Comparison of intraabdominal pressures using the gastroscope and laparoscope for transgastric surgery

Intra-abdominal pressure during endoscopic full-thickness resection comparing manual and automatic control insufflation: a block-randomized porcine study

BACKGROUND AND STUDY AIMS

An automatic carbon dioxide (CO2) insufflating system (SPACE) was developed to stabilize intra-lumenal pressure (ILP) during endoscopic interventions. This study investigated whether SPACE could improve the control and monitoring of extra-lumenal intra-abdominal pressure (IAP) after establishing a perforation during endoscopic full-thickness resection (EFTR) of the gastric wall in porcine models.

MATERIALS AND METHODS

After first establishing the optimal preset pressure for gastric EFTR in four pigs, we compared IAP dynamics during EFTR between manual insufflation and SPACE using a block-randomized study (n = 10). IAP was percutaneously monitored and plotted on a timeline graph every 5 s. The maximal IAP and the area under the IAP curve exceeding 10 mmHg (AUC≥10 mmHg) were compared between groups, with the agreement between IAP and endolumenally monitored ILP also analyzed for animals in the SPACE group.

RESULTS

In the first study, 8 mmHg was identified as the most preferable preset pressure after establishment of the perforation. In the randomized study, the mean maximal IAP in the SPACE group was significantly lower than that in the manual insufflation group (11.0 ± 2.0 mmHg vs. 17.0 ± 3.5 mmHg; P = 0.03). The mean AUC≥10 mmHg was also significantly smaller in the SPACE group. Bland-Altman analysis demonstrated agreement between IAP and ILP within a range of ± 1.0 mmHg.

CONCLUSIONS

SPACE could be used to control and safely monitor IAP during gastric EFTR by measuring ILP during perforation of the gastric wall.

Evaluation of systemic inflammatory responses in cholecystectomy by means of access. Single-port umbilical incision, transvaginal NOTES, laparoscopy and laparotomy

PURPOSE

To evaluate and compare clinical and inflammatory responses to the surgical trauma caused by cholecystectomy via several access approaches: single-port umbilical incision (SILS), transvaginal natural orifice transluminal endoscopic surgery (NOTES), laparoscopy, and Laparotomy.

METHODS

Twenty-eight female pigs were equally divided into four groups and submitted to cholecystectomy by single-port umbilical incision, transvaginal NOTES, laparoscopy, or Laparotomy. An additional five animals served as controls (sham group). Animals were monitored perioperatively regarding anesthesia and surgical procedure times, as well as for the presence of complications. Postoperatively, they were evaluated regarding time to ambulation and feeding, and the presence of clinical events. Procalcitonin, C-reactive protein (CRP), and AQUI feron-gamma (IFN-γ) measurements were performed before surgery and immediately, two days, and seven days after surgery. Animals were sacrificed and necropsied at seven days after surgery.

RESULTS

All procedures were successfully performed as proposed in each group. Only minor complications, such as gallbladder perforation and bleeding from the liver bed, were observed during surgery in all groups. The vaginal NOTES group showed higher anesthesia and surgical procedure times compared to the other groups (p<0.001). No other between-group differences in perioperative or postoperative times, clinical evolution, or serum inflammatory markers were observed. Only adhesions were found on necropsy, with no differences between groups.

CONCLUSION

The single-port umbilical and transvaginal NOTES access approaches were feasible and safe compared to laparoscopic and laparotomy for cholecystectomy.

Natural-orifice transluminal endoscopic surgery

BACKGROUND

Natural-orifice transluminal endoscopic surgery (NOTES) represents one of the most significant innovations in surgery to emerge since the advent of laparoscopy. A decade of progress with this approach has now been catalogued, and yet its clinical application remains controversial.

METHODS

A PubMed search was carried out for articles describing NOTES in both the preclinical and the clinical setting. Public perceptions and expert opinion regarding NOTES in the published literature were analysed carefully.

RESULTS

Two hundred relevant articles on NOTES were studied and the outcomes reviewed. A division between direct- and indirect-target NOTES was established. The areas with the most promising clinical application included direct-target NOTES, such as transanal total mesorectal excision and peroral endoscopic myotomy. The clinical experience with distant-target NOTES, such as for appendicectomy and cholecystectomy, showed feasibility; however, NOTES-specific morbidity was introduced and this represents an important limitation.

CONCLUSION

NOTES experimentation in the preclinical setting has increased substantially. There has also been a significant increase in the application of NOTES in humans in the past decade. Enthusiasm for NOTES should be tempered by the risk of incurring NOTES-specific morbidity. Surgeons should carefully consider patient preferences regarding this new minimally invasive option, as opinions are not unanimously supportive of NOTES. As technical limitations are overcome, the clinical application of NOTES is predicted to increase. It is paramount that, when this complex technique is performed on humans, it is applied judiciously by appropriately trained experts with outcomes recorded in a registry.

