Prosthetic mesh contamination during NOTES(®) transgastric hernia repair: a randomized controlled trial with swine explants.

PURPOSE: Natural Orifice Translumenal Endoscopic Surgery (NOTES(®)) is a developing field in minimally invasive surgery that has been applied across a wide range of procedures; however, infectious concerns remain. Most of the applications have been for extraction, rather than reconstructive procedures. Prosthetic hernia repair, is a constructive procedure, has the unique challenge of avoiding contamination and infection of a permanent implant. Utilizing a novel device, we hypothesize that we can significantly reduce or eliminate prosthetic contamination during a transgastric approach for delivery of a clinically relevant, permanent, synthetic prosthetic. METHODS: 20 swine explants of stomach with attached esophagus were prepared by placing an ultraviolet (UV) light sensitive gel within the lumen of the stomach. Each stomach then underwent endoscopic gastrotomy utilizing a needle, wire guide, and 18-mm balloon dilator. A 10 × 15 cm polypropylene prosthetic was rolled and tied with a 2-0 silk suture, and delivered with one of two methods. Group A (control) utilized a snare to grasp the prosthetic adjacent to the endoscope, which was used to drag it through the gastrotomy. Group B (device) utilized a modified esophageal stent delivery system to deliver the prosthetic through the gastrotomy. Each prosthetic was then digitally photographed with UV illumination, with the contaminated areas illuminating brightly. Software analysis was performed on the photographs to quantify areas of contamination for each group. Statistical analysis was performed using a two-tailed t test with unequal variance. RESULTS: Group A demonstrated a mean of 57 % of the surface area of the prosthetic contaminated with UV light sensitive gel. Group B (experimental group) showed a mean of 0.01 % of the surface area contaminated (p < 0.0001). 95 % confidence intervals indicated that the unprotected delivery technique exposes approximately 6,000 times more of the surface area to contamination than the delivery device. CONCLUSION: Use of this modified stent delivery system can nearly eliminate prosthetic contamination when placed via a transgastric approach in a swine explants model. Theoretically, the reduced inoculum size would reduce or eliminate clinical infection. Since the inoculum size required for clinical prosthetic infection for intraperitoneal mesh is unknown, further study is warranted to test the ability to eliminate clinical infection related to prosthetic delivery with this technique.

NOTES transgastric abdominal wall hernia repair in a porcine model.

INTRODUCTION: With approximately 1 million ventral and inguinal hernia repairs performed in the United States each year, even small rates of complications translate into large numbers of patients. Less invasive approaches that potentially lower morbidity deserve consideration, recognizing there are many technical considerations that currently limit their use. We describe a reproducible technique and lessons learned in our laboratory that answer some existing questions with regards to the use of NOTES for hernia repair. METHODS: A non-survival porcine model with general anesthesia was utilized in all cases. Each animal underwent transgastric peritoneal access with a percutaneous endoscopic gastrostomy (PEG) technique, and the gastrotomy was dilated with a wire-guided balloon dilatation catheter. An Esophageal Z-stent delivery device (Cook Medical, Winston-Salem, NC) was modified ex-vivo to allow us to introduce and protect a 10 x 15 cm lightweight polypropylene hernia prosthetic with pre-placed sutures. Once deployed, the sutures were pulled through the abdominal wall using a looped spinal needle technique in combination with the flexible endoscope. After the four anchoring sutures were tied, proprietary endoscopically placed tacks (Cook Medical) were placed at regular intervals between the sutures to secure the edges of the prosthetic. RESULTS: Hernia repairs were performed on five animals. In each case, we successfully completed prosthetic delivery and deployment into the peritoneal cavity, anchoring to the abdominal wall with full-thickness abdominal wall sutures, and endoscopically placed nitinol tacks. All prosthetics were deployed flat against the anterior abdominal wall. Operative times ranged from 65 to 120 min. CONCLUSION: Transgastric abdominal wall hernia repair is feasible, consistent, and reproducible. In particular, the delivery system can successfully deliver the prosthetic across the gastric wall via a transoral route. Survival animal experiments investigating outcomes related to quality of repair, microbiology, adhesions, and visceral closure need to be done. Human studies are not recommended until these issues are formally investigated.

Natural orifice transluminal endoscopic surgery gastrotomy closure in porcine explants with the Padlock-G clip using the Lock-It system.

BACKGROUND AND STUDY AIMS: The success of transgastric surgery depends on reliable, secure closure of the gastrotomy. Few tests of the integrity of these closures have been published. This study aimed to determine whether a gastrotomy suitable for a NOTES procedure can be closed safely and effectively from within the stomach using a novel endoscopically placed device, the Padlock-G with the Lock-It delivery system. METHODS: In a series of eight consecutive porcine gastric explants gastrotomy was performed in an ex vivo animal laboratory, the gastrotomy being closed with the Padlock-G followed by burst pressure testing after completion of the procedure. Gastrotomies were made in porcine explants. T-tags were placed on either side of the gastrotomy, and, with the T-tags pulled into an endoscopic cap, the Padlock-G was deployed. Gastric transmural pressure gradients at bursting of these closures were measured during insufflation of the explanted stomachs with a high-pressure insufflator. RESULTS: The mean burst pressure of the gastrotomy closures was 68.0 mm Hg (range: 45 - 107 mm Hg). All of the stomachs ultimately ruptured at the closure sites, with the exception of the stomach that ruptured at the highest value (107 mm Hg), which ruptured at a site approximately 5 cm away from the closure site. All of the closures were accomplished in 30 minutes or less. CONCLUSIONS: The Padlock-G clip provides a secure gastric closure for natural-orifice surgery.

