Upper urinary tract pressures in endourology: a systematic review of range, variables and implications
Bibliographic record
Abstract
Objectives To systematically review the literature to ascertain the upper tract pressures generated during endourology, the relevant influencing variables and clinical implications. Materials and Methods A systematic review of the MEDLINE, Scopus and Cochrane databases was performed by two authors independently (S.C., N.D.). Studies reporting ureteric or intrarenal pressures (IRP) during semi‐rigid ureteroscopy (URS)/flexible ureterorenoscopy (fURS)/percutaneous nephrolithotomy (PCNL)/miniaturized PCNL (mPCNL) in the period 1950–2021 were identified. Both in vitro and in vivo studies were considered for inclusion. Findings were independently screened for eligibility based on content, with disagreements resolved by author consensus. Data were assessed for bias and compiled based on predefined variables. Results Fifty‐two studies met the inclusion criteria. Mean IRP appeared to frequently exceed a previously proposed threshold of 40 cmH 2 O. Semi‐rigid URS with low‐pressure irrigation (gravity <1 m) resulted in a wide mean IRP range (lowest reported 6.9 cmH 2 O, highest mean 149.5 ± 6.2 cmH 2 O; animal models). The lowest mean observed with fURS without a ureteric access sheath (UAS) was 47.6 ± 4.1 cmH 2 O, with the maximum peak IRP being 557.4 cmH 2 O ( in vivo human data). UAS placement significantly reduced IRP during fURS, but did not guarantee pressure control with hand‐operated pump/syringe irrigation. Miniaturization of PCNL sheaths was associated with increased IRP; however, a wide mean human IRP range has been recorded with both mPCNL (lowest −6.8 ± 2.2 cmH 2 O [suction sheath]; highest 41.2 ± 5.3 cmH 2 O) and standard PCNL (lowest 6.5 cmH 2 O; highest 41.2 cmH 2 O). Use of continuous suction in mPCNL results in greater control of mean IRP, although short pressure peaks >40 cmH 2 O are not entirely prevented. Definitive conclusions are limited by heterogeneity in study design and results. Postoperative pain and pyrexia may be correlated with increased IRP, however, few in vivo studies correlate clinical outcome with measured IRP. Conclusions Intrarenal pressure generated during upper tract endoscopy often exceeds 40 cmH 2 O. IRP is multifactorial in origin, with contributory variables discussed. Larger prospective human in vivo studies are required to further our understanding of IRP thresholds and clinical sequelae.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.013 | 0.052 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.011 | 0.007 |
| Bibliometrics | 0.027 | 0.024 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.004 | 0.004 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".