Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (744 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
One of a pair of thick-walled tubes that transports urine from the kidney pelvis to the urinary bladder.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Ureters.
Where it fits in the MeSH classification
- Broader topics
- Urinary Tract
- See also
- Ureterostomy; Urinary Diversion; Ureteroscopy; Retrocaval Ureter
Related concepts
- Kidney Pelvis
- Urinary Bladder
Research landscape
PubMed indexes 27,010 records tagged with the MeSH heading “Ureter” (counts retrieved 2026-10-31). 2,940 of them (10.9%) were published from 2020 onward, and the busiest period so far is through 1999 with 16,794 records.
Reviews account for 1,637 records (6.1%) and meta-analyses for 148. Randomized controlled trials number 249 (0.9%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 16,794 |
| 2000-2009 | 3,195 |
| 2010-2019 | 4,081 |
| 2020 onward | 2,940 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,637 | 6.1% |
| Meta-analyses | 148 | 0.5% |
| Randomized controlled trials | 249 | 0.9% |
Method: PubMed query "Ureter"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in anatomy and physiology
Anatomy describes how body structures are built and physiology describes how they normally work, so most findings here are descriptive or mechanistic rather than evidence about treatment. Much of what is known comes from dissection, imaging, tissue studies and experiments in animals, and measurements in healthy volunteers can differ from those in people with disease or at different ages. Normal ranges vary between individuals and populations. Check whether a result was measured in people or in another species, the age and health of the participants, and the method used.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Comparison of novel flexible and traditional ureteral access sheath in retrograde intrarenal surgery | 2024 | Research article Design not recorded in structured metadata | 44 | cc by PMID 38175210 · DOI · PMC10766707 |
| Computed Tomography Urography: State of the Art and Beyond | 2023 | Review article Design not recorded in structured metadata | 22 | cc by PMID 37218935 · DOI · PMC10204399 |
| What is the appropriate gravel size during ureteroscopy lithotripsy? An in vitro evaluation | 2023 | Research article Design not recorded in structured metadata | 18 | cc by PMID 36929459 · DOI · PMC10020258 |
| Mirabegron administration for the prevention of ureteral injuries during ureteral access sheath insertion | 2026 | Research article Design not recorded in structured metadata | 0 | cc by PMID 41591575 · DOI · PMC12847224 |
Comparison of novel flexible and traditional ureteral access sheath in retrograde intrarenal surgery [1]
Abstract reading summary — source excerpts
- Opening excerpt
- ObjectivesTo compare the efficiency and safety of a novel flexible ureteral access sheath (f-UAS) and traditional ureteral access sheath (UAS) during retrograde intrarenal surgery (RIRS).
- Closing excerpt
- 2%; P ConclusionCompared to the traditional UAS during RIRS, the f-UAS showed several advantages, including higher SFR at 1 day postoperatively, shorter operative times, lower incidence of complications, and less use of basket.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (150 words)
ObjectivesTo compare the efficiency and safety of a novel flexible ureteral access sheath (f-UAS) and traditional ureteral access sheath (UAS) during retrograde intrarenal surgery (RIRS).Patients and methodsBetween January 2022 and September 2022, a total of 152 consecutive cases with renal stones underwent RIRS with the f-UAS. Their outcomes were compared with those of another 152 consecutive cases undergoing RIRS with traditional UAS using a 1:1 scenario matched-pair analysis, with matching parameters including age and stone size. The f-UAS is a novel UAS with a 10-cm-long tube at the tip that can follow the bends of flexible ureteroscope (f-URS).ResultsBaseline characteristics were found to be similar between the two groups. The f-UAS group demonstrated significantly higher SFR (76.3% vs. 7.2%; P ConclusionCompared to the traditional UAS during RIRS, the f-UAS showed several advantages, including higher SFR at 1 day postoperatively, shorter operative times, lower incidence of complications, and less use of basket.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 38175210 · DOI · PMC10766707
Computed Tomography Urography: State of the Art and Beyond [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Computed Tomography Urography (CTU) is a multiphase CT examination optimized for imaging kidneys, ureters, and bladder, complemented by post-contrast excretory phase imaging.
