Atlas of surgical instruments and equipment

This article provides an overview of the most common surgical instruments used in the operating room, including forceps, clamps, scissors, retractors, needle holders, and drainage spikes. Instruments are designed with specific characteristics depending on their intended use.

Surgical blades and handles

• Surgical blades are categorized by their shape and size, which dictate their specific clinical use.
• They are typically mounted on a Bard-Parker handle.

Safe instrument handling

Maintaining safety in the operating room is a primary objective for the surgical team.

• Sharps safety
  • Blades should be passed using a "neutral zone" or a kidney tray rather than hand-to-hand to prevent needle-stick and sharps injuries.
  • Blades must be mounted and removed from the handle using a needle driver or specialized blade remover.
• Grip techniques
  • Pencil grip: for precise, small incisions (e.g., with a No. 15 blade)
  • Palmar grip: for larger incisions requiring more pressure (e.g., with a No. 10 blade)

Never use fingers to remove blades!

Anatomical principles: skin tension lines

• Surgical significance: Surgical incisions should be made parallel to skin tension lines whenever possible.
• Benefits
  • Reduced tension on the wound edges
  • Improved wound healing and minimal scarring
• Incisions made perpendicular to these lines are subject to greater tension and are more likely to result in widened, hypertrophic scars.

Scissors are used to cut through or blunt-dissect tissue and materials.

• Shape: Varying lengths and shapes (straight, curved, or angled) are used depending on the depth and position of the tissue.
• Blade tips
  • Blunt/blunt: for dissection in deep areas without adequate visualization
  • Sharp/blunt: a common general-purpose configuration
  • Probe-pointed (with button): to protect underlying tissue when opening lumen-containing organs (e.g., the common bile duct)
• Examples: Mayo-Lexer and Metzenbaum (dissecting) scissors
• Scissors handling: Surgical scissors are generally held with the thumb and ring finger in the rings, similar to a needle driver, to provide stability and control.

Forceps are used to grasp tissue or surgical materials.

• Shape: e.g., straight, angled, curved, or bayonet-shaped, chosen based on the location of the tissue
• Grasping surface
  • Anatomical (standard): features transverse serrations and a blunt tip; allows for a firm grip by compressing tissue without damaging the surface; often used in intestinal surgery and electrocautery
  • Surgical (toothed): features interlocking teeth at the tip; provides a very secure grip on robust tissues such as subcutaneous fat or fascia; can damage the tissue surface
  • Atraumatic: features specialized serrations (e.g., DeBakey serrations) to provide a gentle, noncrushing grip; essential for delicate structures in vascular and intestinal surgery
• Examples: Adson (toothed/surgical), Potts-Smith, and DeBakey (atraumatic) forceps
• Forceps handling: Tissue forceps should be held in the nondominant hand like a pencil (pencil grip).

Use toothed forceps on tough tissue (e.g., skin) to prevent slipping; they should be avoided on delicate tissues (e.g., bowel, vessels) to prevent trauma.

Clamps are used to grasp and hold tissue or material passively using a locking ratchet mechanism.

• Grasping surface
  • Anatomical: used for coarser tissues that could be injured by toothed clamps
  • Surgical: used for robust tissue or tissue intended for resection (e.g., fascia, subcutaneous fat)
  • Atraumatic: used for delicate tissues during vascular or intestinal procedures
• Rigidity
  • Hard clamps: firmly grip and may intentionally crush tissue (e.g., for clamping sutures or the peritoneum)
  • Soft clamps: secure tissue while minimizing damage (e.g., intestinal clamps are often used with textile covers, and vascular clamps preserve arterial wall layers)
• Examples: Pean (anatomical arterial clamp), Kocher (surgical/toothed arterial clamp), mosquito (smaller variant for fine work), and Mikulicz clamps

Retractors (and hooks) are used to pull back tissue, ensuring a clear view and access to the surgical field.

• Types
  • Sharp: used for tough tissues such as fascia or skin; should not be used near delicate structures
  • Blunt: used for retracting delicate structures (e.g., nerves, vessels) or deep tissues
• Examples: Kocher, Roux, Parker, and Desmarres lid retractors

When holding a retractor, always emphasize the tip to maximize exposure for the surgeon.

Overview

Electrosurgery and energy-based devices are used to cut tissue and achieve hemostasis through thermal coagulation. Common clinical applications include endoscopic hemostasis for gastrointestinal bleeding and loop electrosurgical excision procedures for cervical abnormalities.

Electrosurgical modes

The choice between monopolar and bipolar modes depends on the clinical context, safety requirements, and the proximity to vital structures.

Clinical safety notes

• Cautery pad
  • Essential for monopolar electrosurgery
  • Improper placement or a small surface area increases the risk of thermal burns at the pad site.
• Pacemakers
  • Monopolar current can interfere with cardiac conduction.
  • Bipolar or ultrasonic devices (e.g., harmonic scalpel) are preferred.

Avoid monopolar electrosurgery near end arteries and in patients with cardiac conduction devices.

