If you have had a medical procedure performed using minimally invasive techniques, you are well aware of the benefits: less time under anesthesia, less pain, less time in the hospital, and quicker recovery. The same benefits accrue to animals, and since endoscopy was first used for pets in the 1970s, veterinarians have developed new avenues and approaches for minimally invasive surgery and diagnostics. Among the procedures that are available to dogs, cats, and other animals are exploratory thoracoscopy; partial or complete lung lobectomy; pleural biopsies; elbow, shoulder, and stifle arthroscopy; spay/neuter surgeries; bladder stone removal; gallbladder resections; and gastropexy surgery to prevent gastric dilatation volvulus. Collapsing trachea, intrahepatic shunt, ectopic ureters, and urinary incontinence are other examples of conditions that can be treated with minimally invasive procedures. “Minimally invasive procedures have provided treatments for some diseases that did not have good treatments or with less morbidity and mortality for others,” said Andrew Hanzlicek, DVM, DACVIM, associate professor and Kirkpatrick Chair in Small Animal Internal Medicine at Oklahoma State University in Stillwater. Why it’s better, faster Minimally invasive techniques have advanced rapidly since they first began to be used. “The use of thoracoscopy has enabled better visualization for treatment of pyothorax and for treatment of certain vascular disorders,” said Kevin Winkler, DVM, DACVS, who practices at Blue Pearl Specialty and Emergency Hospital in Sandy Springs, Ga. “We actually see a higher success rate in some cases because we have better magnification, better lighting at the actual surgery site. It’s allowed us to send patients home with a shorter hospitalization period by using micro or small approaches compared to the standard thoracotomy.” For instance, a window for a pericardial effusion can be a relatively short procedure using two or three very small incisions to remove part of the pericardium. A scope-assisted gastropexy for a great Dane calls for only a 2-inch incision instead of opening the dog up completely on the belly with a 12-inch incision. In both cases, the recovery period is dramatically decreased, allowing the animal to return to normal much more quickly and decreasing the risk associated with a large incision. One type of surgery that Dr. Winkler says he is now beginning to see requests for is that of laparoscopic ovariectomy. “From a science basis, there is still some discussion over what is the appropriate procedure—an ovariohysterectomy or an ovariectomy—but both can be done with laparoscopy,” he said. “There are certainly some benefits either way. It presents options for the owner.” There are minimally invasive alternatives for orthopedic surgical procedures as well. As scoping procedures developed, orthopedic surgeons began to look at the techniques to work with fractures and try to minimize the soft tissue damage caused by surgery. Now, certain types of fractures and dislocations can be repaired through a much smaller incision, leading to improved healing in significantly traumatized dogs. “Not only do we have a smaller incision from a wound standpoint, but we’re also disrupting a significantly less amount of tissue that may be traumatized from the original injury,” Dr. Winkler said. “The less disruption of tissue like that, the faster we get a chance to heal and in fact the better odds we have of the bone healing. One of the areas where we have had wonderful success with minimally invasive surgery is in sacroiliac dislocations or luxations. Traditionally with a big, open procedure it disrupted a lot of muscle. Now, with minimally invasive surgical techniques, we’re able to work with reducing the sacroiliac luxations and repairing them through typically a 1-centimeter incision with fluoroscopic guidance. We now have patients who are walking on these legs in 24 to 48 hours versus two weeks, so it’s been a wonderful advancement for the dogs.” At Colorado State University College of Veterinary Medicine and Biomedical Sciences, where he is a professor in the department of clinical sciences, David Twedt, DVM, DACVIM, performs a number of minimally invasive diagnostic procedures such as gastrointestinal endoscopy; diagnostic laparoscopy such as liver and kidney biopsies; cystoscopy; and respiratory endoscopy. Recently, a dog with a urinary tract infection came in for an ultrasound to evaluate the urinary bladder. Incidentally, it was discovered that the dog had a gallbladder mucocele, which can have serious consequences if left untreated. “The owner elected to have us remove it laparoscopically, and the dog went home the next day,” Dr. Twedt said. Risks not necessarily negated As with any surgery, not every dog, cat, or other animal is necessarily a good candidate for a minimally invasive procedure. “Being a good or poor