Soft Tissue and Orthopedic Surgery

Below, please find links to all of the clinical trials involving soft tissue or orthopedic surgery. The studies include a multitude of information, including (but not limited to) the study’s purpose, benefits for participating, and financial incentive information. If you have any questions, please contact the individual outlined at the end of each trial summary.

Please visit the Surgery service webpage at the Veterinary Medical Teaching Hospital (VMTH) if you would like to learn more about the amazing things that our surgeons can do for you and your animal.

Cats

NEW! Variety of Tumors: Assessing Minimally Invasive Tumor Ablation

Title: Thermal ablation of cancer in dogs and cats

Purpose of Study: The purpose of this study is to evaluate the outcome of treating veterinary patients with minimally invasive tumor ablation technologies including cryoablation and microwave ablation. These methods are growing in the treatment of a variety of cancers in the human medical field, but information in veterinary patients is currently very limited. To date we have completed a study on cryoablation in nasal tumor patients, and this technique has been very successful in reducing tumor volume in nasal tumor patients – although there are no more spots in the formal nasal tumor study, because of this success, we continue to offer this technique as a clinical service to nasal cancer patients, and are expanding the types of cancer that we are evaluating.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey. The coordinators will likely advise you to send your pet's medical records and imaging results for Dr. Steffey's review. If, based on this information, your pet is deemed an appropriate candidate, an appointment will be scheduled.

Participation Requirements: In order to participate in this study, your pet must have **solitary** malignant soft tissue or bony mass **that is deemed amenable to ablation**. Tumor types that MAY be amenable to this treatment include lung tumors, kidney tumors, adrenal tumors, and bone tumors in certain locations. however determination of eligibility is complex and relates to the size of the lesion as well as proximity to/involvement of other important nearby structures. Tumors that are superficial (involving or near to the skin) or that involve the gastrointestinal tract are not amenable to this treatment.

Initial Evaluation for Participation: Evaluation by the V.M.T.H. Small Animal Surgery, Internal Medicine, or Oncology services.

Procedures: If you agree to participate, under general anesthesia, ablation probes will be placed into your pet’s mass under ultrasound guidance and the tumor will be ablated.

Benefits: This treatment method may only be palliative, but it is our hope that in appropriately selected patients, we may improve quality of life as well as longevity.

Owner Responsibilities: The study will cover the cost of the ablation probes and generator. Costs of pre-operative workup, general anesthesia, recommended imaging, hospitalization, and general management of the disease process or any complications that occur during treatment are your responsibility.

NEW! Variety of Tumors and Diseases: Improving Operative Detection of Tumors

Title: Fluorescent imaging of cancer

Purpose of Study: Near-infrared fluorescent imaging utilizes special wavelengths of light to identify important structures, and is used in surgery to improve surgical decision making. The fluorescent light is generated by a special contrast agent (a “fluorophore”) that is injected into the patient. When a special light source is used to illuminate the surgical site, any tissue in which this fluorophore is located will glow, aiding the surgeon in identifying the location or extent of disease. Based on early experiments in rodents and human clinical trials, this very sensitive tool has the potential to improve surgical decision-making and improve overall treatment for a wide variety of diseases. The purpose of this study is to evaluate the efficacy of this imaging modality in veterinary patients presenting with naturally occurring neuroendocrine tumors disease processes.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey.

Participation Requirements: Dogs with the following conditions are most likely to benefit from this study: hyperparathyroidism, thyroid cancer, pancreatic cancer, adrenal cancer, thymoma, mammary (breast) cancer, lung cancer, anal sac gland cancer, oral cancer, mast cell tumor. Dogs with severe kidney or liver disease are not eligible to participate.

Initial Evaluation for Participation: Evaluation by the V.M.T.H. Small Animal Surgery, Internal Medicine, or Oncology services.

Procedures: If you agree to participate, the best fluorophore for your pet’s tumor will be administered or intravenously, at a dose and timing considered to be optimal by your attending veterinarian.

Benefits: It is hoped, but is not known if there will be a specific benefit to your individual pet. Fluorescent imaging may or may not improve operative localization and dissection of your pet’s tumor.

Owner Responsibilities: Costs of standard pre-operative workup, general anesthesia, recommended imaging, hospitalization, and general management of your pet’s disease process or any complications that occur during treatment are your responsibility. The cost of the fluorophore and special imaging is covered by the study. There are no risks associated with the imaging itself, as it only involves light; there is no radiation exposure to the patient. The fluorophores used in this study are FDA-approved for use in humans and have been used without complication in our hospital for the past 18 months. The primary risk of this procedure is associated with injection of these drugs is an allergic reaction, which is very rare, but unpredictable in an individual patient (like any other drug reaction, including antibiotics). If an allergic reaction should occur, immediate costs of treatment (immediate supportive medications, support of blood pressure) will be covered by the study; however, the owner will be responsible for any treatment costs for prolonged or severe complications.

