Which parameters might predict complications after natural orifice endoluminal surgery (NOTES)? Results from a randomized comparison with open surgical access in pigs

Adrenal natural orifice transluminal endoscopic surgery (NOTES): a step too far?

Surgical approach to adrenal gland has evolved from open to minimally invasive surgery. With the advent of technology, multiple techniques and approaches are available in a surgeon's armamentarium today to deal with adrenal nodules that require surgical intervention. Each approach has its own advantages and disadvantages. The era of minimal invasive surgery has fuelled our quest for better cosmesis, faster recovery, early return to work and reduced hospital stay. While minimal invasive method is the preferred approach for most benign adrenal masses less than 6 cm, its application for large adrenal lesions as well as adrenocortical carcinoma is still debatable. Single incision minimal invasive procedures further try to reduce the incisions and wound morbidity. With the aim to completely remove visible scars and possibly reduced morbidity, the concept of natural orifice transluminal endoscopic surgery (NOTES) has been proposed by some surgeons as well as interventional gastroenterologist. In NOTES, the peritoneal cavity is accessed through a hollow viscus to perform therapeutic as well as diagnostic procedures. While the theoretical advantages of scar less surgery and its advantages sound encouraging, the precise indications and its potential advantages for adrenal pathologies is yet to be defined. It should in no way, compromise our goal of safe patient surgery and outcomes.

Risk of infection after iatrogenic perforation of the gut wall? Evaluation of preventive strategies in a randomized controlled animal trial

BACKGROUND

Interventional endoscopies entail a risk of infection secondary to perforation of the luminal wall. Thereby, bacteria may be introduced into the sterile environment of the peritoneal cavity (PC). Limited data are available regarding the efficacy of prophylactic anti-infective treatments. The aim of the study was to examine the efficacy/safety of anti-infective means in the prevention of infection by interventional endoscopies in a randomized controlled animal trial.

METHODS

Forty pigs were randomized to: 1: control; 2: oral lavage; 3: gastric lavage; 4: oral/gastric lavage; 5: i.m. antibiotics. Lavage was performed with Octenisept prior to the operation. After gastric wall perforation, peritoneoscopy was performed. Before the procedure, after closure and prior to autopsy, intraabdominal lavage for bacterial culture was taken using mini-laparoscopy. At autopsy, macroscopic appearance of the PC was scored. Lavage fluids were grown to identify/quantify bacterial load. Concentration of intraperitoneal bacteria at autopsy was defined as main outcome parameter.

RESULTS

No major complications occurred in any of the procedures. Bacterial load of the PC at autopsy was significantly reduced with antibiotics compared to all other groups, whereas it did not differ between the lavage groups and control. Macroscopic scoring of the PC showed significant lower rate of intraabdominal abscesses in the antibiotic group compared to the lavage groups and control (p < 0.01).

CONCLUSION

Only antibiotic prophylaxis is effective for the prevention of infection after iatrogenic perforation of the gastrointestinal wall. There was no difference between any form of lavage and the control group. Further studies in humans are required to prove these animal data.

Natural Orifice Total Transtracheal Endoscopic Thyroidectomy Surgery: First Reported Experiment

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES(®); American Society for Gastrointestinal Endoscopy [Oak Brook, IL] and Society of American Gastrointestinal and Endoscopic Surgeons [Los Angeles, CA]) is an improvement in surgical interventions. In this study we developed an innovative transtracheal endoscopic thyroidectomy technique and explored its feasibility in animal models.

MATERIALS AND METHODS

Transtracheal endoscopic thyroidectomy was performed in anesthetized dogs and pigs. The endoscope was advanced into the pretracheal space via a longitudinal incision on the anterior tracheal wall. Hemithyroidectomies and partial lobectomy were performed using special double-lumen endotracheal tubes and conventional endoscopic instruments. The tracheal wall incision was closed using absorbable sutures, and the animals were sacrificed at Day 5 postsurgery.

RESULTS

Hemithyroidectomy and partial thyroidectomy were successfully performed on pigs and dogs. The average operative time for each model was 69.4 minutes. No significant complications were encountered during surgery.

