Erwin Rieder

A Stepwise Approach and Early Clinical Experience in Peroral Endoscopic Myotomy for the Treatment of Achalasia and Esophageal Motility Disorders

BACKGROUND Peroral endoscopic myotomy (POEM) has recently been described in humans as a treatment for achalasia. This concept has evolved from developments in natural orifice translumenal endoscopic surgery (NOTES) and has the potential to become an important therapeutic option. We describe our approach as well as our initial clinical experience as part of an ongoing study treating achalasia patients with POEM. STUDY DESIGN Five patients (mean age 64 ± 11 years) with esophageal motility disorders were enrolled in an IRB-approved study and underwent POEM. This completely endoscopic procedure involved a midesophageal mucosal incision, a submucosal tunnel onto the gastric cardia, and selective division of the circular and sling fibers at the lower esophageal sphincter. The mucosal entry was closed by conventional hemostatic clips. All patients had postoperative esophagograms before discharge and initial clinical follow-up 2 weeks postoperatively. RESULTS All (5 of 5) patients successfully underwent POEM treatment, and the myotomy had a median length of 7 cm (range 6 to 12 cm). After the procedure, smooth passage of the endoscope through the gastroesophageal junction was observed in all patients. Operative time ranged from 120 to 240 minutes. No leaks were detected in the swallow studies and mean length of stay was 1.2 ± 0.4 days. No clinical complications were observed, and at the initial follow-up, all patients reported dysphagia relief without reflux symptoms. CONCLUSIONS Our initial experience with the POEM procedure demonstrates its operative safety, and early clinical results have shown good results. Although further evaluation and long-term data are mandatory, POEM could become the treatment of choice for symptomatic achalasia.

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.

A Triangulating Operating Platform Enhances Bimanual Performance and Reduces Surgical Workload in Single-Incision Laparoscopy

BACKGROUND Single-site laparoscopy (SSL) attempts to further reduce the surgical impact of minimally invasive surgery. However, crossed instruments and the proximity of the endoscope to the operating instruments placed through one single site leads to inevitable instrument or trocar collision. We hypothesized that a novel, single-port, triangulating surgical platform (SPSP) might enhance performance by improving bimanual coordination and decreasing the surgeons mental workload. STUDY DESIGN Fourteen participants, proficient in basic laparoscopic skills, were tested on their ability to perform a validated intracorporeal suturing task by either an SSL approach with crossed articulated instruments or a novel SPSP, providing true-right and true-left manipulation. Standard laparoscopic (SL) access served as control. Sutures were evaluated using validated scoring methods and the National Aeronautics and Space Administration Task Load Index was used to rate mental workload. RESULTS All participants proficiently performed intracorporeal knots by SL (mean score 99.0; 95% CI 97.0 to 100.9). Performance decreased significantly (more than 50%, p < 0.001) with the SSL approach using 1 rigid and 1 articulating instrument in a cross-wise manner (mean score 39.2; 95% CI 28.3 to 50.1). The use of the SPSP significantly enhanced bimanual coordination (mean score 67.6; 95% CI 61.3 to 73.9; p < 0.001). Participants recorded lower mental workload when using true-right and true-left manipulation. CONCLUSIONS This study objectively assessed SSL performance and current attempts for instrumentation improvement in single-site access. While SSL significantly impairs basic laparoscopic skills, surgical platforms providing true-left and true-right maneuvering of instruments appear to be more intuitive and address some of the current challenges of SSL that may otherwise limit its widespread acceptance.

A Novel Technique for Natural Orifice Endoscopic Full-Thickness Colon Wall Resection: An Experimental Pilot Study

