WLS Info: Understanding your pouch

[Guest guest]

UNDERSTANDING THE FUNCTION OF THE SMALL GASTRIC POUCH; APPLICATION

TO POST-OP TEACHING AND EVALUATION

By Latham Flanagan, Jr., M.D., FACS

INTRODUCTION

From our earliest experiences in bariatric surgery, we have been

intrigued with the question " How does our operation cause weight

loss and maintenance? " As we talked to the public, and even our

medical peers, it became evident that a common concept of the

uninformed is that the small gastric pouch simply mechanically

restricts intake, preventing the post-op patient from eating too

much. Indeed, superficially, it may appear that way especially in

the first 3-9 months post-op. However, even a short experience with

following our patients shows us that with a meal size of even three

to five ounces, certain patients will stop losing weight and start

to regain. We also note that two to five or more years

postoperatively certain patients seem to have a large meal volume of

six to ten ounces but still maintain good weight control without an

noxious degree of hunger. It has become clear with experience that

the principle of weight control is the achievement of satiety, or

the absence of abnormal hunger, associated with the ingestion of the

appropriate number of calories sufficient to meet the person's need.

If adequate satiety is achieved, our patients are successful. . .

And they fail if that satiety is not achieved. When patients " fail "

there is a tendency, even among bariatric surgeons, to pass it off

as " noncompliance. " Certainly, this can be an appropriate evaluation

in a few persons who are not willing to accept responsibility for

the lifestyle changes necessary to make the small gastric pouch

function properly. But, is this the problem for the majority? I

think not. When failure does occur, it is usually the inability to

maintain the post meal satiety long enough to prevent snacking

before the next meal time arrives. Also, it could be due to

ingestion of a large number of calories in a form that is somewhat

hidden to the patient and is not responsive to the gastric pouch

restriction, especially high calorie liquids.

HYPOTHESES OF POUCH FUNCTION:

At this point in time what have we learned about how the small

gastric pouch works? In the form of an hypothesis, we can now state

that the basic mechanism is that of stretch of the pouch walls with

eating of a small meal, or even the drinking of fluid. This stretch

is sensed by the stretch receptors in the pouch wall and relayed by

neural pathways to the appetite centers in the hypothalamus by way

of the tractus and nucleus solitarius. The second hypothesis is that

successful maintenance of satiety depends upon the creation and

maintenance of a small gastric pouch and a small gastric pouch

outlet (Mason- reference 1). The third hypothesis is that the

observed increase in functional meal volume over the months and

years following a gastric bypass procedure is due to the process of

hyperplasia and is not wholly or in great part due to noncompliance

on the part of the patient. The fourth hypothesis is that

understanding of these principles and effective teaching to a

compliant patient results in better weight loss and maintenance than

if the teaching is not accomplished.

PUBLISHED DATA

To support these four hypotheses, we have two pieces of reasonably

good scientific information from peer reviewed published articles.

From that point we must rely on observational-based science.

Our first question is how does the small gastric pouch create

satiety? Considerable insight on the neurological pathways of

satiety has been obtained through the work of Barber, a

Ph.D. veterinarian, and his associates who published a paper in 1983

entitled " Brain Stem Response to Phasic Gastric Distention. "

(reference 2) They placed a balloon in the stomachs of anesthetized

cats and surrounded the stomach with a strain gauge. Microelectrodes

were placed in the nucleus and tractus solitarius of the brain stem.

They found a population of neurons that faithfully monitor moment to

moment changes in gastric wall tension. The discharge frequency to

wall tension did not adapt for the twelve hour period of the

experiment. This response was dependent upon an intact vagal nerve

in these cats. They concluded that " these neurons may serve as a

critical link between the stomach and higher centers in the

conscious perceptions of fullness. " It seems particularly impressive

and interesting that the neurons continued to fire at an accelerated

rate for as long as twelve hours, if the gastric wall tension

remained high.

Another question of considerable importance to the thinking of a

bariatric surgeon is what is the fate of the small gastric pouch?

Does it enlarge at all after the surgical procedure? If it does

enlarge, is it because the operation was done improperly? Was it

because of gross patient noncompliance and gorging? Or, is it due to

the kind of hyperplasia seen throughout the gastrointestinal tract,

a response to loss of function? Dr. E. E. Mason, at one of the Iowa

Bariatric Symposia in the early 1980's, suggested that it might be

useful to ask patients to eat cottage cheese in a structured manner

in order to attempt to determine their functional meal volume at

different times postoperatively. I took the idea home and began

asking all of my patients to do this simple test with each one of

their follow-up postoperative visits at three, six, nine, twelve,

eighteen, and twenty-four months. We continued to do this over the

next decade (and subsequently to date), and figure 1 reveals a

regular, progressive, stepwise increase in functional pouch volume

over time that strongly suggests the orderly process of hyperplasia.

Stabilization occurred at two years at a mean pouch size of six

ounces with a wide range of three to nine-ten ounces. The pouch

appears to not get larger after the second year. (reference 3) These

gastric bypass pouches were created as a vertically oriented, 30 cc

pouch measured against both volume and pressure of 70 to 85 cm of

water. The curve of pouch enlargement is the inverse of the weight

loss curve.

