative UTI and a 0.3% risk of sepsis, compared with a 8.3% UTI rate and 0.26% chance of sepsis in patients with pre‐operatively sterile urine [5].

In their article, Deng et al. [2] have shown that patients with sterile urine undergoing ureteroscopy had a similar risk of a post‐operative febrile UTI whether or not pre‐ and post‐operative antibiotics were given. This implies the need for specific high‐risk groups to be targeted for antibiotic prophylaxis, and, extending the arguments above, suggests that a more selective approach is needed for pre‐operative urine analysis in low‐risk patients.

In this regard, Grabe and Wullt [6] have commented that ‘undetected pre‐operative bacteriuria is like walking straight into a minefield’. Whilst the knowledge that one is walking into a minefield has the advantage of leading one to take a cautious approach (i.e. treating asymptomatic bacteriuria pre‐operatively), it is possible that not all of the mines in the minefield are live (i.e. certain patients with asymptomatic bacteriuria may be at lower risk of post‐operative problems than others). The real challenge is to determine which patients with asymptomatic bacteriuria need antibiotic treatment and for how long, and therefore which patients need urine analysis before which procedures in the first place. This approach, if shown to be safe, would not only reduce the cost of urine cultures and pre‐surgical eradication of asymptomatic bacteriuria, but also the wider global cost of antibiotic overuse and bacterial resistance.

Daron Smithand Bruce Macrae
*EndoLuminal EndoUrologist, Department of Urology, Westmoreland Street Hospital, and Clinical Microbiology, UCLH NHS Foundation Trust, London, UK

References

  1. WHO. Global action plan on antimicrobial resistance. 2015 (accessed March 23, 2018)https://apps.who.int/iris/bitstream/handle/10665/193736/9789241509763_eng.pdf?sequence=1
  2. Deng T, Liu B, Duan X et al. Antibiotic prophylaxis in ureteroscopic lithotripsy: a systematic review and meta‐analysis of comparative studies. BJU Int 2018122: 29–39
  3. Herr HW. The risk of urinary tract infection after flexible cystoscopy in patients with bladder tumor who did not receive prophylactic antibiotics. J Urol 2015193: 548–51
  4. Kavoussi NL, Viers BR, Pagilara TJ et al. Are urine cultures necessary prior to urologic prosthetic surgery? Sex Med Rev 20186: 157–61
  5. Cai T, Verze P, Palmieri A et al. Is preoperative assessment and treatment of asymptomatic bacteriuria necessary for reducing the risk of postoperative symptomatic urinary tract infections after urologic surgical procedures? Urology 201799: 100–5
  6. Grabe M, Wullt B. Re: Is preoperative assessment and treatment of asymptomatic bacteriuria necessary for reducing the risk of postoperative symptomatic urinary tract infection after urologic surgical procedures? Eur Urol 2017; 73: 476-477

Article of the week: Prostate biopsy: shaking up the old standard

Every week the Editor-in-Chief selects the Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

Finally, the third post under the Article of the Week heading on the homepage will consist of additional material or media. This week we feature a video of Dr Symons discussing his paper.

If you only have time to read one article this week, it should be this one.

Outcomes of transperineal template-guided prostate biopsy in 409 patients

James L. Symons*, Andrew Huo*, Carlo L. Yuen‡§, Anne-Maree Haynes*, Jayne Matthews, Robert L. Sutherland*, Phillip Brenner‡§ and Phillip D. Stricker†‡§

*Cancer Research Programme, Garvan Institute of Medical Research, St Vincent’s Prostate Cancer Centre, Department of Urology, St. Vincent’s Hospital, and §Department of Urology, St. Vincent’s Clinic, Darlinghurst, NSW, Australia

OBJECTIVE

• To present the template-guided transperineal prostate biopsy (TPB) outcomes for patients of two urologists from a single institution.

PATIENTS AND METHODS

• We conducted a prospective study of 409 consecutive men who underwent TPB between December 2006 and June 2008 in a tertiary referral centre using a standardized 14-region technique.

• The procedure was performed as day surgery under general anaesthesia with fluoroquinolone antibiotic cover.

• Follow-up took place within 2 weeks, during which time men were interviewed using a standardized template.

• Results were compared with those of the Australian national prostate biopsy audits performed by the Urological Society of Australia and New Zealand (USANZ).

RESULTS

• Indications for biopsy included elevated prostate-specific antigen (PSA) level (75%), with a median PSA level of 6.5 ng/mL, abnormal digital rectal examination (8%) and active surveillance (AS) re-staging (18%).

• The mean patient age was 63 years and two-thirds of patients were undergoing their first biopsy.