Dogs

Bloat (Gastric Dilation and Volvulus): Investigating a Preventative Surgical Technique

Title: A Radiologic Percutaneous Gastropexy Technique in Dogs

Purpose of Study: Commonly referred to as "bloat", gastric dilation and volvulus (GDV) is a life-threatening syndrome that occurs when a dog’s stomach becomes distended with air and/or food and rotates. The rotation of the stomach restricts outflow of stomach contents and more importantly causes a reduction in the blood flow to the stomach wall causing death of the tissues. This disease is considered universally fatal if left untreated. Additionally, if the stomach wall is devitalized from lack of blood flow, significant post-operative care may be necessary making this surgery cost prohibitive for many owners and resulting in humane euthanasia. Performing a gastropexy has been shown to virtually eliminate the possibility of a subsequent torsion. Therefore, the goal of this study is to the evaluate if a minimally invasive gastropexy (using a T-fastener) is a viable method of performing gastropexies in dogs predisposed to developing GDV.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dog breeds that are predisposed to gastric dilation and volvulus (GDV)

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: Your dog will undergo non-invasive ultrasound evaluations before the procedure as well as 2 days and then 2 months after the procedure. During the procedure, your dog will be anesthetized and a T-fastener gastropexy will be performed utilizing radiography/fluoroscopy (real time “x-rays”).

Benefits: All costs associated with the study will be paid by the sponsor/department with the exception of the anesthesia (average of $300-500) and any complications that may occur as part of that procedure. For more information about possible costs, please contact the investigator.

We cannot promise any benefits to your dog or other animals from your taking part in this clinical trial; however, direct benefits of enrolling in this study include financial support for the ultrasound and procedure. We hope that the data acquired in this study will allow us to advance the treatment of our canine patients.

Owner Responsibilities: You are responsible for cost of anesthesia (average of $300-500) and any complications that may occur as part of that procedure. Dogs enrolled in this study will need an ultrasound performed before the procedure as well as 2 days post-procedure and 2 months post-procedure. If you allow your dog to participate in this study, you will need to bring your dog in for an ultrasonographic evaluation 2 days post-procedure and 2 months post-procedure.

Printable Flyer (PDF/PDF)

Hiatal Hernia / Brachycephalic Obstructor Syndrome: Assessing a Surgical Treatment

Title: Effect of Surgical Treatment of Brachycephalic Obstructor Syndrome on the Lower Esophageal Area of Brachycephalic Dogs with Evidence of Hiatal Herniation and Gastroesophageal Reflux

Purpose of Study: We believe that brachycephalic dogs have a tendency to develop hiatal herniation (HH) with greater frequency than non-brachycephalic dogs. Dogs with relative obstruction of the upper airways may generate a decreased pressure in their chest during inspiration (breathing in) that results in the upper part of the stomach being sucked into the chest (HH). This can lead to clinical signs including regurgitation, esophageal stricture formation and aspiration pneumonia if severe. We hypothesize that, if the upper airway obstruction in these dogs can be alleviated, improvement in their respiratory compromise might be seen as well as a reduction in the severity of their HH.

Contact:

  • Please call (530) 752-1393 to make an appointment with Soft Tissue Surgery or Internal Medicine for Dr. Phil Mayhew's study
  • Email Dr. Phil Mayhew directly at philmayhew@gmail.com

Participation Requirements:

  • Brachycephalic breed (dogs with broad short skulls)
  • No evidence of other upper airway obstructive pathology (especially tracheal collapse and hypoplastic trachea)
  • No previous brachycephalic surgery
  • Evidence of hiatal herniation on fluoroscopic imaging (performed pre-operatively)

Initial Evaluation for Participation: Initial evaluation and discussion for entry into the study can be arranged by making an appointment with our Internal Medicine or Soft Tissue Surgery or by contacting Dr. Phil Mayhew directly (contact information below).

Procedures: Both visits outlined below require hospitalization for 2-4 days at the VMTH.