We then proceeded to compare the patients' weight losses at one and

three years to pouch sizes at one year. Figure two reveals that

there was no difference in percent excess weight loss at one year,

with the different pouch sizes within this range of up to nine-ten

ounces. We then compared the largest third of pouch sizes to the

smallest third of pouch sizes, and still there was no significant

difference in weight loss at one year or of maintenance at three

years. This finding is, perhaps, the most important result to come

from the Cottage Cheese Test work. It strongly suggests that within

these limits of pouch sizes that success in weight loss and

maintenance depends not only on having a small gastric pouch but

even more so in how the patient uses their " pouch/tool. " If this is

true, then the implication is clear that learning how to use the

pouch/tool effectively is important and that it is our

responsibility as bariatric surgeons to see that effective teaching

is made available to our patients over this two year period of

changing intake and satiety control. In brief, the Cottage Cheese

Test data tells us that within the context of a small meal volume,

lifestyle change including exercise is the most important variable.

The stepwise progressive growth in the functional pouch volume (meal

size) probably defines the rate of weight loss for the patients

taken as a whole, but the degree of weight loss and maintenance for

the individual patient is more dependent upon that patient's ability

to make the required lifestyle changes: proper use of the pouch/tool

and adequate amounts of activity and exercise.

OBSERVATIONAL-BASED MEDICINE

Observational-based medicine has a long history of respect going

back to the early work of two of my personal surgical heros, s

Vesalius and Ambrose Paré. Indeed, we often refer to the " art and

craft of surgery " . Although we do make great effort to have a

scientific basis to our surgical decision making, ideally with

prospective randomized studies or double blinded studies, at this

point in time the majority of what we do is based on empiricism, or

observational-based medicine. The observations that I would now like

to share from my own personal thirty-three years of experience in

bariatric surgery are also shared by many other experienced

bariatric surgeons of my acquaintance, although not all would agree

with all of these principles.

For the first fifteen years, although I remained busy in a general

surgical practice, my primary interest, bariatric surgery, lagged

because of the lack of patient material, primarily because of the

profound discrimination of medical insurers against the morbidly

obese in our area of the country. What appeared to be a disadvantage

initially became an advantage, as I thereby had the opportunity to

follow almost all of my patients personally during that time. As

there was little known about the mechanism of action of the gastric

bypass procedure, I spent a good deal of my time thinking about

possible mechanisms and observing the differences between patients

with good weight loss and those with poor weight loss. Since the

beginning, I have performed the short limb gastric bypass procedure

(GBP), only adding the malabsorption procedure of the banded

gastroplasty/distal gastric bypass procedure (BG/DGB) in 1992. The

BG/DGB also uses a small, vertically oriented gastric pouch quite

similar to the gastric bypass procedure pouch, the difference being

that the outlet is controlled by a band as in the vertical banded

gastroplasty and silicone ring gastroplasty, etc., instead of a

gastroenteric anastomosis. My observations seemed to be similar for

the two procedures, although not identical for both. The Cottage

Cheese Test was done only with the GBP. Considering the above, what

do I think that I have learned?

The following are observations that may have an effect on the

function of the gastric bypass pouch:

1. We have come to understand that the accomplishment of satiety, or

suppression of hunger, is fundamental to the success or failure of

bariatric operations.

2. We have come to understand that success relates anatomically to

creating a small pouch that remains relatively small and a small

outlet that remains relatively small (Mason).

3. Meal volumes much larger than ten-twelve ounces usually result in

failure of weight maintenance.

4. The use of the thick, less distensible lesser curve of the

stomach is believed to be important by many surgeons.

5. Satiety is achieved by increasing the tension on the gastric

pouch wall, thus stimulating the stretch receptors.

6. Maintaining satiety is dependent upon maintaining some portion of

that stretch for an undefined period of time.

7. For either the gastric bypass or the banded gastroplasty, almost

all patients have a profound satiety, 24 hours a day, in the first

six months or so following their bariatric surgical procedure. They

do not redevelop a normal appetite preceding the next meal until six

to twelve months postoperatively.

8. If for any reason the patient is NPO for a significant period of

time like eight to twelve hours, a profound hunger will be

experienced.

9. In the mature pouch at one plus years post-op, the more solid of

food that a patient eats, the longer is the satiety period after the

meal.

10. Almost all patients after the gastric bypass procedure, and most

patients after the vertical banded gastroplasty, achieve fifteen to

twenty-five minutes of satiety after simply rapidly drinking water

to a point of fullness, or " water loading. "

11. Some patients fail the banded gastroplasties in association with

shifting their diets to mostly liquids or soft solids, the " soft

calorie syndrome, " and they fail by becoming hungry too soon before

their next meal and giving in to snacking between meals because of

that hunger.

12. Responsible patients who carefully follow the principles of

using their " pouch/tool " continue to have a reliable and progressive

weight loss and weight maintenance.

13. Patients who approach or become underweight at one to two years

following bariatric surgery can reverse their weight loss with

reversing the principles of using their pouch/tool.

HOW DO WE INTERPRET THESE OBSERVATIONS?

POUCH SIZE:

It seems intuitive that the functional meal volume must stay small

in order to limit the patient's caloric intake and provide satiety.

What is not clear is how small it must remain. The Cottage Cheese

Test, discussed previously, gives us some insight. With the data

from that test, the pouch size/functional pouch volume can exceed

six to seven ounces and still give as good a satiety as a smaller

pouch. Obviously, this depends on patient behavior such as choices

of specific foods eaten, frequency of meals, fluid management, and

last but certainly not least, the amount of activity/exercise.

