Metzenbaum vs Mayo Scissors: Differences and Uses

Metzenbaum and Mayo scissors are the two most common dissecting scissors in general surgery, and they appear side by side in almost every basic instrument set. They look alike at a glance: both have finger rings, a screw joint and blunt tips, and both come straight or curved. They do different jobs, though, and using one in place of the other can damage the instrument or the tissue. This guide sets out how to tell them apart, what each is designed for, and what to check when you order them.

The short answer

• Metzenbaum scissors are light, slender scissors with long handles and short blades. They are for delicate cutting and blunt dissection of soft tissue.
• Mayo scissors are heavy scissors with wide, thick blades. They are for dense tissue such as fascia, and the straight version is the standard scissors for cutting sutures.

The American College of Surgeons’ student guide to common surgical instruments puts it in the same terms: Mayo scissors are heavy, with straight ones used for cutting suture and curved ones for heavy tissue such as fascia, while Metzenbaum scissors are lighter scissors for delicate tissue and blunt dissection.

Side-by-side comparison

Feature	Metzenbaum scissors	Mayo scissors
Build	Slender, light	Bulky, heavy
Shank and blade	Long shanks relative to short blades (high shank-to-blade ratio)	Shorter shanks, longer and wider blades with thick, rounded spines
Tips	Usually blunt and rounded	Semi-blunt: rounded on the outside, with a square corner on the cutting side
Usual shape	Usually curved; straight versions exist	Straight and curved both common
Main use	Delicate tissue, blunt dissection, work on organs and neurovascular structures	Dense tissue such as fascia (curved); sutures, mesh, drains and dressings (straight)
Not for	Sutures, drains or heavy tissue	Fine dissection of delicate structures
Common nicknames	“Metz”, Metzenbaum-Lahey	“Suture scissors” (straight pattern)

Metzenbaum scissors

Design

Metzenbaum scissors have a relatively high shank-to-blade ratio. In practice, the handles and shanks are long while the blades are short. This gives the surgeon reach into a wound while keeping the cutting part small and controlled. The tips are almost always rounded, so the closed scissors can be pushed into tissue and opened to spread layers apart without sharp injury. Wikipedia notes that some versions have tungsten carbide blade inserts.

The instrument is named after Myron Firth Metzenbaum (1876–1944), an American surgeon who practised oral and reconstructive surgery.

Uses

Wikipedia describes them as the most common scissors used in operations on organs and complex neurovascular structures. They are used for:

• cutting delicate soft tissue
• blunt dissection, by spreading tissue planes apart with the closed tips
• separating structures where a sharp point would risk injury

What not to use them for

Sklar’s product information states that its Metzenbaum dissecting scissors are not recommended for cutting sutures, drains or heavy tissue. Cutting heavier material is the job of the bulkier Mayo scissors.

Mayo scissors

Design

Mayo scissors have wider blades with thick, rounded spines and semi-blunt tips. Wikipedia describes the tips as rounded on the outside with a right-angled corner on the cutting side. Compared with Metzenbaum scissors they are much bulkier and the pivot sits further back towards the handles. They are named after the Mayo Clinic, where the design was developed. Wikipedia gives typical lengths of 150 to 170 mm, but makers offer other lengths too.

Straight versus curved

The two forms have different jobs:

• Straight Mayo scissors cut tissue near the surface of the wound and are used so often on sutures that they are called suture scissors.
• Curved Mayo scissors reach deeper into the wound and are used to cut thick, dense tissue such as fascia, muscle or uterine tissue.

Sklar notes that the curved instrument is most often used for cutting or dissecting dense or deep tissue and the straight version for surface tissue or sutures, but that both may be used interchangeably depending on the procedure and the surgeon’s preference.

Related patterns

The Mayo-Stille scissors belong to the same family of sturdy dissecting scissors, with rounded edges for deep dissection of tough tissue. Catalogues also list Mayo-type and Metzenbaum-type scissors with extra-sharp or tungsten carbide edges.

How to tell them apart on a tray

1. Look at the blade length relative to the handle. If the blades are short compared with the long shanks, it is a Metzenbaum. If the blades are a large share of the total length, it is a Mayo.
2. Look at the blade thickness. Mayo blades are visibly wide and heavy, with a thick spine. Metzenbaum blades are thin and narrow.
3. Look at the tips. Metzenbaum tips are symmetrically rounded. Mayo tips have a rounded outer edge and a square inner corner.
4. Feel the weight. At the same length, a Mayo is noticeably heavier.

Iris scissors are a third pattern that is sometimes confused with small Metzenbaums. Iris scissors are small, with short blades and very fine, sharp points, and were originally designed for eye surgery.

What to check when ordering

Both patterns are made in many variants, so a catalogue line such as “Metzenbaum scissors, 18 cm” is not a full specification. Before ordering, confirm:

• Length: both patterns come in a range of lengths, from short versions for superficial work to long versions for deep cavities.
• Shape: straight or curved.
• Tips: blunt/blunt is standard, but sharp/blunt and sharp/sharp versions are made.
• Weight: some catalogues list light, standard, heavy or delicate models.
• Edges: standard bevel, extra-sharp edges, or tungsten carbide inserts. Carbide versions are often marked with gold finger rings.
• Material and finish: stainless steel or titanium, mirror or satin finish.
• Reusable or single-use: both patterns are available as reusable instruments and as single-use sterile items.

Our guide to reading a surgical instrument catalogue explains how these options are usually coded in product numbers.

Browse the patterns

You can compare the two patterns, with catalogue lengths and companies that list them, on our Metzenbaum scissors and Mayo scissors pages, or see all scissors in the database. For how scissors fit with the other main instrument groups, see our overview of surgical instrument types.

This article is general reference information about instrument design. It is not clinical guidance. Instrument choice in surgery is a matter for the surgical team and local protocols.

Sources

• American College of Surgeons, Division of Education: Common Surgical Instruments (student module)
• Wikipedia: Metzenbaum scissors
• Wikipedia: Mayo scissors
• Sklar: Metzenbaum Dissecting Scissors, product page
• Sklar: Mayo Dissecting Scissors, product page
• Wikipedia: Iris scissors