Laparoscopic Adjustable Gastric Banding: Management of Complications

Total period

Perigastric era

Pars flaccida era

Lap-Band AP era

Dates and numbers

1994–2011 (N = 3227)

1994–2000 (N = 931)

2001–2005 (N = 926)

2006–2011 (N = 1370)

Enlargements

840 (26 %)

375 (40 %)

377 (41 %)

88 (6.4 %)

Erosions

110 (3.4 %)

79 (8.5 %)

20 (2.2 %)

11 (0.8 %)

Port/tubing

666 (21 %)

281 (30 %)

304 (33 %)

81 (5.9 %)

Explanations

181 (5.6 %)

92 (9.9 %)

59 (6.4 %)

30 (2.2 %)

Proximal Gastric Enlargements

Etiology

Proximal gastric enlargements occur because the band has been placed incorrectly, a part of the gastric wall slips through the band or there is stretching of the stomach or esophagus above the band. The central driver for all enlargements, whether they are posterior prolapse, anterior prolapse, and symmetrical enlargement, is the pressure generated by eating too quickly or taking too big a bite. It is essential that each bite must transit the area of the band before another bite is taken. With correct placement of the band, there is only a virtual stomach present. A typical barium study after placement shows no actual volume reservoir. With eating, space needs to be created for the food before it transits the band into the stomach below. This will generate a force. The two key variables that determine that force are the volume of food present and the rapidity of eating. As the force seeks to create space, any weakness in fixation will be displayed.

Posterior prolapse was seen with the perigastric pathway of placing the band, which often passed across the upper reaches of the lesser sac. The smooth and extensive peritonealized posterior gastric surface was the most likely to slip under the stress of eating, creating a posterior slip. This greater level of posterior weakness protected any deficiency in the anterior fixation and so anterior slips were relatively rare at that time. A randomized controlled trial involving 200 LAGB patients in which the perigastric pathway was compared with the pars flaccida pathway, which always places the band above the lesser sac, showed complete prevention of posterior prolapse by the pars flaccida approach [7].

Physiology and Pathophysiology of the LAGB

An understanding of the anatomy and physiology of the upper stomach when a band is present is needed to understand the mechanisms for proximal gastric enlargements and thereby to prevent them.

The LAGB should be placed at the very top of the stomach, around the cardia and within 1 cm of the esophagogastric junction. The primary mechanism of action of the LAGB is by the induction of a sense of satiety, a lack of appetite or hunger [8]. There are two components to this—satiety and satiation.

Satiety is the state of not being hungry. It is achieved for the LAGB patient by adding or removing of fluid from the system to change the degree of compression of the band on the gastric wall. When this compression is optimal, it induces a sense of satiety which is present throughout the day. Although some hunger may develop at times during the day, there is a general reduction of appetite, less interest in food and less concern about not eating.

Satiation is the resolution of hunger with eating. For the LAGB patient, it is induced by each bite of food as it passes across the band. When the band is optimally adjusted, each bite is squeezed across by esophageal peristalsis, generating increased pressure on that segment of the gastric wall. This reduces any appetite that may have been present and induces a feeling of not being hungry after eating a small amount. The combination of these effects allows the person to eat three or less small meals per day.

Figure 1 shows the components of the lower esophageal contractile segment (LECS), an entity first described by Dr. Paul Burton from extensive study of the physiology of the gastric band [9]. It brings together the key elements that together generate early onset of satiation after eating. The distal esophagus squeezes each bite of food to the stomach proximal to the band. The lower esophageal sphincter relaxes to allow passage and then contracts to maintain the forward pressure. The proximal segment of stomach maintains tonic contraction and detects the pressure increase. The band maintains an optimal compression to provide sufficient resistance to stimulate afferent signals but not sufficient to stop transit. There should be no restrictive component for normal functioning of the LAGB.

Fig. 1.

The four components of the lower esophageal contractile segment (LECS) (© CORE under licence, with permission).

The optimally adjusted LAGB modifies the normal transit of a food bolus into the stomach. With normal swallowing, a food bolus is carried by esophageal peristalsis down the esophagus. The lower esophageal sphincter (LES) relaxes and the bolus passes intact smoothly into the stomach. The LES facilitates the final transfer with an aftercontraction. With the band in its correct place with only 1 cm of cardia above the upper edge of the band and with the band optimally adjusted (exerting a pressure of between 25 and 35 mmHg on the gastric lumen [10]), the esophagus must generate stronger peristalsis, and the after contraction of the LES becomes more important. The bolus is squeezed through by these forces. It takes between two and six squeezes to achieve complete transit of a single small bite. This may take up to 1 min [11].

Figure 2 shows a small bite of food in transit. The aftercontraction of the LES is evident. Just part of each bite will transit on each peristaltic sequence. The remainder will reflux into the body of the distal esophagus, generate a secondary peristalsis wave, and a further squeeze will occur. After several squeezes the bite will have passed. Importantly, each squeeze generates signals to the satiety centre of the hypothalamus. The signalling of both satiety and satiation to the arcuate nucleus of the hypothalamus does not appear to be mediated by any of the hormones known to arise from the cardia as none has been shown to be increased in a basal state after band placement and none increases postprandially [12]. Vagal afferents are the more probable mediators and, among these, the intraganglionic laminar endings (IGLEs) demonstrate the characteristics needed to subserve this role [13, 14].

