Pilot comparison of adhesion formation following colonic perforation and repair in a pig model using a transgastric, laparoscopic, or open surgical technique

Infection during natural orifice transluminal endoscopic surgery peritoneoscopy: a randomized comparative study in a survival porcine model

BACKGROUND

Infection in natural orifice transluminal endoscopic surgery (NOTES) remains controversial.

OBJECTIVE

To estimate the frequency of infection during NOTES peritoneoscopy with different routes of access and to compare with laparoscopy.

DESIGN

Prospective randomized controlled study (Canadian Classification type I).

METHODS

Forty female pigs were randomly assigned to 3 NOTES (transgastric, transrectal, and transvaginal) and laparoscopic groups. Antiseptic technique was used for NOTES, whereas laparoscopy was performed in a sterile environment. Preoperative and postoperative intravenous antibiotics were administered. Closure of the transluminal access site was performed in all animals. Peritoneal fluid was collected for culture at the end of surgery and at necropsy at day 14.

RESULTS

Thirty-nine peritoneoscopies were successfully completed. Necropsy confirmed complete healing of NOTES incisions, but 2 animals in the laparoscopy group had small abscesses in the abdominal incisions. There were no statistical differences in the presence of peritoneal adhesions. Positive culture results were seen in all groups at the end of the procedure and in all animals at necropsy, but this did not lead to clinical signs of gross infection. The most common organisms that colonized the peritoneum were gram-positive cocci and gram-negative bacilli from the normal swine gastrointestinal flora.

LIMITATIONS

Animal model and small sample size.

CONCLUSIONS

In these small series of animals and with the careful lavage and preparation used, NOTES appeared to be comparable to laparoscopy in terms of peritoneal contamination and clinical infection. Despite the adherence to a strict antiseptic protocol, peritoneal contamination occurs but does not lead to septic complications in the swine.

Feasibility and safety of adhesiolysis using transgastric NOTES approach: a pilot survival study in a porcine model

OBJECTIVES

Although adhesions can be removed by adhesiolysis using laparotomy or laparoscopy, they typically recur sometimes with equal severity. It is suggested that minimizing the invasiveness of the operative technique by using natural orifice translumenal endoscopic surgery (NOTES) may reduce adhesion re-formation. The aim of the study was to evaluate the feasibility and safety of adhesiolysis by using a novel transgastric NOTES approach and collect pilot data on adhesion recurrence after transgastric NOTES adhesiolysis.

METHODS

One nonsurvival and 5 survival female pigs were used in this experimental survival study. Interventions included (a) induction of adhesions by laparotomy, (b) 2 weeks survival, (c) transgastric NOTES adhesiolysis with endoscopic evaluation and scoring of adhesions before and immediately after adhesiolysis, (d) 2 weeks survival, and (e) necropsy with endoscopic and necroscopic evaluation and scoring of recurrent adhesions. Main outcome measures were (a) survival and complication rates and (b) assessment of adhesion formation and re-formation using the Hopkins Adhesion Formation Score.

RESULTS

No mortality and no complications were observed. A total of 11 adhesions formed before the adhesiolysis in 5 survival study animals. All were successfully divided. The frequency of adhesions and median adhesion formation score decreased significantly immediately after adhesiolysis compared with that prior to the procedure (frequency, 11 vs 0, P = .011; the median score = 2.0 [range 1-3] vs 0.0 [range 0-0], P = .004). The treatment gains maintained at 2 weeks after the adhesiolysis.

LIMITATIONS

The limitations of this study were the low number of study animals and short-term follow-up data.

CONCLUSIONS

Adhesiolysis using NOTES transgastric approach is feasible, safe, and effective with minimal adhesion re-formation.

Comparison of pain and postoperative stress in dogs undergoing natural orifice transluminal endoscopic surgery, laparoscopic, and open oophorectomy

BACKGROUND

Few studies are available to compare the potential benefits of natural orifice transluminal endoscopic surgery (NOTES) approaches to traditional surgery.

OBJECTIVE

To compare complications, surgical stress, and postoperative pain.

DESIGN

Prospective study in dogs.

SETTING

Research laboratory.

SUBJECTS

Thirty dogs.

INTERVENTIONS

Oophorectomy procedures were performed via NOTES and laparoscopic and traditional open surgery.

MAIN OUTCOME MEASUREMENTS

Operative time, pain scores, systemic stress parameters (cortisol, glucose), surgical stress markers (interleukin 6, C-reactive protein), 3-day observation.

RESULTS

Median operative times were 76, 44, and 35 minutes for the NOTES, laparoscopic, and open procedures, respectively, with the NOTES procedure being significantly longer than the other 2 procedures. All ovaries were completely excised, and all the animals survived without complications. The NOTES animals had greater increases in serum cortisol concentrations at 2 hours but no statistically significant differences in glucose concentrations compared with the other groups. Serum interleukin 6 and C-reactive protein concentrations were significantly increased at specific times compared with baseline in the NOTES group, but not in the open or laparoscopic surgery groups. Based on the cumulative pain score and nociceptive thresholds, the animals in the NOTES group demonstrated less evidence of pain.

