New Hope for Animals Needing Surgery

More than 20 million people have chosen minimally invasive surgery (MIS) over conventional surgery because it allows them to feel better faster and involves less pain and scarring. MIS is now being performed in animal patients at the Veterinary Teaching Hospital of the Purdue University School of Veterinary Medicine.

How Minimally Invasive Procedures Help Patients

Veterinarians employ the same technology used in human surgery to perform minimally invasive procedures on animals such as abdominal exploratory, biopsy, ovariohysterectomy (spay), removal of bladder stones, and gastropexy (sewing the stomach to the body wall to prevent twisting of the stomach). These procedures involve inserting two or three access ports (called “trocars”) through half-inch incisions in the abdomen. The abdomen is filled with carbon dioxide to create a working space between the internal organs and the surface of the skin. Then a laparoscope (camera) is placed through one of the access ports so that the surgical team can watch the procedure on a video monitor. The image on the monitor is magnified, which provides better visibility for the operating room staff. Biopsy forceps and other devices are placed through the other access ports to perform the operation. In some cases, a smaller scope is then inserted into a hollow organ, such as the bladder, to retrieve bladder stones.

Another and perhaps better known minimally invasive technique is arthroscopy, which is a used to examine the joints. This procedure involves inserting a small needle into the joint to inject fluid and create an underwater working space. Additional access ports are made to insert a scope and camera and instruments to examine and treat the joint disease. Controlled studies have demonstrated that animals experience less postoperative pain and less stress when undergoing MIS rather than conventional surgery.

The following images show some of the procedures that can be performed using MIS.

Laparoscopic Ovariohysterectomy

An excellent view of abdominal structures is obtained during laparoscopic surgery.Here, a “Harmonic Scalpel” is used to prevent bleeding and cut tissues to remove the ovaries and uterus.

Laparoscopic-assisted Gastropexy

To perform a gastropexy, the stomach is grasped and pulled to the body wall and sutured there. The adhesion between the stomach and the body wall prevents the stomach from rotating when it becomes dilated. This procedure is effective in preventing Bloat (Gastric Dilatation Volvulous).

Laparoscopic-assisted Bladder Surgery

During laparoscopic assisted bladder surgery, a cystoscope is inserted into the bladder. These images show a view of bladder stones being grasped by forceps and retrieved from the bladder.

This is a view of a mass inside the bladder seen with a cystoscope inserted into the bladder during laparoscopic-assisted surgery.

Current Research Studies

Research in Minimally Invasive surgery

Research In Progress

Clinical Research in Minimally Invasive Surgery

Laparoscopy

• OHE

• Gastropexy

• Exploratory

• Liver Biopsy

Thoracoscopy

Arthroscopy

Minimally Invasive Brain Biopsy – Targeted Radiation Therapy

MIBB-TRT

Technique appears to be feasible

May have application to other disease states

Study is on-going

*Funded by SVM

Natural Orifice Translumenal Endoscopic Surgery

Surgery Meets Gastroenterology. Take NOTES!!

Faculty members at Purdue University and Indiana University are undertaking a study of alternative surgical procedures that could lead to changes in the way surgery is performed in people. Dr. Lynetta Freeman, Associate Professor of Small Animal Surgery at the School of Veterinary Medicine, and Dr. Emad Rahmani, a gastroenterologist and Associate Professor of Clinical Medicine at IU School of Medicine were recently awarded a grant from NOSCARTM (Natural Orifice Surgery Consortium for Assessment and ResearchTM) to investigate the feasibility of performing surgery via a flexible endoscope in dogs. The NOSCAR group is a cooperative group founded by surgeons and gastroenterologists and their respective organizations, SAGES (The Society of American Gastrointestinal and Endoscopic Surgeons) and ASGE (American Society for Gastrointestinal Endoscopy) to study this next evolutionary step in how surgery is performed.

The new surgical approach is termed NOTES (Natural Orifice Translumenal Endoscopic Surgery). NOTES was first described as peritoneoscopy by Kalloo, et al. in 1994.2 He and his co-investigators used a flexible endoscope to create an opening in the gastric wall which allowed the endoscope to be introduced into the abdominal cavity. Much like laparoscopy, the abdomen was insufflated with air through the endoscope to create a working space. By manipulating the endoscope the authors were able to perform minor surgical procedures such as full abdominal exploratory and liver biopsy in swine. Since then others have performed other experimental techniques in porcine models, using the stomach, colon, bladder and vagina as portals, including tubal ligation, enteric anastomosis, lymphadenectomy, cholecystectomy, and splenectomy. Immediate clinical applications have been explored, applying the potential for NOTES approach in ICU patients. Investigators have reported inserting a pacemaker on the diaphragm, performing an exploratory to discover potential sources for sepsis, and repositioning of a dislodged PEG tube. Though the technique is still considered experimental, the first report of a cholecystectomy being performed via a transvaginal approach in a woman was described in the September issue of Archives of Surgery. It is anticipated that other ‘firsts’ will be published this year.

