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Conference report

Non-Inva 2012

Jerome Dargent.
Five-part program examined new techniques, technologies, and issues
New technologies included stents, tools, and cameras
Speakers included Scott Shikora and Pradeep Chowbey

Although growing steadily, bariatric surgery still does not attract the majority of the obese population, despite a good level of information and shared opinions with the rest of the medical community. Peri-operative risks and adverse effects in the long run may explain some of this reluctance.

As emphasised by Paul O’Brien, MD, Centre for Obesity Research and Education (CORE), Monash University, Melbourne, in his presentation on benchmarking, 300,000 patients are operated on each year worldwide, a tiny portion of the morbidly obese population. This means that both health authorities and bariatric surgeons are failing to properly address this issue!

Less-aggressive techniques should be the goal of current research. Non-invasive bariatric procedures are as yet insufficiently standardised and evaluated, even if they are being upgraded.

The purpose of our second meeting was to gather international expertise on new technologies that will allow a greater number of obese patients to access bariatric care. Within one year, evolutions have emerged, and surprises have occurred.

The program was again divided into five parts:

  1. Techniques that diminish the surgical trauma, mostly SILS and NOTES. Their very credibility is at stake: is the technique solid? Is the cosmetic advantage decisive?
  2. Transoral procedures are the most promising, but also questioned in terms of feasibility and duration.
  3. New technologies, like neuro-stimulation: do they keep their promises and is their cost sustainable ?
  4. Transversal issues: the place of the anaesthesiologist, endoscopist, etc. New issues have emerged: the need for comparison (benchmarking) and the equitable allocation of finite resources; ethical problems in front of a vast array of options and the lack of supervision regarding some experiments.
  5. Consensus panels for establishing guide-lines in the near future.

As in 2011, common surgical methods, such gastric bypass or sleeve gastrectomy, were not explicitly addressed, except in comparison with less invasive procedures.

If non-invasive or very minimally invasive procedures are desired, the transition with current techniques raises several questions: access transparency, conformity of the research to ethics and rules for publication, consistency of the steps in implementation.

The topics that were dealt with outline this approach. Seeking the least aggressive surgical approaches while continuing with existing procedures: SILS and NOTES, micro-instrumentation. Transoral procedures should match the current relevant concepts in bariatric surgery, or at least get close enough from them: stapling and endo-stapling, endo-plication, malabsorption, etc. And implementing these strategies should follow a path of clinical research: combining investigational techniques with techniques that have a solid background, being gradual, giving priority to classical procedures when new ones have failed.

The devices and procedures that have been presented will be addressed in detail in our Directory of Non-invasive and New Technologies in Bariatric Surgery, to be edited by Springer Edition in Autumn 2012.

Benchmarking of novel technologies in bariatric surgery

“Bariatric surgery is effective but it is largely unacceptable within the general public, with only around 1% of all potential candidates agreeing to proceed each year. We need something to offer the other 99%.”

Paul O'Brien said that there is a huge unmet need for acceptable, effective treatments for obesity. Bariatric surgery is effective but it is largely unacceptable within the general public, with only around 1% of all potential candidates agreeing to proceed each year. We need something to offer the other 99%.

Among the factors driving people away from bariatric surgery is its invasiveness. The resurgence of bariatric surgery in the early 1990s with the introduction of the laparoscopic approach and of adjustable gastric banding showed that the less invasive the approach, the broader appeal it will have.

A new obesity procedure must be acceptable to the obese person and acceptable to their healthcare provider, and each has different needs.

The patient wants a procedure that is minimally invasive, with very low risk and minimal side effects, while also offering good, durable weight loss and the resolution of comorbidities, and it should also be adjustable and reversible. On the other hand, the healthcare provider wants a low upfront cost, with cost-efficient and cost-effective outcomes, in a readily reproducible and a simple to deliver format.

We need to benchmark any endoscopic procedure against the current best practice on either side of the invasiveness gradient. Endoscopic procedural approaches to weight loss will generally fit between the relative impotence of best medical therapy and the fear of major bariatric surgery. Very low energy diets (VLED) represent the most effective of the former and LAGB represents the least intimidating of the latter. These can provide current best practice norms against which to compare. We need options in between. They must be more effective than VLED, and less invasive than LAGB.