OUTLET SIZE:

The outlet of the small gastric pouch is a fixed ring, either fixed

by scar or fixed by a band or both. There is no longer a valve that

controls the rate of emptying. Therefore, it is intuitive that

liquidy foods will exit the pouch faster than more solid foods.

Certainly, no pouch can control the amount of fluid consumed, nor

would it be tolerable if that could be done. Therefore, the calories

contained in high calorie liquids have the ability to defeat weight

loss or maintenance.

EARLY PROFOUND SATIETY:

The mechanism of action of the profound satiety of the first six

months is presumed to be due to the necessity of the patient

drinking water very frequently throughout the day in order to meet

minimal fluid requirements. From our experience with " water

loading, " we note that water loading will give almost all patients

fifteen to twenty-five minutes of satiety if done when they are

hungry. Presumably, the frequency of water drinking during the first

six months simply overlaps these short periods of water-induced

satiety.

The return of appetite in our patients at about six months

correlates with two-thirds of the pouch hyperplasia as determined by

the Cottage Cheese Test. The average pouch size then is

approximately four ounces when the lesser curve pouch is created at

one ounce in volume at 70-85 cm of water pressure. The mechanism of

action is presumed to be a less frequent stimulation of stretch

receptors in the gastric pouch wall because at this point the

patient can ordinarily drink six to eight ounces of water at a time.

OPTIMUM MATURE POUCH:

How might we describe the optimum mature pouch? The pouch seems to

work best when one, the outlet is not too restrictive to allow

eating of solid foods such as meat and vegetables but two, the

outlet is not so large as to allow early emptying and premature loss

of satiety from solid food, and three, the pouch is not too large to

allow over eight-nine ounces a meal.

IDEAL MEAL PROCESS:

What might be the ideal meal process? The ideal meal process

includes timing of meals. To get through the day without hunger on

three meals a day, there needs to be about five hours between

breakfast and lunch, lunch and dinner, and dinner and bedtime. It

becomes evident that if there are only three hours between breakfast

and lunch, and then six to seven hours between lunch and dinner,

that one cannot expect satiety to be maintained over the full seven

hours, no matter how solid the food eaten, short of frank outlet

obstruction. For the optimum meal, a more solid type of food such as

finely cut meat and minimally cooked or raw vegetables should be

eaten. The meal should be taken over five to fifteen minutes,

depending upon the functional pouch volume. Stringing a meal out

over thirty to forty-five minutes or more is one of the techniques

that has been used to " beat the pouch. " Following the meal, take no

liquids for one and a half hours, or even two hours if satiety is

lost too soon before the next meal. Then, after that one and a half

to two hours is up, begin drinking low or no calorie fluids somewhat

slowly (in order to avoid over load symptoms if there is still

considerable food in the pouch) and then progressively accelerate

drinking up to fifteen minutes before the next meal. The patient

should be urged to drink a lot of water in the two hours or so

before the following meal. This period of rehydration ends with

a " fluid load " fifteen minutes before the next meal. However, a

single pre-meal fluid load can never adequately rehydrate an

individual who has not already been drinking a lot of fluid. Fluid

loading can be done any time in the two to three hours preceding the

meal if hunger is experienced. This use of the fluid load can

substitute for taking in unwanted calories through snacking.

THE MANAGEMENT OF PATIENT TEACHING AND TRAINING

Postoperative patient instruction begins with setting appropriate

expectations preoperatively through the information provided in your

thorough patient information booklet. This is the time to introduce

fundamental principles such as: the small gastric pouch is a " tool "

to gain and maintain satiety. Most patients have a fairly clear

picture that a tool is something that one uses to perform a task but

that the tool itself is relatively useless if it is put away on a

shelf and not used. Patients also seem to appreciate that developing

skill in using a tool will make the tool more effective.

NECESSITY FOR LONG TERM FOLLOW-UP:

We emphasize the need for long term follow up care. It is not

possible in most patients to teach a fundamental change in lifestyle

in " theory " by written materials given preoperatively or immediately

postoperatively. The fine tuning of the teaching of how to use the

pouch/tool to prolong satiety is not probably able to be

accomplished until the patient redevelops hunger before the next

meal, in the sixth to twelfth month postoperatively. Techniques on

delaying the return of hunger are simply not relevant to most

patients when they are not hungry at all, as they are not in the

first six months. Even emphasizing preoperatively the crucial need

for long term follow up care does not always result in patients

returning as they should, but one must set the expectation for those

who will be compliant for long term follow up.

PREVENTION OF VOMITING

We believe strongly in the principle that vomiting should be

prevented if at all possible. This teaching begins in the hospital

on the second postoperative day when we initially instruct the

patients to drink only out of one ounce cups, and to drink only one-

third of that ounce at a time with sufficient time between thirds to

detect fullness. We emphasize that it is not easy to get used to

having a small pouch volume. For the first few months, the patient's

mouth will be larger than their stomach, a situation which otherwise

does not exist in the mammalian kingdom. Also, we keep our standard

gastric bypass patients with their small edematous outlet on liquid

feedings for the first six weeks, gradually advancing from totally

liquid nutrition such as Ensure supplemented by protein powder up

through a blenderized diet and very soft solids. The banded

gastroplasty/distal gastric bypass procedure with its relatively

generous 7.0 cm band on its outlet is advanced more quickly to soft

solid foods by three weeks.

