Chapter 16 - Suture Materials and Patterns Flashcards
What is the maximum tensile strength loss period for absorbable sutures?
A) 30 days B) 45 days C) 60 days D) 90 days
C) 60 days
What classification of sutures undergoes degradation through hydrolysis and enzymatic digestion?
A) Nonabsorbable B) Synthetic C) Natural D) Multifilament
C) Natural
In which year was the European Pharmacopoeia established?
A) 1970 B) 1973 C) 1980 D) 1990
B) 1973
How many components are there in a surgical needle?
A) 1 B) 2 C) 3 D) 4
C) 3
Figure 16-1. Anatomy of a surgical needle.
Figure 16-2. Various points and shaft designs of surgical needles. (A) Taperpoint; (B) tapercut; (C) regular cutting; (D) reverse cutting; (E) spatula point; (F) blunt point.
What is the relative knot security (RKS) formula expressed as a percentage?
A) (TS/KHC) × 100 B) (KHC/TS) × 100 C) (TS/TS) × 100 D) (RKS/TS) × 100
B) (KHC/TS) × 100
What type of needle is specifically mentioned for use in ophthalmologic surgery?
A) Cutting needle B) Taper point needle C) 1/4-circle needle D) Blunt-point needle
C) 1/4-circle needle
What is the typical percentage increase in knot security for multifilament sutures due to their frictional values?
A) 25% B) 50% C) 75% D) 100%
B) 50%
How many types of degradation mechanisms are there for absorbable sutures?
A) 1 B) 2 C) 3 D) 4
C) 3
What is the main component of a surgical needle that affects its tissue penetration?
A) Length B) Body shape C) Point shape D) Attachment end
C) Point shape
How much should a selected suture’s strength compare to normal tissue strength?
A) At least 50% B) At least 75% C) Equal to D) Less than
C) Equal to
What is the tensile strength (TS) of a suture?
A) Maximum load before knot failure B) Force a suture can withstand before breaking C) Strength of tissue surrounding the suture D) Amount of tension during tying
B) Force a suture can withstand before breaking
What is the most common configuration for surgical needles used in general procedures?
A) Straight needles B) 1/4-circle needles C) 3/8- or 1/2-circle needles D) Blunt-point needles
C) 3/8- or 1/2-circle needles
What is the effect of coating on multifilament sutures?
A) Increases capillarity B) Reduces tissue drag C) Decreases knot security D) Both B and C
D) Both B and C
How is suture size expressed in the United States Pharmacopoeia (USP) standard?
A) By millimeter B) By number C) By diameter D) By cross-sectional diameter
D) By cross-sectional diameter
What percentage of knot-holding capacity (KHC) is typically ideal for surgical sutures?
A) 50% B) 70% C) 90% D) 100%
C) 90%
How does the capillarity of multifilament sutures impact surgical outcomes?
A) Reduces infection risk B) Facilitates healing C) Increases risk of infection D) Decreases tissue drag
C) Increases risk of infection
What type of suture is designed to penetrate delicate tissues without causing trauma?
A) Cutting needle B) Blunt-point needle C) Spatula needle D) Taper point needle
D) Taper point needle
What diameter is a 3-0 suture size in the USP system?
A) 0.3 mm B) 0.4 mm C) 0.5 mm D) 0.6 mm
B) 0.4 mm
What is the torsional stiffness and diameter of a suture related to?
A) Elasticity B) Flexibility C) Knot security D) Capillarity
B) Flexibility
How are surgical needles classified based on their shape?
A) Straight, curved, and flexible B) Straight, half-curved, and curved C) Long, short, and medium D) Standard, specialty, and custom
B) Straight, half-curved, and curved
What is the ideal feature of a suture that has low tissue drag?
A) High elasticity B) Smooth surface C) High capillarity D) Monofilament structure
B) Smooth surface
Which type of needle has a cutting edge on the outer curvature?
A) Regular cutting needle B) Reverse cutting needle C) Taper point needle D) Blunt-point needle
B) Reverse cutting needle
What is the relationship between knot security and friction for multifilament sutures?
A) Inversely proportional B) Directly proportional C) No correlation D) Undefined
B) Directly proportional
How long must the suture be to penetrate both wound margins effectively?
A) As long as the wound B) At least 1.5 times the wound length C) At least 2 times the wound length D) At least 3 times the wound length
B) At least 1.5 times the wound length
What type of needle is best for closing skin or tendon?
A) Taper point needle B) Cutting needle C) Blunt-point needle D) Spatula needle
B) Cutting needle
What is the risk associated with oversized suture materials?
