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

Clinical efficacy and safety of transvaginal natural orifice transluminal endoscopic surgery for benign adnexal disease: a prospective trial

BACKGROUND

There is a scarcity of prospective clinical research evidence regarding the utilization of transvaginal natural orifice translumenal endoscopic surgery (vNOTES) as a treatment option for ovarian cysts. The objective of this study was to assess the feasibility and safety of employing vNOTES for the management of ovarian cysts.

METHODS

Our study included women between the ages of 18 and 70 who intended to undergo surgical intervention for benign lesions. Stratified blocked randomization was employed to allocate participants into groups. The main objective was to assess whether the assigned group adhered to the recommended surgical technique for ovarian cystectomy or adnexectomy, without any deviation to alternative surgical methods.

RESULTS

A total of 196 patients were included in the study, with all surgeries in each group being conducted according to the assigned procedures. Among them, the ovarian cystectomy layer included 58 cases in the vNOTES group and 58 cases in the conventional laparoscopy (CL) groups. The adnexectomy layer included 40 cases in the vNOTES group and 40 cases in the CL group. Utilizing a sensitivity analysis, the two-sided 95% lower confidence limit was determined to be 5.5% for the disparity in proportions between the vNOTES groups and CL groups. These lower limits fell below the predetermined non-inferiority margin of 10%.

CONCLUSIONS

The study findings demonstrate that vNOTES was not inferior to CL in terms of adnexectomy or ovarian cystectomy. vNOTES can be considered a more minimally invasive surgical approach, as it results in reduced postoperative pain, faster recovery, and absence of visible incisions. Overall, vNOTES proves to be a safe, feasible, and less invasive treatment option.

TRIAL REGISTRATION

This study retrospectively registered with the China Clinical Trial Registry with the registration number ChiCTR2100052223(22-10-2021).

The endoluminal pressures during flexible gastrointestinal endoscopy

In flexible gastrointestinal (GI) endoscopy, endoscopic insufflation is crucial and directly affects visualization. Optimal visualization enables endoscopists to conduct better examinations and administer optimal treatments. However, endoscopic insufflation is typically performed manually and is subjective. We aimed to measure the GI endoluminal pressure during flexible GI endoscopy. Participants underwent esophagogastroduodenoscopy (EGD) at our endoscopy center. Pressure measurement was conducted after completing diagnostic or follow-up EGD. The endoluminal pressure in the esophagus and stomach was measured at 1-s intervals for 1 min while performing EGD for observational and diagnostic purposes. During the measurements, the endoscopists maintained what they subjectively considered to be adequate exposure for screening for lesions by dilating the lumen. Eighty patients were enrolled in this study. The upper GI endoluminal pressure was assessed during EGD without adverse events. The esophageal endoluminal pressure averaged 8.9 (- 3.0 to 20.7) mmHg, and the gastric endoluminal pressure averaged 10.0 (3.0-17.9) mmHg; the upper GI endoluminal pressures were not affected by patient-related factors or the number of endoscopists' postgraduate years. We have successfully obtained the GI endoluminal pressures during EGD. Further accumulation of these data may lead to more stable and reproducible flexible endoscopic diagnosis and intervention.

Meta-analysis of hybrid natural-orifice transluminal endoscopic surgery versus laparoscopic surgery

Background

Hybrid natural-orifice transluminal endoscopic surgery (NOTES), combining access through a natural orifice with small-sized abdominal trocars, aims to reduce pain and enhance recovery. The objective of this systematic review and meta-analysis was to compare pain and morbidity in hybrid NOTES and standard laparoscopy.

Methods

A systematic literature search was performed to identify RCTs and non- RCTs comparing hybrid NOTES and standard laparoscopy. The main outcome was pain on postoperative day (POD) 1. Secondary outcomes were pain during the further postsurgical course, rescue analgesia, complications, and satisfaction with the cosmetic result. The results of meta-analysis in a random-effects model were presented as odds ratio (ORs) or standard mean differences (MDs) with 95 per cent confidence intervals.

Results

Six RCTs and 21 non-randomized trials including 2186 patients were identified. In hybrid NOTES the score on the numerical pain scale was lower on POD 1 (−0·75, 95 per cent c.i. −1·09 to −0·42; P = 0·001) and on POD 2–4 (−0·58, −0·91 to −0·26; P < 0·001) than that for standard laparoscopy. The need for rescue analgesia was reduced in hybrid NOTES (OR 0·36, 0·24 to 0·54; P < 0·001). The reduction in complications found for hybrid NOTES compared with standard laparoscopy (OR 0·52, 0·38 to 0·71; P < 0·001) was not significant when only RCTs were considered (OR 0·83, 0·43 to 1·60; P = 0·570). The score for cosmetic satisfaction was higher after NOTES (MD 1·14, 0·57 to 1·71; P < 0·001).

Conclusion

Hybrid NOTES reduces postoperative pain and is associated with greater cosmetic satisfaction in selected patients.

