Outcome of video-assisted thoracoscopic treatment of idiopathic chylothorax in 15 cats.

OBJECTIVE: To evaluate the outcomes and complications of video-assisted thoracoscopic (VATS) treatment of chylothorax in cats. STUDY DESIGN: Multi-institutional retrospective study. ANIMALS: Fifteen client-owned cats. METHODS: The medical records of cats undergoing thoracoscopic thoracic duct ligation (TDL) for treatment of idiopathic chylothorax were reviewed. Cats undergoing additional procedures including thoracoscopic pericardectomy and/or laparoscopic cisterna chyli ablation (CCA)_were included. Follow up was obtained through communication with the referring veterinarian or owner. RESULTS: All cats underwent thoracoscopic TDL. Thirteen cats underwent simultaneous pericardectomy and two cats underwent laparoscopic CCA without pericardectomy. Conversion from a thoracoscopic to open approach was necessary in 2/15 (13%) of thoracic duct ligations and 1/11 (9%) of pericardectomies. The most common postoperative complication was persistent pleural effusion in five cats (33%). Four of 15 cats (27%) died or were euthanized prior to hospital discharge following surgery. Recurrence of effusion occurred in 1/7 (14%) of cats that sustained resolution of the effusion at the time of surgery with a median follow up of 8 months. The overall mortality attributed to chylothorax was 47%. CONCLUSION: Thoracoscopic treatment of idiopathic chylothorax resulted in a low incidence of intraoperative complications or conversion in the study population; however, mortality related to feline idiopathic chylothorax remained high. CLINICAL SIGNIFICANCE: While VATS treatment of idiopathic chylothorax is technically feasible, further consideration of the underlying pathology and current treatment algorithm is needed to improve outcomes as this remains a frustrating disease to treat in the feline population.

Evaluation of long-term outcome after lung lobectomy for canine non-neoplastic pulmonary consolidation via thoracoscopic or thoracoscopic-assisted surgery in 12 dogs.

OBJECTIVE: To report outcomes of thoracoscopic (TL) and thoracoscopic-assisted lung lobectomy (TAL) for treatment of non-neoplastic pulmonary consolidation (PC) in dogs. STUDY DESIGN: Retrospective case series. ANIMALS: Twelve client-owned dogs. METHODS: The medical records of 12 dogs that underwent TL or TAL for PC at 3 veterinary institutions between 2011 and 2020 were reviewed. Signalment, history, physical examination, diagnostics, days in hospital, anesthetic and procedure times, intraoperative/postoperative complications, conversion rates, duration of indwelling thoracic drain, and long-term outcomes were recorded. RESULTS: Nine patients underwent a TL approach and 3 underwent TAL. In those that underwent TL, conversion to an intercostal thoracotomy was performed in 4 out of 9 dogs. Conversion was performed due to adhesions (n = 3) or poor visualization (1). Histopathologic examination was consistent with pneumonia due to an infectious process (n = 10), bronchioalveolar malformation with abnormal cilia (1), and left-sided cardiac insufficiency vs. pulmonary alveolar proteinosis (1). The mean duration of hospital stay was 4 days (range, 1-6 days). Complications occurred postoperatively in 7 dogs and included self-limiting hemorrhage (n = 3), self-resolving pneumothorax (2), incisional dehiscence (1), and severe dyspnea in a brachycephalic breed leading to euthanasia (1). For the 11 dogs that survived the perioperative period, there was no evidence of recurrence with a median follow up of 24 months (range, 5-120 months). CONCLUSION: Thoracoscopic (TL) and thoracoscopic-assisted lung lobectomy (TAL) is a reasonable surgical approach in select dogs with PC. CLINICIAL RELEVANCE: Conversion rates were higher than those historically reported for dogs undergoing thoracoscopic lung lobectomy for primary lung tumors.

Complications and outcomes of thoracoscopic-assisted lung lobectomy in dogs.

