SURGICAL INSTRUMENTSClaudia Gherman, Răzvan Ciocan, Ovidiu Fabian

Learning objectivesWhat you should know

The main types of surgical instruments The main instruments used for cutting tissues The main instruments used for tissue manipulation The main instruments used for exposure (retractors) The main instruments used for suturing The functioning principle of electrocautery devices The main laparoscopic instruments

What you should do Recognize the main surgical instruments Attach a scalpel blade to a handle/remove it from the handle Hand a scalpel to another person correctly Perform an incision Handle scissors (hold them correctly, cut under visual control,

hand scissors to another person) Handle a self-retaining forceps (hold it correctly, grip the

tissue, close and open the forceps, hand it to another person) Hold a retractor correctly Hold, close/open and hand over a needle holder correctly Recognize a suturing needle; recognize a sharp needle and an

intestinal needle; find on the needle and suture package the main information about the needle

ClassificationIn order to perform surgery, the surgical team needs a

number of surgical instruments. Each of the thousands of instruments used is designed for a specific function. They can be classified depending on use as follows: Cutting instruments Instruments for tissue grasping and manipulation Instruments for tissue exposure Suturing instruments Hybrid instruments

Endoscopic instruments

Cutting instrumentsScalpels: consist of a handle and a blade; the handle is

made of metal (reusable) or plastic (disposable); blades are disposable, of various shapes and sizes.

The top of the scalpel handle has a special part, with a groove that allows its sliding into the blade slot and securing of the blade in position.The scalpel blade has a slot - larger at its base and narrower at its top. The larger part is fitted to the groove of the handle, and the narrower part secures the blade into the groove.

Figure 1. Handle of a scalpel

Figure 2. Scalpel blades

The attachment of a scalpel blade is illustrated below:

Figure 3. Attachment of a scalpel blade: the larger part of the blade slot is placed in the handle groove, then the blade is moved so that the narrower part

of the slot slides and snaps into the groove

The removal of a scalpel blade is presented below:

Figure 4. Removal of a scalpel blade: the blade is lifted over the securing device and then slided out of the handle groove

A scalpel must be handed from one person to another so as to completely eliminate any risk of injury. The scalpel is held by the upper part of the handle, with the completely visible blade pointing upwards; the recipient takes the scalpel by grasping the lower part of the handle.

During its use, the scalpel can be Figure 5. Handing over

a scalpel

Held as a knife, as a pencil or as a dagger (see the figure below).

Figure 6. Use of scalpels – as a knife, as a pencil, as a dagger

Scissors are used to cut tissues, suture threads, dressings, as well as for blunt dissection (the closed scissors are introduced between the planes to be separated, and are openedbefore they are extracted).

Figure 7. Metzenbaumscissors

Scissors exist in a variety of sizes and shapes. They can be straight, curved or angular. They can have a sharp or blunt tip.

A. B. C. D.Figure 8. Different types of scissors: A. Mayo scissors; B. Potts scissors (used in biliary and vascular surgery); C. Castroviejo scissors (used in microsurgery,

ophthalmology, neurosurgery); D. Scissors for cutting dressingsDuring usage, scissors are held as follows:

The fourth finger is inserted through the ring of the lower arm of the scissors

The third finger supports the lower arm of the scissors The second finger is extended along the arms of the scissors,

ensuring the precision of movement The thumb (about half of the first phalanx) is inserted through

the ring of the upper arm of the scissors

Figure 9. The correct way to hold scissors

It is important that cutting with scissors should be performed under visual control; the tip and the entire length of the blades must be observed in order to avoid damaging other tissuesthan those concerned.

To cut the threads after tying a knot, the following are performed: The open blades are placed around

the threads The scissors are lowered to the

proximity of the knot, they are rotated so as to make the knot clearly visible

Figure 10. Cutting a thread under visual

control

The threads are cut to the desired length This allows to avoid

o Leaving too long or too short thread ends o Cutting the knot

Scissors should be handed from one person to another as follows: The first person holds the tip of

the scissors The second person opens the Figure 11. Handing over scissors

Palm of the hand to receive the instrument The first person places the handle of the scissors in the palm

of the recipientOther cutting instruments are chisels, osteotomes, saws

(used for cutting bones), curettes (used for scraping tissues), dermatomes (used for collecting free skin).

Tissue manipulation instrumentsHemostats are used to grasp, handle and retract tissues. In

certain situations, spaces are too narrow for the surgeon’s hands, so that hemostats can apply force, pressure or can expose certain anatomical structures. There are two types of hemostats: self-retaining and non-self-retaining.

Surgical hemostats are traumatic hemostats (equipped with teeth allowing to grasp tissue firmly). They are used for handling hard tissues (skin, fascias).

Anatomical hemostats are atraumatic (without teeth). They are used for handling sensitive, friable tissues.

A. B.Figure 12. A. Surgical hemostat. B. Anatomical hemostat

A.B.