Gastric endoscopic submucosal dissection under steady pressure automatically controlled endoscopy (SPACE); a multicenter randomized preclinical trial. Surg Endosc. 2015;29:2748-2755. [PMID: 25480619 DOI: 10.1007/s00464-014-4001-0]

BACKGROUND

Steady pressure automatically controlled endoscopy (SPACE) is a new modality that eliminates on-demand insufflation but enables automatic insufflation in the gastrointestinal tract. Though its use in porcine esophageal ESD was reported to be promising, its applicability and potential effectiveness to gastric procedures have not been evaluated.

OBJECTIVE

The aims were (1) to evaluate feasibility and safety of SPACE in the stomach, and (2) to assess its potential advantages over conventional endoscopy in preventing "blind insufflation"-related complications.

DESIGN

A multicenter randomized preclinical animal study.

SETTING

Laboratories at three universities.

INTERVENTIONS

Experiment 1: Gastric ESD was attempted in the swine (n = 17), under either SPACE or manual insufflation. Experiment 2: Gastroscopy was performed for 10 min in the perforated stomach (n = 10) under either SPACE or manual insufflation.

MAIN OUTCOME MEASUREMENTS

Experiment 1: ESD time, energy device activation time, number of forceps exchanges, specimen size, en block resection rate, vital signs and any intraoperative adverse events. Experiment 2: Intra-gastric and intra-abdominal pressures, vital signs, and any adverse events.

RESULTS

Experiment 1: Gastric ESD was completed in all animals. ESD time tended to be shorter in SPACE than in the control, though the difference was not significant (p = 0.18). Experiment 2: Although both intra-gastric and intra-abdominal pressures remained within preset values in SPACE, they showed excessive elevation in control.

LIMITATIONS

An animal study with small sample size.

CONCLUSIONS

SPACE is feasible and safe for complicated and lengthy procedures such as gastric ESD, and is potentially effective in preventing serious consequences related to excessive blind insufflation.

The influence on immunologic parameters during NOTES in a porcine survival model

OBJECTIVE

To analyze the effect of natural orifice transluminal endoscopic surgery (NOTES) on the survival of animals, by comparing the change of intraoperative and postoperative immunologic parameters of NOTES with laparoscopy.

MATERIALS AND METHODS

Twenty pigs were randomized to treatment with NOTES or standard laparoscopy. Each group underwent diagnostic peritoneoscopy by laparoscopy or NOTES in 90 minutes. Laboratory values, including interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α), were obtained at baseline, at intraoperative minute (IOM) 30, 60, and 90, and on postoperative day (POD) 1, 3, and 7.

RESULTS

All procedures were successfully completed and all animals (except one in the NOTES group) survived to POD 14. The level of IL-1 and TNF-α was not significantly different compared with the preoperative level of IL-1 and TNF-α in both groups at IOM 30 and 60. It increased significantly at IOM 90 and POD 1 and 3 in both groups. Although levels of both IL-1 and TNF-α were higher in the NOTES group compared with the other group, there was no significant difference between the groups. At POD 7, the level of IL-1 and TNF-α decreased to near-normal levels in both groups.

CONCLUSIONS

Although preliminary, the findings in this study do not currently support the assumption that NOTES is less invasive than laparoscopy. Further research is required to confirm these findings.

Endoscopic gastrojejunostomy with a natural orifice transluminal endoscopic surgery technique

AIM: To determine the technical feasibility and safety of an endoscopic gastrojejunostomy with a pure natural orifice transluminal endoscopic surgery (NOTES) technique using a T-anchoring device in a porcine survival model.

METHODS: An endoscopic gastrojejunostomy with a pure NOTES technique using a T-anchoring device was performed on 10 healthy female minipigs weighing approximately 40 kg each under general anesthesia. All procedures were performed with a transgastric approach using a 2-channel therapeutic endoscope.

RESULTS: The transgastric gastrojejunostomy was technically successful in all cases. A total of four to six stitched pairs of a T-anchoring device were used to secure the anastomosis. The median time required to enter the peritoneal cavity and pull the small bowel into the stomach was 34 min (range: 19-41 min); the median time required to suture the anastomosis was 67 min (range: 44-78 min). An obstruction of the efferent limb occurred in one case, and a rupture of the anastomosis site occurred in another case. As a result, the functional success rate was 80% (8/10). Small bowel adhesion to the stomach and liver occurred in one case, but the anastomosis was intact without leakage or obstruction.