  • First visit:
    • Day 1: You will be asked to fill out a questionnaire about your dog’s clinical signs. We will give your dog a local anesthetic, place a small catheter down your dogs nose, and give your dog a small amount of water to swallow, so we can trace the pressure profile of your dog’s esophagus (known as high-resolution manometry or HRM study). We will then perform a barium esophagram, which involves imaging of your dog using a fluoroscope (moving x-ray machine) after he/she swallows water and food boluses. Finally, we will place a small pH-monitoring probe in you dog’s nose that will remain in place for no longer than 24-hours for continuous monitoring of the esophageal pH and will be removed prior to surgery the following day.
    • Day 2: Your dog will be prepared for surgery and given general anesthesia. Prior to surgery, we will take measurements of your dog’s lower esophageal area (impedance planimetry or Endoflip), which involves inflation of a very low-pressure balloon within the lower esophagus, and perform an upper gastrointestinal endoscopic study immediately before upper airway surgery.
  • 30 – 60 days post-surgery visit: You will need to bring your dog in for another visit between 30 and 60 days after surgery. During this visit, we need to repeat the questionnaire and the procedures outlined above to gauge the response to surgery.

Benefits: The trial will pay for all of the diagnostic tests associated with the study, including costs associated with the HRM and esophagram studies, Endoflip measurements, pH impedance studies, endosocopic studies, biopsy procedures, pathology fees as well as the hospitalization and anesthesia fees associated with the second visit to the hospital at 30-60 days post-operatively. The owner will have to cover the surgical procedure, hospitalization and any possible complications associated with the surgical procedure and recovery during the first visit.

We cannot promise any benefits to your dog or other animals from your taking part in this clinical trial; however, possible benefits include a better understanding of your dogs presence or absence of hiatal herniation which may aid in longer-term management of this component of his or her clinical signs. Results from this study may influence treatment of other dogs with similar conditions going forward.

Owner Responsibilities: If you allow your dog to participate in this study, you will be responsible for bringing the dog to the VMTH for the study-related visits for the duration of the time stipulated and for providing the clinical information stipulated.

UPDATED! Imaging: Sentinel Lymph Node Mapping

Title: Identification of sentinel lymph nodes with intraoperative fluorescence

Purpose of Study: Near-infrared fluorescent imaging utilizes special wavelengths of light to identify important structures, and is used in surgery to improve surgical decision making. The fluorescent light is generated by a special contrast agent (a “fluorophore”) that is injected into the patient. When a special light source is used to illuminate the surgical site, any tissue in which this fluorophore is located will glow, aiding the surgeon in identifying the location or extent of disease. Based on early experiments in rodents and human clinical trials, this very sensitive tool has the potential to improve surgical decision-making and improve overall treatment for a wide variety of diseases. The purpose of this study is to evaluate the efficacy of this imaging modality in veterinary patients presenting with natural disease processes.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Gigi, Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey.

Participation Requirements: Dogs scheduled for surgery to treat their primary tumor, and for whom clients are interested in improving their pet’s staging information by lymph node biopsy. Dogs most likely to benefit from this technique include those with primary lung tumors, mast cell tumors, oral cancers, and carcinomas in general, as these are types of tumors that tend to exhibit spread by the lymphatic system. Tumors may be external (skin associated) or internal. Dogs with severe kidney or liver disease are not eligible to participate.

Initial Evaluation for Participation: Evaluation by Dr. Michele Steffey on the Soft Tissue Surgery Service.

Procedures: The best fluorophore for your pet’s tumor will be administered either subcutaneously or intravenously, at a dose and timing considered to be optimal by your attending veterinarian.

Benefits: Preliminary, not yet published results have demonstrated that the fluorescent imaging is very helpful in locating the important lymph nodes at surgery, which often reduces the amount of dissection needed, and may reduce the amount of time under anesthesia. The purpose of this study is to aid in identifying lymph nodes for improved staging (lymph node biopsy) at the time your pet’s primary tumor is removed. It is hoped, but is not known, if there will be a specific benefit to your individual pet. Depending upon your pet’s specific tumor type and the biopsy results, use of this technique and lymph node biopsy may or may not impact the postoperative treatment recommendations provided to your dog.

Owner Responsibilities: The cost of the fluorophore and special imaging is covered by the study. There are no risks associated with the imaging itself, as it only involves light; there is no radiation exposure to the patient. The fluorophores used in this study are FDA-approved for use in humans and have been used without complication in our hospital for the past 18 months. The primary risk of this procedure is associated with injection of these drugs is an allergic reaction, which is very rare, but unpredictable in an individual patient (like any other drug reaction, including antibiotics). If an allergic reaction should occur, immediate costs of treatment (immediate supportive medications, support of blood pressure) will be covered by the study; however, the owner will be responsible for any treatment costs for prolonged or severe complications.

