Common suture techniques

Question 1

Suture selection is based on

Answer 1

tissue type.

Some tissues need support for longer than others:
* Skin, muscle, subcutaneous tissue – a few days
* Fascia – weeks
* Tendon – months

Question 2

Suture patterns are classified based on 3 features:

Answer 2

• as interrupted or continuous
• by the way they appose tissue (e.g. appositional, everting, inverting)
• by which tissues they appose (e.g. intradermal, subcutaneous)

In most cases, right-handed surgeons place sutures from right to left and left-handed surgeons from left to right.

Question 3

• When suturing skin – how far from the wound edge are the sutures placed?

Answer 3

sutures are placed at least the length of the skin thickness from the wound edges.

Question 4

the weakest point of a suture

Answer 4

the knot

Offset the knot so that it does not rest on top of the incision.

Question 5

Factors influencing knot security: (5)

Answer 5

• Type of material
• Length of the cut ends
• Structural configuration of the knot
• Number of throws used
• Experience

Square knots are usually recommended,
surgeon’s knots for areas of tension.

Question 6

Describe Interrupted suture patterns. (5)

Answer 6

• The knot is tied after each suture
• Better drainage
• Failure of a single suture does not
  cause the entire suture line to fail
• Relatively time-consuming
• More foreign material (knots)

Question 7

Describe Continuous suture patterns. (5)

Answer 7

• The suture line is begun and completed with a knot.
• Fast in comparison with interrupted sutures.
• Provide good tissue apposition, relatively air and fluid tight.
• Less foreign material
• Tearing of the suture material
  results in an open wound.

Question 8

identify these patterns A-D

Answer 8

• Simple interrupted pattern (A)
• Horizontal mattress pattern (B)
• Cruciate pattern (C)
• Vertical mattress pattern (D)

Question 9

Describe the Simple interrupted pattern. (4)

Answer 9

• Needle inserted through tissue on one side of the wound and passed through the opposite side.
• Knot tied, ends cut
• Appositional (positioning of things side by side or close together) (unless too much tension)
• Sutures in small animals 2-3 mm away from the skin edge.

Question 10

Describe the Cruciate pattern. (3)

Answer 10

• Two simple interrupted sutures placed parallel to each other, then tied across the incision.
• Can relieve low to moderate tension
• Almost as secure as simple interrupted, but less suture material used.

Question 11

Describe Horizontal mattress pattern. (4)

Answer 11

• Needle inserted on the far side of the incision, passed across and exited on the near side.
• Then advanced 6-8 mm along the incision
  and reintroduced through the skin exiting on the far side for the knot to be tied.
• Suture should pass just below the dermis
• Used in areas of tension

Question 12

Describe the Vertical mattress pattern. (4)

Answer 12

• Needle introduced 8-10 mm from the wound edge, passed across, exited at equal distance.
• Needle then reversed and inserted on the same side 4 mm from the wound edge, passed back across and exited at equal distance.
• Sutures generally separated by 4-5 mm
• Used in areas of tension

Question 13

Compare mattress patterns.

Answer 13

Question 14

identify

Answer 14

Continuous mattress pattern – everting

Question 15

Describe the Simple continuous pattern. (4)

Answer 15

• A simple interrupted suture placed and knotted. Needle then passed through the tissue from one side to the other perpendicular to the incision.
• To end the suture – needle end of the suture tied to the last loop of suture that is exterior to the tissue.
• Frequently used to close the linea alba and
  subcutaneous tissue
• Care should be taken to avoid excessive tightening in some areas not to cause purse-stringlike effect (e.g. intestinal anastomosis).

Question 16

Describe the Ford interlocking pattern. (4)

Answer 16

• Each pass is linked to the previous one through a loop of material as the suture exits the tissue.
• To end – needle reversed and introduced in the opposite direction, the loop tied to the single end.
• Might be more comfortable for right-handed surgeons to start from the left and left-handed from the right (usually the other way around!)
• May appose tissue better than simple pattern.

Question 17

Describe the Intradermal pattern. (7)

Answer 17

• The knot is buried in the dermis.
• Suture then advanced in the dermal
  tissue.
• Bites parallel to the incision
• Completed with a buried knot
• May be used instead of skin sutures
  to reduce scarring.
• No need to remove

Question 18

Describe the Subcutaneous pattern. (2)

Answer 18

• To eliminate dead space, provide
  apposition.
• When drainage might be necessary,
  interrupted sutures preferred.

Question 19

identify

Answer 19

subcutaneous pattern

Question 20

Describe and name Sutures used to close hollow organs (inverting). (4)

Answer 20

• Simple interrupted or continuous most commonly used (appositional patterns advocated as this facilitates rapid healing).
• Lembert pattern
• Connell and Cushing patterns
• Schmieden pattern
• Two-layer closure usually not recommended nowadays for most organs
  (e.g. simple continuous or Schmieden + Cushing), but can be used when closing the stomach for instance.

Question 21

Describe the Lembert pattern. (5)

Answer 21

• Continuous variation of a vertical mattress pattern used on hollow organs.
• Serosa and muscularis penetrated 8-10 mm from the incision edge, exited 3-4 mm from the wound.
• Continued in a similar fashion on the other side.
• Repeated along the length of the incision
• Is an inverting pattern

Question 22

Describe Connell and Cushing patterns. (7)

Answer 22

• Began with a simple interrupted or vertical mattress suture.
• Needle advanced parallel to the incision and reintroduced at a point that corresponds to the exit point on the contralateral side.
• The suture should cross the incision perpendicularly.
• Connell pattern enters the lumen (penetrates all layers)
• Cushing pattern extends only to the submucosal layer
• Continuous inverting patterns, create a watertight seal. Inversion occurs when suture tightened.
• Cushing can be used as a second layer in case of two-layer closure.

Question 23

Difference between Connell and Cushing patterns.

Answer 23

Both are inverting patterns for hollow organ closure.

• Connell pattern enters the lumen (penetrates all layers)
• Cushing pattern extends only to the submucosal layer. Cushing can be used as a second layer in case of two-layer closure.

Question 24

Describe Schmieden pattern. (3)

Answer 24

• Insertion of the needle is from under the wound surface passing through all the layers.
• Continuous inverting pattern
• Quick (1st layer) closure of the defect