CONCLUSIONS

The transtracheal endoscopic thyroidectomy technique is feasible and has the potential to be an alternative method for other types of thyroid surgeries.

Acute inflammatory response to transgastric natural orifice transluminal endoscopic surgery peritoneoscopy: an experimental study in swine

OBJECTIVE

To investigate the impact of transgastric peritoneal access on plasma biomarkers of acute inflammatory response in comparison to laparoscopy.

METHODS

This was a prospective and comparative study in a porcine model. Transgastric peritoneal access performed by natural orifice transluminal endoscopic surgery was compared with laparoscopy. Laparotomy and sham groups were used as positive and negative controls, respectively. Thirty-four pigs were assigned to receive transgastric natural orifice transluminal endoscopic surgery (n = 12), laparoscopy (n = 8), laparotomy (n = 8) or a sham procedure involving only anesthesia (n = 6). In the natural orifice transluminal endoscopic surgery group, peritoneoscopy was performed with a gastroscope via transgastric access. Blood samples were collected at baseline and 1, 3, 6, 9 and 24 h after the surgical procedure for measurement of interleukins 1β, 6 and 10 and tumor necrosis factor-α. A complete blood count was performed, and C-reactive protein levels were measured at baseline and at 24 h.

RESULTS

All surgical and endoscopic procedures were performed without major complications. Peritoneal cavity inventory showed no signs of peritonitis in any animal. Interleukin 1β, interleukin 10 and tumor necrosis factor-α levels were below the threshold of detection. The mean level of interleukin 6 was statistically significantly higher in the laparotomy group than in the other groups (p<0.05), with no significant differences among the sham, laparoscopy and natural orifice transluminal endoscopic surgery groups (p>0.05). C-reactive protein analysis indicated significant increases in all groups, with no differences among the groups. Complete blood count analysis showed no differences among the groups.

CONCLUSIONS

Based on the observed interleukin 6 patterns, the systemic inflammatory response resulting from transgastric peritoneal access by natural orifice transluminal endoscopic surgery is similar in intensity to the response that occurs after laparoscopy.

Cardiopulmonary and immunologic effects of transvaginal natural-orifice transluminal endoscopic surgery cholecystectomy compared with laparoscopic cholecystectomy in a porcine survival model

BACKGROUND

A few studies have addressed the physiology related to a basic natural-orifice transluminal endoscopy surgery (NOTES) procedure, such as transgastric peritoneoscopy, but the physiologic impact of more complex NOTES procedures has not been previously examined.

OBJECTIVE

To evaluate the cardiopulmonary and immunologic effects of transvaginal NOTES cholecystectomy compared with laparoscopic cholecystectomy.

SETTING

Survival experiments in 10 40-kg female pigs assigned to transvaginal cholecystectomy and laparoscopic cholecystectomy groups.

INTERVENTIONS

Transvaginal cholecystectomy was performed with the assistance of a needlescopic device, and laparoscopic cholecystectomy was performed in the standard manner.

MAIN OUTCOME MEASUREMENTS

Cardiopulmonary and immunologic parameters in the transvaginal cholecystectomy group were compared with those in the laparoscopic cholecystectomy group. Cardiopulmonary parameters included heart rate, blood pressure, saturation pulse oximetry, intratracheal pressure, and arterial blood gases. Immunologic parameters included white blood cell count, tumor necrosis factor-α, interleukin-1β, and interleukin-6.

RESULTS

All procedures were performed successfully without complications. Although operation times were longer for transvaginal cholecystectomy than for laparoscopic surgery, cardiopulmonary changes were similar and stable in both groups. White blood cell count, interleukin-1β, and interleukin-6 did not differ between the 2 groups, and the increase in tumor necrosis factor α after transvaginal cholecystectomy was significantly smaller on postoperative day 1 than after laparoscopic cholecystectomy (133.4 pg/mL vs 200.4 pg/mL; P < .05).

LIMITATIONS

Animal model and small sample size.

