Posterior musculofascial reconstruction versus no posterior reconstruction during robotic‐assisted laparoscopic prostatectomy for the treatment of clinically localized prostate cancer

Objectives

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effects of posterior musculofascial reconstruction versus no posterior reconstruction during robotic‐assisted laparoscopic prostatectomy for the treatment of clinically localized prostate cancer.

Background

Description of the condition

The most common solid organ malignancy in men is prostate cancer (Siegel 2019). In 2018, the incidence of prostate cancer was 13.5% and the mortality rate 6.7%, with varying prevalence among different racial groups (Bray 2018; Rawla 2019). Risk factors for prostate cancer include having a family history of prostate cancer, being advanced in age, and being of African descent (Rawla 2019). Radical prostatectomy is a well‐established treatment for clinically localized prostate cancer, with trial evidence showing improved long‐term oncological outcomes compared to watchful waiting (Bill‐Axelson 2018; Wilt 2012; Wilt 2017). In recent years, robotic‐assisted laparoscopic prostatectomy (RALP) has become the main approach, especially in the USA (Menon 2018; Sayyid 2017).

Description of the intervention

Prostatectomy outcomes are influenced by surgical skill, technique, and experience of the surgeon (Vickers 2007). The two major adverse effects following a radical prostatectomy are erectile dysfunction and temporary or persistent urinary incontinence (Grasso 2016). Urinary continence is influenced by the muscular component, sphincter support structures, and supportive ligaments of the bladder and urethra towards the pelvis and anterior abdominal wall (Arroyo 2019). Numerous technical modifications to restore the normal anatomy have been implemented in efforts to retain continence after standard RALP (Asimakopoulos 2019; Checcucci 2019; Lim 2014). One of methods involves reconstructing the posterior musculofascial plate (Rocco 2001).

The musculofascial plate is a suspension system which comprises Denonvilliers' fascia, the rhabdosphincter, median fibrous raphe, the posterior fascia of the prostate and the central tendon of the perineum (Rocco 2012). The rhabdosphincter comprises circular striated muscle fibers surrounding the urethra from the membranous aspect to the prostatic apex. The anterolateral walls of the rhabdosphincter contract along the more rigid posterior wall, acting as a fulcrum for the muscular action (Rocco 2012). The purpose of reconstructing the posterior musculofascial plate is to minimize urethrosphincteric sliding after prostatectomy, support the vesicourethral anastomosis, approximate the bladder neck to the urethral stump, and provide a fulcrum for contraction of the rhabdosphincter (Arroyo 2019).

Reconstruction of the posterior aspect of the rhabdosphincter was first described by Rocco and colleagues in 2001 for open surgery, and in 2006 a study suggested that it might shorten time to continence after radical prostatectomy (Rocco 2001; Rocco 2006). In 2007, this type of reconstruction was described in transperitoneal laparoscopic radical prostatectomy (Rocco 2007; Rocco 2007a). Subsequently, in 2011 Coelho and colleagues modified the reconstruction for RALP, and reported no increase in operative time or increase in potential harms to the participant (Coelho 2011; Coelho 2018). Since its worldwide spread, multiple different modifications of posterior musculofascial reconstruction (PMR) have since evolved but there is a disagreement in the existing literature as to whether this improves continence when compared to no posterior reconstruction during RALP (Gautam 2010). Differing continence rates have been reported in trials; this may be due to variations of the original technique, varying degrees of surgical experience, and varying definitions of assessments of urinary continence (Coelho 2011; Coelho 2018; Rocco 2012).

Adverse effects of the intervention

Theoretically, increasing the number of sutures in the area with PMR may increase urethral stenosis and acute urinary retention requiring secondary interventions (Grasso 2016). Other adverse effects of PMR are similar to those associated with standard RALP. PMR provides support for the new vesicourethral anastomosis but persistent urinary incontinence can still occur. Additional adverse effects of the intervention include blood loss, need for transfusions, erectile dysfunction and intraoperative injury to adjacent structures. 

