1. Referral. 2. Clinical Evaluation

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Junior Green
5 years ago
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hacking/retching, increased urination and drinking and 5 days of decreased appetite.

He did not appear to have any coughing or respiratory distress but on chest radiographs at the local veterinarian, an oval soft tissue mass was seen in the

1 VCAWLAspecialty.com 1. Referral Moose, a 13-year-old Labrador Retriever, first came to the Internal Medicine Department at for evaluation of a 1 month history of progressive hacking/retching, increased urination and drinking and 5 days of decreased appetite. He had a history of osteoarthritis and was currently on fish oil and glucosamine. He did not appear to have any coughing or respiratory distress but on chest radiographs at the local veterinarian, an oval soft tissue mass was seen in the cranial left lung. 2. Clinical Evaluation On initial exam, his temperature, heart rate, and respiratory were all within normal limits. He had old age changes to his eyes and mild dental disease but no cardiorespiratory abnormalities. His abdomen, lymph nodes, urogenital, integument and neurologic exams were all normal. He had decreased range of motion to his hips and elbows and generalized mild muscle loss but was ambulatory and showed no specific lameness. 1

2 3. Diagnosis Initial diagnostics included an abdominal ultrasound, which revealed no obvious metastatic disease or other primary neoplastic disease and a thoracic ultrasound-guided fine needle aspirate of the mass. The cytology of the mass came back as an epithelial neoplasm consistent with well-differentiated carcinoma. Full bloodwork (CBC/Chemistry/ T4) and urinalysis were performed and were largely normal with a mild thrombocytosis and an elevated alkaline phosphatase. A CT scan of the chest was performed 6 days later to determine resectability of the mass. The mass measured 3cm in diameter and there were no visible pulmonary metastatic lesions. Because of the location of Moose s mass at the periphery of the lung and its relatively small size (<5cm), a video-assisted thoracoscopic (VATS) procedure was discussed with the owners. 4. Treatment Options In traditional surgery a lateral thoracotomy is required for complete lung lobectomy. An incision covering the entire side of the chest (approximately 15-20cm) is made between two ribs through the skin, underlying subcutaneous muscle and the rib muscles is performed. Then a retractor (Finochetto rib spreader) is used to spread apart the ribs so the affected lung(s) can be visualized. The lung is removed with a combination of stapling devices and electrocautery. The most common risks of this surgery include bleeding and air leakage from the location where the lung is removed, or damage to surrounding lungs or vessels. For closure, the ribs need to be re-apposed with heavy suture and a thoracostomy (chest) tube placed to evacuate the chest cavity and to monitor 2

3 postoperatively for any air leaks or bleeding. All of the tissues are then closed in multiple layers and the chest is bandaged. Postoperatively, discomfort is common due to the muscle disruption and manipulation of the ribs so aggressive pain management strategies are necessary to keep patients comfortable. We manage these patients on multiple constant rate infusions (CRI s) of different types of pain medication (Fentanyl, Ketamine, Lidocaine) and place a wound soaker (diffusion) catheter over the muscle that provides local anesthetic analgesia. Commonly these patients spend 3-4 days in the hospital recovering from surgery. In Video-Assisted Thoracoscopic Surgery (VATS), lung biopsies, partial and complete lobectomies are commonly performed in people and more recently in animals. These procedures utilize specialized instruments and a telescope to gain access to the chest cavity through tiny incisions. These procedures are minimally invasive, allow for rapid recovery and improved visualization due to the magnification afforded by the telescope. Thoracoscopic instruments are placed through ports that range in size from 5-11mm and can cut, staple, cauterize and retract tissue and lungs within the thoracic cavity. The lung can be removed in its entirety by placing it in specialized retrieval bags designed to minimize spread of disease, in the case of cancer, but keep the sample diagnostically viable. One-lung ventilation (OLV) is usually required for VATS, especially in complete lung lobectomies because of the improved visualization and increased working space for the instruments. The procedure for thoracoscopic lung lobectomy is as follows: The patient is placed in an oblique lateral recumbency and three to four ports are placed at the eighth or ninth intercostal space for a cranial lung or the third or fourth intercostal space for a caudal lung lobe. OLV is induced once the patient is in the operating room in the appropriate position under bronchoscopic guidance and time is given for the affected lung to collapse. 3