- Closing excerpt
- In this narrative review, we provide a comprehensive overview of CTU from the traditional to the newest acquisition techniques and reconstruction algorithms, and the possibility of advanced imaging interpretation to provide an up-to-date guide for radiologists who want to better comprehend this technique.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (188 words)
Computed Tomography Urography (CTU) is a multiphase CT examination optimized for imaging kidneys, ureters, and bladder, complemented by post-contrast excretory phase imaging. Different protocols are available for contrast administration and image acquisition and timing, with different strengths and limits, mainly related to kidney enhancement, ureters distension and opacification, and radiation exposure. The availability of new reconstruction algorithms, such as iterative and deep-learning-based reconstruction has dramatically improved the image quality and reducing radiation exposure at the same time. Dual-Energy Computed Tomography also has an important role in this type of examination, with the possibility of renal stone characterization, the availability of synthetic unenhanced phases to reduce radiation dose, and the availability of iodine maps for a better interpretation of renal masses. We also describe the new artificial intelligence applications for CTU, focusing on radiomics to predict tumor grading and patients' outcome for a personalized therapeutic approach. In this narrative review, we provide a comprehensive overview of CTU from the traditional to the newest acquisition techniques and reconstruction algorithms, and the possibility of advanced imaging interpretation to provide an up-to-date guide for radiologists who want to better comprehend this technique.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 37218935 · DOI · PMC10204399
What is the appropriate gravel size during ureteroscopy lithotripsy? An in vitro evaluation [3]
Abstract reading summary — source excerpts
- Opening excerpt
- To propose the suitable diameter of calculus debris produced during flexible ureteroscopy lithotripsy (fURL).
- Closing excerpt
- 50 mm in negative-pressure UAS, respectively.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (177 words)
To propose the suitable diameter of calculus debris produced during flexible ureteroscopy lithotripsy (fURL). A glass tube was used to simulate the stone excretion process during Furl. Different stone diameters (0.50-1.00 mm, 0.25-0.50 mm, and 0.10-0.25 mm) with three sizes of flexible ureteroscopy (fURS) (7.5Fr, 8.7Fr, and 9.9Fr) and ureteral access sheath (UAS) (12/14Fr) with or without negative pressure suction were employed in the experiment. The intraoperative calculi excretion (ICE) was recorded according to the stones discharged from the gap between fURS and UAS. The ICE raised significantly in thinner fURS and UAS due to the smaller Ratio of Endoscope-Sheath Diameter (RESD). The gravel size ≤ 0.25 mm was conducive to drainage with traditional UAS, while using fURS with negative-pressure UAS could significantly improve ICE. The gravel size ≤ 0.5 mm was conducive to expulsion. We clarify that ICE during ureteroscopy relates to RESD and negative pressure suction. The proper size of the stone fragment is critical in ensuring the expulsion during fURL, ≤ 0.25 mm in traditional UAS and ≤ 0.50 mm in negative-pressure UAS, respectively.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 36929459 · DOI · PMC10020258
Mirabegron administration for the prevention of ureteral injuries during ureteral access sheath insertion [4]
Abstract reading summary — source excerpts
- Opening excerpt
- PurposeUrolithiasis is a common condition in urological practice.
