PEER REVIEW REPORT

OVERALL RECOMMENDATION

MAJOR CONCERNS

1. Study Design and "Ambispective" Framing

• Action required: Clearly state in the Methods and Abstract that this report is a retrospective single-arm case series. The prospective component has not yet generated reportable data, and invoking it does not change the study's current evidence tier. If the IRB approval covers both arms, state so, but do not conflate the two.
• The study should be reported according to the STROBE checklist for observational studies. There is no statement of adherence to STROBE or any comparable reporting guideline. A completed STROBE checklist should be submitted as a supplementary table.

2. Sample Size (n=17) and Claims of Generalizability

• The word "reproducible" appears in both the abstract and conclusions. Reproducibility requires demonstration across multiple operators, institutions, or at minimum a formal assessment of intraoperator consistency. With a single surgeon at a single center, the term "reproducible" is not supportable. Suggest replacing with "protocolizable" or "consistent within a single-center, single-surgeon experience."
• Subgroup analyses comparing ileal conduit (n=8) vs. ileal-vesical (n=9) are presented in Table 2, the Results text, and Figure 2. The authors acknowledge these subgroups are too small for formal comparison, yet the text repeatedly juxtaposes them (e.g., "functional success 100% vs 88.9%"). This risks misleading readers. Recommendation: Move subgroup data entirely to a supplementary table, with a single sentence in the main text noting subgroup breakdowns are available as supplementary material given the risk of overinterpretation.

3. Outcome Definitions - Lack of Validated Instruments

• Subjective and functional success are defined by the authors as composite endpoints (absence of tubes/stents, no symptoms, no radiographic obstruction, stable renal function). These are reasonable but non-validated, non-standardized endpoints not previously used in the IUS literature in this exact form.
• No validated patient-reported outcome measure (PROM) was used. The authors acknowledge quality of life was not assessed, and reference Wang et al. (Ref 25) as a forthcoming standard. Given that Wang et al. (2026) is already cited, the absence of a PROM represents a material weakness. The prospective protocol reportedly will address this - but the current paper's conclusions should explicitly state this limitation rather than simply noting it in passing.
• "Functional failure" (1 patient requiring CIC) is described but not clearly explained. The text states "preserved reconstruction patency and a preserved eGFR within the preoperative range" yet defines functional failure here as abnormal voiding. This is internally inconsistent with the definition (which requires normal voiding in patients without diversion). Clarify whether this patient underwent ileal-vesical reconstruction or conduit diversion.

4. The L3 Vertebral Threshold - An Empirical, Unvalidated Criterion

• It is stated to be "empirical" in the Methods section. The manuscript does not describe how this threshold was derived, how it was measured (which bony landmark exactly?), what the inter-reader reliability was between the urologist and the imaging report, or what the anatomical rationale is for L3 specifically.
• Only 1 patient in this series fell above L3 (the hilar avulsion case). The threshold was therefore never seriously stress-tested in this cohort.
• Action required: Either provide the anatomical and biomechanical rationale for L3 as the threshold (e.g., relationship to robotic arm range of motion at left-flank docking position), or reframe this as a hypothesis to be tested rather than a validated criterion. The statement "this L3 threshold is empirical and requires validation in larger cohorts" (line 126) is appropriate and should be moved to the limitations section and amplified, not buried mid-Methods.

5. Incomplete Complication Reporting and Follow-up Attrition

• The median follow-up is 11.7 months (range 2.4-21.0 months), with n=13 reaching 6 months and only n=7 reaching 12 months. This is explicitly noted but then functional success is reported as 94.1% at "last follow-up" - a time point that is less than 3 months for some patients. For those patients, "functional success" has not been meaningfully demonstrated.
• Action required: Report success rates separately for patients with ≥6 months follow-up and for those with ≥12 months follow-up. Do not combine patients with 2.4 months of observation with those at 21 months in a single success rate figure.
• The single grade IVa septic shock case (5.9%) is serious. The text states it "likely related to mucus reflux." This causal attribution requires justification - what clinical, microbiological, or imaging findings support this etiology? Similarly, 4 patients (23.5%) with late-onset fever beyond 30 days is a substantial rate. The organisms, cultures, imaging workup, and resolution should be detailed.
• No mention of metabolic complications (hyperchloremic metabolic acidosis is listed as a surveillance target but no results are reported). This should either be reported or explicitly stated as not yet assessable at current follow-up.
• No reporting of mucus-related complications, urolithiasis, or upper tract deterioration, which the text itself acknowledges typically emerge at 2-5 years. However, their complete absence even as interim findings at up to 21 months should be explicitly documented.

