- Email: [email protected]
Endoscopic Bariatric Procedures and Devices
Gastrointest Endoscopy Clin N Am 17 (2007) 545–557
Endoscopic Bariatric Procedures and Devices Kiyoshi Hashiba, MD Department of Surgery, Sa˜o Paulo University Medical School, Rua Anato´lia, 105, Sa˜o Paulo 05471-000, Brazil
Since the discovery of a correlation between bezoars and weight loss in the early twentieth century, the medical community has been hopeful about the use of iatrogenic bezoars for minimally invasive weight reduction endoscopic treatment [1]. Only recently the presentation of other modalities started. The devices that can be applied in the endoscopic treatment of obesity may be divided now into three categories: those that occupy a space in the gastric lumen, those that make a restriction in the stomach lumen, and finally the devices that alter food absorption. The interest in endoscopic treatment of obese patients is growing as a result of the technical development of endoscopic devices and because several studies have shown that most patients do not need the substantial weight loss afforded by bariatric surgery procedures. This article reviews current and investigational projects and devices not available in the market.
Gastric volume–displacing weight loss devices (GVDD) The intragastric balloons are the most important representatives of these kinds of devices. They are intended to make a reduction in food intake and body weight due to early satiety. Animal studies seem to confound the argument by positively showing efficacy in dogs and rats [2,3]. When balloons of a particular volume were placed in these animals, a reduction in food intake caused some weight loss, although it should be noted that this effect diminished when the balloon volume was reduced, indicating presence of some volume threshold below which the balloon has no physiologic effect and above which patients report undesirable symptoms. This volume varies with population. The
E-mail address: [email protected] 1052-5157/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.giec.2007.05.008 giendo.theclinics.com
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sensations of satiety, fullness, bloatedness, and nausea can all be induced by different volumes; however, the correlation is not so straightforward [4,5]. The true mechanisms triggering weight loss from volume-displacing devices are inconclusive. Isolating a particular mechanism or combination of mechanisms is difficult because of the many factors that can be attributed to weight loss. Hypotheses for weight loss from intragastric balloons include delayed gastric emptying, mechanical volume reduction, hormonal changes, and neuronal effects. The general idea is well perceived and could possibly result in weight loss because of an increased sense of fullness for a longer period of time. Studies conducted with large devices such as the 600-mL saline-filled Bioenterics Intragastric Balloon (BIB) (Bioenterics Corp., Carpinteria, CA) [6] or the 500-mL air-filled Ballobes [7] report a decrease or slowing of gastric emptying rates. However, there are studies performed with Garren-Edwards [8–10] and Willmen gastric bubble [11] that are conflicting. The idea of weight loss from a volume-displacing device is the occupation of a large volume of the stomach and reduction in its capacity to store food. With reduced capacity to store foods, one subsequently eats less because of an early feeling of fullness. Studies conducted by Durrans and colleagues [3], suggest that the 200 mL balloon had no significant effect in intake whereas the 500 mL balloon reduced energy intake. Some chemical and biochemical markers stimulate and suppress appetite and satiety. Cholecystokinin (CCK) has been shown to be associated with appetite suppression. The relation of the serum marker elevation to the balloon is not clear, but one study [12] showed that CCK reduced gastric pressure in response to increasing balloon volume. On the neuronal effects, it seems that distending the stomach stimulates gastric stretch receptors, thus triggering vagal discharges that activate hypothalamic neurons and induce the feeling of satiety [13]. However, there are hypotheses that reject the idea that the weight loss is device-induced and attribute the weight loss to diet modifications, behavior changes, and placebo effects [14]. In general, the intragastric devices are not recommended in patients with a disease of the upper digestive tract. Patients with malignancy, pregnancy, alcoholism, and drug abuse are also excluded. The first intragastric device to be commercialized was the GarrenEdwards balloon. Because of issues regarding the efficacy and safety of the concept itself, it was withdrawn from the market after few years of use. At present, the BIB and the Heliosphere Balloon (HB) (Helioscopie SA, Vienne Cedex, France) seem to have found a niche in the international iatrogenic bezoar market. Both balloons are smooth and spherical. The shell is made of inert, nontoxic silicone elastomer, impervious and resistant to gastric acid. The HB has two layers of the same sheet. Both of them have a valve to retain liquid (BIB) and air (HB), connected with a balloon fill
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tube. The balloon is inserted collapsed within a sheath of plastic (BIB) or cloth (HB). Balloons insertion Both balloons can be inserted under conscious sedation. This introduction is not controlled by endoscopy or radiograph. The balloon placement assembly is inserted a distance from the incisor teeth and calculated so as to be located 10 cm distal to the esophagogastric junction. The procedure is easily performed, although the collapsed HB is more rigid. In both cases a hand maneuver is needed to help the introduction in the hypopharynx. The BIB usually is filled with a solution of methylene-blue (Fig. 1). The balloons when filled adequately may cause some symptoms in the postendoscopic period. It is important to observe the patient in the hospital, because nausea, vomiting, and abdominal cramps are common. To control these undesirable events, it is important to start symptomatic medications (antiemetics and antispasmodics) immediately after insertion. These symptoms are expected to last 72 hours, but, in few patients, they are uncontrolled and the balloon needs to be removed. These events are less frequent and intense with the HB [15]. On discharge, the patients are given a balanced diet of around 1000 to 1500 kcal per day. Physical activity is also recommended.