OBJECTIVE: To describe complications and outcomes of dogs undergoing thoracoscopic-assisted (TA) lung lobectomy. STUDY DESIGN: Multi-institutional, retrospective study. ANIMALS: Client-owned dogs (n = 30). METHODS: Medical records of dogs that underwent TA lung lobectomy were reviewed. Signalment, bodyweight, clinical signs, imaging findings, surgical variables, complications, and short-term/long-term outcome were assessed. Thoracoscopic-assisted lung lobectomy was performed with a mini-thoracotomy. RESULTS: Twelve intraoperative complications were recorded in 11 dogs, 6 requiring conversion to open thoracotomy. Reasons for conversion were reported in 5/6 dogs and included adhesions (2), difficultly manipulating the lesion through the mini-thoracotomy (2), and acute oxygen desaturation (1). One lung ventilation was successful in 4 of the 7 dogs in which this was attempted. A linear stapling device (DST series Medtronic, Minneapolis, Minnesota) was used for lung lobe ligation in 14 dogs. Twenty-three dogs underwent surgery for a neoplastic lesion, with 19 of these being carcinoma. The median lesion size was 4.3 cm (range 1-10 cm); margins were clean, except in 1 dog. Complications were documented in 8 dogs prior to discharge, 5 of these being classified as mild. Twenty-nine dogs were discharged at a median of 47 h postoperatively (range 24-120 h). Death was reported in 9 dogs, with a median survival time of 168 days (range 70-868 days). CONCLUSION: Thoracoscopic-assisted lung lobectomy was achieved with few major complications in the population reported here. Dogs were able to be discharged from hospital quickly, with most surviving beyond the follow-up period. CLINICAL SIGNIFICANCE: Thoracoscopic-assisted lung lobectomy may be considered to facilitate the excision of larger pulmonary lesions or to treat smaller dogs, in which a thoracoscopic excision may be technically more challenging.

A novel video-assisted thoracoscopic approach for pectus excavatum surgical treatment in a dog.

OBJECTIVE: To describe a novel, video-assisted thoracoscopic surgery (VATS) approach used to treat pectus excavatum (PE) in a dog. ANIMALS: A 5 month-old, 5.1 kg, intact, female, Cockapoo. STUDY DESIGN: Case report. METHODS: Clinical, imaging and surgical records of a dog with severe PE who underwent VATS-assisted sternal cast placement were reviewed and reported. Treatment involved introduction of a mild pneumothorax and use of VATS, allowing direct visualization and therefore safe passage of circumsternal sutures as they were placed to reduce the risk of vascular/cardiac or pulmonary penetration and intraoperative complication in this patient. RESULTS: Treatment involved introduction of a mild pneumothorax and use of VATS, allowing direct visualization and therefore safe passage of circumsternal sutures as they were placed to reduce the risk of vascular/cardiac or pulmonary penetration and intraoperative complications in this patient. The patient recovered well and had an excellent long-term outcome with significantly improved vertebral index and frontosagittal index. CONCLUSION: This modified technique resulted in an excellent outcome and minimized the risk of intraoperative complications during the surgical procedure in a dog. CLINICAL SIGNIFICANCE: This novel VATS approach for PE correction may provide a useful technique to help reduce intraoperative risk during PE correction in dogs.

Resorbable self-locking device for canine lung lobectomy: A clinical and experimental study.

OBJECTIVE: To test the feasibility of a resorbable self-locking device for sealing of lung tissue in lung lobectomy in experimental dogs and dogs with pulmonary mass, and to study its resorption with CT. STUDY DESIGN: Experimental study and clinical case series. ANIMALS: Five beagles in the experimental group; six canine patients with a pulmonary mass in the clinical group. METHODS: In both groups, an intercostal incision into thorax was performed. A resorbable self-locking device, LigaTie, was applied at the hilum of left cranial lobe in the experimental group and the affected lobe in the clinical group. Each lobe was removed by cutting the tissue just distal to the device. Video-assisted thoracic surgery was used in the experimental group; postoperative diagnostic imaging was repeated monthly until the device was not apparent on CT. RESULTS: Application of LigaTie was feasible for lung lobectomy in all dogs. The device enabled en bloc ligation of the hilum of the affected lobe including the pulmonary arteries and veins and lobular bronchus. No air leakage from the resection stump was observed in any dog. Trace of the device on CT images gradually decreased and was undetectable at 4 months postoperatively in experimental dogs. CONCLUSION: This study suggested that the resorbable self-locking device may be used for sealing of airways in complete lung lobectomy. CLINICAL RELEVANCE: The resorbable self-locking device is suggested to be useful for canine lung lobectomy and may facilitate thoracoscopic lung lobectomy. Further investigations on its clinical application in small animal surgery are warranted.