CONCLUSION: A transgastric gastrojejunostomy with a T-anchoring device may be safe and technically feasible. A T-anchoring device may provide a simple and effective endoscopic suturing method.

Mechatronic design of a fully integrated camera for mini-invasive surgery

This paper describes the design features of an innovative fully integrated camera candidate for mini-invasive abdominal surgery with single port or transluminal access. The apparatus includes a CMOS imaging sensor, a light-emitting diode (LED)-based unit for scene illumination, a photodiode for luminance detection, an optical system designed according to the mechanical compensation paradigm, an actuation unit for enabling autofocus and optical zoom, and a control logics based on microcontroller. The bulk of the apparatus is characterized by a tubular shape with a diameter of 10 mm and a length of 35 mm. The optical system, composed of four lens groups, of which two are mobile, has a total length of 13.46 mm and an effective focal length ranging from 1.61 to 4.44 mm with a zoom factor of 2.75×, with a corresponding angular field of view ranging from 16° to 40°. The mechatronics unit, devoted to move the zoom and the focus lens groups, is implemented adopting miniature piezoelectric motors. The control logics implements a closed-loop mechanism, between the LEDs and photodiode, to attain automatic control light. Bottlenecks of the design and some potential issues of the realization are discussed. A potential clinical scenario is introduced.

On-demand endoscopic CO2 insufflation with feedback pressure regulation during natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy induces minimal hemodynamic and respiratory changes

BACKGROUND

Endoscopic insufflation has been associated with marked increase in intra-abdominal pressure (IAP) and hemodynamic and respiratory changes during transgastric surgery.

OBJECTIVE

To investigate the hemodynamic and respiratory effects during intraperitoneal cavity exploration through 3 different natural orifice transluminal endoscopic surgery (NOTES) access locations compared with laparoscopy.

DESIGN AND SETTING

Survival experiments using 40 female pigs randomized to transgastric, transcolonic, transvaginal, and laparoscopic peritoneoscopy.

INTERVENTIONS

On-demand endoscopic insufflation of CO(2) with feedback pressure regulation was used in NOTES with a maximum pressure of 14 mm Hg. In the laparoscopy group, the IAP was maintained at 14 mm Hg. NOTES procedures were performed by an endoscopist (with the assistance of a gynecologist in the transvaginal group and a second endoscopist in the transgastric and transrectal groups) and laparoscopy by 2 surgeons.

MAIN OUTCOME MEASUREMENTS

Invasive hemodynamic and respiratory data. Blood samples were drawn for gas analyses.

RESULTS

All experiments except one in the transrectal group were completed. The IAP was significantly lower in all NOTES groups compared with the laparoscopy group. A significant increase in mean systemic arterial blood pressure was observed in the laparoscopy group at 15 and 30 minutes of intraperitoneal cavity exploration, but it remained unchanged during all NOTES procedures. An increase in airway pressures was observed at 15 and 30 minutes of peritoneoscopy in the animals undergoing laparoscopy, whereas those parameters remained unchanged in the NOTES groups. The laparoscopy group showed a significant impairment in pulmonary gas exchange (decrease in Pao(2), increase in Paco(2), and decrease in arterial pH) after 30 minutes of peritoneoscopy, whereas only a slight increase in Paco(2) was observed in the transrectal and transvaginal groups.

LIMITATIONS

Healthy animal model.

CONCLUSION

On-demand endoscopic insufflation of CO(2) with feedback pressure regulation can minimize the risk of hemodynamic and respiratory compromise caused by acute changes in IAP.

Natural orifice transluminal endoscopic surgery: New minimally invasive surgery come of age

Although in the past two decades, laparoscopic surgery, considered as a great revolution in the minimally invasive surgery field, has undergone major development worldwide, another dramatic surgical revolution has quietly appeared in recent years. Ever since Kalloo’s first report on transgastric peritoneoscopy in a porcine model in 2004, interest in a new surgical procedure named natural orifice transluminal endoscopic surgery (NOTES) has blossomed worldwide. Considering that a NOTES procedure could theoretically avoid any abdominal incision, operation-related pain and scarring, many surgeons and endoscopists have been enthusiastic in their study of this new technique. In recent years, several NOTES studies have been carried out on porcine models and even on humans, including transvaginal cholecystectomy, transgastric appendectomy, transvaginal appendectomy, and transvesical peritoneoscopy. So what is the current situation of NOTES and how many challenges do we still face? This review discusses the current research progress in NOTES.

Current limitations in endoscopic CO₂ insufflation for NOTES: flow and pressure study

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) requires fast and steady CO₂ insufflation into the intraluminal and intra-abdominal spaces through a flexible endoscope. However, an optimal endoscopic insufflation system has yet to be determined.