Balloons removal For balloon removal, as much fluid as possible should be removed in the first step, using a needle or one catheter. The BIB balloon can be grasped with a snare or a forceps. Finally, the endoscope and the balloon are removed. Usually this procedure is easily performed. The same does not occur with the
Fig. 1. The BIB in a stomach filled with colored liquid.
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HB. In this case, after the maximum aspiration of the balloon, a specific device must be used. This device has two claws that catch the balloon in the valve (Fig. 2). The HB always finds a resistance in the cardia and the operator has to wait for the relaxation of the muscles of the esophagogastric junction area. Sometimes the first maneuver is not successful and the balloon has to be grasped again. In this case, the removal procedure conducted with snare and basket usually results in important esophageal trauma.
Results During the implant period, the rate of weight loss typically increases in the first week, remains constant for 3 to 4 additional weeks, and finally decreases as patients presumably adapt to the device. Probably, the distended stomach’s increased capacity might contribute to increased food intake and therefore decrease the rate of weight loss [2]. The treatment is effective in well-motivated patients as a method for losing around 1 kg per week. Most published studies are on the BIB balloon. For one of them [16], patients were invited for a randomized, double-blind trial of balloon or sham treatment of 3 months’ duration. Only patients who achieved weight loss were given an additional 9-month treatment. Forty-three patients held an average body mass index (BMI) of 43.3. Balloon and sham groups had similar mean weight loss during the first 3 months. Balloon/balloon patients lost significantly less weight in months 3 to 6 than did sham/balloon patients, evidencing the weight loss plateau effect. Patients who completed the study per protocol lost 25.6 kg (20.5%) after 1 year and 14.6 kg (11.4%) after 2 years. A double-blind, sham-controlled, randomized and crossover study conducted by Genco and colleagues included 32 patients with BMI of 40 to 45 and lasted 6 months [17,18]. The balloon group had a significant
Fig. 2. The HB after the complete deflation.
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reduction in BMI from 43.5 to 38.0. The authors concluded that in association with appropriate diet, the device is significantly effective in weight reduction as compared with sham procedure plus diet control. At the Sı´ rio Libaneˆs Hospital (SLH) in Sa˜o Paulo (Brazil), an open prospective study included 41 patients who did not respond to medical therapy. A dietitian instructed each subject to consume a diet with 1200 kcal. On the first and second days after the insertion, the patients received liquids, 200 mL, 8 times a day. Only water was allowed in the intervals. From the third to seventh days of the postoperative course they received 7 times, 200 mL of a full liquid diet. Between the 8th and the 30th days the patients received 200 g or 200 mL of a soft solid diet. The patients remained in the hospital for 1 day. Antiemetic and antispasmodic medications were administered for 8 days. Acid suppressant drugs were given during all the treatment. Physical activity was advised. There were no complications in the insertion and removal procedures. The mean initial weight was 112.07 kg and the BMI, 38.7. The final results were 92.45 kg and 32.4, respectively. No balloons deflated during the treatment. Only three were removed early. In one case, the patient revealed intolerance for a long time (10 days) and in the other two, the patients lost weight strongly in a short time (1 month) and they were afraid to get sick. The data on the HB are limited and the results seem to be similar to the BIB [15]. Complications The spontaneous deflation of the balloon occurs in about 2% of cases [16]. Probably, this is the most important adverse event in the treatment. When the deflation occurs, the device can remain in the stomach or can migrate distally. In some cases of migration, the balloon had to be removed surgically. However, it is important to emphasize that most balloons lost their contents. Some studies showed that well-functioning balloons deflate at a rate of 2 to 3 mL per day [17]. The rates of complication related to insertion and removal are low [15,16], but unpublished data (Jermid Q and Hashiba K, 2006) show that the HB is more difficult to remove with the current design and it requires a special device to complete the removal procedure after the puncture for deflation. Other balloons The described BIB and HB are the balloons available on the market in some parts of the world. However, since the first well-studied attempt to treat obesity with balloons, there were other devices and few studies with them (Table 1). Recently, some studies were performed with a novel balloon device. It is the Adjustable Totally Implanted Intragastric Prosthesis (ATIIP) Endogast [19] (Districlass Medical S.A., Corbas, France).