Cadaveric evaluation of fluoroscopy-assisted placement of one-lung ventilation devices for video-assisted thoracoscopic surgery in dogs.

OBJECTIVE: To evaluate the feasibility of fluoroscopy-assisted placement of one-lung ventilation (OLV) devices in dogs. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Canine cadavers (n = 8) weighing between 20.2 and 37.4 kg. METHODS: Thoracoscopic access with a two-port approach was established to evaluate bilateral lung ventilation patterns. Advancement of a left-sided Robertshaw double-lumen endobronchial tube (DLT) and the EZ-blocker (EZ) were evaluated under direct fluoroscopic guidance. Each dog also underwent bronchoscopy-assisted placement of an Arndt endobronchial blocker (EBB). Time to initial placement, success of creating complete OLV (after initial placement attempt and after up to two repositionings), and ease of placement score were recorded. Device position was evaluated bronchoscopically after each fluoroscopy-assisted placement attempt. RESULTS: Time to initial placement was significantly shorter for EZ than for DLT and EBB. The rate of successful placement after up to two repositioning attempts was 87.5%, 87.5%, and 100.0% on the right and 87.5%, 100.0%, 100.0% on the left for DLT, EZ, and EBB, respectively, and was not different between devices. Ease of placement scores were significantly higher for DLT compared with EZ and EBB on both the left and the right sides. CONCLUSION: Fluoroscopy-assisted placement of DLT and EZ appears feasible in canine cadavers. EZ-blocker placement was efficient and technically easier than DLT, but positioning must be adapted for dogs. Bronchoscopy-assisted placement of EBB remains highly successful. CLINICAL SIGNIFICANCE: Fluoroscopy-assisted placement of EZ and DLT is a useful alternative to bronchoscopy-assisted placement of these OLV devices.

Efficacy of en bloc thoracic duct ligation in combination with pericardiectomy by video-assisted thoracoscopic surgery for canine idiopathic chylothorax.

OBJECTIVE: To compare the outcomes of pericardiectomy performed with conventional clipping thoracic duct ligation (C-TDL) to those with en bloc thoracic duct ligation (EB-TDL) using video-assisted thoracoscopic surgery (VATS) for canine idiopathic chylothorax. STUDY DESIGN: Retrospective consecutive case series. ANIMALS: Thirteen client-owned dogs with idiopathic chylothorax. METHODS: Medical records of dogs treated with pericardiectomy in combination with TDL by VATS without intraoperative contrast were reviewed. Five and seven dogs underwent C-TDL and EB-TDL, respectively, and 11 dogs were evaluated by preoperative and 7- to 10-days-postoperative computed tomography-lymphography (CTLG). No clinical symptoms with absent or minimal pleural effusion was defined as clinical improvement. Long-term remission (LTR) was defined as rapid resolution of pleural effusion and no recurrence for more than 1 year. Anesthesia time, operation time, the duration of hospitalization, and time until pleural effusion resolution were compared. RESULTS: Clinical improvement was achieved in 91.7% of the cases (C-TDL, 4/5; EB-TDL, 7/7), excluding one case of intraoperative death. The LTR rate was significantly higher with EB-TDL (6/7 [85.7%]) than with C-TDL (1/5 [20%]). Anesthesia time, operation time, and time until pleural effusion resolution were significantly better with EB-TDL than with C-TDL. The rates of thoracic ducts visualization by postoperative CTLG were 100% (5/5) with C-TDL and 42.9% (3/7) with EB-TDL. CONCLUSION: En bloc TDL was an effective treatment for canine idiopathic chylothorax in this patient population. It compared favorably to C-TDL, although missed branches at the time of surgery may explain the difference between C-TDL and EB-TDL in this small population of cases. CLINICAL SIGNIFICANCE: En bloc TDL by VATS was an effective minimally invasive treatment for canine idiopathic chylothorax. Computed tomography-lymphography can be used for surgical planning and postoperative evaluation.

