The procedure performed on very small structures like the nerves and blood vessels using specialized instruments (under a microscope) is called microsurgery.
Microsurgery makes use of techniques that have been performed since the early twentieth century like organ transplantation and blood vessel repair.
Many surgical specialties use microsurgical techniques.
For instance:
- Otolaryngologists (ear, nose, and throat doctors) – performs microsurgery on the delicate and small structures of the vocal cords or the inner ear.
- Ophthalmologists (eye doctors) – performs microsurgery in corneal transplants and cataract removals and when treating eye conditions like glaucoma.
- Urologists and gynecologists – performs microsurgery to reverse vasectomies (male sterilization) and perform tubal ligations (female sterilization).
- Plastic surgeons – performs microsurgical techniques to reconstruct disfigured or damaged muscles, skin, and other tissues and transplant tissues from other parts of the body.
Equipment
Equipment used in microsurgical procedures magnify the operating field, provides precise instrumentation for easier maneuvering under high magnification, and makes it possible for the surgeons to be able operate on structures that are barely visible to the naked eye.
Microscope
While operating microscopes can vary, depending on their specific uses, they share similar standard features.
The microscope can be ceiling or floor mounted and it comes with a moveable arm to ensure easier manipulation.
A high-intensity light source and a set of lenses ensures a clear view of the surgical site.
Two (or more) sets of lenses makes it possible for the surgeon and an assistant not just to view the operating field but to also independently zoom in and focus.
The rest of the surgical team can view the operating site on a display screen.
Other features include motorized zoom and focus and mouth or foot switch controls.
A five to forty times magnification (5–40x) is usually required for microsurgical procedures.
A lower magnification is used when identifying and exposing structures while a higher magnification is needed when performing microsurgical repair.
Instruments
Microsurgical instruments have distinct differences compared to conventional instruments.
They are designed to make delicate manipulation of small structures possible and they come with handles large enough to hold securely and comfortably.
Some of the common instruments used in microsurgery include:
- Forceps
- Scissors
- Irrigators
- Vascular clamps
- Needle holders
- Vessel dilators
- Other standard surgical tools
Suture Materials
Stitching or suturing is done using specialized needles and thread.
The diameter (gauge) of the suture thread can vary in size depending on the tissue that needs suturing and the procedure that will be performed.
Suture threads can be absorbable (broken down in the body after a certain amount of time) or non-absorbable (retains its strength indefinitely).
It can also be natural (made of gut, linen, silk, and other natural materials) or synthetic (made of wire, polyester, nylon, and other man-made materials).
The type of suture thread that will be used will depend on the tissue that will be sutured and the procedure that will be performed.
Suture needles can come in various shapes (curved or straight) and sizes (length and diameter).
It also has different point types (blunt, cutting, or rounded).
Generally, needles that are 0.15 mm in diameter are used in microsurgery.
Techniques
Microsurgical procedures use a set of basic techniques that needs to be mastered by the surgeon.
These techniques include vein grafting, blood vessel repair, and nerve repair and grafting.
Blood Vessel Repair
Connecting two cut or separate blood vessels in order to form a continuous channel is called blood vessel repair or vascular anastomosis.
Anastomoses may be end-to-side (connecting one cut end to the wall of another vessel) or end-to-end (between two cut ends).
Vein Grafting
If the cut ends of a blood vessel cannot be attached without any tension, vein grafting is performed. It is an alternative procedure to end-to-end anastomosis.
Nonessential veins that are same in diameter to the recipient blood vessel can be taken from the foot, arm, or hand.
Nerve Repair
When two cut ends of the nerve are connected, the process is referred to as neurorrhaphy or nerve anastomosis.
Nerve repair may involve suturing of the perineurium only, epineurium only, or through both layers.
Nerve Grafting
If a large gap is present between the end of the nerves that are cut, neurorrhaphy cannot be performed without creating any tension in the nerve.
Any tension created can end up interfering with the patient’s postsurgical function.
A piece of the nerve (from another part of the body) may be utilized to create a nerve graft.
It is then stitched into place using anastomosis techniques.
Training
Before a surgeon performs microsurgery in a clinical setting, extensive practice and training will be required.
In addition, basic knowledge of surgical techniques and anatomy will also be needed.
After comprehensive introduction to microsurgical equipment and the operating microscope, basic techniques will be introduced.
Specifically, surgeons must also learn the following basic skills:
- How to maintain correct posture during the procedure
- How to maintain constant visual contact with the microscope
- How to properly hold the instruments
- How to minimize hand tremors
- How to perform basic techniques
Once proficiency in the abovementioned skills has been attained, more advanced techniques will be introduced including procedures when treating specific conditions.
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