Facilitating gastrotomy closure during natural-orifice transluminal endoscopic surgery using tissue anchors.

BACKGROUND AND STUDY AIMS: Reliable and secure closure of the gastrotomy after natural-orifice transluminal endoscopic surgery (NOTES) remains a critical step for widespread acceptance and use of this mode of surgery. We describe a novel method for gastrotomy closure using endoscopic tissue anchors. METHODS: A standard upper endoscopy and wire placement as used for percutaneous endoscopic gastrostomy placement was performed in five pigs. Prior to gastrotomy, four tissue anchors were placed in four quadrants (1 cm away from the wire). A 12-mm gastrotomy was created endoscopically using a combination of needle-knife and balloon dilation. After transgastric peritoneoscopy, the sutures were approximated using a device knotting element. One additional pair of sutures was placed after evaluation of the gastric closure. The animals underwent in vivo contrast fluoroscopy, methylene blue instillation, and bursting pressure studies for assessment of the closure site. RESULTS: All animals studied showed complete sealing of the gastrotomy site without evidence of leak on fluoroscopic imaging or at final postmortem intragastric methylene blue instillation. Improved insufflation ability following gastrotomy was also noted using this technique, which enhanced overall visualization during the closure. CONCLUSION: Positioning tissue anchors prior to creating a NOTES gastrotomy was a feasible and reliable method to perform gastric closure. Follow-up survival studies will be warranted to support these preliminary findings.

Complete endoscopic closure of gastrotomy after natural orifice translumenal endoscopic surgery using the NDO Plicator.

BACKGROUND: The NDO Plicator is a device developed for endoscopic treatment of gastroesophageal reflux disease (GERD) by approximation of tissues together with a double-pledgeted U-stitch. It was theorized that this device may facilitate transgastric natural orifice translumenal endoscopic surgery (NOTES) because closure of the transgastric defect remains a key component for advancement of this new technology. METHODS: A standardized 12-mm gastrotomy was created endoscopically in four pigs using a combination of needle-knife cautery and balloon dilation. As the endoscope was removed, a Savary soft-tipped wire was introduced into the stomach, and the NDO Plicator was subsequently advanced over the wire. Each defect was identified, and the device was positioned. If necessary, the Plicator's tissue grasper was used to hold the superior aspect of the gastrotomy and bring the opposed borders of the defect within the jaws of the device. The device was fired three times, leaving three pledgeted suture bundles to close the gastric defect. After closure, each animal was explored, and the integrity of the closure was assessed. The animals underwent in vivo contrast fluoroscopy and ex vivo burst pressure testing studies for assessment of leakage at the closure site. RESULTS: The first animal was used to test feasibility, refine techniques, and develop a standard procedure. All of the next three animals studied showed complete sealing of the gastrotomy site without evidence of contrast extravasation on multiplanar fluoroscopic imaging. Each stomach was excised, submerged in water, and subjected to a pressurized air leak test. No leaks were noted until pressures exceeded 55 mmHg. CONCLUSION: This study supports the use of the NDO Plicator for closure of standardized gastric defects in a porcine model. In addition to closing NOTES gastrotomies, the NDO Plicator may be a particularly useful tool for obtaining complete closure of gastric perforations and anastomotic leaks, and for performing stomal reduction after gastric bypass procedures. The mechanical properties of a closure are not the only factor determining whether a leak will develop. Tissue opposition, ischemia, and tension are important factors that are not easily or reliably measured. The physiologic relevance of gastric bursting pressure is not known. Therefore, corollary animal studies with longer-term evaluation are necessary before research proceeds to clinical trials.

Laparoscopic component separation in the single-stage treatment of infected abdominal wall prosthetic removal.

BACKGROUND: The ideal surgical treatment for complicated ventral hernias remains elusive. Traditional component separation provides local advancement of native tissue for tension-free closure without prosthetic materials. This technique requires an extensive subcutaneous dissection, with the division of perforating vessels predisposing to skin flap necrosis and complicated wound infections. The laparoscopic separation of components provides a minimally invasive alternative to open techniques, while eliminating the potential space and subsequent complications of large skin flaps. We report our initial experience with a minimally invasive component separation with early postoperative outcomes. METHODS: We retrospectively reviewed the medical records of all patients who underwent a minimally invasive component separation for abdominal wall reconstruction during the resection of an infected prosthetic. Pertinent details included baseline demographics, reason for contamination, operative technique and details, postoperative morbidity, mortality, and recurrence rates. RESULTS: Between August 2006 and January 2007, seven patients were identified who underwent a laparoscopic component separation. There were four males and three females, with a mean age of 54 years (range 34-84), mean American Society of Anesthesiologist (ASA) score of 3.2 (range 3-4), and mean body mass index (BMI) of 37 kg/m2 (range 30-45). The reason for contamination included exposed non-healing mesh (6) and contaminated fluid collection around the mesh (1). Residual defect size following the removal of all prosthetics was 338 cm2 (range 187-450). The mean operative time was 185 min (range 155-220). Laparoscopic component separation enabled tension-free primary fascial reapproximation in all patients. Three postoperative complications occurred, including superficial surgical site infection (1), respiratory failure (1), and hematoma (1). There was no mortality in this series. During an average follow-up period of 4.5 months, no recurrences were identified. CONCLUSIONS: This study shows that a minimally invasive component separation is feasible and can result in minimal postoperative wound morbidity in these complex patients. Long-term follow-up is necessary to evaluate the outcomes with respect to recurrence rates.