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Table 1 Overview of balloons Name
Material
Approximate date
Volume (mL) filling fluid
Shape
Garren-Edwards Taylor W.Cook Ballobes BIB Heliosphere Endogast
Polyurethane Silicon Polyurethane Polyurethane Silicon Silicon Silicon
Early 1980s 1989–1990 Early 1980s 1980s Current Current Current
250 air 550 water 300 air 500 air 500–800 water 900 air 300–800 air
Cylinder Pear Pear Spherical Spherical Spherical Pear
This device has a tube like a gastrostomy tube that keeps the balloon in place. There are two models, one in which the gastrostomy tube has a valve and the second in which the tube is totally implanted subcutaneously. The advantage is the significant migration reduction and the volume control that can be increased or decreased by the patient. However, the difficulties in making a gastrostomy in obese patients and the complications of the placement of the gastrostomy opening in the abdominal wall are well known. One open study performed in patients with mean BMI of 48.4 showed progressive weight loss: first month, 11 kg; 3 months, 18 kg; and 6 months, 22 kg. Most of the early complications were a result of the gastrostomy procedure. No late postoperative complications occurred [19]. The present results with BIB showed that it is not an alternative to successful bariatric surgery and seems to be most appropriate as a temporazing adjunct measure for bariatric surgery candidates. The ultimate goal would be to provide adequate psychological motivation for patients to maintain their modified diet, thus maximizing the benefits of the balloon. It seems also to be a suitable treatment for not morbidly obese patients with comorbities. At present, there is now general agreement that the treatment should focus on a sustained 10% to 15% weight loss to prevent or to reduce the risk of cardiovascular and other obesity-related diseases [16]. Considering that the balloon treatment is easily reversible, the balloons seem to be a very interesting option to treat some selected obese patients. However, a strong reliance on the placebo effect, the lack of compliance with a modified diet and behavior, and the stigma surrounding the Garren-Edwards bubble failure prevent widespread acceptance of the concept. A different kind of GVDD is the development of a device made with polyethilene (Butterfly; Wilson-Cook Medical Inc., Winston Salem, North Carolina) [20]. In the final design of the experimental phase, a 36-meter strip was made (Fig. 3). This long strip was 75 m thick and 3 cm wide, folded in the middle. The strip was divided into loops of 40 cm that are put together in bundles of seven loops so as to facilitate the insertion (Fig. 4). The loop has a hole, each 20 cm, to allow the passing of a thread to close the device between two drags in the thread ends. A 36-cm long, 1.6-cm diameter overtube
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Fig. 3. Early design of the Butterfly device.
was used in all procedures. Canola oil was used as lubricant. The insertion was performed in a left-side position and under general anesthesia. Intravenous (IV) antibiotics were given immediately after the procedure. The device is easily inserted and removed from the gastric lumen. Some trauma always occurs during the insertion in the posterior wall, near the cardia, but it can be reduced if the stomach is kept distended. When the clinical study started, it was difficult to compress the loops to obtain a compact device. So, some distal loops released from the block and migrated distally to the duodenum. To have a compact plastic device, a 3-m long polyethylene flexible tube 75 m was used. This tube was compressed over a plastic tube used as a guide and pusher. The compressed plastic tube has a plastic ring at every segment of 15 cm (Fig. 4). The pusher holds the ring to insert the polyethylene tube in a continuous movement, without the need to return to the mouth, as in the previous design. To deploy this later generation device, it needs to come back 15 cm to take the other segment to push. As the device has a drag
Fig. 4. Current Butterfly ready to be inserted.
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in the distal end of the central thread, when the insertion finishes, another drag is placed in the proximal end and closes the device after a suitable compression (Figs. 5 and 6). This device seems to have some advantages over the balloons, because it does not need to be inflated or to change in any shape to work and allows for different sizes as needed. It does not have valves to keep fluids and the migration seems to be limited. The mechanisms of action resulting in weight loss can also differ from those of the balloons. While the ideal position for the balloons in the stomach is the fundus/body, the described plastic device can move in the gastric lumen and probably distend the stomach due to its volume and the emptying delay. However, this action can be the same as the majority of balloons, because most of them lose their contents during the treatment [17]. Further studies will show the real usefulness of the device to treat obese patients. Gastric lumen restriction with suture The development of endoscopic suturing devices has enabled the endoscopist to attempt an endoscopic version of the vertical gastroplasty. One initial study [21] was performed in a postmortem specimen of porcine stomach using the endoscopic suturing device available in the US market (Endocinch, C.R. Bard, Inc., Murray Hill, New Jersey) to treat GERD (Gastroesophageal Reflux Disease). With this sewing machine, mounted in the distal end of a flexible upper gastrointestinal endoscope, a tunnel was created by suturing together the anterior and posterior walls of the stomach near the cardia and the side of the lesser curvature. In the distal part of this restricted area a plastic flexible ring, 3 cm in diameter, was sutured to the stomach. The authors suggested that the purpose of the outlet ring was to secure the gastroplasty.
Fig. 5. The shape of the present Butterfly after the insertion maneuvers.
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Fig. 6. Endoscopic view of Butterfly into the stomach.
Gastric reduction has also been performed in live animals using another endoscopic suturing device [22]. The 2-0 stitches were placed in the gastric fundus, 5 cm below the gastroesophageal junction. Differently, the suture was closed using extracorporeal knots. The authors needed 10 to 12 stitches to obtain a gastric pouch with 30 mL at the end of the procedure. There was no follow-up in this study. Certainly, there are many reasons why this procedure has not become more widely attempted. One of them is that the experience with endoscopic sutures in GERD treatment showed that most patients (83%) lost the stitches after 18 months [23]. Moreover, in cases of the open vertical-banded gastroplasty, in the late postoperative course, a staple-line disruption occurred in 30% of cases, allowing an abnormal communication between the ‘‘stomachs’’ and subsequent weight gain [24]. Moreover, the studies performed in Hospital Novo Atibaia Experimental Surgery Center (Sa˜o Paulo, Brazil) on vertical gastroplasty in pigs with a transmural device [25] showed a suture disruption 1 month later. Nevertheless, a recent published report [26] on 10 patients, showed weight loss between 15 to 49 kg after endoscopic vertical gastroplasty. The Bard Endocinch was used in this study (Figs. 7 and 8). The BMI of patients ranged between 25 and 35. Only one plication had to be repeated after 9 months because of rupture of the suture. All patients complained of sore throats for 2 days. No complications occurred in any procedures performed under general anesthesia. Laboratory tests demonstrated clinical significant reductions in cholesterol and triglycerides. Thus, it appears that endoscopic gastric reduction is technically feasible. With the development of new endoscopic suturing devices, more preclinical
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Fig. 7. Endoscopic view of the gastric restriction with Endocinch. (Courtesy of Dr. Roberto Fogel, Caracas, Venezuela.)
research and new clinical studies will evaluate whether an endoscopic procedure can achieve long-lasting results and determine its clinical impact.
