The EURO-NOTES clinical registry for natural orifice transluminal endoscopic surgery: a 2-year activity report. Surg Endosc. 2013;27:3073-3084. [PMID: 23519494 DOI: 10.1007/s00464-013-2908-5]

The vaginal route for minimally invasive surgery: a practical guide for general surgeons

INTRODUCTION

Vaginal approaches have become routine in the field of gynecologic surgery, whereas in general surgery vaginal wall transection is an infrequent practice typically reserved for extensive tumor resections. Approximately two decades ago, natural orifice transluminal endoscopic surgery (NOTES) revolutionized conventional boundaries by accessing the peritoneal cavity transorally, transrectally, or transvaginally, enabling general surgery without visible scars. Although transvaginal approaches have been successfully used for various abdominal procedures by general surgeons, a gap remains in comprehensive training to fully exploit the potential of this route.

MATERIAL AND METHODS

PubMed, Google Scholar, and Scopus databases were searched to retrieve relevant articles illustrating how general surgeons can adeptly manage vaginal approaches.

RESULTS

The article presents a practical framework for general surgeons to execute a complete vaginal approach, addressing the management of vaginal specimen extraction and vaginal cuff closure, even in the absence of an experienced gynecologist.

CONCLUSION

The evolution of abdominal surgery is moving towards less invasive techniques, emphasizing the importance of understanding the nuances and challenges associated with the vaginal route. This approach is linked to minimal oncological, sexual, and infective complications, and to the absence of pregnancy-related complications. Such knowledge becomes increasingly crucial, particularly with the renewed demand for transvaginal access in robot-assisted NOTES procedures.

Transvaginal Laparoscopic Appendectomy: A Systematic Review

Appendectomy remains the gold standard for treating appendicitis, but advancements in laparoscopic techniques have shifted the paradigm. Natural orifice transluminal endoscopic surgery (NOTES) and transvaginal appendectomy (TVA) offer a potentially less invasive alternative to traditional laparoscopic appendectomy (LA). This article systematically reviews the procedures, perceptions, and complications of TVA to assess its viability as a surgical option. Between January 1, 2003, and November 1, 2023, 4832 case reports, case series, and experimental and observational peer-reviewed publications were examined and filtered using the keyword "Transvaginal Laparoscopic Appendectomy." The publications were screened using PRISMA guidelines, and 20 studies were included for analysis and review. Survey results showed that women's acceptance of TVA was 43%, citing reduced invasiveness as a major reason for positive reception. TVA procedures exhibited consistency, with variations in appendectomy methods, appendix removal, and posterior fornix incision closure. Positive outcomes included shorter operation times, reduced postoperative pain, and minimal scarring. Complications were uncommon but included bladder puncture, urinary tract infections, and intra-abdominal abscesses. Indications primarily focused on surgical safety, reduced scarring, and postoperative benefits. Sexual function post-TVA exhibited no significant differences in most cases, with a recovery period of two to four weeks. This systematic review suggests that TVA is a promising alternative to traditional LA, offering potential advantages in terms of postoperative complications. While the existing literature indicates positive outcomes, further research with larger sample sizes and long-term follow-ups is needed to validate the efficacy and safety of TVA and assess how the procedure impacts the reproductive function of patients.

Feasibility and safety of hybrid transvaginal natural orifice transluminal endoscopic surgery for colon cancer: Protocol for a multicenter, single-arm, phase II trial (vNOTESCA)

Introduction

It has been a decade since the first patient with colon cancer underwent colectomy by hybrid transvaginal natural orifice transluminal endoscopic surgery (hvNOTES). However, the efficacy and safety of this procedure is not well established.

Methods

This study is an open-label, multicenter, single-arm, phase 2 trial undertaken at six centers in China. Female patients aged over 18 years and below 80 years old with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with pathologically proven, resectable, cT1-3N0-2M0 disease who have previously untreated colon cancer are eligible for inclusion. The primary endpoint is a composite of major intraoperative and postoperative complications (greater than grade III, the Common Terminology Criteria for Adverse Events [CTCAE], version 5.0). Secondary endpoints include conversion to laparoscopic or open surgery, postoperative concentration of C-Reactive Protein and procalcitonine, complete pathological assessment of complete mesocolic excision specimens, postoperative pain, amount of narcotic pain medication administered, time to first flatus after surgery, number of harvested lymph nodes, R0 resection rate, length of hospital stay, sexual function assessment, quality of recovery, satisfaction with surgical scars, quality of life, postoperative recurrence patterns, relapse-free survival, and overall survival.

Ethics and dissemination

The study was approved by the Research Ethics Committee, Renmin Hospital of Wuhan University, China, number: WDRY2022-K053. All patients will receive written information of the trial and provide informed consent before enrollment. The results of this trial will be disseminated in academic conferences and peer-reviewed medical journals.Trial registration number NCT04048421.

Advances in gastrointestinal surgical endoscopy

Surgeons have a role in observing, detect abnormalities, disease, and other deficiencies in function which could be treated. Diagnosing and treating back days were challenging for many reasons. However, technology's innovation enhances surgeons' ability to treat their patients. The term endoscopy refers to the Greek prefix endo- ("within") and the verb skopein ("to view or observe"). Endoscopy is practical both in the diagnosis and treatment of various pathologies. Technological advances, especially in endoscopy, gradually progress and discover many possibilities which allow rapid advancement. Endoscopy development aims to assess human orifice that has not been inspected, probed, and examined over the centuries. Endoscopy over these decades is improving, which led to new problem solving using advanced technological approaches. Thus, a surgeon can solve any issues from examination, diagnosis, and treatment using progressive endoscopy evolution. This review delivers a brief history of advances in surgical endoscopy and describes current endoscopy development.

