Pericardioscopic imaging findings in cadaveric dogs: comparison of an apical pericardial window and sub-phrenic pericardectomy

Evaluation of Thoracoscopic Pericardial Window Size and Execution Time in Dogs: Comparison of Two Surgical Approaches

Pericardial effusion presents clinicians with a challenge when diagnosing the underlying cause and performing a prognosis. Different techniques have been suggested for canine thoracoscopic pericardiectomy with the creation of variable pericardial window size. The aim of this study was to statistically compare the surgical time and achieved window size of the paraxiphoid transdiaphragmatic and monolateral intercostal approaches. The paraxifoid and monolateral intercostal approaches showed a mean surgical time of 55 ± 20.08 (SD) minutes and 13.94 ± 4.61 (SD) minutes, and a mean pericardial window diameter of 4.23 ± 0.80 (SD) cm and 3.31 ± 0.43 (SD) cm, respectively. A significant correlation was observed between the dogs' bodyweight and window size (r = 0.48; p = 0.04) for both surgical approaches, and between the dogs' bodyweight and surgical time (r = 0.72; p = 0.0016) for monolateral intercostal approach. All treated dogs showed no clinical signs of recurrent cardiac tamponade during the follow-up. Our results provided useful information to help surgeons make the definitive choice of the surgical technique to treat the pericardial effusion.

Outcomes of dogs with recurrent idiopathic pericardial effusion treated with a 3-port right-sided thoracoscopic subtotal pericardiectomy

OBJECTIVE

To describe a 3-port right-sided thoracoscopic subtotal pericardiectomy (TSP) to treat dogs with recurrent idiopathic pericardial effusion (RIPE) and report their long-term survival.

STUDY DESIGN

Retrospective case series.

ANIMALS

Sixteen client-owned dogs.

METHODS

Medical records were searched for dogs with idiopathic pericardial effusion that recurred after 1 or more pericardiocenteses and treated with a 3-port right-sided technique (1 subxiphoid camera port and 2 instrument ports on the right side of the dog). Follow-up consisted of direct examination or communication with referring veterinarians or owners.

RESULTS

Thoracoscopic subtotal pericardiectomy was successfully completed in all dogs, with no surgical complications. The median duration of postoperative follow-up was 191.5 days (range, 5-1345). The median survival time (MST) after surgery was 365 days (range, 5-1345); MST of dogs with a histopathological diagnosis of neoplasia (n = 4) was 76 days, whereas dogs with no evidence of neoplasia had an MST of 367 days (n = 12, P = .14). Recurrent pleural effusion was the ultimate cause of death or reason for euthanasia in 8 of 16 dogs.

CONCLUSION

The technique described here resulted in similar surgical times and outcomes for dogs undergoing TSP for RIPE compared with previous studies. Neoplasia was identified in 4 of 16 dogs.

CLINICAL SIGNIFICANCE

Thoracoscopic subtotal pericardiectomy can be readily performed with only 2 instrument ports, both on the same side of the dog, and without 1-lung ventilation. Recurrent pleural effusion led to the death of half of the dogs in this series.

Epicardial exposure provided by a novel thoracoscopic pericardectomy technique compared to standard pericardial window

OBJECTIVE

(1) To describe a novel technique for thoracoscopic pericardectomy using a pericardial window with vertical pericardial fillets (PW+F). (2) To compare epicardial exposure between a standard pericardial window (PW) and PW+F.

STUDY DESIGN

Experimental study.

ANIMALS

Purpose-bred research dogs (n = 12).

METHODS

PW was performed through a 3-port subxiphoid thoracoscopic approach. After PW, vertical fillets were made in the pericardium for PW+F. Thoracoscopic images from 3 views were acquired after each procedure, and percentage of epicardial surface exposed (PESE) was compared. Epicardial exposure and iatrogenic damage to surrounding structures were directly assessed via postmortem gross examination.

RESULTS

The exposed epicardial surface (PESE) was increased with our novel compared to the standard technique. Median surgery time for PW+F was 25 minutes. The procedure was performed in 11 of 12 dogs without iatrogenic damage to surrounding structures. In 1 dog, the electrosurgery device contacted the epicardium and caused fatal ventricular fibrillation while performing PW+F. Based on postmortem assessment in all dogs with PW+F, the pericardium could move freely away from the heart, exposing the majority of the epicardial surface.

CONCLUSION

Thoracoscopic PW+F is a novel technique that improves the exposure of the epicardium compared to standard PW. While PW+F can be performed successfully and in an efficient manner, the surgeon must be aware of the risk of iatrogenic trauma to thoracic structures when using electrosurgery.

CLINICAL RELEVANCE

PW+F offers a relatively safe, efficient, and effective minimally invasive method that improves the exposure of the epicardium compared to PW.