Optimization of surgical approach for thoracoscopic-assisted pulmonary surgery in dogs.

OBJECTIVE: To determine the optimal intercostal space (ICS) to perform thoracoscopic-assisted lung lobectomy. STUDY DESIGN: Cadaveric study. ANIMALS: Six mature, medium-sized canine cadavers. METHODS: Cadavers were placed in right or left lateral recumbency. A 15-mm thoracoscopic cannula was inserted in the middle third of the 9th or 10th ICS. A wound retraction device was placed into a 7-cm minithoracotomy incision created in the middle third of the 4th-7th ICS on the left side and the 4th-8th ICS on the right side. The pulmonary ligaments were sectioned by using a combined intracorporeal and extracorporeal technique. Each lung lobe was sequentially withdrawn from the wound retraction device at the respective ICS and side. A thoracoabdominal stapler was positioned to simulate lung lobectomy, and the distance from the stapler anvil to the hilus was measured. RESULTS: Simulated thoracoscopic-assisted lung lobectomy performed at left or right ICS 4 and 5, compared with other ICS evaluated, resulted in a significantly shorter median distance from the stapler anvil to the pulmonary hilus of the left cranial and caudal lung lobes and right cranial and middle lung lobes, respectively (all P < .05). Lobectomy at right ICS 5 or 6 resulted in a significantly shorter median distance from the stapler anvil to the pulmonary hilus of the right caudal and accessory lung lobes, respectively (both P < .05). CONCLUSION: These data may inform minithoracotomy positioning to optimize tumor margin excision during thoracoscopic-assisted lung lobectomy for treatment of pulmonary neoplasia in dogs. CLINICAL SIGNIFICANCE: Complete lung lobectomy is possible by using the described thoracoscopic-assisted technique in normal, cadaveric lungs.

Long-term outcome of video-assisted thoracoscopic thoracic duct ligation and pericardectomy in dogs with chylothorax: A multi-institutional study of 39 cases.

OBJECTIVE: To evaluate the long-term outcome of video-assisted thoracoscopic (VATS) thoracic duct ligation (TDL) and pericardectomy for treatment of chylothorax in dogs. STUDY DESIGN: Multi-institutional retrospective study. ANIMALS: Thirty-nine client-owned dogs. METHODS: Dogs were included if they had undergone a VATS TDL and pericardectomy and had at least 1-year follow-up or had died within 1 postoperative year. Medical records were evaluated, and recorded data included clinicopathological and diagnostic imaging results, surgical findings, complications, conversion rates, and long-term resolution and recurrence rates. RESULTS: Thirty-nine dogs met the inclusion criteria. Two dogs died intraoperatively; 1 was euthanized after severe restrictive pleuritis was diagnosed intraoperatively, and 1 underwent ventricular fibrillation and cardiac arrest during pericardectomy and could not be resuscitated. Conversion to an open approach was required in 1 of 39 (3%) dogs for TDL and 4 of 36 (11%) dogs for pericardectomy. Overall follow-up time was median 38 months (range, 3-115). Resolution of pleural effusion occurred in 35 of 37 (95%) dogs that survived the perioperative period. Late recurrence of pleural effusion was seen at 12, 12, and 19 months postoperatively in 3 of 35 (9%) dogs that survived the perioperative period and in which chylothorax had initially resolved. CONCLUSION: Successful long-term resolution of chylothorax was seen in a high proportion of dogs that underwent VATS TDL and pericardectomy, although late recurrence was sometimes seen. CLINICAL SIGNIFICANCE: Video-assisted thoracoscopic thoracic duct ligation and pericardectomy are highly successful in dogs with chylothorax. Future studies should evaluate whether pericardectomy is required in dogs without evidence of pericardial disease.

Cardiorespiratory effects of variable pressure thoracic insufflation in cats undergoing video-assisted thoracic surgery.

