Directed submucosal tunneling permits in-line endoscope positioning for transgastric natural orifice translumenal endoscopic surgery (NOTES)

Peroral traction-assisted natural orifice trans-anal flexible endoscopic rectosigmoidectomy followed by intracorporeal colorectal anastomosis in a live porcine model

BACKGROUND

Compared to traditional open surgery, laparoscopic surgery has become a standard approach for colorectal cancer due to its great superiorities including less postoperative pain, a shorter hospital stay, and better quality of life. In 2007, Whiteford et al reported the first natural orifice trans-anal endoscopic surgery (NOTES) sigmoidectomy using transanal endoscopic microsurgery. To date, all cases of NOTES colorectal resection have included a hybrid laparoscopic approach with the use of established rigid platforms.

AIM

To introduce a novel technique of peroral external traction-assisted transanal NOTES rectosigmoidectomy followed by intracorporeal colorectal end-to-end anastomosis by using only currently available and flexible endoscopic instrumentation in a live porcine model.

METHODS

Three female pigs weighing 25-30 kg underwent NOTES rectosigmoid resection. After preoperative work-up and bowel preparation, general anesthesia combined with endotracheal intubation was achieved. One dual-channel therapeutic endoscope was used. Carbon dioxide insufflation was performed during the operation. The procedure of trans-anal NOTES rectosigmoidectomy included the following eight steps: (1) The rectosigmoid colon was tattooed with India ink by submucosal injection; (2) Creation of gastrostomy by directed submucosal tunneling; (3) Peroral external traction using endoloop ligation; (4) Creation of rectostomy on the anterior rectal wall by directed 3 cm submucosal tunneling; (5) Peroral external traction-assisted dissection of the left side of the colon; (6) Trans-anal rectosigmoid specimen transection, where an anvil was inserted into the proximal segment after purse-string suturing; (7) Intracorporeal colorectal end-to-end anastomosis using a circular stapler by a single stapling technique; and (8) Closure of gastrostomy using endoscopic clips. All animals were euthanized immediately after the procedure, abdominal exploration was performed, and the air-under-water leak test was carried out.

RESULTS

The procedure was completed in all three animals, with the operation time ranging from 193 min to 259 min. Neither major intraoperative complications nor hemodynamic instability occurred during the operation. The length of the resected specimen ranged from 7 cm to 13 cm. With the assistance of a trans-umbilical rigid grasper, intracorporeal colorectal, tension-free, end-to-end anastomosis was achieved in the three animals.

CONCLUSION

Peroral traction-assisted transanal NOTES rectosigmoidectomy followed by intracorporeal colorectal end-to-end anastomosis is technically feasible and reproducible in an animal model and is worthy of further improvements.

Submucosal surgery: novel interventions in the third space

Traditional surgeries involve accessing body cavities, such as the abdomen and thorax, via incisions that divide skin and muscle. These operations result in postoperative pain and convalescence, and a risk of complications such as wound infection and hernia. The development of flexible endoscopy allowed diseases as varied as gastrointestinal bleeding and colon adenomas to be treated without incisions, but this technique is restricted by its endoluminal nature. A novel category of surgical endoscopic procedures has recently been developed that uses flexible endoscopic techniques to enter and access the submucosa of the gastrointestinal tract. Through this approach, the advantages of incisionless endoscopy can be applied to areas of the body that previously could only be reached with surgery. This Review introduces this new class of interventions by describing two examples of such submucosal surgeries for the treatment of benign gastrointestinal disease: per-oral endoscopic myotomy and per-oral pyloromyotomy. The approach to pre-procedure patient evaluation, operative technique, and the published outcomes are discussed, as well as potential future applications of similar techniques and procedures in this so-called third space.

Percutaneous transgastric endoscopic tube ileostomy in a porcine survival model

AIM

To introduce natural orifice transgastric endoscopic surgery (NOTES) tube ileostomy using pelvis-directed submucosal tunneling endoscopic gastrostomy and endoscopic tube ileostomy.

METHODS

Six live pigs (three each in the non-survival and survival groups) were used. A double-channeled therapeutic endoscope was introduced perorally into the stomach. A gastrostomy was made using a 2-cm transversal mucosal incision following the creation of a 5-cm longitudinal pelvis-directed submucosal tunnel. The pneumoperitoneum was established via the endoscope. In the initial three operations of the series, a laparoscope was transumbilically inserted for guiding the tunnel direction, intraperitoneal spatial orientation and distal ileum identification. Endoscopic tube ileostomy was conducted by adopting an introducer method and using a Percutaneous Endoscopic Gastrostomy Catheter Kit equipped with the Loop Fixture. The distal tip of the 15 Fr catheter was placed toward the proximal limb of the ileum to optimize intestinal content drainage. Finally, the tunnel entrance of the gastrostomy was closed using nylon endoloops with the aid of a twin grasper. The gross and histopathological integrity of gastrostomy closure and the abdominal wall-ileum stoma tract formation were assessed 1 wk after the operation.