Reasonable expectations for the comparators are as shown in Table 1, below.

VLED LAGB
15kg weight loss in three months
Short term only
No procedure at all
Very low cost
Modest patient acceptability
30kg weight loss over long term (>10 years)
Less than one hour procedure time,
Outpatient – less than three hour length of stay
Low risk
Upfront cost US$10 – 15K

For each candidate procedure we must ask: Is it safe? Is it feasible generally? Does it work? – What weight loss? What health benefit? Is the effect durable? Will patients accept it? What is the cost – in money, time and effort?

O’Brien encouraged the audience to benchmark each procedure against the comparators by these criteria. Does it measure up? Can it be reasonably expected to measure up in due course? If so, go for it. Try it, measure it but be honest about it.

Ethics and new technologies

Scott Shikora (USA, Boston), former president of the American Society for Metabolic and Bariatric Surgery (ASMBS), has analysed the ethical challenges of the current trials involving new bariatric surgeries. The constant pressure from society, the patients concerns about foreign bodies, the direct (financial), or indirect (academic) benefits have unfortunately too often led to human experimentation within daily clinical practice. (Shikora calls for more careful, ethical trials)

Economical perspectives

The choice of a metabolic operation in Eastern Asia, new technologies and cost-effectiveness, have been outlined by Pradeep Chowbey, president of the forthcoming IFSO world meeting in India. Obesity treatments are indeed highly connected to diabetes: in India, 61 millions people are diabetic, half of them being obese, and 80% uncontrolled. Yet only 1,000 bariatric procedures have been performed in 2007, and 4,200 in 2011. Resources are scarce, and choices have to be made; sleeve gastrectomy is the dominant procedure for the time being.

The state of the art of mixed techniques

This first part of the meeting was dedicated to intermediary techniques, that combine a lesser surgical aggressiveness and typical techniques.

Marie-Cécile Blanchet

Single Port (Single Incision) Access. Most bariatric procedures are feasible through this approach, yet the reproducibility and the upsides have been questioned. SILS gastric banding as a routine procedure has been addressed by Marie-Cécile Blanchet (Lyon) and Jean Cady (Paris). The best patient was a young female, without hepatic steatosis and with a relatively low BMI. Mean operative time was 45 minutes (ranging from 25-90) and the routine approach was trans-umbilical (one or several trocars).

The comparison between 25 SILS patients and five with 3mm micro trocars approach was in favour of the SILS because of flaws in the instruments, which were found to be insufficiently long and rigid.

Jean Cady has a calculated an average 25% extra-time for the SILS versus traditional laparoscopy. He suggested extending the indications to band removal (152 cases), band replacement (20), sleeve gastrectomies (22) and Omega-loop bypass. Although the momentum for bariatric SILS seems to fade away, this method is still sure and reproducible, and above all attractive regarding cosmesis. Both surgeons insisted on the necessity of the trans-umbilical approach versus others (such as sub-costal).

If one can still deem the single-incision or single-trocar approach promising, solutions might come from alternative options:

Micro-instruments: While 3mm micro-trocars with similar instruments can be disappointing, 5 mm and 10mm instruments connected to insertion rods of 3mm seem interesting. The US company Ethicon EndoSurgery has tested the PSS device, that has been used with prototype materials in cholecystectomies and placement of an adjustable band (video presented by Jérôme Dargent, Lyon, France).

Elie Chouillard

NOTES and combined laparoscopy: NOTES has bariatric applications that have been explored by Elie Chouillard (Paris, France), particularly concerning sleeve gastrectomy, an optical device being inserted trans-vaginally. He reported an experience with 106 procedures, with a mean duration 88 min (with a range of 50-280) and 11 conversions to standard laparoscopy.

There was no mortality and a 3.6% morbidity rate(including 2.8% gastric fistula); post-operative pain was decreased.

One year after his first report, he pointed several problems that led him to put this technique on hold: the lack of technical improvement, the lack of long enough instruments and longer stapling devices, the necessity to maintain an umbilical approach for energy power and stapling, medico-legal issues and the near-impossibility of using an endoscope for intra-abdominal purpose, and finally the mediocre acceptance of the trans-vaginal approach in Europe and France.