Vomiting seldom occurs in the immediate postoperative period unless

there is an outlet obstruction problem. However, vomiting can occur

and will do so in most patients at some time after starting on solid

food. There are more complexities when eating solid food especially

rice, pasta, or granola, foods that swell in the stomach after being

eaten because they are generally incompletely rehydrated before

being consumed. The most frequent cause of vomiting is overloading

the pouch. We encourage patients to continue to measure their meals

with their one ounce cups for weeks, even months, following the

surgery if they are experiencing difficulty with vomiting. We

emphasize repeatedly that they should eat only until " comfortably

satisfied " as the word " full " has different meanings to different

persons.

SIX WEEKS

Solid food is begun with emphasis on the fine cutting of fibrous

food to the size of the fifth fingernail or smaller, thoroughly

chewing, three or more foods at each meal to prevent wadding up of

similar fibers, eating only until " comfortably satisfied, " and

beginning, even at this early date, to teach the concept of no

liquids with meals for fifteen minutes before meals and for one and

a half hours after meals.

REASSURANCE OF ADEQUATE NUTRITION

Many patients need reassurance that they can achieve adequate

nutrition in the postoperative period. Without this reassurance,

some patients will deliberately eat six to eight times a day because

of a fear of malnutrition (often initiated by well meaning family

members and friends). We like to point out that in this short period

of time during the pouch growth, there are only two major

nutritional needs: protein on the one hand and vitamins and minerals

on the other. The latter can easily be achieved by the patients

routine twice a day use of the vitamin supplements. Therefore, their

only responsibility and focus is to eat low-fat, animal-source

protein at each meal, three to four times a day. If they do this or

simply come close to doing this, they will end their first year post-

op with a lower than pre-op lean body mass but one that is

appropriate to their body weight at that time.

(reference 4)

MEAL SKIPPING

On the other hand, some patients are likely to skip meals when they

have no appetite, similar to their behavior previously when their

appetite has been diminished by over tiredness or illness. We

emphasize the need for three to four meals a day, including

breakfast, primarily to meet their needs for protein. We emphasize

that one-half or more of each meal should be composed of this low-

fat, animal-source protein (two-thirds of their meal in the distal

gastric bypass procedures) in the first months until their pouch

volume is large enough so that they can eat at least two ounces of

protein at each meal.

ARTIFICIAL SWEETENERS:

We warn our patients to be aware of using artificial sweeteners if

they are experiencing hunger in this early p.o. period. We have

evaluated a few patients who experienced very strong hunger cravings

in the first weeks or months post-op whose hunger abruptly ceased

with stopping artificial sweeteners.

AVOIDING ABSOLUTES

There are so many rules that we teach concerning the use of

the " pouch/tool " that we believe that it is important to emphasize

to the patient that it is not necessary to follow every rule all of

the time. We actually suggest that it is perfectly all right to

break the rules once in a while- the important thing is to be aware

that one is breaking the rule and having a reason for it even if

that reason is simply alleviating frustration. We point out that the

only penalty for eating a liquidy meal when appetite has returned is

the earlier return of hunger in the next four to five hour period.

There is no lasting effect beyond that next meal. We also point out

that deciding to take advantage of a social opportunity to eat a

high calorie, empty calorie meal is the ingestion of a relatively

insignificant 600 to 1,000 calories instead of the 3,000 to 5,000

calories that could be consumed in such a meal with a normal stomach

volume.

THREE MONTHS

At three months we step up the teaching of the nutritional or

protein-containing value of foods related to the " cost " of that

protein food in terms of calories consumed, i.e. a gram of cottage

cheese protein " costs " only five calories, but a gram of cheddar

cheese protein costs sixteen calories, and peanut butter twenty-four

calories. Water loading techniques (see below) are introduced at

three months postoperatively as some patients will begin to see a

return of appetite before their six month office visit. Overall

fluid management is discussed, emphasizing how the Gastric Emptying

Test illustrates the principles of fluid management (see below).

THREE PRINCIPLES FOR GAINING AND MAINTAINING SATIETY

1. The pouch needs to be truly filled with adequate wall distention

with each meal (i.e. no snacking).

2. Keep the pouch filled over time and slow down the emptying time

(by eating solid foods and avoiding liquids for fifteen minutes

before and one and one half to two hours after eating. We understand

this to be the most important lifestyle change after the gastric

bypass procedure. Figure 3 shows the results of a standard gastric

emptying test using radioactive sulfur with a scrambled egg, bread,

and milk. With the milk, 90% of the meal volume has exited the

stomach within forty-five minutes. However, without the milk, only

45% of the meal has exited the stomach by ninety minutes.

3. Finally, adequate protein with each meal. We emphasize three

meals a day including breakfast (defined as the first meal of the

day which is eaten within one to two hours after arising). We define

the " enemy " as high calorie liquids. We point out that snacking and

high calorie liquids cheat the patient because the calories are

taken in without offering significant satiety.