Fig. 2.

A small bite of food is being squeezed across the band, thereby compressing the vagal afferents and generating a feeling of satiety (© CORE under licence, with permission).

A second swallow should not commence until all of the previous bite has passed totally into the stomach below the band or stretching of the upper stomach and distal esophagus will occur. If such stretching occurs repeatedly, disruption of the lower esophageal contractile segment and eventually persisting enlargement will occur.

Classification of Proximal Enlargements

Posterior Slip

When pressure from eating too quickly or taking too big a bite occurs, the weakest link in the chain will show up first. When the LAGB was initially placed along the perigastric pathway, the weakest link was the posterior wall of the stomach and a posterior slip or prolapse occurred. The large smooth posterior surface of the stomach could easily slide through the band to create a pouch above. On a barium meal the band was seen to have moved from a diagonal to a vertical position and the gastric pouch was lying to the patient’s right side of the band. This problem was detected very soon after the introduction of the Lap-Band [15]. A range of technical changes were introduced without important effect until there was a change from the perigastric pathway to the pars flaccida pathway. By this change, the band no longer was passing across the upper reaches of the lesser sac but rather through the tissues posterior to the esophagus and the weakness was removed. A randomized trial comparing to two pathways showed elimination of the posterior slip [7].

Anterior Slip

With change to the pars flaccida approach, the next weakest link was shown to be the lateral, or less often the medial, aspect of the anterior fixation. Anterior prolapse became the common form of proximal enlargement. In this case the band was seen on plain X-ray to lie transversely and the enlargement was seen on barium meal to lie above and to the patient’s left of the band.

Symmetrical Gastric Enlargement

More recently, with the exercise of greater care in completing the anterior fixation, there is generally no weak area posteriorly or anteriorly. If the patient eats too big a volume or too rapidly or the adjustment is excessive, the force simply stretches what is there and, in time, a symmetrical enlargement develops (Fig. 3). If there is too much stomach above the band from the time of the initial placement, as occurs with an unrecognized hiatal hernia, this enlargement occurs more readily.

Fig. 3.

The bite is too large or a second bite has been taken before the first bite has completed transit. There is a proximal enlargement disrupting the action of the lower esophageal contractile segment (© CORE under licence, with permission).

Focal Esophageal Enlargement

A variant of the symmetrical enlargement that is important to recognize is the focal enlargement of the distal esophagus. This will occur in the same setting as symmetrical gastric enlargement when there is too little stomach proximal to the band to expand. The importance of its recognition lies in its management. Revision with replacement of the band above the enlargement is not appropriate and removal of the blocking effect of the band by removal of fluid or possibly removal of the band is required.

Diagnosis of Proximal Enlargements

Each of the forms of proximal gastric enlargement presents clinically as a problem of stasis at the distal esophagus, the principal symptoms being reflux, especially at night, heartburn, vomiting, and food intolerance. There are no “normal” symptoms after LAGB. If your patient has the symptoms mentioned above, there are only three possibilities. The band is too tight, they are eating too quickly or too big a bite and they have a proximal enlargement. All three may be present.

Diagnosis of proximal enlargements is generally achieved by barium meal. A small volume of dilute barium will demonstrate the anatomy as present. However, the abnormal anatomy may be intermittent, occurring only with eating. A stress barium meal is needed to define this problem [16]. For symmetrical enlargements, upper gastrointestinal endoscopy is required to separate the esophageal and gastric enlargements.

If the symptoms persist in spite of removal of fluid from the band, the problem is treated by laparoscopic removal and replacement of the band along a new path above the previous one. It has proven to be a safe procedure, requiring no more than an overnight hospital stay, and has rarely been associated with a second enlargement, and the patients’ weight loss pattern remains on the track they were initially following [6].

Treatment: Nonsurgical

The first two steps in all patients having symptoms are the reduction of fluid in the band and reinforcement of the need to eat small bites slowly. If the clinical suspicion is that the last adjustment was too much, reduction of a small volume, perhaps 0.3 mL or less is sufficient to give relief, and the patient can proceed with their weight loss process. For the more severe symptoms of an acute block, such as a bolus of food sticking and copious vomiting being present, it is preferable to remove a greater volume of fluid, 2–3 mL, check that normal swallowing now occurs and then begin to replace the fluid after a period of rest for several days. If symptoms are not relieved or recur, proceed to barium meal.

If the barium meal shows a proximal enlargement, remove all fluid from the band, wait 1 month and repeat the barium study. Generally there will be a return to normal anatomy. Reinforce the eating rules with the patient, advise of the tendency to recurrence if they are not very careful and then begin the stepwise replacement of the fluid to a level to achieve satiety. Approximately 50 % of our patients need no further action and continue on their weight loss program. If recurrence of symptoms occurs in the months or years after the conservative approach, we will generally discuss revision of the band with repositioning along a new pathway above the enlargement.

Anterior gastric slips are more likely to cause acute problems and are less likely to resolve with a conservative approach. Although we will seek to relieve the problem in some by removal of all fluid and review with barium meal at one month, we are more likely to proceed directly to surgical revision. If there is a marked enlargement and upper abdominal tenderness, this should be done urgently as perforation of the acute anterior slip has occurred. If the symptoms are more modest, early elective revision is planned.

Only gold members can continue reading. Log In or Register to continue