Transvaginal hybrid-NOTES vs. traditional laparoscopic sigmoid resection for diverticulitis: a short-term comparative study

The aim was to compare short-term results of transvaginal hybrid-NOTES (NSR) with traditional laparoscopic technique in sigmoid resection (LSR) in cases of diverticulitis. Natural Orifice Transluminal Endoscopic Surgery has been evolved as a minimally invasive procedure to reduce the operative trauma due to the absence of specimen extraction through the abdominal wall causing less postoperative pain, and shorter hospital stay. Despite the increasing use and published case series of NSR for diverticulitis as a laparoscopic procedure with transvaginal stapling and specimen extraction, there are no studies comparing this procedure with LSR. Twenty NSR patients operated at the Cologne-Merheim Medical Center have been documented and compared with 20 female LSR patients matched for body mass index, American Society of Anesthesiologists-classification (ASA), Hansen/Stock classification, and age. To ensure comparability regarding peri- and postoperative care, only procedures performed by the same surgeon were included. Procedural time, intra- and postoperative complications, conversion rate, postoperative pain, the duration of an epidural catheter, analgesic consumption, and postoperative length of hospital stay were analyzed. There were no significant differences in the sum of pain levels (p = 0.930), length of procedure (p = 0.079), intra- and postoperative complications, as well as duration of an epidural catheter. On the contrary, there were significant positive effects for NSR on morphine requirement at day seven and eight (p = 0.019 and p = 0.035 respectively) as well as the postoperative length of hospital stay (p = 0.031). This retrospective study reveals significant positive effects for NSR compared to LSR regarding length of hospital stay as well as morphine consumption after removal of the epidural catheter, whereas there were no significant differences in complication rate and procedural time. In summary, NSR is an adequate alternative to traditional laparoscopic sigmoid resection considering the surgeons experience and the patient’s personal preferences.

Randomized clinical trial on the use of a colon-occlusion device to assist rectal washout

Background

Transrectal Natural Orifice Transluminal Endoscopic Surgery is currently limited by the inherent risk of surgical site infection due to peritoneal contamination after rectotomy. Coloshield has been developed as a temporary colon occlusion device to facilitate rectal washout. However, effectiveness and safety has not been evaluated in humans.

Methods

Twenty-two patients have been randomly assigned to undergo proctological intervention with a rectal washout with and without the use of Coloshield. Patients and assessors were blinded. Boston Bowel Preparation Scale (BBPS) has been determined 30 min as well as immediately after rectal washout. Feasibility, pain, intra- and postoperative morbidity as well as bowel function and continence 6 weeks after surgery were assessed.

Results

BBPS 30 min after rectal washout with and without Coloshield was in mean 2.42 ± 1.02 and 2.12 ± 0.89 (p = 0.042). Mean BBPS immediately after rectal washout was 2.39 ± 1.02 and 2.24 ± 0.66 (p = 0.269). Mean BBPS immediately after rectal washout and 30 min thereafter did not differ (p = 0.711). Coloshield application was feasible without any complications. The median (interquartile range) numeric rating scale for pain 4 h after surgery was 1 (0–1) and 3 (0–4) (p = 0.212). Six weeks after surgery 0/11 and 1/11 patients suffered from evacuation difficulties (p = 1.0) and the median Vaizey–Wexner score was 1 (0–3) and 1 (0–2) (p = 0.360).

Conclusions

Coloshield application in humans is feasible and safe. Slight benefits in rectal preparation by washout are found when Coloshield is used. Colon occlusion by Coloshield for transrectal NOTES should be evaluated within clinical studies.

Trial registration

Clinicaltrials.gov NCT02579330

Transanal hybrid colon resection: techniques and outcomes for benign colorectal diseases

BACKGROUND

Transanal hybrid rectal and colon resection have been introduced in recent years at dedicated surgical centers. The anus is used as a natural orifice for large size access. The use of transanal hybrid colectomy techniques is still in its infancy with outcomes and unique complications being identified. The purpose of this work is the evaluation of outcomes for transanal hybrid colon resections (ta-CR), including intra operative and postoperative complications, results, and advantages.

METHODS

A prospectively maintained database was analyzed. Inclusion criteria were any patient who underwent ta-CR for rectal prolapse, slow transit, obstructive defaecation, and chronic sigmoid diverticulitis. Patients were excluded from ta-CR if BMI > 30, major previous abdominal surgery, or presence of a large inflammatory mass in diverticulitis. Transanal access was used for all operative steps requiring access of more than 5 mm, such as staplers, large graspers, and specimen retrieval. Data acquisition and analysis was performed for operative time, complications, and postoperative quality of life.

RESULTS

From 2012 to 2017, 82 patients underwent ta-CR [33 males, 49 females, median age 58 (24-80)]. Transanal-subtotal colectomy and ta-CR for constipation was performed in 12 patients; ta-CR and rectopexy in 31, and ta-CR for diverticulitis was performed in 39 patients. Conversion to traditional approach was required in 3 cases (3.6%). Intraoperative complication included 1 rectal tear requiring intervention. Post-op complications included 3 leaks requiring laparoscopic and 1 open revision, the latter developed wound infection and an incisional hernia. Gastrointestinal Quality of Life Index (GIQLI) improved significantly from preoperative 89 to postoperative 119 (p < 0.001). No patients with ta-CR without open revision developed a hernia post-op with median 18 months follow-up.

CONCLUSIONS

ta-CR is a safe and effective NOTES Hybrid technique for colorectal procedures in selected patients with benign colon disorders. GIQLI shows improvement and this technique can have the potential in preventing wound and hernia complications.