FLUID LOADING

Fluid loading is the rapid drinking of a non-calorie or low-calorie

liquid on an empty stomach in order to achieve a maximal intake of

water at that time and/or achieve immediate satiety which lasts for

fifteen to twenty-five minutes. About 80% of the estimated maximum

capacity at any given time should be drunk rapidly over fifteen to

thirty seconds and then topped off with swallows until full satiety

is reached. Patients rather rapidly determine what their capacity

is, and it usually is between eight to twelve ounces when the

Cottage Cheese Test volume is four to six ounces. The fluids should

not be so cold as to be uncomfortable, but it is not necessary to be

warm. The mechanism of action is presumed to be the distention of

the Roux limb with subsequent contraction, stopping the progression

of fluid downwards and backing up the volume and pressure into the

small pouch and, perhaps, even into the distal esophagus. Fluid

loading works with the banded gastroplasty as well but not quite as

effectively. The mechanism here is probably primary distention of

the pouch with a fluid as it is passing through. The volume required

is usually somewhat greater, but it still is far less than two to

four glasses of water required in a normal sized stomach. Clearly,

this small proximal pouch is quite sensitive to distention, and the

satiety gained from that distention lasts far longer than the

distention itself. We teach patients to fluid load before each meal

in order to help prevent post meal thirst, but also to fluid load

whenever they feel the sensation of hunger and are tempted to snack.

POST PRANDIAL THIRST:

It is important that the patient be fully hydrated before coming to

the next meal because the solute load of the meal will create

postprandial thirst. It seems intuitive that persons cannot tolerate

thirst any more than they can tolerate hunger over the long run as

both hunger and thirst are primary noxious stimuli. Initially, when

the functional pouch volume is quite small, the solute load is

correspondingly small, and the patient may not see the point of

adequate rehydration and pre-meal fluid loading. However, as the

pouch volume increases and the solute load increases, it becomes a

significant issue in maintaining that important proscription of

avoiding liquids during and for an hour and a half after the meal.

URGENCY

In these first months we like to emphasize to patients that their

golden opportunity for maximizing their weight loss is in the first

six months after surgery. We illustrate this with the weight loss

curve, with its rapid downward sweep, with two-thirds of their

weight being lost in the first six months postoperatively. The

Cottage Cheese Test shows that two-thirds of the pouch growth occurs

in the first six months. Therefore, we teach our patients that every

day during this early period the exercise and activity that they do

will be more effective in burning calories in excess of their

calorie intake than the same amount of activity/exercise the

following day. . . and a little less effective than the previous day

based on progressive pouch growth. I.e. every single day the patient

should take advantage of their present opportunity and get as much

activity as they can, knowing that never again will that same amount

of activity result in as much weight loss. We try to give them a

sense of urgency about getting the most out of every day.

SIX MONTHS

At this point, or soon after, our patients are beginning to get

hungry before their next meal, and we accelerate the teaching of

satiety mechanisms and the prevention of post meal thirst. As the

meal solute volume increases, they need to push enough fluids in the

two to three hours before the meal to gain good hydration with final

water loading fifteen minutes before the next meal.

INTAKE INFORMATION SHEET AS A TEACHING TOOL

At each visit from three months to two years, the patient is asked

to complete a form before they come into the office. The form

queries them about their performance on the principles of pouch use

(as well as vitamin usage, exercise, pathological symptoms, etc.).

This form is designed so that it is also a teaching tool- each

question reminds the patient about the principles of the use of

their pouch/tool. Many, if not most, patients do very well, and

their weight loss is progressive and satisfying. Some struggle to

make the lifestyle changes necessary, but with these periods of

intermittent monitoring, encouragement, and teaching they

progressively learn and most do well. A few patients never seem to

understand or to remember these simple principles even though they

might be quite intelligent, capable persons in other facets of their

lives. . .

HONEYMOON SYNDROME

The profound satiety that patients experience in the first six

months, along with the rapid weight loss due to intake restriction,

can lead certain patients to believing that these circumstances will

never change in spite of the clear teaching of our patient

information booklet and clinic visit handouts. For these patients,

we will then see a slackening off on their food selection and liquid

calorie control and see them indulge in more recreational eating.

They will cut back on their exercise as they seem to be losing a

great deal of weight without exercising. Their weight loss will

subsequently slow. We have dubbed this situation the " honeymoon

syndrome " and tried to educate our patients, even in our

preoperative informational booklet, that they can expect this

temptation to occur and that they must not get " suckered " into a

false sense of comfort that leads them to not make a sufficient

effort in their own behalf and miss this golden opportunity for

weight loss. We have found that an effective tool for identifying

and reality-orienting the patient is to graphically compare that

patient's weight with the mean weight loss of the group as a whole.

Whatever the patients beginning weight is, we would expect them to

parallel the weight loss curve. If their weight deviates from the

expected, we should be able to find a reason for it and to correct

it if the patient is willing to learn and make this needed lifestyle

change.

EXERCISE

Although this chapter is about understanding the function of the

small proximal gastric pouch and how it relates to patient

management, a word must be mentioned about exercise. We believe that

the scientific data overwhelmingly demonstrates that 1) exercise is

a critical part of a healthy lifestyle for patient and doctor alike,

and 2) that exercise is necessary to maintain weight loss in the

obese patient. Therefore we believe it must be a critical part of

our postoperative patient teaching and encouragement. Exact details

are beyond the scope of this presentation, but we do emphasize to

the patients that the feelings of vigor and energy are in no way

guaranteed by a slender figure. Observations of people on any city

street confirm this. . . We emphasize that the release of endorphins

with aerobic exercise improves emotional stability and mental

clarity and helps any person to cope with the deprivations and

annoyances of everyday life. Endorphins, adrenalin, norepinephrine,

etc., also act in an antidepressive manner. But most importantly,

especially in the first six month period when the gastric pouch is

so small, regular aerobic exercise maintains, or even improves basal

metabolic rate that is observed to drop during rapid weight loss.

