Everything there is to know about trocar
Trocars are specially designed instruments utilized in various medical situations. They usually have a form of a pen equipped with a sharp, well defined triangular point at its end. It merely acts as a gateway for placing different instruments, such as staplers, graspers, and scissors, into the abdominal cavity. They also permit the outflow of gas or any liquids from organs inside the body.
There are three principal parts to a trocar:
- Cannula: it is a long shaft embedded into the patient to offer access to the peritoneal cavity.
- Seal: present at the highest point of the cannula and guarantees that no air escapes from the peritoneal cavity while permitting any essential instrument to go through.
- Obturator: this is the system that allows the cannula to puncture into the abdominal cavity primarily.
- Insufflation tap: often, an insufflation tap is additionally incorporated
They are most frequently useful during laparoscopic surgery, a modern medical procedure that permits a very minimal incision while investigating the internal body parts. It is also helpful to manage patients with hydrothorax or ascites and during the preserving procedures to expel gas and liquids from the body.
Types of trocars
The two basic types, depending on the frequency of usage, are reusable and disposable trocars.
Reusable trocars can become disassembled for cleaning and are commonly made up of metal. They mainly contain designed reduction tubes and converters.
Disposable trocars are usually made of plastic and are discarded after first use.
Trocars have gradually developed from one or two fundamental designs to a wide range depending on the needs. They may contain a cutting tip, bladeless tip, a shield, or carry a small camera for guided passage into the body.
Here, some of the many types mostly used:
- Optical trocars permit a straight view of internal body organs with maximum safety.
- Balloon fixation trocars allow improved painless cannula entry, avoiding its shift in lengthy medical procedures. It also helps to prevent obtrusion hence maximizing visibility and easing the process.
- Bladeless trocars explicitly made to separate the body tissue instead of cutting them.
- Hasson trocars ensure safety while placing primary port with the open technique. It also provides the facility of no extra damage to tissue.
- Shielded blades or cutting trocars are provided with a sharp cut blade with the blind placing. The sharp cut blade ensures minimal tissue damage while penetrating.
Aulus Cornelius Celsus described the usage of instruments resembling trocar in his medical encyclopedia De Medicina (6th vol.) in c.30AD. Albucasis, the Arab physician, explained a similar device in his medical encyclopedia, the Kitab al-Tasrif. Until the 1700s, there was no documentation of the term "trocar." Most probably, the name is a derivative of the French word trochart, i.e., trois, which means "three" and carré, which means "edge."
Its use was as a source of extracting liquids and gases from the body. By the mid 18th century, urologists started using trocars to lead surgical scopes into the bladder. In 1901, George Keller, a German doctor, and advocate of minimally invasive surgery, became attributed as the first validated laparoscopic procedure to check the abdominal organs of dogs. In 1920, Benjamin Henry, a radiologist, explained a pyramidal trocar tip in his paper that is still used by medical professionals.
In the 1950s, Heinz Kalk, a German gastroenterologist, developed a dual trocar method and frequently used it while working, which others later followed. Kalk performed a crucial role in polishing the trocars utilized in different procedures and making them secure and effective. He built the foundation of present-day laparoscopy. Still, innovation is being added to the use and working of trocars and making surgical procedures safer for people.
Indications to its use:
The standard procedures performed using a trocar are:
Hydrothorax or ascites
They are widely used in the medical field to invade and drain fluid accumulation, such as patients with hydrothorax or ascites.
Their most frequent use is in laparoscopic surgery, which is a modern development to ease surgical procedures. It is useful as a channel for exchanging any kind of medical equipment needed at that time, including a camera, scissors, or laparoscope with an incision made through the body wall.
General surgery, gynecological surgery, and urological surgery are other possible surgical procedures that can utilize them.
They are also used during the embalming process. The process follows the replacement of cadaver blood with the embalming chemical. The classic type trocar is useful for tearing the outer skin into three parts, which is later quickly sewed.
For drainage of fluids
They are extensively utilized in veterinary medicine to invade and drain the accumulation of fluid in hydrothorax or ascites.
For laparoscopic surgery
It is also used extensively in veterinary laparoscopic surgeries.