Intrahepatic Portosystemic Shunts: Assessing a New Treatment Technique

Title: Assessment of Outcome in Dogs Undergoing Percutaneous Transvenous Coil Embolization to Treat Intrahepatic Portosystemic Shunts

Purpose of Study: The purposes of this project are to:

  1. Evaluate serum bile acid concentrations and hepatic biochemical functional parameters (BUN, albumin, cholesterol, glucose, and bilirubin) in dogs with intrahepatic portosystemic shunts both pre- and post-treatment to objectively evaluate each patient for improvement in hepatic function.
  2. Assess the improvement in the clinical signs of dogs with IHPSS after the performance of PTCE.
  3. To perform imaging studies pre- and post-PTCE that provide objective assessment of outcome associated with the PTCE procedure.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dogs with intrahepatic portosystemic shunts

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: Dogs with a diagnosis of intrahepatic portosystemic shunts (IHPSS) will be enrolled in the study. The dog will undergo percutanous transvenous coil embolization (PTCE) to treat his/her IHPSS. Prior to and after this procedure, diagnostics including bloodwork, nuclear scintigraphy, abdominal ultrasound and computed tomography (CT) scan will be performed and compared.

Benefits: Enrolling a dog in this study results in a significant financial incentive towards diagnostics that would be recommended for the dog whether or not he/she is enrolled in the study. This benefit includes payment of the preoperative CT scan and the postoperative bloodwork (1 chemistry panel at 3 months postoperative), ultrasound (1 at 3 months postoperative), nuclear scintigraphy scan (1 at 3 months postoperative) and CT scan (1 at 3 months postoperative).

Owner Responsibilities: Return the patient 3 months after treatment for further assessment.

UPDATED! Large Bowel Disease: Evaluating New Diagnostic Tool

Title: Evaluation of CT pneumocolonography as a diagnostic tool for large bowel disease in dogs

Purpose of Study: The purpose of this study is to evaluate the impact of imaging findings on surgical decision-making in dogs with colonic and rectal disease of any kind (cancer or non-cancer). This part of the body can be a very difficult region examine with current imaging methods, which also do not provide optimal spatial information important if a surgical procedure is needed. In early studies, we have demonstrated the safety and efficacy of the CT pneumocolonography procedure in normal dogs, but it is important that we learn to accurately interpret the imaging findings for a wide variety of disease processes in clinical patients so that our CT diagnoses are accurate. Our goal is to compare the imaging findings obtained with CT pneumocolonography with the current standard of care of colonoscopy and colonoscopic biopsies.

Contact: Call 530-752-1393 to schedule an appointment with the Internal Medicine Service. When scheduling, please indicate your interest in the CT pneumocolonography study with Dr. Steffey/Dr Marks.

Participation Requirements: In order to participate in this study, a colonoscopic exam must have been recommended for workup of your dog’s problem, and your dog must be scheduled to receive a colonoscopic exam under general anesthesia at UC Davis.

Initial Evaluation for Participation: None.

Procedures: If you agree to participate, your dog will receive a CT scan (with and without intravenous contrast material) in conjunction with carbon dioxide gas insufflated into the rectal lumen. Following CT pneumocolonography, your dog will receive the scheduled colonoscopy, which is the current standard of care for assessment of these masses, and if clinically indicated for the care of your dog, colonic biopsies or surgery will be obtained according to your discussion with your attending clinician.

Benefits: In return for participation in this study, your dog will receive a free CT scan (an approximately $800 value to you), which may directly benefit your dog, as it can provide important information for treatment recommendations that other types of imaging cannot. CT evaluation of local lymph nodes is an additional benefit as CT has been demonstrated to be very helpful in the evaluation of regional lymph nodes for metastatic disease in other types of cancer in other locations.

Owner Responsibilities: There is no additional cost to you for your dog’s participation in the study. You are financially responsible for hospital costs associated with the standard care of your dog, including abdominal ultrasound, general anesthesia, colonoscopy, hospitalization, biopsies, and any other diagnostic tests recommended for evaluation of your dog’s disease by your attending clinician.

UPDATED!  Lung Tumors: Identifying Lymph Node Metastasis

Title: Assessment of methods of improving identification of regional lymph nodes in patients with lung cancer

Purpose of Study: Knowing whether or not there is metastatic tumor in the regional lymph nodes is very important prognostic information for dogs with lung tumors, as dogs that do not have metastatic disease in their lymph nodes in general have a much longer lifespan. Chemotherapy is often recommended for patients who have metastatic disease, but is not recommended for dogs who do not have metastatic spread. The aim of this study is to provide information that will allow us to better identify these lymph nodes at surgery, to improve the safety of surgical dissection, and to minimize surgical time during removal of these lymph nodes.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Gigi, Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey.