THE IDEAL MEAL FOR WEIGHT LOSS

The ideal meal for weight loss is one-half of the meal volume up to

a total volume of two to three ounces of animal-source, low-fat

protein plus filling the rest of the pouch volume with low starch

vegetables and solid type fruits such as apples and pears. Cut

finely and chewed well, these foods represent coarse, solid food

choices that are likely to stay in the pouch longer and offer good

nutritional value.

VOLUME VERSUS CALORIES

A person with a normal stomach tends to judge how much he/she needs

to eat at a given meal by approximately how many calories are in

that meal (although not necessarily thinking of calories as such).

In other words, we know that we are going to be unpleasantly hungry

before dinner if our noon meal consists of a green salad and a

couple of ounces of cottage cheese. Calories are what keep us from

getting hungry between meals. On the other hand, the post-op gastric

bypass patient needs to learn to think about the volume and

consistency of food choices rather than their caloric content when

judging how to prevent getting hungry before the next meal. I recall

a lecture I once attended in which the lecturer pointed out that one

or two sticks of butter could meet our entire calorie needs for the

day and could be easily consumed by even the small post-op gastric

bypass pouch. However, that same number of calories in the form of

non-starchy raw vegetables could not be consumed by a person with a

normal stomach in only three meals a day. * There is an enormous

variation between calories and volume, and a patient needs to learn

how to " think volume " when making food choices to gain and maintain

satiety in a mature small gastric pouch. * In other words, satiety

can be accomplished with the use of the low fat, high bulk

nutritional program, without the risk of surgery!

ISSUES FOR LONG TERM WEIGHT MAINTENANCE

The previous comments are primarily designed to deal with patient

issues in the first year following a gastric bypass procedure. These

issues should seamlessly slide into long term weight maintenance

and, indeed they do so in most persons.

COUNTER-INTUITIVENESS OF FLUID MANAGEMENT:

It is clear that avoiding liquids with meals and pushing fluids

between meals is counter intuitive. The large capacitance of a

normal stomach is a great convenience factor for that person and,

truly, all animal life. There is a resistance to learning this

technique, and clearly it is counter intuitive to the experience of

the individual. However, if it is important that solid food be taken

rather than liquidy food to maintain satiety, then it is clearly

important to avoid liquids with meals or soon after meals as the

liquid will simply make the food more soup-like and soft and allow

more rapid emptying of the pouch and, therefore, shorten the period

of satiety.

SUPPORT GROUPS

We have found that support groups are very effective in reinforcing

the principles of the pouch/tool use. Many, if not most, patients

will explore these principles on their own by using them and then

for a time not using them. Some patients on their own become

convinced of the value of these principles through this natural

experimentation. However, others may lose their way. The support

group offers an excellent feedback mechanism for individuals who

need reinforcement of the principles of the pouch use. Sometimes,

the feedback of their peers is more effective than that of the

parental figures in the surgeon's office.

TEETER-TOTTER EFFECT

One " visual " that we use when discussing weight maintenance is that

of a teeter-totter. On one end of the teeter-totter is the

exercise/physical activities, and on the other end is the meal

choice discipline and fluid restrictions. When one has a large

amount of exercise and activities, the teeter-totter swings down on

that end, and the amount of effort that need be placed on diet

discipline lightens up. When one is light on the activity/exercise,

one has to be much heavier on the diet discipline side. If one is

light on both exercise and diet discipline, the whole teeter-totter

moves upward as weight is gained. On the other hand, if one

is " heavy " on both exercise and diet discipline, the teeter-totter

bar goes down, and weight is lost.

TOO MUCH WEIGHT LOSS

There are a group of patients in our practice, approaching 15%, who

lose too much weight in the one to two year period postoperatively.

Inevitably, these individuals were only 100 to 150 pounds overweight

to start with and are good exercisers. We encouraged them to taper

off their efforts with diet discipline (maintaining their exercise

routine and thus their vigor) by adding some fat back to their meals

and eating a fourth or fifth meal a day with less discipline on the

fluid management. Basically, it is an exercise on " how to beat the

pouch. " The pouch can be beaten by one, liquid high calorie meals;

two, frequent meals or grazing; three, eating a meal over thirty to

forty-five minutes; four, adding liquid to meals to enhance gastric

emptying; five, liquids are taken shortly after eating which

increases gastric emptying and decreases the satiety period. Some

patients take our advice and taper off their weight loss before they

go underweight. However, a small but significant group of patients

actually go underweight because all of our patients have experienced

the rapid and frightening return of severe hunger cravings when

going from one of their many diets to trying to eat normally once

again. Very similar to a bear coming out of hibernation, their

suppressed appetite center seems to burst out with vigor in order to

save the life of this person who the appetite center sees as a

normal weight person having suffered in a famine. Many patients at

this point have not yet fully accepted that they have had a true

anatomic and physiologic change from their operation and that, using

the principles of the pouch/tool, a return of this overwhelming

appetite will not occur. For these persons, it is not until their

lean body mass is effected and they lose their delightful sense of

vigor that they will begin to " break the rules " and gain some needed

weight back. This is probably the primary reason why, in most

bariatric surgical practices, the weight loss curve bottoms out at

eighteen to twenty-four months with a rise at two to three years.