6. Platform-Specific Context

• The KangDuo Surgical Robot 2000 (KD-SR 2000) is not widely used outside China. A brief, dedicated paragraph describing the platform's key specifications relevant to this procedure (number of arms, instrument degrees of freedom, vision system, differences from da Vinci) is necessary to allow international readers to contextualize the technique. Reference 19 (Fan et al., Int Braz J Urol) is a case report in a different journal and does not fully substitute for this.
• The operating surgeon had "substantial prior robotic experience with the KangDuo system (>130 procedures)." The total robotic case volume is mentioned in the limitations but should appear in the Patient and Methods section, where it contextualizes the learning curve.
• Action required: State clearly whether this workflow is conceptually platform-agnostic (i.e., transferable to da Vinci or CMR Versius) or whether certain steps (e.g., docking geometry, arm reach) depend on KD-SR 2000-specific characteristics.

7. Statistical Reporting

• The paper uses exclusively descriptive statistics, which is appropriate and transparently stated. However:
  • eGFR trends are shown with median and IQR across 5 time points in Figure 2, with decreasing denominators (n=17 at baseline, n=13 at 6 months). Presenting medians from progressively smaller and potentially non-random subsets (patients who reached each visit) creates informative attrition bias. Patients who did not reach the 6-month visit may disproportionately include those with complications or early failures. This must be acknowledged.
  • Consider presenting eGFR trajectories only for patients who completed ≥6 months of follow-up (n=13) as a sensitivity check.

MODERATE CONCERNS

8. Introduction

• The introduction is well-structured and the literature trail from Brandao (2014) to the present is accurately summarized. However, it does not clearly define the specific problem the single-docking workflow solves in quantitative terms (e.g., how many position changes are typically required without this protocol, and what is their estimated impact on operative time or complication risk). Without a quantified "cost" of the problem being solved, readers cannot assess the magnitude of the contribution.
• The claim that this paper addresses a "need for a simplified, protocolized strategy" (line 70-72) is stated but not supported with any citation of studies documenting that positional complexity is a driver of complications or operative time. Add supporting evidence or acknowledge this remains inferential.

9. Antireflux Mechanism

• The distal antireflux "nipple valve" (line 149-150, Ref 23) is described briefly. The long-term performance of this specific technique should be referenced more fully. Xu et al. (Ref 23) uses an iliopsoas muscle tunnel technique - is the technique applied here truly identical, or is it a modification? This distinction matters for reproducibility.
• For the ileal conduit group, was an antireflux mechanism also employed at the ureteroileal anastomosis? This is not specified.

10. ICG Angiography

• ICG angiography was used in only 3 of 17 patients (17.6%). The selection criteria for ICG use are not stated. In radiation cases - where vascular compromise is the primary concern - was ICG routinely used? Given that ICG has been proposed as potentially reducing anastomotic stricture rates (Ref 22), its selective use in only ~18% of patients (including in radiation cases) should be justified.

11. Nephrostomy Tube Management

• 10 of 17 patients had preoperative or perioperative nephrostomy tubes. Removal criteria (unobstructed drainage without leakage) are stated, but:
  • 2 patients had tubes "inadvertently dislodged" at 1 and 3 weeks - this should be classified as a complication under the Clavien-Dindo system, not merely noted parenthetically.
  • The rationale for not placing nephrostomies in 7 patients should be stated.

12. Bowel Preparation

• Polyethylene glycol bowel preparation is listed as a routine preoperative step. Current evidence (e.g., the ERAS Society guidelines) has moved away from mechanical bowel preparation for colorectal procedures. The authors should justify its routine use in this context or acknowledge that this is center-specific practice.