For acute animal-specific conditions
In ruminal tympany, a wide diameter trocar passes through the skin and into the rumen to let the captured gases escape. In dogs, the trocar passes through the skin and relaxes the stomach.
The complications that arise mostly occur because of poor surgical techniques or any accidents that may arise during its usage. Complications can be immediate or delayed in response, and they can be life-threatening if treated improperly.
Immediate complications include vascular injury, bowel injury, visceral injury, subcutaneous emphysema, and air embolus.
Bladder or vascular injury
With the trocar inserted blindly, it can be a cause of bladder or vascular injury. It can occur with primary as well as a secondary trocar. Vessels of retroperitoneum, intraperitoneal, or abdominal wall can be injured. During the initial insertion, the rate of vascular injury is 0.05% and 0.5%.
Bowel and visceral injuries
The incidence rate of bowel injury is 0.04% to 0.5%, typically when viscera is in close approximation to the point of insertion. It also occurs when the depth of its insertion is too much.
This occurs near to its insertion site. Sometimes, it is life-threatening when it reaches the head and neck area and causes swelling. It mostly occurs due to the improper functioning of the insufflation port.
This is a large air mass that can cause cardiovascular complications.
Delayed complications include site infection, tumor implantation, endometriosis implantation, and incisional hernia (can be displayed anytime in post-operative time). Its incidence rate is 21/100,000, specifically at the trocar site.
- Advanced, highly resistant and durable
- Leak-proof characteristic valves
- Ergonomically designed ensuring comfortable handling
- Minimal friction between the valve seal and the instrument
- Stainless steel, rubber, ABS plastic, or titanium material
- Reusable or single-use depending on the requirement
- Can accommodate all laparoscopic devices
- Sleeves with diameters 3mm to 30mm in range
- Cannula sleeve approx.1 mm larger than the instruments through which it is to be introduced.
- Transparent, non-reflective plastic sleeve with optical trocars
How does it work?
As already discussed, a trocar is essentially a surgical instrument passed into the body wall, permitting the placement of different surgical equipment during a medical procedure, such as laparoscopy. When initially inserted, it is known as a primary trocar, and subsequent insertion of all others is known as a secondary trocar. It comes with a leakage-proof valve at its highest-end to permit equipment transfer during surgery without allowing the insufflated carbon dioxide to escape. The cannula remains fixated in its place to exchange equipment like a laparoscope and to keep it insufflated. The cutting system made of metal or plastic edge passes through the tissue with a cut. While the dilating system, as the name indicates, isolates, and dilates the tissue as embedded. A new form is a hybrid one that incorporates all aspects like dilating and cutting.
The optical system has a principle mid-channel to accommodate the laparoscope, which is put close to the edge and fixated for the invasion. Its insertion helps to view subcutaneous fat, fascia, preperitoneal fat, and, lastly, the peritoneum. Following a safe fixation is the insertion of secondary trocars under observation. The numbers, sizes, and positions of the trocars depend on the medical procedure.
Trocars with different designs are available in the market. In this section, we've tried to come up with the top-rated trocar manufacturing companies.
Medtronic plc started in 1949 and is serving in more than 150 countries.
Medtronic plc is involved in the preparation of medical technology equipment to ease and prolong other's life. It is among the top-rated companies providing promising products to its buyers.
Applied Medical Resource Corporation is a medical apparatus manufacturing company providing innovative technology in a range of surgical and minimally invasive instruments.
Other leading brands include:
Braun Melsungen AG, Genicon Inc., XION GmbH, LaproSurge Ltd, Péters Surgical, Teleflex Incorporated, Conmed Corporation, Ethicon Inc.
Trocars provide a way to carry out procedures safely that can be life-threatening if performed openly. It provides an assemblage of benefits like reduced scarring, minimal post-operative bedtime, and reduced immediate or delayed complications. Its usage will be safe if its users adhere strictly to its standard insertion principals, perform procedures based on experience and extensive anatomical knowledge. Surgeons must choose the technique with which they are more comfortable. With modern evolving technology, it is definite that their usage will become smoother and more effortless with time.