Laparoscopy: Underused yet definitive diagnostic tool

Laparoscopy: Underused yet definitive diagnostic tool

A complete and thorough work-up is required before considering minimally invasive techniques
Sep 01, 2006

An oval-cup biopsy forceps taking a biopsy from the right lateral liver lobe.
The laparoscope was developed as a diagnostic tool in the early 20th Century with the first experimental laparoscopy being performed in a dog in 1901. It wasn't until the 1930s that the laparoscope began being used as a diagnostic tool in human medicine. It took another 50 years before the laparoscope was used to perform surgeries such as appendectomies and cholecystectomies.

The first documented laparoscopic cholecystectomy in humans was reported in 1985 and within five years became the standard of care. Today, clientele are more educated and aware of the benefits of minimally invasive surgery and are requesting it for their pets. It is incumbent upon the practicing veterinarian to keep up with these technological advances so that they may be offered to their patients.

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Veterinary medicine has always lagged behind human medicine, and utilization of the laparoscope is no exception. With all the advanced diagnostic tools available to the practicing veterinarian today, laparoscopy is probably the most underutilized. The advantages of laparoscopy are that it is minimally invasive, yet highly accurate, and can provide definitive diagnostic and staging information. By virtue of its small surgical incisions, there is less physiologic stress to the patient, less pain and a quicker recovery. It is generally accepted that laparoscopic biopsies are superior when compared with tissue samples obtained via other percutaneous methods (i.e. ultrasound-guided needle biopsies). Because the organs are directly visualized and magnified by the laparoscope, smaller lesions (<0.5 cm) that may be missed with other imaging modalities may be detected and biopsied. This type of information can be of vital importance when staging neoplastic diseases and formulating treatment plans. Laparoscopy also carries a very low complication rate (<2 percent). The disadvantages of laparoscopy include the lack of tactile feedback, limited field of vision and inability to completely explore the entire abdomen. In many cases, it does not replace the need for a conventional laparotomy. In addition, laparoscopy requires new surgical skills, formal training and a substantial investment in specialized surgical equipment.

The most common indications for diagnostic laparoscopy is to visually inspect and biopsy abdominal organs or masses. This allows for accurate staging of neoplastic processes so that appropriate treatment plans can be implemented. The liver, pancreas, spleen, lymph nodes, adrenal glands, kidneys and abdominal masses are all amenable to laparoscopic biopsy.

Intestinal biopsies are possible with laparoscopic assistance but require that the intestinal loop be exteriorized through a small incision and standard incisional biopsies are then taken. The laparoscope can be used also to perform diagnostic procedures such as splenoportography, cholecentesis for bile culture and cholecystography.

Examples of laparoscopic instrumentation: A) Veress insufflation needle used to establish pneumoperitoneum. B) Trocar. C) Cannula with insufflation port and one-way valve.
The relatively few contraindications to laparoscopy are septic peritonitis, diaphragmatic hernia and cases where conventional laparotomy is indicated. If there is a tear in the diaphragm, the creation of a pneumoperitoneum results in life-threatening tension pneumothorax. Limitations for laparoscopy include small patient size (<2 kg), very obese patients and abdominal effusions.

Procedural considerations

Excessive falciform fat or abdominal effusions can interfere with accurate visualization. In patients with abdominal effusions, as much fluid as possible should be withdrawn before insufflating the abdomen.

The basic instrumentation required for diagnostic laparoscopy includes a 5 mm, 0-degree field-of-view telescope, 2 cannula/trocar units, Veress insufflation needle, xenon light source and cable, insufflator, CO2 source and various instrumentation. A videocamera/monitor is ideal and is now considered standard when purchasing new equipment.

When purchasing equipment, it is important to consider compatibility with other instruments, ability to expand with other scoping procedures, warranties and technical support.