Which suture is most commonly used for subcuticular (cosmetic) skin closure?

Monocryl (poliglecaprone 25). Monocryl is an absorbable monofilament suture that is ideal for subcuticular skin closure. Its monofilament structure slides smoothly through tissue with minimal tissue reaction, and it absorbs over 91-119 days, eliminating the need for suture removal. The result is a cosmetically superior closure.

Which suture size is the finest?

5-0. In the USP suture sizing system, more zeros mean a finer (thinner) suture. Therefore, 5-0 is finer than 3-0, which is finer than 2-0, which is finer than 0. This is a commonly tested concept on the CST exam.

What type of needle should be used for suturing bowel (intestinal) tissue?

Taper (round body) needle. A taper (round body) needle is used for suturing bowel, viscera, fascia, and other internal soft tissues. The smooth, round body separates tissue fibers rather than cutting them, which is essential for delicate structures like bowel that could tear with a cutting needle.

When loading a needle on a needle holder, the needle should be grasped at:

One-third of the distance from the swage (suture attachment point). The needle should be grasped approximately 1/3 of the distance from the swage (where suture attaches). Grasping at the tip damages it, grasping at the swage may break the suture attachment, and grasping at the middle does not provide optimal control. The 1/3 point balances control with needle integrity.

Key Takeaways

Sutures are classified as absorbable or non-absorbable, and as monofilament or braided (multifilament)
Absorbable sutures (Vicryl, Monocryl, chromic gut, PDS) dissolve over time and are used for internal tissues
Non-absorbable sutures (silk, nylon/Ethilon, Prolene, stainless steel) remain permanently and are used for skin or long-term support
Suture size uses the USP system: higher numbers with zeros = smaller diameter (e.g., 5-0 is finer than 2-0)
Needle types include cutting (skin), taper (viscera/fascia), and blunt (liver/spleen)
The surgical technologist loads suture on needle holders, positioning the needle 1/3 from the swage
Common closure techniques include interrupted, continuous (running), subcuticular, figure-of-eight, and retention sutures
Skin closure alternatives include staples, adhesive strips (Steri-Strips), skin glue (Dermabond), and subcuticular suture

Suturing & Wound Closure

Wound closure is one of the most critical phases of any surgical procedure. The surgical technologist must understand suture materials, needle types, and closure techniques.

Suture Classification

By Absorbability

Type	Examples	Absorption Time	Common Uses
Absorbable	Vicryl (polyglactin 910)	56-70 days	Subcutaneous, fascia, bowel
	Monocryl (poliglecaprone 25)	91-119 days	Subcuticular skin closure
	Chromic gut	90 days	GI, GU, GYN
	Plain gut	70 days	Superficial, fast-healing tissues
	PDS (polydioxanone)	180-210 days	Fascia, slow-healing tissues
Non-absorbable	Silk	Permanent	Ligatures, GI (accessible areas)
	Nylon (Ethilon)	Permanent	Skin closure
	Prolene (polypropylene)	Permanent	Cardiovascular, skin
	Stainless steel	Permanent	Sternum closure, tendon repair
	Ethibond (polyester)	Permanent	Cardiovascular, orthopedic

By Structure

Structure	Description	Properties	Examples
Monofilament	Single strand	Less tissue drag, fewer bacteria; harder to handle	Prolene, Ethilon, PDS, Monocryl
Multifilament (braided)	Multiple strands woven	Better handling; more tissue drag; can harbor bacteria	Vicryl, silk, Ethibond

Suture Sizing (USP System)

Sizes range from #5 (largest) to 11-0 (smallest, microsurgery)
The more zeros, the finer the suture: 5-0 is finer than 2-0
General guide:
- #1, #2: Heavy fascia, retention sutures
- 0, 2-0, 3-0: Fascia, bowel, general closure
- 4-0, 5-0: Skin, blood vessels
- 6-0 to 8-0: Microsurgery, ophthalmic, nerve repair

Needle Types

Needle Type	Cross-Section	Use
Cutting	Triangular with sharp edges	Skin, tough tissue (sharpest point)
Reverse cutting	Cutting edge on outer curve	Skin (stronger, less likely to tear through)
Taper (round)	Round, smooth body	Viscera, fascia, bowel, peritoneum
Taper-cut (trocar)	Sharp tip with taper body	Fascia, calcified tissue
Blunt	Rounded, blunt tip	Liver, spleen (reduces needlestick injury)
Keith needle	Straight cutting	Skin (used with hands, not needle holder)

Loading the Needle Holder

The surgical technologist loads the suture:

Grasp the needle 1/3 of the distance from the swage (where the suture attaches to the needle)
The needle tip should point to the left (for a right-handed surgeon) and upward
Lock the needle holder at the first ratchet — do not overtighten, which damages the needle
Present the loaded needle holder handle-first to the surgeon with the needle tip pointing away

Common Closure Techniques

Technique	Description	Use
Simple interrupted	Individual stitches, each tied separately	Most versatile; if one breaks, others hold
Continuous (running)	Single suture run along the wound	Faster closure; peritoneum, fascia
Subcuticular	Continuous suture within the dermis	Cosmetic skin closure
Figure-of-eight	Cross-pattern for added strength	Fascia, tendon
Retention (stay)	Large, through-and-through sutures with bolsters	High-tension closures (obese patients, contaminated wounds)
Purse-string	Circular suture tightened around a structure	Appendix stump, trocar sites
Mattress (horizontal/vertical)	Suture passes through tissue twice	Eversion of wound edges

CST Certified Surgical Technologist Exam

1Introduction: CST Exam Overview

2Chapter 1: Perioperative Care — Preoperative Preparation

3Chapter 2: Perioperative Care — Intraoperative Procedures

4Chapter 3: Postoperative Procedures & Ancillary Duties

5Chapter 4: Basic Science

6Chapter 5: Exam Strategy & Practice