Laparoscopy and thoracoscopy in small animal surgery: A 2020 survey of small animal diplomate and resident veterinary surgeons

OBJECTIVE

To document the utilization and training of laparoscopic and thoracoscopic minimally invasive surgery (MIS) techniques within the American, European, Australian and New Zealand Colleges of Small Animal Veterinary Surgeons (ACVS, ECVS, and ANZCVS) in 2020.

STUDY DESIGN

Observational study.

SAMPLE POPULATION

Diplomates and residents of the ACVS, ECVS, and FANZCVS.

METHODS

An electronic survey was sent using veterinary list servers. Questions were organized into categories evaluating (1) the demographics of the study population and the caseload, (2) comfort level with specific procedures, (3) motivating factors and limitations, and (4) surgical training and the role of the governing bodies.

RESULTS

Respondents included 111 practicing surgeons and 28 residents. Respondents' soft-tissue MIS caseloads had increased since they first started performing MIS; however, most respondents were only comfortable performing basic laparoscopy. Over half of the respondents agreed on the patient benefits and high standard of care provided by MIS. Perceived adequate soft-tissue training in MIS during residency was strongly associated with perceived proficiency at the time of survey response. Most respondents agreed that the specialty colleges should take a more active role in developing standards for soft-tissue MIS, with residents agreeing that a required standardized course would be beneficial.

CONCLUSION

Soft-tissue MIS is widely performed by diplomates and residents. Perceived adequate soft-tissue MIS training was strongly associated with perceived proficiency.

CLINICAL SIGNIFICANCE

There is substantial underutilization of advanced MIS techniques in veterinary specialty surgical practice, which might be improved by a stronger focus on MIS training during residency.

Advances in Minimally Invasive Procedures of the Thoracic Cavity

Significant advances in veterinary minimally invasive surgeries and procedures have occurred in the past 10 years. These advances have been allowed due to continual research into optimizing working space through one-lung ventilation techniques and carbon dioxide insufflation. Additionally, minimally invasive surgery enthusiasts have joined forces with interventionalists and, in many cases, physicians to push the boundaries, minimize pain, suffering, and time away from owners with advances in a variety of procedures. Several larger multi-institutional retrospective studies on various disease processes allow veterinarians and owners to understand that minimally invasive approaches allow for outcomes comparable to traditional open surgery and, in some cases, may now be considered the standard of care in canine and feline patients.

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.

Thoracoscopic treatment of persistent right aortic arch in dogs with and without one lung ventilation

OBJECTIVE

To evaluate thoracoscopic treatment of persistent right aortic arch (PRAA) in dogs with and without the use of one lung ventilation (OLV).

STUDY DESIGN

Retrospective cohort study.

ANIMALS

Twenty-two (client-owned and shelter) dogs diagnosed with PRAA.

METHODS

Medical records were reviewed retrospectively and intraoperative and immediate postoperative data were compared between dogs that underwent thoracoscopic treatment of PRAA with (OLV+) and without (OLV-) OLV.

RESULTS

Ten of the 12 dogs in the OLV+ group and 7/10 dogs in the OLV- group had their left ligamentum arteriosum successfully ligated during thoracoscopy. Median surgical time, surgery complications, anesthesia complications, and rate of conversion to an open thoracotomy due to limited visualization or surgical complications were similar between the two groups.

CONCLUSION

Thoracoscopic treatment of PRAA can be performed with or without OLV. Surgical time, intraoperative complications, and conversion rates were similar between dogs that underwent thoracoscopic treatment of PRAA with and without OLV. OLV may not have contributed to improved visualization in this group of dogs.

CLINICAL SIGNIFICANCE (OR IMPACT)

The use of OLV is safe during thoracoscopic treatment of PRAA. OLV did not appear to provide significant benefits in this case series and thoracoscopic treatment of PRAA in dogs may be performed successfully with or without the use of OLV.

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.

Determination of optimal location for thoracoscopic-assisted pulmonary surgery for lung lobectomy in cats

OBJECTIVE

To determine the optimal intercostal space (ICS) for thoracoscopic-assisted pulmonary surgery for lung lobectomy in cats.

SAMPLE

8 cat cadavers.

PROCEDURES

Cadavers were placed in lateral recumbency. A 5-cm minithoracotomy incision was made in the middle third of ICS 4 through 7 on the left side and 4 through 8 on the right side, and a wound retractor device was placed. A camera port was made in the middle third of ICS 9. Each lung lobe was sequentially exteriorized at each respective ICS. A thoracoabdominal stapler was placed to simulate a lung lobectomy, and distance from the stapler anvil to the hilus was measured.