- Closing excerpt
- Further large-scale, multicenter studies with longer follow-up are necessary to confirm these findings.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (229 words)
PurposeUrolithiasis is a common condition in urological practice. Retrograde intrarenal surgery (RIRS) is widely accepted as a safe and effective treatment modality. However, acute ureteral injuries during ureteral access sheath (UAS) placement remain a significant concern. Although beta-adrenergic receptors have been identified in the ureteral wall, studies investigating beta-agonists for ureteral protection are lacking. This study aimed to assess whether short-term preoperative administration of mirabegron, a beta-3 adrenoreceptor agonist, can reduce the incidence of UAS-related ureteral injuries during RIRS.MethodsIn this prospective non-randomized study, 60 patients undergoing RIRS were enrolled. Allocation was based on clinical indications due to ethical considerations: 30 patients with existing overactive bladder symptoms received preoperative mirabegron, while 30 patients served as controls. Baseline characteristics were comparable between the groups. Ureteral injuries were assessed endoscopically and graded using the Post-Ureteroscopic Lesion Scale (PULS).ResultsThe mirabegron group showed a lower incidence of high-grade ureteral injuries compared to the control group, but the difference was not statistically significant (p = 0.123). No adverse events related to mirabegron were reported. Limitations include the lack of randomization, modest sample size, and single-center design.ConclusionsShort-term preoperative mirabegron use appears to be safe. While our results suggest a potential trend towards reducing high-grade ureteral injuries, this did not reach statistical significance, likely due to the limited sample size of this preliminary cohort. Further large-scale, multicenter studies with longer follow-up are necessary to confirm these findings.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41591575 · DOI · PMC12847224
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Laparoscopic versus open pyeloplasty for ureteropelvic junction obstruction in children: a systematic review and meta-analysis [5]
- Research article Genetic controls and cellular behaviors in branching morphogenesis of the renal collecting system [6]
- Research article International Alliance of Urolithiasis guideline on retrograde intrarenal surgery [7]
- Research article Ureterovesical anastomotic techniques for kidney transplantation: a systematic review and meta-analysis [8]
- Research article Ureteric stents: Overview of current clinical applications and economic implications [9]
- Research article Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review [10]
References
- Yu Y, Chen Y, Zhou X, Li X, Liu W, Cheng X, et al.. Comparison of novel flexible and traditional ureteral access sheath in retrograde intrarenal surgery. . 2024. PMID 38175210 · DOI · PMC10766707
- Cellina M, Cè M, Rossini N, Cacioppa LM, Ascenti V, Carrafiello G, et al.. Computed Tomography Urography: State of the Art and Beyond. . 2023. PMID 37218935 · DOI · PMC10204399
- Song B, Jin D, Cheng Y, Wang Z, Wang F, Fang L. What is the appropriate gravel size during ureteroscopy lithotripsy? An in vitro evaluation. . 2023. PMID 36929459 · DOI · PMC10020258
- Ermiş O, Sabuncu K, Kaçtan Ç, Karakuş B, Sürmeli B, Boz MY, et al.. Mirabegron administration for the prevention of ureteral injuries during ureteral access sheath insertion. . 2026. PMID 41591575 · DOI · PMC12847224
- Mei H, Pu J, Yang C, Zhang H, Zheng L, Tong Q. Laparoscopic versus open pyeloplasty for ureteropelvic junction obstruction in children: a systematic review and meta-analysis. J Endourol. 2011. PMID 21476861 · DOI
- Costantini F. Genetic controls and cellular behaviors in branching morphogenesis of the renal collecting system. Wiley Interdiscip Rev Dev Biol. 2012. PMID 22942910 · DOI · PMC3430146
- Zeng G, Traxer O, Zhong W, Osther P, Pearle MS, Preminger GM, et al.. International Alliance of Urolithiasis guideline on retrograde intrarenal surgery. BJU Int. 2023. PMID 35733358 · DOI · PMC10084014
- Alberts VP, Idu MM, Legemate DA, Laguna Pes MP, Minnee RC. Ureterovesical anastomotic techniques for kidney transplantation: a systematic review and meta-analysis. Transpl Int. 2014. PMID 24606191 · DOI
- Sali GM, Joshi HB. Ureteric stents: Overview of current clinical applications and economic implications. Int J Urol. 2020. PMID 31549458 · DOI
- Houat AP, Guimarães CTS, Takahashi MS, Rodi GP, Gasparetto TPD, Blasbalg R, et al.. Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review. Radiographics. 2021. PMID 33513074 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.