A review of 130 humans enrolled in transgastric NOTES protocols at a single institution

Rectal Eversion as an Anus-sparing Technique in Laparoscopic Low Anterior Resection With Double Stapling Anastomosis: Long-term Functional Results

BACKGROUND

Rectal eversion (RE) is a natural orifice specimen extraction (NOSE) method that allows anus-sparing resection in very low rectal tumors. This study aims to share the long-term results of RE in laparoscopic rectal resection performed with double stapling anastomosis.

MATERIALS AND METHODS

A single-center retrospective cohort study was conducted for patients who underwent laparoscopic low anterior resection with RE. Age, sex, body mass index, American Society of Anesthesiologists (ASA) classification, type of surgery, distance of the tumor to the dentate line, specimen extraction site, cancer stage, preoperative chemoradiotherapy, postoperative complications, and postoperative clinical follow-up findings were recorded. Incontinence was assessed using the Wexner score (WS). Low anterior resection syndrome (LARS) is determined by the LARS score. A 7-point Likert scale was used to evaluate the satisfaction of the patients.

RESULTS

A total of 17 patients underwent resection by RE for rectal tumors. Of the 11 patients included in the study, 4 were female and 7 were male. The mean age was 66.09±15.04 years. The mean follow-up was 64.18±16.83 months. The mean tumor diameter was 3.1 cm (range: 0.9 to 7.2 cm). The mean distance of the tumor from the dentate line was 2.7 cm (range: 1.2 to 5.6 cm). No anastomotic leak was observed in any patient. One patient had an anastomotic stenosis and was treated with balloon dilatation. The median LARS score was 16 (range 0 to 32) and 64% of the patients had no LARS. Two patients had minor LARS and 2 patients had major LARS. The median Wexner score was 3.5 (range 0 to 14). The median Likert scale was 7 (range 5 to 7). It was found that 55% of the patients were extremely satisfied, 18% were satisfied, and 27% were slightly satisfied with their surgery. There were no dissatisfied patients.

CONCLUSION

RE is a safe NOSE technique in laparoscopic double stapling anastomosis for rectal resection. There is a high level of long-term patient satisfaction with anus-sparing procedures via RE, even in the presence of various symptoms.

International consensus on natural orifice specimen extraction surgery (NOSES) for colorectal cancer

In recent years, natural orifice specimen extraction surgery (NOSES) in the treatment of colorectal cancer has attracted widespread attention. The potential benefits of NOSES including reduction in postoperative pain and wound complications, less use of postoperative analgesic, faster recovery of bowel function, shorter length of hospital stay, better cosmetic and psychological effect have been described in colorectal surgery. Despite significant decrease in surgical trauma of NOSES have been observed, the potential pitfalls of this technique have been demonstrated. Particularly, several issues including bacteriological concerns, oncological outcomes and patient selection are raised with this new technique. Therefore, it is urgent and necessary to reach a consensus as an industry guideline to standardize the implementation of NOSES in colorectal surgery. After three rounds of discussion by all members of the International Alliance of NOSES, the consensus is finally completed, which is also of great significance to the long-term progress of NOSES worldwide.

Endoscopic surgery - exploring the modalities

The adoption of endoscopic surgery continues to expand in clinical situations with the recent natural orifice transluminal endoscopic surgery technique enabling abdominal organ resection to be performed without necessitating any skin incision. In recent years, the development of numerous devices and platforms have allowed for such procedures to be carried out in a safer and more efficient manner, and in some ways to better simulate triangulation and surgical tasks (e.g., suturing and dissection). Furthermore, new novel techniques such as submucosal tunneling, endoscopic full-thickness resection and hybrid endo-laparoscopic approaches have further widened its use in more advanced diseases. Nevertheless, many of these new innovations are still at their pre-clinical stage. This review focuses on the various innovations in endoscopic surgery, with emphasis on devices and techniques that are currently in human use.

Risk of infection after iatrogenic perforation of the gut wall? Evaluation of preventive strategies in a randomized controlled animal trial

BACKGROUND

Interventional endoscopies entail a risk of infection secondary to perforation of the luminal wall. Thereby, bacteria may be introduced into the sterile environment of the peritoneal cavity (PC). Limited data are available regarding the efficacy of prophylactic anti-infective treatments. The aim of the study was to examine the efficacy/safety of anti-infective means in the prevention of infection by interventional endoscopies in a randomized controlled animal trial.