NOTES is considered experimental because there are a number of unanswered questions and remaining challenges related to performing surgery in this manner. The stomach, colon, bladder and vagina are considered contaminated environments. The best method of achieving “surgical prep” must be determined. In addition a flexible endoscope instills room air into the abdominal cavity without pressure regulation, whereas standard laparoscopic procedures utilize automatic insufflators to deliver pre-set pressures of carbon dioxide. Another difficulty is that the image obtained with the flexible endoscope may project on the monitor as upside down and backwards, depending on the scope orientation, so navigation is much more difficult than with laparoscopy which uses rigid telescopes. Another critical difference from laparoscopy is that with the NOTES procedures, all of the instrumentation is delivered down the 2.8 and 3.5 mm working channels of the endoscope; as a result the orientation of the instruments is coaxial to the camera, which prohibits triangulation, the foundation of port placement for laparoscopic procedures. In addition, current instruments are limited to very small biopsy forceps, scissors, snares, guide wires, and needle knife devices that are currently used in endoscopic procedures. None of these instruments are as robust as laparoscopic instrumentation. Finally, there is no evidence that currently supports that the NOTES procedure is less invasive – that is, that it causes less tissue trauma or less immunologic impairment to an individual undergoing this procedure, as compared to laparoscopic or open surgery.

The Purdue University/ Indiana University collaboration is a cross functional team of physician surgeons, gastroenterologists, and veterinary surgeons who are interested in evaluating the safety, feasibility, and the practicality of these new techniques. By performing ovariectomy via a flexible endoscope passed into the abdominal cavity through the stomach, Dr. Freeman and Dr. Rahmani have established a NOTES model. The team is researching the intra-operative complications, postoperative pain, and surgical stress of the NOTES approach and comparing it to traditional and laparoscopic procedures.

While many patients are attracted to the idea of surgery without scars, considerable evidence must be obtained to show that these techniques are not only safe, but truly better. And who knows, perhaps they may be better for animals also?

A flexible endoscope is used to perform surgical procedures through the gastric wall. In this step, a guide wire is inserted percutaneously to assist in identifying the site for the gastric incision.

Like laparoscopy, the camera in the endoscope provides visualization and the procedure is viewed on a video monitor.

The ovarian tissue is examined to ensure complete excision.

References:

Rattner, DW, Hawes R. What is NOSCAR? Surg Endosc 2007:21:1045-1046.

Kalloo AN, Singh VK, Jagannath SB, et al. Flexible transgastric peritoneoscopy: a novel approach to diagnostic and therapeutic interventions in the peritoneal cavity. Gastrointest Endosc 2004;60:114-117.

Jagannath SB, Kantesevoy SV, Vaughn CA, et al. Peroral transgastric endoscopic ligation of fallopian tubes with long-term survival in a porcine model. Gastrointest Endosc 2005:61:449-453.

Kantsevoy SV, Jagannath SB, Niiyama H, et al. Endoscopic gastrojejunostomy with survival in a porcine model. Gastrointest Endosc 2005:62:287-292.

Fritscher-Ravens A, Mosse CA, Ikeda K, Swain P. Endoscopic transgastric lymphadenectomy by using EUS for selection and guidance. Gastrointest Endosc 2006:63:307-312.

Pai RD, Fong DG, Bundga ME, et al. Transcolonic endoscopic cyolecystectomy : a NOTES survival study in a porcine model [with video]. Gastrointest Endosc 2006:64:428-434.

Rolanda C, Lima E, Pego JM, et al. Third-generation cholecystectomy by natural orifices: transgastric and transvesical combined approach [with video]. Gastrointest Endosc 2007:65:111-117.

Kantsevoy SV, Hu B, Jagannath SB, et al. Transgastric endoscopic splenectomy: is it possible? Surg Endosc 2006:20-522-525.

Onders R, McGee MF, Marks J, et al. Diaphragm pacing with natural orifice transluminal endoscopic surgery: potential for difficult-to-wean intensive care unit patients. Surg Endosc 2007:21:475-479.

Onders RP, McGee MF, Marks J, et al. Natural orifice transluminal endoscopic surgery (NOTES) as a diagnostic tool in the intensive care unit. Surg Endosc 2007:21:681-683.

Marks JM, Ponsky JL, Pearl JP, McGee MF. PEG “Rescue”: a practical NOTES technique. Surg Endosc 2007:21:816-819.

Marescaux J, Dallemagne B, Perretta S, et al. Surgery without scars: report of transluminal cholecystectomy in a human being. Arch Surg 2007:142:823-826.

VIRTUAL REALITY TRAINING IN VETERINARY SURGERY

Our project goal is to develop virtual reality simulation that can be used to develop technical skills for basic surgical procedures without the use of live animals. We believe that virtual reality environments will allow for more accurate assessment of veterinary student and operative team performance in surgical settings than methods used today.

We will capture digital pressure measurements using pressure sensors engaged on the surgeon’s hands underneath sterile surgical gloves during the targeted tasks. Through collaboration by veterinary surgeons and members of the department of electrical and computer engineering the pressure measurements can then be integrated with the created graphics to create the haptic portion of the virtual simulation.

We envision a computer workstation that allows students to use Wi sticks and 3D goggles to interact with streaming video models to practice their surgical skills. The students will use the computer to click on an instrument and then use the instrument to interact with the video environment to handle tissue and perform simple tasks such as incising, suturing, and knot tying. Once these techniques are simulated sufficiently for the student to learn, the tasks will be sequenced to simulate a surgical procedure. In the future, students will be evaluated by objective criteria such as elapsed time, force measurements, errors in technique, and ability to accomplish the assigned task.