Transluminal Cancer Surgery

Transluminal surgery, also known as natural orifices endoluminal surgery, can be considered the most minimally invasive approach of gaining access to an organ. Although some approaches, such as transgastric or transvaginal cholecystectomy, have remained experimental, peroral endoscopic myotomy to treat achalasia and transanal total mesorectal excision to treat low rectal cancer have become accepted, safe, and feasible approaches by trained surgeons for selected patients. This article recapitulates the development of transluminal surgery from its experimental beginnings to the validated procedure it has become today.

Direct target NOTES: prospective applications for next generation robotic platforms

BACKGROUND

A new era in surgical robotics has centered on alternative access to anatomic targets and next generation designs include flexible, single-port systems which follow circuitous rather than straight pathways. Such systems maintain a small footprint and could be utilized for specialized operations based on direct organ target natural orifice transluminal endoscopic surgery (NOTES), of which transanal total mesorectal excision (taTME) is an important derivative.

METHODS

During two sessions, four direct target NOTES operations were conducted on a cadaveric model using a flexible robotic system to demonstrate proof-of-concept of the application of a next generation robotic system to specific types of NOTES operations, all of which required removal of a direct target organ through natural orifice access. These four operations were (a) robotic taTME, (b) robotic transvaginal hysterectomy in conjunction with (c) robotic transvaginal salpingo-oophorectomy, and in an ex vivo model, (d) trans-cecal appendectomy.

RESULTS

Feasibility was demonstrated in all cases using the Flex^® Robotic System with Colorectal Drive. During taTME, the platform excursion was 17 cm along a non-linear path; operative time was 57 min for the transanal portion of the dissection. Robotic transvaginal hysterectomy was successfully completed in 78 min with transvaginal extraction of the uterus, although laparoscopic assistance was required. Robotic transvaginal unilateral salpingo-oophorectomy with transvaginal extraction of the ovary and fallopian tube was performed without laparoscopic assistance in 13.5 min. In an ex vivo model, a robotic trans-cecal appendectomy was also successfully performed for the purpose of demonstrating proof-of-concept only; this was completed in 24 min.

CONCLUSIONS

A flexible robotic system has the potential to access anatomy along circuitous paths, making it a suitable platform for direct target NOTES. The conceptual operations posed could be considered suitable for next generation robotics once the technology is optimized, and after further preclinical validation.

Feasibility and Technique for Transvaginal Natural Orifice Transluminal Endoscopic Surgery Liver Resection: A Porcine Model

INTRODUCTION

Natural orifice transluminal endoscopic surgery (NOTES) is a challenging minimally invasive procedure. Although laparoscopic techniques for liver resection are gaining acceptance worldwide, few studies have investigated NOTES liver resection. We used a porcine model to assess the feasibility and safety of transvaginal NOTES liver resection (TV NOTES LR).

MATERIALS AND METHODS

Nine female pigs underwent TV NOTES LR. A nonsurvival acute porcine model with general anesthesia was used in all cases. Using hybrid NOTES technique, we placed only 1 umbilical 12-mm umbilical trocar in the abdominal wall, which was used to create pneumoperitoneum. A laparoscope was then advanced to obtain intra-abdominal visualization. A 15-mm vaginal trocar was inserted under direct laparoscopic vision, and a flexible endoscope was introduced through the vaginal trocar. A long, flexible grasper and endocavity retractor were used to stably retract the liver. The liver edge was partially transected using energy devices inserted through the umbilical trocar. To transect the left lateral lobe, a flexible linear stapler was inserted alongside the vaginal trocar. A specimen extraction bag was deployed and extracted transvaginally. Blood loss, bile leakage, operative time, and specimen size were evaluated. Necropsy studies were performed after the procedures.

RESULTS

Eighteen transvaginal NOTES partial liver resections and 4 transvaginal NOTES left lateral lobectomies were successfully performed on 9 pigs. Mean operative time was 165.8 minutes, and mean estimated blood loss was 76.6 mL. All TV NOTES LRs were performed without complications or deaths. Necropsy showed no bile leakage from remnant liver.

CONCLUSIONS

Our porcine model suggests that TV NOTES LR is technically feasible and safe and has the potential for clinical use as a minimally invasive alternative to conventional laparoscopic liver resection.

Analysis of the First 217 Appendectomies of the German NOTES Registry

OBJECTIVE

To analyze the feasibility and safety of Natural Orifice Transluminal Endoscopic Surgery (NOTES) appendectomy, and to analyze separately the transvaginal appendectomy (TVAE) and the transgastric appendectomy (TGAE) procedures.

BACKGROUND

Laparoscopic appendectomy has rare but relevant complications, namely incisional hernias and neuralgia at the trocar sites, which can potentially be avoided by the NOTES techniques.

METHODS

The first 217 data sets of the largest NOTES registry worldwide-the German NOTES registry-were analyzed with respect to demographic data, procedural data, and short-term outcomes. Furthermore, TVAEs were compared with TGAEs.

RESULTS

Almost all procedures were performed in hybrid technique (median of percutaneous trocars: 1). Median age (TVAE: 30.5 yrs vs TGAE: 25 yrs; P < 0.017), body mass index (TVAE: 22.8 kg/m vs TGAE: 24.1 kg/m; P < 0.016), and American Society of Anesthesiologists (ASA) classification (I/II/III; TVAE: 57.1%/41.8%/1.0% vs TGAE: 27.8%/69.4%/2.8%; P < 0.003) significantly differed between both access techniques. Whereas the median number of percutaneous trocars (TVAE: 1 vs TGAE: 1; P < 0.450), the need of additional trocars (TVAE: 6.6% vs TGAE: 13.9%; P < 0.156), the intra, and also postoperative rate of complications (TVAE: 0%/5.5% vs TGAE: 0%/11.1%; P < 1.000/0.258), and the median postoperative hospital stay (TVAE: 3 d vs TGAE: 3 d; P < 0.152) were comparable; the median procedural time (TVAE: 35 minutes vs TGAE: 96 minutes; P < 0.001) and conversion to laparotomy rate (TVAE: 0% vs TGAE: 5.6%; P < 0.023) were significantly less after TVAE.