OBJECTIVE

To verify the performances of 2 currently available CO₂ insufflators in an experimental NOTES setting: (1) an automatic pressure-regulated surgical insufflator (UHI-3) and (2) a manual endoscopic insufflator (UCR).

DESIGN

An inanimate bench study followed by an acute animal experiment.

SETTING

Osaka University and Olympus Research and Development Department.

MAIN OUTCOME MEASUREMENTS

The UHI-3 or UCR was connected to an endoscope of differing length and diameter via an insufflating line of differing length and diameter. The flow rates at the tip of the endoscope (bench test), the time to establish pneumoperitoneum, and the time to re-establish pneumoperitoneum after forceful suction (porcine model) were obtained.

RESULTS

The UHI-3 failed to feed CO₂ through an insufflating channel but fed CO₂ via a working channel but required a large channel (>3 mm) and a wide insufflating line (>7 mm) to accomplish an acceptable flow rate. UCR fed CO₂ through the insufflating channel; however, the time taken to establish pneumoperitoneum and the time taken to re-establish pneumoperitoneum after forceful suction were longer compared with the time taken for UHI-3 insufflation via the working channel or laparoscopic cannula.

LIMITATIONS

Bench/animal study with small sample numbers; no human trial.

CONCLUSIONS

The currently available CO₂ insufflators are not optimal for NOTES. Modification of an endoscopic insufflation system and/or development of a dedicated overtube with an insufflating function are therefore essential.

International multicenter trial on clinical natural orifice surgery--NOTES IMTN study: preliminary results of 362 patients

OBJECTIVES

Natural orifice translumenal endoscopic surgery (NOTES) is evolving as a promising alternative for abdominal surgery. IMTN Registry was designed to prospectively document early results of natural orifice surgery among a large group of clinical cases.

METHODS

Sixteen centers from 9 countries were approved to participate in the study, based on study protocol requirements and local institutional review board approval. Transgastric and transvaginal endoscopic natural orifice surgery was clinically applied in 362 patients. Intraoperative and postoperative parameters were prospectively documented.

RESULTS

Mean operative time for transvaginal cholecystectomy was 96 minutes, compared with 111 minute for transgastric cholecystectomy. A general complication rate of 8.84% was recorded (grade I-II representing 5.8%, grade III-IV representing 3.04%). No requirement for any analgesia was found in one fourth of cholecystectomy and appendectomy patients.

CONCLUSIONS

Results of clinical applications of NOTES in the IMTN Study showed the feasibility of different methods of this new minimally invasive alternative for laparoscopic and open surgery.

Carbon dioxide versus room air for natural orifice transluminal endoscopic surgery (NOTES) and comparison with standard laparoscopic pneumoperitoneum

BACKGROUND

Most studies investigating natural orifice transluminal endoscopic surgery (NOTES) have used room air, whereas carbon dioxide (CO(2)) is traditionally preferred for laparoscopic insufflation.

OBJECTIVE

Evaluation of CO(2) versus room air for NOTES and comparison with standard laparoscopic pneumoperitoneum.

DESIGN

Prospective experiments in an acute porcine model.

INTERVENTIONS

For transgastric peritoneoscopy, either CO(2) or room air were insufflated via the endoscope for a constant intraperitoneal pressure of 12 mm Hg in 16 pigs. Another 8 pigs received laparoscopic insufflation with CO(2). Identification of intra-abdominal organs during NOTES was documented. Additionally, standardized video recordings of peritoneoscopy were evaluated by an independent blinded observer. Complete cardiopulmonary status was assessed every 3 minutes.

MAIN OUTCOME MEASUREMENTS

Quality of transgastric peritoneoscopy and cardiopulmonary response.

RESULTS

In the NOTES room air group, significantly more target organs (18/64, 28%) were missed than in the NOTES CO(2) group (8/64, 13%; P = .028). However, blinded video analysis showed no difference between the groups. An increase in systemic vascular resistance index during pneumoperitoneum in the NOTES room air group was less pronounced than in the NOTES CO(2) group, almost reaching the level of significance (P = .050). With respect to hemodynamics, there were no significant differences between the NOTES CO(2) group and the laparoscopy CO(2) group.

LIMITATIONS

Nonsurvival animal experiments.

CONCLUSIONS

Pressure-controlled endoscopic insufflation of CO(2) for NOTES showed minor advantages compared with insufflation of room air regarding intra-abdominal visualization, but resulted in an increase in cardiac afterload. However, the cardiorespiratory responses during endoscopic insufflation of CO(2) were similar to the widely accepted standard laparoscopic CO(2) insufflation.