How the intervention might work

The original technique described by Rocco and colleagues in 2001 for open prostatectomy used interrupted sutures on both sides of the midline to approximate the Denonvilliers' fascia to the posterior aspect of the rhabdosphincter and posterior median raphe (Gautam 2010; Rocco 2001; Rocco 2007). The technique has since been adapted for RALP by placing continuous sutures, which is faster and technically easier. Multiple different modifications of this technique have since evolved (Gautam 2010). In general, the free edge of the Denonvilliers' fascia after the prostatectomy is identified and approximated to the posterior aspect of the rhabdosphincter and posterior median raphe using a continuous suture. A second layer of reconstruction can be performed, approximating the posterior lip of the bladder neck and the rectourethralis muscle to the posterior urethral edge and to the previously reconstructed median raphe (Coelho 2018). We recognize there are many different nuances in posterior musculofascial reconstruction techniques, along with additional reconstruction techniques such as anterior reconstruction (Checcucci 2019). We will account for this in the reporting of our review, and plan to perform subgroup analyses to explore this variation.

Why it is important to do this review

Many surgeons around the world are performing posterior musculofascial reconstruction after RALP. It is thought to be easily reproducible and quickly executed, with no increased risk of perioperative complication. However, varying reports of urinary continence and peri‐anastomotic urinary leakages have been reported, which brings into question the value of this technique (Grasso 2016; Coelho 2018).

A number of randomized and non‐randomized studies have compared Retzius‐sparing RALP (RS‐RALP) to standard RALP, and their results have been summarized in two  systematic reviews (Grasso 2016; Rocco 2012). However, neither applied the same methodological rigor as in a Cochrane Review, which includes an a priori published protocol, an exhaustive search of the published and unpublished literature (irrespective of language of publication), a focus on patient‐important outcomes and clinically meaningful differences, and the use of the GRADE approach to assess the certainty of evidence for each outcome (Guyatt 2011). Our Cochrane Review will therefore address an important gap in the knowledge on the effectiveness of PMR to guide clinical practice and future research. This brings the potential to change the practice of urologic surgery to minimize the common adverse events experienced after undergoing RALP. The findings of this review will help promote the further refinement and dissemination of a standardized approach to RALP. 

Objectives

To assess the effects of posterior musculofascial reconstruction versus no posterior reconstruction during robotic‐assisted laparoscopic prostatectomy for the treatment of clinically localized prostate cancer.

Methods

Criteria for considering studies for this review

Types of studies

We will include parallel‐group randomized trials only. We will exclude cross‐over and cluster‐randomized trials as they are not relevant to this comparison. We will also not consider pseudo‐randomized controlled trials or observational studies, given their increased risk of selection bias. We will include studies regardless of their publication status or language of publication.

Types of participants

We will include studies of adult men (aged 18 years or older) with clinically localized prostate cancer (clinical stage T1 to T2, N0, M0), who are planning to undergo RALP (Buyyounouski 2017). Clinically localized prostate cancer is defined as T1‐T3a which includes tumors confined to the prostate or with extracapsular extension but without spread the seminal vesicles.

We will exclude studies of men with pre‐existing urinary incontinence. Should we identify studies in which only a subset of participants are relevant to this review, we will include such studies if data are available separately for the relevant subset.

Types of interventions

We plan to investigate the following comparisons of experimental intervention versus comparator intervention. Concomitant interventions will be included providing they are the same in the experimental and comparator groups.

Experimental intervention

• Posterior musculofascial reconstruction during RALP

Comparator intervention

• No posterior reconstruction during RALP

Comparison

• Posterior musculofascial reconstruction during RALP versus no posterior reconstruction during RALP

Types of outcome measures

We will include studies regardless of whether they measured the outcomes to be assessed in this review.