Magnetic Internal Mechanism (MIM) capsule is a highly interesting field of research for intra-abdominal exposure with minimal access. It has been presented Valeria Tognoni and Nicola De Lorenzo (Rome, Italy). Through the cooperation of surgeons and robotic engineers, a magnetic remotely controllable video-endoscopic capsule device dedicated to mini-invasive surgery has been developed. (See the full article Magnetic camera offers surgeons greater freedom)

Laparoscopic gastric plication represents an alternative to sleeve gastrectomy, carried out without any stapling and keeping the greater curve in place. It is promising, although the nickname “Sleeve Killer” seems premature!

Elie Chouillard has reported his French experience on 31 patients since 19 months, with an average follow-up of seven months, and a mean EWL of 66%, a match to sleeve gastrectomy.

This procedure has not been validated in France or in the USA, and it can still be considered under assessment. The discussion has raised three important questions. First, is the rate of complications lower than observed with sleeve gastrectomy as it is now? Secondly, will it have similar efficacy? Lastly, what operation should we consider if and when this procedure fails?

Instrumentation: The French company ENDOCONTROL (Grenoble, Clément Vidal) has created an original robotic 5mm needle-holder, which can bend and rotate with 7 degrees of freedom. The moves can be directed through the thumb, while the wrist, elbow and shoulder can stay still.

25 patients have been operated on with various procedures (urology, gastro-jejunal anastomosis). Gastric bypass should become a favourite indication.

Purely non-invasive techniques

Purely non-invasive techniques may be classified according to their goal, their mechanism of action and the similarities they bear with the common techniques. Each presentation had a focus on the combination endoscopy/usual bariatric procedures and their mutual needs.

Elisabeth Mathus-Vliegen (The Netherlands) has summarized the benefits of upper endoscopy in the aftermath of bariatric surgery. Leaks due to stapling or anastomosis can be cured by an array of endoscopic devices: tissue adhesives, biological glues, clips (possibly larges), or bio-degradable stents. Bleeding and early obstructions were also addressed. Late stenosis (most often anastomotic) is treated by pneumatic dilatation, which should be careful in case of marginal ulcer (that increases the risk of perforation: 1.6 to 3%), from a 10–12mm diameter up to 15mm. Digestive exploration after bypass is a difficult issue, but has benefited from new options: retrograde colonoscopy with a pediatric endoscope, double balloon endoscopy.

The experience of stents for gastric fistula after sleeve gastrectomy has been presented by Rudolf Weiner (Germany), who emphasized the risks of this device (obstruction, migration, sepsis, extraction problems).

Jacques Himpens (Belgium) talked about Revision of failed gastric bypass and the strategy for therapeutic sequences in bariatric surgery, including non-invasive technologies. He insisted on the distinction between hyperphagia and polyphagia. In the first case, gastric volume should be reduced (and optionally the anastomosis): endoplication or pouch ring such as advised by Fobi. In the second case, with excessive meal frequency, malabsorbtion should be installed: distal bypass. In case of adverse effects of the bypass (neurological complications, dumping), he advices to restore a normal anatomy, then transform it into a sleeve gastrectomy, optionally a duodenal switch.

The G-prox “ROSE” method, i.e. an endoscopic plication, has been described by Gontrand Lopez-Nava (Madrid, Spain) and Tom Lavin (New Orleans, USA). The Incisionless Operating Platform (IOP) has been used in over 800 clinical cases which includes many NOTES applications, gastrotomy closure, gastro-gastric fistula closure, repair of dilated stoma and pouch after bypass (ROSE). The IOP consists of the Transport, a flexible, steerable, multi-lumen access device for passage of instrumentation along with an endoscopic grasper and tissue approximation system, the g-Prox , g-lix, and g-cath tissue anchoring system.

To date, the adverse event rate is under 2%, and there have been no mortalities, or long-term complications. The USGI tissue anchoring system has demonstrated durability of the endoscopic plications at one and two years during ROSE study.