Harmonic scalpel

• Harmonic scalpels use ultrasonic energy to achieve coagulation and cutting with minimal lateral heat production.
• Working principle: An oscillatory blade vibrates at high frequencies (20,000–50,000 Hz) to denature proteins.
• Advantages
  • Highly precise cutting and dissection
  • Effective at cutting through dense scar tissue
  • Can be safely used close to vital structures due to minimal thermal spread

Electrosurgery waveforms

The thermal effect on tissue is controlled by adjusting the voltage and continuity of the electrical current.

• Cutting mode: uses low voltage and a continuous waveform to vaporize tissue
• Coagulation mode: uses high voltage and an alternating (interrupted) waveform to create a thermal coagulum

Needle drivers are used to grasp and guide the needle during suturing. They feature a locking mechanism and often have cross-hatched serrations (carbide inserts) for a secure needle grip.

• Granularity
  • The cross-hatched serrations on the jaws are referred to as the "grain."
  • The coarseness of the grain must be matched to the size of the needle.
• Examples: Mayo-Hegar and Crile-Wood needle drivers
• Needle driver grip: The choice of grip depends on whether strength or precision is needed.
  • Thenar grip
    • The instrument is held in the palm of the hand.
    • The thumb is placed distal to one hole, with the middle, ring, and little fingers distal to the other.
    • Allows for greater power and is useful for suturing through tough tissues (e.g., fascia)
  • Thumb-ring finger grip
    • The thumb and ring finger are placed inside the rings of the instrument.
    • The index finger is extended along the shank for stability.
    • Provides maximum precision and control during delicate suturing

The choice of suture material depends on the tissue type, the required strength, and the clinical objective.

For a comprehensive guide on suturing techniques and detailed material properties, see "Wound closure techniques."

• Absorbable vs. nonabsorbable
  • Absorbable (e.g., Vicryl, Monocryl): for deep dermal, mucosal, or fascial layers where removal is not required
  • Nonabsorbable (e.g., nylon, Prolene): for percutaneous skin closure or vessel ligation
• Needle selection
  • Tapered needles: minimize trauma to delicate tissues (e.g., bowel)
  • Cutting needles: penetrate tough tissues (e.g., skin) with sharp edges

Classification of surgical staplers

Mechanical staplers are categorized based on their configuration and intended surgical use.

Stapling vs. suturing

The choice between mechanical stapling and hand-sewn suturing depends on the anatomical location, surgeon preference, and need for speed.

• Advantages of stapling
  • Efficiency: significantly faster than hand sewing
  • Accessibility: easier to use in narrow spaces (e.g., deep pelvis during an LAR)
  • Standardization: provides uniform tension across the entire closure
• Disadvantages of stapling
  • Hemostasis: may provide inferior hemostasis compared to deep, well-placed sutures
  • Cost: significantly higher per-unit cost than suture material
  • Technical limitations: not suitable for very thick, inflamed, or friable tissue

Surgical drains are used to remove air, blood, and other fluids from a wound or body cavity to promote healing and prevent complications such as hematoma or abscess formation.

Technical principle: the inside-out technique

Most active (suction) drainage systems use a sharp metal trocar (spike) for placement.

• Mechanism: The drainage tube is attached to the blunt end of the spike.
• Placement: The spike punctures the skin from the inside of the surgical wound to the outside.
• Advantages
  • Sterility: prevents the tube from dragging external skin flora into the deep surgical site, reducing infection risk
  • Precision: allows for a separate, tight "stab" incision away from the main surgical wound
  • Security: ensures the perforated (draining) portion of the tube is accurately positioned within the deep tissue

Active (closed-suction) drains

These drains use the inside-out technique with an integrated spike to establish a vacuum.

• Redon drain: a high-pressure system typically used in orthopedics (e.g., total joint replacement) or for large tissue flaps to prevent deep hematomas
• Jackson-Pratt (JP) drain: a lower-pressure system consisting of a perforated tube connected to a collapsible bulb reservoir
• Blake drain: similar to a JP drain but includes a fluted silicone tube instead of perforations, which may reduce the risk of tissue ingrowth and clogging

Passive drains

These drains rely on gravity or capillary action and do not typically use the inside-out spike technique.

• Penrose drain: a soft latex tube that allows fluid to drain onto a dressing; often placed directly through the main wound
• T-tube: a specialized drain used in the common bile duct to ensure bile flow during the maturation of a choledochotomy tract

Specialty drains and catheters

• Pigtail catheter
  • A small-bore drain with a curled tip to prevent migration
  • Used for percutaneous drainage of abscesses or effusions (e.g., pericardial or biliary)
• Chest tube
  • A large-bore, fenestrated tube used for draining the pleural space
  • Placement typically involves blunt dissection and a finger sweep rather than an inside-out spike.

While the general surgical tray provides the essential tools for opening, dissection, and closure, many procedures require specialized equipment to navigate complex anatomy or perform highly precise techniques. Surgical subspecialties often use unique sets of instruments that are tailored to their specific technical objectives.