Effect of transgastric natural orifice transluminal endoscopic surgery peritoneoscopy on abdominal organ microcirculation: an experimental controlled study

BACKGROUND AND AIMS

On-demand insufflation during endoscopic peritoneoscopy causes wide variations in intra-abdominal pressure. Its effects on splanchnic microcirculation may differ from those of steady intra-abdominal pressure, because pressure characteristics affect crucial intravascular hemodynamic forces--pressure and shear--adapting flow to local metabolic needs. Our aim was to assess the effect of natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy on splanchnic microcirculatory blood flow.

METHODS

Twenty-one swine were randomized to the following: cholecystectomy by transgastric NOTES (n = 8), cholecystectomy by standard laparoscopy (Lap) (n = 8), and a sham group (n = 5). During NOTES, CO2 was manually insufflated with a maximum allowed pressure of 30 mm Hg. In the Lap group, intra-abdominal pressure was maintained at 14 mm Hg. Systemic hemodynamics were measured, and microcirculatory blood flow was quantified by using colored microspheres.

RESULTS

Mean intra-abdominal pressure was lower in NOTES than in the Lap group (P = .038). In both groups, cardiac index and preload remained unchanged, whereas systemic vascular resistances increased over time, with a lesser increase in the Lap group (2-way analysis of variance; P = .041). In pneumoperitoneum groups, microcirculatory blood flow decreased similarly in the renal medulla, stomach, small bowel, colon, and mesocolon by 30%, 45%, 34%, 32%, and 37%, respectively. In NOTES, there was a greater microcirculatory blood flow decrease in the renal cortex (NOTES 41% vs Lap 35%; P = .044) and mesentery (NOTES 44% vs Lap 38%; P = .041).

CONCLUSIONS

These findings suggest that both types of pneumoperitoneum have similar physiologic effects on microcirculatory blood flow. However, on-demand pneumoperitoneum (NOTES group) caused a greater microcirculatory blood flow decrease in areas with low metabolic needs, redistributing blood flow toward metabolically active areas.

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

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.

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.

The effects of natural orifice translumenal endoscopic surgery (NOTES) on cardiorespiratory physiology: a systematic review

INTRODUCTION

Despite the increasing awareness of natural orifice translumenal endoscopic surgery (NOTES), there remain obstacles to its wider implementation. We aim to examine the current evidence for the effects of variable uncontrolled insufflation pressures using either air or carbon dioxide in NOTES, as well the effects of NOTES procedures themselves, on physiological parameters.

METHOD

We undertook a systematic review of all publications relating to the effects of NOTES on physiology, in particular compared with laparoscopy.

RESULTS

Eleven reports were identified comprising comparative trials involving a total of 237 pigs. With one exception, no difference was found between the effect of NOTES and laparoscopic surgery on cardiopulmonary parameters. No difference was found also for the effect on inflammatory mediators such as interleukin-6. Two studies also assessed the effects choice of insufflation gas, with no change in inflammatory markers. Two further studies assessing the effects of variable pneumoperitoneal pressures found negative cardiorespiratory effects with higher pressures.

DISCUSSION

Existing evidence is limited to small-sample animal trials but appears to show noninferiority for NOTES compared with laparoscopy. The development of a pressure regulation device for NOTES must be considered.

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.

Deep sedation in natural orifice transluminal endoscopic surgery (NOTES): a comparative study with dogs

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has been mostly performed with the animal under general and inhalational anesthesia (IA-NOTES). To date, NOTES using propofol sedation (PS-NOTES) has not been investigated. This study aimed to assess the feasibility and safety of PS-NOTES for transgastric oophorectomy with carbon dioxide insufflation and to compare its success rates with those of conventional IA-NOTES.

METHODS

In this prospective randomized study, NOTES oophorectomy was performed for 19 female dogs randomized to two conditions: PS (study group) and IA (control group). Sedation success rates (ability to visualize and resect ovaries without converting to IA), operative success rates (ability to resect and retrieve both ovaries in full using only NOTES), and vital parameters including hemodynamic and respiratory changes were documented.

RESULTS

In the PS-NOTES group (n = 9), the sedation success rate was 100 %. The operative success rate was 67 % (6 of 9 animals) compared with 80 % (8 of 10 animals) in the IA-NOTES group. No purposeful movement occurred during surgical manipulation and no respiratory or cardiovascular complications in occurred the PS group. Heart rate (HR) and end-tidal carbon dioxide (ETCO(2)) were significantly higher in the PS group than in the IA group. Blood pressure (BP) was significantly higher in the PS group only during the middle part of the procedure. Only mild respiratory depression was noted in the PS group, as indicated by elevated but acceptable ETCO(2). Elevations in BP and HR are thought to be related to elevated CO(2) but did not appear to have an adverse impact on the course of the procedure. Recovery was uneventful for all the animals.

CONCLUSION

The use of PS-NOTES appears to be feasible, resulting in outcomes comparable with those for IA in dogs. Further studies are needed to determine the applicability of this concept in human NOTES.