OBJECTIVE: To evaluate the effects of intrathoracic insufflation on cardiorespiratory variables and working space in cats undergoing video-assisted thoracic surgery. STUDY DESIGN: Prospective randomized study. ANIMALS: Six healthy cats. METHODS: Cats were anesthetized using a standardized protocol. A Swan-Ganz catheter was positioned in the pulmonary artery under fluoroscopic guidance for measurement of cardiac output. Intrathoracic pressures (ITP) of 0 (baseline), 3, and 5 mm Hg were induced with CO2 and maintained for 30 minutes. Statistical comparison of cardiorespiratory variables was performed. After the procedures, all cats were recovered from anesthesia. Videos of thoracic working space at each ITP level were scored in a blinded fashion by 3 board-certified surgeons using a numerical scale from 0-10. RESULTS: All cats tolerated insufflation with 3 and 5 mm Hg for 30 minutes without oxygen desaturation, although ventilatory levels had to be increased substantially to maintain eucapnia and oxygenation. Cardiac index was not significantly different from baseline after 30 minutes at 3 mm Hg but was significantly lower after 30 minutes at 5 mm Hg compared with 3 mm Hg. Oxygen delivery was unaffected by 3 or 5 mm Hg compared with baseline. Scores for working space increased between baseline and 3 and 5 mm Hg but were not different between 3 and 5 mm Hg. CONCLUSION: CO2 insufflation to 5 mm Hg seems well tolerated in healthy cats, provided ventilatory settings are substantially increased as ITP increases. CLINICAL SIGNIFICANCE: Thoracic CO2 insufflation of 3 mm Hg in cats during video-assisted thoracic surgery is associated with less hemodynamic perturbation than 5 mm Hg insufflation and may provide the benefit of improved working space compared with baseline.

Video-assisted thoracoscopic thoracic duct sealing is inconsistent when performed with a bipolar vessel-sealing device in healthy cats.

OBJECTIVE: To describe a technique for video-assisted thoracoscopic (VATS) thoracic duct ligation (TDL) in normal cats with a bipolar vessel-sealing device and to assess durability of the seal. STUDY DESIGN: Prospective case series. ANIMALS: Six healthy research cats. METHODS: Cats were placed under anesthesia for computed tomography lymphangiography (CTLA) to identify thoracic duct anatomy. On the basis of CTLA findings, cats were positioned in either right or left lateral recumbency for a 3-port VATS TDL. Thoracic duct branches were dissected from the aorta after subcutaneous indirect near-infrared fluorescence (NIRF) lymphography with indocyanine green was performed to optimize detection. A vessel-sealing device was used to seal each thoracic duct in 1 or more locations. Postattenuation, indirect NIRF lymphography was repeated to confirm complete occlusion of thoracic duct flow. CTLA was repeated in all cats 3 months postoperatively. RESULTS: The thoracic duct was surgically approached from the right in 3 cats and from the left in 3 cats. A median of 2.5 (range 1-6) TDL seal sites were applied. In 2 cats, leakage of chyle was detected during dissection. At 3 months postoperatively, CTLA confirmed reestablished chylous flow in 5 of 6 cats, appearing to occur through recanalization of previously sealed sites rather than through development of de novo lymphatic vessels. CONCLUSION: VATS TDL is feasible in cats, although the variable and delicate nature of feline thoracic duct anatomy should be considered preoperatively. CLINICAL SIGNIFICANCE: Bipolar vessel-sealing devices are not a durable modality for thoracic duct sealing in healthy cats in a seal only fashion.

Video-assisted thoracic surgery for the management of pyothorax in dogs: 14 cases.