METHODS

Forty pigs were randomized to: 1: control; 2: oral lavage; 3: gastric lavage; 4: oral/gastric lavage; 5: i.m. antibiotics. Lavage was performed with Octenisept prior to the operation. After gastric wall perforation, peritoneoscopy was performed. Before the procedure, after closure and prior to autopsy, intraabdominal lavage for bacterial culture was taken using mini-laparoscopy. At autopsy, macroscopic appearance of the PC was scored. Lavage fluids were grown to identify/quantify bacterial load. Concentration of intraperitoneal bacteria at autopsy was defined as main outcome parameter.

RESULTS

No major complications occurred in any of the procedures. Bacterial load of the PC at autopsy was significantly reduced with antibiotics compared to all other groups, whereas it did not differ between the lavage groups and control. Macroscopic scoring of the PC showed significant lower rate of intraabdominal abscesses in the antibiotic group compared to the lavage groups and control (p < 0.01).

CONCLUSION

Only antibiotic prophylaxis is effective for the prevention of infection after iatrogenic perforation of the gastrointestinal wall. There was no difference between any form of lavage and the control group. Further studies in humans are required to prove these animal data.

Single-incision or conventional laparoscopic adjustable gastric banding: A systematic review

INTRODUCTION

Single-incision laparoscopic surgery (SILS) in gastric banding (SI-LAGB) has been reported to be a safe and technically feasible procedure among various operating methods. However, there is little evidence with regard to the question whether SI-LAGB has more advantages and should be recommended compared with conventional LAGB (CLAGB). Thus, this study was performed to assess the safety and efficacy of SI-LAGB.

MATERIAL AND METHODS

A computerized search of the electronic databases PubMed and EMBASE was performed. Data regarding operative parameters, postoperative recovery parameters, follow-up time, percentage of excess weight loss, and postoperative complication were pooled and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

RESULTS

Ten comparative studies including 2,073 patients (1,038 patients who received SI-LAGB and 1,035 patients who received CLAGB) were included and analyzed. Compared with CLAGB, a similar weight loss could be obtained using SI-LAGB. The postoperative complications of SI-LAGB were within the acceptable range, but one study reported one perioperative death. SI-LAGB required a longer operative time. Other outcome variables, such as blood loss, days of hospitalization, pain score, and hospitalization costs, were not significantly different between the two groups.

CONCLUSIONS

SI-LAGB might be a safe and effective alternative to C-LAGB when performed by experienced surgeons, but available data do not allow to give a definitive answer and randomized controlled trials are needed.

Gastrotomy Healing After Transgastric Peritoneoscopy: A Randomized Study in a Pig Model

INTRODUCTION

Reliable closure and infection prevention are the main barriers for implementation of pure transgastric peritoneoscopy. The primary aim of this study was to assess healing of over the scope clip (OTSC) closed gastrotomies.

MATERIALS AND METHODS

Pure transgastric peritoneoscopy was performed in 7 pigs. The pigs were randomized to 14 or 28 postoperative days (POD) of follow-up. Decontamination of the access route was performed before instrumentation. A full necropsy was performed. Closure was evaluated with histopathological examination of excised gastrorrhaphies.

RESULTS

Three pigs were allowed 14 POD of follow-up, and 4 pigs were allowed 28 POD of follow-up. Survival was achieved in 6 of the 7 animals; 1 pig was euthanized due to diffuse peritonitis. Based on our definition, full-thickness healing had only been achieved in a single pig allowed 28 POD. With respect to clinical relevancy, full-thickness healing was deemed achieved in 4 of 6 pigs completing follow-up and in all pigs allowed and surviving 28 POD. Access required repeated punctures and the use of several endoscopic instruments.

CONCLUSIONS

Full-thickness healing of the gastrotomy was only found in a single case when adhering to the per protocol definition. Endoscopic ultrasonography-guided access was difficult. It lacks reproducibility and needs refinement. Despite a combined decontamination regimen, infectious complications still occurred.

Transvaginal cholecystectomy vs conventional laparoscopic cholecystectomy for gallbladder disease: A meta-analysis

AIM: To compare the results of transvaginal cholecystectomy (TVC) and conventional laparoscopic cholecystectomy (CLC) for gallbladder disease.