Future directions in bariatric surgery

Bariatric surgery is a field in rapid evolution, and the speed of this evolution has been accelerating over the last several decades. A thorough understanding of past developments is crucial to anticipating the future intelligently. The trends that have driven evolution historically often persist, and continue to be influential in the future. With this in mind, this article briefly outlines the historical and current trends in bariatric surgery, and follows the trajectory of these trends into the future to anticipate the technologies and techniques that will be most important to the field in the coming years.

Comparison of anterior transgastric access techniques for natural orifice translumenal endoscopic surgery

BACKGROUND

The advancement of natural orifice translumenal endoscopic surgery (NOTES) into clinical practice is dependent on its safety, efficacy, and efficiency. Access is the obligatory first step in NOTES and serves as a surrogate to technical difficulties associated with this novel surgical approach. This study aimed to compare endoscopic transgastric access techniques in terms of safety, reproducibility, and efficiency.

METHODS

Seven variations for anterior transgastric NOTES access were evaluated with female domestic swine. After marking of an anterior site, electrocautery was used to create a small gastrotomy, followed by balloon dilation and entry into the peritoneal cavity. Methodologic variations incorporated the use of guidewires, electrocautery and dilation combined within a single device, support tubes, and dilation without electrocautery. Access times were recorded, and tissue injury was evaluated.

RESULTS

In 70 access attempts, the most serious complication was bleeding from the gastroepiploic vessel, controlled with electrocautery. High variability in access times was prevalent with almost all the access techniques.

CONCLUSIONS

This study supports the presumption that an anterior transgastric access technique for NOTES procedures is safe. The use of a wire to mark the site and another wire to retain the gastrotomy provided safe, efficient, and reproducible transgastric access. Comparison with laparoscopy exposed the disparity in technical challenges facing NOTES, suggesting that new technology and further refinement in methodology are required for NOTES to be clinically relevant.

Cardiopulmonary and immunologic effects of transvaginal natural-orifice transluminal endoscopic surgery cholecystectomy compared with laparoscopic cholecystectomy in a porcine survival model

BACKGROUND

A few studies have addressed the physiology related to a basic natural-orifice transluminal endoscopy surgery (NOTES) procedure, such as transgastric peritoneoscopy, but the physiologic impact of more complex NOTES procedures has not been previously examined.

OBJECTIVE

To evaluate the cardiopulmonary and immunologic effects of transvaginal NOTES cholecystectomy compared with laparoscopic cholecystectomy.

SETTING

Survival experiments in 10 40-kg female pigs assigned to transvaginal cholecystectomy and laparoscopic cholecystectomy groups.

INTERVENTIONS

Transvaginal cholecystectomy was performed with the assistance of a needlescopic device, and laparoscopic cholecystectomy was performed in the standard manner.

MAIN OUTCOME MEASUREMENTS

Cardiopulmonary and immunologic parameters in the transvaginal cholecystectomy group were compared with those in the laparoscopic cholecystectomy group. Cardiopulmonary parameters included heart rate, blood pressure, saturation pulse oximetry, intratracheal pressure, and arterial blood gases. Immunologic parameters included white blood cell count, tumor necrosis factor-α, interleukin-1β, and interleukin-6.

RESULTS

All procedures were performed successfully without complications. Although operation times were longer for transvaginal cholecystectomy than for laparoscopic surgery, cardiopulmonary changes were similar and stable in both groups. White blood cell count, interleukin-1β, and interleukin-6 did not differ between the 2 groups, and the increase in tumor necrosis factor α after transvaginal cholecystectomy was significantly smaller on postoperative day 1 than after laparoscopic cholecystectomy (133.4 pg/mL vs 200.4 pg/mL; P < .05).

LIMITATIONS

Animal model and small sample size.

CONCLUSIONS

Transvaginal cholecystectomy resulted in cardiopulmonary stability and well preserved immune function similar to those of laparoscopic cholecystectomy, suggesting that NOTES may be less invasive than laparoscopic surgery.

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.

Leaks and endoscopic assessment of break of integrity after NOTES gastrotomy: the LEAKING study, a prospective, randomized, controlled trial

BACKGROUND

Gastric leak testing after natural orifice transluminal endoscopic surgery (NOTES) gastrotomy closure may help reduce the risk of leaks after transgastric procedures.

OBJECTIVE

To develop a novel endoscopy-based system to determine the presence of a leak after NOTES gastrotomy and to compare this system prospectively with radiographic leak testing.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Academic Medical Center laboratory.

SUBJECTS

Fifty swine.

INTERVENTION

During the pretrial phase, an endoscopic system for the measurement of intragastric pressure was developed. In the trial phase, swine with a NOTES gastrotomy were randomized to endoscopic versus radiographic leak testing. If a leak was demonstrated, the gastrotomy was reclosed by using a second-generation prototype T-anchor system. The primary outcome was leak detection after gastrotomy closure. The secondary outcome variables included necropsy findings, peritoneal fluid analysis, histologic examination, and clinical outcome.

