Needles
The needle is half of the suture decision and is at least as important. Point geometry should suit the tissue being approximated. Blunt rather than sharp suture needles reduce occupational exposure during suitable closures.[4][10]
See also: Sutures, Incisions & Closure, Bowel Anastomosis.
Needle Anatomy
Every surgical needle has three components:[1]
- Point (tip). Determines tissue penetration characteristics.
- Body. Determines strength and curvature.
- Swage. Where the suture is attached. A swaged needle need not have a 1:1 needle-to-suture diameter ratio; a closer match is a product-specific design that can reduce the needle hole around the suture.[3][18]
Needle alloy, geometry, coating and finishing can affect resistance to bending, sharpness and tissue drag.[2][3]
Needle Point Types
The point determines how the needle interacts with tissue on entry:[1][9]
| Point type | Cross-section | Action | Urologic use |
|---|---|---|---|
| Conventional cutting | Triangular, cutting edge on inner curve | Cuts tissue | Tough skin; largely displaced by reverse cutting |
| Reverse cutting | Triangular, cutting edge on outer curve | Cuts tissue; reduces cutout risk | Skin closure (standard); penile skin; fascia superficial layer |
| Taper (round body) | Round, tapers to a sharp point | Dilates tissue without cutting | Bowel, urinary tract, vessels, fascia — the urologic default |
| Blunt taper (blunt point) | Round, blunt tip | Passes suitable soft tissue with greater force | Fascial closure when feasible — reduces staff needlestick exposure in the studied operations |
| Taper-cut | Round body + cutting tip | Punctures, then dilates | Vascular anastomosis; tough scar tissue |
Tissue-tearing evidence. In a 2025 artificial-skin model, mean force required to tear through the material was higher with a taper-point BB needle (4.07 N) than with a conventional cutting PC-3 needle (3.26 N); a reverse-cutting PS-3 needle measured 3.75 N. Larger tested suture diameters also resisted tear-through more.[10]
Needle Curvature
| Curvature | Use |
|---|---|
| 3/8 circle | Skin closure in relatively large, superficial wounds[21] |
| 1/2 circle | Confined spaces; a 5/8 circle may be more useful deep in the pelvis[22] |
| 5/8 circle | Deep, confined pelvic or urogenital spaces[23] |
| Straight | Accessible superficial tissue; rarely used in urology |
| Compound curve | Specialized (transseptal cardiac, some microsurgical) |
For pelvic urology (vesicourethral anastomosis, reimplant, fistula repair), a 1/2-circle needle can be used in confined spaces; a 5/8-circle needle may be more useful when the operative site is deep in the pelvis.[24] For perineal urethroplasty, the choice between 1/2 and 3/8 circle depends on exposure: a 1/2 circle is designed for confined space, whereas a 3/8 circle is easier to manipulate with wider access.[26]
Needle Codes — the Ethicon Naming Convention
These are manufacturer-specific example codes; a suffix does not consistently encode length. Confirm point, curvature, size and attached suture on the actual product label or chart.[17]
| Code | Point | Typical curvature | Urologic association |
|---|---|---|---|
| CT (Circle Taper) | Taper | 1/2 circle | Bowel (CT-1, CT-2, CT-3); augment, pyeloplasty |
| SH (Small Half-circle) | Taper | 1/2 circle | Urethra, ureter, small-diameter pelvic work |
| RB (Round Body) | Taper | 1/2 circle | Vessels, fine vascular |
| UR (Urology) | Taper | 5/8 circle | Deep pelvis — dorsal vein complex, bladder neck reconstruction |
| MH (Medium Half-circle) | Taper | 1/2 circle | Fascia, peritoneum |
| CTX | Taper point | 1/2 circle | Large taper-point closure needle |
| CTXB / CTB / SHB | Blunt point | 1/2 circle | Fascial or other suitable soft-tissue closure when a blunt point can pass safely |
| PS (Plastic Surgery) | Reverse cutting | 3/8 circle | Skin; small precise cutting |
| FS (For Skin) | Reverse cutting | 3/8 circle | Skin closure |
| CP (Cutting Point) | Reverse cutting | 1/2 circle | Tougher skin/fascia |
| TP (Taper Point) | Taper | 1/2 circle | Bowel, fascia variants |
A UR-6 on 3-0 Monocryl (a common vesicourethral anastomosis stitch in open RP) is a very different tool from a CT-1 on 2-0 Vicryl (bowel anastomosis). The 5/8-circle UR needle is a taper-point option for deep, confined pelvic or urogenital work.[17][25]
Selection by Urologic Tissue
| Tissue | Point | Example needle |
|---|---|---|
| Skin | Reverse cutting | PS-2, FS, X-1 |
| Urethra (mucosa-to-spongiosum) | Taper | SH, RB-1 |
| Urethra (graft fixation, bulbar BMG) | Taper | RB-1 on 5-0 or 6-0 PDS |
| Ureter | Taper | SH, TF |
| Bladder mucosa / detrusor | Taper | CT-1, CT-2, SH |
| Bowel (for urinary diversion) | Taper | CT-1, CT-2 |
| Fascia (mass closure) | Blunt point when feasible; taper point otherwise | CTXB / CTB / SHB; CTX is not blunt |
| Vascular (renal vein, IVC, iliac) | Taper or taper-cut | RB-1, CV needles |
| Deep pelvic apex / dorsal vein complex | Taper | UR-6 |
| Tendon / sling suspensory arms | Taper | CT-1 on Prolene |
Size — Gauge vs USP
Two parallel systems:
- Hollow or biopsy needles use Stubs Iron Wire Gauge, in which a higher number means a smaller diameter. 18 G > 22 G > 25 G.[5][6]
- Surgical suture needles are specified by length, curvature, point and wire diameter, often through manufacturer codes. Their wire diameter is distinct from the numbered G system used for hollow needles.[21]
Gauge is relevant to urologists primarily in biopsy, access, and percutaneous drainage, and not in suture selection.