Primary outcomes

• Urinary continence within one week after catheter removal (dichotomous outcome)

• Urinary continence three months after surgery (dichotomous outcome)

• Serious adverse events (dichotomous outcome)

Secondary outcomes

• Urinary continence six months after surgery (dichotomous outcome)

• Urinary continence 12 months after surgery (dichotomous outcome)

• Potency 12 months after surgery (dichotomous outcome)

• Positive surgical margins (dichotomous outcome)

• Biochemical recurrence‐free survival (time‐to‐event outcome)

• Urinary function scores on quality‐of‐life scale (continuous outcome)

• Sexual function scores on quality‐of‐life scale (continuous outcome)

Method and timing of outcome measurement

• Urinary continence

  • Self‐reported absence of leakage or use of 0 or 1 pads/day.

  • We will assess this outcome up to 12 months after surgery.

  • We will consider a 5% absolute difference in continence rates as clinically important.

• Serious adverse events

  • Measured as Dindo‐Clavien system grade III or more (Dindo 2004).

  • We will assess this outcome up to 12 months after surgery.

  • We will consider a 2% absolute difference in serious adverse event rates as clinically important.

• Potency

  • Number or percentage of participants achieving potency according to validated potency scales such as the International Index of Erectile Function and IIEF‐5 scores (Rosen 1997; Rosen 2011). We define achieving potency as IIEF‐EF score of 19 or greater (mild erectile dysfunction) and IIEF‐5 score of 17 or greater (no erectile dysfunction).

  • We will assess this outcome at 12 months after surgery.

  • We will consider a 5% absolute difference in potency rates as clinically important.

• Positive surgical margins

  • Positive when cancer cells are found at the ink‐marked resection margin.

  • We will assess this outcome following surgery, on the basis of the prostatectomy specimen.

  • We will consider a 5% absolute difference in positive surgical margins as clinically important.

• Biochemical recurrence‐free survival

  • Defined as any prostate‐specific antigen values greater or equal to 0.2 ng/ml.

  • We will assess this outcome up to 60 months (five years) after surgery.

  • We will consider a 2% absolute difference in biochemical recurrence rates at 60 months as clinically important.

• Urinary function scores on quality‐of‐life scale

  • Final value or change assessed with validated questionnaires such as the urinary domain of the Expanded Prostate Cancer Index Composite (Wei 2000) questionnaire.

  • We will assess this outcome up to 12 months after surgery.

  • We will consider a 5% absolute difference in quality of life as clinically important.

• Sexual function scores on quality‐of‐life scale

  • Final value or change assessed with validated questionnaires, such as the sexual domain of the Expanded Prostate Cancer Index Composite (Wei 2000) questionnaire.

  • We will assess this outcome up to 12 months after surgery.

  • We will consider a 5% absolute difference in quality of life as clinically important.

Search methods for identification of studies

We will perform a comprehensive search with no restrictions on the language of publication or publication status. We plan to repeat searches within three months prior to anticipated publication of the review.

Electronic searches

We will search the following sources, from the inception of each database.

• Cochrane Library via Wiley.

  • NHS Economic Evaluation Database (NHS EED)

  • Database of Abstracts of Reviews of Effects (DARE)

  • Health Technology Assessment database (HTA)

• MEDLINE via Ovid (from 1946)

• Embase via Ovid (from 1947)

• Web of Science Core Collection

• Scopus

• Global Index Medicus

We will also search the following resources.

• ClinicalTrials.gov (www.clinicaltrials.gov/)

• World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal (apps.who.int/trialsearch/)

If we detect additional relevant key words during any of the electronic or other searches, we will modify the electronic search strategies to incorporate these terms and document the changes.

Searching other resources

We will try to identify other potentially eligible trials or ancillary publications by searching the reference lists of retrieved included trials, reviews, meta‐analyses and health technology assessment reports. We will also contact study authors of included trials to identify any further studies that we may have missed. We will contact drug/device manufacturers for ongoing or unpublished trials.

No handsearching for abstract proceedings will be performed, as all relevant meetings — such as those of the American Urological Association, European Association of Urology, and Society of Urologic Oncology, from the last three years (2018 to 2020) — are published electronically and therefore will be captured in our electronic search.

