Feasibility of the transtracheal approach for the thoracic cavity in a large animal model

Subxiphoid single-port video-assisted thoracoscopic surgery

Background

We report the feasibility and safety of chest surgery through the subxiphoid single port approach based on our preliminary experience.

Methods

From December 2013 till January 2016, 39 patients underwent 40 thoracoscopic surgeries via a 3- to 4-cm subxiphoid single incision. A sternal lifter was applied for better entrance and working angle. A zero-degree deflectable scope was preferred. The technique for anatomic resection was similar to that in the traditional single-port approach. Patient characteristics and demographic data were analyzed.

Results

There were 29 females and 10 males, with a median age of 56 years. Indication for surgery included 24 patients with primary lung cancer, eight with lung metastases, two with benign lung lesions, one with bilateral pneumothorax, and five with mediastinal tumors. Surgeries included lobectomy in 21, segmentectomy in five, wedge resection in nine, and mediastinal surgery in five patients. There was no surgical mortality. Complications (10%, 4 in 40) included postoperative bleeding in one patient, chylothorax in one patient, and transient arrhythmia in the early learning curve in two patients.

Conclusions

Our results indicated that subxiphoid single-incision thoracoscopic pulmonary resection could be performed safely but under careful patient selection with modification of instruments. Moreover, having a previous single-port incision experience was crucial. Major limitations of this approach included more frequently encountered instrument fighting; interference of left-side procedure related to heartbeat and radical mediastinal lymph node (LN) dissection; and the ability to handle complex conditions, such as anthracotic LNs, diffuse adhesion, and major bleeding.

Transtracheal thoracic natural orifice transluminal endoscopic surgery (NOTES) in a swine model

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has the potential to be the final frontier in minimally invasive procedures in thoracic surgery. In order for thoracic pleural NOTES to 1 day be ready for clinical trials, each step of the procedure must be independently evaluated for both safety and efficacy. The aim of this study was to evaluate the trachea as a portal of entry for thoracic NOTES.

METHODS

Eight 40-kg swine underwent right thoracic pleuroscopy in a survival model. In order to avoid inadvertent injury to the superior vena cava, endobronchial ultrasound was employed to select the location of airway incision. A 7-mm linear incision was then performed at the chosen location using an endoscopic electrocautery needle knife through a therapeutic flexible videobronchoscope. The mediastinal fat and parietal pleura were then dissected with electrocautery, and complete right pleuroscopy was performed. The tracheal and mediastinal portal of entry were then sealed with 1-2 cc of fibrin sealant. The pigs were kept alive for 21 days postoperatively. Postmortem diagnostic bronchoscopy was performed to assess tracheal healing. All tracheal specimens underwent histologic examination for healing and signs of mediastinal infection.

RESULTS

Thoracic NOTES procedures on all eight pigs were successful. There were no intraoperative complications except for one minor bleeding episode within the mediastinal dissection site which stopped spontaneously. Two pigs died from severe laryngospasm in the early postoperative period. Six pigs survived for 21 days post-procedure and experienced uneventful postoperative courses. Postmortem examination demonstrated complete tracheal healing with appropriate scarring in all pigs.

CONCLUSIONS

The trachea appears to be a safe port of entry for thoracic NOTES procedures in a swine model. Smaller tracheal incisions followed by balloon dilatation are associated with less postoperative morbidity and mortality. Tracheal incisions sealed with fibrin sealant healed rapidly and without signs of mediastinal infection. This procedure represents a work in progress and is not yet ready for human trials.

Feasibility of Transumbilical Surgical Lung Biopsy and Pericardial Window Creation

Background. To date there are no practical platforms for performing natural orifice transluminal endoscopic surgery in the thoracic cavity. This study evaluates the feasibility of transumbilical thoracosopy for lung biopsy and pericardial window creation. Methods. Eleven dogs (6 in the nonsurvival group and 5 in the survival group) were used for this study. A homemade metallic tube was advanced into the abdominal cavity via a 12-mm umbilical incision. The metallic tube was advanced into the thoracic cavity through a subxyphoid diaphragmatic incision under video guidance. Access to the thoracic cavity was achieved by a flexible bronchoscope via the metallic tube. Surgical lung biopsy and pericardial window creation were performed using an electrocautery loop and needle knife. The animals were euthanized 20 minutes after the surgery was complete (nonsurvival group) or 14 days postsurgery (survival group) for necropsy evaluation. Results. Eight pericardial window creations and 21 of 22 preplanned lung biopsies were completed in a median time of 72.18 minutes (range 50-105 minutes). One dog in the nonsurvival group died after tension pneumothorax due to postprocedure massive air leaks. In the survival group, the postoperative period was uneventful in all 5 dogs. Autopsies revealed no signs of vital organ injury and complete healing of the diaphragmatic incision occurred in all animals. Conclusions. The study demonstrated that transumbilical thoracoscopic surgical lung biopsy and pericardial window creation is feasible. The safety and efficacy of the transumbilical approach need to be verified by a more detailed survival study.

Transoral endoscopic surgery versus conventional thoracoscopic surgery for thoracic intervention: safety and efficacy in a canine survival model

PURPOSE

Transoral endoscopic surgery has been shown to be feasible and safe in both humans and animal models. The purpose of this study was to evaluate the safety and efficacy of transoral and conventional thoracoscopy for thoracic exploration, surgical lung biopsy, and pericardial window creation.

