Evaluation for transvaginal and transgastric NOTES cholecystectomy in human and animal natural orifice translumenal endoscopic surgery

Background/purpose  Natural orifice translumenal endoscopic surgery (NOTES) is a novel concept using an endoscope via a translumenal access for abdominal surgery. This study was designed to evaluate the feasibility and technical aspects of NOTES cholecystectomy from our experience on humans and animals. Methods  NOTES cholecystectomies were performed in 12 animal experiments, including 8 pigs (6 by transgastric and 2 by transvaginal accesses) and 4 dogs (4 transvaginal accesses), and a human female cadaver. Results  The entire gallbladder could be removed under direct vision in all experiments. The average time was 60 min by transgastric and 40 min by transvaginal in animals. It was 87 min for human transvaginal cholecystectomy. In all animal and human procedures, there was no major complication concerning the operation. Discussion  The transvaginal route may be the easiest route for abdominal NOTES. Percutaneous endoscopic gastrostomy (PEG) allowed the safe performance of a controlled gastric perforation and shortened the time. The hybrid method allowed performance of a safe procedure and shortened the time. Conclusions  Transvaginal and transgastric NOTES cholecystectomy is technically feasible and safe in both humans and animals. New instrumentation needs to be developed to perform a pure NOTES cholecystectomy without transabdominal assistance.     

Natural Orifice Translumenal Endoscopic Surgery: A Critical Review

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

Current experience and future directions of completely NOTES colorectal resection

Clinical implementation and widespread application of natural orifice translumenal surgery (NOTES) has been limited by the lack of specialized endoscopic equipment, which has prevented the ability to perform complex procedures including colorectal resections. Relative to other types of translumenal access, transanal NOTES using transanal endoscopic microsurgery (TEM) provides a stable platform for endolumenal and direct translumenal access to the peritoneal cavity, and specifically to the colon and rectum. Completely NOTES transanal rectosigmoid resection using TEM, with or without transgastric endoscopic assistance, was demonstrated to be feasible and safe in a swine survival model. The same technique was successfully replicated in human cadavers using commercially available TEM, with endoscopic and laparoscopic instrumentation. This approach also permitted complete rectal mobilization with total mesorectal excision to be performed completely transanally. As in the swine model, transgastric and/or transanal endoscopic assistance extended the length of proximal colon mobilized and overcame some of the difficulties with TEM dissection including limited endoscopic visualization and maladapted instrumentation. This extensive laboratory experience with NOTES transanal rectosigmoid resection served as the basis for the first human NOTES transanal rectal cancer excision using TEM and laparoscopic assistance. Based on this early clinical experience, NOTES transanal approach using TEM holds significant promise as a safe and substantially less morbid alternative to conventional colorectal resection in the management of benign and malignant colorectal diseases. Careful patient selection and substantial improvement in NOTES instrumentation are critical to optimize this approach prior to widespread clinical application, and may ultimately permit completely NOTES transanal colorectal resection.     

Natural orifice translumenal endoscopic surgery (NOTES) renal cryoablation in a porcine model

OBJECTIVE

To present our laboratory experience with natural orifice translumenal endoscopic surgery (NOTES) renal cryoablation.

MATERIALS AND METHODS

In two female farm pigs, we performed four procedures of NOTES renal cryoablation. In each pig, NOTES was performed through a transgastric approach and a transvaginal approach for each kidney, respectively. The pig was placed in the flank position and pneumoperitoneum obtained using a transabdominal Veress needle. In the first pig, we started with the left kidney with a transgastric approach: a dual‐channel video gastroscope (Olympus, Tokyo, Japan) was used, the stomach wall was punctured using a needle‐knife, a guidewire was passed into the abdominal cavity and the access dilated using a controlled radial expansion balloon. The bowel was mobilized medially and the Gerota’s fascia overlying the upper pole was dissected. Under direct endoscopic vision, a cryoablation probe was introduced percutaneously into the anterior upper pole of the kidney. The pig was then flipped to the right flank position and a transvaginal approach was used: the gastroscope was introduced through the posterior fornix of the vagina. For the second pig, we performed initially a transgastric right‐side cryoablation then a transvaginal left‐side cryoablation as described for the first pig.