OBJECTIVE: To report the perioperative findings and outcome of dogs undergoing video-assisted thoracic surgery (VATS) for the management of pyothorax. DESIGN: Multi-institutional, retrospective study. ANIMALS: Client-owned dogs (n = 14). METHODS: Medical records of dogs with pyothorax managed via VATS were reviewed for signalment, history, clinical signs, clinicopathological findings, diagnostic imaging results, surgical variables, bacterial culture and sensitivity results, post-operative management and outcome. VATS was performed after placing a paraxyphoid endoscopic portal and 2-3 intercostal instrument portals. VATS exploration was followed by one or more of the following: mediastinal debridement, tissue sampling, pleural lavage, and placement of a thoracostomy tube. RESULTS: Two dogs (14%) required conversion from VATS to an open thoracotomy to completely resect proliferative mediastinal tissue. These dogs had severe pleural effusion on preoperative thoracic radiographs and one had severely thickened contrast-enhancing mediastinum on preoperative computed tomography (CT). The cause of pyothorax was identified as a penetrating gastric foreign body (n = 2), migrating plant material (n = 2), and idiopathic (n = 10). The median follow-up time was 143 days (range, 14-2402 days). All dogs were discharged from the hospital and their clinical signs resolved. One patient had recurrence of a pyothorax requiring revision surgery 17 months postoperatively. CONCLUSION: VATS allows minimally invasive treatment of uncomplicated canine pyothorax. Preoperative thoracic CT may help identify candidates for VATS among dogs with pyothorax.

Video-Assisted Thoracoscopic Resection of a Noninvasive Thymoma in a Cat with Myasthenia Gravis Using Low-Pressure Carbon Dioxide Insufflation.

OBJECTIVE: To report the use of low-pressure carbon dioxide insufflation during video-assisted thoracoscopic surgery for resection of a noninvasive thymoma in a cat with secondary myasthenia gravis. STUDY DESIGN: Clinical case report. ANIMAL: Client-owned cat. METHODS: An 11-year-old castrated male domestic shorthair cat was examined for generalized weakness, voice change, hypersalivation, hyporexia, vomiting, coughing, and gagging. Thoracic ultrasound revealed a cranial mediastinal mass for which cytology was consistent with a thymoma (or lymphoid tissue). Acetylcholine receptor antibody concentration was elevated at 3.16 mmol/L (reference interval < 0.3 mmol/L). Thoracic computed tomography showed two round, contrast-enhancing structures in the cranioventral mediastinum identified as the sternal lymph node and a cranial mediastinal mass (11 × 17 × 24 mm). A presumptive diagnosis of thymoma with paraneoplastic myasthenia gravis was made and surgical resection of both mediastinal masses was recommended. RESULTS: Video-assisted thoracoscopic resection of the cranial mediastinal mass and sternal lymph node were performed with low-pressure carbon dioxide insufflation maintained at an intrathoracic pressure of 2-3 mmHg. The cat recovered from surgery without serious complications. Nineteen months after surgery, the cat developed hind limb stiffness. Thoracic radiographs ruled out a cranial mediastinal mass or megaesophagus. Acetylcholine receptor antibody concentration remained elevated at 2.72 mmol/L. CONCLUSION: Low-pressure thoracic insufflation facilitated video-assisted thoracoscopic resection of cranial mediastinal masses in this cat.

Evaluation of Video-Assisted Thoracic Surgery for Treatment of Spontaneous Pneumothorax and Pulmonary Bullae in Dogs.

OBJECTIVE: To describe the operative findings and clinical outcome in dogs undergoing video-assisted thoracic surgery (VATS) for treatment of spontaneous pneumothorax and pulmonary bullae. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Dogs (n = 12) with spontaneous pneumothorax and/or pulmonary bullae. METHODS: Medical records (2008-2013) were reviewed for signalment, clinical signs, diagnostic imaging, surgical and histopathologic findings, and outcome in 12 dogs that had VATS for treatment of spontaneous pneumothorax and pulmonary bullae. In particular, conversion to median sternotomy and surgical success were evaluated. RESULTS: Twelve dogs had initial VATS for spontaneous pneumothorax and/or pulmonary bullae. Conversion to median sternotomy because of inability to identify a parenchymal lesion/leak was necessary in 7 (58%) dogs. VATS without conversion to median sternotomy was performed in 6 (50%) dogs. Successful surgical outcomes occurred in 5 (83%) dogs that had conversion to median sternotomy, and in 3 (50%) dogs that had VATS without conversion to median sternotomy. CONCLUSIONS: Exploratory thoracoscopy was associated with a high rate of conversion to median sternotomy because of inability to identify leaking pulmonary lesions in dogs with spontaneous pneumothorax and pulmonary bullae. Failure to convert to a median sternotomy may be associated with recurrent or persistent pneumothorax.

