Endoscopic suture fixation of gastrointestinal stents: proof of biomechanical principles and early clinical experience.

BACKGROUND AND STUDY AIMS: Gastrointestinal stents have become an important therapeutic option for several indications. However, migration in up to 40 % of cases represents a significant drawback, especially when covered prostheses are used. We hypothesized that a novel endoscopic suturing device could enable endoluminal stent fixation, which might increase attachment and thereby potentially reduce migration. PATIENTS AND METHODS: In an initial ex vivo porcine model, stents were attached to the esophageal wall with either endoscopic hemoclips or by endoscopic suture stent fixation (ESSF). The distal tension force required to induce dislocation was measured in Newtons (N) by a digital force gauge and was compared with conventional stent placement. ESSF was then performed clinically in five patients, in whom self-expanding metal stents were sutured in place for endoscopic treatment of gastrointestinal fistulas or strictures. RESULTS: Esophageal ESSF was achieved in all experiments and significantly increased the force needed to displace the stent (n = 12; mean force 20.4 N; 95 % confidence interval [CI]: 15.4 - 25.4; P < 0.01) compared with clip fixation (n = 8; mean 6.1 N; 95 %CI 4.7 - 7.6) or stent placement without fixation (n = 16; mean 4.8 N; 95 %CI 4.0 - 5.6). All clinical cases of ESSF were performed successfully (5 /5) and took a median of 15 minutes. Elective stent removal was achieved without complications. One stent migration (1 /5) due to sutures being placed too superficially was observed. More loosely tied sutures remained intact, with the stent attached in place. CONCLUSION: Endoscopic suture fixation of gastrointestinal stents provided significantly enhanced migration resistance in an ex vivo setting. In addition, early clinical experience found ESSF to be technically feasible and easy to accomplish.

Mediastinal surgery in connective tissue tunnels using flexible endoscopy.

BACKGROUND: Mediastinal surgery most often is performed via a transthoracic or transabdominal approach; however, the pre- and paratracheal mediastinum can be readily accessed with a transcervical approach. The purpose of this study was to evaluate the feasibility, safety, and success rate of using a transcervical approach and flexible endoscopes to perform mediastinal surgery also in the retro- and paraesophageal mediastinum. METHODS: Mediastinal operations on four live pigs and one human cadaver were performed using standard endoscopes through a small cervical incision. The procedure involved marking of four mediastinal lymph nodes using endoscopic ultrasound (EUS). The esophagus was dissected to the phrenoesophageal junction by creating connective tissue tunnels with balloon dilatation and low-pressure CO(2) insufflation. Heller myotomy was performed followed by sequential identification and removal of the marked nodes. Success rate of esophageal dissection to the diaphragm, Heller myotomy, directed mediastinal lymph node harvest, and complication rates were evaluated. RESULTS: Dissection of the esophagus to the diaphragm was achieved in 100% of attempts. Distal esophageal myotomy was performed in all cases. Harvest of marked lymph nodes (ln) was successful in 100% of animals (16/16 ln) and cadavers (2/2 ln). One major complication was recorded in the pig group (tension pneumomediastinum). CONCLUSIONS: The entire visceral mediastinum can be successfully accessed through a transcervical incision using flexible endoscopes. Directed lymph node harvest and esophageal myotomy is feasible with a high success rate. Connective tissue tunnels are safe, atraumatic, and a promising concept for targeted mediastinal exploration. With refinement in technology, this approach may be useful for a variety of mediastinal surgeries.

Building an efficient surgical team using a bench model simulation: construct validity of the Legacy Inanimate System for Endoscopic Team Training (LISETT).

BACKGROUND: Complex laparoscopic tasks require collaboration of surgeons as a surgical team. Conventionally, surgical teams are formed shortly before the start of the surgery, and team skills are built during the surgery. There is a need to establish a training simulation to improve surgical team skills without jeopardizing the safety of surgery. The Legacy Inanimate System for Laparoscopic Team Training (LISETT) is a bench simulation designed to enhance surgical team skills. The reported project tested the construct validity of LISETT. The research question was whether the LISETT scores show progressive improvement correlating with the level of surgical training and laparoscopic team experience or not. METHODS: With LISETT, two surgeons are required to work closely to perform two laparoscopic tasks: peg transportation and suturing. A total of 44 surgical dyad teams were recruited, composed of medical students, residents, laparoscopic fellows, and experienced surgeons. The LISETT scores were calculated according to the speed and accuracy of the movements. RESULTS: The LISETT scores were positively correlated with surgical experience, and the results can be generalized confidently to surgical teams (Pearson's coefficient, 0.73; p = 0.001). To analyze the influences of individual skill and team dynamics on LISETT performance, team quality was rated by team members using communication and cooperation characters after each practice. The LISETT scores are positively correlated with self-rated team quality scores (Pearson's coefficient, 0.39; p = 0.008). CONCLUSIONS: The findings proved LISETT to be a valid system for assessing cooperative skills of a surgical team. By increasing practice time, LISETT provides an opportunity to build surgical team skills, which include effective communication and cooperation.