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Surgical Instruments and Sutures

Surgeons have used specialized tools to perform invasive procedures since Ancient Egypt. Throughout history, new techniques have been developed in close association with novel surgical instruments. Generally speaking, for any successful operation, a surgeon requires tools to cut open and access tissues (cutting, dissection, and retraction instruments), for bleeding control ( hemostasis Hemostasis Hemostasis refers to the innate, stepwise body processes that occur following vessel injury, resulting in clot formation and cessation of bleeding. Hemostasis occurs in 2 phases, namely, primary and secondary. Primary hemostasis involves forming a plug that stops the bleeding temporarily. Secondary hemostasis involves the activation of the coagulation cascade. Hemostasis instruments), and for anatomical restoration and closure of the surgical wound (sutures and needles).

Last updated: Mar 22, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Sutures and Needles

Suturing, also known as “stitching,” is a surgical maneuver carried out with the intent of joining together 2 selected tissues. For this purpose, the use of a needle and thread has proven to be the most cost-effective method up to modern times. Mechanical sutures (i.e., staples) are also available but are more expensive and have limited uses.

Classification of sutures

All sutures are classified according to their material as either absorbable or nonabsorbable. With absorbable sutures, the body will naturally degrade and absorb them over time. All suture materials are foreign bodies that set off an inflammatory response. Some materials are more likely to cause inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation than others.

Absorbable:

  • Catgut:
    • Simple or chromated
    • Collagen Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth). Connective Tissue: Histology from tendons or intestines of healthy mammals
  • Vicryl (braided multifilament lactide–glycoside polymer)
  • PDS (monofilament polymer of polydioxanone)

Nonabsorbable:

  • Silk:
    • Braided
    • Derived from silkworms
  • Synthetic:
    • Prolene
    • Nylon

Material selection Selection Lymphocyte activation by a specific antigen thus triggering clonal expansion of lymphocytes already capable of mounting an immune response to the antigen. B cells: Types and Functions

  • Nonabsorbable materials:
    • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions closure (where the sutures can be removed)
    • Internal tissues and organs (where absorbable sutures do not have the sufficient strength or durability)
  • Absorbable materials:
    • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions closure (sutures will not need to be removed)
    • Any internal organs and tissues where the mechanical strength and durability of absorbable sutures are sufficient

Suture caliber nomenclature

  • The thickest caliber of suture used in general surgery is number 1.
  • The following in descending order is the number 0.
  • As the caliber of the thread continues to decrease, the number of 0s increases (i.e. 2–0, 3–0, 4–0, and so on).
  • The finest thread available: 11–0 for use under a surgical microscope 
  • Caliber selection Selection Lymphocyte activation by a specific antigen thus triggering clonal expansion of lymphocytes already capable of mounting an immune response to the antigen. B cells: Types and Functions depends largely on the location. For example:
    • 3–0 and 4–0 are usually used on the extremities.
    • 5–0 and 6–0 are usually used on the face.

Surgical needles classification

According to shape:

  • Straight
  • Curved: ¼ of a circle, ⅜ of a circle, ½ of a circle, and ⅝ of a circle (require a needle holder and surgical tweezers)
  • Half-curved

According to tip (most common): 

  • Taper-point
  • Conventional cutting
  • Reverse cutting
  • Taper-cutting

The size of a surgical needle is proportional to the caliber of the attached suture.

Surgical needles

Curved and straight surgical needles

Image: “Surgical needles” by Rocco Cusari. License: Public Domain

Needle holder (needle driver)

Needle holders are specialized tools used to hold the needles for suturing. Needle holders are integrated clamps that lock the needle in place for as long as required. There are 2 main types of needle holders:

  • Mayo-Hegar 
  • Mathieu

Surgical Instruments

Cutting instruments

Scalpel:

  • Definitive cutting instrument used to create linear wounds and dissect tissues for procedural purposes 
  • Types:
    • Reusable: metal handle and exchangeable steel blades
    • Single-use: plastic handle and steel blades
Scalpel

Scalpel handle

Image: “Scalpel” by Saltanat ebli. License: CC0 1.0

Electric scalpel:

  • Needlelike surgical instrument that uses radio-frequency alternating current to heat Heat Inflammation tissue
  • Also known as an “electric knife,” “radio knife,” or “Bovie”
  • The current forms a tiny electric arc at the point, and it can:
    • Cut, desiccate, or fulgurate tissue
    • Sterilize the edges of the wound
    • Cauterize the cut blood vessels
  • Used in virtually all surgical disciplines

Laser scalpel: 

