Randomized comparative long-term survival study of endoscopic and thoracoscopic esophageal wall repair after NOTES mediastinoscopy in healthy and compromised animals

Feasibility of transumbilical anatomic "Lung" segmentectomy in a canine model

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Asian perspectives in thoracic surgery: clinical innovation in Taiwan

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.

Recent advances in natural orifice transluminal endoscopic surgery†

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.

Role of transgastric natural orifice transluminal endoscopic surgery in the diagnosis of ascites of unknown origin (with videos)

BACKGROUND

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

OBJECTIVE

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

DESIGN

Prospective study.

SETTING

Two university and teaching hospitals.

PATIENTS

Patients with ascites of unknown origin.

INTERVENTIONS

Diagnostic transgastric NOTES.

MAIN OUTCOME MEASUREMENTS

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

RESULTS

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.

LIMITATIONS

Nonrandomized control analysis.

CONCLUSION

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.

Novel treatment options for perforations of the upper gastrointestinal tract: Endoscopic vacuum therapy and over-the-scope clips

Endoscopic management of leakages and perforations of the upper gastrointestinal tract has gained great importance as it avoids the morbidity and mortality of surgical intervention. In the past years, covered self-expanding metal stents were the mainstay of endoscopic therapy. However, two new techniques are now available that enlarge the possibilities of defect closure: endoscopic vacuum therapy (EVT), and over-the-scope clip (OTSC). EVT is performed by mounting a polyurethane sponge on a gastric tube and placing it into the leakage. Continuous suction is applied via the tube resulting in effective drainage of the cavity and the induction of wound healing, comparable to the application of vacuum therapy in cutaneous wounds. The system is changed every 3-5 d. The overall success rate of EVT in the literature ranges from 84% to 100%, with a mean of 90%; only few complications have been reported. OTSCs are loaded on a transparent cap which is mounted on the tip of a standard endoscope. By bringing the edges of the perforation into the cap, by suction or by dedicated devices, such as anchor or twin grasper, the OTSC can be placed to close the perforation. For acute endoscopy associated perforations, the mean success rate is 90% (range: 70%-100%). For other types of perforations (postoperative, other chronic leaks and fistulas) success rates are somewhat lower (68%, and 59%, respectively). Only few complications have been reported. Although first reports are promising, further studies are needed to define the exact role of EVT and OTSC in treatment algorithms of upper gastrointestinal perforations.

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.

A novel endoscopic prototype device for gastric full-thickness biopsy for the histopathologic diagnosis of GI neuromuscular pathology: in vivo porcine long-term survival study (with videos)

BACKGROUND

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.

OBJECTIVE

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.

DESIGN

Preclinical proof-of-concept study in 30 pigs.

SETTING

Animal laboratory.

INTERVENTION

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.

MAIN OUTCOME MEASUREMENTS

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

RESULTS

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.

LIMITATIONS

Survival animal pilot study, no patients.

CONCLUSION

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.

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.

Comparative study of NOTES alone versus NOTES guided by a new image registration system for navigation in the mediastinum: a study in a porcine model

BACKGROUND

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.

OBJECTIVE

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

DESIGN

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.

SETTING

Animal research laboratory.

INTERVENTIONS

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.

MAIN OUTCOME MEASUREMENTS

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

RESULTS

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).

LIMITATIONS

Nonsurvival animal study.

CONCLUSIONS

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.

Clip closure versus endoscopic suturing versus thoracoscopic repair of an iatrogenic esophageal perforation: a randomized, comparative, long-term survival study in a porcine model (with videos)

BACKGROUND

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).

OBJECTIVE

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

DESIGN

Comparative animal study.

SETTING

Approved animal facility.

SUBJECTS

Eighteen pigs.

INTERVENTIONS

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.

MAIN OUTCOME MEASUREMENT

Long-term survival and histological quality of the repair.

RESULTS

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.

LIMITATIONS

Animal study of limited size.

CONCLUSIONS

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