Endoscopic devices to alter food absorption Recently, investigators have attempted to perform an endoscopic bypass using a sleeve in the duodenum and proximal jejunum. It consists of a very thin polyethylene flexible tube, impermeable, attached to an autoexpandable metal stent in the proximal end [27] (GI Sleeve, GIDinamics Inc.,
Fig. 8. Radiographic study of the stomach after the Endocinch suture. (Courtesy of Dr. Roberto Fogel, Caracas, Venezuela.)
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Fig. 9. GISleeve placed into the duodenum. The arrows show the sleeve. (Courtesy of Dr. Manoel Galva˜o Neto, Sa˜o Paulo, Brazil.)
Watertown, Massachusetts). This stent has a special design to keep the sleeve in place. Thus, food would not have contact with the mucosa for a variable length between 180 and 360 cm. For the same reason, the biliopancreatic secretions are not in contact with ingested foods throughout the same distance (Fig. 9). After experimental studies, a feasibility and safety clinical study was performed in Chile. Ten patients received the device and then 7 had it removed. There were no complications of insertion or removal. After 90 days, the patients showed weight loss around 20% of the baseline weight. The patients’ overall health improved during the treatment period. There have been other attempts to treat obesity through endoscopy, like the botulinum toxin antral injection [28]. However, poor results due to lack of alteration of appetite and minimal weight loss suggest only a limited possibility with further data required.
Summary The development of endoscopic treatments for obesity offers gastroenterologists, surgeons, and endoscopists an exciting and highly desirable lessinvasive therapeutic modality as compared with bariatric surgery. At present, preliminary results cannot compare with those offered by surgical treatment, but in selected patients, all endoscopic procedures have afforded important improvements in patient health by reducing the comorbidities associated with morbid obesity. With the development of new techniques, the possibility of a combined procedure can offer an interesting therapeutic
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alternative. Most modalities of endoscopic treatment of obesity are still at a very early stage and clearly much work remains to be done. However, the results reported in studies such as the ones discussed here should encourage further research and development of the techniques described.
Acknowledgments I thank Mr. Vihar Surti for helping me with the preparation of the text and Ms. Alvamar H.C.A. Lamparelli for helping me with the manuscript revision.
References [1] De Bakey M, Ochsner A. Bezoars and concretions. A comprehensive review of the literature with analysis of 303 colletected cases and a presentation of 8 additional cases. Surgery 1939;5: 132–60. [2] Geliebter A, Westreich S, Hashim SA, et al. Gastric balloon reduces food intake and body weight in obese rats. Physiol Behav 1987;39(3):399–402. [3] Durrans D, Taylor TV, Holt S. Intragastric device for weight loss. Effect on energy intake in dogs. Dig Dis Sci 1991;36(7):893–6. [4] Hennig AE. Abundant weight loss by a balloon placed in the stomach. Innere Medizin 1979; 6:149–52. [5] Nieben OG, Harboe H. Intragastric balloon as an artificial bezoar for treatment of obesity. Lancet 1982;1:198–9. [6] Mion F, Napoleon B, Roman S, et al. Effects of intragastric balloon in gastric emptying and plasma ghrelin levels in non-morbid obese patients. Obes Surg 2005;15(4):510–6. [7] Tosetti C, Corinaldesi R, Stanghellini V, et al. Gastric emptying of solids in morbid obesity. Int J Obes Relat Metab Disord 1996;20(3):200–5. [8] Ziessman HA, Collen MJ, Fahey FH, et al. The effect of the Garren-Edwards gastric bubble on solid and liquid gastric emptying. Clin Nucl Med 1988;13(8):586–9. [9] Barkin JS, Reiner DK, Goldberg RI, et al. The effects of morbid obesity and the GarrenEdwards gastric bubble on solid phase gastric emptying. Am J Gastroenterol 1988;83(12): 1364–7. [10] Velchik MG, Kramer FM, Stunkard AJ, et al. Effect of the Garren-Edwards gastric bubble on gastric emptying. J Nucl Med 1989;30(5):692–6. [11] Lepsien K, nustede R, Schafmayer A, et al. Does the stomach balloon modify the function of the esophagus and lower esophageal sphincter, stomach emptying and release of gastrointestinal peptides? [in German]. Z Gastroenterol 1989;27:247–53. [12] Melton PM. Cholecystokinin (CCK-8) affects gastric pressure and ratings of hunger and fullness in women. Am j Physiol 1992;263:R452–6. [13] Stephan E, Paardo JV, Faris PL, et al. Functional neuroimaging of gastric distention. J Gastrointest Surg 2003;7(6):740–9. [14] Rigaud D, Trostler N, Rozen R, et al. Gastric distention, hunger and energy intake after balloon implantation in severe obesity. Int J Obes 1995;19:489–95. [15] Claudez H. Comparative study of liquid balloons intragastriques and air in the assumption of responsibility of obesity. Gut 2005;54(Suppl VII):A232. [16] Mathus-Vliegen EMH, Tytgat GN. Intragastric balloon for treatment-resistant obesity: safety, tolerance, and efficacy of 1-year balloon treatment followed by a 1-year balloonfree follow-up. Gastrointest Endosc 2005;61(1):19–27.