RESULTS

Fourteen swine were included in the pretrial phase and 36 in the randomized trial. Swine were survived for a mean of 9 days postoperatively. Endoscopic pressure monitoring demonstrated a reproducible change in intragastric pressure with insufflation; r = 0.735, P = .001 and r = 0.769, P < or = .000 for the total and maximum pressures, respectively. Post-peritoneoscopy, there was a detectable and significant decrease in the mean total and mean maximum pressures versus baseline (P = .006 and P = .009). There was no significant difference between the radiologic and endoscopic arms in leak detection rate (4/18 vs 3/18, respectively, P = .500). Clinical outcomes and mean weight gain were equivalent. There was 1 operative abdominal wall injury and no deaths.

LIMITATIONS

Animal study.

CONCLUSION

Endoscopic pressure monitoring was reproducible, demonstrated the presence of gastric leak, and was as reliable as contrast-based radiographic leak testing.

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.

Peritoneal inflammatory response of natural orifice translumenal endoscopic surgery (NOTES) versus laparoscopy with carbon dioxide and air pneumoperitoneum

BACKGROUND

The immunologic and physiologic effects of natural orifice translumenal endoscopic surgery (NOTES) versus traditional surgical approaches are poorly understood. Previous investigations have shown that NOTES and laparoscopy share similar inflammatory cytokine profiles except for a possible late-phase tissue necrosis factor-alpha (TNF-alpha) depression with NOTES. The local peritoneal reaction and immunomodulatory influence of pneumoperitoneum agents in NOTES also are not known and may play an important role in altering the physiologic insult induced by NOTES.

METHODS

In this study, 51 animals were divided into four study groups, which respectively underwent abdominal exploration via transgastric NOTES using room air (AIR) or carbon dioxide (CO(2)) or via laparoscopy (LX) using AIR or CO(2) for pneumoperitoneum. Laparotomy and sham surgeries were additionally performed as control conditions. Measurements of TNF-alpha, interleukin-1beta (IL-1beta), and IL-6 were performed for peritoneal fluid collected after 0, 2, 4, and 6 h and on postoperative days (PODs) 1, 2, and 7.

RESULTS

Of the 45 animals assessed, 6 were excluded because of technical operative complications. The findings showed that LX-CO(2) generated the most pronounced response with all three inflammatory markers. However, no significant differences were detected between LX-CO(2) and either NOTES group at these peak points. No differences were encountered between NOTES-CO(2) and NOTES-AIR. Subgroup comparisons showed significantly higher levels of TNF-alpha and IL-6 with NOTES-CO(2) than with LX-AIR on POD 1 (p = 0.022) and POD 2 (p = 0.002). The LX-CO(2) subgroup had significantly higher levels of TNF-alpha than the LX-AIR subgroup at 4 h (p = 0.013) and on POD 1 (p = 0.021). No late-phase TNF-alpha depression occurred in the NOTES animals.

CONCLUSION

The local inflammatory reaction to NOTES was similar to that with traditional laparoscopy, and the previously described late-phase systemic TNF-alpha depression in serum was not reproduced. At the peritoneal level, NOTES is no more physiologically stressful than laparoscopy. Furthermore, regardless of which gas was used, the role of the pneumoperitoneum agent did not affect the cytokine profile after NOTES, suggesting that air pneumoperitoneum is adequate for NOTES.

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.

[The future of gastrointestinal therapeutic endoscopy: NOTES]

Natural orifice translumenal endoscopic surgery (NOTES) allows access into the peritoneal cavity with a flexible endoscope, through the wall of the digestive or urogenital tracts. NOTES can be combined to laparoscopic surgery in so-called << hybrid >> techniques. In the absence of any incision of the abdominal wall, NOTES procedures provide perfect cosmetic results, with virtually no risk of parietal complications, and with decreased postoperative pain. NOTES could particularly benefit to overweight patients and to patients receiving intensive or palliative care. Most NOTES studies have been performed on animal models, with great interest for both transgastric and transpelvic approaches. Successful NOTES peritoneoscopy, hysterectomy, oophorectomy, tubal ligation, gastrojejunal anastomosis, cholecystectomy, splenectomy, nephrectomy, and abdominal-wall hernia repair have been described. In human studies, the transvaginal route is preferred. NOTES clinical research focuses on low-morbidity procedures, such as cholecystectomy, appendectomy, and peritoneoscopy. Indirect benefits are expected from this research, with possible technological innovations in the field of endoscopic instrumentation (including sutures, anastomosis, traction and triangulation). Overall, NOTES is believed to make evolve both interventional endoscopy and minimally invasive surgery.

Natural orifice translumenal endoscopic surgery: myth or reality?

Interest in natural orifice translumenal endoscopic surgery (NOTES) has blossomed since the publication of transgastric peritoneoscopy in animals in 2004. Laboratory research has demonstrated the feasibility of natural orifice surgery and provided insight into the technical innovations necessary to advance the field. Today, natural orifice surgery is entering the clinical realm, both in hybrid laparoscopic-endoscopic cases and a few pure natural orifice procedures. Although the promise of "scarless" surgery entices clinicians and the public alike, care must be taken to introduce novel techniques as safely as possible with critical evaluation of outcomes.