METHODS: We performed a literature search of PubMed, EMBASE, Ovid, Web of Science, Cochrane Library, Google Scholar, MetaRegister of Controlled Trials, Chinese Medical Journal database and Wanfang Data for trials comparing outcomes between TVC and CLC. Data were extracted by two authors. Mean difference (MD), standardized mean difference (SMD), odds ratios and risk rate with 95%CIs were calculated using fixed- or random-effects models. Statistical heterogeneity was evaluated with the χ² test. The fixed-effects model was used in the absence of statistically significant heterogeneity. The random-effects model was chosen when heterogeneity was found.

RESULTS: There were 730 patients in nine controlled clinical trials. No significant difference was found regarding demographic characteristics (P > 0.5), including anesthetic risk score, age, body mass index, and abdominal surgical history between the TVC and CLC groups. Both groups had similar mortality, morbidity, and return to work after surgery. Patients in the TVC group had a lower pain score on postoperative day 1 (SMD: -0.957, 95%CI: -1.488 to -0.426, P < 0.001), needed less postoperative analgesic medication (SMD: -0.574, 95%CI: -0.807 to -0.341, P < 0.001) and stayed for a shorter time in hospital (MD: -1.004 d, 95%CI: -1.779 to 0.228, P = 0.011), but had longer operative time (MD: 17.307 min, 95%CI: 6.789 to 27.826, P = 0.001). TVC had no significant influence on postoperative sexual function and quality of life. Better cosmetic results and satisfaction were achieved in the TVC group.

CONCLUSION: TVC is safe and effective for gallbladder disease. However, vaginal injury might occur, and further trials are needed to compare TVC with CLC.

Transvaginal and transrectal natural orifice translumenal endoscopic surgery nephrectomy in a porcine survival model: comparison with conventional laparoscopic nephrectomy

PURPOSE

We analyzed the technical feasibility, physiological influence, and safety of transvaginal (TV) and transrectal (TR) natural orifice translumenal endoscopic surgery (NOTES) nephrectomy compared with conventional laparoscopic surgery in a porcine survival model.

METHODS

Fifteen female pigs (32.8-37.2 kg) were randomly assigned to undergo TV NOTES (n=5), TR NOTES (n=5), or conventional laparoscopic nephrectomy (n=5). Postoperatively, all animals were observed for global health status during the recovery from anesthesia. Variable laboratory parameters and inflammatory cytokines were compared among the groups during the entire experimental period. Postmortem examination was performed 1 week after operation for assessment of abdominal complications and cultures for microorganisms.

RESULTS

All experiments were completed successfully without insertion of an extra port or conversion to laparoscopic or open surgery. Although mean operative times were longer in TV and TR NOTES groups than in the conventional laparoscopy group (61 vs 84 vs 24 min, P<0.001), there were no signs of visceral injury or peritonitis on postmortem examination. None of the laboratory parameters, including white blood cell count, tumor necrosis factor-α, interleukin (IL)-1, and IL-6 differed among the groups during the entire experimental period.

CONCLUSIONS

TV and TR NOTES nephrectomy could be completed successfully with similar physiologic influence to those of conventional laparoscopic nephrectomy in a porcine survival model.

Future directions in surgery for colorectal cancer: the evolving role of transanal endoscopic surgery

SUMMARY 

The morbidity associated with radical surgery for rectal cancer has launched a revolution in increasingly less-invasive methods of resection, including a recent resurgence in transanal endoscopic surgical approaches. The next evolution in transanal surgery for rectal cancer is natural orifice translumenal endoscopic surgery (NOTES). To date, 14 series of transanal NOTES total mesorectal excision (TME) for rectal cancer have been published (n = 76). Overall, the intraoperative and postoperative complication rates of 8 and 28%, respectively, compare favorably to those expected from laparoscopic and open TME. Short-term follow-up after NOTES TME has yielded no cancer recurrence in average-risk patients. High-risk patients have cancer recurrence rates similar to those after laparoscopic TME. Overall, these early data support transanal NOTES TME as a safe and viable alternative to conventional TME. Advances in instrumentation, surgical expertise and neoadjuvant treatment may expand current indications for NOTES even further.

Comparison of gastrotomy closure modalities for natural orifice transluminal surgery: a canine study

BACKGROUND

Reliable closure of the gastrotomy after transgastric natural orifice transluminal endoscopic surgery (NOTES) remains unresolved.