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[17] Genco A, Cipriano M, Bacci V, et al. BioEnterics intragastric balloon (BIB): a short term, double-blind, randomised, controlled, crossover study on weight reduction in morbidly obese patients. Int J Obes 2006;30(1):129–33. [18] Mathus-Vliegen EMH, Tytgat GNJ. Intragastric balloons for morbid obesity: results, patient tolerance and balloon life span. Br J Surg 1990;77(1):76–9. [19] Gaggiotti G. Adjustable Totally Implanted Intragastric Prosthesis (ATIIIP) Endogast [abstract]. Minimally Invasive Therapy & Allied Technologies 2005;14(5):324. [20] Hashiba K, Hassegawa RT, Wada S, et al. Plastic device (Butterfly) for endoscopic treatment of obesity: new design and operation [abstract]. Gastrointest Endosc 2003;57(5):AB181. [21] Awan AN, Swain CP. Endoscopic vertical band gastroplasty with an endoscopic sewing machine. Gastrointest Endosc 2002;55:254–6. [22] Hu B, Kantsevoy SV, Jagannath SB, et al. The technical feasibility of endoscopic gastric reduction: a pilot study in a porcine model [abstract]. Gastrointest Endosc 2005;61:AB80. [23] Schiefke I, Zabel-Langhennig A, Neumann S, et al. Long term failure of endoscopic gastroplication (EndoCinch). Gut;54:752–8. [24] Van Dielen FMH, Soeters PB, Brauw LM, et al. Laparoscopic adjustable gastric banding versus open vertical banded gastroplasty: a prospective randomized trial. Obes Surg 2005; 15:1292–8. [25] Hashiba K, Hassegawa RT, Wada AM, et al. New endoscopic gastric suture device: design and perspectives. Gut 2004;53(Suppl I):A85. [26] Fogel R, De la Fuente R, Bonilla Y, et al. Endoscopic vertical gastroplasty: a novel technique for treatment of obesity: a preliminary report [abstract]. Gastrointest Endosc 2005;61: AB106. [27] Galva˜o M, Ramos AC, Campos JM. Marcapasso Ga´strico, Pro´teses Ga´stricas e Duodenais e outras perspectivas. Endoscopia Gastrointestinal Terapeˆutica. Ribeira˜o Preto (Brasil): Tecmed Editora, 2006. [28] Gui D, Mingrone G, Valenza V, et al. Effect of botulism toxin antral injection on gastric emptying and weight reduction in obese patients: a pilot study. Aliment Pharmacol Ther 2006;23(5):675–80.
Endoscopic Bariatric Procedures and Devices Kiyoshi Hashiba, MD Department of Surgery, Sa˜o Paulo University Medical School, Rua Anato´lia, 105, Sa˜o Paulo 05471-000, Brazil
Since the discovery of a correlation between bezoars and weight loss in the early twentieth century, the medical community has been hopeful about the use of iatrogenic bezoars for minimally invasive weight reduction endoscopic treatment [1]. Only recently the presentation of other modalities started. The devices that can be applied in the endoscopic treatment of obesity may be divided now into three categories: those that occupy a space in the gastric lumen, those that make a restriction in the stomach lumen, and finally the devices that alter food absorption. The interest in endoscopic treatment of obese patients is growing as a result of the technical development of endoscopic devices and because several studies have shown that most patients do not need the substantial weight loss afforded by bariatric surgery procedures. This article reviews current and investigational projects and devices not available in the market.
Gastric volume–displacing weight loss devices (GVDD) The intragastric balloons are the most important representatives of these kinds of devices. They are intended to make a reduction in food intake and body weight due to early satiety. Animal studies seem to confound the argument by positively showing efficacy in dogs and rats [2,3]. When balloons of a particular volume were placed in these animals, a reduction in food intake caused some weight loss, although it should be noted that this effect diminished when the balloon volume was reduced, indicating presence of some volume threshold below which the balloon has no physiologic effect and above which patients report undesirable symptoms. This volume varies with population. The
E-mail address: [email protected] 1052-5157/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.giec.2007.05.008 giendo.theclinics.com
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HASHIBA
sensations of satiety, fullness, bloatedness, and nausea can all be induced by different volumes; however, the correlation is not so straightforward [4,5]. The true mechanisms triggering weight loss from volume-displacing devices are inconclusive. Isolating a particular mechanism or combination of mechanisms is difficult because of the many factors that can be attributed to weight loss. Hypotheses for weight loss from intragastric balloons include delayed gastric emptying, mechanical volume reduction, hormonal changes, and neuronal effects. The general idea is well perceived and could possibly result in weight loss because of an increased sense of fullness for a longer period of time. Studies conducted with large devices such as the 600-mL saline-filled Bioenterics Intragastric Balloon (BIB) (Bioenterics Corp., Carpinteria, CA) [6] or the 500-mL air-filled Ballobes [7] report a decrease or slowing of gastric emptying rates. However, there are studies performed with Garren-Edwards [8–10] and Willmen gastric bubble [11] that are conflicting. The idea of weight loss from a volume-displacing device is the occupation of a large volume of the stomach and reduction in its capacity to store food. With reduced capacity to store foods, one subsequently