RESULTS

All four procedures were performed successfully, with no intraoperative complications. No additional laparoscopic ports or open conversions were necessary. The vision of the kidney and the ice‐ball was adequate for all cases. The mean operative duration was 83 min. Stomach closure was tested watertight, and there were no abdominal or pelvic injuries found at autopsy.

CONCLUSIONS

NOTES can provide adequate minimal surgical dissection for safe and effective percutaneous renal cryoablation under direct videoscopic monitoring at kidney locations otherwise not accessible percutaneously. Both transgastric and transvaginal approaches can be used effectively for renal cryoablation providing a minimally invasive scar‐less surgery.     

Natural orifice surgery applied for colorectal diseases

Clinical natural orifice surgery has been applied to abdominal surgery in recent years, mostly using transvaginal and transgastric access. Rectal and transcolonic natural orifice transluminal endoscopic surgery (NOTES) were tested in animal and cadaver models by a few research groups. Despite the potential advantages of transcolonic NOTES for colorectal diseases, it has not yet been clinically applied. The first successful series of human applications of transcolonic NOTES in the literature from the NOTES Research Group in Brazil provide new possibilities in the field in new transrectal procedures for rectal cancer and benign disease. Successful first human reports on Transcolonic NOTES potentially brings new frontiers and applications for minimally invasive surgery. The treatment of colorectal diseases through flexible Perirectal NOTES Access is a promising new approach alongside existing laparoscopic and open surgery to improve patient care.     

NOTES transvaginal cholecystectomy: preliminary clinical application

Background Natural orifice translumenal endoscopic surgery (NOTES) is an emerging concept in the recent literature that could lead to potential benefits in clinical applications. Restricted to animal experiments, however, human procedures have not yet been published. Because of the technical and ethical challenges involved in perforation and closure of a healthy organ—as is also seen in operating via the transgastric route—and because of the lack of understanding of the physiopathology and infection risk with these approaches, they have not been applied in the clinical setting. Thus the present study, based on previous animal experiments, describes preliminary clinical application in four cases of transvaginal NOTES cholecystectomy, and discusses safety, feasibility, and potential benefits of the method. Methods Preliminary acute and survival animal experiments developed by the NOTES Research Group at our institution solved such technical problems for transvaginal NOTES as spatial orientation, insufflation, and instrumentation, making possible the introduction of NOTES as a clinical application. The trials were approved by ethics committee of our institution, and informed consent was obtained from all patients. Since 13 March 2007, four female patients with elective surgical indication for cholecystectomy have undergone transvaginal NOTES cholecystectomy. All intraoperative and postoperative parameters were documented. Vaginal access was achieved under direct vision with conventional instruments, and a 2-channel colonoscope was inserted into the abdominal cavity. After endoscopic insufflation to achieve pneumoperitoneum with CO₂, instruments were inserted through and alongside a colonoscope, allowing successful NOTES cholecystectomy in all patients, with vaginal extraction of the gallbladder. The vaginal wound was closed by direct vision using conventional instruments. Results The procedure was successful in all patients, with operative time of 45–115 min. Patients experienced low need for postoperative analgesia. Free oral intake was permitted 2 h after the procedure. There were no postoperative complications, and patients were discharged, according to the study protocol, 48 h after the procedure. Conclusions Preliminary results showed the feasibility and safety of the transvaginal NOTES method in this small initial study population. The technique, developed in our institution, and not transgastric NOTES, may be the preferred approach to serve as the basis for clinical studies.     