Peroral Dual Scope for Natural Orifice Transluminal Endoscopic Surgery (NOTES) Gastrotomy Closure

Background: Although transgastric intraperitoneal surgery is feasible both in experimental models and humans, secure gastrotomy closure remains challenging. As there is still no method that is simple, reliable, inexpensive, and effective, we aimed to evaluate the feasibility, efficacy, and safety of a novel endoscopic approach to this issue that intends to ensure secure healing by obtaining full thickness gastric wall apposition without requiring specialized instrumentation. Methods: Six pigs underwent general anesthesia followed by peritoneoscopy through a 12-mm gastrotomy by a double-channel endoscope. Gastrotomy closure was performed by our innovative technique. In short, this involves the insertion of a second single-channel gastroscope alongside the NOTES gastroscope. Both scopes are then worked in tandem within the stomach by separate operators using conventional endoscopic graspers and an endoclip device. The first animal was used to ascertain feasibility and standardize the technical steps, whereas the other five were survived. Postoperative follow-up then included endoscopy 1 week later and repeat endoscopy, laparoscopy, and necropsy on day 14. Results: All closures were immediately successful. Postoperatively, each animal demonstrated appropriate weight gain and behavioral pattern without overt postoperative complication. Necropsy showed normal healing at the gastrotomy site although there were signs of minor peritoneal irritation and infection in 2 pigs. Conclusions: This transoral dual-scope clipping method of gastrotomy closure after NOTES, as well as the general concept of employing 2 separate instruments at the same time perorally, is proven technically feasible, safe, and effective in this model.

Natural orifice translumenal endoscopic surgery (N.O.T.E.S)

Natural orifice translumenal endoscopic surgery (N.O.T.E.S) is a technique that allows access to the peritoneal cavity through natural orifices (oral, rectal, vaginal, vesical) without passing through the anterior abdominal wall. Rapid strides have been made in developing this technique, especially in animal models. Majority of research work in this field is originating from USA, while human clinical trials are being reported from India and Southern America. Morbidly obese patients and ITU patients are two target groups where N.O.T.E.S if implemented, will have the highest potential and bearing. With increasing evidence of safe practice in human models, questions on indications and feasibility of practice need to be addressed by rigorous research, strong evidence and collaboration between surgical centers worldwide.

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.

Devices for laparoendoscopic single-site surgery in urology

The quest to make minimally invasive techniques even more 'minimal' has generated a drive within the surgical community to explore novel ways of achieving this. This has led to surgeons attempting to either decrease the number of trocars placed through the abdominal wall or eliminate them completely. This led to the evolution of several approaches, including natural orifice translumenal endoscopic surgery (NOTES), single incision laparoscopic surgery (SILS), single port access surgery and one port umbilical surgery (OPUS) or E-NOTES. The most recent consensus on nomenclature involves the term laparoendoscopic single-site surgery (LESS). The transition from multiple port access surgery to single port access surgery represents a paradigm shift in reconstructive and extirpative surgery and is a testament to the recent advances in surgical technology. Successful LESS involves the use of articulating or bent instrumentation via a single large-caliber trocar or small, adjacent trocars. Advances in technology have led to the development of new laparoscopic access ports (R-Port and Quadriport by Advanced Surgical Concepts, Wicklow, Ireland; and Uni-X Single Port, PNavel Systems, Cleveland, OH, USA) capable of permitting several instruments to be inserted through multiple channels incorporated in, and as part of, a larger single port. The development of articulating and bent instrumentation permits triangulation intracorporeally despite the close proximity of several instruments via a single port. Currently, commercially available instruments can be broadly divided into articulating laparoscopic graspers and shears (Real Hand, Novare Surgical Systems, Cupertino, CA, USA; and Autonomy Laparo-angle, Cambridge Endo, Framingham, MA, USA), endoshears (Cambridge Endo), and laparoscopic needle drivers (Cambridge Endo). Despite the preliminary optimistic results in the outcomes of LESS, an experienced laparoscopic skill set is essential for the safe and effective completion of surgery.

EUS in localizing safe alternate access sites for natural orifice transluminal endoscopic surgery: initial experience in a porcine model

BACKGROUND

Most natural orifice transluminal endoscopic surgery (NOTES) procedures have been performed through the anterior stomach wall, based on the established safety of PEG placement. This approach does not afford mechanically efficient access to all anatomic areas of interest.

OBJECTIVE

To assess the utility of EUS in identifying safe alternate access sites for NOTES.

DESIGN

Nonsurvival animal experiment.

METHODS

Thirty-two EUS-guided access procedures were performed through the antrum, the posterior stomach wall, or the rectum of 12 pigs. Sixteen safe-access procedures (SAP) used sonographic guidance to achieve safe intraperitoneal access by avoiding extraluminal organs and vessels during the initial NOTES puncture. Sixteen unsafe-access procedures (UAP) evaluated potential complications of blind access by performing a standard NOTES puncture at sites adjacent to critical extraluminal structures identified by EUS. Access was achieved by using a similar technique for both SAPs and UAPs. Baseline and completion laparotomies were performed.