candidate for minimally invasive surgery really is not that different from being a good candidate or bad candidate for surgery in general,” Winkler said. “Just because the procedure is minimally invasive does not automatically mean it’s going to be less risky from an anesthetic point of view. You have to look at the patient as a whole and make a decision on what is the risk of anesthesia to this patient no matter what the procedure is. After that, certain conditions lend themselves better to minimally invasive surgical procedures than others, and you have to evaluate the entire risk and benefits of minimally invasive versus traditional procedures.” Continuing education Interest in minimally invasive techniques has increased significantly in the past decade, both from veterinarians and from owners, said Twedt, who teaches such techniques. Veterinary surgeons who wish to become board certified must have experience in performing minimally invasive procedures. A recent two-day course on introduction to laparoscopy drew 18 veterinarians—the maximum number of attendees—from the United States, Canada, and Mexico. Oftentimes pet owners ask if a procedure can be done that way because they or a family member or friend have experienced the benefits. “This is a big area of development, and more and more vets are learning these procedures,” he said. “It is something that is becoming more a part of doing quality patient care.” Among the growing fields of interest are interventional radiology and interventional endoscopy, Dr. Hanzlicek said. He, too, sees more veterinarians offering minimally invasive procedures to their clients. The methods are not necessarily taught during a veterinary school education, although senior students at CSU have an option to perform a laparoscopic spay during their spay/neuter rotation. A number of universities offer weekend training courses for both soft tissue and orthopedic procedures, and CSU has plans to open a minimally invasive endoscopy training center next year, headed by Twedt. “Much like any other major new procedure, successfully completing a weekend course does not make us an expert in that particular procedure,” Winkler said. “We encourage learning with an experienced surgeon through multiple cases before you jump in and try it on your own.” When it comes to training, the important thing to remember is that the procedures are only less invasive if they are done properly, Hanzlicek said. “When not done properly, complications are more likely, and the benefits of the less invasive procedure are potentially lost,” he said. More and more practices are interested in incorporating these techniques, Twedt said, noting that they not only improve quality of care and recovery for patients, they can also be a practice builder. Big investment, bright future Just because a procedure is minimally invasive doesn’t mean it’s minimally expensive for owners—or for veterinarians who want to add the techniques to their repertoire. Use of minimally invasive procedures calls for a significant investment in equipment. Indeed, procedures may require fluoroscopy, endoscopy, computed tomography, and ultrasonography. Depending on the amount and quality of equipment desired or required and whether new or used equipment is purchased, the cost of a complete setup can range from thousands of dollars to $100,000, Winkler said. Practitioners who aren’t yet ready to make that financial or educational leap can build a relationship with a nearby specialty clinic or university. For a specific case, call the referral group and discuss with them the problems and needs of the owner and see if they can accommodate them, said Winkler. If not, they can often make a recommendation about where the procedure could be performed. For surgical or arthroscopic procedures, the American College of Veterinary Surgeons can be a resource, as is the American College of Veterinary Internal Medicine for diagnostic procedures. “Every year there are new procedures and new techniques for doing different minimally invasive things,” Twedt said. “There has also been development of equipment as specifically for veterinary medicine.” Advances in procedures are sometimes spurred by availability of equipment on the human side of surgery. New procedures on the human and veterinary side frequently cross from one field to the other. “We see equipment available on the human side and we look to see if there are uses for it on the veterinary side,” Dr. Winkler said. Veterinary surgeons may also approach instrument manufacturers with their needs. If they are looking for an instrument to perform a certain procedure, they may ask if there’s something like what they want on the human side. If not, the request may drive development of a new piece of equipment. “Minimally invasive surgery is a rapidly evolving field,” Dr. Winkler said. “The range of techniques shows no limit at this point.”