eats less because of an early feeling of fullness. Studies conducted by Durrans and colleagues [3], suggest that the 200 mL balloon had no significant effect in intake whereas the 500 mL balloon reduced energy intake. Some chemical and biochemical markers stimulate and suppress appetite and satiety. Cholecystokinin (CCK) has been shown to be associated with appetite suppression. The relation of the serum marker elevation to the balloon is not clear, but one study [12] showed that CCK reduced gastric pressure in response to increasing balloon volume. On the neuronal effects, it seems that distending the stomach stimulates gastric stretch receptors, thus triggering vagal discharges that activate hypothalamic neurons and induce the feeling of satiety [13]. However, there are hypotheses that reject the idea that the weight loss is device-induced and attribute the weight loss to diet modifications, behavior changes, and placebo effects [14]. In general, the intragastric devices are not recommended in patients with a disease of the upper digestive tract. Patients with malignancy, pregnancy, alcoholism, and drug abuse are also excluded. The first intragastric device to be commercialized was the GarrenEdwards balloon. Because of issues regarding the efficacy and safety of the concept itself, it was withdrawn from the market after few years of use. At present, the BIB and the Heliosphere Balloon (HB) (Helioscopie SA, Vienne Cedex, France) seem to have found a niche in the international iatrogenic bezoar market. Both balloons are smooth and spherical. The shell is made of inert, nontoxic silicone elastomer, impervious and resistant to gastric acid. The HB has two layers of the same sheet. Both of them have a valve to retain liquid (BIB) and air (HB), connected with a balloon fill
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tube. The balloon is inserted collapsed within a sheath of plastic (BIB) or cloth (HB). Balloons insertion Both balloons can be inserted under conscious sedation. This introduction is not controlled by endoscopy or radiograph. The balloon placement assembly is inserted a distance from the incisor teeth and calculated so as to be located 10 cm distal to the esophagogastric junction. The procedure is easily performed, although the collapsed HB is more rigid. In both cases a hand maneuver is needed to help the introduction in the hypopharynx. The BIB usually is filled with a solution of methylene-blue (Fig. 1). The balloons when filled adequately may cause some symptoms in the postendoscopic period. It is important to observe the patient in the hospital, because nausea, vomiting, and abdominal cramps are common. To control these undesirable events, it is important to start symptomatic medications (antiemetics and antispasmodics) immediately after insertion. These symptoms are expected to last 72 hours, but, in few patients, they are uncontrolled and the balloon needs to be removed. These events are less frequent and intense with the HB [15]. On discharge, the patients are given a balanced diet of around 1000 to 1500 kcal per day. Physical activity is also recommended.
Balloons removal For balloon removal, as much fluid as possible should be removed in the first step, using a needle or one catheter. The BIB balloon can be grasped with a snare or a forceps. Finally, the endoscope and the balloon are removed. Usually this procedure is easily performed. The same does not occur with the
Fig. 1. The BIB in a stomach filled with colored liquid.
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HB. In this case, after the maximum aspiration of the balloon, a specific device must be used. This device has two claws that catch the balloon in the valve (Fig. 2). The HB always finds a resistance in the cardia and the operator has to wait for the relaxation of the muscles of the esophagogastric junction area. Sometimes the first maneuver is not successful and the balloon has to be grasped again. In this case, the removal procedure conducted with snare and basket usually results in important esophageal trauma.
Results During the implant period, the rate of weight loss typically increases in the first week, remains constant for 3 to 4 additional weeks, and finally decreases as patients presumably adapt to the device. Probably, the distended stomach’s increased capacity might contribute to increased food intake and therefore decrease the rate of weight loss [2]. The treatment is effective in well-motivated patients as a method for losing around 1 kg per week. Most published studies are on the BIB balloon. For one of them [16], patients were invited for a randomized, double-blind trial of balloon or sham treatment of 3 months’ duration. Only patients who achieved weight loss were given an additional 9-month treatment. Forty-three patients held an average body mass index (BMI) of 43.3. Balloon and sham groups had similar mean weight loss during the first 3 months. Balloon/balloon patients lost significantly less weight in months 3 to 6 than did sham/balloon patients, evidencing the weight loss plateau effect. Patients who completed the study per protocol lost 25.6 kg (20.5%) after 1 year and 14.6 kg (11.4%) after 2 years. A double-blind, sham-controlled, randomized and crossover study conducted by Genco and colleagues included 32 patients with BMI of 40 to 45 and lasted 6 months [17,18]. The balloon group had a significant
Fig. 2. The HB after the complete deflation.