Participation Requirements:

  • A diagnosis of a solitary lung tumor
  • Your decision to pursue surgical removal of your dog’s lung tumor

Initial Evaluation for Participation: Evaluation by the V.M.T.H. Small Animal Surgery, Internal Medicine, or Oncology services. A CT scan at the VMTH is part of the normal expected surgical planning for lung tumor surgery at our institution, and is the financial responsibility of the client, but may be performed under the same anesthetic episode as the planned surgery. Dogs with severe kidney or liver disease are not eligible to participate.

Procedures: During CT and surgery, special dyes will be injected intravenously or into the lung around your dog’s tumor and uptake by the regional lymph nodes will be assessed.

Benefits: Information regarding the status of your dog’s lymph nodes is very important in prognosis for this disease. This technique will help surgeons to identify and more safely remove your dog's lymph nodes at surgery; pathology of the removed lymph node(s) will provide improved information to direct recommendations that we an give you for postoperative care and treatment. If based on the initial CT results you elect to have your dog goes to surgery as part of this study, the study will retroactively pay for the cost of your dog’s CT scan (a $900 value to you).

Owner Responsibilities: There is no anticipated additional cost to you for your dog’s participation in the study. The cost of the dyes and operative imaging are covered by the study. The primary risks of this procedure are 1) allergic reaction to the drugs used to identify the lymph nodes (very rare, but unpredictable in an individual patient (like any other drug reaction, including antibiotics)), and 2) air leakage from the lung at the site of the injection (if it occurs, this should be a short term problem, as removal of the affected lung will be performed as part of the tumor removal). If an allergic reaction should occur, immediate costs of treatment (immediate supportive medications, support of blood pressure) will be covered by the study; however, the owner will be responsible for any treatment costs for prolonged or severe complications. Standard anesthetic and surgical risks of lung surgery and lymph node surgery will apply and will be discussed at the time of your visit.

Nasal cancer: Comparing Imaging Techniques and Assessing Vascular Therapies

Title: Nasal Tumors: Comparison of CT and MRI Findings in the Characterization of Canine Sinonasal Neoplasia and Assessment of Outcome with Vascular-Based Therapies (Embolization/Chemoembolization)

Purpose of Study: The purpose of this study is to prospectively evaluate dogs diagnosed with nasal tumors, including documentation of signalment, histologic diagnosis, treatment, and the results of a CT scan as compared to an MRI scan. We will also assess response to vascular-based therapies, such as embolization and chemoembolization.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dogs with diagnosed nasal tumors

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: If a CT scan is recommended to further characterize the dog’s suspected nasal tumor, an MRI scan will be performed immediately following the CT scan. The MRI scan will be performed under the same general anesthetic event as the CT scan. Additionally, options concerning vascular-based therapies (embolization and chemoembolization) will be discussed and offered.

Benefits: The MRI scan and the anesthesia associated with the MRI scan will be paid for by the study. The MRI scan will offer another imaging modality that your clinician can use to make therapeutic recommendations. 

Owner Responsibilities: The owner will be responsible for scheduling appointments (initial and 2-month follow-up) and keeping those appointments as required by protocol. Financial assistance for some treatments will also be discussed upon consent.

Nasal cancer: Using a Combination of Therapies for Treatment

Title: Nasal tumors: Intra-arterial Chemotherapy and Radiotherapy to Treat Nasal Carcinoma

Purpose of Study: The purpose of this study is to prospectively evaluate the response of nasal cancer to a combination of therapies (chemotherapy and radiation therapy) in dogs.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dogs diagnosed with nasal tumors

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: Dogs that are scheduled to receive radiation therapy for the treatment of nasal cancer can be enrolled in the study. Dogs will be placed into a group receiving radiation therapy alone or with chemotherapy.  Response to these treatments will be assessed with CT scans (done before and after treatment).

Benefits: The CT scans, chemotherapy administration, and part of the radiation therapy will be paid for by the study.

Owner Responsibilities: The owner will be responsible for providing follow-up information to the treating clinicians and returning the dog 4 weeks after initiation of radiation therapy for a second CT evaluation (the first is performed prior to treatment).