Blunt vs Sharp Suture Needles — the Safety Evidence
Percutaneous needlestick injury is a defining occupational hazard of surgery. A Cochrane review of 10 randomized trials found that blunt-tip suture needles reduced staff exposure in the studied operations:[4]
- Glove perforation reduced by 54% (RR 0.46, 95% CI 0.38–0.54).[4]
- Needlestick injuries reduced by 69% (RR 0.31, 95% CI 0.14–0.68).[4]
- Prevents one glove perforation in every 6 operations.
- The ten included trials addressed abdominal closure, cesarean section, vaginal repair and hip replacement.
Surgeon acceptance. In the Cochrane review, blunt needles required greater force and were rated more difficult but acceptable in five of six studies assessing usability.[4] A clinician's cesarean-closure account describes a distinct pop as the blunt needle crosses fascia.[31]
Implementation gap. Despite the evidence existing for decades and American College of Surgeons / OSHA / NIOSH recommendations to use blunt needles for fascial closure, adoption is poor. In a 2006 survey of 104 obstetrician-gynecologists in one small US region, 12% reported currently using blunt needles; in a French survey, blunt-tipped needles were available in 49% of surveyed operating theaters.[4][11]
Practical recommendation for urologic fascial closure (for example, an open abdominal incision): consider a blunt-point needle where the tissue and technique permit, while checking the actual product and using a sharp needle where a blunt one cannot pass appropriately. The evidence concerns staff exposure; patient wound outcomes were not assessed in these trials.[4]
Safe Needle Handling
Grip
- Palmar grip (all fingers around the holder, rings not used) produced more accurate needle exits than the tested ring grip in Seki's 16-surgeon simulation when surgeons sutured without wavering (mean deviation 1.4 versus 2.0 mm); accuracy was equivalent when surgeons waver-corrected.[12]
- Load the needle at approximately 90° to the holder axis; grasp at the two-thirds mark from the tip.
- Follow the curve during passage; do not pry or torque the body of the needle (it will bend or break).
Needle Transfer
- Protected transfer technique: secure the needle tip against the shaft of the needle holder before handing off.[14][15] In a retrospective survey of 107 scrub nurses, 40 (37%) recalled a prior injury with unprotected transfer and 9 (8%) with protected transfer; five recalled injuries with both.[14]
- Before returning to the tray or handing off, pivot the needle 90° toward the instrument joint.
- Never touch the needle point to the needle driver's jaws (dulls the tip).
Microskills That Matter
Assessed in the 2022 JAMA Network Open curriculum study:[13]
- Loading the needle at the correct angle.
- Following the curve through tissue.
- Atraumatic release from tissue.
- Pitch-and-catch. Forceps-assisted transfer of the needle back to the needle driver.
- Push-push-pull. Reloading the needle while still in tissue, avoiding forceps so the non-dominant hand stays on retraction.