OBJECTIVE

To compare the technical aspects and clinical and histologic outcomes of NOTES gastrotomy closure techniques.

DESIGN

Experimental study.

SETTING

Animal laboratory.

PATIENTS

Thirty-four dogs, 14 for nonsurvival study and 20 for survival study.

INTERVENTIONS

The animals randomly received different gastrotomy closures after NOTES: endoclip, omentoplasty, over-the-scope-clip (OTSC), and hand-suturing.

MAIN OUTCOME MEASUREMENTS

Procedure time, closure strength, survival, postoperative adverse events, and histologic evaluation of wound healing.

RESULTS

Omentoplasty and OTSC groups needed shorter procedure times and fewer clips than the endoclip group. The endoclip and omentoplasty groups generated similar leakage pressures (34.5 ± 2.6 vs 42.2 ± 4.1 mm Hg, P > .05), both lower than OTSC and hand-suturing groups (81.5 ± 2.1 and 87.0 ± 3.0 mm Hg, respectively, P < .001). Of the 20 animals in the survival study (all 4 groups), only 2 of 6 in the endoclip group were killed prematurely due to sepsis. Necropsy revealed the OTSC group reached a 100% clip retention rate, higher than the endoclip (47.9%) and omentoplasty groups (44.4%, P < .05) rates. Complete healing, defined as intact and continuous gastric layers microscopically, was seen in 83.3% of animals (5 of 6) in the omentoplasty group, comparable with OTSC (4 of 6, 66.7%, P = .500) but higher than the endoclip group (1 of 6, 16.7%, P = .04).

LIMITATIONS

Animal study.

CONCLUSIONS

Omentoplasty is easier and safer for NOTES gastrotomy closure than endoclips and offers safety profile and efficacy similar to OTSC and hand-suturing.

Euro-NOTES Status Paper: from the concept to clinical practice

BACKGROUND

The concept of natural orifice transluminal endoscopic surgery (NOTES) consists of the reduction of access trauma by using a natural orifice access to the intra-abdominal cavity. This could possibly lead to less postoperative pain, quicker recovery from surgery, fewer postoperative complications, fewer wound infections, and fewer long-term problems such as hernias. The Euro-NOTES Foundation has organized yearly meetings to work on this concept to bring it safely into clinical practice. The aim of this Euro-NOTES status update is to assess the yearly scientific working group reports and provide an overview on the current clinical practice of NOTES procedures.

METHODS

After the Euro-NOTES meeting 2011 in Frankfurt, Germany, an analysis was started regarding the most important topics of the European working groups. All prospectively documented information was gathered from Euro-NOTES and D-NOTES working groups from 2007 to 2011. The top five topics were analyzed.

RESULTS

The statements of the working group activities demonstrate the growing information and changing insights. The most important selected topics were infection issue, peritoneal access, education and training, platforms and new technology, closure, suture, and anastomosis. The focus on research topics changed over time. The principle of hybrid access has overcome the technical and safety limitations of pure NOTES. Currently the following NOTES access routes are established for several indications: transvaginal access for cholecystectomy, appendectomy and colon resections; transesophageal access for myotomy; transgastric access for full-thickness small-tumor resections; and transanal/transcolonic access for rectal and colon resections.

CONCLUSIONS

NOTES and hybrid NOTES techniques have emerged for all natural orifices and were introduced into clinical practice with a good safety record. There are different indications for different natural orifices. Each technique has been optimized for the purpose of finding a safe and realistic solution to perform the procedure according to the specific indication.

Natural orifice translumenal endoscopic surgery (NOTES) second-look peritoneoscopy for staging of limited peritoneal carcinomatosis

BACKGROUND

Over the past decades, staging laparoscopy evolved as a useful tool in multimodality treatment of patients with abdominal malignancies, especially for detection of incurable peritoneal and liver metastasis. Natural orifice translumenal endoscopic surgery (NOTES) is a new, evolving technique which represents the next logical progression in minimally invasive surgery and has theoretical advantages in comparison with standard laparoscopic surgery. A review of the current literature revealed a continuous increasing number of fundamental and clinical studies addressing NOTES approach in multimodal management of oncologic patients. Technical possibility to use this new minimally invasive approach for oncological resection of abdominal malignancies was proved by some investigators.