Prostate cancer: Evaluating Embolization as a Treatment Option

Title: Evaluation of the Use of Embolization in the Treatment of Prostatic Neoplasia

Purpose of Study: The purpose of this project is to describe the procedure of prostatic artery embolization in a group of dogs with naturally-occurring prostate cancer. A secondary objective is to evaluate the effect that prostatic artery embolization has on clinical signs and the size of the tumor.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dogs with prostate cancer

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: Dogs will undergo prostatic artery embolization. Pre-procedural ultrasound imaging and computed tomographic findings will be compared to post-procedural ultrasound imaging and computed tomographic findings. Complications associated with the procedure will be recorded and owners will receive a questionnaire to assess the clinical signs of the dog both pre- and post-procedure.

Benefits: The benefits of enrolling in this study include financial support for both pre- and post-procedure diagnostics. Additionally, funding from this grant will be applied towards the procedure. We hope that the data acquired in this study will allow us to advance the treatment of cancer in both dogs and people.

Owner Responsibilities: The owner will be responsible for scheduling appointments (initial and 1 month follow-up) and keeping those appointments as required by protocol.

Prostate, Urethra and/or Bladder Tumors: Evaluating Urodynamic Testing

Title: Prospective Evaluation of Urodynamic Testing in Dogs Undergoing Urethral Stent Placement to Relieve Malignant Urethral Obstruction

Purpose of Study: The purpose of this project is to determine the urethral and bladder pressures of dogs with cancer-induced urethral obstructions and in dogs with urethral stents.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dogs with tumors causing obstruction of the urethra (bladder, urethra and prostate)

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: Urodynamic studies will be performed at the time of stent placement. Following the urodynamic studies, a urethral stent will be placed. At 3 weeks post-stent placement, canine continence scores will be obtained from clients regarding the dog’s voiding habits and urodynamic studies will be performed again.

Benefits: The goal of placing the stent is to improve the dog’s quality of life. All anesthetic episodes (2) will be paid for by the study. Additionally, all charges associated with the bladder and urethral pressure assessment will be paid for by the study. There are 2 major study benefits:

  1. We will be able to inform clients of the pressures in their dog’s bladder and urethra and discuss the possible implications of this; and,
  2. Financial compensation.

Owner Responsibilities: The owner will be responsible for scheduling appointments (initial and 3 weeks after stent placement) and keeping those appointments as required by protocol. Additionally, the owner will need to fill out forms related to their dog’s continence status.

Urethra/Bladder Tumors: Determining Tumor Size with Imaging

Title: Bladder/Urethra Tumors: Assessment and Comparison of Lower Urinary Tract Neoplasia Size and Location with Multiple Imaging Modalities

Purpose of Study: The purpose of this study is to prospectively evaluate dogs with bladder and urethral tumors and assess the best means for determining tumor size. The overarching goal is to improve our ability to treat these tumors with urethral stenting.

Contact: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Participation Requirements: Dogs with bladder or urethral tumors

Initial Evaluation for Participation: Contact Dr. Culp for details at wculp@ucdavis.edu or (530) 752-1393.

Procedures: Dogs that are undergoing urethral stenting will undergo trans-rectal ultrasound (in addition to abdominal ultrasound) and MRI evaluation of the bladder/urethral tumor in order to determine tumor size and location.

Benefits: The MRI scan, the trans-rectal ultrasound and the anesthesia associated with these diagnostics will be paid for by the study. The MRI scan and trans-rectal ultrasound will offer additional imaging modalities that your clinician can use to make therapeutic recommendations.

Owner Responsibilities: The owner will be responsible for providing follow-up information to the treating clinicians.

Nasolacrimal Apparatus Blockage: A multidisciplinary, minimally invasive treatment

Title: Stenting as a Treatment for Nasolacrimal Apparatus Obstruction

Purpose of Study: Tears from the ocular surface are drained from the eye through several important structures collectively known as the nasolacrimal apparatus (NLA). This frequently becomes blocked and sometimes infected leading to discomfort, tear staining, eye discharge, and skin inflammation, all of which are associated with a decreased quality of life. Clinically, NLA obstructions can be very frustrating to treat and can often lead to permanent obstruction.

We have established a team at the UC Davis Veterinary Medical Teaching Hospital consisting of specialists with expertise in Ophthalmology, Internal Medicine, Endoscopy, Diagnostic Imaging, and Interventional Radiology and have utilized fluoroscopy to successfully treat NLA obstruction in dogs. We have utilized fluoroscopy, CT, and endoscopy and capitalized on improvements in instrumentation and minimally invasive techniques developed for catheterization of other challenging locations such as the ureters to successfully treat NLA obstruction.