13. Bilateral "Reverse 7" Anastomotic Configuration

• The reverse "7" configuration for bilateral cases (end-to-end left, end-to-side right) is a key technical element. The rationale for this asymmetry - why not end-to-end bilaterally, or end-to-side bilaterally - is not explained. Is this driven by ileal segment length, mesenteric geometry, or tension considerations? This is a detail surgeons attempting to replicate the technique will need.

MINOR CONCERNS

14. Typos and Transcription Errors

• Abstract: "intracoorporeal" (line in cover page abstract), "septic shuock" (abstract), "reCconversion"
• Methods: "singele left-flank" (line 126), "hyperschloremic" - should be "hyperchloremic" (line 164)
• Abbreviation table: "uroeteral" (IUS definition), "KD-SR 2000" listed twice (pages 4 and last page) with "substitutuion" in the final page version
• References: "Xiaorng" (Ref 2), "Ileoal" (Ref 5), "Urieteral" (Ref 6), "ileaul" (Ref 7), "Intracorpooreal" (Ref 13) - these appear to be OCR artifacts but must be corrected
• Figure legends: "way s assessed" (Figure 2), "circlers" should be "circles"

15. Reference Issues

• Reference 3 (Xu et al., J Robot Surg 2026;20(1):297) - This is a 2026 publication. Confirm this is published and accessible, not still in press, as this citation supports the stated indication threshold.
• Reference 14 (Ji et al., Eur Urol 2026;89(6):541-549) - A 2026 Eur Urol paper is cited as a key benchmark. The manuscript should clarify whether this was published before or after the current study was designed, to avoid any concern about post-hoc benchmarking.
• Reference 24 (Bourillon et al., World J Urol 2026) - Similarly a 2026 reference. If this is a treatment algorithm paper, it should be prominently cited in the introduction, not only in the discussion.
• The reference list contains several apparent OCR errors as noted in item 14 above. All DOIs should be verified against the published record.

16. Figure 2 Denominators

• The figure legend for Figure 2 states denominators at POM 3 are n=16 and at POM 6 are n=13, but Table 2 footnotes state POM 3 has n=16 total, n=8 ileal conduit, and n=8 ileal-vesical (total adds to 16, consistent), while POM 6 has n=13 total but n=8 ileal conduit and n=5 ileal-vesical. These figures should be explicitly labeled on the figure itself, not only in the legend.

17. Terminology Consistency

• The manuscript alternates between "ileal ureteral substitution," "ileal ureter replacement," and "ileal ureter" without definitional guidance. While these terms are used interchangeably in the literature, the manuscript should define the preferred term at first use and use it consistently.

18. AI Disclosure

• The acknowledgments state AI-based tools were used to improve language and readability. This is properly disclosed. However, the Journal of Endourology's current policy on AI use in manuscript preparation should be verified and the disclosure should align precisely with that policy.

SPECIFIC QUESTIONS FOR THE AUTHORS

1. Of the 4 patients with late-onset fever (>30 days), what were the sources of infection (culture results, imaging findings)? Were any attributable to anastomotic complications, mucus plugging, or ureteroileal obstruction?
2. The single functional failure requiring CIC: Was this patient in the ileal-vesical group? What is the proposed mechanism - bladder dysfunction, ileoileal reflux, neurogenic voiding, or another cause?
3. How was "ileal segment length" standardized at 25 cm - was this calculated preoperatively from imaging, measured intraoperatively from the proximal ureter to the distal target, or both?
4. In the 5 secondary diversion conversion cases, were all original ureterocutaneous stomas functioning prior to surgery, or had some already failed (i.e., were the ureters already obstructed/infected)? This significantly affects the complexity classification.
5. What was the intraoperative assessment for determining adequate bladder function to proceed with ileal-vesical reconstruction versus conduit diversion? Were urodynamics performed in all patients preoperatively?

SUMMARY ASSESSMENT TABLE

DECISION: MAJOR REVISION