BACKGROUND Natural orifice endoscopic full-thickness colon resection attempts to overcome the need for invasive surgery in selected colorectal indications. Because basic technical requirements have not been met so far, the aim of this study was to develop a novel technique for endolumenal colon-wedge resection addressing current shortcomings. STUDY DESIGN Endoscopic full-thickness colon resection was attempted in a human cadaver model (n = 2), explanted porcine colon stumps (n = 10), and 3 acute pig models. A hypothesized colon lesion was created and retracted into an endoscopic clip closure system (ECCS). Initially used endoscopic graspers (n = 2) were replaced by a T-tag suture approach for retraction (n = 13). T-type anchors were deployed circumferentially to the lesion, which simultaneously marked resection margins. The clip was then applied for pre-resection tissue closure. The inverted tissue was excised by snare resection and was removed together with the sutures. Air leak-pressure of tissue closure was tested. RESULTS Endoscopic full-thickness colon resection was achieved in 14 of 15 attempts. The mean diameter (±SD) of resected animal specimen, including the predetermined margins, was 26 ± 4 mm. Using the T-tag sutures for retraction, the defined lesion was neither touched by an endoscopic grasper nor compromised by puncturing the center. Leak pressure tests revealed a significantly higher air pressure resistance of the pre-resection ECCS closure (61 ± 5 mmHg) compared with the hand-sewn control (26 ± 7 mmHg). CONCLUSIONS A novel endoscopic technique for full-thickness colon wall resection using tissue anchors for traction and an ECCS for pre-resection tissue closure appears to address several fundamental surgical principles. However, further studies are necessary before initial clinical application.

Advances in cancer surgery: Natural orifice surgery (NOTES) for oncological diseases

Natural orifice transluminal endoscopic surgery (NOTES) is a new concept that attempts to reduce the impact of surgery on the patient. In surgical oncology several studies have already revealed that a minimally invasive approach provides at least the same, if not a better, long-term outcome. One could hypothesize that a less invasive approach such as NOTES could further enhance such advantages. Since its initial description, NOTES has become clinical reality and today nearly every organ is accessible by a transluminal approach, in at least the experimental setting. Subsequent to published research, first clinical studies on NOTES in oncology were reported and the accuracy of transgastric peritoneoscopy for staging of pancreas cancer was shown to be similar to laparoscopy in humans. A NOTES gastro-jejunostomy via transgastric access has also been proposed to decrease invasiveness of palliative treatment of duodenal, biliary and pancreatic cancers. Colorectal cancer resection via transanal access would offer a clear-cut patient advantage over laparoscopic and would not be subject to the frequent criticism of violating an innocent second organ, as the colon or rectum is always breached in a colectomy. Natural orifice endoluminal therapies, such as endoscopic submucosal dissection, already have been clinically applied for several years. Improved techniques or instruments evolving from NOTES technology might enhance its widespread use for the treatment of early malignancies and thereby again will provide a tremendous benefit for the patient. Although still somewhat controversial, the subject of natural orifice surgery in oncological disease indicates that current laboratory efforts to introduce NOTES into cancer surgery could be ready for cautious clinical investigations. The final determination of patient benefit will need well-constructed prospective study.

Development and technique of per oral endoscopic myotomy (POEM) for achalasia

SummaryBACKGROUND: Achalasia is a primary esophageal motor disorder involving the absence of esophageal body peristalsis and defective relaxation of the lower esophageal sphincter. The optimal treatment is still controversial. Per oral endoscopic myotomy (POEM) has recently evolved from developments in Natural Orifice Translumenal Endoscopic Surgery (NOTES). METHODS: Substantial experimental work in animals and cadavers was performed to establish the technical approach for POEM before clinical implementation. This flexible endoscopic procedure involved incising the mid-esophageal mucosa followed by access into the submucosal space. A tunnel onto the gastric cardia was dissected and selective division of the circular/sling-fibers of the lower esophageal sphincter (LES) was performed by needle knife cautery. The mucosotomy was closed by conventional endoscopic hemoclips. Subsequently, a 61-year-old male patient with achalasia was enrolled in an ongoing study. RESULTS: Based on preclinical work, the steps of endoscopic submucosal myotomy were defined. In the patient described, mucosal balloon-dilatation facilitated access into the submucosal space. Dissection was performed until 3 cm below the gastroesophageal junction and the partial myotomy was 7 cm. The mucosal entry was easily closed. Postoperative esophagogram did not detect esophageal leakage and the patient was discharged on the next morning. He reported immediate symptom relief on the 2-week clinical follow-up without the need of pain medication. CONCLUSIONS: POEM for achalasia is a perfect example of the true surgical revolution resulting from NOTES research. Although the long-term outcome of POEM has still to be evaluated, the promise of this novel procedure seems more than obvious.