This rise has been erroneously interpreted as most patients

regaining 10% to 15% of weight from the nadir of their weight loss.

BARIATRIC MEDICINE

A much more common problem is that of patients who have not lost as

much weight as they would like and are plateauing at a level above

their goal weight. Bariatric medicine techniques can be useful in

helping our postoperative patients who find themselves stuck on a

plateau one or more years postoperatively. However, there can be a

problem with standard weight control and dietary teaching of

Bariatric medicine. The frequently used recommendations of frequent

small feedings or liquid calorie fasts such as a protein sparing

modified fast, neutralizes the satiety function of the pouch/tool,

and tends to negate the teachings of the principles of the pouch

use, and therefore is probably not an optimum way of managing the

patient.

SUMMARY

The principles of the postoperative bariatric surgical follow up

management are as follows:

1. Understanding the fundamentals of the anatomy and physiology of

the pouch/tool.

2. Evaluating the patient's appropriate or inappropriate use of the

tool- What is lacking? What is being done well?

3. Instruct patient with words, drawings, analogies, encouragement,

and passion, on not only what to do but why it needs to be done.

The goal is to make the patient become fully knowledgeable about how

to control their own weight over the long term through the

appropriate use of their pouch/tool, combined with a reasonable

amount of exercise.

EVALUATION FOR WEIGHT LOSS FAILURE

Evaluating a patient who is progressively regaining weight can be

relatively simple- or extremely difficult. The first principle is to

determine that the gastric pouch is anatomically intact. If it is

not intact, it should be made intact by a revision procedure. Only

when the surgeon can be reassured that the pouch is intact does the

complex part begin- evaluating how and why the patient is not using

the pouch/tool properly, and/or getting a reasonable amount of

exercise.

We need to know three things about the small gastric pouch. First,

is the staple line intact; second, is the outlet intact; and third,

is the pouch reasonably small in size.

The upper GI series with thick barium is the basic tool for

evaluating intactness of the staple line and the outlet. If the

pouch has been stapled in continuity with the rest of the stomach,

we must confirm that the staple line remains intact. An eventration

of the staple line will create two gastric outlets leading to rapid

pouch emptying, early loss of satiety, and thus early return of

hunger. An important clue from the patient's history is the presence

of a marginal ulcer after a gastric bypass. Marginal ulcers do

occur, occasionally, with an intact staple line. However, they are

more common with a small hole in the staple line that results in

food stimulation of the antrum. If there is a staple line

eventration, the marginal ulcer is unlikely to be able to be

controlled without reoperation and closure of that eventration,

preferably with complete division of the small pouch from the distal

stomach.

The upper GI series with thick barium in the hands of an experienced

radiographer can usually give the bariatric surgeon a reliable view

of the diameter of the gastric outlet. A diameter of over 18-20

millimeters is usually associated with weight regain, and we term

this " outlet failure. " Outlet failure, like a staple line

eventration, causes rapid emptying of the pouch, early loss of

satiety, and early return of hunger.

On the other hand, weight regain can occur as a result of an outlet

diameter under 7-8 millimeters which can lead to persistent vomiting

of solid foods and gradual persuasion of the patient towards the

Soft Calorie Syndrome with resultant rapid pouch emptying, early

loss of satiety, early return of hunger, and weight regain.

The upper GI series is less effective for evaluating pouch volume

because of the fact that barium is very much of a liquid. To assess

pouch volume, you must turn to the patient's history of the size of

the meal that he/she can consume within a short five to fifteen

minute time frame, and/or to the Cottage Cheese Test (see above).

In the patient whose gastric pouch seems to be anatomically intact

and yet he/she is still regaining weight, the evaluation becomes

more complex. The usual finding is that the patient is not following

the principles of the use of their pouch/tool and/or is extremely

inactive physically. There are four problems that occur with some

frequency: the patient has never been taught/or does not understand

how to use the tool; the patient is significantly depressed; or loss

of contact with a bariatric practice and other bariatric patients

and a gradual erosion of following the principles; or the patient is

truly noncompliant and will not take responsibility for his/her own

behavior.

LACK OF TEACHING

An excellent example of the lack of teaching/understanding of how

the pouch works is found in the history of GC. GC is a 62-year-old

woman who presented in consultation for a total regain of her weight

and complaint of constant hunger, sixteen years following a gastric

bypass procedure in Cambridge, Massachusetts. She stated that she

had not seen the surgeon beyond the six week follow up visit. She

understood nothing about how to use her gastric pouch. She initially

lost fifty pounds and then another forty pounds further with the

help of a commercial weight management program. For the next ten

years she yo-yoed up and down with the usual peer group and doctor

supported programs with a gradual increase in weight and the usual

hunger and deprivation syndromes relating to these programs. She

then developed myasthenia gravis * and her weight regain escalated

to her preoperative weight, resulting in the referral. At the time

of the referral she was being treated effectively for myasthenia

gravis and was reasonably active, being able to walk over a mile at

a time. Her weight loss curve with its abrupt turn around and rapid

weight loss (figure 4) could be consistent with a revision

reoperation. However, there was no revision done. After evaluation

of her pouch/tool with an upper GI series and a Cottage Cheese

Test/functional meal volume estimation, she was given the basic

instructions of how to use her pouch/tool, the same given to all of

our postoperative patients. Her ensuing and continuing weight loss

is impressive, but more impressive to the patient is that she is not

experiencing any distressing hunger cravings, food fantasies, or

food dreams as she had experienced with all of her previous efforts,

since the first months after her gastric bypass procedure sixteen

years ago. * auto immune disorders after surgery are theorized as

possibly caused by afferent limb syndrome wherein the unused portion

of the intestinal limb develops an overgrowth of bacteria.