Endoscopic peritoneal access and insufflation: natural orifice transluminal endoscopic surgery

BACKGROUND

Diagnostic transgastric endoscopic peritoneoscopy is a safe model for exploration of the peritoneum. Endoscopic insufflation of the peritoneal cavity has not been validated in humans. We report here our experience with pneumoperitoneum established endoscopically with a laparoscopic insufflator.

DESIGN

Pneumoperitoneum was established with a laparoscopic insufflator through the biopsy channel of the gastroscope. Intra-abdominal pressure was measured with a transfascial Veress needle and compared with endoscopic values. The gastrotomy was used in the creation of the gastric pouch.

PATIENTS

Twenty patients undergoing laparoscopic Roux-en-Y gastric bypass participated in the study. Ten had undergone no previous surgery, whereas the other 10 patients had a history of abdominal procedures.

INTERVENTIONS

Diagnostic transgastric endoscopic peritoneoscopy was performed through a gastrotomy created endoscopically without laparoscopic visualization.

MAIN OUTCOME MEASUREMENTS

Diagnostic findings, operating times, and clinical course were recorded.

RESULTS

The average time for transgastric access was 9.6 minutes. This did not vary in patients with previous surgery (P = .3). Endoscopic insufflation was successful in all patients. The mean endoscopic and laparoscopic pressures were 9.80 and 9.75 mm Hg, respectively (P = .9). In no patients were there limitations to visualization of the abdomen. Adhesions were noted in 80% and 10% of patients with and without a history of surgery, respectively (P = .005). There were no complications related to transgastric passage of the endoscope or exploration of the peritoneal cavity.

CONCLUSIONS

Although limited by the small sample size in this study, we believe that transgastric access may be considered as an alternative approach to peritoneal insufflation and provides a safe alternative for exploration of the abdomen. Endoscopic insufflation through the biopsy channel by using a laparoscopic insufflator seems to be an effective and safe method for establishing pneumoperitoneum.

Diagnostic transgastric endoscopic peritoneoscopy: extension of the initial human trial for staging of pancreatic head masses

BACKGROUND

The validity of natural orifice transluminal endoscopic surgery (NOTES) was confirmed in a human trial of 10 patients undergoing diagnostic transgastric endoscopic peritoneoscopy (DTEP) for staging of pancreatic head masses. This report is an update with 10 additional patients in the series and includes bacterial contamination data.

METHODS

The patients in this human trial were scheduled to undergo diagnostic laparoscopy for abdominal staging of a pancreatic head mass. A second surgeon, blinded to the laparoscopic findings, performed a transgastric endoscopic peritoneoscopy (TEP). The findings of laparoscopic exploration were compared with that those of the TEP. Diagnostic findings, operative times, and clinical course were recorded. Bacterial contamination data were collected for the second cohort of 10 patients. Bacterial samples were collected from the scope before use and the abdominal cavity before and after creation of the gastrotomy. Samples were assessed for bacterial counts and species identification. Definitive care was rendered based on the findings from laparoscopy.

RESULTS

In this study, 20 patients underwent diagnostic laparoscopy followed by DTEP. The average time for completion of diagnostic laparoscopy was 10 min compared with 21 min for TEP. The experience acquired during the initial 10 procedures translated to a 7-min decrease in TEP time for the second 10 cases. For 19 of the 20 patients, DTEP corroborated laparoscopic findings for surgical decision making. One endoscopic and five laparoscopic biopsies were performed. Pancreaticoduodenectomy was performed for 14 patients and palliative gastrojejunostomy for 6 patients. No cross-contamination of the peritoneum or infectious complications were noted. No significant complications related to either the endoscopic or laparoscopic approach occurred.

CONCLUSIONS

This study supports the authors' previous conclusions that the transgastric approach to diagnostic peritoneoscopy is feasible, safe, and accurate. The lack of documented bacterial contamination further supports the use of this technique. Technical issues, including intraabdominal manipulation and gastric closure, require further investigation.

New hybrid approach for NOTES transvaginal cholecystectomy: preliminary clinical experience

OBJECTIVES

Natural orifice translumenal endoscopic surgery (NOTES) represents the first step toward scar-less surgery. The objective of this study is to evaluate early clinical results of transvaginal cholecystectomy using a new technique.

METHODS

Institutional review board approval was obtained and transvaginal NOTES cholecystectomy was performed in 12 women for cholelithiasis. A 2-channel videoendoscope was inserted in the abdominal cavity through a posterior colpotomy. Two 3-mm trocars were inserted deep in the umbilicus, and a 10-mm trocar was placed through the colpotomy parallel to the endoscope. Dissection was performed with endoscopic instruments combined with 3-mm laparoscopic instruments.

RESULTS

Mean operative time was 125.8 minutes. All procedures occurred without intraoperative complications or conversions, except for 1 vulvar laceration. There were no postoperative complications in the clinical follow-up.