RESULTS

Transgastric endoscopic tube ileostomy was successful in all six pigs, without major bleeding. The mean operating time was 71 min (range: 60-110 min). There were no intraoperative complications or hemodynamic instability. The post-mortem, which was conducted 1-wk postoperatively, showed complete healing of the gastrostomy and adequate stoma tract formation of ileostomy.

CONCLUSION

Transgastric endoscopic tube ileostomy is technically feasible and reproducible in an animal model, and this technique is worthy of further improvement.

Endoscopic clip closure of gastrointestinal perforations, fistulae, and leaks

Development of endoscopic devices to close perforations has certainly revolutionized endoscopy. Immediate closure of perforations eliminates the need for surgery, which allows us to push the limits of endoscopic surgery from the mucosal plane to deep submucosal layers and eventually transmurally. The present article focuses on endoscopic closure devices, closure techniques, followed by a review of animal and clinical studies on endoscopic closure of perforations.

An intestinal occlusion device for prevention of small bowel distention during transgastric natural orifice transluminal endoscopic surgery

An intestinal occlusion catheter that maintains duodenal occlusion significantly improves intra-abdominal visualization during a NOTES procedure.

Background and Objectives:

Bowel distention from luminal gas insufflation reduces the peritoneal operative domain during natural orifice transluminal endoscopic surgery (NOTES) procedures, increases the risk for iatrogenic injury, and leads to postoperative patient discomfort.

Methods:

A prototype duodenal occlusion device was placed in the duodenum before NOTES in 28 female pigs. The occlusion balloon was inflated and left in place during the procedure, and small bowel distension was subjectively graded. One animal had no balloon occlusion, and 4 animals had a noncompliant balloon placed.

Results:

The balloon maintained its position and duodenal occlusion in 22 animals (79%) in which the bowel distention was rated as none (15), minor (4), moderate (3), or severe (0). The intestinal occlusion catheter failed in 6 animals (21%) because of balloon leak (5) or back-migration into the stomach (1), with distention rated as severe in 5 of these 6 cases.

Conclusion:

The intestinal occlusion catheter that maintains duodenal occlusion significantly improves the intra-abdominal working domain with enhanced visualization of the viscera during the NOTES procedure while requiring minimal time and expense.

Direct incision versus submucosal tunneling as a method of creating transgastric accesses for natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy: randomized controlled trial

AIM

The optimal approach for creating accesses for transgastric peritoneoscopy is still uncertain. The present study aims to assess the feasibility of carrying out transgastric submucosal tunnel (SMT) peritoneoscopy and to determine whether this approach improves or restricts access to various sectors within the peritoneal cavity.

METHODS

This was a randomized comparative study carried out in an in-vivo survival porcine model. Sixty-six beads in six swine were visualized and touched via gastrotomies created by either direct incision (DI) or SMT. The influence of the type of gastrotomy on improving or restricting access to particular sites within the peritoneal cavity for natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy was compared. The main outcome measurements were localization score of beads, overall procedural time, morbidities and mortalities.

RESULTS

A significantly higher mean (SD) localization score was observed in peritoneoscopies carried out in the DI group (P < 0.001). Both the visualization and the touching scores were significantly better with the DI technique, and the overall yield of NOTES peritoneoscopy with DI and SMT were 72.73% and 60.6%, respectively (P = 0.043). Significantly more beads that were not touched in the SMT group were located in the sub-phrenic area (P = 0.013). The overall procedural time was significantly shorter in the DI group (P = 0.004). No major morbidities or mortalities occurred in any procedures.

CONCLUSIONS

SMT resulted in lower visualization and touching scores for transgastric NOTES peritoneoscopy. Alternate methods to improve the diagnostic yield to the sub-phrenic area are required.

Human applications of submucosal endoscopy under conscious sedation for pure natural orifice transluminal endoscopic surgery

BACKGROUND

The submucosal endoscopy provide not only a reliable methods of access and closure for peritoneoscopy, but also an endoscopic working space for full-thickness resection. The aim of this study was to report the clinical outcome of submucosal endoscopy for pure natural orifice transluminal endoscopic surgery.

