A novel dissector device that separates anatomic structures during laparoscopic surgery

Introduction

During laparoscopic surgery, it can be useful to have a tool, an endoscopic dissector, that helps visualize, separate, and clean anatomical structures without causing damage to tissues and organs from thermal injury, tearing, bleeding, or visceral perforation (Fig. 1). An endoscopic dissector can be useful in various surgical procedures, such as cholecystectomy^1,2, any fundoplication technique³, esophagocardiomyotomy⁴, colectomy⁵, appendectomy⁶, adhesiolysis, hysterectomy⁷, adrenalectomy⁸, etc. It is possible to improvise an endoscopic dissector with a small gauze ball held by a laparoscopic clamp attached to a long safety suture. Our group has used commercially available laparoscopic dissectors with sponge tips, manufactured by Ethicon and Fabco, and reported low efficiency in dissection; being white, they get saturated with blood, losing pixels on the monitor, and lack an ergonomic handle to facilitate their use (Fig. 2). There are laparoscopic dissectors patented in the United States of America, such as the Laparoscopic Surgical Gauze (USA Patent No. 5,817,121) and the Christoudias Endodissector (USA Patent No. 6,391,040), which are sophisticated instruments, complicated to assemble, sterilizable, and expensive (Fig. 3).

Figure 1. DisePad endoscopic dissector in laparoscopic cholecystectomy. A: dissection of the cystic duct. B: critical view of dissection with the DisePad.

Figure 2. Available and patented laparoscopic dissectors.

Figure 3. Patented, sophisticated, and high-cost instruments.

This article describes a new endoscopic dissector, the DisePad, designed and developed in the experimental surgery service of the Centro Médico Nacional 20 de Noviembre. The device was presented on September 23, 2014 to Instituto Mexicano de la Propiedad Industrial, and after analysis and a national and international search, it was determined to be a surgical innovation, granting it Utility Model Registration No. 3512 dated July 13, 2016, signed by the Divisional Director of Patents (Fig. 4).

Figure 4. Registration certificate No. 3512, signed by the Divisional Director of Patents, Mexico.

The disadvantages of current laparoscopic dissectors are:

The advantages of the DisePad laparoscopic dissector are:

Our group has used the DisePad in 246 patients undergoing various laparoscopic surgery procedures and observed the assistance and safety it offers during dissection. We are developing a comparative study in the laparoscopic cholecystectomy procedure with and without the device, assessing the time to achieve a “critical view” with the cystic duct and artery perfectly dissected and visible before placing the clip on each anatomical structure. With evidence from comparative videos, the results will be the subject of a future publication.

Method

The laparoscopic dissector comes in 2 versions. Version #1 uses a solid aluminum rod with a 4.5 mm diameter and a 35 cm length. One end is reduced to a 3 mm diameter and a 2 cm length. The other end has an ergonomic handle made of polylactic acid (PLA), a biodegradable material, measuring 7 cm along the horizontal axis and 10 cm along the oblique axis. On the reduced end of the aluminum rod, a black cotton-polyester fabric treated with a patented gel that retains high temperature for greater efficiency in tissue dissection is placed. To secure and retain the fabric on the aluminum rod, a black heat-shrink tube (Thermofit) made of olefinic-polyethylene polymer is used, resulting in a dissector tip 1 cm in length and 5 mm in diameter (Fig. 5). Version #2 consists only of the black cotton-polyester fabric tip treated with the same patented gel that retains high temperature and, also, includes the double black Thermofit adhesive tape. The advantage is that it can be placed on any laparoscopic clamp and discarded after the surgical procedure without affecting the tool (Fig. 6). To fix the dissector tip on the clamp, the scrub nurse should immerse the tip in the same thermos with hot saline solution used to defog the laparoscopic lens whenever the surgeon requests the instrument. (See on YouTube: DisePad – Dissector tip placement in reusable dissector forceps). There are 2 calibers available: one for a 10 mm trocar and another for a 5 mm trocar.

Figure 5. To secure and retain the fabric on the aluminum rod, a black heat-shrink tube (made of olefinic-polyethylene polymer) is used, resulting in a dissector tip 1 cm in length and 5 mm in diameter.

Figure 6. Version #2 is only the black cotton-polyester fabric tip treated with the same patented gel that retains high temperature, with the double black adhesive tape, and has the advantage that it can be placed on any laparoscopic clamp and discarded after the surgical procedure without affecting the instrument.

Results

From the first prototype used on September 23, 2008, in a laparoscopic cholecystectomy until now, our group has successfully used the DisePad in 246 laparoscopic cholecystectomies, 114 laparoscopic fundoplications, and 4 laparoscopic colectomies. (See on YouTube: Laparoscopic cholecystectomy with DisePad, Laparoscopic Nissen fundoplication with DisePad, Laparoscopic sigmoidectomy with DisePad, and Laparoscopic Right Colectomy with DisePad.)

Discussion

The device, when heated in a saline solution to 70°C, dissects and separates tissues more easily and with less trauma, achieving better visualization of structures such as blood vessels, ducts, or intra-abdominal organs. The dissector tip, being black, prevents the red color of blood from causing pixel loss on the monitor, as happens with white gauze impregnated with blood. It features an ergonomic PLA handle that allows easy manipulation through the trocar and easy dissection movement while being firmly attached to the aluminum rod. It is easy to manufacture, economical, disposable, and can also be used as a surgical traction instrument. Version #2 is only the dissector tip placed on a laparoscopic clamp, having all the previous advantages but with a greater environmental care concept by not having to discard the rod and handle.

Conclusions

This device, designed and patented by the experimental surgery service of the Centro Médico Nacional 20 de Noviembre, meets the objective of dissecting and separating tissues more easily and with less trauma, achieving better visualization of structures such as blood vessels, ducts, and intra-abdominal organs. Version #1, which has an ergonomic handle, facilitates manipulation when entering through the trocar and performing firm dissection movements within the abdominal cavity. Version #2 has the same efficiency in dissection but adds the advantage that, being just a dissector tip adaptable to a reusable laparoscopic clamp, it simplifies its use, is more economical, and protects the environment by not having to discard the aluminum rod and PLA handle of version #1. It is a safe and easy-to-use device, and we believe it can achieve better visualization and dissection of structures. We are developing a comparative study in laparoscopic cholecystectomy with and without the device, assessing the time to achieve the “critical view” with the cystic duct and cystic artery perfectly dissected before clipping. With evidence from comparative videos, the results will be the subject of another publication.

Funding

None declared.

Conflicts of interest

None declared.

Ethical disclosures

Protection of human and animal subjects. The authors declare that the procedures followed were in accordance with the regulations of the relevant clinical research ethics committee and with those of the Code of Ethics of the World Medical Association (Declaration of Helsinki).

Confidentiality of data. The authors declare that no patient data appear in this article.

Right to privacy and informed consent. The authors declare that no patient data appear in this article.