LIMITATIONS

Small sample size, limited follow-up.

CONCLUSIONS

Although the NOTES oophorectomy procedures took approximately twice as long and there may be more evidence of tissue damage as judged by increases in serum cortisol and interleukin 6 concentrations, the dogs in the NOTES group had lower pain scores, especially when compared with animals undergoing open surgery.

Natural orifice transluminal endoscopic surgery versus laparoscopic surgery for inadvertent colon injury repair: feasibility, risk of abdominal adhesions, and peritoneal contamination in a porcine survival model

BACKGROUND

Adhesions are common after conventional surgery; natural orifice transluminal endoscopic surgery (NOTES) avoids peritoneal disruption and may reduce adhesions.

OBJECTIVES

To determine whether adhesions (and peritoneal contamination) are less common with NOTES transgastric colon injury and repair (TGCR) than with laparoscopic colon repair (LCR).

DESIGN/SETTING

Porcine survival study.

INTERVENTIONS

After colon preparation and administration of antibiotics, forty 25-kg male pigs were randomly assigned to either TGCR or LCR. TGCR involved an endoscopic gastrotomy (needle-knife plus balloon dilation), CO(2) pneumoperitoneum, and a 2-cm needle-knife transmural incision of spiral colon. Colotomies were repaired with clips; gastrotomies were closed with clips and a detachable snare.

MAIN OUTCOME MEASUREMENTS

Adhesions were assessed at necropsy at 21 days; biopsy specimens were blindly reviewed. A 9-point adhesion score (density/vascularity, width, and extent) was averaged from 3 reviewers. Peritoneal lavage was sent for cell count and culture.

RESULTS

Two of 20 TGCR pigs died immediately (unrecognized preoperative autopsy-proven pneumonia). The median procedure times were 70.5 and 19.0 minutes for TGCR and LCR, respectively; weight gains were 7.1 and 8.2 kg, respectively. The median adhesion scores were 4.3 and 3.7, respectively (P = .26); subscores were similar (1.9, 1.5, 1.3 vs 1.7, 1.1, 1.0, respectively (P = .3-.6)). Peritoneal lavage bacterial growth was nonsignificantly lower after TGCR than after LCR (38.9% vs 60.0%, respectively; P = .30); administration of intragastric antibiotics did not decrease contamination. Three TGCR (vs no LCR) pigs had histologic peritonitis.

LIMITATIONS

Animal model, colon prepped, injury immediately recognized.

CONCLUSION

NOTES colon repair is feasible after transmural injury. Adhesions, histologic peritonitis, and contamination were similar to those with laparoscopy and were not helped by intragastric antibiotics.

Consensus statement: natural orifice transluminal endoscopic surgery

Natural orifice transluminal endoscopic surgery (NOTES) has generated healthy and vigorous debate about the introduction of an entirely novel method of surgical therapy. Although there are many reasons for scepticism, there is undoubted interest in this field from both the medical profession and general public. Those Associations currently involved in laparoscopic and endoscopic surgery wish to safeguard patients and the reputation of the profession by issuing clear guidance and support for those wishing to undertake NOTES. The purpose of this document is to review the current status of both NOTES and hybrid NOTES, while at the same time identifying obstacles in both clinical research and training. Furthermore, it aims to provide a consensus statement on behalf of the main UK specialty associations involved in this field of surgery. The primary aim of this consensus statement is to provide a framework within which to develop, safely and effectively, what must still be considered an experimental technique.

Natural orifice translumenal endoscopic surgery 2009: what is the future for the gastroenterologist?

PURPOSE OF REVIEW

In order to predict whether the gastroenterologist will have a role in the rapidly developing field of natural orifice translumenal endoscopic surgery (NOTES), it is helpful to examine the new developments in this field. Our goal in this review is to examine the recent developments in the field and study the gastroenterologists' role to best make this prediction.

RECENT FINDINGS

Perhaps the most significant development in the field of NOTES has been the favorable patient and physician preferences for NOTES. There is evidence that patients would prefer NOTES cholecystectomy to laparoscopic cholecystectomy. The most common reason for this choice appears to be the lack of pain and visible scar. Another very significant development has been the reality of human NOTES procedures. Multiple centers have reported human NOTES procedures, including transgastric appendectomies, transgastric liver biopsies, transgastric tubal ligation and transvaginal cholecystectomy without major complications. Gastroenterologists' expertise with flexible endoscope was critical in the above cases. Recently, a few publications have also shown how gastroenterologists with expertise in endosonography can have a role in affirming safe access.

SUMMARY

Although no one can predict with certainty where the field of NOTES will be in 1 year, it seems likely that gastroenterologist involvement will be necessary and advancements in this field will be applicable and diffuse into our daily practice.