HYPOTHESIS

NOTES can be used as an alternative method for staging patients with limited peritoneal carcinomatosis and may have better results compared to current imaging techniques for small diameter metastatic disease.

CONCLUSIONS

With the continuous development of the NOTES techniques and technology, the second-look peritoneoscopy by NOTES may become an alternative method for staging in patients with peritoneal carcinomatosis. Nevertheless, NOTES is at a very early stage of its development, and its implementation in oncologic surgery should be made very caution, and only after careful evaluation.

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.

Specialized instrumentation facilitates stable peritoneal access, gastric decompression, and visualization during transgastric endoscopic peritoneoscopy

PURPOSE

The lack of high-fidelity instrumentation has impeded the development and implementation of natural orifice transluminal endoscopic surgery (NOTES). A steerable flexible trocar (SFT), a rotary access needle (RAN), and an articulating needle knife were developed as components of a flexible instrument set to facilitate transgastric peritoneal access and transluminal abdominal procedures. This cohort study aimed to assess the safety, feasibility, and efficacy of these devices during transgastric peritoneoscopy.

METHODS

Ten morbidly obese patients undergoing laparoscopic Roux-en-Y gastric bypass participated in the study. Following laparoscopic access, transgastric peritoneal access was established using the SFT and RAN, and transgastric peritoneoscopy performed. NOTES adhesiolysis was performed in 2 patients with significant intra-abdominal adhesions due to prior surgery. Outcome measures included time to enter the peritoneal cavity, ability to visualize each quadrant of the abdomen, ability to perform adhesiolysis, and complications.

RESULTS

Ten patients with a median body mass index as stated in table 1 of 47.5 kg/m(2) were enrolled. Successful transgastric access was achieved in 8 of the 10 patients. One procedure was aborted because of difficulty creating the gastrotomy. Another procedure was aborted because of the difficult passage of the device through the oropharynx. An upper esophageal laceration occurred in one patient. Transgastric peritoneal access required 17.4 ± 5.5 minutes, and peritoneoscopy averaged 24.7 ± 7.6 minutes. The 4 abdominal quadrants were visualized and were accessible with the endoscope in all patients.

CONCLUSIONS

The SFT and RAN facilitate transgastric peritoneal access and visualization of difficult-to-reach areas of the peritoneum. These devices provide advanced instrumentation for transgastric NOTES procedures; however, care must be taken during the transoral insertion to avoid complications.

Natural orifice translumenal endoscopic surgery in humans: a review

Natural orifice translumenal endoscopic surgery (NOTES) had its origins in numerous small animal studies primarily examining safety and feasibility. In human trials, safety and feasibility remain at the forefront; however, additional logistic, practical, and regulatory requirements must be addressed. The purpose of this paper is to evaluate and summarize published studies to date of NOTES in humans. The literature review was performed using PUBMED and MEDLINE databases. Articles published in human populations between 2007 and 2011 were evaluated. A review of this time period resulted in 48 studies describing procedures in 916 patients. Transcolonic and transvesicular procedures were excluded. The most common procedure was cholecystectomy (682, 75%). The most common approach was transvaginal (721, 79%). 424 procedures (46%) were pure NOTES and 491 (54%) were hybrid NOTES cases. 127 (14%) were performed in the United States of America and 789 (86%) were performed internationally. Since 2007, there has been major development in NOTES in human populations. A preponderance of published NOTES procedures were performed internationally. With further development, NOTES may make less invasive surgery available to a larger human population.

Magnetically anchored camera and percutaneous instruments maintain triangulation and improve cosmesis compared with single-site and conventional laparoscopic cholecystectomy

BACKGROUND

This study evaluated operative outcomes and ergonomics for a magnetic camera (MAGS) used in conjunction with percutaneous instruments [percutaneous surgical set (PSS)] compared with single-site laparoscopic (SSL) and conventional laparoscopic (LAP) cholecystectomy techniques.

METHODS

Four surgical trainees each performed three porcine cholecystectomies using three randomized techniques including MAGS/PSS, SSL, and LAP. The operative outcomes, procedure-specific ratings (1-5 scale; 1 = superior), workload (1-10 scale; 1 = superior), and global impressions (1-10 scale; 10 = superior) were recorded. Comparisons used analysis of variance (ANOVA) on ranks (Kruskal-Wallis), and p values lower than 0.05 were considered significant.

