Effect of pneumoperitoneum on hemodynamics and inspiratory pressures during natural orifice transluminal endoscopic surgery (NOTES): an experimental, controlled study in an acute porcine model

Assessment of Optic Nerve Sheath Diameter in Patients Undergoing Endoscopic Retrograde Cholangiopancreatography: A Prospective, Randomized, Controlled Double-Blinded Comparison of Propofol and Ketofol Anesthesia

BACKGROUND

ERCP is an endoscopic procedure for the diagnosis and treatment of biliopancreatic system diseases. An increase in intra-abdominal pressure due to the insufflation of air to the intestinal lumen may be transmitted to ICP through the course of ERCP. In this prospective, randomized, controlled double-blinded study, we aimed to assess the ICP change using ultrasonography measurement of ONSD in patients undergoing ERCP comparing the effects of propofol and ketofol anesthesia.

MATERIAL/METHODS

One hundred and nine patients undergoing ERCP under propofol or ketofol anesthesia were enrolled in the study. Ultrasonography measurement of ONSD was performed before (T0) and immediately after induction of anesthesia (T1), during sphincterotomy (T2), at the end of procedure (T3), and after the patient is fully awake (T4).

RESULTS

Comparison of ONSD values and ONSD alteration between groups showed no statistically significant difference (P > 0.05). Both groups showed significantly greater changes from T0 to T2 compared with values from T0 to T1, T3, and T4, respectively (P = 0,000). T0 to T3 alteration was also significantly greater than T0 to T1 and T4 change in both groups (P = 0,000).

CONCLUSIONS

ERCP procedure increases intracranial pressure most prominently during sphincterotomy both under propofol or ketofol anesthesia. Further studies are needed to investigate the impact of this phenomenon on adverse clinical outcomes.

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.

Transvaginal natural orifice transluminal endoscopic surgery in the diagnosis of ascites of unknown origin

BACKGROUND AND AIMS

Natural orifice transluminal endoscopic surgery (NOTES) has been established in animal models and human studies, but few clinical studies have investigated transvaginal NOTES in the diagnosis of unexplained refractory ascites. We aimed to assess the feasibility, efficacy, and safety of transvaginal NOTES for the diagnosis of unexplained ascites in female patients.

METHODS

A prospective study was done involving 3 female patients with unexplained ascites. After general anesthesia and disinfection, a 1.0-cm incision was made in the posterior fornix of the vagina. A gastroscope was inserted into the abdominal cavity through the transvaginal incision and an artificial pneumoperitoneum was created; NOTES peritoneoscopy was performed to scrutinize the pathologic changes. Endoscopic biopsy specimens were obtained for pathologic examination. The transvaginal incision was closed by direct suturing.

RESULTS

Transvaginal NOTES for diagnostic peritoneoscopy was successfully performed in 3 patients. The mean operative time was 61 minutes. The estimated blood loss was 5 to 10 mL. The pathologic diagnoses were tuberculosis for all patients, and the symptoms and ascites disappeared after antituberculosis therapy. During the 4-year follow-up, no clinically significant adverse events occurred in any patient after NOTES. No patient experienced an annex inflammation, vaginitis, dyspareunia, or sexual dysfunction. All patients were comfortable and satisfied with the nonscarring surgical procedure.

CONCLUSIONS

Transvaginal NOTES for the diagnosis of unexplained ascites is feasible, effective, and safe. This method had no long-term effect on female sexual function and is particularly suitable for women who have special aesthetic requirements. (Clinical trial registration number: ChiCTR-TRC-10001053.).

Pretreatment with endothelium-derived nitric oxide synthesis modulators on gastrointestinal microcirculation during NOTES: an experimental study

BACKGROUND AND STUDY AIMS

On-demand endoscopic insufflation during natural orifice transluminal endoscopic surgery (NOTES) adversely affects microcirculatory blood flow (MBF), even with low mean intra-abdominal pressure, suggesting that shear stress caused by time-varying flow fluctuations has a great impact on microcirculation. As shear stress is inversely related to vascular diameter, nitric oxide (NO) production acts as a brake to vasoconstriction.

OBJECTIVE

To assess whether pretreatment by NO synthesis modulators protects gastrointestinal MBF during transgastric peritoneoscopy.

METHODS

Fourteen pigs submitted to cholecystectomy by endoscope CO₂ insufflation for 60 min were randomized into 2 groups: (1) 150 mg/kg of N-acetyl cysteine (NAC, n = 7) and (2) 4 ml/kg of hypertonic saline 7.5 % (HS, n = 7), and compared to a non-treated NOTES group (n = 7). Five animals made up a sham group. Colored microspheres were used to assess changes in MBF.

RESULTS

The average level of intra-abdominal pressure was similar in all groups (9 mmHg). In NOTES group microcirculation decrease compared with baseline was greater in renal cortex, mesocolon, and mesentery (41, 42, 44 %, respectively, p < 0.01) than in renal medulla, colon, and small bowel (29, 32, 34, respectively, p < 0.05). NAC avoided the peritoneoscopy effect on renal medulla and cortex (4 and 14 % decrease, respectively) and reduced the impact on colon and small bowel (20 % decrease). HS eliminated MBF changes in colon and small bowel (14 % decrease) and modulated MBF in renal medulla and cortex (19 % decrease). Neither treatment influenced mesentery MBF decrease.

CONCLUSIONS

Both pretreatments can effectively attenuate peritoneoscopy-induced deleterious effects on gastrointestinal MBF.