  • Surgical instrument used to cut, ablate, or coagulate tissue
  • Commonly used in: 
    • General surgery
    • Neurosurgery Neurosurgery Neurosurgery is a specialized field focused on the surgical management of pathologies of the brain, spine, spinal cord, and peripheral nerves. General neurosurgery includes cases of trauma and emergencies. There are a number of specialized neurosurgical practices, including oncologic neurosurgery, spinal neurosurgery, and pediatric neurosurgery. Neurosurgery
    • Ophthalmic surgery
    • Ear, nose Nose The nose is the human body’s primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity. Nose and Nasal Cavity: Anatomy, and throat Throat The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking. Pharynx: Anatomy surgery
    • Dentistry

Surgical scissors:

Types:

  • Mayo scissors:
    • Curved: for cutting and dissecting tissues
    • Straight: for cutting textiles and sutures
  • Metzenbaum scissors: for more precise cuts and delicate dissection of tissues
  • Iris scissors: smaller scissors initially used for ophthalmologic and other procedures requiring finesse

Hemostasis Hemostasis Hemostasis refers to the innate, stepwise body processes that occur following vessel injury, resulting in clot formation and cessation of bleeding. Hemostasis occurs in 2 phases, namely, primary and secondary. Primary hemostasis involves forming a plug that stops the bleeding temporarily. Secondary hemostasis involves the activation of the coagulation cascade. Hemostasis instruments and agents

Adequate bleeding control during a surgical procedure is key for reducing the likelihood of complications and reintervention. Hemostasis Hemostasis Hemostasis refers to the innate, stepwise body processes that occur following vessel injury, resulting in clot formation and cessation of bleeding. Hemostasis occurs in 2 phases, namely, primary and secondary. Primary hemostasis involves forming a plug that stops the bleeding temporarily. Secondary hemostasis involves the activation of the coagulation cascade. Hemostasis can be achieved via mechanical methods, such as rudimentary pressure, or hemostats, electrocautery, or hemostatic agents.

Mechanical hemostasis Hemostasis Hemostasis refers to the innate, stepwise body processes that occur following vessel injury, resulting in clot formation and cessation of bleeding. Hemostasis occurs in 2 phases, namely, primary and secondary. Primary hemostasis involves forming a plug that stops the bleeding temporarily. Secondary hemostasis involves the activation of the coagulation cascade. Hemostasis:

  • Hemostats (also hemostatic clamps, Pean or arterial forceps): 
    • Surgical tool used to control bleeding
    • Many available hemostat Hemostat Agents acting to arrest the flow of blood. Absorbable hemostatics arrest bleeding either by the formation of an artificial clot or by providing a mechanical matrix that facilitates clotting when applied directly to the bleeding surface. These agents function more at the capillary level and are not effective at stemming arterial or venous bleeding under any significant intravascular pressure. Basic Procedures models 
  • Surgical clips:
    • Mechanical device used to occlude a blood vessel to achieve definitive hemostasis Hemostasis Hemostasis refers to the innate, stepwise body processes that occur following vessel injury, resulting in clot formation and cessation of bleeding. Hemostasis occurs in 2 phases, namely, primary and secondary. Primary hemostasis involves forming a plug that stops the bleeding temporarily. Secondary hemostasis involves the activation of the coagulation cascade. Hemostasis
    • U-shaped: usually made of surgical steel or titanium
    • Clips are loaded onto a special applicator, brought around the vessel, and placed one at a time by pulling on the applicator’s trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation
Hemostats

Hemostats with straight and curved tips TIPS A type of surgical portasystemic shunt to reduce portal hypertension with associated complications of esophageal varices and ascites. It is performed percutaneously through the jugular vein and involves the creation of an intrahepatic shunt between the hepatic vein and portal vein. The channel is maintained by a metallic stent. The procedure can be performed in patients who have failed sclerotherapy and is an additional option to the surgical techniques of portocaval, mesocaval, and splenorenal shunts. It takes one to three hours to perform. Cirrhosis

Image: “Hemostats” by Splarka. License: Public Domain

Electrocautery:

  • High-frequency electrical current Electrical current The flow of charged particles from one point to another (in physiology, usually across a cell membrane) Cardiac Physiology that is conducted through the patient from an inactive electrode (in contact with the patient’s skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions) and an active electrode (the pen)
  • When the surgeon activates the pen, the circuit is closed and the electrical current Electrical current The flow of charged particles from one point to another (in physiology, usually across a cell membrane) Cardiac Physiology obtained is sufficient to destroy tissues and cause coagulation.

Hemostatic agents:

  • Induce clotting processes when applied to bleeding tissues
  • Come in the form of tissues/sponges, foams, or sprays
  • Examples: Surgicel, Surgifoam

Dissection and retraction instruments

Dissection instruments aid the surgeon in gaining depth in the tissues. Retraction instruments keep the surgical wound, or work area, open for further dissection. 