METHODS

We prospectively evaluated 10 patients who received submucosal endoscopies. The indications of submucosal endoscopy were transgastric peritoneoscopy (TGP) and endoscopic full-thickness resection (EFTR) of a gastric subepithelial tumor. All procedures were performed with a standard gastroscope under conscious sedation with the balanced propofol method in the endoscopic unit. After a 40 mm submucosal tunnel was created using an endoscopic submucosal dissection technique, (1) in TGP, balloon dilation of a serosal puncture and intraperitoneal exploration was performed; (2) in EFTR, a full-thickness incision and snaring resection was performed. Closure of the mucosal incision was performed by endoclips.

RESULTS

All cases were technically feasible. The mean times for creating the submucosal tunnel, main procedure (peritoneal exploration or resection), and closure were acceptable (10.44 ± 2.42 minutes, 18.80 ± 9.41 minutes, and 5.63 ± 2.17 minutes, respectively). The mean hospital stay was 3.8 ± 1.48 days. All TGPs were diagnostic (4 peritoneal carcinomatosis and 1 tuberculosis). En bloc and complete resections were possible in all EFTRs (3 gastrointestinal stromal tumors and 2 schwannomas; mean tumor size, 20.8 ± 3.27 mm). There were no procedure-related complications, such as significant bleeding or peritonitis.

CONCLUSIONS

Human applications of submucosal endoscopy under conscious sedation for pure NOTES were feasible and safe.

Current progress on natural orifice transluminal endoscopic surgery (NOTES)

Natural orifice transluminal endoscopic surgery (NOTES) has received considerable interest in recent years as a novel surgical technique. Here, we aim to review the current progress on NOTES, particularly focusing on the advantages and complications related to NOTES, the recent advances of surgical approaches, new instruments for closure of the natural orifice incision, and the newly developed platform for NOTES. Finally, we make a prediction of the conceivable applications of NOTES on human subjects.

Intramural acellular porcine dermal matrix (APDM)-assisted gastrotomy closure for natural orifice transluminal endoscopic surgery (NOTES)

BACKGROUND

A highly reliable and safe means of gastric closure for natural orifice transluminal endoscopic surgery (NOTES) has yet to be developed. The authors have previously described the self-approximating transluminal access technique (STAT) as a means for gastrotomy closure in transgastric surgery. It has yet to be determined whether biologic mesh can be utilized in facilitating gastrotomy closure via STAT. The aim of this study was to determine the feasibility of implanting an acellular porcine dermal matrix (LifeCell) into the STAT tunnel and investigate whether it will become incorporated into the submucosal plane of the STAT tunnel.

METHODS

Five pigs underwent transgastric left uterine horn resection utilizing STAT. For closure, the acellular porcine dermal matrix was implanted within the submucosal plane, occluding the seromuscular incision. The mucosal incision was then closed over the matrix with endoscopically placed clips. Necropsy was performed after a 3 week survival period. Histopathological evaluation of the tunnel and matrix was performed.

RESULTS

The matrix was successfully implanted in all five animals. Average OR time was 151 ± 68 min. Average time to anchor and embed the matrix within the tunnel was 4 ± 1 and 9 ± 12 min, respectively. There was one duodenal perforation related to a balloon occlusion device. Postoperative course was unremarkable; the average weight gain at 3 weeks was 22 ± 5 lbs. On necropsy, one animal had some protrusion of the matrix at the serotomy, with adhesions to small bowel and liver. Histopathology revealed one clinically insignificant microabscess but otherwise demonstrated local inflammation and fibrovascular ingrowth into the matrix.

CONCLUSIONS

The porcine dermal matrix can be successfully implanted within the gastric submucosal plane and evidence of incorporation into the gastric wall by 3 weeks was demonstrated.

A new in vivo method for testing closures of gastric NOTES incisions using leak of the closure or gastric yield as endpoints

BACKGROUND

We developed a non-survival in vivo model for testing of gastric natural orifice translumenal endoscopic surgery (NOTES) closures based on the gastric yield pressure. The aim of this study was to test our model comparing different endoscopic closure techniques with surgical closure of a NOTES gastric incision.

METHODS

Laparotomy was performed in 30 pigs. One tube for air inflation and one manometry tube were inserted into the stomach via the pylorus, which was closed gas-tight, and the abdominal wall was closed. The stomach was inflated with air, and the gastroesophageal yield pressure was measured. A gastroscopy was performed, and a standard NOTES access was created followed by randomization to closure by surgical suturing, T-tags, Padlock-G over-the-scope (OTS)-clips, OVESCO OTS-clips, and traditional clips. All closures were tested twice with air insufflation. Gastric yield pressure or leak pressure of each closure was recorded.