CONCLUSIONS

Transvaginal cholecystectomy resulted in cardiopulmonary stability and well preserved immune function similar to those of laparoscopic cholecystectomy, suggesting that NOTES may be less invasive than laparoscopic surgery.

[Diagnostic and interventional endoscopy in gastroenterology : from high-resolution chips and procedures for endoscopic resection to NOTES]

In the past 10 years endoscopic diagnostics has benefited from technologies such as big chips, high-definition television (HDTV) and narrow band imaging (NBI). Video capsule endoscopy and double balloon enteroscopy have facilitated visualization of the entire small bowel. A number of studies on mucosal Barrett's and gastric cancers could prove that endoscopic mucosal resection (EMR) is oncologically equivalent to surgical resection when certain criteria are respected. However, EMR is less invasive and carries a substantially lower complication risk and mortality compared to surgery. Endoscopic submucosal dissection (ESD) facilitates en bloc resection with thorough histopathologic evaluation of the specimen, e.g. for mucosal lesions in the stomach and rectum. Endosonography (EUS) guided transgastric necrosectomy using a flexible gastroscope has set a milestone in the treatment of infected pancreatic necroses and has replaced open surgery in many centers. Natural orifice transluminal endoscopic surgery (NOTES) uses natural body openings as minimally invasive access to the abdomen and mediastinum. Interventional GI endoscopists and minimally invasive surgeons have profited from these innovations in micromechanics and microelectronics.

Endoscopic closure of gastrointestinal leaks

Surgery has been the mainstay of therapy in patients with gastrointestinal perforations. This paradigm started to shift with the development of techniques for endoscopic closure of gastrointestinal perforations. A detailed review of the literature on this subject, along with a commentary on practical aspects in the management of patients with gastrointestinal leaks, is provided here.

Natural orifice translumenal endoscopic surgery (N.O.T.E.S)

Natural orifice translumenal endoscopic surgery (N.O.T.E.S) is a technique that allows access to the peritoneal cavity through natural orifices (oral, rectal, vaginal, vesical) without passing through the anterior abdominal wall. Rapid strides have been made in developing this technique, especially in animal models. Majority of research work in this field is originating from USA, while human clinical trials are being reported from India and Southern America. Morbidly obese patients and ITU patients are two target groups where N.O.T.E.S if implemented, will have the highest potential and bearing. With increasing evidence of safe practice in human models, questions on indications and feasibility of practice need to be addressed by rigorous research, strong evidence and collaboration between surgical centers worldwide.

Robotic NOTES (Natural Orifice Translumenal Endoscopic Surgery) in reconstructive urology: initial laboratory experience

OBJECTIVES

To present an initial experience with robotic natural orifice translumenal surgery (R-NOTES) in reconstructive urology using the da Vinci surgical system.

METHODS

In 10 female farm pigs (mean weight, 34.5 kg), 10 pyeloplasties (right 5, left 5), 10 partial nephrectomies (right 5, left 5), and 10 radical nephrectomies (right 5, left 5) were performed. The robot telescope and the first robotic arm were placed through a single 2-cm umbilical incision, and the second robotic arm was placed through the vagina.

RESULTS

All 30 R-NOTES procedures were performed successfully without any addition of laparoscopic port or open conversion. Mean length of the umbilical incision was 2.6 cm. Mean operative time was 154 minutes, and mean estimated total blood loss was 72 mL. Mean warm ischemia time in the partial nephrectomy group was 25.4 minutes. There were no intraoperative complications. There were no robotic system failures during the entire experiment. We did not find any significant difference when comparing right-side and left-side procedures. When analyzing the learning curve, only robot preparation time reached a statistically significant inverse correlation with increasing number of cases (r = -0.72, P = .018).

CONCLUSIONS

Robotic NOTES pyeloplasty, partial nephrectomy, and radical nephrectomy are feasible and safe in the porcine model. This approach has the potential for a less morbid and scarless outcome. Intracorporeal suturing is significantly enhanced using the robot, especially through the challenging translumenal natural orifice approach. Further development of robots adaptive to NOTES would boost efforts toward clinical NOTES applications.