Data collection and analysis

Selection of studies

We will use the reference management software Endnote to identify and remove potential duplicate records. Two review authors (JR, HL, or SL) will independently scan the abstract or title (or both) of remaining records retrieved, to determine which studies should be assessed further. Two review authors (JR, HL, or SL) will investigate all potentially relevant records as full text; they will map records to studies and classify studies as included, excluded, awaiting classification, or ongoing, in accordance with the criteria for each provided in the most recent Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2019). We will resolve any discrepancies through consensus or recourse to a third review author (JHJ or PD). If resolution of a disagreement is not possible, we will designate the study as 'awaiting classification' and we will contact the study authors for clarification. We will document reasons for exclusion of studies that may have reasonably been expected to be included in the review in a 'Characteristics of excluded studies' table. We will present a PRISMA flow diagram showing the process of study selection (Liberati 2009).

Data extraction and management

We will develop a dedicated data abstraction form that we will pilot test ahead of time. For studies that fulfill our inclusion criteria, two review authors (JR, HL, or SL) will independently abstract the following information, which we will provide in the 'Characteristics of included studies' table.

• Study design

• Study dates (if dates are not available then this will be reported as such)

• Study settings and country

• Participant inclusion and exclusion criteria (including tumor stage, PSA values, magnetic resonance imaging (MRI) findings)

• Participant details, baseline demographics (age, comorbidities, body mass index)

• Surgeons' characteristics (surgical experience)

• The number of participants by study and by study arm

• Details of relevant posterior musculofascial reconstruction RALP and no posterior reconstruction RALP interventions (as applicable), e.g. type and extent of nerve‐sparing technique, bladder neck reconstruction, etc.

• Definitions of relevant outcomes, and method and timing of outcome measurement as well as any relevant subgroups

• Study funding sources

• Declarations of interest by primary investigators

We will extract outcome data relevant to this Cochrane Review as needed for calculation of summary statistics and measures of variance. For dichotomous outcomes, we will attempt to obtain numbers of events and totals in order to populate a 2 x 2 table, as well as summary statistics with corresponding measures of variance. For continuous outcomes, we will attempt to obtain means and standard deviations or data necessary to calculate this information. For time‐to‐event outcomes, we will attempt to obtain hazard ratios (HRs) with corresponding measures of variance or data necessary to calculate this information.

We will resolve any disagreements by discussion, or by consultation with a third review author (JHJ or PD), if required. We will provide information, including trial identifier, about potentially relevant ongoing studies in the 'Characteristics of ongoing studies' table. We will attempt to contact authors of included studies to obtain key missing data as needed.

Dealing with duplicate and companion publications

In the event of duplicate publications, companion documents or multiple reports of a primary study, we will maximize yield of information by mapping all publications to unique studies and collating all available data. We will use the most complete dataset, aggregated across all known publications. In case of doubt, we will give priority to the publication reporting the longest follow‐up associated with our primary or secondary outcomes.

Assessment of risk of bias in included studies

Two review authors (JR, HL, or SL) will assess the risk of bias of each included study independently. We will resolve disagreements by consensus, or by consultation with a third review author (JHJ or PD).

We will assess risk of bias using Cochrane's 'Risk of bias' assessment tool (Higgins 2017). We will assess the following domains.

• Random sequence generation (selection bias)

• Allocation concealment (selection bias)

• Blinding of participants and personnel (performance bias)

• Blinding of outcome assessment (detection bias)

• Incomplete outcome data (attrition bias)

• Selective reporting (reporting bias)

• Other sources of bias

For each study, we will judge the risk of bias for each domain as being low, high or unclear, using the guidance described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2017). We will present a 'Risk of bias' summary figure to illustrate these findings.

For performance bias (blinding of participants and personnel) and detection bias (blinding of outcome assessment), we will evaluate the risk of bias separately for each outcome, and we will group outcomes according to whether they were measured subjectively or objectively in the 'Risk of bias' tables. We will consider all outcomes as being similarly susceptible to performance bias. We judge the following endpoints as susceptible to detection bias (i.e. subjective outcomes), thereby making blinding important.

• Urinary continence (at various time points)

• Serious adverse events

• Potency

• Urinary function scores on quality‐of‐life scale

• Sexual function scores on quality‐of‐life scale

We judge the following endpoints as not susceptible to detection bias (i.e. objective outcomes), thereby making blinding unimportant.

