Left atrial appendage ligation with single transthoracic port assistance: a study of survival assessment in a porcine model (with videos)

The Evolution of "New Notes," Origins, and Future Directions

The transformation of the submucosa into a working space provided a paradigm shift for endolumenal endoscopic intervention. The submucosal space can provide an undermining access to the removal of overlying mucosal disease. This space can also provide a protective mucosal barrier accommodating interventions into the deep layers of the gut wall and body cavities, such as the abdomen and mediastinum.

Pericardial Endoscopy–Guided Left Atrial Appendage Ligation

Background—

Approaches for closing the left atrial appendage (LAA) have been developed for stroke prevention. However, the prevailing maneuvers require an open-chest surgery, intravascular access, or transseptal puncture. We evaluated the feasibility and safety of pericardial endoscopy-guided LAA ligation in a canine model.

Methods and Results—

We used a total of 8 canines and computed tomography was performed before the procedures. After a double percutaneous pericardiocentesis, a transurethral rigid endoscope was inserted into the pericardial space. The ENDOLOOP ligature was advanced to the ostium of the LAA by counter pulling the tip of the LAA with forceps. After confirming the positioning guided by transesophageal echocardiography, the ligature was securely tightened. Acute success was evaluated by transesophageal echocardiography and chronic success was evaluated by blood testing, computed tomography, and transesophageal echocardiography. The LAA ligation was safely achieved in all canines without major complications. One month after the ligation, the ligated LAA was replaced by fibrotic tissue, and both the transesophageal echocardiography and computed tomographic images revealed no residual shunt. There was only a localized adhesion of the pericardium, where the original LAA was located, without the need for antibiotic or steroid administration. The postprocedural internal surface of the ligated LAA was smooth by virtue of intimal growth. Blood tests showed a slight elevation of the inflammatory markers, but this normalized spontaneously.

Conclusions—

Pericardial endoscopy-guided LAA ligation could provide an alternative, minimally invasive, and feasible solution for LAA closure that does not require vascular access or a transseptal puncture.

Hybrid endoscopic thymectomy: combined transesophageal and transthoracic approach in a survival porcine model with cadaver assessment

BACKGROUND

Video-assisted thoracoscopic surgery thymectomy has been used in the treatment of Myastenia Gravis and thymomas (coexisting or not). In natural orifice transluminal endoscopic surgery, new approaches to the thorax are emerging as alternatives to the classic transthoracic endoscopic surgery. The aim of this study was to assess the feasibility and reliability of hybrid endoscopic thymectomy (HET) using a combined transthoracic and transesophageal approach.

METHODS

Twelve consecutive in vivo experiments were undertaken in the porcine model (4 acute and 8 survival). The same procedure was assessed in a human cadaver afterward. For HET, an 11-mm trocar was inserted in the 2nd intercostal space in the left anterior axillary line. A 0° 10-mm thoracoscope with a 5-mm working channel was introduced. Transesophageal access was created through a submucosal tunnel using a flexible gastroscope with a single working channel introduced through the mouth. Using both flexible (gastroscope) and rigid (thoracoscope) instruments, the mediastinum was opened; the thymus was dissected, and the vessels were ligated using electrocautery alone.

RESULTS

Submucosal tunnel creation and esophagotomy were performed safely without incidents in all animals. Complete thymectomy was achieved in all experiments. All animals in the survival group lived for 14 days. Thoracoscopic and postmortem examination revealed pleural adhesions on site of the surgical procedure with no signs of infection. Histological analysis of the proximal third of the esophagus revealed complete cicatrization of both mucosal defect and myotomy site. In the human cadaver, we were able to replicate all the procedure even though we were not able to identify the thymus.

CONCLUSIONS

Hybrid endoscopic thymectomy is feasible and reliable. HET could be regarded as a possible alternative to classic thoracoscopic approach for patients requiring thymectomy.