Use of flexible endoscopes for NOTES: sterilization or high-level disinfection? Surg Endosc. 2010;24:1581-1588. [PMID: 20033708 DOI: 10.1007/s00464-009-0815-6]

BEST-PRACTICE GUIDELINES FOR FIELD-BASED SURGERY AND ANESTHESIA ON FREE-RANGING WILDLIFE. II. SURGERY

The principles of surgical asepsis apply to field surgeries with few exceptions. The minimum level for performance of surgeries in the field on free-ranging animals should be the same as for domestic animals undergoing surgery in animal hospitals. Surgeries in the field are typically done as part of research and management projects and usually involve a combination of biologists and veterinarians with the possibility of conflicts in scientific cultures. This article outlines a minimum standard of care for field surgeries and will serve as a resource for Institutional Animal Care and Use Committees and biologists and veterinarians planning projects that involve surgeries on free-ranging wildlife in field conditions.

Is peracetic acid suitable for the cleaning step of reprocessing flexible endoscopes?

The bioburden (blood, protein, pathogens and biofilm) on flexible endoscopes after use is often high and its removal is essential to allow effective disinfection, especially in the case of peracetic acid-based disinfectants, which are easily inactivated by organic material. Cleaning processes using conventional cleaners remove a variable but often sufficient amount of the bioburden. Some formulations based on peracetic acid are recommended by manufacturers for the cleaning step. We performed a systematic literature search and reviewed the available evidence to clarify the suitability of peracetic acid-based formulations for cleaning flexible endoscopes. A total of 243 studies were evaluated. No studies have yet demonstrated that peracetic acid-based cleaners are as effective as conventional cleaners. Some peracetic acid-based formulations have demonstrated some biofilm-cleaning effects and no biofilm-fixation potential, while others have a limited cleaning effect and a clear biofilm-fixation potential. All published data demonstrated a limited blood cleaning effect and a substantial blood and nerve tissue fixation potential of peracetic acid. No evidence-based guidelines on reprocessing flexible endoscopes currently recommend using cleaners containing peracetic acid, but some guidelines clearly recommend not using them because of their fixation potential. Evidence from some outbreaks, especially those involving highly multidrug-resistant gram-negative pathogens, indicated that disinfection using peracetic acid may be insufficient if the preceding cleaning step is not performed adequately. Based on this review we conclude that peracetic acid-based formulations should not be used for cleaning flexible endoscopes.

Oral chlorhexidine and microbial contamination during endoscopy: possible implications for transgastric surgery. A randomized, clinical trial

BACKGROUND

One of the biggest concerns associated with transgastric surgery is contamination and risk of intra-abdominal infection with microbes introduced from the access route. The purpose of this study was to evaluate the effect of oral decontamination with chlorhexidine on microbial contamination of the endoscope.

METHODS

In a prospective, randomized, single-blinded, clinical trial the effect of chlorhexidine mouth rinse was evaluated. As a surrogate for the risk of intra-abdominal contamination during transgastric surgery, microbial contamination of the endoscope during upper endoscopy was examined. Patients referred to upper endoscopy were assessed for eligibility and randomized to either chlorhexidine or no mouth rinse. Culture samples were collected from gastric aspirates and endoscopes. The primary outcome measure was colony forming units (CFU) in the endoscope samples. Secondary outcome measures were species specific effect of chlorhexidine on micro-organisms with abscess forming capabilities and the effect of proton pump inhibitor (PPI) treatment on CFU.

RESULTS

Chlorhexidine mouth rinse resulted in a significant reduction of CFU in the endoscope samples (p = 0.001). There was no species specific effect and micro-organisms with abscess forming capabilities were equally present. PPI treatment was associated with significantly higher CFU counts in both the gastric (p = 0.004) and endoscope samples (p = 0.049).

CONCLUSIONS

Chlorhexidine mouth rinse was effective in reducing microbial contamination of the endoscope, but micro-organisms with abscess forming capabilities were still present. PPI treatment significantly increased CFU and should be discontinued before transgastric surgery.