To date, our team has successfully cannulated the nasolacrimal duct of 5 dogs and 1 horse referred for NLA obstruction, all of which we have managed and monitored for at least 8 weeks here at the VMTH. The initial clinical response in these patients has been extremely encouraging with all 6 cases demonstrating what the owners define as complete resolution of signs.

Based upon the success of this initial pilot study, we have initiated a clinical trial to recruit and treat more cases and to evaluate more objective outcome measures.

Contact: Please call 530-752-3937 to schedule your initial visit to the UC Davis Veterinary Ophthalmology Service

Participation Requirements: Dogs demonstrating signs of nasolacrimal apparatus (NLA) blockage

Initial Evaluation for Participation: None

Procedures: After an initial examination at the UCD VMTH to ensure the patient meets study entry criteria, owners will provide informed consent and complete a questionnaire concerning their dog’s signs. Patients will then undergo initial testing including CT scanning of the NLA, and NLA stenting using endoscopy and fluoroscopy. The stent will be left in position for at least 6 weeks. After stent removal, similar testing including CT scanning will again be performed, and owners will repeat the same questionnaire. Diagnostic test results from before and after stenting will be compared. Some financial subsidization of case management costs is available through the clinical trial.

Benefits: The study will subsidize costs associated with the second CT scan. Based upon results from the 6 patients in the pilot study, it is possible but not assured that your pet will have reduction or resolution of signs associated with NLA obstruction. Information acquired during this study will allow us to advance the treatment for NLA blockage for veterinary patients worldwide.

Owner Responsibilities: You will be responsible for all costs except those associated with the repeat CT scan following stent removal. Additionally, you will need to bring your dog to the VMTH for all scheduled appointments including a follow-up visit at least 6-8 weeks after the procedure. Lastly, you will be required to complete questionnaires prior to and after the NLA stenting procedure

Printable Flyer (PDF)

NEW! Variety of Tumors: Assessing Minimally Invasive Tumor Ablation

Title: Thermal ablation of cancer in dogs and cats

Purpose of Study: The purpose of this study is to evaluate the outcome of treating veterinary patients with minimally invasive tumor ablation technologies including cryoablation and microwave ablation. These methods are growing in the treatment of a variety of cancers in the human medical field, but information in veterinary patients is currently very limited. To date we have completed a study on cryoablation in nasal tumor patients, and this technique has been very successful in reducing tumor volume in nasal tumor patients – although there are no more spots in the formal nasal tumor study, because of this success, we continue to offer this technique as a clinical service to nasal cancer patients, and are expanding the types of cancer that we are evaluating.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey. The coordinators will likely advise you to send your pet's medical records and imaging results for Dr. Steffey's review. If, based on this information, your pet is deemed an appropriate candidate, an appointment will be scheduled.

Participation Requirements: In order to participate in this study, your pet must have **solitary** malignant soft tissue or bony mass **that is deemed amenable to ablation**. Tumor types that MAY be amenable to this treatment include lung tumors, kidney tumors, adrenal tumors, and bone tumors in certain locations. however determination of eligibility is complex and relates to the size of the lesion as well as proximity to/involvement of other important nearby structures. Tumors that are superficial (involving or near to the skin) or that involve the gastrointestinal tract are not amenable to this treatment.

Initial Evaluation for Participation: Evaluation by the V.M.T.H. Small Animal Surgery, Internal Medicine, or Oncology services.

Procedures: If you agree to participate, under general anesthesia, ablation probes will be placed into your pet’s mass under ultrasound guidance and the tumor will be ablated.

Benefits: This treatment method may only be palliative, but it is our hope that in appropriately selected patients, we may improve quality of life as well as longevity.

Owner Responsibilities: The study will cover the cost of the ablation probes and generator. Costs of pre-operative workup, general anesthesia, recommended imaging, hospitalization, and general management of the disease process or any complications that occur during treatment are your responsibility.

NEW! Variety of Tumors and Diseases: Improving Operative Detection of Tumors

Title: Fluorescent imaging of cancer

Purpose of Study: Near-infrared fluorescent imaging utilizes special wavelengths of light to identify important structures, and is used in surgery to improve surgical decision making. The fluorescent light is generated by a special contrast agent (a “fluorophore”) that is injected into the patient. When a special light source is used to illuminate the surgical site, any tissue in which this fluorophore is located will glow, aiding the surgeon in identifying the location or extent of disease. Based on early experiments in rodents and human clinical trials, this very sensitive tool has the potential to improve surgical decision-making and improve overall treatment for a wide variety of diseases. The purpose of this study is to evaluate the efficacy of this imaging modality in veterinary patients presenting with naturally occurring neuroendocrine tumors disease processes.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey.

