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

Anatomical considerations for the surgical approach to the canine accessory lung lobe

OBJECTIVE

To describe (1) the surgical anatomy of the accessory lung lobe (ALL) including vasculature and pulmonary ligamentous attachments and (2) lobectomy through a right thoracotomy and median sternotomy.

STUDY DESIGN

Cadaveric anatomical study.

ANIMALS

Nine adult canine cadavers, free of disease affecting the thoracic cavity and lung parenchyma.

METHODS

Median sternotomy and right and left lateral thoracotomies were performed to describe and image relevant variations in anatomy using accompanying photographs and thorough voice notes. Consideration for ALL removal via right thoracotomy at the fifth through seventh intercostal spaces and median sternotomy were documented and compared.

RESULTS

The median weight of the cadavers was 20.85 kg (6.9-45.5 kg). Variation in the configuration of venous drainage of the ALL was identified. The lateral vein varied in its location and was also observed to combine with the medial vein in one cadaver. The pulmonary ligament attached to the ALL in a caudally pointing apex on the dorsal process of the lobe. Medial and lateral extensions of the ALL parenchyma were found. The ALL was most easily accessed by a right lateral thoracotomy at the sixth intercostal space. Although not optimal, removal of this lung lobe via median sternotomy was feasible.

CONCLUSION

Significant variations were found in the blood supply to the ALL. A right lateral thoracotomy at the sixth intercostal space was preferred for a surgical approach to the ALL.

CLINICAL SIGNIFICANCE

Surgeons should be aware of several anatomical particularities including the venous drainage, ligamentous attachments, and parenchymal extensions of the ALL.

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.

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.

Impact of the internet on veterinary surgery

The advent of the internet, and the technological innovations associated with it, have driven significant advances in surgical teaching and learning. The ease of access to information and the variety of online resources allow rapid sharing of surgical knowledge, promoting new teaching and learning patterns. Educational content from online platforms adds theoretical and practical knowledge to accelerate the learning curve and continuing education of surgeons. This study reviews how the advent of the Internet has influenced the teaching and dissemination of knowledge in veterinary surgery.

Feasibility of thoracoscopic attenuation of the azygos vein as a model for portoazygos shunts: A canine cadaveric study

OBJECTIVE

To evaluate the feasibility of thoracoscopic placement of three vascular attenuation devices by using the azygos vein as a model for portoazygos (PA) shunts and to describe the approach for thoracoscopic placement of these attenuation devices in small breed dogs.

STUDY DESIGN

Randomized, prospective, cadaveric study.

ANIMALS

Cadavers of 10 adult small breed dogs.

METHODS

Cadavers were placed in sternal recumbency with left dorsolateral obliquity, and three thoracoscopic ports were established in the right hemithorax at the mid-10th intercostal space and dorsal third of the ninth and 11th intercostal spaces. The caudal azygos vein was thoracoscopically isolated along three adjacent segments bordered by four intercostal arteries, beginning just cranial to the first intercostal artery visualized cranial to the diaphragm. Three attenuation devices including coated cellophane, uncoated cellophane, and a 5-mm ameroid constrictor were thoracoscopically placed around one segment in each dog. Minor port access modifications were required to improve working space and triangulation in three dogs. Ability to successfully place the device, time required for placement, endoscopic clip configuration, and complications associated with placement were recorded.

RESULTS

Median dog weight was 7.7 kg (range, 1.8-11). All attenuation devices were successfully placed thoracoscopically in all cadavers. No difference was detected in time required for placement between the ameroid constrictor and coated and uncoated cellophane (range, 2.3-33.8 minutes, P = .8).

CONCLUSION

Ameroid constrictors and thin film bands were consistently placed via thoracoscopy around the caudal azygos vein of small breed dogs.

CLINICAL SIGNIFICANCE

These results justify further investigation of thoracoscopic PA shunt attenuation in affected dogs.

The feasibility and effectiveness of thoracoscopic transdiaphragmatic approach for lung biopsy in rabbits. A randomized study

PURPOSE

To assess the feasibility of thoracoscopic transdiaphragmatic approach for biopsy of all lung lobes and to determine the optimal intercostal space (ICS) for biopsy of each lung lobe.

METHODS

Ten rabbits were positioned in dorsal recumbency. Total thoracoscopy lung biopsy was made combined transdiaphragmatic approach and right ICS approaches. A camera port was made in the transdiaphragmatic approach and the instrument port was made of ICS 7 and ICS 9. A pre tied loop ligature was placed to performed a caudal lung lobe biopsy and to simulate biopsies of the others lung lobes.

RESULTS

Biopsy of the cranial aspect of the right caudal lung lobe was performed at ICS 9. Simulated biopsy of the accessory lung lobe was performed at ICS 9. Simulated lung biopsy of the right cranial and middle lung lobes was performed at ICS 7. The caudal and dorsal aspect of the right caudal lung lobe was not visualized by telescope at transdiaphragmatic approach, and biopsy was not performed.

CONCLUSIONS

Thoracoscopic transdiaphragmatic approach for lung lobes biopsies was a feasible technique, except for the caudal aspect of the right caudal lung lobe. An ideal intercostal port for biopsy of each right lung lobe was determined.

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.