There are a number of minimally invasive surgical (MIS) procedures that are currently performed using laparoscopy. Many of these procedures require multiple trocar/cannula portals, specific minimally invasive surgical instruments, loop ligatures, clip applicators and monopolar electrosurgery. The techniques described below are the "tip of the iceberg" in as far as the potential for MIS in veterinary medicine. They can be performed in a small animal practice.
Small intestinal biopsies can be obtained using laparoscopy simply by exteriorizing a piece of intestine through the abdominal wall and then collecting the sample externally as would be done with a standard surgical biopsy. A 5-mm atraumatic grasping forceps with multiple teeth is used to grasp the intestine at the site to be biopsied. It may be necessary to "run" the bowel with two grasping forceps to select a location to biopsy. The antimesenteric boarder is firmly grasped with the forceps. The intestine is then pulled to the cannula. A 3-4 cm loop of intestine is exteriorized. A small full thickness biopsy is then obtained in the same manner as one would use when performing an open abdominal surgical technique. The intestine is then returned to the abdominal cavity. If too much intestine is exteriorized it is difficult to return it to the abdominal cavity through a small incision.
Intestinal feeding tube placement
Duodenostomy or jejunostomy feeding tubes can be placed using the laparoscope simply by exteriorizing a respective piece of intestine through the abdominal wall and inserting the tube externally. Once the location of the bowel for tube placement is determined the antimesenteric boarder is firmly grasped with the forceps. The intestine is then pulled close to the cannula in which the intestine will be exteriorized. A 3-4 cm loop of intestine is exteriorized and four stay sutures (4-0 monofilament absorbable) are placed in the intestine to prevent the intestine from falling back into the abdominal cavity. A purse-string suture is placed on the antimesenteric border of the intestine. A number 11 blade is used to puncture the intestine in the middle of the purse-string suture and the jejunostomy feeding tube (5 French for cats and 8 French for dogs) is introduced in the loop of bowel in the aboral direction. The purse string suture is closed and the intestine is returned to the abdominal cavity except for the segment containing the feeding tube. The stay sutures are then used to pexy the intestine to the abdominal wall using 4.0 monofilament absorbable sutures. The abdominal wall is then closed with simple continuous suture pattern. Subcutaneous tissue and skin are closed in a routine fashion. The feeding tube exits through the incision.
Intestinal foreign body
Single, non-linear foreign body in the jejunum or ileum can be removed under laparoscopy. Dogs or cats with signs of peritonitis are not good candidates for this procedure. The surgical technique is the same as for a jejunostomy tube placement. The loop of intestine with the foreign body is exteriorized and an enterotomy or an enterectomy is performed outside of the abdominal cavity. The loop of intestine is then returned into the abdominal cavity at the end of the procedure.
A preventive gastropexy can be performed using the laparoscope simply by exteriorizing the pyloric antrum region of the stomach through the right abdominal wall. The animal is placed in dorsal recumbency and the telescope portal is placed on the midline at the level of the umbilicus. A 5-mm atraumatic grasping forceps with multiple teeth is used to grasp the pyloric antrum mid-distance between the lesser and the greater curvature. The pyloric antrum is exteriorized after extension of the cannula site situated behind the last rib on the right side. An incisional gastropexy is then performed.
Ovariohysterectomy or ovariectomy can be performed using laparoscopy in most all medium and large size dogs. The space in the abdominal cavity of small dogs and cats make the procedure technically difficult. The advantage of this technique is the perceived rapid patient recovery following the procedure and the improve visualization of the ureters and the pedicle for hemostasis.
The procedure is performed on dorsal recumbency and tilting the dog on the right and the left side to expose the ovaries.
Two cannulas are enough to perform an ovariectomy or an ovariohysterectomy. The ovariohysterectomy is laparoscopically assisted then. The cannula for the endoscope is placed caudal to the umbilicus.
For an ovariohysterectomy the second cannulas is placed caudal in the abdomen. The ovaries are suspended with a transcutaneous suture on the abdominal wall. Each ovarian pedicle is ligated with either suture, or hemostasis control with electrocautery. After ligation of both ovarian pedicles, the uterus is exteriorized in the caudal abdomen through the caudal cannula. The cervix is ligated outside the abdominal cavity like during a regular ovariohysterectomy. The cervix is then returned to the abdomen.
For an ovariectomy the second cannula is placed cranial to the umbilicus. The ovarian pedicles are ligated as described above. Another ligature will be placed on each uterine horn before transecting the ovaries from the uterus. Electrocautery can be used to transect the uterus at the level of the proper ligament. Both ovaries will be removed through one cannula site.
The enlarged cannula sites are sutured with a simple continuous suture pattern with 2-0 monofilament absorbable suture material. Subcutaneous tissue and skin are closed in a routine fashion. The other cannula site requires only subcutaneous and skin sutures.
A testicle that is located in the abdominal cavity can be removed easily with laparoscopy. Laparoscopic vasectomy can also be performed through this technique. The dog is placed in dorsal recumbency. The monitor is placed at the end of the table as described for ovariohysterectomy surgery. The procedure is performed with two cannulas. One is placed cranial to the umbilicus while the other is caudal to the umbilicus.
The ectopic testicle is usually readily visible upon entering the abdominal cavity. The ectopic testicle of one side rarely ever crosses the midline but stays lateral to the bladder on the effected side. The testicle is grabbed with a fine tooth grasper and a transcutaneous suture is placed through the abdominal wall to stabilize the ectopic testicle. The vascular pedicle and the vas deference are ligated with a pre-tied suture, clips, or electrocautery. The ectopic testicle is removed through one the cannula holes that generally must be enlarged. The enlarged cannula site is sutured with a simple continuous suture pattern with 2-0 monofilament absorbable suture material. Subcutaneous tissue and skin are closed in a routine fashion. The other cannula sites require only subcutaneous and skin sutures.
Laparoscopic cystoscopy is an alternate method that allows placement of a laparoscopic telescope into the urinary bladder that has been exteriorized through the abdominal wall for examination, biopsy and calculi removal. The technique involves a standard laparoscopic entry with the telescope placement on the abdominal midline cranial to the umbilicus. Once the urinary bladder is visualized a second trocar cannula is placed directly over the urinary bladder at the location of exteriorization. Using atraumatic forceps with multiple teeth the bladder is grasp and pulled into the trocar cannula as described in intestinal biopsy section. Once the apex of the bladder is exteriorized stay sutures are placed from the bladder wall. The bladder is temporally pexied to the abdominal wall. A small incision is made in the bladder wall, the bladder is then flushed with sterile saline and the telescope is introduced into the bladder. Forceps can be placed in the lumen along the telescope to obtain a biopsy or remove calculi. At the conclusion of the procedure the bladder is closed in a standard manner and placed back into the abdomen. The cannula ports are then closed. The pexy is released and the abdominal wall closed in a routine fashion.
Laparoscopy is a minimally invasive technique for diagnostic and surgical procedures. Once the basic technique of laparoscopy is mastered and the appropriate indications are applied to the procedures it becomes a simple and rewarding addition to small animal veterinary medicine and surgery. As our ability advances newer diagnostic and therapeutic procedures will no doubt be developed.