Video-Assisted Thoracoscopic Extirpation of the Tracheobronchial Lymph Nodes in Dogs.

OBJECTIVE: To describe a technique for video-assisted thoracoscopic surgery (VATS) extirpation of the tracheobronchial lymph nodes (TBLN), and to describe the quality of biopsy specimens obtained. DESIGN: Experimental study. ANIMALS: Purpose-bred male hound-mix research dogs (n = 8). METHODS: Dogs were randomized to groups of left-sided or right-sided VATS approaches. One lung ventilation was used and TBLN dissection was achieved using a vessel-sealing device. RESULTS: TBLNs ipsilateral to the approach were successfully identified and removed thoracoscopically in 7 dogs. A 3-port technique was used in 6 dogs and 4 ports were used in 2 dogs. Observed complications included mild-moderate hemorrhage from the perinodal tissue controlled thoracoscopically (n = 2), inability to locate any TBLN (1), and difficulty achieving or maintaining one-lung ventilation (4). No other major complications occurred and all dogs recovered uneventfully. Median percentage surface area of the bisected lymph nodes affected by crush artifact was 20% (range, 0-40%). Areas of crush artifact were present in central (7/11) and peripheral (9/11) locations. CONCLUSIONS AND CLINICAL RELEVANCE: Thoracoscopic TBLN extirpation is a feasible technique in dogs with normal TBLN and may be useful for obtaining more detailed staging on microscopic disease status in oncologic patients with normal-sized TBLNs. Further study is warranted to determine the feasibility and limitations of this technique in clinical patients with overt lymphadenopathy.

Video-assisted thoracoscopic surgery for pneumothorax induced by migration of a K-wire to the chest.

A 2 yr old female English setter dog was admitted for acute dyspnea. The dog underwent treatment of a T9T10 thoracic vertebral fracture subluxation at the authors' institution 15 mo earlier. Upon admission, a chest X-ray revealed a pneumothorax and a metallic foreign body in the left hemithorax. An emergency video-assisted thoracoscopic surgery was successfully performed to remove a 4.6-mm long Kirschner wire that migrated from the thoracic vertebral column to the thoracic cavity. The operating time was 27 min. The dog made an uneventful recovery and was discharged on the third day after surgery. Pneumothorax should be considered in patients that develop acute dyspnea and have a history of wire fixation in the thoracic vertebral column. Video-assisted thoracoscopic surgery is a safe and effective treatment of this condition.

Feasibility of the single-incision subxiphoid approach for video-assisted thoracoscopic surgery in dogs.

OBJECTIVES: To report early results of uniportal video-assisted thoracoscopic surgery in dogs using a single-incision subxiphoid approach. MATERIALS AND METHODS: Retrospective study of 10 client-owned dogs with: pyothorax (n=5), pericardial effusion (n=2), bilateral pneumothorax (n=1), retained surgical swab (n=1), cranial mediastinal mass (n=1). With the dog in dorsal recumbency a 3-4 cm incision was made over the xiphoid process. After resection of the xiphoid process, a tunnel was created towards the pleura and open access maintained with an Alexis™ wound retractor. The pleural cavity was explored with a 10 mm 30° or 5 mm 0° telescope and straight laparoscopic instruments. RESULTS: Median surgical time was 75 minutes. The SISA technique was performed successfully in five of 10 cases and allowed easy and adequate inspection of the intra-thoracic structures. One case was converted to lateral thoracotomy after laceration of the vena cava and one converted to median sternotomy because of adhesions. An additional port was placed in three cases to facilitate triangulation and surgical manipulation. No other intra-operative complications were encountered. CLINICAL SIGNIFICANCE: In this initial report of uniportal thoracic approach in dogs, this technique allowed excellent access and treatment of mediastinal structures. Further cases are required to assess its suitability for pulmonary surgery.

Long-term clinical outcomes following surgery for spontaneous pneumothorax caused by pulmonary blebs and bullae in dogs - a multicentre (AVSTS Research Cooperative) retrospective study.