• A positive biopsy was found in 232 men, 74% of whom had a Gleason score of ≥7. The overall cancer detection rate was 56.7% (USANZ 2005 national audit = 56.5%). Stratified between those having their first TPB or a repeat procedure (after a previous negative biopsy), the detection rates were 64.4 and 35.6%, respectively. Significantly higher detection rates were found in prostates <50 mL in volume than in larger prostates (65.2 vs 38.3%, respectively, P < 0.001).

• Haematuria was the most common side effect (51.7%). Others included dysuria (16.4%), acute urinary retention (4.2%) and fever (3.2%). One patient (0.2%) had septicaemia requiring i.v. antibiotics.

• Repeat biopsy was not associated with increased complication rates.

CONCLUSIONS

• TPB is a safe and efficacious technique, with a cancer detection rate of 56.7% in the present series, and a low incidence of major side effects. Stratified by prostate volume, the detection rate of TPB was higher in smaller glands.

• Given the relatively low rate of serious complications, clinicians could consider increasing the number of TPB biopsy cores in larger prostates as a strategy to improve cancer detection within this group. Conversely, in patients on AS programmes, a staging TPB may be a superior approach for patients undergoing repeat biopsy so as to minimize their risk of serious infection.

Editorial: Contemplate the template: a new prostate biopsy approach

Transperineal magnetic resonance imaging – ultrasound fusion targeted biopsies (MRI-US FTB) of the prostate: the future of prostate diagnostics

The prostate cancer diagnostic pathway has remained unchanged for 25 years. At best, laterally directed, peripheral zone (PZ) 12-core transrectal biopsies identify cancer in 44% of cases [1] but transrectal biopsies have an inherent sampling error with a risk of misdiagnosis or mischaracterisation of disease. Of those with negative biopsies who undergo transperineal (TP) biopsies, 30% have cancer, most in the anterior PZ. Active surveillance and the promise of less invasive treatment options are becoming popular because of concerns about ‘over treatment’ for low-risk disease.

Saturation transrectal biopsies have been advocated to improve diagnostic yield but do not address the issue of under sampling of the anterior PZ, particularly in the larger gland [2]. TP biopsies can be used to address the issue of under sampling but prostate template-mapping biopsies are labour intensive and require large numbers of biopsies, often between 60 to 90 cores; however, they have been an essential component of focal therapy trials and the evaluation of novel treatment methods [3].

Primary TP biopsy is the subject of the paper published in this edition of the BJUI titled ‘Outcomes of transperineal template-guided prostate biopsy in 409 patients’ [4]. The authors report a single centre experience of primary TP biopsies. The 14-region protocol described is simpler than prostate template-mapping requiring fewer cores (median of 15 and mean of 19 cores) with a comparable primary diagnostic detection rate of 60% and an encouraging side-effect profile. Unfortunately, the approach still has limitations and the authors admit that their limited biopsy protocol may still mischaracterise disease in the larger gland. In a recent paper from the same group, there was a disappointing correlation between their TP biopsy pathology, MRI abnormalities and radical prostatectomy specimens [5]. Uncertainty prevails, the problem is how best to sample the larger gland. The authors [4] and others, often conclude that more biopsies are necessary for larger glands and resort to mapping protocols and many more biopsies. The solution may not be more biopsies but rather better systematic targeting of the PZ. The impact of hyperplasia within the transition zone (TZ) has a profound effect on PZ anatomy. In the smaller prostate, up to 30 mL, there is little TZ and the PZ is much thicker posteriorly than anteriorly, this difference is even more apparent in glands of 30–50 mL. Above 50 mL TZ expansion causes marked attenuation of the PZ, which becomes much thinner, but the overall volume of the PZ does not change. Less than 4% of cancers originate in the TZ [6], consequently biopsies should be concentrated primarily on the PZ.

The future of prostate cancer diagnosis is likely to be a combination of pre-biopsy multiparametric MRI, followed by targeted biopsies of MRI-identified lesions combined with fewer but better systematic targeted biopsies of the PZ. MRI-ultrasound (MRI-US) fusion techniques have been developed in which axial T2 images of the prostate, diffusion-weighted images and/or dynamic contrast-enhanced MRI images are ‘fused’ with the live US images to allow precise targeting of both regions of interest and the PZ. Commercially available biopsy programs, developed from brachytherapy software systems programs allow individual biopsy sites to be recorded and if combined with inking of the specimen can provide precise pathological localisation of disease within the prostate [7].