Specialty Needles
Spinal and Epidural
A prostatectomy-specific PROSPECT review recommends transversus abdominis plane block as the first-choice regional technique for laparoscopic or robotic prostatectomy.[20]
| Needle | Tip | PDPH risk |
|---|---|---|
| Quincke | Cutting, beveled | Higher |
| Greene | Rounded, non-cutting bevel | Low PDPH incidence in historical reports[27] |
| Whitacre | Pencil-point (atraumatic) | Lower |
| Sprotte | Pencil-point (atraumatic) | Lower |
| Atraucan | Curved bilateral tip | PDPH was 6.8% with 26 G Atraucan versus 2.8% with 25 G and 0% with 27 G pencil-point needles in one cesarean RCT[28] |
A network meta-analysis ranked 26 G atraumatic needles highest for avoiding both post-dural-puncture headache and procedural failure.[9] A 2024 multisociety guideline recommends non-cutting needles for lumbar puncture (Grade A; high certainty) but finds limited evidence to prefer one non-cutting design.[29]
Biopsy Needles (Percutaneous Urologic)
- Fine needle aspiration: 21–25 G; primarily for cytology, but adequate cell blocks or other validated cytology preparations may also support molecular testing.[19]
- Core needle biopsy: Core samples provide histologic architecture. In a 19-respondent abdominal radiology survey, automatic 18 G variable-throw devices were most common for solid-organ biopsy; both 16 G and 18 G needles have been studied for renal parenchymal biopsy. Molecular adequacy depends on specimen handling and the requested assay.[7][8][30]
- Choose gauge, trajectory and sampling device for the target and required specimen; complication risk depends on the organ, route and patient.
Needle–Tissue Interaction Physics
Three phases during penetration:[16]
- Deformation. Tissue stretches before puncture.
- Insertion. Needle advances through tissue.
- Extraction. Needle withdrawn, tissue relaxes.
In Jiang's bench experiments, these variables had a large influence on insertion force:
- Needle diameter (0.7–3.2 mm); larger diameters require more force.
- Tip shape (blunt, diamond, conical, beveled); blunter tips require more force.
- Bevel angle (10–85°); smaller angles require less force.
- Insertion velocity (0.5–10 mm/s), drive mode (robot-assisted or hand-held) and interrupted versus continuous insertion.
- Tissue type. Skin, muscle, fat, liver capsule and vessel produce different force curves.
These bench experiments show how needle geometry and tissue affect insertion force.[16] In operations where a blunt fascial needle can pass the tissue, randomized trials support its use to reduce staff glove perforation and needlestick exposure.[4]
References
1. Byrne M, Aly A. "The Surgical Needle." Aesthet Surg J. 2019;39(Suppl_2):S73–S77. doi:10.1093/asj/sjz035
2. Thacker JG, Rodeheaver GT, Towler MA, Edlich RF. "Surgical Needle Sharpness." Am J Surg. 1989;157(3):334–9. doi:10.1016/0002-9610(89)90565-5
3. Edlich RF, Thacker JG, McGregor W, Rodeheaver GT. "Past, Present, and Future for Surgical Needles and Needle Holders." Am J Surg. 1993;166(5):522–32. doi:10.1016/s0002-9610(05)81147-x
4. Parantainen A, Verbeek JH, Lavoie MC, Pahwa M. "Blunt Versus Sharp Suture Needles for Preventing Percutaneous Exposure Incidents in Surgical Staff." Cochrane Database Syst Rev. 2011;(11):CD009170. doi:10.1002/14651858.CD009170.pub2
5. Arevalo-Rodriguez I, Muñoz L, Godoy-Casasbuenas N, et al. "Needle Gauge and Tip Designs for Preventing Post-Dural Puncture Headache (PDPH)." Cochrane Database Syst Rev. 2017;4:CD010807. doi:10.1002/14651858.CD010807.pub2
6. Beirne PV, Hennessy S, Cadogan SL, et al. "Needle Size for Vaccination Procedures in Children and Adolescents." Cochrane Database Syst Rev. 2018;8:CD010720. doi:10.1002/14651858.CD010720.pub3
7. Wildman-Tobriner B, Ho LM, Bowman AW. "Needle Types Used in Abdominal Cross-Sectional Interventional Radiology: A Survey of the Society of Abdominal Radiology Emerging Technology Commission." Abdom Radiol. 2022;47(8):2623–2631. doi:10.1007/s00261-021-03145-1
8. Roy-Chowdhuri S, Dacic S, Ghofrani M, et al. "Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies: Guideline From the College of American Pathologists." Arch Pathol Lab Med. 2020. doi:10.5858/arpa.2020-0119-CP