RESULTS

For the left cranial lung lobe, there was no significant difference in median distance from the stapler anvil to the pulmonary hilus for ICS 4 through 6. Simulated lobectomy of the left caudal lung lobe performed at ICS 5 and 6 resulted in a significantly shorter distance, compared with lobectomy performed at ICS 4 and 7. Simulated lobectomy of the right cranial and right middle lung lobes performed at ICS 4 and 5 resulted in a significantly shorter distance, compared with lobectomy performed at ICS 7. Simulated lobectomy of the accessory and right caudal lung lobes at ICS 5 and 6 resulted in a significantly shorter distance than for lobectomy performed at ICS 8.

CONCLUSIONS AND CLINICAL RELEVANCE

An optimal ICS for a minithoracotomy incision was determined for thoracoscopic-assisted lung lobectomy in cats.

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.

Use of Minimally Invasive Surgery in the Diagnosis and Treatment of Cancer in Dogs and Cats

Surgical management of neoplastic disease is common in veterinary medicine. Minimally invasive surgery (MIS) has gained widespread acceptance by veterinary surgeons and is experiencing rapid growth and frequency of use. Many neoplastic diseases in the abdomen and thorax of dogs and cats can be treated as effectively with MIS as with traditional open surgery. Additionally, MIS allows for less invasive options for organ biopsy in cancer patients either for initial diagnosis or for staging to inform prognosis and treatment. Despite the recent increase in MIS, additional research is required to further characterize the benefits to oncology patients and to ensure that surgical oncologic principles and patient outcomes are not compromised by the use of MIS.

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.

Utility of Lung Ultrasonography for Detection of Pleural Adhesions in Dogs

OBJECTIVES

To assess lung respiratory movement ("lung sliding") in dogs using B-mode ultrasonography (US) and to develop a method that assesses adhesions between the parietal pleura and the lung.

METHODS

Seventeen male beagles were anesthetized, and respiratory management was performed with intermittent positive pressure ventilation. Lung-sliding assessments and adhesion examinations were performed with lung US under general anesthesia before and 2 weeks after thoracotomy. Lung sliding was scored on a 4-level scale based on the percentage of the area that showed lung sliding (3, an area of roughly ≥80% of the intercostal space; 2, about 50% of the area of the intercostal space; 1, a small area of the intercostal space; or 0, movement absent); scores of 0, 1, and 2 indicated adhesions, whereas a score of 3 indicated no adhesions. The animals were then euthanized, and necropsy was performed to examine pleural adhesions.

RESULTS

Lung US and necropsy findings were compared. The median lung-sliding score for the 12 sites with pleural adhesions on necropsy was 1.5, whereas it was 3.0 for the 532 sites without pleural adhesions. The lung-sliding score was significantly lower in the group with adhesions (P < .0001). Adhesion sites detected on necropsy were in accordance with the sites that had decreased lung-sliding scores. Lung US could detect pleural adhesions with sensitivity of 100.0% and specificity of 87.8%.

CONCLUSIONS

Examination of lung sliding by thoracic US has high diagnostic value for detecting canine pleural adhesions and is useful in predicting adhesion sites before thoracic surgery in healthy dogs.

Comparison of acute phase reaction and postoperative stress in pigs undergoing video-assisted thoracoscopic versus thoracotomy pneumonectomy

Background

Video-assisted thoracoscopic surgery (VATS) has been used for many thoracic diseases as an alternate approach to thoracotomy. The aim of this study was to compare the surgical outcome of pneumonectomy using VATS with that using thoracotomy pneumonectomy in pigs. Fourteen pigs were equally divided into two groups; one group underwent VATS and the other group underwent transthoracic pneumonectomy. We monitored pre-, intra-, and post-operative physiologic parameters, along with blood cell count, serum C-reactive protein (CRP), serum amyloid A (SAA), interleukin-6 (IL-6) and cortisol. The differences between the two approaches were analyzed.

Results

Mean surgical time in the VATS group (160.6 ± 16.2 min) was significantly longer than that in the thoracotomy group (123.7 ± 13.2 min). In both groups, CRP and IL-6 concentrations were significantly increased at postoperative 4 h, and then gradually decreased to preoperative levels. CRP and IL-6 at postoperative day 1 were significant lower in the VATS group compared with the thoracotomy group. SAA was significantly increased at postoperative days 1 and 3 in both groups compared with preoperative levels. Cortisol was significantly increased immediately after surgery in both groups compared with preoperative levels, and was significantly higher in the thoracotomy group than the VATS group at postoperative 4 h and 1 day.

Conclusions

There was no difference between the two groups in physiologic parameters and blood cell count. However, the results indicate that VATS resulted in a smaller incision, less acute-phase reaction, less stress and less pain compared with thoracotomy pneumonectomy.