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

PURPOSE: Natural Orifice Transluminal Endoscopic Surgery (NOTES) is an emerging technology that uses endoscopic instruments passed into the peritoneal cavity through hollow viscera to perform surgical procedures without the use of abdominal incisions. There are, however, limitations regarding the equipment available to simulate traditional surgery. The aim of this study was to determine the feasibility of a pure NOTES nephrectomy by using standard laparoscopic instruments through a modified transvaginal trocar. MATERIALS AND METHODS: One 40-kg female swine underwent transgastric peritoneoscopy. Transgastric endoscopic visualization guided the introduction of a second transvaginal endoscope through a novel laparoscopic trocar/endoscopic overtube device. The retroflexed transgastric endoscope provided triangulated visualization as standard endoscopic instruments provided retraction, which allowed dissection of the kidney with standard laparoscopic instruments through our modified transvaginal trocar device. Each renal hilum, artery, vein, and ureter was dissected and divided with a transvaginal laparoscopic stapler. RESULTS: Transgastric and transvaginal NOTES accesses were easily achieved, and bilateral nephrectomies were performed. Completion of peritoneoscopy revealed complete hemostasis and identification of ligated ureters and hilar vessels. Total operative time was 40 and 20 minutes for the right and left kidney, respectively. One kidney was captured with a laparoscopic retrieval sac and removed intact through the vaginal defect. CONCLUSIONS: Pure NOTES nephrectomies are technically feasible in the porcine model by using standard laparoscopic instruments. Survival studies are necessary to determine the long-term complications and physiologic implications of NOTES nephrectomy. The development of innovative NOTES access trocars may allow for an increased armamentarium of NOTES instruments.     

Natural-orifice transgastric endoscopic peritoneoscopy in humans: Initial clinical trial

Background Natural-orifice translumenal endoscopic surgery (NOTES) is a possible advancement for surgical interventions. We initiated a pilot study in humans to investigate feasibility and develop the techniques and technology necessary for NOTES. Reported herein is the first human clinical trial of NOTES, performing transoral transgastric diagnostic peritoneoscopy. Methods Patients were scheduled to undergo diagnostic laparoscopic evaluation of a pancreatic mass. The findings of traditional laparoscopy were recorded by anatomical abdominal quadrant. A second surgeon, blinded to the laparoscopic findings, performed transgastric peritoneoscopy. Diagnostic findings between the two methods were compared and operative times and clinical course were recorded. Definitive care was based on findings at diagnostic laparoscopy. Results Ten patients completed the protocol with an average age of 67.6 years. All patients underwent diagnostic laparoscopy followed by successful transgastric access and diagnostic endoscopic peritoneoscopy. The average time of diagnostic laparoscopy was 12.3 minutes compared to 24.8 minutes for the transgastric route. Transgastric abdominal exploration corroborated the decision to proceed to open exploration made during traditional laparoscopic exploration in 9 of 10 patients. Peritoneal or liver biopsies were obtained in four patients by traditional laparoscopy and in one patient by the transgastric access route. Findings were confirmed by laparotomy in nine patients. Eight patients underwent pancreaticoduodenectomy and two underwent palliative gastrojejunostomy and/or hepaticojejunostomy. Conclusions Transgastric diagnostic peritoneoscopy is safe and feasible. This study demonstrates the initial steps of NOTES in humans, providing a potential platform for incisionless surgery. Technical issues, including instrumentation, visualization, intra-abdominal manipulation, and gastric closure need further development.     

经自然腔道内镜手术实验研究

目的探讨NOTES完成动物腹部多种手术成功与失败的原因,为其应用于临床提供实验依据。方法回顾分析2007年8月～2009年9月完成的全部动物实验数据。研究分为急性实验和存活实验2部分,采用雌性小型猪和成年杂种犬,分别开展了单纯NOTES和腹腔镜辅助的NOTES。进行诊断性腹腔探查和肝脏活检术,治疗性胆囊切除、输卵管结扎切除、卵巢切除、脾切除和胃空肠吻合等腹部手术。记录术中和术后并发症的发生情况,以及操作过程中遇到的技术难题。结果采用37只小型猪和16只杂种犬,完成急性实验22例,存活实验31例。共开展各种NOTES手术91例次,其中单一经胃路径25例次,单一经结肠路径8例次,经胃和结肠联合路径16例次,经胃和阴道联合路径6例次,传统腹腔镜辅助经胃路径26例次,单孔腹腔镜辅助经胃路径10例次。完成诊断性腹腔探查术33例,成功率100%（33/33）,肝脏活检术11例,成功率100%（11/11）,输卵管结扎切除术11例,成功率100%（11/11）,卵巢切除术6例,成功率100%（6/6）,胆囊切除术27例,成功率44.4%（12/27）。另行脾切除术1例和胃空肠吻合术2例,均未成功。总的并发症发生率为39.6%（21/53）,其中穿孔8例,脏器损伤5例,出血4例,腹腔感染3例,腹压过高导致动物死亡1例。结论NOTES用于诊断性腹腔探查和简单治疗是安全有效的,但完成腹部较复杂的手术尚不可行。腹腔镜辅助NOTES的方法或许是此项技术从动物实验过渡到临床应用的桥梁。     