The role of diagnostic laparoscopy for chronic abdominal conditions: an evidence-based review.

BACKGROUND: Diagnostic laparoscopy is minimally invasive surgery for the diagnosis of intraabdominal diseases. The aim of this review is a critical examination of the available literature on the role of laparoscopy for chronic intraabdominal conditions. METHODS: A systematic literature search of English-language articles on MEDLINE, the Cochrane database of evidence-based reviews, and the Database of Abstracts of Reviews of Effects was performed for the period 1995-2006. The level of evidence in the identified articles was graded. The search identified and reviewed six main categories that have received attention in the literature: pelvic pain and endometriosis, primary and secondary infertility, nonpalpable testis, and liver disease. RESULTS: The indications, contraindications, risks, benefits, diagnostic accuracy of the procedure, and its associated morbidity are discussed. CONCLUSIONS: The limitations of the available literature are highlighted, and evidence-based recommendations for the use of laparoscopy to stage intraabdominal cancers are provided.

The role of staging laparoscopy for intraabdominal cancers: an evidence-based review.

Diagnostic laparoscopy is minimally invasive surgery for the diagnosis of intraabdominal diseases. The aim of this review is a critical examination of the available literature on the role of laparoscopy for the staging of intraabdominal cancers. A systematic literature search of English-language articles on MEDLINE, the Cochrane database of evidence-based reviews, and the Database of Abstracts of Reviews of Effects was performed for the period 1995-2006. The level of evidence in the identified articles was graded. The search identified and reviewed seven main categories that have received attention in the literature: esophageal cancer, gastric cancer, pancreatic cancer, hepatocellular carcinoma, biliary tract cancer, colorectal cancer, and lymphoma. The indications, contraindications, risks, benefits, diagnostic accuracy of the procedure, and its associated morbidity are discussed. The limitations of the available literature are highlighted, and evidence-based recommendations for the use of laparoscopy to stage intraabdominal cancers are provided.

Laparoscopic resection of curable colon and rectal cancer: an evidence-based review.

The initial enthusiastic application of laparoscopic techniques to colorectal surgical procedures was tempered in the early 1990s by reports of tumor implants in the laparoscopic incisions. Substantial evidence has accumulated, including evidence from randomized controlled trials, to support that laparoscopic resection results in oncologic outcomes similar to open resection, when performed by well-trained, experienced surgeons. This review was developed in conjunction with guidelines published by the Society of American Gastrointestinal and Endoscopic Surgeons. Data from the surgical literature concerning laparoscopic resection of curable colorectal cancer was evaluated regarding diagnostic evaluation, preoperative preparation, operative techniques, prevention of tumor implants, and training and experience. Recommendations are accompanied by an assessment of the level of supporting evidence available at the time of the development of the guidelines.

Performance and ergonomic characteristics of expert surgeons using a face-mounted display during virtual reality-simulated laparoscopic surgery: an electromyographically based study.

BACKGROUND: Display positions for laparoscopy in current operating rooms may not be optimal for surgeon comfort or task performance, and face-mounted displays (FMDs) have been forwarded as a potential ergonomic solution. Little is known concerning expert use characteristics of these devices that might help define their role in future surgical care. The authors report the performance and ergonomic characterization of an FMD using virtual reality simulation technology to recreate the surgical environment. METHODS: An FMD was studied in short- and long-duration trials of validated virtual reality-simulated surgical tasks. For the short-duration phase 7, expert surgeons were familiarized with a task on a conventional monitor, then returned on two separate occasions to repeat the task with the FMD while digital photos were taken during task performance and at the end in a standardized fashion. For the long-duration phase 5, expert surgeons performed two separate trials with repetitive groups of validated tasks for a minimum of 30 min while electromyelogram and performance data were measured. Photos of their gaze angle during and at the end of the trial were taken. RESULTS: All the participants consistently assumed a gaze angle slightly below horizontal during task performance. Performance scores on the FMD did not differ from those obtained with a conventional display, and remained stable with repetitive task performance. No participant had electromyelogram signals that exceeded the established thresholds for fatigue, but some had values within the threshold range. CONCLUSION: The natural gaze angle during simulated surgery was consistently a bit below horizontal during rigorous virtual reality-simulated tasks. Performance was not compromised during expert surgeons' use of an FMD, nor did muscle fatigue characteristics arise under these conditions. The findings suggest that these devices may represent a viable alternative to conventional displays for minimally invasive surgery, but definition of specific roles requires further investigation.

Gas extravasation complicating laparoscopic extraperitoneal inguinal hernia repair.

Carbon dioxide can extravasate from the abdominal cavity during insufflation and result in pneumomediastinum, pneumothorax, and subcutaneous emphysema. We report a case of unilateral pneumothorax with pneumomediastinum and subcutaneous emphysema after laparoscopic extraperitoneal bilateral inguinal hernia repair. Additionally, we discuss the pathophysiology, diagnostic work-up, and management of this malady. Because of the natural resolution of CO2 pneumothoraces, observation for asymptomatic patients is appropriate, whereas tube thoracostomy should be reserved for symptomatic patients. It is utmost importance to determine the etiology of gas extravastion and consider other complications such as airway or esophageal injury or pulmonary barotrauma.

A simple and inexpensive technique for closing trocar sites and grasping sutures.

Grasping sutures during laparoscopic surgery is useful in closing trocar sites, repairing ventral hernias, and securing abdominal wall bleeding. This can be a cumbersome task through small incisions. An 18 gauge spinal needle and the suture of choice for accomplishing the job at hand can be used with a laparoscopic-assisted technique that is simple, inexpensive, and easy to learn. Surgeons performing laparoscopy should add this technique to their repertoire.