CONCLUSION

Transvaginal NOTES is a feasible and safe alternative for cholecystectomy in this preliminary clinical experience, allowing good cosmetic benefits and low analgesic requirement.

NOTES: new dimension of minimally invasive surgery

Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery. NOTES eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. Since the first NOTES was reported by Kalloo et al. in 2004, significant achievements in the laboratory have occurred. Clinical use in humans has been limited, but several cases and one small clinical trial were published recently. As a further technical revolution in minimally invasive surgery, NOTES has the promising potential to be safer, less invasive, provide better cosmesis and possibly be more cost-effective. The purpose of the present article was to review the development and current status of NOTES and highlight important advances associated with this innovative approach.

Natural orifice transluminal endoscopic surgery gastrotomy closure with an over-the-endoscope clip: a randomized, controlled porcine study (with videos)

BACKGROUND

Secure endoscopic closure of transgastric natural orifice transluminal endoscopic surgery (NOTES) access is of paramount importance. The over-the-scope clip (OTSC) system has previously been shown to be effective for NOTES gastrotomy closure.

OBJECTIVE

To compare OTSC gastrotomy closure with surgical closure.

DESIGN

Randomized, controlled animal study.

SETTING

Animal facility laboratory.

ANIMALS

Thirty-six female domestic pigs.

INTERVENTIONS

Gastrotomies were created by using a needle-knife and an 18-mm balloon. The animals were subsequently randomized to either open surgical repair with interrupted sutures or endoscopic repair with 12-mm OTSCs. In addition, pressurized leak tests were performed in ex vivo specimens of 18-mm scalpel incisions closed with suture (n = 14) and of intact stomachs (n = 10).

MAIN OUTCOME MEASUREMENTS

The mean time for endoscopic closure was 9.8 minutes (range 3-22, SD 5.5). No complications occurred during either type of gastrotomy closure. At necropsy, examination of all OTSC and surgical closures demonstrated complete sealing of gastrotomy sites without evidence of injury to adjacent organs. Pressurized leak tests showed a mean burst pressure of 83 mm Hg (range 30-140, SD 27) for OTSC closures and 67 mm Hg (range 30-130, SD 27.7) for surgical sutures. Ex vivo hand-sewn sutures of 18-mm gastrotomies (n = 14) exhibited a mean burst pressure of 65 mm Hg (range 20-140, SD 31) and intact ex vivo stomachs (n = 10) had a mean burst pressure of 126 mm Hg (range 90-170, SD 28). The burst pressure of ex vivo intact stomachs was significantly higher compared with OTSC closures (P < .01), in vivo surgical closures (P < .01), and ex vivo hand-sewn closures (P < .01). There was a trend toward higher burst pressures in the OTSC closures compared with surgical closures (P = .063) and ex vivo hand-sewn closures (P = .094). In vivo surgical closures demonstrated similar burst pressures compared with ex vivo hand-sewn closures (P = .848).

LIMITATIONS

Nonsurvival setting.

CONCLUSION

Endoscopic closure by using the OTSC system is comparable to surgical closure in a nonsurvival porcine model. This technique is easy to perform and is suitable for NOTES gastrotomy closure.

Natural orifice surgery: initial clinical experience

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) has moved quickly from preclinical investigation to clinical implementation. However, several major technical problems limit clinical NOTES including safe access, retraction and dissection of the gallbladder, and clipping of key structures. This study aimed to identify challenges and develop solutions for NOTES during the initial clinical experience.

METHODS

Under an Institutional Review Board (IRB)-approved protocol, patients consented to a natural orifice operation for removal of either the gallbladder or the appendix via either the vagina or the stomach using a single umbilical trocar for safety and assistance.

RESULTS

Nine transvaginal cholecystectomies, one transgastric appendectomy, and one transvaginal appendectomy have been completed to date. All but one patient were discharged on postoperative day 1 as per protocol. No complications occurred.

CONCLUSION

The limited initial evidence from this study demonstrates that NOTES is feasible and safe. The addition of an umbilical trocar is a bridge allowing safe performance of NOTES procedures until better instruments become available. The addition of a flexible long grasper through the vagina and a flexible operating platform through the stomach has enabled the performance of NOTES in a safe and easily reproducible manner. The use of a uterine manipulator has facilitated visualization of the cul de sac in women with a uterus to allow for safe transvaginal access.

Totally NOTES (T-NOTES) transvaginal cholecystectomy using two endoscopes: preliminary report

BACKGROUND

Clinical applications of transvaginal Natural Orifice Transluminal Endoscopic Surgery (NOTES) are still limited in the literature, mostly case reports performed by hybrid procedures with laparoscopic assistance. Avoiding complications from incisions is the main goal for natural orifice surgery. This study reports on a technique developed at our institution that uses two endoscopes inserted into the vagina to perform a Totally NOTES (T-NOTES) transvaginal cholecystectomy, and describes preliminary results.

