Experimental foundation for natural orifice transluminal endoscopic surgery and hybrid natural orifice transluminal endoscopic surgery

Transcolonic Perirectal NOTES Access (PNA): A feasibility study with survival in swine model

Transrectal access still has some unsolved issues such as spatial orientation, infection, access and site closure. This study presents a simple technique to perform transcolonic access with survival in a swine model series. A new technique for NOTES perirectal access to perform retroperitoneoscopy, peritoneoscopy, liver and lymphnode biopsies was performed in 6 pigs, using Totally NOTES technique. The specimens were extracted transanally. The flexible endoscope was inserted through a posterior transmural incision and the retrorectal space. Cultures of bacteria were documented for the retroperitoneal space and intra abdominal cavity after 14 days. Rectal site was closed using non-absorbable sutures. There was no bowel cleansing, nor preoperative fasting. The procedures were performed in 6 pigs through transcolonic natural orifice access using available endoscopic flexible instruments. All animals survived 14 days without complications, and cultures were negative. Histopathologic examination of the rectal closure site showed adequate healing of suture line and no micro abscesses. The results of feasibility and safety of experimental Transcolonic NOTES potentially brings new frontiers and future wider applications for minimally invasive surgery. The treatment of colorectal, abdominal and retroperitoneal diseases through a flexible Perirectal NOTES Access (PNA) is a promising new approach.

Natural orifice transluminal endoscopic surgery (NOTES): where are we going? A bibliometric assessment

The aim of this study was to analyse natural orifice transluminal endoscopic surgery (NOTES)-related publications over the last 5 years. A systematic literature search was done to retrieve publications related to NOTES from 2006 to 2011. The following variables were recorded: year of publication; article type; study design; setting; Journal Citation Reports® journal category; authors area of surgical speciality; geographic area of origin; surgical procedure; NOTES technique; NOTES access route; number of clinical cases. A time-trend analysis was performed by comparing early (2006-2008) and late (2009-2011) study periods. Overall, 644 publications were included in the analysis and most papers were found in general surgery journals (50.9%). Studies were most frequently clinical series (43.9%) and animal experimental (48%), with the articles focusing primarily on cholecystectomy, access creation and closure, and peritoneoscopy. Pure NOTES techniques were performed in most of the published reports (85%) with the remaining cases being hybrid NOTES (7.4%) and NOTES-assisted procedures (6.1%). The access routes included transgastric (52.5%), transcolonic (12.3%), transvesical (12.5%), transvaginal (10.5%), and combined (12.3%). From the early to the late period, there was a significant increase in the number of randomised controlled trials (5.6% vs 7.2%) or non-randomised but comparative studies (5.6% vs 22.9%) (P < 0.001) and there was also a significant increase in the number of colorectal procedures and nephrectomies (P = 0.002). Pure NOTES remained the most studied approach over the years but with increased investigation in the field of NOTES-assisted techniques (P = 0.001). There was also a significant increase in the adoption of transvesical access (7% vs 15.6%) (P = 0.007). NOTES is in a developmental stage and much work is still needed to refine techniques, verify safety and document efficacy. Since the first description of the concept of NOTES, >2000 clinical cases, irrespective of specialty, have been reported. NOTES remains a field of intense clinical and experimental research in various surgical specialities.

Recent advances of natural orifice transluminal endoscopic surgery in urological surgery

Natural orifice transluminal endoscopic surgery designates a surgical procedure that utilizes one or more patent natural orifices of the body with the intention to puncture a hollow viscera in order to enter the abdominal cavity. First carried out at the beginning of the 2000s in experimental models, it can be considered the natural evolution of laparoscopy towards the ideal of scarless surgery, as the avoidance of a large abdominal scar is associated with better cosmetic results and better recovery. However, the technology currently available does not allow the performance of complete pure natural orifice transluminal endoscopic surgery procedures. The surgical tools used are not specially designed for this approach, so difficulties in retracting organs, bleeding control and clashing of instruments are the main obstacle surgeons face. For this reason, the current available technique is the so-called hybrid approach, where a natural orifice approach is combined with some abdominal trocars, using the natural orifice as the exit door for the specimen removal. As not many comparative studies have been published evaluating the advantages of natural orifice transluminal endoscopic surgery in front of traditional laparoscopic surgery, a review of the history of natural orifice transluminal endoscopic surgery, and an assessment of the available evidence of this technique regarding renal and urological pelvic surgery are performed in this article.

A novel transvesical port for natural orifice translumenal endoscopic surgery

PURPOSE

To evaluate the feasibility of a novel transvesical port (TVEP) for natural orifice translumenal endoscopic surgery (NOTES) in the porcine model.

MATERIALS AND METHODS

The TVEP consisted of an internal guide core and external sheath design using computer-aided design software. Transvesical peritoneoscopy, renal biopsy, as well as combined transvesical/transgastric nephrectomy were performed through the TVEP in a porcine model. Operative parameters and port performance were measured.

RESULTS

Twelve procedures were successfully performed by four surgeons. No complications occurred with introduction of the TVEP. The mean time for placement was 5.6 minutes. Steady pressure controlled CO(2) pneumoperitoneum up to 15 mm Hg with a flow of 2 L/min was achievable. The average scoring by physician of the TVEP was 4.75 for ease of placement, 5 for ability to maintain pneumoperitoneum, 4.25 for convenience of inserting instruments, and 4.5 for overall satisfaction. The average score regarding instruments exchangeability, however, was relatively low: 3.25.

CONCLUSIONS

Real surgery using a novel TVEP is feasible in performing transvesical NOTES.

Transvesical natural orifice transluminal endoscopic surgery (NOTES) nephrectomy with kidney morcellation: a proof of concept study

Study Type - Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Until now, the transvaginal approach has been the only method of removing larger specimens from the abdominal cavity using natural orifice transluminal endoscopic surgery. There has been no means of extracting larger specimens in men and the means are restricted even in women, particularly in young women. The present study shows that the difficulty of large specimen retrieval can be overcome, irrespective of the diameter of the chosen port, through natural orifices using morcellation.

OBJECTIVE

To show, in a porcine model, the feasibility of a complete transvesical natural orifice transluminal endoscopic surgery (NOTES) nephrectomy with kidney extraction after morcellation through the same port.

MATERIALS AND METHODS

Transvesical nephrectomy and morcellation were performed in six pigs at Minho University, Braga, Portugal after institutional review board approval. The transvesical port and the cystotomy were created under the guidance of a ureteroscope, while the remaining steps were done under the guidance of an operating telescope. Dissection of the renal vessels and kidney was performed using dissection grasping forceps and a vessel sealing system (LigaSure(™) ; Covidien, Mansfield, MA, USA) and morcellation was done using a Piranha(™) morcellator (Richard Wolf, Knittlingen, Germany).

RESULTS

There were no complications related to the creation of transvesical access. The image provided by the telescope was superior to that of the ureteroscope, especially underwater. Morcellation was quick and effective, with the support of a fixing needle through the abdominal wall, designed to fix the kidney, after laceration of a bowel loop occurred in the first experiment.  It was found that technical improvements are needed to ensure safety of NOTES morcellation.

CONCLUSIONS

Kidney morcellation after nephrectomy, using a natural orifice exclusively, is feasible.  Despite technical limitations, this proof of concept study can be regarded as a potential step towards the application of NOTES in urology.