CONCLUSIONS

The evaluation of the largest patient collective so far indicates that hybrid NOTES appendectomy is a safe procedure, with advantages for the transvaginal technique with respect to procedural time and conversion rate.

Hybrid transgastric appendectomy is feasible but does not offer advantages compared with laparoscopic appendectomy: Results from the transgastric appendectomy study

BACKGROUND

Very few transgastric procedures, the original objective of natural orifice translumenal surgery, have been reported in the international Natural Orifice Translumenal Surgery registers. In addition, most cases were controlled mainly by laparoscopy. To show the feasibility of hybrid transgastric appendectomy and to compare results with laparoscopic a prospective, nonrandomized study was conducted.

METHODS

From October 2010 to May 2013, patients with acute appendicitis were screened. If the patients met the inclusion criteria, transgastric appendectomy was offered. If the patient decided on laparoscopy, the consenting patients took part in the observational part of the study. The transgastric appendectomy procedure was controlled completely by the gastroscope, although a 3 mm grasper was used to tauten the appendix. Demographic and clinical parameters were collected. Quality of life and pain were measured with a Short Form-8 questionnaire and the Visual Analogue Scale.

RESULTS

Of the 273 patients who underwent an appendectomy, 65 agreed to take part in this study. Out of these, 30 (46.15%) underwent transgastric appendectomy and 35 (53.85%) underwent laparoscopy. No intraoperative complications were recorded. The operation duration rate was greater in the transgastric appendectomy group (94.5 minutes vs 69 minutes; P < .001). Conversions to open appendectomy and complications were the same. There were no differences in pain preoperatively or postoperatively. In both the transgastric appendectomy and laparoscopic groups, the quality of life of all the subscales increased markedly after successful resection of the pathology.

CONCLUSION

These preliminary results demonstrate the feasibility of transgastric appendectomy. The postoperative course and quality of life are comparable with laparoscopic appendectomy, but no improvement due to transgastric appendectomy could be demonstrated.

[Natural orifice transluminal endoscopic surgery in Germany: Data from the German NOTES registry]

BACKGROUND

The German NOTES registry (GNR) was initiated by the German Society for General and Visceral Surgery (DGAV) as a treatment and outcome database for natural orifice transluminal endoscopic surgery (NOTES).

AIM

The aim of this study was the descriptive analysis of all GNR data collected over a 5-year period since its start in 2008 with more than 3000 interventions.

MATERIAL AND METHODS

The GNR is an online database with voluntary participation available to all German-speaking clinics. Demographic data, therapy details, complications and data on the postoperative course of patients are recorded. All cases in the GNR between March 2008 and November 2013 were included in the analysis.

RESULTS

From a total of 3150 data sets 2992 (95 %) were valid and suited for the analysis. Hybrid transvaginal cholecystectomy was the most frequently used procedure (88.7 %), followed by hybrid transvaginal/transgastric appendectomy (6.1 %) and hybrid transvaginal/transrectal colon procedures (5.1 %). Intraoperative complications occurred in 1.6 %, postoperative complications in 3.7 % and conversions were reported in 1.5 %. Intraoperative bladder injuries and postoperative urinary tract infections were identified as method-specific complications of transvaginal procedures. Bowel injuries occurred as a rare (0.2 %) but potentially serious complication of transvaginal operations.

CONCLUSION

The German surgical community ensures a safe and responsible introduction of the new NOTES operation techniques with its active participation in the GNR. Despite an overall low complication rate, the high number of procedures in the GNR permitted the identification of method-specific complications. This knowledge can be used to further increase the safety of NOTES in practice.

Pure Natural Orifice Transluminal Endoscopic Surgery (NOTES) with a new elongated, curved Transanal Endoscopic Operation (TEO) device for rectosigmoid resection: a survival study in a porcine model

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has seen considerable new developments in its evolution to a platform for rectal and sigmoid resection, but to date no true single NOTES procedure has been convincing. This study investigates the safety and feasibility of a further developed transanal NOTES platform for single-access NOTES rectosigmoid resection.

METHODS

Ten large female pigs, mean weight 99.3 kg [standard deviation (SD) 7 kg, range 85.1-112.6 kg], underwent transanal rectosigmoid resection. Five animals were included in an acute study group with immediate postoperative euthanization. A second group included five animals in a survival study. Transanal rectosigmoid resections were performed with an elongated and curved transanal endoscopic operation (TEO) device. Coloanal anastomosis was performed using the transanal circular stapler technique. Survival follow-up was at 7 and 28 days via colonoscopy under sedation.

RESULTS

Single-access NOTES transanal rectosigmoid resection with coloanal anastomosis was performed in nine out of ten female pigs. Mean length of rectosigmoid specimens exteriorized was 18.7 cm (SD 2.9 cm, range 14-23 cm). Mean operating time was 124 min (SD 35.7 min, range 70-166 min). Within the survival group, no complications occurred during the monitoring phase. In one case, there was ascites and colitis at necropsy as well as fibrosis at the anastomosis site.

CONCLUSIONS

Pure transanal rectosigmoid resection is a feasible procedure. The approach via a single transanal access is demanding but viable with the elongated and curved TEO device. The newly developed scope offers an excellent view of the area cephalad to the promontory.