METHODS

IRB approval was obtained at the institution for transvaginal NOTES clinical trials, and informed consent was obtained. The technique of T-NOTES transvaginal cholecystectomy was clinically applied in four female patients with symptomatic cholelithiasis, and data were prospectively documented. Transvaginal NOTES access was obtained by direct vaginal incision, and two endoscopes were simultaneously introduced in the abdominal cavity. Dissection was accomplished with available endoscopic instruments. Ligation of cystic duct and artery was performed using endoscopic clips. Vaginal closure was achieved using the direct-vision sutured technique.

RESULTS

The technique was successfully performed in the four patients. Insufflation and spatial orientation was of good quality. Mean operative time was 210 min. There were no complications during the 30-day follow-up. Postoperative course was uneventful, and patients were released from the hospital on the first postoperative day.

CONCLUSION

Tranvaginal T-NOTES using two endoscopes provides a feasible method for natural orifice cholecystectomy using available technology. Large-series studies are needed to evaluate the results with respect to safety of the approach.

Flexible transgastric peritoneoscopy and liver biopsy: a feasibility study in human beings (with videos)

BACKGROUND

Multiple studies have demonstrated the feasibility of natural orifice transluminal endoscopic surgery in animal models.

OBJECTIVE

To determine the feasibility of transgastric peritoneoscopy and liver biopsy in human beings.

SETTING

Our institutional review board approved the procedures in the operating room with the patients under general anesthesia.

DESIGN AND INTERVENTIONS

During laparoscopic gastric bypass surgery a flexible endoscope was introduced into the peritoneal cavity through the gastric-wall incision. A peritoneoscopy with a liver biopsy was performed, then the flexible endoscope was withdrawn into the stomach, and gastric bypass surgery was completed laparoscopically.

PATIENTS

Three patients who were morbidly obese (mean weight 115.22 +/- 9.07 kg [254 +/- 20 lb]).

MAIN OUTCOME MEASUREMENTS

The ability to navigate a flexible endoscope inside the peritoneal cavity, to visualize the intra-abdominal organs, and to perform a liver biopsy without laparoscopic assistance.

RESULTS

It was very easy to navigate the flexible endoscope inside the abdomen by using torque, advancement, and withdrawal of the endoscopic shaft, as well as by movement of the endoscope tip. The flexible endoscope provided an excellent view and adequate illumination of the peritoneal cavity. The orientation of the flexible endoscope inside the peritoneal cavity was technically easy, even in the retroflex position. Systematic visualization of the liver, the spleen, the omentum, and the small and large intestine was easily achieved through the flexible endoscope without laparoscopic assistance. A liver biopsy was successfully completed in all cases by obtaining adequate tissue samples for histologic examination.

LIMITATION

This was a pilot feasibility study.

CONCLUSIONS

Transgastric flexible endoscopic peritoneoscopy in human beings is technically feasible, simple, and can become a valuable tool that complements and facilitates laparoscopic interventions inside the peritoneal cavity.

Natural orifice translumenal endoscopic surgery (NOTES) transvaginal cholecystectomy in a morbidly obese patient

Transvaginal natural orifice translumenal endoscopic surgery (NOTES) is a new diagnostic and potentially therapeutic method of surgical endoscopy. The first case of NOTES transvaginal cholecystectomy in a morbid obese patient in the literature is described. IRB approval was obtained at the institution for transvaginal NOTES clinical trials. A 58-year-old female patient with cholelithiasis, hypertension, and type II diabetes, and BMI of 35.8 kg/m(2) was submitted to the technique. After transvaginal access, a two-channel gastroscope was introduced into the abdominal cavity along with a laparoscopic trocar. There were 2 umbilical punctures for use of 3 mm laparoscopic equipment. Operative time was 85 min. There was no use of postoperative analgesia, and the patient was discharged on the third postoperative day. Transvaginal NOTES is a feasible alternative method for cholecystectomy in the morbidly obese, although available technology is limited for natural orifice surgery.

Reliable gastric closure after natural orifice translumenal endoscopic surgery (NOTES) using a novel automated flexible stapling device

BACKGROUND

Reliable closure of the translumenal incision is one of the main challenges facing natural orifice translumenal endoscopic surgery (NOTES). This study aimed to evaluate the use of an automated flexible stapling device (SurgASSIST) for closure of the gastrotomy incision in a porcine model.