METHODS

The animals (n = 20) were randomly assigned to the transoral endoscopic approach group (n = 10) or conventional thoracoscopic approach group (n = 10). Transoral thoracoscopy was performed with a flexible bronchoscope via an incision over the vestibulum oris. In conventional thoracoscopy, access to the thoracic cavity was obtained through a thoracic incision. Surgical outcomes (body weight, operating time, operative complications, and time to resumption of normal diet), physiologic parameters (respiratory rate, body temperature), inflammatory parameters [white blood cell (WBC) counts and C-reactive protein (CRP)], and pulmonary parameters (arterial blood gases) were compared for both procedures.

RESULTS

The surgical lung biopsy and pericardial window creation were successfully performed in all animals except one animal in the transoral group. There was no significant difference in operating times between the groups. The increase in WBC in the transoral thoracoscopy group was significantly smaller on postoperative day 1 than in the conventional thoracoscopy group (p = 0.0029). The transoral group had an earlier return to preoperative body temperature (p = 0.041) and respiratory rate (p = 0.045) on day 7. With respect to pulmonary parameters, there was no significant difference in blood pH, pCO2, or PaCO2 between the transoral and transthoracic groups. All animals survived without complications 14 days after surgery.

CONCLUSIONS

This study demonstrated that the transoral approach was comparable to conventional thoracoscopic surgery for lung biopsy and pericardial window creation in terms of safety and efficacy.

Comparison of hemodynamic and inflammatory changes between transoral and transthoracic thoracoscopic surgery

BACKGROUND

Natural orifice transluminal endoscopy has been developed for abdominal surgical procedures. The aim of this study was to compare the surgical outcome between a novel transoral approach and a standard transthoracic approach for the thoracic cavity in a canine model.

METHODS

Twenty-eight dogs were assigned to transoral (n = 14) or standard thoracoscopy (n = 14). Each group underwent thoracic exploration, pre-determined surgical lung biopsy, and pericardial window creation. Blood draws were obtained before surgery and at postoperative days 1, 3, 7, and 14. Operative time, complications, laboratory parameters, hemodynamic parameters, and inflammatory parameters were compared between the two procedures. The animals were monitored for two weeks and necropsy were performed for surgical outcome evaluation.

RESULTS

The thoracic procedures were successfully performed in all of the dogs, with the exception of one animal in the transoral group. There were no serious acute or delayed complications related to surgery. There was no difference between the two surgical groups for each of the hemodynamic parameters that were evaluated. Regarding the immunological impact of the surgeries, transoral thoracoscopy was associated with significant elevations in interleukin 6 and c-reactive protein levels on postoperative days 1 and 3, respectively, when compared with the standard thoracoscopy. All dogs recovered well, without signs of mediastinitis or thoracic infection. Necropsy revealed absence of infection, no injury to vital organs, and confirmed the success of the novel procedure.

CONCLUSIONS

This study suggests that both techniques were comparable with respect to procedure success rate, hemodynamic impact, and inflammatory changes. Furthermore, there was no difference in the incidence of postoperative discomfort between groups.

The lateral decubitus position improves transoral endoscopic access to the posterior aspects of the thorax

BACKGROUND

The success of natural orifice transluminal endoscopic surgery (NOTES) depends on an adequate exploration of surgical regions. Currently, limited data are available regarding the optimal position for the NOTES approach for thoracic surgery. This study therefore aimed to evaluate the effectiveness of transoral thoracic exploration in a canine model placed in a lateral decubitus position.

METHODS

A total of 14 dogs were used in this study. Transoral thoracoscopy was performed using a custom-made metal tube via an incision over the vestibular incision with the animal in a supine position. After thoracic exploration, the animal was placed in a lateral decubitus position. The thoracic intervention (surgical lung biopsy, pericardial window creation, and dorsal sympathectomy) was performed by passing a flexible bronchoscope through the lumen of a metal tube.

RESULTS

The mean operative time for this procedure was 70 min (range 45-100 min). For 12 dogs, all procedures were completed without major complications. However, for one dog, the exploration of the thoracic cavity was incorrect (the right lower lobe had been misinterpreted as the left lower lobe). Another dog had minor bleeding because of an intercostal artery injury that occurred during sympathectomy.

CONCLUSION

The posterior aspect of the thoracic cavity can be exposed via a transoral approach with the animal in a lateral decubitus position. This approach may be considered as an adjuvant to the supine approach, in which exploration of the posterior thoracic cavity is restricted.

Endoscopic closure of a tracheal access site using bioglue after transtracheal thoracoscopy in a nonsurvival canine model

OBJECTIVES

An ideal wound closure device would repair the wound with minimal complexity. In this report, we describe a simple wound closure method using BioGlue sealant.

METHOD

Eleven canines underwent transtracheal pericardial window creation under endoscopic guidance for natural orifice transluminal endoscopic surgery (NOTES). The tracheal wound was closed using BioGlue sealant. The integrity of the wound was assessed by determining the amount of air leaking under mechanical ventilation.

RESULTS

Transtracheal thoracic exploration and pericardial window creation was successful for all of the canines, and adequate wound closure was achieved in 10 of the canines. There was 1 case of NOTES-related death arising from misplacement of the endotracheal tube in the left lower lobar bronchus. This caused a collapse of the left upper lobe and ventilatory failure. Minor lung injuries occurred in 3 canines and minor mediastinal bleeding was encountered in 1 canine during the creation of the access site.

CONCLUSION

BioGlue sealant was found to be effective in sealing the tracheal wound in all but 1 of the canines. This study demonstrates that the use of the sealant is a simple and efficient means of endoscopically closing the tracheal access site in NOTES.