There are many potential benefits to this approach. Patients who opt for active surveillance will have an archived record of their disease at a given time to facilitate precise replication of further interval biopsies and assess progression. Improved disease management for an individual should be the aim. The suitability or not for focal or targeted therapies, the planning or boosting of identifed lesions with radiotherapy and/or brachytherapy, and the planning of nerve-sparing surgery or wide excisions should be possible. Feedback to the radiologists of both benign and malignant pathology and grade of disease will improve reporting accuracy and provide imaging sciences with the histopathological characteristics of both MRI ‘visible’ and ‘invisible’ cancer to improve MRI interpretation.

MRI–US fusion targeted biopsies are a significant advance in prostate diagnostics and may resolve some uncertainty within the prostate cancer diagnostic pathway. Benefit vs cost is a recurring issue across health care and questions will continue to be asked about the use of increasingly expensive technology in such an indolent disease. The challenge for investigators will be how to prove the benefit of this approach over standard biopsy protocols and integrate this work in to clinical practice.

Richard Popert
Department of Urology, Guy’s Hospital, London, UK

References
  1. Presti JC, O’Dowd GL, Miller MC et al. Extended peripheral zone biopsy schemes increase cancer detection rates and minimize variance in prostate specific antigen and age related cancer rates: results of a community multi-practice study. J Urol 2003; 169:125–129
  2. Stewart CS, Leibovich BC, Weaver AL, Lieber MM. Prostate cancer diagnosis using a saturation needle biopsy technique after previous negative sextant biopsies. J Urol 2001; 166: 86–92
  3. Onik G, Barzell W. Transperineal 3D mapping biopsy of the prostate: an essential tool in selecting patients for focal prostate cancer therapy. Urol Oncol 2008; 26: 506–510
  4. Symons JL, Huo A, Yuen CL et al. Outcomes of transperineal template-guided prostate biopsy in 409 patients. BJU Int 2013; 112: 585–593
  5. Huo AS, Hossack T, Symons JL et al. Accuracy of primary systematic template guided transperineal biopsy of the prostate for locating prostate cancer: a comparison with radical prostatectomy specimens. J Urol 2012; 187: 2044–2050
  6. Patel V, Merrick GS, Allen ZA et al. The incidence of transition zone prostate cancer diagnosed by transperineal template guided mapping biopsy: implications for treatment planning. Urology 2011; 77: 1148–1152
  7. Hadaschik BA, Kuru TH, Tulea C et al. A novel stereotactic prostate biopsy system integrating pre-interventional magnetic resonance imaging and live ultrasound fusion. J Urol 2011; 186: 2214–2220

Video: Transperineal prostate biopsy: how good is the tumour detection rate?

Outcomes of transperineal template-guided prostate biopsy in 409 patients

James L. Symons*, Andrew Huo*, Carlo L. Yuen‡§, Anne-Maree Haynes*, Jayne Matthews, Robert L. Sutherland*, Phillip Brenner‡§ and Phillip D. Stricker†‡§

*Cancer Research Programme, Garvan Institute of Medical Research, St Vincent’s Prostate Cancer Centre, Department of Urology, St. Vincent’s Hospital, and §Department of Urology, St. Vincent’s Clinic, Darlinghurst, NSW, Australia

OBJECTIVE

• To present the template-guided transperineal prostate biopsy (TPB) outcomes for patients of two urologists from a single institution.

PATIENTS AND METHODS

• We conducted a prospective study of 409 consecutive men who underwent TPB between December 2006 and June 2008 in a tertiary referral centre using a standardized 14-region technique.

• The procedure was performed as day surgery under general anaesthesia with fluoroquinolone antibiotic cover.

• Follow-up took place within 2 weeks, during which time men were interviewed using a standardized template.

• Results were compared with those of the Australian national prostate biopsy audits performed by the Urological Society of Australia and New Zealand (USANZ).

RESULTS

• Indications for biopsy included elevated prostate-specific antigen (PSA) level (75%), with a median PSA level of 6.5 ng/mL, abnormal digital rectal examination (8%) and active surveillance (AS) re-staging (18%).

• The mean patient age was 63 years and two-thirds of patients were undergoing their first biopsy.

• A positive biopsy was found in 232 men, 74% of whom had a Gleason score of ≥7. The overall cancer detection rate was 56.7% (USANZ 2005 national audit = 56.5%). Stratified between those having their first TPB or a repeat procedure (after a previous negative biopsy), the detection rates were 64.4 and 35.6%, respectively. Significantly higher detection rates were found in prostates <50 mL in volume than in larger prostates (65.2 vs 38.3%, respectively, P < 0.001).

• Haematuria was the most common side effect (51.7%). Others included dysuria (16.4%), acute urinary retention (4.2%) and fever (3.2%). One patient (0.2%) had septicaemia requiring i.v. antibiotics.

• Repeat biopsy was not associated with increased complication rates.