METHODS

A double-channel gastroscope was advanced into the stomach. A gastric wall incision was made, and the endoscope was advanced into the peritoneal cavity. After peritoneoscopy, the endoscope was withdrawn into the stomach. The SurgASSIST stapler was advanced orally into the stomach. The gastrotomy edges were positioned between the opened stapler arms using two endoscopic grasping forceps. Stapler loads with and without a cutting blade were used for gastric closure. After firing of the stapler to close the gastric wall incision, x-ray with contrast was performed to assess for gastric leakage. At the end of the procedure, the animals were killed for a study of closure adequacy.

RESULTS

Four acute animal experiments were performed. The delivery and positioning of the stapler were achieved, with technical difficulties mostly due to a short working length (60 cm) of the device. Firing of the staple delivered four rows of staples. Postmortem examination of pig 1 (when a cutting blade was used) demonstrated full-thickness closure of the gastric wall incision, but the cutting blade caused a transmural hole right at the end of the staple line. For this reason, we stopped using stapler loads with a cutting blade. In the three remaining animals (pigs 2-4), we were able to achieve a full-thickness closure of the gastric wall incision without any complications.

CONCLUSIONS

The flexible stapling device may provide a simple and reliable technique for lumenal closure after NOTES procedures. Further survival studies are currently under way to evaluate the long-term efficacy of gastric closure with the stapler after intraperitoneal interventions.

Infection prevention in NOTES

Prevention of infection during natural orifice translumenal endoscopic surgery (NOTES) was identified as one of the most important challenges for translumenal surgery. Does infection prevention during NOTES warrant such attention? This article summarizes the accumulated data about septic complications during translumenal surgery.

The eagle or the snake: platforms for NOTES and radical endoscopic therapy

It has only been about 3 years since natural orifice translumenal endoscopic surgery (NOTES) first began to gather the attention of the medical and surgical community at large. The concepts behind NOTES, however, have been under development for almost a decade. It is important to revisit some basic concepts regarding therapeutic flexible endoscopy and in the process understand the fundamental premises on which a sound technology development program for NOTES should be built. This article provides such a review and emphasizes general principles rather than specific embodiments, which are very much at a nascent stage.

Late phase TNF-alpha depression in natural orifice translumenal endoscopic surgery (NOTES) peritoneoscopy

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) allows access to the peritoneal cavity without skin incisions. Contamination of the peritoneal cavity by enteric contents may render NOTES more physiologically and immunologically invasive than previously thought. Measurement of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) is a validated method to quantify surgical stress. The physiologic and immunologic impact of NOTES is unknown.

METHODS

A total of 37 swine underwent abdominal exploration via transgastric NOTES peritoneoscopy, laparoscopy (LX), laparotomy (OPEN), or sham surgery (CONTROL) and were allowed to survive. TNF-alpha, IL-1beta, and IL-6 plasma levels were determined at the start and completion of surgery, and at 1 hour, 2 days, and 14 days postoperatively.

RESULTS

At surgical completion, OPEN animals demonstrated higher TNF-alpha levels than all groups. TNF-alpha levels were similar for all groups at 1 hour and 2 days. NOTES animals had significantly reduced plasma levels of TNF-alpha than all other groups on postoperative days 7 and 14. Controlling for baseline cytokine variability, analysis was repeated using normalized data, which confirmed significantly reduced TNF-alpha levels for NOTES compared with all groups at 14 days. Subset analysis excluding LX and OPEN complications revealed lower NOTES TNF-alpha levels at 7 and 14 days compared with all groups. IL-1beta and IL-6 levels were undetectable in 66.8% and 70.5% of samples, respectively, without significant trends.

CONCLUSIONS

Diagnostic NOTES peritoneoscopy demonstrated similar levels of systemic proinflammatory cytokine TNF-alpha compared with diagnostic laparoscopy and exploratory laparotomy in the immediate postoperative period despite gross intraperitoneal contamination. None of the surgical groups, however, produced a measurable, consistent trend in IL-1beta or IL-6. Consistently reduced levels of TNF-alpha in NOTES animals in the late postoperative period indicates an immunomodulatory effect of the NOTES surgical technique not present in laparoscopy or laparotomy.

[Natural orifice transluminal endoscopic surgery]

In Natural Orifice Transluminal Endoscopic Surgery (NOTES) a flexible endoscope is passed through a natural orifice of the body and intra-abdominal procedures can be performed through a transvisceral (transgastric, -colonic, -vaginal or -vesical) incision. Principally, this state-of-the-art technology decreases invasiveness and postoperative pain, prevents postoperative hernia formation and improves cosmetic results. However, numerous questions regarding the technique are unanswered yet. Further research is necessary to extend the armamentarium of minimally invasive surgery. This article reviews the current state of experimental results and clinical approaches of NOTES.