Participation Requirements: Dogs with the following conditions are most likely to benefit from this study: hyperparathyroidism, thyroid cancer, pancreatic cancer, adrenal cancer, thymoma, mammary (breast) cancer, lung cancer, anal sac gland cancer, oral cancer, mast cell tumor. Dogs with severe kidney or liver disease are not eligible to participate.

Initial Evaluation for Participation: Evaluation by the V.M.T.H. Small Animal Surgery, Internal Medicine, or Oncology services.

Procedures: If you agree to participate, the best fluorophore for your pet’s tumor will be administered or intravenously, at a dose and timing considered to be optimal by your attending veterinarian.

Benefits: It is hoped, but is not known if there will be a specific benefit to your individual pet. Fluorescent imaging may or may not improve operative localization and dissection of your pet’s tumor.

Owner Responsibilities: Costs of standard pre-operative workup, general anesthesia, recommended imaging, hospitalization, and general management of your pet’s disease process or any complications that occur during treatment are your responsibility. The cost of the fluorophore and special imaging is covered by the study. There are no risks associated with the imaging itself, as it only involves light; there is no radiation exposure to the patient. The fluorophores used in this study are FDA-approved for use in humans and have been used without complication in our hospital for the past 18 months. The primary risk of this procedure is associated with injection of these drugs is an allergic reaction, which is very rare, but unpredictable in an individual patient (like any other drug reaction, including antibiotics). If an allergic reaction should occur, immediate costs of treatment (immediate supportive medications, support of blood pressure) will be covered by the study; however, the owner will be responsible for any treatment costs for prolonged or severe complications.

NEW! Variety of Tumors: Sentinel Lymph Node Mapping

Title: Identification of sentinel lymph nodes with intraoperative fluorescence

Purpose of Study: Near-infrared fluorescent imaging utilizes special wavelengths of light to identify important structures, and is used in surgery to improve surgical decision making. The fluorescent light is generated by a special contrast agent (a “fluorophore”) that is injected into the patient. When a special light source is used to illuminate the surgical site, any tissue in which this fluorophore is located will glow, aiding the surgeon in identifying the location or extent of disease. Based on early experiments in rodents and human clinical trials, this very sensitive tool has the potential to improve surgical decision-making and improve overall treatment for a wide variety of diseases. The purpose of this study is to evaluate the efficacy of this imaging modality in veterinary patients presenting with natural disease processes.

Contact: Call 530-752-1393 and ask to speak to the Soft Tissue Surgery scheduling coordinators (Conni, or Caleb) to schedule an appointment with Dr. Michele Steffey.

Participation Requirements: Dogs scheduled for surgery to treat their primary tumor, and for whom clients are interested in improving their pet’s staging information by lymph node biopsy. Dogs most likely to benefit from this technique include those with primary lung tumors, mast cell tumors, oral cancers, and carcinomas in general, as these are types of tumors that tend to exhibit spread by the lymphatic system. Tumors may be external (skin associated) or internal. Dogs with severe kidney or liver disease are not eligible to participate.

Initial Evaluation for Participation: Evaluation by Dr. Michele Steffey on the Soft Tissue Surgery Service.

Procedures: The best fluorophore for your pet’s tumor will be administered either subcutaneously or intravenously, at a dose and timing considered to be optimal by your attending veterinarian.

Benefits: Preliminary, not yet published results have demonstrated that the fluorescent imaging is very helpful in locating the important lymph nodes at surgery, which often reduces the amount of dissection needed, and may reduce the amount of time under anesthesia. The purpose of this study is to aid in identifying lymph nodes for improved staging (lymph node biopsy) at the time your pet’s primary tumor is removed. It is hoped, but is not known, if there will be a specific benefit to your individual pet. Depending upon your pet’s specific tumor type and the biopsy results, use of this technique and lymph node biopsy may or may not impact the postoperative treatment recommendations provided to your dog.

Owner Responsibilities: The cost of the fluorophore and special imaging is covered by the study. There are no risks associated with the imaging itself, as it only involves light; there is no radiation exposure to the patient. The fluorophores used in this study are FDA-approved for use in humans and have been used without complication in our hospital for the past 18 months. The primary risk of this procedure is associated with injection of these drugs is an allergic reaction, which is very rare, but unpredictable in an individual patient (like any other drug reaction, including antibiotics). If an allergic reaction should occur, immediate costs of treatment (immediate supportive medications, support of blood pressure) will be covered by the study; however, the owner will be responsible for any treatment costs for prolonged or severe complications.