Overview

Minimally invasive surgery refers to surgical techniques that use small incisions (or "keyholes") to minimize tissue trauma and postoperative pain and accelerate recovery. Laparoscopy is the primary minimally invasive surgical technique used for procedures within the abdominal and pelvic cavities. While traditional laparotomy (open surgery) requires large incisions for direct visualization and manual manipulation of organs, laparoscopy uses specialized, long-shafted instruments and a fiber-optic camera (laparoscope) introduced through small incisions made in the abdominal wall. Advanced iterations of this technique include single-incision laparoscopic surgery (SILS) and robotic surgery (e.g., the da Vinci system), which further refine the precision and cosmetic outcomes of the procedure.

Peritoneal access and insufflation

For a detailed overview of the technique, see "Technique/steps" in "Laparoscopic surgery."

Operating instruments and safety

Laparoscopic instruments are long, thin tools designed to pass through 5–12-mm cannulas.

• Insulated instruments
  • Most laparoscopic graspers and dissectors feature a black insulation coating along the shaft.
  • Safety warning: If this insulation breaks, capacitance coupling or direct current leakage can occur, causing unintended thermal injury to adjacent tissue (e.g., bowel).
  • Prevention: regular inspection of insulation and the use of plastic trocars to reduce coupling risk
• SILS port: a multichannel flexible port that allows the laparoscope and multiple operating instruments to be inserted through a single periumbilical incision to minimize scarring

Robotic surgery

• Robotic platforms provide a computer interface between the surgeon and the patient, addressing many technical limitations of traditional laparoscopy.
• Disadvantages
  • Significantly higher cost
  • Lack of haptic (tactile) feedback for the surgeon

Bone preparation and dissection

This category includes both power-driven and manual tools used to shape or cut the bone.

• Surgical power tools
  • Drills and saws: used for high-speed drilling (e.g., for screws) and precise osteotomies (bone cuts) using oscillating blades
  • Reamers: specialized drill bits for hollowing the medullary cavity before the insertion of intramedullary nails
• Manual tools
  • Periosteal elevator: a flat, broad-bladed tool used to strip the periosteum from the bone surface before fixation or osteotomy
  • Bone chisel: beveled on only one side of the tip; used for scraping or shaping the bone surface
  • Bone osteotome: beveled on both sides of the tip; designed specifically for cutting through bone (e.g., during a corrective osteotomy)
  • Bone gouge: features a curved, trough-like blade used to scoop out cancellous bone or marrow
  • Bone curette: a small, spoon-shaped instrument used for scraping out cavities or removing diseased tissue (e.g., in osteomyelitis)

Bone holding and stabilization

These instruments provide the necessary grip to stabilize fractures or plates during internal fixation.

• Bone plate holding forceps: features curved jaws with serrations to grip a bone plate against the bone surface
• Lane bone holding forceps: heavy-duty forceps with large, curved jaws and a ratchet to lock onto the shaft of a long bone
• Fergusson bone holding forceps: similar to Lane forcepts but often have a smaller, more focused grip for smaller bone fragments

Bone resection (cutting and nibbling)

These instruments are used to remove segments or fragments of bone, often using double-action hinges for mechanical advantage.

• Double-action bone cutter: features a compound hinge for cutting through small to medium bone shafts or fragments with minimal effort
• Double-action bone nibbler (rongeur): used to "nibble" away small pieces of bone in layers; essential for smoothing bone ends and creating space in narrow areas

Fixation hardware

• Kirschner wires (K-wires): sharp, thin stainless steel wires used for provisional fixation or to stabilize small bone fragments
• Redon spikes (drain trocars): specialized sharp needles used in orthopedic surgery to pull drainage tubes through the skin from the inside out to prevent deep hematoma formation

These tools are specialized for the female reproductive system and are designed to provide access, visualization, and traction with minimal tissue trauma.

Diagnostic and localization tools

These tools are used to assess internal anatomy before starting a primary surgical or diagnostic procedure.

• Uterine sound: a thin, flexible, calibrated rod used to measure the depth and determine the position of the uterus before procedures such as IUD insertion or dilation and curettage
• Bladder sound: similar to a uterine sound but without calibrations; used to localize the bladder during pelvic surgery to prevent unintentional injury

Exposure and grasping instruments

These tools are used to provide the necessary traction and visualization of the cervix and vaginal walls.

• Anterior vaginal wall retractor: a loop-shaped tool with a serrated surface; used to retract the anterior vaginal wall to improve visualization of the cervix
• Sponge-holding forceps (Foerster): preferred for grasping the cervix during pregnancy due to its blunt, looped surface, which reduces the risk of trauma compared with toothed cervical forceps

Comparison of grasping forceps

Obstetric delivery forceps

Obstetric delivery forceps are specialized metal instruments designed to apply traction to or rotate the fetal head to facilitate delivery. They should be used only by skilled clinicians and when specific criteria are met (e.g., full cervical dilation, engaged fetal head, and emptied maternal bladder).

Forceps should be used only by a skilled clinician and when specific criteria are met, including full cervical dilation, engagement of the fetal head, an emptied maternal bladder, and known fetal position and attitude.