Transumbilical approach has been shown to be feasible to perform lung wedge resection and anatomic lobectomy. This study uses a canine model to assess the feasibility of transumbilical segmentectomy.

Transumbilical segmentectomy was performed in 10 beagle dogs using a 3-cm umbilical incision combined with a 2.5-cm diaphragmatic incision. We evaluated the surgical outcomes, operative complications, physiologic changes, hemodynamic changes, and inflammatory changes of the procedures.

Transumbilical segmentectomy was successfully completed in eight of ten animals. There was one mortality complication related to lung injury causing hemodynamic collapse. Another animal required conventional thoracotomy to complete the surgery due to limited working space. There were no notable events in the postoperative period for all eight dogs that completed the segmentectomy via the transumbilical approach.

This animal study demonstrates that the pulmonary segmentectomy can be performed with current standard endoscopic instruments via a single transumbilical incision.We believe that advancing surgical innovation and good collaboration between multi-disciplinary research teams will further establish clearer roles for transumbilical segmentectomy in thoracic surgery.

The development of minimally-invasive surgery of the thorax began in the 1990s, but not until the recent decade did we see dramatic improvements in patient care and refinement of technique. The current generation has witnessed the evolution from traditional thoracotomy, to a single-port, non-intubated thoracoscopic approach. The investigation of subxiphoid single-port, transumbilical approach, and natural orifice transluminal endoscopic surgery (NOTES) in animal model are also undergoing. In Taiwan, several talented young surgeons have vigorously devoted their ideas and innovations to this field, making the Taiwan surgical society vivid and prosperous. The desire to improve, and willingness to change are the foundation of those surgeons. Providing better patient care is their impetus to strive for improvement. This article provides an account of how minimally-invasive thoracic surgery has evolved in recent years, and what clinical innovations have been developed by the Taiwan surgical society.

Natural orifice transluminal endoscopic surgery (NOTES) has emerged as one of the most exciting areas in the field of minimally invasive surgery during the last decade. NOTES comprises a wide spectrum of procedures from various natural accesses such as transgastric or transvaginal routes, and different direct-target or distant-target organs. Since polypectomy was first performed in 1955, major advances in technology and refinement of endoscopic technique have allowed endoscopic surgeons to perform complex endoscopic interventions such as endoscopic submucosal dissection. Recognizing the safety and feasibility of submucosal tunnelling and mucosal closure, endoscopic resection beyond the level of mucosa has been increasingly reported. One of these procedures, peroral endoscopic myotomy for achalasia, has gained much popularity and excellent results have been published comparable with that of traditional Heller's cardiomyotomy. Submucosal tunnelling endoscopic resection has also been reported for tumours situated in the muscular layer of the gastrointestinal tract. To overcome the difficulty of intestinal closure after NOTES, researchers have collaborated with the industry in developing different endoscopic suturing devices such as the Eagle Claw (Olympus Medical Systems, Tokyo, Japan) and Overstitch™ (Apollo Endosurgery, Austin TX, USA). These devices allow precise and secure suture application with the ordinary flexible endoscope, achieving tissue approximation similar to open surgical suturing. To further expand the potential of NOTES, investigators had also developed multitasking platforms enabling the performance of surgical procedures of even higher complexity. Recently, a novel endoscopic robotic system 'Master and Slave Transluminal Endoscopic Robot' (MASTER) has been developed. Early results of endoscopic resection utilizing this system have been encouraging, allowing both experts and novices in endoscopy to perform difficult endoscopic resection with a high degree of flexibility.

Natural orifice transluminal endoscopic surgery (NOTES) has been established in animal models and human studies.

The aim of this study was to assess the feasibility and efficacy of applying transgastric NOTES to diagnose patients with ascites of unknown origin.

Prospective study.

Two university and teaching hospitals.

Patients with ascites of unknown origin.

Diagnostic transgastric NOTES.

Characteristic of ascites cases, conditions of the abdominal cavity, diagnostic accuracy, adverse events, and follow-up time.

Transgastric NOTES was performed successfully in 78 patients with ascites of unknown origin, and 72 cases (92.3%) were clearly diagnosed. They included malignant tumors (39 cases), tuberculous peritonitis (28 cases), chronic hepatic inflammation (3 cases), necrotizing lymphadenitis (1 case), and eosinophilic serositis of the small intestine (1 case). In addition, there were 6 nondiagnostic cases, and no severe adverse events were found.

Nonrandomized control analysis.

Transgastric NOTES in combination with biopsy can elucidate the causes of ascites of unknown origin in the majority of cases. Therefore, it is a feasible and effective approach to access the peritoneal cavity and also a valuable modality to detect the cause of diseases with ascites of unknown origin.

Many GI motility disorders are associated with underlying GI neuromuscular pathology, which requires full-thickness biopsies (FTB) for histopathologic diagnosis. Currently, none of the endoscopy-based attempts to obtain FTB specimens have proven suitable for routine use. This study evaluated a novel endoscopic prototype device (ED) for this purpose.