9. Maranhao B, Liu M, Palanisamy A, Monks DT, Singh PM. "The Association Between Post-Dural Puncture Headache and Needle Type During Spinal Anaesthesia: A Systematic Review and Network Meta-Analysis." Anaesthesia. 2021;76(8):1098–1110. doi:10.1111/anae.15320
10. Potter CT, Maloney ME, Riopelle AM, Fudem GM, Schanbacher CF. "Impact of Needle Design and Suture Gauge on Tissue Tearing During Skin Suturing: A Comparative Analysis." Dermatol Surg. 2025;51(2):148–151. doi:10.1097/DSS.0000000000004389
11. Catanzarite V, Byrd K, McNamara M, Bombard A. "Preventing Needlestick Injuries in Obstetrics and Gynecology." Obstet Gynecol. 2007;110(6):1399–403. doi:10.1097/01.AOG.0000287617.12113.3e
12. Seki S. "Suturing Techniques of Surgeons Utilizing Two Different Needle-Holder Grips." Am J Surg. 1988;155(2):250–2. doi:10.1016/s0002-9610(88)80707-4
13. Greenberg AL, Karimzada MM, Brian R, et al. "Assessment of Surgeon Performance of Advanced Open Surgical Skills Using a Microskills-Based Novel Curriculum." JAMA Netw Open. 2022;5(9):e2229787. doi:10.1001/jamanetworkopen.2022.29787
14. Williams GJ, Nicolaou M, Athanasiou T, Coleman D. "Suture Needle Handling in the Operating Theatre: What Is the Safest Method? A Survey of Surgical Nursing Opinion." Inj Prev. 2016;22(2):135–9. doi:10.1136/injuryprev-2015-041607
15. Kunishige J, Wanitphakdeedecha R, Nguyen TH, Chen TM. "Surgical Pearl: A Simple Means of Disarming the 'Locked and Loaded' Needle." Int J Dermatol. 2008;47(8):848–9. doi:10.1111/j.1365-4632.2008.03651.x
16. Jiang S, Li P, Yu Y, Liu J, Yang Z. "Experimental Study of Needle-Tissue Interaction Forces: Effect of Needle Geometries, Insertion Methods and Tissue Characteristics." J Biomech. 2014;47(13):3344–53. doi:10.1016/j.jbiomech.2014.08.007
17. Ethicon. Needle true-to-scale diagram. ©2015; manufacturer needle-point and code chart.
18. Sergeant P, Kocharian R, Patel B, et al. "Needle-to-suture ratio, as well as suture material, impacts needle-hole bleeding in vascular anastomoses." Interact Cardiovasc Thorac Surg. 2016;22(6):813–816. doi:10.1093/icvts/ivw042
19. Balla A, Hampel KJ, Sharma MK, Cottrell CE, Sidiropoulos N. "Comprehensive validation of cytology specimens for next-generation sequencing and clinical practice experience." J Mol Diagn. 2018;20(6):812-821. doi:10.1016/j.jmoldx.2018.06.001
20. Lemoine A, Witdouck A, Beloeil H, Bonnet F. "PROSPECT guidelines update for evidence-based pain management after prostatectomy for cancer." Anaesth Crit Care Pain Med. 2021;40(4):100922. doi:10.1016/j.accpm.2021.100922
21. Ethicon Products. Wound Closure Manual. 2005. Chapter 3, "The Surgical Needle," pp. 46–47. Manufacturer manual.
22. Ethicon Products. Wound Closure Manual. 2005. Chapter 3, "The Surgical Needle," pp. 46–47. Manufacturer manual.
23. Ethicon Products. Wound Closure Manual. 2005. Chapter 3, "The Surgical Needle," pp. 46–47. Manufacturer manual.
24. Ethicon Products. Wound Closure Manual. 2005. Chapter 3, "The Surgical Needle," pp. 46–47. Manufacturer manual.
25. Ethicon Products. Wound Closure Manual. 2005. Chapter 3, "The Surgical Needle," pp. 46–47. Manufacturer manual.
26. Ethicon Products. Wound Closure Manual. 2005. Chapter 3, "The Surgical Needle," pp. 46–47. Manufacturer manual.
27. Calthorpe N. "The history of spinal needles: getting to the point." Anaesthesia. 2004;59(12):1231–1241. doi:10.1111/j.1365-2044.2004.03976.x
28. Akyol D, Çelik M, Ay N, Yıldız GÖ. "The Effect of Spinal Needle Type on Post-Dural Puncture Headache in Spinal Anesthesia: Prospective Randomized Study." Eurasian J Med. 2024;56(1):42–46. doi:10.5152/eurasianjmed.2024.23223
29. Uppal V, Russell R, Sondekoppam RV, et al. "Evidence-based clinical practice guidelines on postdural puncture headache: a consensus report from a multisociety international working group." Reg Anesth Pain Med. 2024;49(7):471–501. doi:10.1136/rapm-2023-104817
30. Zhan T, Lou A. "Comparison of outcomes of an 18-gauge vs 16-gauge ultrasound-guided percutaneous renal biopsy: a systematic review and meta-analysis." Ren Fail. 2023;45(2):2257806. doi:10.1080/0886022X.2023.2257806
31. Contemporary OB/GYN. "Clinician to Clinician: The virtues of blunt suture needles." 2006. Article.