Natural orifice transluminal endoscopic surgery (NOTES): where are we going? A bibliometric assessment
Authors: Autorino Riccardo , Yakoubi Rachid , White Wesley M. , Gettman Matthew , De Sio Marco , Quattrone Carmelo , Di Palma Carmine , Izzo Alessandro , Correia‐Pinto Jeorge , Kaouk Jihad H. , Lima Estevão 
Published: December 2012

What's known on the subject? and What does the study add?
The safe and successful development of NOTES has the potential to create a paradigm shift in minimally invasive surgery. However, anecdotal diagnostic and therapeutic NOTES procedures, many of which were strictly performed in an investigative fashion, have taught us that continued, focused translational research is imperative to address myriad, and as yet unaddressed, technical issue.
This study analyses the NOTES‐related research in the medical literature over the last 5 years in an attempt to identify trends and/or progress towards its meaningful use. It shows that NOTES is still 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 specialties.
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.