RESULTS

All 16 UAPs resulted in clinically relevant complications, such as liver laceration and iliac artery injury. In contrast, 13 SAPs were without complication. The 3 complications in the SAP group occurred with transrectal access and consisted of 2 minor complications and a small-bowel perforation.

CONCLUSIONS

Blind NOTES access through the antrum, posterior stomach wall, and rectum could result in catastrophic complications. In contrast, EUS-guided access through these sites substantially reduced but did not completely eliminate this risk. EUS appears promising as an adjunct to NOTES access, particularly as more experience is gained in definitively excluding the presence of at-risk extraluminal structures.

NOTES: a review of the technical problems encountered and their solutions

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) is currently investigated and developed worldwide. In the past few years, multiple groups have confronted this challenge. Many technical problems are encountered in this technique due to the currently available tools for this approach. Some of the unique technical problems in NOTES include: blindly performed primary incisions; uncontrolled pneumoperitoneal pressure; no support for the endoscope in the abdominal cavity; inadequate vision; insufficient illumination; limited retraction and exposure; and the complexity of suturing and performing a safe anastomosis. In this paper, we review the problems encountered in NOTES and provide possible temporary solutions.

METHODS

Acute and survival studies were performed on 15 farm pigs. The hybrid technique approach (i.e., endoscopic surgery with the aid of laparoscopic vision) was performed in all cases. Procedures performed included liver biopsies, bilateral tubal ligation, oophprectomy, cholecystectomy, splenectomy and small bowel resection, and anastomosis.

RESULTS

All attempted procedures were successfully performed. New methods and techniques were developed to overcome the technical problems. Closure of the gastrotomy was achieved by T-bar sutures and by stapler closure of the stomach incision. Small bowel anastomosis was achieved by the dual-lumen NOTES technique.

CONCLUSIONS

The hybrid technique serves as a temporary approach to aid in developing the NOTES technique. A rectal or vaginal port of entry enables and facilitates gastrointestinal NOTES by using available laparoscopic instruments. The common operations performed today in the laparoscopic fashion could be probably performed in the NOTES approach. The safety of these procedures, however, is yet to be determined.

Natural orifice translumenal surgery: from scales to symphonies

PURPOSE OF REVIEW

Natural orifice transluminal endoscopic surgery is a new therapeutic procedure that combines surgical and endoscopic skills. Although not currently widely used, it is gaining momentum both in the animal laboratory and in human case reports.

RECENT FINDINGS

To date, 15 procedures have been successfully performed on humans worldwide. These included appendectomies (eight), liver biopsies (three), tubal ligation (one), and cholecystectomies (three). Numerous other procedures, using hybrid techniques that combine natural orifice transluminal endoscopic surgery technology with alternative conventional laparoscopic techniques, have been described in human clinical trials. In this review, we will discuss the potential benefits of this procedure over conventional surgical interventions, briefly review the major challenges to the technique (access, spatial orientation, anastomosis, and closure), and point out the technological limitations that severely handicap its potential.

SUMMARY

Despite the widespread interest in this technology, there are a lot of shortcomings: limitations in equipment, lack of clinical outcome data, and absence of randomized trials that compare it with alternative conventional surgical interventions. Nevertheless, it is crucial to remember that we have just started the evaluation process for this new exiting technology, and that, clearly, the best is yet to come.

Comparison of transgastric access techniques for natural orifice transluminal endoscopic surgery

BACKGROUND

Different transgastric access techniques for natural orifice transluminal endoscopic surgery (NOTES) have been described.

OBJECTIVE

To evaluate different methods of transluminal access with regard to leak pressures after the procedure.

DESIGN AND SETTING

Experimental endoscopic study in an ex vivo porcine stomach model.

METHODS

The following endoscopic techniques for transgastric access were evaluated in 34 stomachs: (1) 1.5-cm to 2-cm linear incision, (2) balloon dilation after needle-knife puncture, (3) via a short submucosal tunnel, and (4) via an extended submucosal tunnel. For techniques 3 and 4, a submucosal tract was endoscopically created by physically separating the mucosa from the muscularis. Mucosal incisions were closed by the standardized application of clips. Handsewn gastric closure after a linear needle-knife incision served as a positive control, whereas, open 1.5-cm to 2-cm gastrotomies were negative controls. After the procedure, pressures to liquid leakage were recorded.

RESULTS

The unclosed controls demonstrated leakage at mean (SD) 2 +/- 2 mm Hg, which represents a baseline system resistance. The handsewn gastric closure after linear incision leaked at 50 +/- 7 mm Hg. The needle-knife gastrotomy, the balloon dilation, the short submucosal tunnel, and the extended submucosal tunnel leaked at 37 +/- 15 mm Hg, 41 +/- 24 mm Hg, 44 +/- 13 mm Hg, and 87 +/- 19 mm Hg, respectively. There were significant differences in leakage pressures between the group with the extended submucosal tunnel and all other transgastric access techniques (all P < or = .002).