Forceps:

  • Indented: for avascular Avascular Corneal Abrasions, Erosion, and Ulcers tissues (i.e., aponeurosis)
  • Nonindented: for vascularized and delicate tissues (i.e., skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions)

Graspers and clamps:

  • Used to handle and to hold structures in place
  • Designed to minimize trauma to the tissues
  • Different graspers are suitable for different structures.
  • Some examples include:
    • Allis clamps
    • Babcock clamps (used to handle bowel)
    • Laparoscopic graspers (indented and nonindented)

Dissectors:

Numerous instruments are available to aid with tissue dissection. Some commonly used ones include:

  • Hemostats 
  • Tonsil forceps
  • Right-angle dissectors
  • Laparoscopic:
    • Maryland dissector (curved tip)
    • Dolphin nose Nose The nose is the human body’s primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity. Nose and Nasal Cavity: Anatomy dissector (straight tip)

Retractors:

  • Surgical instrument used to help with exposure Exposure ABCDE Assessment
  • Retractors are used to:
  • Types of retraction:
    • Manual: Retraction is done by handheld instruments, usually by a surgical assistant.
    • Self-retaining: a mechanical device that holds tissues apart 
  • Manual retractors (commonly used):
    • Richardson 
    • Deaver 
    • Miller-Senn
    • Army-Navy
    • Sweetheart
  • Self-retaining retractors:
    • Balfour
    • Finocchietto
    • Gosset
    • Munster

Bowel staplers

  • Mechanical devices used for intestinal anastomoses
  • Anastomosis is accomplished with rows of titanium staples fired by the stapler.
  • Some examples include:
Gia stapler

GIA (gastrointestinal anastomosis) stapler

Image: “Stapler GIA” by Rocco Cusari. License: Public Domain

Suture and Knot Techniques

Suture techniques

  • Simple interrupted suture: Each stitch is knotted.
  • Simple running (continuous) suture: Stitches are made in succession, with a knot at the very end.
  • Vertical mattress: 
    • Also known as “far-far, near-near” stitch
    • Used where wound edges are difficult to approximate
  • Horizontal mattress: A simple stitch is made and reversed (parallel to the wound).
  • Subcuticular suture: buried subepidermal stitches that can be running or interrupted
  • Purse-string suture: running encircling suture that is usually placed around tubes to hold them in place (e.g., gastrostomy tube)
  • Suture ligature:
    • A suture is anchored in a structure (e.g., blood vessel).
    • Then it is wrapped around the structure and tied to occlude it.

Knot tying

There are 2 basic types of surgical knots:

  • Square knot:
    • Most commonly used
    • Single wraps are thrown in alternating directions.
    • The number of throws depends on suture material and surgeon’s preference.
  • Surgeon’s knot: 
    • A double-wrap is used for the 1st throw.
    • Reduces loosening of the knot

Knot-tying techniques:

  • 2-handed tie: the most basic technique that needs to be mastered 1st
  • 1-handed tie
  • Instrument tie: Throws are made with a needle holder.
  • Laparoscopic tie: a variation of an instrument tie usually done with 2 laparoscopic needle drivers

References

  1. Ochsner, J. (2009). Surgical knife. Texas Heart Institute Journal 36:441–443. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763477
  2. Kirkup, John (2006-05-15). The Evolution of Surgical Instruments – An Illustrated History from Ancient Times to the Twentieth Century. Norman Publishing. https://books.google.com/books?id=eg_SpXBf4eIC&q=history+retractor&pg=PA279
  3. Bonfils-Roberts, E. (1972). The Rib Spreader: A Chapter in the History of Thoracic Surgery Chest 61:469–474. Archived from the original) December 2008: https://web.archive.org/web/20081217025255/http://www.chestjournal.org/cgi/reprint/61/5/469.pdf
  4. Shiel WC. Medical Definition of Laser surgery. MedicineNet. Retrieved 10 May 2020, from https://www.medicinenet.com/script/main/art.asp?articlekey=31889
  5. Hainer BL. (1991). Fundamentals of electrosurgery. Journal of the American Board of Family Practice xx:419–426.
  6. Barry L. Hainer M.D., Richard B. Usatine, M.D. (2002). Electrosurgery for the skin. American Family Physician 66:1259–66. http://www.aafp.org/afp/20021001/1259.html
  7. Boughton RS, Spencer SK. (1987). Electrosurgical fundamentals. J Am Acad Dermatol 16:862–867. https://www.jaad.org/article/S0190-9622(87)70113-3/pdf
  8. Chih-Chang Chu; J. Anthony von Fraunhofer; Howard P. Greisler. (1996). Wound Closure Biomaterials and Devices. CRC Press. pp. 35 ff. https://books.google.com/books?id=oFlXOeHboL8C&pg=PA35

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