A case of transvaginal NOTES partial gastrectomy using new techniques and devices

The latest technique of transvaginal NOTES partial gastrectomy is described in detail. The procedure involves new “over-tube steering” technique and usage of two newly developed endoscopic accessories. The technique is feasible, safe, and practical, since all devices used in the case are off-the-shelf products.

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.

Role of transgastric natural orifice transluminal endoscopic surgery in the diagnosis of ascites of unknown origin (with videos)

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has been established in animal models and human studies.

OBJECTIVE

The aim of this study was to assess the feasibility and efficacy of applying transgastric NOTES to diagnose patients with ascites of unknown origin.

DESIGN

Prospective study.

SETTING

Two university and teaching hospitals.

PATIENTS

Patients with ascites of unknown origin.

INTERVENTIONS

Diagnostic transgastric NOTES.

MAIN OUTCOME MEASUREMENTS

Characteristic of ascites cases, conditions of the abdominal cavity, diagnostic accuracy, adverse events, and follow-up time.

RESULTS

Transgastric NOTES was performed successfully in 78 patients with ascites of unknown origin, and 72 cases (92.3%) were clearly diagnosed. They included malignant tumors (39 cases), tuberculous peritonitis (28 cases), chronic hepatic inflammation (3 cases), necrotizing lymphadenitis (1 case), and eosinophilic serositis of the small intestine (1 case). In addition, there were 6 nondiagnostic cases, and no severe adverse events were found.

LIMITATIONS

Nonrandomized control analysis.

CONCLUSION

Transgastric NOTES in combination with biopsy can elucidate the causes of ascites of unknown origin in the majority of cases. Therefore, it is a feasible and effective approach to access the peritoneal cavity and also a valuable modality to detect the cause of diseases with ascites of unknown origin.

Spindle-like abdominal wall-lifting device in gasless laparoscopic surgery in animal experiments

INTRODUCTION

CO2 pneumoperitoneum has been used to establish an operation space in laparoscopic surgery. It may have some bad consequences, such as respiratory and circulatory system changes, hypotension and hypoxia in infants and the release of free tumor cells into the abdominal cavity. Gasless laparoscopic technique can avoid these adverse effects. But present gasless laparoscopic techniques have their own disadvantages. The main shortcoming of gasless laparoscopic techniques is inadequate operative space.

MATERIAL AND METHODS

We herein describe a new technique. We used a self-designed spindle-like abdominal wall-lifting device to perform gasless laparoscopic cholecystectomy in seven pigs, recording the operation time, bleeding volume and unexpected occurrences during the operation.

RESULTS

Seven pigs underwent laparoscopic cholecystectomy using this technique with no conversion to open operation. The operation time was between 21 minutes and 65 minutes, with a mean operative time of 42.5 minutes. The range of bleeding volumes was 2 ml to 8 ml, with a mean operative bleeding volume of 4.3 ml. There were no massive hemorrhages, internal organ injuries or other complications during the operation.

CONCLUSIONS

These preliminary outcomes indicate that the spindle-like abdominal wall-lifting device is feasible and safe in gasless laparoscopic cholecystectomy, which can provide sufficient exposure of the operative filed.

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.

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.

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.

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.

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: critical appraisal of applications in clinical practice

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES), with its focus on eliminating incision-related complications, promises to revolutionize the way surgery is performed. This study aimed to summarize the clinical applications of NOTES for humans, outline the techniques used, and discuss the complications and limitations of current techniques.

METHODS

A literature search was performed using PubMed and Medline search tools to review the extent and outcomes of human procedures undertaken using the NOTES technique in its pure form or as a hybrid procedure reported until July 2008. The end points were the types of operation performed, the approach and technique used for each operation, and the procedure-related complications and technical limitations.

RESULTS

This review considered 16 publications reporting on 49 human subjects. All the studies except three used hybrid NOTES procedures, with varying amounts of transabdominal assistance. Three transvaginal cholecystectomies, one transvaginal appendectomy, and eight transgastric appendectomies have been performed using a pure NOTES technique. To date, 15 NOTES transvaginal cholecystectomies and 10 NOTES appendectomies (8 transgastric and 2 transvaginal) are reported. Other procedures including peritoneoscopy and sigmoid colectomy are described. Three cases of minor morbidity are reported and no mortality.

CONCLUSIONS

Although initial human results seem encouraging, it is important that this research be conducted in a way that minimizes bad publicity and describes both favorable and adverse outcomes. Robust trials must be conducted at established centers with appropriate experience and institutional board ethical review to allow safe introduction of this novel technique, with adequate and expedient reporting of serious adverse events. The limitations of the current tools and methods are discussed, and suggestions are made for further improvements in the technology to facilitate NOTES operations.

EUS-guided NOTES interventions

Entering the peritoneal cavity with the echoendoscope has been avoided because this endoscope is rather rigid and difficult to handle and maneuver in a limited space. Endoscopic ultrasound may be of help, however, to guide natural orifice translumenal endoscopic surgery (NOTES) procedures. This article provides an overview of the potential benefit and the few endoscopic ultrasound-based natural NOTES procedures performed to date.

NOTES: human experience

Human natural orifice translumenal endoscopic surgery (NOTES) is already being reported from numerous centers, and the results seem promising. There are key issues to be addressed and benefits over traditional safe procedures need to be demonstrated. Interestingly, however, human NOTES seem to be progressing at a fast pace compared with the evolution of surgical procedures or techniques described previously. This article examines the current status of NOTES in humans, the challenges, and the implications on the future of minimal access surgery.