Primary Obesity Surgery Intervention (POSE) is a newer application of this anchoring system. It is proposed to work by preventing fundal accommodation to a meal, triggering earlier fullness and reduced food capacity. It is not anatomically restrictive like a balloon. Furthermore, anchors placed at the antrum slow emptying. A 41%EWL at nine months (N=12) has been reported.

The TRIM method has been detailed by Stacy Brethauer (USA), following upon the steps of Fogel (64 patients, 2008) and Thompson. As a primary procedure, both running sutures and separated sutures have been attempted on the antrum and the fundus (four to eight).

As in the Stomaphyx system (now discarded), a suction device allows to grab the sub-mucosal and mucosal tissues properly. In his experience, 18 patients have been included, with a BMI 38 (range 30–45, and a mean duration of the procedure of 125 minutes. Mean EWL has been 27.7% at 12 months (14 patients), i.e. 11kg, and 7/14 patients were responders (>30% EWL); two bypass have been eventually performed, after the sutures had been taken out through endoscopy.

Restrictive implants:

Elisabeth Mathus-Vliegen

The Barosense endoscopic system (TERIS) could be compared to an endoscopic ring. Elisabeth Mathus-Vliegen has been one of the investigators of this procedure. The first generation of implant has been discarded due to clogging and dislocation issues, but the second one (TERIS 2) is secured and promising; trials are going on with satisfactory results.

Bariatric endo-stapling (TOGA device). The preliminary results of this technique have been described by Jacques Devières and Mustafa Ibrahim (Brussels, Belgique). It consists in a regular gastric stapling such as achieved in Mason’s vertical banded gastroplasty. Despite good initial results, the production of this device has been suspended due to financial reasons.

Several other devices are currently being tested by the Brussels team: OBALON system (a capsule containing a balloon, that can be swallowed), TERIS device, HOURGLASS technology, endoscopic magnets for a gastro-jejunal anastomosis (also tested in cancers), endoscopic suture Over-stitch APOLLO and G-Prox, ENDOMINA and ENDOSAMOURAI systems.

The possibility of injection at the GE junction has been presented by Jérôme Dargent, Frederic Pontette, François Mion (Lyon, France). They previously suggested that sleeve gastrectomy (SG) can be associated with a sub-GE junction injection of hyaluronic acid (HA).

Hyaluronic acid is currently used in cosmetic surgery; the device we implanted is also used for knee arthritis. Four patients have been operated on a three-month period (from November 2008 to January 2009) by SG + HA injection, and matched with four patients with SG alone. The procedure has two intra-operative stages, and has been described in details.

The current stage of the trial (prospective, single blind, randomised and controlled study) has compared the effects of HA injection, balloon, and the combination of both in a sequential mode (2010-2012). It has involved three groups of patients: group 1 (balloon alone), group 2 (balloon followed by injection at the time of removal, i.e. six months), group 3 (injection, and balloon placement at six months). Preliminary results are in favor of group 3.

Intra Gastric Balloon, placement and removal, state of the art, have been reported by Viana Costil (France) and Elisabeth Mathus-Vliegen. The modern aspects of the balloon strategy should not be underestimated, particularly as a pre-operative weight-loss tool, and it has even been shown as a good predictor of further weight loss, such as obtained with gastric banding.

“Can we afford the devices we desire? Is bariatric surgery only going to be for the wealthiest? Is it the right thing to do to test a device that is not upgraded? Is there a European vs. Asian perspective?”

Christophe Bastid (France) has introduced a new adjustable air balloon – like the previous experience with the Spatz Balloon – reported by Gontrand Lopez-Nava (Spain). The duration of implant is longer (one year), which makes this strategy similar to Alfredo Genco’s Italian experience (two consecutive balloons). The Easy Life balloon has been tested in nine patients, with an initial capacity of 400–500ml of air, up to 700–800ml owing to a catheter available for refill.

The Reshape Balloon has been presented by Franco Favretti (Vicenza, Italy). The ReShape Duo has two connected balloons, and is placed for six months. It is filled with evenly distributed 900cc (450cc in each balloon), 60% more volume than typical single balloon.