Scarless cholecystectomy with combined transvaginal and transumbilical approach in a series of 20 patients

Background  

Laparoscopic surgery has dramatically improved surgical care of patients reducing postoperative pain, wound infection rate, hospital stay, inability to work, risk of hernia, and cosmetic result. Natural orifice transluminal endoscopic surgery (NOTES) is even less traumatic to the abdominal wall and might further improve minimal invasive surgery of patients, but might also increase surgical risk when used by a transgastric or transcolonic approach with flexible endoscopes. Therefore we decided to use a transvaginal approach using rigid laparoscopic instruments for cholecystectomies.     

Natural Orifice Transluminal Endoscopic Gastric Bypass Performed in a Cadaver

Natural orifice transluminal surgery (NOTES) offers a new option for abdominal surgery. However, despite the initial interest and enthusiasm for its potential advantages, NOTES has some major drawbacks which include the purposeful injury to an organ that may not be otherwise injured or diseased. Roux-en-Y gastric bypass may be a procedure that is suited for NOTES because the stomach wall is breached during the normal course of the operation. We have experimented with a technique for a NOTES gastric bypass in the human. A transvaginal, transgastric gastric bypass (TVTG-GBP) was performed in a human cadaver.     

Primera nefrectomía transvaginal híbrida por cáncer renal

NOTES (Natural Orifice Transluminal Endoscopic Surgery) is a surgical modality that uses empty organs as an access to the peritoneal cavity, avoiding skin incisions. If we combine this surgery with the classical laparoscopic approach, a new hybrid technique is obtained. This approach will permit us to work on wide operating fields with large organs, as the kidney, minimizing skin incisions. We present the first hybrid transvaginal radical nephrectomy due to renal cancer. In order to perform this procedure, we used a vaginal access for introduction of a deflectable camera and the assistance of two additional abdominal trocars. The vaginal incision for the trocar was enlarged for organ removal. Hybrid transvaginally NOTES assisted radical nephrectomy is a reproducible and feasible technique that has to be kept in mind for women who are candidates to nephrectomy for renal cancer.     

Transvaginal specimen removal in minimally invasive surgery

The demand for urological surgical treatment associated with better cosmesis, lower morbidity rates and shorter hospitalization constantly grows. The transvaginal route has been proposed in an attempt to avoid long abdominal incisions for the removal of the large laparoscopic specimens. Moreover, the transvaginal NOTES approach represents a promising evolution of laparoscopic surgery to a more “minimally invasive” alternative. The current review summarizes the available experience in the literature in transvaginal conventional laparoscopy and NOTES in urology, gynecology and general surgery. The clinical outcome is presented. The most important issues associated with the transvaginal approach are the complications and the postoperative sexual function. These issues are presented.     

Natural orifice translumenal endoscopic surgery: critical appraisal of applications in clinical practice

Background  Natural orifice translumenal endoscopic surgery (NOTES), with its focus on eliminating incision-related complications, promises to revolutionize the way surgery is performed. This study aimed to summarize the clinical applications of NOTES for humans, outline the techniques used, and discuss the complications and limitations of current techniques. Methods  A literature search was performed using PubMed and Medline search tools to review the extent and outcomes of human procedures undertaken using the NOTES technique in its pure form or as a hybrid procedure reported until July 2008. The end points were the types of operation performed, the approach and technique used for each operation, and the procedure-related complications and technical limitations. Results  This review considered 16 publications reporting on 49 human subjects. All the studies except three used hybrid NOTES procedures, with varying amounts of transabdominal assistance. Three transvaginal cholecystectomies, one transvaginal appendectomy, and eight transgastric appendectomies have been performed using a pure NOTES technique. To date, 15 NOTES transvaginal cholecystectomies and 10 NOTES appendectomies (8 transgastric and 2 transvaginal) are reported. Other procedures including peritoneoscopy and sigmoid colectomy are described. Three cases of minor morbidity are reported and no mortality. Conclusions  Although initial human results seem encouraging, it is important that this research be conducted in a way that minimizes bad publicity and describes both favorable and adverse outcomes. Robust trials must be conducted at established centers with appropriate experience and institutional board ethical review to allow safe introduction of this novel technique, with adequate and expedient reporting of serious adverse events. The limitations of the current tools and methods are discussed, and suggestions are made for further improvements in the technology to facilitate NOTES operations.     