To determine (1) the ability of the ED to obtain suitable FTB specimens, (2) associated complications, (3) feasibility of reliable defect closure, and (4) ability to evaluate intramural neuromuscular components.

Preclinical proof-of-concept study in 30 pigs.

Animal laboratory.

Gastric FTB specimens were obtained with a circular cutter and anchor. The defect was closed by over-the-scope clips/T-tags. The resection site was inspected via laparoscopy. After 2 to 4 weeks, necropsy was carried out to evaluate late complications.

Feasibility, safety, and closure rate of the procedure. FTB specimens were assessed by histology/immunohistochemistry to visualize enteric neuromusculature.

A total of 29 of 30 procedures were successfully performed; one hemorrhage required endoscopic treatment. A total of 29 of 30 FTB specimens (mean diameter 9.1 mm) were retrieved in 7.1 ± 0.4 minutes (range 3.0-12.5 minutes), displaying optimal tissue quality. Defect closure took 10.8 ± 0.9 minutes (range 7.2-32 minutes). Laparoscopy did not reveal damage to adjacent organs. Necropsy showed well-healed scars at the resection site and no complications, peritonitis, or abscess formation. Histology showed smooth muscle layers and submucosal and myenteric ganglia.

Survival animal pilot study, no patients.

The novel ED enabled safe harvesting of well-preserved FTB specimens. Defect closure proved to be reliable. All neuromuscular structures relevant for histopathologic evaluation of GI neuromuscular pathology were demonstrated. Further studies are needed to verify the efficacy of this prototype device in the entire gut and in humans.

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.

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.

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.

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.

Natural orifice transluminal endoscopic surgery (NOTES) mediastinoscopy (MED) through the esophagus has proved to be feasible in the animal model. However, injury of the adjacent pleura and pneumothorax has been reported as a frequent adverse event when using a blind access.

To assess the utility and safety of a CT-based image registration system (IRS) for navigation in the mediastinum.

Prospective, randomized, controlled trial in 30 Yorkshire pigs. Thirty-minute MEDs were performed: 15 MEDs were performed with IRS guidance (MED-IRS), and 15 MEDs were performed with a blind access.

Animal research laboratory.

In both groups, the mediastinum was accessed through a 10-cm submucosal tunnel in the esophageal wall. Timed exploration was performed with identification of 8 mediastinal structures.

Technical feasibility, adverse events, and the number of mediastinal structures identified.

Thirty animals weighing 31.5 ± 3.5 kg were included in this study. MED was not possible in 2 animals in the "MED with blind access" group but was possible in all MEDs performed with IRS. The mean number of identified organs was slightly higher in "with IRS-MED" (6.13 ± 1.3) than with MED with blind access (4.7 ± 2.3; P = .066). Moreover, the right atrium and vena cava were identified in more cases with IRS-MED than in MED with blind access (13 vs 3 and 15 vs 11, P = .000 and P = .03, respectively). There were 3 (23%) adverse events with IRS-MED and 4 (27%) with "MED with blind access" (P = not significant), with pneumothorax being the most frequent (2 and 3, respectively).

Nonsurvival animal study.

This study demonstrates that the IRS system appears feasible in natural orifice transluminal endoscopic surgery MED and suggests that IRS guidance might be useful for selected procedures.

Esophageal full-thickness wall repair is an important but unsolved issue in endoscopy. It is unknown how well endoscopic clip closure (ECC) and endoscopic closure with suturing (ECS) perform compared with the criterion standard of thoracoscopic closure (TC).

Comparison of technical success, feasibility, long-term patency, complications, and histological quality of the different closure techniques (ECC, ECS, TC) for esophageal perforations.

Comparative animal study.

Approved animal facility.

Eighteen pigs.

Eighteen pigs were randomized, 6 each into 3 groups (ECC, ECS, TC). After endoscopic wall incision and mediastinoscopy, closure was performed by using 1 of the 3 techniques. After 8 to 12 weeks, pre-euthanasia endoscopic, necropsy, histological, and morphometric analyses were performed.

Long-term survival and histological quality of the repair.

The closure of the esophageal incisions was successful in all pigs. On days 2 and 6, 1 animal died of mediastinitis, 1 in the ECS group because of reflux of gastric contents into the mediastinum before the repair and 1 in the TC group because of leakage of the sutured closure (P = 1.0). No strictures were seen on prenecropsy endoscopy. At necropsy, 1 mediastinal abscess was found in an ECS animal (P = 1.0). Minor complications included periesophageal adhesions and reactive lymph nodes in 3 of 6 (ECC group) and 5 of 6 (TC and ECS groups). Histology showed muscle layer defects up to 12 mm in width and 21 mm in length, with a trend toward smaller defect size of width and length in the ECS group of animals.

Animal study of limited size.

Overall, ECS and ECC performed similarly to TC. ECS showed the smallest histological defects in the long-term repair.