CONCLUSIONS

The extended submucosal tunnel yielded the best leak resistance, which is superior to standard transgastric access methods and rival handsewn interrupted stitches.

Anatomy of NOTES gastrotomy in human tissue

BACKGROUND

Transoral natural orifice translumenal endoscopic surgery (NOTES) procedural success depends on a secure gastrotomy closure. Balloon gastrotomy is the most common technique to date, but the stomach-layer defect sizes and their relationship in human tissue has not been determined.

METHODS

Ten 2-cm diameter controlled radial expansion balloon gastrotomies were performed in ex vivo human tissue. All gastrotomies were located on the anterior stomach wall. The main axis of the elliptical-shaped serosal and longitudinal muscle layer opening, the mucosal opening, and the circular muscle layer opening (after removal of mucosa) was measured. All steps were photo documented and electronically analyzed for common opening size.

RESULTS

The average common opening was 1 +/- 0.6 to 1.3 cm, although the main axis of a single layer can be as long as 2.2 cm. The average serosal/longitudinal muscle layer defect measured 1.5 cm, the average mucosal defect 1.6 cm, and the average circular muscle layer defect 1.5 cm.

CONCLUSION

These findings on NOTES gastrotomy anatomy demonstrate the complexity of the stomach wall opening and the challenge of providing a fail-safe gastrotomy closure. Further in vivo human studies are advised.

NOTES: Transvaginal for Cancer Diagnostic Staging: Preliminary Clinical Application

Laparoscopy is now a reliable method for staging gastrointestinal cancer, orienting the therapy, and avoiding unnecessary laparotomy. Natural orifice transluminal endoscopic surgery (NOTES) is an emerging concept with potential advantages for patient recovery. The first case of clinical diagnostic application of transvaginal NOTES for diagnostic cancer staging is presented. Informed consent and Institutional Commission approval were obtained for transvaginal clinical trials. On February 28, 2007, a patient with elective surgical indication for diagnostic cancer staging was submitted to transvaginal NOTES procedure, and intra- and postoperative parameters were documented. In a 50-year-old female patient presenting with ascitis, diffuse abdominal pain, and weight loss for 2 months, diagnosis of peritoneal carcinomatosis was suspected, which was also found when a CT scan was performed. Transvaginal NOTES was used for diagnostic staging of the patient, using a colonoscope introduced into the abdomen through a small incision in the vagina. Biopsies of liver, diaphragm, ovaries, and peritoneum were successfully performed. Operative time was 105 min, vaginal access and closure was obtained in 15 min. Abdominal inventory was reliable, and all 16 biopsies taken were positive for ovarian adenocarcinoma. The patient was dismissed 48 hours after the procedure without complications. Recent literature and experience of the study group suggest possibilities for preliminary clinical applications by transvaginal natural orifice surgery for diagnostic purposes.

Pure natural orifice transluminal endoscopic surgery (NOTES) nephrectomy using standard laparoscopic instruments in the porcine model

PURPOSE

Natural Orifice Transluminal Endoscopic Surgery (NOTES) is an emerging technology that uses endoscopic instruments passed into the peritoneal cavity through hollow viscera to perform surgical procedures without the use of abdominal incisions. There are, however, limitations regarding the equipment available to simulate traditional surgery. The aim of this study was to determine the feasibility of a pure NOTES nephrectomy by using standard laparoscopic instruments through a modified transvaginal trocar.

MATERIALS AND METHODS

One 40-kg female swine underwent transgastric peritoneoscopy. Transgastric endoscopic visualization guided the introduction of a second transvaginal endoscope through a novel laparoscopic trocar/endoscopic overtube device. The retroflexed transgastric endoscope provided triangulated visualization as standard endoscopic instruments provided retraction, which allowed dissection of the kidney with standard laparoscopic instruments through our modified transvaginal trocar device. Each renal hilum, artery, vein, and ureter was dissected and divided with a transvaginal laparoscopic stapler.

RESULTS

Transgastric and transvaginal NOTES accesses were easily achieved, and bilateral nephrectomies were performed. Completion of peritoneoscopy revealed complete hemostasis and identification of ligated ureters and hilar vessels. Total operative time was 40 and 20 minutes for the right and left kidney, respectively. One kidney was captured with a laparoscopic retrieval sac and removed intact through the vaginal defect.

CONCLUSIONS

Pure NOTES nephrectomies are technically feasible in the porcine model by using standard laparoscopic instruments. Survival studies are necessary to determine the long-term complications and physiologic implications of NOTES nephrectomy. The development of innovative NOTES access trocars may allow for an increased armamentarium of NOTES instruments.

Infectious implications in the porcine model of natural orifice transluminal endoscopic surgery (NOTES) with PEG-tube closure: a quantitative bacteriologic study

BACKGROUND

Obtaining reliable closure of transvisceral defects currently limits natural orifice transluminal endoscopic surgery (NOTES). PEG tubes are potential means of managing NOTES gastrotomies.