RESULTS

The operative outcomes were similar except for significantly higher blood loss with SSL (16.3 ± 10.3) versus LAP (2.8 ± 1.5; p < 0.05) but not with MAGS/PSS (4.8 ± 3.8). Several inadvertent tissue-damaging events occurred with SSL but not with MAGS/PSS or LAP. The incision was significantly shorter with MAGS/PSS (29.3 ± 2.8 mm) and SSL (29.3 ± 2.5 mm) than with LAP (48.0 ± 3.6 mm; p < 0.05). Compared with SSL (3.6 ± 0.5), the procedure-specific ratings significantly favored MAGS/PSS (2.8 ± 0.4) and LAP (1.7 ± 0.2; p < 0.05). Ergonomics and technical challenges both were rated significantly inferior with SSL (4.3 ± 1.0 and 3.8 ± 0.5, respectively) versus LAP (1.5 ± 0.6 and 2.0 ± 0.8, respectively; p < 0.05) but not with MAGS/PSS (2.5 ± 1.0 and 3.0 ± 0.8, respectively). Both MAGS/PSS (4.5 ± 0.5) and SSL (4.8 ± 1.0) were associated with a significantly greater workload than LAP (2.5 ± 0.6; p < 0.05). Global impression ratings were significantly higher for LAP (8.7 ± 1.3) versus SSL (5.8 ± 2.0; p < 0.05) but not for MAGS/PSS (7.1 ± 1.8). Cosmesis was significantly better with MAGS/PSS (9.5 ± 0.6) versus LAP (6.5 ± 2.4; p < 0.05) but not with SSL (8.8 ± 1.3).

CONCLUSION

The MAGS/PSS technique allows better triangulation and fewer technical difficulties than SSL and better cosmesis than LAP. Further development of these devices is warranted.

A randomized trial comparing rates of abdominal contamination and postoperative infection among natural orifice transluminal endoscopic surgery, laparoscopic surgery, and open surgery in pigs

BACKGROUND

Bacterial contamination of the abdominal cavity and infectious complications have been debated concerning transgastric natural orifice transluminal endoscopic surgery (NOTES) procedures.

OBJECTIVE

The aim of this study was to compare bacterial contamination of the abdominal cavity and clinically relevant infections after open, laparoscopic, and transgastric NOTES procedures.

DESIGN

Randomized survival study in a porcine model.

SETTING

Animal laboratory at a university hospital.

INTERVENTION

Thirty pigs were randomized to open, laparoscopic, or transgastric NOTES uterine horn resection under sterile conditions. Bacterial cultures were obtained from the pelvic area immediately at entry of the abdominal cavity and just before closure. The left uterine horn was dissected and ligated. The animals survived for 4 weeks. At necropsy, bacterial culture was obtained from the pelvic area.

MAIN OUTCOME MEASUREMENTS

Perioperative: operation time and incision length, bacterial growth in abdominal samples. Postoperative: infections or complications, weight gain. Necropsy: signs of peritonitis or infection, abdominal bacterial growth.

RESULTS

Procedure time was significantly longer for transgastric NOTES. At the start of the procedure, 4 of the NOTES animals showed positive cultures, but only 1 showed positive cultures at the end. No open surgery or laparoscopic surgery animals showed positive cultures at these time points. At necropsy, none of the animals in the NOTES group showed bacterial growth, whereas 4 open surgery animals and 3 laparoscopic surgery animals had positive cultures. Four of these animals (2 from each group) had concurrent wound infections.

LIMITATIONS

Small sample size and lack of power calculation.

CONCLUSION

This study indicates that clinically relevant infections are rare after transgastric NOTES procedures despite evidence of bacterial contamination and longer operating times.

Pure natural orifice transluminal endoscopic surgery (NOTES) with ultrasonography-guided transgastric access and over-the-scope-clip closure: a porcine feasibility and survival study

BACKGROUND

Most natural orifice transluminal endoscopic surgery (NOTES) procedures to date rely on the hybrid technique with simultaneous laparoscopic access to protect against access-related complications and to achieve adequate triangulation for dissection. This is done at the cost of the potential benefits of this new minimally invasive technique. This study aimed to evaluate the feasibility and safety of a transgastric (TG) pure-NOTES procedure in a diagnostic setting.