Shifting Paradigms in Minimally Invasive Surgery: Applications of Transanal Natural Orifice Transluminal Endoscopic Surgery in Colorectal Surgery

Since the advent of laparoscopy, minimally invasive techniques such as single port laparoscopy, robotics, endoscopically assisted laparoscopy, and transanal endoscopic surgery continue to revolutionize the field of colorectal surgery. Transanal natural orifice transluminal endoscopic surgery (NOTES) represents a further paradigm shift by combining the advantages of these earlier techniques to reduce the size and number of abdominal incisions and potentially optimize rectal dissection, especially with respect to performance of an oncologically adequate total mesorectal excision (TME) for rectal cancer. Since the first experimental report of transanal rectosigmoid resection in 2007, the potential impact of transanal NOTES in colorectal surgery has been extensively investigated in experimental models and recently transitioned to clinical application. There have been 14 clinical trials of transanal TME (taTME) for rectal cancer that have demonstrated the feasibility and preliminary oncologic safety of this approach in carefully selected patients, with results comparable to outcomes after laparoscopic and open TME, including cumulative intraoperative and postoperative complication rates of 5.5 and 35.5%, respectively, 97.3% rate of complete or near-complete specimens, and 93.6% rate of negative margins. Transanal NOTES has also been safely applied to proctectomy and colectomy for benign indications. The consensus among published series suggests that taTME is most safely performed with transabdominal assistance by surgeons experienced with laparoscopic TME, transanal endoscopic surgery, and sphincter-preserving techniques including intersphincteric resection. Future applications of transanal NOTES may include evolution to a pure endoscopic transanal approach for TME, colectomy, and sentinel lymph node biopsy for rectal cancer, with a potential role for robotic assistance.

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.

Recent advances in natural orifice transluminal endoscopic surgery†

Natural orifice transluminal endoscopic surgery (NOTES) has emerged as one of the most exciting areas in the field of minimally invasive surgery during the last decade. NOTES comprises a wide spectrum of procedures from various natural accesses such as transgastric or transvaginal routes, and different direct-target or distant-target organs. Since polypectomy was first performed in 1955, major advances in technology and refinement of endoscopic technique have allowed endoscopic surgeons to perform complex endoscopic interventions such as endoscopic submucosal dissection. Recognizing the safety and feasibility of submucosal tunnelling and mucosal closure, endoscopic resection beyond the level of mucosa has been increasingly reported. One of these procedures, peroral endoscopic myotomy for achalasia, has gained much popularity and excellent results have been published comparable with that of traditional Heller's cardiomyotomy. Submucosal tunnelling endoscopic resection has also been reported for tumours situated in the muscular layer of the gastrointestinal tract. To overcome the difficulty of intestinal closure after NOTES, researchers have collaborated with the industry in developing different endoscopic suturing devices such as the Eagle Claw (Olympus Medical Systems, Tokyo, Japan) and Overstitch™ (Apollo Endosurgery, Austin TX, USA). These devices allow precise and secure suture application with the ordinary flexible endoscope, achieving tissue approximation similar to open surgical suturing. To further expand the potential of NOTES, investigators had also developed multitasking platforms enabling the performance of surgical procedures of even higher complexity. Recently, a novel endoscopic robotic system 'Master and Slave Transluminal Endoscopic Robot' (MASTER) has been developed. Early results of endoscopic resection utilizing this system have been encouraging, allowing both experts and novices in endoscopy to perform difficult endoscopic resection with a high degree of flexibility.

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.

Women’s Perception of Transvaginal Natural Orifice Transluminal Endoscopic Surgery (NOTES)

Objective. Over the past 8 years, natural orifice transluminal endoscopic surgery (NOTES) has developed from preclinical to routine clinical practice. However, there are still concerns regarding the transvaginal approach. In our survey, we were interested in females with a professional medical background, thus having at least a basic medical understanding, which might discriminate between objective and subjective concerns. Material and Methods. A questionnaire with 14 items was distributed among 1895 female physicians and nursing and administration staff of the University Medical Center Hamburg-Eppendorf. In addition, a qualitative literature review was performed. Data analysis was carried out using statistical package R version 2.15.0. Results. The questionnaire was answered anonymously by 553 employees (29%). Fifty-seven percent were nurses, 18.6% belonged to administration, and 17% were physicians. A total of 63.1% of our respondents would choose the transvaginal NOTES technique for an assumed ovariectomy, while only 30.4% would choose this access for cholecystectomy. Doubts regarding transvaginal NOTES were related to sexual dysfunction (44.8%), its experimental nature (43.8%), future pregnancies (36.8%), and ethical reasons (30.3%). The literature review showed that women’s perception of the transvaginal access is documented very heterogeneously and therefore difficult to compare. Conclusions. Despite the good reported results of NOTES and the medical background of the surveyed female employees, our study and the literature review clearly shows that there are  fears regarding the transvaginal access, which might be a result of limited information. More accurate explanation of the available methods by the attending surgeon can lead to a better choice of the patient’s preferred method.

Transrectal Rigid-Hybrid Natural Orifice Translumenal Endoscopic Sigmoidectomy for Diverticular Disease: A Prospective Cohort Study

BACKGROUND

Our goal was to evaluate the feasibility of transrectal rigid hybrid natural orifice translumenal endoscopic surgery (NOTES) sigmoidectomy (trNS) in a series of consecutive prospective patients with diverticular disease. The NOTES for left colectomy offers patients reduced pain and easier recovery. Limited data are available for trNS, which is considered safe for various indications. However, the technique is not standardized, and patients in the reported series are highly selected.

STUDY DESIGN

Patients scheduled for trNS were entered into a prospective registry on an intention-to-treat basis. The primary endpoint was trNS feasibility, and secondary endpoints were morbidity, pain, length of stay, and inflammatory response. A medial-to-lateral dissection with full mobilization of the splenic flexure and total intracorporeal anastomosis was performed. The rectum was covered with a wound protector for transrectal extraction.