Feasibility of transumbilical flexible endoscopic preperitoneoscopy (FLEPP) and its utility for inguinal hernia repair: experimental animal study

BACKGROUND AND STUDY AIMS

Various NOTES (natural orifice translumenal endoscopic surgery) hernia repair techniques have been described. The aim of this study was to evaluate the feasibility of a transumibilically introduced conventional double-channel flexible endoscope for performing preperitoneoscopy (FLEPP, flexible endoscopic preperitoneoscopy technique) and to perform totally extraperitoneal (TEP) inguinal hernia meshplasty in an animal model.

MATERIAL AND METHODS

The study was done in 2 steps on 8 swines weighing 25 to 30 kg each: (1) establishing feasibility of preperitoneal dissection of the inguinal region using a conventional double-channel flexible gastroscope and making bed for mesh placement and (2) placement of a polypropylene mesh in the inguinal region to cover the myopectineal orifice.

RESULTS

The flexible endoscope provided good vision and maneuverability to identify preperitoneal structures--namely, the arcuate line, insertion of rectus abdominis on pubis symphysis, inferior epigastric vessels, deep inguinal ring, spermatic cord, pubic symphysis, and psoas muscle--without causing any damage to any of the structures. The spermatic cord could be dissected to identify the vas deference. A 9 × 7 cm(2) oval mesh was successfully placed over the myopectineal orifice of Fruchaud with good overlap. Average time required for the complete FLEPP procedure (including mesh placement) was 55 minutes (range 45-90 minutes).

CONCLUSIONS

This study demonstrates, for the first time, the feasibility of the transumbilical FLEPP technique and its utility for performing TEP inguinal hernia repair with prosthetic mesh placement in a swine model.

Evaluation of bacterial contamination after "pure" (totally) transvaginal NOTES diagnostic peritoneoscopy with biopsies in swine: a comparative study with laparoscopy

INTRODUCTION

Bacterial contamination from viscerotomy is a barrier to natural orifice translumenal endoscopic surgery (NOTES). The aim of this survival study is to evaluate pure (totally) transvaginal NOTES bacterial contamination compared with laparoscopy in pigs.

METHODS

Twelve adult female pigs underwent peritoneoscopy with liver and peritoneal biopsies, using either laparoscopy (Glap, six animals) or pure transvaginal (GNOTES) access, and were maintained alive for 7 days. In all animals, blood cultures were taken at baseline, and after 24 h and 7 days postoperatively. Swab cultures from vagina (GNOTES) and skin (Glap) were obtained pre- and post-antisepsis. Peritoneal fluid culture was obtained at necropsy. For statistical analysis, Glap and GNOTES were compared for presence of positive bacterial cultures (qualitative bacterial analysis) using Fisher's test, with level of significance set at p < 0.05.

RESULTS

All animals had good postoperative outcome. One animal had transient perioperative bleeding from a transvaginal access. Two animals in Glap and one in GNOTES had positive blood cultures after the procedure. All animals from GNOTES and Glap presented with mixed flora pre-antisepsis. After antisepsis, one animal (GNOTES) presented with a positive vaginal swab culture (a single bacterial strain was identified). There was no positive skin swab culture in Glap. There were no signs of intra-abdominal infection at necropsy. In two animals, one from Glap and another from GNOTES, intra-abdominal culture was positive for Corynebacterium spp. and Escherichia coli, respectively. There was no correlation between the bacterial flora found at the access site and in the peritoneal cultures.

CONCLUSIONS

Pure transvaginal peritoneoscopy with liver and peritoneal biopsy in swine is feasible and associated with bacterial contamination comparable to laparoscopy. Peritoneal bacterial contamination was clinically insignificant after 1 week postoperatively. Preoperative antisepsis provided significant reduction of bacterial load prior to transvaginal and laparoscopic procedures.

