Lift Laparoscopy for Liver Biopsy in Dogs

The major objective of this project is to describe the use of a novel, 3D-printed abdominal wall lift construct for laparoscopic liver biopsy in dogs, which is a common cranial abdominal procedure used to further classify clinical liver disease in canine patients. We will use a construct that has been created and tested by our team in an ex-vivo study: the findings of this study reveal a maximum device tensile load that is over twice that of the load needed for ideal visualization of the cranial abdomen. We will track patient intraoperative
and postoperative complications and the rate of surgical conversion to assess efficacy of lift laparoscopic liver biopsy in dogs using our device. We hypothesize that our construct will be successful at providing appropriate cranial abdominal visualization and access for laparoscopic liver biopsy in dogs.

Enrollment Status: Currently Enrolling

Inclusion/Exclusion Criteria:  There are no specific breed, weight, age, or sex restrictions for dogs included. Prior to being enrolled in our study, each dog will undergo a complete physical
examination and must have a complete blood count and chemistry panel performed. All dogs must undergo preoperative transabdominal ultrasonography to assess the liver and localize lesions/abnormalities prior to enrollment into our study: fine needle aspirates of abnormal areas under ultrasound guidance may be performed with owner consent and at clinician discretion for diagnostic purposes prior to study enrollment. The lift laparoscopic biopsy procedure is the only part of the study that is experimental – all other procedures described above are considered part of a normal clinical work-up for dogs with clinical liver disease.

Treatment: All dogs will be anesthetized based on an individualized protocol determined by a board-certified anesthesiologist. The patient will be placed in dorsal recumbency. The abdomen will be clipped and prepped and aseptically prepared with chlorhexidine scrub and alcohol. Sterile drapes will be placed to create a sterile surgical field. Surgical instrumentation will be either steam autoclaved or gas sterilized depending on the specific heat tolerance of the item in question. Surgeons and all assistants will undergo preparation with a five-minute chlorhexidine hand and arm scrub followed by aseptic gowning and gloving.

A 2-5 cm incision will be made just cranial to the umbilicus. The gray ring of the Covidien SurgiSleeve wound retractor (size extra small (2-4 cm), small (2.5-5 cm) or medium (5-9 cm)) will be placed within the incision. The appropriate size (extra small, small or medium) of the 3D-printed custom-made abdominal wall lifting construct will be secured beneath the blue ring of the Covidien SurgiSleeve wound retractor, and the body wall will be lifted to 15% of the patient’s body weight (recorded in kilograms on the hanging scale). The laparoscope will be inserted into the body wall incision through the retractor along with laparoscopic biopsy forceps. A thorough exploration of the abdominal cavity will be performed. The liver appearance and size will be recorded. Biopsy samples of multiple lobes will be taken. Hemostasis will be achieved using a combination of pressure and electrocautery. Closure will include intradermal or cutaneous sutures. The procedure may be converted to an open laparotomy if visualization is poor or complications arise.

Following recovery from anesthesia, each dog will be monitored in the recovery wards at the University of Florida Small Animal Hospital for a minimum of 24 hours.

Cost: The study will provide a $100 stipend towards the cost of the initial workup. The client will be responsible for the costs of diagnostics (bloodwork/imaging), anesthesia, surgical procedures, and any required medications and hospitalization exceeding $100. The stipend will be awarded only after surgery is performed. The current estimate for laparoscopic liver biopsy and anesthesia is $2,500- $3,500 not including initial workup: this estimate may increase each year and should be confirmed with the UF Small Animal Soft Tissue Surgery department at the time of study enrollment.
There are no additional expected expenses for participating in this study. The costs of all other procedures that may be performed at the time of surgery, are NOT covered by the
research study. Clients will be responsible for all clinic costs. An estimate of costs for which clients will be responsible will be prepared for the client at the time of admission.

PI: Dr. J Brad Case

J. Misha Lubanski

Contact: Email caseb@ufl.edu

jm.harrison@ufl.edu

Background: Minimally Invasive Surgery (“MIS”) is the standard of care in human medicine for most nonemergent procedures: it involves significantly smaller incisions compared to
conventional (“open”) techniques, resulting in significant decreases in complication rates, postoperative pain, and patient hospitalization time. The same perioperative benefits have been recognized in dogs and cats as in humans. MIS for abdominal procedures is called “laparoscopy” and is typically facilitated by insufflating the abdomen, which consists of adding pressurized gas (typically carbon dioxide) to displace the abdominal wall from the underlying internal organs. This displacement creates space for the surgeon to see and manipulate instruments during surgery. Despite the many benefits of laparoscopic surgery, abdominal insufflation has been associated with potentially serious complications in dogs. The most concerning complications are seen in dogs undergoing diaphragm repair surgeries: prior research shows that nearly half of dogs with diaphragmatic compromise undergoing insufflated
laparoscopy for surgical correction of diaphragmatic hernias experience major, life-threatening complications leading to cardiac arrest and sometimes death. Other less
serious complications of insufflation have also been reported including but not limited to port site metastasis, increased intracranial pressure, and peritoneal acidosis. Furthermore, traditional insufflated laparoscopy is ineffective at removing large amounts of tissue and maneuvering instruments through small incisions.

MIS benefits without the complications and risks of insufflation can be achieved with lift laparoscopy (LL). LL relies on suspension of the body wall via an abdominal wall lift (AWL) device rather than intraabdominal gas insufflation to provide visualization and surgical access. LL has been performed in humans since the 1980’s and provides similar surgical visualization and surgical safety statistically similar to those of insufflated laparoscopic procedures in humans without significantly increased operative times. LL in humans utilizes commercially available AWL devices: these are not readily available to veterinarians. Rather, custom-made AWL devices have been created for use in veterinary patients: other veterinary studies have shown that LL is safe and effective in caudal abdominal surgeries but veterinary LL cranial abdominal procedures have not been performed.

Liver cancer is common in dogs and can include primary tumors (starting in the liver) or metastatic tumors (spread from another location in the body). Dogs can also be affected by noncancerous liver diseases that may be inflammatory or metabolic in origin. The best way to assess this disease and determine an appropriate treatment plan is by biopsy, which is more sensitive and specific than sampling the liver under sedation by fine needle aspiration. The current investigators have recently evaluated the feasibility of performing lift laparoscopy using a new construct in canine cadavers and shown it to provide adequate visualization of the cranial abdomen in dogs up to 44 kg. Biomechanical testing of the apparatus suggests that its use will be effective in dogs up to 114 kg (about 251.33 lb). Obtaining laparoscopic liver biopsies via LL with our device will show that this method is feasible in dogs and may allow for minimally invasive biopsy—or other cranial abdominal procedures— to be performed by veterinarians who do not have access to equipment for abdominal insufflation.