Minimally Invasive Surgery: Surgery with Less Pain
Robert J. McCarthy, DVM, MS, DACVS
“I learned a long time ago that minor surgery is when they do the operation on someone else, not you”
-Bill Walton of the Boston Celtics
History and Rationale
Although still in its infancy in veterinary medicine, minimally invasive surgery (MIS) has been performed in humans since the early 1800’s, when Bozzini described examination of the bladder and rectum with an instrument referred to as a “lichtleiter”. . While initially used sparingly, and only as a diagnostic tool, operative MIS gained explosive popularity after description of the first laparoscopic cholecystectomy in 1985. It is estimated that a staggering 600,000 laparoscopic cholecystectomies are now performed annually in the United States alone! MIS has now been investigated as an option to replace almost every imaginable open surgical procedure in humans.
Colleagues have argued to me that if you add up the length of all the stab wounds for a MIS procedure, they could do the same intervention through an open approach. The lack of understanding is that it is not the total length of the incision that causes the trauma, but rather the extent of the manipulations required to accomplish the surgical task. The aim of MIS is not just to work through small holes, but also to minimize the amount of dissection and handling needed to perform a procedure. An example of this situation is laparoscopic ovariohysterectomy, which has been documented in several studies to cause significantly less pain compared to median celiotomy and ligation. Although the total length of the required stab incisions for MIS may be substantial, less pain occurs because the suspensory ligament and associated ovarian pedicle can be easily ligated without stretching (FIGURE 2, below)
Set Up and Equipment
Minimally invasive surgery (MIS) involves operating through short (1cm) incisions using specially designed instruments (FIGURE 3, above). The operative cavity is visualized through a video camera attached to the end of an optical telescope, and the camera projects the image onto a television monitor via fiberoptic light. Both the telescope and surgical instruments are placed with the use of specially designed trocar assemblies. In the case of MIS of the abdomen (laparoscopic surgery) the abdominal cavity is kept distended by insufflation with CO2.
Common Minimally Invasive Surgical Procedures Performed at Tufts
Common forms of minimally invasive surgery being used frequently at the Tufts Foster Hospital include laparoscopy, thoracoscopy, and arthroscopy.
Elective sterilization of female dogs by ovariectomy is probably the most useful and frequently performed laparoscopic procedure. Removal of just the ovaries while leaving the uterus in situ is easier and recommended. Postoperative development of pyometra is not a worry, as pyometra is a progesterone-mediated disease only possible in a patient with intact ovaries. Laparoscopic sterilization has a particular advantage in large, obese and/or multiparous dogs in which the traditional open technique can be difficult and time consuming. Compared to sterilization by laparotomy, patients recover quicker, require less pain medication, and can return to activity earlier. Incisional problems are exceptionally rare (FIGURE 4, VIDEO 1)
Additional laparoscopic procedures being performed frequently at Tufts include liver biopsy and elective gastropexy.. Multiple studies have demonstrated the superiority of large liver biopsies obtained by laparoscopy compared to fine needle aspirates or core biopsies obtained with ultrasound guidance. Laparoscopic gastropexy provides an excellent method to prevent future gastric dilatation and volvulus and can easily be combined with ovariectomy in large female dogs. Other procedures easily amenable to lapararoscopic technique include cryptorchidectomy, bladder stone removal, intestinal biopsy, and intra-abdominal foreign body removal (FIGURE 5).
Thoracoscopy is an excellent method of performing intrathoracic procedures without the significant pain and morbidity of a lateral thoracotomy or median sternotomy. Patients requiring lung biopsy, ligation of the thoracic duct for chylothorax, or pericardectomy are excellent candidates for minimally invasive surgical technique. Animals that would have required several days’ hospitalization in the past are now discharged after a single night of observation.
Arthroscopic technique is being utilized with increased frequency for essentially every joint and condition in both human and veterinary surgery. Arthroscopy has become such a vital aspect to human medicine that in its 40th anniversary issue, Sports Illustrated named Dr. Robert Jackson, a pioneer of arthroscopic technique, as one of the 40 people who have “most significantly altered or elevated the world of sports in the last four decades”. Other members of this group included such notables as Wayne Gretzky, Muhammad Ali and Michael Jordan. At present, more than 1.5 million arthroscopic procedures are performed in humans globally every year.
Arthroscopy is utilized most frequently at the Foster Hospital to treat a variety of conditions of the elbow, shoulder, stifle. Removal of fragmented coronoid process in dogs with canine elbow dysplasia, curettage of shoulder osteochondritis dissecans (OCD) lesions, and evaluation and treatment of shoulder soft tissue injuries are all performed routinely with minimally invasive technique.
Debridement of the cranial cruciate ligament (CCL) and examination and treatment of medial meniscal injuries in dogs with injury to the CCL are also frequently managed in this manner.
While still in its infancy in veterinary medicine, minimally invasive surgery is a major advance in the cause of gentle, less painful surgery. Minimally invasive techniques are now considered standard of care in humans, and can be offered with increasing frequency for a great number of veterinary conditions as well. The advantages in animals are the same as they are in humans. In the words of Hippocrates, “first do no harm”.