OBJECTIVE

To determine the efficacy of PEG closure after NOTES.

DESIGN

An experimental animal study.

SETTING

A laboratory.

INTERVENTIONS

The pigs received gastric lavage with saline solution, chloramphenicol, or no lavage, and then underwent transgastric NOTES peritoneoscopy. Cultures were obtained by endoscopy during the surgery. A sterile foreign body was left in the peritoneal cavity. The gastrotomy was closed with a 20F PEG tube. The animals were observed for 14 days and underwent sterile laparotomy. Cultures of the foreign body and the peritoneal cavity were obtained.

MAIN OUTCOME MEASUREMENTS

Abscess rate, peritoneal quantitative cultures.

RESULTS

After 1 exclusion for anesthetic complications, 19 animals underwent NOTES; 18 (94.7%) survived the entire postoperative period. One animal died on postoperative day 2 after the PEG tube dislodged. At 14 days, 5 animals (27.8%) had intra-abdominal abscesses, 8 (44.4%) had positive peritoneal cultures, and 9 (50%) foreign bodies were contaminated on culture. Infectious complications were not altered by the type of gastric lavage or peritoneal bacterial inoculum introduced at the time of surgery.

LIMITATION

An animal model.

CONCLUSIONS

PEG closure of a NOTES gastrotomy is associated with subclinical intra-abdominal abscess formation and can result in death when the tube is dislodged during the early postoperative period. Preprocedural gastric lavage does not alter the intra-abdominal bacterial burden introduced at the time of surgery or subsequent infectious outcomes in the porcine model. These concerning findings necessitate additional studies to determine if porcine models are appropriate and applicable to human subjects in the NOTES setting.

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: a critical review

Natural orifice translumenal endoscopic surgery (NOTES) involves the intentional puncture of one of the viscera (e.g., stomach, rectum, vagina, urinary bladder) with an endoscope to access the abdominal cavity and perform an intraabdominal operation. Early laboratory work focused on feasibility studies, including such accomplishments as pure transgastric splenectomy and gastrojejunostomy. Contemporary laboratory work is investigating the infectious and immunologic implications of NOTES and honing the tools and techniques required for complex abdominal operations. Today NOTES has entered the clinical arena in a few cases: the first clinical series of transgastric peritoneoscopy has recently been published; multiple groups are accumulating patients in studies of NOTES cholecystectomy, either via the transgastric or transvaginal route; and a series of transgastric appendectomies has been well publicized, yet it remains unpublished. Although clinical NOTES is gaining momentum, the field should remain in check while rigorous laboratory work is performed and cogent clinical trials are undertaken. The zeal for NOTES should not take precedence over the welfare of the patient.

[New generation of abdominal surgery: the Natural Orifice Transluminal Endoscopic Surgery]

Minimal invasive surgical techniques, namely laparoscopic procedures to the abdominal surgery have been introduced more than 20 years ago. In view of clinical results, the majority of these are considered as routinely performed procedure today. Natural Orifice Transluminal Endoscopic Surgery can be considered as a new generation of abdominal surgery. It means a method directed through natural orifices, and abdominal surgery operated by transluminal endoscopic techniques (transgastric, transcolonic, transvaginal) to reach diagnostic and therapeutic goals. Theoretically, this method allows the possibility to decrease invasiveness and postoperative pain, to prevent postoperative hernias and to improve cosmetic results. At present numerous researchers work worldwide to receive scientifically based answers to arising questions (surgical technique, indication, contraindication, complications, monitoring) and concerns in this area. The present paper gives an overview of the national and international literature on experimental results and clinical approaches in the field of this new surgical technique.

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.

NOTES--case report of a unidirectional flexible appendectomy

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) refers to a new surgical procedure using flexible endoscopes in the abdominal cavity. With this procedure, access is gained by way of organs which are reached through a natural, already-existing external orifice. The hoped-for advantages associated with this method include the reduction of post-operative wound pain, shorter convalescence, avoidance of wound infection and abdominal-wall hernias as well as the absence of scars. We performed a trans-vaginal appendectomy on a human subject.

MATERIALS AND METHODS

In experimental operations on animals, we first evaluated the trans-vaginal access site. After them, we started first operation in human. The procedure was carried out under preventive administration of antibiotics. We used a therapeutic single-canal gastroscope. The appendix was located after exploration of the abdomen. After preparation of the mesenteriolum, ligature of the appendix base was performed by means of endoloop, followed by transsection with scissors. Recovery of the specimen was achieved by pulling it out with the instrument.

RESULTS

On the evening of the day on which surgery had taken place, administration of nourishment was begun. After the procedure, the patient reported slight soreness in the muscles of the abdominal wall; she felt otherwise perfectly well.

INTERPRETATION

In the space of a year, the first operations have been performed on human subjects by a few select work groups. NOTES procedures are still in the initial stages of clinical development. Until they can be introduced into surgical daily routine, further improvements are required as to equipment, technology and operative procedure.

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.