METHODS

A TG pure-NOTES procedure with endoscopic ultrasonograpy (EUS)-guided access and over-the-scope-clip (OTSC) closure was performed for 10 pigs in a survival and feasibility study. A full macroscopic necropsy with subsequent histologic evaluation was performed on postoperative day (POD) 14. The outcome parameters were uncomplicated follow-up assessment, survival, intraoperative complications, intraabdominal pathology, macroscopic full-thickness closure, and histology-proven full-thickness healing of the gastrotomy.

RESULTS

An uncomplicated postoperative course was reported for 9 of the 10 pigs, and survival was reported for all 10 pigs. For all the pigs, EUS-guided access was performed successfully with a median duration of 25 min (range, 12-62 min) and without intraoperative complications or access-related lesions at necropsy. An OTSC closure was achieved with a median duration of 11 min (range, 3-28 min). The OTSC provided immediate closure, but according to the authors' definition of a full-thickness healing evaluated by histologic examination, this was not achieved in any of the cases. Although all the animals survived until POD 14, intraabdominal chronic abscesses were present in 3 of the 10 pigs at necropsy.

CONCLUSIONS

The EUS-guided TG access proved to be feasible without access-related complications. Although OTSC provided an immediate closure, the histopathology raised concerns regarding the risk of perforation. Together with the high risk of intraabdominal infection, TG pure-NOTES is not yet ready for routine clinical practice.

Transgastric pure-NOTES peritoneoscopy and endoscopic ultrasonography for staging of gastrointestinal cancers: a survival and feasibility study

BACKGROUND

Human natural orifice transluminal endoscopic surgery (NOTES) has mainly been based on simultaneous laparoscopic assistance (hybrid NOTES), forgoing the theoretical benefits of the NOTES technique. This is due to a lack of NOTES-specific instruments and endoscopes, making pure-NOTES procedures difficult and time consuming. An area where pure NOTES could be adopted at its present stage of development is minimally invasive staging of gastrointestinal (GI) cancer. The aim of this study is to evaluate the feasibility of combining transgastric (TG) pure-NOTES peritoneoscopy and intraperitoneal endoscopic ultrasonography (ip-EUS) with intraluminal EUS (il-EUS) for peritoneal evaluation.

METHODS

This was a feasibility and survival study where il-EUS followed by ip-EUS and peritoneoscopy was performed in 10 pigs subjected to TG pure NOTES. A score was given with regard to achieved visualisation of predefined anatomical structures. Survival was assessed at postoperative day (POD) 14.

RESULTS

All animals survived until POD 14. Median total procedural time was 94 min (range 74-130 min). Median time for il-EUS, ip-EUS and peritoneoscopy was 11 min (range 7-14 min), 13 min (range 8-20 min) and 10 min (range 6-23 min). Il-EUS, ip-EUS and peritoneoscopy resulted in a score of 15/15 points (range 14-15 points), 6/9 points (range 1-8 points) and 12/13 points (range 8-13 points).

CONCLUSIONS

TG pure-NOTES peritoneoscopy and ip-EUS combined with il-EUS is feasible and provides sufficient peritoneal evaluation. The technique could have potential for minimally invasive staging of GI cancers.

A randomized comparison of laparoscopic, magnetically anchored, and flexible endoscopic cameras in performance and workload between laparoscopic and single-incision surgery

BACKGROUND

This study aimed to evaluate the surgeon performance and workload of a next-generation magnetically anchored camera compared with laparoscopic and flexible endoscopic imaging systems for laparoscopic and single-site laparoscopy (SSL) settings.

METHODS

The cameras included a 5-mm 30° laparoscope (LAP), a magnetically anchored (MAGS) camera, and a flexible endoscope (ENDO). The three camera systems were evaluated using standardized optical characteristic tests. Each system was used in random order for visualization during performance of a standardized suturing task by four surgeons. Each participant performed three to five consecutive repetitions as a surgeon and also served as a camera driver for other surgeons. Ex vivo testing was conducted in a laparoscopic multiport and SSL layout using a box trainer. In vivo testing was performed only in the multiport configuration and used a previously validated live porcine Nissen model.