RESULTS

The mean baseline gastric yield pressure was 80.5 mm Hg. Post-closure yield pressure was 79.9 mm Hg. Leak test results after closure were as follows: surgery, 0/6 leaked; T-tags, 1/6 leaked before reaching yield pressure (56 mm Hg); Padlock-G, 2/5 leaked (71.5 mm Hg); OVESCO OTS-clips, 3/6 leaked (27.2 mm Hg); and traditional clips, 5/6 leaked (27.2 mm Hg). TAS T-tags and surgical closures leaked significantly less than the other groups (P=.01). Traditional clips and OVESCO OTS-clips leaked at significantly lower pressures than the other three groups (P=.007).

CONCLUSION

This in vivo model using leak of the closure or the gastric yield pressure as endpoints for testing of the closure strength of a NOTES gastric access site seems to be reproducible. Our results support closure with T-tags and Padlock-G-clips over OVESCO OTS-clips and standard endoscopic clips.

Reliability of gastric access closure with the self-approximating transluminal access technique (STAT) for NOTES

BACKGROUND

STAT, or the self-approximating transluminal access technique, has been previously described and involves the dissection of a submucosal tunnel for peritoneal or mediastinal access from the esophagus and stomach. The objective of this study was to assess the safety and reliability of gastric access and closure in a porcine experience using STAT for natural orifice transluminal endoscopic surgery (NOTES).

METHODS

A review of the experience using STAT access tunnels for intraperitoneal access was performed in 39 female pigs at a university animal lab. All animals underwent a predetermined NOTES surgical procedure using a STAT transgastric access tunnel based on a specific protocol. Details of the procedure, complications, and clinical course were documented. Necropsy was performed at 2 weeks. The main outcome measurements were clinical or necropsy evidence of gastrostomy site leak or inadequate access site closure.

RESULTS

STAT was successful in providing safe peritoneal access in all animals. The width of the tunnel ranged from 1.5 to 5.5 cm and the length was up to 27 cm. There was no evidence of gastrostomy site leak in any animals. One animal required a single laparoscopic suture to help with tunnel closure.

CONCLUSION

STAT provides safe transgastric access and allows secure closure of the gastrotomy site.

Current developments in natural orifices transluminal endoscopic surgery: An evidence-based review

Tremendous advances have been made in recent years addressing the key obstacles to safe performance and introduction of human natural orifice transluminal endoscopic surgery (NOTES). Animal studies have focused on identifying optimal solutions to these obstacles, in particular methods of creating transluminal access, safe closure of the point of access, and development of a multitasking platform with dedicated instruments. Whether the performance data generated from these animal studies can be reproduced in humans has yet to be determined. Reports of human NOTES procedures are emerging, and the possibility of accomplishing human NOTES based on existing technology has been demonstrated. However, dedicated platforms and devices are still lacking to allow for pure NOTES procedures, and whether NOTES can deliver the postulated benefits of earlier recovery and improved cosmesis remains uncertain.

Durability of the self-approximating translumenal access technique (STAT) for potential use in natural orifice translumenal surgery (NOTES)

BACKGROUND

The self-approximating translumenal access technique (STAT) has been shown to provide a safe and reliable means of abdominal access for natural orifice translumenal endoscopic surgery (NOTES). However, the feasibility of using STAT for translumenal organ resection is unknown. This study aimed to evaluate the technical performance of organ resection using STAT, the integrity of the STAT gastric tunnel after organ resection, and the postoperative morbidity of organ resection using STAT.

METHODS

In this study, 14 domestic swine underwent transgastric organ resection (7 cholecystectomies, 7 uterine horn resections) followed by sequential removal of two different sizes of standardized specimens. Evaluation of operative injury to the tunnel and difficulty of specimen extraction was performed. After 2 weeks of observation, necropsy was performed for evaluation and documentation of gross findings.

RESULTS

The mean operating room time (intubation recovery) was 4.1 h. A tunnel with a mean length of 12 cm and a mean width of 4 cm was created. The tunnel remained fully intact in 14 of 14 animals after organ resection, in 13 of 13 animals after balloon extraction, and in 12 of 14 animals after rigid specimen extraction (1 clinically significant tear occurred). Postoperatively, all the animals gained weight appropriately. Necropsy findings included adhesions (n = 4), bile leak (n = 2), minor lap-port abscess (n = 1), and ventral hernia (n = 1).

CONCLUSIONS

Although this study was a limited, prospective, animal survival study without a control arm, it again indicates that STAT allows safe abdominal access, a reliable means of closure, and directed endoscope positioning. Although one significant mucosal tear did occur, this study suggests STAT will tolerate the mechanical forces of peroral transgastric procedures provided the organ resected is small to moderate in size (<8 × 3 cm).