RESULTS

Of 95 elective sigmoidectomies, 81% (n = 77) were enrolled for either transvaginal NOTES resection (n = 37) or trNS (n = 40). There was no difference in body mass index or indication between patients undergoing laparoscopic-assisted sigmoidectomy (LAS), transvaginal resection, or trNS, although trNS patients were younger. Mainly because of a mismatch of bulky specimen and narrow pelvis, 17.5% of trNS were converted to LAS. Major morbidity was 10%, including 2 septic complications. During the study, the anastomosis technique was changed from double stapled end-to-end to side-to-end anastomosis.

CONCLUSIONS

Transrectal rigid hybrid natural orifice translumenal endoscopic sigmoidectomy is feasible and safe in a high proportion of unselected consecutive patients with diverticular disease undergoing elective treatment. Intracorporeal side-to-end anastomosis is the preferred technique, and trNS should be offered for elective sigmoidectomy presupposing advanced laparoscopic experience.

Emerging Techniques in Minimally Invasive Surgery. Pros and Cons

New trends have emerged regarding the best minimally invasive access approaches to perform gastrointestinal surgery. However, these newer approaches are seen critically by those who demand a more strict assessment of outcomes and safety. An international panel of expert gathered at the 2014 American College of Surgeons Meeting with the goal of providing an evidence-based understanding of the real value of these approaches in gastrointestinal surgery. The panel has compared the efficacy and safety of most established approaches to gastrointestinal diseases to those of new treatment modalities: peroral esophageal myotomy vs. laparoscopic myotomy for achalasia, transgastric vs. transvaginal approach, and single-incision vs. multi-port access minimally invasive surgery. The panel found that (1) the outcome of these new approaches was not superior to that of established surgical procedures; (2) the new approaches are generally performed in few highly specialized centers; and (3) transgastric and transvaginal approaches might be safe and feasible in very experienced hands, but cost, training, operative time, and tools seem to limit their application for the treatment of common procedures such as cholecystectomy and appendectomy. Because the expected advantages of new approaches have yet to be proven in controlled trials, new approaches should be considered for adoption into practice only after thorough analyses of their efficacy and effectiveness and appropriate training.

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.

Single-incision multiport laparoendoscopic surgery using a short-type flexible endoscope and its usefulness in cholecystectomy

INTRODUCTION

We previously demonstrated the advantages of a short-type flexible endoscope as a working scope in laparoscopic surgery through single-incision procedures in animal experiments. In this report, we examined the outcomes of laparoscopic surgery through a single incision using a flexible endoscope in a clinical setting. Specifically, we performed cholecystectomy using single-incision multiport laparoendoscopic (SIMPLE) surgery.

METHODS

Thirteen patients with cholecystolithiasis or gallbladder polyp underwent SIMPLE cholecystectomy using a newly developed short-type flexible endoscope with a working length of 60 cm. Twenty-seven patients underwent standard single-incision laparoscopic cholecystectomy using a 5-mm rigid laparoscope. We retrospectively compared the surgical outcomes between the two groups.

RESULTS

SIMPLE cholecystectomy using the short-type flexible endoscope was successfully carried out. No gallbladder perforation occurred, but perforation occurred in four cases in the standard laparoscopic cholecystectomy group; however, the difference was not statistically significant. Although no other surgical outcomes differed between the two groups, the flexible endoscope had several advantages over the standard laparoscope. The scope provided a flexible view of the operating field. The gallbladder dissection using the cutting device via the scope was easier and safer than that in standard single-incision laparoscopic cholecystectomy. The water-jet, suctioning, and self-cleaning lens functions of the scope served the surgery well.

CONCLUSIONS

SIMPLE cholecystectomy using a short-type flexible endoscope has surgical outcomes equivalent to those of standard single-incision laparoscopic cholecystectomy, but this endoscope with multiple functions may make the surgical procedures less stressful and safer.

Transvaginal appendectomy: a systematic review

Background. Natural orifice transluminal endoscopic surgery (NOTES) is a new approach that allows minimal invasive surgery through the mouth, anus, or vagina. Objective. To summarize the recent clinical appraisal, feasibility, complications, and limitations of transvaginal appendectomy for humans and outline the techniques. Data Sources. PubMed/MEDLINE, Cochrane, Google-Scholar, EBSCO, clinicaltrials.gov and congress abstracts, were searched. Study Selection. All related reports were included, irrespective of age, region, race, obesity, comorbidities or history of previous surgery. No restrictions were made in terms of language, country or journal. Main Outcome Measures. Patient selection criteria, surgical techniques, and results. Results. There were total 112 transvaginal appendectomies. All the selected patients had uncomplicated appendicitis and there were no morbidly obese patients. There was no standard surgical technique for transvaginal appendectomy. Mean operating time was 53.3 minutes (25–130 minutes). Conversion and complication rates were 3.6% and 8.2%, respectively. Mean length of hospital stay was 1.9 days. Limitations. There are a limited number of comparative studies and an absence of randomized studies. Conclusions. For now, nonmorbidly obese females with noncomplicated appendicitis can be a candidate for transvaginal appendectomy. It may decrease postoperative pain and enable the return to normal life and work off time. More comparative studies including subgroups are necessary.