• Positive surgical margins

• Biochemical recurrence‐free survival

We will also assess attrition bias (incomplete outcome data) on an outcome‐specific basis, and will present the judgement for each outcome separately when reporting our findings in the 'Risk of bias' tables.

We will further summarize the risk of bias across domains for each outcome in each included study, as well as across studies and domains for each outcome, in accordance with the approach for summary assessments of the risk of bias presented in the most recent Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2019).

Measures of treatment effect

We will express dichotomous data as risk ratios with 95% confidence intervals (CIs). We will express continuous data as mean differences (MDs) with 95% CIs unless different studies use different measures to assess the same outcome, in which case we will re‐express data as standardized mean differences (SMDs) with 95% CIs. We will express as time‐to‐event data as HRs with 95% CIs.

Unit of analysis issues

The unit of analysis will be the individual participant. 

Dealing with missing data

We will obtain missing data from study authors, if feasible, and will perform intention‐to‐treat (ITT) analyses if data are available; we will otherwise perform available case analyses. We will investigate attrition rates, e.g. dropouts, losses to follow‐up and withdrawals, and will critically appraise issues of missing data. We will not impute missing data.

Assessment of heterogeneity

We will only perform meta‐analysis where this is meaningful, i.e. where the treatments, participants and outcomes are sufficiently similar. In the event of excessive heterogeneity unexplained by subgroup analyses, we will not report outcome results as the pooled effect estimate in a meta‐analysis but will provide a narrative description of the results of each study.

We will identify heterogeneity (inconsistency) through visual inspection of the forest plots to assess the amount of overlap of CIs, and by using the I² statistic, which quantifies inconsistency across studies to assess the impact of heterogeneity on the meta‐analysis (Deeks 2019; Higgins 2003). We will interpret the I² statistic as follows (Deeks 2019).

• 0% to 40%: may not be important

• 30% to 60%: may indicate moderate heterogeneity

• 50% to 90%: may indicate substantial heterogeneity

• 75% to 100%: considerable heterogeneity

When we identify heterogeneity, we will attempt to determine possible reasons for it by examining individual study and subgroup characteristics.

Assessment of reporting biases

We will attempt to obtain study protocols to assess for selective outcome reporting. If we include 10 studies or more investigating a particular outcome, we will use funnel plots to assess small‐study effects. Several explanations can be offered for the asymmetry of a funnel plot, including true heterogeneity of effect with respect to trial size, poor methodological design (and hence bias of small trials) and publication bias. We will therefore interpret results carefully. We will work in line with recommendations within the Cochrane Handbook (Page 2019).

Data synthesis

Unless we find good evidence for homogeneous effects across studies, we will summarize data using a random‐effects model. We will interpret random‐effects meta‐analyses with due consideration of the whole distribution of effects. In addition, we will perform statistical analyses according to the statistical guidelines contained in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2019). For dichotomous outcomes, we will use the Mantel‐Haenszel method and for continuous and time‐to‐event outcomes, we will use the generic inverse variance method. We will use Review Manager Web software (Review Manager 2019) software to perform analyses.

Subgroup analysis and investigation of heterogeneity

We expect the following characteristics to introduce clinical heterogeneity, and plan to carry out subgroup analyses with investigation of interactions.

• Participant age (less than 65 years versus 65 years and above). The decision to perform this subgroup analysis is based on studies suggesting the prognostic importance of age on continence recovery (Lavigueur‐Blouin 2015).

• Nerve‐sparing approach (complete or partial nerve‐sparing versus non‐nerve‐sparing). The decision to perform this subgroup analysis is based on studies suggesting the prognostic importance of nerve‐sparing status on continence recovery (Sridhar 2017).

• Clinical stage (cT1 versus cT2). The decision to perform this subgroup analysis is due to the fact that outcomes, especially PSM and BCRFS, can vary based on clinical stage (Retèl 2014).

• Anterior reconstruction technique when combined with posterior reconstruction versus only posterior reconstruction. This is based on studies suggesting the prognostic importance of anterior reconstruction on continence recovery (Arroyo 2019).