NOTES Rectosigmoid Resection Using Transanal Endoscopic Microsurgery (TEM) with Transgastric Endoscopic Assistance: A Pilot Study in Swine

Introduction  Transanal endoscopic microsurgery (TEM) provides direct endoscopic access to the rectum and peritoneal cavity. The feasibility of natural orifice translumenal endoscopic surgery (NOTES) rectosigmoid resection using TEM was evaluated in swine. Transgastric endoscopic assistance to extend transanal colon mobilization was also investigated. Full-thickness circumferential rectal dissection was performed and extended proximally. After maximal sigmoid mobilization, the specimen was exteriorized and transected, and the proximal colon was stapled to the distal rectum. In a subset of animals, transgastric endoscopic access was used to mobilize the colon further. Results  Rectosigmoid resection using TEM was performed in two non-survival and seven swine cadavers (n = 9). The mean procedure time was 3 h (2.5–4 h), and mean length of resected colon was 16.7 cm (10–25 cm). Transgastric endoscopic assistance was used in three cadavers and two non-survival swine (n = 5) with a mean operative time of 3.5 h (3.5–3.75 h). The mean length of colon mobilized with transgastric and transanal endoscopic access was 24.4 cm (20–27 cm) vs. 16.7 cm which mobilized the transanal approach alone (p = 0.016). A posterior anastomotic defect was noted in two animals. Conclusion  Transanal rectosigmoid resection with TEM is feasible in swine. Combined transgastric and TEM access is a promising new technique for NOTES colorectal resection. Meeting presentations This study was accepted for presentation at the SSAT Plenary Session May 20, 2008 at Digestive Disease Week in San Diego, CA.     

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.     

NOTES: cadaveric rendezvous hybrid small bowel resection

Background  Natural orifice translumenal endoscopic surgery (NOTES) is an emerging field in minimally invasive surgery that is driving the development of new technology and techniques [1–4]. Before NOTES gains widespread popularity, it must be proven to be a safe and efficacious technique [5]. There are several proposed benefits to the NOTES approach, including potentially decreased abdominal pain, wound infections, and hernia formation. Methods  Currently, most investigational NOTES procedures are performed using a single transgastric, transcolonic, or transvaginal access point to the abdomen. In order to provide greater range of motion and freedom of movement, a rendezvous procedure using simultaneous transgastric and transcolonic approaches was used to perform a small bowel resection. This video demonstrates a successful NOTES hybrid small bowel resection with the use of two laparoscopic ports in a cadaveric model. A powered stapling device attached to a flexible shaft is introduced transcolonically and facilitates division and re-anastamosis of the small bowel. A dual-channel operating endoscope introduced transgastrically allows for precise dissection and creation of enterotomies necessary for the small bowel resection. Conclusions  While technically challenging, NOTES hybrid small bowel resection can be accomplished with specially designed instrumentation utilizing the rendezvous technique. There are several technical limitations preventing this procedure from being completed in a pure NOTES fashion. A safe method of creating blind enterotomies will be needed to eliminate laparoscopic visualization of the enterotomy sites. Adequate endoscopic exposure and retraction of tissue is still difficult and currently requires percutaneous adjuncts. New closure devices will be needed for safe and reliable NOTES enterotomy closure. With the development of such instruments, this, as well as other NOTES procedures, will become more technically feasible. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Transvaginal endoscopic appendectomy in humans: a unique approach to NOTES—world’s first report