An anatomical or Surgical hemostat should be held with the thumb on one side and with the second and third fingers on the other

Figure 13. Holding an anatomical/surgical hemostat: A. Correct B. Incorrect

Side, towards the volar part of the hand – similarly to a pencil. Holding A hemostat with its handle in the palm should be avoided; this position is uncomfortable and does not allow precision.An anatomical or surgical hemostat should be passed from one person to another by placing the instrument with its handle (not its tip) in the recipient’s hand.

Figure 14. Handing over ananatomical/surgical hemostat

Self-retaining forcepsare used for grasping tissues and they have a locking (rack and pinion) mechanism that keeps them closed, allowing them to hold the tissue Figure 15. Self-retaining forcepsBetween their arms. They are similar in shape to scissors, the locking mechanism being situated near the rings. They can be straight or curved.

The most widely used self-retaining forceps are: P�an’s forceps – without teeth Kocher’s forceps – with teeth

A. B.Figure 16. A. P�an’s forceps. B. Kocher’s forceps

Other forceps, similar to the two above, are Mosquito forceps – a fine, small size Pean’s forceps Overholt forceps – a fine, curved P�an’s forceps, used for

dissection or hemostasis

A. B.

Figure 17. A. Mosquito forceps. B. Overholt forceps

To secure drapes that cover the patient during surgery, special self-retaining forceps are used1: Backhaus forceps (with a rack and pinion mechanism) Doyen forceps (with a spring mechanism)

A. B.Figure 18. Forceps for securing surgical drapes: A. Backhaus forceps B.

Doyen forceps

Handling of self-retaining forceps: Forceps should be

held similarly to scissors: the fourth finger is inserted through the lower ring, the middle finger supports the forceps, Figure 19. Holding a self-retaining forcepsThe index finger is extended along the arms of the forceps to ensure precision of movement, and the thumb (the proximalhalf of the first phalanx) is inserted through the upper ring

A self-retaining forceps is closed by moving its arms so as to allow engagement of the teeth of the locking mechanism

The forceps is opened by pushing the rings (arms) apart so as to disengage the teeth of the rack and pinion mechanism

Figure 20. Opening a self-retaining forceps by pushing apart the teeth of the locking mechanism

1 Known as “crayfish”, due to their arms similar to the claws of crayfish

A self-retaining forceps should be handed from one person to another similarly to scissors: the handing person holds the tip of the instrument and places thehandle (rings) of the forceps Figure 21. Handing over a self-

retaining forcepsIn the recipient’s open palm.

Instruments for exposure (retractors)They are used to hold back tissues/organs in order to

expose only those organs/tissues that are being operated on; they ensure visibility of the surgical site. Retractors come in different shapes and sizes, depending on anatomical location. To minimize trauma to the retracted organs and tissues, the position of retractors must be frequently changed during surgery. Below are some examples of retractors:A. B. C.

Figure 22. Retractors: A. Farabeuf retractor; B. Doyen retractor; C. Self-retaining (Weitlaner) retractor

Handling retractors is difficult and fastidious, but exposure provided by them is important because it ensures visibility of the surgical site. Traction on retractors is generally exerted in two directions:

Figure 23. Handling the Farabeufretractor

Laterally and downwards; consequently, the most effective way to hold a mobile retractor is using the thumb and the third-fifth fingers (ensuring lateral traction), while the second (index) finger is extended along the instrument and ensures downward pressure.

Suturing instrumentsNeedle holders are special self-retaining forceps used to

maneuver the needle during suturing (they hold and guide the suturing needle). X-shaped striations allow a secure grip of the needle between the arms.

There are 2 main types of needle holders, the others being variations of these: the Mathieu needle holder and the Hegarneedle holder.

A. B.Figure 24. A. Mathieu needle holder; B. Hegar needle holder

The Mathieu needle holder is held in the palm of the hand; it is closed and opened by pushing the rack and pinion mechanism situated at the end of the arms.

Figure 25. How to correctly hold the Mathieu needle holder

The Mathieu needle holder is passed from one person to another by placing the handle in the recipient’s palm. Figure 26. Handing over the Mathieu needle

holder

The Hegar needle holder can be held: With the thumb and the second-fourth fingers (like a self-

retaining forceps) In the palm (like the Mathieu needle holder)

A. B.Figure 27. Maneuvering the Hegar needle holder: A. Like a self-retaining

forceps; B. Held in the palm

The Hegar needle holder should be handed over similarly to a self-retaining forceps; in addition, care should be taken to correctly orient the needle and keep the thread free (out of the palm of the hand).

Figure 28. Handing over the Hegar needle holder

Needles are used to pass threads through tissues during suturing. They should be sharp enough to penetrate the tissue with minimal resistance, rigid enough not to bend, and flexible enough to allow the movements desired by the surgeon. The most frequently used needles are curved (Hagedorn) needles – due to their maneuverability, but there are also straight needles, as well as other types2.

Curved needles usually have the shape of a circle segment(half, two-thirds, three/five-eighths of a circle, etc.); there are also needles with a special curve (compound curve – hook-shaped or J-shaped, ski-shaped), but these are rarely used.