CONCLUSIONS

• TPB is a safe and efficacious technique, with a cancer detection rate of 56.7% in the present series, and a low incidence of major side effects. Stratified by prostate volume, the detection rate of TPB was higher in smaller glands.

• Given the relatively low rate of serious complications, clinicians could consider increasing the number of TPB biopsy cores in larger prostates as a strategy to improve cancer detection within this group. Conversely, in patients on AS programmes, a staging TPB may be a superior approach for patients undergoing repeat biopsy so as to minimize their risk of serious infection.

Article of the week: Prolonged SNM testing effective despite bacteria presence

Every week the Editor-in-Chief selects the Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.

Prolonged percutaneous SNM testing does not cause infection-related explanation

Bastian Amend, Jens Bedke, Mahmoud Khalil, Arnulf Stenzl and Karl-Dietrich Sievert

Department of Urology, Eberhard Karls University Tuebingen, Tuebingen, Germany

OBJECTIVE

• To evaluate the impact of prolonged stage 1 testing on bacterial electrode colonization, infection and treatment success.

MATERIALS AND METHODS

• In all, 21 patients who underwent sacral neuromodulation (SNM) for periods 1 month were prospectively evaluated; nine patients had overactive bladder syndrome (OAB), 10 had urinary retention, two had faecal incontinence (FI), and 13 had diabetes and overweight/obesity.

• After stage 1 testing electrode extension leads were microbiologically analysed to assess bacterial colonization.

• The primary measurements were pre- and post-SNM treatment comparisons based on patient-agreed criteria using an increased 70% minimum improvement rate; secondary measurements were bacterial colonization and impact of infection.

RESULTS

• The mean stage 1 evaluation period was 52.3 days; 16 patients (76%) progressed to stage 2, and five patients were explanted due to inadequate improvement (<70%).

• There was bacterial colonization in 42.9% of patients and 38.2% of extension leads.

• Stage 2 patients showed no infection or wound-healing disorders at a mean follow-up of 33.9 months.

• The success rate for stage 2 implantation treatment was 94%.

CONCLUSIONS

• There are few studies in the literature evaluating SNM testing periods vs the risk of clinically relevant implant infection rates. The present study shows that prolonged testing could potentially enhance treatment efficacy without infection-related explantations of the chronic implant, despite the identification of bacteria.

• SNM-implanted patients with diabetes mellitus or obesity should be followed closely.

• Clinicians might consider using prolonged testing under everyday conditions.

• Prolonged SNM stage 1 testing is a very effective minimally invasive treatment option to evaluate pelvic-related dysfunction.

 

Read Previous Articles of the Week

Editorial: What is the optimal length of time for SNM testing?

The authors are to be commended for their unique investigation of an extended stage 1 SNM test period. To our knowledge, no other series has included a minimum 4-week duration and microbiologic testing. Optimal duration for the test phase has not been elucidated and initial responses are likely compounded by a short-term placebo effect that may dissipate after time. Knowledge of when maximal improvement occurs would define a population of true responders and reduce implant failure rates. This series shows the feasibility of an extended test phase in a small cohort, but does not identify the optimal length of time for testing.

One must question how many responders are in the 2- to -4 week interval and if such patients would do as well with earlier implantation. Current testing with permanent leads and externalized hardware is cumbersome and not always convenient for activities of daily living, especially showering. Furthermore, knowing the sampling interval used by the authors to assess response and the time at which the majority of patients reached the established implant criteria could clarify the time needed for maximal response. In this small cohort, however, the difference would fail to show significance.

As the authors note, a low stage 2 failure rate is important in an era with rising concern over health care expenditure, but it generates questions on what to do for responders
who have symptomatic improvement >50% but <70%. Do we risk not helping an individual who has 50% improvement in order to reduce stage 2 failures, and how do we justify making this quality-of-life decision? The low stage 2 failure rate in this study may have resulted from the strict criteria for stage 1 success, specifically a 70% or greater response, and not necessarily the prolonged test phase.

Notably, there were no infections in this series despite an extended stage 1 test phase. This is considerably lower than the 5–7% infection rate reported in the literature (UrologyEur Urol). Perhaps the degree of hygiene and antibiotic regimen contributed to the lack of infectious complications, but concern remains that such results are not generalizable. Infectious events not captured in this series may become evident with a larger sample size and surely the rate will be greater than zero. Granted, the results of this study add to our knowledge of SNM, it is not conclusive that the outcomes can be applied to the population at large, and further evidence from randomized trials are needed to identify the balance between benefits and risks associated with an extended test phase.

Brian K. Marks and Sandip P. Vasavada
Center for Female Urology and Reconstructive Pelvic Surgery, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA

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