DEPRESSION

Depression is a powerful inhibiter of success after bariatric

surgical procedures. A small but significant number of our patients

have been doing well following their gastric bypass procedure only

to drop out of sight for a time and then reappear with a significant

weight regain. Upon evaluating these patients, it would appear that

in many instances they seemingly deliberately reverse all of their

learned principles of the use of their pouch/tool: grazing and

snacking through much of the day, drinking high calorie liquids,

drinking liquids with meals, and stopping their exercise, even when

they are intellectually aware that exercise in itself releases

numerous vasoactive substances which act like antidepressants. DB is

a 46-year-old woman who had an excellent initial weight loss

following a gastric bypass procedure (figure 5). While still in the

first year after her gastric bypass, her life, already made

difficult by divorce and economic circumstances, became severely

disrupted when her only daughter developed a drug problem, an

abusive relationship, and finally HIV, and was forced to give up her

newborn child. Her weight regain was dramatic. However, even more

dramatic was her weight loss once her depression eased, and she was

able to look after herself once again. She relates that she did

nothing dramatic such as fasting. She simply returned to using her

pouch/tool in the manner in which she had been taught and resumed a

moderate exercise program.

What can the bariatric surgeon do when patients are obviously

depressed and regaining weight? Obviously, the most important thing

is to steer them to professional counseling, if they are not already

in counseling. Then, the surgeon can be encouraging. We can

encourage them to continue to use the tool as best as they can; we

can encourage them to return to exercise which will improve the

spirits and reassure them that the improvement

is " deserved, " " because you really are a good person, and you

deserve to feel better. . . " Most of all, the surgeon can reassure

them that the pouch/tool is not ruined by this overeating and

gradual weight regain if it does not result in persistent vomiting

of solids. When they are ready once again to use their pouch/tool,

it will be there for them, and they will be able to once again lose

weight without being hungry.

EROSION OF THE USE OF THE PRINCIPLES:

In a third subset of weight maintenance failure patients, a subtle

weight creep can occur to patients who are otherwise compliant, non-

depressed, and have intact pouches. The patient will see it

as " struggling " with his/her weight, and by definition, he/she will

not have seen you in follow up and will have usually lost contact

with the support group or other bariatric surgical patients. There

seems to be a progressive erosion of following the principles of the

pouch/tool use. This may be due to denial as seen in diabetic

patients, or it may be due to the influence of their peer group and

the fact that some of the principles of the use of the pouch/tool,

especially fluid management, are counter- intuitive and counter to

behavior of their peer group. The patient will often not come back

for evaluation because " I know what I'm doing wrong! " (meaning that

he/she is eating the wrong things and too often), and these patients

will internalize their " failure " with an increasing sense of guilt

which itself acts as an inhibition to coming back to their surgeon's

office for help.

From the beginning, in our preoperative teaching, we emphasize the

possible need for a " refresher course " in the use of the principles

of the pouch/tool at some time in the future. Some patients still do

not return. The trick is identifying these patients and somehow

getting them back either into the office or into a support group.

In these three examples- lack of teaching, depression, and gradual

erosion of the use of their tool, weight once regained can be lost

once again if the pouch is anatomically intact and the patient

decides to use it, or learns how to use it or relearns how to use

it.

In these three examples, we are working with compliant, reasonably

responsible persons who, when they can, are willing to take

responsibility for their own behavior.

TRUE NON COMPLIANCE:

The most difficult problem is determining, and being comfortable

with that determination, when a patient is being fundamentally

noncompliant and obstructive. This type of individual may leave your

care and go to others complaining about a " personality conflict, " or

perhaps even that you have not given them the time and attention

that they need and deserve. Inexplicably, some will actually stay in

your care. In this instance, when the patient tends to return

perhaps even more frequently than usual, depression will be more

likely the underlying mechanism rather than noncompliance. It can be

difficult to be reasonably sure of what is going on in one or two

visits. The truly noncompliant patient will very likely end up with

multiple revisions and/or a reversal due to weight regain or

complications. This kind of patient is often quite resistant to

counseling, but I know of no other management option that offers

much hope for success. Luckily, this type of patient represents a

very small minority of our patients. Obviously, prevention in the

form of patient selection is better than cure, but after twenty-

three years of a bariatric surgical practice, I have yet to be able

to effectively identify these persons preoperatively. I have, in

fact, suspected significant noncompliance in a number of my patients

who have turned out to be quite compliant particularly after control

of other problems, such as sleep apnea, that effect understanding

and complying with our instructions. With the current lack of an

effective psychological screening tool to reliably identify these

individuals, I tend to lean towards giving each person a chance at a

good and healthy life provided by bariatric surgery.

BIBLIOGRAPHY

1) Mason, EE, Personal Communication, 1980

2) Barber, W, Diet al, Brain Stem Response To Phasic Gastric

Distention. Am J. Physiol 1983; 245(2): G242-8

3) Flanagan, L. Measurement of Functional Pouch Volume Following the

Gastric Bypass Procedure. Ob Surg 1996; 6:38-43

4) Rosemurgy, A.