Needles are mainly classified depending on their cross-section shape: Sharp needles – they have a triangular (sometimes

trapezoidal3) cross-section; they cut tissues with both their tip and sharp edges; they are appropriate for hard tissues (skin, aponeuroses)

2 For example, Reverdin or Deschamp needles3 Spatulated needles

Intestinal needles – they have a round cross-section; they cut tissues only with the tip and are adequate for friable tissues(digestive tract, blood vessels)

A.B.

Figure 29. Types of needles: A. Cutting needle; B. Round (smooth) needle

The tip of the needle can be: Sharp (cone/pyramid top): penetrating tip Round (blunt): round tip

A. B.Figure 30. The tip of needles can be: A. Penetrating, B. Round

Suture threads can be swaged (the suture thread is attachedto the needle by an industrial method), double swaged (a suture thread has needles at both ends) or unswaged (the suture thread is passed through the needle manually, and the needle is reusable, after sterilization).

Swaged needles have the same diameter as the thread and are termed atraumatic. Needles through which the thread is passed manually have a larger eye diameter; in addition, tissues are traversed by A.A double thread;consequently, these needles induce tissue trauma not only with their tip and edges, but also with their base; these needles are termed traumatic needles4.

B.Figure 31. A. Traumatic needle; B. Atraumatic needle (swaged suture)

Traumatic needles usually have a closed lower eye (similarly to usual sewing needles) and a half-open upper eye5 (through which the thread is inserted by pushing the slot between the lateral

4 Simplified: needles with swaged (attached) threads are atraumatic5 In Anglo-Saxon manuals, it is called “a French eye”

edges).The package of swaged suture threads provides relevant

information about needles: The needle type (sharp/intestinal) and cross-section shape

o Are suggested by a symbol: For intestinal needles (round): a circle For sharp needles: a triangle with the top pointing

upwards or downwards (depending on the cross-section shape) or a trapezoid (for spatulated needles)

The shape of the needle o Suggested by a symbol and marked by circle divisions

(1/2c, 1/3c, 3/8c, etc.) The length of the needle

o Suggested by a symbol at a 1:1 scale and expressed in mm The thickness of the needle

o Usually on the USP (United States Pharmacopeia) scale: Needles/threads with a thickness 0 = 0.35 mm Thinner needles/threads are marked as 2-0, 3-0 ... Up

to 11-06

Thicker needles/threads are marked with figures from1 to 67

Instruments for electrosurgeryElectrosurgery is based on the effects of high-frequency

electric current on tissues. Electrocauters are hybrid instruments, having both a

cutting function (signalled by a yellow led) and a coagulation function (signalled by a blue led). There are two types of electrocauters: monopolar and bipolar.

In the case of monopolar electrocauters, the current passes between a sharp active electrode (handled by the surgeon and applied to the tissue) and a passive return electrode (a large surface plate applied to the patient’s skin, outside the surgical field). The effects of the current occur only in the active electrode.

6 A 2-0 needle/thread corresponds to a 0.3 mm diameter, and an 11-0 needle corresponds to a 0.01 mm diameter7 A 1 needle/thread corresponds to a 0.4 mm diameter, and a 6 needle/thread corresponds to a 0.8 mm diameter

Figure 32. Information about a swaged needle marked on the package

In the case of bipolar electrocauters, the electric current passes between two active electrodes – a special hemostat.

A. B.Figure 33. A. Monopolar electrode; B. Bipolar electrode

A. B.

Figure 34. A. Monopolar cautery; B. Bipolar cautery

Over the past years, other electrosurgical instruments, used both for hemostasis and cutting, have been introduced8.

Laparoscopic, thoracoscopic instrumentsLaparoscopic/thoracoscopic surgery is performed by

creating a chamber filled with air in the body cavities (pneumoperitoneum, pneumothorax). With a special needle, carbon dioxide is introduced into the peritoneal/pleural cavity. Through the abdominal/thoracic wall, special trocars are inserted, and through these trocars, a video camera, allowing visualization of the internal cavity, and surgical instruments are introduced.

Laparoscopic/thoracoscopic instruments are special long instruments, having metal and plastic components; most of them also have an electrosurgical function.

A. B.Figure 35. A. Laparoscopic instruments; B. Trocar for laparoscopy

8 For example, LigaSure or ForceTriad hemostats

Assessment / self-assessment form

Stage / Criterion Correct IncorrectRecognize cutting instrumentsHandle a scalpel correctly

Attach and remove the bladePerform an incisionHand over the scalpel

Handle scissors correctlyHold scissors, cut under visual controlHand over scissors

Recognize tissue manipulation instrumentsHandle an anatomical/surgical hemostat

Grasp tissue with a hemostatHand over a hemostat

Handle a self-retaining forcepsGrasp tissue with a forcepsHand over a forceps

Recognize mobile/self-retaining retractorsRecognize the main types of needle holdersHandle a needle holder

Hold a Mathieu/Hegar needle holderHand over a Mathieu/Hegar needle

holderRecognize the types of needlesIdentify information about a swaged needle on the package Explain the principle of electrosurgeryRecognize the types of electrodes for electrosurgeryRecognize laparoscopic instruments