New trends in colorectal surgery: Single port and natural orifice techniques

Single-incision laparoscopic surgery (SILS) and natural orifice transluminal endoscopic surgery (NOTES) have rapidly gained pace worldwide, potentially replacing conventional laparoscopic surgery (CLS) as the preferred colorectal surgery technique. Currently available data mainly consist of retrospective series analyzed in four meta-analyses. Despite conflicting results and lack of an objective comparison, SILS appears to offer cosmetic advantages over CLS. However, due to conflicting results and marked heterogeneity, present data fail to show significant differences in terms of operative time, postoperative morbidity profiles, port-site complications rates, oncological appropriateness, duration of hospitalization or cost when comparing SILS with conventional laparoscopy for colorectal procedures. The application of “pure” NOTES in humans remains limited to case reports because of unresolved issues concerning the ideal access site, distant organ reach, spatial orientation and viscera closure. Alternatively, minilaparoscopy-assisted natural orifice surgery techniques are being developed. The transanal “down-to-up” total mesorectum excision has been derived for transanal endoscopic microsurgery (TEM) and represents the most encouraging NOTES-derived technique. Preliminary experiences demonstrate good oncological and functional short-term outcomes. Large-scale randomized controlled trials are now mandatory to confirm the long-term SILS results and validate transanal TEM for the application of NOTES in humans.

Safety of transvaginal hybrid NOTES cholecystectomy: a systematic review and meta-analysis

BACKGROUND

Despite increasing data regarding clinical outcomes following transvaginal hybrid NOTES cholecystectomy (TVC), a consensus regarding safety based on comparative studies has yet to be reached. The aim of this systematic review and meta-analysis was to compare safety and clinical outcomes of TVC with conventional laparoscopic cholecystectomy (CLC) for the treatment of benign gallstone disease.

METHODS

A comprehensive search for published studies comparing TVC and CLC was performed. Review of each study was conducted and data were extracted. All pooled outcome measures were determined using random-effects models.

RESULTS

Data were retrieved from 14 studies describing 1,145 patients. There was no difference in total complications (POR = 0.68; 95 % CI 0.40-1.14; P = 0.14), incidence of bile duct injury (POR = 1.33; 95 % CI 0.31-5.66; P = 0.70), Clavien-Dindo Grade II (POR = 0.48; 95 % CI 0.14-1.60; P = 0.23) or Grade III (POR = 0.63; 95 % CI 0.24-1.65; P = 0.34) complications between TCV and CLC. Time of return to normal activities was significantly reduced in the TVC group (WMD = -4.86 days; 95 % CI -9.33 to -0.39; P = 0.03), and there was a non-significant reduction in postoperative pain on days 1 (WMD = -0.80; 95 % CI -1.60 to 0.01; P = 0.05) and 3 (WMD = -0.89; 95 % CI -1.77 to -0.01; P = 0.05).

CONCLUSIONS

TVC is safe when performed by appropriately trained surgeons and may be associated with a faster return to normal activities and decreased postoperative pain.

Characterization of force and torque interactions during a simulated transgastric appendectomy procedure

We have developed an instrumented endoscope grip handle equipped with a six-axis load cell and measured forces and torques during a simulated transgastric natural orifice translumenal endoscopic surgery appendectomy procedure performed in an EASIE-R ex vivo simulator. The data were collected from ten participating surgeons of varying degrees of expertise which was analyzed to compute a set of six force and torque parameters for each coordinate axis for each of the nine tasks of the appendectomy procedure. The mean push/pull force was found to be 3.64 N (σ = 3.54 N) in the push direction and the mean torque was 3.3 N · mm (σ = 38.6 N · mm) in the counterclockwise direction about the push/pull axis. Most interestingly, the force and torque data about the nondominant x and z axes showed a statistically significant difference (p < 0.05) between the expert and novice groups for five of the nine tasks. These data may be useful in developing surgical platforms especially new haptic devices and simulation systems for emerging natural orifice procedures.

Transvaginal cholecystectomy learning curve

BACKGROUND

There are few surgeons in the United States, within private practice and academic centers, currently performing transvaginal cholecystectomies (TVC). The lack of exposure to TVC during residency or fellowship training, coupled with a poorly defined learning curve, further limits interested surgeons who want to apply this technique to their practice. This study describes the learning curve encountered during the introduction of TVC to our academic facility.

METHODS

This study is an analysis of consecutive TVCs performed between August 14, 2009 and August 3, 2012 at an academic center. The TVC patients were divided into sequential quartiles (n = 15/16). The learning curve outcome was measured as the operative time of TVC patients and compared to the operative time of female laparoscopic cholecystectomy (LC) patients performed during the same time period.

RESULTS

Sixty-one patients underwent a TVC with a mean age of 38 ± 12 years and mean BMI was 29 ± 6 kg/m(2). Sixty-seven female patients who underwent a LC with average age 41 ± 15 years and average BMI 33 ± 12 kg/m(2). The average operative time of LC patients and TVC patients was 48 ± 20 and 60 ± 17 min, respectively. Significant improvement in TVC operative times was seen between the first (n = 15 TVCs) and second quartiles (p = 0.04) and stayed relatively constant for third quartile, during which there was no statistically significant difference between the mean LC operative time for the second and third TVC quartiles

CONCLUSIONS

The learning curve of a fellowship-trained surgeon introducing TVC to their surgical repertoire, as measured by improved operative times, can be achieved with approximately 15 cases.

Natural Orifice Transluminal Endoscopic Surgery (NOTES) for colon resections--analysis of the first 139 patients of the German NOTES Registry (GNR)

BACKGROUND

The German NOTES registry (GNR) is the largest published database for natural orifice transluminal endoscopic surgery (NOTES) worldwide. Although transvaginal cholecystectomy is the most frequent procedure in the GNR, the number of colorectal resections is increasing. The objective of this study was to analyze the first 139 colonic procedures of the GNR.

METHODS

All colonic procedures from the GNR were analyzed regarding patient- and therapy-related parameters. A multivariate analysis was conducted for transvaginal sigmoid resections regarding procedural time, hospital stay, conversion rate, and rate of complications.