A reliable method for monitoring intraabdominal pressure during natural orifice translumenal endoscopic surgery.

BACKGROUND: Natural orifice translumenal endoscopic surgery (NOTES) provides surgical access to the peritoneal cavity without skin incisions. The NOTES procedure requires pneumoperitoneum for visualization and manipulation of abdominal organs, similar to laparoscopy. Accurate measurement of the pneumoperitoneum pressure is essential to avoid potentially deleterious effects of intraabdominal compartment syndrome. A reliable method for monitoring pneumoperitoneum pressures during NOTES has not been identified. This study evaluated several methods of monitoring intraabdominal pressures with a standard gastroscope during NOTES. METHODS: Four female pigs (25 kg) were sedated, and a single-channel gastroscope was passed transgastrically into the peritoneal cavity. Pneumoperitoneum was achieved via a pressure insufflator through a percutaneous, intraperitoneal 14-gauge catheter. Three other pressures were recorded via separate catheters. First, a 14-gauge percutaneous catheter passed intraperitoneally measured true intraabdominal pressure. Second, a 14-gauge tube attached to the endoscope was used to measure endoscope tip pressure. The third pressure transducer was connected directly to the accessory channel of the endoscope. The abdomen was insufflated to a range of pressures (10-30 mmHg), and simultaneous pressures were recorded from all three pressure sensors. RESULTS: Pressure correlation curves were developed for all animals across all intraperitoneal pressures (mean error, -4.25 to -1 mmHg). Endoscope tip pressures correlated with biopsy channel pressures (R2 = 0.99). Biopsy channel and endoscope tip pressures fit a least-squares linear model to predict actual intraabdominal pressure (R = 0.99 for both). Both scope tip and biopsy channel port pressures were strongly correlative with true intraabdominal pressures (R2 = 0.98 and R2 = 0.99, respectively). CONCLUSION: This study demonstrates that monitoring pressure through an endoscope is reliable and predictive of true intraabdominal pressure. Gastroscope pressure monitoring is a useful adjunct to NOTES. Future NOTES procedures should incorporate continuous intraabdominal pressure monitoring to avoid the potentially deleterious effects of pneumoperitoneum during NOTES. This can be achieved by the integration of pressure-monitoring capabilities into gastroscopes.

Diaphragm pacing with natural orifice transluminal endoscopic surgery: potential for difficult-to-wean intensive care unit patients.

BACKGROUND: Up to 50% of the patients in the intensive care unit (ICU) require mechanical ventilation, with 20% requiring the use of a ventilator for more than 7 days. More than 40% of this time is spent weaning the patient from mechanical ventilation. Failure to wean from mechanical ventilation can in part be attributable to rapid onset of diaphragm atrophy, barotrauma, posterior lobe atelectasis, and impaired hemodynamics, which are normally improved by maintaining a more natural negative chest pressure. The authors have previously shown that laparoscopic implantation of a diaphragm pacing system benefits selected patients. They now propose that an acute ventilator assist with interventional neurostimulation of the diaphragm in the ICU is feasible and could facilitate the weaning of ICU patients from mechanical ventilation. Natural orifice transluminal endoscopic surgery (NOTES) has the potential to expand the benefits of the diaphragm pacing system to this acute patient population by allowing it to be performed at the bedside similarly to insertion of the common gastrostomy tube. This study evaluates the feasibility of this approach in a porcine model. METHODS: Pigs were anesthetized, and peritoneal access with the flexible endoscope was obtained using a guidewire, needle knife cautery, and balloon dilation. The diaphragm was mapped using a novel endoscopic electrostimulation catheter to locate the motor point (where stimulation provides complete contraction of the diaphragm). An intramuscular electrode then was placed at the motor point with a percutaneous needle. The gastrotomy was managed with a gastrostomy tube. RESULTS: Four pigs were studied, and the endoscopic mapping instrument was able to map the diaphragm to identify the motor point. In one animal, a percutaneous electrode was placed into the motor point under transgastric endoscopic visualization, and the diaphragm could be paced in conjunction with mechanical ventilation. CONCLUSIONS: These animal studies demonstrate the feasibility of transgastric mapping of the diaphragm and implantation of a percutaneous electrode for therapeutic diaphragmatic stimulation.