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reduction in BMI from 43.5 to 38.0. The authors concluded that in association with appropriate diet, the device is significantly effective in weight reduction as compared with sham procedure plus diet control. At the Sı´ rio Libaneˆs Hospital (SLH) in Sa˜o Paulo (Brazil), an open prospective study included 41 patients who did not respond to medical therapy. A dietitian instructed each subject to consume a diet with 1200 kcal. On the first and second days after the insertion, the patients received liquids, 200 mL, 8 times a day. Only water was allowed in the intervals. From the third to seventh days of the postoperative course they received 7 times, 200 mL of a full liquid diet. Between the 8th and the 30th days the patients received 200 g or 200 mL of a soft solid diet. The patients remained in the hospital for 1 day. Antiemetic and antispasmodic medications were administered for 8 days. Acid suppressant drugs were given during all the treatment. Physical activity was advised. There were no complications in the insertion and removal procedures. The mean initial weight was 112.07 kg and the BMI, 38.7. The final results were 92.45 kg and 32.4, respectively. No balloons deflated during the treatment. Only three were removed early. In one case, the patient revealed intolerance for a long time (10 days) and in the other two, the patients lost weight strongly in a short time (1 month) and they were afraid to get sick. The data on the HB are limited and the results seem to be similar to the BIB [15]. Complications The spontaneous deflation of the balloon occurs in about 2% of cases [16]. Probably, this is the most important adverse event in the treatment. When the deflation occurs, the device can remain in the stomach or can migrate distally. In some cases of migration, the balloon had to be removed surgically. However, it is important to emphasize that most balloons lost their contents. Some studies showed that well-functioning balloons deflate at a rate of 2 to 3 mL per day [17]. The rates of complication related to insertion and removal are low [15,16], but unpublished data (Jermid Q and Hashiba K, 2006) show that the HB is more difficult to remove with the current design and it requires a special device to complete the removal procedure after the puncture for deflation. Other balloons The described BIB and HB are the balloons available on the market in some parts of the world. However, since the first well-studied attempt to treat obesity with balloons, there were other devices and few studies with them (Table 1). Recently, some studies were performed with a novel balloon device. It is the Adjustable Totally Implanted Intragastric Prosthesis (ATIIP) Endogast [19] (Districlass Medical S.A., Corbas, France).
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Table 1 Overview of balloons Name
Material
Approximate date
Volume (mL) filling fluid
Shape
Garren-Edwards Taylor W.Cook Ballobes BIB Heliosphere Endogast
Polyurethane Silicon Polyurethane Polyurethane Silicon Silicon Silicon
Early 1980s 1989–1990 Early 1980s 1980s Current Current Current
250 air 550 water 300 air 500 air 500–800 water 900 air 300–800 air
Cylinder Pear Pear Spherical Spherical Spherical Pear
This device has a tube like a gastrostomy tube that keeps the balloon in place. There are two models, one in which the gastrostomy tube has a valve and the second in which the tube is totally implanted subcutaneously. The advantage is the significant migration reduction and the volume control that can be increased or decreased by the patient. However, the difficulties in making a gastrostomy in obese patients and the complications of the placement of the gastrostomy opening in the abdominal wall are well known. One open study performed in patients with mean BMI of 48.4 showed progressive weight loss: first month, 11 kg; 3 months, 18 kg; and 6 months, 22 kg. Most of the early complications were a result of the gastrostomy procedure. No late postoperative complications occurred [19]. The present results with BIB showed that it is not an alternative to successful bariatric surgery and seems to be most appropriate as a temporazing adjunct measure for bariatric surgery candidates. The ultimate goal would be to provide adequate psychological motivation for patients to maintain their modified diet, thus maximizing the benefits of the balloon. It seems also to be a suitable treatment for not morbidly obese patients with comorbities. At present, there is now general agreement that the treatment should focus on a sustained 10% to 15% weight loss to prevent or to reduce the risk of cardiovascular and other obesity-related diseases [16]. Considering that the balloon treatment is easily reversible, the balloons seem to be a very interesting option to treat some selected obese patients. However, a strong reliance on the placebo effect, the lack of compliance with a modified diet and behavior, and the stigma surrounding the Garren-Edwards bubble failure prevent widespread acceptance of the concept. A different kind of GVDD is the development of a device made with polyethilene (Butterfly; Wilson-Cook Medical Inc., Winston Salem, North Carolina) [20]. In the final design of the experimental phase, a 36-meter strip was made (Fig. 3). This long strip was 75 m thick and 3 cm wide, folded in the middle. The strip was divided into loops of 40 cm that are put together in bundles of seven loops so as to facilitate the insertion (Fig. 4). The loop has a hole, each 20 cm, to allow the passing of a thread to close the device between two drags in the thread ends. A 36-cm long, 1.6-cm diameter overtube
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Fig. 3. Early design of the Butterfly device.
was used in all procedures. Canola oil was used as lubricant. The insertion was performed in a left-side position and under general anesthesia. Intravenous (IV) antibiotics were given immediately after the procedure. The device is easily inserted and removed from the gastric lumen. Some trauma always occurs during the insertion in the posterior wall, near the cardia, but it can be reduced if the stomach is kept distended. When the clinical study started, it was difficult to compress the loops to obtain a compact device. So, some distal loops released from the block and migrated distally to the duodenum. To have a compact plastic device, a 3-m long polyethylene flexible tube 75 m was used. This tube was compressed over a plastic tube used as a guide and pusher. The compressed plastic tube has a plastic ring at every segment of 15 cm (Fig. 4). The pusher holds the ring to insert the polyethylene tube in a continuous movement, without the need to return to the mouth, as in the previous design. To deploy this later generation device, it needs to come back 15 cm to take the other segment to push. As the device has a drag
Fig. 4. Current Butterfly ready to be inserted.