• Posterior musculofascial reconstruction with one layer versus two or more layers. This is based on studies suggesting further reinforcement creates less tension on the vesicourethral anastomosis which could lead to earlier recovery of urinary continence (Ogawa 2017).

We will use the test for subgroup differences in Review Manager 2019 to compare subgroup analyses if there are sufficient studies.

Sensitivity analysis

We plan to perform sensitivity analyses in order to explore the influence of the following factors (when applicable) on effect sizes.

• Restricting the definition of continence to no pad use.

• Restricting the analysis by taking into account risk of bias, by excluding studies at high or unclear risk of bias.

Summary of findings and assessment of the certainty of the evidence

We will present the overall certainty of the evidence for each outcome according to the GRADE approach (GRADEpro GDT), which takes into account criteria related to internal validity (risk of bias, inconsistency, imprecision, publication bias) and external validity (such as directness of results) (Guyatt 2008). For each comparison, two review authors (JR, HL, or SL) will independently rate the certainty of evidence for each outcome as 'high', 'moderate', 'low', or 'very low' using GRADEpro GDT. We will resolve any discrepancies by consensus, or, if needed, by arbitration by a third review author (JHJ or PD). For each comparison, we will present a summary of the evidence for the main outcomes in a 'Summary of findings' table, which provides key information about the best estimate of the magnitude of the effect in relative terms and absolute differences for each relevant comparison of alternative management strategies; numbers of participants and studies addressing each important outcome; and the rating of the overall confidence in effect estimates for each outcome (Guyatt 2011; Schünemann 2011). If meta‐analysis is not possible, we will present results in a narrative 'Summary of findings' table.

Main outcomes for 'Summary of findings' table

We will present a 'Summary of findings' table reporting the following outcomes, listed according to priority.

1. Urinary continence within one week after catheter removal

2. Urinary continence three months after surgery

3. Serious adverse events

4. Urinary continence six months after surgery

5. Urinary continence 12 months after surgery

6. Potency 12 months after surgery

7. Positive surgical margins

8. Biochemical recurrence‐free survival

History

Protocol first published: Issue 7, 2020

Notes

We have based parts of the Methods section of this protocol on a standard template developed by the Cochrane Metabolic and Endocrine Disorders Group, which has been modified and adapted for use by the Cochrane Urology Group. We acknowledge that some sections of this protocol are very similar or intentionally identical to the parallel, closely related review title on Retzius‐sparing RALP (Rosenberg 2020).

Appendices

Appendix 1. MEDLINE search strategy

Ovid MEDLINE(R) and Epub Ahead of Print, In‐Process & Other Non‐Indexed Citations, Daily and Versions(R) (1946 to present)

1. exp Prostatectomy/

2. exp Prostatic Neoplasms/

3. (prostat* adj3 (neoplas* or cancer* or tumor* or tumour*)).mp.

4. or/1‐3

5. exp Robotic Surgical Procedures/

6. exp Robotics/

7. 5 or 6

8. 4 and 7

9. ((robot* OR radical OR laparoscopic) adj5 prostat*).mp

10. (RARP or RALP).mp.

11. or/8‐10

12. ((posterior OR musculofascial or rhabdosphincter) adj5 reconstruct*).mp.

13. PMPR.mp

14. or/12‐13

15. 11 and 14

16. ..dedup 15

Appendix 2. Embase search strategy

1. exp robot‐assisted prostatectomy/

2. exp prostatectomy/

3. exp prostate tumor/

4. (prostat* adj3 (neoplas* or cancer* or tumor* or tumour*)).mp.

5. or/2‐4

6. exp robotic surgical procedure/

7. exp robotics/

8. or/6‐7

9. 5 and 8

10. ((robot* OR radical OR laparoscopic) adj5 prostat*).mp

11. (RARP or RALP).mp.

12. or/1,9‐11

13. ((posterior OR musculofascial or rhabdosphincter) adj5 reconstruct*).mp.