A) Improved knot security B) Excessive tissue reaction C) Reduced tensile strength D) Decreased flexibility
B) Excessive tissue reaction
What happens to the tensile strength of absorbable sutures over time?
A) Increases significantly B) Remains constant C) Gradually decreases D) Fluctuates
C) Gradually decreases
What should be avoided in contaminated surgical sites regarding suture materials?
A) Absorbable sutures B) Nonabsorbable sutures C) Monofilament sutures D) Multifilament sutures
D) Multifilament sutures
How much of a suture’s diameter is a 5-0 suture in the metric system?
A) 0.5 mm B) 0.6 mm C) 0.7 mm D) 0.8 mm
A) 0.5 mm
What is the implication of high memory in a suture material?
A) Better handling B) Increased knot security C) Difficult to manage D) Low tissue drag
C) Difficult to manage
What is the ideal usage for tapered needles?
A) Skin closure B) Dense connective tissue C) Delicate tissues D) Viscera suturing
C) Delicate tissues
What is the maximum load to failure of a knot referred to as?
A) Knot security B) Knot-holding capacity C) Knot strength D) Loop security
B) Knot-holding capacity
What material primarily causes significant inflammatory reactions in sutures?
A) Synthetic polymers B) Natural materials C) Metallic fibers D) Coated sutures
B) Natural materials
Which type of needle is less traumatic and should be used whenever possible?
A) Blunt-point needle B) Cutting needle C) Taper point needle D) Spatula needle
C) Taper point needle
What is the primary benefit of coated multifilament sutures?
A) Increased capillarity B) Reduced drag and friction C) Higher knot security D) Increased tissue reaction
B) Reduced drag and friction
What type of sutures are indicated where prolonged wound support is required?
A) Absorbable B) Natural C) Nonabsorbable D) Multifilament
C) Nonabsorbable
How much does the knot-holding capacity typically decrease when using coated sutures?
A) 10% B) 20% C) 30% D) 40%
B) 20%
Which sutures are better for reducing tissue reaction?
A) Multifilament B) Natural C) Coated D) Monofilament
D) Monofilament
What defines loop security in surgical sutures?
A) Ability to maintain tightness B) Resistance to slipping C) Capacity to absorb tension D) Length of the suture
A) Ability to maintain tightness
What is the risk associated with using sutures with high capillarity?
A) Enhanced healing B) Increased infection risk C) Better knot security D) Reduced tissue drag
B) Increased infection risk
Figure 16-3. Deschamps needles, showing the left- and right-handed configuration, respectively. The threaded eye near the pointed tip allows easy retrieval of the suture without the need for complete penetration by the needle. When the suture is grasped at the tip of the needle, the instrument is rotated backward out of the tissue and can be rethreaded for the next bite.
surgical knots
Polyglactin 910 composition? Trade name?
Copolymer of 90% glycolide and 10% L-lactide; coating: polyglactin and calcium stearate.
Vicryl
Polyglactin 910 structure
Braided multifilament; coated
Polyglactin 910 absorption
Resorption time: 56–70 days
Polyglactin 910 tensile strength
Tensile strength reduction by 25% at day 14, 50% at day 21, and by 100% at day 35
advantages
Good size-to-strength ratio; greater initial breaking strength and stiffness than polydioxanone; minimal tissue reaction; excellent handling properties
disadvantages
May cut through friable tissue (especially if not coated)
Polyglycolic acid composition?
Polymer of glycolic acid; Dexon II is coated with polycaprolate
Safil Dexon
Polyglycolic acid structure? Trade name?
Braided multifilament; can be coated
Polyglycolic acid absorption time
Resorption time: 60–90 days
Polyglycolic acid tensile strength
Tensile strength reduction by 35% at day 14 and by 65% at day 21
Polyglycolic acid advantages
Good handling characteristics
Polyglycolic acid disadvantages
Very rapid absorption in the oral cavity; tends to drag through tissues; less knot-breaking strength than polyglactin 910
Braided lactomer composition? Trade name?
Copolymer of glycolide and lactide; coating: mixture of a caprolactone/glycolide copolymer and calcium stearoyl lactylate
Polysorb
Braided lactomer structure
Braided multifilament; coated
Braided lactomer absorption
Resorption time: 56–70 days
Braided lactomer advantages
Tensile strength is 140% of minimum knot strength requirements of the European/United States Pharmacopoeia initially, 80% at day 14 and 30% at day 21; biomechanically superior to polyglactin 910
Braided lactomer disadvantages
High initial tensile strength; good knot security; excellent handling properties
Braided lactomer
Rapid loss of strength when exposed to serum or inflamed peritoneal fluid
Glycomer 631 composition? Trade name?