4 Mediastinum is resected with bipolar electrocautery or a vessel sealing device (LigaSure ) as it is commonly impeding visualization. The appropriate lung is gently grasped with thoracoscopic Babcock forceps and the hilus of the lung identified. Any ligamentous structures are dissected and a thoracoscopic stapling device is placed and positioned across the hilus. After firing and releasing the staples, the lung is placed in a sterile retrieval bag to prevent seeding of tumor and the port site is enlarged to 2cm or large enough to pull the bag from the thoracic cavity. The hilus is checked for any signs of bleeding or air leakage, a chest tube is placed and the port sites closed routinely. The patients are usually just hospitalized for 1 night and the pain protocol consists of local anesthetic injections at the port sites and a CRI of Fentanyl or IV bolus hydromorphone injections. 5. Surgery and In-Hospital Care Moose came for surgery a week later and a Video-assisted thoracoscopic complete lung lobectomy of the left cranial lung lobe with OLV was successfully performed (see Figures 1-7). He recovered uneventfully from the anesthesia and procedure and rested comfortably overnight. He was placed on IV fluids, a pain CRI, chest tube aspirations and icing to his incisions. The next morning he was BAR, comfortable on palpation of his incisions, and they were clean and dry (see Figure 8). His chest tube was pulled in the morning as it was not productive and he could have been discharged the next day but was kept for observation, per the owner s wishes. 4

5 6. Postop Care and Recheck Evaluation When he went home with the owner the next day, he was sent with Tramadol, Carprofen and an E-collar. Instructions were given to keep his incisions dry and keep his activity to a minimum for the next 7 days. He was so comfortable that he actually laid down on his surgery side during the discharge visit (see Figures 9 and 10, and Video 1). At 10 days Moose returned for suture removal and recheck exam. He looked amazing, extremely active and comfortable and his incisions were all healed up (see Figure 11 and Video 2). He was given the green light for full return to normal activity and bath and no more t-shirt or E-collar. 7. Discussion Moose s biopsy returned as a pulmonary papillary carcinoma with clean margins. These type of tumors spread by local invasion and metastasize through lymphatics to other lung lobes and hilar lymph nodes. Because this mass was removed completely and there was no evidence of metastasis yet on staging, Moose was given a very good prognosis. He will have recheck thoracic radiographs every 3 months for the first year. Two months later, Moose has still been doing very well and the owners are so pleased with the minimal pain and downtime their family member had to endure for such a major surgery. Because he was 13 they struggled with putting him through surgery, even though it had such a great potential outcome. The minimally invasive procedure really allowed Moose to get the most advanced care available with minimal pain or decrease in activity. 5

6 Figure 1 Figure 2 Figure 3 Figure 4 6

7 Figure 5 Figure 6 Figure 7 Figure 8 7

8 Figure 9 Figure 10 Figure 11 8

9 Please click on photo to view video Video 1 Video 2 9

10 Nicole Buote, DVM, DACVS Chief of Surgery VCA West Los Angeles Animal Hospital Dr. Nicole Buote obtained her doctorate of veterinary medicine from Tufts University Cummings School of Veterinary Medicine in She completed a one year rotating internship at Angell Animal Medical Center in Boston, Massachusetts and then pursued a specialty surgical internship at the Dallas Veterinary Surgical Center in Texas in In 2009 she completed her surgical residency from The Animal Medical Center in New York and was awarded Diplomate status in the American College of Veterinary Surgeons in Dr. Buote practices soft tissue, orthopedics and neurosurgery but her special interests are in minimally invasive procedures including laparoscopy, thoracoscopy, and arthroscopy. Dr. Buote also has a strong interest in clinical research and has published in textbooks and scientific journals the field of small animal surgery, on topics including gallbladder disease, cruciate (knee) stabilization, Vacuum assisted closure for abdomens, and laparoscopy. Dr. Buote also enjoys lecturing and teaching at national conferences. 10

Proceedings of the World Small Animal Veterinary Association Sydney, Australia 2007

Proceedings of the World Small Animal Sydney, Australia 2007 Hosted by: Next WSAVA Congress THE LAST GASP II: LUNGS AND THORAX David Holt, BVSc, Diplomate ACVS University of Pennsylvania School of Veterinary