The un-inflated balloons are advanced over a guidewire and precisely placed in the stomach. Each balloon is inflated with saline and independently sealed. Studies in Italy and the US have shown that patients lose on average 38% of their excess weight in six months. One hundred and fifty patients have been treated so far.

The duodeno-jejunal bypass sleeve, is a novel endoscopic approach for type 2 diabetes that was advocated by Jan Greve (Pays-Bas). It is supposed to replicate the gastro-jejunal bypass model: bilio-pancreatic secretions are excluded from the alimentary tract along the first 70 cm of jejunum. The procedure has been upgraded (radio-guided).

500 patients have already been treated worldwide in 15 centers. The average weight-loss at two years has been 24%. EWL at oe year has been 46% in a recent study (Chili, 15 patients), with a reduction of the HbA1c level from 8.9% to 6.6% among 13 patients. Complications did occur yet: bleeding (<1%), obstruction of the jejunal tube (3%), migration (2), esophageal perforation (2).

The Satiety Inducing-Full Sense Device for obesity has been described as a device inducing early satiety through pressure, rather than a purely restrictive one. It is promoted by the company Full Sense Technology (USA) and presented by Randal Baker (Grand Rapid, Michigan, USA). It has two parts that are connected: an esophageal stent (such as used for a leaks) and a conic device secured by tethers and applied under the gastro-esophageal junction, that is thus preserved. (see full story New endoscopic stent leads to 100% EWL)

New technologies

Several years of evolution of neuromodulation in obesity treatments have been summarized by Scott Shikora (Boston, USA), since the rather inconclusive trials with the IGS system in 1999-2002 (Intra Gastric Stimulation, Transneuronix) – a double-blind controlled study had failed to deliver results, despite a tool for patients selection, the Baroscreen – till duodenal stimulation (BETASTIMED).

The Tantalus System, a meal initiated GI stimulator, is implanted in T2DM obese patients using a reversible laparoscopic procedure. Rudolf Weiner (Germany) has reported some of the results obtained, particularly in reducing the HbA1c in diabetics patients. Six months data have demonstrated clinically significant improvement in all metabolic parameters. This effect was maintained in 89% of the patients two years post implantation (n=29). HbA1c or body weight or both showed reductions of up to -3.3% (mean change -0.9%, P< 0.05) and of up to -16kg (mean change -4.8kg, P< 0.05) respectively.

The V-Bloc system was presented by Karl Miller (Austria). It is an active implantable device designed to induce sub-diaphramatic vagal block, and has demonstrated clinically important weight loss, and glycemic control in obese type 2 diabetic subjects. Improvements in HbA1c and reductions in blood pressure in hypertensive subjects have been demonstrated as well.

Alterations of eating behavior in obese subjects treated with the Abiliti System (IntraPace, Inc.) were assessed in an ongoing prospective clinical multicenter trial. They were presented by Günther Meyer (Germany). So far, 150 devices have been implanted.

It is a closed loop gastric electrical stimulation device which features a transgastric sensor to detect food intake and an accelerometer to record physical activity. The stimulator delivers a tailored gastric stimulation in response to food consumption, aiming to induce early satiety. 33 subjects reached three month’s therapy with a mean EWL of 15.9% (±9.3) and a mean total weight loss (WL) of 7.2kg (±4.0). Twenty seven subjects reached six months therapy with a mean EBWL of 23% (±11.7) and a mean total WL of 10kg (±5.5). Updated results: 27% EWL has been achieved at nine months in 31 patients.

It is suggested that weight-loss is achieved due to the assessed alteration of eating behavior in particular the reduction of loss of control and hunger.

Transversal issues

An original approach for the follow-up through modern communication systems has been presented by Maxime Sodji (France), who runs a pilot-study in the French region Limousin, consisting in a modern application of telemedicine with a central platform dedicated to bariatric cares and visits. Text messages are being used, and the platform keeps track of the visits, appointments, and feedback from the patients.