14. PMPR.mp.

15. or/13‐14

16. 12 and 15

17. ..dedup 16

Appendix 3. Cochrane Library search strategy

1. MeSH descriptor: [Prostatectomy] explode all trees

2. MeSH descriptor: [Prostatic Neoplasms] explode all trees

3. (prostat* near/3 (neoplas* or cancer* or tumor* or tumour*)):ti,ab,kw

4. {OR #1‐#3}

5. MeSH descriptor: [Robotic Surgical Procedures] explode all trees

6. MeSH descriptor: [Robotics] explode all trees

7. {OR #5‐#6}

8. #4 AND #7

9. ((robot* OR radical OR laparoscopic) near/5 prostat*):ti,ab,kw

10. (RARP or RALP):ti,ab,kw

11. {OR #8‐#10}

12. ((posterior OR musculofascial or rhabdosphincter) near/5 reconstruct*):ti,ab,kw

13. (PMPR):ti,ab,kw

14. {OR #12‐#13}

15. #11 AND #14

Appendix 4. PubMed search strategy

((("Prostatectomy"[Mesh] OR "Prostatic Neoplasms"[Mesh] OR (prostat*[tw] AND (neoplas*[tw] OR cancer*[tw] OR tumor*[tw] OR tumour*[tw]))) AND ("Robotic Surgical Procedures"[Mesh] OR "Robotics"[Mesh])) OR (((robot*[tw] OR radical[tw] OR laparoscopic[tw]) AND prostat*[tw]) OR RARP[tw] OR RALP[tw])) AND (((posterior*[tw] OR musculofascial[tw] OR rhabdosphincter[tw]) AND reconstruct*[tw]) OR PMPR[tw])

Appendix 5. Scopus search strategy

(INDEXTERMS("robot‐assisted prostatectomy") OR (INDEXTERMS("prostatectomy" OR "prostatic neoplasms" OR "prostate tumor") OR TITLE‐ABS‐KEY(prostat* W/3 (neoplas* or cancer* or tumor* or tumour*)) AND INDEXTERMS("robotic surgical procedure" OR "robotic surgical procedures" OR "robotics")) OR TITLE‐ABS‐KEY(((robot* OR radical OR laparoscopic) W/5 prostat*) OR RARP OR RALP)) AND TITLE‐ABS‐KEY(((posterior OR musculofascial or rhabdosphincter) W/5 reconstruct*) OR PMPR)

Appendix 6. Web of Science search strategy

1. TS=(((robot* OR radical OR laparoscopic) near/5 prostat*) OR RALP OR RARP)

2. TS=(((posterior OR musculofascial or rhabdosphincter) near/5 reconstruct*) OR PMPR)

3. #1 AND #2

Appendix 7. WHO ICTRP search strategy

rhabdosphincter AND reconstruction

Appendix 8. ClinicalTrials.gov search strategy

(musculofascial OR rhabdosphincter OR posterior) AND (reconstruct OR reconstruction OR reconstructing)

Appendix 9. Global Index Medicus search strategy

(( mh:("Prostatectomy")) OR ( mh:("Prostatic Neoplasms")) OR ( tw:(prostat* AND (neoplas* OR cancer* OR tumor* OR tumour*)))) AND (( mh:("Robotic Surgical Procedures")) OR ( mh:("Robotics")) OR ( tw:(((robot* OR radical OR laparoscopic) AND prostat*) OR RARP OR RALP))) AND ( tw:(((posterior* OR musculofascial OR rhabdosphincter) AND reconstruct*) OR PMPR))

Contributions of authors

Joel Rosenberg (JR) drafted and revised the protocol.
Caitlin Bakker (CB) devised the search strategy.
Hunju Lee (HL) revised the protocol.
Solam Lee (SL) revised the protocol.
Jae Hung Jung (JHJ) revised the protocol.
Phillip Dahm (PD) drafted and revised the protocol.

Sources of support

Internal sources

• None, Other

  No sources of support

External sources

• None, Other

  No sources of support

Declarations of interest

JR: none known.
HL: none known.
SL: none known.
JHJ: none known.
PD: none known.

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