OBJECTIVES: To report the clinical characteristics and recurrence rate of spontaneous pneumothorax secondary to pulmonary blebs and bullae following surgical management in a large cohort of dogs. To explore potential risk factors for recurrence and describe outcome. MATERIALS AND METHODS: Medical records were retrospectively reviewed for cases with spontaneous pneumothorax managed surgically between 2000 and 2017. Signalment, clinical presentation, diagnostic imaging, surgery, histopathology findings and patient outcomes were recorded. Follow-up was performed via patient records and telephone contact. RESULTS: Records of 120 dogs with surgically treated pneumothorax were identified and reviewed, with 99 cases appropriate for exploratory statistical analysis. Median follow-up was 850 days (range: 9-5105 days). Two- and 5-year survival rates were 88.4% and 83.5%, respectively. There was recurrence in 14 of 99 dogs (14.1%) with adequate follow-up, with a median time to recurrence of 25 days (1-1719 days). Univariable Cox regression analysis suggested increased risk for recurrence in giant breeds (hazard ratio = 11.05, 95% confidence interval: 2.82-43.35) and with increasing bodyweight (HR = 1.04, 95% confidence interval: 1.00-1.09). Of 14 dogs with recurrence, six were euthanased, two died of causes related to pneumothorax and six underwent further treatment, of which five were resolved. CLINICAL SIGNIFICANCE: Long-term survival for dogs with surgically managed spontaneous pneumothorax was good and associated with a low risk of recurrence. Giant breed dogs and increased bodyweight were the only variables identified as possible risk factors for recurrence. The outcome for dogs with recurrence undergoing a second intervention was also favourable.

Video-assisted thoracic surgery anatomical lobectomy for a primary lung tumor in a dog.

A female Bernese Mountain Dog was diagnosed with a right middle lung lobe mass. The dog was positioned in a left lateral recumbency and one-lung ventilation was used under general anesthesia. Video-assisted thoracic surgery anatomical lobectomy was performed with 4 cm small thoracotomy and two 6-mm ports. Pulmonary vessels and bronchus were dissected and isolated individually at the hilum of the right middle lung lobe. Pulmonary vessels were ligated and were coagulated and transected using a vessel sealing device. The bronchus was ligated and transected. The mass in the right middle lung lobe was removed with a clean margin and without complications. Video-assisted thoracic surgery anatomical lobectomy was used to successfully remove a primary lung tumor in a dog.

Video-assisted thoracoscopic resection of noninvasive thymomas using one-lung ventilation in two dogs.

OBJECTIVE: To report the technique and outcome of video-assisted thoracoscopic surgery (VATS) for resection of cranial mediastinal thymoma in 2 dogs. STUDY DESIGN: Case report. ANIMALS: Eleven-year-old Labrador Retrievers (n=2). METHODS: Two dogs had VATS resection of thymoma. Preoperative computed tomography (CT) scans revealed well-circumscribed cranial mediastinal masses with dimensions of 4.5 cm x 4.2 cm x 3.7 cm and 2.1 cm x 2.1 cm x 4.1 cm (at the time of resection) without CT evidence of vascular invasion. One-lung ventilation (OLV) was achieved using a bronchoscopically placed double-lumen endobronchial tube. A 3-portal technique was used for VATS access to the thorax. Thymomas were dissected from the tissues of the cranial mediastinum with the aid of a harmonic scalpel and retrieved in specimen retrieval bags. RESULTS: Two cranial mediastinal thymomas were resected successfully, with their capsules intact, using a VATS technique. One dog developed aspiration pneumonia postoperatively which resolved with treatment and remains healthy 18 months postoperatively with no radiographic evidence of tumor recurrence. The second dog was diagnosed with myasthenia gravis, megaesophagus, and aspiration pneumonia preoperatively and despite recovering well from the procedure had a second episode of aspiration pneumonia 5 days postoperatively and was euthanatized. CONCLUSIONS: VATS resection of modestly sized noninvasive thymoma is possible in dogs. Careful case selection and preoperative imaging are the keys. CLINICAL RELEVANCE: Thoracoscopic resection of modestly sized mediastinal masses forms part of an increasingly expansive set of indications for minimally invasive surgery in select veterinary patients.