Wound Healing Suture & Needles John P. Hunt LSU New Orleans Department of Surgery

Objectives Understand basic science of wound healing Relate this to clinical wound care Learn different types of suture & there applications Understand the different types of needles available and there uses

The cells that are central to wound healing are: A) Fibroblasts B) Macrophages C) Polymorphic Neutrophils D) T-cells E) B-cells American Board of Surgery In-training Exam

Ans – B PMN’s arrive at the site of injury in hours, but are gone with another 24 to 48 hours. There primary function involves phagocytosis and release of superoxides. Macrophages peak in the wound at approximately three days post-injury. They have numerous tasks which include phagocytosis, oxidative species production, wound debridement, elaboration of growth factors to stimulate fibroblast production of extracellular matrix materials and production of enzymes to destroy injured cellular matrix components (collagenase and elastase), and elaboration of growth factors to stimulate angiogenesis. Fibroblasts occur in the lag phase of wound healing and typically arrive 3-5 days post-injury and are responsible for collagen formation. T-cells peak at the 5 th day and do receive antigen from macrophages. B-cells have little to do with wound healing and may even exhibit an inhibitory effect.

Phases of Wound Healing

The most common collagen found in skin and bone is: A) Type I B) Type II C) Type III D) Type IV E) Type VI

Ans – A The most common collagen found in adults is type I comprising 80% of all collagen found in skin and bone. The majority of the remaining 20% is type III. There are higher concentrations of type III collagen in children and early wound healing. Type II collagen is found predominantly in articular surfaces. Type IV collagen is found in basal lamina.

Phases of Wound Healing Wound strength is directly proportional to Type I collagen content Maximum strength is 80% of original and does not occur for 1-2 years

Layers of Bowel Mucosa- epithelial cells lamina propria muscularis mucosa Submucosa- Collagen Muscularis propria- smooth muscle Serosa- mesothelium connective tissue

Intestinal Anastomoses Strength-Submucosa Collagenase Versus Collagen Deposition Weakest at 3-7 days

Wound Healing Times Days

Wound Healing Impediments Tension Blood supply Infection Hypovolemia/Shock Immunodeficiency Blood Transfusion Malnutrition Medication

Suture & Needles

Identifying suture/needles

Suture Types Absorbable versus Non-absorbable Monofilament versus Braided Synthetic versus Natural

Suture Strength #5 = 5 #4 = 4 #3 = 3 #2 = 2 #1 = 1 0 = = = = = = Etc.

Suture Strength #1#2

Suture Strength

Vicryl –75% of strength at 2 weeks –50% of strength at 3 weeks

Suture Strength

Anatomy of a Needle

The Point Tapered needles Cutting needles Blunt needles Combination

Needle Types

Reading the Packaging

Non-Absorbable Suture NaturalSynthetic MonofilamentBraidedMonofilamentBraided SteelSilk Nylon Prolene Ethibond Mersilene Sternal closure Ortho Abdomen Ubiquitous Not skin/SubQ Vascular Skin Adbomen Hernia Abdomen

Absorbable Suture NaturalSynthetic MonofilamentBraidedMonofilamentBraided Chromic Gut X PDS Monocryl Vicryl Dexon Liver GU SubQ X Hepato-biliary GU Skin GI Skin/SubQ GU Abdomen