RESULTS

Optical testing showed superior resolution for MAGS at 5 and 10 cm compared with LAP or ENDO. The field of view ranged from 39 to 99°. The depth of focus was almost three times greater for MAGS (6-270 mm) than for LAP (2-88 mm) or ENDO (1-93 mm). Both ex vivo and in vivo multiport combined surgeon performance was significantly better for LAP than for ENDO, but no significant differences were detected for MAGS. For multiport testing, workload ratings were significantly less ex vivo for LAP and MAGS than for ENDO and less in vivo for LAP than for MAGS or ENDO. For ex vivo SSL, no significant performance differences were detected, but camera drivers rated the workload significantly less for MAGS than for LAP or ENDO.

CONCLUSION

The data suggest that the improved imaging element of the next-generation MAGS camera has optical and performance characteristics that meet or exceed those of the LAP or ENDO systems and that the MAGS camera may be especially useful for SSL. Further refinements of the MAGS camera are encouraged.

Critical analysis of hot topics in NOTES

Natural orifice transluminal endoscopic surgery (NOTES) has gained a great deal of attention from gastroenterologists and surgeons all over the world since its introduction in 2000. The field of NOTES has advanced tremendously since that time and exciting and well-designed research has been reported. Both randomized controlled trials and results from large national and international registries have been published. Many experimental and clinical studies have discussed transesophageal, transgastric, transvaginal and transrectal access for a variety of NOTES procedures. Transvaginal access has been the most frequently reported NOTES access route in clinical trials. When suitable instruments become available, a true comparison of NOTES with current laparoscopic approaches can be realized.

Disinfection of the Access Orifice in NOTES: Evaluation of the Evidence Base

Introduction. Appropriate prevention of infection is a key area of research in natural orifice translumenal endoscopic surgery (NOTES), as identified by the Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR). Methods. A review of the literature was conducted evaluating the evidence base for access orifice preparation/treatment in NOTES procedures in the context of infectious complications. Recommendations based on the Oxford Centre for Evidence-Based Medicine guidelines were made. Results. The most robust evidence includes several experimental randomised controlled trials assessing infectious complications in the transgastric approach to NOTES. Transvaginal procedures are long established for accessing the peritoneal cavity following disinfection with antiseptic. Only experimental case series for transcolonic and transvesical approaches are described. Conclusion. Grade C recommendation requiring no preoperative preparation can be made for the transgastric approach. Antiseptic irrigation is recommended for transvaginal (grade C) NOTES access, as is current practice. Further human trials need to be conducted to corroborate the current evidence base for transgastric closure. It is important that future trials are conducted in a methodologically robust fashion, with emphasis on clinical outcomes and standardisation of enterotomy closure and postoperative therapy.

Development of a pancreatic tumor animal model and evaluation of NOTES tumor enucleation

BACKGROUND

Laparoscopic distal pancreatectomy is associated with high morbidity and mortality. NOTES tumor enucleation may provide an alternative to laparoscopic distal pancreatectomy. The goal of this study was to determine the feasibility of NOTES tumor creation and enucleation as a multidisciplinary approach.

METHODS

A linear-array endoscopic ultrasound (EUS) endoscope was used to inject a thermosensitive ABA triblock polymer mixed with methylene blue through the stomach wall and into the distal pancreas using a 22-gauge EUS needle. Due to its thermosensitive character, the polymer solidifies in response to body temperature, creating an artificial tumor. Seventeen swine underwent NOTES transgastric pancreatic tumor enucleation. Nine nonsurvival animals were sacrificed immediately after the NOTES procedure, with subsequent necropsy. Eight survival animals were observed for up to 16 days after the procedure, subsequently sacrificed, followed by necropsy.

RESULTS

The procedure was performed successfully in all 17 pigs studied, 9/9 nonsurvival (100%) and 8/8 survival (100%) animals, using a pure NOTES approach without any laparoscopic ports. Complications included two esophageal dissections (1 in nonsurvival group, 1 in survival group) caused by the introduction of the endoscopic overtube (2/17, 12%), unrelated to the actual surgical procedure. In the survival animals, there were two small splenic lacerations caused during retraction with the endoscopic forceps, for which hemostasis was achieved prior to closure of the gastrotomy (2/7, 29%). At necropsy of the animals, there was sufficient closure of 15/17 gastrotomy sites (88%).

CONCLUSIONS

The creation of artificial pancreatic tumors via EUS guidance is feasible. Pancreatic tumor enucleation using a transgastric NOTES approach is technically feasible and could be an alternative to laparoscopic distal pancreatectomy with further development. Further adoption and adaptation of this technique will require the development of more sophisticated specialized tools to improve the safety profile of the procedure.