RESULTS

From October 2008 to January 2013, 139 colon NOTES procedures (12 male, 127 female) were registered. Main diagnoses were sigmoid diverticulitis (85.6 %), colon carcinoma (9.4 %), and ulcerative colitis (3.6 %). Sigmoid resections (87.1 %), proctocolectomies (3.6 %), right-sided resections (2.9 %), left-sided resections (3.6 %), segmental resections (2.2 %), and 1 ileocecal resection (0.7 %) were performed. All procedures were conducted in transvaginal (87.8 %) or transrectal (12.2 %) hybrid technique, with a median of 3 percutaneous trocars. Conversions to laparoscopic technique were necessary in 3.6 % (none to conventional technique). Intraoperative complications were recorded in 2.9 % and postoperative complications in 12.2 %. The institutional case number in transvaginal sigmoid resections correlated negatively with procedural time (p = 0.041) and the number of percutaneous trocars (p = 0.002).

CONCLUSION

The analysis of the first 139 colon NOTES operations of the GNR shows the feasibility of co on operations in hybrid technique, especially for transvaginal sigmoid resection as the most frequent procedure.

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.

Natural orifice transluminal endoscopic surgery for intra-abdominal emergency conditions

BACKGROUND

Patient benefits from natural orifice transluminal endoscopic surgery (NOTES) are of interest in acute-care surgery. This review provides an overview of the historical development of NOTES procedures, and addresses their current uses and limitations for intra-abdominal emergency conditions.

METHODS

A PubMed search was carried out for articles describing NOTES approaches for appendicectomy, percutaneous gastrostomy, hollow viscus perforation and pancreatic necrosectomy. Pertinent articles were reviewed and data on available outcomes synthesized.

RESULTS

Emergency conditions in surgery tax the patient's cardiovascular and respiratory systems, and fluid and electrolyte balance. The operative intervention itself leads to an inflammatory response and blood loss, thus adding to the physiological stress. NOTES provides a minimally invasive alternative access to the peritoneal cavity, avoiding abdominal wall incisions. A clear advantage to the patient is evident with the implementation of an endoscopic approach to deal with inadvertently displaced percutaneous endoscopic gastrostomy tubes and perforated gastroduodenal ulcer. The NOTES approach appears less invasive for patients with infected pancreatic necrosis, in whom it allows surgical debridement and avoidance of open necrosectomy. Transvaginal appendicectomy is the second most frequently performed NOTES procedure after cholecystectomy. The NOTES concept has provided a change in perspective for intramural and transmural endoscopic approaches to iatrogenic perforations during endoscopy.

CONCLUSION

NOTES approaches have been implemented in clinical practice over the past decade. Selected techniques offer reduced invasiveness for patients with intra-abdominal emergencies, and may improve outcomes. Steady future development and adoption of NOTES are likely to follow as technology improves and surgeons become comfortable with the approaches.

Transvaginal organ extraction: potential for broad clinical application

BACKGROUND

Natural orifice transluminal endoscopic surgery procedures have evolved over the past few years. A transvaginal approach is a promising alternative for intraperitoneal procedures. Our objective was to evaluate the safety and feasibility of transvaginal organ extraction.

METHODS

This institutional review board-approved protocol involved retrospective review of an ongoing prospective study. Female subjects who presented to our hospital for elective cholecystectomy, appendectomy, or sleeve gastrectomy were offered participation in the study. Eligible patients met the following criteria: age between 18 and 75, diagnosis of gallbladder disease, acute appendicitis, or morbid obesity who desired surgical treatment. A hybrid transvaginal natural orifice approach was used in this series.

RESULTS

Thirty-four women underwent transvaginal organ extraction between September 2007 and January 2012. The mean age was 40 ± 12.1 years (range 23-63 years). The mean body mass index was 27 ± 6.4 kg/m(2) (range 16-43 kg/m(2)). All patients had an American Society of Anesthesiologists classification of two or below. The mean operative time for cholecystectomy, appendectomy, and sleeve gastrectomy was 90, 71, and 135 min, respectively. There were no conversions to open operation and no intraoperative complications. The mean hospital stay was 2 days for all cases. Patients were followed for a mean of 24 months (range 1-61 months). There were two pregnancies and two successful vaginal deliveries. Six patients (18 %) had minor complaints of spotting or heavy menses in the immediate postoperative period that resolved with conservative measures. There were no abdominal wall complications. There were no long-term complications and no mortalities.

CONCLUSIONS

This initial experience suggests that this surgical approach is safe, does not increase length of stay, and has no long-term vaginal complications. Given this attractive profile, a transvaginal approach may prove to be a superior mode of organ extraction, although randomized studies and long-term follow-up are needed.

Innovations in minimally invasive surgery: lessons learned from translational animal models

PURPOSE

Animal models are key elements of surgical research and promotion of new techniques. Inanimate models, anatomical specimens, and living animals are all necessary to solve the various problems encountered by the advent of a new surgical technique. The development of Natural Orifice Transluminal Endoscopic Surgery (NOTES) procedures is a representative model.

METHODS

Over 400 experimental procedures were performed in inanimate models, ex vivo tissues and animals to solve all problems faced by the development of NOTES surgery: peritoneal access, gastrotomy closure, exposure, retraction, dissection as well as education to start this new procedure.

RESULTS

The successive use of all models allows to identify the ideal solution for each problem and to precisely define the safest and most reliable option to apply the new technique in patients. It allowed to perform the first transvaginal and transgastric cholecystectomy in patients in a safe way.

CONCLUSION

Animal experimentation remains necessary as even sophisticated computer-based solutions are unable to model all interactions between molecules, cells, tissues, organisms, and their environment. Animal research is required in many areas to validate new technologies, develop training, let alone its major goal (namely to avoid using patients for experimentation) which is to be the first "model" for the surgeon.