Combined polymer of glycolide, dioxanone and trimethylene carbonate.
Biosyn
Glycomer 631 structure
monofilament
Glycomer 631 resorption time
90-110 days
Glycomer 631 tensile strength
Tensile strength is 75% of minimum knot strength requirements of the European/United States Pharmacopoeia at day 14 and 40% at day 21
Glycomer 631 advantages
Monofilament suture with only minimal memory and excellent handling properties; minimal tissue reaction
Glycomer 631 disadvantages
None known
Polyglytone 6211 structure
Monofilament
Polyglytone 6211 composition? trade name
Copolymer of glycolide, caprolactone, trimethylene carbonate, and lactide.
Caprosyn
Polyglytone 6211 absorption
Resorption complete within 56 days
Polyglytone 6211 tensile strenght
Loses almost all tensile strength within 21 days
Polyglytone 6211 advantages
Provides short-term tensile strength combined with very rapid absorption
Polyglytone 6211 disadvantages
Rapid absorption
Polydioxanone structure
monofilament
Polydioxanone composition? Trade name?
Polymer of poly-p-dioxanone
PDS II
Polydioxanone Absorption?
Resorption time: 180 days
Polydioxanone tensile strenght?
Tensile strength reduction by 25% at day 14, 30% at day 28, 50% at day 42
Polydioxanone advantages
Absorbable suture material that maintains tensile strength over a prolonged period of time; less memory effect than polyglyconate
Polydioxanone disadvantages
Moderate knot security, moderate handling characteristics
Polyglyconate structure
Monofilament
Polyglyconate composition and trade name
Copolymer of glycolide and trimethylene carbonate
Maxon
Polyglyconate resorption
Resorption time: 180 days
Polyglyconate tensile strength
Tensile strength reduction by 25% at day 14, 50% at day 28, 75% at day 42
Polyglyconate advantages
Slow resorption and loss of tensile strength; three-times stronger than polyglactin 910 at day 21 of wound healing; good knot security
Polyglyconate disadvantages
High memory effect, limited pliability, and moderate handling properties
What other polyglyconate exists?
Monosyn copolymer of glycolide trimethylene carbonate, caprolactone
What is polyglyconate Monosyn resorption?
Resorption time: 60–90 days
What is polyglyconate Monosyn tensile strenght?
Tensile strength reduction by 30% at day 7, 50% at day 14 and 80% at 21 days
What is polyglyconate Monosyn advantages?
Very good handling properties and good knot security; quick resorption after loss of tensile strength
What is polyglyconate Monosyn disadvantages?
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Poliglecaprone composition? Trade name?
Copolymer of glycolide and caprolactone
Monocryl
Poliglecaprone structure?
Monofilament
Poliglecaprone absorption?
Resorption time: 90–120 days
Poliglecaprone tensile strength?
Tensile strength reduction by 50% at day 7 and 80% at day 14; complete loss of tensile strength within 21 days
Poliglecaprone advantages
Very low tissue drag owing to smooth surface; good handling characteristics; high initial tensile strength; minimal tissue reaction
Poliglecaprone disadvantages
Rapid loss of tensile strength but moderate resorption time
Silk composition and trade name
Raw silk spun by silkworm; Sofsilk, Silkam
Silk structure
braided multifilament coated or uncoated
Silk tensile strength
doesn’t have
Silk advantages
Excellent handling characteristics; useful for ligatures
Silk disadvantages
Does not maintain tensile strength more than 6 months; may potentiate infection – should be avoided in contaminated sites; has significant capillarity; incites some inflammatory reaction
Surgical steel composition and trade name
Alloy or iron
Steelex
Surgical steel structure
Monofilament or as multifilament twisted wire
Surgical steel tensile strength
Greatest tensile strength of all sutures
Surgical steel advantages
Greatest knot security of all sutures; no inflammatory reaction
Surgical steel disadvantages
Tissue movements against the inflexible ends may cause inflammation and necrosis; poor handling properties; cannot withstand repeated bending without breaking; multifilament wire can fragment and migrate, leading to sinus tract formation
Nylon composition and trade name
Polymer of polyamide
Dafilon
Monosof
Nylon structure
Monofilament or multifilament
Nylon tensile strength
Intermediate tensile strength; monofilament nylon loses about 30% of its original tensile strength by 2 years because of chemical degradation; multifilament nylon retains no tensile strength after 6 months
Nylon advantages
Suitable for use in contaminated wounds; degradation products act as antibacterial agents
Nylon disadvantages
Poor handling characteristics and poor knot security; not recommended for use within serous or synovial cavities because buried sharp ends may cause frictional irritation
Polycaprolactam composition and trade name
Polymerized caprolactam (=polyamide 6)
Supramid
Braunamid
Polycaprolactam structure
Multifilament with a polyamide coating
Polycaprolactam tensile strength
Better tensile strength than nylon