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in the distal end of the central thread, when the insertion finishes, another drag is placed in the proximal end and closes the device after a suitable compression (Figs. 5 and 6). This device seems to have some advantages over the balloons, because it does not need to be inflated or to change in any shape to work and allows for different sizes as needed. It does not have valves to keep fluids and the migration seems to be limited. The mechanisms of action resulting in weight loss can also differ from those of the balloons. While the ideal position for the balloons in the stomach is the fundus/body, the described plastic device can move in the gastric lumen and probably distend the stomach due to its volume and the emptying delay. However, this action can be the same as the majority of balloons, because most of them lose their contents during the treatment [17]. Further studies will show the real usefulness of the device to treat obese patients. Gastric lumen restriction with suture The development of endoscopic suturing devices has enabled the endoscopist to attempt an endoscopic version of the vertical gastroplasty. One initial study [21] was performed in a postmortem specimen of porcine stomach using the endoscopic suturing device available in the US market (Endocinch, C.R. Bard, Inc., Murray Hill, New Jersey) to treat GERD (Gastroesophageal Reflux Disease). With this sewing machine, mounted in the distal end of a flexible upper gastrointestinal endoscope, a tunnel was created by suturing together the anterior and posterior walls of the stomach near the cardia and the side of the lesser curvature. In the distal part of this restricted area a plastic flexible ring, 3 cm in diameter, was sutured to the stomach. The authors suggested that the purpose of the outlet ring was to secure the gastroplasty.
Fig. 5. The shape of the present Butterfly after the insertion maneuvers.
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Fig. 6. Endoscopic view of Butterfly into the stomach.
Gastric reduction has also been performed in live animals using another endoscopic suturing device [22]. The 2-0 stitches were placed in the gastric fundus, 5 cm below the gastroesophageal junction. Differently, the suture was closed using extracorporeal knots. The authors needed 10 to 12 stitches to obtain a gastric pouch with 30 mL at the end of the procedure. There was no follow-up in this study. Certainly, there are many reasons why this procedure has not become more widely attempted. One of them is that the experience with endoscopic sutures in GERD treatment showed that most patients (83%) lost the stitches after 18 months [23]. Moreover, in cases of the open vertical-banded gastroplasty, in the late postoperative course, a staple-line disruption occurred in 30% of cases, allowing an abnormal communication between the ‘‘stomachs’’ and subsequent weight gain [24]. Moreover, the studies performed in Hospital Novo Atibaia Experimental Surgery Center (Sa˜o Paulo, Brazil) on vertical gastroplasty in pigs with a transmural device [25] showed a suture disruption 1 month later. Nevertheless, a recent published report [26] on 10 patients, showed weight loss between 15 to 49 kg after endoscopic vertical gastroplasty. The Bard Endocinch was used in this study (Figs. 7 and 8). The BMI of patients ranged between 25 and 35. Only one plication had to be repeated after 9 months because of rupture of the suture. All patients complained of sore throats for 2 days. No complications occurred in any procedures performed under general anesthesia. Laboratory tests demonstrated clinical significant reductions in cholesterol and triglycerides. Thus, it appears that endoscopic gastric reduction is technically feasible. With the development of new endoscopic suturing devices, more preclinical
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Fig. 7. Endoscopic view of the gastric restriction with Endocinch. (Courtesy of Dr. Roberto Fogel, Caracas, Venezuela.)
research and new clinical studies will evaluate whether an endoscopic procedure can achieve long-lasting results and determine its clinical impact.
Endoscopic devices to alter food absorption Recently, investigators have attempted to perform an endoscopic bypass using a sleeve in the duodenum and proximal jejunum. It consists of a very thin polyethylene flexible tube, impermeable, attached to an autoexpandable metal stent in the proximal end [27] (GI Sleeve, GIDinamics Inc.,
Fig. 8. Radiographic study of the stomach after the Endocinch suture. (Courtesy of Dr. Roberto Fogel, Caracas, Venezuela.)
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Fig. 9. GISleeve placed into the duodenum. The arrows show the sleeve. (Courtesy of Dr. Manoel Galva˜o Neto, Sa˜o Paulo, Brazil.)
Watertown, Massachusetts). This stent has a special design to keep the sleeve in place. Thus, food would not have contact with the mucosa for a variable length between 180 and 360 cm. For the same reason, the biliopancreatic secretions are not in contact with ingested foods throughout the same distance (Fig. 9). After experimental studies, a feasibility and safety clinical study was performed in Chile. Ten patients received the device and then 7 had it removed. There were no complications of insertion or removal. After 90 days, the patients showed weight loss around 20% of the baseline weight. The patients’ overall health improved during the treatment period. There have been other attempts to treat obesity through endoscopy, like the botulinum toxin antral injection [28]. However, poor results due to lack of alteration of appetite and minimal weight loss suggest only a limited possibility with further data required.
Summary The development of endoscopic treatments for obesity offers gastroenterologists, surgeons, and endoscopists an exciting and highly desirable lessinvasive therapeutic modality as compared with bariatric surgery. At present, preliminary results cannot compare with those offered by surgical treatment, but in selected patients, all endoscopic procedures have afforded important improvements in patient health by reducing the comorbidities associated with morbid obesity. With the development of new techniques, the possibility of a combined procedure can offer an interesting therapeutic
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alternative. Most modalities of endoscopic treatment of obesity are still at a very early stage and clearly much work remains to be done. However, the results reported in studies such as the ones discussed here should encourage further research and development of the techniques described.
Acknowledgments I thank Mr. Vihar Surti for helping me with the preparation of the text and Ms. Alvamar H.C.A. Lamparelli for helping me with the manuscript revision.
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