Background Natural orifice translumenal endoscopic surgery (NOTES) is the newest technique emerging in the field of surgery. There are several techniques described in the literature; however there is no standardization yet. We describe the transvaginal approach for endoscopic appendectomy in humans, probably the world’s first report. Materials and methods Pneumoperitoneum was achieved via a Veress needle in the umbilicus. Routine 12-mm endoscope and routine instruments were used. Peritoneal access was gained via a transvaginal approach through the posterior fornix. Results Out of a total of six patients, a totally endoscopic transvaginal appendectomy was successfully performed for one patient. The other five patients were either converted to conventional laparoscopy or aided by a laparoscope. The average age of the patients was 29.5 years. The mean operating time was 103.5 min. Hospital stay was 1–2 days. The follow-ups were scheduled at 7 days, 30 days, 90 days, and 6 months. The vaginal wound was examined by the gynecologist and found to have completely healed during the first and second follow–up. Discussion So far in humans, transgastric appendectomy and cholecystectomy, and transvaginal cholecystectomy have been reported. A transvaginal endoscopic appendectomy in humans has not been reported yet. The transvaginal approach provided a normal image of the target organ, unlike the inverted image of a transgastric approach caused by the inability to manipulate the scope outside the mouth. The technical ease of the procedure and early outcome seem satisfactory, although comparative studies are needed to confirm this.     

Natural orifice surgery: initial clinical experience

Background  Natural orifice translumenal endoscopic surgery (NOTES) has moved quickly from preclinical investigation to clinical implementation. However, several major technical problems limit clinical NOTES including safe access, retraction and dissection of the gallbladder, and clipping of key structures. This study aimed to identify challenges and develop solutions for NOTES during the initial clinical experience. Methods  Under an Institutional Review Board (IRB)-approved protocol, patients consented to a natural orifice operation for removal of either the gallbladder or the appendix via either the vagina or the stomach using a single umbilical trocar for safety and assistance. Results  Nine transvaginal cholecystectomies, one transgastric appendectomy, and one transvaginal appendectomy have been completed to date. All but one patient were discharged on postoperative day 1 as per protocol. No complications occurred. Conclusion  The limited initial evidence from this study demonstrates that NOTES is feasible and safe. The addition of an umbilical trocar is a bridge allowing safe performance of NOTES procedures until better instruments become available. The addition of a flexible long grasper through the vagina and a flexible operating platform through the stomach has enabled the performance of NOTES in a safe and easily reproducible manner. The use of a uterine manipulator has facilitated visualization of the cul de sac in women with a uterus to allow for safe transvaginal access.     

Adrenalectomy using natural orifice translumenal endoscopic surgery (NOTES): A transvaginal retroperitoneal approach

Background  Endoscopic adrenalectomy currently is performed using either a retroperitoneal or transperitoneal approach. The retroperitoneal approach is ideal for patients with small lesions who have undergone previous intraabdominal surgery. This study aimed to explore transvaginal retroperitoneal right and left adrenalectomies in porcine and cadaver models. Methods  Right and left adrenalectomies were performed for two female pigs. With the pig supine under general anaesthesia, the retroperitoneal space was entered with a double-channel endoscope (Storz) through a posterior colpotomy. A retroperitoneal tunnel was fashioned using blunt dissection with the assistance of low carbon dioxide insufflation up to the inferior pole of the kidney. Dissection of the upper renal pole allowed access to the adrenal gland. Using blunt dissection, a plane was created between the aorta on the left and the adrenal gland and inferior vena cava on the right. The left main middle vascular pedicle was identified and taken between clips, whereas an endoloop was used on the right side. The specimen was retrieved intact with a polypectomy snare. The same access then was reproduced with two female cadavers. Results  Transvaginal retroperitoneal adrenalectomies were successfully accomplished with a transvaginal approach using natural orifice translumenal endoscopic surgery (NOTES). The operative time was 70 min, and there was no injury to the retroperitoneal structures. The access was effectively reproduced in the cadaver model, with prompt identification of the retroperitoneal anatomic landmarks. Conclusion  Transvaginal retroperitoneal NOTES adrenalectomy is feasible in the porcine model. It reaches the adrenal proper anatomic plane with no need for dissection or retraction of the surrounding organs. This technique might be especially valuable for patients with multiple previous abdominal operations and obese patients in that allows direct access to the adrenal gland and minimizes the cardiovascular and pulmonary risk related to carbon dioxide pneumoperitoneum. Although the operation was successfully validated with cadavers, further experiments and better tools are needed before NOTES transvaginal retroperitoneal access is considered for humans. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.