Polycaprolactam advantages
Excellent handling properties, high knot security
Polycaprolactam disadvantages
Intermediate tissue reactivity; has a tendency to form sinuses on implantation in tissues and is therefore best suited for use in the skin
Polyester composition and trade name
Polyethylene terephthalate
Mersilene
Synthofil
Dragofil
Ethibond
Ticron
Polyester structure
Monofilament or multifilament; uncoated or coated with polybutilate or silicone or polyethylene/vinyl acetate
Polyester tensile strength
Very high and sustained tensile strength
Polyester advantages
High tensile strength
Polyester disadvantages
Noncoated polyester fibers have a high coefficient of friction; knot security is poor and is further reduced by coating; causes marked tissue reaction and fibrous encapsulation; should not be used in contaminated wounds
Ultra high–molecular weight polyethylene composition and trade name
Ultra high–molecular weight polyethylene
FiberWire
Ultra high–molecular weight polyethylene structure
Multifilament with a polyethylene/polyester coating
Figure 16-5. Technique for tying an Aberdeen knot. (A) The single strand of the suture end and the last suture loop are used; (B) the fingers of one hand are slipped through this loop; the thumb and index finger hold the loop open while the middle and ring fingers grasp the single strand; (C) the loop is slipped off the thumb and the hitch is tightened by exerting traction in the direction of the arrow; (D to H), then steps (B to C) are repeated at least two times to add additional throws; (I) finally, the single strand of suture is passed through the last loop and tightened to lock the knot.
Figure 16-7. The 4S-modified Roeder knot is tied by (A) starting the knot with a single throw; (B) wrapping the tail of the suture three times around both strands of the loop entering the abdomen; (C) completing the knot with a half hitch knot around the standing part of the suture; and (D) completed knot is tightened by alternately pulling on the standing part and strand of the abdominal loop that exits from the cannula and is then slid into the abdominal cavity using a knot pusher.
Figure 16-8. A barbed suture equipped with a loop at one end for fixation of the first suture loop and unidirectional barbs throughout the length of the suture strand can be used for tissue apposition. These barbed suture materials allow knotless suturing.
Figure 16-6. Technique for tying a Forwarder knot. (A) The standing and the working end of the suture are positioned adjacent to each other and the needle holders and the working end of the suture is turned around the standing end of the suture and the needle holder; (B) the needle holder is used to grasp the working end of the suture through the preplaced loops; (C) the working end of the suture is pulled through the loops and locks the knot.
Appositional and everting suture patterns. (A) Simple interrupted
C) cruciate
(B) interrupted intradermal/subcuticular;
D) Gambee; this pattern can be used as an appositional suture pattern for skin (a) or intestine
D) Gambee; this pattern can be used as an appositional suture pattern for skin (a) or intestine this is intestine!
(E) interrupted vertical mattress;
(F) Allgöwer corium vertical mattress;
G) interrupted horizontal mattress; (H) simple continuous;
(H) simple continuous
(I) continuous intradermal;
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(J) Ford interlocking (a); to terminate this pattern, the needle is introduced in the opposite direction from that used previously, and the end is held on that side; the loop of the suture formed on the opposite side is tied to the single end (b).
(J) Ford interlocking (a); to terminate this pattern, the needle is introduced in the opposite direction from that used previously, and the end is held on that side; the loop of the suture formed on the opposite side is tied to the single end (b).
Inverting suture patterns. (A) Cushing
Inverting suture patterns B) Connell;
Inverting suture patterns C) Lembert interrupted
Inverting suture patterns B) Lembert continuous
Inverting suture pattern (D) Parker-Kerr;
Inverting suture pattern (E) purse-string.
Tension suture patterns. (A) Interrupted vertical mattress pattern used as a tension suture;
Tension suture patterns. (B) interrupted horizontal mattress pattern placed as a tension suture with stents to reduce focal pressure on the skin, followed by a simple interrupted suture pattern to achieve wound closure;
Tension suture patterns. C) quilled/stented; (D) far-near-near-far;
Tension suture patterns.(E) walking suture;
Tension suture patterns. (F) locking loop (a) and double-locking loop (b); for the locking loop patterns, bites perpendicular to the tendon fibers are superficial relative to bites that are aligned parallel to the fibers;
Tension suture patterns. (G) 3-loop pulley pattern (a) with a cross-sectional view (b) of this pattern demonstrating that each loop is oriented 120 degrees relative to the others.