Natural orifice transesophageal endoscopic surgery: state of the art

The main goal of Natural Orifice Transluminal Endoscopic Surgery (NOTES) is performing surgery avoiding skin incisions. Theoretical advantages of NOTES include decreased postoperative pain, reduction/elimination of general anesthesia, improved cosmetic outcomes, elimination of skin incision-related complications such as wound infections and hernias, and increased overall patient satisfaction. Although various forms of port creation to accomplish thoracic NOTES procedures have been proposed, transesophageal NOTES has been shown to be the most reliable one. The evolution of endoscopic submucosal transesophageal access resulted in the development of per-oral endoscopic myotomy (POEM), which had a fast transition to clinical practice. The authors present a review of the current state of the art concerning transesophageal NOTES, looking at its potential for diagnostic and therapeutic interventions as well as the hurdles yet to be overcome.

Totally stapled gastrojejunal anastomosis using hybrid NOTES: single 12-mm trocar approach in a porcine model

BACKGROUND

The aim of this study was to evaluate the feasibility of a totally stapled gastrojejunal anastomosis performed using one transabdominal 12-mm trocar and a gastroscope in a porcine model.

METHODS

The procedure was carried out on six domestic pigs weighing 45 kg using a hybrid technique with a gastroscope and a 12-mm Hasson trocar, positioned in the left hypochondrium. At the end of the procedure a mechanical circular 21-mm gastrojejunal anastomosis was performed by inserting the stapler through a small gastrotomy after enlarging the trocar incision.

RESULTS

In all six cases the procedure was completed through a single 3 cm abdominal incision and without complications. The mean operating time was 2 h, and endoscopic investigation showed that the anastomoses were intact, patent, and airtight.

CONCLUSIONS

Totally stapled gastrojejunal anastomosis using a hybrid NOTES-single 12-mm trocar approach is a feasible procedure in the porcine model. Further survival studies are warranted, particularly to evaluate the functional results of this procedure.

Natural orifice transluminal endoscopy surgery: A review

Minimally invasive surgery started spreading worldwide in 1987, when the first laparoscopic cholecystectomy was performed. Meanwhile, improvement of endoscopic equipment and instruments allowed gastroenterologists to attempt more aggressive endoluminal interventions, even beyond the wall barrier. The first transgastric peritoneoscopy, in 2004, brought to light the concept of natural orifice transluminal endoscopic surgery (NOTES). The idea of incisionless surgery is attractive and has become a new goal for both surgeons and other people interested in this field of investigation. The authors present a review of all developments concerning NOTES, including animal studies and human experience.

Antimicrobial efficacy of chemical disinfectants on contaminated full metal crowns

Prosthetic restorations that have been tried in the patient's mouth are potential sources of infection. In order to avoid cross-infection, protocols for infection control should be established in dental office and laboratory. This study evaluated the antimicrobial efficacy of disinfectants on full metal crowns contaminated with microorganisms. Full crowns cast in a Ni-Cr alloy were assigned to one control group (n=6) and 5 experimental groups (n=18). The crowns were placed in flat-bottom glass balloons and were autoclaved. A microbial suspension of each type of strain - S. aureus, P. aeruginosa, S. mutans, E. faecalis and C. albicans- was aseptically added to each experimental group, the crowns being allowed for contamination during 30 min. The contaminated specimens were placed into recipients with the chemical disinfectants (1% and 2% sodium hypochlorite and 2% glutaraldehyde) for 5, 10 and 15 min. Thereafter, the crowns were placed into tubes containing different broths and incubated at 35ºC. The control specimens were contaminated, immersed in distilled water for 20 min and cultured in Thioglycollate broth at 35ºC. Microbial growth assay was performed by qualitative visual examination after 48 h, 7 and 12 days. Microbial growth was noticed only in the control group. In the experimental groups, turbidity of the broths was not observed, regardless of the strains and immersion intervals, thus indicating absence of microbial growth. In conclusion, all chemical disinfectants were effective in preventing microbial growth onto full metal crowns.