The position of the anaesthesiologist has been presented by two experts:

Jan Mulier (Belgium), president of ESPCOP (European Society of peri Operative Care of the Obese patient): What are the basis of non-invasive anaesthesia today? While surgery is moving from less invasive laparoscopy to non-invasive natural orifice surgery, anaesthesia is following: lower inflation pressures for laparoscopy whilekeeping surgical workspace sufficient, opioid free anaesthesia improving the postoperative analgesia, spontaneous breathing with support during pneumoperitoneum, permissive hypercapnia improving oxygen delivery and faster recovery.

All these approaches are used today, and minimize the peri-operative complications of bariatric anaesthesia and improve the enhanced recovery after bariatric surgery.

Although the morbidly obese patient is at higher risk, the use of a multimodal technique allows giving a non-invasive sedation or a monitored anaesthesia care for a non-invasive surgery. As surgeons are moving in this non-invasive direction, anaesthesiologist should follow upon their steps to keep their role in the multidisciplinary team.

Ashish C Sinha (Philadelphia, USA): Anesthetic Issues in Minimally Invasive Surgery.

Are there anaesthesia perspective based advantages or disadvantages to the anaesthesiologist when the surgeon prefers a minimal approach? Does it affect outcomes during the intraoperative or immediate post-operative period? Can we speculate to these advantages in the absence of hard data? If there is no hard evidence to these advantages, do we at least have an expert viewpoint, or what an experienced anaesthesia practitioner intuitively feel would be advantageous?

While all minimal approach surgeries have obvious advantages, both to patients and surgeons, in terms of rapid discharge, minimal pain, rapid return to function among others, the degree of advantage to anesthetic care remains to be established.

To an anesthesiologist, minimal approach surgery, whether laparoscopic, robotic or NOTES, offer a different set of challenges. It starts from limited access to the patient who may be surrounded by robotic arms with very little approach area left. On the other hand is Trans Oral Robotic Surgery (TORS) where the access to the patients’ airway is severely restricted for the anaesthesia provider and the patient’s head is the furthest away from the anaesthesia machine and anaesthetist. In this instance, it is difficult to diagnose airway disconnect and then take the necessary rapid corrective action.

Another issue is the length of surgery, which is especially longer during the first dozen or two cases of any surgeon, and also in training centre, where the very nature of practice implies longer surgical times. This comes to a head when at midnight or later the surgeon posts what would be a 20-minute open appendectomy as a laparoscopic procedure and it takes 60 minutes of laparoscopic attempts and an additional 20 minutes after the decision is made to convert it to an open surgery.

The true challenge is to be vigilant to the potential for a vascular mishap as even in the initial trocar placement for laparoscopic surgery when the aperture may create a big enough vascular opening that the initial insufflations of gas causes a venous air embolism (VAE). This of course presents itself in a dramatic fashion with a cardiac arrest!

The therapy is a head down position, immediate central access to the right atrium and withdrawal of the air, usually resulting in a good outcome. The other aspect, at least in a case like robotic prostatectomy, is the amount of time spent by the patient in a head-down position.

This can result in head and neck swelling, clearly demonstrated by periorbital oedema. In this instance the question is: does the facial swelling reflect airway swelling as well? To extubate or not to extubate, and if so, how to do it safely? The leak test can help guide that decision.

On the flip side, the anaesthesiologist has the advantages of decreased blood loss, at least usually; and a shorter case, at least eventually. Plus, smaller incisions imply less surgical pain and thereby increased patient comfort.

Conclusions

The idea of gathering information solely on new devices has gained acceptance, and has been proven instrumental outside of the bigger meetings dedicated to the state of the art in bariatric surgery. Hence, several options can be discussed very informally in a research meeting. Some of the debates that took place in 2011 have become less relevant (SILS versus endoscopy?), some of the devices presented will not be here in 2013, and some are disclosed but are not yet available.

New issues have come up. For instance, the need for encompassing the changes we are envisioning, benchmarking the new technologies versus the ones we have on display, setting economical perspectives and a solid ethical background.

Can we afford the devices we desire? Is bariatric surgery only going to be for the wealthiest? Is it the right thing to do to test a device that is not upgraded? Is there a European vs. Asian perspective? Can we imagine new business models for physicians and patients, and for companies making new devices, given the background of scarce resources and the current legal restrictions? These issues, and more, shall be addressed at next year’s conference – in Lyon, 26-27 April, 2013!

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